179 research outputs found
Laser light scattering (LLS) to observe plasma impact on the adhesion of micrometer-sized particles to a surface
Laser light scattering (LLS) method, combined with a long-distance microscope was utilized to detect micrometer-sized particles on a smooth substrate. LLS was capable to detect individual particle release, shrink, or fragmentation during exposure to a plasma or a gas jet. In-situ monitoring of hundreds of particles was carried out to investigate the effect of hydrogen plasma exposure on particle adhesion, morphology, and composition. LLS was calibrated with monodisperse melamine resin spheres with known sizes of 2.14 µm, 2.94 µm, and 5.26 µm in diameter. The lowest achievable noise level of approximately 3% was demonstrated for counting 5.26 µm spherical melamine particles. The accuracy for melamine particle size measurements ranged from 50% for 2.14 µm particles to 10% for 5.26 µm particles. This scatter was taken as the imprecision of the method. Size distribution for polydisperse particles with known refractive index was obtained by interpolating to an effective scattering cross-section of a sphere using Mie theory. While the Abbe diffraction limit was about 2 µm in our system, the detection limit for Si particles in LLS according to Mie approximation was assessed to about 3 µm, given the limitations of the laser flux, microscope resolution, camera noise, and particle composition. Additionally, the gradual changes in forward scattering cross-sections for Si particles during the exposure to the hydrogen plasma were consistent with Si etching reported in the literature.</p
Student accounts of space and safety at a South African university: implications for social identities and diversity
Transformation efforts in South African higher education have been under increased scrutiny in recent years, especially following the last years of student activism and calls for decolonization of universities. This article presents data from a participatory photovoice study in which a group of students reflect on their experiences of feeling safe and unsafe at an urban-based historically disadvantaged university. Findings highlight the way in which historical inequalities on the basis of social identities of race, class, and gender, among others, continue to shape experiences, both materially and social-psychologically, in South African higher education. However, and of particular relevance in thinking about a socially just university, participants speak about the value of diversity in facilitating their sense of both material and subjective safety. Thus, a diverse classroom and one that acknowledges and recognizes students across diversities, is experienced as a space of comfort, belonging and safety. Drawing on feminist work on social justice, we argue the importance of lecturer sensitivity and reflexivity to their own practices, as well as the value of social justice pedagogies that not only focus on issues of diversity and equality but also destabilize dominant forms of didactic pedagogy, and engage students’ diverse experiences and perceptions
Mongolian Part of the Transboundary Sailugem Natural Plague Focus in 2017. Communication 1. Epizootic condition
Objective – estimation of current epizootic condition of Mongolian part of transboundary Sailugem natural plague focus. Materials and methods. Epizootiological survey was performed for the area of 2335 km2, 277 mammals and 516 ectoparasites were investigated for plague. Results and conclusions. Eight Yersinia pestis subsp. pestis strains were isolated, including 7 strains – from grey marmots (6 – from the remains of meals of predatory birds, 1 from a corpse) and 1 – from long-tailed souslik (corpse). Y. pestis DNA was detected in 52 objects. Serological samples showed 40 positive results. Epizootic manifestations, confirmed by isolation of Y. pestis cultures, detection of plague microbe DNA, and positive serological results, were observed across the area of 1611 km2 covering 69 % of the inspected territory. Epizootic results indicated high infection rate of mass mammal species and first of all grey marmots. The data demonstrated that the extended plague epizooty caused by Y. pestis of the main subspecies occurred in the inspected territory in the carrier settlements. For the first time the circulation of Y. pestis subsp. pestis was registered in the Mongolian part of the transboundary Sailugem focus
Reduced Satellite Cell Numbers and Myogenic Capacity in Aging Can Be Alleviated by Endurance Exercise
Background: Muscle regeneration depends on satellite cells, myogenic stem cells that reside on the myofiber surface. Reduced numbers and/or decreased myogenic aptitude of these cells may impede proper maintenance and contribute to the age-associated decline in muscle mass and repair capacity. Endurance exercise was shown to improve muscle performance; however, the direct impact on satellite cells in aging was not yet thoroughly determined. Here, we focused on characterizing the effect of moderate-intensity endurance exercise on satellite cell, as possible means to attenuate adverse effects of aging. Young and old rats of both genders underwent 13 weeks of treadmill-running or remained sedentary. Methodology: Gastrocnemius muscles were assessed for the effect of age, gender and exercise on satellite-cell numbers and myogenic capacity. Satellite cells were identified in freshly isolated myofibers based on Pax7 immunostaining (i.e., exvivo). The capacity of individual myofiber-associated cells to produce myogenic progeny was determined in clonal assays (in-vitro). We show an age-associated decrease in satellite-cell numbers and in the percent of myogenic clones in old sedentary rats. Upon exercise, there was an increase in myofibers that contain higher numbers of satellite cells in both young and old rats, and an increase in the percent of myogenic clones derived from old rats. Changes at the satellite cell level in old rats were accompanied with positive effects on the lean-to-fat Gast muscle composition and on spontaneous locomotion levels. The significance of these data is that they suggest that the endurance exercise-mediated boost in bot
Effectiveness of Disinsection and Deratization in Gorno-Altai High-Mountain Natural Plague Focus
Epidemic complications in the territory of Gorno-Altai high-mountain natural plague focus, associated with increase in numbers of carriers and vectors of the dangerous diseases, entailed strengthening of preventive element in the system of epidemiological surveillance. Objective of the study was to assess the efficiency of disinsection and deratization during anti-epidemic campaign. Materials and methods. Investigations were performed in 2014-2017 in the territory of Kosh-Agach district of the Republic of Altai, based on the archival and operational records from Altai Plague Control Station, Rospotrebnadzor Administration in the Republic of Altai, and our own data. “Interactive Map on Management of Health Promotion Measures in Gorno-Altai high-mountain natural plague focus” was used as an assessment tool. Results and conclusions. The most hard-hitting sections of preventive complex as regards plague are still disinsection and deratization. Application of advanced methods and means of control over numbers of carriers and vectors of the infection testify to their high anti-epidemic effectiveness. Insecticide and rodenticide treatments of encampments situated in epizootic areas, disinsection and deratization in major population centers in the territory of the focus allowed for the reduction in risk of population infection. Technical efficiency of the field disinsection amounted to 96.7 %, community deratization and disinsection varied from 91.6 to 100 %. Emergency insecticide and rodent treatments in epizootic areas alongside other measures provided for epidemiological welfare on plague
Measles transmission following the tsunami in a population with a high one-dose vaccination coverage, Tamil Nadu, India 2004–2005
BACKGROUND: On 26 December 2004, a tsunami struck the coast of the state of Tamil Nadu, India, where one-dose measles coverage exceeded 95%. On 29 December, supplemental measles immunization activities targeted children 6 to 60 months of age in affected villages. On 30 December, Cuddalore, a tsunami-affected district in Tamil Nadu reported a cluster of measles cases. We investigated this cluster to estimate the magnitude of the problem and to propose recommendations for control. METHODS: We received notification of WHO-defined measles cases through stimulated passive surveillance. We collected information regarding date of onset, age, sex, vaccination status and residence. We collected samples for IgM antibodies and genotype studies. We modeled the accumulation of susceptible individuals over the time on the basis of vaccination coverage, vaccine efficacy and birth rate. RESULTS: We identified 101 measles cases and detected IgM antibodies against measles virus in eight of 11 sera. Cases were reported from tsunami-affected (n = 71) and unaffected villages (n = 30) with attack rates of 1.3 and 1.7 per 1000, respectively. 42% of cases in tsunami-affected villages had an onset date within 14 days of the tsunami. The median ages of case-patients in tsunami-affected and un-affected areas were 54 months and 60 months respectively (p = 0.471). 36% of cases from tsunami-affected areas were above 60 months of age. Phylogenetic analyses indicated that the sequences of virus belonged to genotype D8 that circulated in Tamil Nadu. CONCLUSION: Measles virus circulated in Cuddalore district following the tsunami, although there was no association between the two events. Transmission despite high one-dose vaccination coverage pointed to the limitations of this vaccination strategy. A second opportunity for measles immunization may help reducing measles mortality and morbidity in such areas. Children from 6 month to 14 years of age must be targeted for supplemental immunization during complex emergencies
Новая мутация в гене PALB2, ассоциированная с наследственным раком молочной железы у молодой пациентки, принадлежащей к якутской этнической группе
Background. Breast cancer (BC) is the most common female malignancy worldwide. Partner And Localizer of BRCA2 gene (PALB2) is directly involved in DNA damage response. Germline mutation in PALB2 has been identified in breast cancer and familial pancreatic cancer cases, accounting for approximately 1–2% and 3–4%, respectively. The goal of this report was to describe new PALB2 mutation in a young Yakut breast cancer patient with family history of cancer. Material and Methods. Genomic DNA were isolated from blood samples and used to prepare libraries using a capture-based target enrichment kit, Hereditary Cancer Solution™ (SOP HiA GE NETICS , Switzerland), covering 27 genes (ATM, APC, BARD1, BRCA1, BRCA2, BRIP1, CDH1, CHEK2, EPCAM, FAM175A, MLH1, MRE11A, MSH2, MSH6, MUTYH, NBN, PALB2, PIK3CA, PMS2, PMS2CL, PTEN, RAD50, RAD51C, RAD51D, STK11, TP53 and XRCC2). Paired-end sequencing (2 × 150 bp) was conducted using NextSeq 500 system (Illumina, USA ). Results. Here we describe a case of a never-before-reported mutation in the PALB2 gene that led to the early onset breast cancer. We report the case of a 39-year-old breast cancer Yakut woman with a family history of pancreatic cancer. Bioinformatics analysis of the NGS data revealed the presence of the new PALB2 gene germinal frameshift deletion (NM_024675:exon1:c.47delA:p.K16fs). In accordance with dbPubMed ClinVar, new mutation is located in codon of the PALB2 gene, where the likely pathogenic donor splice site mutation (NM_024675.3:c.48+1delG) associated with hereditary cancer-predisposing syndrome has been earlier described. Conclusion. We found a new never-before-reported mutation in PALB2 gene, which probably associated with early onset breast cancer in Yakut indigenous women with a family history of pancreatic cancer.Актуальность. Рак молочной железы занимает лидирующие позиции по уровню заболеваемости во всем мире. Ген онкосупрессор PALB2 наряду с такими генами, как BRCA1, BRCA2, вовлечен в процессы репарации поврежденной ДНК. Частота встречаемости герминальных мутаций гена PALB2 при раке молочной железы и семейных случаях рака поджелудочной железы составляет приблизительно 1–2 % и 3–4 % соответственно. Представлен клинический случай 39-летней женщины, принадлежащей к якутской этнической группе, с диагнозом рак молочной железы с семейной историей рака поджелудочной железы. Материал и методы. Геномная ДНК выделена из периферической крови, ДНК-библиотеки приготавливали с использованием набора Hereditary Cancer Solution™ (Sophia Genetics, Швейцария) для изучения статуса 27 генов (ATM, APC, BARD1, BRCA1, BRCA2, BRIP1, CDH1, CHEK2, EPCAM, FAM175A, MLH1, MRE11A, MSH2, MSH6, MUTYH, NBN, PALB2, PIK3CA, PMS2, PMS2CL, PTEN, RAD50, RAD51C, RAD51D, STK11, TP53 и XRCC2). Секвенирование (2 × 150 п.н.) проводилось с использованием системы NextSeq 500 (Illumina, США). Результаты. По результатам биоинформатического анализа данных NGS у 39-летней женщины, принадлежащей к якутской этнической группе, с диагнозом рак молочной железы с семейной историей рака поджелудочной железы обнаружена новая герминальная мутация гена PALB2 со сдвигом рамки считывания (NM_024675: Exon1: c.47delA: p.K16FS). В соответствии с dbPubmed ClinVar новая мутация гена PALB2 расположена в том же кодоне, где ранее была описана, вероятно патогенная, мутация сайта сплайсинга (NM_024675.3: Exon1: c.48+1delG), вовлеченная в патогенез наследственных форм рака молочной железы и яичника. Заключение. Впервые у 39-летней женщины, принадлежащей к якутской этнической группе, с диагнозом рак молочной железы и с семейной историей рака поджелудочной железы обнаружена новая, вероятно патогенная, герминальная мутация гена PALB2 со сдвигом рамки считывания (NM_024675: Exon1: c.47delA: p.K16FS)
Chronic fatigue syndrome in an ethnically diverse population: the influence of psychosocial adversity and physical inactivity
<p>Abstract</p> <p>Background</p> <p>Chronic fatigue syndrome (CFS) is a complex multifactorial disorder. This paper reports the prevalence of chronic fatigue (CF) and CFS in an ethnically diverse population sample and tests whether prevalence varies by social adversity, social support, physical inactivity, anxiety and depression.</p> <p>Methods</p> <p>Analysis of survey data linking the Health Survey for England (1998 and 1999) and the Ethnic Minority Psychiatric Illness Rates in the Community (EMPIRIC) study undertaken in 2000. The study population comprised a national population sample of 4,281 people ages 16 to 74 years. CF and CFS were operationally defined on the basis of an interview in the EMPIRIC study, alongside questions about psychosocial risk factors. Previous illnesses were reported in the Health Survey for England during 1998 and 1999, as was physical inactivity.</p> <p>Results</p> <p>All ethnic minority groups had a higher prevalence of CFS than the White group. The lowest prevalence was 0.8% in the White group, and it was highest at 3.5% in the Pakistani group (odds ratio (OR), 4.1; 95% confidence interval (95% CI), 1.6 to 10.4). Anxiety (OR, 1.8; 95% CI, 1.4 to 2.2), depression (OR, 1.4; 95% CI, 1.1 to 1.8), physical inactivity (OR, 2.0; 95% CI, 1.1 to 3.8), social strain (OR, 1.24; 95% CI, 1.04 to 1.48) and negative aspects of social support (OR, 2.12; 95% CI, 1.4 to 3.3) were independent risk factors for CFS in the overall sample. Together these risk factors explained ethnic differences in the prevalence of CFS, but no single risk factor could explain a higher prevalence in all ethnic groups.</p> <p>Conclusions</p> <p>The prevalence of CFS, but not CF, varies by ethnic group. Anxiety, depression, physical inactivity, social strain and negative aspects of social support together accounted for prevalence differences of CFS in the overall sample.</p
Microgenomic Analysis in Skeletal Muscle: Expression Signatures of Individual Fast and Slow Myofibers
BACKGROUND: Skeletal muscle is a complex, versatile tissue composed of a variety of functionally diverse fiber types. Although the biochemical, structural and functional properties of myofibers have been the subject of intense investigation for the last decades, understanding molecular processes regulating fiber type diversity is still complicated by the heterogeneity of cell types present in the whole muscle organ.
METHODOLOGY/PRINCIPAL FINDINGS: We have produced a first catalogue of genes expressed in mouse slow-oxidative (type 1) and fast-glycolytic (type 2B) fibers through transcriptome analysis at the single fiber level (microgenomics). Individual fibers were obtained from murine soleus and EDL muscles and initially classified by myosin heavy chain isoform content. Gene expression profiling on high density DNA oligonucleotide microarrays showed that both qualitative and quantitative improvements were achieved, compared to results with standard muscle homogenate. First, myofiber profiles were virtually free from non-muscle transcriptional activity. Second, thousands of muscle-specific genes were identified, leading to a better definition of gene signatures in the two fiber types as well as the detection of metabolic and signaling pathways that are differentially activated in specific fiber types. Several regulatory proteins showed preferential expression in slow myofibers. Discriminant analysis revealed novel genes that could be useful for fiber type functional classification.
CONCLUSIONS/SIGNIFICANCE: As gene expression analyses at the single fiber level significantly increased the resolution power, this innovative approach would allow a better understanding of the adaptive transcriptomic transitions occurring in myofibers under physiological and pathological condition
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