bluuebunny/crossref_metadata_2025 huggingface dataset:
Sunflower seed deterioration as related to moisture content during ageing, energy metabolism and active oxygen species scavenging
Authors: Kibinza Serge , Vinel Dominique , Côme Daniel , Bailly Christophe , Corbineau Françoise
Published: September 2006

The objectives of the present work were to investigate whether loss of sunflower (Helianthus annuus L.) seed viability was affected by the embryo moisture content (MC) during seed pretreatment at 35°C, and was related to changes in energy metabolism and in the antioxidant defence system. Non‐dormant seeds were equilibrated at MC of the embryonic axis ranging from 0.037 to 0.605 g H2O g−1 dry matter (DM) for 1 day at 15°C, and they were then placed at 35°C for various durations up to 14 days before the germination assays at 15°C. As expected, the higher the MC, the faster was seed deterioration. There existed a negative linear relationship between the time taken for germination to drop to 50% (P50) and the embryonic axis MC ranging from 0.108 and 0.438 g H2O g−1 DM. In dry seeds, adenosine triphosphate (ATP), adenosine diphosphate (ADP) and adenosine monophosphate represented 6.3, 14.8 and 70.9% of the adenylate pool, respectively, and the energy charge (EC) was very low (0.14). ATP and ADP levels and EC increased sharply during the first day of equilibrium of seeds at a MC above 0.158 g H2O g−1 DM. Subsequent controlled deterioration at 35°C resulted in a decrease in the adenylate pool, and consequently in ATP level. The higher the energy metabolism during ageing, the lower was seed viability. Loss of seed viability was associated with an accumulation of H2O2, and then of malondialdehyde (MDA) suggesting that lipid peroxidation was not the only cause of seed deterioration. When there was a sublinear relationship between H2O2 content in the embryonic axis and seed viability, MDA accumulation only occurred when 50% of the seed population died within 7 days, i.e. when MC was higher than 0.248 g H2O g−1 DM. Ageing was associated with a decrease in the activity of superoxide dismutase, catalase and glutathione reductase, the main enzymes involved in cell detoxification. The involvement of seed MC, as key factor of ageing is discussed with regards to energy metabolism and the regulation of active oxygen species accumulation.
Resolving the tragedy of the commons: the feedback between intraspecific conflict and population density
Authors: RANKIN D. J.
Published: September 2006

Competition and conflict among individuals can favour exploitative strategies that undermine the common good. Theory suggests that this can lead to a tragedy of the commons and ultimately population extinction, a phenomenon known as evolutionary suicide. Here, I present a model of the evolutionary tragedy of the commons that explicitly considers the population dynamics where individuals invest in individually costly competitive traits. In the simplest form, this supports the notion that selection for high levels of conflict can cause evolutionary suicide. However, as competition comes with survival and fecundity costs, a feedback between the investment in competition and population density can act to reduce the level of conflict and prevent the population from going extinct. This suggests that the interaction between population ecology and the evolution of competition and conflict among individuals may be an important mechanism in resolving the level of competition and conflict among individuals.
Evolutionary domestication in Drosophila subobscura
Authors: SIMÕES P. , ROSE M. R. , DUARTE A. , GONÇALVES R. , MATOS M.
Published: September 2006

The domestication of plants and animals is historically one of the most important topics in evolutionary biology. The evolutionary genetic changes arising from human cultivation are complex because of the effects of such varied processes as continuing natural selection, artificial selection, deliberate inbreeding, genetic drift and hybridization of different lineages. Despite the interest of domestication as an evolutionary process, few studies of multicellular sexual species have approached this topic using well‐replicated experiments. Here we present a comprehensive study in which replicated evolutionary trajectories from several Drosophila subobscura populations provide a detailed view of the evolutionary dynamics of domestication in an outbreeding animal species. Our results show a clear evolutionary response in fecundity traits, but no clear pattern for adult starvation resistance and juvenile traits such as development time and viability. These results supply new perspectives on the confounding of adaptation with other evolutionary mechanisms in the process of domestication.
Phrenic Nerve Distribution in the Rabbit Diaphragm and Morphometric Analysis of Nerve Branches
Authors: Turgut H. B. , Peker T. , Karaköse M. , Anil A. , Gülekon N. , Demırtaş K.
Published: September 2006

The best method to evaluate the pathogenesis of diaphragmatic disorders is to demonstrate the distribution pattern of the phrenic nerve in the diaphragm. For this purpose the branching pattern and the microanatomic features of the phrenic nerve were observed in six rabbits. All diaphragms were stained by using Sihler's stain method. The phrenic nerve divided into three to four branches when entering the diaphragm. These branches were classified as sternal, anterolateral, posterolateral and crural. The crural branches were the thickest whereas the anterolateral branches were the thinnest. Knowledge about the distribution pattern of the phrenic nerve may be important in surgical approach to the diaphragm.
The Gross Anatomy of Larynx, Trachae and Syrinx in the Long‐Legged Buzzard (Buteo rufinus)
Authors: Kabak M. , Orhan I. O. , Haziroglu R. M.
Published: September 2006

Five long‐legged buzzards (Buteo rufinus), weighing 475–570 g, were used in this study. It was determined that long‐legged buzzards’ larynx is composed of three different cartilages. Among these cartilages, the cricoid and procricoid cartilages were single and the arytenoid cartilage was double. The partially ossified corpus and ala of the cricoid cartilage were connected with cartilaginous plate. Trachea was formed up of complete cartilage circles. The tracheal cartilages were notched in dorsal and ventral directions and a number of the tracheal cartilages inter‐mingling one another were between 89–96. Syrinx, which was covered with the inter‐clavicular air sac, was in contact with basis cordis. It was observed that there is tracheobronchial type syrinx in long‐legged buzzard and this syrinx is formed by two different cartilage groups named as the cartt. tracheosyringeales and cartt. bronchosyringeales. The first cartilage rings of the cartt. tracheosyringeales formed the tympanum. The tympanum, cartt. tracheosyringeales and cartt. bronchosyringeales were created of three, two or three and four cartilage rings, respectively. Membrana tympaniformis lateralis and medialis, two pairs of thin membranes constituting voice formation, also determined in long‐legged buzzard. Membrana tympaniformis lateralis was observed to be very short between the first and second cartilage rings of cartt. bronchosyringeales. Although the instrictic syringeal muscles were not present in long‐legged buzzard, the sternotracheal and tracheolateral muscles, expressed as extrinsic syringeal muscles, were evident. In this study, which is expected to give contribution to veterinary anatomy literature, the similarities and differences in larynx, trachea and syrinx of long‐legged buzzard with other bird species were exposed.
Normal Morphometry of the Thoracic Aorta in the German Shepherd Dog: a Computed Tomographic Study
Authors: Dabanoglu I.
Published: September 2006

Computed tomographic images of the thoracic aorta of 14 German shepherd dogs were examined in order to determine the morphometry of the thoracic aorta. Examinations were carried out in the transverse plane at both intervertebral and mid‐vertebral levels of each thoracic vertebra between T5 and T13. The dorsoventral and transversal diameters as well as cross‐section area of the thoracic aorta were measured. The widest transversal diameter was observed at T4‐‐5, whereas the largest dorsoventral diameter was detected at T5. The maximum cross‐section area was detected at T4‐‐5. When dorsoventral and transversal diameters were compared between males and females, the aortic diameter was found to be smaller in males than in females. Although the shape of the thoracic aorta was transversal oval in the majority of the examined females, the shape of the thoracic aorta was dorsoventral oval in the majority of the males. There were significant differences between all levels measured for transversal (P < 0.001), dorsoventral (P < 0.001) diameters and cross‐section area (P < 0.001) of the thoracic aorta. And there was a significant correlation between the three parameters examined. However, the correlation coefficient was highest in females.
Gross Anatomy of the Portal Vein and Hepatic Artery Ramifications in Dogs: Corrosion Cast Study
Authors: Uršič M. , Ravnik D. , Hribernik M. , Pečar J. , Butinar J. , Fazarinc G.
Published: September 2006

The anatomical variations of the portal vein and the hepatic artery ramifications were analysed on liver corrosion casts in 20 dogs as a possible aid in the surgical management of the organ. The portal vein ramified similarly in all dogs. It divided into the smaller right portal branch from which vessels for the caudate process and both right lobes arose and the substantial left portal branch, which supplied the remaining liver portions and in 12 cases also the dorsal part of the right lateral lobe. Right lateral, right medial and left branches are the major arteries originating from the hepatic artery; however, their origin and course varied among individual animals. In 10 livers, the right lateral and the left branches originated from the hepatic artery, while the right medial branch arose from the left branch and usually supplied the right medial lobe solely. In nine livers, the right medial branch arose directly from the hepatic artery and supplied quadrate lobe and gallbladder as well, while in one liver the common artery, which subsequently divided into lobar branches, branched away from the hepatic artery. An additional branch for the caudate process, originating directly from the hepatic artery, was observed in 10 livers. Certain liver portions received the arterial blood from two major branches, which was particularly characteristic for the right medial lobe (six livers) and caudate process (10 livers). The course of the major arterial branches was also variable, although they proceeded in close anatomical relationship with the portal vein branches. The left arterial branch accompanied the left portal branch on its dorsal aspect (15 cases) or crossed it from the caudal aspect (five cases). The right lateral branch crossed the initial parts of the left and right portal branches either from cranial (12 cases) or caudal aspects (eight cases), while the right medial branch always crossed the left portal branch from its caudal aspect.
Effect of losartan on early liver fibrosis development in a rat model of nonalcoholic steatohepatitis
Authors: Ibañez Patricio , Solis Nancy , Pizarro Margarita , Aguayo Gloria , Duarte Ignacio , Miquel Juan Francisco , Accatino Luigi , Arrese Marco
Published: September 2006

Background and Aim:  Nonalcoholic steatohepatitis (NASH) is a metabolic disorder of the liver that may evolve into fibrosis or cirrhosis. Recent studies have shown reduction of experimental liver fibrosis with the use of angiotensin‐converting‐enzyme inhibitors or angiotensin‐receptor antagonists. The aim of this study was to determine whether losartan can influence the early phase of fibrogenesis in an animal model of NASH.

Methods:  To induce NASH, a choline‐deficient diet (CDD) was given to Sprague‐Dawley rats for 12 weeks. These animals were then compared with a control group receiving choline‐supplemented diet (CSD) and a group fed a CDD plus losartan (10 mg/kg/day). Biochemical (serum levels of alanine aminotransferase and aspartate aminotransferase) and histological evaluation of fatty liver was performed by conventional techniques. Hydroxyproline content in liver tissue was assayed by spectrophotometry. In addition, mRNA levels of procollagen I and transforming growth factor (TGF)‐β were assessed by semiquantitative RT‐PCR and stellate cell activation by α‐actin immunofluorescence stain.

Results:  After 12 weeks CDD induced a marked elevation of serum aminotranferases, a severe fatty liver infiltration with mild histological inflammation and fibrosis. These findings correlated with a significant increase in mRNA levels of both procollagen I and TGF‐β and significant increased liver hydroxyproline content. No differences were seen between rats receiving CDD alone and rats receiving CDD plus losartan with regard to the biochemical, morphological or molecular alterations induced by the CDD.

Conclusion:  Losartan does not seem to influence liver injury and fibrogenic events in the CDD model of NASH.
Effect of esomeprazole and rabeprazole on intragastric pH in healthy Chinese: An open, randomized crossover trial
Authors: Li Zhao‐Shen , Zhan Xian‐Bao , Xu Guo‐Ming , Cheng Neng‐Neng , Liao Zhuan
Published: September 2006

Background and Aim:  Esomeprazole is the S‐isomer of omeprazole, with a stronger acid suppressive effect than omeprazole. This open, randomized crossover study was designed to evaluate the effect of esomeprazole and another proton‐pump inhibitor, rabeprazole, on intragastric pH in healthy Chinese.

Methods:  Thirty‐six healthy volunteers (26 men and 10 women, aged between 20 and 31 years) were enrolled. Subjects were given either esomeprazole 40 mg (n = 18) or rabeprazole 10 mg (n = 18) orally once daily for 5 days during the first dosing period, then the other medicine at the set dosage for the second dosing period. The two periods were separated by a 14‐day washout phase. The doses were chosen according to the State Food and Drug Administration of China for the treatment of acid‐related diseases. Intragastric pH was continuously monitored for 24 h on days 1 and 5 of each dosing period. CYP2C19 genotypes were analyzed to identify the extensive metabolizers (EM) and poor metabolizers (PM).

Results:  The percentage of time with intragastric pH >4 was significantly higher (P < 0.001) in subjects receiving esomeprazole than in those receiving rabeprazole in the first 4 h after administration of the first dose (70.65% vs 44.87%), at 24 h on day 1 (73.7% vs 54.8%) and at 24 h on day 5 (84.2% vs 76.2%). The median intragastric pH was also higher in subjects receiving esomeprazole than in those receiving rabeprazole in the first 6 h, day 1 and day 5 (P ≤ 0.001). The percentage of subjects with intragastric pH >4 for at least 16 h on day 1 (63.9% vs 33.3%) and on day 5 (88.9% vs 61.1%) was higher after administration of esomeprazole than after rabeprazole (both P < 0.05). On genotype analysis, 28 of the subjects were EM and eight were PM. Those who were PM tended to have a higher, albeit not statistically significant, percentage of time with intragastric pH >4 and the median 24‐h intragastric pH than those who were EM. Both drugs were well tolerated.

Conclusions:  Esomeprazole 40 mg orally once daily is more effective and faster in increasing intragastric pH than rabeprazole 10 mg orally once daily, and thus offers a potential for improved efficacy in acid‐related diseases.
Investigation into the signal transduction pathway via which heat stress impairs intestinal epithelial barrier function
Authors: Yang Ping‐Chang , He Shao‐Heng , Zheng Peng‐Yuan
Published: September 2006

Background and Aims:  Intact protein absorption is thought to be a causative factor in several intestinal diseases, such as food allergy, celiac disease and inflammatory bowel disease. However, the mechanism remains unclear. The aim of this study was to characterize a novel signal transduction pathway via which heat stress compromises intestinal epithelial barrier function.

Methods:  Heat stress was carried out by exposing confluent human intestinal epithelial cell line T84 cell monolayers to designated temperatures (37–43°C) for 1 h. Transepithelial electric resistance (TER) and permeability to horseradish peroxidase (HRP, molecular weight = 44 000) were used as indicators to assess the intestinal epithelial barrier function. Phosphorylated myosin light chain (MLC), MLC kinase (MLCK) and protein kinase C (PKC) protein of the T84 cells were evaluated in order to identify the signal transduction pathway in the course of heat stress‐induced intestinal epithelial barrier dysfunctions.

Results:  The results showed that exposure to heat stress significantly increased intact protein transport across the intestinal epithelial monolayer; the amount of phospho‐PKC, phospho‐MLCK and phospho‐MLC proteins in T84 cells decreased significantly at 41°C and 43°C although they increased at 39°C. The heat stress‐induced T84 monolayer barrier dysfunction was inhibited by pretreatment with PKC inhibitor, MLCK inhibitor, or HSP70.

Conclusion:  Heat stress can induce intestinal epithelial barrier dysfunction via the PKC and MLC signal transduction pathway.
Esophageal motility differences among aged patients with achalasia: A Taiwan report
Authors: Chuah Seng‐Kee , Changchien Chi‐Sin , Wu Keng‐Liang , Hu Tsung‐Hui , Kuo Chung‐Mou , Chiu Yi‐Chun , Chiu King‐Wah , Kuo Chung‐Huang , Chiou Shue‐Shian , Lee Chuan‐Mo
Published: September 2006

Background and Aim:  There are limited reports on esophageal motility pressures in aged patients with achalasia and these are inconclusive. The aim of the present retrospective study was to understand the changes of esophageal motility in aged achalasia patients among the Taiwan population.

Methods:  Manometric studies of 49 patients with achalasia had been performed through January 1998 to June 2005. The findings of lower esophageal sphincter (LES) basal and residual pressures and esophageal body contraction amplitudes were calculated and compared between the older and younger patient groups at different age cut‐offs.

Results:  Higher basal LES pressure increased significantly from the cut‐off age of 65 years (i.e. patients over 65 had significantly higher basal LES pressure than younger patients: 37.0 ± 4.19 mmHg vs 30.0 ± 1.32 mmHg, P = 0.045). With patients ≥70 years old, it was more obvious (46.0 ± 3.7 mmHg vs 29.6 ± 1.2 mmHg, P = 0.001). Beginning at the cut‐off age of 55, the LES residual pressure was significantly higher in older patients than those who were younger (14.0 ± 11.06 mmHg vs 11.1 ± 0.6 mmHg, P = 0.017). LES residual pressure is more significant in the older groups. A linear correlation between age and residual LES pressures (r = 0.383) was found. No differences were found in esophageal contraction pressure.

Conclusions:  Older achalasia patients in Taiwan have higher basal LES pressures, with a linear correlation between age and residual LES pressures. Age has no influence on esophageal contraction pressure.
Population screening for celiac disease: Follow up of patients identified by positive serology
Authors: Shamir Raanan , Yehezkely‐Schildkraut Vered , Hartman Corina , Eliakim Rami
Published: September 2006

Background and Aim:  A previous study that evaluated the prevalence of celiac disease (CD) in a cohort of healthy blood donors, found that 3.8% of subjects had positive serology for CD. The aim of the present study was to examine how the screening results and the diagnosis of CD affected these patients' lifestyle and attitude toward CD.

Methods:  All subjects with positive serology for CD (n = 59) found in the previous study of healthy blood donors (n = 1571) were contacted and interviewed. Data collected included current and previous symptoms compatible with CD, medical follow up since being informed of positive serology for CD and adherence to gluten‐free diet (GFD). Information was obtained regarding attitude towards the screening for CD, the results of the screening, and the effect of screening on subjects' lifestyle.

Results:  Of the 59 subjects, 51 were available for telephone interview, including all 10 subjects diagnosed with CD (positive serology and biopsy), 17/20 with positive serology and normal intestinal mucosa, and 24/29 with positive serology who refused to undergo intestinal biopsy. Of the 10 patients diagnosed with CD, four adhere to GFD. Only 1/17 subjects with normal intestinal mucosa repeated serology. Two of the 24 who initially refused a biopsy, underwent an intestinal biopsy, and one of them was currently diagnosed with CD. Only one patient diagnosed with CD had all his family members screened for CD.

Conclusions:  The data suggest that many of the patients identified in this screened population do not ultimately benefit from the purpose of the screening, which was early identification and treatment of a common disease with potential serious consequences.
Determinants of local abundance and range size in forest vascular plants
Authors: Kolb Annette , Barsch Frank , Diekmann Martin
Published: September 2006

Aim  For a large set of forest herbs we tested: (1) whether there is a positive relationship between local abundance and geographical range size; (2) whether abundance or range size are affected by the niche breadths of species or niche availability; and (3) whether these are affected by the species life‐history traits.

Location  Northwestern Germany.

Methods  We measured abundance as mean density in 22 base‐rich deciduous forests and recorded range size as area of occupancy on four different spatial scales (local to national). Niche breadth was expressed in terms of habitat specificity (specialists, generalists) and of the ability to grow across a broad range of soil pH. The species’ pH niche position was used as a measure of the importance of habitat availability. As life‐history traits we used diaspore mass and number, plant height, seed longevity, lifespan/clonality, pollination mode, dispersal capability and flowering time.

Results  There were mainly no positive relationships between the abundance of species and their range size, as tested across species and across phylogenetically independent contrasts. Forest specialists were generally distributed less widely than generalists, but habitat specificity was not related to local abundance. Species with a broader pH niche breadth were more common, but the positive relationships between niche breadth and abundance or range size disappeared when accounting for sample size effects. Clonal species with few and heavy diaspores were most abundant, as well as early‐flowering species and those lacking dispersal structures. Local and regional range size were determined largely by habitat availability, while national range was positively affected by plant height and diaspore mass.

Main conclusions  Different processes determine the local density of species and their range size. Abundance within habitat patches appears to be related mainly to the species life histories, especially to their capacity for extensive clonal reproduction, whereas range size appears to be determined strongly by the availability of suitable habitat.
The influence of matrix and edges on species richness patterns of ground beetles (Coleoptera: Carabidae) in habitat islands
Authors: Lövei Gábor L. , Magura Tibor , Tóthmérész Béla , Ködöböcz Viktor
Published: September 2006

Aim  The aim of this study was to analyse whether, and how, the inclusion of habitat specialists and edge‐preferring species modifies the species–area relationship predictions of the island biogeography theory for an insect group (ground beetles, Coloptera: Carabidae) living in natural fragments. Species–habitat island area relationships applied to terrestrial habitat islands can be distorted by the indiscriminate inclusion of all species occurring in the fragments. Matrices surrounding terrestrial habitat fragments can provide colonists that do not necessarily distinguish the fragment from the matrix and can survive and reproduce there. Edge‐preferring species can further distort the expected relationship, as smaller fragments have larger edge:core ratios.

Location  Nineteen forest fragments were studied in the Bereg Plain, Hungary, and SW Ukraine. This area contains natural forest patches, mainly of oak and hornbeam, and supports a mountain entomofauna.

Methods  Ground beetles (Carabidae) present in the 19 forest patches were categorized into generalists, forest specialists and edge‐preferring species. We analysed the relationship between species richness and fragment area using species richness in the different categories.

Results  The assemblages contained a high share of generalist species (species that occur also in the surrounding matrix). Forest patch size and the number of generalist species showed a marginally significant negative relationship, indicating that generalist species were more important in smaller patches. Forest specialist species richness was correlated positively with patch area. Edge‐preferring species were shown to influence the species–area relationship: the number of edge‐preferring species increased with the edge:area ratio.

Main conclusions  Both generalist and edge‐preferring species can considerably distort the species–area relationship. Island biogeography theory can be applied to habitat islands only if the habitat islands are defined correctly from the viewpoint of the target species.
A test of the mechanisms behind avian generalized individuals–area relationships
Authors: Pautasso Marco , Gaston Kevin J.
Published: September 2006

Aim  Questions related to abundances of organisms are central to ecological research. A priori, a scale independent estimation of abundances would be expected. However, we find estimates of numbers of bird individuals from all over the world to increase less than proportionately with increasing plot size. At the whole assemblage level, the pattern holds across biogeographical regions and habitats. The slope of the interspecific and, for the majority of species, the intraspecific individuals–area relationship is also significantly shallower than 1. The question arises as to which mechanisms cause these patterns.

Location  Global.

Methods  At the assemblage, interspecific and intraspecific levels, we tested three mechanisms that could be responsible for these patterns by comparing the slope of the individuals–plot area relationship for subsets of a database compiled from the literature. Spatial autocorrelation was controlled for.

Results  There was no evidence for an influence of plot area choice in order to sample a constant number of individuals. Evidence for higher survey efficiency was available only with increasing number of visits at the intraspecific level. Evidence for influences of habitat heterogeneity was present at the assemblage, interspecific and intraspecific levels. This mechanism can work only if small plots are delimited non‐randomly in homogeneous habitat.

Main conclusions  Avian population size estimates without indication of the area over which they were obtained are of substantially less value than those coupled with that information. Ecologists planning to compare avian abundances between plots varying in some other factor of interest should minimize variations in their areas and/or account for them in data analyses. Population viability analyses, regional and global population size estimates, site prioritization and the scaling of ecosystem and species energy utilization need to address the plot area effect on assemblage and individual species abundances.
A resource‐based conceptual model of plant diversity that reassesses causality in the productivity–diversity relationship
Authors: Lavers Chris , Field Richard
Published: September 2006

Biogeographical studies frequently reveal positive correlations between species richness and estimates of environmental water and/or energy. A popular interpretation of this relationship relates the supply of water and energy to productivity, and then, in turn, to richness. Productivity–diversity theories are now legion, yet none has proved sufficiently intuitive to gain broad acceptance. Like productivity, heterogeneity is known to influence diversity at fine spatial scales, yet the possibility that richness might relate to water–energy dynamics at coarse spatial scales via a heterogeneity‐generating mechanism has received little attention. In this paper we outline such a conceptual model for plants that is internally consistent and testable. We believe it may help to explain the capacity of environments receiving different inputs of water and energy to support variable numbers of species at a range of spatial scales, the pervasive correlation between productivity and richness, some exceptions to the productivity–diversity relationship, the form of productivity–diversity curves and the link between richness and environmental ‘harshness’. The model may also provide an answer to one of the most venerable puzzles in the field of diversity studies: why high inputs of water and energy correspond to more species rather than simply more individuals.
Sensitivity of African biomes to changes in the precipitation regime
Authors: Hély Christelle , Bremond Laurent , Alleaume Samuel , Smith Benjamin , Sykes Martin T. , Guiot Joël
Published: September 2006

Aim  Africa is identified by the Inter‐governmental Panel on Climate Change (IPCC) as the least studied continent in terms of ecosystem dynamics and climate variability. The aim of this study was (1) to adapt the Lund‐Postdam‐Jena‐GUESS (LPJ‐GUESS) ecological modelling framework to Africa by providing new parameter values for tropical plant functional types (PFT), and (2) to assess the sensitivity of some African biomes to changes in precipitation regime.

Location  The study area was a representative transect (0–22° N and 7–18° E) through the transition from equatorial evergreen forests to savannas, steppes and desert northwards. The transect showed large latitudinal variation in precipitation (mean rainfall ranged from 50 to 2300 mm year−1).

Methods  New PFT parameters used to calibrate LPJ‐GUESS were based on modern pollen PFTs and remote sensed leaf area index (LAI). The model was validated using independent modern pollen assemblages, LAI and through comparison with White's modern potential vegetation map. Several scenarios were developed by combining changes in total rainfall amount with variation in the length of the dry season in order to test the sensitivity of African biomes.

Results  Simulated vegetation compared well to observed data at local and regional scales, in terms of ecosystem functioning (LAI), and composition (pollen and White's vegetation map). The assessment of the sensitivity of biomes to changes in precipitation showed that none of the ecosystems would shift towards a new type under the range of precipitation increases suggested by the IPCC (increases from 5 to 20%). However, deciduous and semi‐deciduous forests may be very sensitive to small reductions in both the amount and seasonality of precipitation.

Main conclusions  This version of LPJ‐GUESS parameterized for Africa simulated correctly the vegetation present over a wide precipitation gradient. The biome sensitivity assessment showed that, compared with savannas and grasslands, closed canopy forests may be more sensitive to change in precipitation regime due to the synergetic effects of changed rainfall amounts and seasonality on vegetation functioning.
Epicardial fat: properties, function and relationship to obesity
Authors: Rabkin S. W.
Published: September 2006

Epicardial fat is a relatively neglected component of the heart. The purpose of this review was to examine the anatomic and biochemical data on epicardial fat; to examine the relationship of epicardial fat to obesity and to explore the potential role of epicardial fat in the relationship of obesity to coronary atherothrombotic disease. Epicardial fat covers 80% of the heart’s surface and constitutes 20% of total heart weight. It is present along the distribution of the coronary arteries, over the right ventricle especially along the right border, anterior surface and at the apex. There is three‐ to fourfold more epicardial fat associated with the right than the left ventricle. Putative physiologic functions of epicardial fat are based on observational data and include: buffering coronary arteries against the torsion induced by the arterial pulse wave and cardiac contraction, facilitating coronary artery remodelling, regulating fatty acid homeostasis in the coronary microcirculation and providing fatty acids to cardiac muscle as a local energy source in times of high demand. A considerable amount of the data on epicardial fat originates from autopsy series that have the inherent problem that conditions leading to death may have altered body composition and adiposity. With this caveat, data indicate that epicardial fat mass increases age until age 20–40 years but thereafter the amount of epicardial fat is not dependent on age. The amount of epicardial fat correlates with heart weight but the presence of myocardial ischemia and hypertrophy does not alter the ratio of epicardial fat to cardiac muscle mass. A number of properties differentiate epicardial fat from other fat depots specifically its smaller adipocytes size; different fatty acid composition, high protein content; high rates of fatty acid incorporation, fatty acid synthesis, insulin‐induced lipogenesis or fatty acid breakdown; low rates of glucose utilization, low expression (mRNA) of lipoprotein lipase, stearoyl‐CoA desaturase and acetyl‐CoA carboxylase‐α, and slow regression during weight loss. There is a significant direct relationship between the amount of epicardial fat and general body adiposity. Clinical imaging studies have demonstrated a strong direct correlation between epicardial fat and abdominal visceral adiposity. Several lines of evidence support a role for epicardial fat in the pathogenesis of coronary artery disease, namely the close anatomic relationship between epicardial fat and coronary arteries; the positive correlation between the amount of epicardial fat and the presence of coronary atherosclerosis and the ability of adipose tissue to secrete hormones and cytokines that modulate coronary artery atherothrombosis. Thus, epicardial fat maybe an important factor responsible for cardiovascular disease in obesity.
Measurement of television viewing in children and adolescents: a systematic review
Authors: Bryant M. J. , Lucove J. C. , Evenson K. R. , Marshall S.
Published: September 2006

The relationship between television (TV) viewing and overweight in children is likely to be influenced by the quality of measures used. We systematically reviewed studies related to overweight in children that had included a measure of TV exposure. Literature searches were conducted in MedLINE, PsychInfo, SportDiscus and ISIWeb of Science. Methods of assessing TV viewing were evaluated, including the type of measure, the administration procedure and reported psychometric properties. The majority of studies assessed TV viewing using self‐report surveys and very few studies used direct observation. The validity or reliability of measures was often not examined. The majority of tools that were evaluated were compared with another self‐report measure or an objective measure of physical activity. TV viewing measures should be selected that are specific to the research question, the study design, as well as methodological feasibility. However, it is recommended that measures of TV viewing be used only if they have psychometric data to support their validity and reliability. Selecting measures that are valid and reliable enables us to examine with greater accuracy the influence of TV viewing on childhood overweight, as well as the efficacy of interventions designed to reduce TV viewing in children.
The prevalence and determinants of obesity in adults with intellectual disabilities
Authors: Melville C. A. , Hamilton S. , Hankey C. R. , Miller S. , Boyle S.
Published: September 2006

People with intellectual disabilities experience significant health inequalities compared with the general population, including a shorter life expectancy and high levels of unmet health needs. Another accepted measure of health inequalities, the prevalence of obesity, has been shown to be higher in adults with intellectual disabilities than in the general population. While the factors contributing to the increased prevalence among adults with intellectual disabilities are not well understood, the high rates of obesity among younger adults highlight the need for further research involving children and adolescents with intellectual disabilities. To take forward the priorities for research and the development of effective, accessible services, there is a need for collaboration between professionals working in the fields of intellectual disabilities and obesity.
Racial‐Ethnic Identity in Mid‐Adolescence: Content and Change as Predictors of Academic Achievement
Authors: Altschul Inna , Oyserman Daphna , Bybee Deborah
Published: September 2006

Three aspects of racial‐ethnic identity (REI)—feeling connected to one's racial‐ethnic group (Connectedness), being aware that others may not value the in‐group (Awareness of Racism), and feeling that one's in‐group is characterized by academic attainment (Embedded Achievement)—were hypothesized to promote academic achievement. Youth randomly selected from 3 low‐income, urban schools (n=98 African American, n=41 Latino) reported on their REI 4 times over 2 school years. Hierarchical linear modeling shows a small increase in REI and the predicted REI–grades relationship. Youth high in both REI Connectedness and Embedded Achievement attained better grade point average (GPA) at each point in time; youth high in REI Connectedness and Awareness of Racism at the beginning of 8th grade attained better GPA through 9th grade. Effects are not moderated by race‐ethnicity.
Changing Children's Intergroup Attitudes Toward Refugees: Testing Different Models of Extended Contact
Authors: Cameron Lindsey , Rutland Adam , Brown Rupert , Douch Rebecca
Published: September 2006

The present research evaluated an intervention, derived from the “extended contact hypothesis,” which aimed to change children's intergroup attitudes toward refugees. The study (n=253) tested 3 models of extended contact among 5‐ to 11‐year‐old children: dual identity, common ingroup identity, and decategorization. Children read friendship stories based upon these models featuring in‐ and outgroup members. Outgroup attitudes were significantly more positive in the extended contact conditions, compared with the control, and this was mediated by “inclusion of other in self.” The dual identity intervention was the most effective extended contact model at improving outgroup attitudes. The effect of condition on outgroup intended behavior was moderated by subgroup identity. Implications for theoretically based prejudice‐reduction interventions among children are discussed.
Neighborhood Matters: Racial Socialization of African American Children
Authors: Caughy Margaret O'Brien , Nettles Saundra Murray , O'Campo Patricia J. , Lohrfink Kimberly Fraleigh
Published: September 2006

Differences in racial socialization practices and their effects were examined in a sample of 241 African American 1st graders (average age 6.59 years) living in an urban area. Child outcomes included cognitive development, receptive language skills, and child problem behavior. The cultural environment of the home was associated with higher cognitive scores for boys living in high negative social climate and low social capital neighborhoods and for girls living in high social capital neighborhoods. The positive association of promotion of mistrust and child behavior problems was magnified in neighborhoods that had low levels of social capital. A high negative social climate in the neighborhood attenuated the positive association between preparation for bias/promotion of mistrust and externalizing problems.
Cultural Variations in the Socialization of Young Children's Anger and Shame
Authors: Cole Pamela M. , Tamang Babu Lal , Shrestha Srijana
Published: September 2006

Tamang and Brahman Nepali children have culturally specific emotion scripts that may reflect different emotion socialization experiences. To study emotion socialization, the child–adult interactions of 119 children (3–5 years old) were observed and 14 village elders were interviewed about child competence in Tamang and Brahman villages. Tamang rebuke the angry child but reason with and yield to the child who appears ashamed. Brahmans respond to child anger with reasoning and yielding but ignore shame. Tamang practices are consistent with their view that competent children are socially graceful and never angry. Brahman practices appear to be consistent with the privileges and duties of high caste status. The roles of cultural heritage, religious differences, and majority and minority status in emotion socialization are discussed.
From American City to Japanese Village: A Cross‐Cultural Investigation of Implicit Race Attitudes
Authors: Dunham Yarrow , Baron Andrew Scott , Banaji Mahzarin R.
Published: September 2006

This study examined the development of implicit race attitudes in American and Japanese children and adults. Implicit ingroup bias was present early in both populations, and remained stable at each age tested (age 6, 10, and adult). Similarity in magnitude and developmental course across these 2 populations suggests that implicit intergroup bias is an early‐emerging and fundamental aspect of human social cognition. However, implicit race attitudes toward favored outgroups are more positive in older than in younger participants, indicating that “cultural prestige” enjoyed by a group moderates implicit bias as greater knowledge of group status is acquired. These results demonstrate (a) the ready presence, (b) early cultural invariance, and (c) subsequent cultural moderation of implicit attitudes toward own and other groups.
Parental Control in Latino Families: An Integrated Review of the Literature
Authors: Halgunseth Linda C. , Ispa Jean M. , Rudy Duane
Published: September 2006

Using social information processing and cultural change models as explanatory frameworks, this article reviews the literature on Latino parental control and its implications for child development. It is argued that the use of parental control in Latino families may have motivational roots in cultural childrearing goals such as familismo (familism), respeto (respect), and educación (moral education). Consideration of these underpinnings, in conjunction with psychological and methodological issues, helps to explain variability in the use of Latino parental control and its effect on child development. Recommendations for future research include refinement of control and acculturation instruments, and attention to both contextual and individual variables.
Racial Self‐Categorization in Adolescence: Multiracial Development and Social Pathways
Authors: Hitlin Steven , Scott Brown J. , Elder Glen H.
Published: September 2006

Research on multiracial individuals is often cross‐sectional, obscuring the fluid nature of multiracial self‐categorization across time. Pathways of racial self‐identification are developed from a nationally representative sample of adolescents aged 14–18, measured again 5 years later. A significant proportion of multiracial adolescents change racial self‐identification across time. Youth who ever report being multiracial are 4 times as likely to switch self‐identification as to report consistent multiracial identities. Across this time, more multiracial adolescents either add a racial category (diversify) or subtract one (consolidate) than maintain consistent multiracial self‐categorization. Exploratory multinomial analyses show few differences between these pathways on select psychological and social characteristics. Results lend quantitative support to qualitative studies indicating the fluidity of racial self‐categorization.
A Longitudinal Investigation of Personality and Social Adjustment Among Chinese American and European American Adolescents
Authors: Huntsinger Carol S. , Jose Paul E.
Published: September 2006

A 2‐wave longitudinal study of personality in adolescence was conducted with data obtained at ages 12 and 17 years from approximately 60 European American and 60 second‐generation Chinese American youth. At Time 1 they completed the Children's Personality Questionnaire and at Time 2 they completed the High School Personality Questionnaire and self‐report measures of high school grades, depression, and self‐esteem. Chinese American and European American adolescents became more similar to each other over time through developmental and acculturative processes. Adolescents of both ethnicities increased in Extraversion and Independence. Despite this general trend, the Chinese American youth continued to report lower levels of Extraversion than European American youth. Extraversion and Anxiety predicted school grades for European Americans and psychological adjustment for Chinese Americans.
Classroom Contextual Effects of Race on Children's Peer Nominations
Authors: Jackson Melissa Faye , Barth Joan M. , Powell Nicole , Lochman John E.
Published: September 2006

Black children generally receive poorer sociometric nominations compared with Whites. This effect is not fully understood because Black children rarely hold a classroom majority and teachers' race is rarely investigated. Research from a person–environment perspective suggests that the effects of children's race depend on the racial composition of the classroom and society's racial attitudes. Sociometric nominations were obtained from 1,268 5th graders, between 9 and 11 years old (53% Black), across 57 classrooms (3–95% Black students). Half of the teachers were Black. The results indicated that ratings of Black children were more influenced by the racial context of classrooms than were ratings of White children. The implications of this study are discussed in relation to group dynamics and racial discrimination.
Immigrant Differences in School‐Age Children's Verbal Trajectories: A Look at Four Racial/Ethnic Groups
Authors: Leventhal Tama , Xue Yange , Brooks‐Gunn Jeanne
Published: September 2006

This study explored inter‐ and intraindividual immigrant group differences in children's English verbal ability over ages 6–16 in 4 racial/ethnic groups—White Americans, Black Americans, Mexican Americans, and Puerto Ricans (N=2,136). Although all children's mean verbal scores increased with age, immigrant children (except for Black Americans) had lower scores than respective nonimmigrant children. In contrast, immigrant children (except for Mexican Americans) had more persistent verbal growth into adolescence than respective nonimmigrant children. Family resources moderately accounted for immigrant differences in children's mean verbal scores only. The findings support different theoretical models for understanding inter‐ and intraindividual immigrant differences in achievement. Mexican‐American immigrants and Black American nonimmigrants were struggling and merit policy attention.
Mothers' and Fathers' Racial Socialization in African American Families: Implications for Youth
Authors: McHale Susan M. , Crouter Ann C. , Kim Ji‐Yeon , Burton Linda M. , Davis Kelly D. , Dotterer Aryn M. , Swanson Dena P.
Published: September 2006

Mothers' and fathers' cultural socialization and bias preparation with older (M=13.9 years) and younger (M=10.31 years) siblings were studied in 162 two‐parent, African American families. Analyses examined whether parental warmth and offspring age and gender were linked to parental practices and whether parents' warmth, spouses' racial socialization, or youth age or gender moderated links between racial socialization and youth outcomes. Parental warmth was linked to parents' socialization. Mothers engaged in more socialization with older offspring, and fathers more with sons. Mothers' cultural socialization was positively related to youth ethnic identity and fathers' was negatively related to youth depression symptoms. Youth exhibited a lower locus of control when mothers were high but fathers were low in racial socialization.