bluuebunny/crossref_metadata_2025 huggingface dataset:
Dopaminergic and brain‐derived neurotrophic factor signalling in inbred mice exposed to a restricted feeding schedule
Authors: Gelegen C. , Van Den Heuvel J. , Collier D. A. , Campbell I. C. , Oppelaar H. , Hessel E. , Kas M. J. H.
Published: March 2008

Increased physical activity and decreased motivation to eat are common features in anorexia nervosa. We investigated the development of these features and the potential implication of brain‐derived neurotrophic factor (BDNF) and dopaminergic signalling in their development in C57BL/6J and A/J inbred mice, using the ‘activity‐based anorexia’ model. In this model, mice on a restricted‐feeding schedule are given unlimited access to running wheels. We measured dopamine receptor D2 and BDNF expression levels in the caudate putamen and the hippocampus, respectively, using in situ hybridization. We found that in response to scheduled feeding, C57BL/6J mice reduced their running wheel activity and displayed food anticipatory activity prior to food intake from day 2 of scheduled feeding as an indication of motivation to eat. In contrast, A/J mice increased running wheel activity during scheduled feeding and lacked food anticipatory activity. These were accompanied by increased dopamine receptor D2 expression in the caudate putamen and reduced BDNF expression in the hippocampus. Consistent with human linkage and association studies on BDNF and dopamine receptor D2 in anorexia nervosa, our study shows that dopaminergic and BDNF signalling are altered as a function of susceptibility to activity‐based anorexia. Differences in gene expression and behaviour between A/J and C57BL/6J mice indicate that mouse genetic mapping populations based on these progenitor lines are valuable for identifying molecular determinants of anorexia‐related traits.
Variation in Galr1 expression determines susceptibility to excitotoxin‐induced cell death in mice
Authors: Kong S. , Lorenzana A. , Deng Q. , McNeill T. H. , Schauwecker P. E.
Published: March 2008

Inbred strains of mice differ in their susceptibility to excitotoxin‐induced cell death, but the genetic basis of individual variation in differential susceptibility is unknown. Previously, we identified a highly significant quantitative trait locus (QTL) on chromosome 18 that influenced susceptibility to kainic acid‐induced cell death (Sicd1). Comparison of susceptibility to seizure‐induced cell death between reciprocal congenic lines for Sicd1 and parental background mice indicates that genes influencing this trait were captured in both strains. Two positional gene candidates, Galr1 and Mbp, map to 55 cM, where the Sicd1 QTL had been previously mapped. Thus, this study was undertaken to determine if Galr1 and/or Mbp could be considered as candidate genes. Genomic sequence comparison of these two functional candidate genes from the C57BL/6J (resistant at Sicd1) and the FVB/NJ (susceptible at Sicd1) strains showed no single‐nucleotide polymorphisms. However, expression studies confirmed that Galr1 shows significant differential expression in the congenic and parental inbred strains. Galr1 expression was downregulated in the hippocampus of C57BL/6J mice and FVB.B6‐Sicd1 congenic mice when compared with FVB/NJ or B6.FVB‐Sicd1 congenic mice. A survey of Galr1 expression among other inbred strains showed a significant effect such that ‘susceptible’ strains showed a reduction in Galr1 expression as compared with ‘resistant’ strains. In contrast, no differences in Mbp expression were observed. In summary, these results suggest that differential expression of Galr1 may contribute to the differences in susceptibility to seizure‐induced cell death between cell death‐resistant and cell death‐susceptible strains.
Molecular analyses and identification of promising candidate genes for loci on mouse chromosome 1 affecting alcohol physical dependence and associated withdrawal
Authors: Denmark D. L. , Buck K. J.
Published: March 2008

We recently mapped quantitative trait loci (QTLs) with large effects on predisposition to physical dependence and associated withdrawal severity following chronic and acute alcohol exposure (Alcdp1/Alcw1) to a 1.1‐Mb interval of mouse chromosome 1 syntenic with human chromosome 1q23.2‐23.3. Here, we provide a detailed analysis of the genes within this interval and show that it contains 40 coding genes, 17 of which show validated genotype‐dependent transcript expression and/or non‐synonymous coding sequence variation that may underlie the influence of Alcdp1/Alcw1 on ethanol dependence and associated withdrawal. These high priority candidates are involved in diverse cellular functions including intracellular trafficking, oxidative homeostasis, mitochondrial respiration, and extracellular matrix dynamics, and indicate both established and novel aspects of the neurobiological response to ethanol. This work represents a substantial advancement toward identification of the gene(s) that underlies the phenotypic effects of Alcdp1/Alcw1. Additionally, a multitude of QTLs for a variety of complex traits, including diverse behavioral responses to ethanol, have been mapped in the vicinity of Alcdp1/Alcw1, and as many as four QTLs on human chromosome 1q have been implicated in human mapping studies for alcoholism and associated endophenotypes. Thus, our results will be primary to further efforts to identify genes involved in a wide variety of behavioral responses to alcohol and may directly facilitate progress in human alcoholism genetics.
Effects of sex chromosome aneuploidy on male sexual behavior
Authors: Park J. H. , Burns‐Cusato M. , Dominguez‐Salazar E. , Riggan A. , Shetty S. , Arnold A. P. , Rissman E. F.
Published: March 2008

Incidence of sex chromosome aneuploidy in men is as high as 1:500. The predominant conditions are an additional Y chromosome (47,XYY) or an additional X chromosome (47,XXY). Behavioral studies using animal models of these conditions are rare. To assess the role of sex chromosome aneuploidy on sexual behavior, we used mice with a spontaneous mutation on the Y chromosome in which the testis‐determining gene Sry is deleted (referred to as Y−) and insertion of a Sry transgene on an autosome. Dams were aneuploid (XXY−) and the sires had an inserted Sry transgene (XYSry). Litters contained six male genotypes, XY, XYY−, XXSry, XXY−Sry, XYSry and XYY−Sry. In order to eliminate possible differences in levels of testosterone, all of the subjects were castrated and received testosterone implants prior to tests for male sex behavior. Mice with an additional copy of the Y− chromosome (XYY−) had shorter latencies to intromit and achieve ejaculations than XY males. In a comparison of the four genotypes bearing the Sry transgene, males with two copies of the X chromosome (XXSry and XXY−Sry) had longer latencies to mount and thrust than males with only one copy of the X chromosome (XYSry and XYY−Sry) and decreased frequencies of mounts and intromissions as compared with XYSry males. The results implicate novel roles for sex chromosome genes in sexual behaviors.
Cognitive effects of acute tryptophan depletion in the healthy elderly
Authors: Mace Janet , Porter Richard , O’Brien John , Gallagher Peter
Published: March 2008

Background:

Studies investigating the cognitive effects of serotonin depletion, using the technique of acute tryptophan depletion (ATD) by dietary means, have generally suggested that ATD impairs delayed verbal recall and recognition. In two previous studies in the elderly, this result has not been replicated and ATD impaired working memory. These results may be susceptible to type II error but a similar testing schedule in the individual studies allows data to be pooled in a larger analysis.

Methods:

Data from two separate double-blind placebo-controlled studies of the effects of ATD on cognitive function in the elderly were combined. In one study, a low dose and in the other a high dose of amino acids was used. In a repeated measures analysis of variance, the effects of ATD and the interaction of this with the other factors (age, gender and dose) on cognitive measures was examined.

Results:

Data from 31 healthy subjects aged between 60 and 81 years were analysed. There were no main effects of ATD or consistent interactions between ATD and age, gender or dose. There were significant interactions between ATD, gender and dose. When tryptophan depleted, females having the higher dose drink had reduced scores on Digit span and immediate recall on the Rey Auditory Verbal Learning Test.

Conclusion:

The enlarged data set did not confirm an overall effect of ATD on working memory or on delayed word recall but does suggest an effect of ATD on encoding or registration in the subgroup of females receiving a higher strength drink.
Weight change in the term baby in the first 2 weeks of life
Authors: Crossland DS , Richmond S , Hudson M , Smith K , Abu‐Harb M
Published: March 2008

Background: Midwives once used serial weighing to highlight lactation problems, but this is now discouraged for the fear of undermining maternal confidence.

Aim: To explore weight changes in healthy newborn term babies, to gain information to aid interpretation of such measurements and to construct a centile chart for those exclusively breastfed during the first 2 weeks.

Method: Two hundred ninety‐nine mothers weighed their baby daily using the same electronic scales. In 46 cases, three or more consecutive measurements were omitted leaving 253 series to evaluate, of which 111 were exclusively breastfed.

Results: Breastfed babies lost a mean 6.4% of birthweight (95% CI: 5.5–7.3%) before starting to gain, and 54% took more than 8 days to regain birthweight. Artificially fed babies lost less (3.7%, 95% CI: 2.7–4.7%), but 39% had not regained their birthweight by 8 days. Once birthweight was regained, average gain was about 1% of birthweight per day in both breast‐ and artificially‐fed babies. Measurements less than 5 days apart predicted average weight gain poorly.

Conclusions: Feeding problems should be considered if weight is not increasing by 6 days, but some healthy babies take 17 days to regain their birthweight.
Foetal brain imaging: ultrasound or MRI. A comparison between magnetic resonance imaging and a dedicated multidisciplinary neurosonographic opinion
Authors: Hagmann Cornelia F , Robertson Nicola J , Leung Wee C , Chong Kling W , Chitty Lyn S
Published: March 2008

Objectives: (i) To compare original foetal brain ultrasound findings with a multidisciplinary expert opinion; (ii) to compare the multidisciplinary expert ultrasound opinion with foetal magnetic resonance imaging (MRI) findings and (iii) to determine in which circumstances foetal MRI gives additional information, and in how many cases management is changed by having information from MRI.

Study design: Ultrasound scans of 51 consecutive foetuses where foetal brain MR had been performed were retrospectively reviewed by a panel consisting of maternal‐foetal‐medicine (MFM) consultants, a geneticist, neonatologists and MFM subspecialty trainees. The original ultrasound opinion was compared with the multidisciplinary opinion, which was then compared with MRI findings. In the cases where MRI gave additional information, an assessment was made as to whether this changed management.

Results: The multidisciplinary ultrasound opinion differed from the original opinion in 9 of 51 (17%) cases. In 19 patients (37%), the MRI gave additional information to the original ultrasound, in 7 (13%) cases, management, and in 7 (13%) cases, counselling was altered by additional information gained from MRI. The multidisciplinary ultrasound and MRI diagnoses were similar in 36 cases (71%).

Conclusion: Multidisciplinary review of an apparently abnormal foetal brain ultrasound can provide additional diagnostic information. When compared with this level of ultrasound expertise, MRI gave additional information in 29% of cases, but only resulted in change in management in about 13%.
Time trend for the prevalence of asthma among school children in a Swedish district in 1985–2005
Authors: Kälvesten Lena , Bråbäck Lennart
Published: March 2008

Aim: To assess the temporal trend for asthma and asthma‐like symptoms over a period of 20 years.

Method: Repeated cross‐sectional surveys with identical study design were carried out among all school children (7–16 years) in a well‐defined area in Sweden in 1985, 1995 and 2005.

Results: In 2005, the parents of 1110 out of 7825 children (14.2%) answered yes to a screening question on asthmatic symptoms. Of these, 783 out of 1110 (70.5%) replied to a postal questionnaire with detailed questions concerning symptoms and asthma management. The rate of affirmative response to the screening question was unchanged between 1995 and 2005. However, the percentage of children with wheezing or three or more asthma‐like symptoms decreased, whereas the percentage of children with physician‐diagnosed asthma increased steadily since 1985. The number of reported symptoms was closely associated with the number of days with physical restriction. The annual sale of inhaled steroids from local pharmacies was stable between 1995 and 2005.

Conclusion: The increase in asthmatic symptoms in school children has peaked. Reduced severity of symptoms and divergent trends for wheezing and physician‐diagnosed asthma suggest an increased awareness of asthma with improved management of the symptoms. However, differences in trends between allergic and nonallergic asthma could not be excluded.
Cardiac manifestations of Anderson‐Fabry disease in children and adolescents
Authors: Kampmann Christoph , Wiethoff Christiane M. , Whybra Catharina , Baehner Frank A. , Mengel Eugen , Beck Michael
Published: March 2008

Aim: Fabry disease (Fabry) is a rare X‐linked disorder caused by a deficiency of the lysosomal enzyme α‐galactosidase A. The progressive accumulation of the major substrate, globotriaosylceramide, leads to renal dysfunction and hypertrophic cardiomyopathy, which are reported to become apparent in the third decade. This study was performed to determine if signs of cardiac manifestations of Fabry are seen in younger Fabry patients.

Methods: Twenty children and adolescents of ≤18 years of age with confirmed Fabry underwent a standard 12‐lead electrocardiogram (ECG), a 2‐h Holter ECG, blood pressure measurements and a two‐dimensional echocardiogram. Follow‐up examinations were conducted for 14 patients after a mean interval of 25.9 months.

Results: At baseline, mean left ventricular mass (LVM) indexed to height (LVM/h2.7) was 45.0 ± 2.3 and 47.0 ± 3.4 g/m2.7 in boys (n = 8) and girls (n = 12), respectively, and all patients had LVM/h2.7 of >75th percentile of that in healthy controls. After a mean 26‐month follow‐up, 12 out of 14 patients (85.7%) showed a mean increase of 7.5 ± 3.2 g/m2.7 in LVM/h2.7. Heart rate variability (HRV) analyses revealed that male, but not female, Fabry patients had significantly reduced HRV, reflecting a reduction in parasympathetic stimulation of the heart (p < 0.05).

Conclusion: Cardiac involvement in children with Fabry is frequent and may progress even at young age.
Musculoskeletal pain in obese children and adolescents
Authors: Stovitz Steven D , Pardee Perrie E , Vazquez Gabriela , Duval Sue , Schwimmer Jeffrey B
Published: March 2008

Aim: To determine whether bodyweight is associated with musculoskeletal pain within a population of obese children and adolescents.

Methods: A descriptive, cross‐sectional study of subjects evaluated at a tertiary care medical centre for the management of obesity. Analyses were conducted using both a person‐specific model, and then again, using a joint site model in order to account for correlations between joints within children.

Results: We evaluated 135 children and adolescents (68 girls, 67 boys) with a mean age of 12.3 years (range: 3–18). The study population was racially and ethnically diverse – Hispanic (51%), non‐Hispanic white (26%), non‐Hispanic black (13%), other (10%). The majority of subjects (61%) complained of at least one joint hurting more than once per month. Back pain was the most common complaint (39%), followed by foot (26%) and knee (24%) pain. After adjustment for age, pain in the knees and hips were associated with increased weight and/or body mass index (BMI).

Conclusions: In this cross‐sectional analysis of obese children and adolescents, musculoskeletal pain was common and, in the knee and hip joints, was positively associated with extra bodyweight. Clinicians may want to ask about musculoskeletal pain when recommending physical activity for weight management counselling.
International Migration as a Tool in Development Policy: A Passing Phase?
Authors: Skeldon Ronald
Published: March 2008

This essay examines the recent emergence of migration and development as a major area of policy concern. The focus up to now has been almost entirely upon international migration, which accounts for the minority of people who move. A consensus has emerged that migration can be managed so as to promote development, and the essay critically assesses three of the major areas of concern: remittances, skilled migration, and the diaspora. While welcoming the growing acceptance that migration is no longer seen as negative for development, the essay cautions against essentializing migration and placing too great a responsibility upon migrant agency at the expense of the institutional change necessary to bring about development. Internal as well as international migrations will need to be integrated into any development framework, and it is further argued that these migrations are essentially a consequence of development. Planning for migration as an outcome rather than a cause of development is likely to provide a more balanced policy approach.
Childless or Childfree? Paths to Voluntary Childlessness in Italy
Authors: Tanturri Maria Letizia , Mencarini Letizia
Published: March 2008

This article investigates childlessness in Italy. Trends in childlessness are presented and compared with trends elsewhere in Europe. Different paths to childlessness are outlined, using data from a survey carried out among childless women aged 40‐44 in five Italian cities in 2002. Individual characteristics of the childless and reasons for childlessness are investigated. As many as one‐third of the interviewees who live with a partner and do not suffer from any physical impediment are voluntarily childless. These women, in contrast to mothers, appear to be less religious and to have partners who are less religious; they tend to come from smaller families; to have been in a nonmarital cohabitation at least once in life; to have entered their first union later; and to have had, in the initial period of their union, temporary work and flexible work schedules and limited leisure time. In other cases, childlessness is the unintended outcome of a decision to delay having a child or the result of adverse external circumstances, particularly dissolution of partnership.
Demography and Policy: A View from Outside the Discipline
Authors: Ehrlich Paul R.
Published: March 2008

Scientists, individually and through their national academies, have often pointed to the major role of population growth in damaging humanity's life‐support systems, emphasizing the overriding need for population stabilization. Demography and its practitioners, however, in focusing on technical analyses of population change and its components, have largely neglected these critical issues. Where they have taken an interest in population—environment relationships, their voices have been little heard in public debate and have had scant political impact. Demographers should promote their expertise more aggressively, in particular through a new environmental demography, modeled perhaps on environmental economics. This should be a collaborative enterprise with ecologists and other environmental scientists, concerned with issues of carrying capacity, encouraging and planning for future population reduction, and researching population policies that are humane and accord due attention to environmental sustainability.
Separating Culture from Institutions: The Use of Semantic Spaces as a Conceptual Domain and the Case of China
Authors: Redding Gordon
Published: March 2008

The analysis of societies, and of systems of business within them, has tended to be heavily influenced by institutionalist perspectives. Many scholars using this approach include culture as a subset of institutions, but often without specifying the logics of doing so. Others remove culture from the account, or acknowledge its significance without placing it clearly in their models. Culturalists, however, tend not to venture into the details of economic coordination and action. To resolve the theoretical challenges posed by this set of contrasting views, it is necessary to specify how culture works and how it is different from institutions. As ‘the societal effect’ is the influence of culture on institutions, it may thus be easier to study its workings. Here culture is seen, following Sorge, as meaning relevant within a series of semantic spaces, each related to a field of action, the total integrated coherently by social axioms binding the spaces and the meanings within them into a total societal fabric of meaning. The private sector of the Chinese economy is analysed, drawing from recent extensive empirical reports as to its functioning. Theory development is in line with business systems theory.
Concept Analysis of Fear
Authors: Whitley Georgia Griffith
Published: March 2008

The nursing diagnosis fear is clarified through the technique of concept analysis. Uses of the concept of fear in prominent theories of human behavior and in nursing arc reviewed. Five critical attributes occurring in all cases of fear are identified—a model case, a related case, a contrary case, and an illegitimate case are presented. Antecedents lo fear are derived Cunsequences of fear are discussed and are related to nursing interventions. Empirical referents that demonstrate occurrence of the concept of fear are determined, classified, and related to critical attributes. This concept analysis provides an essential conceptual base for instrument development and clinical research on fear.
Phenolic compounds in peach (Prunus persica) cultivars at harvest and during fruit maturation
Authors: Andreotti C. , Ravaglia D. , Ragaini A. , Costa G.
Published: March 2008

Six peach and six nectarine cultivars were evaluated for the phenolic content in their pulp and peel tissues. Chlorogenic acid, catechin, epicatechin, rutin and cyanidin‐3‐glucoside were detected as the main phenolic compounds of ripened fruits. The concentration was always higher in peel tissue, with average values ranging from 1 to 8 mg g−1 dry weight (DW) depending on cultivar. Of the tested varieties, the white‐flesh nectarine ‘Silver Rome’ emerged as the cultivar with the highest amount of total phenolics. Phenolic compounds were also profiled during fruit growth and ripening in the yellow nectarine cv. ‘Stark Red Gold’, which showed a decreasing concentration during fruit development in both peel and pulp tissues. Average amounts of total phenolics were approximately 25 mg g−1 DW 60 days after full bloom and decreased to 3 mg g−1 DW at ripening in pulp tissue. Differences among peel and pulp composition show the different dietetic and antioxidant potential of fruits consumed unpeeled and peeled.
Documenting the Effect of Foundress Number in a Dioecious Fig, Ficus fistulosa, in Malaysia
Authors: Katabuchi Masatoshi , Harrison Rhett D. , Nakashizuka Tohru
Published: March 2008

We studied foundress number and its effect on seed production in a dioecious fig Ficus fistulosa in Sarawak, Malaysia. The effects of flowering time and the two‐way interaction of flowering time and tree location on foundress number were statistically significant. A multiple regression indicated seed production increased significantly with the number of foundresses. Our results indicate that phenology and local ecological factors generate a large variance in foundress number, which in turn affects the reproductive success of F. fistulosa.
Importance of Interhabitat Gaps and Stepping‐Stones for Lesser Woodcreepers (Xiphorhynchus fuscus) in the Atlantic Forest, Brazil
Authors: Boscolo Danilo , Candia‐Gallardo Carlos , Awade Marcelo , Metzger Jean Paul
Published: March 2008

Translocation experiments showed that a woodcreeper bird species is able to move between isolated forest fragments, but this ability is limited by increasing interpatch distances. Larger distances (> 100 m) were overcome by using small stepping‐stones (isolated trees), which enhance connectivity and are useful for the species conservation in fragmented landscapes.
Survival of Flower‐visiting Chrysomelids during Non General‐flowering Periods in Bornean Dipterocarp Forests
Authors: Kishimoto‐Yamada Keiko , Itioka Takao
Published: March 2008

In SE Asian rain forests, general flowering, a community‐wide synchronous flowering, occurs at irregular and supra‐annual intervals. During general flowering periods (GFP), most Dipterocarpaceae and many other trees flower profusely, while flowering plants are scant between GFP. During flowerless periods, anthophilous animals that depend on floral resources for food may suffer food shortages and subsequently decrease in abundance. Flower‐visiting chrysomelid adults are major pollinators for some canopy tree species that flower during GFP. Although such chrysomelids feed on flower petals, the means by which they survive flowerless periods remains unknown. We determined the abundance of flower‐visiting chrysomelids in GFP and non‐GFP through light trap samples and examined the effects of the presence of young leaves and flowers of dipterocarps on local abundance, and feeding preferences of flower‐visiting chrysomelids. We found no clear tendency that the chrysomelid species number and the abundance during GFP were consistently higher than those during non‐GFP. Chrysomelid adults were more abundant on trees with many young leaves or flowers than on trees lacking young leaves and flowers. At least a few flower‐visiting chrysomelids were observed feeding on young dipterocarp leaves and visiting young leaves and flowers of non‐dipterocarps in the canopy during non‐GFP. All results consistently suggest that chrysomelids are able to survive flowerless periods by feeding on the young leaves of dipterocarps and on the young leaves and flowers of non‐dipterocarps; through this alternate feeding, chrysomelid populations are maintained at sufficient levels to function as effective pollinators of trees that flower during GFP.
Dynamical evolution of the mass function and radial profile of the Galactic globular cluster system
Authors: Shin Jihye , Kim Sungsoo S. , Takahashi Koji
Published: March 2008

Evolution of the mass function (MF) and radial distribution (RD) of the Galactic globular cluster (GC) system is calculated using an advanced and a realistic Fokker–Planck (FP) model that considers dynamical friction, disc/bulge shocks and eccentric cluster orbits. We perform hundreds of FP calculations with different initial cluster conditions, and then search a wide-parameter space for the best-fitting initial GC MF and RD that evolves into the observed present-day Galactic GC MF and RD. By allowing both MF and RD of the initial GC system to vary, which is attempted for the first time in the present Letter, we find that our best-fitting models have a higher peak mass for a lognormal initial MF and a higher cut-off mass for a power-law initial MF than previous estimates, but our initial total masses in GCs, MT,i= 1.5–1.8 × 108 M⊙, are comparable to previous results. Significant findings include that our best-fitting lognormal MF shifts downward by 0.35 dex during the period of 13 Gyr, and that our power-law initial MF models well-fit the observed MF and RD only when the initial MF is truncated at ≳105 M⊙. We also find that our results are insensitive to the initial distribution of orbit eccentricity and inclination, but are rather sensitive to the initial concentration of the clusters and to how the initial tidal radius is defined. If the clusters are assumed to be formed at the apocentre while filling the tidal radius there, MT,i can be as high as 6.9 × 108 M⊙, which amounts to ∼75 per cent of the current mass in the stellar halo.
A new algorithm for difference image analysis
Authors: Bramich D. M.
Published: March 2008

In the context of difference image analysis (DIA), we present a new method for determining the convolution kernel matching a pair of images of the same field. Unlike the standard DIA technique which involves modelling the kernel as a linear combination of basis functions, we consider the kernel as a discrete pixel array and solve for the kernel pixel values directly using linear least squares. The removal of basis functions from the kernel model is advantageous for a number of compelling reasons. First, it removes the need for the user to specify such functions, which makes for a much simpler user application and avoids the risk of an inappropriate choice. Secondly, basis functions are constructed around the origin of the kernel coordinate system, which requires that the two images are perfectly aligned for an optimal result. The pixel kernel model is sufficiently flexible to correct for image misalignments, and in the case of a simple translation between images, image resampling becomes unnecessary. Our new algorithm can be extended to spatially varying kernels by solving for individual pixel kernels in a grid of image subregions and interpolating the solutions to obtain the kernel at any one pixel.
The mass—metallicity relation of interacting galaxies
Authors: Michel-Dansac Leo , Lambas Diego G. , Alonso M. Sol , Tissera Patricia
Published: March 2008

We study the mass–metallicity relation of galaxies in pairs and in isolation taken from the Sloan Digital Sky Survey-Data Release 4 (SDSS-DR4) using the stellar masses and oxygen abundances derived by Tremonti et al. Close galaxy pairs, defined by projected separation rp < 25 kpc h−1 and radial velocity ΔV < 350 km s−1, are morphologically classified according to the strength of the interaction signs. We find that only for pairs showing signs of strong interactions, the mass–metallicity relation differs significantly from that of galaxies in isolation. In such pairs, the mean gas-phase oxygen abundances of galaxies with low stellar masses (M*≲ 109 M⊙h−1) exhibit an excess of 0.2 dex. Conversely, at larger masses (M*≳ 1010 M⊙h−1) galaxies have a systematically lower metallicity, although with a smaller difference (−0.05 dex). Similar trends are obtained if g-band magnitudes are used instead of stellar masses. In minor interactions, we find that the less massive member is systematically enriched, while a galaxy in interaction with a comparable stellar mass companion shows a metallicity decrement with respect to galaxies in isolation.

We argue that metal-rich starbursts triggered by a more massive component, and inflows of low-metallicity gas induced by comparable or less massive companion galaxies, provide a natural scenario to explain our findings.
Entrepreneurship as a Liberal Art
Authors: Rennie Henry G.
Published: March 2008

This article looks at the role liberal arts colleges or universities can play in developing individuals with a comparative advantage in new enterprise creation. The thesis is that entrepreneurship is a creative act and, as such, has more in common with the liberal arts than the narrower fields of both market economics and business. The article concludes by integrating entrepreneurship, creativity, and liberal arts. It is shown that entrepreneurship can be the foundation of a liberal education because: (1) entrepreneurship will create a distinctive competency and generate increased value added in the liberal arts experience of students; (2) entrepreneurship will promote learning through applications of the consilience of inductions; (3) it will integrate the curriculum, reduce time, and subject compartmentalization of the curriculum; and (4) entrepreneurship will minimize external competitive threats to the liberal arts college. Implications of this conclusion for the curriculum in American colleges are suggested.
The Role of Universities in Building Local Economic Capacities
Authors: Taylor Michael , Plummer Paul , Bryson John R. , Garlick Steve
Published: March 2008

As the knowledge economy develops and intensifies, increasing pressure is being placed on universities to help in local economic capacity building to meet the challenges of globalization. This article explores this expanded university role from the perspective of the provision of policy analysis and advice they can provide. It proposes the use of mixed‐methods analysis, combining informed empirical modeling and “intensive” case studies to reveal local economic processes. An analysis of Australia's regional problems to exemplify this approach highlights the significance of “enterprising human capital” in promoting regional economic growth and suggests a policy prescription that includes enterprising education. In contradistinction, using U.K. evidence, the pitfalls of entrepreneurship education are outlined as it relates to the role of universities in local economic capacity building. The study calls for dialogue to bring about radical rethinking of policy analysis, advice, and the role universities can play in local economic capacity building.
Entrepreneurs, Organizational Strength, and the Pursuit of Public Goods by Voluntary Organizations
Authors: Stiles Elizabeth A.
Published: March 2008

Robert Salisbury has assumed that interest group entrepreneurs are profit‐driven and make attempts to procure collective goods to increase their membership and revenue. This article's research question takes the reverse of Salisbury's claim: can interest group entrepreneurs increase the likelihood of procuring collective goods by increasing their organizational strength? Results of a study of statewide Lesbian, Gay, Bisexual, and Transgender (LGBT) organizations show that larger memberships are positively and significantly associated with success in procuring collective goals while increased budgets are significantly but negatively associated. The implications are twofold. First, the assumption that entrepreneurs pursue collective goods for reasons of self‐interest may be more complicated than Salisbury suggests. The relationship could be the opposite—interest group entrepreneurs build their membership to secure collective goals. Second, because of the finding that more members means more legislative success, but greater budgets means less legislative success, interest group entrepreneurs interested in procuring collective goals should consider maximizing their membership rather than their budgets.
The Entrepreneurial Assumption: Thinking about Taxes in Contemporary Political Theory
Authors: Peden Mindy
Published: March 2008

This article argues that contemporary political theory often contains an obscured supposition that I call the entrepreneurial assumption. This assumption can be seen most clearly when political theorists who do not have economic expertise per se theorize the relationship between their political thought and taxation. In order to explicate the entrepreneurial assumption, the article engages in close readings of John Rawls, Robert Nozick, and Ronald Dworkin. By elaborating on each of these authors' views, the importance of preserving “talent” through a system of taxation, the centrality of the entrepreneurial assumption can be seen more clearly.
Commercializing “Creative” Expertise: Business and Professional Services and Regional Economic Development in the West Midlands, United Kingdom
Authors: Bryson John R. , Taylor Michael , Daniels Peter W.
Published: March 2008

In the economically developed world, over 75 percent of all jobs involve some form of service work. Over the last 30 years, there has been a dramatic growth in business and professional services (BPS) or those firms that provide “creative” intermediate inputs into the activities of client companies. BPS firms have a double impact on regional economic performance: they add value in their own right but also create productivity improvements in client companies. This article explores the development of a BPS‐focused regional economic development policy in the West Midlands, United Kingdom. Developing a policy framework for BPS is problematic as the heterogeneous nature of BPS activities means that no single lobbying group exists to represent their interests. The West Midlands has tried to overcome this difficulty by creating subregional networking organizations and, more recently, by developing a policy approach that attempts to enhance the added value BPS firms provide to their clients. This represents a major, but as yet untested, development in policy intervention as it recognizes the complex interactions that occur between BPS firms and their clients.
RESEARCH ARTICLE: Intravascular Thrombosis in Central Nervous System Malignancies: A Potential Role in Astrocytoma Progression to Glioblastoma
Authors: Tehrani Mahtab , Friedman Theodore M. , Olson Jeffrey J. , Brat Daniel J.
Published: March 2008

The presence of necrosis within a diffuse glioma is a powerful predictor of poor prognosis, yet little is known of its origins. Intravascular thrombosis is a frequent finding in glioblastoma [GBM; World Health Organization (WHO) grade IV] specimens and could potentially be involved in astrocytoma progression to GBM or represent a surrogate marker of GBM histology. We investigated whether intravascular thrombosis was more frequent or prominent in GBM than other central nervous system (CNS) malignancies and considered its prognostic significance in anaplastic astrocytoma (AA; WHO grade III), which lacks necrosis. Histologic sections were examined for thrombosis, necrosis and microvascular hyperplasia from each of 297 CNS tumors, including 103 GBMs, 46 AAs, 20 diffuse astrocytoma (DAs; WHO grade II), eight anaplastic oligodendrogliomas (AOs; WHO grade III), 20 oligodendrogliomas (ODs; WHO grade II), 49 metastatic carcinomas (METs), 31 primary central nervous system lymphomas (PCNSLs) and 20 medulloblastomas (MBs). Among newly diagnosed tumors, thrombosis was present in 92% of GBM resections, significantly greater than other types of CNS malignancies. Of tumors with thrombosis, GBMs had a higher frequency of affected vessels than AAs, DAs, AOs, ODs and MBs, but had a frequency similar to METs and PCNSLs. The sensitivity of thrombosis for the diagnosis of GBM in this set of tumors was 92% and the specificity was 91%. Intravascular thrombosis was uncommon in AAs and was only noted in stereotactic biopsies. This subset of patients had shorter survivals than those AAs without thrombosis. Thus, intravascular thrombosis is more frequent in GBM than other CNS malignancies. When present in AAs, it appears to indicate aggressive clinical behavior.
RESEARCH ARTICLE: Systematic Assessment of BDNF and Its Receptor Levels in Human Cortices Affected by Huntington's Disease
Authors: Zuccato Chiara , Marullo Manuela , Conforti Paola , MacDonald Marcy E , Tartari Marzia , Cattaneo Elena
Published: March 2008

One cardinal feature of Huntington's disease (HD) is the degeneration of striatal neurons, whose survival greatly depends on the binding of cortical brain‐derived neurotrophic factor (BDNF) with high‐affinity (TrkB) and low‐affinity neurotrophin receptors [p75 pan‐neurotrophin receptor (p75NTR)]. With a few exceptions, results obtained in HD mouse models demonstrate a reduction in cortical BDNF mRNA and protein, although autopsy data from a limited number of human HD cortices are conflicting. These studies indicate the presence of defects in cortical BDNF gene transcription and transport to striatum. We provide new evidence indicating a significant reduction in BDNF mRNA and protein in the cortex of 20 HD subjects in comparison with 17 controls, which supports the hypothesis of impaired BDNF production in human HD cortex. Analyses of the BDNF isoforms show that transcription from BDNF promoter II and IV is down‐regulated in human HD cortex from an early symptomatic stage. We also found that TrkB mRNA levels are reduced in caudate tissue but not in the cortex, whereas the mRNA levels of T‐Shc (a truncated TrkB isoform) and p75NTR are increased in the caudate. This indicates that, in addition to the reduction in BDNF mRNA, there is also unbalanced neurotrophic receptor signaling in HD.
Silymarin, a Flavonoid from Milk Thistle (Silybum marianum L.), Inhibits UV‐induced Oxidative Stress Through Targeting Infiltrating CD11b+ Cells in Mouse Skin†
Authors: Katiyar Santosh K. , Meleth Sreelatha , Sharma Som D.
Published: March 2008

Phytochemicals have shown promise in inhibiting UV‐induced oxidative stress, and therefore are considered as potent inhibitors of UV‐induced oxidative stress‐mediated skin diseases. We have shown previously that topical treatment of silymarin, a flavonoid from milk thistle (Silybum marianum), inhibits UV‐induced oxidative stress in mouse skin. However, the cellular targets responsible for the inhibition of UV‐induced oxidative stress by silymarin are not clearly defined. To address this issue, C3H/HeN mice were UV irradiated (90 mJ cm−2) with or without topical treatment with silymarin (1 mg cm−2 skin area). Mice were killed 48 h later and skin samples collected. Flow cytometric analysis of viable dermal cells revealed that the number of infiltrating CD11b+ cells were the major source of oxidative stress (31.8%) in UV‐irradiated skin compared with non–UV‐exposed skin (0.4%). Treatment of silymarin inhibited UV‐induced oxidative stress through inhibition of infiltrating CD11b+ cells. The analysis of myeloperoxidase also indicated that silymarin significantly (P < 0.001) decreased UV‐induced infiltration of leukocytes, and this effect of silymarin was similar to that of intraperitoneal treatment of mice with monoclonal antibodies to CD11b. The inhibitory effect of silymarin, regardless of whether it is topically treated before or after UV irradiation, was of similar magnitude. Intraperitoneal administration of monoclonal antibodies to CD11b (rat IgG2b) to C3H/HeN mice inhibited UVB‐induced oxidative stress generated by both epidermal and dermal cells as is evident by relative fluorescence intensity of oxidized rhodamine. Similar to the effect of anti‐CD11b, silymarin also inhibited UV‐induced oxidative stress in both epidermal and dermal cells. Further, CD11b+ and CD11b− cell subsets from UV‐treated or silymarin+UV‐treated mice were separated by immunomagnetic cell isolation technique from total epidermal and dermal single cell suspensions and analyzed for reactive oxygen species (ROS)/H2O2 production. Analytic data revealed that CD11b+ cell population from UV‐irradiated skin resulted in significantly higher production of ROS in both epidermis and dermis than CD11b− cell population, and that silymarin inhibited UV‐induced oxidative stress through targeting infiltrating the CD11b+ cell type in the skin.
Inflammatory Doses of UV May Not Be Necessary for Skin Carcinogenesis†
Authors: Halliday Gary M. , Lyons J. Guy
Published: March 2008

The UV wavelengths in sunlight are the main cause of skin cancer in humans. Sunlight causes gene mutations, immunosuppression and, at higher doses, inflammation. While it is clear that immunosuppression and gene mutations are essential biologic events via which UV causes skin cancer, the requirement for UV‐induced inflammation is less certain. Both the UVB (290–320 nm) and UVA (320–400 nm) wavebands within sunlight can cause skin cancer, gene mutations and immunosuppression. However, UVB, but not UVA, at realistic doses can cause inflammation, and UVB induces skin cancer, immunosuppression and gene mutations at doses much lower than those required to cause inflammation. Inflammation enhances skin carcinogenesis, but may not be UV induced, and inflammatory mediators at doses too low to cause inflammation may be required. UV‐induced mutations can cause epidermal cells to make proinflammatory factors or to induce them in the surrounding stroma, creating an oxidizing environment in which additional oncogenic mutations are likely to take place, even in the absence of UV. Our hypothesis is therefore that subinflammatory doses of both UVA and UVB cause benign skin tumors. One of the effects of sunlight‐induced mutations may be the production of inflammatory mediators that enhance carcinogenesis.
Protection from Sunburn with β‐Carotene—A Meta‐analysis†
Authors: Köpcke Wolfgang , Krutmann Jean
Published: March 2008

Nutritional protection against skin damage from sunlight is increasingly advocated to the general public, but its effectiveness is controversial. In this meta‐analysis, we have systematically reviewed the existing literature on human supplementation studies on dietary protection against sunburn by beta‐carotene. A review of literature until June 2007 was performed in PubMed, ISI Web of Science and EBM Cochrane library and identified a total of seven studies which evaluated the effectiveness of β‐carotene in protection against sunburn. Data were abstracted from these studies by means of a standardized data collection protocol. The subsequent meta‐analysis showed that (1) β‐carotene supplementation protects against sunburn and (2) the study duration had a significant influence on the effected size. Regression plot analysis revealed that protection required a minimum of 10 weeks of supplementation with a mean increase of the protective effect of 0.5 standard deviations with every additional month of supplementation. Thus, dietary supplementation of humans with β‐carotene provides protection against sunburn in a time‐dependent manner.
Understanding Signaling Cascades in Melanoma†
Authors: Lopez‐Bergami Pablo , Fitchman Boris , Ronai Ze’ev
Published: March 2008

Understanding regulatory pathways involved in melanoma development and progression has advanced significantly in recent years. It is now appreciated that melanoma is the result of complex changes in multiple signaling pathways that affect growth control, metabolism, motility and the ability to escape cell death programs. Here we review the major signaling pathways currently known to be deregulated in melanoma with an implication to its development and progression. Among these pathways are Ras, B‐Raf, MEK, PTEN, phosphatidylinositol‐3 kinase (PI3Ks) and Akt which are constitutively activated in a significant number of melanoma tumors, in most cases due to genomic change. Other pathways discussed in this review include the [Janus kinase/signal transducer and activator of transcription (JAK/STAT), transforming growth factor‐β pathways which are also activated in melanoma, although the underlying mechanism is not yet clear. As a paradigm for remodeled signaling pathways, melanoma also offers a unique opportunity for targeted drug development.
Naringenin Protects HaCaT Human Keratinocytes Against UVB‐induced Apoptosis and Enhances the Removal of Cyclobutane Pyrimidine Dimers from the Genome†
Authors: El‐Mahdy Mohamed A. , Zhu Qianzheng , Wang Qi‐En , Wani Gulzar , Patnaik Srinivas , Zhao Qun , Arafa El‐Shaimaa , Barakat Bassant , Mir Safita N. , Wani Altaf A.
Published: March 2008

Many naturally occurring agents are believed to protect against UV‐induced skin damage. In this study, we have investigated the effects of naringenin (NG), a naturally occurring citrus flavonone, on the removal of UVB‐induced cyclobutane pyrimidine dimers (CPD) from the genome and apoptosis in immortalized p53‐mutant human keratinocyte HaCaT cells. The colony‐forming assay shows that treatment with NG significantly increases long‐term cell survival after UVB irradiation. NG treatment also protects the cells from UVB‐induced apoptosis, as indicated by the absence of the 180 base pair DNA ladders and the appearance of sub‐G1 peak using agarose gel electrophoresis and flow cytometric analysis, respectively. The UVB‐induced poly (ADP‐ribose) polymerase‐1 (PARP‐1) cleavage, caspase activation and Bax/Bcl2 ratio were modulated following NG treatment, indicating an antiapoptotic effect of NG in UVB‐damaged cells that occurs at least in part via caspase cascade pathway. Moreover, treatment of UVB‐irradiated HaCaT cells with NG enhances the removal of CPD from the genome, as observed by both direct quantitation of CPD in genomic DNA and immuno‐localization of the damage within the nuclei. The study provides a molecular basis for the action of NG as a promising natural flavonoid in preventing skin aging and carcinogenesis.