Association of Alanine Aminotransferase Flares to Hepatitis B Surface Decline During Tenofovir Alone or With Pegylated Interferon Alfa

INTRODUCTION

We aimed to determine whether the intensity of alanine aminotransferase (ALT) flares during antiviral therapy is associated with the level of hepatitis B surface antigen (HBsAg) decline.

METHODS

Quantitative HBsAg was determined during tenofovir monotherapy or tenofovir plus peginterferon alfa-2a in 201 participants with hepatitis B e antigen-positive or -negative chronic hepatitis B. A multivariable analysis identified factors associated with a shorter time to reduction in HBsAg.

RESULTS

Fifty flares occurred during treatment of which 74% were moderate (ALT >5-10 × upper limit of normal) or severe (ALT >10 × upper limit of normal). These flares were associated with greater HBsAg decline compared with no flares. Significantly faster times to HBsAg decline >1 log 10 IU ( P = 0.04) and to HBsAg level <100 IU/mL ( P = 0.01) were observed with severe flares.

DISCUSSIONS

Flare severity is a potentially important factor associated with shorter time to HBsAg reduction. These findings can be useful when evaluating HBsAg response to evolving hepatitis B virus therapies.

Observation of high-energy neutrinos from the Galactic plane

The origin of high-energy cosmic rays, atomic nuclei that continuously impact Earth's atmosphere, is unknown. Because of deflection by interstellar magnetic fields, cosmic rays produced within the Milky Way arrive at Earth from random directions. However, cosmic rays interact with matter near their sources and during propagation, which produces high-energy neutrinos. We searched for neutrino emission using machine learning techniques applied to 10 years of data from the IceCube Neutrino Observatory. By comparing diffuse emission models to a background-only hypothesis, we identified neutrino emission from the Galactic plane at the 4.5σ level of significance. The signal is consistent with diffuse emission of neutrinos from the Milky Way but could also arise from a population of unresolved point sources.

Evidence for neutrino emission from the nearby active galaxy NGC 1068

A supermassive black hole, obscured by cosmic dust, powers the nearby active galaxy NGC 1068. Neutrinos, which rarely interact with matter, could provide information on the galaxy’s active core. We searched for neutrino emission from astrophysical objects using data recorded with the IceCube neutrino detector between 2011 and 2020. The positions of 110 known gamma-ray sources were individually searched for neutrino detections above atmospheric and cosmic backgrounds. We found that NGC 1068 has an excess of 79 − 20 + 22 neutrinos at tera–electron volt energies, with a global significance of 4.2σ, which we interpret as associated with the active galaxy. The flux of high-energy neutrinos that we measured from NGC 1068 is more than an order of magnitude higher than the upper limit on emissions of tera–electron volt gamma rays from this source.

Living in relationship with the Ocean to transform governance in the UN Ocean Decade

Humanity's relationship with the Ocean needs to be transformed to effectively address the multitude of governance crises facing the Ocean, including overfishing, climate change, pollution, and habitat destruction. Earth law, including Rights of Nature, provides a pathway to center humanity as a part of Nature and transform our relationship from one of dominion and separateness towards holism and mutual enhancement. Within the Earth law framework, an Ocean-centered approach views humanity as interconnected with the Ocean, recognizes societies' collective duty and reciprocal responsibility to protect and conserve the Ocean, and puts aside short-term gain to respect and protect future generations of all life and the Ocean's capacity to regenerate and sustain natural cycles. This Essay presents Ocean-centered governance as an approach to help achieve the 10 challenges for collective impact put forward as part of the UN Decade of Ocean Science for Sustainable Development and therefore living in a harmonious relationship with the Ocean.

Search for Unstable Sterile Neutrinos with the IceCube Neutrino Observatory

We present a search for an unstable sterile neutrino by looking for a resonant signal in eight years of atmospheric ν_{μ} data collected from 2011 to 2019 at the IceCube Neutrino Observatory. Both the (stable) three-neutrino and the 3+1 sterile neutrino models are disfavored relative to the unstable sterile neutrino model, though with p values of 2.8% and 0.81%, respectively, we do not observe evidence for 3+1 neutrinos with neutrino decay. The best-fit parameters for the sterile neutrino with decay model from this study are Δm_{41}^{2}=6.7_{-2.5}^{+3.9}  eV^{2}, sin^{2}2θ_{24}=0.33_{-0.17}^{+0.20}, and g^{2}=2.5π±1.5π, where g is the decay-mediating coupling. The preferred regions of the 3+1+decay model from short-baseline oscillation searches are excluded at 90% C.L.

Two-eyed seeing: Embracing the power of Indigenous knowledge for a healthy and sustainable Ocean

Indigenous knowledge is often disregarded and opportunities for positive change are lost. To protect the Ocean, a "two-eyed seeing" approach combining Indigenous and western knowledge systems can create advancements while empowering coastal Indigenous Peoples.

Strong Constraints on Neutrino Nonstandard Interactions from TeV-Scale ν_{μ} Disappearance at IceCube

We report a search for nonstandard neutrino interactions (NSI) using eight years of TeV-scale atmospheric muon neutrino data from the IceCube Neutrino Observatory. By reconstructing incident energies and zenith angles for atmospheric neutrino events, this analysis presents unified confidence intervals for the NSI parameter ε_{μτ}. The best-fit value is consistent with no NSI at a p value of 25.2%. With a 90% confidence interval of -0.0041≤ε_{μτ}≤0.0031 along the real axis and similar strength in the complex plane, this result is the strongest constraint on any NSI parameter from any oscillation channel to date.

Search for Relativistic Magnetic Monopoles with Eight Years of IceCube Data

We present an all-sky 90% confidence level upper limit on the cosmic flux of relativistic magnetic monopoles using 2886 days of IceCube data. The analysis was optimized for monopole speeds between 0.750c and 0.995c, without any explicit restriction on the monopole mass. We constrain the flux of relativistic cosmic magnetic monopoles to a level below 2.0×10^{-19}  cm^{-2} s^{-1} sr^{-1} over the majority of the targeted speed range. This result constitutes the most strict upper limit to date for magnetic monopoles with β≳0.8 and up to β∼0.995 and fills the gap between existing limits on the cosmic flux of nonrelativistic and ultrarelativistic magnetic monopoles.

Analysis of Instrument Motion and the Impact of Residency Level and Concurrent Distraction on Laparoscopic Skills

OBJECTIVE

Using a laparoscopic box trainer fitted with motion analysis trackers and software, we aim to identify differences between junior and senior residents performing the peg transfer task, and the impact of a distracting secondary task on performance.

DESIGN

General surgery residents were asked to perform the laparoscopic peg transfer task on a trainer equipped with a motion tracker. They were also asked to perform the laparoscopic task while completing a secondary task. Extreme velocity and acceleration events of instrument movement in the 3 rotational degrees of freedom were measured during task completion. The number of extreme events, defined as velocity or acceleration exceeding 1 SD above or below their own mean, were tabulated. The performance of junior residents was compared to senior residents.

SETTING

Simulation learning institute, Beaumont Hospital, Royal Oak, Michigan.

PARTICIPANTS

Thirty-seven general surgery residents from Beaumont Hospital, Royal Oak.

RESULTS

When completing the primary task alone, senior residents executed significantly fewer extreme motion events specific to acceleration in pitch (16.63 vs. 20.69, p = 0.04), and executed more extreme motion events specific to velocity in roll (16.14 vs. 15.11, p = 0.038), when compared to junior residents. With addition of a secondary task, senior residents had fewer extreme acceleration events specific to pitch, (14.69 vs. 22.22, p < 0.001).

CONCLUSIONS

While junior and senior residents completed the peg transfer task with similar times, motion analysis identified differences in extreme motion events between the groups, even when a secondary task was added. Motion analysis may prove useful for real-time feedback during laparoscopic skill acquisition.

eV-Scale Sterile Neutrino Search Using Eight Years of Atmospheric Muon Neutrino Data from the IceCube Neutrino Observatory

The results of a 3+1 sterile neutrino search using eight years of data from the IceCube Neutrino Observatory are presented. A total of 305 735 muon neutrino events are analyzed in reconstructed energy-zenith space to test for signatures of a matter-enhanced oscillation that would occur given a sterile neutrino state with a mass-squared differences between 0.01 and 100  eV^{2}. The best-fit point is found to be at sin^{2}(2θ_{24})=0.10 and Δm_{41}^{2}=4.5  eV^{2}, which is consistent with the no sterile neutrino hypothesis with a p value of 8.0%.

Characteristics of the Diffuse Astrophysical Electron and Tau Neutrino Flux with Six Years of IceCube High Energy Cascade Data

We report on the first measurement of the astrophysical neutrino flux using particle showers (cascades) in IceCube data from 2010-2015. Assuming standard oscillations, the astrophysical neutrinos in this dedicated cascade sample are dominated (∼90%) by electron and tau flavors. The flux, observed in the sensitive energy range from 16 TeV to 2.6 PeV, is consistent with a single power-law model as expected from Fermi-type acceleration of high energy particles at astrophysical sources. We find the flux spectral index to be γ=2.53±0.07 and a flux normalization for each neutrino flavor of ϕ_{astro}=1.66_{-0.27}^{+0.25} at E_{0}=100  TeV, in agreement with IceCube's complementary muon neutrino results and with all-neutrino flavor fit results. In the measured energy range we reject spectral indices γ≤2.28 at ≥3σ significance level. Because of high neutrino energy resolution and low atmospheric neutrino backgrounds, this analysis provides the most detailed characterization of the neutrino flux at energies below ∼100  TeV compared to previous IceCube results. Results from fits assuming more complex neutrino flux models suggest a flux softening at high energies and a flux hardening at low energies (p value ≥0.06). The sizable and smooth flux measured below ∼100  TeV remains a puzzle. In order to not violate the isotropic diffuse gamma-ray background as measured by the Fermi Large Area Telescope, it suggests the existence of astrophysical neutrino sources characterized by dense environments which are opaque to gamma rays.

Time-Integrated Neutrino Source Searches with 10 Years of IceCube Data

This Letter presents the results from pointlike neutrino source searches using ten years of IceCube data collected between April 6, 2008 and July 10, 2018. We evaluate the significance of an astrophysical signal from a pointlike source looking for an excess of clustered neutrino events with energies typically above ∼1  TeV among the background of atmospheric muons and neutrinos. We perform a full-sky scan, a search within a selected source catalog, a catalog population study, and three stacked Galactic catalog searches. The most significant point in the northern hemisphere from scanning the sky is coincident with the Seyfert II galaxy NGC 1068, which was included in the source catalog search. The excess at the coordinates of NGC 1068 is inconsistent with background expectations at the level of 2.9σ after accounting for statistical trials from the entire catalog. The combination of this result along with excesses observed at the coordinates of three other sources, including TXS 0506+056, suggests that, collectively, correlations with sources in the northern catalog are inconsistent with background at 3.3σ significance. The southern catalog is consistent with background. These results, all based on searches for a cumulative neutrino signal integrated over the 10 years of available data, motivate further study of these and similar sources, including time-dependent analyses, multimessenger correlations, and the possibility of stronger evidence with coming upgrades to the detector.

Research Methodology and Community Participation: A Decade of Indigenous Social Science Research in Canada

Those engaged in community-based participatory research often comment on tensions between social scientific and community values, yet little systematic evidence exists about the relationship between social science research methodologies and community participation. We analyze nearly 500 peer-reviewed articles published between 2005 and 2015 on Indigenous issues in Canada, where policies encourage participatory research methods with disempowered groups. We find that research that includes Indigenous participation is more likely to include Indigenous epistemologies and participatory evidence sources and analysis methods. We also find that peer-reviewed research involving Indigenous participants often fails to go beyond minimum levels of consultation required by policies.

Constraints on Minute-Scale Transient Astrophysical Neutrino Sources

High-energy neutrino emission has been predicted for several short-lived astrophysical transients including gamma-ray bursts (GRBs), core-collapse supernovae with choked jets, and neutron star mergers. IceCube's optical and x-ray follow-up program searches for such transient sources by looking for two or more muon neutrino candidates in directional coincidence and arriving within 100 s. The measured rate of neutrino alerts is consistent with the expected rate of chance coincidences of atmospheric background events and no likely electromagnetic counterparts have been identified in Swift follow-up observations. Here, we calculate generic bounds on the neutrino flux of short-lived transient sources. Assuming an E^{-2.5} neutrino spectrum, we find that the neutrino flux of rare sources, like long gamma-ray bursts, is constrained to <5% of the detected astrophysical flux and the energy released in neutrinos (100 GeV to 10 PeV) by a median bright GRB-like source is <10^{52.5}  erg. For a harder E^{-2.13} neutrino spectrum up to 30% of the flux could be produced by GRBs and the allowed median source energy is <10^{52}  erg. A hypothetical population of transient sources has to be more common than 10^{-5}  Mpc^{-3}  yr^{-1} (5×10^{-8}  Mpc^{-3}  yr^{-1} for the E^{-2.13} spectrum) to account for the complete astrophysical neutrino flux.

Search for neutrinos from decaying dark matter with IceCube: IceCube Collaboration

With the observation of high-energy astrophysical neutrinos by the IceCube Neutrino Observatory, interest has risen in models of PeV-mass decaying dark matter particles to explain the observed flux. We present two dedicated experimental analyses to test this hypothesis. One analysis uses 6 years of IceCube data focusing on muon neutrino 'track' events from the Northern Hemisphere, while the second analysis uses 2 years of 'cascade' events from the full sky. Known background components and the hypothetical flux from unstable dark matter are fitted to the experimental data. Since no significant excess is observed in either analysis, lower limits on the lifetime of dark matter particles are derived: we obtain the strongest constraint to date, excluding lifetimes shorter than10 28 s at 90% CL for dark matter masses above 10 TeV .

The Irish approach to postaccident preparedness

Ireland does not have any nuclear installations, but a nuclear accident at a site elsewhere, particularly in Europe, could result in widespread but low-level contamination of the Irish environment. Ireland's National Emergency Plan for Nuclear Accidents was established, following the Chernobyl accident, for the national response to a nuclear accident abroad affecting Ireland. It has since been extended to also cover domestic radiological emergencies for which a national-level input is required to support the local response. This paper describes the approach taken to developing and maintaining arrangements for a nuclear accident abroad. The use of hazard assessments to prioritise resource use and planned protective actions, and the specifics of Ireland's situation in terms of location, governance, economy, and available resources have heavily influenced the preparedness arrangements. In particular, the importance of the ingestion pathway to projected doses, together with the significance of agricultural exports to the Irish economy, has had a key influence on the arrangements in place.

Improving the safety and tolerability of local anaesthetic outpatient transperineal prostate biopsies: A pilot study of the CAMbridge PROstate Biopsy (CAMPROBE) method

OBJECTIVES

The aim of this study was to pilot the use of a bespoke device (CAMPROBE, the CAMbridge PROstate Biopsy) to enable routine outpatient free-hand local anaesthetic (LA) transperineal prostate biopsies.

MATERIALS AND METHODS

The CAMPROBE prototype was designed and built in our institution. Men on active surveillance due prostate resampling were invited to have a CAMPROBE biopsy as an alternative to repeat transrectal ultrasound-guided prostate biopsies (TRUSBx) as part of an approved trial (NCT02375035). Biopsies were performed using LA infiltration only, without sedation or additional analgesia. Patient-reported outcomes were recorded at day 0 and 7 using validated questionnaires and visual analogue scales (VAS). Complications were recorded prospectively.

RESULTS

Thirty men underwent biopsies with a median of 11 cores taken per procedure (interquartile range 10-12). There were no infections, sepsis or retention episodes. Haematuria and haematospermia occurred in 67% and 62% of patients, which are similar to rates reported for TRUSBx. Mean VAS for pain (0-10 scale) was less than 3 for every part of the procedure. All 30 men described the procedure as tolerable under LA. In total, 26/30 (86.7%) men expressed a preference for a CAMPROBE procedure over TRUSBx and a further 3 (10.0%) would have either.

CONCLUSIONS

In this small pilot study, the CAMPROBE device and method appears to be a safe, simple and well-tolerated out-patient transperineal replacement for TRUSBx. A major new National Institute for Health Research grant will allow its further development from a prototype to a single use, low-cost disposable device ready for multi-centre testing.

LEVEL OF EVIDENCE

1b: individual cohort study.

The Impact of Library Resources and Services on the Scholarly Activity of Medical Faculty and Residents

Librarians at an academic medical center library gathered data to determine if library services and resources impacted scholarly activity. A survey was developed and sent out to faculty and residents asking how they used the library during scholarly activity. Sixty-five faculty members and residents responded to the survey. The majority of respondents involved with scholarly activity use the library's services and resources. PubMed is the most frequently used database. The positive results show the library impacts the scholarly activity of medical faculty and residents.

Assessing the Print Communication and Technology Attributes of an Academic Medical Center

Background:

Historically, health literacy has been viewed as the patient's problem; however, it is now accepted that the responsibility for improving health literacy lies with the health care professionals and systems. An Institute of Medicine report outlines the health literacy attributes, such as printed patient education and technology, which both play a role in patient decision-making and engaging them in their health care. Research suggests that patients who are engaged in their health care have improved health outcomes. For health care organizations to accommodate the needs of all patients, it is imperative that they determine the current organizational state and discover opportunities for improvement.

Methods:

The Health Literacy Environment of Hospitals and Health Centers (HLEHHC) Print Communication Rating and Technology Rating Tool were used to measure the internal aspects of organizational health literacy at The University of Tennessee Medical Center (UTMC). Included in the print assessment were the 150 most distributed patient education handouts. Researchers also used the Simple Measure of Gobbledygook and Patient Education Materials Assessment Tool to assess print material. Technology was assessed using UTMC's website as the authoritative source.

Key Results:

The HLEHHC was useful for assessing print material and technology. Reviewing and reporting the data question-by-question revealed more granular, actionable information on where there are opportunities to improve the health care environment for all patients. This analysis resulted in proposing actions based on best practices that UTMC could implement in the coming year. The process is replicable in other settings.

Implications:

Responsibility for improving informed medical decision-making lies with health care organizations. Low health literacy influences the effectiveness of print patient education and technology in informing patients about their health. Assessing these aspects of the health care organization as part of quality improvement provides necessary data for improvements. The Health Literacy Environment of Hospital and Health Centers was a useful tool to measure characteristics of print and technology. [HLRP: Health Literacy Research and Practice. 2018;2(1):e26–e34.]

Plain Language Summary:

A task force at an academic medical center assessed the health literacy attributes of their organization. Researchers assessed print patient education and patient-related technology. The researchers found areas for improvements to make health information easier to understand.

The IUR Forum: Worldwide Harmonisation of Networks to Support Integration of Scientific Knowledge and Consensus Development in Radioecology

During the past decades, many specialised networks have formed to meet specific radioecological objectives, whether regional or sectorial (purpose-oriented). Regional networks deal with an array of radioecological issues related to their territories. Examples include the South Pacific network of radioecologists, and the European network of excellence in radioecology. The latter is now part of the European platform for radiation protection. Sectorial networks are more problem-oriented, often with wider international representativeness, but restricted to one specific issue, (e.g. radioactive waste, low-level atmospheric contamination, modelling). All such networks, while often working in relative isolation, contribute to a flow of scientific information which, through United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR's) efforts of synthesis, feeds into the radiation protection frameworks of protecting humans and the environment. The IUR has therefore prompted a co-construction process aimed at improving worldwide harmonisation of radioecology networks. An initiative based on an initial set of 15 networks, now called the IUR FORUM, was launched in June 2014. The IUR Forum agreed to build a framework for improved coordination of scientific knowledge, integration and consensus development relative to environmental radioactivity. Three objectives have been collectively assigned to the IUR FORUM: (1) coordination, (2) global integration and construction of consensus and (3) maintenance of expertise. One particular achievement of the FORUM was an improved description and common understanding of the respective roles and functions of the various networks within the overall scene of radioecology R&D. It clarifies how the various networks assembled within the IUR FORUM interface with UNSCEAR and other international regulatory bodies (IAEA, ICRP), and how consensus on the assessment of risk is constructed. All these agencies interact with regional networks covering different geographical areas, and with other networks which address specific topics within radiation protection. After holding its first Consensus Symposium in 2015, examining the possible ecological impact of radiation from environmental contamination, the IUR FORUM continues its work towards improved radiation protection of humans and the environment. We welcome new members.

Growth Evolution of (Zn,Cd)Se Quantum Dots Deduced from Spatially Resolved Structural and Optical Characterization

The growth mode of CdSe layers grown by migration enhanced epitaxy between ZnSe barriers has been investigated. In situ reflection high-energy electron diffraction shows a gradual transition to a three-dimensional growth mode which, however, is not accompanied by a change of the surface lattice constant. High-resolution transmission electron micrographs reveal a strong Cd diffusion, leading to ternary ZnCdSe quantum wells. Furthermore. composition fluctuations perpendicular to the growth direction on a nanometer scale are found already prior to the beginning of the growth mode transition. In the case of heterostructures containing a CdSe layer that has undergone the growth mode transition, micrographs show Cd-rich quantum dots with diameters of around 8 nm and heights of around 1.5 nm within a ternary quantum well. By spatially resolved photoluminescence the emission from single quantum dots could be observed. The polarization dependence of the emission from single dots indicates an asymmetric shape of the dots with certain preferential orientations along the [110] and [110] directions.

Amphipols: polymeric surfactants for membrane biology research

Membrane proteins classically are handled in aqueous solutions as complexes with detergents. The dissociating character of detergents, combined with the need to maintain an excess of them, frequently results in more or less rapid inactivation of the protein under study. Over the past few years, we have endeavored to develop a novel family of surfactants, dubbed amphipols (APs). APs are amphiphilic polymers that bind to the transmembrane surface of the protein in a noncovalent but, in the absence of a competing surfactant, quasi-irreversible manner. Membrane proteins complexed by APs are in their native state, stable, and they remain water-soluble in the absence of detergent or free APs. An update is presented of the current knowledge about these compounds and their demonstrated or putative uses in membrane biology.

Crystallization and preliminary X-ray analysis of Drosophila glutathione S-transferase-2

The sigma-class glutathione S-transferase-2 (GST-2) from Drosophila melanogaster is predominantly found within the indirect flight muscles (IFMs), where it is bound to the 'heavy' subunit of the IFM thin filament troponin complex (Tn-H). An N-terminal extension found in GST-2 is unique within the sigma GST class and may be involved in its interaction with Tn-H or modulate its enzymatic function. The recombinant protein has been crystallized at room temperature using ammonium sulfate as precipitant. Synchrotron radiation was used to measure a complete native data set to 1.75 A resolution from flash-cooled crystals. The crystals belong to one of the trigonal space groups P3(1)21 or P3(2)21, with unit-cell parameters a = b = 89.7, c = 131.8 A. The self-rotation function is consistent with a GST-2 dimer in the asymmetric unit.

Links in the chain: the contribution of kettin to the elasticity of insect muscles

Asynchronous flight muscle fibers are activated by periodic stretches and need to be stiff for strain to be transmitted to the contractile system. Kettin associated with thin filaments and projectin with thick filaments contribute to fiber stiffness. Kettin extends along thin filaments with the N-terminus in the Z-disc and the C-terminus outside. C filaments connecting thick filaments to the Z-disc contain projectin but not kettin. Insect flight myofibrils have a titin PEVK epitope which is only exposed on stretch, suggesting it is short and inaccessible. It is concluded that kettin stiffens thin filaments near the Z-disc and projectin and titin provide elasticity to C filaments.

Gas chromatography-mass spectrometry determination of phosphine residues in stored products and processed foods

A gas chromatography-mass spectrometry (GC-MS) method was used for the quantitative confirmation of phosphine residues in stored products and processed foods. An established extraction technique was utilized for the preparation of headspace samples, which were analyzed by GC-MS and gas chromatography-nitrogen-phosphorus detection (GC-NPD). Wheat, oats, maize, white rice, brown rice, cornflakes, tortilla cornchips, groundnuts, and raisins were validated, showing excellent agreement between detectors when spiked at levels equivalent to 0.001 and 0.01 mg/kg phosphine and for samples containing incurred residues. The GC-MS method was reproducible and accurate when compared to the GC-NPD method and allowed five samples to be quantified in a working day. Subambient GC-MS oven temperatures were most suitable for phosphine residues ranging from 0.001 to 0.005 mg/kg, and a GC oven temperature of 100 degrees C was appropriate for residues >0.005 mg/kg. The method was sufficiently robust to be evaluated for other similar commodities as the need arises.

Sequence and expression of the kettin gene in Drosophila melanogaster and Caenorhabditis elegans

Kettin is a large modular protein associated with thin filaments in the Z-disc region of insect muscles. The sequence of a 21.3 kb contig of the Drosophila gene has been determined. The corresponding protein sequence has 35 immunoglobulin-like (Ig) domains which are separated by shorter linker sequences, except near the N and C termini of the molecule where linker sequences are short or missing. This confirms a model in which each Ig domain binds to an actin protomer. The Drosophila kettin gene is at 62C 1-3 on the third chromosome. Two P-element insertions, l(3)j1D7 and l(3)rL182 are in the kettin gene, and complementation tests showed that existing l(3)dre8 mutations are in the same gene. The RNA was detected in wild-type Drosophila embryos at stage 11, first in the gut invagination region of the mesoderm, and by stage 13 in both visceral and somatic mesoderm. Somatic mesoderm expression became segmental at stage 13. RNA expression was greatly reduced in embryos of P-element homozygotes but normal in heterozygotes. The structure of the flight muscle in all the heterozygous mutants was normal, including the myofibril-cuticle connections, and they were able to fly. Kettin sequence homologous to the Drosophila protein, was identified in the Caenorhabditis elegans genome database. The RNA was detected in pharyngeal, body wall and anal depressor muscles of larvae and adult worms, as well as in the male gonad. Antibody to insect kettin labelled the pharyngeal, body wall, anal depressor and proximal gonadal muscles in adult worms. Body wall muscles were labelled in an obliquely striated pattern consistent with the Z-disc localisation in insect muscle. The relationship of kettin to D-titin, which has been assigned to the same chromosomal locus in Drosophila, is discussed.

Information systems for healthcare: why haven't more success. The top 15 reasons

Over the last number of years, I have often been asked: "Why haven't we had more success in implementing Information Technology (IT) in Healthcare?" Unfortunately, there is no simple answer to this question. The answer is usually heavily dependent on several factors that "define" the specific implementation in question--consequently, the answer is one comprised of a number of interrelated factors or components. In order to facilitate this answer process, this paper attempts to identify these individual answer components. At the very least, this will help simplify the process of answering future questions by referring to the components outlined herein. At most, in addition to providing a reference compendium for others, it will assist in increasing the solution implementation success rate by exploring the problem definition in detail: The first step in solving a problem is to have it fully articulated.

Association of kettin with actin in the Z-disc of insect flight muscle

The Z-discs of insect muscle contain kettin, a modular protein of 500-700 kDa. The Drosophila protein is made up of a chain of immunoglobulin (Ig) domains separated by linker sequences. Kettin differs from other modular muscle proteins of the Ig superfamily in binding to thin filaments rather than thick filaments. Kettin isolated from Lethocerus (waterbug) muscle is an elongated molecule 180 nm long, which binds to F-actin with high affinity (Kd=1.2 nM) and a stoichiometry of one Ig domain per actin protomer. Competition between kettin and tropomyosin for binding to actin excludes tropomyosin from the Z-disc. In contrast, kettin and alpha-actinin bind simultaneously to actin, which would reinforce the Z-disc lattice. In vitro, kettin promotes the antiparallel association of actin filaments, and a similar process may occur in the developing sarcomere: actin filaments interdigitate in an antiparallel fashion in the Z-disc with the N terminus of kettin within the Z-disc, and the C terminus some way outside. We propose a model for the association of kettin with actin in which the molecule follows the genetic helix of actin and Ig domains, separated by linker sequences, bind to each actin protomer.