Hydrogen-Poor Disks in Compact X-Ray Binaries

We show that accretion disks in several compact X-ray binaries with hydrogen-depleted donors are likely subject to a thermal ionization instability, unless they are strongly irradiated. These disks are particularly interesting in that their MHD-turbulent properties in the neutral phase may be quite different from those of standard, hydrogen-rich disks.Comment: 10 pages, accepted for publication in ApJ

ELN and FBN2 gene variants as risk factors for two sports-related musculoskeletal injuries

The proteins ELN and FBN2 are important in extracellular matrix function. The ELN rs2071307 and FBN2 rs331079 gene variants have been associated with soft tissue pathologies. We aimed to determine whether these variants were predisposing factors for both Achilles tendinopathy (AT) and anterior cruciate ligament (ACL) ruptures. For the AT study, 135 cases (TEN group) and 239 asymptomatic controls were recruited. For the ACL rupture study our cohort consisted of 141 cases (ACL group) and 219 controls. Samples were genotyped for both the ELN rs2071307 and FBN2 rs331079 variants using TaqMan assays. Analysis of variance and chi-squared tests were used to determine whether either variant was associated with AT or ACL rupture with significance set at p<0.05. The GG genotype of the FBN2 variant was significantly over-represented within the TEN group (p=0.035; OR=1.83; 95% CI 1.04–3.25) compared to the CON group. We also found that the frequency of the G allele was significantly different between the TEN (p=0.017; OR=1.90; 95% CI 1.11–3.27) and ACL groups (p=0.047; OR=1.76; 95% CI 1.00–3.10) compared to controls. The ELN rs207137 variant was not associated with either AT or ACL rupture. In conclusion, DNA sequence variation within the FBN2 gene is associated with both AT and ACL rupture

The effect of entomopathogenic nematodes and fungi against four xylophagous pests

The effects of entomopathogenic nematodes EPN (Steinernematidae and Heterorhabditidae) and fungi EPF (Beauveria bassiana) strains were evaluated in laboratory assays against larvae of four xylophagous pests: the Asparagus moth Parahypopta caestrum, the European goat moth Cossus cossus, the pine longhorn Arhopalus syriacus and the black Buprestid Capnodis tenebrionis. Due to their biology and ethology, these insects may be included in the category of pests residing in cryptic habitats. The control of these species is considered difficult, due to the inability of chemical pesticides to penetrate the cryptic habitats and reach the targets. The pathogenicity of the entomopathogenic nematodes and fungi was tested in vitro against the pests. Two experimental models were considered and aimed to imitate the natural environment of the pests, in Petri dishes filled with plant material and inside wood galleries respectively. Main results showed that the majority of the tested strains of nematodes and fungi affected the insects’ survival rate. Steinernema feltiae and B. bassiana caused the highest percentage of larval mortality (80–100%). Considering the lack of effective chemical control means, the microbial control of the xylophagous pests by EPN and EPF reveals promising perspectives. Nematodes and fungi are able to penetrate the cryptic habitats because they are living organisms and may be horizontally transmitted by infected hosts. The distribution of EPF as preventive control method and the injection of EPN suspensions to reach and infect the larvae inside the wood galleries can be a combined sustainable control system

MMP3 and TIMP2 gene variants as predisposing factors for Achilles tendon pathologies: attempted replication study in a British case–control cohort

Variants within the MMP3 (rs679620) and TIMP2 (rs4789932) genes have been associated with the risk of Achilles tendon pathology (ATP) in populations from South Africa and Australia. This study aimed to determine whether these variants were associated with the risk of ATP in British Caucasians. We recruited 118 cases with ATP, including a subset of 25 individuals with Achilles tendon rupture (RUP) and 131 controls. DNA samples were isolated from saliva and genotyped using qPCR. For the TIMP2 rs4789932 variant we found a significant (p = 0.038) difference in the genotype distribution frequency between males with ATP (CC, 39.4%; CT, 43.7%; TT, 16.9%) compared to male controls (CC, 20.7%; CT, 59.8%; TT, 19.5%). We also observed a difference in the TIMP2 rs4789932 genotype distribution between males with rupture compared to male controls (p = 0.038). The MMP3 rs679620 GG genotype was found to be overrepresented in the Achilles tendon rupture (RUP) group (AA, 24.0%; AG, 32.0%; GG, 44.0%) compared to controls (AA, 26.7%; AG, 54.2%; GG, 19.1%). In conclusion, the CT genotype of the TIMP2 rs4789932 variant was associated with lower risk of ATP in males. Furthermore, while we revealed differences for both variants in genotype distribution between the RUP and control groups, the sample size of the RUP group was small and confirmation would be required in additional cohorts. Finally, although both the TIMP2 rs4789932 and MMP3 rs679620 variants tentatively associated with ATP, there were differences in the direction of association compared to earlier work

TIMP2 and GDF-5 gene variants and achilles tendon pathology: replication study in a British case-control population

Introduction: Achilles tendon pathology (ATP) encompasses a range of tendon overuse injuries that can be sub-classified into separate pathologies [Weinfeld, 2014]. To date, a number of single nucleotide polymorphisms (SNPs) have been associated with ATP [Raleigh and Collins, 2012] but, with the exception of the COL5A1 rs12722 variant, limited work has been published on attempting to replicate these findings in cohorts other than those recruited from either South Africa or Australia. We selected variants within the TIMP2 (rs4789932) and GDF-5 (rs143383) genes, that have previously been shown to associate with ATP [El Khoury et al, 2013 and Posthumus et al, 2010], and attempted to replicate previous associations in a newly recruited British-based, case-control, Caucasian cohort. Methods: We recruited 133 ATP Caucasian patients from the County Clinic in Northampton along with 131 physically active controls from various sports clubs within the East Midlands region. DNA samples were collected from saliva (DNA genotek Ltd) and Taqman technology, using allele specific probes and primers, was used to genotype all DNA samples. Reactions were run on a StepOne Plus real-time PCR instrument (ABI). Genotypes were called according to post run cluster profiles and data were analysed using Chi-squared (c2) analysis or Fisher’s exact test. Significance was accepted at p < 0.05. All procedures were approved by the University of Northampton Research Ethics Committee. Results: For the TIMP2 rs4789932 variant we found no association between genotype and case or control status in the entire cohort (p = 0.279). However, in sex specific analysis we did find that the CC genotype was associated (p = 0.043) with male ATP cases compared to controls (Table 1). For the GDF-5 rs143383 variant, we found no association between genotype and case or control status in the entire cohort (p = 0.538) or in either male (p = 0.319) or female (p = 0.737) specific analysis (data not shown). Genotypes did not associate with any other potential confounding variables. Conclusions: The TIMP2 rs478992 CC genotype was associated with male cases of ATP. Although this locus was previously associated with ATP in cohorts recruited from the Southern Hemisphere it was the CT genotype that was the risk factor and the association was not sex specific [El Khoury et al, 2013]. This result might be related to differences in unknown environmental exposures between the cohorts investigated that may modify the effect of the genotype. We found no evidence of an association between ATP and the GDF-5 variant. These data should be viewed as preliminary findings and will need to be repeated in a larger cohort

Sight Distance Standards Based On Observational Data Risk Evaluation Of Passing

The paper presents an application of a reliability analysis for evaluating the risk associated with passing sight distance (PSD) standards in terms of the expected probability of noncompliance. Calculation of PSD is required to determine where drivers can safely execute passing maneuvers. Traditional PSD standards are based on deterministic, theoretical models, which are calibrated with conservative percentile values for uncertain design inputs to account for uncertainty. The PSD standards do not provide information about the risk of deviation from them. Reliability analysis is a technique that is based on limit state design and that accounts for the propagation of variability from input random parameters to the design outputs. A total of 1,098 passing maneuvers were observed on several two-lane highways in Spain; two data collection methodologies were used: external observations and an instrumented vehicle. The most significant factors affecting PSD were impeding-vehicle speed, passing-vehicle acceleration, and head-ways between impeding and passing vehicles. A uniform acceleration model described the passing-vehicle trajectory. The characterized input parameters and the passing model were used to perform a reliability analysis. The results showed the probability of noncompliance in different scenarios, defined as the proportion of cases in which the required PSD would exceed the available sight distance. American and Spanish PSD standards were evaluated. Geometric design standards presented a probability of noncompliance of about 0.15, whereas some marking standards had a probability of noncompliance exceeding 0.85. These standards may be associated with higher risk levels if they are followed by drivers. As well, PSD risk levels were not consistent for different design speeds, since they underestimated operating speed at some locationsThis paper was developed as a result of a mobility study at the University of British Columbia funded by the Erasmus Mundus Program of the European Commission under the Transatlantic Partnership for Excellence in Engineering project. The authors thank the Spanish Ministry of Economy and Competitiveness, which subsidized the research project, and the Spanish Directorate General of Traffic, Spanish Ministry of Public Works, Valencia Regional Department of Transport, and Valencia province road department for their collaboration during the field study.Llorca Garcia, C.; Moreno Chou, AT.; Sayed, T.; García García, A. (2014). Sight Distance Standards Based On Observational Data Risk Evaluation Of Passing. Transportation research record. 2404:18-26. doi:10.3141/2404-03S18262404Ismail, K., & Sayed, T. (2009). Risk-based framework for accommodating uncertainty in highway geometric design. Canadian Journal of Civil Engineering, 36(5), 743-753. doi:10.1139/l08-146Ismail, K., & Sayed, T. (2010). Risk-Based Highway Design. Transportation Research Record: Journal of the Transportation Research Board, 2195(1), 3-13. doi:10.3141/2195-01Richl, L., & Sayed, T. (2006). Evaluating the Safety Risk of Narrow Medians Using Reliability Analysis. Journal of Transportation Engineering, 132(5), 366-375. doi:10.1061/(asce)0733-947x(2006)132:5(366)Harwood, D. W., Gilmore, D. K., & Richard, K. R. (2010). Criteria for Passing Sight Distance for Roadway Design and Marking. Transportation Research Record: Journal of the Transportation Research Board, 2195(1), 36-46. doi:10.3141/2195-05Wang, Y., & Cartmell, M. P. (1998). New Model for Passing Sight Distance on Two-Lane Highways. Journal of Transportation Engineering, 124(6), 536-545. doi:10.1061/(asce)0733-947x(1998)124:6(536)Polus, A., Livneh, M., & Frischer, B. (2000). Evaluation of the Passing Process on Two-Lane Rural Highways. Transportation Research Record: Journal of the Transportation Research Board, 1701(1), 53-60. doi:10.3141/1701-07Llorca, C., & García, A. (2011). Evaluation of Passing Process on Two-Lane Rural Highways in Spain with New Methodology Based on Video Data. Transportation Research Record: Journal of the Transportation Research Board, 2262(1), 42-51. doi:10.3141/2262-05Carlson, P., Miles, J., & Johnson, P. (2006). Daytime High-Speed Passing Maneuvers Observed on Rural Two-Lane, Two-Way Highway: Findings and Implications. Transportation Research Record: Journal of the Transportation Research Board, 1961, 9-15. doi:10.3141/1961-02Llorca, C., Moreno, A. T., García, A., & Pérez-Zuriaga, A. M. (2013). Daytime and Nighttime Passing Maneuvers on a Two-Lane Rural Road in Spain. Transportation Research Record: Journal of the Transportation Research Board, 2358(1), 3-11. doi:10.3141/2358-01Easa, S. M. (1993). Reliability‐Based Design of Intergreen Interval at Traffic Signals. Journal of Transportation Engineering, 119(2), 255-271. doi:10.1061/(asce)0733-947x(1993)119:2(255)Selvanathan, E. A., & Selvanathan, S. (1994). The demand for transport and communication in the United Kingdom and Australia. Transportation Research Part B: Methodological, 28(1), 1-9. doi:10.1016/0191-2615(94)90027-2Easa, S. M. (2000). Reliability Approach to Intersection Sight Distance Design. Transportation Research Record: Journal of the Transportation Research Board, 1701(1), 42-52. doi:10.3141/1701-06Ibrahim, S. E.-B., & Sayed, T. (2011). Developing safety performance functions incorporating reliability-based risk measures. Accident Analysis & Prevention, 43(6), 2153-2159. doi:10.1016/j.aap.2011.06.006Khoury, J. E., & Hobeika, A. G. (2007). Assessing the Risk in the Design of Passing Sight Distances. Journal of Transportation Engineering, 133(6), 370-377. doi:10.1061/(asce)0733-947x(2007)133:6(370)Khoury, J. E., & Hobeika, A. G. (2012). Integrated Stochastic Approach for Risk and Service Estimation: Passing Sight Distance Application. Journal of Transportation Engineering, 138(5), 571-579. doi:10.1061/(asce)te.1943-5436.0000366Kim, S., & Choi, J. (2013). Effects of preceding geometric conditions on operating speed consistency of multilane highways. Canadian Journal of Civil Engineering, 40(6), 528-536. doi:10.1139/cjce-2012-005

Human genetic variation, Sport and Exercise Medicine, and Achilles tendinopathy: role for angiogenesis-associated genes

Sport and Exercise Medicine is one of the important subspecialties of 21st century healthcare contributing to improving the physical function, health, and vitality of populations while reducing the prevalence of lifestyle-related diseases. Moreover, sport and exercise are associated with injuries such as Achilles tendinopathy, which is a common tendon injury. The angiogenesis-associated signaling pathway plays a key role in extracellular matrix remodeling, with increased levels of angiogenic cytokines reported after cyclic stretching of tendon fibroblasts. We investigated the variants in angiogenesis genes in relation to the risk of Achilles tendinopathy in two population samples drawn independently from South Africa (SA) and the United Kingdom (UK). The study sample comprised 120 SA and 130 UK healthy controls, and 108 SA and 87 UK participants with Achilles tendinopathy. All participants were genotyped for five functional polymorphisms in the vascular endothelial growth factor, A isoform (VEGFA) (rs699947, rs1570360, rs2010963) and kinase insert-domain receptor (KDR) genes (rs1870377, rs2071559). The VEGFA A-G-G inferred haplotype was associated with an increased risk of Achilles tendinopathy in the SA group (15% in controls vs. 20% in cases, p = 0.048) and the combined SA+UK group (14% in controls vs. 20% in cases, p = 0.009). These new findings implicate the VEGFA gene with Achilles tendinopathy risk, while highlighting the potential biological significance of the angiogenesis signaling pathway in the etiology of Achilles tendinopathy. The evidence suggesting a genetic contribution to the susceptibility of sustaining a tendon injury is growing. We anticipate that high-throughput and multi-omics approaches, building on genomics, proteomics, and metabolomics, may soon uncover the pathophysiology of many diseases in the field of Sports and Exercise Medicine, as a new frontier of global precision medicine

Mapping variability of soil water content and flux across 1¿1000 m scales using the actively heated fiber optic method

The Actively Heated Fiber Optic (AHFO) method is shown to be capable of measuring soil water content several times per hour at 0.25 m spacing along cables of multiple kilometers in length. AHFO is based on distributed temperature sensing (DTS) observation of the heating and cooling of a buried fiber-optic cable resulting from an electrical impulse of energy delivered from the steel cable jacket. The results presented were collected from 750 m of cable buried in three 240 m colocated transects at 30, 60, and 90 cm depths in an agricultural field under center pivot irrigation. The calibration curve relating soil water content to the thermal response of the soil to a heat pulse of 10 W m−1 for 1 min duration was developed in the lab. This calibration was found applicable to the 30 and 60 cm depth cables, while the 90 cm depth cable illustrated the challenges presented by soil heterogeneity for this technique. This method was used to map with high resolution the variability of soil water content and fluxes induced by the nonuniformity of water application at the surface

Stability and Evolution of Supernova Fallback Disks

We show that thin accretion disks made of Carbon or Oxygen are subject to the same thermal ionization instability as Hydrogen and Helium disks. We argue that the instability applies to disks of any metal content. The relevance of the instability to supernova fallback disks probably means that their power-law evolution breaks down when they first become neutral. We construct simple analytical models for the viscous evolution of fallback disks to show that it is possible for these disks to become neutral when they are still young (ages of a few 10^3 to 10^4 years), compact in size (a few 10^9 cm to 10^11 cm) and generally accreting at sub-Eddington rates (Mdot ~ a few 10^14 - 10^18 g/s). Based on recent results on the nature of viscosity in the disks of close binaries, we argue that this time may also correspond to the end of the disk activity period. Indeed, in the absence of a significant source of viscosity in the neutral phase, the entire disk will likely turn to dust and become passive. We discuss various applications of the evolutionary model, including anomalous X-ray pulsars and young radio pulsars. Our analysis indicates that metal-rich fallback disks around newly-born neutron stars and black holes become neutral generally inside the tidal truncation radius (Roche limit) for planets, at \~10^11 cm. Consequently, the efficiency of the planetary formation process in this context will mostly depend on the ability of the resulting disk of rocks to spread via collisions beyond the Roche limit. It appears easier for the merger product of a doubly degenerate binary, whether it is a massive white dwarf or a neutron star, to harbor planets because it can spread beyond the Roche limit before becoming neutral.[Abridged]Comment: 34 pages, 2 figures, accepted for publication in Ap

Variation within three apoptosis associated genes as potential risk factors for Achilles tendinopathy in a British based case-control cohort

Achilles tendon pathology (ATP) is a degenerative condition which exhibits excessive tenocyte apoptosis. Tumour necrosis factor receptor 1 (TNFR1), caspase-3 (CASP3) and caspase-8 (CASP8) are important regulators of apoptosis. To date, the effect of variation within the genes for TNFR1 and CASP3 as risk factors for ATP have not been described. There is evidence that two single nucleotide polymorphisms (SNPs) within the CASP8 gene are associated with ATP, but only in populations from the Southern Hemisphere. The primary aim of this study was to determine whether SNPs within the TNFRSF1A and CASP3 genes were associated with ATP in British Caucasians. We additionally sought to determine whether copy number variation (CNV) within the CASP8 gene was associated with ATP. We recruited 262 (131 ATP cases and 131 asymptomatic controls) Caucasian participants for this genetic association study and used quantitative PCR with chi-squared (χ2) tests and ANOVA to detect significant associations. We found no association between the TNFRSF1A rs4149577 (p = 0.561), CASP3 rs1049253 (p = 0.643) and CASP8 copy number variants (p = 0.219) and ATP. Likewise, when we tested potential interactions between gender, genotype and the risk of ATP, we found no association with the variants investigated. In conclusion, the TNFRSF1A, CASP3 and CASP8 gene variants were not associated with ATP in British Caucasians