Adrenal corticosterone secretion of newborn mice rapidly desensitizes to repeated maternal absence. The present study investigated the effects of novelty exposure, maternal care and genotype on... Show moreAdrenal corticosterone secretion of newborn mice rapidly desensitizes to repeated maternal absence. The present study investigated the effects of novelty exposure, maternal care and genotype on this phenomenon. Maternal separation (MS) took place on postnatal days (pnd) 3-5. In Wistar rats, the degree of novelty in the MS-environment was varied by exposing pups to: (i) "home separation": pups remained in the home cage: (ii) "novel separation": pups were placed individually in a novel cage. Maternal care was recorded on pnd 1 to 4. To investigate the effect of genotype, we also examined Long Evans in the "home separation" condition. Basal and stress-induced ACTH and corticosterone levels were measured. Adrenal tyrosine hydroxylase (TH) and melanocortin receptor-2 (MCR-2) proteins served as markers for adrenal function.We show, in both rat strains, that the rise in plasma corticosterone induced by a single 8 h-MS on pnd 5 was abolished, when this separation procedure had also been performed on pnd 3 and 4. Habituation to maternal absence occurred irrespective of housing conditions. However, pups in the "home separation" condition received less maternal care upon reunion than those placed in the "novel separation". These "home separation" pups appeared more responsive to a subsequent acute novelty-stressor, and their adrenal TH and MCR-2 were higher. Long Evans rats appeared more stress responsive than the Wistars, in the home separation condition.In conclusion, separation environment, maternal care and genotype do not affect adrenal desensitization to repeated 8 h-MS itself, but may modulate the adrenal stress-responsiveness of separated pups. (C) 2011 Elsevier Inc. All rights reserved. Show less
This thesis explores cognitive vulnerability to depression and the interplay between genetic and environmental influences. Cognitive vulnerability to depression is characterized by negative... Show moreThis thesis explores cognitive vulnerability to depression and the interplay between genetic and environmental influences. Cognitive vulnerability to depression is characterized by negative patterns of information processing. One aspect is cognitive reactivity - the tendency to respond with maladaptive thoughts when mood is challenged. Vulnerable individuals also show negative cognitive biases in emotion perception and attention, and impaired decision-making. How one processes personal and socially relevant information plays an important role in the development and maintenance of depression. The first part of the thesis reports how the interplay between genes and environment affects cognitive reactivity and emotional information processing. We observed that genes and environmental stressors interact to determine a person’s vulnerability to depression or resilience. Cognitive reactivity was also found to be a residual vulnerability factor in individuals with history of suicidal tendencies. The second part of the thesis is comprised of two experimental manipulations on emotional cognition. Effects of omega-3 fatty acid supplementation were examined on mood and cognition of healthy participants and recovered depressed individuals. Omega-3 fatty acids can have selective effects on mood and cognition of individuals, but the pathways through which this happens remain to be investigated. Show less
By the turn of century, increasing interest in archaeology in Jordan had resulted in more excavations and explorations of archaeological sites, and an increase in the number of monuments and... Show moreBy the turn of century, increasing interest in archaeology in Jordan had resulted in more excavations and explorations of archaeological sites, and an increase in the number of monuments and antiquities being revealed. In response, it was necessary and urgent to establish museums in which to display such remains, aesthetically and historically and to ensure their protection. This was achieved over a fairly short period of time, and museums have the role of displaying and safeguarding the collection in its custody. However, a preliminary check gave the impression that most museums in Jordan do not have the necessary human and material resources to perform this function satisfactorily. In recent years, museum science experienced a strong advancement, in particular when dealing with issues of indoor environment, and models of requirements have been designed. This thesis aims to describe, analyse and discuss the current situation of a number of selected museums in Jordan, with a focus on aspects of indoor environment. It intends to be an inclusive study that would provide recommendations and suggestions, hopefully enabling official senior level museum staff to address these needs, and work to improve them in order to portray a good image of Jordan and its historical legacy. It has been noticed that, at present, some artefacts are suffering deterioration and damage due to uncontrolled environmental conditions and mishandling by untrained staff; if this situation is not addressed promptly it may well lead to the destruction of these valuable and vulnerable objects. For this reason, a study of the processes of deterioration is required, prior to any recommendations concerning conservation treatments. In fact, excavated archaeological objects can be conserved and stabilized by a combination of instruments, whether these objects are on display or kept in storage. Therefore the indoor museum environment should be controlled and the staff properly trained to deal with objects adequately. These are basic necessities to ensure that museums and staff are able to fulfil the role of a modern museum, i.e. to be a sustainable social and educational resource. Show less
We study several aspects of the formation of galaxies, using numerical simulations. We investigate the influence of about thirty different sub-grid physics recipes for cooling, star formation,... Show moreWe study several aspects of the formation of galaxies, using numerical simulations. We investigate the influence of about thirty different sub-grid physics recipes for cooling, star formation, supernova feedback, AGN feedback etc. on the resulting galaxy populations with large SPH simulations. We investigate several parameters that quantify the environment of galaxies and present the strongest measure of halo mass and a new parameter that is insensitive to halo mass. We look at the effects of input physics and dust attenuation on the simulated luminosity functions and compare luminosity functions directly obtained from simulations, with those using observers' tools on mock images. Regardless of most parameters used for the mock image creation and the detection of sources, these two LFs agree well. The last chapter compares several ways of sampling stellar IMFs in clusters that follow a cluster mass function in order to see how the choice of CMF and sampling method influence the resulting integrated galactic initial mass function. The effects are only significant if the CMF extends as a steep power-law down to a few solar masses. We study the effects of these IGIMFs on the galaxies' integrated photometry and metal and O-star content. Show less
Sustainable economic development is essential for hundreds of millions of poor households in rural areas. This book represents a merger of environmental science and rural development economics. It... Show moreSustainable economic development is essential for hundreds of millions of poor households in rural areas. This book represents a merger of environmental science and rural development economics. It elucidates the linkage between rational choice theory and theories on land use change. It builds a quantitative framework to connect the environmental method of Material Flow Analysis to basic issues of rural development such as agricultural intensification and food security. And finally, it develops a unique measuring rod of wealth and poverty called Freely Disposable Time, which integrates time and cash flows of households. With this indicator, we can quantify the much-cherished concepts of freedoms and development capacity. Along the way, the book provides critical discussions on ‘standard’ Material Flow Analysis, systems versus actor-based approaches, and the oversupply of inductive studies in land use and development science. Empirical data are drawn from the Philippines, Vietnam, India, Laos and the Netherlands, in a comparative perspective. Show less
The making of commitments is often used as an intervention aimed at increasing pro-environmental behavior. Research shows that when people commit to changing their environmental behaviors, they... Show moreThe making of commitments is often used as an intervention aimed at increasing pro-environmental behavior. Research shows that when people commit to changing their environmental behaviors, they tend to adhere to their commitments. In this dissertation it is investigated whether commitment making is effective in improving agricultural nature conservation and with that, environmental quality of farm lands. Furthermore, a conceptual review is offered, as well as an experimental investigation of the conditions under which people are willing to make such commitments. Results show that commitment making combined with tailored information is indeed effective in improving farmers’ nature conservation. Several explanations of the effect of commitment making on behavior are offered. Also, it is shown that that the willingness to invest in commitment making is contingent on the interplay of dispositional trust and situational expectations. Taken together, this dissertation aims to provide the reader with a perspective on the entire process of commitment making: under which conditions people engage in it, if it is successful in altering behavior, and how it is successful. Show less
The central issue in this thesis is the work related causes and consequences of job stress among nurses. The relationships between a wide range of work characteristics and characteristics of the... Show moreThe central issue in this thesis is the work related causes and consequences of job stress among nurses. The relationships between a wide range of work characteristics and characteristics of the organization and environment on the one hand, and different outcomes (such as job satisfaction and emotional exhaustion) on the other hand are explored in three studies. The influence of goal orientation on the outcomes is studied in a fourth study. Data were gathered by means of questionnaires that were spread among all nurses of the Leiden University Medical Centre in 2000 and in 2003. Nurses’ job satisfaction is influenced by their possibilities to develop nursing skills and by having good working relationships with supervisors. Nurses’ ill health is largely determined by their workload. However, it seems not (necessarily) to be the emotional demand of patient contact that burdens nurses. More likely, ill-health is the effect of the fact that nurses cannot give each patient the attention they want to give, due to too many tasks. The thesis deals with methodological issues such as causality. Moreover, it deals with theoretical issues such as the influence of person and environmental factors on the stress reaction. Finally, practical considerations are outlined. Show less
An alarming decline of vulture populations (up to 95%) in Pakistan in the late 1990__s has recently been attributed to the use of the anti-inflammatory drug diclofenac in cattle. Several species... Show moreAn alarming decline of vulture populations (up to 95%) in Pakistan in the late 1990__s has recently been attributed to the use of the anti-inflammatory drug diclofenac in cattle. Several species are now threatened with extinction, a tragedy that demonstrates that an environmental risk assessment of veterinary medicines is legitimate. The fate and behaviour of pharmaceuticals in the environment has been studied incidentally since the second half of the 20th century. The possible effect of residues on the quality of the environment was a concern that had been recognised since shortly after medicines were actually found in the environment towards the end of the 1960s. About a decade or two later, these concerns about pollution and effects had reached the regulatory agenda and were addressed in the European legislation on veterinary medicines. Notably from 1994 onwards, when the EU Committee for Veterinary Medicinal Products (CVMP) initiated the drafting of a guidance document for the risk assessment of veterinary medicines, an increasing number of publications on use, emission, fate, occurrence, effect, and risk of pharmaceuticals has been published. In this thesis, the representation of the environment in the risk model and the consequences of the choices regarding variables and relationships in the natural system were addressed in light of existing legislation and policy on environmental quality. Where possible, empirical validation of individual exposure models was performed, demonstrating the accuracy of the model for a specified use. I have outlined and discussed several technical and conceptual flaws in the use of risk assessment in the registration process. The formalisation of the protection goals by the Note for Guidance has no legal status, the guidance does not contain all European environmental quality criteria and includes a soil exposure trigger for the full risk assessment that was not well founded. Particularly the variability in possible outcomes for the soil exposure trigger is troublesome, since it gives the impression that science may produce information that will not lead to better judgement. Screening level exposure models are not always protective and lack standardised scenarios for uniform assessment. Risk mitigation measures are not validated, and give a false impression that the risk to the environment is reduced to acceptable levels. Products that pose a threat to environmental quality at or after use may now be registered and be used. Authorities responsible for water and land quality cannot infer from the registration of a veterinary medicine that the use complies with the quality standards set by environmental legislation. This legislation now obliges these authorities to regulate and enforce product use and slurry use on a case by case basis through permits. All of the shortcomings identified undermine, to a greater or to a lesser extent, the legitimacy of the registration process and the use of scientific opinions. Policy makers, regulators, and scientists should engage in a reconnaissance of regulatory goals, assessment scales, model approaches, and uncertainty and variability of data associated with the assessment. Only then, a risk model (with or without triggers) can be applicable to the situation of interest and provide a solid framework for making risk-benefit decisions to the satisfaction of producers, decision-makers and consumers. Show less
