bluuebunny/crossref_metadata_2025_split huggingface dataset:
The response of heterotrophic activity and carbon cycling to nitrogen additions and warming in two tropical soils
Authors: CUSACK DANIELA F. , TORN MARGARET S. , McDOWELL WILLIAM H. , SILVER WHENDEE L. 
Published: November 2009

AbstractNitrogen (N) deposition is projected to increase significantly in tropical regions in the coming decades, where changes in climate are also expected. Additional N and warming each have the potential to alter soil carbon (C) storage via changes in microbial activity and decomposition, but little is known about the combined effects of these global change factors in tropical ecosystems. In this study, we used controlled laboratory incubations of soils from a long‐term N fertilization experiment to explore the sensitivity of soil C to increased N in two N‐rich tropical forests. We found that fertilization corresponded to significant increases in bulk soil C concentrations, and decreases in C loss via heterotrophic respiration (P< 0.05). The increase in soil C was not uniform among C pools, however. The active soil C pool decomposed faster with fertilization, while slowly cycling C pools had longer turnover times. These changes in soil C cycling with N additions corresponded to the responses of two groups of microbial extracellular enzymes. Smaller active C pools corresponded to increased hydrolytic enzyme activities; longer turnover times of the slowly cycling C pool corresponded to reduced activity of oxidative enzymes, which degrade more complex C compounds, in fertilized soils. Warming increased soil respiration overall, and N fertilization significantly increased the temperature sensitivity of slowly cycling C pools in both forests. In the lower elevation forest, respired CO2 from fertilized cores had significantly higher Δ14C values than control soils, indicating losses of relatively older soil C. These results indicate that soil C storage is sensitive to both N deposition and warming in N‐rich tropical soils, with interacting effects of these two global change factors. N deposition has the potential to increase total soil C stocks in tropical forests, but the long‐term stability of this added C will likely depend on future changes in temperature.
Nurses' satisfaction with shiftwork and associations with work, home and health characteristics: a survey in the Netherlands
Authors: Peters Velibor P.J.M. , De Rijk Angelique E. , Boumans Nicolle P.G. 
Published: November 2009

AbstractTitle.  Nurses' satisfaction with shiftwork and associations with work, home and health characteristics: a survey in the Netherlands. Aim.  This paper is a report of a study conducted to determine if satisfaction with irregular working hours that are a form of shiftwork operates as a mediator between work and home characteristics and health problems.Background.  Shiftwork contributes to health problems, decreased well‐being and poorer health habits. It also affects employees’ decisions to leave the healthcare sector. Although many nurses voluntarily work shifts, there have been few studies of their satisfaction with irregular working hours when these are a form of shiftwork.Methods.  A survey was carried out with 144 nurses working in three nursing homes and one care home in the Netherlands. Questionnaires were distributed in 2003 to 233 nurses who worked shifts (response rate 60%). The questionnaire contained items on work and home characteristics, satisfaction with irregular working hours that are a form of shiftwork and health. A new scale to measure satisfaction with irregular working hours was constructed.Results.  All work characteristics, but no home characteristics, were associated with satisfaction with irregular working hours. The work characteristics ‘job demands’ and the home characteristics ‘autonomy at home’ and ‘home demands’ were associated with health. Satisfaction with irregular working hours did not mediate between work/home characteristics and health. Those reporting more social support, lower job demands and more job autonomy were more satisfied with their irregular working times that were a form of shiftwork.Conclusions.  Satisfaction with irregular working hours is a useful construct that requires further longitudinal study. The results also underline the importance of considering home characteristics when predicting health outcomes.
Nurses’ attitudes towards perinatal bereavement care
Authors: Moon Fai Chan , Gordon Arthur David 
Published: November 2009

AbstractTitle.  Nurses’ attitudes towards perinatal bereavement care. Aim.  This paper is a report of a study conducted to explore the factors associated with nurses and midwives’ attitudes towards perinatal bereavement care.Background.  Caring for and supporting parents whose infant has died is extremely demanding, difficult and stressful. In some situations nurses may experience personal failure, feel helpless, and need to distance themselves from bereaved parents because they feel unable to deal with the enormity of the parental feelings of loss.Method.  A correlational questionnaire study using convenience sampling was carried out in Singapore in 2007 with 185 nurses/midwives in one obstetrics and gynaecology unit.Results.  Regression models showed that nurses/midwives with religious beliefs and those with more positive attitudes to the importance of hospital policy and training for bereavement care were statistically significantly more likely to have a positive attitude towards perinatal bereavement care. Nurses emphasized their need for increased knowledge and training on how to cope with bereaved parents and requested greater support from team members and the hospital.Conclusion.  Bereavement counselling education and preceptorship supervision are recommended to reduce this stressful experience, increase the confidence and expertise of novices, and lead to increased quality of care for bereaved parents.
Dundee Ready Education Environment Measure: psychometric testing with Chinese nursing students
Authors: Wang Jian , Zang Shuang , Shan Tianming 
Published: November 2009

AbstractTitle.  Dundee Ready Education Environment Measure: psychometric testing with Chinese nursing students. Aim.  This paper is a report of the psychometric testing of the Dundee Ready Education Environment Measure with Chinese nursing students.Background.  Although the Dundee Ready Education Environment Measure has been widely used to measure educational environments in the healthcare professions, no psychometric evaluation of the measure with Chinese nursing students has been reported.Method.  Data from 214 nursing students were collected during a 2‐month period between December, 2004 and January, 2005. Exploratory factor analysis, internal consistency reliability and Cronbach’s alpha were examined.Results.  Five factors were found by principal components analysis with Oblimin with Kaiser Normalization rotation. The original factor names were maintained, but items in each factor changed. These five factors all achieved eigenvalues >1, and in total accounted for 52·186% of the variance. Cronbach’s alpha ranged from 0·623 to 0·9 across factors, with an overall alpha of 0·949.Conclusion.  The Chinese version of the Dundee Ready Education Environment Measure could be a valuable measurement for nursing educators in professional development programmes and nursing curriculum design. Further studies need in different Chinese nursing schools and larger sample sizes to be conducted to validate its stability and factor structure.
Response of the prairie–forest border to climate change: impacts of increasing drought may be mitigated by increasing CO2
Authors: Wyckoff Peter H. , Bowers Rachel 
Published: November 2009

Summary 1.
Quercus macrocarpa (bur oak) is the dominant tree species along much of the prairie–forest border in the northern‐central United States, and movement of Q. macrocarpa in response to climate change may determine the rate at which the prairie–forest ecotone shifts. To investigate likely controls over Q. macrocarpa performance at the edge of its range, we used tree rings to establish the links between drought, growth‐rate and mortality for three sites spanning the prairie–forest border in Minnesota. 2.
Quercus macrocarpa growth during the 20th century correlates strongly with the Palmer Drought Severity Index (PDSI) and more weakly with raw temperature and precipitation values for all three sites. However, the sensitivity of annual growth rates to drought has steadily declined over time as evidenced by increasing growth residuals and higher growth rates for a given PDSI value after 1950 compared with the first half of the century. We hypothesize that increased atmospheric carbon dioxide concentration may lead to increased water‐use efficiency, although we cannot rule out other environmental factors. 3. Because growth is an excellent predictor of Q. macrocarpa mortality, growth–climate relationships provide information on whether oak forests will contract, because of individual tree death, when climate changes. For Q. macrocarpa, declining sensitivity of growth to drought translates into lower predicted mortality rates at all sites. At one site, declining moisture sensitivity yields a 49% lower predicted mortality from a severe drought (PDSI = −8, on par with the worst 1930s ‘American Dust Bowl’ droughts in our study region). 4. Unless the changing relationship between growth and climate is incorporated into forest simulation models, the predicted rate of established tree dieback in a warmer, drier climate may be exaggerated. 5.
Synthesis. Adult Quercus macrocarpa trees appear to be increasingly insensitive to drought‐induced mortality. Because the species is dominant at the prairie–forest ecotone in the northern‐central United States, movement of the ecotone in response to climate change may be delayed for decades.
Detection and identification of Bartonella sp. in fleas from carnivorous mammals in Andalusia, Spain
Authors: MÁRQUEZ F. J. , MILLÁN J. , RODRÍGUEZ‐LIÉBANA J. J. , GARCÍA‐EGEA I. , MUNIAIN M. A. 
Published: November 2009

Abstract.A total of 559 fleas representing four species (Pulex irritans, Ctenocephalides felis, Ctenocephalides canis and Spilopsyllus cuniculi) collected on carnivores (five Iberian lynx Lynx pardinus, six European wildcat Felis silvestris, 10 common genet Genetta genetta, three Eurasian badger Meles meles, 22 red fox Vulpes vulpes, 87 dogs and 23 cats) in Andalusia, southern Spain, were distributed in 156 pools of monospecific flea from each carnivore, and tested for Bartonella infection in an assay based on polymerase chain reaction (PCR) amplification of the 16 S–23 S rRNA intergenic spacer region. Twenty‐one samples (13.5%) were positive and the sequence data showed the presence of four different Bartonella species. Bartonella henselae was detected in nine pools of Ctenocephalides felis from cats and dogs and in three pools of Ctenocephalides canis from cats; Bartonella clarridgeiae in Ctenocephalides felis from a cat, and Bartonella alsatica in Spilopsyllus cuniculi from a wildcat. DNA of Bartonella sp., closely related to Bartonella rochalimae, was found in seven pools of Pulex irritans from foxes. This is the first detection of B. alsatica and Bartonella sp. in the Iberian Peninsula. All of these Bartonella species have been implicated as agents of human diseases. The present survey confirms that carnivores are major reservoirs for Bartonella spp.
A lethal ovitrap‐based mass trapping scheme for dengue control in Australia: I. Public acceptability and performance of lethal ovitraps
Authors: RITCHIE S. A. , RAPLEY L. P. , WILLIAMS C. , JOHNSON P. H. , LARKMAN M. , SILCOCK R. M. , LONG S. A. , RUSSELL R. C. 
Published: November 2009

AbstractWe report on the first field evaluation of the public acceptability and performance of two types of lethal ovitrap (LO) in three separate trials in Cairns, Australia. Health workers were able to set standard lethal ovitraps (SLOs) in 75 and 71% of premise yards in the wet and dry season, respectively, and biodegradable lethal ovitraps (BLOs) in 93% of yards. Public acceptance, measured as retention of traps by residents, was high for both trap types, with <9% of traps missing after 4 weeks. Traps retaining water after 4 weeks were 78 and 34% for the two SLO trials and 58% for the BLOs. The ‘failure rate’ in the 535 BLOs set in the field for 4 weeks was 47%, of which 19% were lost, 51% had holes from probable insect chewing, 23% were knocked over, 7% had dried by evaporation and 1% were split. There was no significant difference in the failure rate of BLOs set on porous (grass, soil and mulch) versus solid (tiles, concrete, wood and stone) substrates. The SLOs and the BLOs were readily acceptable to ovipositing Aedes aegypti L. (Diptera: Culicidae); the mean number of eggs/trap was 6 and 15, for the dry season and wet season SLO trial, respectively, and 15 for the BLO wet season trial. Indeed, 84–94% of premise yards had egg positive SLOs or BLOs. A high percentage of both wet and dry season SLOs (29 and 70%, respectively) and BLOs (62%) that were dry after 4 weeks were egg positive, indicating the traps had functioned. Lethal strips from SLOs and BLOs that had been exposed for 4 weeks killed 83 and 74%, respectively, of gravid Ae. aegypti in laboratory assays. These results indicate that mass trapping schemes using SLOs and BLOs are not rejected by the public and effectively target gravid Ae. aegypti. The impact of the interventions on mosquito populations is described in a companion paper.
Effects of dexmedetomidine sedation on the EEG in children
Authors: MASON KEIRA P. , O’MAHONY ELIZABETH , ZURAKOWSKI DAVID , LIBENSON MARK H. 
Published: November 2009

SummaryObjectives: To examine the effects of dexmedetomidine sedation on EEG background and epileptiform activity in children, comparing it to natural sleep.Aim: To provide quantitative and qualitative descriptions of the effect of dexmedetomidine sedation on the EEG of children.Background: Children with intractable epilepsy admitted for surgery undergo 5 days of continuous EEG monitoring as well as nuclear medicine imaging studies with dexmedetomidine for sedation. Continuous EEG monitoring of each child during both natural sleep and dexmedetomidine‐induced sedation provides a unique opportunity to evaluate the effects of dexmedetomidine on the EEG of children.Materials/methods: Sixteen children undergoing dexmedetomidine sedation for nuclear medicine studies and simultaneous continuous EEG monitoring were studied. EEG segments during sedation were compared to samples of naturally occurring stage II sleep from the same child. Standard visual EEG analysis, quantification of delta, theta, alpha, beta, and total RMS power, number and location of spike foci, and frequency of spike activity were compared.Results: The EEG during dexmedetomidine sedation resembled stage II sleep. During sedation, statistically significant increases in power of 16% for theta (P = 0.01), 21% for alpha (P = 0.03), and 40% for beta (P < 0.01) were observed, but not for delta (P = 0.63) or total EEG power (P = 0.61). Spike frequency increased by 47% during sedation but no new spike foci or seizures were observed.Conclusion: Dexmedetomidine sedation elicited an EEG pattern similar to that of Stage II sleep with modest increases in theta, alpha, and beta activity. Dexmedetomidine does not hinder interpretation of the EEG, suggesting that it may be a uniquely useful agent for EEG sedation in children.
Presurgical fentanyl vs caudal block and the incidence of adverse respiratory events in children after orchidopexy
Authors: KHALIL SAMIA N. , MATUSZCZAK MARIA E. , MAPOSA DOUGLAS , BOLOS MARIANA E. , LINGADEVARU HEMANETH S. , CHUANG ALICE Z. 
Published: November 2009

SummaryBackground:  There is controversy about the etiology of early postoperative hypoxemia. Age, weight, intubation, surgical procedure, use of muscle relaxants, and/or administration of opioids may affect the incidence of early postoperative hypoxemia. In this prospective, randomized, and single‐blinded study, we evaluated whether the administration of caudal analgesia vs i.v. fentanyl affected the number of children who develop postextubation adverse upper airway respiratory events, (upper airway obstruction, laryngospasm) and/or early postoperative hypoxemia.Methods/materials:  Institutional approval and written parental informed consents were obtained. Thirty‐eight healthy outpatient boys, aged 1–6 years, scheduled for elective orchidopexy were randomized to receive pain relief either with a presurgical caudal block or by i.v. fentanyl. The primary outcome of the study was the number of children who developed postextubation adverse upper airway respiratory events and/or early postoperative hypoxemia.Results:  The number of boys who developed postextubation adverse upper airway respiratory events and/or early postoperative hypoxemia in the caudal group was less compared with those in the fentanyl group (P = 0.04).Conclusions:  Compared to fentanyl, placement of a presurgical caudal block in boys scheduled for orchidopexy was associated with a lower incidence of postextubation adverse upper airway respiratory events and/or early postoperative hypoxemia.
Reduction of fumarate, mesaconate and crotonate by Mfr, a novel oxygen‐regulated periplasmic reductase in Campylobacter jejuni
Authors: Guccione Edward , Hitchcock Andrew , Hall Stephen J. , Mulholland Francis , Shearer Neil , Van Vliet Arnoud H. M. , Kelly David J. 
Published: November 2009

SummaryMethylmenaquinol : fumarate reductase (Mfr) is a newly recognized type of fumarate reductase present in some ε‐proteobacteria, where the active site subunit (MfrA) is localized in the periplasm, but for which a physiological role has not been identified. We show that the Campylobacter jejuni mfrABE operon is transcribed from a single promoter, with the mfrA gene preceded by a small open reading‐frame (mfrX) encoding a C. jejuni‐specific polypeptide of unknown function. The growth characteristics and enzyme activities of mutants in the mfrA and menaquinol : fumarate reductase A (frdA) genes show that the cytoplasmic facing Frd enzyme is the major fumarate reductase under oxygen limitation. The Mfr enzyme is shown to be necessary for maximal rates of growth by fumarate respiration and rates of fumarate reduction in intact cells measured by both viologen assays and 1H‐NMR were slower in an mfrA mutant. As periplasmic fumarate reduction does not require fumarate/succinate antiport, Mfr may allow more efficient adaptation to fumarate‐dependent growth. However, a further rationale for the periplasmic location of Mfr is suggested by the observation that the enzyme also reduces the fumarate analogues mesaconate and crotonate; fermentation products of anaerobes with which C. jejuni shares its gut environment, that are unable to be transported into the cell. Both MfrA and MfrB subunits were localized in the periplasm by immunoblotting and 2D‐gel electrophoresis, but an mfrE mutant accumulated unprocessed MfrA in the cytoplasm, suggesting a preassembled MfrABE holoenzyme has to be recognized by the TAT system for translocation to occur. Gene expression studies in chemostat cultures following an aerobic‐anaerobic shift showed that mfrA is highly upregulated by oxygen limitation, as would be experienced in vivo. Our results indicate that in addition to a role in fumarate respiration, Mfr allows C. jejuni to reduce analogous substrates specifically present in the host gut environment.
Complex regulatory network encompassing the Csr, c‐di‐GMP and motility systems of Salmonella Typhimurium
Authors: Jonas Kristina , Edwards Adrianne N. , Ahmad Irfan , Romeo Tony , Römling Ute , Melefors Öjar 
Published: November 2009

SummaryBacterial survival depends on the ability to switch between sessile and motile lifestyles in response to changing environmental conditions. In many species, this switch is governed by (3′‐5′)‐cyclic‐diguanosine monophosphate (c‐di‐GMP), a signalling molecule, which is metabolized by proteins containing GGDEF and/or EAL domains. Salmonella Typhimurium contains 20 such proteins. Here, we show that the RNA‐binding protein CsrA regulates the expression of eight genes encoding GGDEF, GGDEF‐EAL and EAL domain proteins. CsrA bound directly to the mRNA leaders of five of these genes, suggesting that it may regulate these genes post‐transcriptionally. The c‐di‐GMP‐specific phosphodiesterase STM3611, which reciprocally controls flagella function and production of biofilm matrix components, was regulated by CsrA binding to the mRNA, but was also indirectly regulated by CsrA through the FlhDC/FliA flagella cascade and STM1344. STM1344 is an unconventional (c‐di‐GMP‐inactive) EAL domain protein, recently identified as a negative regulator of flagella gene expression. Here, we demonstrate that CsrA directly downregulates expression of STM1344, which in turn regulates STM3611 through fliA and thus reciprocally controls motility and biofilm factors. Altogether, our data reveal that the concerted and complex regulation of several genes encoding GGDEF/EAL domain proteins allows CsrA to control the motility‐sessility switch in S. Typhimurium at multiple levels.
Microclimate and limits to photosynthesis in a diverse community of hypolithic cyanobacteria in northern Australia
Authors: Tracy Christopher R. , Streten‐Joyce Claire , Dalton Robert , Nussear Kenneth E. , Gibb Karen S. , Christian Keith A. 
Published: November 2009

SummaryHypolithic microbes, primarily cyanobacteria, inhabit the highly specialized microhabitats under translucent rocks in extreme environments. Here we report findings from hypolithic cyanobacteria found under three types of translucent rocks (quartz, prehnite, agate) in a semiarid region of tropical Australia. We investigated the photosynthetic responses of the cyanobacterial communities to light, temperature and moisture in the laboratory, and we measured the microclimatic variables of temperature and soil moisture under rocks in the field over an annual cycle. We also used molecular techniques to explore the diversity of hypolithic cyanobacteria in this community and their phylogenetic relationships within the context of hypolithic cyanobacteria from other continents. Based on the laboratory experiments, photosynthetic activity required a minimum soil moisture of 15% (by mass). Peak photosynthetic activity occurred between approximately 8°C and 42°C, though some photosynthesis occurred between −1°C and 51°C. Maximum photosynthesis rates also occurred at light levels of approximately 150–550 μmol m−2 s−1. We used the field microclimatic data in conjunction with these measurements of photosynthetic efficiency to estimate the amount of time the hypolithic cyanobacteria could be photosynthetically active in the field. Based on these data, we estimated that conditions were appropriate for photosynthetic activity for approximately 942 h (∼75 days) during the year. The hypolithic cyanobacteria community under quartz, prehnite and agate rocks was quite diverse both within and between rock types. We identified 115 operational taxonomic units (OTUs), with each rock hosting 8–24 OTUs. A third of the cyanobacteria OTUs from northern Australia grouped with Chroococcidiopsis, a genus that has been identified from hypolithic and endolithic communities from the Gobi, Mojave, Atacama and Antarctic deserts. Several OTUs identified from northern Australia have not been reported to be associated with hypolithic communities previously.