Dust trajectory sensor: accuracy and data analysis

The Dust Trajectory Sensor (DTS) instrument is developed for the measurement of the velocity vector of cosmic dust particles. The trajectory information is imperative in determining the particles' origin and distinguishing dust particles from different sources. The velocity vector also reveals information on the history of interaction between the charged dust particle and the magnetospheric or interplanetary space environment. The DTS operational principle is based on measuring the induced charge from the dust on an array of wire electrodes. In recent work, the DTS geometry has been optimized [S. Auer, E. Grün, S. Kempf, R. Srama, A. Srowig, Z. Sternovsky, and V Tschernjawski, Rev. Sci. Instrum. 79, 084501 (2008)] and a method of triggering was developed [S. Auer, G. Lawrence, E. Grün, H. Henkel, S. Kempf, R. Srama, and Z. Sternovsky, Nucl. Instrum. Methods Phys. Res. A 622, 74 (2010)]. This article presents the method of analyzing the DTS data and results from a parametric study on the accuracy of the measurements. A laboratory version of the DTS has been constructed and tested with particles in the velocity range of 2-5 km/s using the Heidelberg dust accelerator facility. Both the numerical study and the analyzed experimental data show that the accuracy of the DTS instrument is better than about 1% in velocity and 1° in direction.

Number needed to treat and treatment cost per fracture avoided with denosumab compared with zoledronic acid in patients with breast cancer with bone metastases

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Background: Pathologic fractures (PF) are a common and expensive-to-treat skeletal-related event (SRE), which affect over two-thirds of metastatic breast cancer (MBC) patients, and cost $26,936 (2009 US dollars) per event on average for inpatient treatment. In a phase III trial ( NCT20050136 ), MBC patients randomized to denosumab (Dmab; n=1,026) demonstrated longer time to SRE, but comparable rates of survival and disease progression relative to those randomized to zoledronic acid (ZOL; n=1,020). We calculated the number needed to treat (NNT) to avoid one PF and the treatment cost per PF avoided with Dmab vs. ZOL in MBC patients.

Methods: Phase III trial results from the Dmab product label were used to determine the rate of PFs and SREs in MBC patients treated with Dmab vs. ZOL. Treatment cost included only the wholesale acquisition cost of Dmab and ZOL, and assumed 12 months of treatment. The NNT calculated the number of patients who would need to be treated with Dmab vs. ZOL to avoid one additional PF. Sensitivity analyses included expanding the treatment outcome from PFs to SREs and adding drug administration costs for Dmab and ZOL, and, renal monitoring costs only for ZOL.

Results: Based on the estimated differences in PF risk of 2.7%, 37.4 patients would need to be treated with Dmab vs. ZOL to avoid one additional PF, resulting in a treatment cost per PF avoided of $346,911. The lower 95% confidence limit for the cost per PF avoided with Dmab vs. ZOL was $148,114, which is significantly greater than the mean inpatient cost of treating a PF event. Including drug administration and renal monitoring costs led to a cost per PF avoided of $323,069. Expanding the treatment outcome from PFs to SREs showed that 17.3 patients would need to be treated with Dmab vs. ZOL to avoid one additional SRE (95% CI: 10.2 to 59.7; absolute risk reduction 5.8%), resulting in a treatment cost of $160,595 per SRE avoided.

Conclusions: PFs have a debilitating effect on patients, and treatment with Dmab compared to ZOL was associated with a treatment cost per PF avoided that exceeded 12 times the mean inpatient cost of a PF. Decision makers need to consider the high costs associated with Dmab prior to formulary inclusion.

Social consensus through the influence of committed minorities

We show how the prevailing majority opinion in a population can be rapidly reversed by a small fraction p of randomly distributed committed agents who consistently proselytize the opposing opinion and are immune to influence. Specifically, we show that when the committed fraction grows beyond a critical value p(c) ≈ 10%, there is a dramatic decrease in the time T(c) taken for the entire population to adopt the committed opinion. In particular, for complete graphs we show that when p < pc, T(c) ~ exp [α(p)N], whereas for p>p(c), T(c) ~ ln N. We conclude with simulation results for Erdős-Rényi random graphs and scale-free networks which show qualitatively similar behavior.

Application of multifocal visual evoked potentials in the assessment of visual dysfunction in macular diseases

PURPOSE

To evaluate the use of AccuMap multifocal visual evoked potentials (mfVEP) in visual dysfunction caused by macular diseases.

METHODS

Forty-eight eyes with known macular diseases underwent AccuMap mfVEP and microperimetry 1 (MP1) assessments. Evaluation of mfVEP abnormality was based on an amplitude deviation probability plot and the AccuMap Severity Index (ASI). Correlation analyses of the mean mfVEP amplitude corresponding to a radius of 2°, 5°, and 10° of the central visual field, minimum angle of resolution best-corrected visual acuity (BCVA), and MP1 mean sensitivity of the corresponding areas were performed.

RESULTS

Among the 48 affected eyes, AccuMap mfVEP detected an abnormality of the central visual field in 45 eyes, with a sensitivity of 93.8%. The mean mfVEP amplitudes within a radius of 2°, 5°, and 10° of the central visual field were found to be positively correlated with BCVA (P<0.01 for all groups). The mean amplitudes also positively correlated with the MP1 mean sensitivity value of the corresponding visual field (P<0.01 for all groups). In the group with stable fixation or predominantly central fixation, the mean mfVEP amplitudes did not correlate with the BCVA or the MP1 mean sensitivity value. Regardless of the fixation status, the ASI was found to correlate with both the BCVA and the total MP1 mean defect value.

CONCLUSION

Objective perimetry using AccuMap mfVEP might be applied in the assessment of macular function, with the ASI offering a potentially useful indicator for evaluating macular dysfunction.

Social influencing and associated random walk models: Asymptotic consensus times on the complete graph

We investigate consensus formation and the asymptotic consensus times in stylized individual- or agent-based models, in which global agreement is achieved through pairwise negotiations with or without a bias. Considering a class of individual-based models on finite complete graphs, we introduce a coarse-graining approach (lumping microscopic variables into macrostates) to analyze the ordering dynamics in an associated random-walk framework. Within this framework, yielding a linear system, we derive general equations for the expected consensus time and the expected time spent in each macro-state. Further, we present the asymptotic solutions of the 2-word naming game and separately discuss its behavior under the influence of an external field and with the introduction of committed agents.

Two novel HLA-A alleles: HLA-A*31:01:09 and HLA-A*33:30

The HLA-A*31:01:09 differs from the closest allele HLAA*31:01:02 by a C to T silent substitution at position 447 in exon 3. The HLA-A*33:30 differs from the closest allele HLA-A*33:03:01 by a single nucleotide substitution at position 453 in exon 3, leading to a change of Arg 131 Cys.

Xeroderma pigmentosum: a rare cause of chorea

Xeroderma pigmentosum (XP) is an uncommon inherited dermatological disorder characterized by a high degree of skin photosensitivity with development of carcinomas at an early age. Neurological manifestations may be encountered in XP but few detailed descriptions have been provided. Here we describe a sister and a brother presenting chorea, dystonia, myoclonus, ataxia and polyneuropathy related to XP.

Molecular cloning and characterization of phospholipase C zeta in equine sperm and testis reveals species-specific differences in expression of catalytically active protein

Oocyte activation at fertilization is brought about by the testis-specific phospholipase C zeta (PLCZ), owing to its ability to induce oscillations in intracellular Ca(2+) concentration ([Ca(2+)](i)). Whereas this is a highly conserved mechanism among mammals, important species-specific differences in PLCZ sequence, activity, and expression have been reported. Thus, the objectives of this research were to clone and characterize the intracellular Ca(2+)-releasing activity and expression of equine PLCZ in sperm and testis. Molecular cloning of equine PLCZ yielded a 1914-bp sequence that translated into a protein of the appropriate size (~73 kDa), as detected with an anti-PLCZ-specific antibody. Microinjection of 1 μg/μl of equine PLCZ cRNA supported [Ca(2+)](i) oscillations in murine oocytes that were of a higher relative frequency than those generated by an equivalent concentration of murine Plcz cRNA. Immunofluorescence revealed expression of PLCZ over the acrosome, equatorial segment, and head-midpiece junction; unexpectedly, PLCZ also localized to the principal piece of the flagellum in all epididymal, uncapacitated, and capacitated sperm. Immunostaining over the acrosome was abrogated after induction of acrosomal exocytosis. Moreover, injection of either sperm heads or tails into mouse oocytes showed that PLCZ in both fractions is catalytically active. Immunohistochemistry on equine testis revealed expression as early as the round spermatid stage, and injection of these cells supported [Ca(2+)](i) oscillations in oocytes. In summary, we report that equine PLCZ displays higher intrinsic intracellular Ca(2+)-releasing activity than murine PLCZ and that catalytically active protein is expressed in round spermatids as well as the sperm flagellum, emphasizing important species-specific differences. Moreover, some of these results may suggest potential novel roles for PLCZ in sperm physiology.

Appetitive and consummatory sexual and agonistic behaviour elicits FOS expression in aromatase and vasotocin neurones within the preoptic area and bed nucleus of the stria terminalis of male domestic chickens

Some components of male sexual and agonistic behaviours are considered to be regulated by the same neurocircuitry in the medial preoptic nucleus (POM) and the medial portion of bed nucleus of the stria terminalis (BSTM). To better understand this neurocircuitry, numbers of aromatase- (ARO) or arginine vasotocin- (AVT) immunoreactive (ir) neurones expressing immediate early gene protein FOS were compared in the POM and BSTM of male chickens following sexual or agonistic behaviours. Observations were made on males showing: (i) appetitive (courtship) and consummatory (copulation) sexual behaviours; (ii) only appetitive sexual behaviour, or (iii) displaying agonistic behaviour toward other males. Control males were placed on their own in the observation pen, or only handled. In the POM, appetitive sexual behaviour increased ARO+FOS colocalisation, whereas agonistic behaviour decreased the number of visible ARO-ir cells. In the dorsolateral subdivision of BSTM (BSTM1), appetitive sexual behaviour also increased ARO+FOS colocalisation, although the numbers of visible ARO-ir and AVT-ir cells were not altered by sexual or agonistic behaviours. In the ventromedial BSTM (BSTM2), appetitive sexual behaviour increased ARO+FOS and AVT+FOS colocalisation, and all behaviours decreased the number of visible ARO-ir cells, particularly in males expressing consummatory sexual behaviour. Positive correlations were found between numbers of cells with ARO+FOS and AVT+FOS colocalisation in both subdivisions of the BSTM. Waltzing frequency was positively correlated with ARO+FOS colocalisation in the lateral POM, and in both subdivisions of the BSTM in males expressing sexual behaviour. Waltzing frequency in males expressing agonistic behaviour was negatively correlated with the total number of visible ARO-ir cells in the lateral POM and BSTM2. These observations suggest a key role for ARO and AVT neurones in BSTM2 in the expression of appetitive sexual behaviour, and differential roles for ARO cells in the POM and BSTM in the regulation of components of sexual and agonistic behaviours.

Mass mortality of pond-reared Carassius gibelio caused by Myxobolus ampullicapsulatus in China

From June to August 2009, allogynogenetic silver crucian carp Carassius gibelio (Bloch) pond-cultured at the Nanquan Experimental Station, China, were found to be heavily infected with myxosporeans, which caused mortalities ranging from 33% (13/40) to 90% (36/40) in the cages. The pharynxes of infected fish were swollen, nodular, and severely damaged. Based on morphological characters and 18S small subunit ribosomal DNA sequence similarity, the myxosporean was identified as Myxobolus ampullicapsulatus. This is the first report of M. ampullicapsulatus causing mass mortality of pond-reared C. gibelio.

LITAF and TNFSF15, two downstream targets of AMPK, exert inhibitory effects on tumor growth

Lipopolysaccharide (LPS)-induced tumor necrosis factor (TNF) α factor (LITAF) is a multiple functional molecule whose sequence is identical to the small integral membrane protein of the lysosome/late endosome. LITAF was initially identified as a transcription factor that activates transcription of proinflammatory cytokine in macrophages in response to LPS. Mutations of the LITAF gene are associated with a genetic disease, called Charcot-Marie-Tooth syndrome. Recently, we have reported that mRNA levels of LITAF and TNF superfamily member 15 (TNFSF15) are upregulated by 5' adenosine monophosphate (AMP)-activated protein kinase (AMPK). The present study further assesses their biological functions. Thus, we show that 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR), a pharmacological activator of AMPK, increases the abundance of LITAF and TNFSF15 in LNCaP and C4-2 prostate cancer cells, which is abrogated by small hairpin RNA (shRNA) or the dominant-negative mutant of AMPK α1 subunit. Our data further demonstrate that AMPK activation upregulates the transcription of LITAF. Intriguingly, silencing LITAF by shRNA enhances proliferation, anchorage-independent growth of these cancer cells and tumor growth in the xenograft model. In addition, our study reveals that LITAF mediates the effect of AMPK by binding to a specific sequence in the promoter region. Furthermore, we show that TNFSF15 remarkably inhibits the growth of prostate cancer cells and bovine aortic endothelial cells in vitro, with a more potent effect toward the latter. In conjuncture, intratumoral injection of TNFSF15 significantly reduces the size of tumors and number of blood vessels and induces changes that are characteristic of tumor cell differentiation. Therefore, our studies for the first time establish the regulatory axis of AMPK-LITAF-TNFSF15 and also suggest that LITAF may function as a tumor suppressor.