A model of heterogeneous, composite material is introduced, consisting of randomly distributed identical structural micro-domains endowed with electric charges or dipoles. Two cases are presented, ...one corresponding to a tightly packed (dense) material, another corresponding to highly-dispersed, small domains. The polarizability is computed in both cases, under the action of an external uniform electric field oscillating in time (a quasi-stationary field), and it is related to the displacement of the micro-domains from their positions of local equilibrium (translations or rotations). It is shown that the polarizability (or electric susceptibility) can exhibit characteristic (resonance) frequencies in the radio-frequency range and, even for moderate external fields, the material can undergo a displacive transition (similar to a ferroelectric transition), governed by non-linearities in the interaction energy of the micro-domains. The shift in the characteristic frequencies of the polarizability is estimated, as caused by the displacive modification.
Objective
Current medicines are ineffective in approximately one‐third of people with epilepsy. Therefore, new antiseizure drugs are urgently needed to address this problem of pharmacoresistance. ...However, traditional rodent seizure and epilepsy models are poorly suited to high‐throughput compound screening. Furthermore, testing in a single species increases the chance that therapeutic compounds act on molecular targets that may not be conserved in humans. To address these issues, we developed a pipeline approach using four different organisms.
Methods
We sequentially employed compound library screening in the zebrafish, Danio rerio, chemical genetics in the worm, Caenorhabditis elegans, electrophysiological analysis in mouse and human brain slices, and preclinical validation in mouse seizure models to identify novel antiseizure drugs and their molecular mechanism of action.
Results
Initially, a library of 1690 compounds was screened in an acute pentylenetetrazol seizure model using D rerio. From this screen, the compound chlorothymol was identified as an effective anticonvulsant not only in fish, but also in worms. A subsequent genetic screen in C elegans revealed the molecular target of chlorothymol to be LGC‐37, a worm γ‐aminobutyric acid type A (GABAA) receptor subunit. This GABAergic effect was confirmed using in vitro brain slice preparations from both mice and humans, as chlorothymol was shown to enhance tonic and phasic inhibition and this action was reversed by the GABAA receptor antagonist, bicuculline. Finally, chlorothymol exhibited in vivo anticonvulsant efficacy in several mouse seizure assays, including the 6‐Hz 44‐mA model of pharmacoresistant seizures.
Significance
These findings establish a multiorganism approach that can identify compounds with evolutionarily conserved molecular targets and translational potential, and so may be useful in drug discovery for epilepsy and possibly other conditions.
A high survival rate to a salinity stress test applied to 15-day-old shrimp postlarva (P15) is supposed to be associated with improved performance during growout, or at least during pond stocking. ...However, there is no direct evidence (e.g. correlation) for this association. The present study analyzed survival to a salinity stress for correlation to subsequent performance in 40 larval batches (individual spawns) that were cultured simultaneously under the same conditions, as a predictive criterion of survival during stocking and growout to juvenile stages. We also determined some osmoregulatory capacities (gill area, Na
+/K
+-ATPase) associated with survival to the salinity stress test. The activity of Na
+/K
+-ATPase was higher in P15 subjected to lower salinities, but it did not reach significance in batches with higher survival to the salinity stress test. Survival to a stress test was positively correlated to P15 length (
r=0.62;
P<0.001). The batches that had higher survival to the stress test also had higher survival during stocking, and a positive correlation was found between survival during stocking and survival to the stress test (
r=0.34;
P<0.05). Thus, the salinity stress test applied to P15 was useful for predicting survival during stocking. However, it was not correlated to survival during growout (
r=0.04;
P>0.05), or to size of juveniles during growout (
r=0.12;
P>0.05), and thus it was not reliable as predictive indicator of performance (survival and growth) during growout under our experimental conditions. To our knowledge, these are the first published results of a relationship between survival to a salinity stress test applied to P15, and subsequent survival during stocking and growout assessed in controlled experiments.
We estimated the heritabilities and genetic correlations for reproductive traits and egg composition in female shrimp,
Penaeus (Litopenaeus) vannamei. The traits under analysis were days to first ...spawn after ablation (DTFS), egg diameter (ED) and number (EN), and egg triacylglycerides (TG), vitellin (VIT), total protein (PROT) and total lipids (LIP) for first spawned eggs. Estimates were based on 1–11 females from 30 full-sib families produced in 2000 and derived from the so-called ‘Melagos’ line in Mexico. Heritabilities were estimated using REML procedures from data on females that spawned at least once (56%). For ED, EN, and VIT, TG, PROT, and LIP in eggs, a square root transformation was done to normalize the data. Data was analysed using two models, one did not include any other trait as covariate, and the other included other trait as covariate. For DTFS the total number of spawns/female was used as covariate. For VIT, TG, PROT, and LIP in eggs the covariate used was egg number in that spawn. For egg number and egg diameter the other variable was reciprocally used as covariate. Heritabilities estimated without covariates were 0.41 for DTFS, 0.09 for EN, 0 for ED, 0.28 for VIT, 0.20 for TG, 0.13 for PROT, and 0 for LIP. Heritabilities for all traits but lipids increased when the covariates were introduced in the estimation of variance components; 0.54 for DTFS, 0.17 for EN, 0.07 for ED, 0.47 for VIT, and 0.35 for TG, 0.18 for PROT, and 0 for LIP. Despite large standard errors caused by small effective sample size, the estimates of the heritabilities indicate that these traits can be subjected to selection to improve reproductive output from females.
Approximately 80% of acquired eso-tracheal or mediastinal fistulae are of malignant nature. The occurrence of an eso-respiratory malignant fistula is a devastating complication for both patient and ...doctor, and, if not treated, records a survival time of 1 to 6 weeks.
We present a patient, aged 51, smoker,with progressive dysphagia, at first to solids, then to semi-solids and liquids, followed by manifestation of post-deglutition cough due to eso-tracheal fistula, incapability of feeding, and decline of the general condition. Surgical intervention consists of esophageal transstenotic endo-prosthesing by transtumoral drilling with prosthetic montage and the occlusion of the eso-tracheal fistulous orifice.
The post-operatory evolution is favorable, the feeding per os resumes in 8 hours after surgery, good digestive tolerance. The radiologic examination using contrast medium, performed in 48 hours after surgery, reveals a permeable esophageal endo-prosthesis, without reflux of contrast substance in the tracheobronchial tree.
The laparo-gastroscopic montage of prosthesis through transtumoral drilling, using siliconized semi-rigid prostheses, represents the only efficient palliative treatment of malignant eso-tracheal or eso-bronchial fistula.
Recent advances in the stepwise multichannel quantum defect theory approach of electron/molecular cation reactive collisions have been applied to perform computations of cross sections and rate ...coefficients for dissociative recombination and electron-impact ro-vibrational transitions of H2+, BeH+ and their deuterated isotopomers. At very low energy, rovibronic interactions play a significant role in the dynamics, whereas at high energy, the dissociative excitation strongly competes with all other reactive processes.
From the group of parasitic protozoa, Giardia and Cryptosporidium are the most common pathogens spread in surface water sources, representing a continuous threat to public health and water ...authorities. The aim of this survey was to assess the occurrence and human infective potential of these pathogens in treated wastewaters and different surface water sources. A total of 76 western Romanian water bodies in four counties (Arad, Bihor, Caraș-Severin and Timiș) were investigated, including the effluents of wastewater treatment plants (n = 11) and brooks (n = 19), irrigation channels (n = 8), lakes (n = 16), and ponds (n = 22). Water samples were collected through polyester microfiber filtration. Giardia cysts and Cryptosporidium oocysts were isolated using immunomagnetic separation, according to the US EPA 1623 method, followed by their identification and counting by immunofluorescence (IF) microscopy. All samples were screened through PCR-based techniques targeting the gdh gene for Giardia spp. and the 18S rRNA gene for Cryptosporidium spp., followed by sequencing of the positive results. Cryptosporidium-positive samples were subtyped based on sequence analysis of the GP60 gene. Giardia spp. was found in all tested water types with a cumulative detection rate of 90.1% in wastewaters, 26.3% in brooks, 37.5% in irrigation channels, 31.2% in lakes, and 36.4% in ponds. Except for ponds, all monitored water bodies harbored the Giardia duodenalis AII subassemblage with human infective potential. In addition, the ruminant origin assemblage E was widely distributed, and the domestic/wild canid-specific assemblage D was also recorded in a pond. Three (27.3%) wastewater samples were Cryptosporidium positive, and the identified species was the zoonotic Cryptosporidium parvum, with IIaA15G2R1 (n = 2) and IIdA18G1 subtypes. The results highlight that this threat to the public health must be brought to the attention of epidemiologists, health officials, and water authorities.
Abstract
Eggs of 20 females were sampled to analyze lipid, protein, and carbohydrate content during the embryonic development of Cherax quadricarinatus. Sampling was performed on recently spawned ...eggs to first juvenile stage. Ten eggs were sampled every 48 h during the first two weeks and every 72 h thereafter for biochemical analysis. Total proteins, lipids, and carbohydrates were measured. Proteins were the most abundant egg component (63.2%), followed by lipids (32.3%), and carbohydrates (4.4%). A steady decrease of lipid content was observed ( y = 895.38 − 9.93x, r2 = 0.94; y = lipid concentration, x = days). For proteins, two different depletion rates were observed, with the initial rate maintained for 30 days ( y1 = 1,443.0 − 4.46x1, r2 = 0.90) and an increased depletion rate after hatching ( y2 = 1,936.60 − 21.10x2, r2 = 0.96). Carbohydrates were always present as a minor constituent, and its concentration did not change significantly. Water content increased from 52% in recently spawned egg to 85% in juveniles. Energy equivalents were calculated from each component, and the overall energy expenditure is represented by the equation y = 13.86 − 0.11x (r2 = 0.95). Relevant morphological features for each sample day are indicated.
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