bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differential effects of anthropogenic edges and gaps on the reproduction of a forest‐dwelling plant: The role of plant reproductive effort and nectar robbing by bumblebees
Authors: MAGRACH AINHOA , SANTAMARÍA LUIS , LARRINAGA ASIER R. 
Published: November 2011

AbstractForest fragmentation produces sharp changes in the spatial configuration of remnant forest patches, which include the increasing influence of patch edges on the interior of forest patches (‘edge effects’). Human activities responsible for forest fragmentation tend also to change the internal characteristics of remnant patches, for example, through the creation of gaps by selective logging. While edges and gaps can be expected to cause comparable changes in the micro‐environmental conditions of the forest, their effects on forest‐dwelling species and their interactions are not necessarily comparable. This study compares the effect of forest edges and anthropogenic gaps on the reproductive success of a self‐incompatible epiphytic plant (Mitraria coccinea), mediated by changes in its relationship with mutualists (pollinators) and antagonists (flower larcenists). Mitraria coccinea's flowers are pollinated by hummingbirds and robbed by the bumblebee Bombus dahlbomii. Edges and gaps had comparable positive effects on flower production and fruit set; however, nectar robbing was up to sevenfold higher in patches with numerous gaps and resulted in lower reproductive success (fruit set and total fruit crop). Forest fragmentation studies should therefore avoid treating forest remnants as homogeneous units (i.e. focusing exclusively on their characteristics and connectivity), without taking into account the internal heterogeneity caused by anthropogenic pressures (e.g. gaps and edge effects).
Experimental evidence for a phylogenetic Janzen–Connell effect in a subtropical forest
Authors: Liu Xubing , Liang Minxia , Etienne Rampal S. , Wang Yongfan , Staehelin Christian , Yu Shixiao 
Published: November 2011

Ecology Letters (2011)AbstractObservational evidence increasingly suggests that the Janzen–Connell effect extends beyond the species boundary. However, this has not been confirmed experimentally. Herein, we present both observational and experimental evidence for a phylogenetic Janzen–Connell effect. In a subtropical forest in Guangdong province, China, we observed that co‐occurring tree species are less phylogenetically related than expected. The inhibition effects of neighbouring trees on seedling survival decreased with increasing phylogenetic distance between them. In a shade‐house experiment, we studied seedling survival of eight species on soil collected close to Castanopsis fissa relative to their survival on soil close to their own adult trees, and found that this relative survival rate increased with phylogenetic distance from C. fissa. This phylogenetic signal disappeared when seedlings were planted in fungicide‐treated soil. Our results clearly support negative effects of phylogenetically similar neighbouring trees on seedling survival and suggest that these effects are caused by associated host‐specific fungal pathogens.
Rapid successions affect microbial N‐acetyl‐glucosamine uptake patterns during a lacustrine spring phytoplankton bloom
Authors: Eckert Ester M. , Salcher Michaela M. , Posch Thomas , Eugster Bettina , Pernthaler Jakob 
Published: November 2011

SummaryThe vernal successions of phytoplankton, heterotrophic nanoflagellates (HNF) and viruses in temperate lakes result in alternating dominance of top‐down and bottom‐up factors on the bacterial community. This may lead to asynchronous blooms of bacteria with different life strategies and affect the channelling of particular components of the dissolved organic matter (DOM) through microbial food webs. We followed the dynamics of several bacterial populations and of other components of the microbial food web throughout the spring phytoplankton bloom period in a pre‐alpine lake, and we assessed bacterial uptake patterns of two constituents of the labile DOM pool (N‐acetyl‐glucosamine [NAG] and leucine). There was a clear genotypic shift within the bacterial assemblage, from fast growing Cytophaga–Flavobacteria (CF) affiliated with Fluviicola and from Betaproteobacteria (BET) of the Limnohabitans cluster to more grazing resistant AcI Actinobacteria (ACT) and to filamentous morphotypes. This was paralleled by successive blooms of viruses and HNF. We also noted the transient rise of other CF (related to Cyclobacteriaceae and Sphingobacteriaceae) that are not detected by fluorescence in situ hybridization with the general CF probe. Both, the average uptake rates of leucine and the fractions of leucine incorporating bacteria were approximately five to sixfold higher than of NAG. However, the composition of the NAG‐active community was much more prone to genotypic successions, in particular of bacteria with different life strategies: While ‘opportunistically’ growing BET and CF dominated NAG uptake in the initial period ruled by bottom‐up factors, ACT constituted the major fraction of NAG active cells during the subsequent phase of high predation pressure. This indicates that some ACT could profit from a substrate that might in parts have originated from the grazing of protists on their bacterial competitors.
Chironomid midges: a forgotten model of developmental biology research
Authors: Thorat Leena J. , Nath Bimalendu B. 
Published: November 2011

AbstractFor more than a century, embryologists have been exploring various model systems to gain insights into developmental processes. This article presents an overview of the role of chironomid midges in embryology research since their introduction as model organisms in the 19th century. We present the vestiges of bibliography since the days of Weismann (1834–1914), who raised preliminary queries to unravel many unique features of insect embryogenesis using midges as a crucible. Unfortunately, over the years, chironomid midges got lost into obscurity as a model for developmental biology, which is evident from the paucity of developmental biology–related literature on midges in the past decades. Through this essay, the authors intend to share reminiscences of the heydays of chironomid research with the wider community of zoologists with an aim of reviving chironomid embryology. Midges not only possess the basic qualities essential for an ideal model system, but being one of the ancestral dipteran stocks, they can also prove an excellent test system for evo‐devo, transgenetic, and embryogenomic investigations that utilize methodologies at the interface of developmental biology and high‐throughput molecular genetic and genomics approach. An introspection of re‐introducing chironomid midgesas model system will be rewarding for the contemporary developmental biologists.
WORLD IMBALANCES AND MACROECONOMIC ADJUSTMENTS: A THREE‐COUNTRY STOCK‐FLOW CONSISTENT MODEL WITH FIXED OR FLEXIBLE PRICES
Authors: Mazier Jacques , Tiou‐Tagba Aliti Gnanonobodom 
Published: November 2011

ABSTRACTWorld macroeconomic adjustments are analysed with a three‐country Stock‐Flow Consistent (SFC) models. Three SFC models are considered, the first one with a fixed dollar–yuan parity including a version with Chinese foreign reserves' diversification, the second with a flexible dollar–yuan parity which can be freely floating or following a more managed float, the third one being a generalization of the two others with flexible prices instead of constant prices. The fixity of the dollar–yuan parity limits the adjustments facing shocks and world imbalances while a more flexible dollar–yuan exchange rate appears as a powerful adjustment mechanism to reduce these imbalances.
A NEO‐KALECKIAN MODEL OF PROFIT SHARING, CAPACITY UTILIZATION AND ECONOMIC GROWTH
Authors: Lima Gilberto Tadeu 
Published: November 2011

ABSTRACTThis paper sets forth a Neo‐Kaleckian model of capacity utilization and growth with distribution featuring a profit‐sharing arrangement. While a given proportion of firms compensate workers with only a base wage, the remaining proportion do so with a base wage and a share of profits. Consistent with the empirical evidence, workers hired by profit‐sharing firms have a higher productivity than their counterparts in base‐wage firms. While a higher profit‐sharing coefficient raises capacity utilization and growth irrespective of the distribution of compensation strategies across firms, a higher frequency of profit‐sharing firms does likewise only if the profit‐sharing coefficient is sufficiently high.
Alpha‐adrenergic receptor gene polymorphisms and cardiovascular reactivity to stress in Black adolescents and young adults
Authors: Kelsey Robert M. , Alpert Bruce S. , Dahmer Mary K. , Krushkal Julia , Quasney Michael W. 
Published: November 2011

AbstractCardiovascular reactivity to stress and α‐adrenergic receptor (α‐AR) function may contribute to the development of hypertension. As Black Americans have an increased risk of hypertension, we evaluated associations between α1A‐AR (Arg492Cys), α2A‐AR (‐1291C/G), and α2B‐AR (Ins/Del301‐303) gene variants and cardiovascular reactivity in 500 normotensive Black youth. Heart rate, preejection period, total peripheral resistance, and blood pressure were measured during cold and psychological stress. The Arg492Cys polymorphism in the α1A‐AR gene was associated with heart rate reactivity to stress, but the association depended on sex. The ‐1291C/G promoter polymorphism in the α2A‐AR gene was associated with vascular reactivity to stress; vasoconstriction increased as a linear function of the number of copies of the variant G allele. Thus, specific associations emerged between genetic variations in α‐Ars and cardiovascular reactivity in young Blacks.
Different mental rotation strategies reflected in the rotation related negativity
Authors: ter Horst Arjan C. , Jongsma Marijtje L.A. , Janssen Lieneke K. , van Lier Rob , Steenbergen Bert 
Published: November 2011

AbstractIn a mental rotation task of objects, typically, reaction time (RT) increases and the rotation related negativity (RRN) increases in amplitude with increasing angles of rotation. However, in a mental rotation task of hands, different RT profiles can be observed for outward and inward rotated hands. In the present study, we examined the neurophysiological correlates of these asymmetries in the RT profiles. We used a mental rotation task with stimuli of left and right hands. In line with previous studies, the behavioral results showed a linear increase in RT for outward rotations, but not for inward rotations as a function of angular disparity. Importantly, the ERP results revealed an RRN for outward rotated stimuli, but not for inward rotated stimuli. This is the first study to show that the behaviorally observed differences in a mental rotation task of hands is also reflected at the neurophysiological level.
New genes that extend Caenorhabditis elegans’ lifespan in response to reproductive signals
Authors: McCormick Mark , Chen Kan , Ramaswamy Priya , Kenyon Cynthia 
Published: November 2011

SummaryIn Caenorhabditis elegans and Drosophila, removing germline stem cells increases lifespan. In C. elegans, this lifespan extension requires DAF‐16, a FOXO transcription factor, and DAF‐12, a nuclear hormone receptor. To better understand the regulatory relationships between DAF‐16 and DAF‐12, we used microarray analysis to identify downstream genes. We found that these two transcription factors influence the expression of distinct but overlapping sets of genes in response to loss of the germline. In addition, we identified several new genes that are required for loss of the germline to increase lifespan. One, phi‐62, encodes a conserved, predicted RNA‐binding protein. PHI‐62 influences DAF‐16‐dependent transcription, possibly by collaborating with TCER‐1, a putative transcription elongation factor, and FTT‐2, a 14‐3‐3 protein known to bind DAF‐16. Three other genes encode proteins involved in lipid metabolism; one is a triacylglycerol lipase, and another is an acyl‐CoA reductase. These genes do not noticeably affect bulk fat storage levels; therefore, we propose a model in which they may influence production of a lifespan‐extending signal or metabolite.
A comprehensive assessment of mitochondrial protein synthesis and cellular proliferation with age and caloric restriction
Authors: Miller Benjamin F. , Robinson Matthew M , Bruss Matthew D. , Hellerstein Marc , Hamilton Karyn L. 
Published: November 2011

SummaryIt is proposed that caloric restriction (CR) increases mitochondrial biogenesis. However, it is not clear why CR increases an energetically costly biosynthetic process. We hypothesized that 40% CR would decrease mitochondrial protein synthesis and would be regulated by translational rather than transcriptional mechanisms. We assessed cumulative mitochondrial protein synthesis over 6 weeks and its transcriptional and translational regulation in the liver, heart, and skeletal muscle of young (6 month), middle (12 month), and old (24 month) male B6D2F1 mice that were lifelong CR or ad lib (AL) controls. Mitochondrial protein synthesis was not different between AL and CR (fractional synthesis over 6 weeks (range): liver, 91–100%; heart, 74–85%; skeletal muscle, 53–72%) despite a decreased cellular proliferation in liver and heart with CR. With CR, there was an increase in AMP‐activated protein kinase phosphorylation/total (P:T) in heart and liver, and an increase in peroxisome proliferator‐activated receptor gamma coactivator 1‐α mRNA in all tissues, but not protein. Ribosomal protein S6 was decreased with CR. In conclusion, CR maintained mitochondrial protein synthesis while decreasing cellular proliferation during a time of energetic stress, which is consistent with the concept that CR increases somatic maintenance. Alternative mechanisms to global translation initiation may be responsible for selective translation of mitochondrial proteins.
Comparison of nanofiltration efficacy in reducing infectivity of centrifuged versus ultracentrifuged 263K scrapie‐infected brain homogenates in “spiked” albumin solutions
Authors: Cardone Franco , Simoneau Steve , Arzel Aude , Puopolo Maria , Berardi Vito Angelo , Abdel‐Haq Hanin , Galeno Roberta , De Pascalis Angela , Sbriccoli Marco , Graziano Silvia , Valanzano Angelina , Porte Pierre , Diringer Heino , Brown Paul , Flan Benoît , Pocchiari Maurizio 
Published: November 2011

BACKGROUND: The safety of plasma‐derived products is of concern for possible transmission of variant Creutzfeldt‐Jakob disease. The absence of validated screening tests requires the use of procedures to remove or inactivate prions during the manufacture of plasma‐derived products to minimize the risk of transmission. These procedures need proper validation studies based on spiking human plasma or intermediate fractions of plasma fractionation with prions in a form as close as possible to that present in blood.STUDY DESIGN AND METHODS: Human albumin was spiked with low‐speed or high‐speed supernatants of 263K scrapie‐infected hamster brain homogenates. Spiked albumin was then passed through a cascade of filters from 100 nm down to 20 to 15 nm. Residual infectivity was measured by bioassay.RESULTS: The overall removal of infectivity spiked into albumin through serial nanofiltration steps was 4 to 5 logs using low‐speed supernatant and 2 to 3 logs with high‐speed supernatant.CONCLUSION: These findings confirm the utility of nanofiltration in removing infectivity from plasma (or other products) spiked with scrapie brain homogenate supernatants. However, efficiency is diminished using supernatants that have been ultracentrifuged to reduce aggregated forms of the infectious agent. Thus, filtration removal data based on experiments using “standard” low‐speed centrifugation supernatants might overestimate the amount of prion removal in plasma or urine‐derived therapeutic products.
Donors' perspectives on their postdonation information (PDI) event: a qualitative interview study of PDI donors
Authors: Wilkinson Susan L. , Vij Vibha , Steele Whitney R. ,   for the NHLBI Retrovirus Epidemiology Donor Study‐II (REDS‐II)
Published: November 2011

BACKGROUND: Postdonation information (PDI) occurs when a donor fails to report a risk that would have resulted in deferral, but at some subsequent point is disclosed. Donors' perspectives on and perceived reasons for their PDIs have not been previously studied.STUDY DESIGN AND METHODS: A qualitative interview study was conducted with PDI, appropriately deferred (and not PDI), and accepted donors from the six REDS‐II blood centers. Telephone interviews were conducted with donors using semistructured discussion guides after their most recent donation or donation attempt. Salient themes were identified within and across the three donor categories using interview recordings and notes.RESULTS: Sixty‐six donors were interviewed (35 PDIs, 21 appropriately deferred, and 10 accepted). Cases could be grouped into one of three broad clusters according to the apparent primary reason for the PDI event: perceived changes in rules or application of more intensive screening procedures at this visit versus prior visit(s), issues of recall or interpretation of a question, and discrepancies in recollections of timing.CONCLUSIONS: While descriptive and demographic information exists on the numbers and types of PDI events and donors, there has never been a qualitative study exploring donation experiences and possible reasons for their PDIs. This exploratory study based on semistructured interviews of donors identified several potentially actionable areas including the need for screeners to clarify the meaning of and answers to certain questions and helping donors accurately remember the details and dates of deferrable activities.
DARCalleles and Duffy phenotypes in African Americans
Authors: Schmid Pirmin , Ravenell Kanaeko R. , Sheldon Sherry L. , Flegel Willy A. 
Published: November 2011

BACKGROUND:TheDARC(Duffy blood group, chemokine receptor) gene encodes for a transmembrane glycoprotein that functions as a chemokine transporter, is a receptor forPlasmodium vivaxandP. knowlesi, and expresses the Duffy blood group antigens (Fy). The Fy(a−b−) phenotype found in people of African descent is typically associated with a −67t>c mutation in the 5′‐untranslated region (UTR), which prevents red blood cells being invaded byP. vivaxandP. knowlesi. The aim of this study was to establishDARCallele frequencies in an African American blood donor cohort, determine a phylogenetic tree forDARC, and compare human and NeandertalDARCgenes.STUDY DESIGN AND METHODS:TheDARCnucleotide sequence of 54 African American blood donors was determined from genomic DNA. Heterozygous substitutions were resolved by sequencing of haplotype‐specific amplifications. A phylogenetic tree forDARCwas established using the neighbor‐joining method withPan troglodytesas root.RESULTS:A total of 108 haplotypes of theDARCgene could be unambiguously determined from nucleotide position −300 in the 5′ UTR to +300 in the 3′ UTR. Eleven different alleles were found, including the clinically relevantFY*A,FY*B,FY*B‐67C,FY*B298A, andFY*Xalleles. All phenotype predictions based on genotypes matched the serologically determined phenotypes exactly: 52% Fy(a−b−), 28% Fy(a−b+), and 20% Fy(a+b−).CONCLUSIONS:The nucleotide sequencing approach using one amplicon is a practical genotyping method forDARCand allows the determination of haplotypes even in heterozygous constellations. We developed a phylogenetic tree forDARCalleles and postulated a distinctFY*Ballele as ancestral for the extantDARCalleles in humans.
Platelet transfusion alters CD40L blood level and release capacity in patients suffering from thrombocytopenia
Authors: Wenzel Folker , Günther Wiebke , Baertl Anja , Gruber Wolfgang , Sorg Rüdiger Volker , Haas Rainer , Giers Günther 
Published: November 2011

BACKGROUND: Platelet (PLT)‐derived cytokines, such as soluble CD40 ligand (sCD40L), play an important role in the development of adverse transfusion reactions associated with the administration of PLT products. In this study, we determined sCD40L concentration and release capacity in patients with thrombocytopenia before and after receiving a PLT transfusion.STUDY DESIGN AND METHODS: The study included 12 patients suffering from chemotherapy‐induced thrombocytopenia. sCD40L levels and release capacity were measured in plasma samples of the patients before and after PLT administration as well as in the respective plateletpheresis concentrates by enzyme‐linked immunosorbent assay. Sixteen healthy blood donors served as a control group.RESULTS: In PLT concentrates, elevated sCD40L levels (2567 ± 134 pg/mL) were observed in comparison to plasma sCD40L levels in controls (238.4 ± 35.3 pg/mL). sCD40L plasma concentration of patients with thrombocytopenia was significantly reduced (86.3 ± 16.7 pg/mL) before transfusion and increased to nearly normal levels (204.4 ± 24.8 pg/mL) after PLT administration. In parallel, the sCD40L release capacity per PLT showed no significant difference between controls and patients with thrombocytopenia before transfusion (33.3 ± 2.6 and 29.3 ± 4.6 ag/PLT, respectively) but was significantly reduced after PLT transfusion (22.4 ± 2.7 compared to 29.3 ± 4.6 ag/PLT).CONCLUSIONS: In patients with thrombocytopenia, sCD40L levels were clearly influenced by PLT transfusions: PLT administration led to a normalization of sCD40L plasma concentration. Nevertheless, adverse transfusion reactions did not occur in these patients. The sCD40L release capacity was enhanced by PLT administration dependent on the increase in the amount of PLT count.
Microbiologic Characteristics and In Vitro Susceptibility to Antimicrobials in a Large Population of Patients with Cardiovascular Implantable Electronic Device Infection
Authors: JAN EMILIE , CAMOU FABRICE , TEXIER‐MAUGEIN JEANNETTE , WHINNETT ZACHARY , CAUBET OLIVIER , PLOUX SYLVAIN , PELLEGRIN JEAN‐LUC , RITTER PHILIPPE , METAYER PHILIPPE L. , ROUDAUT RAYMOND , HAISSAGUERRE MICHEL , BORDACHAR PIERRE 
Published: November 2011

Microbiologic Characteristics and In Vitro Susceptibility to Antimicrobials.Introduction: The incidence of cardiovascular implantable electronic device (CIED) infection is steadily increasing. However, no consensus has been reached with respect to the type and duration of antimicrobial therapy in this specific population of patients. The role played by new anti‐Staphylococcus agents has not been defined. The aims of this study were to describe the microbiological characteristics of a large population of patients with CIED infections and to test the in vitro susceptibility of the various strains to different antimicrobials.Methods: Two hundred eighty‐six patients with CIED infection were included. The minimal inhibitory concentrations of 9 antimicrobials, including linezolid, tigecycline, and daptomycin were measured against all strains of staphylococci isolated.Results: Microbiologic confirmation was obtained in 252 (88%) patients, the vast majority were from Staphylococcus species (86%), 90% of these were coagulase negative strains and 10% were Staphylococcus aureus; 30.5% were methicillin‐resistant. All strains were susceptible to vancomycin, nearly 15% of coagulase negative strains were nonsusceptible to teicoplanin, and nearly 100% of the strains were susceptible to the 3 new antimicrobials.Conclusions: In this large contemporary study, we show that Staphylococcus is by far the most common cause of CIED infections, with the majority due to coagulase negative strains. Methicillin‐resistance is common in this population. Currently, we would recommend vancomycin as first‐line empirical therapy. However, given that not all patients tolerate vancomycin, we believe that newer antimicrobial therapies should now be tested in clinical trials to establish their clinical effectiveness in treating patients with device infections.