bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regulation of the Histidine Utilization (Hut) System in Bacteria
Authors: Bender Robert A. 
Published: August 2012

SUMMARYThe ability to degrade the amino acid histidine to ammonia, glutamate, and a one-carbon compound (formate or formamide) is a property that is widely distributed among bacteria. The four or five enzymatic steps of the pathway are highly conserved, and the chemistry of the reactions displays several unusual features, including the rearrangement of a portion of the histidase polypeptide chain to yield an unusual imidazole structure at the active site and the use of a tightly bound NAD molecule as an electrophile rather than a redox-active element in urocanase. Given the importance of this amino acid, it is not surprising that the degradation of histidine is tightly regulated. The study of that regulation led to three central paradigms in bacterial regulation: catabolite repression by glucose and other carbon sources, nitrogen regulation and two-component regulators in general, and autoregulation of bacterial regulators. This review focuses on three groups of organisms for which studies are most complete: the enteric bacteria, for which the regulation is best understood; the pseudomonads, for which the chemistry is best characterized; andBacillus subtilis, for which the regulatory mechanisms are very different from those of the Gram-negative bacteria. The Hut pathway is fundamentally a catabolic pathway that allows cells to use histidine as a source of carbon, energy, and nitrogen, but other roles for the pathway are also considered briefly here.
Anaerobic Ammonium-Oxidizing Bacteria: Unique Microorganisms with Exceptional Properties
Authors: van Niftrik Laura , Jetten Mike S. M. 
Published: August 2012

SUMMARY

Anaerobic ammonium-oxidizing (anammox) bacteria defy many microbiological concepts and share numerous properties with both eukaryotes and archaea. Among their most intriguing characteristics are their compartmentalized cell plan and archaeon-like cell wall. Here we review our current knowledge about anammox cell biology. The anammox cell is divided into three separate compartments by bilayer membranes. The anammox cell consists of (from outside to inside) the cell wall, paryphoplasm, riboplasm, and anammoxosome. Not much is known about the composition or function of both the anammox cell wall and the paryphoplasm compartment. The cell wall is proposed to be proteinaceous and to lack both peptidoglycan and an outer membrane typical of Gram-negative bacteria. The function of the paryphoplasm is unknown, but it contains the cell division ring. The riboplasm resembles the standard cytoplasmic compartment of other bacteria; it contains ribosomes and the nucleoid. The anammoxosome occupies most of the cell volume and is a so-called “prokaryotic organelle” analogous to the eukaryotic mitochondrion. This is the site where the anammox reaction takes place, coupled over the curved anammoxosome membrane, possibly giving rise to a proton motive force and subsequent ATP synthesis. With these unique properties, anammox bacteria are food for thought concerning the early evolution of the domains
Bacteria
,
Archaea
, and
Eukarya
.
Culture History and Population Heterogeneity as Determinants of Bacterial Adaptation: the Adaptomics of a Single Environmental Transition
Authors: Ryall Ben , Eydallin Gustavo , Ferenci Thomas 
Published: August 2012

SUMMARYDiversity in adaptive responses is common within species and populations, especially when the heterogeneity of the frequently large populations found in environments is considered. By focusing on events in a single clonal population undergoing a single transition, we discuss how environmental cues and changes in growth rate initiate a multiplicity of adaptive pathways. Adaptation is a comprehensive process, and stochastic, regulatory, epigenetic, and mutational changes can contribute to fitness and overlap in timing and frequency. We identify culture history as a major determinant of both regulatory adaptations and microevolutionary change. Population history before a transition determines heterogeneities due to errors in translation, stochastic differences in regulation, the presence of aged, damaged, cheating, or dormant cells, and variations in intracellular metabolite or regulator concentrations. It matters whether bacteria come from dense, slow-growing, stressed, or structured states. Genotypic adaptations are history dependent due to variations in mutation supply, contingency gene changes, phase variation, lateral gene transfer, and genome amplifications. Phenotypic adaptations underpin genotypic changes in situations such as stress-induced mutagenesis or prophage induction or in biofilms to give a continuum of adaptive possibilities. Evolutionary selection additionally provides diverse adaptive outcomes in a single transition and generally does not result in single fitter types. The totality of heterogeneities in an adapting population increases the chance that at least some individuals meet immediate or future challenges. However, heterogeneity complicates the adaptomics of single transitions, and we propose that subpopulations will need to be integrated into future population biology and systems biology predictions of bacterial behavior.
Injury trend analysis from the US Open Tennis Championships between 1994 and 2009
Authors: Sell Katie , Hainline Brian , Yorio Michael , Kovacs Mark 
Published: August 2012

ObjectiveInjuries can be a debilitating aspect of professional tennis. Injury rates and trends at the US Open Tennis Championships over multiple years are unknown. The purpose of this study was to examine injury trends in professional tennis players competing in a major professional tennis tournament between 1994 and 2009.MethodsFrom 1994 to 2009, injury data from the US Open Tennis Championships were recorded. Injuries were classified by location and type using terminology derived from a consensus statement developed specifically for tennis. Injury rates were determined based on the exposure of an athlete to a match event, and were calculated as the ratio of injuries per 1000 match exposures (MEs).ResultsThere was a statistically significant fluctuation in injuries across the timeframe analysed (p<0.05). There were 76.2±19.6 total injuries and 43.8±11.8 acute injuries per year seeking medical assistance. Muscle or tendon injuries were the most common type of acute injury. The rate of lower limb injuries was significantly higher than upper limb and trunk injuries (p<0.01). The ankle, followed by the wrist, knee, foot/toe and shoulder/clavicle were the most common injury sites.ConclusionsAcute injuries occurred more frequently than gradual-onset injuries, and most common injury types were similar to previously examined populations. However, there were differences in injury location trends compared to previous research, suggesting that further research in this elite-level population is warranted.
Taking the long view: a systematic review reporting long-term perspectives on child unintentional injury
Authors: Mytton Julie A , Towner Elizabeth M L , Powell Jane , Pilkington Paul A , Gray Selena 
Published: August 2012

ObjectiveThe relative significance of child injury as a cause of preventable death has increased as mortality from infectious diseases has declined. Unintentional child injuries are now a major cause of death and disability across the world with the greatest burden falling on those who are most disadvantaged. A review of long-term data on child injury mortality was conducted to explore trends and inequalities and consider how data were used to inform policy, practice and research.MethodsThe authors systematically collated and quality appraised data from publications and documents reporting unintentional child injury mortality over periods of 20 years or more. A critical narrative synthesis explored trends by country income group, injury type, age, gender, ethnicity and socioeconomic group.Findings31 studies meeting the inclusion criteria were identified of which 30 were included in the synthesis. Only six were from middle income countries and none were from low income countries. An overall trend in falling child injury mortality masked rising road traffic injury deaths, evidence of increasing vulnerability of adolescents and widening disparities within countries when analysed by ethnic group and socioeconomic status.ConclusionsChild injury mortality trend data from high and middle income countries has illustrated inequalities within generally falling trends. There is scope for greater use of existing trend data to inform policy and practice. Similar evidence from low income countries where the burden of injury is greatest is needed.
Elevated, combined serum free light chain levels and increased mortality: a 5-year follow-up, UK study
Authors: Anandram Seetharam , Assi Lakhvir Kaur , Lovatt Tracy , Parkes Jayne , Taylor Joanne , Macwhannell Alan , Jacob Abraham , Handa Sunil , Harding Stephen , Basu Supratik 
Published: August 2012

AimsAbnormal serum free light chain (FLC) ratios are diagnostically important in almost all plasma cell disorders. However, absolute increases in polyclonal FLC levels are often discarded as inconsequential. Here we report an association between increased combined polyclonal FLC (cFLC: FLCκ plus FLCλ) concentrations and mortality.Methods723 patients sent for 30 routine haematological assessments were enrolled. Patients with a confirmed monoclonal gammopathy were removed. The remaining 527 patients were followed up for up to 4.5 years. Statistical analysis was performed using SPSS (V.19).ResultsDuring follow-up, there were 99 deaths (18.8%). Kaplan-Meier survival analysis revealed 29% of these deaths occurred within the first 100 days (N=29). Multivariate analysis identified only cFLC >65 mg/l, albumin <33 g/l and estimated glomerular filtration rate <30 ml/min/1.73 m2to be independently associated with mortality within 100 days and 4.5 years with, cFLC having the highest HR of 7.1. A simple risk stratification model based only on albumin and cFLC identified 86% mortality within 100 days and 62% over 4.5 years.ConclusionsElevated cFLC is significantly associated with increased mortality and with albumin can be used to identify patients at risk of mortality at 4.5 years with high-risk patients detected within 100 days.
Is the human sex ratio at birth a sentinel health indicator that is associated with HIV/AIDS and tuberculosis prevalences in the 21st century?
Authors: Shifotoka Anna , Fogarty Andrew W 
Published: August 2012

BackgroundA reduction in sex ratio at live birth has been proposed as a sentinel health indicator that can be used to monitor the health of populations.ObjectiveTo test the hypothesis that a lower sex ratio is associated with adverse national population health using the prevalences of HIV and tuberculosis as measures of societal well-being.MethodsAn ecological study design using routinely collected data and adjusting for potential confounding factors.ResultsThe mean global sex ratio was 1.05. There was marked heterogeneity in the sex ratio between different global regions (p<0.0001). Those regions with the highest prevalences of HIV infection had lower sex ratios, with the value for the highest quartile being 0.022 (95% CIs CI 0.013 to 0.031) lower than the lowest quartile. Similarly, those areas with the highest quartile of tuberculosis infection had a sex ratio of 0.016 (95% CI 0.004 to 0.028) lower than those in the lowest quartile. Similar results were observed in a subgroup analysis limited to countries from the African continent.ConclusionsThe data are consistent with the hypothesis that a reduced sex ratio at live birth is a potential sentinel health indicator of lower population health. However, these data do not demonstrate either a casual relationship or reveal any biological mechanisms that may account for these observations.
Dynamic relations between fast-food restaurant and body weight status: a longitudinal and multilevel analysis of Chinese adults
Authors: Xu Hongwei , Short Susan E , Liu Tao 
Published: August 2012

BackgroundMixed findings have been reported on the association between Western fast-food restaurants and body weight status. Results vary across study contexts and are sensitive to the samples, measures and methods used. Most studies have failed to examine the temporally dynamic associations between community exposure to fast-food restaurants and weight changes.MethodsBayesian hierarchical regressions are used to model changes in body mass index, waist-to-height ratio (WHtR) and waist-to-hip ratio (WHpR) as a function of changes in Western fast-food restaurants in 216 communities for more than 9000 Chinese adults followed up multiple times between 2000 and 2009.ResultsNumber of Western fast-food restaurants is positively associated with subsequent increases in WHtR and WHpR among rural population. More fast-food restaurants are positively associated with a future increase in WHpR for urban women. Increased availability of fast food between two waves is related to increased WHtR for urban men over the same period. A past increase in number of fast-food restaurants is associated with subsequent increases in WHtR and WHpR for rural population.ConclusionsThe associations between community exposure to Western fast food and weight changes are temporally dynamic rather than static. Improved measures of exposure to community environment are needed to achieve more precise estimates and better understanding of these relationships. In light of the findings in this study and China's rapid economic growth, further investigation and increased public health monitoring is warranted since Western fast food is likely to be more accessible and affordable in the near future.
Evaluation of a community pharmacy delivered oral contraception service
Authors: Parsons Judith , Adams Christine , Aziz Najia , Holmes Jo , Jawad Ruhi , Whittlesea Cate 
Published: August 2012

IntroductionIn the UK half of all pregnancies are unplanned and half of teenage pregnancies terminated. Southwark and Lambeth have the highest teenage conception rates in London. In 2009, many teenage pregnancies in Southwark led to terminations. A contraception service was established where qualified pharmacists supplied oral contraception (OC) using a patient group direction (PGD). This service evaluation aimed to assess this service delivered in five community pharmacies.MethodsMonthly data were submitted by each pharmacy to the Primary Care Trust on consultations, pills supplied, initial or subsequent supply and client referral. For specified periods consultation time was collected and a clinical notes audit undertaken. Client satisfaction was determined using a structured questionnaire returned to the pharmacy. Mystery shoppers were employed to assess the service.ResultsA total of 741 consultations were undertaken by seven pharmacists at five community pharmacies (October 2009–June 2011) with many (45.5%) occurring following emergency contraception supply. The mean consultation time was 19 minutes . Combined OC was most commonly supplied with nearly half (46.1%) of initial supplies to first-time pill users. Most consultations (92.2%) were with women aged under 30 years, with 22.5% aged under 20. Most consultations were with black or black British clients. Of the 99 women who completed the satisfaction questionnaires, most clients were very satisfied or satisfied with the service and felt comfortable talking to the pharmacist about contraception.ConclusionsTrained pharmacists were clinically competent and provided OC in community pharmacy according to a PGD. This service was accessed by the target population; young women using emergency hormonal contraception who had not previously used OC. Clients were largely very satisfied with the service.
Evidence of nitrogen fixation in lodgepole pine inoculated with diazotrophicPaenibacillus polymyxa
Authors: Bal Amandeep , Chanway Christopher P. 
Published: August 2012

Diazotrophic bacteria previously isolated from internal tissues of naturally regenerating lodgepole pine ( Pinus contorta var. latifolia (Dougl.) Engelm.) seedlings were tested for their ability to colonize and fix nitrogen (N) in pine germinants in two experiments. Surface sterilized pine seed was sown in glass tubes containing an autoclaved sand – montmorillonite clay mixture that contained a N-limited nutrient solution labeled with15N as 0.35 mmol·L–1Ca(15NO3)2(5%15N label). Pine seed was inoculated with one of three of the following bacterial strains: Paenibacillus polymyxa P2b-2R, P. polymyxa P18b-2R, or Dyadobacter fermentans P19a-2R, and seedlings grew for either 27 or 35 weeks. At the end of each plant growth period, P. polymyxa strain P2b-2R was detected in the pine rhizosphere but not inside plant tissues. Pine foliar N concentrations were not affected by bacterial inoculation but significant foliar15N dilution was observed in seedlings treated with strain P2b-2R (30% and 66%, P < 0.05, in the first and second experiments, respectively). This strain also reduced seedling biomass in both experiments but effects were significant only in the second experiment (36%, P < 0.05). Notwithstanding the negative effect of bacterial inoculation on seedling growth, pine seedlings inoculated with strain P2b-2R derived 30% and 66%, respectively, of their foliar N from bacterial N fixation in two seedling growth experiments. These results demonstrate the possibility that some endophytic diazotrophs facilitate pine seedling growth in N-poor soils.
Pollination biology and genetic variability of a giant perfumed flower (Aristolochia giganteaMart. and Zucc., Aristolochiaceae) visited mainly by small Diptera
Authors: Hipólito Juliana , Viana Blandina Felipe , Selbach-Schnadelbach Alessandra , Galetto Leonardo , Kevan Peter G. 
Published: August 2012

The genus Aristolochia presents conserved features in its basic structural plan of trap flowers and in its pollination syndrome. Visitors, usually flies, are attracted to the rotting-meat scented flowers and remain trapped until the second day, when the protogynous flowers release them. Aristolochia gigantea Mart. and Zucc showed many of these floral traits but display a citronella-like odour, giving the opportunity to study the reproductive ecology in this atypical species. Characteristics and behavior of pollinators, coupled with the distances between individual plants and populations, are important factors in patterns of genetic diversity. Thus, our objectives were to study the flower visitors, reproductive success, and gene flow in A. gigantea in the Chapada Diamantina, Bahia, Brazil. Results suggest that pollination by flies remains as a conserved interaction within the genus Aristolochia. The main pollinators appeared to be Megaselia spp. (Phoridae), evidenced primarily by the frequency of their occurrence within flowers and the transference of compatible pollen. On the other hand, the moderate to low levels of intrapopulation genetic variability found in A. gigantea, combined with low effective pollination and its reproductive dependence on biotic vectors, indicate that this species may be suffering gene erosion in the remaining populations located at Chapada Diamantina.
Development of mycelial slurries containing surfactant for cultivation of the edible ectomycorrhizal mushroom Rhizopogon roseolus (syn. Rhizopogon rubescens)
Authors: Shimomura Norihiro , Matsuda Miyuki , Ariyoshi Kunio , Aimi Tadanori 
Published: August 2012

Rhizopogon roseolus (Corda) Th. M. Fr., known as shoro in Japanese, is an edible ectomycorrhizal mushroom. To successfully cultivate ectomycorrhizal mushrooms, inoculation and propagation methods must be developed, and isolates with superior traits must be selected. Pinus thunbergii Parl. seedlings were inoculated with several isolates of R. roseolus using the Petri dish technique and their mycorrhizal abilities were assessed. We selected a superior isolate that rapidly colonized and produced a lot of ectomycorrhizas in the roots of P. thunbergii. The selected strain was cultured in liquid medium, and the resultant mycelia were homogenized in saline solution to make a slurry. Adding surfactant to the mycelial slurry stimulated mycorrhizal formation in host roots. We investigated the effects of mycelial slurry containing surfactant on ectomycorrhizal formation of P. thunbergii and fruiting body formation in mother plant systems. Stimulatory effects of the slurry were observed not only on ectomycorrhizal formation of the seedlings but also on fruiting body formation. These results suggest that the mycelial slurries containing surfactant could serve as mycelial spawns for the cultivation of shoro under greenhouse conditions.
Two new species ofUndifilum, fungal endophytes ofAstragalus(locoweeds) in the United States
Authors: Baucom Deana L. , Romero Marie , Belfon Robert , Creamer Rebecca 
Published: August 2012

New species of Undifilum , from locoweeds Astragalus lentiginosus Vitman and Astragalus mollissimus Torr., are described using morphological characteristics and molecular phylogenetic analyses as Undifilum fulvum Baucom & Creamer sp. nov. and Undifilum cinereum Baucom & Creamer sp. nov. Fungi were isolated from dried plants of A. lentiginosus var. araneosus , diphysus , lentiginosus , and wahweapensis collected from Arizona, Oregon, and Utah, USA, and A. mollissimus var. biglovii , earleii , and mollissimus collected from New Mexico, Oklahoma, and Texas, USA. Endophytic fungi from Astragalus locoweeds were compared to Undifilum oxytropis isolates obtained from dried plant material of Oxytropis lamberteii from New Mexico and Oxytropis sericea from Arizona, Colorado, New Mexico, Utah, and Wyoming. Extremely slow growth in vitro was observed for all, and conidia, if present, were ellipsoid with transverse septa. However, in vitro color, growth on four different media, and conidium size differed between fungi from Astragalus spp. and U. oxytropis. Neighbor-joining analyses of internal transcribed spacer (ITS) region and glyceraldehyde-3-phosphate dehydrogenase (GPD) gene sequences revealed that U. fulvum and U. cinereum formed a clade distinct from U. oxytropis. This was supported by neighbor-joining analyses of results generated from random amplified polymorphic DNA (RAPD) fragments using two different primers.
Support for a Long Lifetime and Short End-to-End Delays with TDMA Protocols in Sensor Networks
Authors: Brzozowski Marcin , Salomon Hendrik , Langendoerfer Peter 
Published: August 2012

This work addresses a tough challenge of achieving two opposing goals: ensuring long lifetimes and supporting short end-to-end delays in sensor networks. Obviously, sensor nodes must wake up often to support short delays in multi-hop networks. As event occurs seldom in common applications, most wake-up are useless: nodes waste energy due to idle listening. We introduce a set of solutions, referred to as LETED (limiting end-to-end delays), which shorten the wake-up periods, reduce idle listening, and save energy. We exploit hardware features of available transceivers that allow early detection of idle wake-up periods. This feature is introduced on top of our approach to reduce idle listening stemming from clock drift owing to the estimation of run-time drift. To evaluate LETED and other MAC protocols that support short end-to-end delays we present an analytical model, which considers almost 30 hardware and software parameters. Our evaluation revealed that LETED reduces idle listening by 15x and more against similar solutions. Also, LETED outperforms other protocols and provides significant longer lifetimes. For example, nodes with LETED work 8x longer than those with a common TDMA and 2x-3x longer than with protocols based on preamble sampling, like B-MAC.