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Replica symmetry broken states of some glass models. Phys Rev E 2023; 108:054134. [PMID: 38115428 DOI: 10.1103/physreve.108.054134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Accepted: 11/07/2023] [Indexed: 12/21/2023]
Abstract
We have studied in detail the M-p balanced spin-glass model, especially the case p=4. These types of model have relevance to structural glasses. The models possess two kinds of broken replica states; those with one-step replica symmetry breaking (1RSB) and those with full replica symmetry breaking (FRSB). To determine which arises requires studying the Landau expansion to quintic order. There are nine quintic-order coefficients, and five quartic-order coefficients, whose values we determine for this model. We show that it is only for 2≤M<2.4714⋯ that the transition at mean-field level is to a state with FRSB, while for larger M values there is either a continuous transition to a state with 1RSB (when M≤3) or a discontinuous transition for M>3. The Gardner transition from a 1RSB state at low temperatures to a state with FRSB also requires the Landau expansion to be taken to quintic order. Our result for the form of FRSB in the Gardner phase is similar to that found when 2≤M<2.4714⋯, but differs from that given in the early paper of Gross et al. [Phys. Rev. Lett. 55, 304 (1985)0031-900710.1103/PhysRevLett.55.304]. Finally we discuss the effects of fluctuations on our mean-field solutions using the scheme of Höller and Read [Phys. Rev. E 101, 042114 (2020)2470-004510.1103/PhysRevE.101.042114] and argue that such fluctuations will remove both the continuous 1RSB transition and discontinuous 1RSB transitions when 8>d≥6 leaving just the FRSB continuous transition. We suggest values for M and p which might be used in simulations to confirm whether fluctuation corrections do indeed remove the 1RSB transitions.
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Study of the de Almeida-Thouless line in the one-dimensional diluted power-law XY spin glass. Phys Rev E 2023; 108:014116. [PMID: 37583164 DOI: 10.1103/physreve.108.014116] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 06/21/2023] [Indexed: 08/17/2023]
Abstract
We study the de Almeida-Thouless (AT) line in the one-dimensional power-law diluted XY spin-glass model, in which the probability that two spins separated by a distance r interact with each other, decays as 1/r^{2σ}. Tuning the exponent σ is equivalent to changing the space dimension of a short-range model. We develop a heat bath algorithm to equilibrate XY spins; using this in conjunction with the standard parallel tempering and overrelaxation sweeps, we carry out large-scale Monte Carlo simulations. For σ=0.6, which is in the mean-field regime above six dimensions-it is similar to being in 10 dimensions-we find clear evidence for an AT line. For σ=0.75 and σ=0.85, which are in the non-mean-field regime and similar to four and three dimensions, respectively, our data is like that found in previous studies of the Ising and Heisenberg spin glasses when reducing the temperature at fixed field. For σ=0.75, there is evidence from finite-size-scaling studies for an AT transition but for σ=0.85, the evidence for a transition is nonexistent. We have also studied these systems at fixed temperature varying the field and discovered that at both σ=0.75 and at σ=0.85 there is evidence of an AT transition! Confusingly, the correlation length and spin-glass susceptibility as a function of the field are both entirely consistent with the predictions of the droplet picture and hence the nonexistence of an AT line. In the usual finite-size critical point scaling studies used to provide evidence for an AT transition, there is seemingly good evidence for an AT line at σ=0.75 for small values of the system size N, which is strengthening as N is increased, but for N>2048 the trend changes and the evidence then weakens as N is further increased. We have also studied with fewer bond realizations the system at σ=0.70, which is the analog of a system with short-range interactions just below six dimensions, and found that it is similar in its behavior to the system at σ=0.75 but with larger finite-size corrections. The evidence from our simulations points to the complete absence of the AT line in dimensions outside the mean-field region and to the correctness of the droplet picture. Previous simulations which suggested there was an AT line can be attributed to the consequences of studying systems which are just too small. The collapse of our data to the droplet scaling form is poor for σ=0.75 and to some extent also for σ=0.85, when the correlation length becomes of the order of the length of the system, due to the existence of excitations which only cost a free energy of O(1), just as envisaged in the TNT picture of the ordered state of spin glasses. However, for the case of σ=0.85 we can provide evidence that for larger system sizes, droplet scaling will prevail even when the correlation length is comparable to the system size.
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Free-energy barriers in the Sherrington-Kirkpatrick model. Phys Rev E 2022; 105:034138. [PMID: 35428069 DOI: 10.1103/physreve.105.034138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 02/23/2022] [Indexed: 06/14/2023]
Abstract
The free-energy landscape of the Sherrington-Kirkpatrick (SK) Ising spin glass is simple in the framework of the Thouless-Anderson-Palmer (TAP) equations as each solution (which are minima of the free energy) has associated with it a nearby index-one saddle point. The free-energy barrier to escape the minimum is just the difference between the saddle point free energy and that at its associated minimum. This difference is calculated for the states with free energies f>f_{c}. It is very small for these states, decreasing as 1/N^{2}, where N is the number of spins in the system. These states are not marginally stable. We argue that such small barriers are why numerical studies never find these states when N is large. Instead, the states that are found are those that have marginal stability. For them the barriers are at least of O(1). f_{c} is the free energy per spin below which the states develop broken replica-symmetry-like overlaps with each other. In the regime f<f_{c} we can only offer some possibilities based around scaling arguments. One of these suggest that the barriers might become as large as N^{1/3}. That might be consistent with recent numerical studies on the Viana-Bray model, which were at variance with the expectations of Cugliandolo and Kurchan for the SK model.
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4
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Droplet-scaling versus replica symmetry breaking debate in spin glasses revisited. Phys Rev E 2021; 103:062111. [PMID: 34271696 DOI: 10.1103/physreve.103.062111] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 05/21/2021] [Indexed: 11/07/2022]
Abstract
Simulational studies of spin glasses since the early 2010s have focused on the so-called replicon exponent α as a means of determining whether the low-temperature phase of spin glasses is described by the replica symmetry breaking picture of Parisi or by the droplet-scaling picture. On the latter picture, it should be zero, but we shall argue that it will only be zero for systems of linear dimension L>L^{*}. The crossover length L^{*} may be of the order of hundreds of lattice spacings in three dimensions and approach infinity in six dimensions. We use the droplet-scaling picture to show that the apparent nonzero value of α when L<L^{*} should be 2θ, where θ is the domain wall energy scaling exponent. This formula is in reasonable agreement with the reported values of α.
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Marginally jammed states of hard disks in a one-dimensional channel. Phys Rev E 2020; 102:042614. [PMID: 33212608 DOI: 10.1103/physreve.102.042614] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 10/05/2020] [Indexed: 06/11/2023]
Abstract
We have studied a class of marginally jammed states in a system of hard disks confined in a narrow channel-a quasi-one-dimensional system-whose exponents are not those predicted by theories valid in the infinite dimensional limit. The exponent γ which describes the distribution of small gaps takes the value 1 rather than the infinite dimensional value 0.41269⋯. Our work shows that there exist jammed states not found within the tiling approach of Ashwin and Bowles. The most dense of these marginal states is an unusual state of matter that is asymptotically crystalline.
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Possible instability of one-step replica symmetry breaking in p-spin Ising models outside mean-field theory. Phys Rev E 2020; 101:032127. [PMID: 32289897 DOI: 10.1103/physreve.101.032127] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 03/09/2020] [Indexed: 11/07/2022]
Abstract
The fully connected Ising p-spin model has for p>2 a discontinuous phase transition from the paramagnetic phase to a stable state with one-step replica symmetry breaking (1RSB). However, simulations in three dimension do not look like these mean-field results and have features more like those which would arise with full replica symmetry breaking (FRSB). To help understand how this might come about we have studied in the fully connected p-spin model the state of two-step replica symmetry breaking (2RSB). It has a free energy degenerate with that of 1RSB, but the weight of the additional peak in P(q) vanishes. We expect that the state with full replica symmetry breaking (FRSB) is also degenerate with that of 1RSB. We suggest that finite-size effects will give a nonvanishing weight to the FRSB features, as also will fluctuations about the mean-field solution. Our conclusion is that outside the fully connected model in the thermodynamic limit, FRSB is to be expected rather than 1RSB.
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Realizable solutions of the Thouless-Anderson-Palmer equations. Phys Rev E 2019; 100:032127. [PMID: 31640029 DOI: 10.1103/physreve.100.032127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Indexed: 06/10/2023]
Abstract
We show that the only solutions of the Thouless-Anderson-Palmer (TAP) equations for the Sherrington-Kirkpatrick model of Ising spin glasses which can be found by iteration are those whose free energy lies on the border between replica-symmetric and broken-replica-symmetric states, when the number of spins N is large. Convergence to this same borderline also happens in quenches from a high-temperature initial state to a locally stable state where each spin is parallel to its local field; both are examples of self-organized criticality. At this borderline the band of eigenvalues of the Hessian associated with a solution extends to zero, so the states reached have marginal stability. We have also investigated the factors which determine the free-energy difference between a stationary solution corresponding to a saddle point and its associated minimum, which is the barrier which has to be surmounted to escape from the vicinity of a TAP minimum or pure state.
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Absence of Hyperuniformity in Amorphous Hard-Sphere Packings of Nonvanishing Complexity. PHYSICAL REVIEW LETTERS 2018; 121:075503. [PMID: 30169077 DOI: 10.1103/physrevlett.121.075503] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 05/25/2018] [Indexed: 06/08/2023]
Abstract
We relate the structure factor S(k→0) in a system of jammed hard spheres of number density ρ to its complexity per particle Σ(ρ) by the formula S(k→0)=-1/[ρ^{2}Σ^{″}(ρ)+2ρΣ^{'}(ρ)]. We have verified this formula for the case of jammed disks in a narrow channel, for which it is possible to find Σ(ρ) and S(k) analytically. Hyperuniformity, which is the vanishing of S(k→0), will therefore not occur if the complexity is nonzero. An example is given of a jammed state of hard disks in a narrow channel which is hyperuniform when generated by dynamical rules that produce a nonextensive complexity.
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Gardner Transition in Physical Dimensions. PHYSICAL REVIEW LETTERS 2018; 120:225501. [PMID: 29906167 DOI: 10.1103/physrevlett.120.225501] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 01/19/2018] [Indexed: 06/08/2023]
Abstract
The Gardner transition is the transition that at mean-field level separates a stable glass phase from a marginally stable phase. This transition has similarities with the de Almeida-Thouless transition of spin glasses. We have studied a well-understood problem, that of disks moving in a narrow channel, which shows many features usually associated with the Gardner transition. We show that some of these features are artifacts that arise when a disk escapes its local cage during the quench to higher densities. There is evidence that the Gardner transition becomes an avoided transition, in that the correlation length becomes quite large, of order 15 particle diameters, even in our quasi-one-dimensional system.
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Fractal dimension of interfaces in Edwards-Anderson spin glasses for up to six space dimensions. Phys Rev E 2018; 97:032104. [PMID: 29776053 DOI: 10.1103/physreve.97.032104] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Indexed: 11/07/2022]
Abstract
The fractal dimension of domain walls produced by changing the boundary conditions from periodic to antiperiodic in one spatial direction is studied using both the strong-disorder renormalization group algorithm and the greedy algorithm for the Edwards-Anderson Ising spin-glass model for up to six space dimensions. We find that for five or fewer space dimensions, the fractal dimension is lower than the space dimension. This means that interfaces are not space filling, thus implying that replica symmetry breaking is absent in space dimensions fewer than six. However, the fractal dimension approaches the space dimension in six dimensions, indicating that replica symmetry breaking occurs above six dimensions. In two space dimensions, the strong-disorder renormalization group results for the fractal dimension are in good agreement with essentially exact numerical results, but the small difference is significant. We discuss the origin of this close agreement. For the greedy algorithm there is analytical expectation that the fractal dimension is equal to the space dimension in six dimensions and our numerical results are consistent with this expectation.
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Multicritical Point on the de Almeida-Thouless Line in Spin Glasses in d>6 Dimensions. PHYSICAL REVIEW LETTERS 2018; 120:130602. [PMID: 29694168 DOI: 10.1103/physrevlett.120.130602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2018] [Indexed: 06/08/2023]
Abstract
The de Almeida-Thouless (AT) line in Ising spin glasses is the phase boundary in the temperature T and magnetic field h plane below which replica symmetry is broken. Using perturbative renormalization group (RG) methods, we show that, when the dimension d of space is just above six, there is a multicritical point (MCP) on the AT line, which separates a low-field regime, in which the critical exponents have mean-field values, from a high-field regime, where the RG flows run away to infinite coupling strength; as d approaches six from above, the MCP approaches the zero-field critical point exponentially in 1/(d-6). Thus, on the AT line, perturbation theory for the critical properties breaks down at a sufficiently large magnetic field even above 6 dimensions, as well as for all nonzero fields when d≤6, as was known previously. We calculate the exponents at the MCP to first order in ϵ=d-6>0. The fate of the MCP as d increases from just above six to infinity is not known.
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Corrigendum to "Relationship between spontaneous γH2AX foci formation and progenitor functions in circulating hematopoietic stem and progenitor cells among atomic-bomb survivors" [Mutat. Res. - Genet. Toxicol. Environ. Mutagen. 802 (2016) 59-65]. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2018; 827:68. [PMID: 29502739 DOI: 10.1016/j.mrgentox.2017.11.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Suppression of luteinizing hormone enhances HSC recovery after hematopoietic injury. Nat Med 2018; 24:239-246. [PMID: 29309056 PMCID: PMC5803436 DOI: 10.1038/nm.4470] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 12/13/2017] [Indexed: 12/15/2022]
Abstract
There is a substantial unmet clinical need for new strategies to protect the hematopoietic stem cell (HSC) pool and regenerate hematopoiesis after radiation injury from either cancer therapy or accidental exposure. Increasing evidence suggests that sex hormones, beyond their role in promoting sexual dimorphism, regulate HSC self-renewal, differentiation, and proliferation. We and others have previously reported that sex-steroid ablation promotes bone marrow (BM) lymphopoiesis and HSC recovery in aged and immunodepleted mice. Here we found that a luteinizing hormone (LH)-releasing hormone antagonist (LHRH-Ant), currently in wide clinical use for sex-steroid inhibition, promoted hematopoietic recovery and mouse survival when administered 24 h after an otherwise-lethal dose of total-body irradiation (L-TBI). Unexpectedly, this protective effect was independent of sex steroids and instead relied on suppression of LH levels. Human and mouse long-term self-renewing HSCs (LT-HSCs) expressed high levels of the LH/choriogonadotropin receptor (LHCGR) and expanded ex vivo when stimulated with LH. In contrast, the suppression of LH after L-TBI inhibited entry of HSCs into the cell cycle, thus promoting HSC quiescence and protecting the cells from exhaustion. These findings reveal a role of LH in regulating HSC function and offer a new therapeutic approach for hematopoietic regeneration after hematopoietic injury.
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Fate Decision Between Group 3 Innate Lymphoid and Conventional NK Cell Lineages by Notch Signaling in Human Circulating Hematopoietic Progenitors. THE JOURNAL OF IMMUNOLOGY 2017; 199:2777-2793. [PMID: 28893953 DOI: 10.4049/jimmunol.1601711] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 08/14/2017] [Indexed: 12/19/2022]
Abstract
The role of Notch signaling in human innate lymphoid cell (ILC) differentiation is unclear, although IL-7 and IL-15 promote differentiation of natural cytotoxicity receptor (NCR) NKp44+ group 3 ILCs (NCR+ILC3s) and conventional NK (cNK) cells from CD34+ hematopoietic progenitor cells (HPCs) ex vivo. In this study, we analyzed the functions of Notch in the differentiation of NCR+ILC3s and cNK cells from human HPC subpopulations circulating in peripheral blood by limiting dilution and clonal assays using high-throughput flow cytometry. We demonstrated that Notch signaling in combination with IL-7 induced NCR+ILC3 differentiation, but conversely suppressed IL-15-dependent cNK cell generation in CD45RA+Flt-3-c-Kitlow, a novel innate lymphocyte-committed HPC subpopulation. In contrast, Notch signaling induced CD45RA-Flt-3+c-Kithigh multipotent HPCs to generate CD34+CD7+CD62Lhigh, the earliest thymic progenitor-like cells, which preserved high cNK/T cell potential, but lost NCR+ILC3 potential. These findings implicate the countervailing functions of Notch signaling in the fate decision between NCR+ILC3 and cNK cell lineages at different maturational stages of human HPCs. Inhibition of Notch functions by Abs specific for either the Notch1 or Notch2 negative regulatory region suggested that both Notch1 and Notch2 signals were involved in the fate decision of innate lymphocyte-committed HPCs and in the generation of earliest thymic progenitor-like cells from multipotent HPCs. Furthermore, the synergistic interaction between Notch and IL-7 in NCR+ILC3 commitment was primarily explicable by the induction of IL-7 receptor expression in the innate lymphocyte-committed HPCs by Notch stimulation, suggesting the pivotal role of Notch in the transcriptional control required for human NCR+ILC3 commitment.
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Fractal Dimension of Interfaces in Edwards-Anderson and Long-range Ising Spin Glasses: Determining the Applicability of Different Theoretical Descriptions. PHYSICAL REVIEW LETTERS 2017; 119:100602. [PMID: 28949153 DOI: 10.1103/physrevlett.119.100602] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2017] [Indexed: 06/07/2023]
Abstract
The fractal dimension of excitations in glassy systems gives information on the critical dimension at which the droplet picture of spin glasses changes to a description based on replica symmetry breaking where the interfaces are space filling. Here, the fractal dimension of domain-wall interfaces is studied using the strong-disorder renormalization group method pioneered by Monthus [Fractals 23, 1550042 (2015)FRACEG0218-348X10.1142/S0218348X15500425] both for the Edwards-Anderson spin-glass model in up to 8 space dimensions, as well as for the one-dimensional long-ranged Ising spin-glass with power-law interactions. Analyzing the fractal dimension of domain walls, we find that replica symmetry is broken in high-enough space dimensions. Because our results for high-dimensional hypercubic lattices are limited by their small size, we have also studied the behavior of the one-dimensional long-range Ising spin-glass with power-law interactions. For the regime where the power of the decay of the spin-spin interactions with their separation distance corresponds to 6 and higher effective space dimensions, we find again the broken replica symmetry result of space filling excitations. This is not the case for smaller effective space dimensions. These results show that the dimensionality of the spin glass determines which theoretical description is appropriate. Our results will also be of relevance to the Gardner transition of structural glasses.
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Abstract
Breast cancer among women occupies a leading position in the profile of cancer incidence in most parts of the world. The present study of the incidence and prevalence of breast cancer was carried out using data from the Chelyabinsk population cancer registry for 2006-2015. A stable growth trend in the incidence over time was noted overall, as well as major differences in the figures for women of different ethnicities (Russian, Tatar, Bashkir), by far the highest incidences being observed for Russian women. Urban rates were generally higher than in rural sites and a shift towards older age at presentation was seen between 2006 and 2015. At the same time a slight decrease in mortality was noted, from 42.4% to 33.5% relative to incidence, with a decrease in the proportion of stage IV cancers. This might have been related to increasing use of mammography screening.The data have obvious connotations for primary prevention and particularly for measures adopted for secondary prevention in detection of the disease in its early stages, facilitating reduction in associated mortality. Improvement in screening rates is thus a high priority for more effective management of breast cancer in the region.
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Prevalence and Factors Associated with Opisthorchis viverrini Infection in Khammouane Province, Lao PDR. Asian Pac J Cancer Prev 2017; 17:1589-93. [PMID: 27039810 DOI: 10.7314/apjcp.2016.17.3.1589] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Opisthorchis viverrini (OV) liver flukes are common parasites found in central and southern Laos and constitute a major public health problem in the country. Laos people continue to have the habit of extensively consuming raw or half-cooked fish which are intermediate hosts. This study aimed to study the prevalence and factors associated with OV infection in the population of Thakek district, Khammouane Province. This cross-sectional analytic study covered 237 subjects who filled out structured questionnaires. Fecal examination for OV infection was performed by Kato's thick smear method. Data analysis was carried out using STATA Version 10.0. Multiple logistic regression was applied. The results showed that the infection rate of OV was 54.8 %. Factors associated with OV infections were gender, a habit of defecation in fields and raw fish (goi bplaa dip) consumption. Opisthorchiasis and associated cholangiocarcinoma development thus appear to remain as important concerns in Laos.
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Development of a Breast Cancer Awareness Scale for Thai Women: Moving towards a Validated Measure. Asian Pac J Cancer Prev 2017; 17:851-6. [PMID: 26925691 DOI: 10.7314/apjcp.2016.17.2.851] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Breast cancer is a major health problem among women around the world. Recent developments in screening and treatment have greatly improved the prognosis of patients with breast cancer in developed countries. However, in developing countries breast cancer mortality remains high.Breast cancer awareness is a first and important step in reducing breast cancer mortality. The development of a validated instrument to measure breast cancer awareness is crucial for the understanding and implementation of suitable health education programs to facilitate early deletion and minimize mortality. OBJECTIVE The objective of this study was to develop an instrument for the assessment of breast cancer awareness in Thai women. MATERIALS AND METHODS This methodological study was conducted in two stages: (1) literature searches and semi-structured interviews were conducted to generate items of the breast cancer awareness scale (B-CAS) which were subsequently examined for content and face validity, and (2) an exploration of the factor structure of the resulting instrument and an examination of its reliability. Data were collected using a self-administered questionnaire in Thai women aged 20-64 in August, 2015. RESULTS A total of 219 women (response rate 97.4 %) participated in this validation study. The B-CAS contains five domains with 53 items on breast cancer awareness: 1) knowledge of risk factors, 2) knowledge of signs and symptoms, 3) attitude to breast cancer prevention, 4) barriers of breast screening, and 5) health behavior related to breast cancer awareness. Items with a content validity index <0.80 were excluded, and factor structure for the remaining items reflected the hypothesized five factor model. The scales based on all retained items was shown to have strongly internal consistency reliability (Cronbach's α=0.86). CONCLUSIONS The B-CAS provides good psychometric properties to assess breast cancer awareness in women. It can be used to examine breast cancer awareness in Thai women and it could lead to the development and evaluation of suitable educational interventions for raising breast cancer awareness. Future research should focus on further validating the B-CAS including an assessment of construct and criterion-based validity.
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Metastable minima of the Heisenberg spin glass in a random magnetic field. Phys Rev E 2016; 94:052143. [PMID: 27967114 DOI: 10.1103/physreve.94.052143] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2016] [Indexed: 11/07/2022]
Abstract
We have studied zero-temperature metastable minima in classical m-vector component spin glasses in the presence of m-component random fields for two models, the Sherrington-Kirkpatrick (SK) model and the Viana-Bray (VB) model. For the SK model we have calculated analytically its complexity (the log of the number of minima) for both the annealed case where one averages the number of minima before taking the log and the quenched case where one averages the complexity itself, both for fields above and below the de Almeida-Thouless (AT) field, which is finite for m>2. We have done numerical quenches starting from a random initial state (infinite temperature state) by putting spins parallel to their local fields until there is no further decrease of the energy and found that in zero field it always produces minima that have zero overlap with each other. For the m=2 and m=3 cases in the SK model the final energy reached in the quench is very close to the energy E_{c} at which the overlap of the states would acquire replica symmetry-breaking features. These minima have marginal stability and will have long-range correlations between them. In the SK limit we have analytically studied the density of states ρ(λ) of the Hessian matrix in the annealed approximation. Despite the fact that in the presence of a random field there are no continuous symmetries, the spectrum extends down to zero with the usual sqrt[λ] form for the density of states for fields below the AT field. However, when the random field is larger than the AT field, there is a gap in the spectrum, which closes up as the AT field is approached. The VB model behaves differently and seems rather similar to studies of the three-dimensional Heisenberg spin glass in a random vector field.
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Malignant Neoplasm Burden in Nepal - Data from the Seven Major Cancer Service Hospitals for 2012. Asian Pac J Cancer Prev 2016; 16:8659-63. [PMID: 26745133 DOI: 10.7314/apjcp.2015.16.18.8659] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
In Nepal, while no population based cancer registry program exists to assess the incidence, prevalence, morbidity and mortality of cancer, at the national level a number of hospital based cancer registries are cooperating to provide relevant data. Seven major cancer diagnosis and treatment hospitals are involved, including the BP Koirala Memorial Cancer hospital, supported by WHO-Nepal since 2003. The present retrospective analysis of cancer patients of all age groups was conducted to assess the frequencies of different types of cancer presenting from January 1st to December 31st 2012. A total of 7,212 cancer cases were registered, the mean age of the patients being 51.9 years. The most prevalent age group in males was 60-64 yrs (13.6%), while in females it was 50-54 yrs (12.8%). The commonest forms of cancer in males were bronchus and lung (17.6%) followed by stomach (7.3%), larynx (5.2%) and non Hodgkins lymphoma (4.5%). In females, cervix uteri (19.1%) and breast (16.3%), were the top ranking cancer sites followed by bronchus and lung (10.2%), ovary (6.1%) and stomach (3.8%). The present data provide an update of the cancer burden in Nepal and highlight the relatively young age of breast and cervical cancer patients.
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Interface free-energy exponent in the one-dimensional Ising spin glass with long-range interactions in both the droplet and broken replica symmetry regions. Phys Rev E 2016; 94:022116. [PMID: 27627255 DOI: 10.1103/physreve.94.022116] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Indexed: 11/07/2022]
Abstract
The one-dimensional Ising spin-glass model with power-law long-range interactions is a useful proxy model for studying spin glasses in higher space dimensions and for finding the dimension at which the spin-glass state changes from having broken replica symmetry to that of droplet behavior. To this end we have calculated the exponent that describes the difference in free energy between periodic and antiperiodic boundary conditions. Numerical work is done to support some of the assumptions made in the calculations and to determine the behavior of the interface free-energy exponent of the power law of the interactions. Our numerical results for the interface free-energy exponent are badly affected by finite-size problems.
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Abstract
Foci of altered hepatocytes are regularly observed early during hepatocarcinogenesis in rodents. The abnormal hepatocytes may show a number of different phenotypes as characterized by various cytomorphological and cytochemical markers. The first appearance and the further development of the abnormal cell populations depend on the dose of the carcinogen given and on the duration of the carcinogenic treatment. According to cytochemical, morphometric and autoradiographic findings in rats receiving low doses (2–10% of the LD 50/kg bw/day) of hepatocarcinogens for limited periods (“stop” experiments), glycogenotic (clear or acidophilic) hepatocytes indicate the first step of the neoplastic cell transformation which can be detected by these methods at present. The glycogenotic cells undergo a characteristic metamorphosis and give rise to basophilic tumor cells poor in glycogen, but rich in ribosomes. Under extreme experimental conditions, such as a single or repeated application of higher doses of one or several chemical carcinogens a puzzling picture emerges which is “reversible” to a large extent after withdrawal of the respective compounds. This observation points to a phenotypic instability of the cellular changes induced in certain experimental systems. Foci of altered hepatocytes persisting after withdrawal of the carcinogenic compounds are considered preneoplastic lesions. They may transform into neoplastic nodules which are also persistent and share a number of cytomorphological and cytochemical markers with the focal lesions. The persistent nodules progress to hepatocarcinomas after lag periods of weeks or months. However, the foci may also progress to hepatocarcinomas without passing a nodular intermediate stage. The development of both neoplastic nodules and carcinomas from the preneoplastic glycogen storage foci can proceed independent of further administration of carcinogen. The sequence of cellular changes during hepatocarcinogenesis derived from the experimental results in rodents is strongly supported by observations in humans, especially by the increasing reports on the appearance of hepatic tumors in patients who suffer from inborn hepatic glycogenosis.
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Finite-size critical scaling in Ising spin glasses in the mean-field regime. Phys Rev E 2016; 93:032123. [PMID: 27078308 DOI: 10.1103/physreve.93.032123] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Indexed: 11/07/2022]
Abstract
We study in Ising spin glasses the finite-size effects near the spin-glass transition in zero field and at the de Almeida-Thouless transition in a field by Monte Carlo methods and by analytical approximations. In zero field, the finite-size scaling function associated with the spin-glass susceptibility of the Sherrington-Kirkpatrick mean-field spin-glass model is of the same form as that of one-dimensional spin-glass models with power-law long-range interactions in the regime where they can be a proxy for the Edwards-Anderson short-range spin-glass model above the upper critical dimension. We also calculate a simple analytical approximation for the spin-glass susceptibility crossover function. The behavior of the spin-glass susceptibility near the de Almeida-Thouless transition line has also been studied, but here we have only been able to obtain analytically its behavior in the asymptotic limit above and below the transition. We have also simulated the one-dimensional system in a field in the non-mean-field regime to illustrate that when the Imry-Ma droplet length scale exceeds the system size one can then be erroneously lead to conclude that there is a de Almeida-Thouless transition even though it is absent.
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Glasslike behavior of a hard-disk fluid confined to a narrow channel. Phys Rev E 2016; 93:032101. [PMID: 27078286 DOI: 10.1103/physreve.93.032101] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Indexed: 06/05/2023]
Abstract
Disks moving in a narrow channel have many features in common with the glassy behavior of hard spheres in three dimensions. In this paper we study the caging behavior of the disks that sets in at characteristic packing fraction ϕ(d). Four-point overlap functions similar to those studied when investigating dynamical heterogeneities have been determined from event-driven molecular dynamics simulations and the time-dependent dynamical length scale has been extracted from them. The dynamical length scale increases with time and, on the equilibration time scale, it is proportional to the static length scale associated with the zigzag ordering in the system, which grows rapidly above ϕ(d). The structural features responsible for the onset of caging and the glassy behavior are easy to identify as they show up in the structure factor, which we have determined exactly from the transfer-matrix approach.
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Circulating Hematopoietic Stem and Progenitor Cells in Aging Atomic Bomb Survivors. Radiat Res 2015; 185:69-76. [PMID: 26720799 DOI: 10.1667/rr14209.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
It is not yet known whether hematopoietic stem and progenitor cells (HSPCs) are compromised in the aging population of atomic bomb (A-bomb) survivors after their exposure nearly 70 years ago. To address this, we evaluated age- and radiation-related changes in different subtypes of circulating HSPCs among the CD34-positive/lineage marker-negative (CD34(+)Lin(-)) cell population in 231 Hiroshima A-bomb survivors. We enumerated functional HSPC subtypes, including: cobblestone area-forming cells; long-term culture-initiating cells; erythroid burst-forming units; granulocyte and macrophage colony-forming units; and T-cell and natural killer cell progenitors using cell culture. We obtained the count of each HSPC subtype per unit volume of blood and the proportion of each HSPC subtype in CD34(+)Lin(-) cells to represent the lineage commitment trend. Multivariate analyses, using sex, age and radiation dose as variables, showed significantly decreased counts with age in the total CD34(+)Lin(-) cell population and all HSPC subtypes. As for the proportion, only T-cell progenitors decreased significantly with age, suggesting that the commitment to the T-cell lineage in HSPCs continuously declines with age throughout the lifetime. However, neither the CD34(+)Lin(-) cell population, nor HSPC subtypes showed significant radiation-induced dose-dependent changes in counts or proportions. Moreover, the correlations of the proportions among HSPC subtypes in the survivors properly revealed the hierarchy of lineage commitments. Taken together, our findings suggest that many years after exposure to radiation and with advancing age, the number and function of HSPCs in living survivors as a whole may have recovered to normal levels.
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Growth and responsiveness of human granulocytic leukemic cells in vitro. BIBLIOTHECA HAEMATOLOGICA 2015:235-41. [PMID: 1057945 DOI: 10.1159/000397538] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Cells from patients with acute myeloid leukemia (AML) and chronic myeloid leukemia (CML) can be grown and their properties analyzed in agar gel cultures. Levels of the glycoprotein regulator colony stimulating factor (CSF) were found to be elevated in 19-66% of plasmas tested from patients with various types of granulocytic leukemia, and the growth of AML and CML cells in vitro was observed to be dependent on, and responsive to, stimulation by CSF-containing material. In both diseases, the leukemic cells appear to be in a responsive state with respect to normal growth regulators, and potentially alterations in regulator levels may therefore be able to achieve sustained arrest of the growth of leukemic populations.
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Sample convection in liquid-state NMR: why it is always with us, and what we can do about it. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2015; 252:120-129. [PMID: 25681799 DOI: 10.1016/j.jmr.2014.12.006] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2014] [Accepted: 12/14/2014] [Indexed: 06/04/2023]
Abstract
Many NMR experiments on liquids suffer if the sample convects. This is particularly true for applications, such as the measurement of diffusion, that rely on spatial labelling of spins. It is widely assumed that, in most well-conducted experiments with stable temperature regulation, samples do not convect. Unfortunately this is not the case. It is shown here that typical NMR samples show measurable convective flow for all but a very narrow range of temperatures; convection is seen both above and below this range, which can be as small as a degree or so for a mobile solvent such as chloroform. This convection is driven by both vertical and horizontal temperature gradients. Measurements of convection velocity are presented for a range of samples, sample tubes, probes, and temperatures. Both decreasing sample tube inner diameter and changing sample tube material from glass to sapphire can slow convection markedly, with sapphire tubes being particularly effective. Such tubes are likely to be particularly helpful for accurate measurement of diffusion by NMR.
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Understanding the ideal glass transition: lessons from an equilibrium study of hard disks in a channel. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 91:022120. [PMID: 25768471 DOI: 10.1103/physreve.91.022120] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Indexed: 06/04/2023]
Abstract
We use an exact transfer-matrix approach to compute the equilibrium properties of a system of hard disks of diameter σ confined to a two-dimensional channel of width 1.95σ at constant longitudinal applied force. At this channel width, which is sufficient for next-nearest-neighbor disks to interact, the system is known to have a great many jammed states. Our calculations show that the longitudinal force (pressure) extrapolates to infinity at a well-defined packing fraction ϕ(K) that is less than the maximum possible ϕ(max), the latter corresponding to a buckled crystal. In this quasi-one-dimensional problem there is no question of there being any real divergence of the pressure at ϕ(K). We give arguments that this avoided phase transition is a structural feature, the remnant in our narrow channel system of the hexatic to crystal transition, but that it has the phenomenology of the (avoided) ideal glass transition. We identify a length scale ξ̃(3) as our equivalent of the penetration length for amorphous order: In the channel system, it reaches a maximum value of around 15σ at ϕ(K), which is larger than the penetration lengths that have been reported for three-dimensional systems. It is argued that the α-relaxation time would appear on extrapolation to diverge in a Vogel-Fulcher manner as the packing fraction approaches ϕ(K).
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Asian Cancer Registry Forum 2014 - regional cooperation for cancer registration: priorities and challenges. Asian Pac J Cancer Prev 2014; 15:1891-4. [PMID: 24716906 DOI: 10.7314/apjcp.2014.15.5.1891] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
On February 6-7th, the Thai National Cancer Institute, the International Agency for Research on Cancer and its Mumbai Hub for Cancer Registration, together with the International Association of Cancer Registries and the APOCP/APJCP, jointly organized an Asian cancer registry forum to discuss regional cooperation for cancer registration. Held in the Grande Mercure Fortune Hotel, Bangkok, the meeting brought together leading scientists in cancer registration from South-East and North-East Asia as well as Australia, India and Iran and IARC itself, with coverage of various priorities and challenges of cancer registries regarding cancer control policy, operational parameters, assessment of survival and contributions to screening, for example. The current situation was highlighted and future directions and possible expansion of activities were discussed, with especial attention to the necessity for networks to help improve cancer registration across Asia and Africa.
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Dealing with correlated choices: how a spin-glass model can help political parties select their policies. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2014; 90:042117. [PMID: 25375448 DOI: 10.1103/physreve.90.042117] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2014] [Indexed: 06/04/2023]
Abstract
Starting from preferences on N proposed policies obtained via questionnaires from a sample of the electorate, an Ising spin-glass model in a field can be constructed from which a political party could find the subset of the proposed policies which would maximize its appeal, form a coherent choice in the eyes of the electorate, and have maximum overlap with the party's existing policies. We illustrate the application of the procedure by simulations of a spin glass in a random field on scale-free networks.
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Abstract 3980: Pre-clinical evaluation of a novel DNA crosslinking agent, Ureidomustin (BO-1055) in pediatric sarcomas. Cancer Res 2014. [DOI: 10.1158/1538-7445.am2014-3980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
DNA crosslinking agents continue to be an important part of chemotherapy for pediatric sarcomas. We tested potent analogues of phenyl N-mustard-benzene conjugates in several tumor models. In this work, we compared the efficacy of a novel water-soluble DNA alkylating agent, Ureidomustin (BO-1055) in Ewing sarcoma, rhabdomyosarcoma, osteosarcoma, desmoplastic small round cell tumor (DSRCT) cell lines and early cultures derived from primary patient samples. We tested its toxicity in normal human cells in vitro including the proliferation of mesenchymal stromal cells, bone marrow-derived endothelial cells and purified cord blood CD34+ cells in colony-forming assay (for hematopoietic progenitor cells) and in cobblestone area forming assay (for hematopoietic stem cells). We performed cell viability, cytotoxicity and caspase activation assays in a dose-dependent and time-dependent manner. We also performed apoptosis, cell cycle analyses using flow cytometry, immunoblot analysis and in vivo experiments in nude mice using Ewing sarcoma (A673) cell line transduced with GFP/luciferase for bioimaging. We evaluated cardiotoxicity in the HL-1 cardiomyocyte line in vitro and noted a 227 fold less cytotoxicity using BO-1055 compared to Doxorubicin. Based on MTD testing in nude mice, we used 30mg/kg q2d for 5 doses after tumors reached 75-100mm3 and were detected on luciferase bioimaging. Our results indicated that BO-1055 has a significant therapeutic window in its activity (mean IC50±SD μM) for rhabdomyosarcoma (0.16±0.11), Ewing sarcoma (0.48±0.29) and DSRCT (3.07±0.94) but not for osteosarcoma (IC50>10μM). The mean IC50 in benign cells was >10μM. Treatment with BO-1055 resulted in G2 arrest and activation of caspases 3 and 7 in a dose dependent manner. A673 xenografts were significantly inhibited by BO-1055 compared to the control mice injected with vehicle, based on mean fluorescence intensity and size of the tumors. Our results suggest that BO-1055 has potent activity against Ewing sarcoma and rhabdomyosarcoma and presents a strong rationale for further development as a therapeutic agent.
Citation Format: Srikanth R. Ambati, Elissa WP Wong, Benet Pera, Elizabeth Peguero, Eloisi Caldas Lopes, Jin-Jer Chen, Jae-Hung Shieh, Tsann-Long Su, Malcolm AS Moore. Pre-clinical evaluation of a novel DNA crosslinking agent, Ureidomustin (BO-1055) in pediatric sarcomas. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3980. doi:10.1158/1538-7445.AM2014-3980
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Abstract
Cancer is a major health problem facing the entire world, and Kazakhstan is not the exception. The aim of this study was to present an epidemiological assessment of leukemia in the population of Kazakhstan during 2003-2012. This descriptive and retrospective study was based on data obtained from all oncological organizations of the whole country. Age standardized incidence rates per 100,000 population for leukemia were calculated. Totally, 6,741 new cases of leukemia were registered in Kazakhstan during the 10 year period. The mean age of patients with leukemia was 48.5. The ASRs for leukemia among men and women were 5.3 and 3.6, respectively (p<0.001). In conclusion, our results showed a high incidence rate of leukemia in Kazakhstan, especially in the north of the country. The incidence of leukemia was significantly higher in males and increased with age. Determining and controlling important risk factors of leukemia may lead to decrease in its burden.
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Cancer control programs in East Asia: evidence from the international literature. J Prev Med Public Health 2014; 47:183-200. [PMID: 25139165 PMCID: PMC4162122 DOI: 10.3961/jpmph.2014.47.4.183] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 07/23/2014] [Indexed: 12/31/2022] Open
Abstract
Cancer is a major cause of mortality and morbidity throughout the world, including the countries of North-East and South-East Asia. Assessment of burden through cancer registration, determination of risk and protective factors, early detection and screening, clinical practice, interventions for example in vaccination, tobacco cessation efforts and palliative care all should be included in comprehensive cancer control programs. The degree to which this is possible naturally depends on the resources available at local, national and international levels. The present review concerns elements of cancer control programs established in China, Taiwan, Korea, and Japan in North-East Asia, Viet Nam, Thailand, Malaysia, and Indonesia as representative larger countries of South-East Asia for comparison, using the published literature as a guide. While major advances have been made, there are still areas which need more attention, especially in South-East Asia, and international cooperation is essential if standard guidelines are to be generated to allow effective cancer control efforts throughout the Far East. Cancer is a major cause of mortality and morbidity throughout the world, including the countries of North-East and South-East Asia. Assessment of burden through cancer registration, determination of risk and protective factors, early detection and screening, clinical practice, interventions for example in vaccination, tobacco cessation efforts and palliative care all should be included in comprehensive cancer control programs. The degree to which this is possible naturally depends on the resources available at local, national and international levels. The present review concerns elements of cancer control programs established in China, Taiwan, Korea, and Japan in North-East Asia, Viet Nam, Thailand, Malaysia, and Indonesia as representative larger countries of South-East Asia for comparison, using the published literature as a guide. While major advances have been made, there are still areas which need more attention, especially in South-East Asia, and international cooperation is essential if standard guidelines are to be generated to allow effective cancer control efforts throughout the Far East.
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Linkage between dendritic and T cell commitments in human circulating hematopoietic progenitors. THE JOURNAL OF IMMUNOLOGY 2014; 192:5749-60. [PMID: 24835400 DOI: 10.4049/jimmunol.1303260] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The relationships between commitments of dendritic cells (DCs) and T cells in human hematopoietic stem cells are not well understood. In this study, we enumerate and characterize conventional DC and plasmacytoid DC precursors in association with T cell and thymus-derived types of NK cell precursors among CD34(+) hematopoietic progenitor cells (HPCs) circulating in human peripheral blood. By limiting-dilution analyses using coculture with stroma cells expressing Notch1 ligand, the precursor frequencies (PFs) of DCs in HPCs were found to significantly correlate with T cell PFs, but not with NK cell PFs, among healthy donors. Clonal analyses showed that the majority of T/NK dual- and T single-lineage precursors-but only a minority of NK single-lineage precursors-were associated with the generation of DC progenies. All clones producing both DC and T cell progenies were found with monocyte and/or granulocyte progenies, suggesting DC differentiation via myeloid DC pathways. Analyses of peripheral blood HPC subpopulations revealed that the lineage split between DC and T/NK cell progenitor occurs at the stage prior to bifurcation into T and NK cell lineages. The findings suggest a strong linkage between DC and T cell commitments, which may be imprinted in circulating lymphoid-primed multipotent progenitors or in more upstream HPCs.
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Static and dynamical properties of a hard-disk fluid confined to a narrow channel. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2014; 89:032111. [PMID: 24730794 DOI: 10.1103/physreve.89.032111] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Indexed: 06/03/2023]
Abstract
The thermodynamic properties of disks moving in a channel sufficiently narrow that they can collide only with their nearest neighbors can be solved exactly by determining the eigenvalues and eigenfunctions of an integral equation. Using it, we have determined the correlation length ξ of this system. We have developed an approximate solution which becomes exact in the high-density limit. It describes the system in terms of defects in the regular zigzag arrangement of disks found in the high-density limit. The correlation length is then effectively the spacing between the defects. The time scales for defect creation and annihilation are determined with the help of transition-state theory, as is the diffusion coefficient of the defects, and these results are found to be in good agreement with molecular dynamics simulations. On compressing the system with the Lubachevsky-Stillinger procedure, jammed states are obtained whose packing fractions ϕJ are a function of the compression rate γ. We find a quantitative explanation of this dependence by making use of the Kibble-Zurek hypothesis. We have also determined the point-to-set length scale ξPS for this system. At a packing fraction ϕ close to its largest value ϕmax, ξPS has a simple power law divergence, ξPS∼1/(1-ϕ/ϕmax), while ξ diverges much faster, ln(ξ)∼1/(1-ϕ/ϕmax).
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Boolean decision problems with competing interactions on scale-free networks: equilibrium and nonequilibrium behavior in an external bias. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2014; 89:022118. [PMID: 25353433 DOI: 10.1103/physreve.89.022118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Indexed: 06/04/2023]
Abstract
We study the equilibrium and nonequilibrium properties of Boolean decision problems with competing interactions on scale-free networks in an external bias (magnetic field). Previous studies at zero field have shown a remarkable equilibrium stability of Boolean variables (Ising spins) with competing interactions (spin glasses) on scale-free networks. When the exponent that describes the power-law decay of the connectivity of the network is strictly larger than 3, the system undergoes a spin-glass transition. However, when the exponent is equal to or less than 3, the glass phase is stable for all temperatures. First, we perform finite-temperature Monte Carlo simulations in a field to test the robustness of the spin-glass phase and show that the system has a spin-glass phase in a field, i.e., exhibits a de Almeida-Thouless line. Furthermore, we study avalanche distributions when the system is driven by a field at zero temperature to test if the system displays self-organized criticality. Numerical results suggest that avalanches (damage) can spread across the whole system with nonzero probability when the decay exponent of the interaction degree is less than or equal to 2, i.e., that Boolean decision problems on scale-free networks with competing interactions can be fragile when not in thermal equilibrium.
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Abstract
Esophageal cancer (EC) incidence rates in Kazakhstan were assessed by component analysis based on primary registered cases in 2001-2010. It was found that despite an apparent general decrease in the number of EC patients in Kazakhstan, a potential increase should be evaluated, due to changes in aging as well as the increase in population. Some problems of EC patients' registration were broached with an emphasis on the importance of the expected absolute number and reasons for undercounting in the country. Based on these, ways of improving the recording and registration of such patients in the country were suggested.
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Transition state theory and the dynamics of hard disks. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2013; 88:052132. [PMID: 24329239 DOI: 10.1103/physreve.88.052132] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 09/18/2013] [Indexed: 06/03/2023]
Abstract
The dynamics of two- and five-disk systems confined in a square has been studied using molecular dynamics simulations and compared with the predictions of transition state theory. We determine the partition functions Z and Z(‡) of transition state theory using a procedure first used by Salsburg and Wood for the pressure. Our simulations show this procedure and transition state theory are in excellent agreement with the simulations. A generalization of the transition state theory to the case of a large number of disks N is made and shown to be in full agreement with simulations of disks moving in a narrow channel. The same procedure for hard spheres in three dimensions leads to the Vogel-Fulcher-Tammann formula for their alpha relaxation time.
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Update on the APJCP and the APOCP in 2013 - what is going to be achieved in the future? Asian Pac J Cancer Prev 2013; 14:2151-3. [PMID: 23725104 DOI: 10.7314/apjcp.2013.14.4.2151] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The history of the APOCP/APJCP goes back to 1999 when a number of interested scientists joined together to form the organization and to launch a new journal to support cancer prevention research in the Asian-Pacific area. Since the initial Founding Conference, some six General Assemblies (GAs) and ten Regional Conferences (RCs) and Special Study Sessions have been organized. Already the decisions have been made for two further GAs and at least three RCs. As of the April issue of 2013, a total of nearly 3,700 papers have already been published in regular issues of the APJCP or special supplements. With support of the Korean National Cancer Center, housing the Chief Editorial Office, the journal is now including approximately 100 papers a month. Although it experienced a set-back by reduction in the Impact Factor (IF) from 1.29 in 2010 to 0.67 in 2011, there are good grounds to expect an improvement in 2012. However, the future of the APOCP/APJCP will continue to depend on its membership, making continuous efforts to attend our conferences and submit good quality manuscripts. It is particularly important to cite papers in the APJCP wherever possible, if the wish is for an IF commensurate with our long term aims. In that sense it is up to all authors, since the journal will continue to have a very positive policy towards accepting papers from all countries within the Asian-Pacific, with its very varied levels of resources. The editorial team looks forward to your considered support. The APOCP also hopes to see you in person at future meeetings, so that you have a more active voice in deciding the best way forward in our cooperative enterprise.
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Overview of Cancer Registration Research in the Asian Pacific from 2008-2013. Asian Pac J Cancer Prev 2013; 14:4461-84. [DOI: 10.7314/apjcp.2013.14.8.4461] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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New APJCP Impact Factor for 2012 is 1.271 - Time to Make a Major Effort to Break Through the 2.0 Barrier. Asian Pac J Cancer Prev 2013; 14:3377-8. [DOI: 10.7314/apjcp.2013.14.6.3377] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Age-associated changes in the differentiation potentials of human circulating hematopoietic progenitors to T- or NK-lineage cells. THE JOURNAL OF IMMUNOLOGY 2013; 190:6164-72. [PMID: 23670190 DOI: 10.4049/jimmunol.1203189] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Age-associated changes of T and NK cell (T/NK) potential of human hematopoietic stem cells are unknown. In this study, we enumerate and characterize T/NK precursors among CD34(+)Lin(-) cell populations circulating in normal human adult peripheral blood (PB) by a limiting-dilution assay using coculture with OP9-DL1 stroma cells expressing Notch 1 ligand, Delta-like 1. The frequency of T cell precursors in CD34(+)Lin(-) cells was found to decrease with donor age, whereas the ratio of NK to T cell precursor frequency (NK/T ratio) increased with age, suggesting that lymphoid differentiation potential of PB progenitors shifts from T to NK cell lineage with aging. Clonal analyses of CD34(+)Lin(-) cells showed that differences in the NK/T ratio were attributable to different distributions of single- and dual-lineage T/NK precursor clones. Because nearly all of the clones retained monocyte and/or granulocyte differentiation potentials in coculture with OP9-DL1 cells, T/NK precursors in PB are considered to be contained in the pool of T/NK/myeloid multipotent progenitors. The age-associated increase in NK over T cell commitment might occur in precursor cells with T/NK/myeloid potential.
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Abstract
The incidence of esophageal cancer in Kazakhstan was analysed for the period of 1989-2010 years, with a focus on trends by age, gender and region. The highest rates of incidence were evident in the Western regions. The dynamics for cancer of the esophagus in the Republic demonstrated decrease, except in the Karaganda region, where a tendency for increase was noted. Considerable variation between regions pointed to differences in risk factor exposure which need to be targeted for future control efforts.
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Origin of the growing length scale in M-p-spin glass models. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2012; 86:052501. [PMID: 23214832 DOI: 10.1103/physreve.86.052501] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2012] [Indexed: 06/01/2023]
Abstract
Two versions of the M-p-spin glass model have been studied with the Migdal-Kadanoff renormalization group approximation. The model with p = 3 and M = 3 has at mean-field level the ideal glass transition at the Kauzmann temperature and at lower temperatures still the Gardner transition to a state like that of an Ising spin glass in a field. The model with p = 3 and M = 2 has only the Gardner transition. In the dimensions studied, d = 2,3, and 4, both models behave almost identically, indicating that the growing correlation length as the temperature is reduced in these models--the analog of the point-to-set length scale--is not due to the mechanism postulated in the random first-order transition theory of glasses but is more like that expected on the analogy of glasses to the Ising spin glass in a field.
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Abstract
It is shown by means of a 1/m expansion about the large-m limit of the m-vector spin glass that the value of the intercept of the de Almeida-Thouless line on the zero temperature axis h(AT) is proportional to T(c)(d), the zero-field transition temperature of the large-m model in d dimensions. Since numerical studies indicate that T(c)(d)=0 for d≤6, it follows that there should be no Almeida-Thouless line for d≤6.
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Abstract
The Paf oncogene is highly expressed in cycling hematopoietic stem cells (HSCs) and is required for the development of long-term HSCs. Hematopoietic stem cells (HSCs) self-renew to maintain the lifelong production of all blood populations. Here, we show that the proliferating cell nuclear antigen–associated factor (Paf) is highly expressed in cycling bone marrow HSCs and plays a critical role in hematopoiesis. Mice lacking Paf exhibited reduced bone marrow cellularity; reduced numbers of HSCs and committed progenitors; and leukopenia. These phenotypes are caused by a cell-intrinsic blockage in the development of long-term (LT)-HSCs into multipotent progenitors and preferential loss of lymphoid progenitors caused by markedly increased p53-mediated apoptosis. In addition, LT-HSCs from Paf−/− mice had increased levels of reactive oxygen species (ROS), failed to maintain quiescence, and were unable to support LT hematopoiesis. The loss of lymphoid progenitors was likely due the increased levels of ROS in LT-HSCs caused by treatment of Paf−/− mice with the anti-oxidant N-acetylcysteine restored lymphoid progenitor numbers to that of Paf+/+ mice. Collectively, our studies identify Paf as a novel and essential regulator of early hematopoiesis.
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Finite-size scaling at the jamming transition: corrections to scaling and the correlation-length critical exponent. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2011; 83:030303. [PMID: 21517442 DOI: 10.1103/physreve.83.030303] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2010] [Revised: 03/03/2011] [Indexed: 05/30/2023]
Abstract
We carry out a finite-size scaling analysis of the jamming transition in frictionless bidisperse soft core disks in two dimensions. We consider two different jamming protocols: (i) quench from random initial positions and (ii) quasistatic shearing. By considering the fraction of jammed states as a function of packing fraction for systems with different numbers of particles, we determine the spatial correlation length critical exponent ν ≈ 1 and show that corrections to scaling are crucial for analyzing the data. We show that earlier numerical results yielding ν < 1 are due to the improper neglect of these corrections.
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Lung cancer incidence in the arab league countries: risk factors and control. Asian Pac J Cancer Prev 2011; 12:17-34. [PMID: 21517227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023] Open
Abstract
Although lung cancer incidence rates and mortalities are still low in the Arab world as compared to Europe or USA, they is gradually increasing in the region. Furthermore, there is great variation between different parts of the Arab world. For instance, the age-standardized rates (ASRs) for lung cancer incidence are about 15 fold higher in Tunisia than in Sudan for men, and about 10 fold higher in Bahrain than in Yemen for females. Percentage data for both sexes of lung cancer in the Arab world show that 15/22 (68.1%) of the Arab countries have lung cancer as one of the most frequent five types of cancer. Despite major advances in understanding and treating cancer, the 5-year relative survival rate in North Africa and the Middle East is only 8%. With the notable exception of Algeria, and to a lesser extent Tunisia, where squamous cell carcinomas are more common, the two main types show approximately the same proportions in males, while adenocarcinomas tend to predominate in females.The estimated numbers of new lung cancer cases in 2008 were 9,537 in ages below 65 for both sexes, and 7,059 cases for ages above 65. In 2020 there is expected to be 14,788 new lung cancer cases in the Arab countries for ages below 65, and 14,788 cases for ages above 65 in both males and females. Between 1990 and 1997, cigarette consumption increased 24% in the Middle East, one of only two regions of the world where cigarette sales increased during that period, so that continued rise in cancer rates can be expected. Improvement of tobacco control, registration and treatment are all necessary to decrease the burden of lung cancer in the Arab world.
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Age characteristics of incidences of prevalent cancers in the Aral Sea area of Kazakhstan. Asian Pac J Cancer Prev 2011; 12:2295-2297. [PMID: 22296373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023] Open
Abstract
The aim of the research was to examine age-specific features of incidence of cancer of the esophagus, lung, stomach, breast, cervix and thyroid gland in the Aral Sea area in Kazakhstan. A retrospective study of 11 years (1999-2009) was conducted using descriptive and analytical methods with calculated age incidence rates. The average age of patients with esophageal cancer and lung cancer had a tendency for increase with "aging", while in other cases "juvenation" was noted. The peak incidence of malignant tumors in general, and in the studied forms of cancer was found at 70 years of age or older, except for breast cancer and cervical cancer, where the peak incidence was found at 60-69 years. Trends in age-varied incidence rates had different tendencies in particular organ sites.
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Situation analysis of risk factors related to non-communicable diseases in Khon Kaen Province, Thailand. Asian Pac J Cancer Prev 2011; 12:1337-1340. [PMID: 21875293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023] Open
Abstract
A descriptive cross-sectional study was carried out in Khon Kaen Province during January 1 to June 30, 2008. The aims were to assess: (1) the prevalence of risk factors for chronic diseases such as cancer, diabetes, blood pressure; and (2) health behaviour and health education needs. There were 338 sample subjects aged between 20-60 years, from urban, semi-urban and rural areas. Some 20.4 % of the sample subjects reported that they were unhealthy (10.4% diagnosed with hypertension, 9.8% with diabetes, and 0.9% with cancer). For history of illness in the family, the most common were diabetes (42%), high blood pressure (16.5 %) and cancer (14.8 %), and 66.9% reported stress within the last 6 months. In terms of risk behavior, 82.3% of males smoked cigarettes but only 1.9% of females. The respective figures for alcohol were 68.4% and 26.6%. The majority (61.2) had low physical activity (sitting or standing, little movement). Almost one third (32%) reported testing positive for Opisthorchis viverrini eggs in stool. For health education needs, 64.2%, 54.7% and 42.6% wanted to learn more about cancer, diabetes and hypertension, respectively. For means of health education delivery, 31.7% want to learn from medical doctors, 20.4% from TV, 16.3% from village's broadcasting and 13.6% from health volunteers. Suitable means to delivery health education are needed to convey knowledge to the population. Community health volunteers may be one of the best sustainable alternative methods to transfer knowledge.
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