bluuebunny/crossref_metadata_2025_split huggingface dataset:
Is flight architecture determined by physical constraints or by natural selection?: the case of the midge Chironomus plumosus
Authors: McLachlan A. J. , Neems R. M. 
Published: May 2009

Males of the midge Chironomus plumosus fly solely to mate. They maintain station for long periods in moving air. Females patrol in search of males and, after receiving a spermatophore, fly to oviposition sites. The requirements of flight in males and females are therefore fundamentally different. Females are larger than males, on average, so these differences could stem from scaling rules governing the geometry of space. The same explanation might apply to flight differences within the sexes and even to peculiarities of flight architecture in C. plumosus compared to other flying animals. In other words, might flight design be accounted for entirely by mechanical constraints without recourse to natural selection?To test this hypothesis, the power output of C. plumosu was measured as size‐specific muscle mass. Contrary to expectation, little evidence was found of scaling effects in this measure of power. Despite its being among the smallest of animals to fly, C. plumosus turns out to have the largest mass of flight muscle, relative to body size, yet found among animals. Differences both between C. plumosus and other species and within C. plumosus are, in general, more readily accounted for by the requirements of the mating system within the viscous universe encountered by small flying animals. We conclude that it is natural selection rather than mechanical constraint that is the primary influence determining the architecture of flight in this small animal.
Sexual dimorphism, reproductive biology, and food habits of two species of African filesnakes (Mehelya, Colubridae)
Authors: Shine R. , Branch W. R. , Harlow P. S. , Webb J. K. 
Published: May 2009

The ecology and general biology of African snakes remains virtually unstudied, even in highly distinctive species such as the filesnakes (genera Mehelya and Gonionotophis). Our measurements and dissections of preserved specimens provided information on body sizes, sexual dimorphism in size and bodily proportions, clutch sizes, and food habits of two Mehelya species. In both M. capensis and M. nyassae, females attain sexual maturity at the same size as conspecific males, but grow to much larger sizes. Mehelya capensis displays extreme differences in body shape between males and females at the same body length: females have longer and wider heads, thicker bodies, and larger eyes (relative to both head length and head width) than do conspecific males. Dimorphism in body proportions is less marked in M. nyassae. Female reproductive cycles are seasonal in M. capensis, and clutch sizes are larger in this species than in its smaller congener (5‐11 eggs in M. capensis, 2‐6 eggs in M. nyassae).Contrary to popular wisdom, Mehelya are not specialized ophiophages. Mehelya nyassae feeds primarily upon lygosomatine skinks, including many fossorial taxa. Mehelya capensis has a broader diet, feeding on a wide variety of terrestrial lizards (especially agamids and gerrhosaurids) and snakes. Toads are also common prey items. The diversity of prey types taken by M. capensis suggests that these snakes may use ambush predation as well as active foraging. Mehelya is strongly convergent with Asian elapids of the genus Bungarus in its morphology (triangular body shape; powerful jaws; visible interstitial skin), behaviour (nocturnality; reluctance to bite when harassed), and diet (feeding on elongate reptiles, including snakes). Observations of preyhandling and ingestion by captive snakes are needed to clarify possible selective forces for the evolution of the unusual traits shared by these taxa.
Nicotinamide enhances mitochondria quality through autophagy activation in human cells
Authors: Kang Hyun Tae , Hwang Eun Seong 
Published: May 2009

SummaryNicotinamide (NAM) treatment causes a decrease in mitochondrial respiration and reactive oxygen species production in primary human fibroblasts and extends their replicative lifespan. In the current study, it is reported that NAM treatment induces a decrease in mitochondrial mass and an increase in membrane potential (ΔΨm) by accelerating autophagic degradation of mitochondria. In the NAM‐treated cells, the level of LC3‐II as well as the number of LC3 puncta and lysosomes co‐localizing with mitochondria substantially increased. Furthermore, in the NAM‐treated cells, the levels of Fis1, Drp1, and Mfn1, proteins that regulate mitochondrial fission and fusion, increased and mitochondria experienced dramatic changes in structure from filaments to dots or rings. This structural change is required for the decrease of mitochondrial mass indicating that NAM accelerates mitochondrial autophagy, at least in part, by inducing mitochondrial fragmentation. The decrease in mitochondria mass was attenuated by treatment with cyclosporine A, which prevents the loss of mitochondrial membrane potential by blocking the mitochondrial permeability transition, suggesting autophagic degradation selective for mitochondria with low ΔΨm. All these changes were accompanied by and dependent on an increase in the levels of GAPDH, and are blocked by inhibition of the cellular conversion of NAM to NAD+. Taken together with our previous findings, these results suggest that up‐regulation of GAPDH activity may prolong healthy lifespan of human cells through autophagy‐mediated mitochondria quality maintenance.
Radiation sensitivity increases with proliferation‐associated telomere dysfunction in nontransformed human epithelial cells
Authors: Soler David , Pampalona Judit , Tusell Laura , Genescà Anna 
Published: May 2009

SummaryEpidemiological studies have demonstrated age differences among human adults in susceptibility to radiation, with cancer cases attributable to radiation being more frequent for older individuals at time of exposure. In addition to the notion that susceptibility increases because of progressive decline in DNA monitoring and immunosurveillance, telomere function is now emerging as a new and important factor in modulating cellular and organism sensitivity to ionizing radiation. The link between telomeres and radiosensitivity is well‐documented in humans, but the causal events remain elusive. In this paper, it is shown that irradiated human epithelial cells with short dysfunctional telomeres derived from normal mammary gland display elevated DNA damage. An approach identifying the specific chromosomes with critically shortened telomeres in each donor has allowed us to conclude that short dysfunctional telomeres in human epithelial cells join radiation‐induced DNA broken ends, thus interfering with their efficient repair. These findings argue against telomeres participating as sensors or transducers of DNA damage, as previously suggested. Rather, our current findings give support to the idea that dysfunctional telomeres, by acting as an additional joining option, reduce the repair fidelity of DNA broken‐ends induced by radiation throughout the genome. In the mammary gland, age‐dependent telomere attrition due to epithelial turnover, together with the accretion of checkpoint deficiencies, might render the accumulation of short dysfunctional telomeres. This implies that the risks associated with mammography screening could be higher than previously assumed. Our results have the possibility of imprinting a temporal dimension onto radiation sensitivity, namely, that shortened telomeres in aged cells may more easily compromise normal tissue function in the elderly.
Fibrin sealant combined with fibroblasts and platelet‐derived growth factor enhance wound healing in excisional wounds
Authors: Mogford Jon E. , Tawil Bill , Jia Shengxian , Mustoe Thomas A. 
Published: May 2009

ABSTRACTWe test the hypothesis that the fibrinogen‐thrombin formulation of fibrin sealant combined with fibroblasts and PDGF‐BB enhance cutaneous wound healing. Four formulations varying in fibrinogen and thrombin concentration were applied to full‐thickness biopsy wounds in the rabbit ear cutaneous wound healing model with or without cultured rabbit dermal fibroblasts (RDFs; 3 × 105 cells/wound) embedded in the fibrinogen component. At post‐wounding day 7, there was no difference in the diluted vs. non‐diluted formulations for either the promotion of granulation tissue coverage of the open wounds or total granulation tissue area when tested without embedded cells. Including the RDFs, the highest degree of wound coverage by granulation tissue was observed in the combined dilution formulation (17.3 mg/mL fibrinogen, 167 U/mL thrombin; n=10 wounds) that was 167% (p<0.05) of the nondiluted FS containing cells (50 mg/mL fibrinogen, 250 U/mL thrombin; n=10 wounds). Inclusion of fibroblasts increased granulation tissue area within the wounds vs. FS alone (p<0.05) for each diluted formulation although no differences in this parameter were observed within each group (FS alone or with embedded cells). However, addition of the vulnerary growth factor PDGF‐BB (3 mg; n=4) with the embedded RDFs in the combined dilution formulation increased granulation tissue area over two‐fold (p<0.01) over FS alone. Additionally, the presence of the RDFs promoted incorporation of the granulation tissue with and epithelial migration over the FS suggesting an active interaction between cells delivered to the wound by FS and the host repair cells. The findings suggest the progress of cutaneous defect repair can be enhanced by ex vivo cell delivery in fibrin sealant.
A combination of curcumin and ginger extract improves abrasion wound healing in corticosteroid‐impaired hairless rat skin
Authors: Bhagavathula Narasimharao , Warner Roscoe L. , DaSilva Marissa , McClintock Shannon D. , Barron Adam , Aslam Muhammad N. , Johnson Kent J. , Varani James 
Published: May 2009

ABSTRACTHairless rats were topically treated with a combination of 10% curcumin and 3% ginger extract (or with each agent alone) for a 21‐day period. Following this, the rats were treated topically with Temovate (corticosteroid) for an additional 15 days. At the end of the treatment period, superficial abrasion wounds were induced in the treated skin. Abrasion wounds healed more slowly in the skin of Temovate‐treated rats than in skin of control animals. Healing was more rapid in skin of rats that had been pretreated with either curcumin or ginger extract alone or with the combination of curcumin–ginger extract (along with Temovate) than in the skin of rats treated with Temovate and vehicle alone. Skin samples were obtained at the time of wound closure. Collagen production was increased and matrix metalloproteinase‐9 production was decreased in the recently healed skin from rats treated with the botanical preparation relative to rats treated with Temovate plus vehicle. In none of the rats was there any indication of skin irritation during the treatment phase or during wounding and repair. Taken together, these data suggest that a combination of curcumin and ginger extract might provide a novel approach to improving structure and function in skin and, concomitantly, reducing formation of nonhealing wounds in “at‐risk” skin.
Thomas Pynchon: Gravity’s Rainbow. The Ideas of the Opposite
Authors: Paz Menahem 
Published: May 2009

Thomas Pynchon’s highly complex novel deals with the personal and social difficulty of accepting a new worldview. Set at the end of World War II and in its aftermath, the protagonists find themselves at the crossroads between Newtonian mechanics, epitomized by the V2 rockets, and the foreshadowed atom bomb, which is based on the theory of relativity and quantum mechanics.The style of Gravity’s Rainbow resembles the scene of a subatomic world: it is presented as an ever‐changing kaleidoscope of characters, places, events and interactions, which are constantly redetermined in relation to each other in an unpredictable manner. Pynchon manages to create a unifying theme by making all the twists in the plot comprehensible as manifestations of the underlying attempt to reconstruct selfhood. In addition, he refers recurrently to the motif of light, both as a physical entity at the center of modern physics and as a literary symbol of classical stability. In the end, his main protagonist himself turns into a mysterious source of light.
Effects of dietary supplementation with conjugated linoleic acid on fatty acid composition and lipid oxidation in chicken breast meat
Authors: KAWAHARA Satoshi , TAKENOYAMA Shin‐ichi , TAKUMA Kazuaki , MUGURUMA Michio , YAMAUCHI Kiyoshi 
Published: May 2009

ABSTRACTWe investigated the effects of dietary conjugated linoleic acid (CLA) on fatty acid composition and lipid oxidation in breast meat of broiler chickens. Broiler chickens (28‐day‐old females) were fed diets containing experimental oils at 20 g/kg diet for 28 days. The experimental oils consisted of either a 2:0, 1:1, or a 0:2 (wt : wt) ratio of safflower oil (high linoleic acid content) to a commercial CLA mixture. In this study, dietary CLA supplementation significantly increased the composition and content of CLA in chicken meat. The predominant CLA in meat from birds with supplemented diets was the cis‐9, trans‐11 isomer. The proportion of saturated fatty acid in meat significantly increased with increasing CLA supplementation, with a corresponding decrease in monounsaturated fatty acid. Dietary CLA also reduced thiobarbituric acid reactive substances (TBARS) values in raw meat during storage at 4°C for 5 days. These results provide evidence that CLA feeding is a practical strategy not only for adding nutritional benefits to chicken meat but also for improving meat quality including oxidative stability.
A fine map for maternal lineage analysis by mitochondrial hypervariable region in 12 Chinese goat breeds
Authors: WU Yan‐Ping , GUAN Wei‐Jun , ZHAO Qian‐Jun , HE Xiao‐Hong , PU Ya‐Bin , HUO Jun‐Hong , XIE Jin‐Fang , HAN Jian‐Lin , RAO Shao‐Qi , MA Yue‐Hui 
Published: May 2009

ABSTRACTAs the fast pace of genomic research continues to identify mitochondrial lineages in animals, it has become apparent that many independent studies are needed to support a robust phylogenetic inference. The aim of this study was thus to further characterize the maternal lineage, proposed to originate in southwestern region of China, using a wider survey of diverse goat breeds in China. To this end, we sequenced the mitochondrial hypervariable region 1 (HVR1) of the mtDNA control region in 145 goats of 12 Chinese breeds. Phylogenetic analysis revealed that Chinese goats were classified into four distinct lineages (A, B, C and D) as previously reported. A Mantel test and the analysis of Analysis of Molecular Variance (ANOVA) indicated that there was not an obvious geographic structure among Chinese goat breeds. Population expansion analysis based on mismatch distribution and Fu's Fs statistic indicate that two expansion events in Chinese goats occurred respectively at about 11 and 29 mutational time units ago, revealing two star‐like subclades in lineage B corresponding to two population expansion events. Moreover, lineage B sequences were presented only in the breeds of southwestern or surrounding regions of China. Multiple lines of evidence from this study and previous studies indicate that for Chinese goats mtDNA lineage B originated from the southwestern region of China.
Association of BoLA‐DRB3 alleles identified by a sequence‐based typing method with mastitis pathogens in Japanese Holstein cows
Authors: YOSHIDA Tatsuyuki , MUKOYAMA Harutaka , FURUTA Hiroki , KONDO Yasuko , TAKESHIMA Shin‐nosuke , AIDA Yoko , KOSUGIYAMA Motoaki , TOMOGANE Hiroshi 
Published: May 2009

ABSTRACTThe association of the polymorphism of bovine leukocyte antigen (BoLA‐DRB3) genes identified by the polymerase chain reaction sequence‐based typing (PCR‐SBT) method with resistance and susceptibility to mastitis caused by pathogenic bacteria was investigated. Blood samples for DNA extraction were collected from 194 Holstein cows (41 healthy cows and 153 mastitis cows including 24 mixed‐infection cows infected with 2 or 3 species of pathogens) from 5 districts of Chiba prefecture, Japan. Sixteen BoLA‐DRB3 alleles were detected. The 4 main alleles of DRB3*0101, *1501, *1201, and *1101 constituted 56.8% of the total number of alleles detected. Mastitis cows were divided into 2 groups: group 1 with single‐infection cows and group 2 with all mastitis cows including 24 mixed‐infection cows. The differences in the frequencies of BoLA‐DRB3 alleles and the number of cows homozygous or heterozygous for each BoLA‐DRB3 allele between healthy cows and the 2 groups of mastitis cows were evaluated. Furthermore, similar comparisons were performed between healthy cows and the 2 groups of mastitis cows for each mastitis pathogen. It was considered that the 4 alleles, namely, DRB3*0101, *1501, *1201, and *1101 had specific resistance and susceptibility to 4 different mastitis pathogens. Thus, DRB3*0101 might be associated with susceptibility to coagulase‐negative Staphylococci and Escherichia coli, and DRB3*1501 might be associated with susceptibility to Escherichia coli. However, DRB3*1101 might be associated with resistance to Streptococci and coagulase‐negative Staphylococci, and DRB3*1201, with resistance to Streptococci, Escherichia coli, and Staphylococcus aureus.
Mary, the Reformation and some Scots! In Memory of John Macquarrie (1919–2007)
Authors: Cummings Owen F. 
Published: May 2009

AbstractSince Vatican II great progress has been made towards an ecumenical understanding and appreciation of our Blessed Lady, even as there has been a certain development in Catholic understanding. This essay looks briefly at Reformation mariologies, those of Luther, Calvin and Zwingli before moving on to consider three Scots: John Knox, Edwin Muir and John Macquarrie. Arguably, John Macquarrie has shown one of the most careful retrievals of Marian theology, not least in his Principles of Christian Theology and Mary for All Christians. His final mariological sounding took him back to his Celtic roots, and is summarized here. John Macquarrie died in 2007, and this essay is dedicated to his memory.
Demography and population viability of polar bears in the Gulf of Boothia, Nunavut
Authors: Taylor Mitchell K. , Laake Jeff , McLoughlin Philip D. , Cluff H. Dean , Messier François 
Published: May 2009

AbstractWe estimated demographic parameters and harvest risks for polar bears (Ursus maritimus) inhabiting the Gulf of Boothia, Nunavut, from 1976 to 2000. We computed survival and abundance from capture–recapture and recovery data (630 marks) using a Burnham joint live–dead model implemented in program MARK. Annual mean total survival (including harvest) was 0.889 ± 0.179 (x̄± 1 SE) for cubs, 0.883 ± 0.087 for subadults (ages 1–4), 0.919 ± 0.044 for adult females, and 0.917 ± 0.041 for adult males. Abundance in the last 3 yr of study was 1,592 ± 361 bears. Mean size of newborn litters was 1.648 ± 0.098 cubs. By age 7, 0.97 ± 0.30 of available females were producing litters. Harvest averaged 38.4 ± 4.2 bears/year in the last 5 yr of study; however, the 2002–2007 kill averaged 56.4 bears/yr. We used a harvested Population Viability Analysis (PVA) to examine impacts of increasing rates of harvest. We estimated the current population growth rate, λH, to be 1.025 ± 0.032. Although this suggests the population is growing, progressive environmental changes may require more frequent population inventory studies to maintain the same levels of harvest risk.
Exploring the Anomalous Positive Relationship between AIDS and Poverty in Africa
Authors: Gould B. 
Published: May 2009

AbstractHIV/AIDS is very different from most epidemic diseases in the basis of its patterning at the local, national and international scales. Unlike most epidemic diseases, HIV/AIDS is not a disease directly associated with poverty and a lack of development; in Africa it disproportionately affects the wealthy, the educated and the mobile, and prevalence rates are much higher in richer Africa countries than in the poorest countries. The anomalous relationships between HIV/AIDS and poverty in Sub‐Saharan Africa are discussed to illustrate firstly, that the disease is not directly caused by extreme poverty, nor by lack of development in the region, as are most common communicable epidemic diseases, such as malaria or measles, and secondly, that it is not a disease that can be or will be eradicated or even greatly alleviated in its severity by ‘development’, as traditionally conceived in terms of rising incomes or better health services and public health.
Identification, Characterization, and Molecular Application of a Virulence-Associated Autotransporter from a Pathogenic
Pseudomonas fluorescens
Strain
Authors: Hu Yong-hua , Liu Chun-sheng , Hou Jin-hui , Sun Li 
Published: May 2009

ABSTRACT

A gene,
pfa1
, encoding an autotransporter was cloned from a pathogenic
Pseudomonas fluorescens
strain, TSS, isolated from diseased fish. The expression of
pfa1
is enhanced during infection and is regulated by growth phase and growth conditions. Mutation of
pfa1
significantly attenuates the overall bacterial virulence of TSS and impairs the abilities of TSS in biofilm production, interaction with host cells, modulation of host immune responses, and dissemination in host blood. The putative protein encoded by
pfa1
is 1,242 amino acids in length and characterized by the presence of three functional domains that are typical for autotransporters. The passenger domain of PfaI contains a putative serine protease (Pap) that exhibits apparent proteolytic activity when expressed in and purified from
Escherichia coli
as a recombinant protein. Consistent with the important role played by PfaI in bacterial virulence, purified recombinant Pap has a profound cytotoxic effect on cultured fish cells. Enzymatic analysis showed that recombinant Pap is relatively heat stable and has an optimal temperature and pH of 50°C and pH 8.0. The domains of PfaI that are essential to autotransporting activity were localized, and on the basis of this, a PfaI-based autodisplay system (named AT1) was engineered to facilitate the insertion and transport of heterologous proteins. When expressed in
E. coli
, AT1 was able to deliver an integrated
Edwardsiella tarda
immunogen (Et18) onto the surface of bacterial cells. Compared to purified recombinant Et18, Et18 displayed by
E. coli
via AT1 induced significantly enhanced immunoprotection.
Genetic Modification of Carbon Catabolite Repression in
Trichoderma reesei
for Improved Protein Production
Authors: Nakari-Setälä Tiina , Paloheimo Marja , Kallio Jarno , Vehmaanperä Jari , Penttilä Merja , Saloheimo Markku 
Published: May 2009

ABSTRACT

The cellulase and hemicellulase genes of the filamentous fungus
Trichoderma reesei
have been shown to be under carbon catabolite repression mediated by the regulatory gene
cre1
. In this study, strains were constructed in which the
cre1
gene was either completely removed or replaced by a truncated mutant variant,
cre1
-
1
, found previously in the Rut-C30 mutant strain with enhanced enzyme production capability. The
T
.
reesei
transformants with either deletion or truncation of
cre1
had clearly altered colony morphology compared with the parental strains, forming smaller colonies and fewer aerial hyphae and spores. Liquid cultures in a medium with glucose as a carbon source showed that the transformants were derepressed in cellulase and hemicellulase production. Interestingly, they also produced significantly elevated levels of these hydrolytic enzymes in fermentations carried out in a medium inducing the hydrolase genes. This suggests that
cre1
acts as a modulator of cellulase and hemicellulase gene expression under both noninducing and inducing conditions. There was no phenotypic difference between the Δ
cre1
and
cre1
-
1
mutant strains in any of the experiments done, indicating that the
cre1
-
1
gene is practically a null allele. The results of this work indicate that
cre1
is a valid target gene in strain engineering for improved enzyme production in
T
.
reesei
.