Triploidy induction in Nile tilapia,Oreochromis niloticus L. using pressure,heat and cold shocks

Summary The results of a study aimed at the identification of treatment optima for triploidy induction in recently fertilised Oreochromis niloticus L. eggs by altering the intensity, duration and timing of application of pressure, heat and cold shocks are reported. Preliminary, but not directly comparable, trials suggested the following treatments to be close to the individual agent optima. Pressure: 8,000 psi 2-min duration applied 9 min after fertilisation (a.f.); heat: 41 °C, 3.5-min duration applied 5 min a.f., cold: 9°C, 30-min duration applied 7 min a.f. In a directly comparable trial in which the eggs of eight different females were separately exposed to the optimum shocks listed above, individual triploid yields were more variable following cold shocks and mean triploid yields were, therefore, higher following pressure and heat shock. These and other results obtained are presented and the light they shed on the timing of the second meiotic division in this species is discussed.     

Cotton somatic embryo morphology affects its conversion to plant

Somatic embryos differentiated from hypocotyl explant in cotton (Gossypium hirsutum L.) exhibited very divergent morphologies. Six different types of somatic embryos based on cotyledon development were observed. The growth hormones (2,4-dichlorophenoxyacetic acid and kinetin) used in induction and maintenance media did not affect embryo rooting and germination. The 95 % conversion of normal embryos (with two cotyledons) was achieved, while an overall conversion was only 38 %. Horn shaped embryos failed to exhibit shoot growth. Poorly developed apical meristems were responsible for lower conversion percentages in some of embryo classes. However, regenerated plants phenotypically resembled to seed grown control plants regardless of somatic embryo morphology.     

Predicting Physical Time Series Using Dynamic Ridge Polynomial Neural Networks

Forecasting naturally occurring phenomena is a common problem in many domains of science, and this has been addressed and investigated by many scientists. The importance of time series prediction stems from the fact that it has wide range of applications, including control systems, engineering processes, environmental systems and economics. From the knowledge of some aspects of the previous behaviour of the system, the aim of the prediction process is to determine or predict its future behaviour. In this paper, we consider a novel application of a higher order polynomial neural network architecture called Dynamic Ridge Polynomial Neural Network that combines the properties of higher order and recurrent neural networks for the prediction of physical time series. In this study, four types of signals have been used, which are; The Lorenz attractor, mean value of the AE index, sunspot number, and heat wave temperature. The simulation results showed good improvements in terms of the signal to noise ratio in comparison to a number of higher order and feedforward neural networks in comparison to the benchmarked techniques.     

Role of post translational modifications and novel crosstalk between phosphorylation and O-beta-GlcNAc modifications in human claudin-1, -3 and -4

The precise characterization of post translational modifications (PTMs) is important for the understanding of protein regulatory mechanisms and their role in disease. However, experimental studies on PTMs, especially with multifunctional proteins are difficult to follow and investigate. Bioinformatic tools are therefore helpful in predicting key protein modifications. To study the role of PTMs in claudin proteins, specifically claudin-1, -3 and -4 in the onset or progression of human cancers, we performed an in silico study of various PTMs and investigated their interplay. Given that the activity of claudins is known to be influenced by two types of PTMs, specifically palmitoylation and kinase- dependent phosphorylation, we predicted two conserved regions in the topological domains of claudin-1, -3 and -4 as potential palmitoylation sites. Furthermore, conserved phosphorylation residues, which may be targets for kinases and can alter claudin’s ability to maintain the integrity of tight junctions, were identified. To our knowledge, this is the first report to suggest O-glycosylation of claudin proteins, as well as a potential novel interplay between phosphorylation and O-glycosylation at Yin Yang sites. Thus, our findings may facilitate the production of anti-cancer drugs, and suggest that novel therapeutic strategies should target post translational events.     

Transcriptional profiling of Zea mays roots reveals roles for jasmonic acid and terpenoids in resistance against Phytophthora cinnamomi

Phytophthora cinnamomi is a soil-borne plant pathogen that has caused widespread damage to vulnerable native ecosystems and agriculture systems across the world and shows no sign of abating. Management of the pathogen in the natural environment is difficult and the options are limited. In order to discover more about how resistant plants are able to defend themselves against this generalist pathogen, a microarray study of plant gene expression following root inoculation with P. cinnamomi was undertaken. Zea mays was used as a resistant model plant, and microarray analysis was conducted using the Affymetrix GeneChip Maize Genome Array on root samples collected at 6- and 24-h post-inoculation. Over 300 genes were differentially expressed in inoculated roots compared with controls across the two time points. Following Gene Ontology enrichment analysis and REVIGO visualisation of the up-regulated genes, many were implicated in plant defence responses to biotic stress. Genes that were up-regulated included those involved in phytoalexin biosynthesis and jasmonic acid/ethylene biosynthesis and other defence-related genes including those encoding glutathione S-transferases and serine-protease inhibitors. Of particular interest was the identification of the two most highly up-regulated genes, terpene synthase11 (Tps11) and kaurene synthase2 (An2), which are both involved in production of terpenoid phytoalexins. This is the first study that has investigated gene expression at a global level in roots in response to P. cinnamomi in a model plant species and provides valuable insights into the mechanisms involved in defence.     

Abortion-seeking behaviour among Nigerian women

This study used data from a community-based survey to examine women's experiences of abortion in Nigeria. Fourteen percent of respondents reported that they had ever tried to terminate a pregnancy, and 10% had obtained an abortion. The majority of women who sought an abortion did so early in the pregnancy. Forty-two percent of women who obtained an abortion used the services of a non-professional provider, a quarter experienced complications and 9% sought treatment for complications from their abortions. Roughly half of the women who obtained an abortion used a method other than D&C or MVA. The abortion prevalence and conditions under which women sought abortions varied by women's socio-demographic characteristics. Because abortion is illegal in Nigeria except to save the woman's life, many women take significant risks to terminate unwanted pregnancies. Reducing the incidence of unwanted pregnancy and unsafe abortion can significantly impact the reproductive health of women in Nigeria.     

A Pilot Study of Diffusion-Weighted MRI in Patients Undergoing Neoadjuvant Chemoradiation for Pancreatic Cancer

PURPOSE: In the current study we examined the ability of diffusion MRI (dMRI) to predict pathologic response in pancreatic cancer patients receiving neoadjuvant chemoradiation. METHODS: We performed a prospective pilot study of dMRI in patients with resectable pancreatic cancer. Patients underwent dMRI prior to neoadjuvant chemoradiation. Surgical specimens were graded according to the percent tumor cell destruction. Apparent diffusion coefficient (ADC) maps were used to generate whole-tumor derived ADC histogram distributions and mean ADC values. The primary objective of the study was to correlate ADC parameters with pathologic and CT response. RESULTS: Ten of the 12 patients enrolled on the study completed chemoradiation and had surgery. Three were found to be unresectable at the time of surgery and no specimen was obtained. Out of the 7 patients who underwent pancreaticoduodenectomy, 3 had a grade III histopathologic response (> 90% tumor cell destruction), 2 had a grade IIB response (51% to 90% tumor cell destruction), 1 had a grade IIA response (11% to 50% tumor cell destruction), and 1 had a grade I response (> 90% viable tumor). Median survival for patients with a grade III response, grade I-II response, and unresectable disease were 25.6, 18.7, and 6.1 months, respectively. There was a significant correlation between pre-treatment mean tumor ADC values and the amount of tumor cell destruction after chemoradiation with a Pearson correlation coefficient of 0.94 (P = .001). Mean pre-treatment ADC was 161 × 10^− 5 mm²/s (n = 3) in responding patients (> 90% tumor cell destruction) compared to 125 × 10^− 5 mm²/s (n = 4) in non-responding patients (> 10% viable tumor). CT imaging showed no significant change in tumor size in responders or non-responders. CONCLUSIONS: dMRI may be useful to predict response to chemoradiation in pancreatic cancer. In our study, tumors with a low ADC mean value at baseline responded poorly to standard chemoradiation and would be candidates for intensified therapy.     

Isolation and characterization of enteroaggregative,enterotoxigenic, diffusely adherent <Emphasis Type="Italic">Escherichia coli</Emphasis> and <Emphasis Type="Italic">Salmonella</Emphasis> Worthington from human diarrhoeic faecal samples in Kashmir and Secunderabad,India

Seven hundred and thirty-five diarrhoeic faecal samples from children were investigated for presence of enteroaggregative E. coli (EAEC), enterotoxigenic E. coli (ETEC), diffusely adherent E. coli (DAEC) and Salmonella spp. by polymerase chain reaction (PCR) and bacterial culture. Out of 675 samples from Kashmir, 55 isolates were obtained, which carried at least one virulence gene studied. Out of the 55 isolates, 36 (65.45%) were EAEC, 18 (32.72%) were ETEC while only one isolate (1.81%) was DAEC. All the EAEC isolates were found to be typical as they possessed aggR gene. Six (16.66%) EAEC isolates carried the astA gene. Out of the 18 ETEC isolates, 13 carried the elt gene alone, four possessed both the elt and est genes and the remaining one harboured the est gene alone. Five ETEC isolates also possessed astA gene. Nineteen EAEC isolates belonged to 10 different serogroups. Serogroup O153 was most frequent. The ETEC isolates also belonged to 10 different serogroups of which O159 was most predominant. Out of 224 E. coli isolates from 60 samples of Secunderabad, 27 isolates carried at least one virulence gene. Out of 27 isolates 22 (81.48%) were typical EAEC, three (11.11%) were ETEC and two (7.4%) were DAEC. Fifteen EAEC isolates belonged to seven different serogroups with O86 as most frequent. Four EAEC isolates also possessed the astA gene. All the three ETEC isolates harboured elt gene only and belonged to three different serogroups. Two isolates of Salmonella Worthington were obtained from only two samples in Kashmir.     

Development of synaptic responses and plasticity at the SC-CA1 and MF-CA3 synapses in rat hippocampus

1. The development of synaptic transmission and indicators of short- and long-term plasticity was studied by recording from areas CA1 and CA3 upon activation of monosy- naptic excitatory inputs in rat hippocampal brain slices obtained from Wistar rats of different ages.2. Although population field excitatory postsynaptic potentials (fEPSPS) are small in animals at postnatal day 10 (P10), both areas already exhibited short-term [posttetanic potentiation (PTP) and paired pulse potentiation (PPF)] and long-term [long-term potentiation (LTP)] plastic responses.3. The amplitudes of the fEPSP and LTP increased with age in both regions, but peaked at P30 in CA3 while they were still increasing at the oldest age studied (P60) in CA1. In CA3, but not CA1, LTP at P60 was less than at P30.4. PTP did not show clear alterations with age in either region. PPF decreased with age in CA1 but not CA3.