The structure of dominance hierarchies in the primitively eusocial wasp Ropalidia marginata

In queenright colonies of the old world tropical primitively eusocial polistine wasp, Ropalidia marginata, queens are behaviourally docile and subordinate individuals. Yet, they are completely successful in suppressing reproduction by all nestmates. Here we show that dominance hierarchies in queenright colonies are never significantly linear but, in the queen determination stage, when new queens use overt physical aggression to establish their status, dominance hierarchies among the same individuals are significantly linear. This striking difference in the structure of dominance hierarchies in queenright colonies as compared to the queen determination stage, is consistent with the previously postulated hypothesis that, while dominance behaviour functions to regulate worker reproduction in the queen determination stage, the same behaviours are used by the workers to regulate each others' foraging in queenright colonies

Challenges and opportunities for checkpoint blockade in T-cell lymphoproliferative disorders

Abstract The T-cell lymphoproliferative disorders are a heterogeneous group of non-Hodgkin’s lymphomas (NHL) for which current therapeutic strategies are inadequate, as most patients afflicted with these NHL will succumb to disease progression within 2 years of diagnosis. Appreciation of the genetic and immunologic landscape of these aggressive NHL, including PD-L1 (B7-H1, CD274) expression by malignant T cells and within the tumor microenvironment, provides a strong rationale for therapeutic targeting this immune checkpoint. While further studies are needed, the available data suggests that responses with PD-1 checkpoint blockade alone will unlikely approach those achieved in other lymphoproliferative disorders. Herein, we review the unique challenges posed by the T-cell lymphoproliferative disorders and discuss potential strategies to optimize checkpoint blockade in these T-cell derived malignancies.http://deepblue.lib.umich.edu/bitstream/2027.42/134748/1/40425_2016_Article_201.pd

Workers of the primitively eusocial wasp Ropalidia marginata do not perceive their queen across a wire mesh partition

Queens of primitively eusocial wasps generally have active and behaviourally dominant queens who use physical aggression to suppress worker reproduction. Although a Ropalidia marginata queen is strikingly docile and behaviourally non-dominant, she is completely successful in maintaining reproductive monopoly. R. marginata queens must achieve such reproductive monopoly by some means other than overt physical aggression. Upon loss or removal of the queen, one of the workers (referred to as the potential queen) becomes extremely aggressive and will eventually go on to become the next queen of the colony, if the original queen is not returned. The fact that potential queens are not discernible in the presence of the queen but become obvious within minutes after removal of the queen raises the question of how workers in general and the potential queens in particular, perceive the presence or absence of their queens. Here, we have conducted experiments in which we separate half of the workers from their queen by a wire mesh screen and study their behavioural response to such separation. We demonstrate that the presence of the queen is not perceived across the wire mesh screen, which suggests that if the queen uses a pheromone to signal her presence, then that pheromone is not very volatile

An observational study of evaluation of extended first trimester screening test to predict early preterm pre-eclampsia in pregnant women

Background: Pre-eclampsia is hypertensive disorder with several complications. Contributes to increased maternal mortality and morbidity. Pre-eclampsia is associated with pre term labour, IUGR and several other complications like end organ failure in mother. So, it is important to diagnose early and take appropriate steps to mitigate maternal mortality and morbidity. Aim was to detect and predict early preterm pre-eclampsia using extended first trimester screening test in pregnant women. Objectives were to assess the sensitivity and specificity of extended first trimester screening test to predict development pre-eclampsia in pregnancy.Methods: Method used in this study was observational study.Results: All three parameters, PAPPA, mean arterial pressure (MAP) and uterine artery pulsatility index found to be significantly associated in predicting early preterm preeclampsiaConclusions: This screening test enables us to predict preeclampsia before its clinical presentation. It can be used as a reliable and a cost-effective screening test. This will help prevent the progression of the disease by taking necessary timely interventions such as ecosprin administration, close and frequent follow up of screen positive mothers. Thus, it is useful tool in reducing the burden of maternal and fetal morbidity on the health system. This study also has confounding factors due to starting of prophylactic treatment with ecosprin based on ACOG/ NICE guidelines, which increased false positive rate.

Integrated graphene quantum dot decorated functionalized nanosheet biosensor for mycotoxin detection

Decoration of graphene quantum dots (GQDs) on molybdenum disulfide (MoS2) nanosheets serves as an active electrode material which enhances the electrochemical performance of the analyte detection system. Herein, ionic surfactant cetyltrimethylammonium bromide (CTAB)-exfoliated MoS2 nanosheets decorated with GQD material are used to construct an electrochemical biosensor for aflatoxin B1 (AFB1) detection. An antibody of AFB1 (aAFB1) was immobilized on the electrophoretically deposited MoS2@GQDs film on the indium tin oxide (ITO)-coated glass surface using a crosslinker for the fabrication of the biosensor. The immunosensing study investigated by the electrochemical method revealed a signal response in the range of 0.1 to 3.0 ng/mL AFB1 concentration with a detection limit of 0.09 ng/mL. Also, electrochemical parameters such as diffusion coefficient and heterogeneous electron transfer (HET) were calculated and found to be 1.67 x 10(-5) cm(2)/s and 2 x 10(-5)cm/s, respectively. The effective conjugation of MoS2@GQDs that provides abundant exposed edge sites, large surface area, improved electrical conductivity, and electrocatalytic activity has led to an excellent biosensing performance with enhanced electrochemical parameters. Validation of the fabricated immunosensor was performed in a spiked maize sample, and a good percentage of recoveries within an acceptable range were obtained (80.2 to 98.3%)

Classical Electron Model with Negative Energy Density in Einstein-Cartan Theory of Gravitation

Experimental result regarding the maximum limit of the radius of the electron \sim 10^{-16} cm and a few of the theoretical works suggest that the gravitational mass which is a priori a positive quantity in Newtonian mechanics may become negative in general theory of relativity. It is argued that such a negative gravitational mass and hence negative energy density also can be obtained with a better physical interpretation in the framework of Einstein-Cartan theory.Comment: 12 Latex pages, added refs and conclusion

Glass-ceramic Flexural Strength after Hydrofluoric Acid and Unfilled Resin Treatment

poster abstractThe use of hydrofluoric (HF) acid is considered one of the most effective methods for achieving durable resin bond to glass-ceramics. Nonetheless, HF acid etching effect on glass-based ceramics strength remains uncertain and only a few contradictory studies have reported the influence of an unfilled resin (UR) application on the ceramic strength. Objectives: To investigate the effect of HF acid etching followed by silane and UR applications on the biaxial flexural strength of a nanofluorapatite glass-ceramic. Methods: 144 disc-shaped (15±1mm in diameter and 0.8±0.1mm in thickness) nanofluorapatite ceramic specimens were allocated into 12 groups: G1-control (no etching), G2-30s, G3-60s, G4-90s, G5-120s, G6-60s+60s. Meanwhile, G7-G12 were treated in the same fashion as G1-G6, but followed by silane and UR applications. Surface morphology of G1-G12 was assessed by scanning electron microscopy/SEM. The flexural strength was determined by biaxial testing per ISO 6872. Statistical analyses were two-way ANOVA and the Sidak multiple comparisons procedure (α=0.05). Additionally, Weibull statistics and finite element analysis (FEA) were carried out. Results: A significant effect of etching time (p=0.0290) on flexural strength was observed. G4 led to a significantly (p=0.0392) higher flexural strength than G1. Correspondingly, G10 revealed a considerably higher flexural strength than G7 (p=0.0392). Furthermore, flexural strength was significantly higher for G7-G12 than for G1-G6 (p<0.0001). For G1-G6, G4 showed the highest Weibull characteristic strength and G10 also presented the highest Weibull characteristic strength among G7-G12. FEA showed lower stress concentration in G7-G12 with the gradient stress supporting the fracture types of the biaxial test. Finally, the SEM data revealed that the HF acid etching affected the surface of ceramic specimens by generating pores and irregularities and more importantly that the UR was able to penetrate into the ceramic microstructure. Conclusions: HF acid etching followed by silane and UR applications enhanced the ceramic biaxial flexural strength

The properties conferred upon triple-helical collagen-mimetic peptides by the presence of cysteine residues

AbstractRecently, the ability of polymeric collagen-like peptides to regulate cell behavior has generated great interest. A triple-helical peptide known as collagen-related peptide (CRP) contains the sequence (Gly-Pro-Hyp)10. With Gly-Pro-Cys triplets appended to both of its termini, designated CRPcys, chemical cross-linking using heterobifunctional reagents generates CRPcys-XL, a potent, widely used, polymeric agonist for platelet Glycoprotein VI, whereas non-cross-linked, monomeric CRPcys antagonizes Glycoprotein VI. Here, we describe how cysteine in these triplets may also undergo random air-induced oxidation, especially upon prolonged storage or repeated freeze–thawing, to form disulphide bonds, resulting in a lesser degree of polymerization than with chemical cross-linking. We investigated the monomeric and polymeric states of these and other cysteine-containing collagen-derived peptides, using gel filtration and dynamic light scattering, allowing the size of a CRP-XL aggregate to be estimated. The effect of cysteine thiols upon peptide adsorption to surfaces and subsequent platelet responses was investigated. This demonstrated that cysteine is required for strong binding to glass coverslips and to plastic plates used in ELISA assays