A computational study of the aerodynamic performance of a dragonfly wing section in gliding flight

A comprehensive computational fluid-dynamics-based study of a pleated wing section based on the wing of Aeshna cyanea has been performed at ultra-low Reynolds numbers corresponding to the gliding flight of these dragonflies. In addition to the pleated wing, simulations have also been carried out for its smoothed counterpart (called the 'profiled' airfoil) and a flat plate in order to better understand the aerodynamic performance of the pleated wing. The simulations employ a sharp interface Cartesian-grid-based immersed boundary method, and a detailed critical assessment of the computed results was performed giving a high measure of confidence in the fidelity of the current simulations. The simulations demonstrate that the pleated airfoil produces comparable and at times higher lift than the profiled airfoil, with a drag comparable to that of its profiled counterpart. The higher lift and moderate drag associated with the pleated airfoil lead to an aerodynamic performance that is at least equivalent to and sometimes better than the profiled airfoil. The primary cause for the reduction in the overall drag of the pleated airfoil is the negative shear drag produced by the recirculation zones which form within the pleats. The current numerical simulations therefore clearly demonstrate that the pleated wing is an ingenious design of nature, which at times surpasses the aerodynamic performance of a more conventional smooth airfoil as well as that of a flat plate. For this reason, the pleated airfoil is an excellent candidate for a fixed wing micro-aerial vehicle design.     

Testicular development and its relationship to semen production in Murrah buffalo bulls

The objectives of this study were to determine the relationship of age and body weight to testicular development and to establish norms for breeding soundness evaluations of Murrah buffalo bulls. Testicular measurements of 133 Murrah buffalo bulls of various ages were recorded with a caliper and a tape. Semen was collected twice a week for 5 weeks from groups of bulls which were 25-36 (n=17), 37-48 (n=16), 49-60 (n=14), of >60 (n=10) months of age. After examining volume, sperm concentration, and progressive motility semen was diluted in Tris-citric acid-egg yolk-fructose extender and frozen in 0.5 ml French straws. Testicular measurements of buffalo bulls were lower than those recorded for European breeds of cattle bulls. Nevertheless, like cattle bulls, scrotal circumference was highly correlated with other testicular measurements. Also, it had a significant positive relationship with semen volume and sperm concentration per ejaculate. Average sperm output per week in order of increasing age group was 15.3, 18.2, 19.8 and 23.6 x 10(9). Corresponding values for sperm output per week per gram of testis were 59.1, 45.8, 41.1, 36.2 x 10(6) indicating a reduction in spermatogenesis per unit of testis with advancing age. Compared to European breeds, daily sperm output in Murrah bulls was nearly 45% lower, presumably due to their nearly 40% lower scrotal circumference than Holstein bulls of the same age. These results indicate that in buffalo, as in cattle, scrotal circumference is a useful indicator of potential sperm output and may serve as an important criterion for selecting young bulls as AI sires.     

Cinnamaldehyde regulates H2O 2-induced skeletal muscle atrophy by ameliorating the proteolytic and antioxidant defense systems

Skeletal muscle atrophy/wasting is associated with impaired protein metabolism in diverse physiological and pathophysiological conditions. Elevated levels of reactive oxygen species (ROS), disturbed redox status, and weakened antioxidant defense system are the major contributing factors toward atrophy. Regulation of protein metabolism by controlling ROS levels and its associated catabolic pathways may help in treating atrophy and related clinical conditions. Although cinnamaldehyde (CNA) enjoys the established status of antioxidant and its role in ROS management is reported, impact of CNA on skeletal muscle atrophy and related pathways is still unexplored. In the current study, the impact of CNA on C2C12 myotubes and the possible protection of cultured cells from H ₂O ₂-induced atrophy is examined. Myotubes were treated with H ₂O ₂ in the presence and absence of CNA and the changes in the antioxidative, proteolytic systems, and mitochondrial functions were scored. Morphological analysis showed significant protective effects of CNA on length, diameter, and nuclei fusion index of myotubes. The evaluation of biochemical markers of atrophy; creatine kinase, lactate dehydrogenase, succinate dehydrogenase along with the study of muscle-specific structural protein (i.e., myosin heavy chain-fast [MHCf] type) showed significant protection of proteins by CNA. CNA pretreatment not only checked the activation of proteolytic systems (ubiquitin-proteasome E3-ligases [MuRF1/Atrogin1]), autophagy [Beclin1/LC3B], cathepsin L, calpain, caspase), but also prevented any alteration in the activities of antioxidative defense enzymes (catalase, glutathione- S-transferase, glutathione-peroxidase, superoxide dismutase, glutathione reductase). The results suggest that CNA protects myotubes from H ₂O ₂-induced atrophy by inhibiting/resisting the amendments in proteolytic systems and maintains cellular redox-balance.     

The Acetyltransferase Activity of the Bacterial Toxin YopJ of Yersinia Is Activated by Eukaryotic Host Cell Inositol Hexakisphosphate

Plague, one of the most devastating diseases in human history, is caused by the bacterium Yersinia pestis. The bacteria use a syringe-like macromolecular assembly to secrete various toxins directly into the host cells they infect. One such Yersinia outer protein, YopJ, performs the task of dampening innate immune responses in the host by simultaneously inhibiting the MAPK and NFκB signaling pathways. YopJ catalyzes the transfer of acetyl groups to serine, threonine, and lysine residues on target proteins. Acetylation of serine and threonine residues prevents them from being phosphorylated thereby preventing the activation of signaling molecules on which they are located. In this study, we describe the requirement of a host-cell factor for full activation of the acetyltransferase activity of YopJ and identify this activating factor to be inositol hexakisphosphate (IP₆). We extend the applicability of our results to show that IP₆ also stimulates the acetyltransferase activity of AvrA, the YopJ homologue from Salmonella typhimurium. Furthermore, an IP₆-induced conformational change in AvrA suggests that IP₆ acts as an allosteric activator of enzyme activity. Our results suggest that YopJ-family enzymes are quiescent in the bacterium where they are synthesized, because bacteria lack IP₆; once injected into mammalian cells by the pathogen these toxins bind host cell IP₆, are activated, and deregulate the MAPK and NFκB signaling pathways thereby subverting innate immunity.     

Statistical optimization of growth media for Paecilomyces lilacinus 6029 using non-edible oil cakes

The development of biofriendly and economical alternatives to chemical pesticides is a globally important scientific challenge. In this work, Karanja-based media conditions were optimized for obtaining high production of biomass and spores of a biocontrol agent, the entomopathogenic fungus Paecilomyces lilacinus 6029, using a two-step statistical approach coupled with rigorous experimentation. In the first step, non-edible Karanja cake was screened out as a major substrate from other oil cakes. In the second step, biomass production was maximized by applying response surface methodology to experimental variations in key physico-chemical factors: carbon/nitrogen (C/N) ratio and pH. This approach eventually predicted a maximum biomass production of 10.559 g/l with a medium having a C/N ratio of 35.88 and pH 5.9. An experimental production of 10.529 g/l biomass was obtained. The remarkable agreement between the predicted and the experimentally obtained biomass confirm the validity of the approach utilized to maximize production of P. lilacinus.     

Role of p-glycoprotein expression in predicting response to neoadjuvant chemotherapy in breast cancer-a prospective clinical study

Background

Lung cancer still remains one of the most commonly occurring solid tumors and even in stage Ia, surgery fails in 30% of patients who develop distant metastases. It is hypothesized that these must have developed from occult circulating tumor cells present at the time of surgery, or before. The aim of the present study was to detect such cells in the peripheral blood and to monitor these cells following surgery.

Methods

30 patients treated for lung cancer with surgery were monitored for circulating epithelial cells (CEC) by taking peripheral blood samples before, 2 weeks and 5 months after surgery and/or radiotherapy (RT) chemotherapy (CT) or combined RT/CT using magnetic bead enrichment and laser scanning cytometry (MAINTRAC^®) for quantification of these cells.

Results

In 86% of the patients CEC were detected before surgery and in 100% at 2 weeks and 5 months after surgery. In the control group, which consisted of 100 normal donors without cancer, 97 % were negative for CEC. A significantly higher number of CEC was found preoperatively in patients with squamous cell carcinoma than in those with adenocarcinoma. In correlation to the extent of parenchymal manipulation 2 weeks after surgery, an increase in numbers of CEC was observed with limited resections (18/21) whereas pneumonectomy led to a decrease (5/8) of CEC, 2 weeks after surgery. The third analysis done 5 months after surgery identified 3 groups of patients. In the group of 5 patients who received neo- or adjuvant chemo/radiotherapy there was evidence that monitoring of CEC can evaluate the effects of therapy. Another group of 7 patients who underwent surgery only showed a decrease of CEC and no signs of relapse. A third group of 11 patients who had surgery only, showed an increase of CEC (4 with an initial decrease after surgery and 7 with continuous increase). In the group with a continuous increase during the following 24 months, 2 early relapses in patients with stage Ia adenocarcinoma were observed. The increase of CEC preceded clinical detection by six months.

Conclusion

We consider, therefore, that patients with adenocarcinoma and a continuous increase of CEC after complete resection for lung cancer are at an increased risk of early relapse.     

No Correlation between TIMP2 -418 G>C Polymorphism and Increased Risk of Cancer: Evidence from a Meta-Analysis

Aim

Tissue inhibitor of metalloproteinase (TIMP2) is involved in the regulation of matrix metalloproteinase 2 (MMP2) and shown to implicate in cancer development and progression. The results from the published studies based on the association between TIMP2 -418 G>C polymorphism and cancer risk are inconsistent. In this meta-analysis, we aimed to evaluate the potential association between TIMP2 -418 G>C polymorphism and cancer risk.

Methodology

We searched PubMed (Medline) and EMBASE web databases to cover all studies based on relationship of TIMP2 -418 G>C polymorphism and risk of cancer until October 2013. The meta-analysis was performed for selected case-control studies and pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated for all genetic models.

Results

A total of 2225 cancer cases and 2532 controls were included from ten eligible case-control studies. Results from overall pooled analysis suggested no evidence of significant risk between TIMP2 -418 G>C polymorphism and cancer risk in any of the genetic models, such as, allele (C vs. G: OR = 1.293, 95% CI = 0.882 to 1.894, p = 0.188), homozygous (CC vs. GG: OR = 0.940, 95% CI = 0.434 to 2.039, p = 0.876), heterozygous (GC vs. GG: OR = 1.397, 95% CI = 0.888 to 2.198, p = 0.148), dominant (CC+GC vs. GG: OR = 1.387, 95% CI = 0.880 to 2.187, p = 0.159) and recessive (CC vs. GG+GC: OR = 0.901, 95% CI = 0.442 to 1.838, p = 0.774) models. No evidence of publication bias was detected during the analysis.

Conclusions

The present meta-analysis suggests that the TIMP2 -418 G>C polymorphism may not be involved in predisposing risk factor for cancer in overall population. However, future larger studies with group of populations are needed to analyze the possible correlation.     

Structure and histochemistry of the epithelia of lips and associated structures of a catfishRita rita

InRita rita the upper lip is associated with the rostral cap and the lower lip with a skin fold. The epithelia of the lips, which are modified with respect to the peculiar feeding behaviour of the fish, are mucogenic. The superficial layer of epithelial cells, in addition to the mucous cells, are involved in active secretion of mucopolysaccharides. Mucus, apart from its diverse functions, as in fish epidermis, lubricates the epithelia giving protection against possible mechanical injury during the searching and catching of prey from bottom debris. Furthermore, the epithelia are thick, an adaptation to their mucogenic nature, so as to provide additional protection. The contents of the club cells are proteinaceous, which correlates with the helical filaments reported in similar cells in fish epidermis. Characteristic ridges on the surface of the lips are considered to be an adaptation to assist in manipulation during the procuring of food. Mucus secreted in the grooves between them reduces friction and prevents the deposition of foreign matter. The skin fold facilitates an increase in gape. The taste buds and ampullary organs, which on the lips and the rostral cap are associated with the localization of prey and triggering of a pick-up reflex, are not located on the skin fold, as the latter often remains concealed between the lower lip and the ventral head skin. The importance of histochemical analysis as a supplement to histological studies is emphasised.