A Simple Method for Isolating DNA of High Yield and Quality from Cotton (shape Gossypium hirsutum L.) Leaves

An easy, reproducible and fast procedure to isolate DNA from cotton leaves is described. The addition of 0.5 M glucose in the extraction buffer avoids browning by polyphenolic compounds and improves the quality of DNA for molecular analysis. The DNA yield ranged between 150–400 mg per gram of fresh tissue. The DNA was suitable for digestion by restriction enzymes and amplificatiion by Taq DNA polymerase.     

Mesocyclops longisetus effects on survivorship of Aedes aegypti immature stages in car tyres

Abstract .The effect of the introduction of the entomophagous copepod Mesocyclops longisetus (Acuacultura F.C.B. strain) on the survival of Aedes aegypti immature stages in car tyres was evaluated under semi-natural conditions in the municipality of Merida, Yucatan, Mexico. Life tables were constructed for the immature stages of the mosquito in the presence and absence of M. longisetus , and the survival data were compared using log–linear models. The data set was adjusted using the GLIM statistical package and the quality of adjustment was evaluated with a chi-squared test . Survivorship curves were constructed for each treatment.
In the absence of M. longisetus , the survivorship of Ae. aegypti immature stages averaged 9%. The highest mortality rate was observed during the fourth larval instar (54%) and the resulting survival pattern corresponded to a type II survivorship curve. The mortality rate of Ae. aegypti first-instar larvae (fifty per tyre) increased more than 200-fold in the presence of M. longisetus (twenty per tyre) and the highest mortality was during the first two larval instars, where it reached 98.9%, with a resulting survivorship of 0.2%. Overall mortality was sixfold greater in the presence of the copepod than in its absence. The survival pattern of immature stages of Ae. aegypti in the presence of the copepod corresponded to a type III survivorship curve. As M. longisetus was so effective against Ae. aegypti immature stages in tyres under semi-natural conditions, its long-term effectiveness should be evaluated under socially and ecologically realistic field conditions in Mexico.     

The incidence of Weeksella- and Bergeyella-like bacteria in the food environment

Eighty-five catalase- and oxidase-positive Gram-negative rods and cocci susceptible to penicillin G were isolated from a variety of food sources. The phenotypic relationships of these isolates with reference cultures of Bergeyella -like, Chryseobacterium, Empedobacter, Myroides , Moraxella , Sphingobacterium and Weeksella -like strains were examined by numerical taxonomy. Seventy-three isolates were recovered in five groups; 80% of the isolates clustered in groups 1, 2 and 3 and produced indole, bearing a strong resemblance to Weeksella and Bergeyella . They could not, however, be regarded as belonging to the known species of W. virosa and B. zoohelcum . It is suggested that three species may be necessary to accommodate the environmental Weeksella - or Bergeyella -like bacteria. The isolates in groups 4 and 5 had white colonies and were unable to produce indole, in this way resembling the Moraxella genus.     

E‐Clic – easy climate data converter

There are an increasing number of studies that are now focussing on the influence of climate change on species’ distributions. However, access to predictive climatic datasets for future scenarios is difficult due to their specific formats and/or the need to be geographically downscaled. The TYN dataset is freely available to users and provides a synthetic format with several climatic models and IPCC future climate scenarios. Moreover, the CRU historical dataset (1901–2000) is also available which allows users to create baseline models for current climatic variables. E‐clic is a free, user‐friendly software package that offers three different ways to convert these two datasets into a spatially explicit raster format which is compatible with the most common geographic information systems and usable on different platforms.     

Long-term effects of postovulatory aging of mouse oocytes on offspring: a two-generational study.

Aims of this study were to analyze the long-term effects of postovulatory aging of mouse oocytes on 1) reproductive traits of parental (F(0)) and first (F(1))-generation females (pregnancy rate, gestation length, litter size, perinatal death, and sex ratio of offspring) and 2) developmental and behavioral variables of F(1) and second-generation (F(2)) offspring (birth weight and weight gain during preweaning development, postnatal day of attainment of immediate righting, spontaneous motor activity, and passive and active conditioned learning ability). Hybrid (C57BL/6JIco x CBA/JIco) females were artificially inseminated at 13 h (control group) or 22 h (oocyte-aged group) after GnRH injection. Experimental (oocyte-aged group) F(0) females exhibited lower pregnancy rate, shortened gestation length, decreased litter size, higher perinatal death of their pups, and increased percentage of male offspring compared to control F(0) females. Postovulatory aging of oocytes was also associated with increased number of growth-retarded pups, delayed development of the righting reflex, and higher spontaneous motor activity and emotionality of F(1) offspring. Postovulatory aging of F(0) oocytes did not affect birth weight, weight gain during preweaning development, passive and active conditioned learning ability of F(1) offspring, or reproductive traits of F(1) females or developmental and behavior variables of F(2) offspring.     

β-Amyloid (Aβ) Oligomers Impair Brain-derived Neurotrophic Factor Retrograde Trafficking by Down-regulating Ubiquitin C-terminal Hydrolase,UCH-L1

We previously found that BDNF-dependent retrograde trafficking is impaired in AD transgenic mouse neurons. Utilizing a novel microfluidic culture chamber, we demonstrate that Aβ oligomers compromise BDNF-mediated retrograde transport by impairing endosomal vesicle velocities, resulting in impaired downstream signaling driven by BDNF/TrkB, including ERK5 activation, and CREB-dependent gene regulation. Our data suggest that a key mechanism mediating the deficit involves ubiquitin C-terminal hydrolase L1 (UCH-L1), a deubiquitinating enzyme that functions to regulate cellular ubiquitin. Aβ-induced deficits in BDNF trafficking and signaling are mimicked by LDN (an inhibitor of UCH-L1) and can be reversed by increasing cellular UCH-L1 levels, demonstrated here using a transducible TAT-UCH-L1 strategy. Finally, our data reveal that UCH-L1 mRNA levels are decreased in the hippocampi of AD brains. Taken together, our data implicate that UCH-L1 is important for regulating neurotrophin receptor sorting to signaling endosomes and supporting retrograde transport. Further, our results support the idea that in AD, Aβ may down-regulate UCH-L1 in the AD brain, which in turn impairs BDNF/TrkB-mediated retrograde signaling, compromising synaptic plasticity and neuronal survival.     

Sex differences in antipredator tail-waving displays of the diurnal yellow-headed gecko Gonatodes albogularis from tropical forests of Colombia

Many vertebrate species show display behaviors when predators are in their vicinity. Some of these displays may inform the predator of the improbability of capturing the prey (i.e., pursuit-deterrent displays) and are potentially advantageous to both predator and prey. Here we present data on a tail display performed by Gonatodes albogularis, a diurnal tropical gecko. We performed transect surveys in three habitats near Bogotá in Colombia. Geckos detected during transects were approached by the observer in a standardized way, and details of their tail-waving displays were recorded. In control recordings animals were watched from a distant site without approaching them. Results showed sexual differences in tail-waving display: when approached by the observer, males performed this behavior more frequently than females. We found no significant differences between males and females in flight-initiation distances and height above the substratum when they were initially located. Results also showed that males displayed more frequently when approached than when the simulated predator remained stationary. We interpret these results as evidence that the display functions as a pursuit-deterrent signal to potential predators. However, as some tail displays were performed in the presence of conspecifics, the display may also have a social function.     

Comparative radionuclide and thermodilution determinations of cardiac output and stroke volume in the baboon (Papio ursinus)

Thermodilution cardiac output determinations and multigated equilibrium blood-pool scintigraphy were performed in ten healthy chacma baboons (Papio ursinus). The correlation was moderately good between both the radionuclide and thermodilution stroke volume (r = 0.58, SEE = 3 ml; SVth = 0.78SVr + 15.6 ml) as well as the cardiac output (r = 0.72, SEE = 0.2 liter/min; COth = 0.56 Cor + 2.1 liter/min). The attenuation depth dr as determined by radionuclide techniques was found to correlate well with the radiologically determined values dx (r = 0.8, SEE = 0.4 cm; dx = 0.87dr + 0.72 cm) which validated the depth values used in the calculations.