bluuebunny/crossref_metadata_2025_split huggingface dataset:
Above‐ground forest biomass is not consistently related to wood density in tropical forests
Authors: Stegen James C. , Swenson Nathan G. , Valencia Renato , Enquist Brian J. , Thompson Jill 
Published: June 2009

ABSTRACTAim  It is increasingly accepted that the mean wood density of trees within a forest is tightly coupled to above‐ground forest biomass. It is unknown, however, if a positive relationship between forest biomass and mean community wood density is a general phenomenon across forests. Understanding spatial variation in biomass as a function of wood density both within and among forests is important for predicting changes in stored carbon in response to global change, and here we evaluated the generality of a positive biomass–wood density relationship within and among six tropical forests.Location  Costa Rica, Panama, Puerto Rico and Ecuador.Methods  Individual stem data, including diameter at breast height and spatial position, for six forest dynamics plots were merged with an extensive wood density database. Individual stem biomass values were calculated from these data using published statistical models. Total above ground biomass, total basal area and mean community wood density were also quantified across a range of subcommunity plot sizes within each forest.Results  Among forests, biomass did not vary with mean community wood density. The relationship between subcommunity biomass and mean wood density within a forest varied from negative to null to positive depending on the size of subcommunities and forest identity. The direction of correlation was determined by the associated total basal area–mean wood density correlation, the slope of which increased strongly with whole forest mean wood density.Main conclusions  There is no general relationship between forest biomass and wood density, and in some forests, stored carbon is highest where wood density is lowest. Our results suggest that declining wood density, due to global change, will result in decreased or increased stored carbon in forests with high or low mean wood density, respectively.
Pervasive effects of dispersal limitation on within‐ and among‐community species richness in agricultural landscapes
Authors: Hendrickx Frederik , Maelfait Jean‐Pierre , Desender Konjev , Aviron Stephanie , Bailey Debra , Diekotter Tim , Lens Luc , Liira Jaan , Schweiger Oliver , Speelmans Marjan , Vandomme Viki , Bugter Rob 
Published: June 2009

ABSTRACTAim  To determine whether the effect of habitat fragmentation and habitat heterogeneity on species richness at different spatial scales depends on the dispersal ability of the species assemblages and if this results in nested species assemblages.Location  Agricultural landscapes distributed over seven temperate Europe countries covering a range from France to Estonia.Methods  We sampled 16 local communities in each of 24 agricultural landscapes (16 km2) that differ in the amount and heterogeneity of semi‐natural habitat patches. Carabid beetles were used as model organisms as dispersal ability can easily be assessed on morphological traits. The proximity and heterogeneity of semi‐natural patches within the landscape were related to average local (alpha), between local (beta) and landscape (gamma) species richness and compared among four guilds that differ in dispersal ability.Results  For species assemblages with low dispersal ability, local diversity increased as the proximity of semi‐natural habitat increased, while mobile species showed an opposite trend. Beta diversity decreased equally for all dispersal classes in relation to proximity, suggesting a homogenizing effect of increased patch isolation. In contrast, habitat diversity of the semi‐natural patches affected beta diversity positively only for less mobile species, probably due to the low dispersal ability of specialist species. Species with low mobility that persisted in highly fragmented landscapes were consistently present in less fragmented ones, resulting in nested assemblages for this mobility class only.Main conclusions  The incorporation of dispersal ability reveals that only local species assemblages with low dispersal ability show a decrease of richness as a result of fragmentation. This local species loss is compensated at least in part by an increase in species with high dispersal ability, which obscures the effect of fragmentation when investigated across dispersal groups. Conversely, fragmentation homogenizes the landscape fauna for all dispersal groups, which indicates the invasion of non‐crop habitats by similar good dispersers across the whole landscape. Given that recolonization of low dispersers is unlikely, depletion of these species in modern agricultural landscapes appears temporally pervasive.
What Wall Street Wants – Exploring the Role of Security Analysts in the Evolution and Spread of Management Concepts
Authors: Nicolai Alexander T. , Schulz Ann‐Christine , Thomas Thomas W. 
Published: June 2009

abstractThis paper discusses the role of security analysts in the dissemination of popular management concepts, drawing on neo‐institutional and management fashion theory. Focusing on the core competence concept, we investigate whether security analysts swing with the popularity of a management concept or serve as a corrective that secures the rationality of managerial actions. Through our analysis, which uses data for US‐based firms spanning the period 1990–2002, we show that during the 1990s analysts systematically overvalued the future earnings of refocusing firms that incorporated principles derived from the core competence concept. Moreover, we present evidence that their valuations were positively influenced by the popularity of the core competence discourse and exhibited a systematic bias. Our results suggest a more nuanced understanding of the dynamics underlying the popularization processes of management concepts. In addition to the classical bandwagon‐effects discussed in neo‐institutional theory, we argue that the mediating role of security analysts and their impact on stock‐market prices promote the diffusion of new management concepts.
Immigration, Ethnic Wage Differentials and Output Pay in Canada
Authors: Fang Tony , Heywood John S. 
Published: June 2009

AbstractRecent work suggests that ethnic minority wage differentials in Canada are smaller among those receiving performance pay and that the returns to performance pay are larger for ethnic minorities. This article adds to these findings. First, it demonstrates critical gender differences. The earlier findings are generated almost exclusively by males, as we show that the minority wage differential is small or zero for women in both the time rate sector and the performance pay sector. Second, accounting for immigration and language tends to move the ethnic wage differential in favour of minorities. Minority women on output pay are shown to earn more than non‐minority women. While the differential often remains negative for minority men on time rates, it becomes insignificant in our most narrow comparison.
The Political Economy of Occupational Family Policies: Comparing Workplaces in Britain and Germany
Authors: Seeleib‐Kaiser Martin , Fleckenstein Timo 
Published: June 2009

AbstractWith a shift in the political debate to more market‐driven social policy approaches during the past decade, politicians in a number of European countries have argued that employers should take on greater responsibilities in the provision of social policy. But why should employers get involved? After reviewing the relevant literature on firm‐level social policy, we analyse the conditions and causal pathways that lead to their provision. Our findings show that (i) the skill structure and level of the workforce are important conditions for firm‐level engagement; (ii) employers have usually been the ‘protagonists’; (iii) the role of unions has been more limited — in Germany they can largely be characterized as ‘consenters’, whereas in Britain, their impact is negligible; (iv) in accordance with the specific systems of industrial relations, the design in Germany very much follows the concept of social partnership; in Britain the design is usually based on unilateral management decisions; and (v) based on these conditions and causal pathways, ‘enclave social policy’ is the likely result of the expansionary policy development, although in Germany, these policies have the potential of becoming an element of ‘industrial citizenship’.
ON CONSUMERS' VALUATION OF NUTRITION INFORMATION
Authors: Drichoutis Andreas C. , Lazaridis Panagiotis , Nayga Jr Rodolfo M. 
Published: June 2009

ABSTRACTThe European Union (EU) is contemplating regulations requiring mandatory provision of nutritional information on food products. This study analyses consumers' valuation of nutritional information using data collected from a field survey. The results generally suggest that consumers value and are willing to pay about 5.9 percent of the original price for nutritional information on the food product we studied. Individuals who are non‐price‐sensitive, nutritionally knowledgeable and with longer time horizon are willing to pay more for nutritional information than others. Considering consumers' willingness to pay for nutritional information on food products and an EU impact assessment study, the costs of provision of this information are not prohibitive to firms. We estimate that the least conservative cost of labelling to the firm for a specific food product can be as much as €29,431, whereas the average economic value of nutrition information is estimated at €17,064. The firm can therefore recoup the associated costs in less than two months.
COMMODITY TAX STRUCTURE AND INFORMAL ACTIVITY
Authors: Delipalla Sophia 
Published: June 2009

ABSTRACTCommodity tax structure affects the firm's choice between formality and informality. An increase in the specific tax rate, relative to an equivalent increase in ad valorem taxation, makes informality attractive to more firms. Formality becomes attractive at lower levels of profits under ad valorem taxation. For both the maximization of welfare subject to a revenue constraint and the unconstrained maximization of revenue, the optimal rate of specific taxation is zero.
PUBLIC PROGRAMS PARE POVERTY: EVIDENCE FROM CHILE
Authors: Glick David , Menon Nidhiya 
Published: June 2009

ABSTRACTThis study examines the effect of government health care and education programs on the poor in Chile from 2000 to 2006. Results are obtained from a country‐wide provincial‐level panel data set with information on poverty and indigence head‐count ratios, measures on the severity of poverty as captured by the Foster–Greer–ThorbeckeP2statistic, per capita public expenditures on health and education, as well as other variables that are thought to influence well‐being. We use fixed‐effects techniques to correct for time‐invariant province‐specific characteristics that may affect program placement. Our analysis demonstrates that per capita public health and education expenditures significantly reduce the incidence of poverty and indigence in Chile. In particular, for a 10,000 pesos (about $23) increase in provincial per capita health spending, the poverty head‐count ratio decreases by 0.48 percent. Per capita education expenditures are particularly important to reducing the severity of poverty. Our results indicate that for a 10,000 pesos increase in education spending, the severity of poverty declines by as much as 1.53 percent. Furthermore, we provide evidence that public spending in Chile is non‐random. In particular, government education expenditures may be allocated in keeping with compensatory motives.
ENVY, INSTITUTIONS AND GROWTH
Authors: Mitsopoulos Michael 
Published: June 2009

ABSTRACTThe use of interdependent preferences provides an intuitive link between institutions and growth. Envious agents that care about relative wealth choose to use an available destruction technology to inflict harm on the wealth of other agents when institutions fail to make property rights secure, while they use a production technology to increase their wealth when institutions make it easy and hassle‐free to engage in production. The use of interdependent preferences is justified by an extensive literature and can provide a motive for agents to take actions that block growth in the absence of theft or other concrete gains.
Representation of Uncertainty and Integration of PGIS‐based Grazing Intensity Maps Using Evidential Belief Functions
Authors: Bemigisha Jane , Carranza John , Skidmore Andrew K. , McCall Mike , Polce Chiara , Prins Herbert H.T. 
Published: June 2009

AbstractIn a project to classify livestock grazing intensity using participatory geographic information systems (PGIS), we encountered the problem of how to synthesize PGIS‐based maps of livestock grazing intensity that were prepared separately by local experts. We investigated the utility of evidential belief functions (EBFs) and Dempster's rule of combination to represent classification uncertainty and integrate the PGIS‐based grazing intensity maps. These maps were used as individual sets of evidence in the application of EBFs to evaluate the proposition that “This area or pixel belongs to the high, medium, or low grazing intensity class because the local expert(s) says (say) so”. The class‐area‐weighted averages of EBFs based on each of the PGIS‐based maps show that the lowest degree of classification uncertainty is associated with maps in which “vegetation species” was used as the mapping criterion. This criterion, together with local landscape attributes of livestock use may be considered as an appropriate standard measure for grazing intensity. The maps of integrated EBFs of grazing intensity show that classification uncertainty is high when the local experts apply at least two mapping criteria together. This study demonstrates the usefulness of EBFs to represent classification uncertainty and the possibility to use the EBF values in identifying and using criteria for PGIS‐based mapping of livestock grazing intensity.
Oral manifestations of inflammatory bowel disease: a review based on the observation of six cases
Authors: Lourenço SV , Hussein TP , Bologna SB , Sipahi AM , Nico MMS 
Published: June 2009

AbstractInflammatory bowel disease (IBD) comprises two chronic, tissue‐destructive, clinical entities: Crohn's disease (CD) and ulcerative colitis (UC), both immunologically based. Bowel symptoms are predominant, but extra‐intestinal complications may occur, including involvement of the oral cavity. Oral involvement during IBD includes several types of lesions: the most common are aphthae; uncommon lesions include, among others, pyostomatitis vegetans and granulomatous lesions of CD. Starting with a presentation of six patients with oral manifestations, which were crucial for the final diagnosis of IBD, a review on the subject is presented. Oral involvement in IBD may be previous or simultaneous to the gastrointestinal symptoms. However, in the majority of cases, bowel disease precedes the onset of oral lesions by months or years. In many patients, the intestinal symptoms may be minimal and can go undetected; thus, most authors believe that the bowel must be thoroughly examined in all patients with suspected IBD even in the absence of specific symptoms. Usually, the clinical course of oral lesions is parallel to the activity of IBD; therefore, oral manifestations are a good cutaneous marker of IBD.
Expression of human neutrophil proteins in acne vulgaris
Authors: Adışen E , Yüksek J , Erdem O , Aksakal FN , Aksakal AB 
Published: June 2009

AbstractBackground  In acne vulgaris patients, the presence of a dysregulation of the production of innate and specific antimicrobial peptides has been postulated.Objective  This study aims to determine whether human neutrophil proteins (HNP) 1–3 are expressed in acne patients.Materials and methods  HNP 1–3 expression was investigated in 35 acne patients treated with isotretinoin and in 25 healthy subjects. At the beginning of the study, two skin biopsies were taken from acne patients; one biopsy was taken from an established pustule and one from uninvolved skin, and the biopsies were repeated after treatment. Only one biopsy was obtained from controls.Results  The statistical analysis showed that pustular lesions of acne patients had significantly higher levels of perivascular and interstitial HNP 1–3 expression when compared with the biopsy of uninvolved skin of these patients (P = 0.003, P = 0.001, respectively) and with that of healthy controls (P = 0.007, P = 0.014, respectively). Isotretinoin treatment achieved a decrease in the perivascular and interstitial HNP 1–3 expression of pustular lesions (P = 0.01, P = 0.001, respectively).Conclusion  Our current study demonstrates the novel observation that a recently identified antimicrobial peptide, HNP 1–3, is expressed in neutrophils of acne inflammation but not in uninvolved skin of these patients. These results suggest that HNP 1–3 may contribute to the development of inflammatory lesions of acne.
The movement of African elephants in a human‐dominated land‐use mosaic
Authors: Graham M. D. , Douglas‐Hamilton I. , Adams W. M. , Lee P. C. 
Published: June 2009

AbstractLand outside of gazetted protected areas is increasingly seen as important to the future of elephant persistence in Africa. However, other than inferential studies on crop raiding, very little is understood about how elephantsLoxodonta africanause and are affected by human‐occupied landscapes. This is largely a result of restrictions in technology, which made detailed assessments of elephant movement outside of protected areas challenging. Recent advances in radio telemetry have changed this, enabling researchers to establish over a 24‐h period where tagged animals spend their time. We assessed the movement of 13 elephants outside of gazetted protected areas across a range of land‐use types on the Laikipia plateau in north‐central Kenya. The elephants monitored spent more time at night than during the day in areas under land use that presented a risk of mortality associated with human occupants. The opposite pattern was found on large‐scale ranches where elephants were tolerated. Furthermore, speed of movement was found to be higher where elephants were at risk. These results demonstrate that elephants facultatively alter their behaviour to avoid risk in human‐dominated landscapes. This helps them to maintain connectivity between habitat refugia in fragmented land‐use mosaics, possibly alleviating some of the potential negative impacts of fragmentation. At the same time, however, it allows elephants to penetrate smallholder farmland to raid crops. The greater the amount of smallholder land within an elephant's range, the more it was utilized, with consequent implications for conflict. These findings underscore the importance of (1) land‐use planning to maintain refugia; (2) incentives to prevent further habitat fragmentation; (3) the testing and application of conflict mitigation measures where fragmentation has already taken place.
Vascular dysfunction in the diabetic placenta: causes and consequences
Authors: Leach Lopa , Taylor Alice , Sciota Flavia 
Published: June 2009

AbstractThe development and functioning of the human fetoplacental vascular system are vulnerable to the maternal diabetic milieu. These vessels are in direct continuum with the fetal vascular system and are therefore also vulnerable to fetal endocrine derangements. Increased angiogenesis, altered junctional maturity and molecular occupancy, together with increased leakiness, constitute a well‐described phenotype of vessels in the Type 1 diabetic human placenta and can be related to increased levels of placental vascular endothelial growth factor. The causes of these observed changes, whether maternal hyperglycaemia or fetal hyperinsulinaemia, still remain to be shown in the human placenta. Mechanistic studies using different vascular systems have shown high glucose and insulin to have profound vascular effects, with elevations in vascular endothelial growth factor, nitric oxide and protein kinase C being behind alterations in junctional adhesion molecules such as occludin and vascular endothelial‐cadherin and vascular leakage of albumin. The role of advanced glycation products and oxidative stress in this vascular pathology is also discussed. The altered molecular mechanisms underlying the vascular changes in the diabetic human placenta may reflect similar consequences of high glucose and hyperinsulinaemia.
Linked morphological changes during palate evolution in early tetrapods
Authors: Kimmel Charles B. , Sidlauskas Brian , Clack Jennifer A. 
Published: June 2009

AbstractWe examined the shapes and sizes of dermal bones of the palate of selected Palaeozoic tetrapods in order to identify the ancestral states of palatal bone morphologies in the earliest tetrapods, to learn how the composition of the palate varies within and among early tetrapod radiations, and to recognize evolutionary correlations among the size and shapes of skeletal elements in this important group of animals. We find that whereas the palatal bones themselves and their arrangements are usually conserved, considerable correlated evolutionary change occurs in the shapes and sizes of the bones. Some of the changes in the bones are allometrically linked to overall palate size, which varies more than 100‐fold among the taxa in our sample. Often, these allometries were only hinted at in traditional independent contrasts‐based regressions of log transformed data, particularly because many allometries are subtle, their slopes may vary among subclades, and the scatter around some trendlines is high. Rather, the allometries showed up in analyses of size‐standardized palatal bone dimensions investigated using independent contrasts, bivariate phylomorphospace plots, and mirrored character reconstructions on the phylogenetic tree. We find negative allometry for parasphenoid lengths and widths essentially across the entire tree of Palaeozoic tetrapods, but with different trajectories characterizing the two largest clades, the temnospondyls and the lepospondyls. The lengths of several other elements may show positive allometries, either across the entire tree or in just a subclade. One possible positive allometry exists for the ectopterygoid, which appears to shorten allometrically in temnospondyls that evolve small body and palate size, and, as inDoleserpetoncan be lost altogether. Both shortening and loss could be by the same developmental change, paedomorphosis, a form of heterochrony. Paedomorphosis might also account for evolution of relatively large parasphenoids in both lepospondyls and diminutive temnospondyls, but does not seem to explain evolution of ectopterygoid loss in lepospondyls. A regularity observed across nearly all taxa in our study set is an inverse correlation between the lengths of the vomer and pterygoid, bones that lie adjacent to one another along the long palatal axis. Further work is needed to learn whether such correlated evolution might be due to adaptation and/or to developmental bias, and particularly to learn how correlations and allometries themselves evolve.