Aerodynamic Characteristics of a Feathered Dinosaur Measured Using Physical Models. Effects of Form on Static Stability and Control Effectiveness

We report the effects of posture and morphology on the static aerodynamic stability and control effectiveness of physical models based on the feathered dinosaur, Microraptor gui, from the Cretaceous of China. Postures had similar lift and drag coefficients and were broadly similar when simplified metrics of gliding were considered, but they exhibited different stability characteristics depending on the position of the legs and the presence of feathers on the legs and the tail. Both stability and the function of appendages in generating maneuvering forces and torques changed as the glide angle or angle of attack were changed. These are significant because they represent an aerial environment that may have shifted during the evolution of directed aerial descent and other aerial behaviors. Certain movements were particularly effective (symmetric movements of the wings and tail in pitch, asymmetric wing movements, some tail movements). Other appendages altered their function from creating yaws at high angle of attack to rolls at low angle of attack, or reversed their function entirely. While M. gui lived after Archaeopteryx and likely represents a side experiment with feathered morphology, the general patterns of stability and control effectiveness suggested from the manipulations of forelimb, hindlimb and tail morphology here may help understand the evolution of flight control aerodynamics in vertebrates. Though these results rest on a single specimen, as further fossils with different morphologies are tested, the findings here could be applied in a phylogenetic context to reveal biomechanical constraints on extinct flyers arising from the need to maneuver.     

Quantitative analysis of sugar constituents of glycoproteins by capillary electrophoresis

A method for quantitative analysis of monosaccharides including N- acetylneuraminic acid derived from sialic acid-containing oligosaccharides and glycoproteins is presented. The analysis is based on the combination of chemical and enzymatic methods coupled with capillary electrophoretic (CE) separation and laser-induced fluorescence (LIF) detection. The present method utilizes a simplified acid hydrolysis procedure consisting of mild hydrolysis (0.1 M TFA) to release sialic acid and strong acid hydrolysis (2.0 N TFA) to produce amino and neutral sugars. Amino sugars released from strong acid hydrolysis of oligosaccharides and glycoproteins were reacetylated and derivatized with 8-aminopyrene-1,3,6-trisulfonate (APTS) along with neutral sugars in the presence of sodium cyanoborohydride to yield quantitatively the highly stable fluorescent APTS adducts. N- acetylneuraminic acid (Neu5Ac), a major component of most mammalian glycoproteins, was converted in a fast specific reaction by the action of neuraminic acid aldolase (N-acylneuraminate pyruvate-lyase EC 4.1.3.3) to N-acetylmannosamine (ManNAc) and pyruvate. ManNAc was then derivatized with APTS in the same manner as the other monosaccharides. This method was demonstrated for the quantitation of pure Neu5Ac and the species derived from mild acid hydrolysis of 6'-sialyl-N- acetyllactosamine and bovine fetuin glycan. Quantitative recovery of the N-acetylmannosamine was obtained from a known amount of Neu5Ac in a mixture of seven other monosaccharides or from the sialylated oligosaccharides occurring in glycoproteins. The sequence of procedures consists of acid hydrolysis, enzymatic conversion and APTS derivatization which produced quantitative recovery of APTS- monosaccharide adducts. The detection limits for sugars derivatized with APTS and detected by CE-LIF are 100 pmol for Neu5Ac and 50 pmol for the other sugars.      

Enzyme-amplified lanthanide luminescence for enzyme detection in bioanalytical assays

Enzyme-amplified lanthanide luminescence (EALL) is a new method which has been developed for enzymatically amplified signal detection in ultrasensitive bioanalytical assays where an enzyme is used as label or is itself the analyte of interest. Signal generation is performed by enzymatically transforming a substrate into a product which forms a luminescent lanthanide chelate; the product chelate can then be detected using time-resolved or normal fluorescence methods. Alkaline phosphatase substrates have been developed and demonstrated in a model immunoassay in microwell format. The method has also been demonstrated for detection of a variety of other hydrolytic and oxidative enzymes. Thus the EALL method shows promise for use in a wide variety of bioanalytical applications.     

DjPum, a homologue of Drosophila Pumilio, is essential to planarian stem cell maintenance

As stem cells are rare and difficult to study in vivo in adults, the use of classical models of regeneration to address fundamental aspects of the stem cell biology is emerging. Planarian regeneration, which is based upon totipotent stem cells present in the adult--the so-called neoblasts--provides a unique opportunity to study in vivo the molecular program that defines a stem cell. The choice of a stem cell to self-renew or differentiate involves regulatory molecules that also operate as translational repressors, such as members of PUF proteins. In this study, we identified a homologue of the Drosophila PUF gene Pumilio (DjPum) in the planarian Dugesia japonica, with an expression pattern preferentially restricted to neoblasts. Through RNA interference (RNAi), we demonstrate that gene silencing of DjPum dramatically reduces the number of neoblasts, thus supporting the intriguing hypothesis that stem cell maintenance may be an ancestral function of PUF proteins.     

Does circadian and seasonal variation in occurrence of acute aortic dissection influence in-hospital outcomes?

The risk of acute aortic dissection (AAD) exhibits chronobiological variations with peak onset in the morning and in winter. However, it is not known whether the time of day or season of the year of the AAD affects clinical outcomes. We studied 1,032 patients enrolled in the International Registry of Acute Aortic Dissection from January 1997 to December 2001. For circadian and seasonal analysis, the time and date of symptom onset were available for 741 and 1,007 patients, respectively, and were grouped into four 6 h periods (morning, afternoon, evening, and night) and four seasons (winter, spring, summer, and autumn). The χ² test for goodness of fit was used to evaluate non-uniformity of the time of day and time of year for critical in-hospital clinical events, including death. While highest incidence of AAD occurred in the morning and winter, clinical events (including mortality) were similar during the four different periods of the 24 h (χ²=1.9, p=0.60) and seasonal (χ²=1.2, p=0.75) periods.     

Nuclear phosphoinositide specific phospholipase C (PI-PLC)-beta 1: a central intermediary in nuclear lipid-dependent signal transduction

Several studies have demonstrated the existence of an autonomous intranuclear phospho-inositide cycle that involves the activation of nuclear PI-PLC and the generation of diacylglycerol (DG) within the nucleus. Although several distinct isozymes of PI-PLC have been detected in the nucleus, the isoform that has been most consistently highlighted as being nuclear is PI-PLC-beta1. Nuclear PI-PLC-beta1 has been linked with either cell proliferation or differentiation. Remarkably, the activation mechanism of nuclear PI-PLC-beta1 has been shown to be different from its plasma membrane counterpart, being dependent on phosphorylation effected by p44/42 mitogen activated protein (MAP) kinase. In this review, we report the most up-dated findings about nuclear PI-PLC-beta1, such as the localization in nuclear speckles, the activity changes during the cell cycle phases, and the possible involvement in the progression of myelodisplastic syndrome to acute myeloid leukemia.     

Diversity of Cetoniidae (Insecta: Coleoptera) in the Cerrado of Central Brazil

Cetoniidae is a diverse family containing approximately 4,000 species, most of which feed on flowers and fruits. In Brazil, 72 species and 24 genera are recorded. Little is known about this family in the Central region of Brazil, and no research has previously been conducted in the ecologically important Cerrado biome. In this study, we evaluated the diversity and temporal variation of the Cetoniidae in an area of the Cerrado in the Federal District (Brazil) and verified whether the abundance and species richness were influenced by climatic variables. The study was carried out in an area of Cerrado sensu stricto at Água Limpa Farm in Brasília/DF. Beetles were collected weekly from October 2013 to September 2014 using 40 traps baited with banana and pineapple fermented with sugarcane juice. A total of 398 specimens comprising 8 genera and 15 species were collected. We observed temporal variation in abundance and richness of the Cetoniidae in direct relation to the climatic characteristics of the Cerrado, with a greater number of individuals and species appearing in the rainy season. Climatic variables such as temperature and humidity appear to have a significant effect on the diversity of Cetoniidae. This is the first study conducted on this family in Central Brazil.     

Evidence for a role of adrenals in the capsaicin-sensitive "gastric defence mechanism" in rats

Capsaicin desensitization increases the degree of indomethacin-induced gastric ulcers in sham-operated but not in adrenalectomized rats. These results suggest that adrenals play a role in the capsaicin-sensitive "gastric defence mechanism".     

Cholecystokinin-8 protects gastric mucosa against ethanol-induced lesions in rats

Subcutaneous administration of cholecystokinin-8 (CCK-8, 10-100 micrograms/kg) reduces in a dose-dependent manner gastric lesions induced by 96% ethanol in rats, and CCK-4, CCK-7, and the CCK-8 nonsulfated form (all up to 100 micrograms/kg sc) were inactive. The presence of the entire molecule and sulfation of the tyrosine in position 2 are necessary for the mucosal protective properties of CCK-8 against 96% ethanol-induced gastric lesions. These effects are probably at least in part, due to a sulfhydryl-sensitive process.     

Influence of ACE I/D Polymorphism on Circulating Levels of Plasminogen Activator Inhibitor 1, D-Dimer,Ultrasensitive C-Reactive Protein and Transforming Growth Factor β1 in Patients Undergoing Hemodialysis

Background

There is substantial evidence that chronic renal and cardiovascular diseases are associated with coagulation disorders, endothelial dysfunction, inflammation and fibrosis. Angiotensin-Converting Enzyme Insertion/Deletion polymorphism (ACE I/D polymorphism) has also be linked to cardiovascular diseases. Therefore, this study aimed to compare plasma levels of ultrassensible C-reactive protein (usCRP), PAI-1, D-dimer and TGF-β1 in patients undergoing HD with different ACE I/D polymorphisms.

Methods

The study was performed in 138 patients at ESRD under hemodialysis therapy for more than six months. The patients were divided into three groups according to the genotype. Genomic DNA was extracted from blood cells (leukocytes). ACE I/D polymorphism was investigated by single polymerase chain reaction (PCR). Plasma levels of D-dimer, PAI-1 and TGF-β1 were measured by enzyme-linked immunosorbent assay (ELISA), and the determination of plasma levels of usCRP was performed by immunonephelometry. Data were analyzed by the software SigmaStat 2.03.

Results

Clinical characteristics were similar in patients with these three ACE I/D polymorphisms, except for interdialytic weight gain. I allele could be associated with higher interdialytic weight gain (P = 0.017). Patients genotyped as DD and as ID had significantly higher levels of PAI-1 than those with II genotype. Other laboratory parameters did not significantly differ among the three subgroups (P = 0.033). Despite not reaching statistical significance, plasma levels of usCRP were higher in patients carrying the D allele.

Conclusion

ACE I/D polymorphisms could be associated with changes in the regulation of sodium, fibrinolytic system, and possibly, inflammation. Our data showed that high levels of PAI-1 are detected when D allele is present, whereas greater interdialytic gain is associated with the presence of I allele. However, further studies with different experimental designs are necessary to elucidate the mechanisms involved in these associations.