bluuebunny/crossref_metadata_2025_split huggingface dataset:
X-rays from the redshift 7.1 quasar ULAS J1120+0641
Authors: Page M. J. , Simpson C. , Mortlock D. J. , Warren S. J. , Hewett P. C. , Venemans B. P. , McMahon R. G. 
Published: March 2014

Abstract
We present X-ray imaging and spectroscopy of the redshift z = 7.084 radio-quiet quasar ULAS J112001.48+064124.3 obtained with Chandra and XMM–Newton. The quasar is detected as a point source with both observatories. The Chandra observation provides a precise position, confirming the association of the X-ray source and the quasar, while a sufficient number of photons is detected in the XMM–Newton observation to yield a meaningful X-ray spectrum. In the XMM–Newton observation, the quasar has a 2–10 keV luminosity of 4.7 ± 0.9 × 1044 erg s−1 and a spectral slope $\alpha = 1.6^{+0.4}_{-0.3}$ (where fν ∝ ν−α). The quasar appears to have dimmed in the 15 months between the two observations, with a 2–10 keV luminosity of $1.8^{+1.0}_{-0.7}\times 10^{45}$ erg s−1 during the Chandra observation. We derive optical-to-X-ray spectral slopes αOX of 1.76 ± 0.07 and $1.54^{+0.09}_{-0.08}$ at the times of the XMM–Newton and Chandra observations, respectively, consistent with the range of αOX found in other quasars of comparable ultraviolet luminosity. The very soft X-ray spectrum suggests that the quasar is accreting above the Eddington rate, $L/L_{\rm Edd} = 5^{+15}_{-4}$, compared to $L/L_{\rm Edd} = 1.2^{+0.6}_{-0.5}$ derived from the rest-frame ultraviolet. Super-Eddington accretion would help to reduce the discrepancy between the age of the quasar implied by the small size of the ionized near-zone in which it sits (&lt;107 yr) and the characteristic e-folding time (2.5 × 107 yr if L/LEdd = 2). Such super-Eddington accretion would also alleviate the challenging constraints on the seed black hole mass provided that the quasar has been rapidly accreting throughout its history. The remnant of an individual Population III star is a plausible progenitor if an average L/LEdd &gt; 1.46 has been maintained over the quasar's lifetime.
A novel inference of the fundamental biodiversity number for multiple immigration-limited communities
Authors: Beeravolu Reddy Champak , Couteron Pierre , Munoz François 
Published: March 2014

AbstractNeutral community theory postulates a fundamental quantity, θ, which reflects the species diversity on a regional scale. While the recent genealogical formulation of community dynamics has considerably enhanced quantitative neutral ecology, its inferential aspects have remained computationally prohibitive. Here, we make use of a generalized version of the original two-level hierarchical framework in order to define a novel estimator forθ;, which proves to be computationally efficient and robust when tested on a wide range of simulated neutral communities. Estimatingθ; from field data is also illustrated using two tropical forest datasets consisting of spatially separated permanent field plots. Preliminary results also reveal that our inferred regional diversity parameter based on community dynamics may be linked to widely used ordination techniques in ecology. This paper essentially paves the way for future work dealing with the parameter inference of neutral communities with respect to their spatial scale and structure.
The Leucine-Rich Repeat Receptor-Like Kinase BRASSINOSTEROID INSENSITIVE1-ASSOCIATED KINASE1 and the Cytochrome P450 PHYTOALEXIN DEFICIENT3 Contribute to Innate Immunity to Aphids in Arabidopsis
Authors: Prince David C. , Drurey Claire , Zipfel Cyril , Hogenhout Saskia A. 
Published: March 2014

Abstract
The importance of pathogen-associated molecular pattern-triggered immunity (PTI) against microbial pathogens has been recently demonstrated. However, it is currently unclear if this layer of immunity mediated by surface-localized pattern recognition receptors (PRRs) also plays a role in basal resistance to insects, such as aphids. Here, we show that PTI is an important component of plant innate immunity to insects. Extract of the green peach aphid (GPA; Myzus persicae) triggers responses characteristic of PTI in Arabidopsis (Arabidopsis thaliana). Two separate eliciting GPA-derived fractions trigger induced resistance to GPA that is dependent on the leucine-rich repeat receptor-like kinase BRASSINOSTEROID INSENSITIVE1-ASSOCIATED KINASE1 (BAK1)/SOMATIC-EMBRYOGENESIS RECEPTOR-LIKE KINASE3, which is a key regulator of several leucine-rich repeat-containing PRRs. BAK1 is required for GPA elicitor-mediated induction of reactive oxygen species and callose deposition. Arabidopsis bak1 mutant plants are also compromised in immunity to the pea aphid (Acyrthosiphon pisum), for which Arabidopsis is normally a nonhost. Aphid-derived elicitors induce expression of PHYTOALEXIN DEFICIENT3 (PAD3), a key cytochrome P450 involved in the biosynthesis of camalexin, which is a major Arabidopsis phytoalexin that is toxic to GPA. PAD3 is also required for induced resistance to GPA, independently of BAK1 and reactive oxygen species production. Our results reveal that plant innate immunity to insects may involve early perception of elicitors by cell surface-localized PRRs, leading to subsequent downstream immune signaling.
STENOFOLIA Recruits TOPLESS to RepressASYMMETRIC LEAVES2at the Leaf Margin and Promote Leaf Blade Outgrowth inMedicago truncatula
Authors: Zhang Fei , Wang Yewei , Li Guifen , Tang Yuhong , Kramer Elena M. , Tadege Million 
Published: March 2014

AbstractThe Medicago truncatula WUSCHEL-related homeobox (WOX) gene, STENOFOLIA (STF), plays a key role in leaf blade outgrowth by promoting cell proliferation at the adaxial-abaxial junction. STF functions primarily as a transcriptional repressor, but the underlying molecular mechanism is unknown. Here, we report the identification of a protein interaction partner and a direct target, shedding light on the mechanism of STF function. Two highly conserved motifs in the C-terminal domain of STF, the WUSCHEL (WUS) box and the STF box, cooperatively recruit TOPLESS (Mt-TPL) family corepressors, and this recruitment is required for STF function, as deletion of these two domains (STFdel) impaired blade outgrowth whereas fusing Mt-TPL to STFdel restored function. The homeodomain motif is required for direct repression of ASYMMETRIC LEAVES2 (Mt-AS2), silencing of which partially rescues the stf mutant phenotype. STF and LAMINALESS1 (LAM1) are functional orthologs. A single amino acid (Asn to Ile) substitution in the homeodomain abolished the repression of Mt-AS2 and STF's ability to complement the lam1 mutant of Nicotiana sylvestris. Our data together support a model in which STF recruits corepressors to transcriptionally repress its targets during leaf blade morphogenesis. We propose that recruitment of TPL/TPL-related proteins may be a common mechanism in the repressive function of modern/WUS clade WOX genes.
RAP, the Sole Octotricopeptide Repeat Protein in Arabidopsis, Is Required for Chloroplast 16S rRNA Maturation
Authors: Kleinknecht Laura , Wang Fei , Stübe Roland , Philippar Katrin , Nickelsen Jörg , Bohne Alexandra-Viola 
Published: March 2014

Abstract
The biogenesis and activity of chloroplasts in both vascular plants and algae depends on an intracellular network of nucleus-encoded, trans-acting factors that control almost all aspects of organellar gene expression. Most of these regulatory factors belong to the helical repeat protein superfamily, which includes tetratricopeptide repeat, pentatricopeptide repeat, and the recently identified octotricopeptide repeat (OPR) proteins. Whereas green algae express many different OPR proteins, only a single orthologous OPR protein is encoded in the genomes of most land plants. Here, we report the characterization of the only OPR protein in Arabidopsis thaliana, RAP, which has previously been implicated in plant pathogen defense. Loss of RAP led to a severe defect in processing of chloroplast 16S rRNA resulting in impaired chloroplast translation and photosynthesis. In vitro RNA binding and RNase protection assays revealed that RAP has an intrinsic and specific RNA binding capacity, and the RAP binding site was mapped to the 5′ region of the 16S rRNA precursor. Nucleoid localization of RAP was shown by transient green fluorescent protein import assays, implicating the nucleoid as the site of chloroplast rRNA processing. Taken together, our data indicate that the single OPR protein in Arabidopsis is important for a basic process of chloroplast biogenesis.
Time buying and time saving: effects on service convenience and the shopping experience at the mall
Authors: Elizabeth Lloyd Alison , Y.K. Chan Ricky , S.C. Yip Leslie , Chan Andrew 
Published: March 2014

Purpose
– The domain of service convenience remains relatively unexplored. However, as time pervades all aspects of consumption, the value placed on time is likely to influence the importance of convenience. Prior studies call for the investigation of convenience beyond the store context; and malls being a one-stop shopping destination, present an ideal environment for investigation.

Design/methodology/approach
– A conceptual model delineating the relationships between service convenience, shopping trip value, customer satisfaction and several retail outcomes is developed. This model is empirically tested using survey data collected from 619 mall shoppers; and analyzed using structural equation modelling.

Findings
– For shoppers who place high economic value on time, the effects of service convenience are greater on hedonic value. Conversely, those who place low economic value on time, effects of service convenience are greater on utilitarian value. Effects of shopping value on retail outcomes also vary according to value placed on time.

Research limitations/implications
– Further investigation utilizing full convenience scale and more elaborate time style measures encouraged.

Practical implications
– Results signal the importance of enhancing the experiential aspects of the mall for high economic time value shoppers. Conversely, for low economic time value shoppers, findings suggest the importance of boosting the visual distinctiveness and ease of mall navigation.

Originality/value
– This study sheds light on research gaps by examining the link between service convenience and its effects on retail evaluation in the mall. It also considers how the economic value placed on time impact perceptions of convenience and the shopping experience.
High glucose improves healing of periodontal wound by inhibiting proliferation and osteogenetic differentiation of human PDL cells
Authors: Li Min , Li Cheng‐Zhang 
Published: March 2014

AbstractPeriodontal ligament (PDL) cells play an important role in wound healing of periodontal tissues. Response of PDL cells' cellular activity to high‐glucose concentration levels may be the key in understanding the relationship between periodontal disease and diabetes mellitus. We studied the effect of high‐glucose medium on proliferation of PDL cells in vitro. PDL cells were cultured for 1, 4, 7, 10, 14 and 17 days in normal (1100 mg/l) glucose or in high (4500 mg/l) glucose medium. The 3‐(4,5‐dimethylithiazol‐2‐yl)‐2,5‐diphenyl tetrazolium bromide (MTT) assay for proliferation was performed. In order to evaluate the osteogenetic differentiation of human PDL cells, the cells were induced with normal‐ or high‐glucose medium for 1, 7, 14, 21 and 28 days. The results indicated that high glucose significantly inhibited proliferation of PDL cells. Concerning the mineralised nodule formation, the percentage of calcified area to total culture dish of PDL cells in high glucose level was lower than that in normal glucose medium. The increase in alkaline phosphatase activity and collagen expression could be observed in high‐glucose‐containing osteogenetic factor. In conclusion, high glucose improves healing of periodontal wound by inhibiting proliferation and differentiation of PDL cells, which could explain for delayed periodontal regeneration and healing in diabetic patients.
The use of keratin‐based wound products on refractory wounds
Authors: Batzer Annette T , Marsh Clive , Kirsner Robert S 
Published: March 2014

AbstractKeratin proteins have been shown to play a key role in wound healing. Controlled keratin gene (KRT) expression promotes cell growth, migration and differentiation, and as an example of the importance of keratin proteins, absence of KRT17 has been shown to delay wound closure. In addition, downregulation of KRT6 and KRT16 in non‐healing chronic venous ulcers suggests that deregulation of keratin expression contributes to non‐healing phenotype. A sample of 45 chronic wounds of mixed aetiologies presenting in 31 patients were treated with keratin‐based novel topical wound healing products. Thirty‐seven wounds or 82% of wounds were either healed or reduced in size of >50% during treatment, with 29 (64%) healing completely and an additional 8 wounds experiencing 50% wound size reduction or greater. Of the wounds that responded, 15 required antimicrobial treatment during their course of treatment, suggesting that keratin dressing treatment should be interrupted briefly and then restarted when wound infection occur.
Brain imaging of affective disorders and schizophrenia
Authors: KISHIMOTO H. , YAMADA K. , ISEKI E. , KOSAKA K. , OKOSHI T. 
Published: March 2014

AbstractWe review recent findings in human brain imaging, for example, which brain areas are used during perception of colors, moving objects, human faces, facial expressions, sadness and happiness etc. One study used fluorine‐18‐labeled deoxyglucose positron emission tomography (PET) in patients with unipolar depression and bipolar depression, and found hypometabolism in the left anterolateral prefrontal cortex. Another study reported increased regional cerebral blood flow in the amygdala in familial pure depressive disease. Using 11C‐glucose PET, we reported that the glutamic acid pool was reduced in cortical areas of the brain in patients with major depression. We also found that the thalamic and cingulate areas were hyperactive in drug‐naive (never medicated) acute schizophrenics, while the associative frontal, parietal, temporal gyri were hypoactive in drug‐naive chronic schizophrenics. Drain biochemical disturbances of schizophrenic patients involved glutamic acid, N‐acetyl aspartic acid, phosphatidylcholine and sphingomyelin which are important chemical substances in the working brain. The areas of the thalamus and the cingulate which become hyperactive in acute schizophrenic patients are important brain areas for perception and communication. The association areas of the cortex which become disturbed in chronic schizophrenia are essential brain areas in human creativity (language, concepts, formation of cultures and societies) and exist only in human beings.
Post‐traumatic stress disorder in Asian refugees
Authors: TON‐THAT NIEM 
Published: March 2014

AbstractThis study profiles 127 cases of Vietnamese, Cambodian, Laotian and Chinese refugee outpatients diagnosed with post‐traumatic stress disorder (PTSD). Traumatic etiologies included victims of wars such as political refugees, concentration camp prisoners and victims of rape, severe personal losses (property or human lives). These traumata were experienced by our subjects during the period between the end of the Vietnam war in April 1975 and recent times, when they finally arrived in the USA. Clinical symptoms of these subjects reflected many influences of their oriental culture background and are characterized by internalization that needs to be overcome for assessment as well as for therapy. Symptomatic treatment with psychopharmacology and supportive therapy are helpful while cultural approaches have been adopted by many patients to reach the inner self pathology that could be of both mental and organic in nature. These facts need to be taken into consideration in the future description of the PTSD clinical picture. Recommendations are made for future PTSD studies in Vietnam, Cambodia and Laos, and to promote a global movement for prevention of any socio‐political situation that may generate PTSD.
Population displacement after the 2007 floods in Kingston upon Hull, England
Authors: Milojevic A. , Kovats S. , Leonardi G. , Murray V. , Nye M. , Wilkinson P. 
Published: March 2014

AbstractFlooding can result in the temporary or permanent displacement of affected populations from their homes. This displacement is not only an important factor determining health and social impacts, but it also has bearing on the monitoring of such impacts. We present descriptive analyses of data from the 2007 floods of Kingston‐upon‐Hull, UK, which quantify the frequency, timing and duration of household displacements. Very high proportions (59%) of flooded households were displaced, though many displacements did not begin until several months after flooding. Twelve per cent of displaced households remained out of their homes for longer than a year, a further 5% for more than 2 years. These figures suggest that linkages between a flood incident, flood impacts and then recovery might not always follow a neat linear progression, which has important implications for epidemiological research design as well as flood risk management plans. This is the first reported investigation on population displacement after the flood event in the UK.
Environmental Dependence of Stationary-Phase Metabolism in Bacillus subtilis and Escherichia coli
Authors: Chubukov Victor , Sauer Uwe 
Published: March 2014

ABSTRACT

When microbes lack the nutrients necessary for growth, they enter stationary phase. In cases when energy sources are still present in the environment, they must decide whether to continue to use their metabolic program to harvest the available energy. Here we characterized the metabolic response to a variety of types of nutrient starvation in
Escherichia coli
and
Bacillus subtilis
. We found that
E. coli
exhibits a range of phenotypes, with the lowest metabolic rates under nitrogen starvation and highest rates under magnesium starvation. In contrast, the phenotype of
B. subtilis
was dominated by its decision to form metabolically inactive endospores. While its metabolic rates under most conditions were thus lower than those of
E. coli
, when sporulation was suppressed by a genetic perturbation or an unnatural starvation condition, the situation was reversed. To further probe stationary-phase metabolism, we used quantitative metabolomics to investigate possible small-molecule signals that may regulate the metabolic rate of
E. coli
and initiate sporulation in
B. subtilis
. We hypothesize a role for phosphoenolpyruvate (PEP) in regulating
E. coli
glucose uptake and for the redox cofactors NAD(H) and NADP(H) in initiation of sporulation. Our work is directly relevant to synthetic biology and metabolic engineering, where active metabolism during stationary phase, which uncouples production from growth, remains an elusive goal.
Altered Transcription of Murine Genes Induced in the Small Bowel by Administration of Probiotic Strain Lactobacillus rhamnosus HN001
Authors: Tannock Gerald W. , Taylor Corinda , Lawley Blair , Loach Diane , Gould Maree , Dunn Amy C. , McLellan Alexander D. , Black Michael A. , McNoe Les , Dekker James , Gopal Pramod , Collett Michael A. 
Published: March 2014

ABSTRACTLactobacillus rhamnosusHN001 is a probiotic strain reported to increase resistance to epithelium-adherent and -invasive intestinal pathogens in experimental animals. To increase understanding of the relationship between strain HN001 and the bowel, transcription of selected genes in the mucosa of the murine small bowel was measured. Mice previously naive to lactobacilli (Lactobacillus-free mice) were examined after daily exposure to HN001 in drinking water. Comparisons were made to results from matchedLactobacillus-free mice. Infant and adult mice were investigated to provide a temporal view of gene expression in response to exposure to HN001. Genessgk1,angptl4, andhspa1b, associated with the apoptosis pathway, were selected for investigation by reverse transcription-quantitative PCR on the basis of a preliminary duodenal DNA microarray screen. Normalized togapdhgene transcription, these three genes were upregulated after 6 to 10 days exposure of adult mice to HN001. Angptl4 was shown by immunofluorescence to be upregulated in duodenal epithelial cells of mucosal samples. Epithelial cell migration was faster in HN001-exposed mice than in theLactobacillus-free controls. Transcriptional responses in infant mice differed according to bowel region and age. For example,sgk1was upregulated in duodenal, jejunal, and ileal mucosa of mice less than 25 days old, whereasangptl4andhspa1bwere upregulated at 10 days in the duodenum but downregulated in the jejunal mucosa until mice were 25 days old. Overall, the results provide links between a probiotic strain, mucosal gene expression, and host phenotype, which may be useful in delineating mechanisms of probiotic action.
The Iron Stimulon and Fur Regulon of Geobacter sulfurreducens and Their Role in Energy Metabolism
Authors: Embree Mallory , Qiu Yu , Shieu Wendy , Nagarajan Harish , O'Neil Regina , Lovley Derek , Zengler Karsten 
Published: March 2014

ABSTRACT

Iron plays a critical role in the physiology of
Geobacter
species. It serves as both an essential component for proteins and cofactors and an electron acceptor during anaerobic respiration. Here, we investigated the iron stimulon and ferric uptake regulator (Fur) regulon of
Geobacter sulfurreducens
to examine the coordination between uptake of Fe(II) and the reduction of Fe(III) at the transcriptional level. Gene expression studies across a variety of different iron concentrations in both the wild type and a Δ
fur
mutant strain were used to determine the iron stimulon. The stimulon consists of a broad range of gene products, ranging from iron-utilizing to central metabolism and iron reduction proteins. Integration of gene expression and chromatin immunoprecipitation (ChIP) data sets assisted in the identification of the Fur transcriptional regulatory network and Fur's role as a regulator of the iron stimulon. Additional physiological and transcriptional analyses of
G. sulfurreducens
grown with various Fe(II) concentrations revealed the depth of Fur's involvement in energy metabolism and the existence of redundancy within the iron-regulatory network represented by IdeR, an alternative iron transcriptional regulator. These characteristics enable
G. sulfurreducens
to thrive in environments with fluctuating iron concentrations by providing it with a robust mechanism to maintain tight and deliberate control over intracellular iron homeostasis.