Diffraction of light by a planar aperture in a metallic screen

We present a complete derivation of the formula of Smythe [Phys.Rev.72, 1066 (1947)] giving the electromagnetic field diffracted by an aperture created in a perfectly conducting plane surface. The reasoning, valid for any excitating field and any hole shape, makes use only of the free scalar Green function for the Helmoltz equation without any reference to a Green dyadic formalism. We compare our proof with the one previously given by Jackson and connect our reasoning to the general Huygens Fresnel theorem.Comment: J. Math. Phys. 47, 072901 (2006

Leucine-enriched essential amino acid supplementation in mechanically ventilated trauma patients: a feasibility study

Background Critically ill patients lose up to 2% of muscle mass per day. We assessed the feasibility of administering a leucine-enriched essential amino acid (L-EAA) supplement to mechanically ventilated trauma patients with the aim of assessing the effect on skeletal muscle mass and function. Methods A randomised feasibility study was performed over six months in intensive care (ICU). Patients received 5 g L-EAA five times per day in addition to standard feed (L-EAA group) or standard feed only (control group) for up to 14 days. C-reactive protein, albumin, IL-6, IL-10, urinary 3-MH, nitrogen balance, protein turnover ([1-13C] leucine infusion), muscle depth change (ultrasound), functional change (Katz and Barthel indices) and muscle strength Medical Research Council (MRC) sum score to assess ICU Acquired Weakness were measured sequentially. Results Eight patients (9.5% of screened patients) were recruited over six months. L-EAA doses were provided on 91/124 (73%) occasions. Inflammatory and urinary marker data were collected; serial muscle depth measurements were lacking due to short length of stay. Protein turnover studies were performed on five occasions. MRC sum score could not be performed as patients were not able to respond to the screening questions. The Katz and Barthel indices did not change. L-EAA delivery was achievable, but meaningful functional and muscle mass outcome measures require careful consideration in the design of a future randomised controlled trial. Conclusion L-EAA was practical to provide, but we found significant barriers to recruitment and measurement of the chosen outcomes which would need to be addressed in the design of a future, large randomised controlled trial

Lyophilisation of influenza, rabies and Marburg lentiviral pseudotype viruses for the development and distribution of a neutralisation-assay based diagnostic kit

Pseudotype viruses (PVs) are chimeric, replication-deficient virions that mimic wild-type virus entry mechanisms and can be safely employed in neutralisation assays, bypassing the need for high biosafety requirements and performing comparably to established serological assays. However, PV supernatant necessitates -80°C long-term storage and cold-chain maintenance during transport, which limits the scope of dissemination and application throughout resource-limited laboratories. We therefore investigated the effects of lyophilisation on influenza, rabies and Marburg PV stability, with a view to developing a pseudotype virus neutralisation assay (PVNA) based kit suitable for affordable global distribution. Infectivity of each PV was calculated after lyophilisation and immediate reconstitution, as well as subsequent to incubation of freeze-dried pellets at varying temperatures, humidities and timepoints. Integrity of glycoprotein structure following treatment was also assessed by employing lyophilised PVs in downstream PVNAs. In the presence of 0.5M sucrose-PBS cryoprotectant, each freeze-dried pseudotype was stably stored for 4 weeks at up to 37°C and could be neutralised to the same potency as unlyophilised PVs when employed in PVNAs. These results confirm the viability of a freeze-dried PVNA-based kit, which could significantly facilitate low-cost serology for a wide portfolio of emerging infectious viruses

Applying the Coulomb Failure Function with an optimally oriented plane to the 2008 Mw 7.9 Wenchuan earthquake triggering

The Coulomb failure function (CFF) quantitatively describes static stress changes in secondary faults near the source fault of an earthquake. CFF can be employed to monitor how static stress transfers and then shed some light on the probability of successive events occurring around a source fault. In this paper we focus on the CFF and particularly on optimally oriented planes. We present a unified model to determine an optimally oriented plane and its corresponding Coulomb stress, then apply the model to the 2003 Mw 6.6 Bam (Iran) earthquake and the 2008 Mw 7.9 Wenchuan (China) earthquake, thereby checking its effectiveness. Our results show that spatial correlation between positive Coulomb stress changes and aftershocks are, for the 2003 Bam earthquake, 47.06% when elastic Coulomb stress changes are resolved on uniform planes and 87.53% when these are resolved on optimally oriented planes at depth; for the 2008 Wenchuan earthquake the correlations are 45.68% and 58.20%, respectively. It is recommended that account be taken of optimally oriented planes when drawing a Coulomb stress map for analyzing earthquake triggering effects

Association of PCSK1 rs6234 with Obesity and Related Traits in a Chinese Han Population

Background: Common variants in PCSK1 have been reported to be associated with obesity in populations of European origin. We aimed to replicate this association in Chinese. Methodology/Principal Findings: Two PCSK1 variants rs6234 and rs6235 (in strong LD with each other, r 2 = 0.98) were genotyped in a population-based cohort of 3,210 Chinese Hans. The rs6234 was used for further association analyses with obesity and related traits. We found no significant association of rs6234 with obesity, overweight, BMI, waist circumference, or body fat percentage (P.0.05) in all participants. However, the rs6234 G-allele showed a significant association with increased risk of combined phenotype of obesity and overweight (OR 1.21[1.03–1.43], P = 0.0193) and a trend toward association with obesity (OR 1.25[0.98–1.61], P = 0.08) in men, but not in women (P$0.29). Consistently, the rs6234 G-allele showed significant association with increased BMI (P = 0.0043), waist circumference (P = 0.008) and body fat percentage (P = 0.0131) only in men, not in women (P$0.24). Interestingly, the rs6234 G-allele was significantly associated with increased HOMA-B (P = 0.0059) and decreased HOMA-S (P = 0.0349) in all participants. Conclusion/Significance: In this study, we found modest evidence for association of the PCSK1 rs6234 with BMI and overweight in men only but not in women, which suggested that PCSK1 rs6234 might not be an important contributor t

Aberrant Cell Cycle and Apoptotic Changes Characterise Severe Influenza A Infection – A Meta-Analysis of Genomic Signatures in Circulating Leukocytes

Influenza A infection is a global disease that has been responsible for four pandemics over the last one hundred years. However, it remains poorly understood as to why some infected individuals succumb to life threatening complications whilst others recover and are relatively unaffected. Using gene-expression analysis of circulating leukocytes, here we show that the progression towards severe influenza A infection is characterised by an abnormal transcriptional reprogramming of cell cycle and apoptosis pathways. In severely infected humans, leukocyte gene-expression profiles display opposing cell cycle activities; an increased aberrant DNA replication in the G1/S phase yet delayed progression in the G2/M phase. In mild infection, cell cycle perturbations are fewer and are integrated with an efficient apoptotic program. Importantly, the loss of integration between cell cycle perturbations and apoptosis marks the transition from a mild viral illness to a severe, life threatening infection. Our findings suggest that circulating immune cells may play a significant role in the evolution of the host response. Further study may reveal alternative host response factors previously unrecognized in the current disease model of influenza

The Characterization of Varicella Zoster Virus-Specific T Cells in Skin and Blood during Aging

Reactivation of the varicella zoster virus (VZV) increases during aging. Although the effects of VZV reactivation are observed in the skin (shingles), the number and functional capacity of cutaneous VZV-specific T cells have not been investigated. The numbers of circulating IFN-γ-secreting VZV-specific CD4+ T cells are significantly decreased in old subjects. However, other measures of VZV-specific CD4+ T cells, including proliferative capacity to VZV antigen stimulation and identification of VZV-specific CD4+ T cells with an major histocompatibility complex class II tetramer (epitope of IE-63 protein), were similar in both age groups. The majority of T cells in the skin of both age groups expressed CD69, a characteristic of skin-resident T cells. VZV-specific CD4+ T cells were significantly increased in the skin compared with the blood in young and old subjects, and their function was similar in both age groups. In contrast, the number of Foxp3+ regulatory T cells and expression of the inhibitory receptor programmed cell death -1 PD-1 on CD4+ T cells were significantly increased in the skin of older humans. Therefore, VZV-specific CD4+ T cells in the skin of older individuals are functionally competent. However, their activity may be restricted by multiple inhibitory influences in situ

Leucine-enriched essential amino acid supplementation in mechanically ventilated trauma patients: a feasibility study

Background: Critically ill patients lose up to 2% muscle mass per day. We assessed the feasibility of administering a leucine-enriched essential amino acid (L-EAA) supplement to mechanically ventilated trauma patients with the aim of assessing the effect on skeletal muscle mass and function. Methods: A randomised feasibility study was performed over 6 months in intensive care (ICU), patients received 5g L-EAA five times per day in addition to standard feed (L-EAA group) or standard feed only (control group) up to 14 days. CRP, albumin, IL-6, IL-10, urinary 3-MH, nitrogen balance, protein turnover ([1-13C] leucine infusion), muscle depth change (ultrasound), functional change (Katz & Barthel indices) and muscle strength Medical Research Council (MRC) sum score to assess ICU Acquired Weakness, were measured sequentially. Results: Eight patients (9.5% of screened patients) were recruited over 6 months. L-EAA doses were provided on 91/124 (73%) occasions. Inflammatory and urinary marker data were collected; serial muscle depth measurements were lacking due to short length of stay. Protein turnover studies were performed on five occasions. MRC-sum score could not be performed as patients were not able to respond to the screening questions. The Katz & Barthel indices did not change. L-EAA delivery was achievable, but meaningful functional and muscle mass outcome measures require careful consideration in the design of a future RCT. Conclusion: L-EAA was practical to provide, but we found significant barriers to recruitment and measurement of the chosen outcomes which would need to be addressed in the design of a future, large randomised controlled trial

Measurements of natives of N.W. Territories

p. 53-68, [5] leaves of plates : ill. ; 24 cm.Includes bibliographical references