bluuebunny/crossref_metadata_2025 huggingface dataset:
Delta-like 4 is the essential, nonredundant ligand for Notch1 during thymic T cell lineage commitment
Authors: Koch Ute , Fiorini Emma , Benedito Rui , Besseyrias Valerie , Schuster-Gossler Karin , Pierres Michel , Manley Nancy R. , Duarte Antonio , MacDonald H. Robson , Radtke Freddy
Published: September 2008

Thymic T cell lineage commitment is dependent on Notch1 (N1) receptor–mediated signaling. Although the physiological ligands that interact with N1 expressed on thymic precursors are currently unknown, in vitro culture systems point to Delta-like 1 (DL1) and DL4 as prime candidates. Using DL1- and DL4-lacZ reporter knock-in mice and novel monoclonal antibodies to DL1 and DL4, we show that DL4 is expressed on thymic epithelial cells (TECs), whereas DL1 is not detected. The function of DL4 was further explored in vivo by generating mice in which DL4 could be specifically inactivated in TECs or in hematopoietic progenitors. Although loss of DL4 in hematopoietic progenitors did not perturb thymus development, inactivation of DL4 in TECs led to a complete block in T cell development coupled with the ectopic appearance of immature B cells in the thymus. These immature B cells were phenotypically indistinguishable from those developing in the thymus of conditional N1 mutant mice. Collectively, our results demonstrate that DL4 is the essential and nonredundant N1 ligand responsible for T cell lineage commitment. Moreover, they strongly suggest that N1-expressing thymic progenitors interact with DL4-expressing TECs to suppress B lineage potential and to induce the first steps of intrathymic T cell development.
Prolongation of Hospital Stay and Additional Costs Due to Nosocomial Bloodstream Infection in an Algerian Neonatal Care Unit
Authors: Atif Mohamed Lamine , Sadaoui Fetta , Bezzaoucha Abdeldjallil , Kaddache Chawki Ahmed , Boukari Rachida , Djelato Salima , Boubechou Nora
Published: September 2008

Background.

Previous studies from developed countries reported that nosocomial bloodstream infection (BSI) in neonatal care units (NCUs) increases length of stay and costs. However, no such information is available for Algerian NCUs.

Objective.

To evaluate the influence of BSI in neonates on additional charges and length of hospital stay.

Design.

Prospective, nested case-control study.

Setting.

The 47-bed NCU of the University Hospital of Blida, Algeria.

Patients and Methods.

A total of 83 neonates with BSIs (case patients) and 166 neonates without BSIs (control patients), admitted to the NCU during the study period (April 2004 through December 2007), were matched for sex, birth weight, length of NCU stay, and year of hospital admission. Each patient's length of stay in the NCU was obtained prospectively on daily rounds. The estimated cost of each NCU-day was provided by the hospital's finance department. The cost of antibiotics prescribed was provided by the hospital's pharmacy department.

Results.

The mean additional length of NCU stay for case patients, compared with control patients, was 9.2 days (24.3 vs 15.1 days). The mean additional cost of antibiotics was $546. The mean cumulative additional cost was $1,315.

Conclusion.

This study highlights the effect of BSI on extra costs for NCU patients, especially costs due to prolongation of hospital stay and increased antibiotic use, and suggests that NCUs in Algeria have a financial interest in reducing the rate of BSI.
Ghrelin suppresses secretion of FSH in males
Authors: Kluge Michael , Uhr Manfred , Bleninger Philipp , Yassouridis Alexander , Steiger Axel
Published: September 2008

Background  Ghrelin decreases the secretion of LH probably by suppressing the release of hypothalamic GnRH. So far however, there is no evidence that ghrelin affects also the secretion of FSH in humans, the other gonadotrophin regulated by GnRH.

Objective  Our objective was to study the effect of ghrelin on secretion of FSH in humans.

Design/study subjects  Nocturnal (20:00–07:00 h) secretion profiles of FSH were measured in 10 healthy males (25·3 ± 3·2 years) twice, receiving 50 µg ghrelin or placebo at 22:00, 23:00, 24:00, and 01:00 h, in this single‐blind, randomized, cross‐over study.

Results  Mean FSH plasma levels were significantly (P < 0·05) lower with ghrelin than placebo between 01:00 and 02:20. Consistently, a significant decrease from baseline was only observed in the ghrelin but not in the placebo condition.

Conclusion  This study provides first evidence that ghrelin suppresses the secretion of FSH in humans.
F plasmid partition depends on interaction of SopA with non‐specific DNA
Authors: Castaing Jean‐Philippe , Bouet Jean‐Yves , Lane David
Published: September 2008

Bacterial ATPases belonging to the ParA family assure partition of their replicons by forming dynamic assemblies which move replicon copies into the new cell‐halves. The mechanism underlying partition is not understood for the Walker‐box ATPase class, which includes most plasmid and all chromosomal ParAs. The ATPases studied both polymerize and interact with non‐specific DNA in an ATP‐dependent manner. Previous work showed that in vitro, polymerization of one such ATPase, SopA of plasmid F, is inhibited by DNA, suggesting that interaction of SopA with the host nucleoid could regulate partition. In an attempt to identify amino acids in SopA that are needed for interaction with non‐specific DNA, we have found that mutation of codon 340 (lysine to alanine) reduces ATP‐dependent DNA binding > 100‐fold and correspondingly diminishes SopA activities that depend on it: inhibition of polymer formation and persistence, stimulation of basal‐level ATP hydrolysis and localization over the nucleoid. The K340A mutant retained all other SopA properties tested except plasmid stabilization; substitution of the mutant SopA for wild‐type nearly abolished mini‐F partition. The behaviour of this mutant indicates a causal link between interaction with the cell's non‐specific DNA and promotion of the dynamic behaviour that ensures F plasmid partition.
Detection of antigen receptor gene rearrangements in lymphoproliferative malignancies by fluorescent polymerase chain reaction
Authors: Kerlan‐Candon S. , Sous Z. , Lefranc M.‐P. , Clot J. , Eliaou J.‐F.
Published: September 2008

Abstract: Monoclonal rearrangements of antigen receptor genes in lymphoproliferative diseases are characterized by the specific sequence and the length of their junctional region, which can be used as markers of the proliferating clone. PCR techniques have greatly simplified routine detection of monoclonal rearrangements. But on the one hand, identification of the sequences requires sequencing methods and on the other hand, sizing of rearrangements by conventional analysis of PCR products on agarose or nondenaturing polyacrylamide gels may be uncertain. We have developed an approach based on amplification of rearranged IGH, TCRG and TCRD locus by fluorescent PCR associated to a computerized analysis of generated PCR products allowing their objective sizing. We tested this method on DNA samples from patients with acute lymphoblastic leukemia and chronic lymphocytic leukemia, whose pattern of IGH and TCRG rearrangements had been previously identified by Southern blot techniques. TCRG‐PCR assay allowed detection of 100% of rearranged samples. No false‐negative results were found but a high rate (60%) of Southern‐negative and PCR‐positive samples were identified. TCRD PCR‐assay detected VD1JD1 or VD2‐D2/3 rearrangements in both acute lymphoblastic leukemia and chronic lymphocytic leukemia samples. IGH PCR assay permitted detection of all known rearranged samples. The sensitivity of these three different PCR assays (1% leukemic cells) was equivalent to that of other published PCR protocols. These results show the validity and reliability of the fluorescent PCR method for routine detection of IGH, TCRG and TCRD rearrangements. Sizing of PCR products by computerized analysis was also validated. It provides additional information on rearrangement patterns in lymphoproliferative diseases, as clonal rearrangements can be recognized by their size. This can be of great interest in various circumstances, particularly for detection and follow‐up of oligoclonality.
Effects of oleoresins and monoterpenes on in vitro growth of fungi associated with pine decline in the Southern United States
Authors: Eckhardt L. G. , Menard R. D. , Gray E. D.
Published: September 2008

As a means of exploring pine resistance to root disease and declines, the effects of host plant secondary metabolites on the growth of root colonizing fungi associated with three diseases/declines of southern pines – loblolly pine decline, littleleaf disease and annosum root rot were tested. The associated fungi –Leptographium huntii, L. serpens, L. terebrantis, L. procerum, Heterobasidion annosum and Phytophthora cinnamomi– were grown in saturated atmospheres or in direct contact with, pure monoterpenes and crude oleoresin collected from the four southern pines (Pinus taeda, P. eschinata, P. palustris and P. elliotti) for 7 day. Fungal growth was measured at 3, 5 and 7 day. Root‐infecting fungi differed significantly in sensitivity to crude oleoresin and pure monoterpenes. All fungi tested were inhibited, to some extent, by the resins tested. H. annosum and P. cinnamomi were strongly inhibited by all the monoterpenes tested. The ophiostomatoid fungi were significantly less affected by the compounds tested. L. huntii and L. serpens were less inhibited by monoterpenes than either L. terebrantis or L. procerum. These fungal growth studies show that the kind and amount of secondary metabolite produced by the host plant have a profound effect on tree pathogens. Alterations of tree physiology may have implications for defenses against tree pathogens as well as to the ecology and management of forest ecosystems. Difference in incidence of root disease observed in the field may be explained by the ability of the fungus to tolerate these host defense mechanisms.
Tracing retinal fiber trajectory with a method of transposon‐mediated genomic integration in chick embryo
Authors: Harada Hidekiyo , Takahashi Yoshiko , Kawakami Koich , Ogura Toshihiko , Nakamura Harukazu
Published: September 2008

We report convenient retinal fiber tracing by transfecting the tracer cDNA by in ovo electroporation. Long‐term and stable expression of tracer proteins such as green fluorescent protein is achieved by transposon‐mediated genome integration of the tracer protein expression cassette. We carried out coelectroporation of a plasmid containing CAGGS‐tracer cDNA flanked by the Tol2 transposable element along with a transposase expression vector to the optic vesicle of chick embryos at stage 11. By selecting electrodes, we can label a large group of retinal ganglion cells, or a small group of retinal ganglion cells; parallel electrodes assure transfection of large areas of the retina, and needle type electrodes label small areas of the retina. The retinal fiber trajectory and terminal zone (TZ) could be detected in the precise retinotopic manner on the contra‐lateral side of the optic tectum. The method has advantage in that we can show the retinal fiber trajectory in relation to the molecules that are responsible for pathfinding for the retinal fibers in the same specimen.
Relationship between saliva level of 3‐methoxy‐4‐hydroxyphenylglycol and mental health in the elderly general population
Authors: Li Guang Y. , Watanabe Itaru , Kunitake Yutaka , Sugataka Kazuhiro , Muraoka Toshifumi , Kojima Naoki , Kawashima Toshiro , Yamada Shigeto
Published: September 2008

Aims:  A large number of studies on the monoamine systems in Alzheimer's disease (AD) have found abnormalities of the noradrenergic system in the brain, but there has been no report concerning the relationship between noradrenergic activity and cognitive function in elderly living in a community. The aim of the present study was to explore the relationship between saliva level of 3‐methoxy‐4‐hydroxyphenylglycol (sMHPG) and mental health in this population.

Methods:  The study was to examine the relationship between sMHPG and performance on the Mini‐Mental State Examination (MMSE), Frontal Assessment Battery (FAB), and Beck Depression Inventory (BDI) in 213 elderly people living in the local community.

Results:  sMHPG in female subjects was positively correlated with age (r = 0.24, P = 0.003) and negatively correlated with scores on the MMSE (r = −0.26, P = 0.0016) and FAB (r = −0.19, P = 0.024), even after controlling for the effect of age (MMSE r = −0.20, P = 0.013). Notably, sMHPG was correlated with the pentagon drawing score (P = 0.0008) of MMSE. sMHPG was significantly correlated with BDI score in male subjects, but negatively correlated in female subjects. A gender difference was found in the relationship between the sMHPG and BDI score.

Conclusion:  The measurement of sMHPG may be a useful marker of mental health in elderly community‐dwelling subjects.
Decrease in heart rate variability response to task is related to anxiety and depressiveness in normal subjects
Authors: Shinba Toshikazu , Kariya Nobutoshi , Matsui Yasue , Ozawa Nobuyuki , Matsuda Yoshiki , Yamamoto Ken‐ichi
Published: September 2008

Aims:  Previous studies have shown that heart rate variability (HRV) measurement is useful in investigating the pathophysiology of various psychiatric disorders. The present study further examined its usefulness in evaluating the mental health of normal subjects with respect to anxiety and depressiveness.

Methods:  Heart rate (HR) and HRV were measured tonometrically at the wrist in 43 normal subjects not only in the resting condition but also during a task (random number generation) to assess the responsiveness. For HRV measurement, high‐frequency (HF; 0.15–0.4 Hz) and low‐frequency (LF; 0.04–0.15 Hz) components of HRV were obtained using MemCalc, a time series analysis technique that combines a non‐linear least square method with maximum entropy method. For psychological evaluation of anxiety and depressiveness, two self‐report questionnaires were used: State–Trait Anxiety Inventory (STAI) and Self‐Rating Depression Scale (SDS).

Results:  No significant relation was observed between HR and HRV indices, and the psychological scores both in the resting and task conditions. By task application, HF decreased, and LF/HF and HR increased, and significant correlation with psychological scores was found in the responsiveness to task measured by the ratio of HRV and HR indices during the task to that at rest (task/rest ratio). A positive relationship was found between task/rest ratio for HF, and STAI and SDS scores. Task/rest ratio of HR was negatively correlated with STAI‐state score.

Conclusion:  Decreased HRV response to task application is related to anxiety and depressiveness. Decreased autonomic responsiveness could serve as a sign of psychological dysfunction.
FOREIGN CAPITAL AND EFFICIENCY IN DEVELOPING COUNTRIES
Authors: Mastromarco Camilla
Published: September 2008

This paper uses stochastic frontier methodology to analyse foreign direct investment, imported capital goods and human capital as channels for increased efficiency in less‐developed countries. Empirical investigation reveals that developing countries differ with respect to the efficiency with which they use frontier technology. Foreign direct investment and human capital play a significant and quantitatively important role in explaining these differences.
Return Predictability of Higher‐Moment CAPM Market Models
Authors: Hung Chi‐Hsiou
Published: September 2008

Abstract:  This paper examines the relative performance of the higher‐moment CAPM market models and the CAPM in explaining realised returns and predicting one‐period‐ahead returns on individual stocks and (both equally‐ and value‐weighted) portfolios of momentum, size and country sorts. The three‐moment CAPM, the quadratic‐marke model, provides the best ex post estimates in respect of the time‐variation in returns on both the return winner and the smallest size portfolios. Further analysis using an orthogonal factor model for tackling multicollinearity confirms the findings. Parameter uncertainty, however, impinges on forecast accuracy and hence hampers the predictive ability of the higher‐moment models.
Examining the Role of Race, NIMBY, and Local Politics in FEMA Trailer Park Placement*
Authors: Davis Belinda Creel , Bali Valentina A.
Published: September 2008

Objective.In this article, we use the placement of Federal Emergency Management Agency (FEMA) trailer parks as a vehicle for examining how siting agents and approving agents factor race, NIMBY obstacles, and local politics into the overall approval process for projects that are viewed as undesirable.

Methods.Using data on where FEMA trailer parks were proposed and approved in South Louisiana after Hurricanes Katrina and Rita, we test a range of hypotheses about the determinants of temporary housing siting.

Results.Our results reveal the need to view the consideration of potential locations and the procedure of gaining approval as two distinct stages of a process. The findings suggest FEMA placed a great deal of emphasis on displaced residents' needs, but neglected to factor in the constituent pressures and the electoral calendar that local politicians would encounter when approving the site. In addition, the racial composition of a neighborhood had a substantial effect on both the consideration and approval stages.

Conclusions.Beyond need, politics and race can shape the governmental allocation of disaster relief solutions.
Working Toward a Just, Equitable, and Local Food System: The Social Impact of Community‐Based Agriculture*
Authors: Macias Thomas
Published: September 2008

Objective. This article serves as a pilot study of three central aspects of sociological research concerning the impact of local agriculture on local communities: food equity, social integration, and natural human capital.

Methods. Four CSA farmers, four partners in a direct‐market organic farm, and four community garden site coordinators working in the Intervale, a local agriculture project in Burlington, Vermont, were interviewed in person for this research. Additionally, the author collected observational data in the Intervale, at two local farmers' markets, and as a member of a local community garden.

Result. Different modes of local agricultural production have distinctive effects on the local population with regard to equitable access to healthy food, social inclusion, and experiential knowledge of the natural world.

Conclusions. Given class‐based disparities in local agricultural participation, local food projects should consider promoting programs designed for broader social inclusion, including subsidized farmer‐to‐family coupons.
Social Movement Identity: Validating a Measure of Identification with the Environmental Movement*
Authors: Dunlap Riley E. , McCright Aaron M.
Published: September 2008

Objective.We offer an empirical measure of “social movement identity” vis‐à‐vis the environmental movement. Our measure of environmental movement identity complements existing efforts to measure the ambiguous concept of “environmental identity.”

Methods.We utilize data from a 2000 Gallup Poll of 1,004 adults to examine relationships between our measure of environmental movement identity and self‐reported membership in environmental organizations, assessments of the environmental movement, and self‐reported pro‐environmental behaviors.

Results.The measure appears to have face validity, and our results suggest it also has construct and predictive validity since it is related to environmental organization memberships, assessments of the environmental movement, and self‐reported pro‐environmental behaviors—even when controlling for relevant sociopolitical characteristics.

Conclusions.The measure is useful for analyses of the environmental movement, can be adapted for research on other movements, and can help social movement analysts respond to calls to investigate linkages between public opinion and movement dynamics.
When it Works and Where it Fails: Spatial, Temporal, and Budgetary Constraints to Civic Environmentalism*
Authors: Morris Mary Hallock
Published: September 2008

Objectives.With its focus on civic engagement, market‐based tools, and public‐private partnerships, the model of civic environmentalism has been successful in dealing with small, localized problems. Yet, a serious investigation of its use to deal with large‐scale, complex problems has not been undertaken. This article expands on the original model and applies it to the problem of the dead zone in the Gulf of Mexico.

Methods.An exploratory case‐study framework is used to analyze the usefulness of this second‐generation model of environmental policy. Archival data sources, in the form of media reports, congressional hearings, case histories, and organizational websites, were used to develop the case study.

Results.The case study demonstrated that polycentric governance, local‐level participation, civic leadership, and voluntary, incentive‐based programs were integral components of the model of civic environmentalism. However, in the case of the Gulf of Mexico's dead zone, the model's success is limited by spatial, budgetary, and temporal factors, as well as a lack of issue salience and minimal negative impacts on fishery resources.

Conclusions.In the end analysis, civic environmentalism faces significant barriers when applied to large‐scale, complex environmental problems such as the Gulf of Mexico's dead zone. In this case, the Mississippi River/Gulf of Mexico Task Force will continue to have difficulties in generating a more successful implementation plan unless it broadens its base of support, develops the social capacity of its stakeholders, and resolves the debate over the science behind its action plan.
The concentration of TNF‐α correlate with number of inflammatory cells and degree of vascularization in radicular cysts
Authors: Jurisic V , Terzic T , Colic S , Jurisic M
Published: September 2008

Objective:  To correlate values of tumor necrosis factor‐alpha (TNF‐α) depending on the count of inflammatory cells with degree of vascularization in cystic fluid of radicular cysts.

Material and methods:  We investigated TNF‐α concentration in 43 radicular cysts obtained from patients undergoing surgery, under local anaesthesia, and after aspiration of cystic fluid from non‐ruptured cysts by enzyme‐linked immunosorbent assay assay in respect of different clinical parameters as well as by histomorphometric analyses.

Results:  Significantly higher concentration of TNF‐α is associated with smaller radicular cysts, higher protein concentration in cystic fluid as well as with higher presence of inflammatory cells, and increased degree of vascularization in pericystic tissues and cyst wall thickness.

Conclusions:  We believe that determination of TNF‐α in cystic fluid simultaneously with other parameters can be an additional parameter for clinical diagnosis of inflammed cysts.
Claudin rather than occludin is essential for differentiation in rat incisor odontoblasts
Authors: Hoshino M , Hashimoto S , Muramatsu T , Matsuki M , Ogiuchi H , Shimono M
Published: September 2008

Many morphological and developmental studies have demonstrated the characteristics of tight junctions (TJs) between odontoblasts. However, detailed localization of TJ‐associated proteins in odontoblasts and their functions has not yet been clarified. To elucidate the relationship between the establishment of TJ structures and the differentiation of odontoblasts during early dentinogenesis, we studied the expression and localization of constituent proteins of TJs (claudin‐1, occludin, ZO‐1 and ZO‐2) between odontoblasts in rat lower incisors using Western blotting, immunofluorescence and immunoelectron microscopy. When the expression of claudin‐1 increases at the distal portion of mature odontoblasts, the TJs form complex networks of strands, and odontoblasts differentiated by developing distal membrane domains and by secreting specific molecules for mineralization. We conclude that the TJs of odontoblasts may play an important role in the differentiation of odontoblasts in rat lower incisors during early dentinogenesis.
Keeping the Peace in Africa: Why “African” Solutions Are Not Enough
Authors: Williams Paul D.
Published: September 2008

Since the early 1990s, a variety of African and Western governments alike have often suggested that finding “African solutions to African problems” represents the best approach to keeping the peace in Africa. Not only does the empirical evidence from post-Cold War Africa suggest that there are some fundamental problems with this approach, it also rests upon some problematic normative commitments. Specifically in relation to the problem of armed conflict, the “African solutions” logic would have at least three negative consequences: it would undermine the UN; it would provide a convenient excuse for powerful Western states that wished to avoid sending their own soldiers to peace operations in Africa; and it would help African autocrats fend off international, especially Western, criticism of their policies. After providing an overview of the constituent elements of the “African solutions” approach, this article sets out in general terms the central problems with it before turning to a specific illustration of how these problems affected the international responses to the ongoing war in Darfur, Sudan. Instead of searching for “African solutions”, policymakers should focus on developing effective solutions for the complex challenges raised by the issue of armed conflict in Africa. To this end, Western states in general and the P-3 in particular should give greater support to conflict management activities undertaken by the United Nations, develop clearer guidelines for how these should relate to regional initiatives, and facilitate the efforts of civic associations to build the foundations for stable peace in the continent's war zones.
Prolonged exposure to inhaled nitric oxide transiently modifies tubular function in healthy piglets and promotes tubular apoptosis
Authors: Goździk W. , Albert J. , Harbut P. , Zieliński S. , Ryniak S. , Lindwall R. , Dziegiel P. , Podhorska‐Okolow M. , Kübler A. , Frostell C.
Published: September 2008

Aim:  Inhaled nitric oxide (iNO) is a selective pulmonary vasodilator. We hypothesized that those piglets exposed to prolonged iNO react with a modified renal function.

Methods:  Randomized, placebo‐controlled exposure to 40 p.p.m. iNO (30 h) in piglets (n = 20). Plasma and urine were sampled during three periods (first and second 12 h periods, and finally a 6 h period). We measured urine volumes, plasma and urine electrolytes (UNa, UK, UCl), plasma creatinine and urea. We calculated creatinine clearance (Ccr), and fractional excretions of sodium and potassium (FENa, FEK) and urinary excretions of electrolytes (UENa, UEK, UECl). Haemodynamic data were recorded and renal tubular apoptosis detected.

Results:  For the first 12 h, certain parameters significantly increased in the iNO group (mean ± SD): UNa (mmol L−1), 87.7 (±35.0) vs. 39.3 (±22.9), UCl (mmol L−1) 80.4 (±32.8) vs. 48.0 (±26.7), FENa (%) 2.1 (±0.8) vs. 0.7 (±0.5), FEK (%) 31.7 (±7.0) vs. 20.7 (±12.3), as well as UENa (mmol) 61.0 (±21.1) vs. 27.6 (±17.9) and UECl (mmol) 57.3 (24.5) vs. 37.6 (29.0). These changes were absent in the second and third periods of the study. Significant differences in percentage of apoptotic cell nuclei in the renal cortex and medulla were found after iNO exposure: 39% vs. 15%.

Conclusion:  Exposure to 40 p.p.m. iNO in healthy anaesthetized piglets has a transient natriuretic effect that disappears after 12 h. We also found evidence of renal tubular apoptosis promotion after 30 h of iNO.
Niobium and Tantalum Concentrations in NIST SRM 610 Revisited
Authors: Hu Zhaochu , Gao Shan , Liu Yongsheng , Xu Juan , Hu Shenghong , Chen Haihong
Published: September 2008

Niobium and Ta concentrations in MPI‐DING and USGS (BCR‐2G, BHVO‐2G, BIR‐1G) silicate rock glasses and the NIST SRM 610–614 synthetic soda‐lime glasses were determined by 193 nm ArF excimer laser ablation and quadrupole ICP‐MS. Measured Nb and Ta values of MPI‐DING glasses were found to be consistently lower than the recommended values by about 15% and 25%, respectively, if calibration was undertaken using commonly accepted values of NIST SRM 610 given by Pearce et al. Analytical precision, as given by the 1 s relative standard deviation (% RSD) was less than 10% for Nb and Ta at concentrations higher than 0.1 μg g−1. A significant negative correlation was found between logarithmic concentration and logarithmic RSD, with correlation coefficients of ‐0.94 for Nb and ‐0.96 for Ta. This trend indicates that the analytical precision follows counting statistics and thus most of the measurement uncertainty was analytical in origin and not due to chemical heterogeneities. Large differences between measured and expected Nb and Ta in glasses GOR128‐G and GOR132‐G are likely to have been caused by the high RSDs associated with their very low concentrations. However, this cannot explain the large differences between measured and expected Nb and Ta in other MPI‐DING glasses, since the differences are normally higher than RSD by a factor of 3. Count rates for Nb and Ta, normalised to Ca sensitivity, for the MPI‐DING, USGS and NIST SRM 612–614 glasses were used to construct calibration curves for determining NIST SRM 610 concentrations at crater diameters ranging from 16 (im to 60 μm. The excellent correlation between the Nb/Ca1μgg‐1 signal (Nb represents the Nb signal intensity; Ca1μg g‐1 represents the Ca sensitivity) and Nb concentration, and between the Ta/Ca1μg g‐1 signal (where Ta represents the Ta signal intensity; Ca1μg g‐1 represents the Ca sensitivity) and Ta concentration (R2= 0.9992–1.00) in the various glass matrices suggests that matrix‐dependent fractionation for Nb, Ta and Ca was insignificant under the given instrumental conditions. The results confirm that calibration reference values of Nb and Ta in NIST SRM 610 given by Pearce et al. are about 16% and 28% lower, respectively. We thus propose a revision of the preferred value for Nb from 419.4 ± 57.6 μg g−1 to 485 ± 5 μg g−1 (1 s) and for Ta from 376.6 ± 77.6 μg g−1 to 482 ± 4 μg g−1 (Is) in NIST SRM 610. Using these revised values for external calibration, most of the determined average values of MPI‐DING, USGS and NIST SRM 612–614 reference glasses agree within 3% with the calculated means of reported reference values. Bulk analysis of NIST SRM 610 by standard additions using membrane desolvation ICP‐MS gave Nb = 479 ± 6 μg g−1 (1 s) and Ta = 468 ± 7 μg g−1 (1 s), which agree with the above revised values within 3%.
Zircon M257 ‐ a Homogeneous Natural Reference Material for the Ion Microprobe U‐Pb Analysis of Zircon
Authors: Nasdala Lutz , Hofmeister Wolfgang , Norberg Nicholas , Martinson James M. , Corfu Fernando , Dörr Wolfgang , Kamo Sandra L. , Kennedy Allen K. , Kronz Andreas , Reiners Peter W. , Frei Dirk , Kosler Jan , Wan Yusheng , Götze Jens , Häger Tobias , Kröner Alfred , Valley John W.
Published: September 2008

We introduce and propose zircon M257 as a future reference material for the determination of zircon U‐Pb ages by means of secondary ion mass spectrometry. This light brownish, flawless, cut gemstone specimen from Sri Lanka weighed 5.14 g (25.7 carats). Zircon M257 has TIMS‐determined, mean isotopic ratios (2s uncertainties) of 0.09100 ± 0.00003 for 206pb/238U and 0.7392 ± 0.0003 for 207pb/235U. Its 206pb/238U age is 561.3 ± 0.3 Ma (unweighted mean, uncertainty quoted at the 95% confidence level); the U‐Pb system is concordant within uncertainty of decay constants. Zircon M257 contains ∼ 840 μg g−1 U (Th/U ∼ 0.27). The material exhibits remarkably low heterogeneity, with a virtual absence of any internal textures even in cathodoluminescence images. The uniform, moderate degree of radiation damage (estimated from the expansion of unit‐cell parameters, broadening of Raman spectral parameters and density) corresponds well, within the “Sri Lankan trends”, with actinide concentrations, U‐Pb age, and the calculated alpha fluence of 1.66 × 1018 g−1. This, and a (U+Th)/He age of 419 ± 9 Ma (2s), enables us to exclude any unusual thermal history or heat treatment, which could potentially have affected the retention of radiogenic Pb. The oxygen isotope ratio of this zircon is 13.9%o VSMOW suggesting a metamorphic genesis in a marble or calc‐silicate skarn.
Novel Genetic Determinants of Low-Level Aminoglycoside Resistance in
Pseudomonas aeruginosa
Authors: Schurek Kristen N. , Marr Alexandra K. , Taylor Patrick K. , Wiegand Irith , Semenec Lucie , Khaira Bhavjinder K. , Hancock Robert E. W.
Published: September 2008

Pseudomonas aeruginosa
strains isolated from patients with persistent lung infections and cystic fibrosis have been found to gradually develop aminoglycoside resistance over time. The aim of this study was to identify potential contributors to low-level aminoglycoside resistance, which may cause such graduated increases in resistance. The Harvard
P. aeruginosa
PA14 nonredundant library, consisting of approximately 5,800 mutants, was screened for twofold or greater increases in tobramycin resistance. Mutants carrying mutations in a total of 135 unique genes were identified and confirmed to have reduced susceptibility to tobramycin. Many of these genes were involved predominantly in energy metabolism; however, most of these mutants did not exhibit growth defects under the conditions tested, although some exhibited the small-colony phenotype and/or defects in growth under anaerobic conditions. Lipopolysaccharide mutants were also identified, and it was found that tobramycin had a reduced ability to permeabilize the outer membranes of these mutants. The results of this study emphasize the complexity of the interactions that tobramycin may have within the bacterial cell and introduce a large number of novel genes which may play a role in tobramycin resistance.
Impact of recent legislative bills regarding clinical research on Italian ethics committee activity
Authors: Porcu L , Poli D , Torri V , Rulli E , Di Tullio M C , Cinquini M , Bajetta E , Labianca R , Di Costanzo F , Nitti D , Floriani I
Published: September 2008

Aims and background:

The present work assessed the impact of two decrees on ethics committees in Italy, aimed at bringing the national laws on the conduct of clinical trials into line with the rest of the EC, and regulating and facilitating not-for-profit research.

Material and methods:

Prospectively collected data from an Italian multicentre study were examined with respect to the ethics review process. Administrative and time elements of the review process were audited. Main outcome measures were time between the application submission and the ethics committee definitive opinion, type and number of application submission forms, number of ethics committees that refused fee exemption, and time between the ethics committee approval and the administrative authorisation.

Results:

A total of 134 local research ethics committees (LRECs) were approached. Application submission procedures and application forms varied greatly; paper submission was mandatory. The median time from submission to approval was 72 days. Only two LRECs refused the fee exemption. The median time from LREC approval to administrative agreement was 50 days and only 9.6% of local authorities came to a verbal agreement with the sponsor.

Conclusions:

Italian LRECs are still not sufficiently efficient in complying with the Directive 2001/20/EC requirement (60 days). Better coordination of LRECs work is needed although the optimal level of coordination between them is still not known. In the meantime, national guidelines are needed concerning the application of Directive 2001/20/EC. The behaviour of Italian LRECs towards not-for-profit research was excellent although only the fee exemption was requested.
The ethics of paediatric anti-depressant use: erring on the side of caution
Authors: Shearer M C , Bermingham S L
Published: September 2008

This paper aims to outline the ethical concerns regarding the use of antidepressant medication in children and adolescents. Recent debates surrounding this issue have focused on the link between selective serotonin reuptake inhibitor use and an increased risk of suicidal thinking/behaviour, and weighed that against the benefit of the alleviation of depressive symptoms. It is argued here that such an approach is simplistic. There are several serious risks surrounding antidepressant use in the young that ought to be included in the equation, along with a consideration of the neuroethical concerns surrounding pharmacotherapy for affective disorders. Using the precautionary principle as a framework for analysis it is concluded that the risks are sufficiently serious and plausible that the prescribing of antidepressant medication to the young ought to be severely restricted; further it is imperative that the child and their parents are made fully aware of the risks, short-term and long-term, involved.
Facial allograft transplants: where’s the catch?
Authors: White B E , Brassington I
Published: September 2008

Face transplantation—or, more properly, facial allograft transplantation (FAT)—generates much public interest and academic debate. In this paper, we suggest that it is up to opponents of FAT to make the case for its impermissibility. We allow that there is a number of apparently strong arguments that might be deployed against FAT. However, all but one of these turn out not to be compelling after examination. The remaining argument is not so easily dismissed—but its central point is fairly workaday and certainly does not tell us anything about FAT in particular. Therefore, qua argument about facial transplant surgery, it fails to hit its target. Overall, we conclude that a compelling case against FAT remains to be made.
Theological reflections on donation after circulatory death: the wisdom of Paul Ramsey and Moshe Feinstein
Authors: Jotkowitz A
Published: September 2008

Due to the worldwide shortage of organs for transplantation, there has been an increased use of organs obtained after circulatory death alone. A protocol for this procedure has recently been approved by a major transplant consortium. This development raises serious moral and ethical concerns. Two renowned theologians of the previous generation, Paul Ramsey and Moshe Feinstein, wrote extensively on the ethical issues relating to transplantation, and their work has much relevance to current moral dilemmas. Their writings relating to definition of death, organ transplantation and the care of the terminally ill are briefly presented, and their potential application to the moral problem of organ donation after circulatory death is discussed.
Embryonic stem cells: the disagreement debate and embryonic stem cell research in Israel
Authors: Simonstein F
Published: September 2008

While some people claim that the present disagreement over embryonic stem (ES) cell research cannot be resolved, others argue that developing transparency and trust are key elements that could resolve the existing disagreements over such research. This paper reveals that transparency is not necessarily a requirement for advancing ES cell research, since in Israel, for instance, there is (almost) no transparency, and research nevertheless flourishes. Moreover, trust is not independent of cultural values and religious beliefs. Because of these beliefs, the environment in Israel for ES cell research has been pragmatic and liberal. The Israeli case illustrates the key role that culture and religion can play in biomedical research; it also suggests that as far as cultural values or religious beliefs of people in Western countries strongly oppose research on embryonic tissue, it would be very difficult, if not impossible, to overcome the disagreements.
Calibrating jack pine allometric relationships with simultaneous regressions
Authors: Schneider Robert , Berninger Frank , Ung Chhun-Huor , Bernier Pierre Y. , Swift D. Edwin , Zhang S.Y.
Published: September 2008

Allometric equations for estimating foliage biomass, sapwood area, and branch basal area from tree diameters and crown lengths for jack pine ( Pinus banksiana Lamb.) in eastern Canada were calibrated using mixed models. A first model is presented that relates branch foliage biomass to branch diameter and relative position within the crown. These results show that a branch’s foliage biomass is inversely proportional to its depth within the crown. At the tree level, foliage biomass was found to be proportional to crown length and to vary with stem age and slenderness. Pipe model parameters (sapwood area and branch basal area to foliage biomass) were also calculated. The sapwood area to foliage biomass parameter is proportional to stand density, whereas branch basal area to foliage biomass is constant. The tree-level allometeric models were calibrated using a mixed-effects seemingly unrelated regression to account for between-model correlations.
Preadaptation and spatial effects on retention-tree survival in cut areas in Estonia
Authors: Rosenvald Raul , Lõhmus Asko , Kiviste Andres
Published: September 2008

Survival of live retention trees is a key issue for stand-scale applications of natural-disturbance-based silviculture. We explored the survival of 3255 trees in 102 cut areas (mean size 2.3 ha) in Estonia for 6 years, focusing on spatial variation and preadaptation of the trees. Altogether, 35% of the trees died during the study period, contributing 4.4 m3 of downed dead trunks and 1 m3 of standing dead trees per hectare. The annual mortality rates declined over time. The main survival determinants were tree species (higher for hardwood deciduous trees), diameter (species dependent), position relative to forest edge (higher for trees near current or former forest edges), retention density (positive), and exposure (negative). The results suggest that (1) green-tree retention can effectively increase the abundance of large shade-tolerant trees, but it is equally important for producing deadwood; (2) larger individuals, former interior-forest trees near current forest edges, and preadapted trees in open conditions should be preferably retained; (3) there is no obvious necessity to modify tree-retention techniques for tree survival according to geographical region or forest site type.
Geographic variation in chloroplast haplotypes in the California red fir-noble fir species complex and the status of Shasta red fir
Authors: Oline David K.
Published: September 2008

I present the results of a molecular investigation into taxonomically unresolved issues of the California red fir – noble fir species complex. Samples were collected throughout the range of California red fir ( Abies magnifica A. Murray), from the southern Sierra Nevada to the region in northern California and southern Oregon where morphological variation has suggested it hybridizes with noble fir ( Abies procera Rehder). Two rbcL sequences were found within A. magnifica and showed perfect linkage with variation at the chloroplast trnD locus. Only populations in the region of hypothesized hybridization were polymorphic for rbcL. One haplotype is unique to A. magnifica in the southern part of its range, and the other is identical to that found in A. procera to the north, supporting a broad zone of hybridization. There was no evidence for a cryptic geographic barrier between the two species. A single A. procera tree from southwestern Washington also had the A. magnifica haplotype, suggesting that introgression from A. magnifica may be widespread. The type locality of Abies magnifica var. shastensis Lemmon was polymorphic, whereas the disjuct southern A. magnifica var. shastensis was monomorphic for rbcL. I also present corrections, based on replication, to two rbcL sequences for A. magnifica previously deposited in GenBank.
The effect of planted tree species on the development of herbaceous vegetation in a reclaimed opencast
Authors: Pensa Margus , Karu Helen , Luud Aarne , Rull Elga , Vaht Riina
Published: September 2008

The establishment of plantations is the most common method of opencast reclamation, but few studies have addressed the influence of planted trees on the recovery of biodiversity in new forest sites. The goal of this study was to determine whether the formation of herbaceous vegetation was dependent on the tree species planted on the spoil of a reclaimed oil shale opencast in northeastern Estonia. From 2002 to 2005, the vegetation in eight different site types (distinguished according to the age and composition of tree layer) was surveyed. The results confirmed that the development of herbaceous vegetation was controlled by the dominant species of tree layer. The highest number of herbaceous species was recorded in naturally developed mixed stands. As compared with other site types, the herb layers of the pioneer stage (the vegetation in recently reclaimed sites) and alder stands were the most different. In the terms of the competitive, stress-tolerant, and ruderal strategy types, alder (Alnus spp.) stands tended to enhance the growth of competitors, whereas stress-tolerant species were more abundant in pine stands. Herbaceous vegetation remained sparse in coniferous stands, whereas broad-leaved trees tended to improve the performance of herbaceous species. Our results concur with the suggestions that planting with different tree species is one prerequisite for the development of diverse herb layer.
Breakdown and invertebrate colonization of dead wood in wetland, upland, and river habitats
Authors: Braccia A. , Batzer D. P.
Published: September 2008

Breakdown of woody debris in river and upland habitats as well as the interactions between wood and invertebrates have been well described. Studies of wood in wetlands are rare, and far less is known about breakdown and invertebrate use of wood in these transitional habitats. This study experimentally assessed breakdown and invertebrate colonization of wood in a floodplain wetland and directly related patterns in the wetland to adjacent river and upland habitats. Over a 2.7 year period, we monitored breakdown and invertebrate presence in 10 cm diameter × 150 cm long sweetgum ( Liquidambar styraciflua L.) logs in a floodplain wetland (n = 8), river (n = 5), and upland (n = 4) habitat. Mass loss, decay condition change, and C/N ratios of wetland wood more closely resembled upland than river wood. The overall invertebrate assemblage associated with wetland wood was also more similar to that associated with upland than river wood. Breakdown and invertebrate colonization of wood in the floodplain wetland shared more characteristics with upland than river wood, perhaps because of the seasonal nature of flooding in the wetland. However, the ecology of wood in wetlands also had unique characteristics compared with either the uplands or the river.
STABLE RANK FOR INCLUSIONS OF C*-ALGEBRAS
Authors: OSAKA HIROYUKI
Published: September 2008

When a unital C*-algebra A has topological stable rank one (write tsr (A) = 1), we know that tsr (pAp) = 1 for a non-zero projection p ∈ A. When, however, tsr (A) ≥ 2, it is generally false. We prove that if a unital C*-algebra A has a simple unital C*-subalgebra D of A with common unit such that D has Property (SP) and supp ∈ P(D)tsr (pAp) < ∞, then tsr (A) ≤ 2. As an application let A be a simple unital C*-algebra with tsr (A) = 1 and Property (SP), [Formula: see text] finite groups, αkactions from Gkto Aut ((⋯((A × α1G1) ×α2G2)⋯) ×αk-1Gk-1). (G0= {1}). Then [Formula: see text]
THE POINTWISE DENSITIES OF NON-SYMMETRIC CANTOR SETS
Authors: LI WENXIA , YAO YUANYUAN
Published: September 2008

We consider a class of non-symmetric Cantor sets C determined by C = a0C ∪ (a1C + 1 - a1), a0, a1 ∈ (0, 1). Under certain conditions on a0 and a1, the upper and lower densities are obtained explicitly for each x ∈ C. It extends the results for symmetric Cantor sets obtained by Feng, Hua and Wen (The pointwise densities of the Cantor measure, J. Math. Anal. Appl.250 (2000) 692–705).