4,526 research outputs found
Do Species and Functional Diversity Indices Reflect Changes in Grazing Regimes and Climatic Conditions in Northeastern Spain?
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)
Los depósitos lacustres del Terciario de Bicorp (Valencia)
La Cuenca de Bicorp pertenece al conjunto de cuencas sinorogénicas del Terciario de la provÃncia de Valencia. Está emplazada en el sector sur de la zoia de transición entre la cadena ibérica y las Béticas. La Cuenca de Bicorp es una cuenca continental emplazada sobre un substrato mesozoico formado por materiales triásicos, jurásicos y cretácicos. Sus limites norte y sur son dos fallas normales de orientación ENE-WSW, las cuales actuaron sinsedimentariamente. Los depósitos de la Cuenca de Bicorp tienen un espesor máximo de 450 metros. La base de la serie está formada por materiales de origen aluvial, mientras que el resto lo constituyen facies lacustres. En los depósitos lacustres pueden reconocerse cuatro unidades formadas, desde la base hacia el techo, por: a) margas carbonosas grises, b) calizas laminadas y margas con lignito, c) yesos seleniticos y d) alternancias de calizas y pelitas laminadas bituminosas. De estas unidades la que posee los depósitos de mayor potencia y extensión areal, es la formada por las alternancias de calizas y pelitas bituminosas. Estos son los materiales que caracterizan mejor la serie de la cuenca lacustre de Bicorp. Las alternancias de calizas y pelitas bituminosas están organizadas en secuencias, estrato- y granocrecientes hacia el techo, que se repiten cÃclicamente. Cada secuencia está formada por un término superior de calizas y otro inferior de pelitas bituminosas. Las calizas están compuestas, en su mayor parte, por restos esqueléticos de invertebrados acuáticos, y presentan en su techo evidencias de emersión subarea (grietas de desecación, huellas de vertebrados terrestres...). Las pelitas bituminosas se caracterizan por su alto contenido en materia orgánica y por tener una laminación continua milimétrica. Sus caracterÃsticas son indicativas de haber sido formadas en un ambiente sin el contenido de oxigeno necesario para permitir la presencia de fauna bentónica en el fondo. En su conjunto, los depósitos de la Cuenca de Bicorp son representativos de un ambiente lacustre salino con unestado permanente de estratificación de sus aguas y con un epilimnion oxigenado y un hipolimnion anóxico
Soil and water pollution in a banana production region in tropical Mexico
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
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
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
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 polÃtica 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 famÃlias, 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 indivÃduos, na faixa etária de 12 a 91 anos. Os exames intrabucais foram realizados, utilizando a metodologia preconizada pelo Levantamento SB Brasil 2010. Resultados: o Ãndice ceo-d foi 4,3 e o CPOD encontrado foi de 0,9, com predomÃnio 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
Identifying and prioritising services in European terrestrial and freshwater ecosystems
Ecosystems are multifunctional and provide humanity with a broad array of vital services. Effective management of services requires an improved evidence base, identifying the role of ecosystems in delivering multiple services, which can assist policy-makers in maintaining them. Here, information from the literature and scientific experts was used to systematically document the importance of services and identify trends in their use and status over time for the main terrestrial and freshwater ecosystems in Europe. The results from this review show that intensively managed ecosystems contribute mostly to vital provisioning services (e.g. agro-ecosystems provide food via crops and livestock, and forests provide wood), while semi-natural ecosystems (e.g. grasslands and mountains) are key contributors of genetic resources and cultural services (e.g. aesthetic values and sense of place). The most recent European trends in human use of services show increases in demand for crops from agro-ecosystems, timber from forests, water flow regulation from rivers, wetlands and mountains, and recreation and ecotourism in most ecosystems, but decreases in livestock production, freshwater capture fisheries, wild foods and virtually all services associated with ecosystems which have considerably decreased in area (e.g. semi-natural grasslands). The condition of the majority of services show either a degraded or mixed status across Europe with the exception of recent enhancements in timber production in forests and mountains, freshwater provision, water/erosion/natural hazard regulation and recreation/ecotourism in mountains, and climate regulation in forests. Key gaps in knowledge were evident for certain services across all ecosystems, including the provision of biochemicals and natural medicines, genetic resources and the regulating services of seed dispersal, pest/disease regulation and invasion resistance
Modeling viral coevolution: HIV multi-clonal persistence and competition dynamics
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
\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
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