Identification of Neural Outgrowth Genes using Genome-Wide RNAi

While genetic screens have identified many genes essential for neurite outgrowth, they have been limited in their ability to identify neural genes that also have earlier critical roles in the gastrula, or neural genes for which maternally contributed RNA compensates for gene mutations in the zygote. To address this, we developed methods to screen the Drosophila genome using RNA-interference (RNAi) on primary neural cells and present the results of the first full-genome RNAi screen in neurons. We used live-cell imaging and quantitative image analysis to characterize the morphological phenotypes of fluorescently labelled primary neurons and glia in response to RNAi-mediated gene knockdown. From the full genome screen, we focused our analysis on 104 evolutionarily conserved genes that when downregulated by RNAi, have morphological defects such as reduced axon extension, excessive branching, loss of fasciculation, and blebbing. To assist in the phenotypic analysis of the large data sets, we generated image analysis algorithms that could assess the statistical significance of the mutant phenotypes. The algorithms were essential for the analysis of the thousands of images generated by the screening process and will become a valuable tool for future genome-wide screens in primary neurons. Our analysis revealed unexpected, essential roles in neurite outgrowth for genes representing a wide range of functional categories including signalling molecules, enzymes, channels, receptors, and cytoskeletal proteins. We also found that genes known to be involved in protein and vesicle trafficking showed similar RNAi phenotypes. We confirmed phenotypes of the protein trafficking genes Sec61alpha and Ran GTPase using Drosophila embryo and mouse embryonic cerebral cortical neurons, respectively. Collectively, our results showed that RNAi phenotypes in primary neural culture can parallel in vivo phenotypes, and the screening technique can be used to identify many new genes that have important functions in the nervous system

Combined Tevatron upper limit on gg->H->W+W- and constraints on the Higgs boson mass in fourth-generation fermion models

Report number: FERMILAB-PUB-10-125-EWe combine results from searches by the CDF and D0 collaborations for a standard model Higgs boson (H) in the process gg->H->W+W- in p=pbar collisions at the Fermilab Tevatron Collider at sqrt{s}=1.96 TeV. With 4.8 fb-1 of integrated luminosity analyzed at CDF and 5.4 fb-1 at D0, the 95% Confidence Level upper limit on \sigma(gg->H) x B(H->W+W-) is 1.75 pb at m_H=120 GeV, 0.38 pb at m_H=165 GeV, and 0.83 pb at m_H=200 GeV. Assuming the presence of a fourth sequential generation of fermions with large masses, we exclude at the 95% Confidence Level a standard-model-like Higgs boson with a mass between 131 and 204 GeV.We combine results from searches by the CDF and D0 collaborations for a standard model Higgs boson (H) in the process gg→H→W+W- in pp̅ collisions at the Fermilab Tevatron Collider at √s=1.96  TeV. With 4.8  fb-1 of integrated luminosity analyzed at CDF and 5.4  fb-1 at D0, the 95% confidence level upper limit on σ(gg→H)×B(H→W+W-) is 1.75 pb at mH=120  GeV, 0.38 pb at mH=165  GeV, and 0.83 pb at mH=200  GeV. Assuming the presence of a fourth sequential generation of fermions with large masses, we exclude at the 95% confidence level a standard-model-like Higgs boson with a mass between 131 and 204 GeV.Peer reviewe

Physiological responses of the red rocky crab Cancer antennarius exposed to different concentrations of copper sulfate

In this study we evaluated physiological, metabolic and hematological responses for the crab Cancer antennarius to different copper sulfate concentrations (0.5, 1.0, 1.5, 2.0 mg L-1). The evaluated responses were: the median lethal dose, osmoregulatory capacity, oxygen consumption, ammonium excretion, atomic relation O:N, glucose, THC and hemocyanin concentration. The median lethal dose (LD50) we found was 1.6 mg L-1 of copper sulfate. The pattern followed on most of the observed responses was an increase directly proportional to the amount of copper sulfate concentration, except for osmoregulatory capacity where the osmoregulation pattern, usually isosmotic in normal conditions, was modified to hyposmotic. In the atomic relation O:N we observed a decrease in values due to changes in metabolic substrate as a result of stress caused by exposure to copper sulfate.Se evaluaron en el cangrejo de roca Cancer antennarius las respuestas fisiológicas, metabólicas y hematológicas a diferentes concentraciones de sulfato de cobre (0,5, 1,0, 1,5, 2,0 mg L-1). Las respuestas a determinar fueron: dosis letal media, capacidad osmorreguladora, consumo de oxígeno, excreción de amonio, relación atómica O:N, glucosa, el CTH y la concentración de hemocianina. En cuanto a la dosis letal media (LD50) se determinó que la concentración fue de 1,6 mg L-1 de sulfato de cobre. El patrón observado en la mayoría de las respuestas medidas fue un aumento directamente proporcional a la concentración de sulfato de cobre; a excepción de la capacidad osmorreguladora, en la que el patrón de osmorregulación, de ser típicamente isosmótico en condiciones normales, se modificó a hiposmótico. En la relación atómica O:N se observó una disminución en los valores debido a cambios en sustrato metabólico como un resultado del estrés causado por la exposición al sulfato de cobre

Antioxidant properties of aqueous and ethanolic extracts of tara (Caesalpinia spinosa) pods in vitro and in model food emulsions

The successful replacement of some synthetic food antioxidants by safe natural antioxidants has fostered intensive search for new vegetable sources of antioxidants. In our study the phenol and flavonoid content of extracts of tara pods was determined. The antioxidant activity was also studied by three different analytical assays: the measurement of scavenging capacity against a radical ABTS + , the oxygen radical absorbance capacity (ORAC) and the ferric reducing antioxidant power (FRAP).Peer ReviewedPostprint (published version