961 resultados para Environmental effects on human beings
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Concept maps are a technique used to obtain a visual representation of a person's ideas about a concept or a set of related concepts. Specifically, in this paper, through a qualitative methodology, we analyze the concept maps proposed by 52 groups of teacher training students in order to find out the characteristics of the maps and the degree of adequacy of the contents with regard to the teaching of human nutrition in the 3rd cycle of primary education. The participants were enrolled in the Teacher Training Degree majoring in Primary Education, and the data collection was carried out through a training activity under the theme of what to teach about Science in Primary School? The results show that the maps are a useful tool for working in teacher education as they allow organizing, synthesizing, and communicating what students know. Moreover, through this work, it has been possible to see that future teachers have acceptable skills for representing the concepts/ideas in a concept map, although the level of adequacy of concepts/ideas about human nutrition and its relations is usually medium or low. These results are a wake-up call for teacher training, both initial and ongoing, because they shows the inability to change priorities as far as the selection of content is concerned.
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Purpose Drafting in cycling influences collective behaviour of pelotons. Whilst evidence for collective behaviour in competitive running events exists, it is not clear if this results from energetic savings conferred by drafting. This study modelled the effects of drafting on behavior in elite 10,000 m runners. Methods Using performance data from a men’s elite 10,000 m track running event, computer simulations were constructed using Netlogo 5.1 to test the effects of three different drafting quantities on collective behaviour: no drafting, drafting to 3m behind with up to ~8% energy savings (a realistic running draft); and drafting up to 3m behind with up to 38% energy savings (a realistic cycling draft). Three measures of collective behaviour were analysed in each condition; mean speed, mean group stretch (distance between first and last placed runner), and Runner Convergence Ratio (RCR) which represents the degree of drafting benefit obtained by the follower in a pair of coupled runners. Results Mean speeds were 6.32±0.28m.s-1, 5.57±0.18 m.s-1, and 5.51±0.13 m.s-1 in the cycling draft, runner draft, and no draft conditions respectively (all P<0.001). RCR was lower in the cycling draft condition, but did not differ between the other two. Mean stretch did not differ between conditions. Conclusions Collective behaviours observed in running events cannot be fully explained through energetic savings conferred by realistic drafting benefits. They may therefore result from other, possibly psychological, processes. The benefits or otherwise of engaging in such behavior are, as yet, unclear.
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This thesis examines the effect of combating of human trafficking as a crime. Special emphasis has been placed on forced labour and the rights of trafficked victims and their protection. The study explores various legislations undertaken at regional, national and international levels and considers rights of trafficked victims under international human rights and Islamic rights. The aim of the thesis is to provide a critical and comparative analysis of the legal systems of the Kingdom of Saudi Arabia (KSA) and the United Kingdom (UK) in terms of human trafficking. The thesis consists of eight chapter; each covering a different aspect of the study. It begins by providing background information regarding the issue of human trafficking and proceeds to examine developments of legal frameworks across the two jurisdictions to combat this crime and penalize the criminals. It seeks to examine the legal system pertaining to human trafficking for forced labour and analyse the three distinct platforms, that is, prevention, protection, and punishment, by comparing the legal systems of the KSA and the UK. The examination of both countries aims to identify the strength and weaknesses of the KSA system as compared to the UK system. Thus, it concludes that the KSA can improve its ranking from Tier 2 watch list to Tier 1 if reforms are introduced in the legislation and enforcement domains. The study also demonstrates how the UK and the KSA portray ‘human trafficking’ in their regional laws. A problem often faced during the information-gathering and investigation stages is the lack of available evidence against traffickers, a particular issue in the KSA. The thesis concludes that the transnational aspect of this phenomenon makes it necessary to establish a thorough and comprehensive legal framework to cover all matters pertaining to this crime, including the protection of victims and punishment of criminals in the KSA and the UK, including immigration and ‘kafala’ strategies that may be of value in future researches.
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Human exposure to Bisphenol A (BPA) results mainly from ingestion of food and beverages. Information regarding BPA effects on colon cancer, one of the major causes of death in developed countries, is still scarce. Likewise, little is known about BPA drug interactions although its potential role in doxorubicin (DOX) chemoresistance has been suggested. This study aims to assess potential interactions between BPA and DOX on HT29 colon cancer cells. HT29 cell response was evaluated after exposure to BPA, DOX, or co-exposure to both chemicals. Transcriptional analysis of several cancer-associated genes (c-fos, AURKA, p21, bcl-xl and CLU) shows that BPA exposure induces slight up-regulation exclusively of bcl-xl without affecting cell viability. On the other hand, a sub-therapeutic DOX concentration (40 nM) results in highly altered c-fos, bcl-xl, and CLU transcript levels, and this is not affected by co-exposure with BPA. Conversely, DOX at a therapeutic concentration (4 μM) results in distinct and very severe transcriptional alterations of c-fos, AURKA, p21 and CLU that are counteracted by co-exposure with BPA resulting in transcript levels similar to those of control. Co-exposure with BPA slightly decreases apoptosis in relation to DOX 4 μM alone without affecting DOX-induced loss of cell viability. These results suggest that BPA exposure can influence chemotherapy outcomes and therefore emphasize the necessity of a better understanding of BPA interactions with chemotherapeutic agents in the context of risk assessment.
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Since 1993 Atlantic menhaden has experienced sustained low juvenile production (recruitment) in the Chesapeake Bay. Factors controlling growth, abundance, and mortality of larval and juvenile menhaden change throughout ontogeny such that larval growth rates could carry over to juvenile growth and survival. The effects of winter thermal conditions on the hatch dates and growth of larval and juvenile Atlantic menhaden in Atlantic shelf and Chesapeake Bay habitats were examined using otolith (ear-stone) increment analyses and growth models. For 2010-2013, truncated hatch-date distributions provided evidence for a winter recruitment bottleneck in Atlantic menhaden caused by cold temperatures. Hatch-dates of surviving juveniles were skewed towards warmer months for years characterized by colder temperatures. Reduced larval growth rates, influenced by reduced temperature and food availability, carried over to juvenile growth rates. A growing degree-day model performed well in simulating observed juvenile growth rates in the Choptank River tributary of Chesapeake Bay.
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Common terns currently are listed as endangered or threatened in many states, including Illinois, Vermont, Pennsylvania, Ohio, Wisconsin, Michigan, and New York, and a species of special concern by the U.S. Fish and Wildlife Service (USFWS, 2002). The sole remaining nesting colony in Illinois is located at the Naval Station Great Lakes (NSGL) in Lake County where intensive management by the Illinois Department of Natural Resources has reduced nest predation and increased the number of eggs that hatch. However, the overall reproductive success (the number of young successfully reaching independence) has not improved. Observations of gross deformities in hatchlings (i.e. compromised feather development and cross-bill), lethargic behavior of young birds, and lesions, suggested the influence of environmental contaminants (Jablonski et al., 2005). I investigated if there were significant levels of environmental contaminants in eggs and nestlings of common terns. While there were minimal concentration of selenium, mercury, lead, and cadmium, there were large concentration of polychlorinated biphenyls (PCBs) in both the eggs and nestlings. The greater amounts of PCBs in older chicks than younger chicks suggest local contamination. In order to potentially manage the factors responsible for exposing the terns to PCBs I investigated the pathway by which PCBs were exposed to terns. The two most likely biological pathways as determined by research on Great Lake fishes were investigated. The first pathway is through atmospheric deposition of PCBs and resuspension of PCB-ladel sediment which are subsequently acquired by filter-feeding fish (e.g. alewives, Alosa pseudoharengus) and then pelagic fish (e.g. lake trout, Salvelinus namaychus) or in this case terns. The second pathway explored was via the biodeposits of zebra mussels which are consumed by round gobies (Neogobius melanostromus) and ultimately littoral fish (e.g. small-mouthed bass, Micropterus dolomieui) or terns. Because common terns breed in near-shore sites where concentrations of zebra mussels are found, as well as forage in more pelagic environments it is possible that either or both pathways may be contributing to their PCB exposure. Field experiments and stable isotope analyses demonstrated that the most likely pathway by which terns are exposed to PCBs is via alewives, similar to how apex predators such as lake trout acquire PCBs. Biodeposits from zebra mussels do not appear to be a significant factor in PCB accumulation in terns. The impact of PCB exposure on birds can vary widely, however in this situation we choise to investigate one specific behavior often affected by PCB exposure, parental attentiveness. PCBs are known to cause endocrine disruption which ultimately results in reduced brooding of young and incubation of eggs. I used temperature sensors to quantify nest temperatures and parental attentiveness during incubation. High concentrations of PCBs in our study population appear to be leading to poor parental attentiveness, and extended periods of absence during incubation and brooding, ultimately leading to poor reproductive success. Common terns are perilously close to being extirpated in Illinois and management of PCB exposure will be difficult. I propose that additional testing should be conducted to locate a site with less PCB contamination and then to move the tern colony to this location, possibly using social cues as has been done with other tern species in Illinois. PCBs are having a profound impact on common tern populations in Illinois and without moving the colony it is likely that the population will continue to decline.
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There is increasing interest in evaluating the environmental effects on crop architectural traits and yield improvement. However, crop models describing the dynamic changes in canopy structure with environmental conditions and the complex interactions between canopy structure, light interception, and dry mass production are only gradually emerging. Using tomato (Solanum lycopersicum L.) as a model crop, a dynamic functional-structural plant model (FSPM) was constructed, parameterized, and evaluated to analyse the effects of temperature on architectural traits, which strongly influence canopy light interception and shoot dry mass. The FSPM predicted the organ growth, organ size, and shoot dry mass over time with high accuracy (>85%). Analyses of this FSPM showed that, in comparison with the reference canopy, shoot dry mass may be affected by leaf angle by as much as 20%, leaf curvature by up to 7%, the leaf length: width ratio by up to 5%, internode length by up to 9%, and curvature ratios and leaf arrangement by up to 6%. Tomato canopies at low temperature had higher canopy density and were more clumped due to higher leaf area and shorter internodes. Interestingly, dry mass production and light interception of the clumped canopy were more sensitive to changes in architectural traits. The complex interactions between architectural traits, canopy light interception, dry mass production, and environmental conditions can be studied by the dynamic FSPM, which may serve as a tool for designing a canopy structure which is 'ideal' in a given environment.
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Low protein diet and odour emissions in meat chickens
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Presenteeism consists in going to work without conditions to produce, which can have a much higher impact than absenteeism on the productivity of an organisation. Presenteeism translates in both physical as psychological perturbations. It is a difficult to quantify reality, as is its translation into direct and indirect costs within the organisation. Our goal was to analyse the effects of presenteeism on the productivity of a company in the food-procession sector through a descriptive and transversal study of exploratory nature. The Stanford Presenteeism Scale SPS-6 (validated by Ferreira et al, 2010) and a semi-structured interview were used. Most of the workers referred having already gone to work feeling ill at least two days in the last year, mentioning that their health condition affected their performance, made them feel desperate and lacking pleasure from work. Management mentioned that presenteeism has a direct impact on productivity without, however, being able to quantify the true costs. Presenteeism is a reality in organisational scenarios, exceling in the educational and health sectors. We underline the importance of making organisations aware of the psychosocial risks and the importance of having healthy leaderships, work stress control and the presence of clinical psychologists and professional coaches.
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Introduction: Polycyclic aromatic hydrocarbons (PaH) are a group of semi-volatile organic compounds composed of 2 or more aromatic rings, generated during incomplete combustion of organic matter. These compounds have been considered as major air pollutants, and also, there is evidence of potential mutagenic and carcinogenic effects in some of them. One of the most important sources of these compounds is industry, and particularly, in processes such as aluminium or coke production, waste incineration and petrochemical and oil reining. This last process is the subject of this article, whose aim is to review the health effects in persons potentially exposed to PAH generated during petroleum reining. Methods: a descriptive review of the available literature was performed, in which PubMed was used as an information source. The following search descriptors were used: refinery, PaH, health, health impact assessment, air pollutants and environmental, as well as their translations in Spanish. Results: eleven articles were included, and most of them correspond to epidemiological studies in which a high incidence of cancer is reported. Conclusions: The reviewed studies concur that there is a signiicant relationship between the presence of oil reineries and the increase of adverse health effects of workers and people living in areas that are close to these industries, particularly, respiratory diseases and cancer. However, it is important to develop studies that simultaneously evaluate the effects on human health and the concentration of these substances in the environment, in order to establish a more direct relationship between the 2 variables.
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"The emergence and abuse of synthetic cannabinoids has been increasing as an alternative to cannabis, mainly among youth. As their appearance on the drug market has been recent, the pharmacological and toxicological profiles of these psychoactive substances are poorly understood. Current studies suggest that they have stronger effects compared to their natural alternatives and their metabolites retain affinity towards CB1 receptors in CNS. Since studies on its toxicological properties are scarce, the effects of the drug in human derived cell lines were investigated. The present study was designed to explore the toxicological impact of parent drug versus phase I metabolites of synthetic cannabinoids on human cells with and without CB1 receptor. The human cell line of neuroblastoma SH-SY5Y and human kidney cell line HEK-293T were exposed to JWH-018 and to its N-(3-hydroxypentyl) metabolite. Cell toxicity was evaluated using the MTT and LDH assay. Additionally, a dual staining methodology with fluorescent Annexin V-FITC and propidium iodide was performed to address the question of whether JWH-018 N-(3-hydroxypentyl) metabolite is inducing cell death through apoptosis or necrosis, in HEK293T and SH-SY5Y cell lines. The obtained results show that JWH-018 does not cause a statistically significant decrease in cell viability, in contrast to its N-(3-hydroxypentyl) metabolite, which at ≥25μM causes a significant decrease in cell viability. Both cell lines are affected by JWH-018 metabolite. Our results point to higher toxicity of JWH-018 metabolite when compared to its parent drug, suggesting a non-CB1 receptor mediated toxicological mechanism. Comparing the results from Annexin V/PI with MTT and LDH assays of SH-SY5Y and HEK293T in the presence of the synthetic cannabinoid metabolite, emerges the picture that cellular viability decreases and associated death is occurring through necrosis."
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Aquatic organisms are considered excellent biomarkers of mercury (Hg) occurrence in the environment. Selenium (Se) acts in antagonism to this metal, stimulating its elimination, and reducing its toxicity. In this paper, tilapia (Oreochromis niloticus) were chronically acclimated in sub-lethal Hg2+, Hg2+ + Se4+ and Hg2+ + Se6+ concentrations. Distribution and bioaccumulation of both elements were evaluated in fish tissues. The kidney was the main target of the Hg and Se uptake, and the presence of Hg induced the Se hepatic elimination. The Hg bioaccumulation in the gill, spleen and heart were higher in the presence of Se6+ than in the presence of Se4+.
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Tall buildings are wind-sensitive structures and could experience high wind-induced effects. Aerodynamic boundary layer wind tunnel testing has been the most commonly used method for estimating wind effects on tall buildings. Design wind effects on tall buildings are estimated through analytical processing of the data obtained from aerodynamic wind tunnel tests. Even though it is widely agreed that the data obtained from wind tunnel testing is fairly reliable the post-test analytical procedures are still argued to have remarkable uncertainties. This research work attempted to assess the uncertainties occurring at different stages of the post-test analytical procedures in detail and suggest improved techniques for reducing the uncertainties. Results of the study showed that traditionally used simplifying approximations, particularly in the frequency domain approach, could cause significant uncertainties in estimating aerodynamic wind-induced responses. Based on identified shortcomings, a more accurate dual aerodynamic data analysis framework which works in the frequency and time domains was developed. The comprehensive analysis framework allows estimating modal, resultant and peak values of various wind-induced responses of a tall building more accurately. Estimating design wind effects on tall buildings also requires synthesizing the wind tunnel data with local climatological data of the study site. A novel copula based approach was developed for accurately synthesizing aerodynamic and climatological data up on investigating the causes of significant uncertainties in currently used synthesizing techniques. Improvement of the new approach over the existing techniques was also illustrated with a case study on a 50 story building. At last, a practical dynamic optimization approach was suggested for tuning structural properties of tall buildings towards attaining optimum performance against wind loads with less number of design iterations.
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The use of natural areas for underwater coastal marine activities such as snorkelling is growing, but the amount of ecological and socioeconomic data on these activities is scarce and relates mainly to coral reef areas. Three underwater self-guided routes were designed at Marinha Beach (Algarve, Portugal), based on scientific information, with in situ interpretation and guidance, as a way to enhance biodiversity awareness and, hence, reduce the probability of human impacts. The routes were implemented in two consecutive summer seasons and after each season, visual census techniques were used to describe flora composition and cover area (seaweeds and seagrasses) in order to understand patterns and evaluate human impacts. Snorkelers' opinions and perceptions about several issues related to the routes' environmental education role (e.g. role in enhancing biocliversity awareness) were investigated by questionnaire after the snorkelling activity. An inter-annual difference inflora assemblages was found, probably associated to natural variability, rather than snorkelers' impacts. Results indicate that, in fact, in situ education and interpretation can raise environmental awareness if properly addressed, resulting in a satisfactory way of engaging snorkelers in the protection and in the conservation of the visited environments, thereby preventing negative ecological impacts. (C) 2015 Elsevier Ltd. All rights reserved.