bluuebunny/crossref_metadata_2025_split huggingface dataset:
Understanding nutrient dynamics in an African savanna: local biotic interactions outweigh a major regional rainfall gradient
Authors: Veldhuis Michiel P. , Hulshof Anneleen , Fokkema Wimke , Berg Matty P. , Olff Han 
Published: March 2016

Summary

Nutrient availability in terrestrial ecosystems has been found to vary along regional climatic and soil gradients and drive variation in plant community composition and vegetation structure. However, more local biotic feedbacks also affect nutrient availability, but their importance in determining vegetation structure relative to regional drivers is yet unclear.

Mesic African savannas form a transition zone between the dry grasslands with relatively low nitrogen availability (indicated by low plant N:P ratios) and the wet woodlands of the continent characterized by relatively low phosphorous availability (high plant N:P ratios). They host strong feedback mechanisms of both vegetation and consumers, where large grazers can create short grazing lawns that alternate over short distances with tall fire‐dominated bunch grasslands, and patches dominated by woody species with abundant macrodetritivores. Here, we test if such local biotic interactions can overrule regional, landscape‐level drivers of plant nutrient availability.

In a South African savanna, we find that plant N:P ratios, N and P resorption efficiencies and proficiencies, were indeed much stronger affected by small‐scale biotic‐created heterogeneity than by a regional rainfall gradient (530–830 mm yr−1). Furthermore, we observe that differences in N:P ratios between vegetation structural types are not caused by simple differences in inherent plant traits.

This suggests that availability of N and P to plants is strongly contingent on the local biotic interplay between different vegetation structural types and within‐system feedbacks linked to each vegetation type. The regional rainfall gradient did affect nutrient availability, but mainly through its effect on the relative distribution of the different vegetation structural types thus setting the range of possible outcomes of biotic interactions.

Synthesis. Regional and global studies that model savanna carbon and nutrient cycling only on the basis of regional gradients in soil and climatic conditions may insufficiently capture the dominant ecosystem processes involved.
Distance‐dependent effects of pathogenic fungi on seedlings of a legume tree: impaired nodule formation and identification of antagonistic rhizosphere bacteria
Authors: Liu Lan , Yu Shixiao , Xie Zhi‐Ping , Staehelin Christian 
Published: March 2016

Summary

The Janzen‐Connell (JC) hypothesis proposes that diversity of tree communities is promoted by species‐specific enemies that suppress seedling recruitment. Pathogenic soil‐borne fungi are often responsible for JC effects. However, previous ecological studies have not placed JC effects in the context of beneficial soil bacteria. Using the JC effect surrounding a subtropical legume tree (Ormosia glaberrima) as a model, we characterized tripartite interactions between seedlings, soil fungi and plant‐associated bacteria.

Survival of seedlings grown in soil inocula collected at close distances to focal adult trees was reduced. Half of the experimental units were treated with fungicides to confirm the presence of pathogenic fungi. In a parallel experiment, nitrogen‐fixing rhizobia induced fewer nodules on O. glaberrima seedlings when soil inocula were collected closer to focal adult trees. An inoculation experiment with rhizobial isolates promoted nodulation of seedlings grown in soil taken at close distances to adult trees, suggesting that rhizobial densities are suboptimal at these locations.

Fusarium oxysporum, a pathogen of O. glaberrima seedlings, produced exudates that inhibited growth of most bacteria isolated from nodules. Accordingly, F. oxysporum negatively affected rhizosphere colonization of rhizobia in a co‐inoculation experiment. Contrariwise, certain Burkholderia isolates (from nodules and the rhizosphere) were identified that possess the ability to inhibit growth of F. oxysporum. The majority of the antagonistic bacteria were isolated from locations with fungal pathogens, suggesting competition between fungi and rhizosphere bacteria.

Exclusion of pathogenic fungi by application of fungicides promoted nodulation of O. glaberrima seedlings under growth‐room and field conditions.

Synthesis. Our findings indicate that soil‐borne pathogens surrounding adult trees are microbial keystone species that locally influence interactions between seedlings and plant‐associated bacteria.
Salt marsh‐mangrove ecotones: using structural gradients to investigate the effects of woody plant encroachment on plant–soil interactions and ecosystem carbon pools
Authors: Yando Erik S. , Osland Michael J. , Willis Jonathan M. , Day Richard H. , Krauss Ken W. , Hester Mark W. 
Published: March 2016

Summary

Changing winter climate extremes are expected to result in the poleward migration of mangrove forests at the expense of salt marshes. Although mangroves and marshes are both highly valued ecosystems, the ecological implications of mangrove expansion have not been fully investigated.

Here, we examined the effects of mangrove expansion on below‐ground properties related to peat development and carbon storage. We investigated plant–soil interactions in marshes and across mangrove forest structural gradients in three locations in the northern Gulf of Mexico (USA). We compared our results to those from terrestrial grasslands where the effects of woody plant encroachment are often influenced by rainfall and plant traits.

Abiotic conditions at our study locations differed, particularly in terms of physicochemical properties related to precipitation. Marsh species composition, marsh above‐ground biomass, and mangrove forest structural complexity also varied across these locations. Marshes in the driest location (Central Texas) had higher salinities and were dominated by low biomass succulent plants and lower soil carbon pools. Marshes in the wetter, less saline locations (Louisiana and North Florida) contained high biomass grasses and higher soil carbon pools.

At all locations, above‐ground biomass and above‐ground carbon pools were higher in mangroves than marshes; however, below‐ground soil carbon pools were only higher in mangroves than marshes in the driest location. In the wetter locations, the linkages between mangrove forest structure and soil properties were minimal or not significant. However, in the driest location, there was a significant increase in soil properties related to peat development and carbon storage with increased mangrove forest structural development.

Synthesis: Our results indicate that the ecological implications of woody plant encroachment in tidal saline wetlands are dependent upon precipitation controls of plant–soil interactions. Although the above‐ground effects of mangrove expansion are consistently large, below‐ground influences of mangrove expansion appear to be greatest along low‐rainfall coasts where salinities are high and marshes being replaced are carbon poor and dominated by succulent plants. Collectively, these findings complement those from terrestrial ecosystems and reinforce the importance of considering rainfall and plant–soil interactions within predictions of the ecological effects of woody plant encroachment.
Isolation and characterization of Dehalobacter sp. strain UNSWDHB capable of chloroform and chlorinated ethane respiration
Authors: Wong Yie K. , Holland Sophie I. , Ertan Haluk , Manefield Mike , Lee Matthew 
Published: March 2016

SummaryDehalobacter sp. strain UNSWDHB can dechlorinate up to 4 mM trichloromethane at a rate of 0.1 mM per day to dichloromethane and 1,1,2‐trichloroethane (1 mM, 0.1 mM per day) with the unprecedented product profile of 1,2‐dichloroethane and vinyl chloride. 1,1,1‐trichloroethane and 1,1‐dichloroethane were slowly utilized by strain UNSWDHB and were not completely removed, with minimum threshold concentrations of 0.12 mM and 0.07 mM respectively under growth conditions. Enzyme kinetic experiments confirmed strong substrate affinity for trichloromethane and 1,1,2‐trichloroethane (Km = 30 and 62 µM respectively) and poor substrate affinity for 1,1,1‐trichloroethane and 1,1‐dichloroethane (Km = 238 and 837 µM respectively). Comparison of enzyme kinetic and growth data with other trichloromethane respiring organisms (Dehalobacter sp. strain CF and Desulfitobacterium sp. strain PR) suggests an adaptation of strain UNSWDHB to trichloromethane. The trichloromethane RDase (TmrA) expressed by strain UNSWDHB was identified by BN‐PAGE and functionally characterized. Amino acid comparison of homologous RDases from all three organisms revealed only six significant amino acid substitutions/deletions, which are likely to be crucial for substrate specificity. Furthermore, strain UNSWDHB was shown to grow without exogenous supply of cobalamin confirming genomic‐based predictions of a fully functional cobalamin synthetic pathway.
Risk factors and newborn outcomes associated with maternal deaths in the UK from 2009 to 2013: a national case–control study
Authors: Nair M , Knight M , Kurinczuk JJ 
Published: March 2016

ObjectivesTo identify the risk factors for and adverse newborn outcomes associated with maternal deaths from direct and indirect causes in the UK.DesignUnmatched case–control analysis.SettingAll hospitals caring for pregnant women in the UK.PopulationComprised 383 women who died (cases) from direct or indirect causes from 2009 to 2013 (Confidential Enquiry into Maternal Deaths in the UK) and 1516 women who did not have any life‐threatening complications during pregnancy and childbirth (controls) obtained from UK Obstetric Surveillance System (UKOSS).MethodsMultivariable regression analyses were undertaken to examine potential risk factors, their incremental effects, and adverse newborn outcomes associated with maternal deaths.OutcomesOdds ratios associated for risk factors for maternal death and newborn outcomes (stillbirth, admission to neonatal intensive care unit [NICU], early neonatal death) and incremental risk.ResultsSeven factors, of 13 examined, were independently associated with increased odds of maternal death: pre‐existing medical comorbidities (adjusted odds ratio [aOR] 8.65; 95% CI 6.29–11.90), anaemia during pregnancy (aOR 3.58; 95% CI 1.14–11.21), previous pregnancy problems (aOR 1.85; 95% CI 1.33–2.57), inadequate use of antenatal care (aOR 46.85; 95% CI 19.61–111.94), substance misuse (aOR 12.21; 95% CI 2.33–63.98), unemployment (aOR 1.81; 95% CI 1.08–3.04) and maternal age (aOR 1.06; 95% CI 1.04–1.09). There was a four‐fold increase in the odds of death per unit increase in the number of risk factors. Odds of stillbirth, admission to NICU and early neonatal death were higher among women who died.ConclusionThis study reiterates the need for optimal care for women with medical comorbidities and older age, and the importance of adequate antenatal care. It demonstrates the existence of socio‐economic inequalities in maternal death in the UK.Tweetable abstractMedical comorbidities and socio‐economic inequalities are important risk factors for maternal death in the UK.
Understanding Racial and Ethnic Disparities in Postsurgical Complications Occurring in U.S. Hospitals
Authors: Witt Whitney P. , Coffey Rosanna M. , Lopez‐Gonzalez Lorena , Barrett Marguerite L. , Moore Brian J. , Andrews Roxanne M. , Washington Raynard E. 
Published: March 2016

ObjectiveTo examine the role of patient, hospital, and community characteristics on racial and ethnic disparities in in‐hospital postsurgical complications.Data SourcesHealthcare Cost and Utilization Project, 2011 State Inpatient Databases; American Hospital Association Annual Survey of Hospitals; Area Health Resources Files; Centers for Medicare & Medicaid Services Hospital Compare database.MethodsNonlinear hierarchical modeling was conducted to examine the odds of patients experiencing any in‐hospital postsurgical complication, as defined by Agency for Healthcare Research and Quality Patient Safety Indicators.Principal FindingsA total of 5,474,067 inpatient surgical discharges were assessed using multivariable logistic regression. Clinical risk, payer coverage, and community‐level characteristics (especially income) completely attenuated the effect of race on the odds of postsurgical complications. Patients without private insurance were 30 to 50 percent more likely to have a complication; patients from low‐income communities were nearly 12 percent more likely to experience a complication. Private, not‐for‐profit hospitals in small metropolitan or micropolitan areas and higher nurse‐to‐patient ratios led to fewer postsurgical complications.ConclusionsRace does not appear to be an important determinant of in‐hospital postsurgical complications, but insurance and community characteristics have an effect. A population‐based approach that includes improving the socioeconomic context may help reduce disparities in these outcomes.
Accuracy and adequacy of food supplied in therapeutic diets to hospitalised patients: An observational study
Authors: Larby Annabel , Roberts Shelley , Desbrow Ben 
Published: March 2016

AimThis study assessed the accuracy (including sources and reasons for errors) and adequacy (of patients’ intakes relative to requirements) among patients prescribed therapeutic diets in the hospital setting.MethodsThis observational study was conducted across six wards in a metropolitan tertiary hospital over 14 consecutive days. Meal accuracy was assessed by comparing each individual food or fluid item provided to each patient to items allowed on their specific diet code. Errors were defined by severity (critical or non‐critical threat to patient safety) and source (foodservice system, staff or patient). Nutritional adequacy was determined by comparing patients’ daily energy and protein intakes to individually estimated requirements. Intakes were considered adequate if consumption was ≥75% of requirements.ResultsMeals of 67 patients (31 females, aged 60.0 ± 19.4 years) were assessed for accuracy for up to two days. Of the total 347 therapeutic meals observed, 69 (19.9%) were inaccurate. A large proportion of these errors were critical (64.8%). Foodservice errors were the most common source. Of the 48 patients with complete dietary intake data, mean energy and protein intakes were 3192 ± 2220 kJ and 33 ± 27 g protein, respectively. Only five and seven patients consumed adequate energy and protein to meet their estimated requirements, respectively.ConclusionPatients requiring therapeutic diets during hospitalisation are frequently exposed to food and/or fluid errors that may pose an acute threat to their safety. In addition, prescription of these diets may result in patients being unable to adequately meet their nutritional requirements.
The Importance of Global Extinction in Climate Change Policy
Authors: Ng Yew‐Kwang 
Published: March 2016

AbstractFor problems like global climate change that may involve global extinction, we must not just focus, as most economic analysts do, on the trading‐off of current consumption (current mitigation investment reduces consumption) against future consumption (less need for future investment), but also consider the effects of mitigation investment in reducing the extinction probabilities. Future utility/welfare values should only be discounted at the uncertainty of their realization, making these values even in the far future important as this discount rate should be very low (0.01 per cent per annum or less). Immediate and strong actions of environmental protection including greenhouse gas reduction may thus be justified despite high consumption discount rates (about 5 per cent). Unexpectedly, an increase in the extinction probabilities may increase or decrease our willingness to reduce them; precise conditions are given. The related intuition that, the higher the probability of destruction of your house by fire, the less willing you will be in investing on things like interior decoration that does not change the probability of destruction, but the higher your willingness to pave a fire clearance that does reduce the probability of destruction, is examined.
Accountability in International Governance and the 2030 Development Agenda
Authors: Ocampo José Antonio , Gómez‐Arteaga Natalie 
Published: March 2016

AbstractAfter revisiting the concept of accountability in national governance, this paper analyzes the challenges of its application to international governance, including an assessment of some of the modalities it has assumed. It then proposes a bottom‐up multilayered and multistakeholder accountability framework for the 2030 Development Agenda: national follow‐up processes at the base of the pyramid, consultations and possibly peer reviews at the regional level, a global accountability system led by the High‐Level Political Forum (HLPF) and supported by the ECOSOC system, United Nations and other international organizations, and active participation by civil society and the private sector with their own accountability frameworks in place.
Mediastinal irradiation in a patient affected by lung carcinoma after heart transplantation: Helical tomotherapy versus three dimensional conformal radiotherapy
Authors: Giugliano Francesca M. , Iorio Vincenzo , Cammarota Fabrizio , Toledo Diego , Senese Rossana , Francomacaro Ferdinando , Muto Matteo , Muto Paolo 
Published: March 2016

AbstractPatients who have undergone solid organ transplants are known to have an increased risk of neoplasia compared with the general population. We report our experience using mediastinal irradiation with helical tomotherapy versus three‐dimensional conformal radiation therapy to treat a patient with lung carcinoma 15 years after heart transplantation. Our dosimetric evaluation showed no particular difference between the techniques, with the exception of some organs. Mediastinal irradiation after heart transplantation is feasible and should be considered after evaluation of the risk. Conformal radiotherapy or intensity‐modulated radiotherapy appears to be the appropriate treatment in heart‐transplanted oncologic patients.
Dividend persistence and dividend behaviour
Authors: Chan Kam Fong , Powell John G. , Shi Jing , Smith Tom 
Published: March 2016

AbstractThis article demonstrates how a spurious regression problem caused by dividend persistence is compounded by a spurious correlation problem when the dependent and independent variables in dividend behaviour regressions are ratios composed of common component variables. This article utilises a simulation procedure to take account of these problems, with the findings implying that extreme care should be taken when using ratios as predictor or explanatory variables in time series regression. This article introduces a reformulated Lintner first difference dividend behaviour model that is not subject to spurious regression in which past prices predict subsequent changes in dividends.
Categorizing species by niche characteristics can clarify conservation planning in rapidly‐developing landscapes
Authors: Gangadharan A. , Vaidyanathan S. , St. Clair C. C. 
Published: March 2016

AbstractIn biodiversity‐rich landscapes that are developing rapidly, it is generally impossible to delineate land use and prioritize conservation actions in relation to the full variability of species and their responses to anthropogenic activity. Consequently, conservation policy often focuses on protecting habitat used by a few flagship, indicator or umbrella species like tigers Panthera tigris and Asian elephants Elephas maximus, which potentially leaves out species that do not share these habitat preferences. We demonstrate an empirical approach that clustered 14 mammals into surrogate groups that reflect their unique conservation needs. We surveyed a 787 km2 multiple‐use area in the Shencottah Gap of the Western Ghats, India, using foot surveys and camera‐trap surveys. Using ecological niche factor analysis, we generated indices of species prevalence (marginality and tolerance) and habitat preferences (factor correlations to marginality axis). We then clustered species by both of the above index types to reveal four clusters based on prevalence and four clusters based on habitat preference. Most clusters contained at least one threatened species. Low‐prevalence lion‐tailed macaques Macaca silenus and tigers were strongly associated with closed forests and low human disturbance. But elephants, sloth bears Melursus ursinus and gaur Bos gaurus were more tolerant of anthropogenic impact, and sloth bears and gaur preferred open forests and grasslands. Dhole Cuon alpinus and sambar Rusa unicolor were associated with highly anthropogenic habitat (farmland, cash crop and forestry plantations) with high human use. Thus, reliance on flagship species for conservation planning can both underestimate and overestimate the ability of other species to persist in multiple‐use landscapes; protecting flagship species would only protect species with similar habitat preferences. For species that avoid human impacts more than the flagship species, core habitat must be protected from human disturbance. For more tolerant species, conservation in anthropogenic habitat may hinge on policies that bolster coexistence with humans.
Behavioral flexibility predicts increased ability to resist excessive methamphetamine self‐administration
Authors: Istin Marine , Thiriet Nathalie , Solinas Marcello 
Published: March 2016

AbstractDrug addiction is often associated with cognitive deficits and behavioral inflexibility that may contribute to the development and maintenance of addictive behaviors by reducing addicts' ability to control their behavior toward the drug. In this study, we investigated the relationships between pre‐drug levels of behavioral flexibility and the risk to develop uncontrolled methamphetamine (METH) self‐administration. First, we measured individual performance in an inter‐dimensional set‐shifting procedure in which animals have to switch between an external visual rule and an internal side rule in order to obtain food pellets. Then we allowed rats to self‐administer METH for twenty long 14‐hour sessions, and we investigated the relationships between behavioral flexibility and measures of control over drug intake. Rats rapidly acquired to self‐administer high levels of METH which resulted in moderate weight loss. After several sessions of self‐administration, whereas some rats progressively increased their METH intake, other rats showed very long voluntary pauses between drug injections and showed no escalation in METH self‐administration. Interestingly, we found that behavioral flexibility is correlated with METH self‐administration and that more flexible rats take less METH and do not escalate drug taking. These results suggest that traits of behavioral flexibility may protect against the development of excessive and dysregulated drug taking. Conversely, the inability to adapt behavioral responses as a function of the environmental contingencies may contribute to the risks to develop addiction to METH.