Variety Of Types (variety + of_type)

Distribution by Scientific Domains


Selected Abstracts


Circuits and systems in stress.

DEPRESSION AND ANXIETY, Issue 1 2002

Abstract This paper follows the preclinical work on the effects of stress on neurobiological and neuroendocrine systems and provides a comprehensive working model for understanding the pathophysiology of posttraumatic stress disorder (PTSD). Studies of the neurobiology of PTSD in clinical populations are reviewed. Specific brain areas that play an important role in a variety of types of memory are also preferentially affected by stress, including hippocampus, amygdala, medial prefrontal cortex, and cingulate. This review indicates the involvement of these brain systems in the stress response, and in learning and memory. Affected systems in the neural circuitry of PTSD are reviewed (hypothalamic-pituitary-adrenal axis (HPA-axis), catecholaminergic and serotonergic systems, endogenous benzodiazepines, neuropeptides, hypothalamic-pituitary-thyroid axis (HPT-axis), and neuro-immunological alterations) as well as changes found with structural and functional neuroimaging methods. Converging evidence has emphasized the role of early-life trauma in the development of PTSD and other trauma-related disorders. Current and new targets for systems that play a role in the neural circuitry of PTSD are discussed. This material provides a basis for understanding the psychopathology of stress-related disorders, in particular PTSD. Depression and Anxiety 16:14,38, 2002. © 2002 Wiley-Liss, Inc. [source]


Ecological responses to altered flow regimes: a literature review to inform the science and management of environmental flows

FRESHWATER BIOLOGY, Issue 1 2010
N. LEROY POFF
Summary 1.,In an effort to develop quantitative relationships between various kinds of flow alteration and ecological responses, we reviewed 165 papers published over the last four decades, with a focus on more recent papers. Our aim was to determine if general relationships could be drawn from disparate case studies in the literature that might inform environmental flows science and management. 2.,For all 165 papers we characterised flow alteration in terms of magnitude, frequency, duration, timing and rate of change as reported by the individual studies. Ecological responses were characterised according to taxonomic identity (macroinvertebrates, fish, riparian vegetation) and type of response (abundance, diversity, demographic parameters). A ,qualitative' or narrative summary of the reported results strongly corroborated previous, less comprehensive, reviews by documenting strong and variable ecological responses to all types of flow alteration. Of the 165 papers, 152 (92%) reported decreased values for recorded ecological metrics in response to a variety of types of flow alteration, whereas 21 papers (13%) reported increased values. 3.,Fifty-five papers had information suitable for quantitative analysis of ecological response to flow alteration. Seventy per cent of these papers reported on alteration in flow magnitude, yielding a total of 65 data points suitable for analysis. The quantitative analysis provided some insight into the relative sensitivities of different ecological groups to alteration in flow magnitudes, but robust statistical relationships were not supported. Macroinvertebrates showed mixed responses to changes in flow magnitude, with abundance and diversity both increasing and decreasing in response to elevated flows and to reduced flows. Fish abundance, diversity and demographic rates consistently declined in response to both elevated and reduced flow magnitude. Riparian vegetation metrics both increased and decreased in response to reduced peak flows, with increases reflecting mostly enhanced non-woody vegetative cover or encroachment into the stream channel. 4.,Our analyses do not support the use of the existing global literature to develop general, transferable quantitative relationships between flow alteration and ecological response; however, they do support the inference that flow alteration is associated with ecological change and that the risk of ecological change increases with increasing magnitude of flow alteration. 5.,New sampling programs and analyses that target sites across well-defined gradients of flow alteration are needed to quantify ecological response and develop robust and general flow alteration,ecological response relationships. Similarly, the collection of pre- and post-alteration data for new water development programs would significantly add to our basic understanding of ecological responses to flow alteration. [source]


Performance of finite volume solutions to the shallow water equations with shock-capturing schemes

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 10 2002
K. S. Erduran
Abstract Numerical methods have become well established as tools for solving problems in hydraulic engineering. In recent years the finite volume method (FVM) with shock capturing capabilities has come to the fore because of its suitability for modelling a variety of types of flow; subcritical and supercritical; steady and unsteady; continuous and discontinuous and its ability to handle complex topography easily. This paper is an assessment and comparison of the performance of finite volume solutions to the shallow water equations with the Riemann solvers; the Osher, HLL, HLLC, flux difference splitting (Roe) and flux vector splitting. In this paper implementation of the FVM including the Riemann solvers, slope limiters and methods used for achieving second order accuracy are described explicitly step by step. The performance of the numerical methods has been investigated by applying them to a number of examples from the literature, providing both comparison of the schemes with each other and with published results. The assessment of each method is based on five criteria; ease of implementation, accuracy, applicability, numerical stability and simulation time. Finally, results, discussion, conclusions and recommendations for further work are presented. Copyright © 2002 John Wiley & Sons, Ltd. [source]


Benefit of Adherence With Bisphosphonates Depends on Age and Fracture Type: Results From an Analysis of 101,038 New Bisphosphonate Users,,

JOURNAL OF BONE AND MINERAL RESEARCH, Issue 9 2008
Jeffrey R Curtis
Abstract The relationship between high adherence to oral bisphosphonates and the risk of different types of fractures has not been well studied among adults of different ages. Using claims data from a large U.S. health care organization, we quantified adherence after initiating bisphosphonate therapy using the medication possession ratio (MPR) and identified fractures. Cox proportional hazards models were used to evaluate the rate of fracture among nonadherent persons (MPR < 50%) compared with highly adherent persons (MPR , 80%) across several age strata and a variety of types of clinical fractures. In conjunction with fracture incidence rates among the nonadherent, these estimates were used to compute the number needed to treat with high adherence to prevent one fracture, by age and fracture type. Among 101,038 new bisphosphonate users, the proportion of persons with high adherence at 1, 2, and 3 yr was 44%, 39%, and 35%, respectively. Among 65- to 78-yr-old persons with a physician diagnosis of osteoporosis, the crude and adjusted rate of hip fracture among the nonadherent was 1.96 (95% CI, 1.48,2.60) and 1.74 (95% CI, 1.30,2.31), respectively, resulting in a number needed to treat with high adherence to prevent one hip fracture of 107. The impact of high adherence was substantially less for other types of fractures and for younger persons. Analysis of adherence in a non,time-dependent fashion artifactually magnified differences in fracture rates between adherent and nonadherent persons. The antifracture effectiveness associated with high adherence to oral bisphosphonates varied substantially by age and fracture type. These results provide estimates of absolute fracture effectiveness across age subgroups and fracture types that have been minimally evaluated in clinical trials and may be useful for future cost-effectiveness studies. [source]


On the shape of the fringe of various types of random trees

MATHEMATICAL METHODS IN THE APPLIED SCIENCES, Issue 10 2009
Michael Drmota
Abstract We analyze a fringe tree parameter w in a variety of settings, utilizing a variety of methods from the analysis of algorithms and data structures. Given a tree t and one of its leaves a, the w(t,,a) parameter denotes the number of internal nodes in the subtree rooted at a's father. The closely related w,(t,,a) parameter denotes the number of leaves, excluding a, in the subtree rooted at a's father. We define the cumulative w parameter as W(t) = ,aw(t,,a), i.e. as the sum of w(t,,a) over all leaves a of t. The w parameter not only plays an important rôle in the analysis of the Lempel,Ziv '77 data compression algorithm, but it is captivating from a combinatorial viewpoint too. In this report, we determine the asymptotic behavior of the w and W parameters on a variety of types of trees. In particular, we analyze simply generated trees, recursive trees, binary search trees, digital search trees, tries and Patricia tries. The final section of this report briefly summarizes and improves the previously known results about the w, parameter's behavior on tries and suffix trees, originally published in one author's thesis (see Analysis of the multiplicity matching parameter in suffix trees. Ph.D. Thesis, Purdue University, West Lafayette, IN, U.S.A., May 2005; Discrete Math. Theoret. Comput. Sci. 2005; AD:307,322; IEEE Trans. Inform. Theory 2007; 53:1799,1813). This survey of new results about the w parameter is very instructive since a variety of different combinatorial methods are used in tandem to carry out the analysis. Copyright © 2008 John Wiley & Sons, Ltd. [source]


Mechanisms of renal disease in indigenous populations: influences at work in Canadian indigenous peoples

NEPHROLOGY, Issue 1 2001
Roland F Dyck
SUMMARY: Canadian aboriginal people experience end-stage renal disease at rates 2.5,4 times higher than those found in the general population. Up to 60% of cases are due to diabetic end-stage renal disease, while most of the remainder are caused by a variety of types of glomerulonephritis. The greatest increase in cases of end-stage renal disease among aboriginal people since 1981 has been observed in those with diabetes. There appear to be three major contributing influences to the increase in diabetic end-stage renal disease among Canadian aboriginal people. First, the rates of type 2 diabetes mellitus have increased from virtually zero to several times those seen in the general population in less than 60 years. Second, aboriginal people with diabetes have seven times the rate of diabetic end-stage renal disease compared with their non-aboriginal counterparts. Finally, birth rates among aboriginal people are higher than in any other segment of the population. An epidemic of diabetic end-stage renal disease is the most important nephrological issue facing Canadian aboriginal people and threatens to overwhelm health care resources in many parts of the country unless effective early recognition and prevention programmes are established. [source]


Lobular capillary hemangioma of the oral mucosa: Clinicopathological study of 43 cases with a special reference to immunohistochemical characterization of the vascular elements

PATHOLOGY INTERNATIONAL, Issue 1 2003
Makoto Toida
Clinical and histopathological features were investigated in 43 cases of oral lobular capillary hemangiomas (LCH) with a special reference to characteristics of the vascular elements. The lesions affected females more than males by a ratio of 1:1.5. Average age of the patients was 52.7 years. The lesions involved the gingiva (n = 15), the tongue (n = 13), the labial mucosa (n = 10) and other sites. The lesions appeared usually as a pedunculated mass with ulceration; size of the lesions was up to 15 mm. Histologically, a lobular area and an ulcerative area were distinguished. The density of vessels was about 1045/mm2 and 160/mm2 in the lobular and ulcerative areas, respectively. The average diameter of the vascular lumen was 9.1 5.6 mm (range: 2.8,42.0 mm) and 18.8 20.9 mm (range: 5.6,139.7 mm) in the lobular and ulcerative areas, respectively. In the lobular area, most of the vessels had an inner layer of endothelial cells showing positive reaction for von Willebrand factor (vWF) and CD34, as well as an outer layer of mesenchymal cells showing positive reaction for alpha-smooth muscle actin (ASMA). However, in the ulcerative area, there was a variety of types of vessels consisting of various proportions of both endothelial and ASMA-positive perivascular mesenchymal cells. These results indicate that most of the vascular elements in the lobular area resemble more pericapillary microvascular segments than they do capillaries. Thus, the authors propose the term ,lobular pericapillary hemangioma' to represent this type of lesion. [source]


Religious and Non-Religious Pathways to Stress-Related Growth in Cancer Survivors

APPLIED PSYCHOLOGY: HEALTH AND WELL-BEING, Issue 3 2009
Crystal L. Park
While religiousness and spirituality are important to many cancer survivors, relations of religiousness and spirituality with the stress-related growth commonly reported by survivors have not been well documented. In the present study, we examined the linkages between personal religiousness, religious control appraisals for the cancer, and religious coping with subsequent stress-related growth, and compared them with a parallel secular pathway, hope, self-control appraisals, and active coping. In all, 172 young to middle-aged adult survivors (113 women, 59 men, mean age = 45 years) of a variety of types of cancer who had been diagnosed approximately 2.5 years prior were assessed twice across a 1-year period. A structural equation model indicated that while both pathways predicted stress-related growth, the religious pathway was a much stronger predictor of subsequent stress-related growth than was the secular pathway. We suggest that more attention should be given to the influence of multiple dimensions of religiousness and spirituality on growth to better understand the transformative processes reported by many survivors. [source]


Overproduction, crystallization and preliminary crystallographic analysis of a novel human DNA-­repair enzyme that recognizes oxidative DNA damage

ACTA CRYSTALLOGRAPHICA SECTION D, Issue 6 2004
Viswanath Bandaru
DNA glycosylases repair oxidative DNA damage caused by free radicals. Recently, NEIL1, a human homolog of Escherichia coli DNA glycosylase endonuclease VIII, has been identified and shown to exhibit broad substrate specificity for a variety of types of pyrimidine-base damage. An active C-terminal deletion construct of NEIL1 was overexpressed in E. coli and crystallized. The unliganded NEIL1 crystallizes in space group R3, with unit-cell parameters a = b = 132.2, c = 51.1,Ĺ. Complete data sets were collected from native, selenomethionyl and iodinated NEIL1 to 2.1, 2.3 and 2.4,Ĺ, respectively. [source]


The autogenic (self-generated) massacre

BEHAVIORAL SCIENCES & THE LAW, Issue 3 2004
D.Sc., F.R.A.N.Z.C.P., F.R.C. Psych.Article first published online: 21 DEC 200, Paul E. Mullen M.B.B.S.
Mass killings can be of a variety of types including family slayings, cult killings, and the by-product of other criminal activities. This article focuses on massacres where the perpetrators indiscriminately kill people in pursuit of a highly personal agenda arising from their own specific social situation and psychopathology. Five cases are presented of this type of autogenic (self-generated) massacre, all of whom survived and were assessed by the author. Not only do these massacres follow an almost stereotypical course, but the perpetrators tend to share common social and psychological disabilities. They are isolates, often bullied in childhood, who have rarely established themselves in effective work roles as adults. They have personalities marked by suspiciousness, obsessional traits, and grandiosity. They often harbour persecutory beliefs, which may occasionally verge on the delusional. The autogenic massacre is essentially murder suicide, in which the perpetrators intend first to kill as many people as they can and then kill themselves. The script for this particular form of suicide has established itself in western society and is continuing to spread, and to diversify. Copyright © 2003 John Wiley & Sons, Ltd. [source]