bluuebunny/crossref_metadata_2025 huggingface dataset:
Climate‐mediated habitat selection in an arboreal folivore
Authors: Crowther Mathew S. , Lunney Daniel , Lemon John , Stalenberg Eleanor , Wheeler Robert , Madani George , Ross Karen A. , Ellis Murray
Published: October 2013

The decisions that animals must make to achieve a balance between quantity and quality of resources become more difficult when their habitats are patchy and differ greatly in quality across space and time. Koalas are a prime subject to study this problem because they have a specialised diet of eucalypt leaves and need to balance nutrient and water intake against toxins in the leaves, all of which can change with soil type and climate. Koalas are nocturnal and spend most of the day resting and therefore choose trees for reasons other than feeding, particularly for thermoregulation. We GPS‐tracked 40 koalas over 3 yr to determine their shift in tree selection between day and night, and in relation to daily maximum temperature, in a patchy rural landscape in north‐western NSW, Australia. The species, degree of shelter, diameter, height and elevation of each visited tree were recorded. We used generalised linear mixed effects models to compare tree use between day and night and maximum daily temperature. Koalas used more feed‐trees during the night, and more shelter‐trees during the day. They also selected taller trees with more shelter in the day compared with night. As daytime temperatures rose, koalas increasingly selected taller trees at lower elevations. Our results demonstrate that koalas need taller trees, and non‐feed species with shadier/denser foliage, to provide shelter from heat. This highlights the need both for the retention of taller, mature trees, such as remnant paddock trees, and the planting of both food and shelter trees to increase habitat area and connectivity across the landscape for arboreal species. Retaining and planting trees that provide optimum habitat will help arboreal folivores cope with the more frequent droughts and heatwaves expected with climate change.
A new approach for rapid detection of nearby thresholds in ecosystem time series
Authors: Carpenter Stephen R. , Brock William A. , Cole Jonathan J. , Pace Michael L.
Published: October 2013

Massive changes to ecosystems sometimes cross thresholds from which recovery can be difficult, expensive and slow. These thresholds are usually discovered in post hoc analyses long after the event occurred. Anticipating these changes prior to their occurrence could give managers a chance to intervene. Here we present a novel approach for anticipating ecosystem thresholds that combines resilience indicators with Quickest detection of change points. Unlike existing methods, the Quickest detection method is updated every time a data point arrives, and minimizes the time to detect an approaching threshold given the users’ tolerance for false alarms. The procedure accurately detected an impending regime shift in an experimentally manipulated ecosystem. An ecosystem model was used to determine if the method can detect an approaching threshold soon enough to prevent a regime shift. When the monitored variable was directly involved in the interaction that caused the regime shift, detection was quick enough to avert collapse. When the monitored variable was only indirectly linked to the critical transition, detection came too late. The procedure is useful for assessing changes in resilience as ecosystems approach thresholds. However some thresholds cannot be detected in time to prevent regime shifts, and surprises will be inevitable in ecosystem management.
Impact of extreme and fluctuating temperatures on aphid–parasitoid dynamics
Authors: Bannerman Jordan A. , Roitberg Bernard D.
Published: October 2013

Climate change is predicted to increase the occurrence of extreme temperature events. We constructed a stage‐structured Leslie matrix model with intra‐generational dynamics to explore the impact of extreme and fluctuating temperatures on host–parasitoid dynamics. We varied three temperature parameters to generate a range of temperature regimes that varied in their daily maximum temperatures, the number of warmer‐than‐average days and the autocorrelation of those warmer‐than‐average days. All three temperature parameters influenced host–parasitoid dynamics. Increasing the frequency of warmer than average days and the degree of autocorrelation only exerted significant impacts on host– parasitoid dynamics when daily maximum temperatures were sufficient to produce temperature‐dependent mortality. The effects of increasing autocorrelation of daily temperatures were dependent on the maximum daily temperatures and the frequency of warmer than average days. When daily maximum temperatures were severely warm, but the frequency of those severely warm days was low, increasing autocorrelation increased the probability that the aphids and parasitoids will persist, but when the frequency of severely warm days is increased, increasing autocorrelation decreases the probability that the populations will persist. These temperature phenomena exert significant effects on host–parasitoid dynamics in addition to those effects produced by changes in mean temperatures and warrant further investigation at the community level.
Informed dispersal in plants: Heterosperma pinnatum (Asteraceae) adjusts its dispersal mode to escape from competition and water stress
Authors: Martorell Carlos , Martínez‐López Marcela
Published: October 2013

Informed‐dispersal theory (IDT) states that organisms may use information on the quality of the local environment when deciding whether to disperse or not. Dispersal is expected to occur from adverse patches where the costs of philopatry (lack of dispersal) are greater than those of dispersal. Evidence of informed dispersal in plants is scarce, and experiments under natural conditions are lacking. We tested IDT in a semiarid grassland using the annual forb Heterosperma pinnatum, which produces awned, zoochorous achenes and unawned, philopatric ones. We expected the proportion of awned seeds to increase under adverse conditions that reduce fitness, (i.e. under high competition and water stress). Heterosperma pinnatum was sown along natural moisture gradients with and without a shade that increased water availability. We found that competition (number of conspecific neighbors) and water stress reduced fitness. As expected, the proportion of highly dispersible seeds increased under such conditions, probably as a strategy to escape from unsuitable patches. Many plants species do not behave as expected by IDT. Our results suggest that experiments under natural conditions in systems where the assumptions of IDT are met may prove to be a wealthy source of evidence for informed dispersal in plants.
Form, function and consequences of density dependence in a long‐distance migratory bird
Authors: McKellar Ann E. , Marra Peter P. , Boag Peter T. , Ratcliffe Laurene M.
Published: October 2013

The density dependence of demographic parameters and its implications for population regulation have long been recognized. Recent work has revealed potential effects of density on mating systems and sexual selection, but few studies concurrently assess the consequences of density on both demography and sexual selection. Such an approach is important because population processes and individual behaviors can interact to influence population growth and evolutionary trajectories. In this study, we tested the density dependence of breeding success, extra‐pair paternity, and the opportunity for sexual selection in a population of American redstarts Setophaga ruticilla using two different measures of density. To evaluate temporal patterns, we analyzed annual territory density, based on the total number of territories at our study site each year. To evaluate spatial patterns, we analyzed local territory density within years, based on the number of territories surrounding a focal territory. Greater annual density was associated with fewer offspring fledged per female, a reduced mean population rate of fledging success, and a lower relative contribution of extra‐pair paternity to male fitness. Greater local density was associated with fewer offspring fledged, reduced fledgling success, higher rates of nest loss, and higher rates of paternity loss on focal territories. Interestingly, greater local density was also associated with greater nestling mass on focal territories, which could imply that more densely‐packed territories contain superior resources. Overall, our results suggest that the effects of crowding via greater territory density reduce fecundity through increased nest predation, rather than reduced food availability, and increase rates of extra‐pair paternity. Thus, the selective pressures faced by individuals and their reproductive behaviors are likely to differ based on the annual and local density they experience, which may then feed back into population demography.
Proposal for an International Molybdenum Isotope Measurement Standard and Data Representation
Authors: Nägler Thomas F. , Anbar Ariel D. , Archer Corey , Goldberg Tatiana , Gordon Gwyneth W. , Greber Nicolas D. , Siebert Christopher , Sohrin Yoshiki , Vance Derek
Published: October 2013

Molybdenum isotopes are increasingly widely applied in Earth Sciences. They are primarily used to investigate the oxygenation of Earth's ocean and atmosphere. However, more and more fields of application are being developed, such as magmatic and hydrothermal processes, planetary sciences or the tracking of environmental pollution. Here, we present a proposal for a unifying presentation of Mo isotope ratios in the studies of mass‐dependent isotope fractionation. We suggest that the δ98/95Mo of the NIST SRM 3134 be defined as +0.25‰. The rationale is that the vast majority of published data are presented relative to reference materials that are similar, but not identical, and that are all slightly lighter than NIST SRM 3134. Our proposed data presentation allows a direct first‐order comparison of almost all old data with future work while referring to an international measurement standard. In particular, canonical δ98/95Mo values such as +2.3‰ for seawater and −0.7‰ for marine Fe–Mn precipitates can be kept for discussion. As recent publications show that the ocean molybdenum isotope signature is homogeneous, the IAPSO ocean water standard or any other open ocean water sample is suggested as a secondary measurement standard, with a defined δ98/95Mo value of +2.34 ± 0.10‰ (2s).
Order Stability in Supply Chains: Coordination Risk and the Role of Coordination Stock
Authors: Croson Rachel , Donohue Karen , Katok Elena , Sterman John
Published: October 2013

The bullwhip effect describes the tendency for the variance of orders in supply chains to increase as one moves upstream from consumer demand. We report on a set of laboratory experiments with a serial supply chain that tests behavioral causes of this phenomenon, in particular the possible influence of coordination risk. Coordination risk exists when individuals' decisions contribute to a collective outcome and the decision rules followed by each individual are not known with certainty, for example, where managers cannot be sure how their supply chain partners will behave. We conjecture that the existence of coordination risk may contribute to bullwhip behavior. We test this conjecture by controlling for environmental factors that lead to coordination risk and find these controls lead to a significant reduction in order oscillations and amplification. Next, we investigate a managerial intervention to reduce the bullwhip effect, inspired by our conjecture that coordination risk contributes to bullwhip behavior. Although the intervention, holding additional on‐hand inventory, does not change the existence of coordination risk, it reduces order oscillation and amplification by providing a buffer against the endogenous risk of coordination failure. We conclude that the magnitude of the bullwhip can be mitigated, but that its behavioral causes appear robust.
Comparison of Drought Tolerance of Maize, Sweet Sorghum and Sorghum‐Sudangrass Hybrids
Authors: Schittenhelm S. , Schroetter S.
Published: October 2013

In drought‐prone environments, sweet sorghum and sorghum‐sudangrass hybrids are considered worthy alternatives to maize for biogas production. The biomass productivity of the three crops was compared by growing them side‐by‐side in a rain‐out shelter under different levels of plant available soil water (PASW) during the growing periods of 2008 to 2010 at Braunschweig, Germany. All crops were established under high levels of soil water. Thereafter, the crops either remained at the wet level (60–80 % PASW) or were subjected to moderate (40–50 % PASW) and severe drought stress (15–25 % PASW). While the above‐ground dry weight (ADW) of sweet sorghum and maize was insignificantly different under well‐watered conditions, sweet sorghum under severe drought stress produced 27 % more ADW than maize. The ADW of sorghum‐sudangrass hybrids significantly lagged behind sweet sorghum at all levels of water supply. The three crops differed markedly in their susceptibility to water shortage. Severe drought stress reduced the ADW of maize by 51 %, but only by 37 % for sweet sorghum and 35 % for sorghum‐sudangrass hybrids. The post‐harvest root dry weight (RDW) in the 0–100 cm soil layer for maize, sweet sorghum and sorghum‐sudangrass hybrids averaged 4.4, 6.1 and 2.9 t ha−1 under wet and 1.9, 5.7 and 2.4 t ha−1 under severe drought stress. Under these most dry conditions, the sorghum crops had relatively higher RDW and root length density (RLD) in the deeper soil layers than maize. The subsoil RDW proportion (20–100 vs. 0–20 cm) for maize, sweet sorghum and sorghum‐sudangrass hybrids amounted to 6 %, 10 % and 20 %. The higher ADM of sweet sorghum compared with maize under dry conditions is most likely attributable to the deep root penetration and high proportion of roots in the subsoil, which confers the sorghum crop a high water uptake capacity.
Temperature Gradient Introduced Ferroelectric Self‐Poling in BiFeO3 Ceramics
Authors: Chen Xiaomin , Zou Yuhong , Yuan Guoliang , Zeng Min , Liu J. M. , Yin Jiang , Liu Zhiguo
Published: October 2013

The as‐prepared BiFeO3 ceramic shows a piezoelectric d33 coefficient of −14 pC/N, that is, an obvious ferroelectric self‐poling phenomenon. The temperature gradient between the two surfaces of BiFeO3 ceramic was intentionally enlarged when BiFeO3 was prepared with a rapid liquid sintering method. This temperature gradient and the corresponding thermal strain can introduce defect dipoles through separating bismuth vacancies from oxygen vacancies. A mass of these dipoles introduce a macroscopic internal electric field (Ein) which downward poles BiFeO3 ceramic during its cooling down process. As expected, an Ein of >10 kV/cm is confirmed by the asymmetrical polarization/strain versus electric field curves.
Nanoscaled Interface Between Microgold Particles and Biphase Glass‐Ceramic Matrix
Authors: Yi Wei , Hu Xiaozhi , Ichim Paul , Sun Xudong
Published: October 2013

This article presents a detailed study on the nanoscaled interface between microelongated gold particles (GP) and biphase leucite/feldspar glass‐ceramic matrix. The glass‐ceramic composite with a nonuniform GP distribution was processed through hot‐pressing under vacuum using a commercial dental ceramic furnace for glass‐ceramic dental crown manufacturing. Heat treatments at 900°C, 1100°C, and 1300°C were conducted, and microstructural features along the interface were used to verify the chemical reactions between GP and glass‐ceramic matrix. It was observed that the amorphous glass‐ceramic matrix had nanoscaled biphase structures, and the distributed nanoscaled amorphous leucite phase was attracted to GP during hot‐pressing, and was more reactive with GP than the feldspar phase. The thickness of the interfacial phase formed through chemical reactions between GP and glass‐ceramic matrix is around 30 nm. The chemically bonded interface has contributed significantly toward the substantial improvements in both strength and toughness of the GP‐reinforced glass‐ceramic matrix composite. Characterization techniques, including X‐ray diffraction and field‐emission scanning electron Microscopy, incorporating X‐ray microanalysis using energy dispersive spectrometry, have been employed in this study.
Luminescence Properties of Dual‐Emission (UV/Visible) Long Afterglow Phosphor SrZrO3: Pr3+
Authors: Jin Yahong , Hu Yihua , Chen Li , Wang Xiaojuan , Ju Guifang , Mou Zhongfei
Published: October 2013

A dual‐emission (UV/Visible) phosphor SrZrO3: Pr3+ was prepared by a high‐temperature solid‐state reaction method. The afterglow including ultraviolet (UV) and visible region which originated from self‐trapped excitons and f–f transitions in Pr3+ was first observed after the short UV‐irradiation. All as‐prepared phosphors were studied systematically by X‐ray diffraction, photoluminescence (PL) spectra, decay curves, long afterglow spectra (LAG), and thermoluminescence (TL) glow curves. The PL intensity and the performance of afterglow are dependent on the concentration of Pr3+ ions. The optimal concentration of Pr3+ ions for the brightest PL emission and the best afterglow characteristic were experimentally to be 0.5% and 0.4%, respectively. The different mechanisms for concentration quenching in both cases were discussed. A model was proposed on the basis of experimental results to discuss the mechanism of LAG in SrZrO3: Pr3+ in detail.
Solvothermal Synthesis of Acmite Conversion Coatings on Steel
Authors: Whalen Terence , VanSaders Bryan , Vakifahmetoglu Cekdar , Mughal Asad , Zlotnikov Eugene , Cho Seung‐Beom , Riman Richard E.
Published: October 2013

Acmite (NaFeSi2O6) films were formed on steel coupons via solvothermal reaction of silica, sodium hydroxide, and 1, 4‐butanediol in an autoclave under autogenous pressure. Systematic variation in processing variables led to homogenous coatings comprised of pinacoidal acmite grains with an average grain size of ~33 μm. The coatings were produced on the steel coupons from reactant conditions of 0.635 m SiO2, 2.546 m NaOH, and 3.087 m 1,4‐butanediol for 72 h at 240°C.
Direct Formation and Luminescence Properties of Yttrium Niobate YNbO4 Nanocrystals via Hydrothermal Method
Authors: Hirano Masanori , Dozono Hayato
Published: October 2013

Yttrium niobate YNbO4 nanocrystals with ellipsoidal morphology were directly formed from the precursor solution mixtures of YCl3 and NbCl5 under weakly basic conditions in the presence of aqueous ammonia by hydrothermal method. The hydrothermal treatment at 180°C for 5 h was necessary to obtain nanocrystals (18 nm) with sufficient crystallinity. The optical band gap of the as‐prepared samples was 3.6 eV. The as‐prepared YNbO4 nanocrystals showed UV‐blue and broadband emission centered at 405 nm under excitation at 235 nm, which was due to the blue recombination luminescence, associated with charge‐transfer transitions involving the tetrahedral NbO4 group. The emission intensity increased with increased hydrothermal treatment temperature. The photoluminescence intensity of the YNbO4 was extremely improved via heating above 1000°C in air, which was accompanied by the increase in the optical band gap from 3.6 to 4.0 eV. By heat treatment at 1300°C, the intensity of the UV‐blue and broadband emission (with maximum at 400 nm) for the YNbO4 became more than 22.5 times as strong as that before heat treatment.
Sexual desire, erectile dysfunction and the biomedicalization of sex in older heterosexual men
Authors: Gledhill Susan , Schweitzer Robert D.
Published: October 2013

Aim

To examine sexual desire in older age and the use of pharmaceuticals for sexual enhancement in the context of erectile dysfunction.

Background

The ability of the older person to fulfil sexual desire has not been well supported in Western society.

Design

The paper draws on themes that emerged during a phenomenological study of sexual desire in older age.

Method

Narratives were collected between 2008–2010 from in‐depth interviews with six men and two women aged 65–84 years who were part of a larger Australian study of sexual desire in older age.

Findings

Emergent themes reveal that for some older people, the biomedicalization of sex can be a disappointing experience.

Conclusion

The findings illuminate the need for nurses who are at the front line of health care, health policy makers and educators, to consider sexual desire experienced in older age in the context of sexual health and healthy ageing. This study will contribute to a growing body of knowledge about sexual desire in older age.
Evaluation of a Psychoeducational intervention for patients with Advanced Cancer who have Cachexia and their lay Carers (EPACaCC): study protocol
Authors: Reid Joanne , Scott David , Santin Olinda , Cardwell Chris R. , Donnelly Michael , Kernohan W. George , O'Halloran Peter Dominic , Regan Joan , Porter Sam
Published: October 2013

Aim

To evaluate a psychoeducational intervention for patients with advanced cancer who have cachexia and their lay carers.

Background

Cachexia is a frequent and devastating syndrome of advanced cancer. It has an impact on patients biologically, psychologically and socially and has profound impact on their lay carers. Prior research has predominately focused on the biological components of cachexia and associated potential treatment modalities. At present, there is no standardized supportive healthcare intervention in current practice that targets the psychosocial impact of this syndrome.

Design

A pragmatic multicentre randomized controlled trial.

Methods

Patient/carer dyads (n = 200) will be recruited into a randomized controlled trial of a DVD intervention for cachexia management. The sample will be recruited from two urban hospices in the UK. The primary outcome measure will be the General Health Questionnaire‐12. Additional questionnaires focusing on distress, readiness to give care and coping skills will be used as secondary outcome measures. In addition, lay carers in the intervention group will be asked to participate in semi‐structured interviews following the death of their loved one. Both Office for Research Ethics Committee approval and local governance approval at both hospices have been obtained as of February 2013.

Discussion

This is the first time that a psychoeducational DVD has been tested in a randomized controlled trial in this population. Dissemination of findings will make a significant contribution to international knowledge and understanding in this area. Findings will inform education, practice and policy.
Navigating conflict and power at work: the effects of power and interdependence asymmetries on conflict in organizations
Authors: Coleman Peter T. , Kugler Katharina G. , Mitchinson Adam , Foster Chris
Published: October 2013

Many of the most difficult conflicts people face at work are up and down; with bosses, supervisors, and important clients, or with direct reports, staff, or other employees who differ from them in terms of their power and interests. However, much of the research on power differences and conflict tends to be piecemeal, decontextualized, and focused on negative consequences. This paper presents 2 studies that investigated a new situated model of conflict and power at work. They build on classic areas of research on social conflict, power, and interdependence; and integrate them into a coherent framework for organizational conflict research. The study methods and findings are presented, and their implications for research on work conflict are discussed.
Disaster threat and justice sensitivity: a terror management perspective
Authors: Kastenmüller Andreas , Greitemeyer Tobias , Hindocha Neil , Tattersall Andrew J. , Fischer Peter
Published: October 2013

Based on terror management theory, we tested the idea that reminders of death strengthen justice sensitivity. In Study 1, we exposed participants to three different kinds of death‐related pictures (terrorism vs. natural disasters vs. graveyards) or neutral pictures. The results showed that death‐related visual material led to more justice sensitivity from three perspectives (victim, observer, and perpetrator) than neutral visual material. Likewise, Study 2 indicated that fake newspaper articles claiming that the likelihood of terrorism is very high (vs. low) strengthened these three justice sensitivity types. Theoretical and practical implications are discussed.
Investigating the motivations underlying harmful social behaviors and the motivational nature of social norms
Authors: Amiot Catherine E. , Sansfaçon Sophie , Louis Winnifred R.
Published: October 2013

The present research applies a self‐determination theory framework to capture the broad spectrum of reasons why individuals engage in harmful normative behaviors. This correlational study (N = 242) focused on harmful behaviors that were either supported by one's in‐group or not. Participants whose in‐group encourages them to engage in a harmful behavior reported stronger motivation, both self‐determined and non‐self‐determined. Perceiving strong in‐group norms in favor of these behaviors was associated positively with the non‐self‐determined motivation pertaining to introjected regulation. The more participantsagreedwith an in‐group norm in favor of a harmful behavior, the stronger their self‐determination for engaging in this behavior. Results are discussed in light of self‐determination theory, normative models of social influence, and intergroup theories.
Personality and engagement at work: the mediating role of psychological meaningfulness
Authors: Woods Stephen A. , Sofat Juilitta A.
Published: October 2013

In this study, we examined the associations of personality traits of the Big Five model with work engagement, and tested a theoretical model in which these associations are mediated by the positive state of psychological meaningfulness (perceptions that work is valuable and meaningful). In a sample of 238 UK working adults, we found that the personality facets assertiveness and industriousness were the strongest predictors of work engagement, and that both exhibited direct and indirect effects, mediated by psychological meaningfulness. Neuroticism demonstrated a marginal indirect association with engagement, again mediated by psychological meaningfulness. Our findings offered good support for our model, explaining a pathway from personality traits to engagement. Practical implications for management are discussed.
Psychological disaster myths in the perception and management of mass emergencies
Authors: Drury John , Novelli David , Stott Clifford
Published: October 2013

Disaster myths are said to be widespread and consequential. However, there has been little research on whether those involved in public safety and emergency response believe them. A survey examined how far police officers, civilian safety professionals, sports event stewards and comparison samples from the public believe the myths “mass panic,” “civil disorder,” and “helplessness.” Respondents endorsed the first two myths. However, they rejected the myth of helplessness and endorsed the view that emergency crowds display resilience. Despite these contradictions in stated beliefs, there was also evidence of ideological coherence: each model of mass emergency behavior (maladaptive vs. resilient) was linked to a model of crowd management (coercive and paternalistic vs. mass‐democratic). The practical implications of these findings are discussed.
Application of SWAT with and without Variable Source Area Hydrology to a Large Watershed
Authors: Woodbury Joshua D. , Shoemaker Christine A. , Easton Zachary M. , Cowan Dillon M.
Published: October 2013

In this study, two different versions of the Soil and Water Assessment Tool (SWAT) model were used to simulate the hydrology and biogeochemical response of the Cannonsville Reservoir watershed, in New York. The first version distributes overland flow in ways that are consistent with variable source area (VSA) hydrology driven by saturation excess runoff, whereas the second version is the standard version of SWAT. These two models were each calibrated for streamflow (Flow), particulate phosphorus (PP), total dissolved phosphorus (TDP), and sediment (Sed) against measured data from the 1,200 km2 Cannonsville watershed. The standard version of the model yielded an r2 between the measured and simulated data of 0.85, 0.73, 0.70, and 0.72 for Flow, Sed, TDP, and PP, respectively. The VSA version yielded an r2 of 0.84, 0.69, 0.72, and 0.53 for Flow, Sed, TDP, and PP, respectively. The two models were then used to determine the maximum upper bound on the reduction in phosphorus loading by removing all of the corn in the watershed. The average reductions between the two models were 65 and 37% for PP and TDP, respectively. The VSA version was also used to estimate the effect of moving corn land in the watershed from the wettest, most runoff prone areas to the driest, least runoff prone areas, which cannot be done directly with the standard SWAT model.
Island biogeography from regional to local scales: evidence for a spatially scaled echo pattern of fern diversity in the Southeast Asian archipelago
Authors: Karger Dirk Nikolaus , Weigelt Patrick , Amoroso Victor B. , Darnaedi Dedy , Hidayat Arief , Kreft Holger , Kessler Michael
Published: October 2013

Aim

The aim of this study was to investigate whether the equilibrium theory of island biogeography (ETIB) is equally applicable at regional and local spatial scales, and whether the ‘echo pattern’, the correlation between regional species pool and local diversity by which the diversity of the regional species pool ‘trickles down’ to local scales, influences local diversity equally across a range of sampling scales.

Location

Twelve mountain regions on islands having different sizes, degrees of isolation and environmental conditions in Indonesia and the Philippines.

Methods

We sampled ferns in standardized field plots within a fixed spatial design at six spatial scales (with the grain size varying from plot to island). Using ordinary least squares regression and relative variable importance, we tested for the predictive power of area and isolation as well as of local and regional environmental factors for explaining diversity at the chosen spatial scales.

Results

Consistent with MacArthur and Wilson's ETIB, we found the strongest correlations of area and isolation with diversity at regional scales. The explanatory power of area increased with increasing spatial scale. The strength of the negative relationships among diversity and isolation decreased with increasing spatial scale. We found evidence for an ‘echo pattern’ at large to intermediate but not at small spatial scales.

Main conclusions

Area and isolation are strong predictors of biodiversity at regional scales. The size of the species pool has a scale‐dependent influence on diversity at smaller scales but is unimportant at the most local scale, where environmental conditions dominate as predictors of diversity. To make predictions about local diversity on islands it is therefore important to take the scale dependence of the ‘echo pattern’ into account.
Island biogeography of tropical alpine floras
Authors: Sklenář Petr , Hedberg Inga , Cleef Antoine M.
Published: October 2013

Aim

We analysed the effects of alpine area, geographical distance between mountains and isolation due to topography on mountain plant species richness, regional species turnover and patterns of species distribution.

Location

Equatorial mountains of East Africa, South America and New Guinea.

Methods

We collated lists of alpine species and estimated the extent of alpine area for seven mountains in each geographical region to construct species–area curves. We tested the observed frequency distribution of species among mountains against the expected distribution (assuming random dispersal) by means of a log‐likelihood test. We compared species turnover among mountains using species accumulation curves. We expressed floristic similarity between mountain pairs as chi‐square distance between observed and expected numbers of shared species and tested its correlation with geographical distance using the Mantel test.

Results

Samples of East African, South American and New Guinean alpine floras contained 371, 489 and 279 species, respectively. Andean genera tended to be more species rich than genera in the other regions. Species richness of the mountains correlated with log‐transformed area except in East Africa. Species distributions among mountains significantly deviated from random in all regions. Species turnover was lowest among East African sites and highest among South American sites, and the slopes of the cumulative species–area relationship were significantly different. Floristic similarity between mountains significantly declined with log(distance) in all regions, and the slope of the relationship was steepest in South America.

Main conclusions

The flora of the Andean páramo is confirmed to be the most species rich of the tropical alpine regions. Páramo genera tend to be richer in species than afroalpine and tropicalpine Asian genera. There is higher species turnover in the Andes and the floras of individual mountains are therefore quite distinct. In contrast, the floras of the East African mountains are more uniform and possess a relatively large number of widespread species.
Climate and species richness patterns of freshwater fish in North America and Europe
Authors: Griffiths David , McGonigle Chris , Quinn Rory
Published: October 2013

Aim

To investigate the effect of climatic, historical and spatial variables on species richness patterns in freshwater fish.

Location

NorthAmerica andEurope.

Methods

Regional species lists were used to document the spatial richness patterns. Three realms,Europe andPacific andAtlanticNorthAmerica, were identified. The numbers of species, by habitat, migration and distributional range categories, were calculated and the contributions of regional mean and seasonal temperature and rainfall, historical (realm, glaciation), and spatial (area, elevational range) variables to predicting richness were assessed using boosted regression trees, model‐averaging and spatially explicit models.

Results

The latitudinal temperature gradient is stronger than that for rainfall in theAtlantic realm whereas the rainfall gradient inEurope is independent of the temperature gradient. Species richness is more strongly correlated with temperature than rainfall, and the effects are stronger in theAtlantic realm than inEurope. The influence of environmental variables differs between habitat specialist and generalist species. Climate, particularly maximum monthly temperature, is the best predictor of richness in rivers whereas climate variables are less important than historical/spatial variables for diadromous species.

Main conclusions

Freshwater fish richness differences between realms follow differences in spatial climatic trends. The contributions of climatic, historical and spatial predictor variables vary with ecology: temperature is a better predictor than rainfall in river‐dwellers. The richness gradient is driven more by physiological than by energetic constraints on species. The importance of history is probably underestimated because of correlations with climate variables.
High Blood Pressure in Overweight and Obese Youth: Implications for Screening
Authors: Koebnick Corinna , Black Mary Helen , Wu Jun , Martinez Mayra P. , Smith Ning , Kuizon Beatriz , Cuan David , Young Deborah Rohm , Lawrence Jean M. , Jacobsen Steven J.
Published: October 2013

In the absence of evidence‐based guidelines for high blood pressure screening in asymptomatic youth, a reasonable strategy is to screen those who are at high risk. The present study aimed to identify optimal body mass index (BMI) thresholds as a marker for high‐risk youth to predict hypertension prevalence. In a cross‐sectional study, youth aged 6 to 17 years (n=237,248) enrolled in an integrated prepaid health plan in 2007 to 2009 were classified according to theirBMIand hypertension status. In moderately and extremely obese youth, the prevalence of hypertension was 3.8% and 9.2%, respectively, compared with 0.9% in normal weight youth. The adjusted prevalence ratios (95% confidence intervals) of hypertension for normal weight, overweight, moderate obesity, and extreme obesity were 1.00 (Reference), 2.27 (2.08–2.47), 4.43 (4.10–4.79), and 10.76 (9.99–11.59), respectively. The prevalence of hypertension was best predicted by aBMI‐for‐age ≥94th percentile. These results suggest that all obese youth should be screened for hypertension.
Repeated H2O2 exposure drives cell cycle progression in an in vitro model of ulcerative colitis
Authors: Poehlmann Angela , Reissig Kathrin , Schönfeld Peter , Walluscheck Diana , Schinlauer Antje , Hartig Roland , Lessel Wiebke , Guenther Thomas , Silver Andrew , Roessner Albert
Published: October 2013

The production of hydrogen peroxide (H2O2) drives tumourigenesis in ulcerative colitis (UC). Recently, we showed that H2O2 activates DNA damage checkpoints in human colonic epithelial cells (HCEC) through c‐Jun N‐terminal Kinases (JNK) that induces p21WAF1. Moreover, caspases circumvented the G1/S and intra‐S checkpoints, and cells accumulated in G2/M. The latter observation raised the question of whether repeated H2O2 exposures alter JNK activation, thereby promoting a direct passage of cells from G2/M arrest to driven cell cycle progression. Here, we report that increased proliferation of repeatedly H2O2‐exposed HCEC cells (C‐cell cultures) was associated with (i) increased phospho‐p46 JNK, (ii) decreased total JNK and phospho‐p54 JNK and (iii) p21WAF1 down‐regulation. Altered JNK activation and p21WAF1 down‐regulation were accompanied by defects in maintaining G2/M and mitotic spindle checkpoints through adaptation, as well as by apoptosis resistance following H2O2 exposure. This may cause increased proliferation of C‐cell cultures, a defining initiating feature in the inflammation‐carcinoma pathway in UC. We further suggest that dysregulated JNK activation is attributed to a non‐apoptotic function of caspases, causing checkpoint adaptation in C‐cell cultures. Additionally, loss of cell‐contact inhibition and the overcoming of senescence, hallmarks of cancer, contributed to increased proliferation. Furthermore, there was evidence that p54 JNK inactivation is responsible for loss of cell‐contact inhibition. We present a cellular model of UC and suggest a sinusoidal pattern of proliferation, which is triggered by H2O2‐induced reactive oxygen species generation, involving an interplay between JNK activation/inactivation, p21WAF1, c‐Fos, c‐Jun/phospho‐c‐Jun, ATF2/phospho‐ATF2, β‐catenin/TCF4‐signalling, c‐Myc, CDK6 and Cyclin D2, leading to driven cell cycle progression.
Sinus augmentation using BMP‐2 in a bovine hydroxyapatite/collagen carrier in dogs
Authors: Cha Jae‐Kook , Lee Jung‐Seok , Kim Min‐Soo , Choi Seong‐Ho , Cho Kyoo‐Sung , Jung Ui‐Won
Published: October 2013

Aim

The objective of this study was to determine the efficacy of bone morphogenetic protein 2 (BMP‐2) in a bovine hydroxyapatite/collagen (BHC) carrier to augment bone formation in a canine nasal sinus model.

Methods

Eight mongrel dogs, approximately 12 months old and 30 kg in weight were used. Following preparation of bilateral sinus access windows, BHC alone (control) or loaded with E. coli‐derived BMP‐2 at 0.1 mg/ml was implanted in four animals, and BHC loaded with E. coli‐derived BMP‐2 at 0.5 and 1.5 mg/ml was implanted in four animals. The animals were euthanized at 20 weeks when block sections were obtained for micro‐computed tomography and histometric analyses.

Results

Total augmented volumes did not differ significantly between groups. Histometric analysis showed significantly enhanced bone formation for the BMP‐2 groups compared with control.

Conclusion

BMP‐2 in a BHC carrier, even at the low 0.1‐mg/ml concentration, induces osteogenic activity, enhancing local bone formation in a canine sinus model.
Derivation of a short form of the Dentine Hypersensitivity Experience Questionnaire
Authors: Machuca Carolina , Baker Sarah R. , Sufi Farzana , Mason Stephen , Barlow Ashley , Robinson Peter G.
Published: October 2013

Aim

To derive and evaluate a short form of the Dentine Hypersensitivity Experience Questionnaire.

Methods

Data from three previous studies of dentine hypersensitivity (n = 353) were pooled and randomly divided into half. Ten‐ and 15‐item short forms were derived in the first half of the data using the item impact and regression methods. The four short forms were evaluated in the second half.

Results

The 10 and 15‐item versions of the regression short form detected impacts in 37% and 61% of participants, respectively, compared to 68% and 93% using the item impact method. All short forms had internal consistency (Cronbach's α) >0.84 and test–retest reliability (ICC) >0.89. All correlated with the long form (all r > 0.93, p < 0.001) and with the effect of the mouth on everyday life (all r ≥ 0.73, p < 0.001). None of the short forms detected a treatment effect in two trials although all four showed a tendency to detect an effect in a trial where the long form had done so.

Conclusions

The 15‐item short form derived with the item impact method performed better than other short forms and appears to be sufficiently robust for use in individual patients.
Comorbidities in preschool children at family risk of dyslexia
Authors: Gooch Debbie , Hulme Charles , Nash Hannah M. , Snowling Margaret J.
Published: October 2013

Background

Comorbidity among developmental disorders such as dyslexia, language impairment, attention deficit/hyperactivity disorder and developmental coordination disorder is common. This study explores comorbid weaknesses in preschool children at family risk of dyslexia with and without language impairment and considers the role that comorbidity plays in determining children's outcomes.

Method

The preschool attention, executive function and motor skills of 112 children at family risk for dyslexia, 29 of whom also met criteria for language impairment, were assessed at ages 3½ and 4½ years. The performance of these children was compared to the performance of children with language impairment and typically developing controls.

Results

Weaknesses in attention, executive function and motor skills were associated with language impairment rather than family risk status. Individual differences in language and executive function are strongly related during the preschool period, and preschool motor skills predicted unique variance (4%) in early reading skills over and above children's language ability.

Conclusion

Comorbidity between developmental disorders can be observed in the preschool years: children with language impairment have significant and persistent weaknesses in motor skills and executive function compared to those without language impairment. Children's early language and motor skills are predictors of children's later reading skills.
Longitudinal relations between maternal depressive symptoms and child sleep problems: the role of parasympathetic nervous system reactivity
Authors: Keller Peggy S. , Kouros Chrystyna D. , Erath Stephen A. , Dahl Ronald E. , El‐Sheikh Mona
Published: October 2013

Background

We examined maternal depressive symptoms (MDS) as longitudinal predictors of actigraphy‐measured sleep; children's respiratory sinus arrhythmia (RSA) was tested as a moderator of these relations.

Method

A total of 271 children (145 boys and 126 girls) participated in a three‐wave study (M age at T1 = 9.38 years), with a 1‐year lag between waves. Children wore actigraphs to derive sleep parameters. RSA reactivity was assessed during a social stress test.

Results

Contrary to hypotheses, MDS were related to less sleep over time for children exhibiting greater RSA withdrawal. Consistent with hypotheses, MDS were related longitudinally to decreased sleep activity for children exhibiting less RSA withdrawal.

Conclusions

Findings illustrate the importance of maternal influences and physiological regulation as predictors of children's sleep.
Annual Research Review: A developmental psychopathology approach to understanding callous‐unemotional traits in children and adolescents with serious conduct problems
Authors: Frick Paul J. , Ray James V. , Thornton Laura C. , Kahn Rachel E.
Published: October 2013

Recent research has suggested that the presence of significant levels of callous‐unemotional (CU) traits designates a clinically important and etiologically distinct subgroup of children and adolescents with serious conduct problems. Based on this research,CUtraits have been included in the most recent revision of the Diagnostic and Statistical Manual of Mental Disorders – 5th Edition (DSM‐5; American Psychiatric Association, 2013) – as a specifier for the diagnosis of conduct disorder. In this review, we attempt to understandCUtraits within a developmental psychopathological framework. Specifically, we summarize research on the normal development of the prosocial emotions of empathy and guilt (i.e., conscience) and we illustrate how the development ofCUtraits can be viewed as the normal development of conscience gone awry. Furthermore, we review research on the stability ofCUtraits across different developmental periods and highlight factors that can influence this stability. Finally, we highlight the implications of this developmental psychopathological framework for future etiological research, for assessment and diagnostic classification, and for treatment of children with serious conduct problems.
Obesity as an effect modifier of the association between leptin and diabetic kidney disease
Authors: Hanai Ko , Babazono Tetsuya , Takagi Michino , Yoshida Naoshi , Nyumura Izumi , Toya Kiwako , Tanaka Nobue , Uchigata Yasuko
Published: October 2013

Aims/Introduction

Obesity has been shown to be a modifier of the association between leptin levels and cardiovascular events. We examined whether obesity modifies the association between serum leptin levels and the progression of diabetic kidney disease.

Materials and Methods

This was an observational longitudinal study on patients with type 2 diabetes. We enrolled 410 and 348 patients in the eGFR and ACR cohorts, respectively. Patients were classified into three groups by sex‐specific tertile of leptin levels. Obesity was defined as body mass index ≥25 kg/m2. Outcomes were the rate of change in estimated glomerular filtration rate (eGFR) and progression to a more advanced stage of albuminuria.

Results

In the eGFR cohort, the mean eGFR change during the median follow‐up period of 4.7 years was −1.4 mL/min/1.73 m2/year. An interaction between leptin levels (low, medium or high) and obesity (present or absent) on the change in eGFR was detected (P interaction = 0.003). In the lean group, adjusted eGFR decline in patients with low leptin was steeper than that in patients with medium leptin (2.1 and 0.8 mL/min/1.73 m2/year, P = 0.023). In the obese group, patients with high leptin had a steeper adjusted eGFR decline than those with medium leptin (1.7 and 0.6 mL/min/1.73 m2/year, P = 0.044). In the ACR cohort, 29 patients showed progression of albuminuria during the median follow‐up period of 3.9 years. There was no interaction between leptin levels and obesity on the outcome (P interaction = 0.094).

Conclusions

Obesity might modify the effects of leptin on kidney function decline in patients with type 2 diabetes.