bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optical afterglow luminosities in the Swift epoch: confirming clustering and bimodality
Authors: Nardini M. , Ghisellini G. , Ghirlanda G. 
Published: March 2008

Abstract
We show that gamma-ray bursts (GRBs) of known redshift and rest-frame optical extinction detected by the Swift satellite fully confirm earlier results concerning the distribution of the optical afterglow luminosity at 12 h after trigger (rest-frame time). This distribution is bimodal and relatively narrow, especially for the high-luminosity branch. This is intriguing, given that Swift GRBs have, on average, a redshift larger than pre-Swift ones, and is unexpected in the common scenario explaining the GRB afterglow. We investigate if the observed distribution can be the result of selection effects affecting a unimodal parent luminosity distribution, and find that either the distribution is intrinsically bimodal, or most (60 per cent) of the bursts are absorbed by a substantial amount of grey dust. In both cases we suggest that most dark bursts should belong to the underluminous optical family.
Transatlantic Similarities and Contrasts in Rural Development Policies Transatlantische Ähnlichkeiten und Gegensätze bei den Politiken zur Entwicklung des ländlichen Raums Points communs et divergences transatlantiques sur le développement rural
Authors: Cochrane Nancy , Wojan Tim 
Published: March 2008

Transatlantic Similarities and Contrasts in Rural Development PoliciesThe United States (US) and European Union (EU) share many general policy aims for rural areas, but they differ in the ways in which they try to achieve these aims. The principal difference lies in the role envisioned by agriculture in overall rural development. EU policies treat agriculture as a provider of public goods, and many of its ‘rural’ programmes target agriculture. In the US, very few Federal rural development programs are focused solely on agriculture. Differences of approach may be linked to different farm distributions, population densities, historical settlement patterns, and the historical policy process per se. In particular, in the US rural development policy does not cover the environment or income support to farmers; these are addressed through other programmes. In contrast, the EU classifies its agri‐environmental programmes as rural development, claiming that more environmentally‐friendly farm practices bring benefits to the broader rural economy. US State and local initiatives emphasize many themes found in the EU’s Pillar II programmes, such as value‐added or sustainable agriculture. Overall, although there are marked differences in the ways in which policies are implemented, the coverage of these policies in the EU and US is rather similar.
Human and Social Capital in Rural Development – EU and US Perspectives Human‐ und Sozialkapital in der Entwicklung des ländlichen Raums – Perspektiven aus der EU und den USA Le capital social et humain dans le développement rural: Perspectives aux États‐Unis et dans l’Union européenne
Authors: Dwyer Janet , Findeis Jill 
Published: March 2008

Human and Social Capital in Rural Development – EU and US PerspectivesHuman and social capital play critical roles in rural development, in both the US and Europe. The development of these resources at the individual and community levels is both an ultimate goal of sustainable rural development (RD), and a key means to pursue it. Rural areas face a range of specific issues and challenges for human and social capital. In this article we examine some of these, finding similarity in many issues faced by EU and US rural areas, including the trend toward counter‐urbanization in some locations. We also give examples of some apparently useful policy and grass‐root approaches in the EU and US used to support farmers and in some cases rural people more generally. We assert that the US lags behind the EU in recognising the value of social capital development, but that it could learn from EU experience in terms of alternative approaches and their successes or failures. Traditionally, policies which promote the enhancement of rural human capital and strengthen social capital in rural areas have failed to attract large‐scale RD funding or prominence. They have, however, gained in credibility, and influence within the policy rhetoric, in recent years. We suggest that they deserve a higher profile in RD policies given likely future trends and challenges.
Infrastructure and Rural Development: US and EU Perspectives Infrastruktur und Entwicklung des ländlichen Raums: Perspektiven aus den USA und der EU Infrastructures et développement rural : Perspectives aux États‐Unis et dans l’Union européenne
Authors: Blandford David , Boisvert Richard N. , Davidova Sophia 
Published: March 2008

Infrastructure and Rural Development: US and EU PerspectivesInfrastructural development remains a cornerstone of rural development policy in both the United States and Europe. It is evident that rural development objectives differ, but similar policy measures are used. The economic rationale for infrastructure development centres on efficiency and creation of competitive advantage. Policy intervention is justified because of the added costs of infrastructure provision in remote, sparsely populated areas. Although this policy focus does not guarantee success, regions leading in economic development typically have better physical infrastructure. In the United States, policy must adapt to challenges posed by an ageing rural infrastructure and demographic change that will increase demands on social infrastructure such as housing and health facilities. There will be greater local responsibility for funding, and expanded use of public/private partnerships. In the European Union, the major challenge is in redirecting resources to new member states, where there is urgent need for both large new investments in transport networks and small investments to improve local access. Although two current options for funding these diverse needs focus on European policies only, investments in non‐farm physical capital and public infrastructure cannot be sustained without active national policies to complement the European efforts, perhaps through co‐financing requirements.
5‐HT1A, but not 5‐HT2 and 5‐HT7, receptors in the nucleus raphe magnus modulate hypoxia‐induced hyperpnoea
Authors: Nucci T. B. , Branco L. G. S. , Gargaglioni L. H. 
Published: March 2008

AbstractAim:  In the present study, we assessed the role of 5‐hydroxytryptamine (5‐HT) receptors (5‐HT1A, 5‐HT2 and 5‐HT7) in the nucleus raphe magnus (NRM) on the ventilatory and thermoregulatory responses to hypoxia.Methods:  To this end, pulmonary ventilation (VE) and body temperature (Tb) of male Wistar rats were measured in conscious rats, before and after a 0.1 μL microinjection of WAY‐100635 (5‐HT1A receptor antagonist, 3 μg 0.1μL−1, 56 mm), ketanserin (5‐HT2 receptor antagonist, 2 μg 0.1μL−1, 36 mm) and SB269970 (5‐HT7 receptor antagonist, 4 μg 0.1 μL−1, 103 mm) into the NRM, followed by 60 min of severe hypoxia exposure (7% O2).Results:  Intra‐NMR microinjection of vehicle (control rats) or 5‐HT antagonists did not affect VE or Tb during normoxic conditions. Exposure of rats to 7% O2 evoked a typical hypoxia‐induced anapyrexia after vehicle microinjections, which was not affected by microinjection of WAY‐100635, SB269970 or ketanserin. The hypoxia‐induced hyperpnoea was not affected by SB269970 and ketanserin intra‐NMR. However, the treatment with WAY‐100635 intra‐NRM attenuated the hypoxia‐induced hyperpnoea.Conclusion:  These data suggest that 5‐HT acting on 5‐HT1A receptors in the NRM increases the hypoxic ventilatory response.
CFTR and its key role in in vivo resting and luminal acid‐induced duodenal HCO3− secretion
Authors: Singh A. K. , Sjöblom M. , Zheng W. , Krabbenhöft A. , Riederer B. , Rausch B. , Manns M. P. , Soleimani M. , Seidler U. 
Published: March 2008

AbstractBackground and aims:  We investigated the role of the recently discovered, villous‐expressed anion exchanger Slc26a6 (PAT1) and the predominantly crypt‐expressed cystic fibrosis transmembrane regulator (CFTR) in basal and acid‐stimulated murine duodenal HCO3− secretion in vivo, and the influence of blood HCO3− concentration on both.Methods:  The proximal duodenum of anaesthetized mice was perfused in situ, and HCO3− secretion was determined by back‐titration. Duodenal mucosal permeability was assessed by determining 51Cr‐EDTA leakage from blood to lumen.Results:  Compared with wild type (WT) littermates basal duodenal HCO3− secretory rates were slightly reduced in Slc26‐deficient mice at low (∼21 mm), and markedly reduced at high blood HCO3− concentration (∼29 mm). In contrast, basal HCO3− secretion was markedly reduced in CFTR‐deficient mice compared with WT littermates both at high and low blood HCO3− concentration. A short‐term application of luminal acid increased duodenal HCO3− secretory rate in Slc26a6‐deficient and WT mice to the same degree, but had no stimulatory effect in the absence of CFTR. Luminal acidification to pH 2.5 did not alter duodenal permeability.Conclusions:  The involvement of Slc26a6 in basal HCO3− secretion in murine duodenum in vivo is critically dependent on the systemic acid/base status, and this transporter is not involved in acid‐stimulated HCO3− secretion. The presence of CFTR is essential for basal and acid‐induced HCO3− secretion irrespective of acid/base status. This suggests a coupled action of Slc26a6 with CFTR for murine basal duodenal HCO3− secretion, but not acid‐stimulated secretion, in vivo.
Here, There, Everywhere: The Ubiquitous Geographies of Heteronormativity
Authors: Hubbard Phil 
Published: March 2008

AbstractFrom its first tentative forays into questions of gay and lesbian residence, the discipline of geography has made increasingly important contributions to literatures on sexual identities, practices and politics. In this paper, I seek to highlight the breadth and depth of recent work on sexuality and space by exploring the contributions made by geographers to the theorisation of heteronormativity. Specifically, this paper explores how heterosexual norms are constructed ansd reproduced spatially, noting the increasing corpus of work which moves beyond examination of heterosexuality's Other (i.e. homosexuality) to consider the multiple desires and bodies that can be accommodated within the category ‘heterosexual’. Moving from urban to rural contexts, this paper hence reviews literatures detailing how particular heterosexualities are rendered normal and concludes that the literature is usefully shifting from a focus on identity and community to questions of practice and performance.
Understanding Dryland Landscape Dynamics: Do Biological Crusts Hold the Key?
Authors: Viles Heather A. 
Published: March 2008

AbstractUnderstanding landscape dynamics in arid and semi‐arid areas is becoming increasingly important, as global change threatens to upset linked ecological and geomorphological systems with potentially serous impacts on livelihoods and environments. Biological crusts (composed of lichens, algae, fungi and bacteria) cover many rock, soil and sediment surfaces in arid and semi‐arid areas and provide a key to understanding future dryland landscape dynamics. Such crusts have been found to play a number of key geomorphic and ecological roles, and are identified as important ecosystem engineers and biogeomorphological agents that could be used in environmental restoration. However, they have also been reported to be highly fragile and susceptible to disturbance, and damage to them may result in non‐linear consequences for linked dryland geomorphological and ecological systems. This paper outlines the current state of knowledge on biological crusts in arid and semi‐arid areas and calls for increased collaboration between geomorphologists and ecologists and better links between studies of biological crusts on rock and soil surfaces.
Diasporic and Transnational Social Practices in Central Asia
Authors: Diener Alexander C. 
Published: March 2008

AbstractDiaspora has become such a popular concept in recent years because it so effectively challenges the authenticity of the nation‐state and the bounded identities it supports. A core premise of this critique is thatnotevery diaspora or nation‐state is the same. An ideal context in which to explore this idea is the region of Central Asia. Transnational practices emerging among dispersed members of each state's population draw into question the very idea ofdiasporaas connoting a condition of displacement andnationas relating to a discreet territorially fixed identity community. The complexity of the diasporic form among Central Asia's dispersed communities highlights the need to be mindful of the material, historical, and political settings within which individuals and groups create and sustain their own social and cultural networks. This essay reviews major debates and offers a survey of diasporic conditions within Central Asia.
Modeling the Thermal Conductivity and Phonon Transport in
Nanoparticle Composites Using Monte Carlo Simulation
Authors: Jeng Ming-Shan , Yang Ronggui , Song David , Chen Gang 
Published: March 2008

Abstract
This paper presents a Monte Carlo simulation scheme to study the phonon transport and the thermal conductivity of nanocomposites. Special attention has been paid to the implementation of periodic boundary condition in Monte Carlo simulation. The scheme is applied to study the thermal conductivity of silicon germanium (Si–Ge) nanocomposites, which are of great interest for high-efficiency thermoelectric material development. The Monte Carlo simulation was first validated by successfully reproducing the results of (two-dimensional) nanowire composites using the deterministic solution of the phonon Boltzmann transport equation reported earlier and the experimental thermal conductivity of bulk germanium, and then the validated simulation method was used to study (three-dimensional) nanoparticle composites, where Si nanoparticles are embedded in Ge host. The size effects of phonon transport in nanoparticle composites were studied, and the results show that the thermal conductivity of nanoparticle composites can be lower than that of the minimum alloy value, which is of great interest to thermoelectric energy conversion. It was also found that randomly distributed nanopaticles in nanocomposites rendered the thermal conductivity values close to that of periodic aligned patterns. We show that interfacial area per unit volume is a useful parameter to correlate the size effect of thermal conductivity in nanocomposites. The key for the thermal conductivity reduction is to have a high interface density where nanoparticle composites can have a much higher interface density than the simple 1D stacks, such as superlattices. Thus, nanocomposites further benefit the enhancement of thermoelectric performance in terms of thermal conductivity reduction. The thermal conductivity values calculated by this work qualitatively agrees with a recent experimental measurement of Si–Ge nanocomposites.
Neonatal bone marrow transplantation of ADA-deficient SCID mice results in immunologic reconstitution despite low levels of engraftment and an absence of selective donor T lymphoid expansion
Authors: Carbonaro Denise A. , Jin Xiangyang , Cotoi Daniel , Mi Tiejuan , Yu Xiao-Jin , Skelton Dianne C. , Dorey Frederick , Kellems Rodney E. , Blackburn Michael R. , Kohn Donald B. 
Published: March 2008

Abstract
Adenosine deaminase (ADA)–deficient severe combined immune deficiency (SCID) may be treated by allogeneic hematopoietic stem cell transplantation without prior cytoreductive conditioning, although the mechanism of immune reconstitution is unclear. We studied this process in a murine gene knockout model of ADA-deficient SCID. Newborn ADA-deficient pups received transplants of intravenous infusion of normal congenic bone marrow, without prior cytoreductive conditioning, which resulted in long-term survival, multisystem correction, and nearly normal lymphocyte numbers and mitogenic proliferative responses. Only 1% to 3% of lymphocytes and myeloid cells were of donor origin without a selective expansion of donor-derived lymphocytes; immune reconstitution was by endogenous, host-derived ADA-deficient lymphocytes. Preconditioning of neonates with 100 to 400 cGy of total body irradiation before normal donor marrow transplant increased the levels of engrafted donor cells in a radiation dose–dependent manner, but the chimerism levels were similar for lymphoid and myeloid cells. The absence of selective reconstitution by donor T lymphocytes in the ADA-deficient mice indicates that restoration of immune function occurred by rescue of endogenous ADA-deficient lymphocytes through cross-correction from the engrafted ADA-replete donor cells. Thus, ADA-deficient SCID is unique in its responses to nonmyeloablative bone marrow transplantation, which has implications for clinical bone marrow transplantation or gene therapy.
Improving the prediction of mRNA extremities in the parasitic protozoan Leishmania
Authors: Smith Martin , Blanchette Mathieu , Papadopoulou Barbara 
Published: March 2008

Abstract

Background

Leishmania and other members of the Trypanosomatidae family diverged early on in eukaryotic evolution and consequently display unique cellular properties. Their apparent lack of transcriptional regulation is compensated by complex post-transcriptional control mechanisms, including the processing of polycistronic transcripts by means of coupled trans-splicing and polyadenylation. Trans-splicing signals are often U-rich polypyrimidine (poly(Y)) tracts, which precede AG splice acceptor sites. However, as opposed to higher eukaryotes there is no consensus polyadenylation signal in trypanosomatid mRNAs.

Results
We refined a previously reported method to target 5' splice junctions by incorporating the pyrimidine content of query sequences into a scoring function. We also investigated a novel approach for predicting polyadenylation (poly(A)) sites in-silico, by comparing query sequences to polyadenylated expressed sequence tags (ESTs) using position-specific scanning matrices (PSSMs). An additional analysis of the distribution of putative splice junction to poly(A) distances helped to increase prediction rates by limiting the scanning range. These methods were able to simplify splice junction prediction without loss of precision and to increase polyadenylation site prediction from 22% to 47% within 100 nucleotides.

Conclusion
We propose a simplified trans-splicing prediction tool and a novel poly(A) prediction tool based on comparative sequence analysis. We discuss the impact of certain regions surrounding the poly(A) sites on prediction rates and contemplate correlating biological mechanisms. This work aims to sharpen the identification of potentially functional untranslated regions (UTRs) in a large-scale, comparative genomics framework.
Establishment of a new method for precisely determining the functions of individual mitochondrial genes, using Dictyostelium cells
Authors: Chida Junji , Amagai Aiko , Tanaka Masashi , Maeda Yasuo 
Published: March 2008

Abstract

Background
Disruption of mitochondrial genes may become a powerful tool for elucidating precisely the functions of individual mitochondrial genes. However, it is generally difficult to manipulate genetically mitochondrial genes, because 1) a mitochondrion is surrounded by inner and outer membranes, and 2) there are a large number of mtDNA copies in a single cell. This is the reason why we tried to establish a novel method for disrupting a certain mitochondrial gene (rps4), using Dictyostelium cells.

Results
Here, we have developed a new method for specifically disrupting a mitochondrial gene (rps4 ; ribosomal protein subunit S4), by a combination of homologous recombination and delivery of an appropriate restriction endonuclease (Sfo I) into mitochondria. First, mitochondrially targeted Sfo I whose expression is under control of the tetracycline (Tet)-regulated gene expression system was introduced into cells heteroplasmic with respect to the rps4 gene. Then, the heteroplasmic cells were produced by homologous recombination by use of the construct in which the unique Sfo I site and the 5'-half of the rps4 coding region were deleted not to be digested by Sfo I, and therefore their mitochondria have both the wild-type mtDNA and the mutant mtDNA with the disrupted rps4 gene. In response to removal of Tet from growth medium, Sfo I was selectively delivered into mitochondria and digested only the wild-type mtDNA but not the mutated rps4. Thus one can gain rps4-null cells with only the mutated mtDNA, under the Tet-minus condition.

Conclusion
The mitochondrial gene-disruption method presented here must be widely useful for precisely determining the functions of individual mitochondrial genes. This is the first report to demonstrate complete and specific mitochondrial gene disruption.
Semaphorin 3B Is a 1,25-Dihydroxyvitamin D3-Induced Gene in Osteoblasts that Promotes Osteoclastogenesis and Induces Osteopenia in Mice
Authors: Sutton Amelia L. M. , Zhang Xiaoxue , Dowd Diane R. , Kharode Yogendra P. , Komm Barry S. , MacDonald Paul N. 
Published: March 2008

AbstractThe vitamin D endocrine system is important for skeletal homeostasis. 1,25-Dihydroxyvitamin D3 [1,25(OH)2D3] impacts bone indirectly by promoting intestinal absorption of calcium and phosphate and directly by acting on osteoblasts and osteoclasts. Despite the direct actions of 1,25(OH)2D3 in bone, relatively little is known of the mechanisms or target genes that are regulated by 1,25(OH)2D3 in skeletal cells. Here, we identify semaphorin 3B (SEMA3B) as a 1,25(OH)2D3-stimulated gene in osteoblastic cells. Northern analysis revealed strong induction of SEMA3B mRNA by 1,25(OH)2D3 in MG-63, ST-2, MC3T3, and primary osteoblastic cells. Moreover, differentiation of these osteogenic cells enhanced SEMA3B gene expression. Biological effects of SEMA3B in the skeletal system have not been reported. Here, we show that osteoblast-derived SEMA3B alters global skeletal homeostasis in intact animals and osteoblast function in cell culture. Osteoblast-targeted expression of SEMA3B in mice resulted in reduced bone mineral density and aberrant trabecular structure compared with nontransgenic littermates. Histomorphometry studies indicated that this was likely due to increased osteoclast numbers and activity. Indeed, primary osteoblasts obtained from SEMA3B transgenic mice stimulated osteoclastogenesis to a greater extent than nontransgenic osteoblasts. This study establishes that SEMA3B is a 1,25(OH)2D3-induced gene in osteoblasts and that osteoblast-derived SEMA3B impacts skeletal biology in vitro and in vivo. Collectively, these studies support a putative role for SEMA3B as an osteoblast protein that regulates bone mass and skeletal homeostasis.