Environmental Pressure (environmental + pressure)

Distribution by Scientific Domains


Selected Abstracts


Effect of xylanase on ozone bleaching kinetics and properties of Eucalyptus kraft pulp

JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 10 2003
M Blanca Roncero
Abstract Environmental pressure has led the pulp and paper industry to develop new technologies in order to reduce or suppress the presence of various pollutants in effluents from bleaching plants. One of the choices for this purpose is enzyme-based biotechnology. This study deals with the effect of using a xylanase-based enzymatic pretreatment, in a TCF (Totally Chlorine Free) sequence, on the properties of the resulting paper pulps. The hexenuronic acid content in the pulp and the physical properties of the paper were also studied. The performance of the xylanase was analysed through kinetic studies on ozone bleaching. The enzymatic pretreatment results in easier bleaching and delignification of the pulp, causing a bleach-boosting effect. The decreased consumption of reagent is related to a decreased content of hexenuronic groups. The physical properties of the treated pulp are similar to those of untreated pulps. Cellulose degradation, delignification and chromophores' removal show first-order kinetics. Enzyme pretreatment leads to differences between the kinetic constants of cellulose degradation and chromophores' removal, due to an increased accessibility to bleaching agents. The xylanase treatment leads to a lower floor kappa number (IK,) during the ozone stage. Copyright © 2003 Society of Chemical Industry [source]


Childhood growth and age at diagnosis with Type 1 diabetes in Colorado young people

DIABETIC MEDICINE, Issue 10 2009
K. Vehik
Abstract Objective, Studies have suggested that the age at diagnosis of Type 1 diabetes (T1D) is decreasing over time. The overload hypothesis postulates that risk factors, such as accelerated growth, may be responsible for this decrease. We assessed changes in age, body mass index (BMI), weight and height at diagnosis with T1D in non-Hispanic white (NHW) and Hispanic (HISP) young people from Colorado, using data from the IDDM Registry and SEARCH Study. Methods, In three time periods, 656 (1978,1983), 562 (1984,1988) and 712 (2002,2004) young people aged 2,17 years were newly diagnosed with T1D. Age, weight, height and presence of diabetic ketoacidosis (DKA) at diagnosis with T1D were obtained from medical records. Trends over the three time periods were assessed with regression analyses. Results, Age at diagnosis decreased by 9.6 months over time (P = 0.0002). Mean BMI standard deviation score (SDS), weight SDS and height SDS increased over time (P < 0.0001), while prevalence of DKA decreased (P < 0.0001). Increasing height over time accounted for 15% (P = 0.04) of the decreasing age at diagnosis with T1D. Conclusions, Our study provides evidence that increased linear growth, but not increased BMI or weight over time, may account, at least in part, for the younger age at diagnosis of T1D in Colorado children. This finding supports the hypothesis that increasing environmental pressure resulting from changes in potentially preventable risk factors may accelerate the onset of T1D in children. [source]


Theoretical and conceptual issues in time,place discrimination

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 9 2009
Jonathon D. Crystal
Abstract The need to discover resources that are available under specific environmental constraints represents a fundamental environmental pressure on the evolution of behavior. Time,place discrimination refers to the ability to secure resources when they are available under specific temporal and spatial contingencies. This article reviews a number of examples of time,place discrimination. The review highlights theoretical and conceptual issues that are needed to behaviorally identify the mechanisms responsible for time,place performance. Next, limitations on time,place performance that may be imposed by a circadian system are described. Finally, a number of lines of research that broaden these limitations are discussed. These lines of research include studies that suggest that (i) a broad range of long intervals (outside the limited range of circadian entrainment) are timed, (ii) at least some long intervals (16,21 h) are timed with an endogenous self-sustaining oscillator, (iii) short intervals (in the range of 1,3 min) are timed with an endogenous self-sustaining oscillator, and (iv) memory for specific unique events (including when and where they occurred) is based on a circadian representation of time. It is concluded that a unified theory of timing that can retain the times of occurrence of individual events is needed. The time of occurrence of an event may be encoded not only with respect to a circadian oscillator but also with respect to other oscillators in the long-interval and short-interval ranges. [source]


The Life and Death of Public Organizations: A Question of Institutional Design?

GOVERNANCE, Issue 3 2010
ARJEN BOIN
Why do some public organizations grow old and others die young? Since Herbert Kaufman first posed this question, considerable research has been devoted to answering it. The findings of that research suggest that the design of new public organizations affects, to a significant degree, their survival chances. In this article, we test whether and how "design factors" affected the durability of the so-called New Deal organizations initiated under FDR's first term. Our findings confirm that design factors do matter, but their effects change over time. We draw out some potential implications for institutional design and sketch a renewed research agenda to determine why some public organizations survive environmental pressure whereas others succumb to it. [source]


Material Flow Indicators in the Czech Republic in Light of the Accession to the European Union

JOURNAL OF INDUSTRIAL ECOLOGY, Issue 4 2010
Jan Kovanda
Summary This article deals with the economy-wide material flows in the Czech Republic in 1990,2006. It presents in brief the overall trends of the material flow indicators in 1990,2002. The major part of the article is focused on the years 2002,2006, which immediately preceded and followed the accession of the Czech Republic to the European Union in 2004. It is shown that this accession had quite a significant impact on the volume and character of the material flows of the Czech Republic. The accession was beneficial from an economic point of view, as it allowed for an increased supply of materials needed for economic growth. Furthermore, it was accompanied by an improvement in the efficiency of material transformation into economic output. From an environmental and broader sustainability point of view, however, this accession brought about some controversial outcomes. There was a significant increase in the net export of environmental pressure, on one hand, and an increase in net additions to the physical stock of the economy, on the other. Although the former is controversial from the viewpoint of equity in sharing area and resources, the latter places an additional burden on future generations because all physical stocks will turn into waste and emissions at some point, when their life span expires. [source]


A study of determinant factors of stakeholder environmental pressure perceived by industrial companies

BUSINESS STRATEGY AND THE ENVIRONMENT, Issue 3 2010
Javier González-Benito
Abstract Although several articles have studied the effect that stakeholder pressure has on the environmental behavior of firms, little research has attempted to identify the contingencies that explain such pressure. This article investigates the effects of six relevant variables on stakeholder environmental pressure perceived by industrial companies: size, internationalization, location of manufacturing activities, position in the supply chain, industrial sector, and managerial values and attitudes. The effect is theoretically determined by distinguishing between pressure intensity and perception capacity and empirically tested with a sample of 186 Spanish manufacturers. The analyses reveal two dimensions of stakeholder pressure, governmental and nongovernmental, and show that variables such as environmental awareness among managers, internationalization, industrial sector and company size play important roles in determining both dimensions. Copyright © 2008 John Wiley & Sons, Ltd and ERP Environment. [source]


Pan-European regional-scale modelling of water and N efficiencies of rapeseed cultivation for biodiesel production

GLOBAL CHANGE BIOLOGY, Issue 1 2009
MARIJN VAN DER VELDE
Abstract The energy produced from the investment in biofuel crops needs to account for the environmental impacts on soil, water, climate change and ecosystem services. A regionalized approach is needed to evaluate the environmental costs of large-scale biofuel production. We present a regional pan-European simulation of rapeseed (Brassica napus) cultivation. Rapeseed is the European Union's dominant biofuel crop with a share of about 80% of the feedstock. To improve the assessment of the environmental impact of this biodiesel production, we performed a pan-European simulation of rapeseed cultivation at a 10 × 10 km scale with Environmental Policy Integrated Climate (EPIC). The model runs with a daily time step and model input consists of spatialized meteorological measurements, and topographic, soil, land use, and farm management practices data and information. Default EPIC model parameters were calibrated based on literature. Modelled rapeseed yields were satisfactory compared with yields at regional level reported for 151 regions obtained for the period from 1995 to 2003 for 27 European Union member countries, along with consistent modelled and reported yield responses to precipitation, radiation and vapour pressure deficit at regional level. The model is currently set up so that plant nutrient stress is not occurring. Total fertilizer consumption at country level was compared with IFA/FAO data. This approach allows us to evaluate environmental pressures and efficiencies arising from and associated with rapeseed cultivation to further complete the environmental balance of biofuel production and consumption. [source]


Dental hygiene regulation: a global perspective

INTERNATIONAL JOURNAL OF DENTAL HYGIENE, Issue 3 2008
PM Johnson
Abstract:, Occupational regulation of health personnel is important to professional associations and their members, the public that relies on their services and the regulatory agencies responsible for their conduct. There is increasing interest in ensuring that dental hygiene regulation fosters the continuing evolution of the profession and its contribution to oral health. The keynote address for the 2007 Regulatory Forum on Dental Hygiene, this paper discusses the rationale for and issues pertaining to occupational regulation, outlines the evolvement of dental hygiene and identifies regulatory options for the profession. Professional regulation exists to ensure public safety, health and welfare. However, negative political-economic side effects coupled with environmental pressures have resulted in increased scrutiny for health professionals. One such profession is dental hygiene. Its evolution has been dramatic, in particular over the past few decades, as illustrated by its rapidly increasing numbers and broader distribution globally, gradual shift to the baccalaureate as the entry-level educational requirement and increase in postgraduate programs and expanding scope of practice and increased professional autonomy. Regulatory changes have been more gradual. Regulation is mandatory for the vast majority of dental hygienists. Of the options available, the practice act , the most rigorous type, is predominant. Globally, regulation tends to be administered directly by the government (n = 9 countries) more so than indirectly through a dental board (n = 4) or self-regulation (n = 3). Whether regulated directly or indirectly, dental hygienists increasingly are seeking a greater role in shaping their professional future. Self-regulation, its responsibilities, misperceptions and challenges, is examined as an option. [source]


Designing Police: Interpol and the Study of Change in International Organizations

INTERNATIONAL STUDIES QUARTERLY, Issue 4 2005
Michael Barnett
On those rare occasions when scholars of international organizations (IOs) consider the issue of change, they typically highlight the centrality of states. Although states are important for understanding when and why there is a change in the tasks, mandate, and design of IO, IOs themselves can initiate change. Drawing from sociological institutional and resource dependence approaches, in this article we treat IOs as strategic actors that can choose among a set of strategies in order to pursue their goals in response to changing environmental pressures and constraints that potentially threaten their relevance and resource base. We delineate six strategies,acquiescence, compromise, avoidance, defiance, manipulation, and strategic social construction, and suggest that the strategic choice by IOs is contingent on the level of both organizational insecurity and the congruence between the content of environmental pressures and organizational culture. We emphasize how IOs must make a trade-off between acquiring the resources necessary to survive and be secure, on the one hand, and maintaining autonomy, on the other. We apply this framework to the case of Interpol, investigating how different calculations of these trade-offs led Interpol staff to adopt different strategies depending on its willingness to accept, resist, or initiate changes that demand conformity to external pressures. [source]


Beyond control: wider implications for the management of biological invasions

JOURNAL OF APPLIED ECOLOGY, Issue 5 2006
PHILIP E. HULME
Summary 1Government departments, environmental managers and conservationists are all facing escalating pressure to address and resolve a diversity of invasive alien species (IAS) problems. Yet much research to date is primarily concerned with quantifying the scale of the problem rather than delivering robust solutions and has not adequately addressed all stages of the invasion process, and only a few studies embrace the ecosystem approach. 2Three successive steps, prevention, eradication and control, form the cornerstones of recommended best practices aimed at managing IAS. The goal of such actions is the restoration of ecosystems to preserve or re-establish native biodiversity and functions. 3Prevention is widely promoted as being a more environmentally desirable strategy than actions undertaken after IAS establishment, yet is hindered by the difficulty in separating invasive from non-invasive alien species. Furthermore, the high number of candidate IAS, the investment required in taxonomic support and inspection capacity, and the expense of individual risk assessments may act against the net benefits of prevention. More rewarding avenues may be found by pursuing neural networks to predict the potential composition of pest assemblages in different regions and/or model introduction pathways to identify likely invasion hubs. 4Rapid response should be consequent on early detection but, when IAS are rare, detection rates are compromised by low occurrence and limited power to discern significant changes in abundance. Power could be increased by developing composite indicators that track trends in a suite of IAS with similar life histories, shared pathways and/or habitat preferences. 5The assessment of management options will benefit from an ecosystem perspective that considers the manipulation of native competitors, consumers and mutualists, and reviews existing management practices as well as mitigates other environmental pressures. The ease with which an IAS can be targeted should not only address the direct management effects on population dynamics but also indirect effects on community diversity and structure. Where the goal is to safeguard native biodiversity, such activities should take into account the need to re-establish native species and/or restore ecosystem function in the previously affected area. 6Synthesis and applications. A comprehensive approach to IAS management should include consideration of the: (i) expected impacts; (ii) technical options available; (iii) ease with which the species can be targeted; (iv) risks associated with management; (v) likelihood of success; and (vi) extent of public concern and stakeholder interest. For each of these issues, in addition to targeting an individual species, the management of biological invasions must also incorporate an appreciation of other environmental pressures, the importance of landscape structure, and the role of existing management activities and restoration efforts. [source]


ALSPAC,The Avon Longitudinal Study of Parents and Children

PAEDIATRIC & PERINATAL EPIDEMIOLOGY, Issue 1 2001
Golding
ALSPAC (The Avon Longitudinal Study of Parents and Children, formerly the Avon Longitudinal Study of Pregnancy and Childhood) was specifically designed to determine ways in which the individual's genotype combines with environmental pressures to influence health and development. To date, there are comprehensive data on approximately 10 000 children and their parents, from early pregnancy until the children are aged between 8 and 9. The study aims to continue to collect detailed data on the children as they go through puberty noting, in particular, changes in anthropometry, attitudes and behaviour, fitness and other cardiovascular risk factors, bone mineralisation, allergic symptoms and mental health. The study started early during pregnancy and collected very detailed data from the mother and her partner before the child was born. This not only provided accurate data on concurrent features, especially medication, symptoms, diet and lifestyle, attitudes and behaviour, social and environmental features, but was unbiased by parental knowledge of any problems that the child might develop. From the time of the child's birth many different aspects of the child's environment have been monitored and a wide range of phenotypic data collected. By virtue of being based in one geographic area, linkage to medical and educational records is relatively simple, and hands-on assessments of children and parents using local facilities has the advantage of high quality control. The comprehensiveness of the ALSPAC approach with a total population sample unselected by disease status, and the availability of parental genotypes, provides an adequate sample for statistical analysis and for avoiding spurious results. The study has an open policy in regard to collaboration within strict confidentiality rules. [source]


The evolution of human fatness and susceptibility to obesity: an ethological approach

BIOLOGICAL REVIEWS, Issue 2 2006
Jonathan C. K. Wells
ABSTRACT Human susceptibility to obesity is an unusual phenomenon amongst animals. An evolutionary analysis, identifying factors favouring the capacity for fat deposition, may aid in the development of preventive public health strategies. This article considers the proximate causes, ontogeny, fitness value and evolutionary history of human fat deposition. Proximate causes include diet composition, physical activity level, feeding behaviour, endocrine and genetic factors, psychological traits, and exposure to broader environmental factors. Fat deposition peaks during late gestation and early infancy, and again during adolescence in females. As in other species, human fat stores not only buffer malnutrition, but also regulate reproduction and immune function, and are subject to sexual selection. Nevertheless, our characteristic ontogenetic pattern of fat deposition, along with relatively high fatness in adulthood, contrasts with the phenotype of other mammals occupying the tropical savannah environment in which hominids evolved. The increased value of energy stores in our species can be attributed to factors increasing either uncertainty in energy availability, or vulnerability to that uncertainty. Early hominid evolution was characterised by adaptation to a more seasonal environment, when selection would have favoured general thriftiness. The evolution of the large expensive brain in the genus Homo then favoured increased energy stores in the reproducing female, and in the offspring in early life. More recently, the introduction of agriculture has had three significant effects: exposure to regular famine; adaptation to a variety of local niches favouring population-specific adaptations; and the development of social hierarchies which predispose to differential exposure to environmental pressures. Thus, humans have persistently encountered greater energy stress than that experienced by their closest living relatives during recent evolution. The capacity to accumulate fat has therefore been a major adaptive feature of our species, but is now increasingly maladaptive in the modern environment where fluctuations in energy supply have been minimised, and productivity is dependent on mechanisation rather than physical effort. Alterations to the obesogenic environment are predicted to play a key role in reducing the prevalence of obesity. [source]