bluuebunny/crossref_metadata_2025_split huggingface dataset:
Temporal and shrub adaptation effect on soil microbial functional diversity in a desert system
Authors: Saul‐Tcherkas V. , Steinberger Y. 
Published: July 2009

SummaryThe Negev Desert is characterized by spatial and temporal patterns of resource distribution, in which soil biota are considered to be among the most sensitive biological characteristics, easily influenced by changes related to soil and abiotic factors. Soil water availability and organic matter are among the most important factors, acting as triggers that determine the length of the period of activity. The main source of organic matter in this xeric environment is input from annual and perennial shrubs. In order to persist and propagate in this xeric environment, the plants have developed different ecophysiological adaptations (e.g. the excretion of salt (Reaumuria negevensis) and chemical compounds (Artemisia sieberi) via the leaves). We found that the values of soil moisture obtained for soil samples collected in the vicinity of R. negevensis were larger than for samples collected in the vicinity of Noaea mucronata and A. sieberi and in the open area. The maximum values of CO2 evolution, microbial biomass and Shannon index (H′) were obtained for the samples collected from the vicinity of N. mucronata. Therefore, we assume that the vicinity of N. mucronata afforded the best conditions for the soil bacterial community. In the Negev Desert, we also found that water availability and pulses of rain compared with frequent rainfall influenced CO2 evolution, microbial biomass, qCO2 and the Shannon index (H′). The differences in water amount and availability between the two rainy seasons caused larger values in most of the properties during the first four seasons (December 2005–November 2006) compared with the last four seasons (December 2006–November 2007) for most of the samples.
Effects of culture, social presence, and group composition on trust in technology‐supported decision‐making groups
Authors: Lowry Paul Benjamin , Zhang Dongsong , Zhou Lina , Fu Xiaolan 
Published: July 2009

AbstractThis study examines trust in technology‐supported groups from the perspectives of culture, social presence and group composition. Our results demonstrate that, in culturally homogeneous groups, individualism has a negative impact on the level of interpersonal trust; however, in culturally heterogeneous groups consisting of Chinese and U.S. participants, individualism has a positive impact on interpersonal trust among members. There were also significant differences in the level of trust between homogeneous Chinese groups and heterogeneous groups consisting of Chinese and U.S. participants. In addition, the mediating role of communication quality was identified to explain the effect for trust‐of social presence on trust. These findings have important implications on building and communication in global technology‐supported decision‐making groups.
Spatio‐temporal structure of multi‐storied, multi‐aged interior Douglas fir (Pseudotsuga menziesiivar.glauca) stands
Authors: LeMay Valerie , Pommerening Arne , Marshall Peter 
Published: July 2009

Summary1. We used replicated, repeated‐measures data to examine the spatio‐temporal structure of multi‐storied, multi‐aged interior Douglas fir (Pseudotsuga menziesiivarglauca(Mirb.) Franco) stands growing on dry sites under more than 50 years of fire protection. Along with the univariate and bivariate Ripley’sKand related functions, we used a random coefficients mixed model to investigate the variation in these functions over replicates and time.2. The spatio‐temporal analyses revealed that trees greater than 1.3 m in height were clustered over space, and clustering was more evident for small trees (i.e. diameter at breast height (d.b.h.) ≤ 7.0 cm).3. Bivariate functions indicated that small trees were spatially aggregated with large trees, indicating higher germination success and early survival near large trees. For these dry sites, moisture is more limiting than light and large trees provide moister microsites.4. Dead trees were clustered, more commonly smaller in size and aggregated near large trees, indicating competition for moisture.5. For the 16‐year period of the study, there was very little evidence that the spatio‐temporal patterns changed from a clustered to a more regular arrangement over time, unlike evidence from studies in other forest types.6. Using the random coefficients mixed model approach, the majority of spatio‐temporal variation was due to differences among replicates, with little variation over time.7. Under fire protection, interior Douglas fir stands on dry sites might be expected to have lower mortality but any increase in density will be limited by moisture availability. Since interior Douglas fir is moderately shade‐tolerant, this may result in an approach to a steady state of regeneration and death over the long term.8.Synthesis. Spatio‐temporal analysis using replicated, repeated‐measures data, including a random coeffcieints mixed model approach, gave useful insights into mortality and recruitment in multi‐storied and multi‐aged stands. Similar patterns might be expected in other naturally occurring multi‐storied and multi‐aged stands. The use of replicated, repeated‐measures data rather than chronosequence data allows for the examination of true changes in spatial patterns over time.
Waiting for fungi: the ectomycorrhizal invasion of lowland heathlands
Authors: Collier Fay A. , Bidartondo Martin I. 
Published: July 2009

Summary 1. In England, the loss of lowland heathland, a habitat of global conservation importance, is primarily due to the invasion of birch and pine. This encroachment has been researched in depth from a plant perspective but little is known about the role of mycorrhizal fungi. In lowland heathlands the resident dwarf shrubs form ericoid mycorrhizas whereas invading trees form ectomycorrhizas. Therefore, tree encroachment into heathlands can be regarded as the replacement of a resident mycorrhizal community by an invading one. 2. This study examined how fungi form mycorrhizas with Betula and Pinus in lowland heathlands. We addressed the question of whether there are mycorrhizal fungi that mediate invasion using a molecular ecology approach to compare the mycorrhizal inoculum potential of soil at three levels of invasion (uninvaded heathland, invaded heathland and woodland) and the fungi forming mycorrhizas on tree seedlings and trees across diverse sites. 3. We show that in lowland heathlands: (i) seedlings have severely limited access to ectomycorrhizal fungi relative to woodlands, (ii) there are few keystone spore‐dispersed ectomycorrhizal fungi that can mediate tree invasion, (iii) tree seedlings can remain non‐mycorrhizal for at least one year when no inoculum is present, even near saplings, and (iv) mycorrhizal seedlings achieve greater biomass than non‐mycorrhizal seedlings. Within uninvaded heathland we detected only Rhizopogon luteolus, Suillus variegatus, S. bovinus (Pinus symbionts) and Laccaria proxima (primarily a Betula symbiont). 4.
Synthesis. Overall, ectomycorrhizal inoculum in lowland heathlands is rare; most tree seedlings growing in heathland soil are not mycorrhizal due to limited spore dispersal, poorly developed spore banks and weak common mycorrhizal networks. These seedlings can persist awaiting mycorrhization to boost their growth.
Mutational analyses of HAMP helices suggest a dynamic bundle model of input–output signalling in chemoreceptors
Authors: Zhou Qin , Ames Peter , Parkinson John S. 
Published: July 2009

SummaryTo test the gearbox model of HAMP signalling in the Escherichia coli serine receptor, Tsr, we generated a series of amino acid replacements at each residue of the AS1 and AS2 helices. The residues most critical for Tsr function defined hydrophobic packing faces consistent with a four‐helix bundle. Suppression patterns of helix lesions conformed to the predicted packing layers in the bundle. Although the properties and patterns of most AS1 and AS2 lesions were consistent with both proposed gearbox structures, some mutational features specifically indicate the functional importance of an x‐da bundle over an alternative a‐d bundle. These genetic data suggest that HAMP signalling could simply involve changes in the stability of its x‐da bundle. We propose that Tsr HAMP controls output signals by modulating destabilizing phase clashes between the AS2 helices and the adjoining kinase control helices. Our model further proposes that chemoeffectors regulate HAMP bundle stability through a control cable connection between the transmembrane segments and AS1 helices. Attractant stimuli, which cause inward piston displacements in chemoreceptors, should reduce cable tension, thereby stabilizing the HAMP bundle. This study shows how transmembrane signalling and HAMP input–output control could occur without the helix rotations central to the gearbox model.
Comprehensive mutational analysis of BRCA1/BRCA2 for Korean breast cancer patients: evidence of a founder mutation
Authors: Seong M‐W , Cho SI , Noh D‐Y , Han W , Kim S‐W , Park C‐M , Park H‐W , Kim SY , Kim JY , Park SS 
Published: July 2009

The BRCA1 and BRCA2 genes are the strongest susceptibility genes identified for breast cancer worldwide. However, BRCA1/BRCA2 have been incompletely investigated due to their large size and the genomic rearrangements that occasionally occur within them. Here we performed a comprehensive mutational analysis for BRCA1/BRCA2 in 206 Korean patients with breast cancer.We analyzed all exons and flanking regions of BRCA1/BRCA2 by direct sequencing and screened deletions or duplications involving BRCA1/BRCA2 by multiplex ligation‐dependent probe amplification. We reconstructed haplotypes using intragenic single nucleotide polymorphisms (SNPs) to investigate the possibility of a founder effect among recurrent mutations. In our series, 38 patients (18.4%) had one or more BRCA1/BRCA2 mutations including 10 novel ones. Three additional patients carried novel distinct unclassified variants with potentially harmful effects. No large deletions or duplications involving BRCA1/BRCA2 were identified in our series. Haplotype analyses and allele separation suggested that the most frequent mutation in Koreans, BRCA2:c.7480C>T, might have originated from a common ancestor. BRCA1/BRCA2 mutations were more frequent in a group with family history, bilateral cancer or multiple site cancer than in a group without the risk factors described or an unknown risk group. In contrast, mutation frequencies in the early‐onset cancer group were not higher than in the unknown risk group.Our results will be helpful to understand the mutation spectrum in BRCA1/BRCA2 genes and establish a genetic screening strategy. In addition, this study suggests the possibility of the first true founder mutation of BRCA1/BRCA2 identified in the Korean population.
NR2B subunit‐dependent long‐term potentiation enhancement in the rat cortical auditory system in vivo following masking of patterned auditory input by white noise exposure during early postnatal life
Authors: Hogsden Jennifer L. , Dringenberg Hans C. 
Published: July 2009

AbstractThe composition of N‐methyl‐d‐aspartate (NMDA) receptor subunits influences the degree of synaptic plasticity expressed during development and into adulthood. Here, we show that theta‐burst stimulation of the medial geniculate nucleus reliably induced NMDA receptor‐dependent long‐term potentiation (LTP) of field postsynaptic potentials recorded in the primary auditory cortex (A1) of urethane‐anesthetized rats. Furthermore, substantially greater levels of LTP were elicited in juvenile animals (30–37 days old; ∼55% maximal potentiation) than in adult animals (∼30% potentiation). Masking patterned sound via continuous white noise exposure during early postnatal life (from postnatal day 5 to postnatal day 50–60) resulted in enhanced, juvenile‐like levels of LTP (∼70% maximal potentiation) relative to age‐matched controls reared in unaltered acoustic environments (∼30%). Rats reared in white noise and then placed in unaltered acoustic environments for 40–50 days showed levels of LTP comparable to those of adult controls, indicating that white noise rearing results in a form of developmental arrest that can be overcome by subsequent patterned sound exposure. We explored the mechanisms mediating white noise‐induced plasticity enhancements by local NR2B subunit antagonist application in A1. NR2B subunit antagonists (Ro 25‐6981 or ifenprodil) completely reversed white noise‐induced LTP enhancement at concentrations that did not affect LTP in adult or age‐matched controls. We conclude that white noise exposure during early postnatal life results in the maintenance of juvenile‐like, higher levels of plasticity in A1, an effect that appears to be critically dependent on NR2B subunit activation.
In the ear of the beholder: neural correlates of adaptation to voice gender
Authors: Zäske Romi , Schweinberger Stefan R. , Kaufmann Jürgen M. , Kawahara Hideki 
Published: July 2009

AbstractWhile high‐level adaptation to faces has been extensively investigated, research on behavioural and neural correlates of auditory adaptation to paralinguistic social information in voices has been largely neglected. Here we replicate novel findings that adaptation to voice gender causes systematic contrastive aftereffects such that repeated exposure to female voice adaptors causes a subsequent test voice to be perceived as more male (and vice versa), even minutes after adaptation [S.R. Schweinberger et al., (2008), Current Biology, 18, 684–688). In addition, we recorded event‐related potentials to test‐voices morphed along a gender continuum. An attenuation in frontocentral N1–P2 amplitudes was seen when a test voice was preceded by gender‐congruent voice adaptors. Additionally, similar amplitude attenuations were seen in a late parietal positive component (P3, 300–700 ms). These findings suggest that contrastive coding of voice gender takes place within the first few hundred milliseconds from voice onset, and is implemented by neurons in auditory areas that are specialised for detecting male and female voice quality.
Tonically active neurons in the striatum differentiate between delivery and omission of expected reward in a probabilistic task context
Authors: Apicella Paul , Deffains Marc , Ravel Sabrina , Legallet Eric 
Published: July 2009

AbstractTonically active neurons (TANs) in the primate striatum are responsive to rewarding stimuli and they are thought to be involved in the storage of stimulus–reward associations or habits. However, it is unclear whether these neurons may signal the difference between the prediction of reward and its actual outcome as a possible neuronal correlate of reward prediction errors at the striatal level. To address this question, we studied the activity of TANs from three monkeys trained in a classical conditioning task in which a liquid reward was preceded by a visual stimulus and reward probability was systematically varied between blocks of trials. The monkeys’ ability to discriminate the conditions according to probability was assessed by monitoring their mouth movements during the stimulus–reward interval. We found that the typical TAN pause responses to the delivery of reward were markedly enhanced as the probability of reward decreased, whereas responses to the predictive stimulus were somewhat stronger for high reward probability. In addition, TAN responses to the omission of reward consisted of either decreases or increases in activity that became stronger with increasing reward probability. It therefore appears that one group of neurons differentially responded to reward delivery and reward omission with changes in activity into opposite directions, while another group responded in the same direction. These data indicate that only a subset of TANs could detect the extent to which reward occurs differently than predicted, thus contributing to the encoding of positive and negative reward prediction errors that is relevant to reinforcement learning.
Subcutaneous and visceral adipose tissue: structural and functional differences
Authors: Ibrahim M. Mohsen 
Published: July 2009

SummaryObesity is a heterogeneous disorder. Obese individuals vary in their body fat distribution, their metabolic profile and degree of associated cardiovascular and metabolic risk. Abdominal obesity carries greater risk of developing diabetes and future cardiovascular events than peripheral or gluteofemoral obesity. There are differences between adipose tissue present in subcutaneous areas (SCAT) and visceral adipose tissue (VAT) present in the abdominal cavity. These include anatomical, cellular, molecular, physiological, clinical and prognostic differences. Anatomically, VAT is present mainly in the mesentery and omentum, and drains directly through the portal circulaion to the liver. VAT compared with SCAT is more cellular, vascular, innervated and contains a larger number of inflammatory and immune cells, lesser preadipocyte differentiating capacity and a greater percentage of large adipocytes. There are more glucocorticoid and androgen receptors in VAT than in SCAT. VAT adipocytes are more metabolically active, more sensitive to lipolysis and more insulin‐resistant than SCAT adipocytes. VAT has a greater capacity to generate free fatty acids and to uptake glucose than SCAT and is more sensitive to adrenergic stimulation, while SCAT is more avid in absorption of circulating free fatty acids and triglycerides. VAT carries a greater prediction of mortality than SCAT.
Prevalence of obesity in Thailand
Authors: Aekplakorn W. , Mo‐suwan L. 
Published: July 2009

SummaryThe prevalence of obesity in Thailand has been doubled in the past two decades. Data from three consecutive National Health examination surveys (NHES) have shown a secular trend, as the prevalence of obesity with body mass index ≥25 kg m−2 in adults increased from 13.0% in men and 23.2% in women in 1991 to 18.6% and 29.5% in 1997 and 22.4% and 34.3% in 2004 respectively. Obesity prevalence in children, using weight for height criteria, increased from 5.8% in 1997 to 7.9% in 2001 for the 2–5‐year‐olds and from 5.8% to 6.7% for the 6–12‐year‐olds. The data also show disproportionate increases of obesity in the rural area, which indicates the problem no longer restricts to the higher socioeconomic group.
Induction of labour in nulliparous women with an unfavourable cervix: a randomised controlled trial comparing double and single balloon catheters and PGE2 gel
Authors: Pennell CE , Henderson JJ , O’Neill MJ , McCleery S , Doherty DA , Dickinson JE 
Published: July 2009

Objective  To compare the efficacy and patient satisfaction of three methods of labour induction (double balloon catheters, single balloon catheters and prostaglandin gel) in term nulliparous women with unfavourable cervices.Design  Randomised controlled trial.Population  A total of 330 nulliparous women with unfavourable cervices induced at term.Methods  Three cervical ripening study arms were used: double balloon catheter (107 women); 16F Foley catheter (110 women) and PGE2 gel (2 mg) (113 women).Main outcome measures  Caesarean section, induction to delivery interval, adverse reactions and patient satisfaction.Results  There was no difference in caesarean delivery rates between groups (double balloon 43%, single balloon 36%, PGE2 37%, P = 0.567). The induction to delivery interval was longer in the double balloon group (median 24.5; 95% CI 23.7, 30.6 hours) than the single balloon (23.2; 20.8, 25.8 hours) or PGE2 (23.8; 21.7, 26.8 hours) (P = 0.043). Uterine hyperstimulation occurred in 14% of the PGE2 group with none occurring with mechanical cervical ripening. Cord blood gases were worse in the PGE2 group: median arterial pH double balloon 7.26 (range 7.03–7.40); single balloon 7.26 (7.05–7.44); PGE2 7.25 (6.91–7.41) (P = 0.050). Cervical ripening with the single balloon catheter was associated with significantly less pain (pain score ≥4: double balloon 55%, single balloon 36%, PGE2 63%, P < 0.001).Conclusions  Labour induction in nullipara with unfavourable cervices results in high caesarean delivery rates. Although all methods in this study had similar efficacy, the single balloon catheter offers the best combination of safety and patient comfort.
Surgery for menorrhagia within English regions: variation in rates of endometrial ablation and hysterectomy
Authors: Cromwell DA , Mahmood TA , Templeton A , van der Meulen JH 
Published: July 2009

Objective  To examine variation between English regions in the use of surgery (endometrial ablation or hysterectomy) for the treatment of menorrhagia.Design  Analysis of Hospital Episodes Statistics (HES) data to produce rates of surgery for English Strategic Health Authorities (SHAs) and Primary Care Trusts (PCTs).Population  Women aged between 25 and 59 years who had endometrial ablation or hysterectomy for menorrhagia between April 2003 and March 2006 in English NHS hospitals.Methods  Multilevel Poisson regression was used to determine the level of systematic variation in the regional rates of surgery and their association with regional characteristics (deprivation, service provision and mix of surgical procedures).Main outcome measure  Age‐standardised annual rates of surgery.Results  The English rate of surgery for menorrhagia was 143 procedures per 100 000 women. Surgical rates within SHAs ranged from 52 to 230 procedures per 100 000 women, while rates within PCTs ranged from 20 to 420 procedures per 100 000 women. While, 60% of all procedures were endometrial ablations, the proportion across SHAs varied, ranging from 46% to 75%. Surgery rates were associated with the regional characteristics, but only weakly, and risk adjustment reduced the amount of unexplained variation by <15% at both SHA and PCT levels.Conclusion  Regional differences in surgical rates for menorrhagia have persisted despite changes in practice and improved evidence, suggesting there is scope for improving the management of menorrhagia within England.
Garnet‐filled trails associated with carbonaceous matter mimicking microbial filaments in Archean basalt
Authors: LEPOT K. , PHILIPPOT P. , BENZERARA K. , WANG G.‐Y. 
Published: July 2009

AbstractThe study of the earliest traces of life on Earth can be complicated by abiotically formed biomorphs. We report here the finding of clustered micrometer‐sized filaments of iron‐ and calcium‐rich garnets associated with carbonaceous matter in an agate amygdale from a 2.7‐billion‐year‐old basalt of the Maddina Formation, Western Australia. The distribution of carbonaceous matter and the mineral phases composing the filaments were analyzed using a combination of confocal laser scanning microscopy, laser‐Raman micro‐spectroscopy, focused ion beam sectioning and transmission electron microscopy. The results allow consideration of possible biogenic and abiotic processes that produced the filamentous structures. The filaments have a range of sizes, morphologies and distributions similar to those of certain modern iron‐mineralized filamentous bacteria and some ancient filamentous structures interpreted as microfossils. They also share a high morphological similarity with tubular structures produced by microbial boring activity. However, the microstructures and the distribution of carbonaceous matter are more suggestive of an abiotic origin for the filaments. They are characteristic features of trails produced by the displacement of inclusions associated with local dissolution of their silica matrix. Organic compounds found in kerogen or bitumen inclusions may have contributed significantly to the dissolution of the quartz (or silica gel) matrix driving filamentous growth. Discriminating the products of such abiotic organic‐mediated processes from filamentous microfossils or microbial borings is important to the interpretation of the scarce Precambrian fossil record and requires investigation down to the nanoscale.