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Underlying Factors (underlying + factor)
Terms modified by Underlying Factors Selected AbstractsDiversity Tension and Other Underlying Factors in Discrimination SuitsEMPLOYMENT RELATIONS TODAY, Issue 4 2001R. Roosevelt Thomas Jr. [source] Pancreatitis in adult orthotopic liver allograft recipients: Risk factors and outcomeLIVER TRANSPLANTATION, Issue 3 2000Deborah J. Verran Acute pancreatitis (AP) has been described after orthotopic liver transplantation but is uncommon in stable patients after the initial perioperative phase. The aim of this study is to review our experience with AP occurring more than 2 months after primary allografting and determine possible contributing factors plus patient outcome. A review of patient files and the unit database was performed. AP was diagnosed in 9 of 298 patients (3%) on 12 occasions. The incidence of AP was greater in men (8 of 163 men) than women (1 of 135 women; P< .04). Underlying factors to each episode of AP were biliary manipulation (4 of 12 episodes; 33%), history of recent alcohol ingestion (3 of 12 episodes; 25%), and malignancy in the region of the pancreas (2 of 12 episodes; 16%). AP was associated with a diagnosis of either hepatic artery thrombosis combined with biliary tract complications (P< .005) or malignancy (P< .004). In 7 of 12 episodes of AP (58%), conservative management alone was successful. In 3 of 9 patients (33%), subsequent surgery was required. One patient died of pancreatic malignancy. In conclusion, AP is uncommon in stable liver transplant recipients. Male sex, complications of hepatic artery thrombosis, and malignancy in the region of the pancreas are associated with AP in this study. [source] Beta diversity of geometrid moths (Lepidoptera: Geometridae) in an Andean montane rainforestDIVERSITY AND DISTRIBUTIONS, Issue 5 2003Gunnar Brehm Abstract. Turnover in species composition of the extremely species-rich family Geometridae (Lepidoptera) was investigated along an elevational gradient ranging from 1040 m to 2677 m above sea level. Moths were sampled using weak light traps (30 W) in three field periods in 1999 and 2000 in an Andean montane rainforest in the province of Zamora-Chinchipe in southern Ecuador. A total of 13 938 specimens representing 1010 species were analysed. Similarities of ensembles of all geometrid moths and of the subfamilies Ennominae and Larentiinae were calculated using the NESS index (with mmax). Ordinations performed using nonmetric multidimensional scaling (NMDS) and correspondence analysis depicted a gradual change of the ensembles along the altitudinal gradient. Extracted ordination scores significantly correlate with altitude (,0.97 , r , ,0.95, P < 0.001) and with ambient air temperature (0.93 , r , 0.97, P < 0.001). Temperature is therefore assumed to be the most important abiotic determinant responsible for the species turnover among the moths. Matrix correlation tests were performed in order to compare faunal matrices with matrices derived from available environmental factors. Both tree diversity and vegetation structure significantly correlate with faunal data, but tree diversity explains considerably more of the data variability (range: Mantel r = 0.81,0.83, P < 0.001) than vegetation structure (range: Mantel r = 0.35, P < 0.005 to r = 0.43, P < 0.001). Tree diversity also changes gradually and scores of the first NMDS dimension are highly significantly correlated with altitude (r = 0.98, P < 0.001). A common underlying factor such as ambient temperature might also be responsible for such vegetation changes. Additionally, simulated model data was developed that assumed a constant turnover of moth species and equal elevational ranges of all species involved. Despite the simplicity of the models, they fit empirical data very well (Mantel r > 0.80 and P < 0.001 in all models). [source] Examining the Intersection of Sex and Stress in Modelling Neuropsychiatric DisordersJOURNAL OF NEUROENDOCRINOLOGY, Issue 4 2009N. Goel Sex-biased neuropsychiatric disorders, including major depressive disorder and schizophrenia, are the major cause of disability in the developed world. Elevated stress sensitivity has been proposed as a key underlying factor in disease onset. Sex differences in stress sensitivity are associated with corticotrophin-releasing factor (CRF) and serotonin neurotransmission, which are important central regulators of mood and coping responses. To elucidate the underlying neurobiology of stress-related disease predisposition, it is critical to develop appropriate animal models of stress pathway dysregulation. Furthermore, the inclusion of sex difference comparisons in stress responsive behaviours, physiology and central stress pathway maturation in these models is essential. Recent studies by our laboratory and others have begun to investigate the intersection of stress and sex where the development of mouse models of stress pathway dysregulation via prenatal stress experience or early-life manipulations has provided insight into points of developmental vulnerability. In addition, examination of the maturation of these pathways, including the functional importance of the organisational and activational effects of gonadal hormones on stress responsivity, is essential for determination of when sex differences in stress sensitivity may begin. In such studies, we have detected distinct sex differences in stress coping strategies where activational effects of testosterone produced females that displayed male-like strategies in tests of passive coping, but were similar to females in tests of active coping. In a second model of elevated stress sensitivity, male mice experiencing prenatal stress early in gestation showed feminised physiological and behavioural stress responses, and were highly sensitive to a low dose of selective serotonin reuptake inhibitors. Analyses of expression and epigenetic patterns revealed changes in CRF and glucocorticoid receptor genes in these mice. Mechanistically, stress early in pregnancy produced a significant sex-dependent effect on placental gene expression that was supportive of altered foetal transport of key growth factors and nutrients. These mouse models examining alterations and hormonal effects on development of stress pathways provide necessary insight into how specific stress responses can be reprogrammed early in development resulting in sex differences in stress sensitivity and neuropsychiatric disease vulnerability. [source] Fulminant hepatitis associated with hepatitis A virus superinfection in patients with chronic hepatitis CJOURNAL OF VIRAL HEPATITIS, Issue 2000S. Vento There have been conflicting reports of the clinical outcome of acute hepatitis A virus (HAV) infection in patients with chronic hepatitis C virus (HCV) infection. A prospective study evaluated 432 patients with chronic hepatitis C (183 with cirrhosis) over a 7-year period. Of the 17 patients with concurrent HAV infection, seven developed fulminant hepatitis and six died. None of these patients had cirrhosis; however, the HLA phenotype (A1; B8:DR3) appeared to be a significant factor in the development of fulminant hepatitis. Patients with this phenotype had high titres of antinuclear antibodies, antismooth muscle antibodies and antiasialoglycoprotein-receptor antibodies, possibly reflecting the induction of autoimmune hepatitis in this group. The high frequency of fulminant hepatitis in patients with HAV/HCV coinfection contrasts with other surveys, although a large Centers for Disease Control and Prevention (CDC) survey demonstrated that HAV infection in patients with pre-existing chronic liver disease (CLD) is associated with increased mortality. It is likely that CLD has some importance as an underlying factor in the development of fulminant hepatitis following HAV infection. Further prospective studies are needed to clarify this issue. [source] Neuromuscular manifestations of critical illness,MUSCLE AND NERVE, Issue 2 2005Charles F. Bolton MD Abstract Critical illness, more precisely defined as the systemic inflammatory response syndrome (SIRS), occurs in 20%,50% of patients who have been on mechanical ventilation for more than 1 week in an intensive care unit. Critical illness polyneuropathy (CIP) and myopathy (CIM), singly or in combination, occur commonly in these patients and present as limb weakness and difficulty in weaning from the ventilator. Critical illness myopathy can be subdivided into thick-filament (myosin) loss, cachectic myopathy, acute rhabdomyolysis, and acute necrotizing myopathy of intensive care. SIRS is the predominant underlying factor in CIP and is likely a factor in CIM even though the effects of neuromuscular blocking agents and steroids predominate in CIM. Identification and characterization of the polyneuropathy and myopathy depend upon neurological examination, electrophysiological studies, measurement of serum creatine kinase, and, if features suggest a myopathy, muscle biopsy. The information is valuable in deciding treatment and prognosis. Muscle Nerve, 2005 [source] Grapevine productivity and yield components: A case study using field vines of Zante currantAUSTRALIAN JOURNAL OF GRAPE AND WINE RESEARCH, Issue 2 2004JOHN A. CONSIDINE Abstract Yield components of the parthenocarpic cultivar Zante were analysed for five vineyards of diverse age and management. The data was obtained as part of an experiment to improve fruit set and yield by applying combinations of gibberellin and 2-chloroethyltrimethyl ammonium chloride or 4-chlorophenoxyacetic acid. Four of the vineyards were located in the Brockman valley north of Perth, Western Australia, two of these were irrigated, one was rain fed and one received supplementary flood irrigation. The fifth lay in an adjacent area of coastal sand plain, at the foot of the Darling scarp, and was irrigated. The vines were aged from 6 to 50 years. Principal component analysis showed that vine age was negatively correlated with vigour (pruning weight) and with berry number per bunch. Vine age however was not strongly related to either yield or yield components (bunch number and berry volume). Sugar concentration was negatively correlated with all yield components but imprecisely modelled based on any combination of the measured variables. Berry number per vine appeared to be the underlying factor determining ,sink' strength though this was inextricably confounded with bunch number per vine. Interpretation of the data leads to the conclusion that increased berry volume is an inefficient means of increasing dried yield. This conclusion argues for caution in the application of plant growth regulators that act primarily to increase berry volume. Yield of sugar per vine was accurately modelled based on second order relationships with bunch number per vine, berry number per bunch, berry volume and pruning weight. Vine age also showed a second order relationship to yield although the range was relatively small. The observations are considered in terms of developing strategies for maximising dried yield and devising mathematical models to account for photoassimilate (dry matter) partitioning in Vitis. [source] A cross-Canada analysis of the efficiency of residential recycling servicesCANADIAN PUBLIC ADMINISTRATION/ADMINISTRATION PUBLIQUE DU CANADA, Issue 4 2008James C. McDavid The findings are based on a survey of 128 residential recycling producers from all regions of Canada. One of the most significant findings is the lack of a relationship between private-sector companies collecting recyclables and the overall efficiency of collection operations. The dominance of the private-sector collection of recyclables (over seventy-seven per cent of all producers were contracted companies) does not translate into greater efficiencies. The most important variables in the model are amenable to local control. They include tonnes collected per vehicle per year, requiring full bins, inclusion of composting operations in the overall recycling program, the number of different kinds of materials recycled, participation rate, and reliance on side-loading collection vehicles. Among the direct predictors of unit costs, the key underlying factor is the productivity of residential recycling operations. Because recyclables are marketed, handling them takes time, reduces the weights that collection vehicles can carry, and generally reduces productivity. Even diligent efforts to improve productivity will not bring recycling costs down to the levels for residential solid-waste collection. Sommaire: L'objectif principal du présent article est d'examiner les facteurs qui prévoient l'efficacité des services de collecte de produits recyclables résidentiels dans les municipalités canadiennes. Les résultats reposent sur un sondage réalisé auprès de 128 producteurs de collecte de produits recyclables résidentiels opérant dans toutes les régions du Canada. L'un des résultats les plus notoires est le manque de relations entre les sociétés du secteur privé qui récupèrent les produits recyclables et l'efficacité d'ensemble des opérations de collecte. La prédominance de la collecte de produits recyclables par le secteur privé (plus de soixante-dix-sept pour cent de tous les producteurs étaient des sociétés contractuelles) ne se traduit pas par une plus grande efficacité. Les variables les plus importantes du modèle peuvent faire l'objet d'un contrôle local. Elles comprennent les tonnes récupérées par véhicule par an, l'exigence de poubelles pleines, l'inclusion d'opérations de compostage au programme général de recyclage, le nombre de différentes sortes de matériaux recyclés, le taux de participation, et le recours à des camions de collecte à chargement latéral. Parmi les variables explicatives directes des coûts unitaires, le principal facteur sous-jacent est la productivité des opérations de recyclage résidentiel. Comme les produits recyclables sont commercialisés, leur manutention prend du temps, réduit le poids que les camions de collecte peuvent transporter, et réduit d'une manière générale la productivité. Même des efforts diligents pour améliorer la productivité ne feront pas baisser les coûts du recyclage aux niveaux de ceux de la collecte des déchets solides résidentiels. [source] Potentiation of allergic bronchoconstriction by repeated exposure to formaldehyde in guinea-pigs in vivoCLINICAL & EXPERIMENTAL ALLERGY, Issue 12 2003T. Kita Summary Background Indoor formaldehyde (FA) might worsen allergies and be an underlying factor for the increasing incidence and severity of asthma; the exact mechanism, however, remains unclear. Objective The present study examined the effects of repeated exposure to FA on methacholine- and antigen-induced bronchoconstriction in guinea-pigs in vivo. Methods First, non-sensitized guinea-pigs were transnasally treated with 0.1 or 1.0% FA or saline three times a week for 6 weeks, and increasing concentrations of methacholine (50, 100, and 200 ,g/mL) were inhaled at 5-min intervals. Second, guinea-pigs pre-treated with transnasal administration of FA or saline using the same protocol were passively sensitized with anti-ovalbumin (OA) serum 7 days before antigen challenge. Third, guinea-pigs were actively sensitized with OA and pre-treated with transnasal administration of FA or saline using the same protocol. The lateral pressure of the tracheal tube (Pao) was measured under anesthesia and artificial ventilation. Results The antigen-induced increase in Pao in actively sensitized guinea-pigs was significantly potentiated by FA exposure in a dose-dependent manner. The dose,response curve of the methacholine-induced increase in Pao in non-sensitized guinea-pigs or of the antigen-induced increase in Pao in passively sensitized guinea-pigs was not altered by FA exposure. Transnasal administration of FA significantly increased the serum anti-OA homocytotropic antibody titre (IgG) as measured by the passive cutaneous anaphylaxis reaction in actively sensitized guinea-pigs. Conclusion The results suggest that repeated exposure to FA worsens allergic bronchoconstriction through enhancing antigen sensitization. [source] A model for range expansion of an introduced species: the common waxbill Estrilda astrild in PortugalDIVERSITY AND DISTRIBUTIONS, Issue 6 2002Tiago Silva Abstract. The common waxbill Estrilda astrild was first introduced to Portugal from Africa in 1964, and has spread across much of the country and into Spain. We modelled the expansion of the common waxbill on a 20 × 20 km UTM grid in 4-year periods from 1964 to 1999. The time variation of the square root of the occupied area shows that this expansion process is stabilizing in Portugal, and reasons for this are discussed. Several methods used to model biological expansions are not appropriate for the present case, because little quantitative data are available on the species ecology and because this expansion has been spatially heterogeneous. Instead, colonization on a grid was modelled as a function of several biophysical and spatio-temporal variables through the fitting of a multivariate autologistic equation. This approach allows examination of the underlying factors affecting the colonization process. In the case of the common waxbill it was associated positively with its occurrence in adjacent cells, and affected negatively by altitude and higher levels of solar radiation. [source] Linking habitat selection, emigration and population dynamics of freshwater fishes: a synthesis of ideas and approachesECOLOGY OF FRESHWATER FISH, Issue 2 2006T. E. McMahon Abstract,,, The consequences of individual behaviour to dynamics of populations has been a critical question in fish ecology, but linking the two has proven difficult. A modification of Sale's habitat selection model provides a conceptual linkage for relating resource availability and individual habitat selection to exploratory behaviour, emigration and population-level responses. Whole-population experiments with pupfish Cyprinodon macularius that linked all factors along this resource to population continuum lend support to this conceptual model, and illustrate that emigration may be much more common in fish populations than considered in most individual- or population-based models. Accommodating emigration can enhance the ecological appropriateness of behavioural experiments and increase confidence in extrapolation of experimental observations to population-level effects. New experimental designs and advancing technologies offer avenues for assessing population consequences of habitat selection and emigration by individual fish. Emigration often is the key linkage between individual behaviour and population responses, and greater understanding of the underlying factors affecting this often-overlooked demographic parameter could offer new approaches for management and conservation of fishes. [source] Lactose intolerance: analysis of underlying factorsEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 1 2003R. J. Vonk Abstract Background We studied the degree of lactose digestion and orocecal transit time (OCTT) as possible causes for the variability of symptoms of lactose intolerance (LI) in a sample of a population with genetically determined low lactase activity. Methods Lactose digestion index (LDI) was measured by the recently developed 13C-lactose/2H-glucose test. The OCTT was determined using the breath hydrogen test. Based on a 6-h symptom score (SSC) after a challenge dose of 25 g of lactose the subjects were divided into a tolerant group (T: n= 15; SSC = 0) and an intolerant group (IT: n= 28; SSC 1,40). The intolerant group was subdivided according to the severity of symptoms: group ITa (n = 17; mild symptoms without diarrhoea) and group ITb (n = 11; with diarrhoea). Results The LDI was lower in the intolerant group (0·34 ± 0·14) (mean ± SD) than in the tolerant group (0·47 ± 0·14) (P = 0·008). The OCTT of group IT (60, 30,90 min) (median, quartiles) was significantly shorter than that of group T (105, 60,120 min) (P = 0·003) and was positively correlated with the LDI (P = 0·050). In groups ITa and ITb the OCTT (60, 30,90 min; 60, 26,83 min) and LDI (0·30 ± 0·14; 0·39 ± 0·14) were similar. Conclusions Lactose digestion capacity, which is determined by small intestinal lactase activity as well as by OCTT, affects the occurrence of lactose intolerance. However, the major difference in intolerance symptoms is caused by differences in the colonic processing of maldigested lactose. [source] Cutaneous T-cell lymphoma-associated lung cancers show chromosomal aberrations differing from primary lung cancerGENES, CHROMOSOMES AND CANCER, Issue 2 2008Sonja Hahtola Cutaneous T-cell lymphoma (CTCL) patients have an increased risk of certain secondary cancers, the most common of which are lung cancers, especially small cell lung cancer. To reveal the molecular pathogenesis underlying CTCL-associated lung cancer, we analyzed genomic aberrations in CTCL-associated and reference lung cancer samples. DNA derived from microdissected lung cancer cells of five CTCL-associated lung cancers and five reference lung cancers without CTCL association was analyzed by comparative genomic hybridization (CGH). Fluorescent in situ hybridization (FISH), immunohistochemistry (IHC), and loss of heterozygosity (LOH) analysis were performed for selected genes. In CTCL-associated lung cancer, CGH revealed chromosomal aberrations characterizing both lung cancer and CTCL, but also losses of 1p, and 19, and gains of 4q and 7, hallmarks of CTCL. LOH for the CTCL-associated NAV3 gene was detected in two of the four informative primary lung cancers. FISH revealed increased copy number of the KIT gene in 3/4 of CTCL-associated lung cancers and 1/5 of primary lung cancers. PDGFRA and VEGFR2 copy numbers were also increased. IHC showed moderate KIT expression when the gene copy number was increased. CTCL-associated lung cancer shows chromosomal aberrations different from primary lung cancer, especially amplifications of 4q, a chromosome arm frequently deleted in the latter tumor type. Copy numbers and expression of selected genes in chromosome 4 differed between CTCL-associated and reference lung cancers. These preliminary observations warrant further prospective studies to identify the common underlying factors between CTCL and CTCL-associated lung cancer. This article contains Supplementary Material available at http://www.interscience.wiley.com/jpages/1045-2257/suppmat. © 2007 Wiley-Liss, Inc. [source] Geography and Environmental Studies in Australia: Symbiosis for Survival in the 21st Century?GEOGRAPHICAL RESEARCH, Issue 1 2002N. Harvey This paper presents the results of a detailed survey into the reasons for the spate of mergers between Geography and Environment Studies that took place in Australian universities from 1989 to 1999. The results, from a 1998 survey, suggest that the development of a symbiotic relationship between the two areas of study is merely a veneer masking a complexity of underlying factors. These include financial reasons, internal university politics, staff changes and mobility, and only in some cases, a genuine academic rationale for a merger. The paper concludes that the superficial appearance of a symbiosis between Geography and Environment Studies generally masks an opportunistic pragmatism which is very site specific in its complexity. The result has been a series of departmental mergers which, although providing a firmer financial footing, raise questions about the academic implications for the development of both study areas as we move into the third millennium. [source] Development Zones, Foreign Investment, and Global City Formation in Shanghai*GROWTH AND CHANGE, Issue 1 2005YEHUA DENNIS WEI ABSTRACT The rapid economic ascent of China and the increasing integration of the world economy in the past two decades have made metropolises in China such as Shanghai and Beijing emerging global cities. Foreign investment is a central force underlying the emergence and transformation of the Chinese metropolises into global cities. This is especially true in Shanghai, which has experienced massive infusion of foreign investment. Varied forms of foreign investment or development zones have been created to promote foreign investment inflows, yet remain under-studied. This paper analyzes structure, performance, and underlying factors of development zones in Shanghai, and discusses the implications for global city-formation; it unfolds the variations among development zones, and illustrates the significant role of the state and local conditions. As the literature on global cities dwells primarily on the experiences of advanced economies, this paper further contributes to a better understanding of the dynamics of emerging global cities in the developing world. [source] Relationship between cribra orbitalia and enamel hypoplasia in the early medieval Slavic population at Borovce, SlovakiaINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 3 2008Z. Obertová Abstract Cribra orbitalia and enamel hypoplasia were examined in an early medieval (8th to beginning of 12th century AD) skeletal sample of 451 individuals from Borovce, Slovakia. More than 40% of these individuals died before reaching 20 years of age. The relationship between the occurrence of orbital and enamel lesions was analysed by focusing on the age-specific distribution, and on its influence on demographic parameters. Both features were found in 11.2% of the observed skulls. The presence of orbital and dental lesions showed a considerable impact on mortality as well as the life expectancy. Generally, the highest mortality was observed among 0,4 year old individuals. The greatest discrepancy in the demographic parameters, however, appeared between the affected and unaffected individuals aged 10,14 and 15,19 years. In these two age groups the co-occurrence of both lesions was most frequently recorded. These individuals obviously had a history of sickness, and thus could not cope with further bouts of disease and with the increased physiological demands of pubertal growth. The missing correlation in younger age categories can be largely explained by the difficulty of macroscopically examining the permanent dentition, since an interrelationship between the age at hypoplasia development and the occurrence of cribra orbitalia was detected. Several differences between the individuals with enamel defects and both conditions were observed in the distribution of age at hypoplasia formation. According to these results, several factors, such as impaired health status, growth demands and diet, influence the development of enamel hypoplasia and cribra orbitalia in a particular population. It is possible that after reaching a certain threshold, the underlying factors act synergistically in a kind of vicious cycle as the balance between the immune system, metabolism, and exogenous factors such as pathogens and nutrition, is disturbed. Copyright © 2007 John Wiley & Sons, Ltd. [source] Selling adventure tourism: a distribution channels perspectiveINTERNATIONAL JOURNAL OF TOURISM RESEARCH, Issue 4 2007Christian Schott Abstract This paper examines the distribution channels structure as well as the underlying factors influencing the most prominent channel choices within the adventure tourism industry. It is based on in-depth interviews with adventure tourism operators in Queenstown, New Zealand. The findings suggest that the distribution structure is similar to other attraction sectors and that business size has some bearing on the ,length' of the distribution chains. However, regardless of business size, the sector places a clear priority on ,at destination' distribution, and the factors underlying this choice were found to be varied and reflective of both sector-specific demand and supply characteristics. Copyright © 2007 John Wiley & Sons, Ltd. [source] Phylogeographical structure in the coastal species Senecio rodriguezii (Asteraceae), a narrowly distributed endemic Mediterranean plantJOURNAL OF BIOGEOGRAPHY, Issue 7 2009Arántzazu Molins Abstract Aim, Our goals were (1) to assess the levels of chloroplast DNA variation in a narrowly distributed plant restricted to continental islands, (2) to ascertain whether a phylogeographical structure is present in plants restricted to coastal linear systems, and (3) to interpret the results in the light of the known palaeogeography of these islands. Location, The Eastern Balearic Islands (Majorca and Minorca) in the Western Mediterranean Basin. Methods, Sampling included 134 individuals from 28 populations of Senecio rodriguezii covering the entire range of the species. Sequences of the chloroplast genome (trnT,trnL spacer) were obtained and parameters of population genetic diversity and substructure were determined (hsht, Gst). The geographical structure of genetic variation was assessed by an analysis of molecular variance (AMOVA). Additionally, a spatial AMOVA (SAMOVA) was used to identify groups of populations that were geographically homogeneous and maximally differentiated from each other. Finally, a pattern of isolation by distance was assessed by testing the correlation between the matrix of pairwise ,ST values and the matrix of geographical distances between pairs of populations using a Mantel test. Results, Seven haplotypes were detected in S. rodriguezii. Only two of them were shared between islands; all of the others were restricted to Majorca (two) or Minorca (three). Overall, we found high levels of genetic diversity and significant geographical structuring of cpDNA markers. Most of the variation detected can be attributed to differences among populations (84.6%), but there was also a significant differentiation between the islands. Main conclusions, Our results support the view that the Balearic Islands constitute a reservoir of genetic diversity, not only for widespread Mediterranean taxa, but also for endemic ones. The intraspecific genetic structure found in S. rodriguezii suggests that its population history was dominated by both expansion and contraction events. This has resulted in a species that is highly structured genetically, showing very few shared haplotypes between islands, and a high number of haplotypes restricted to small geographical areas within the islands. Changes in habitat availability and dynamic processes of population fragmentation and connectivity due to repeated cycles of sea-level changes during the Quaternary are the possible underlying factors that have shaped the cpDNA pool of this endemic species on a regional scale. [source] Inhibitory effects of Cu, Zn, Ni and Co on nitrification and relevance of speciationJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 4 2010Ferhan Çeçen Abstract BACKGROUND: The speciation of metals is often overlooked in understanding their observed inhibitory effect in biological systems, in particular in nitrification systems. This study examines the effects of Cu, Zn, Ni and Co on a nitrifying sludge, where the aim is to relate inhibition to speciation. RESULTS: Nitrification inhibition was monitored by O2 and CO2 measurements, an approach rarely followed to date. The IC50 value of each metal was expressed in terms of total, free and labile metal. Zn and Cu formed similar species, but had different free and labile fractions. Although free and labile fractions of Cu were much lower than the others, it was the most inhibitory metal. Ni and Co exhibited quite different inhibitory effects on nitrification despite the formation of similar metal species. Co was the least inhibitory metal and exhibited its effect very slowly. CONCLUSION: The study is among the few which examine inhibition and speciation of several metals in a comparative way. In the same nitrification medium each metal formed different species, which is a factor to be considered in interpretation of inhibition. The results may be projected to nitrifying systems to clarify the underlying factors in inhibition. Copyright © 2009 Society of Chemical Industry [source] On the self-weighted alternating trilinear decomposition algorithm,the property of being insensitive to excess factors used in calculationJOURNAL OF CHEMOMETRICS, Issue 5 2001Zeng-Ping Chen Abstract PARAFAC is well known as an iterative trilinear decomposition method. In practice, an accurate estimation of the number of underlying factors is required; otherwise it is difficult to guarantee the chemical meaning of the results obtained. The absence of a versatile chemometric method for factor estimation has often caused problems for analysts. With the advent of ATLD followed by SWATLD, the above relatively strict constraint can be relaxed. Experiments have shown that the profiles of the underlying factors can be extracted by ATLD (Wu et al., J. Chemometrics 1998; 12: 1) and SWATLD (Chen et al., Chemometrics Intell. Lab. Syst. 2000; 52: 75) as long as the number of factors used in calculation is no less than the number of actual factors. In other words, an overestimation of the number of factors will not affect the obtainment of chemically meaningful results by SWATLD and ATLD. In this paper the authors provide some simple mathematical explanations of this valuable property of SWATLD. Along with these explanations, some other properties of SWATLD as well as some guidelines for designing new trilinear decomposition methods are also discussed. Copyright © 2001 John Wiley & Sons, Ltd. [source] Heritable variation and genetic correlation of quantitative traits within and between ecotypes of Avena barbataJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 3 2008K. M. GARDNER Abstract We examined heritable variation for quantitative traits within and between naturally occurring mesic and xeric ecotypes of the slender wild oat (Avena barbata), and in 188 recombinant inbred lines derived from a cross between the ecotypes. We measured a suite of seedling and adult traits in the greenhouse, as well as performance-related traits in field sites native to the two ecotypes. Although the ecotypes were genetically diverged for most traits, few traits showed significant heritable variation within either ecotype. In contrast, considerable heritable variation was released in the recombinant progeny of the cross, and transgressive segregation was apparent in all traits. Heritabilities were substantially greater in the greenhouse than in the field, and this was associated with an increase in environmental variance in the field, rather than a decrease in genetic variance. Strong genetic correlations were evident among the recombinants, such that 22 measured traits could be well represented by only seven underlying factors, which accounted for 80% of the total variation. The primary axis of variation in the greenhouse described a trade-off between vegetative and reproductive allocation, mediated by the date of first flowering, and fitness was strongly correlated with this trade-off. Other factors in the greenhouse described variation in size and in seedling traits. Lack of correlation among these factors represents the release of multivariate trait variation through recombination. In the field, a separate axis of variation in overall performance was found for each year/site combination. Performance was significantly correlated across field environments, but not significantly correlated between greenhouse and field. [source] Underlying mechanism of portal hypertensive gastropathy in cirrhosis: A hemodynamic and morphological approachJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 9 2009Lílian Amorim Curvêlo Abstract Background and Aim:, Portal hypertensive gastropathy (PHG) is an important cause of bleeding in patients with cirrhosis associated with portal hypertension. Histologically, the condition is characterized by dilation of the mucosal and submucosal vessels of the stomach; however, its mechanisms remain unclear. The aim of the present cross-sectional study was to evaluate the role of portal and systemic hemodynamic features, humoral factors and hepatocellular function in the development and severity of PHG in patients with cirrhosis. Methods:, Forty-six patients with cirrhosis of different etiologies underwent endoscopy. Portal hypertension was evaluated by hepatic venous pressure gradient (HVPG). The gastric mucosa was analyzed using two diagnostic methods: endoscopy according to the McCormack criteria and histological by histomorphometric analysis. Results:, The prevalence of PHG according to the endoscopic and histomorphometric methods was 93.4% and 76.1%, respectively. There were no statistically significant differences in HVPG measurements between the patients with mild (16.0 ± 5.9 mmHg) and severe PHG (16.9 ± 6.5 mmHg; P = 0.80) or between patients who did not have (15.2 ± 8.0 mmHg) and those who had PHG (16.3 ± 5.7 mmHg). No correlation was found between the presence or severity of PHG and systemic vascular resistance index (P = 0.53 and 0.34, respectively), Child,Pugh classification (P = 0.73 and 0.78, respectively) or glucagon levels (P = 0.59 and 0.62, respectively). Conclusions:, The present data show no correlation between the presence or the severity of PHG and portal pressure, Child,Pugh classification or systemic hemodynamics, suggesting that other factors may be involved in the physiopathology of PHG, such as local gastric mucosal factors or other underlying factors. [source] An econometric analysis of regional adoption patterns of Bt maize in GermanyAGRICULTURAL ECONOMICS, Issue 3-4 2010Nicola Consmüller Bt maize; Genetically modified organisms (GMO); Germany; Panel data analysis Abstract In this study, our goal is to identify and explain the underlying factors that drive regional adoption of Bt maize MON810 in Germany. Since regional differences cannot be explained by the occurrence of the target pest alone, we assume that under the given regulatory framework for genetically modified (GM) crop production in Germany, farm structures as well as the sociopolitical environment have also influenced regional adoption rates during the past years. Following a description of the relevant legal and economic framework in Germany, we develop theoretical hypotheses for regional variation in Bt maize adoption and test them econometrically with unique data at the federal state (Laender) and county (Landkreis) level. According to our analysis at the federal state level, the maize acreage per farm is the main driver of Bt maize adoption. In addition, there are signs that public opposition to GM cultivation as measured by membership in the German Friends of the Earth association significantly dampens GM cultivation. At the level of Brandenburg counties, the regional infestation frequency of the European Corn Borer, the target pest of Bt-Maize, is the major determinant of adoption. Although Bt maize is a scale-neutral technology for controlling damages caused by the Corn Borer, additional fixed costs due to regulation make the technology scale dependent. [source] Markers of Overcrowding in a Pediatric Emergency DepartmentACADEMIC EMERGENCY MEDICINE, Issue 2 2010Antonia S. Stang MD Abstract Objectives:, The objective of this study was to identify markers of overcrowding in pediatric emergency departments (PEDs) according to expert opinion and then to use statistical methods to further explore the underlying construct of overcrowding. Methods:, A cross-sectional survey of all PED directors (n = 12) and pediatric emergency medicine fellowship program directors (n = 10) across Canada was conducted to elicit expert opinion on relevant markers of emergency department (ED) crowding. The list of markers was reduced to those specific to the ED for which data could be extracted from one tertiary care PED from an existing computerized patient tracking system. Data representing 2,190 consecutive shifts and 138,361 patient visits were collected between April 2005 and March 2007. Common factor analysis (CFA) was used to determine the underlying factors that best represented overcrowding as determined by markers identified by experts in pediatric emergency medicine Results:, The main markers of overcrowding identified by the survey included measures of patient volume (25%), ED operational processes (55%), and delays in transferring patients to inpatient beds (13%). Data collected on 41 markers were retained for the CFA. The results of the CFA indicated that the largest portion of variation in the data (48%) was accounted for by markers describing patient volumes and flow through the ED. Measures of admission delays accounted for a smaller proportion of variability (9%). Conclusions:, The results suggest that for this tertiary PED, markers of ED operational processes and patient volume may be more relevant for determination of overcrowding than markers reflecting delays in transferring patients to inpatient beds. This study provides a foundation for further research on markers of overcrowding specific to the pediatric setting. ACADEMIC EMERGENCY MEDICINE 2010; 17:151,156 © 2010 by the Society for Academic Emergency Medicine [source] Maternal, paternal and environmental tobacco smoking and breast feedingPAEDIATRIC & PERINATAL EPIDEMIOLOGY, Issue 3 2002Gabriel M. Leung Summary The effects of environmental tobacco smoke (ETS) on breast-feeding patterns are poorly understood, while those of parental smoking on breast-feeding initiation vs. duration have not been clearly delineated. We conducted a prospective, population-based birth cohort study to examine the independent effects of maternal, paternal and ETS on breast-feeding initiation and duration. A total of 6747 Hong Kong Chinese infants were recruited and followed up in 1997,8. We obtained detailed household smoking history and recorded breast-feeding patterns in three follow-up interviews over 9 months. We found that both maternal and paternal smoking were associated with not initiating breast feeding (odds ratio [OR] for ever maternal smoking = 2.51, 95% confidence interval [CI] = 1.63, 3.86; OR for ever paternal smoking = 1.22, 95% CI = 1.08, 1.39). Exposure to ETS in utero and post partum were also related to not starting breast feeding (ORETS in utero = 1.10, 95% CI = 0.99,1.24; ORETS post partum = 1.21, 95% CI = 1.08, 1.36). These effects, however, did not persist for breast-feeding duration of , 4 months. Cox proportional hazards modelling confirmed the lack of association between any form of smoking and breast-feeding duration. Our findings suggest that smoking of any kind, during or after pregnancy, is a strong risk indicator for not initiating breast feeding. Smoking as a risk indicator for underlying socio-economic, demographic and psychosocial factors is probably responsible for most of the observed adverse effects, although we cannot rule out direct contributions from pathophysiological mechanisms. Public health strategies directed at these underlying factors should be vigorously pursued to reduce the adverse effects of tobacco on breast feeding and infant health in general. [source] Determinants of Chinese consumers' green purchase behaviorPSYCHOLOGY & MARKETING, Issue 4 2001Ricky Y. K. Chan This study examines the influence of various cultural and psychological factors on the green purchase behavior of Chinese consumers. To this end, a conceptual model has been proposed and subjected to empirical verification with the use of a survey. The survey results obtained in two major Chinese cities provide reasonable support for the validity of the proposed model. Specifically, the findings from the structural-equation modeling confirm the influence of the subjects' man,nature orientation, degree of collectivism, ecological affect, and marginally, ecological knowledge, on their attitudes toward green purchases. Their attitudes toward green purchases, in turn, are also seen to affect their green purchase behavior via the mediator of green purchase intention. Although the present findings provide a better understanding of the process and significant antecedents of green purchasing, they also highlight two areas for more thorough investigation. These are the exact role of ecological knowledge in Chinese consumers' green purchasing process and the underlying factors that account for their low level of green purchase. This study also discusses how the present findings may help the Chinese government and green marketers to fine-tune their environmental programs. © 2001 John Wiley & Sons, Inc. [source] Assessing spiritual growth and spiritual decline following a diagnosis of cancer: reliability and validity of the spiritual transformation scalePSYCHO-ONCOLOGY, Issue 2 2008Brenda S. Cole Abstract This study assessed the factor structure, reliability, and validity of an instrument designed to assess spiritual transformations following a diagnosis of cancer,the Spiritual Transformation Scale (STS). The instrument was administering to 253 people diagnosed with cancer within the previous 2 years. Two underlying factors emerged (spiritual growth (SG) and spiritual decline (SD)) with adequate internal reliability (alpha=0.98 and 0.86, respectively) and test,retest reliability (r=0.85 and 0.73, respectively). Validity was supported by correlations between SG and the Positive and Negative Affect Scale (PANAS) Positive Affect Subscale (r=0.23, p<0.001), the Daily Spiritual Experiences Scale (r=0.57, p<0.001), and the Post-traumatic Growth Inventory (r=0.68, p<0.001). SD was associated with higher scores on the Center for Epidemiological Studies Depression scale (r=0.38, p<0.001) and PANAS-Negative Affect Subscale (r=0.40, p<0.001), and lower scores on the PANAS-Positive Affect Subscale (r=,0.23, p<0.001), and the Daily Spiritual Experiences Scale (r=,0.30, p<0.001). Hierarchical regression analyses indicated that the subscales uniquely predicted adjustment beyond related constructs (intrinsic religiousness, spiritual coping, and general post-traumatic growth). The results indicate that the STS is psychometrically sound, with SG predicting better, and SD predicting poorer, mental and spiritual well-being following a diagnosis of cancer. Copyright © 2007 John Wiley & Sons, Ltd. [source] Fiscal Decentralization and Provincial-Level Fiscal Disparities in China: A Sino-U.S. Comparative PerspectivePUBLIC ADMINISTRATION REVIEW, Issue 2009Zhirong Jerry Zhao Since China's 1994 fiscal reform, increasing concerns have been voiced about fiscal disparities across the country. Can local governments fairly and effectively fulfill basic public services such as primary education, public health, and social welfare? This essay traces the evolution of intergovernmental relations in China since 1978. The fluctuation of provincial level fiscal distribution over time and the underlying factors behind fiscal inequality, as compared to a decentralized American revenue system, are analyzed. The author, Zhirong Jerry Zhao of the University of Minnesota, argues for additional research on alternative measures of local fiscal capacity. [source] Reducing Infant Mortality Rates Using the Perinatal Periods of Risk ModelPUBLIC HEALTH NURSING, Issue 1 2005Paulette G. Burns Abstract, Despite decreases in the last 50 years, infant mortality rates in the United States remain higher than in other industrialized countries. Using overall infant mortality rates to determine the effectiveness of interventions does not help communities focus on particular underlying factors contributing to static, and sometimes increasing, community rates. This study was designed to determine and rank contributing factors to fetal-infant mortality in a specific community using the Perinatal Periods of Risk (PPOR) model. The PPOR model was used to map fetal-infant mortality for 1995 to 1998 in the Tulsa, Oklahoma, Healthy Start Program as compared to traditional calculation methods. The overall fetal-infant mortality rate using the PPOR model was 12.7 compared to 7.11 calculated using the traditional method. The maternal health cell rate was 5.4, maternal care cell rate was 2.9, newborn care cell was 1.9 compared to a 4.1 neonatal death rate calculated using the traditional method, and the infant health cell was 2.4 compared to a 2.9 postneonatal rate calculated using the traditional method. Because the highest infant mortality was in the maternal health cell, intervention strategies were designed to promote the health of women prior to and between pregnancies. The PPOR model was helpful in targeting interventions to reduce fetal-infant mortality based on the prioritization of contributing factors. [source] Primate communities: Past, present, and possible futureAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue S39 2004Kaye E. Reed Abstract An understanding of the fundamental causes of the structure of primate communities is important for studies of primate evolutionary history, primate behavioral ecology, and development of conservation strategies. Research into these structuring factors has benefited from new perspectives such as consideration of primate phylogenetic history, metacommunities, and interactions with predators and nonprimate competitors. This review presents the underlying factors of primate community structure within the biogeographic regions of Madagascar, the Neotropics, Africa, and Asia. One of the major differences among these locations likely resulted from the initial primate taxa that colonized each region (a single colonization event in the case of Madagascar and South America, and multiple radiations of higher-level taxa in Africa and Asia). As most primates live in forests, the differences among the forests in these locations, caused by various climatic influences, further influenced speciation and the development of primate communities. Within these habitats, species interactions with different groups of organisms were also instrumental in developing community dynamics. Through an investigation of these fundamental factors, we identify some of the most important effects on primate communities in each region. These findings suggest that low primate richness in Asia may be caused by either the abundance of dipterocarp trees or high levels of monsoon rains. High numbers of frugivores and a lack of folivores in neotropical communities may be associated with competiton with sloths that were already present at the time of initial radiation. Climatic patterns which affect forest structure and productivity in Madagascar may be responsible for high numbers of folivorous lemurs. The identification of these factors are important for the conservation of existing primate communities, and indicate directions for future studies. Yrbk Phys Anthropol 47:2,39, 2004. © 2004 Wiley-Liss, Inc. [source] | |||||||||||||||||||||||||||||||