On the ranks of skew-centrosymmetric matrices over finite fields

AbstractFor any finite field F we determine the number of n by n matrices of skew-centrosymmetric form which are invertible over F. This result is obtained using a unimodality property of the ranks of matrices of this form. As a corollary to this result we count the n by n matrices of skew-centrosymmetric form of any specified rank

Vaccinia Virus Gene B7R Encodes an 18-kDa Protein That is Resident in the Endoplasmic Reticulum and Affects Virus Virulence

AbstractThis paper presents a characterisation of vaccinia virus (VV) gene B7R that was predicted to encode a polypeptide of 182 amino acids with an N-terminal signal peptide. In vitro transcription and translation analysis showed the B7R gene product was a 21-kDa protein that, in the presence of microsomes, was processed into an 18-kDa mature form. The 18-kDa form associated with the microsomal membranes and was within the lumen of the vesicle where it was inaccessible to exogenous protease or an antibody raised against the B7R C terminus. Within VV-infected cells, the 18-kDa form of B7R was detected late during infection in the endoplasmic reticulum where it colocalised with protein disulphide isomerase. The B7R protein was detected neither in the culture supernatant nor associated with virus particles. A virus deletion mutant lacking the B7R gene and a revertant virus were constructed. Compared to wild-type and revertant viruses, the deletion mutant replicated normally in cell culture and had unaltered virulence in a murine intranasal model of infection. However, the deletion mutant was attenuated in a murine intradermal model where it induced a smaller lesion than the control viruses

Granite disposal of U.S. high-level radioactive waste.

This report evaluates the feasibility of disposing U.S. high-level radioactive waste in granite several hundred meters below the surface of the earth. The U.S. has many granite formations with positive attributes for permanent disposal. Similar crystalline formations have been extensively studied by international programs, two of which, in Sweden and Finland, are the host rocks of submitted or imminent repository license applications. This report is enabled by the advanced work of the international community to establish functional and operational requirements for disposal of a range of waste forms in granite media. In this report we develop scoping performance analyses, based on the applicable features, events, and processes (FEPs) identified by international investigators, to support generic conclusions regarding post-closure safety. Unlike the safety analyses for disposal in salt, shale/clay, or deep boreholes, the safety analysis for a mined granite repository depends largely on waste package preservation. In crystalline rock, waste packages are preserved by the high mechanical stability of the excavations, the diffusive barrier of the buffer, and favorable chemical conditions. The buffer is preserved by low groundwater fluxes, favorable chemical conditions, backfill, and the rigid confines of the host rock. An added advantage of a mined granite repository is that waste packages would be fairly easy to retrieve, should retrievability be an important objective. The results of the safety analyses performed in this study are consistent with the results of comprehensive safety assessments performed for sites in Sweden, Finland, and Canada. They indicate that a granite repository would satisfy established safety criteria and suggest that a small number of FEPs would largely control the release and transport of radionuclides. In the event the U.S. decides to pursue a potential repository in granite, a detailed evaluation of these FEPs would be needed to inform site selection and safety assessment

Production and characterization of algae extract from Chlamydomonas reinhardtii

Background: Algae offer many advantages as biofuel sources including: high growth rates, high lipid content, the ability to grow on non-agricultural land, and the genetic versatility to improve strains rapidly and produce co-products. Research is ongoing to make algae biofuels a more financially attractive energy option; however, it is becoming evident that the economic viability of algae-based fuels may hinge upon high-value co-products. This work evaluated the feasibility of using a co-product, algae extract, as a nutrient source in cell culture media. Results: Algae extract prepared from autolysed Chlamydomonas reinhardtii was found to contain 3.0% protein, 9.2% total carbohydrate, and 3.9% free \u3b1-amino acid which is similar to the nutrient content of commercially available yeast extract. The effects of algae extract on the growth andmetabolism of laboratory strains of Escherichia coli and Saccharomyces cerevisiae were tested by substituting algae extract for yeast extract in LB and YPAD growth media recipes. Complex laboratory media supplemented with algae extract instead of yeast extract showed markedly improved effects on the growth and metabolism of common laboratory microorganisms in all cases except ethanol production rates in yeast. Conclusions: This study showed that algae extract derived from C. reinhardtii is similar, if not superior, to commercially available yeast extract in nutrient content and effects on the growth and metabolism of E. coli and S. cerevisiae. Bacto\u2122 yeast extract is valued at USD $0.15\u20130.35 per gram, if algae extract was sold at similar prices, it would serve as a high-value co-product in algae-based fuel processes

VFR-into-IMC Accident Trends: Perceptions of Deficiencies in Training

Pilots who operate under visual flight rules (VFR) and in visual meteorological conditions, who then continue flight into instrument meteorological conditions (IMC), remain as one of the leading causes of fatal aircraft accidents in general aviation. This paper examines past and current research initiatives, in seeking to identify causal factors and gaps in training that lead to VFR-into-IMC aircraft accidents, using a mixed methods approach. The Aircraft Owners and Pilots Association Air Safety Institute database and the National Transportation Safety Board database search engines were used to identify accident reports associated with VFR flight into IMC/deteriorating weather conditions for a 10-year time period (2003 to 2012). A national survey was also conducted to gain deeper insight into the self-identified training deficiencies of pilots. There is evidence that situational awareness is linked to decision-making, and there is a lack of proper training with regards to weather and weather technology concepts, making it difficult for pilots to gain these knowledge areas, skills, and abilities throughout their initial flight training and subsequent experience

Internal and external cooling methods and their effect on body temperature, thermal perception and dexterity

© 2018 The Authors. Published by PLOS. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.1371/journal.pone.0191416© 2018 Maley et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Objective The present study aimed to compare a range of cooling methods possibly utilised by occupational workers, focusing on their effect on body temperature, perception and manual dexterity. Methods Ten male participants completed eight trials involving 30 min of seated rest followed by 30 min of cooling or control of no cooling (CON) (34C, 58% relative humidity). The cooling methods utilised were: ice cooling vest (CV0), phase change cooling vest melting at 14C (CV14), evaporative cooling vest (CVEV), arm immersion in 10C water (AI), portable water-perfused suit (WPS), heliox inhalation (HE) and ice slushy ingestion (SL). Immediately before and after cooling, participants were assessed for fine (Purdue pegboard task) and gross (grip and pinch strength) manual dexterity. Rectal and skin temperature, as well as thermal sensation and comfort, were monitored throughout. Results Compared with CON, SL was the only method to reduce rectal temperature (P = 0.012). All externally applied cooling methods reduced skin temperature (P0.05). Conclusion The present study observed that ice ingestion or ice applied to the skin produced the greatest effect on rectal and skin temperature, respectively. AI should not be utilised if workers require subsequent fine manual dexterity. These results will help inform future studies investigating appropriate pre-cooling methods for the occupational worker.This project is financially supported by the US Government through the Technical Support Working Group within the Combating Terrorism Technical Support Office.Published versio

Learning From Early Attempts to Generalize Darwinian Principles to Social Evolution

Copyright University of Hertfordshire & author.Evolutionary psychology places the human psyche in the context of evolution, and addresses the Darwinian processes involved, particularly at the level of genetic evolution. A logically separate and potentially complementary argument is to consider the application of Darwinian principles not only to genes but also to social entities and processes. This idea of extending Darwinian principles was suggested by Darwin himself. Attempts to do this appeared as early as the 1870s and proliferated until the early twentieth century. But such ideas remained dormant in the social sciences from the 1920s until after the Second World War. Some lessons can be learned from this earlier period, particularly concerning the problem of specifying the social units of selection or replication

Outcomes of Older Patients (≥ 70 Years) Treated With Targeted Therapy in Metastatic Chemorefractory Colorectal Cancer: Retrospective Analysis of NCIC CTG CO.17 and CO.20

© 2018 Elsevier Inc. This manuscript version is made available under the CC-BY-NC-ND 4.0 license: http://creativecommons.org/licenses/by-nc-nd/4.0/ This author accepted manuscript is made available following 12 month embargo from date of publication (November 2018) in accordance with the publisher’s archiving policyBackground The safety and efficacy of targeted therapy in older patients (≥ 70 years) with metastatic colorectal cancer is not well evaluated. Patients and Methods Outcomes of older patients (including overall survival [OS], progression-free survival [PFS], toxicity, and quality of life [QoL]) were compared to young patients using data from 2 large previously reported clinical trials, CO.17 (cetuximab vs. best supportive care) and CO.20 (cetuximab plus placebo vs. cetuximab plus brivanib). Only patients with wild-type KRAS tumors were included. Results A total of 251 (26.3%) of 955 patients were ≥ 70 years old. No significant differences in OS, PFS, or grade 3/4 adverse events were observed between older and younger patients treated with cetuximab (or cetuximab with placebo) in either trial. Younger patients trended toward superior OS in both CO.17 (hazard ratio = 1.80; P = .16) and CO.20 (hazard ratio = 1.34; P = .07). QoL maintenance favored younger patients in CO.17 (3.6 vs. 5.7 months; P = .046) but no difference of QoL maintenance was observed in the larger CO.20 trial (1.7 vs. 1.8 months; P = .64). Combination therapy of cetuximab and brivanib was significantly more toxic in older adults (87% vs. 77%; P = .03). Conclusion OS, PFS, and toxicities were similar between older and younger patients with wild-type KRAS metastatic colorectal cancer when treated with cetuximab. Both age groups likely experience similar QoL maintenance with cetuximab. Dual targeted therapy was significantly more toxic in older patients

Molecular epidemiology of methicillin-resistant Staphylococcus aureus isolated from Australian veterinarians

This work investigated the molecular epidemiology and antimicrobial resistance of methicillinresistant Staphylococcus aureus (MRSA) isolated from veterinarians in Australia in 2009. The collection (n = 44) was subjected to extensive molecular typing (MLST, spa, SCCmec, dru, PFGE, virulence and antimicrobial resistance genotyping) and antimicrobial resistance phenotyping by disk diffusion. MRSA was isolated from Australian veterinarians representing various occupational emphases. The isolate collection was dominated by MRSA strains belonging to clonal complex (CC) 8 and multilocus sequence type (ST) 22. CC8 MRSA (ST8-IV [2B], spa t064; and ST612-IV [2B] , spa variable,) were strongly associated with equine practice veterinarians (OR = 17.5, 95% CI = 3.3-92.5, P < 0.001) and were often resistant to gentamicin and rifampicin. ST22-IV [2B], spa variable, were strongly associated with companion animal practice veterinarians (OR = 52.5, 95% CI = 5.2-532.7, P < 0.001) and were resistant to ciprofloxacin. A single pig practice veterinarian carried ST398-V [5C2], spa t1451. Equine practice and companion animal practice veterinarians frequently carried multiresistant-CC8 and ST22 MRSA, respectively, whereas only a single swine specialist carried MRSA ST398. The presence of these strains in veterinarians may be associated with specific antimicrobial administration practices in each animal species