A vivid model of chiral recognition

Hands can be used to demonstrate the three-point model of chiral recognition. The points of attachment are thumb, forefinger, and middle finger. This vivid model has the advantages of simplicity, perspicuity, and availability at any time, although two persons are necessary. It can be shown that two interactions are not sufficient for chiral recognition but that three attractive or two attractive and one repulsive attraction are needed. It can also be used to explain some possibilities of weakening or elusion of the three-point model.     

Cloning, nucleotide sequence, and expression of the Brucella melitensis bp26 gene coding for a protein immunogenic in infected sheep

Abstract We have previously identified a Brucella melitensis 28 kDa cytosoluble protein (CP28) which was highly immunogenic in infected sheep and which in addition made possible the serological differentiation between infected and B. melitensis Rev.l vaccinated sheep. Monoclonal antibodies against CP28 were used to screen a B. melitensis 16M genomic library and to clone the corresponding gene. DNA sequencing of the gene encoding CP28 of B. melitensis 16M revealed that it was nearly identical to that of the recently published bp26 gene of Brucella abortus vaccine strain S19 coding for a periplasmic protein. The differences between the B. melitensis 16M gene and that of B. abortus S19 consisted of single nucleotide substitutions, one or two codon deletions, one codon addition, and most importantly a 21-bp deletion. The corresponding region of B. abortus S19 contains two 10-bp direct repeats which could have been involved in the genesis of the deletion. Expression of the B. melitensis 16M bp26 gene in Escherichia coli studied by the use of the monoclonal antibodies showed the same characteristics as reported for the B. abortus S19 bp26 gene, i.e. the presence of a higher molecular mass preprotein and a lower molecular mass band which probably corresponds to the mature protein exported to the periplasm. Immunoblotting performed with sera from either naturally infected or B. melitensis H38 experimentally infected sheep confirmed the importance of the B. melitensis CP28/BP26 protein as diagnostic antigen.     

Broad diversity of Mycobacterium tuberculosis complex strains isolated from humans and cattle in Northern Algeria suggests a zoonotic transmission cycle

Mycobacterium tuberculosis complex (MTBC) comprises closely related species responsible for human and animal tuberculosis (TB). Efficient species determination is useful for epidemiological purposes, especially for the elucidation of the zoonotic contribution. In Algeria, data on MTBC genotypes are largely unknown. In this study, we aimed to investigate the occurrence and diversity of MTBC genotypes causing human and bovine TB in Northern Algeria. During a two-year sampling period (2017–2019) in two regions of Northern Algeria, we observed an overall prevalence of 6.5% of tuberculosis (TB) among slaughtered cattle, which is higher than previous Algerian data yet comparable to neighboring countries. A total of 296 Mycobacterium tuberculosis complex (MTBC) isolates were genotyped by spoligotyping: 181 from tissues with TB-like lesions collected from 181 cattle carcasses and 115 from TB patients. In human isolates, we identified 107 M. tuberculosis, seven M. bovis and one “M. pinnipedii-like”, while for bovine samples, 174 isolates were identified as M. bovis, three as M. caprae, three as “M. pinnipedii-like” and one as “M. microti-like”. The majority of isolates (89.2%) belonged to 72 different known Shared International Types (SIT) or M. bovis spoligotypes (SB), while we also identified seven new SB profiles (SB2695 to SB2701). Twenty-eight of the SB profiles were new to Algeria. Our data suggest zoonotic transmission in Sétif, where significantly more TB was observed among cattle (20%) compared to the slaughterhouses from the three other regions (5.4%–7.3%) (p < 0.0001), with the isolation of the same M. bovis genotypes from TB patients. The present study showed a high genetic diversity of MTBC isolated from human and cattle in Northern Algeria. Even though relatively small in terms of numbers, our data suggest the zoonotic transmission of TB from cattle to humans, suggesting the need for stronger eradication strategies for bovine TB.     

Evaluation of (ɳ6-p-cymene) ruthenium diclofenac complex as anticancer chemotherapeutic agent: interaction with biomolecules,cytotoxicity assays

abstract

The designing of metal-based anticancer therapeutic agents can be optimized in a better and rapid way if the ligands utilized have standalone properties. Therefore, even when the organometallic/coordination complex (i.e., metallodrug) gets dissociated in extreme conditions, the ligand can endorse its biological properties. Herein, we have synthesized and characterized ?⁶-p-cymene ruthenium diclofenac complex. Furthermore, the ruthenium complex interactions with human serum albumin (HSA) and ct-DNA have been studied using various spectroscopic studies viz., UV, fluorescence, and circular dichroism and exhibited a significant binding propensity. Furthermore, in vitro cytotoxicity assays were carried out against human breast cancer “MCF-7” cell line. The ?⁶-p-cymene ruthenium diclofenac complex registered significant cytotoxicity with an IC₅₀ value of ～25.0?µM which is comparable to the standard drugs. The ?⁶-p-cymene ruthenium diclofenac complex was able to decrease the MCF-7 cell proliferation and induced significant levels of apoptosis with relatively low toxicity.     

Nest survival of Woodpigeons (Columba palumbus) in North African forests

Capsule The nesting success of the Woodpigeon Columba palumbus in oak forests in Morocco is affected by human disturbance and nest-site characteristics.

Aims To determine factors affecting the nesting success of Woodpigeons subject to two levels of disturbance in a holm oak Middle Atlas forest.

Methods Woodpigeon nests were monitored in highly disturbed (n?=?30) and less-disturbed sites (n?=?60) over two years (2010–11). Logistic-exposure models were used to estimate daily nest-survival rate and evaluate mechanisms (altitude, temporal factors, nest location, nest-site habitat and degree of human influence) affecting nest survival.

Results Daily nest-survival rate was higher in less-disturbed sites (0.987; 95% CL: 0.980–0.991) than in high-disturbance sites (0.967; 95% CL: 0.949–0.978). Increasing density of trees surrounding nest sites and distance from the nest tree to the closest track increased daily nest-survival rate.

Conclusions Less-disturbed sites confer better nesting conditions than highly disturbed ones. Management measures should control the access of vehicles, especially trucks, in the forest of the Middle Atlas and introduce a grazing regime that will allow the forest regeneration, which would improve Woodpigeon nesting success by increasing the density of holm oak trees.     

Intérêt de la scintigraphie pulmonaire de perfusion dans les dilatations des bronches de l’enfant

IntroductionBronchiectasis is a chronic disease of the lungs by repeated respiratory infection. An early and adequate diagnosis and management reduce the morbidity and mortality of this disease. The aim of this study is to emphasize the importance of the combination of Computer Tomography (CT) and lung perfusion scan (SPP) in the diagnosis and therapeutic approach.Materials and methodsForty-three children were referred in the nuclear medicine department with a clinical diagnosis of bronchiectasis; they underwent a CT and a SPP.Results and conclusionBy analyzing the results of the SPP and CT separately, we conclude that there is no significant difference between the two investigations. The combination of the two explorations provides a gain in most surgical therapeutic orientation.     

Deterministic Somatic Cell Reprogramming Involves Continuous Transcriptional Changes Governed by Myc and Epigenetic-Driven Modules

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Studying vertical dependence to improve NFS performance in wireless networks

Wireless networks experience a high level of errors and losses. These physical layer characteristics have an impact on the performance of the higher layers. In addition, the performance of each protocol layer is contingent on the behavior of the other layers. Vertical dependency is a term which describes this inter-dependence between layers. In the wireless and mobile environment, the effects of vertical dependence are particularly pronounced due to the dynamic nature of the environment and due to the fact that traditional assumptions about protocol layer interactions do not always hold. In this paper, we consider the vertical dependencies between various layers in the protocol stack, studying the performance of the Network File System under various error models and improvement techniques. Our experimental results demonstrate the dependency of the application performance on the details of the error characteristics and other protocol layers. After studying the vertical dependencies, we improve NFS performance by implementing changes to the application level reliability mechanisms. Understanding of the vertical dependencies enables development of effective methods for performance enhancement and efficient reaction to errors and changes on the wireless media. This revised version was published online in August 2006 with corrections to the Cover Date.