Adolescent reproductive health and awareness of HIV among rural high school students, North Western Ethiopia.

Ethiopia is faced with an increasing problem from HIV infection, and the vulnerability of adolescents is a key concern. There is little information on the knowledge, attitudes and practices of this age group with respect to HIV, sexually transmitted diseases and preventive measures. We conducted a cross-sectional study among 260 students from two rural high schools in North Western Ethiopia. We found that although the general awareness of HIV was high, correct knowledge of the virus and its modes of transmission was shown in only 44% of adolescent boys and 41% of adolescent girls. Knowledge of HIV and condoms was lower among students whose parents were farmers, significant so among girls (p=0.02). Use of condoms among sexually active single male students (49%) was insufficient but was higher than among adolescents in many other African settings. Knowledge of STDs was generally low: 82% of adolescent males and 37% of adolescent females had some awareness of STDs. Almost 20% of sexually active males in the study had previously experienced an STD, almost all of whom had visited a commercial sex worker. Targeted interventions are warranted among adolescents and sex workers in Ethiopia complemented by STD treatment services

Intergenerational and interethnic mental health: an analysis for the United Kingdom

This paper uses a nationally representative data set to examine the extent to which family migration history helps explains inter-ethnic variations in mental health in the UK. We confirm that there is significant variation in mental health across ethnic group and generation of migration. Furthermore, we show how these dimensions interact. The analysis explores the extent to which neighbourhood, personal characteristics and migration experience are related to mental health. We find evidence that all are important. Our results are consistent with a dynamic view of migration and settlement whereby individuals' circumstances and how they might contribute to mental health change over time and across generations

Comparative analysis of morphological and morphometrical characters in six isolates of Pratylenchus vulnus Allen & Jensen, 1951 (Nemata : Tylenchida)

Six populations de #Pratylenchus vulnus$ Allen & Jensen, 1951 provenant d'Europe et d'Amérique ont été analysées du point de vue morphologique et morphométrique. Certaines différences ont été observées pour quelques caractères morphologiques (structure du sac post-vulvaire, forme de la spermathèque, largeur des champs latéraux). Par contre, des différences significatives concernant tous les caractères morphométriques (excepté le rapport "m") ont été constatées entre les populations. Une analyse de corrélation canonique montre que les relations entre populations pourraient être fonction de leur origine géographique et/ou de leur plante hôte. (Résumé d'auteur

An Integral Formulation for Rectangular Wires in a 3D Magneto-Quasi-Static Field

This paper proposes an integral formulation for calculating the magnetic and ohmic losses in rectangular wires immersed in an external 3D magneto-quasi-static field. The formulation is based on some simplifying assumptions that allow to employ a collocation method with constant elements for the discretization, reducing the computational burden. Even if the assumptions introduce an approximation, for the application at hand the numerical tests have shown that the accuracy is still acceptable. Moreover, the computational time is drastically reduced with respect to other approaches based on the finite element method

Surfactants: physicochemical interactions with biological macromolecules

Macromolecules are essential cellular components in biological systems responsible for performing a large number of functions that are necessary for growth and perseverance of living organisms. Proteins, lipids and carbohydrates are three major classes of biological macromolecules. To predict the structure, function, and behaviour of any cluster of macromolecules, it is necessary to understand the interaction between them and other components through basic principles of chemistry and physics. An important number of macromolecules are present in mixtures with surfactants, where a combi- nation of hydrophobic and electrostatic interactions is responsible for the specific properties of any solution. It has been demonstrated that surfactants can help the formation of helices in some proteins thereby promot- ing protein structure formation. On the other hand, there is extensive research towards the use of surfac- tants to solubilize drugs and pharmaceuticals; there- fore, it is evident that the interaction between surfactants with macromolecules is important for many applications which includes environmental processes and the pharmaceutical industry. In this review, we describe the properties of different types of surfactants that are relevant for their physicochemical interactions with biological macromolecules, from macromolecules–surfactant complexes to hydrophobic and electrostatic interactions

Molecular dynamics simulations reveal canonical conformations in different pMHC/TCR interactions

The major defense system against microbial pathogens in vertebrates is the adaptive immune response and represents an effective mechanism in cancer surveillance. T cells represent an essential component of this complex system. They can recognize myriads of antigens as short peptides (p) originated from the intracellular degradation of foreign proteins presented by major histocompatibility complex (MHC) proteins. The clonotypic T-cell antigen receptor (TCR) is specialized in recognizing pMHC and triggering T cells immune response. It is still unclear how TCR engagement to pMHC is translated into the intracellular signal that initiates T-cell immune response. Some work has suggested the possibility that pMHC binding induces in the TCR conformational changes transmitted to its companion CD3 subunits that govern signaling. The conformational changes would promote phosphorylation of the CD3 complex ζ chain that initiates signal propagation intracellularly. Here, we used all-atom molecular dynamics simulations (MDs) of 500 ns to analyze the conformational behavior of three TCRs (1G4, ILA1 and ILA1α1β1) interacting with the same MHC class I (HLA-A*02:01) bound to different peptides, and modelled in the presence of a lipid bilayer. Our data suggest a correlation between the conformations explored by the β-chain constant regions and the T-cell response experimentally determined. In particular, independently by the TCR type involved in the interaction, the TCR activation seems to be linked to a specific zone of the conformational space explored by the β-chain constant region. Moreover, TCR ligation restricts the conformational space the MHC class I groove

2D Zernike polynomial expansion: finding the protein-protein binding regions

We present a method for efficiently and effectively assessing whether and where two proteins can interact with each other to form a complex. This is still largely an open problem, even for those relatively few cases where the 3D structure of both proteins is known. In fact, even if much of the information about the interaction is encoded in the chemical and geometric features of the structures, the set of possible contact patches and of their relative orientations are too large to be computationally affordable in a reasonable time, thus preventing the compilation of reliable interactome. Our method is able to rapidly and quantitatively measure the geometrical shape complementarity between interacting proteins, comparing their molecular iso-electron density surfaces expanding the surface patches in term of 2D Zernike polynomials. We first test the method against the real binding region of a large dataset of known protein complexes, reaching a success rate of 0.72. We then apply the method for the blind recognition of binding sites, identifying the real region of interaction in about 60% of the analyzed cases. Finally, we investigate how the efficiency in finding the right binding region depends on the surface roughness as a function of the expansion order

The effect of sophorolipids against microbial biofilms on medical-grade silicone

Recent medical strategies rely on the search for effective antimicrobials as surface coatings to prevent and treat infections in humans and animals. Biosurfactants have recently been shown to have properties as antiadhesive and antibiofilm agents. Sophorolipids in particular are biosurfactant molecules known to act as therapeutic agents. This study aimed to evaluate antimicrobial properties of sophorolipids in medical-grade silicone discs using strains of clinical relevance. Sophorolipids were produced under fed batch conditions, ESI-MS analyses were carried out to confirm the congeners present in each formulation. Three different products were obtained SLA (acidic congeners), SL18 (lactonic congeners) and SLV (mixture of acidic and lactonic congeners) and were tested against Staphylococcus aureus ATCC 6538, Pseudomonas aeruginosa ATCC 10145 and Candida albicans IHEM 2894. All three congener mixtures showed a biofilms disruption effect (> 0.1% w/v) of 70%, 75% and 80% for S. aureus, P. aeruginosa and C. albicans, respectively. On pre-coated silicone discs, biofilm formation of S. aureus was reduced by 75% using SLA 0.8% w/v. After 1.5 h the inhibition of C. albicans attachment was between 45-56% whilst after 24 h incubation the percentage of inhibition for the cell attachment increased to 68-70% when using SLA 0.8% w/v. Finally, in co-incubation experiments SLA 0.05% w/v significantly reduced the ability of S. aureus and C. albicans to form biofilms and to adhere to surfaces by 90-95% at concentrations between 0.025-0.1% w/v. In conclusion sophorolipids significantly reduced the cell attachment of both tested strains which suggests that these molecules could have a potential role as coating agents on medical grade silicone devices for the preventions of Gram positive bacteria and yeast infections

Correlation between female sex and allergy was significant in patients presenting with dysphonia

Aim of the present study was to investigate the prevalence of allergy in patients affected by both organic and/or functional vocal fold disorders. The secondary aim was to assess the correlation between sex and allergy in dysphonic patients. A retrospective chart review was performed on dysphonic patients. A total of 76 patients underwent fiberoptic endoscopy to assess the objective picture. Logistic regression analyses have been conducted to assess the association between sex and the outcome variables. The laryngoscopic examination revealed the presence of poor glottic closure in 32.9%, hyperkinesias in 11.8%, redness in 11.84%, polyps in 5.3%, oedema in 3.95%, vocal fold hypertrophy in 5.3%, nodules in 42.1%, cordectomy in 2.6%. Allergic rhinitis was present in 56.6%, milk intolerance in 13.2%, asthma in 9.2%, atopic dermatitis in 3.9%, drugs intolerance in 11.8%. A total of 76.32% patients presenting with dysphonia were allergic. A statistically significant association was found between female sex and presence of allergy. In conclusion, allergy testing should be performed routinely on female professional voice users. Mild respiratory disorders must be taken into serious consideration in female professional voice users, who may primarily complain of vocal dysfunction rather than upper and lower respiratory diseases