3,767 research outputs found

    Do Species and Functional Diversity Indices Reflect Changes in Grazing Regimes and Climatic Conditions in Northeastern Spain?

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    Understanding the mechanisms that maintain biodiversity in various ecosystems enables the development of management practices that prevent degradation (Canals & Sebastia, 2000). Each diversity index reflects some compositional properties and could be influenced differently by stress and disturbance factors (Magurran, 2004). In this study, we aim to reveal 1) which management practices and environmental factors affect biodiversity in rangelands of northeastern Spain and 2) the relationship between species diversity and functional diversity (SD and FD)

    Soil and water pollution in a banana production region in tropical Mexico

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    The effects of abundant Mancozeb (Mn, Zn— bisdithiocarbamate) applications (2.5 kg ha-1week-1 for 10 years) on soil and surface-, subsurface- and groundwater pollution were monitored in a banana production region of tropical Mexico. In soils, severe manganese accumulation was observed, wheras the main metabolite ethylenethiourea was near the detection limit. Surface and subsurface water was highly polluted with ethylenethiourea, the main metabolite of Mancozeb (22.5 and 4.3 lg L-1, respectively), but not with manganese. In deep ground water, no ethylenethiourea was detected. The level of pollution in the region presents a worrisome risk for aquatic life and for human health

    Risk perception and ethnic background in construction workers: Results of a cross-sectional study in a group of trainees of a vocational school in italy

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    Risk perception can be influenced by cultural background. The study aims to evaluate risk perception, considering different ethnicities of construction workers from vocational schools in Italy. We administered a questionnaire investigating four different dimensions: Perceived behavioral control (PBC), Danger perception (DP), Safety climate (SC), and Attitude towards safe actions (ATSA). 562 workers answered: 72.4% from Italy, 14.2% from eastern Europe, 9.4% from Balkans, and 3.9% from North Africa. The participants indicated quite low control, attributable to the haste in performing the job. The workers perceived their specific job tasks as riskier compared to the tasks of their colleagues. They reported as fundamental the respecting of safety rules, but indicating that supervisors do not adequately promote safety behaviors. Finally, construction workers judged as \u201cbrave\u201d the colleagues working without protective equipment. When compared to Italians, North Africa workers showed a lower perception of the possibility to control their safe behaviors (p = 0.040), while both eastern Europeans and Balkan obtained higher scores at the ATSA dimension, indicating a kind of fatalistic acceptance of the risky situations at work. Eastern Europeans also showed a lower perception of the dangers (p = 0.002), while Balkan demonstrated a perception of SC even better than the Italian group (p = 0.005)

    Shell Evolution towards Ni 78: Low-Lying States in Cu 77

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    The level structure of the neutron-rich Cu77 nucleus is investigated through β-delayed γ-ray spectroscopy at the Radioactive Isotope Beam Factory of the RIKEN Nishina Center. Ions of Ni77 are produced by in-flight fission, separated and identified in the BigRIPS fragment separator, and implanted in the WAS3ABi silicon detector array, surrounded by Ge cluster detectors of the EURICA array. A large number of excited states in Cu77 are identified for the first time by correlating γ rays with the β decay of Ni77, and a level scheme is constructed by utilizing their coincidence relationships. The good agreement between large-scale Monte Carlo shell model calculations and experimental results allows for the evaluation of the single-particle structure near Ni78 and suggests a single-particle nature for both the 5/21- and 3/21- states in Cu77, leading to doubly magic Ni78. © 2017 American Physical Society

    Saúde bucal dos quilombolas valencianos: estudo transversal

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    Dados do IBGE revelam que o Brasil tem aproximadamente 50% da sua população auto classificada como afrodescendente. Contudo, a desigualdade de oportunidades com os brancos faz-se evidente. Há significantes iniquidades em saúde bucal entre pretos, pardos e brancos: 56,8% dos pretos utilizam o serviço odontológico público na mesma proporção em que os brancos utilizam outros serviços; a perda dental dos pardos foi de 14,2% enquanto a dos brancos foi de 12,8%. Duas problemáticas fazem parte da pauta da política social brasileira. Uma delas é o enfrentamento da pobreza, a outra é a desigualdade racial. No caso das comunidades quilombolas, estas duas questões se imbricam. As informações referentes a tais comunidades são escassas e os parcos dados divulgados revelam que vivem precariamente, muitas vezes sem acesso aos serviços de saúde. Almeja-se por meio deste trabalho, relatar a prevalência da cárie dentária e necessidade de tratamento dos integrantes do quilombo São José da Serra (SJS), em Valença/RJ. A comunidade foi oficialmente reconhecida como remanescente de quilombo pela Fundação Cultural Palmares em 1999. Atualmente moram no quilombo 31 famílias, totalizando 70 pessoas. Trata-se de uma pesquisa de base regional, fundamentada no levantamento de dados primários da cárie dentária em quilombolas. Do universo de 70 quilombolas, foram examinados 29 indivíduos, na faixa etária de 12 a 91 anos. Os exames intrabucais foram realizados, utilizando a metodologia preconizada pelo Levantamento SB Brasil 2010. Resultados: o índice ceo-d foi 4,3 e o CPOD encontrado foi de 0,9, com predomínio do componente cariado. O tratamento restaurador representou a maior necessidade desta população. Conclusões: os dados evidenciaram a necessidade de implementação de medidas de atenção à saúde bucal que sejam capazes de intervir nos determinantes da cárie dentária na população estudada

    Modeling viral coevolution: HIV multi-clonal persistence and competition dynamics

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    The coexistence of different viral strains (quasispecies) within the same host are nowadays observed for a growing number of viruses, most notably HIV, Marburg and Ebola, but the conditions for the formation and survival of new strains have not yet been understood. We present a model of HIV quasispecies competition, that describes the conditions of viral quasispecies coexistence under different immune system conditions. Our model incorporates both T and B cells responses, and we show that the role of B cells is important and additive to that of T cells. Simulations of coinfection (simultaneous infection) and superinfection (delayed secondary infection) scenarios in the early stages (days) and in the late stages of the infection (years) are in agreement with emerging molecular biology findings. The immune response induces a competition among similar phenotypes, leading to differentiation (quasi-speciation), escape dynamics and complex oscillations of viral strain abundance. We found that the quasispecies dynamics after superinfection or coinfection has time scales of several months and becomes even slower when the immune system response is weak. Our model represents a general framework to study the speed and distribution of HIV quasispecies during disease progression, vaccination and therapy.Comment: 20 pages, 10 figure

    Monitoring root rot in flat-leaf parsley via machine vision by unsupervised multivariate analysis of morphometric and spectral parameters

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    \ua9 The Author(s) 2024.Use of vertical farms is increasing rapidly as it enables year-round crop production, made possible by fully controlled growing environments situated within supply chains. However, intensive planting and high relative humidity make such systems ideal for the proliferation of fungal pathogens. Thus, despite the use of bio-fungicides and enhanced biosecurity measures, contamination of crops does happen, leading to extensive crop loss, necessitating the use of high-throughput monitoring for early detection of infected plants. In the present study, progression of foliar symptoms caused by Pythium irregulare-induced root rot was monitored for flat-leaf parsley grown in an experimental hydroponic vertical farming setup. Structural and spectral changes in plant canopy were recorded non-invasively at regular intervals using a 3D multispectral scanner. Five morphometric and nine spectral features were selected, and different combinations of these features were subjected to multivariate data analysis via principal component analysis to identify temporal trends for early segregation of healthy and infected samples. Combining morphometric and spectral features enabled a clear distinction between healthy and diseased plants at 4–7 days post inoculation (DPI), whereas use of only morphometric or spectral features allowed this at 7–9 DPI. Minimal datasets combining the six most effective features also resulted in effective grouping of healthy and diseased plants at 4–7 DPI. This suggests that selectively combining morphometric and spectral features can enable accurate early identification of infected plants, thus creating the scope for improving high-throughput crop monitoring in vertical farms

    Radioisotopic purity and imaging properties of cyclotron-produced 99mTc using direct 100Mo(p,2n) reaction

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    Evaluation of the radioisotopic purity of technetium-99m (99mTc) produced in GBq amounts by proton bombardment of enriched molibdenum-100 (100Mo) metallic targets at low proton energies (i.e. within 15\u201320 MeV) is conducted. This energy range was chosen since it is easily achievable by many conventional medical cyclotrons already available in the nuclear medicine departments of hospitals. The main motivation for such a study is in the framework of the research activities at the international level that have been conducted over the last few years to develop alternative production routes for the most widespread radioisotope used in medical imaging. The analysis of technetium isotopes and isomeric states (9xTc) present in the pertechnetate saline Na99mTcO4 solutions, obtained after the extraction/purification procedure, reveals radionuclidic purity levels basically in compliance with the limits recently issued by European Pharmacopoeia 9.3 (2018 Sodium pertechnetate (99mTc) injection 4801\u20133). Moreover, the impact of 9xTc contaminant nuclides on the final image quality is thoroughly evaluated, analyzing the emitted high-energy gamma rays and their influence on the image quality. The spatial resolution of images from cyclotron-produced 99mTc acquired with a mini-gamma camera was determined and compared with that obtained using technetium-99m solutions eluted from standard 99Mo/99mTc generators. The effect of the increased image background contribution due to Compton-scattered higher-energy gamma rays (E \u3b3 \u2009\u2009>\u2009\u2009200\u2009keV), which could cause image-contrast deterioration, was also studied. It is concluded that, due to the high radionuclidic purity of cyclotron-produced 99mTc using 100Mo(p,2n)99mTc reaction at a proton beam energy in the range 15.7\u201319.4 MeV, the resulting image properties are well comparable with those from the generator-eluted 99mTc

    Prevalence and genotype specific concordance of oro-genital and anal human papillomavirus infections among sexually active Nigerian women

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    Background: Human papillomavirus (HPV) associated cancers are increasingly reported globally, including in sub-Saharan Africa (SSA). However, with the exception of cervical HPV infection, data from SSA on the epidemiology of oral and genital HPV infections are limited. This study assessed the prevalence and concordance of oro-genital and anal HPV genotype specific infections among women in the general population. Methods: We conducted a cross-sectional study in sexually active women aged 18-45 years in Ibadan, Nigeria. After a face-to-face interview and clinical examination, oral, cervical, vulvar, and anal samples were collected from participants and tested by the Anyplex II 28 HPV assay. Descriptive and multivariable analyses were used to report prevalence and risk factors associated with HPV infections. Results: The prevalence of any vulva, cervical, anal, and oral HPV infections was 68.0% (210/309), 59.7% (182/305), 56.8% (172/303), and 16.1% (14/286), respectively. There was an inverse relationship between age-group and HPV prevalence of HPV in all anatomic sites except for the oral HPV infections. HPV 35 was the most prevalent high-risk HPV genotype in the vulva, cervix and oral cavity. Associated risk factors for HPV infection in each of the anatomic sites were reported. Overall, 10.0% (31/310) women had concordance of any HPV type in the four anatomic sites. Conclusion: There was a high prevalence of oro-genital and anal HPV infections among sexually active Nigerian women, with concordance of HPV types in the cervix, vulva, anus and oral cavity. We advocate large longitudinal studies that will involve sampling of multiple anatomic sites and inclusion of other women in the community for better understanding of HPV epidemiology in this region
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