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Modern Environments (modern + environment)
Selected AbstractsAge and Origin of Upland block Fields on Melville Peninsula, Eastern Canadian ArcticGEOGRAFISKA ANNALER SERIES A: PHYSICAL GEOGRAPHY, Issue 4 2000Lynda A. Dredge Block fields have developed on gently graded uplands of granite and gneiss on central and southern Melville Peninsula. The location of block fields is not controlled by elevation, but rather by areas covered by cold,based ice during the last glaciation. Block fields consist either of angular boulders, sorted circles 3,4 m across having blocky rims and central areas of weathered grus, concentrations of openwork boulders, or in the southeast, of immature bouldery till. The block fields are primarily relict features predating the last glaciation, produced by weakening of bedrock by weathering along joints, followed by frost heave, although some block fields have been modified by meltwater from regional glacier down,wasting. Frost processes are active in the modern environment but the extent of riven bedrock and the size of recent patterned ground forms on postglacial surfaces are insufficient to account for the forms in the block fields. [source] Dental hygienists' work environment: motivating, facilitating, but also tryingINTERNATIONAL JOURNAL OF DENTAL HYGIENE, Issue 3 2010A Candell To cite this article: Int J Dent Hygiene,8, 2010; 204,212 DOI: 10.1111/j.1601-5037.2009.00420.x Candell A, Engström M. Dental hygienists' work environment: motivating, facilitating, but also trying Abstract:, The aim of the present study was to describe dental hygienists' experiences of their physical and psychosocial work environment. The study was descriptive in design and used a qualitative approach. Eleven dental hygienists participated in the study and data were collected during spring 2008 using semi-structured interviews. The material was analysed using qualitative content analysis. The results showed that the dental hygienists experienced their work environment as motivating and facilitating, but at the same time as trying. The three categories revealed a theme: Being controlled in a modern environment characterized by good relationships. Motivating factors were the good relationship with co-workers, managers and patients, seeing the results of your work, having your own responsibility and making your own decisions. The new, pleasant and modern clinics, good cooperation between co-workers and varying duties were described as facilitating factors. The trying factors, as described by the dental hygienists, were above all being controlled by time limits or by some elements of the work, such as teamwork. The dental hygienists also felt stress because appointments were too-short. To conclude, the participants described their work environment as trying in several ways, despite the modern clinics and good relationships. [source] Individual differences in the drive to overeatNUTRITION BULLETIN, Issue 2007M. M. Hetherington Summary, Obesity is considered a public health crisis. In order to tackle this, an enhanced appreciation of what drives some consumers to overeat is required. It is clear that several features of the modern environment encourage over-consumption in many people, at least some of the time. However, there is variation in the extent to which this translates into weight gain. Understanding whether susceptibility is dispositional or learned will shape prevention and treatment programmes. This review identifies situational cues that promote overeating and dispositional traits, such as impulsivity and sensitivity to reward, which make some individuals specifically vulnerable to overeating. These traits are likely to contribute to the development of the obese state, but also present barriers to weight management. Personalised nutrition and behavioural strategies may provide a novel and innovative approach, as these take account of individual differences in vulnerability to overeating. [source] The evolution of human fatness and susceptibility to obesity: an ethological approachBIOLOGICAL REVIEWS, Issue 2 2006Jonathan 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] Using Rock-Eval 6 pyrolysis for tracking fossil organic carbon in modern environments: implications for the roles of erosion and weatheringEARTH SURFACE PROCESSES AND LANDFORMS, Issue 2 2006Yoann Copard Abstract This work relates to the debate on the fossil organic carbon (FOC) input in modern environments and its possible implication for the carbon cycle, and suggests the use of Rock-Eval 6 pyrolysis as a relevant tool for tracking FOC in such environments. Considering that such a delivery is mainly due to supergene processes affecting the continental surface, we studied organic matter in different reservoirs such as bedrocks, alterites, soils and rivers in two experimental catchments at Draix (Alpes de Haute Provence, France). Samples were subjected to geochemical (Rock-Eval 6 pyrolysis) investigations and artificial bacterial degradations. After comparing the geochemical fingerprint of samples, geochemical markers of FOC were defined and tracked in the different reservoirs. Our results confirm the contribution of FOC in modern soils and rivers and display the various influences of weathering and erosional processes on the fate of FOC during its exchange between these pools. In addition, the contrasting behaviour of these markers upon the supergene processes has also highlighted the refractory or labile characters of the fossil organic matter (FOM). Bedrock to river fluxes, controlled by gully erosion, are characterized by a qualitative and quantitative preservation of FOM. Bedrock to alterite fluxes, governed by chemical weathering, are characterized by FOC mineralization without qualitative changes in deeper alterites. Alterite to soils fluxes, controlled by (bio)chemical weathering, are characterized by strong FOC mineralization and qualitative changes of FOM. Thus weathering and erosional processes induce different FOM evolution and affect the fate of FOC towards the global carbon cycle. In this study, gully erosion would involve maintenance of an ancient sink for the global carbon cycle, while (bio)chemical processes provide a source of CO2. Finally, this study suggests that Rock-Eval 6 pyrolysis can be considered as a relevant tool for tracking FOC in modern environments. Copyright © 2006 John Wiley & Sons, Ltd. [source] Haloarchaeal diversity in 23, 121 and 419 MYA saltsGEOBIOLOGY, Issue 5 2009J. S. PARK DNA was extracted from surface-sterilized salt of different geological ages (23, 121, 419 million years of age, MYA) to investigate haloarchaeal diversity. Only Haloarcula and Halorubrum DNA was found in 23 MYA salt. Older crystals contained unclassified groups and Halobacterium. The older crystals yielded a unique 55-bp insert within the 16S rRNA V2 region. The secondary structure of the V2 region completely differed from that in haloarchaea of modern environments. The DNA demonstrates that unknown haloarchaea and the Halobacterium were key components in ancient hypersaline environments. Halorubrum and Haloarcula appear to be a dominant group in relatively modern hypersaline habitats. [source] Targeted genomic detection of biosynthetic pathways: anaerobic production of hopanoid biomarkers by a common sedimentary microbeGEOBIOLOGY, Issue 1 2005W. W. FISCHER ABSTRACT The lipid biomarker principle requires that preservable molecules (molecular fossils) carry specific taxonomic, metabolic, or environmental information. Historically, an empirical approach was used to link specific taxa with the compounds they produce. The lipids extracted from numerous, but randomly cultured species provided the basis for the interpretation of biomarkers in both modern environments and in the geological record. Now, with the rapid sequencing of hundreds of microbial genomes, a more focused genomic approach can be taken to test phylogenetic patterns and hypotheses about the origins of biomarkers. Candidate organisms can be selected for study on the basis of genes that encode proteins fundamental to the synthesis of biomarker compounds. Hopanoids, a class of pentacyclic triterpenoid lipid biomarkers, provide an illustrative example. For many years, interpretations of biomarker data were made with the assumption that hopanoids are produced only by aerobic organisms. However, the recent discovery of 13C-depleted hopanoids in environments undergoing anaerobic methane oxidation and in enrichment cultures of anammox planctomycetes indicates that some hopanoids are produced anaerobically. To further examine the potential distribution of hopanoid biosynthesis by anaerobes, we searched publicly available genomic databases for the presence of squalene-hopene cyclase genes in known obligate or facultative anaerobes. Here we present evidence that Geobacter sulfurreducens, Geobacter metallireducens, and Magnetospirillum magnetotacticum, all bacteria common in anoxic environments, have the appropriate genes for hopanoid biosynthesis. We further show that these data accurately predict that G. sulfurreducens does produce a variety of complex hopanoids under strictly anaerobic conditions in pure culture. [source] An effective strategy for legacy systems evolutionJOURNAL OF SOFTWARE MAINTENANCE AND EVOLUTION: RESEARCH AND PRACTICE, Issue 5 2003Maseud Rahgozar Abstract A large number of organizations depend on the business-critical information systems for their daily activities that have been developed over the last two decades or more. These systems are called Legacy Information Systems (LISs). They mostly run on old software and hardware technology tools and environments. They are hard to modify, expensive to maintain and difficult to integrate with new technology tools and programs. They need to be evolved into modern environments. The LIS modernization is a long outstanding problem of the IT community. This paper presents a classification of current approaches to this problem and suggests guidelines and a methodology for an optimal solution based on many years of professional experiences of the authors in this area. Parts of this methodology have been implemented and tested in many migration projects and they have proven to be effective. This approach optimizes the time, the human resources and the global costs and reduces the risk factors and side effects of renovation projects by developing migration tools once per platform. Copyright © 2003 John Wiley & Sons, Ltd. [source] The physical scale modelling of braided alluvial architecture and estimation of subsurface permeabilityBASIN RESEARCH, Issue 3 2002D. J. Moreton ABSTRACT The quantitative modelling of fluvial reservoirs, especially in the stages of enhanced oil recovery, requires detailed three-dimensional data at both the scale of the channel belt and within-channel. Although studies from core, analogue outcrop and modern environments may partially meet these needs, they often cannot provide detail on the smaller-scale (i.e. channel-scale) heterogeneity, frequently suffer from limited three-dimensional exposure and cannot be used to examine the influence of different variables on the process,deposit relationship. Physical modelling offers a complementary technique that can address many of these quantitative requirements and holds great future potential for integration with reservoir modelling. Physical modelling provides the potential to upscale results and derive reservoir information on three-dimensional facies geometry, connectivity and permeability. This paper describes the development and use of physical modelling, which employs generic Froude-scaling principles, in an experimental basin that permits aggradation in order to model the morphology and subsurface depositional stratigraphy of coarse-grained braided rivers. An example is presented of a 1:50 scale model based on the braided Ashburton River, Canterbury Plains, New Zealand and the adjacent late Quaternary braided alluvium exposed in the coastal cliffs. Critically, a full, bimodal grain size distribution (20% sand and 80% gravel) was used to replicate the prototype, which allows the realistic reproduction of the surface morphology and importantly permits grain size sorting during deposition. Uncertainties associated with the compression of time, sediment mass balance and the hydrodynamics of the finest particle sizes do not appear to affect the reproducibility of stratigraphy between experimental and natural environments. Sectioning of the preserved sedimentary sequence in the physical model allows quantification of the geometry, shape, spatial distribution and internal sedimentary structure of the coarse- and fine-grained facies. A six-fold facies scheme is proposed for the model braided alluvium and a direct link is established between the grain size distribution and facies type: this allows permeability to be estimated for each facies, which can be mapped onto two-dimensional vertical cross-sections of the preserved stratigraphy. Results demonstrate the dominance of four facies based on permeability that range over three orders of magnitude in hydraulic conductivity. Quantification of such variability, and linkage to both vertical proportion curves for facies distribution and connectivity presents significant advantages over other methodologies and offers great potential for the modelling of heterogeneous braided river sediments at the within channel-belt scale. This paper outlines how physical models may be used to develop high-resolution, geologically-accurate, object-based reservoir simulation models. [source] Child Development and Evolutionary PsychologyCHILD DEVELOPMENT, Issue 6 2000David F. Bjorklund Evolutionary developmental psychology involves the expression of evolved, epigenetic programs, as described by the developmental systems approach, over the course of ontogeny. There have been different selection pressures on organisms at different times in ontogeny, and some characteristics of infants and children were selected in evolution to serve an adaptive function at that time in their life history rather than to prepare individuals for later adulthood. Examples of such adaptive functions of immaturity are provided from infancy, play, and cognitive development. Most evolved psychological mechanisms are proposed to be domain specific in nature and have been identified for various aspects of children's cognitive and social development, most notably for the acquisition of language and for theory of mind. Differences in the quality and quantity of parental investment affect children's development and influence their subsequent reproductive and childcare strategies. Some sex differences observed in childhood, particularly as expressed during play, are seen as antecedents and preparations for adult sex differences. Because evolved mechanisms were adaptive to ancestral environments, they are not always adaptive for contemporary people, and this mismatch of evolved mechanisms with modern environments is seen in children's maladjustment to some aspects of formal schooling. We argue that an evolutionary perspective can be valuable for developing a better understanding of human ontogeny in contemporary society and that a developmental perspective is important for a better understanding of evolutionary psychology. [source] | |||||||||||||