Hasil untuk "Environmental sciences"

Yasmine Bedoui, Zein Kallas, Adrià Menéndez i Molist et al.

Pricing is an essential element that significantly impacts the supply chain mechanisms. The primary objective of this study is to explore the transmission of producer-to-consumer prices in the Spanish fresh tomato industry. Employing the Threshold Vector Autoregressive model, and subsequently utilizing the Generalized Impulse Response Function, we investigated the nonlinear price adjustments that occur in response to positive and negative shocks affecting both tomato prices of consumers and producers. The findings show a clear pattern of distinct reactions between segments in response to shocks. Specifically, the speed and intensity of consumer price responses to producer price shocks appear to surpass those observed when producer prices respond to consumer price shocks. Furthermore, it is evident from the current research that the behavior of producers has evolved from earlier studies that utilized outdated information, suggesting a more competitive approach. The research identifies a new trend in producer behavior within the supply chain. By analyzing tomato price fluctuations, it advances current knowledge and provides essential market insights to support informed decision-making.

Junchao Li, Lifang Wang, Zheng Liu et al.

Abstract In this study, the characteristics of rural domestic wastewater discharge in the Yangtze River Basin, China, are analysed via geographic information visualization, pollutant load assessment, and correlation analysis. Through the use of a geographic information visualization system, this study intuitively presents the characteristics of rural domestic wastewater discharge in the Yangtze River Basin. In pollutant load assessment, the pressure caused by rural domestic wastewater discharge on maintaining the target water quality standards in the tributaries and main stream of the Yangtze River is comprehensively analysed. Correlation analysis reveals the social and natural factors influencing the levels of rural domestic wastewater discharge. The findings indicate that the average discharge level of rural domestic wastewater in the Yangtze River Basin remains low, with an average water discharge level of 39.24 L/(capita·day), a chemical oxygen demand (COD) of 27.50 mg/(capita·day), an ammonia nitrogen (NH3-N) content of 1.53 mg/(capita·day), a total nitrogen (TN) amount of 2.74 mg/(capita·day), and a total phosphorus (TP) content of 0.22 mg/(capita·day). Based on the current levels of rural domestic wastewater discharge and the concentrations of the above substances in the natural environment, the impact of rural domestic wastewater discharge on maintaining water quality functions in the tributaries and main stream of the Yangtze River can be considered negligible, although regional differences exist. Discharge levels are significantly influenced by various social factors, including educational level, per capita disposable income, and consumption expenditures, as well as natural factors such as average annual temperature, average annual humidity, and average annual rainfall. Overall, this study provides reference data for the analysis and management of rural domestic wastewater discharge in both similar regions in China and globally.

C. P. B. O'Malley, C. P. B. O'Malley, G. G. Roberts et al.

<p>The modern state of the mantle and its evolution on geological timescales are of widespread importance for the Earth sciences. For instance, it is generally agreed that mantle flow is manifest in topographic and drainage network evolution, glacio-eustasy, and the distribution of sediments. There are now a variety of theoretical approaches to predict histories of mantle convection and its impact on surface deflections. A general goal is to make use of observed deflections to identify Earth-like simulations and constrain the history of mantle convection. Several important insights into the role of radial and non-radial viscosity variations, gravitation, and the importance of shallow structure already exist. Here we seek to bring those insights into a single framework to elucidate the relative importance of popular modeling choices for predicted instantaneous vertical surface deflections. We start by comparing results from numeric and analytic approaches to solving the equations of motion that are ostensibly parameterized to be as similar as possible. Deflections predicted by such numeric and analytic models can vary by <span class="inline-formula">∼</span> 10 %, and the difference increases to <span class="inline-formula">∼</span> 25 % when viscosity is temperature-dependent. Including self-gravitation and the gravitational potential of the deflected surface is a relatively small source of discrepancy. However, spherical harmonic correlations between model predictions decrease dramatically with the removal of shallow structure to increasing depths and when radial viscosity structure is modified. The results emphasize the sensitivity of instantaneous surface deflections to density and viscosity anomalies in the upper mantle. They reinforce the view that a detailed understanding of lithospheric structure is crucial for relating mantle convective history to observations of vertical motions at Earth's surface.</p>

Florian Herbolsheimer, Annette Peters, Sarah Wagner et al.

Abstract Background The COVID-19 pandemic restrictions posed challenges to maintaining healthy lifestyles and physical well-being. During the first mobility restrictions from March to mid-July 2020, the German population was advised to stay home, except for work, exercise, and essential shopping. Our objective was to comprehensively assess the impact of these restrictions on changes in physical activity and sedentary behavior to identify the most affected groups. Methods Between April 30, 2020, and May 12, 2020, we distributed a COVID-19-specific questionnaire to participants of the German National Cohort (NAKO). This questionnaire gathered information about participants’ physical activity and sedentary behavior currently compared to the time before the restrictions. We integrated this new data with existing information on anxiety, depressive symptoms, and physical activity. The analyses focused on sociodemographic factors, social relationships, physical health, and working conditions. Results Out of 152,421 respondents, a significant proportion reported altered physical activity and sedentary behavioral patterns due to COVID-19 restrictions. Over a third of the participants initially meeting the WHO’s physical activity recommendation could no longer meet the guidelines during the restrictions. Participants reported substantial declines in sports activities (mean change (M) = -0.38; 95% CI: -.390; -.378; range from -2 to + 2) and reduced active transportation (M = -0.12; 95% CI: -.126; -.117). However, they also increased recreational physical activities (M = 0.12; 95% CI: .117; .126) while engaging in more sedentary behavior (M = 0.24; 95% CI: .240; .247) compared to pre-restriction levels. Multivariable linear and log-binomial regression models indicated that younger adults were more affected by the restrictions than older adults. The shift to remote work, self-rated health, and depressive symptoms were the factors most strongly associated with changes in all physical activity domains, including sedentary behavior, and the likelihood to continue following the physical activity guidelines. Conclusions Mobility patterns shifted towards inactivity or low-intensity activities during the nationwide restrictions in the spring of 2020, potentially leading to considerable and lasting health risks.

Arne Tobian, Dieter Gerten, Ingo Fetzer et al.

The planetary boundaries framework defines a safe operating space for humanity. To date, these boundaries have mostly been investigated separately, and it is unclear whether breaching one boundary can lead to the transgression of another. By employing a dynamic global vegetation model, we systematically simulate the strength and direction of the effects of different transgression levels of the climate change boundary (using climate output from ten phase 6 of the Coupled Model Intercomparison Project models for CO _2 levels ranging from 350 ppm to 1000 ppm). We focus on climate change-induced shifts of Earth’s major forest biomes, the control variable for the land-system change boundary, both by the end of this century and, to account for the long-term legacy effect, by the end of the millennium. Our simulations show that while staying within the 350 ppm climate change boundary co-stabilizes the land-system change boundary, breaching it (>450 ppm) leads to critical transgression of the latter, with greater severity the higher the ppm level rises and the more time passes. Specifically, this involves a poleward treeline shift, boreal forest dieback (nearly completely within its current area under extreme climate scenarios), competitive expansion of temperate forest into today’s boreal zone, and a slight tropical forest extension. These interacting changes also affect other planetary boundaries (freshwater change and biosphere integrity) and provide feedback to the climate change boundary itself. Our quantitative process-based study highlights the need for interactions to be studied for a systemic operationalization of the planetary boundaries framework.

Simone Varandas, Conceição Fernandes, Edna Cabecinha et al.

Freshwater bivalves are widely used as accumulation indicators and monitoring tools for assessing contaminant effects on different levels of biological integration. This pilot study aimed to explore the phylogenetic diversity of <i>Escherichia coli</i> isolated from freshwater mussels (<i>Margaritifera margaritifera</i> and <i>Potomida littoralis</i>) and characterize their phenotypes and antibiotic resistance profiles. Samples were collected in the Rabaçal and Tua Rivers, in the Douro basin, Portugal—two sites representing different levels of anthropogenic contamination. Antimicrobial susceptibility testing was performed via the disk diffusion method with 21 antibiotics. Results showed that 31% of isolates were multidrug-resistant (MDR). Thus, freshwater mussels provide an effective and time-integrated approach for identifying/quantifying fecal indicators, including MDR bacteria. PCR-based assays were designed for assessing phylogenetic <i>E. coli</i> groups. Among the <i>E. coli</i> isolates, the highest prevalence (44%) was observed in group D or E, followed by group E or Clade I (25%), group A (19%), and group B1 (13%). <i>E. coli</i> isolated from <i>M. margaritifera</i> predominantly exhibited a higher prevalence of phylogroups D or E, whereas <i>E. coli</i> from <i>P. littoralis</i> showed associations with phylogroups E or clade I, B1, A, and D or E. Our results provide new insights into the phylogenetic diversity of <i>E. coli</i> in freshwater bivalves. Additionally, the findings highlight the possible linkage of phylogroups with the host species, the geographical location in the water stream, and human activity. Using <i>E. coli</i> as a bioindicator isolated from freshwater mussels helps us grasp how human activities affect the environment. This study has important implications for those interested in safeguarding water resources, especially in tackling antibiotic resistance in aquatic ecosystems.

Edward Armstrong, Miikka Tallavaara, Peter O. Hopcroft et al.

Abstract The Sahara region has experienced periodic wet periods over the Quaternary and beyond. These North African Humid Periods (NAHPs) are astronomically paced by precession which controls the intensity of the African monsoon system. However, most climate models cannot reconcile the magnitude of these events and so the driving mechanisms remain poorly constrained. Here, we utilise a recently developed version of the HadCM3B coupled climate model that simulates 20 NAHPs over the past 800 kyr which have good agreement with NAHPs identified in proxy data. Our results show that precession determines NAHP pacing, but we identify that their amplitude is strongly linked to eccentricity via its control over ice sheet extent. During glacial periods, enhanced ice-albedo driven cooling suppresses NAHP amplitude at precession minima, when humid conditions would otherwise be expected. This highlights the importance of both precession and eccentricity, and the role of high latitude processes in determining the timing and amplitude of the NAHPs. This may have implications for the out of Africa dispersal of plants and animals throughout the Quaternary.

Julia R. Varshavsky, Swati D. G. Rayasam, Jennifer B. Sass et al.

Abstract A key element of risk assessment is accounting for the full range of variability in response to environmental exposures. Default dose-response methods typically assume a 10-fold difference in response to chemical exposures between average (healthy) and susceptible humans, despite evidence of wider variability. Experts and authoritative bodies support using advanced techniques to better account for human variability due to factors such as in utero or early life exposure and exposure to multiple environmental, social, and economic stressors. This review describes: 1) sources of human variability and susceptibility in dose-response assessment, 2) existing US frameworks for addressing response variability in risk assessment; 3) key scientific inadequacies necessitating updated methods; 4) improved approaches and opportunities for better use of science; and 5) specific and quantitative recommendations to address evidence and policy needs. Current default adjustment factors do not sufficiently capture human variability in dose-response and thus are inadequate to protect the entire population. Susceptible groups are not appropriately protected under current regulatory guidelines. Emerging tools and data sources that better account for human variability and susceptibility include probabilistic methods, genetically diverse in vivo and in vitro models, and the use of human data to capture underlying risk and/or assess combined effects from chemical and non-chemical stressors. We recommend using updated methods and data to improve consideration of human variability and susceptibility in risk assessment, including the use of increased default human variability factors and separate adjustment factors for capturing age/life stage of development and exposure to multiple chemical and non-chemical stressors. Updated methods would result in greater transparency and protection for susceptible groups, including children, infants, people who are pregnant or nursing, people with disabilities, and those burdened by additional environmental exposures and/or social factors such as poverty and racism.

Wills Adam, Banister Carsen, Pellissier Mathieu et al.

This work explores the importance of renewable resource temporal distribution for solar and wind energy deployment in Arctic communities to meet building and ancillary loads. An analysis of ten years of historic weather data was performed for six locations in the Canadian Arctic to assess renewable resource variation. Simulations of similar capacity solar and wind generation systems were then coupled with the historic data to compare and contrast generation potential. This analysis highlighted the importance of considering hourly, daily, monthly, and year-to-year renewable generation when deploying solar and wind to the Arctic. As many northern communities in Canada have local electricity generation and distribution systems, and no connection to the continental grid, managing grid interactions effectively is crucial to the success of deployment, integration, and operation. The results for the solar energy analysis showed high consistency of production year-to-year. The results for the wind energy analysis showed that the annual outputs have significantly less variation than the year-to-year output of individual months for all the locations under study. For the high latitude locations studied, solar energy can still provide useful electricity generation output, but the more pronounced bias of the annual output to the summer months can leave several months with little or no output. The use of additional renewable sources is crucial in beginning to transition some electricity generating capacity within Arctic communities from being solely reliant on fossil fuels.

Francesco Carubbi, Francesco Carubbi, Philipp Bosch et al.

Objectives: To investigate opinion and routine practice of specialists from different disciplines on imaging techniques for interventional procedures related to rheumatic and musculoskeletal diseases (RMDs).Methods: An English-language questionnaire was developed by an international working group and distributed to health care providers of various disciplines involved in the care of people with RMDs via an online survey tool (SoSci Survey®) from December 2019 to May 2020.Results: A total of 1,105 respondents from 56 countries completed the survey, over 60% of participants were rheumatologists. The majority of respondents (88%) performed interventional procedures in RMDs patients and 90% of them used imaging guidance. Ultrasonography was the most frequently used technique, particularly among rheumatologists. X-ray and computed tomography were mainly used by radiologists. A discrepancy emerged between the importance assigned to certain items such as the availability of a second operator and their actual implementation in clinical practice. Local barriers, lack of resources and facilities were mentioned as the most relevant obstacles in this regard. Lack of training on imaging and/or imaging guided procedures did not emerge as a barrier to perform such interventions; in fact, 19% of respondents performing the procedures indicated not to have received adequate training in this field.Conclusions: This is the first multinational multidisciplinary survey exploring in detail the opinions and practice on imaging guidance for interventional procedures in RMDs. A harmonization of protocols based on international guidelines, along with adequate training programmes and interventions on barriers at national/local levels are the main unmet needs requiring attention.

Peter Kidd, Paul Rose

Behaviour signals the internal states that relate to an individual’s welfare and its development is influenced by the early social environment that an animal experiences. Husbandry practices can alter this early social environment, for example different rearing conditions (e.g., foster rearing by a surrogate parent of another species). Widespread implementation of altered rearing can lack empirical support and non-parent-reared animals may experience poorer welfare resulting from maternal deprivation. An opportunity presented itself to measure the effect of foster-rearing on Chilean flamingo behaviour and social preferences at WWT Slimbridge Wetland Centre and compare findings to parent-reared conspecifics in the same time period. Data were collected from April to July 2019 at three timepoints during each observation day. Binomial generalized linear mixed models were used to assess the relationship between focal chicks’ rearing background with behaviour, zone usage, and flock position whilst accounting for climatic factors and visitor numbers. The development of social preferences was assessed using social network analysis. Our results showed limited impacts on flamingo behavioural development due to foster rearing. Foster-reared chicks spent less time feeding, were more likely to occupy the nesting area of the enclosure, and had fewer significant preferred associations than parent-reared chicks, but preferred social bonds were as equally strong and durable for both foster-reared and parent-reared chicks. Our results have important welfare implications for the use of foster-rearing in captive environments; altered early social rearing environments through cross-fostering in Chilean flamingos is associated with limited differences in behavioural and social development.

Jei Ha Lee, Cha Soon Kim, Soo Im Choi et al.

Tritium is an important nuclide that must be monitored for radiation safety management. In this study, HTO was orally administered to rats at the level of 37 kBq (1 μCi) or 370 kBq (10 μCi) to examine tissue distribution and excretion levels. After sacrifice, wet and dry tissue samples were weighed and analyzed for tissue free-water tritium (TFWT) and organically bound tritium (OBT). The mean tissue concentrations of TFWT (OBT) were 30.9 (17.8) and 4.4 (8.1) Bq/g on days 7 and 13 at the 37 kBq level and 30.8 (64.6) Bq/g on day 17 at the 370 kBq level. To assess the cytogenetic damage due to tritium exposure, a cytokinesis-blocked micronucleus (MN) assay was performed in blood samples from rats exposed to HTO for 14 and 21 days after oral administration. There was no significant difference in the MN frequencies between the control and exposed rats. Keywords: Tritium, Organically bound tritium (OBT), Tissue free-water tritium (TFWT)

Alessandra Helena Schneider, Cristiane Coradin, Camila Kahlau et al.

O presente artigo é resultado de um esforço interdisciplinar realizado pelos(as) pesquisadores(as) da turma XII de Doutorado do Programa de Pós-Graduação em Meio Ambiente e Desenvolvimento da Universidade Federal do Paraná (PPGMADE-UFPR). Como objetivo principal, buscou-se contribuir com a construção do conhecimento para o aprofundamento teórico e embasamento de trabalhos empíricos relativos à temática “alternatividades”. O conceito de alternatividades vem sendo proposto e utilizado por pesquisadores(as) críticos(as) à lógica dominante de modernização social, sobretudo no que tange ao meio rural. A fim de compreender a sua aplicação no campo do conhecimento socioambiental, partiu-se da aplicação do método de investigação conhecido como pesquisa bibliométrica, que possibilitou empreender análises quantitativas e qualitativas sobre a utilização do termo, bem como identificar lacunas e oportunidades de pesquisa. Como resultado, encontrou-se que o termo é predominantemente usado nas áreas das Ciências Ambientais e Sociais, partindo de amadurecimentos vinculados, sobretudo, a Boaventura de Sousa Santos. À nível qualitativo, observou-se que as alternatividades em ruralidades estão estreitamente vinculadas a uma opção epistemológica que tem buscado, por meio das experiências e narrativas de sujeitos ausentes e emergentes, compreender de que forma as ruralidades e os atores sociais rurais se constituem como socioambientais e produzem novas experiências; entendidas como emergências-resistências, quando o ponto de referência é a modernidade-colonial hegemônica.

Joonas Plaan

This article explores the roots and paths of changing discourses about the natural environment and marine resources in the seascape of Kihnu, Estonia. The ontology of the seascape is never static, being subjected to constant transformation, as local experiences and understandings collide with external influences, regulations and constraints. By focusing on the indeterminacies of agency, and human encounters and environmental events, I show how Soviet pasts and perceptions, shifting scientific paradigms and practices, the dynamics of local-global articulations, and unforeseen transformation in the marine environment have progressively contributed to new understandings of the seascape, seals and other marine resources. These changing perceptions fundamentally challenge previously-held notions that humans and nature belong together. A traditional seal hunt had endured in the Baltic Sea for centuries, but the decline of the seal population in the 1970s was widely understood as anthropogenic, related to overfishing, large scale seal hunts and pollution.  While most Baltic Sea coastal waters have remained closed to any type of seal hunting for more than 40 years, many fishers and marine scientists agree that grey seal population has recovered and some Baltic Sea countries have lifted the ban on hunting grey seal. While the seal hunt and meat used to have great cultural importance, there was also commercial value in seal skin and fat for many coastal communities. Several representatives of fishery-dependent coastal communities in Estonia now publicly express a view that seals now compete with fishers. Consequently the seal has lost its cultural importance and is considered as an intruder to Kihnu cultural space. I argue that making sense of the concerns and uncertainties that presently surround the question of knowing about and managing marine ecosystems, requires paying close attention to the ways in which access to the seascape and its resources have been enforced and altered over time. Key Words: Estonia; small-scale fisheries; seascape approach; ontology; local knowledge

Shevtsov Boris, Shevtsova Olga

Resonance propagation of radiation in the ionosphere, solar activity, magnetic dynamos, lightning discharges, fracture processes, plastic deformations, seismicity, turbulence and hydrochemical variability are considered as examples of complex dynamical systems in which similar fluctuation and nonlinear oscillation regimes arise. Collective effects in the systems behavior and chaotic oscillations in individual subsystems, the ratio of random and deterministic, the analysis of variability factors and the change of dynamic regimes, the scaling relation between the elements of the system and the interaction of scales are discussed. It is shown that consolidation and branching in disruptions or thunderstorm activity is the transfer of disturbances to up and down of cascades as in turbulence, and the alpha-omega effects of the magnetic dynamo are the same cascade processes, but in the presence of an external magnetic field or rotation that removes the degeneracy in the system by directions. Particular attention is paid to natural generators and oscillation amplifiers, in which the Lorentz triplet plays the role of a universal model of a nonlinear oscillator.

Everton Jose da Silva, Fermin Garcia Velasco, Celso Fornari Junior et al.

A superfície da fibra vegetal é constituída principalmente por compostos como celulose, hemicelulose, lignina, pectina e extrativos. Esses compostos orgânicos são sensíveis à ação de muitos agentes químicos e ao pH básico, o que dificulta seu emprego em compósitos cimentícios para torná-los mais sustentáveis. Objetivou-se com este trabalho avaliar a eficiência do poliestireno (0, 1, 3 , 5% e 3% mais tratamento térmico a 140 °C) na proteção da fibra de coco em meio alcalino. As fibras ficaram imersas em solução alcalina (pH 14) em um total de 63 dias e foram avaliadas periodicamente por meio de ensaio gravimétrico. Ao final do ensaio, as fibras foram analisadas através de microscopia eletrônica de varredura. De acordo com as análises, a amostra de fibra de coco sem revestimento protetor perdeu 80% da sua massa inicial e, através da microscopia eletrônica de varredura, foi possível verificar a destruição da estrutura superficial da fibra, expondo os feixes de microfibras celulósicas localizados na sua região interior. As fibras de coco com revestimento de 3% de poliestireno associado ao tratamento térmico terminaram o ensaio com uma porcentagem de massa final superior a 50% da sua massa inicial. Assim, a associação do revestimento de poliestireno (3%) com posterior tratamento térmico a 140 ºC melhorou a durabilidade das fibras de coco em aproximadamente 30% quando inseridas em meio alcalino.

A. Vahí Serrano, V. Rodríguez Díaz, C. Hurtado Rodríguez

Texto resumen.

Anima Biswal, M. V. R. Sesha Sai, S. V. C. Kameswar Rao

Crop Simulation models are mathematical representations of the soil plant-atmosphere system that calculate crop growth and yield, as well as the soil and plant water and nutrient balances, as a function of environmental conditions and crop management practices on daily time scale. Crop simulation models require meteorological data as inputs, but data availability and quality are often problematic particularly in spatialising the model for a regional studies. Among these weather variables, daily total solar radiation and air temperature (Tmax and Tmin) have the greatest influence on crop phenology and yield potential. The scarcity of good quality solar radiation data can be a major limitation to the use of crop models. Satellite-sensed weather data have been proposed as an alternative when weather station data are not available. These satellite and modeled based products are global and, in general, contiguous in time and also been shown to be accurate enough to provide reliable solar and meteorological resource data over large regions where surface measurements are sparse or nonexistent. In the present study, an attempt was made to evaluate the satellite and model derived daily solar radiation for simulating groundnut crop growth in the rainfed distrcits of Andhra Pradesh. From our preliminary investigation, we propose that satellite derived daily solar radiation data could be used along with ground observed temperature and rainfall data for regional crop simulation studies where the information on ground observed solar radiation is missing or not available.

MEJÍA RUIZ ROBERTO

En esta investigación, se estudió la condición ambiental y el funcionamiento de las lagunas de estabilización para el tratamiento de las aguas residuales del municipio de La Ceja, Antioquia. Este sistema ha presentado deficiencias en su operación, reflejadas en problemas organolépticos, hidráulicos y metabólicos. &#13; El sistema de lagunas del municipio de La Ceja está conformado por dos lagunas anaerobias y una laguna facultativa, que reciben las aguas residuales domésticas provenientes de un alcantarillado combinado. En los años 2003 y 2004, se realizaron mediciones de variables físicas, químicas y biológicas, incluyendo tres muestreos generales. &#13; El sistema funcionó deficientemente debido a problemas hidráulicos. La deficiencia del sistema estuvo acompañada de una baja remoción de nutrientes disueltos en la laguna facultativa asociada a un pobre desarrollo de la comunidad de microorganismos. El sistema presentó una remoción de carga orgánica del 75 %, relacionada principalmente con la sedimentación en las lagunas anaerobias.

José Martiniano de Azevedo Netto