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Related Processes (relate + process)
Selected AbstractsWater-Yield Reduction After Afforestation and Related Processes in the Semiarid Liupan Mountains, Northwest China,JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 5 2008Yanhui Wang Abstract:, The increase of coverage of forest/vegetation is imperative to improve the environment in dry-land areas of China, especially for protecting soil against serious erosion and sandstorms. However, inherent severe water shortages, drought stresses, and increasing water use competition greatly restrict the reforestation. Notably, the water-yield reduction after afforestation generates intense debate about the correct approach to afforestation and forest management in dry-land areas. However, most studies on water-yield reduction of forests have been at catchment scales, and there are few studies of the response of total evapotranspiration (ET) and its partitioning to vegetation structure change. This motivates us to learn the linkage between hydrological processes and vegetation structure in slope ecosystems. Therefore, an ecohydrological study was carried out by measuring the individual items of water balance on sloping plots covered by different vegetation types in the semiarid Liupan Mountains of northwest China. The ratio of precipitation consumed as ET was about 60% for grassland, 93% for shrubs, and >95% for forestland. Thus, the water yield was very low, site-specific, and sensitive to vegetation change. Conversion of grassland to forest decreased the annual water yield from slope by 50-100 mm. In certain periods, the plantations at lower slopes even consumed the runon from upper slopes. Reducing the density of forests and shrubs by thinning was not an efficient approach to minimize water use. Leaf area index was a better indicator than plant density to relate ET to vegetation structure and to evaluate the soil water carrying capacity for vegetation (i.e., the maximum amount of vegetation that can be supported by the available soil water for an extended time). Selecting proper vegetation types and plant species, based on site soil water condition, may be more effective than the forest density regulation to minimize water-yield reduction by vegetation coverage increase and notably by reforestation. Finally, the focuses in future research to improve the forest-water relations in dry-land areas are recommended as follows: vegetation growth dynamics driven by environment especially water conditions, coupling of ecological and hydrological processes, further development of distributed ecohydrological models, quantitative relation of eco-water quota of ecosystems with vegetation structures, multi-scaled evaluation of soil water carrying capacity for vegetation, and the development of widely applicable decision support tools. [source] Blob Transport in the Tokamak Scrape-off-LayerCONTRIBUTIONS TO PLASMA PHYSICS, Issue 1-3 2004D. A. D'Ippolito Abstract Recent experimental evidence suggests the importance of fast radial plasma transport in the scrape-off-layer (SOL) of tokamaks. The outward transport appears to be convective rather than diffusive, extends into the far SOL, and can produce significant recycling from the main-chamber walls, partially bypassing the divertor. A plausible theoretical mechanism to explain this phenomenon is the radial transport of "blobs" of locally dense plasma created by turbulent processes. A related process is the inward transport of "holes" of reduced density plasma, which provides a mechanism for rapid inward transport of impurities. The blob model is also consistent with the spatial and temporal intermittency and the non-Gaussian statistics observed in the SOL plasma. This paper reviews the present status of blob theory, including analytic models and simulations, and discusses the preliminary comparisons of the blob model with experimental data. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] A simple in vivo assay for measuring the efficiency of gene length-dependent processes in yeast mRNA biogenesisFEBS JOURNAL, Issue 4 2006Macarena Morillo-Huesca We have developed a simple reporter assay useful for detection and analysis of mutations and agents influencing mRNA biogenesis in a gene length-dependent manner. We have shown that two transcription units sharing the same promoter, terminator and open reading frame, but differing in the length of their 3,-untranslated regions, are differentially influenced by mutations affecting factors that play a role in transcription elongation or RNA processing all along the transcription units. In contrast, those mutations impairing the initial steps of transcription, but not affecting later steps of mRNA biogenesis, influence equally the expression of the reporters, independently of the length of their 3,-untranslated regions. The ratio between the product levels of the two transcription units is an optimal parameter with which to estimate the efficiency of gene length-dependent processes in mRNA biogenesis. The presence of a phosphatase-encoding open reading frame in the two transcription units makes it very easy to calculate this ratio in any mutant or physiological condition. Interestingly, using this assay, we have shown that mutations in components of the SAGA complex affect the level of mRNA in a transcript length-dependent fashion, suggesting a role for SAGA in transcription elongation. The use of this assay allows the identification and/or characterization of new mutants and drugs affecting transcription elongation and other related processes. [source] An evaluation of the process and initial impact of disseminating a nursing e-thesisJOURNAL OF ADVANCED NURSING, Issue 5 2009Colin Macduff Abstract Title.,An evaluation of the process and initial impact of disseminating a nursing e-thesis. Aim., This paper is a report of a study conducted to evaluate product, process and outcome aspects of the dissemination of a nursing PhD thesis via an open-access electronic institutional repository. Background., Despite the growth of university institutional repositories which make theses easily accessible via the world wide web, nursing has been very slow to evaluate related processes and outcomes. Method., Drawing on Stake's evaluation research methods, a case study design was adopted. The case is described using a four-phase structure within which key aspects of process and impact are reflexively analysed. Findings., In the conceptualization/re-conceptualization phase, fundamental questions about the purpose, format and imagined readership for a published nursing PhD were considered. In the preparation phase, seven key practical processes were identified that are likely to be relevant to most e-theses. In the dissemination phase email invitations were primarily used to invite engagement. The evaluation phase involved quantitative indicators of initial impact, such as page viewing and download statistics and qualitative feedback on processes and product. Conclusion., Analysis of process and impact elements of e-thesis dissemination is likely to have more than intrinsic value. The advent of e-theses housed in web-based institutional repositories has the potential to transform thesis access and use. It also offers potential to transform the nature and scope of thesis production and dissemination. Nursing scholars can exploit and evaluate such opportunities. [source] Ecosystem functioning in stream assemblages from different regions: contrasting responses to variation in detritivore richness, evenness and densityJOURNAL OF ANIMAL ECOLOGY, Issue 3 2008B. G. McKie Summary 1The diversity of species traits in a biological assemblage varies not only with species richness, but also with species evenness and organism density, which together influence the concentration of traits within functional guilds. Potential trait diversity at local scales is also constrained by the regional species pool. Implications of such variation for spatio-temporal variability in biodiversity,ecosystem functioning relationships are likely to be complex, but are poorly understood. 2In microcosm experiments conducted at laboratories in Sweden, Ireland and Romania, we investigated effects of species richness, evenness and density of stream-living detritivores on two related processes: detritivore leaf-processing efficiency (LPE) and growth. Assemblage composition varied among laboratories: one taxonomic order (Plecoptera) was studied in Sweden, whereas two orders, encompassing wider trait variation, were studied in Romania (Trichoptera and Plecoptera) and Ireland (Trichoptera and Isopoda). 3Relationships between density and both LPE and growth ranged from negative to positive across the study species, highlighting the potential for density-dependent variation in process rates to alter ecosystem functioning, but indicating that such effects depend on species identity. 4LPE varied with species diversity in the two more heterogeneous assemblages, but whereas LPE in the Romanian study was generally enhanced as richness increased, LPE in the Irish study increased only in less-even polycultures dominated by particular species. Transgressive overyielding was detected in the Irish experiment, indicating complementary resource use and/or facilitation (complementarity). These mechanisms could not be distinguished from the selection effect in the Romanian study. 5Growth was elevated in Romanian species mixtures, reflecting positive complementarity, but lower than expected growth in some Swedish mixtures was associated with negative complementarity, indicating interspecific interference competition. 6Our results emphasize the potential importance of detritivore diversity for stream ecosystem functioning, but both the effects of diversity on the studied processes, and the mechanisms underlying those effects, were specific to each assemblage and process. Such variability highlights challenges in generalizing impacts of diversity change for functional integrity in streams and other ecosystems in which the occurrence of important species traits fluctuates over relatively small spatio-temporal scales. [source] Ethanol-Sensitive Brain Regions in Rat and Mouse: A Cartographic Review, Using Immediate Early Gene ExpressionALCOHOLISM, Issue 6 2009Catherine Vilpoux Background:, Ethanol addiction has been conceptualized as a progression from occasional, impulsive use to compulsive behavior. Ethanol-dependence is a chronic pathology with repeated cycles of withdrawal, craving, and relapse. Specific molecular and cellular mechanisms underlie these transition stages. Methods:, This review aimed at elucidating whether there are also adaptations in the pattern of brain regions responding to ethanol. This paper reviews the evidence in rodents for activation of specific brain regions, assessed by induction of IEG expression, following acute and chronic ethanol exposure. Results:, The review sheds light on the specific patterns of response in regions of the brain to different types of ethanol exposure and shows that activation of specific brain regions may occur in particular phases of the development of ethanol addiction. Some brain regions respond consistently following acute or chronic treatments or withdrawal: the prefrontal cortex; nucleus accumbens; lateral septum; hippocampus; perioculomotor urocortin-containing cells population (pIIIu), also known as Edinger-Westphal nucleus; central nucleus of the amygdale; and the paraventricular nucleus of hypothalamus. The two last brain areas are particularly activated by relapse-inducing stressors. It is of interest that the amygdala, hippocampus, and prefrontal cortex, which belong to the reward system, are activated by cue-induced relapse to ethanol self-administration in rodents and humans, while activation of these regions is reversed with anticraving compounds. Following chronic exposure, IEG induction desensitizes while withdrawal reactivates these regions. Discussion:, Some responding regions are implicated in reward related processes (VTA, extended amygdala, hypothalamus, hippocampus, prelimbic cortex, ventral part of lateral septum) and some others in aversive-related processes (area postrema, nucleus of solitary tract). Conclusion:, A better understanding of the neural circuits affected by ethanol and their adaptations during the development of ethanol addiction will provide new opportunities for developing appropriate therapies. [source] Language Impairment and Reading Disability: Connections and Complexities Introduction to the Special IssueLEARNING DISABILITIES RESEARCH & PRACTICE, Issue 1 2006Elaine R. Silliman Researchers and practitioners in the fields of reading and language are well informed about the importance of phonological awareness in beginning reading. The purpose of this special issue of Learning Disabilities Research & Practice is to present recent research that extends the search for language and reading connections beyond the realm of phonological awareness. Many children with language impairment (LI) identified before formal schooling experience persistent difficulty in learning to read. Two interrelated issues are prerequisite for understanding the developmental course of events that might link language and reading (dis)ability in these children. One is an appreciation of exactly what is meant by LI, while the second concerns how LI should be explained. In this introductory article, we explore the complexities of these two issues, in particular the controversy between the domain-specific perspective and the domain-general perspective on the nature of specific LI (SLI). Consistent with these perspectives, future studies on possible language-reading links will need to measure language and related processes in greater breadth and depth, over time, and within a variety of experiential contexts. The five articles in this issue represent a critical first step in this direction. [source] Dual inverse effects of lipoprotein(a) on the dementia process in Japanese late-onset Alzheimer's diseasePSYCHOGERIATRICS, Issue 3 2004Toshihiko IWAMOTO Abstract Background: The role of lipoprotein metabolism in the dementia process has attracted increasing attention. It is universally accepted that apolipoprotein E4 (ApoE) is a risk factor for late-onset Alzheimer's disease, however, the role of lipoprotein(a) (Lp(a)) remains unclear. Therefore, we conducted the present study to clarify the association between Lp(a) and dementia. Methods: Lipoprotein(a) serum concentrations were examined in relation to ApoE phenotypes and periventricular lucency (PVL) on brain computed tomography in 150 patients with late-onset Alzheimer's disease (AD group), compared with 46 patients with vascular dementia (VaD group) and 150 controls without dementia. Results: The incidences of hypertension, hypercholesterolaemia, and severe PVL were significantly higher in the VaD group than in the AD group. The distributions of Lp(a) concentrations showed left-skewed deviation in each group, but we found the concentration of 40 mg/dL to be the best cut-off point to distinguish the frequency of Alzheimer's disease from that of the controls. Compared with the frequency of high Lp(a) concentrations of 40 mg/dL or more in the controls (16.7%), that in the AD group (10.0%) was significantly lower, while that in the VaD group (45.7%) was significantly higher. Separating the AD group according to the presence or absence of ApoE4, the same findings were recognized. However, severe PVL was more frequent in the AD group with high Lp(a) concentrations (53.3%) than in the AD group without high Lp(a) concentrations (7.4%) (P < 0.01). Conclusions: These findings suggest the possibility of dual inverse effects of Lp(a) on the occurrence of Japanese late-onset Alzheimer's disease, via suppression of Alzheimer's related processes and promotion of PVL formation presumably caused by ischemia. [source] Development of guidelines for the safe prescribing, dispensing and administration of cancer chemotherapyASIA-PACIFIC JOURNAL OF CLINICAL ONCOLOGY, Issue 3 2010Christine CARRINGTON Abstract Aim: The issue of medication safety is highly significant when anti-cancer therapy is used due to the high potential for harm from these agents and the disease context in which they are being used. This article reports on the development of multidisciplinary consensus guidelines for the safe prescribing, dispensing and administration of cancer chemotherapy undertaken by a working group of the Clinical Oncological Society of Australia (COSA). Methods: A working group of pharmacists, nurses and medical oncologists was convened from the COSA membership. A draft set of guidelines was proposed and circulated to the COSA council and the wider membership of COSA for comment. The final version of the guidelines was then distributed to 25 key stakeholders in Australia for feedback and endorsement. Results: An initial draft was developed based on existing standards, evidence from the literature and consensus opinion of the group. It was agreed that published case studies would be used as evidence for a particular statement where related processes had resulted in patient harm. The group defined 13 areas where a guidance statement was applicable to all professional disciplines and three individual sections based on the processes and the professionals involved in the provision of cancer therapy. Conclusion: The guidelines development represents a multidisciplinary collaboration to standardize the complex process of providing chemotherapy for cancer and to enhance patient safety. These are consensus guidelines based on the best available evidence and expert opinion of professionals working in cancer care. They should be seen as a point of reference for practitioners providing chemotherapy services. [source] Configuration, history and impact of the Norwegian Channel Ice StreamBOREAS, Issue 1 2003Hans Petter Sejrup The Norwegian Channel between Skagerrak, in the southeast, and the continental margin of the northern North Sea, in the northwest, is the result of processes related to repeated ice stream activity through the last 1.1 m yr. In such periods the Skagerrak Trough (700 m deep) has acted as a confluence area for glacial ice from southeastern Norway, southern Sweden and parts of the Baltic. Possibly related to the threshold in the Norwegian Channel off Jæren (250 m deep), the ice stream, on a number of occasions over the last 400 ka, inundated the coastal lowlands and left an imprint of NW-oriented ice directional features (drumlins, stone orientations in tills and striations). Marine interstadial sediments found up to 200 m a.s.l. on Jæren have been suggested to reflect glacial isostasy related to the Norwegian Channel Ice Stream (NCIS). In the channel itself, the ice stream activity is evidenced by mega-scale glacial lineations on till surfaces. As a result of subsidence, the most complete sedimentary records of early phases of the NCIS are preserved close to the continental margin in the North Sea Fan region. The strongest evidence for ice stream erosion during the last glacial phase is found in the Skagerrak. On the continental slope the ice stream activity is evidenced by the large North Sea Fan, which is mainly a result of deposition of glacial-fed debris flows. Northwards of the North Sea Fan, rapid deposition of meltwater plume deposits, possibly related to the NCIS, is detected as far north as the Vøring Plateau. The NCIS system offers a unique possibility to study ice stream related processes and the impact the ice stream development had on open ocean sedimentation and circulation. [source] Vinyl-, Propargyl-, and Allenylsilicon Reagents in Asymmetric Synthesis: A Relatively Untapped Resource of Environmentally Benign ReagentsCHEMISTRY - A EUROPEAN JOURNAL, Issue 22 2009Marcus Abstract Green carbanion surrogates: Organotrialkylsilanes occupy a niche in the array of ,green' carbon nucleophiles open to chemists that few other reagents can fill. Despite being known for over 30 years, it is only recently that their true worth in stereoselective carbonyl addition and related processes has started to emerge, primarily due to their low reactivity. It is our hope that this minireview will make the true worth of these reagents more widely known, setting the stage for expanded usage of these versatile yet benign reagents in organic synthesis. An up-to-date in-depth review of the current virtues and limitations in the realm of carbonyl addition reactions with allenyl-, propargyl-, and vinylsilicon reagents, encompassing numerous practical as well as pedagogical principles is presented. Comparisons of chemo-, regio-, and stereoselectivity and reactivity are drawn. Synthetic applications and challenges associated with each class of organosilane are discussed threading together the prospects of these green carbanion surrogates. [source] RNA: Prebiotic Product, or Biotic Invention?CHEMISTRY & BIODIVERSITY, Issue 4 2007Carole Anastasi Abstract Spectacular advances in structural and molecular biology have added support to the ,RNA world' hypothesis, and provide a mandate for chemistry to explain how RNA might have been generated prebiotically on the early earth. Difficulties in achieving a prebiotically plausible synthesis of RNA, however, have led many to ponder the question posed in the title of this paper. Herein, we review recent experimental work on the assembly of potential RNA precursors, focusing on methods for stereoselective CC bond construction by aldolisation and related processes. This chemistry is presented in the context of a broader picture of the potential constitutional self-assembly of RNA. Finally, the relative accessibility of RNA and alternative nucleic acids is considered. [source] | |||||||||||||