bluuebunny/crossref_metadata_2025 huggingface dataset:
Dichoptic Completion, Rather than Binocular Rivalry or Binocular Summation
Authors: Zhaoping Li , Meng Gao
Published: October 2011

When one monocular image contains a red square partly occluding a green square, and the other monocular image is the same except that the green square is partly occluding the red one, the two images resemble each other's amodal completion. Observers typically perceive two complete squares as if the red and green surfaces are transparent or penetrating each other at their overlapping image location, which never appears yellow. With this example, we introduce dichoptic completion as a perception with the following characteristics. (1) Similar to binocular rivalry, it is evoked by dichoptic stimuli with monocular images so disparate that they cannot arise from physical scenes; however, (2) it occurs when objects inferred from one monocular image are identified with, or do not conflict with, objects inferred from the other; and, consequently, (3) it is a form of perceptual superposition, distinct from the result of binocular summation or rivalry.
Phenotypically aberrant astrocytes that promote motoneuron damage in a model of inherited amyotrophic lateral sclerosis
Authors: Díaz-Amarilla Pablo , Olivera-Bravo Silvia , Trias Emiliano , Cragnolini Andrea , Martínez-Palma Laura , Cassina Patricia , Beckman Joseph , Barbeito Luis
Published: October 2011

Motoneuron loss and reactive astrocytosis are pathological hallmarks of amyotrophic lateral sclerosis (ALS), a paralytic neurodegenerative disease that can be triggered by mutations in Cu-Zn superoxide dismutase (SOD1). Dysfunctional astrocytes contribute to ALS pathogenesis, inducing motoneuron damage and accelerating disease progression. However, it is unknown whether ALS progression is associated with the appearance of a specific astrocytic phenotype with neurotoxic potential. Here, we report the isolation of astrocytes with aberrant phenotype (referred as “AbA cells”) from primary spinal cord cultures of symptomatic rats expressing the SOD1
G93A
mutation. Isolation was based on AbA cells’ marked proliferative capacity and lack of replicative senescence, which allowed oligoclonal cell expansion for 1 y. AbA cells displayed astrocytic markers including glial fibrillary acidic protein, S100β protein, glutamine synthase, and connexin 43 but lacked glutamate transporter 1 and the glial progenitor marker NG2 glycoprotein. Notably, AbA cells secreted soluble factors that induced motoneuron death with a 10-fold higher potency than neonatal SOD1
G93A
astrocytes. AbA-like aberrant astrocytes expressing S100β and connexin 43 but lacking NG2 were identified in nearby motoneurons, and their number increased sharply after disease onset. Thus, AbA cells appear to be an as-yet unknown astrocyte population arising during ALS progression with unprecedented proliferative and neurotoxic capacity and may be potential cellular targets for slowing ALS progression.
Contribution of Interfacility Patient Movement to Overall Methicillin-Resistant Staphylococcus aureus Prevalence Levels
Authors: Barnes Sean L. , Harris Anthony D. , Golden Bruce L. , Wasil Edward A. , Furuno Jon P.
Published: October 2011

Objectives.

The effect of patient movement between hospitals and long-term care facilities (LTCFs) on methicillin-resistant Staphylococcus aureus (MRSA) prevalence levels is unknown. We investigated these effects to identify scenarios that may lead to increased prevalence in either facility type.

Methods.

We used a hybrid simulation model to simulate MRSA transmission among hospitals and LTCFs. Transmission within each facility was determined by mathematical model equations. The model predicted the long-term prevalence of each facility and was used to assess the effects of facility size, patient turnover, and decolonization.

Results.

Analyses of various healthcare networks suggest that the effect of patients moving from a LTCF to a hospital is negligible unless the patients are consistently admitted to the same unit. In such cases, MRSA prevalence can increase significantly regardless of the endemic level. Hospitals can cause sustained increases in prevalence when transferring patients to LTCFs, where the population size is smaller and patient turnover is less frequent. For 1 particular scenario, the steady-state prevalence of a LTCF increased from 6.9% to 9.4% to 13.8% when the transmission rate of the hospital increased from a low to a high transmission rate.

Conclusions.

These results suggest that the relative facility size and the patient discharge rate are 2 key factors that can lead to sustained increases in MRSA prevalence. Consequendy, small facilities or those with low turnover rates are especially susceptible to sustaining increased prevalence levels, and they become more so when receiving patients from larger, high-prevalence facilities. Decolonization is an infection-control strategy that can mitigate these effects.
Moving CLABSI Prevention beyond the Intensive Care Unit: Risk Factors in Pediatric Oncology Patients
Authors: Kelly Matthew , Conway Margaret , Wirth Kathleen , Potter-Bynoe Gail , Billett Amy L. , Sandora Thomas J.
Published: October 2011

Background and Objective.

Central line-associated bloodstream infections (CLABSIs) frequently complicate the use of central venous catheters (CVCs) among pediatric patients with cancer. Our objectives were to describe the microbiology and identify risk factors for hospital-onset CLABSI in this patient population.

Design.

Retrospective case-control study.

Setting.

Oncology and stem cell transplant units of a freestanding, 396-bed quaternary care pediatric hospital.

Participants.

Case subjects (N= 54) were patients with a diagnosis of malignancy and/or stem cell transplant recipients with CLABSI occurring during admission. Controls (N= 108) were identified using risk set sampling of hospitalizations among patients with a CVC, matched on date of admission.

Methods.

Multivariate conditional logistic regression was used to identify independent predictors of CLABSI.

Results.

The majority of CLABSI isolates were gram-positive bacteria (58%). The most frequently isolated organism wasEnterococcus faecium, and 6 of 9 isolates were resistant to vancomycin. In multivariate analyses, independent risk factors for CLABSI included platelet transfusion within the prior week (odds ratio [OR], 10.90 [95% confidence interval (CI), 3.02-39.38];P<.001) and CVC placement within the previous month (<1 week vs ≥1 month: OR, 11.71 [95% CI, 1.98-69.20];P= .02; ≥1 week and <1 month vs ≥1 month: OR, 7.37 [95% CI, 1.85-29.36];P= .004).

Conclusions.

Adjunctive measures to prevent CLABSI among pediatric oncology patients may be most beneficial in the month following CVC insertion and in patients requiring frequent platelet transfusions. Vancomycin-resistant enterococci may be an emerging cause of CLABSI in hospitalized pediatric oncology patients and are unlikely to be treated by typical empiric antimicrobial regimens.
Efficacy of a Novel Light-Activated Antimicrobial Coating for Disinfecting Hospital Surfaces
Authors: Ismail Salim , Perni Stefano , Pratten Jonathan , Parkin Ivan , Wilson Michael
Published: October 2011

Silicone polymers containing the light-activated antimicrobial agent methylene blue with or without gold nanoparticles were evaluated for their ability to reduce the microbial load on surfaces in a clinical environment. When irradiated with white light, polymers containing nanogold were more effective in this respect than those containing only methylene blue.
Microstructure and magnetic anisotropy of electrospun Cu1−xZnxFe2O4 nanofibres: a local probe study
Authors: Li Zhiwei , Pan Weiwei , Zhang Junli , Yi Haibo
Published: October 2011

Understanding phenomena at the nanometre scale is of fundamental importance for future improvements of desired properties of nanomaterials. We report a detailed investigation of the microstructure and the resulting magnetic anisotropy by magnetic, transmission electron microscopy (TEM) and Mössbauer measurements of electrospun Cu1−x
Zn
x
Fe2O4 nanofibres. Our results show that the electrospun Cu1−x
Zn
x
Fe2O4 nanofibres exhibit nearly isotropic magnetic anisotropy. TEM measurements indicate that the nanofibres are composed of loosely connected and randomly aligned nanograins. As revealed by the Henkel plot, these nanofibres and the nanograins within the nanofibres are dipolar coupled, which reduces the effective shape anisotropy leading to a nearly random configuration of the magnetic moments inside the nanofibres; hence, the observed nearly isotropic magnetic anisotropy can be easily understood.
On the linear independency of monoidal natural transformations
Authors: Shimizu Kenichi
Published: October 2011

Let

F
F

,

G
:

I

→

C

G: \mathcal {I} \to \mathcal {C}

be monoidal functors from a monoidal category

I

\mathcal {I}

to a linear abelian rigid monoidal category

C

\mathcal {C}

over an algebraically closed field

k

\mathbf {k}

. Then the set

N
a
t

(
F
,
G
)

\mathrm {Nat}(F, G)

of natural transformations

F
→
G

F \to G

is naturally a vector space over

k

\mathbf {k}

. Under certain assumptions, we show that the set of monoidal natural transformations

F
→
G

F \to G

is linearly independent as a subset of

N
a
t

(
F
,
G
)

\mathrm {Nat}(F, G)

.

As a corollary, we can show that the group of monoidal natural automorphisms on the identity functor on a finite tensor category is finite. We can also show that the set of pivotal structures on a finite tensor category is finite.
RalA and RalB differentially regulate development of epithelial tight junctions
Authors: Hazelett C. Clayton , Sheff David , Yeaman Charles
Published: October 2011

Tight junctions (TJs) are structures indispensable to epithelial cells and are responsible for regulation of paracellular diffusion and maintenance of cellular polarity. Although many interactions between TJ constituents have been identified, questions remain concerning how specific functions of TJs are established and regulated. Here we investigated the roles of Ral GTPases and their common effector exocyst complex in the formation of nascent TJs. Unexpectedly, RNA interference–mediated suppression of RalA or RalB caused opposing changes in TJ development. RalA reduction increased paracellular permeability and decreased incorporation of components into TJs, whereas RalB reduction decreased paracellular permeability and increased incorporation of components into TJs. Activities of both Ral GTPases were mediated through the exocyst. Finally, we show that TJ-mediated separation of apical–basal membrane domains is established prior to equilibration of barrier function and that it is unaffected by Ral knockdown or specific composition of TJs.
Job the Silent
Authors: Zuckerman Bruce
Published: October 2011

This book offers an original reading of the book of Job, one of the great classics of biblical literature, and in the process develops a new formula for understanding how biblical texts evolve in the process of transmission. The book presents the thesis that the book of Job was intended as a parody the stereotypical righteous sufferer. In this extended analogy, the book compares the book of Job and its fate to that of a famous Yiddish short story, “Bontshe Shvayg,” another covert parody whose protagonist has come to be revered as a paradigm of innocent Jewish suffering. The history of this story is used to show how a literary text becomes separated from the intention of its author, and comes to have a quite different meaning for a specific community of readers.
Introduction
Authors: Scott Clive
Published: October 2011

The Vers Libre aims to provide a history of free verse in France by providing accounts of events that marked the emergence of free verse. The book also aims to describe the theoretical and formal contexts that made the emergence of free verse inevitable. In addition, the book also provides methods for disengaging the rhythmic structure of free verse text and for analysing its significance. The main focus of this book is the prosody of free verse. In this book, the introduction of free verse by Alain Fourier, the origin and theoretical foundations of free verse, the methods of scansion and its application to poems of Rimbaud, Laforgue, Claudel, and Apollinaire are carefully discussed and studied.
Truth, Fiction, and Literature
Authors: Lamarque Peter , Olsen Stein Haugom
Published: October 2011

This book examines the complex and varied ways in which fictions relate to the real world, and offers a precise account of how imaginative works of literature can use fictional content to explore matters of universal human interest. While rejecting the traditional view that literature is important for the truths that it imparts, the authors also reject attempts to cut off literature altogether from real human concerns. Their detailed account of fictionality, mimesis, and cognitive value helps restore to literature its distinctive status among cultural practices. The authors also explore the limits of fictionality, particularly in relation to metaphysical and sceptical views, prevalent in modern thought, according to which the world itself is a kind of fiction, and truth no more than a cultural construct. They identify different conceptions of fiction in science, logic, epistemology, and make-believe, and thereby challenge the idea that discourse per se is fictional and that different modes of discourse are, at root, indistinguishable. They offer analyses of the roles of narrative, imagination, metaphor, and ‘making’ in human thought processes. Both in their methods and in their conclusions, the authors aim to bring rigour and clarity to debates about the values of literature, and to provide philosophically sound foundations for a genuine change of direction in literary theorizing.
Online social network size is reflected in human brain structure
Authors: Kanai R. , Bahrami B. , Roylance R. , Rees G.
Published: October 2011

The increasing ubiquity of web-based social networking services is a striking feature of modern human society. The degree to which individuals participate in these networks varies substantially for reasons that are unclear. Here, we show a biological basis for such variability by demonstrating that quantitative variation in the number of friends an individual declares on a web-based social networking service reliably predicted grey matter density in the right superior temporal sulcus, left middle temporal gyrus and entorhinal cortex. Such regions have been previously implicated in social perception and associative memory, respectively. We further show that variability in the size of such online friendship networks was significantly correlated with the size of more intimate real-world social groups. However, the brain regions we identified were specifically associated with online social network size, whereas the grey matter density of the amygdala was correlated both with online and real-world social network sizes. Taken together, our findings demonstrate that the size of an individual's online social network is closely linked to focal brain structure implicated in social cognition.
Protein Disulfide Isomerase and Host-Pathogen Interaction
Authors: Stolf Beatriz S. , Smyrnias Ioannis , Lopes Lucia R. , Vendramin Alcione , Goto Hiro , Laurindo Francisco R. M. , Shah Ajay M. , Santos Celio X. C.
Published: October 2011

Reactive oxygen species (ROS) production by immunological cells is known to cause damage to pathogens. Increasing evidence accumulated in the last decade has shown, however, that ROS (and redox signals) functionally regulate different cellular pathways in the host-pathogen interaction. These especially affect (i) pathogen entry through protein redox switches and redox modification (i.e., intra- and interdisulfide and cysteine oxidation) and (ii) phagocytic ROS production via Nox family NADPH oxidase enzyme and the control of phagolysosome function with key implications for antigen processing. The protein disulfide isomerase (PDI) family of redox chaperones is closely involved in both processes and is also implicated in protein unfolding and trafficking across the endoplasmic reticulum (ER) and towards the cytosol, a thiol-based redox locus for antigen processing. Here, we summarise examples of the cellular association of host PDI with different pathogens and explore the possible roles of pathogen PDIs in infection. A better understanding of these complex regulatory steps will provide insightful information on the redox role and coevolutional biological process, and assist the development of more specific therapeutic strategies in pathogen-mediated infections.
Compaction of chromatin by diverse Polycomb group proteins requires localized regions of high charge
Authors: Grau Daniel J. , Chapman Brad A. , Garlick Joe D. , Borowsky Mark , Francis Nicole J. , Kingston Robert E.
Published: October 2011

Polycomb group (PcG) proteins are required for the epigenetic maintenance of developmental genes in a silent state. Proteins in the Polycomb-repressive complex 1 (PRC1) class of the PcG are conserved from flies to humans and inhibit transcription. One hypothesis for PRC1 mechanism is that it compacts chromatin, based in part on electron microscopy experiments demonstrating that Drosophila PRC1 compacts nucleosomal arrays. We show that this function is conserved between Drosophila and mouse PRC1 complexes and requires a region with an overrepresentation of basic amino acids. While the active region is found in the Posterior Sex Combs (PSC) subunit in Drosophila, it is unexpectedly found in a different PRC1 subunit, a Polycomb homolog called M33, in mice. We provide experimental support for the general importance of a charged region by predicting the compacting capability of PcG proteins from species other than Drosophila and mice and by testing several of these proteins using solution assays and microscopy. We infer that the ability of PcG proteins to compact chromatin in vitro can be predicted by the presence of domains of high positive charge and that PRC1 components from a variety of species conserve this highly charged region. This supports the hypothesis that compaction is a key aspect of PcG function.
Genomic analysis identifies association of Fusobacterium with colorectal carcinoma
Authors: Kostic Aleksandar D. , Gevers Dirk , Pedamallu Chandra Sekhar , Michaud Monia , Duke Fujiko , Earl Ashlee M. , Ojesina Akinyemi I. , Jung Joonil , Bass Adam J. , Tabernero Josep , Baselga José , Liu Chen , Shivdasani Ramesh A. , Ogino Shuji , Birren Bruce W. , Huttenhower Curtis , Garrett Wendy S. , Meyerson Matthew
Published: October 2011

The tumor microenvironment of colorectal carcinoma is a complex community of genomically altered cancer cells, nonneoplastic cells, and a diverse collection of microorganisms. Each of these components may contribute to carcinogenesis; however, the role of the microbiota is the least well understood. We have characterized the composition of the microbiota in colorectal carcinoma using whole genome sequences from nine tumor/normal pairs. Fusobacterium sequences were enriched in carcinomas, confirmed by quantitative PCR and 16S rDNA sequence analysis of 95 carcinoma/normal DNA pairs, while the Bacteroidetes and Firmicutes phyla were depleted in tumors. Fusobacteria were also visualized within colorectal tumors using FISH. These findings reveal alterations in the colorectal cancer microbiota; however, the precise role of Fusobacteria in colorectal carcinoma pathogenesis requires further investigation.
New Insights into the Control of Endoreduplication: Endoreduplication Could Be Driven by Organ Growth in Arabidopsis Leaves
Authors: Massonnet Catherine , Tisné Sébastien , Radziejwoski Amandine , Vile Denis , De Veylder Lieven , Dauzat Myriam , Granier Christine
Published: October 2011

Enormous progress has been achieved understanding the molecular mechanisms regulating endoreduplication. By contrast, how this process is coordinated with the cell cycle or cell expansion and contributes to overall growth in multicellular systems remains unclear. A holistic approach was used here to give insight into the functional links between endoreduplication, cell division, cell expansion, and whole growth in the Arabidopsis (Arabidopsis thaliana) leaf. Correlative analyses, quantitative genetics, and structural equation modeling were applied to a large data set issued from the multiscale phenotyping of 200 genotypes, including both genetically modified lines and recombinant inbred lines. All results support the conclusion that endoreduplication in leaf cells could be controlled by leaf growth itself. More generally, leaf growth could act as a “hub” that drives cell division, cell expansion, and endoreduplication in parallel. In many cases, this strategy allows compensations that stabilize leaf area even when one of the underlying cellular processes is limiting.
A Functional Component of the Transcriptionally Active Chromosome Complex, Arabidopsis pTAC14, Interacts with pTAC12/HEMERA and Regulates Plastid Gene Expression
Authors: Gao Zhi-Ping , Yu Qing-Bo , Zhao Tuan-Tuan , Ma Qian , Chen Guo-Xiang , Yang Zhong-Nan
Published: October 2011

The SET domain-containing protein, pTAC14, was previously identified as a component of the transcriptionally active chromosome (TAC) complexes. Here, we investigated the function of pTAC14 in the regulation of plastid-encoded bacterial-type RNA polymerase (PEP) activity and chloroplast development. The knockout of pTAC14 led to the blockage of thylakoid formation in Arabidopsis (Arabidopsis thaliana), and ptac14 was seedling lethal. Sequence and transcriptional analysis showed that pTAC14 encodes a specific protein in plants that is located in the chloroplast associated with the thylakoid and that its expression depends on light. In addition, the transcript levels of all investigated PEP-dependent genes were clearly reduced in the ptac14-1 mutants, while the accumulation of nucleus-encoded phage-type RNA polymerase-dependent transcripts was increased, indicating an important role of pTAC14 in maintaining PEP activity. pTAC14 was found to interact with pTAC12/HEMERA, another component of TACs that is involved in phytochrome signaling. The data suggest that pTAC14 is essential for proper chloroplast development, most likely by affecting PEP activity and regulating PEP-dependent plastid gene transcription in Arabidopsis together with pTAC12.
Arabidopsis Actin Depolymerizing Factor4 Modulates the Stochastic Dynamic Behavior of Actin Filaments in the Cortical Array of Epidermal Cells
Authors: Henty Jessica L. , Bledsoe Samuel W. , Khurana Parul , Meagher Richard B. , Day Brad , Blanchoin Laurent , Staiger Christopher J.
Published: October 2011

Actin filament arrays are constantly remodeled as the needs of cells change as well as during responses to biotic and abiotic stimuli. Previous studies demonstrate that many single actin filaments in the cortical array of living Arabidopsis thaliana epidermal cells undergo stochastic dynamics, a combination of rapid growth balanced by disassembly from prolific severing activity. Filament turnover and dynamics are well understood from in vitro biochemical analyses and simple reconstituted systems. However, the identification in living cells of the molecular players involved in controlling actin dynamics awaits the use of model systems, especially ones where the power of genetics can be combined with imaging of individual actin filaments at high spatial and temporal resolution. Here, we test the hypothesis that actin depolymerizing factor (ADF)/cofilin contributes to stochastic filament severing and facilitates actin turnover. A knockout mutant for Arabidopsis ADF4 has longer hypocotyls and epidermal cells when compared with wild-type seedlings. This correlates with a change in actin filament architecture; cytoskeletal arrays in adf4 cells are significantly more bundled and less dense than in wild-type cells. Several parameters of single actin filament turnover are also altered. Notably, adf4 mutant cells have a 2.5-fold reduced severing frequency as well as significantly increased actin filament lengths and lifetimes. Thus, we provide evidence that ADF4 contributes to the stochastic dynamic turnover of actin filaments in plant cells.
Single-Molecule Analysis of PIP2;1 Dynamics and Partitioning Reveals Multiple Modes of Arabidopsis Plasma Membrane Aquaporin Regulation
Authors: Li Xiaojuan , Wang Xiaohua , Yang Yong , Li Ruili , He Qihua , Fang Xiaohong , Luu Doan-Trung , Maurel Christophe , Lin Jinxing
Published: October 2011

PIP2;1 is an integral membrane protein that facilitates water transport across plasma membranes. To address the dynamics of Arabidopsis thaliana PIP2;1 at the single-molecule level as well as their role in PIP2;1 regulation, we tracked green fluorescent protein–PIP2;1 molecules by variable-angle evanescent wave microscopy and fluorescence correlation spectroscopy (FCS). Single-particle tracking analysis revealed that PIP2;1 presented four diffusion modes with large dispersion of diffusion coefficients, suggesting that partitioning and dynamics of PIP2;1 are heterogeneous and, more importantly, that PIP2;1 can move into or out of membrane microdomains. In response to salt stress, the diffusion coefficients and percentage of restricted diffusion increased, implying that PIP2;1 internalization was enhanced. This was further supported by the decrease in PIP2;1 density on plasma membranes by FCS. We additionally demonstrated that PIP2;1 internalization involves a combination of two pathways: a tyrphostin A23-sensitive clathrin-dependent pathway and a methyl-β-cyclodextrin–sensitive, membrane raft–associated pathway. The latter was efficiently stimulated under NaCl conditions. Taken together, our findings demonstrate that PIP2;1 molecules are heterogeneously distributed on the plasma membrane and that clathrin and membrane raft pathways cooperate to mediate the subcellular trafficking of PIP2;1, suggesting that the dynamic partitioning and recycling pathways might be involved in the multiple modes of regulating water permeability.
Recombinant activated protein C usage in Scotland: a comparison with published guidelines and a survey of attitudes*
Authors: Puxty A. , McConnell P. , Crawley S. , McAree S. , Quasim T. , Ramsay S.
Published: October 2011

Severe sepsis is a common cause of admission to the intensive care unit and is associated with a high hospital mortality. This audit explored the current use of, and attitudes towards, recombinant activated protein C therapy across Scotland, and compared these with current guidance. Patients with severe sepsis were followed for three days. Consideration and/or usage of recombinant activated protein C were compared with two different guidelines. Ninety‐seven patients were admitted to the intensive care unit over the audit period. Recombinant activated protein C was used in nine of these patients. Depending on the criteria used, between 50% and 81% of the patients who qualified for recombinant activated protein C therapy did not receive it. Subsequent to the audit, a survey was performed to study intensive care unit consultants’ attitudes to recombinant activated protein C therapy. A total of 125 consultants responded to the survey (77%). Of these, 104 (83%) stated that they used recombinant activated protein C in their clinical practice, 56 (52%) of whom prescribed it to patients with two‐organ failures and an Acute Physiology and Chronic Health Evaluation II score of ≥ 25. Thirty‐nine respondents (38%) stated that two‐organ failures alone would be an adequate trigger for therapy. We conclude that recombinant activated protein C is potentially under‐used to treat severe sepsis. Many consultants seem to reserve the drug for the most severely ill sub group of patients.
Genetic stability in the Icelandic horse breed
Authors: Campana M. G. , Stock F. , Barrett E. , Benecke N. , Barker G. W. W. , Seetah K. , Bower M. A.
Published: October 2011

Despite the Icelandic horse enjoying great popularity worldwide, the breed’s gene pool is small. This is because of a millennium of isolation on Iceland, population crashes caused by natural disasters and selective breeding. Populations with small effective population sizes are considered to be more at risk of selection pressures such as disease and environmental change. By analysing historic and modern mitochondrial DNA sequences and nuclear coat colour genes, we examined real‐time population dynamics in the Icelandic horse over the last 150 years. Despite the small gene pool of this breed, we found that the effective population size and genetic profile of the Icelandic horse have remained stable over the studied time period.
Genetic variants affecting meat and milk production traits appear to have effects on reproduction traits in cattle
Authors: Collis E. , Fortes M. R. S. , Zhang Y. , Tier B. , Schutt K. , Barendse W. , Hawken R.
Published: October 2011

Polymorphisms located in the genes ABCG2, DGAT1, LEP, PRLR, RORC, CAPN1 and CAST previously have been associated with milk or meat production traits. In this study, these polymorphisms were examined for significant effects on reproductive traits [age at puberty (AGECL), post‐partum anoestrus interval (PPAI) and the ability ovulate prior to weaning (PW)] and on a panel of correlated traits such as weight, growth and serum concentration of insulin‐like growth factor I. The effects of the polymorphisms were examined in two samples of tropically adapted beef cattle: Brahman (N = 932) and Tropical Composites (N = 1097). A polymorphism in the gene DGAT1 was associated with age at puberty in the combined sample (P = 0.042), and two polymorphisms in CAPN1 were associated with PPAI (P = 0.033) and with the ability ovulate PW (P = 0.017). The favourable allele for reproductive traits was not always the favourable allele associated with production traits. The effects of these polymorphisms on reproductive traits were small compared to their effects on the traits for which they were originally discovered.
A premature stop codon in the ADAMTS2 gene is likely to be responsible for dermatosparaxis in Dorper sheep
Authors: Zhou H. , Hickford J. G. H. , Fang Q.
Published: October 2011

We have used polymerase chain reaction‐single‐strand conformational polymorphism analysis to investigate variation in exon 2 of the ADAM metalloproteinase with thrombospondin type I motif, 2 (ADAMTS2) gene in 598 sheep, including three white Dorper lambs that had a pathology consistent with dermatosparaxis. Four sequence variants (A, B, C and D) were identified at this exon, with the lambs having the dermatosparaxis phenotype being uniquely B homozygous and their mothers being B‐containing heterozygous for ADAMTS2. Analysis of the amplified exon 2 sequences revealed the B variant had a nucleotide substitution that creates a premature stop codon and would notionally abbreviate the ADAMTS2 peptide. The B variant was not found in any other breed aside from the white Dorper sheep that were studied.
Contrasted breeding strategies in four sympatric sibling insect species: when a proovigenic and capital breeder copes with a stochastic environment
Authors: Pélisson Pierre‐François , Bel‐Venner Marie‐Claude , Rey Benjamin , Burgevin Lorraine , Martineau François , Fourel François , Lecuyer Christophe , Menu Frédéric , Venner Samuel
Published: October 2011

1. The evolution of strategies of resource acquisition and allocation is often considered to be closely dependent on the degree of environmental variability. Within this framework, female insects that experience stochastic fluctuations in the availability of their egg‐laying sites in time or space can be expected to be fully synovigenic (i.e. they start maturing eggs after a delay once reaching adulthood), which allows them to tailor their reproductive investment to variations in the resource. Proovigenic females (that have most of their eggs already mature at the onset of their adult life, which corresponds to a capital breeding strategy), on the contrary, should have an advantage when the availability of the egg‐laying sites is predictable. There is, however, a dearth of empirical studies testing these predictions.

2. Here, we tested the hypothesis that four phytophagous insect species of the genus Curculio, which coexist on a strongly fluctuating resource that they exploit for egg‐laying purposes, would all be synovigenic as strict proovigeny should be counterselected. The resource consisted of the acorns of oak trees Quercus spp. We conducted field surveys to determine the date of adult emergence in each weevil species and the ability of newly emerged females to produce eggs. We also analysed the stable isotope profile of wild‐caught females as a proxy for their feeding activity. Finally, we tested females under laboratory conditions for their ability to produce mature eggs when not fed and investigated whether dietary intake influenced their longevity.

3. Taken together, our results show that, contrary to the usual predictions, the four weevil species that were all exposed to a markedly fluctuating environment exhibited sharply contrasting strategies of resource acquisition and allocation: three species were synovigenic, while the fourth was proovigenic. Unexpectedly, therefore, our findings show that a strict capital breeding species might not always be counterselected in a temporally stochastic environment. They further suggest that fluctuations in the environment should not promote a sole, optimal strategy of energy acquisition and allocation to reproduction but instead should favour their diversification.
Survival and population size of a resident bird species are declining as temperature increases
Authors: Santisteban Leonard , Benkman Craig W. , Fetz Trevor , Smith Julie W.
Published: October 2011

1. A large number of migratory bird species appear to be declining as the result of climate change, but whether resident bird species have or will be adversely affected by climate change is less clear. We focus on the South Hills crossbill (Loxia curvirostracomplex), which is endemic to about 70 km2of Rocky Mountain lodgepole pine (Pinus contorta latifolia) forest in southern Idaho, USA.

2. Our results indicate that the South Hills crossbill has declined by over 60% between 2003 and 2008, and that decreasing adult survival drives this population decline.

3. We evaluated the relative support for multiple hypotheses linking crossbill survival to climate, an ectoparasitic mite (scaly‐leg mitesKnemidokoptes jamaicensis), and the recent emergence of West Nile virus. Changes in adult apparent survival rate were closely associated with average spring and annual temperatures, and with high temperatures (≥32 °C) during summer, which have increased during the last decade. In contrast, there was little evidence that scaly‐leg mites or West Nile virus contributed to recent declines in adult survival.

4. The most probable mechanism causing the decline in adult survival and population size is a decrease in the availability of their primary food resource, seeds in serotinous pine cones. Cone production has declined with increasing annual temperatures, and these cones appear to be prematurely opening owing to increasingly hot summer conditions releasing their seeds and reducing the carrying capacity for crossbills later in the year.

5. In light of regional climate change forecasts, which include an increase in both annual temperature and hot days (>32 °C), and the likely disappearance of lodgepole pine from southern Idaho by the end of this century, additional research is needed to determine how to maintain lodgepole pine forests and their supply of seeds to conserve one of the few bird species endemic to the continental United States.
Molecular and morphological support for a Florida origin of the Cuban oak
Authors: Gugger Paul F. , Cavender‐Bares Jeannine
Published: October 2011

Aim  The origins of the Cuban biota are of long‐standing interest in biogeography, and the source of a small live oak (Quercus series Virentes) population on Cuba remains unresolved. Based on morphological evidence, previous authors have hypothesized a Florida origin from either Q. geminata or Q. virginiana or both; a Mexican origin from Q. oleoides; or a hybrid origin from both sources. We use molecular data and taxonomically informative leaf morphology to identify the source species and timing of colonization.

Location  Cuba, Central America, Mexico and the south‐eastern United States.

Methods  We collected representative samples of Cuban oaks and each putative source species and genotyped each sample at 12 nuclear microsatellites and two chloroplast DNA sequences. We estimated population structure using a Bayesian clustering analysis and F‐statistics, pairwise migration rates among taxa, and divergence time using an isolation‐with‐migration model. We measured seven leaf traits and conducted an analysis of similarity (ANOSIM) to determine which putative source species was most similar to Cuban oaks.

Results  Cuban oak contains one chloroplast DNA haplotype, which is common in southern Florida. Bayesian clustering analysis of microsatellites revealed that the Cuban oak forms a distinct and pure population cluster, and F‐statistics showed that Cuban oaks are differentiated least from Q. virginiana and most from Q. geminata. Migration rates were highest out of Cuba to Q. oleoides. Molecular diversity, the ratio of allelic richness to allele size range, and effective population size of the Cuban oak were relatively low, suggesting a founder effect. Divergence time estimates fell entirely within the Pleistocene (628–6 ka), considering a range of mutation rates and generation times. Cuban oaks were morphologically most similar to Q. virginiana and least similar to Q. geminata.

Main conclusions  Molecular and morphological data support a Pleistocene dispersal of Q. virginiana from Florida to Cuba, followed by isolation and divergence, then limited dispersal and introgression from Cuba to Q. oleoides in Central America. Birds could have dispersed acorns to Cuba during a glacial period when sea levels were low. These results highlight the varied origin of the Cuban biota and the possible role of Pleistocene glaciations in the establishment of temperate taxa in the tropics.
Plasma zinc concentrations during the first 2 years after diagnosis of insulin‐dependent diabetes mellitus: a prospective study
Authors: MELCHIOR T. , SIMONSEN K. WIESE , JOHANNESSEN A. C. , BINDER C.
Published: October 2011

Abstract Melchior T, Wiese Simonsen K, Johannessen AC, Binder C (Steno Memorial Hospital, Gentofte and Department of Chemistry AD, Royal Danish School of Pharmacy. Copenhagen. Denmark). Plasma zinc concentrations during the first 2 years after diagnosis of insulin‐dependent diabetes mellitus: a prospective study.

Studies of zinc status in insulin‐dependent diabetes mellitus (IDDM) have shown contradictory results. Zinc is essential for many enzymes involved in the human metabolism and may play a role in the biosynthesis and storage of insulin in the B‐cell. We therefore prospectively followed 26 patients (14 males and 12 females) with newly diagnosed IDDM in order to determine the plasma zinc variation at the time of diagnosis and after 1, 3, 6, 12 and 24 months. Seventy‐two healthy persons (36 males and 36 females) served as controls.

Only minor differences in plasma zinc were demonstrated during the first 2 years of IDDM. A sex difference was found in healthy controls but only after 24 months in the diabetics.

Quantitative changes of the B‐cell function, development of insulin antibodies, age. body weight and serum albumin did not correlate with the course of plasma zinc.
Factors influencing progression in patients with chronic renal failure
Authors: STENVINKEL P. , ALVESTRAND A. , BERGSTRÖM J.
Published: October 2011

Abstract Stenvinkel P, Alvestrand A, Bergström J (Department of Renal Medicine. Huddinge University Hospital, Karolinska Institute, Stockholm, Sweden). Factors influencing progression in patients with chronic renal failure.

To identify factors influencing the progression rate of chronic renal failure (CRF) in non‐diabetics, the medical records of 124 patients with established CRF were reviewed retrospectively (serum creatinine between 200–350 μmol l−1 at the start of follow‐up) for the period 1980–86. Sixteen patients were excluded because they did not fulfil the inclusion criteria. The remaining 108 patients were divided, using their original diagnosis, into four groups and were also assigned into one of three groups expressing their rate of progression. The definitions of these rates of progression were chosen arbitrarily. Comparisons with respect to mean arterial pressure (MAP), urinary protein excretion (UPE) and the progression rate of CRF were then made between the groups. In the group showing no progression of CRF (n = 17) there was a significantly lower MAP and UPE than in the two groups showing progression. Over all the patients and in the various diagnosis groups there was a strong correlation between UPE and the progression rate of CRF. There was no significant correlation between MAP and the progression rate of CRF in the diagnosis groups. These results indicate that an increasing magnitude of proteinuria is an adverse prognostic factor in CRF, irrespective of aetiology, and support the view that excessive glomerular protein filtration leads to glomerulosclerosis.
Sulphur amino acids in plasma and muscle in patients with chronic renal failure: evidence for taurine depletion
Authors: BERGSTRÖM J. , ALVESTRAND A. , FÜRST P. , LINDHOLM B.
Published: October 2011

Abstract Bergström J. Alvestrand A. Fürst P. Lindholm B (Department of Renal Medicine and the Research Center. Karolinska Institute and Huddinge University Hospital, Stockholm, Sweden). Sulphur amino acids in plasma and muscle in patients with chronic renal failure: evidence for taurine depletion.

The sulphur amino acids methionine, cysteine (1/2‐cystine) and taurine were determined by ion‐exchange chromatography in plasma and muscle biopsy material obtained from 46 patients with chronic renal failure. Twelve patients were untreated, eight patients were treated with a low protein diet supplemented with essential amino acids. 11 patients treated with maintenance haemodialysis and 15 patients with continuous ambulatory peritoneal dialysis (CAPD). Patient data were compared to data obtained from 18 healthy subjects. Plasma cysteine was elevated in the untreated patients, in the patients treated with low protein diet and in the maintenance haemodialysis patients. Muscle methionine was significantly elevated in the CAPD patients. Plasma taurine was decreased in the untreated patients and in the CAPD patients and muscle taurine was borderline low in the untreated patients and significantly decreased in the other patient groups. The results show that taurine depletion may occur in patients with chronic uraemia despite normal or elevated concentrations of precursor sulphur amino acids, suggesting inhibited synthesis or enhanced degradation of taurine in the uraemic state.
Effects of acute myocardial infarction on the displacement of the atrioventricular plane: an echocardiographic study
Authors: HÖGLUND C. , ALAM M. , THORSTRAND C.
Published: October 2011

Abstract Höglund C, Alam M, Thorstrand C (Section of Cardiology. Department of Medicine I, Karolinska Institute at Södersjukhuset (South Hospital), Stockholm, Sweden). Effects of acute myocardial infarction on the displacement of the atrioventricular plane: an echocardiographic study.

The effects of acute myocardial infarction (MI) on the displacement of the left ventricular (LV) atrioventricular (AV) plane is presented. The material consisted of 40 patients with first‐time Q‐wave MI (26 pts with ant. MI and 14 with post. MI). Nineteen age‐matched healthy subjects were used as controls.

The displacement of the AV plane was determined at four sites corresponding to anterior (AV‐A), septal (AV‐S), posterior (AV‐P) and lateral (AV‐L) parts of the LV wall. In anterior and posterior MI all the sites showed significantly reduced AV‐plane displacement compared to healthy subjects (P < 0.001). Moreover, within the anterior MI group the AV‐A and AV‐S displacements were significantly reduced compared to the points AV‐L and AV‐P (P < 0.001) and the AV‐L displacement was reduced compared to AV‐P (P < 0.001). In posterior MI the displacement at AV‐P was reduced compared to other points (P < 0.001) and, to a certain extent, AV‐S was reduced compared to the points AV‐A and AV‐L (P < 0.001).

The reduced magnitude of the AV plane displacement seems to be an expression of regionally reduced systolic function. The method described may provide a simple means of defining regional wall motion abnormalities of the LV following MI.
Dyspnoea in chronic primary fibromyalgia
Authors: CAIDAHL K. , LURIE M. , BAKE B. , JOHANSSON G. , WETTERQVIST H.
Published: October 2011

Abstract Caidahl K, Lurie M, Bake B, Johansson G, Wetterqvist H, (Departments of Clinical Physiology and Medical Rehabilitation, Sahlgren's University Hospital, Gothenburg, Sweden). Dyspnoea in chronic primary fibromyalgia.

We investigated the prevalence of dyspnoea, according to a 5‐grade score proposed by the World Health Organization (WHO), among 87 consecutive women (age 44.0 ± 8.4, range 26–65 years), with severe chronic primary fibromyalgia (CPF). In total 73 women (84%) were dyspnoeic, 47, 17, six and four patients reported dyspnoea corresponding to WHO grades 1, 2, 3 and 4, respectively. In multivariate analysis WHO dyspnoea grade was the most important determinator of exercise capacity. The higher WHO dyspnoea grade reported, the lower exercise capacity and heart rate were reached at graded bicycle exercise tests (r = −0.48, P < 0.001 and r = −0.40, P < 0.001). WHO dyspnoea grade correlated directly to breathing frequency at rest (r = 0.45, P < 0.001) and inversely to maximum inspiratory pressure (r = −0.29, P < 0.01). It did not correlate with maximum expiratory pressure, nor with spirometric measurements of pulmonary function.

It is concluded that dyspnoea is common among CPF patients and is not explained by cardiac or pulmonary causes, but may partly be due to diaphragmatic muscular insufficiency and physical inactivity.
Early determination of serum lipids and apolipoproteins in acute myocardial infarction: possibility for immediate intervention
Authors: AHNVE S. , ANGELIN B. , EDHAG O. , BERGLUND L.
Published: October 2011

Abstract Ahnve S, Angelin B, Edhag O, Berglund L (Division of Cardiology and Metabolism Unit. Department of Medicine, and Department of Clinical Chemistry, Karolinska Institute, Huddinge University Hospital, Stockholm, Sweden). Early determination of serum lipids and apolipoproteins in acute myocardial infarction: possibility for immediate intervention.

Early identification of elevated cholesterol in patients with acute myocardial infarction (MI) is of interest as secondary prevention can then be initiated when patients are highly motivated. However, since the lipid pattern changes during acute MI, screening for lipid disturbances is often not performed until 6 months later. We prospectively studied lipid and apolipoprotein levels during acute MI and 3 and 6 months later in 123 consecutive acute MI patients, mean age 64 ± 10 (SD) years, who were admitted within 24 h from onset of symptoms, mean delay 5.5 h. Blood was taken at admission to the Coronary Care Unit (CCU), the first morning in the CCU, at hospital discharge and at 3 and 6 months follow‐up. Patients were fasted overnight except at admission, and no specific dietary advice was given. Total serum cholesterol, triglycerides, and apolipoprotein (apo) A‐I concentrations did not differ significantly (1–3%) between CCU admission and the 3 and 6 months control. During the subsequent hospital period, lipid concentrations generally decreased and at discharge were 15–25% below those at 6 months follow‐up (P < 0.001). The highest correlations between immediate CCU determination and 6 months follow‐up were obtained for cholesterol (r = +0.71) and apo B (r = +0.67).

Thus, lipid levels obtained early at CCU admission in acute MI patients are representative of the patient's baseline levels which are in contrast to those registered later during hospital stay. This information could be used to identify patients for early intervention.