bluuebunny/crossref_metadata_2025 huggingface dataset:
Formyl peptide receptors are candidate chemosensory receptors in the vomeronasal organ
Authors: Liberles Stephen D. , Horowitz Lisa F. , Kuang Donghui , Contos James J. , Wilson Kathleen L. , Siltberg-Liberles Jessica , Liberles David A. , Buck Linda B.
Published: June 2009

The identification of receptors that detect environmental stimuli lays a foundation for exploring the mechanisms and neural circuits underlying sensation. The mouse vomeronasal organ (VNO), which detects pheromones and other semiochemicals, has 2 known families of chemoreceptors, V1Rs and V2Rs. Here, we report a third family of mouse VNO receptors comprising 5 of 7 members of the formyl peptide receptor (FPR) family. Unlike other FPRs, which function in the immune system, these FPRs are selectively expressed in VNO neurons in patterns strikingly similar to those of V1Rs and V2Rs. Each FPR is expressed in a different small subset of neurons that are highly dispersed in the neuroepithelium, consistently coexpress either Gα
i2
or Gα
o
, and lack other chemoreceptors examined. Given the presence of formylated peptides in bacteria and mitochondria, possible roles for VNO FPRs include the assessment of conspecifics or other species based on variations in normal bacterial flora or mitochondrial proteins.
Functional computational model for optimal color coding
Authors: Romney A. Kimball , Chiao Chuan-Chin
Published: June 2009

This paper presents a computational model for color coding that provides a functional explanation of how humans perceive colors in a homogeneous color space. Beginning with known properties of human cone photoreceptors, the model estimates the locations of the reflectance spectra of Munsell color chips in perceptual color space as represented in the CIE L*a*b* color system. The fit between the two structures is within the limits of expected measurement error. Estimates of the structure of perceptual color space for color anomalous dichromats missing one of the normal cone photoreceptors correspond closely to results from the Farnsworth–Munsell color test. An unanticipated outcome of the model provides a functional explanation of why additive lights are always red, green, and blue and provide maximum gamut for color monitors and color television even though they do not correspond to human cone absorption spectra.
Mitotic control of kinetochore-associated dynein and spindle orientation by human Spindly
Authors: Chan Ying Wai , Fava Luca L. , Uldschmid Andreas , Schmitz Michael H.A. , Gerlich Daniel W. , Nigg Erich A. , Santamaria Anna
Published: June 2009

Mitotic spindle formation and chromosome segregation depend critically on kinetochore–microtubule (KT–MT) interactions. A new protein, termed Spindly in Drosophila and SPDL-1 in C. elegans, was recently shown to regulate KT localization of dynein, but depletion phenotypes revealed striking differences, suggesting evolutionarily diverse roles of mitotic dynein. By characterizing the function of Spindly in human cells, we identify specific functions for KT dynein. We show that localization of human Spindly (hSpindly) to KTs is controlled by the Rod/Zw10/Zwilch (RZZ) complex and Aurora B. hSpindly depletion results in reduced inter-KT tension, unstable KT fibers, an extensive prometaphase delay, and severe chromosome misalignment. Moreover, depletion of hSpindly induces a striking spindle rotation, which can be rescued by co-depletion of dynein. However, in contrast to Drosophila, hSpindly depletion does not abolish the removal of MAD2 and ZW10 from KTs. Collectively, our data reveal hSpindly-mediated dynein functions and highlight a critical role of KT dynein in spindle orientation.
Pediatric and NeonatalStaphylococcus aureusBacteremia Epidemiology, Risk Factors, and Outcome
Authors: Burke Robert E. , Halpern Meira S. , Baron Ellen Jo , Gutierrez Kathleen
Published: June 2009

Objective.

To evaluate the impact of methicillin-resistantStaphylococcus aureuson the prevalence ofS. aureusbloodstream infection among children.

Methods.

Retrospective analysis of demographic data, risk factors for infection, and clinical outcomes for children (age, less than 18 years) withS. aureusbacteremia hospitalized at a children's hospital during 2001–2006.

Results.

We identified 164 episodes ofS. aureusbacteremia among 151 children. The prevalence of bacteremia due to methicillin-susceptibleS. aureusduring 2001–2003 was approximately the same as that during 2004–2006 (29 and 30 cases, respectively, per 10,000 hospitalized children [hereafter, “per 10,000 hospitalizations”]), but the prevalence of bacteremia due to methicillin-resistantS. aureusincreased from 4 to 11 cases, respectively, per 10,000 hospitalizations (P= .015). A total of 48% of infections involved children who hadS. aureus-positive blood cultures less than 3 days after hospital admission. Seventy-four percent of these children had a preexisting comorbidity. When the prevalence ofS. aureusbacteremia was stratified by race, sex, or age, neonates hospitalized at birth and Hispanic children had significantly reduced risks of infection. Children younger than 1 year of age (excluding neonates hospitalized at birth) had an increased prevalence of hospital-onsetS. aureusbacteremia. There was a disproportionate increase in the risk ofS. aureusbacteremia for each additional week of hospitalization among children with hospital-onsetS. aureusbacteremia. Children with methicillin-resistantS. aureusbacteremia had a longer hospital stay, were transferred to another facility at a greater rate than they were discharged home, and had a greater mortality rate, compared with children with methicillin-susceptibleS. aureusbacteremia.

Conclusion.

This study documents the prevalence ofS. aureusbacteremia among children with a high risk for acquiring this infection, and it describes populations of children who are at higher risk for bacteremia due to either methicillin-susceptible or methicillin-resistantS. aureus. Methods to improve prevention ofS. aureusbacteremia are needed for children with healthcare-associated risk factors forS. aureusbacteremia.
Carbapenem Resistance Among Klebsiella pneumoniae Isolates Risk Factors, Molecular Characteristics, and Susceptibility Patterns
Authors: Hussein Khetam , Sprecher Hanna , Mashiach Tania , Oren Ilana , Kassis Imad , Finkelstein Renato
Published: June 2009

Background.

Carbapenem resistance among isolates of Klebsiella pneumoniae has been unusual.

Objectives.

To identify risk factors for infection with carbapenem-resistant K. pneumoniae (CRKP) and to characterize microbiological aspects of isolates associated with these infections.

Design.

Retrospective case-control study.

Setting.

A 900-bed tertiary care hospital.

Results.

From January 2006 through April 2007, K. pneumoniae was isolated from 461 inpatients; 88 had CRKP infection (case patients), whereas 373 had carbapenem-susceptible K. pneumoniae infection (control subjects). The independent risk factors for infection with CRKP were prior fluoroquinolone use (odds ratio [OR], 1.87 [95% confidence interval {CI}, 1.07–3.26]; P = .026), previous receipt of a carbapenem drug (OR, 1.83 [95% CI, 1.02–3.27]; P = .042), admission to the intensive care unit (OR, 4.27 [95% CI, 2.49–7.31]; P < .001), and exposure to at least 1 antibiotic drug before isolation of K. pneumoniae (OR, 3.93 [95% CI, 1.15–13.47]; P = .029). All CRKP isolates carried the blaKPC gene. Approximately 90% of the tested isolates carried the blaKPC-2 allele, suggesting patient-to-patient transmission. Almost all CRKP isolates were resistant to all antibiotics, except to Colistin (resistance rate, 4.5%), gentamicin (resistance rate, 7%), and tigecycline (resistance rate, 15%).

Conclusions.

CRKP should be regarded as an emerging clinical threat. Because these isolates are resistant to virtually all commonly used antibiotics, control of their spread is crucial.
Surveillance for Healthcare-Acquired Febrile Respiratory Infection in Pediatric Hospitals Participating in the Canadian Nosocomial Infection Surveillance Program
Authors: Vayalumkal Joseph V. , Gravel Denise , Moore Dorothy , Matlow Anne ,   Canadian Nosocomial Infection Surveillance Program
Published: June 2009

Objective.

To determine the rates of healthcare-acquired febrile respiratory infection (HA-FRI) in Canadian pediatric hospitals and to determine the vaccination status of patients with healthcare-acquired respiratory syncytial virus (RSV) infection, influenza, or pneumococcal infection who were also eligible for immunoprophylaxis.

Methods.

Prospective surveillance was conducted in 8 hospitals from January 1 to April 30, 2005. All hospitalized patients less than 18 years of age were eligible, except for patients housed in standard newborn nurseries or psychiatric units. Infection control professionals reviewed laboratory reports, conducted ward rounds, and reviewed medical records to identify case patients. Descriptive analyses were completed, as well.

Results.

A total of 96 case patients were identified; 52 (54%) were male, and 48 (50%) were aged 1 year or less. Seventy-two patients (75%) had chronic medical conditions. Respiratory viruses accounted for 72 (71%) of 101 pathogens identified, and RSV was the virus most frequently identified. Of these 96 patients, 9 (9%) died, and 3 (3%) of the deaths were related to the patient's HA-FRI. The mean incidence rate was 0.97 infections/1,000 patient-days (range, 0.29–1.50 infections/1,000 patient-days). Only 2 (15%) of 13 influenza vaccine-eligible children who acquired influenza while hospitalized were reported to have been vaccinated, but influenza vaccination status was unknown for most children. However, 4 (80%) of 5 RSV prophylaxis-eligible children who had healthcare-acquired RSV infection had received immunoprophylaxis with anti-RSV monoclonal antibody.

Conclusions.

HA-FRI is mainly caused by viruses such as RSV, and it primarily affects children under 1 year of age and those with chronic medical conditions.
Prevention of Central Venous Catheter-Associated Bloodstream Infections in Pediatric Intensive Care Units A Performance Improvement Collaborative
Authors: Jeffries Howard E. , Mason Wilbert , Brewer Melanie , Oakes Katie L. , Mufioz Esther I. , Gornick Wendi , Flowers Lee D. , Mullen Jodi E. , Gilliam Craig Harris , Fustar Stana , Thurm Cary W. , Logsdon Tina , Jarvis William R.
Published: June 2009

Objective.

The goal of this effort was to reduce central venous catheter (CVC)-associated bloodstream infections (BSIs) in pediatric intensive care unit (ICU) patients by means of a multicenter evidence-based intervention.

Methods.

An observational study was conducted in 26 freestanding children's hospitals with pediatric or cardiac ICUs that joined a Child Health Corporation of America collaborative. CVC-associated BSI protocols were implemented using a collaborative process that included catheter insertion and maintenance bundles, daily review of CVC necessity, and daily goals. The primary goal was either a 50% reduction in the CVC-associated BSI rate or a rate of 1.5 CVC-associated BSIs per 1,000 CVC-days in each ICU at the end of a 9-month improvement period. A 12-month sustain period followed the initial improvement period, with the primary goal of maintaining the improvements achieved.

Results.

The collaborative median CVC-associated BSI rate decreased from 6.3 CVC-associated BSIs per 1,000 CVC-days at the start of the collaborative to 4.3 CVC-associated BSIs per 1,000 CVC-days at the end of the collaborative. Sixty-five percent of all participants documented a decrease in their CVC-associated BSI rate. Sixty-nine CVC-associated BSIs were prevented across all teams, with an estimated cost avoidance of $2.9 million. Hospitals were able to sustain their improvements during a 12-month sustain period and prevent another 198 infections.

Conclusions.

We conclude that our collaborative quality improvement project demonstrated that significant reduction in CVC-associated BSI rates and related costs can be realized by means of evidence-based prevention interventions, enhanced communication among caregivers, standardization of CVC insertion and maintenance processes, enhanced measurement, and empowerment of team members to enforce adherence to best practices.
The Exosome Associates Cotranscriptionally with the Nascent Pre-mRNP through Interactions with Heterogeneous Nuclear Ribonucleoproteins
Authors: Hessle Viktoria , Björk Petra , Sokolowski Marcus , González de Valdivia Ernesto , Silverstein Rebecca , Artemenko Konstantin , Tyagi Anu , Maddalo Gianluca , Ilag Leopold , Helbig Roger , Zubarev Roman A. , Visa Neus
Published: June 2009

Eukaryotic cells have evolved quality control mechanisms to degrade aberrant mRNA molecules and prevent the synthesis of defective proteins that could be deleterious for the cell. The exosome, a protein complex with ribonuclease activity, is a key player in quality control. An early quality checkpoint takes place cotranscriptionally but little is known about the molecular mechanisms by which the exosome is recruited to the transcribed genes. Here we study the core exosome subunit Rrp4 in two insect model systems, Chironomus and Drosophila. We show that a significant fraction of Rrp4 is associated with the nascent pre-mRNPs and that a specific mRNA-binding protein, Hrp59/hnRNP M, interacts in vivo with multiple exosome subunits. Depletion of Hrp59 by RNA interference reduces the levels of Rrp4 at transcription sites, which suggests that Hrp59 is needed for the exosome to stably interact with nascent pre-mRNPs. Our results lead to a revised mechanistic model for cotranscriptional quality control in which the exosome is constantly recruited to newly synthesized RNAs through direct interactions with specific hnRNP proteins.
Chromatin-dependent Transcription Factor Accessibility Rather than Nucleosome Remodeling Predominates during Global Transcriptional Restructuring in Saccharomyces cerevisiae
Authors: Zawadzki Karl A. , Morozov Alexandre V. , Broach James R.
Published: June 2009

Several well-studied promoters in yeast lose nucleosomes upon transcriptional activation and gain them upon repression, an observation that has prompted the model that transcriptional activation and repression requires nucleosome remodeling of regulated promoters. We have examined global nucleosome positioning before and after glucose-induced transcriptional reprogramming, a condition under which more than half of all yeast genes significantly change expression. The majority of induced and repressed genes exhibit no change in promoter nucleosome arrangement, although promoters that do undergo nucleosome remodeling tend to contain a TATA box. Rather, we found multiple examples where the pre-existing accessibility of putative transcription factor binding sites before glucose addition determined whether the corresponding gene would change expression in response to glucose addition. These results suggest that selection of appropriate transcription factor binding sites may be dictated to a large extent by nucleosome prepositioning but that regulation of expression through these sites is dictated not by nucleosome repositioning but by changes in transcription factor activity.
Cisternal Organization of the Endoplasmic Reticulum during Mitosis
Authors: Lu Lei , Ladinsky Mark S. , Kirchhausen Tom
Published: June 2009

The endoplasmic reticulum (ER) of animal cells is a single, dynamic, and continuous membrane network of interconnected cisternae and tubules spread out throughout the cytosol in direct contact with the nuclear envelope. During mitosis, the nuclear envelope undergoes a major rearrangement, as it rapidly partitions its membrane-bound contents into the ER. It is therefore of great interest to determine whether any major transformation in the architecture of the ER also occurs during cell division. We present structural evidence, from rapid, live-cell, three-dimensional imaging with confirmation from high-resolution electron microscopy tomography of samples preserved by high-pressure freezing and freeze substitution, unambiguously showing that from prometaphase to telophase of mammalian cells, most of the ER is organized as extended cisternae, with a very small fraction remaining organized as tubules. In contrast, during interphase, the ER displays the familiar reticular network of convolved cisternae linked to tubules.
Molecular Distinctions between Aurora A and B: A Single Residue Change Transforms Aurora A into Correctly Localized and Functional Aurora B
Authors: Hans Fabienne , Skoufias Dimitrios A. , Dimitrov Stefan , Margolis Robert L.
Published: June 2009

Aurora A and Aurora B, paralogue mitotic kinases, share highly similar primary sequence. Both are important to mitotic progression, but their localizations and functions are distinct. We have combined shRNA suppression with overexpression of Aurora mutants to address the cause of the distinction between Aurora A and Aurora B. Aurora A residue glycine 198 (G198), mutated to asparagine to mimic the aligned asparagine 142 (N142) of Aurora B, causes Aurora A to bind the Aurora B binding partner INCENP but not the Aurora A binding partner TPX2. The mutant Aurora A rescues Aurora B mitotic function. We conclude that binding to INCENP is alone critical to the distinct function of Aurora B. Although G198 of Aurora A is required for TPX2 binding, N142G Aurora B retains INCENP binding and Aurora B function. Thus, although a single residue change transforms Aurora A, the reciprocal mutation of Aurora B does not create Aurora A function. An Aurora A-Δ120 N-terminal truncation construct reinforces Aurora A similarity to Aurora B, because it does not associate with centrosomes but instead associates with kinetochores.
Using a double codend to reduce discard mortality
Authors: Broadhurst Matt K. , Millar Russell B. , Uhlmann Sebastian S.
Published: June 2009

Broadhurst, M. K., Millar, R. B., and Uhlmann, S. S. 2009. Using a double codend to reduce discard mortality. – ICES Journal of Marine Science, 66: 2077–2081. Traditional technical strategies for mitigating collateral fishing mortality have involved improving gear selectivity (to reduce bycatch) and, more recently, concomitant changes to onboard handling procedures to reduce some of the negative impacts to the remaining discards. A less common approach is to modify gears physically to minimize deleterious catching mechanisms and subsequent mortalities during fishing. This study aimed to investigate the utility of the latter category of modifications for penaeid trawls by separating a codend into two compartments (termed a double codend) to alleviate interactions between catches. Compared with a conventional design, the double codend significantly reduced the immediate (from 17.1 to 13.8%) and short-term (22.5 to 17.1%) mortalities of discarded juvenile school prawns (Metapenaeus macleayi). The effectiveness of the double codend remained independent of other factors known to affect the fate of discarded juvenile M. macleayi, including cloud cover and, owing to minimal variability, the weight of the total catch. However, irrespective of the codend configuration, overall mortalities were also positively correlated with the quantity of jellyfish. We conclude that when combined with modifications to improve selectivity and appropriate onboard handling strategies, compartmentalizing codend catches could cumulatively reduce unaccounted fishing mortality.
Dynamic neuromodulation of aggression by vasotocin: influence of social context and social phenotype in territorial songbirds
Authors: Goodson James L. , Kabelik David , Schrock Sara E.
Published: June 2009

The homologous neuropeptides vasotocin (VT) and vasopressin (VP) influence agonistic behaviours across many taxa, but peptide–behaviour relationships are complex and purportedly species-specific. Putative species-specific effects in songbirds are confounded with context, however, such that territorial species have been tested only in resident–intruder paradigms and gregarious species have been tested only in a mate competition paradigm. Using the territorial violet-eared waxbill (Estrildidae:
Uraeginthus granatina
), we now show that a V
1a
receptor antagonist reduces male aggression during mate competition (as in gregarious finches), but does not affect resident–intruder aggression in dominant males. However, the V
1a
antagonist disinhibits aggression in less aggressive (typically subordinate) males. These results are consistent with recent data on the activation of different VT cell groups during positive and negative social interactions. Thus, VT influences aggression similarly across territorial and gregarious species, but in context- and phenotype-specific ways that probably reflect the differential activation of discrete VT cell groups.
Sexual conflict in twins: male co-twins reduce fitness of female Soay sheep
Authors: Korsten Peter , Clutton-Brock Tim , Pilkington Jill G. , Pemberton Josephine M. , Kruuk Loeske E. B.
Published: June 2009

Males and females often have different requirements during early development, leading to sex-specific interactions between developing offspring. In polytocous mammals, competition for limited resources
in utero
may be asymmetrical between the sexes, and androgens produced by male foetuses could have adverse effects on the development of females, with potentially long-lasting consequences. We show here, in an unmanaged population of Soay sheep, that female lambs with a male co-twin have reduced birth weight relative to those with a female co-twin, while there was no such effect in male twins. In addition, females with a male co-twin had lower lifetime breeding success, which appeared to be mainly driven by differences in first-year survival. These results show that sex-specific sibling interactions can have long-term consequences for survival and reproduction, with potentially important implications for optimal sex allocation.
A novel jet-based nano-hydroxyapatite patterning technique for osteoblast guidance
Authors: Li Xiang , Koller Garrit , Huang Jie , Di Silvio Lucy , Renton Tara , Esat Minoo , Bonfield William , Edirisinghe Mohan
Published: June 2009

Surface topography is well known to play a crucial role in influencing cellular responses to an implant material and is therefore important in bone tissue regeneration. A novel jet-based patterning technique, template-assisted electrohydrodynamic atomization spraying, was recently devised to control precisely the surface structure as well as its dimensions. In the present study, a detailed investigation of this patterning process was carried out. A range of nano-hydroxyapatite (nHA) line-shaped patterns <20 µm in width were successfully deposited on a commercially pure Ti surface by controlling the flow of an nHA suspension in an electric field.In vitrostudies showed that the nHA patterns generated are capable of regulating the human osteoblast cell attachment and orientation.
The value of constant surveillance in a risky environment
Authors: Bell M. B. V. , Radford A. N. , Rose R. , Wade H. M. , Ridley A. R.
Published: June 2009

In risky environments, where threats are unpredictable and the quality of information about threats is variable, all individuals face two fundamental challenges: balancing vigilance against other activities, and determining when to respond to warning signals. The solution to both is to obtain continuous estimates of background risk, enabling vigilance to be concentrated during the riskiest periods and informing about the likely cost of ignoring warnings. Human surveillance organizations routinely produce such estimates, frequently derived from indirect cues. Here we show that vigilant individuals in an animal society (the pied babbler,
Turdoides bicolor
) perform a similar role. We ask (i) whether, in the absence of direct predator threats, pied babbler sentinels react to indirect information associated with increased risk and whether they communicate this information to group mates; (ii) whether group mates use this information to adjust their own vigilance, and whether this influences foraging success; and (iii) whether information provided by sentinels reduces the likelihood of inappropriate responses to alarm calls. Using playback experiments, we show that: (i) sentinels reacted to indirect predator cues (in the form of heterospecific alarm calls) by giving graded surveillance calls; (ii) foragers adjusted their vigilance in reaction to changes in surveillance calls, with substantial effects on foraging success; and (iii) foragers reduced their probability of responding to alarm calls when surveillance calls indicated lowered risk. These results demonstrate that identifying attacks as they occur is only part of vigilance: equally important is continuous surveillance providing information necessary for individuals to make decisions about their own vigilance and evasive action. Moreover, they suggest that a major benefit of group living is not only the increased likelihood of detecting threats, but a marked improvement in the quality of information available to each individual.
Oral vaccination reduces the incidence of tuberculosis in free-living brushtail possums
Authors: Tompkins D. M. , Ramsey D. S. L. , Cross M. L. , Aldwell F. E. , de Lisle G. W. , Buddle B. M.
Published: June 2009

Bovine tuberculosis (Tb) caused by
Mycobacterium bovis
has proved refractory to eradication from domestic livestock in countries with wildlife disease reservoirs. Vaccination of wild hosts offers a way of controlling Tb in livestock without wildlife culling. This study was conducted in a Tb-endemic region of New Zealand, where the introduced Australian brushtail possum (
Trichosurus vulpecula
) is the main wildlife reservoir of Tb. Possums were trapped and vaccinated using a prototype oral-delivery system to deliver the Tb vaccine bacille Calmette–Guerin. Vaccinated and control possums were matched according to age, sex and location, re-trapped bimonthly and assessed for Tb status by palpation and lesion aspiration; the site was depopulated after 2 years and post-mortem examinations were conducted to further identify clinical Tb cases and subclinical infection. Significantly fewer culture-confirmed Tb cases were recorded in vaccinated possums (1/51) compared with control animals (12/71); the transition probability from susceptible to infected was significantly reduced in both males and females by vaccination. Vaccine efficacy was estimated at 95 per cent (87–100%) for females and 96 per cent (82–99%) for males. Hence, this trial demonstrates that orally delivered live bacterial vaccines can significantly protect wildlife against natural disease exposure, indicating that wildlife vaccination, along with existing control methods, could be used to eradicate Tb from domestic animals.
Monkeys crying wolf? Tufted capuchin monkeys use anti-predator calls to usurp resources from conspecifics
Authors: Wheeler Brandon C.
Published: June 2009

The use of ‘tactical deception’ is argued to have been important in the cognitive evolution of the order Primates, but systematic studies of active deception in wild non-human primates are scant. This study tests whether wild tufted capuchin monkeys (Cebus apella nigritus) use alarm calls in a functionally deceptive manner to usurp food resources. If capuchins use alarm calls ‘deceptively’, it was predicted that false alarms should be: (i) given by subordinates more than by dominants, (ii) more frequent when food is most contestable, (iii) more frequent when less food is available, and (iv) given when the caller is in a spatial position in which it could increase its feeding success if conspecifics react to the call. These predictions were tested by observing subjects in experimental contexts, in which the amount and distribution of a high-value resource (banana pieces) were manipulated using wooden platforms suspended from tree branches. While false alarms were non-significantly more common when more food was available, the three remaining predictions were supported. These results generally support the hypothesis that alarm calls are used by capuchins to reduce the effects of feeding competition. Whether this is intentional on the part of the caller requires further investigation.
A test of the social cohesion hypothesis: interactive female marmots remain at home
Authors: Blumstein Daniel T. , Wey Tina W. , Tang Karisa
Published: June 2009

Individuals frequently leave home before reaching reproductive age, but the proximate causes of natal dispersal remain relatively unknown. The social cohesion hypothesis predicts that individuals who engage in more (affiliative) interactions are less likely to disperse. Despite the intuitive nature of this hypothesis, support is both limited and equivocal. We used formal social network analyses to quantify precisely both direct and indirect measures of social cohesion in yellow-bellied marmots. Because approximately 50 per cent of female yearlings disperse, we expected that social relationships and network measures of cohesion would predict dispersal. By contrast, because most male yearlings disperse, we expected that social relationships and cohesion would play a less important role. We found that female yearlings that interacted with more individuals, and those that were more socially embedded in their groups, were less likely to disperse. For males, social interactions were relatively unimportant determinants of dispersal. This is the first strong support for the social cohesion hypothesis and suggests that the specific nature of social relationships, not simply the number of affiliative relationships, may influence the propensity to disperse.
In Vivo Cell Wall Loosening by Hydroxyl Radicals during Cress Seed Germination and Elongation Growth
Authors: Müller Kerstin , Linkies Ada , Vreeburg Robert A.M. , Fry Stephen C. , Krieger-Liszkay Anja , Leubner-Metzger Gerhard
Published: June 2009

Loosening of cell walls is an important developmental process in key stages of the plant life cycle, including seed germination, elongation growth, and fruit ripening. Here, we report direct in vivo evidence for hydroxyl radical (·OH)-mediated cell wall loosening during plant seed germination and seedling growth. We used electron paramagnetic resonance spectroscopy to show that ·OH is generated in the cell wall during radicle elongation and weakening of the endosperm of cress (Lepidium sativum; Brassicaceae) seeds. Endosperm weakening precedes radicle emergence, as demonstrated by direct biomechanical measurements. By 3H fingerprinting, we showed that wall polysaccharides are oxidized in vivo by the developmentally regulated action of apoplastic ·OH in radicles and endosperm caps: the production and action of ·OH increased during endosperm weakening and radicle elongation and were inhibited by the germination-inhibiting hormone abscisic acid. Both effects were reversed by gibberellin. Distinct and tissue-specific target sites of ·OH attack on polysaccharides were evident. In vivo ·OH attack on cell wall polysaccharides were evident not only in germinating seeds but also in elongating maize (Zea mays; Poaceae) seedling coleoptiles. We conclude that plant cell wall loosening by ·OH is a controlled action of this type of reactive oxygen species.
Genome-Wide Analysis of Plastid Gene Expression in Potato Leaf Chloroplasts and Tuber Amyloplasts: Transcriptional and Posttranscriptional Control
Authors: Valkov Vladimir T. , Scotti Nunzia , Kahlau Sabine , MacLean Daniel , Grillo Stefania , Gray John C. , Bock Ralph , Cardi Teodoro
Published: June 2009

Gene expression in nongreen plastids is largely uncharacterized. To compare gene expression in potato (Solanum tuberosum) tuber amyloplasts and leaf chloroplasts, amounts of transcripts of all plastid genes were determined by hybridization to plastome arrays. Except for a few genes, transcript accumulation was much lower in tubers compared with leaves. Transcripts of photosynthesis-related genes showed a greater reduction in tubers compared with leaves than transcripts of genes for the genetic system. Plastid genome copy number in tubers was 2- to 3-fold lower than in leaves and thus cannot account for the observed reduction of transcript accumulation in amyloplasts. Both the plastid-encoded and the nucleus-encoded RNA polymerases were active in potato amyloplasts. Transcription initiation sites were identical in chloroplasts and amyloplasts, although some differences in promoter utilization between the two organelles were evident. For some intron-containing genes, RNA splicing was less efficient in tubers than in leaves. Furthermore, tissue-specific differences in editing of ndh transcripts were detected. Hybridization of the plastome arrays with RNA extracted from polysomes indicated that, in tubers, ribosome association of transcripts was generally low. Nevertheless, some mRNAs, such as the transcript of the fatty acid biosynthesis gene accD, displayed relatively high ribosome association. Selected nuclear genes involved in plastid gene expression were generally significantly less expressed in tubers than in leaves. Hence, compared with leaf chloroplasts, gene expression in tuber amyloplasts is much lower, with control occurring at the transcriptional, posttranscriptional, and translational levels. Candidate regulatory sequences that potentially can improve plastid (trans)gene expression in amyloplasts have been identified.
Dissection of Bacterial Wilt on Medicago truncatula Revealed Two Type III Secretion System Effectors Acting on Root Infection Process and Disease Development
Authors: Turner Marie , Jauneau Alain , Genin Stéphane , Tavella Marie-José , Vailleau Fabienne , Gentzbittel Laurent , Jardinaud Marie-Françoise
Published: June 2009

Ralstonia solanacearum is the causal agent of the devastating bacterial wilt disease, which colonizes susceptible Medicago truncatula via the intact root tip. Infection involves four steps: appearance of root tip symptoms, root tip cortical cell invasion, vessel colonization, and foliar wilting. We examined this pathosystem by in vitro inoculation of intact roots of susceptible or resistant M. truncatula with the pathogenic strain GMI1000. The infection process was type III secretion system dependent and required two type III effectors, Gala7 and AvrA, which were shown to be involved at different stages of infection. Both effectors were involved in development of root tip symptoms, and Gala7 was the main determinant for bacterial invasion of cortical cells. Vessel invasion depended on the host genetic background and was never observed in the resistant line. The invasion of the root tip vasculature in the susceptible line caused foliar wilting. The avrA mutant showed reduced aggressiveness in all steps of the infection process, suggesting a global role in R. solanacearum pathogenicity. The roles of these two effectors in subsequent stages were studied using an assay that bypassed the penetration step; with this assay, the avrA mutant showed no effect compared with the GMI1000 strain, indicating that AvrA is important in early stages of infection. However, later disease symptoms were reduced in the gala7 mutant, indicating a key role in later stages of infection.
Tris[2-(2-pyridyliminomethyl)phenolato(0.67−)]europium(III) nitrate
Authors: Zhao Qi-Hua , Chen Hong-Yan , Li Li-Nan , Xie Ming-Jin
Published: June 2009

The title compound, [Eu(C12H9.33N2O)3]NO3, was obtained by the reaction of Eu(NO3)·3H2O and the Schiff base ligand 2-(2-pyridyliminomethyl)phenol. The Eu atom is located on a threefold rotation axis and is nine-coordinated by three tridentate Schiff base ligands in a distorted tricapped trigonal-prismatic geometry. The O atom at the phenol hydroxy group is partially deprotonated and the H atoms are modelled with one-third occupancy according to the space groupR\overline{3}. Offset face-to-face π–π [centroid–centroid distance = 3.886 (3) Å] and edge-to-face C—H...π interactions are found between adjacent molecules. An intramolecular O—H...N hydrogen bond is also present.
Methyl 5-ferrocenyl-5a-hydroxy-1-methyl-10-oxo-2,3,3a,4,5a,10-hexahydro-1H-indeno[1,2:2′,3′]furo[3′,4′-b]pyrrole-3a-carboxylate
Authors: Kamala E. Theboral Sugi , Nirmala S. , Sudha L. , Kathiravan S. , Raghunathan R.
Published: June 2009

In the title compound, [Fe(C5H5)(C21H20NO5)], the pyrrolidine and cyclopentanone rings exhibit a twist conformation. The pyrrolidine ring is almost perpendicular to the cyclopentanone ring, making a dihedral angle of 81.91 (6)°. The molecular conformation is stabilized by an intramolecular O—H...N hydrogen bond and C—H...O interactions. The crystal structure is stabilized by intermolecular C—H...O interactions.
catena-Poly[[(nitrato-κ2O,O′)silver(I)]-μ3-4-pyridone-κ3O:O:O]
Authors: Wu Xian-Ge , Xiao Jun-Xia , Qin Liang
Published: June 2009

In the title complex, [Ag(NO3)(C5H5NO)]n, the AgIatom is coordinated by two O atoms from two different 4-pyridone ligands and two O atoms from one nitrate anion, displaying a nearly planar coordination geometry. The O atoms of two 4-pyridone ligands bridge two symmetrically related AgNO3units, forming a dimer, with an Ag...Ag separation of 3.680 (2) Å. Neighbouring dimers are linked into an infinite chain through weak Ag...O interactions [2.765 (2) Å], Ag...Ag interactions [3.1511 (4) Å] and π–π stacking interactions [centroid–centroid distance = 3.623 (4) Å]. N—H...O and C—H...O hydrogen bonds assemble these chains into a three-dimensional network.
[5,10,15,20-Tetrakis(4-chlorophenyl)porphyrinato]bis(tributylphosphine)cobalt(III) perchlorate
Authors: Etemadi Bijan , Kia Reza , Asadi Mozaffar , Mohammadi Kh.
Published: June 2009

In the molecule of the title compound, [Co(C44H24Cl4N4){(C4H9)3P}2]ClO4, the CoIIIcentre has a slightly distorted octahedral geometry and is coordinated by four N atoms of the tetrapyrrolic ring in the equatorial positions and two phosphine ligands in the axial positions. The dihedral angles betweenmeso-substituted chlorophenyl rings and the basic tetrapyrrolic ring are 82.66 (9), 82.16 (7), 83.97 (11) and 76.87 (8)°. In one of the phosphine ligands, the two terminal methyl groups are disordered over two positions with refined site-occupancy ratios of 0.70 (7):0.30 (7) and 0.66 (2):0.34 (2). In the crystal structure, molecules are linked together along theaaxis by intermolecular C—H...Cl interactions. The crystal structure is further stabilized by intramolecular C—H...O and C—H...N interactions and intermolecular C—H...O and C—H...π interactions.
Dibromido(2,2′:6′,2′′-terpyridine-κ3N,N′,N′′)zinc(II)
Authors: Zhao Qing-Lan , Li Guo-Peng
Published: June 2009

In the title compound, [ZnBr2(C15H11N3)], the ZnIIion is five-coordinated by the three N atoms from a 2,2′:6′,2′′-terpyridine ligand (terpy) and two bromide anions in a distorted trigonal bipyramidal configuration. Each molecule is situated on a twofold rotational axis that passes through the ZnIIion and the central ring of the terpy ligand. In the crystal structure, aromatic π–π interactions between terpy ligands [centroid–centroid distances = 3.6265 (9) Å] link molecules into stacks propagated in the [001] direction.
Bis(acetato-κ2O,O′)bis(3,5-dimethyl-1H-pyrazole-κN2)copper(II)
Authors: Davydenko Yuliya M. , Fritsky Igor O. , Pavlenko Vadim O. , Meyer Franc , Dechert Sebastian
Published: June 2009

In the title compound, [Cu(C2H3O2)2(C5H8N2)2], the CuIIatom has a distorted tetragonal–bipyramidal geometry, with the equatorial plane formed by two N atoms belonging to two 3,5-dimethyl-1H-pyrazole ligands and two O atoms from two acetate anions. The second O atoms of the acetate groups provide elongated Cu—O axial contacts, so that the acetates appear to be coordinated in a pseudo-chelate fashion. The pyrazole ligands are situated incispositions with respect to each other. In the crystal structure, molecules are linked through intermolecular N—H...O hydrogen bonds, forming a one-dimensional chain.
catena-Poly[[[bis(1,10-phenanthroline-κ2N,N′)manganese(II)]-μ-9,10-dioxoanthracene-1,5-disulfonato-κ2O1:O5] tetrahydrate]
Authors: Jia Jia , Feng Wen , Zhao Hong-Kun , Yang En-Cui
Published: June 2009

The title complex, {[Mn(C14H6O8S2)(C12H8N2)2]·4H2O}n, exhibits a chain-like polymeric structure with 9,10-dioxoanthracene-1,5-disulfonate anions bridging MnIIatoms in a bis-monodentate mode. The unique MnIIatom is located on a crystallographic centre of inversion. Four N atoms from two chelating 1,10-phenanthroline ligands and two sulfonate O atoms from two symmetry-related 9,10-dioxoanthracene-1,5-disulfonate anions give rise to a slightly distorted octahedral coordination environment around the MnIIcentre. The centroid of the central ring of the anthraquinone ligand represents another crystallographic centre of inversion. In the crystal structure, interligand π–π stacking [centroid-to-centroid distances 3.532 (1) and 3.497 (3) Å] and intermolecular O—H...O hydrogen-bonding interactions assemble the chains into a three-dimensional supramolecular network.
Pentaaqua(1H-benzimidazole-5,6-dicarboxylato-κN3)cobalt(II) pentahydrate
Authors: Song Wen-Dong , Wang Hao , Li Shi-Jie , Qin Pei-Wen , Hu Shi-Wei
Published: June 2009

In the title mononuclear complex, [Co(C9H4N2O4)(H2O)5]·5H2O, the CoIIatom exhibits a distorted octahedral geometry involving an N atom of a 1H-benzimidazole-5,6-dicarboxylate ligand and five water O atoms. A supramolecular network is generated through intermolecular O—H...O hydrogen-bonding interactions involving the coordinated and uncoordinated water molecules and the carboxyl O atoms of the organic ligand. An intermolecular N—H...O hydrogen bond is also observed.
SodiumN-chloro-2-methylbenzenesulfonamidate sesquihydrate
Authors: Gowda B. Thimme , Foro Sabine , Fuess Hartmut
Published: June 2009

In the title salt, Na+·C7H7ClNO2S−·1.5H2O, one of the water molecules lies on a twofold axis. The sodium ion shows an O6octahedral coordination defined by three water O atoms and three sulfonyl O atoms derived from three different anions. The S—N distance of 1.5898 (19) Å is consistent with an S=N double bond. The crystal structure is stabilized by N—H...O and O—H...Cl hydrogen bonds.
On the Rapid Rise of Social Networking Sites: New Findings and Policy Implications
Authors: Livingstone Sonia , Brake David R
Published: June 2009

Social networking sites have been rapidly adopted by children and, especially, teenagers and young people worldwide, enabling new opportunities for the presentation of the self, learning, construction of a wide circle of relationships, and the management of privacy and intimacy. On the other hand, there are also concerns that social networking increases the likelihood of new risks to the self, these centring on loss of privacy, bullying, harmful contacts and more. This article reviews recent findings regarding children and teenagers’ social networking practices in order to identify implications for future research and public policy. These focus on the interdependencies between opportunities and risks, the need for digital or media literacy education, the importance of building safety considerations into the design and management of social networking sites, the imperative for greater attention to ‘at risk’ children in particular, and the importance of a children’s rights framework in developing evidence‐based policy in this area.
A survey of tobacco dependence treatment guidelines in 31 countries
Authors: Raw Martin , Regan Susan , Rigotti Nancy A. , McNeill Ann
Published: June 2009

Aims  The Framework Convention on Tobacco Control (FCTC) asks countries to develop and disseminate comprehensive evidence‐based guidelines and promote adequate treatment for tobacco dependence, yet to date no summary of the content of existing guidelines exists. This paper describes the national tobacco dependence treatment guidelines of 31 countries.

Design, setting, participants  A questionnaire on tobacco dependence treatment guidelines was sent by e‐mail to a convenience sample of contacts working in tobacco control in 31 countries in 2007. Completed questionnaires were received from respondents in all 31 countries. During the course of these enquiries we also made contact with people in 14 countries that did not have treatment guidelines and sent them a short questionnaire asking about their plans to produce guidelines.

Measurements  The survey instrument was a 17‐item questionnaire asking the following key questions: do the guidelines recommend brief interventions, intensive behavioural support, medications; which medications; do the guidelines apply to the whole health‐care system and all professionals; do they refer explicitly to the Cochrane database; are they based on another country's guidelines; are they national or more local; are they endorsed formally by government; did they undergo peer review; who funded them; where were they published; do they include evidence on cost effectiveness of treatment?

Findings  According to respondents, all their countries' guidelines recommended brief advice, intensive behavioural support and nicotine replacement therapy (NRT); 84% recommended bupropion; 19% recommended varenicline; and 35% recommended telephone quitlines. Nearly half (48%) included cost‐effectiveness evidence. Seventy‐one per cent were supported formally by their government and 65% were supported financially by the government. Most (84%) used the Cochrane reviews as a source of evidence, 84% underwent a peer review process and 55% were based on the guidelines of other countries, most often the United States and England.

Conclusion  Overall, the guidelines reviewed followed the evidence base closely, recommending brief interventions, intensive behavioural support and NRT, and most recommended bupropion. Varenicline was not on the market in most of the countries in this survey when their guidelines were written, illustrating the need for guidelines to be updated periodically. None recommended interventions not proven to be effective, and some recommended explicitly against specific interventions (for lack of evidence). Most were peer‐reviewed, many through lengthy and rigorous procedures, and most were endorsed or supported formally by their governments. Some countries that did not have guidelines expressed a need for technical support, emphasizing the need for countries to share experience, something the FCTC process is well placed to support.
Effect of isometric exercise and body scanning on cigarette cravings and withdrawal symptoms
Authors: Ussher Michael , Cropley Mark , Playle Sally , Mohidin Roshane , West Robert
Published: June 2009

Aims To examine the acute effects of a guided relaxation routine (body scan) and isometric exercise on desire to smoke and tobacco withdrawal symptoms.

Design Experimental comparison of three conditions.

Participants Forty‐eight individuals reporting smoking ≥10 cigarettes daily.

Intervention Random assignment to one of three interventions delivered via a 10‐minute audio: isometric exercise (IE,n = 14), body scanning (BS,n = 18) or a reading about natural history (control group,n = 16). Interventions were delivered twice on the same day: in the laboratory, then in their ‘normal’ environment.

Measurements Desire to smoke (primary outcome) and withdrawal symptoms were rated at pre‐intervention and up to 30 minutes post‐intervention.

Findings Controlling for baseline scores, post‐intervention desire to smoke and withdrawal symptoms were significantly lower for IE and BS groups, compared with the controls, in both environments. There were no significant differences for IE versus BS. For desire to smoke, controlling for baseline values, ratings in the laboratory were significantly lower for IE and BS versus the control up to 30 minutes post‐intervention. In the normal environment, these ratings were significantly lower only up to 5 minutes post‐intervention.

Conclusions Brief IE and BS interventions are effective for reducing desire to smoke and withdrawal symptoms in temporarily abstaining smokers. These interventions were found to be more effective in the laboratory than in the smoker's normal environment, but this may be an artefact of there not being a sufficient ‘wash‐out’ period between interventions. These techniques may be beneficial for managing desire to smoke and tobacco withdrawal.