bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determining When to Change Course in Management Actions
Authors: NG CHOOI FEI , MCCARTHY MICHAEL A. , MARTIN TARA G. , POSSINGHAM HUGH P. 
Published: August 2014

AbstractTime is of the essence in conservation biology. To secure the persistence of a species, we need to understand how to balance time spent among different management actions. A new and simple method to test the efficacy of a range of conservation actions is required. Thus, we devised a general theoretical framework to help determine whether to test a new action and when to cease a trial and revert to an existing action if the new action did not perform well. The framework involves constructing a general population model under the different management actions and specifying a management objective. By maximizing the management objective, we could generate an analytical solution that identifies the optimal timing of when to change management action. We applied the analytical solution to the case of the Christmas Island pipistrelle bat (Pipistrelle murrayi), a species for which captive breeding might have prevented its extinction. For this case, we used our model to determine whether to start a captive breeding program and when to stop a captive breeding program and revert to managing the species in the wild, given that the management goal is to maximize the chance of reaching a target wild population size. For the pipistrelle bat, captive breeding was to start immediately and it was desirable to place the species in captivity for the entire management period. The optimal time to revert to managing the species in the wild was driven by several key parameters, including the management goal, management time frame, and the growth rates of the population under different management actions. Knowing when to change management actions can help conservation managers’ act in a timely fashion to avoid species extinction.Determinar Cuándo Cambiar el Rumbo en las Acciones de Manejo
Impact of habitat alteration on endemic Afromontane chameleons: evidence for historical population declines using hierarchical spatial modelling
Authors: Shirk Philip L. , Linden Daniel W. , Patrick David A. , Howell Kim M. , Harper Elizabeth B. , Vonesh James R. 
Published: August 2014

AbstractAimWe map estimated historical population declines resulting from species‐specific models of sensitivity to habitat fragmentation for three forest‐dependent chameleons.LocationEast Usambara Mountains, Eastern Arc Mountains, Tanzania.MethodsWe surveyed three chameleon species (Rhampholeon spinosus,Rhampholeon temporalisandTrioceros deremensis) along 32.2 km of transects and used a hierarchical, distance‐sampling model to estimate densities. The model included habitat characteristics at the landscape (patch) and local (transect) scales while accounting for detectability. By analysing the model in a Bayesian framework, we were able to propagate error through the entire analysis and obtain exact solutions despite small sample sizes. We then used our estimated relationships between habitat and density to project chameleon population sizes across current and historical land cover maps of the study area (230 km2), giving an estimate of the impact of anthropogenic habitat alteration on these species.ResultsSpecies’ densities increased in larger patches and further from patch edges and varied seasonally. Local vegetation characteristics had significant relationships with expected chameleon densities, though effect sizes were small. Estimates of total current population sizes varied by two orders of magnitude among species, but each was 49–79% higher than detection‐naïve estimates. All three declined from estimated historical levels by approximately 60% in the study area, approximately one‐third more than would be expected from forest loss alone. Remaining populations of the study species are predominantly located in protected nature reserves, so the future of these species will likely be determined by the degree of protection offered by the nature reserves.Main conclusionsHabitat loss and fragmentation have greatly reduced forest‐dependent chameleon population sizes in the East Usambara Mountains. Populations of these species in other areas are experiencing higher rates of habitat loss. Efforts aimed at ensuring the efficacy of protected forests may be a key to conserving remaining populations.
Longitudinal study of perception of structured optic flow and random visual motion in infants using high‐density EEG
Authors: Agyei Seth B. , Holth Magnus , van der Weel F.R. (Ruud) , van der Meer Audrey L.H. 
Published: August 2014

AbstractElectroencephalogram (EEG) was used in infants at 3–4 months and 11–12 months to longitudinally study brain electrical activity as the infants were exposed to structured forwards and reversed optic flow, and non‐structured random visual motion. Analyses of visual evoked potential (VEP) and temporal spectral evolution (TSE, time‐dependent amplitude changes) were performed on EEG data recorded with a 128‐channel sensor array. VEP results showed infants to significantly differentiate between the radial motion conditions, but only at 11–12 months where they showed shortest latency for forwards optic flow and longest latency for random visual motion. When the TSE results of the motion conditions were compared with those of a static non‐flow dot pattern, infants at 3–4 and 11–12 months both showed significant differences in induced activity. A decrease in amplitudes at 5–7 Hz was observed as desynchronized theta‐band activity at both 3–4 and 11–12 months, while an increase in amplitudes at 9–13 Hz was observed as synchronized alpha‐band activity only at 11–12 months. It was concluded that brain electrical activities related to visual motion perception change during the first year of life, and these changes can be observed both in the VEP and induced activities of EEG. With adequate neurobiological development and locomotor experience infants around 1 year of age rely, more so than when they were younger, on structured optic flow and show a more adult‐like specialization for motion where faster oscillating cell assemblies have fewer but more specialized neurons, resulting in improved visual motion perception.
Characteristics associated with physical activity among independently ambulant children and adolescents with unilateral cerebral palsy
Authors: Mitchell Louise E , Ziviani Jenny , Boyd Roslyn N 
Published: August 2014

AimThis study aimed to quantify the contribution of physical, personal and environmental characteristics to physical activity among independently ambulant children with unilateral cerebral palsy (CP).MethodOne‐hundred and two children with unilateral CP (52 males, 50 females; 52 right hemiplegia; mean age 11y 3mo, range 8–17y [SD 2y 4mo]) classified at Gross Motor Function Classification System (GMFCS) levels I = 44 and II = 58 participated. Physical activity was measured over 4 days using ActiGraph accelerometers recording as activity counts. GMFCS, functional strength, 6‐minute walk test (6MWT), mobility limitations (MobQues28), age, sex, Assessment of Life‐Habits recreation domain, Participation and Environment Measure for Children and Youth (PEM‐CY) and environmental characteristics were considered for selection in a linear regression model. These served as independent variables which were determined using a backwards selection procedure.ResultsYounger age, male sex, increased performance on the 6MWT, and increased participation in the home and community measured using the PEM‐CY were significantly associated with activity counts (p<0.001). However, the model fit was somewhat weak (R2=0.32), indicating that much of the variation was unexplained. Older age and reduced community participation were associated with high inactivity (p<0.001).InterpretationPhysical activity interventions should primarily target adolescents and females. Walking endurance and participation in the home and community may represent modifiable characteristics to increase physical activity.
Does vigabatrin treatment for infantile spasms cause visual field defects? An international multicentre study
Authors: Riikonen Raili , Rener‐Primec Zvonka , Carmant Lionel , Dorofeeva Maria , Hollody Katalin , Szabo Ilona , Krajnc Branka S , Wohlrab Gabriele , Sorri Iiris 
Published: August 2014

AimThe aim of this study was to examine whether vigabatrin treatment had caused visual field defects (VFDs) in children of school age who had received the drug in infancy.MethodIn total, 35 children (14 males, 21 females; median age 11y, SD 3.4y, range 8–23y) were examined by static Humphrey perimetry, Goldmann kinetic perimetry, or Octopus perimetry. The aetiologies of infantile spasms identified were tuberous sclerosis (n=10), other symptomatic causes (n=3), or cryptogenic (n=22).ResultsTypical vigabatrin‐attributed VFDs were found in 11 out of 32 (34%) children: in one out of 11 children (9%) who received vigabatrin for <1 year (group 1), in three out of 10 children (30%) who received vigabatrin for 12 to 24 months (group 2), and in seven out of 11 children (63%) who received vigabatrin treatment for longer than 2 years (group 3). VFDs were mild in five and severe in six children. Patients with tuberous sclerosis were at higher risk of VFDs (six out of 10 children). The mean cumulative doses of vigabatrin were 140.5, 758.8, and 2712g in group 1, 2, and 3, respectively.InterpretationVFDs were found in 34% of the cohort of children in this study. The rate of VFD increased from 9% to 63% as duration of treatment increased. The results of this study showed that the risk–benefit ratio should always be considered when using vigabatrin.
Seizures and epilepsy in hypoglycaemia caused by inborn errors of metabolism
Authors: Gataullina Svetlana , Delonlay Pascale , Lemaire Eric , Boddaert Nathalie , Bulteau Christine , Soufflet Christine , Laín Gemma Aznar , Nabbout Rima , Chiron Catherine , Dulac Olivier 
Published: August 2014

AimThe aim of the study was to characterize seizures and epilepsy related to hypoglycaemia.MethodWe analyzed the files of 170 consecutive patients referred for hypoglycaemia (onset 1h to 4y) caused by inborn errors of metabolism (glycogen storage disease type I, fatty acid β‐oxidation disorders, and hyperinsulinism).ResultsNinety patients (42 males and 48 females; 38 neonates and 52 infants/children) had brief hypoglycaemic seizures (68%) or status epilepticus (32%). Status epilepticus occurred earlier (mean 1.4d) than brief neonatal seizures (4.3d, p=0.02). Recurrent status epilepticus followed initial status epilepticus and was often triggered by fever. Epilepsy developed in 21 patients. In 18 patients, epilepsy followed hypoglycaemic status epilepticus and began with shorter delay when associated with grey matter lesions (1.9mo, standard error of the mean [SEM] 1mo) than with white matter damage (3.3y [SEM 1y], p=0.003). Three patients with hyperinsulinism developed idiopathic epilepsy following brief neonatal seizures.InterpretationBrief neonatal hyperinsulinaemic hypoglycaemic seizures have characteristics of idiopathic neonatal seizures. Neonatal status epilepticus should be prevented by the systematic measurement of glucose blood level. Recurrent seizures never consist of status epilepticus when following brief initial seizures. Epilepsy is symptomatic of brain damage with shorter delay in the case of grey rather than white matter lesions, except in a few idiopathic cases in which epilepsy and hyperinsulinism may share a common genetic background.
Emotions and motivated behavior converge on an amygdala‐like structure in the zebrafish
Authors: von Trotha Jakob William , Vernier Philippe , Bally‐Cuif Laure 
Published: August 2014

AbstractThe brain reward circuitry plays a key role in emotional and motivational behaviors, and its dysfunction underlies neuropsychiatric disorders such as schizophrenia, depression and drug addiction. Here, we characterized the neuronal activity pattern induced by acute amphetamine administration and during drug‐seeking behavior in the zebrafish, and demonstrate the existence of conserved underlying brain circuitry. Combining quantitative analyses of cfos expression with neuronal subtype‐specific markers at single‐cell resolution, we show that acute d‐amphetamine administration leads to both increased neuronal activation and the recruitment of neurons in the medial (Dm) and the lateral (Dl) domains of the adult zebrafish pallium, which contain homologous structures to the mammalian amygdala and hippocampus, respectively. Calbindin‐positive and glutamatergic neurons are recruited in Dm, and glutamatergic and γ‐aminobutyric acid (GABAergic) neurons in Dl. The drug‐activated neurons in Dm and Dl are born at juvenile stage rather than in the embryo or during adulthood. Furthermore, the same territory in Dm is activated during both drug‐seeking approach and light avoidance behavior, while these behaviors do not elicit activation in Dl. These data identify the pallial territories involved in acute psychostimulant response and reward formation in the adult zebrafish. They further suggest an evolutionarily conserved function of amygdala‐like structures in positive emotions and motivated behavior in zebrafish and mammals.
Resampling strategies for regression
Authors: Torgo Luís , Branco Paula , Ribeiro Rita P. , Pfahringer Bernhard 
Published: August 2014

AbstractSeveral real world prediction problems involve forecasting rare values of a target variable. When this variable is nominal, we have a problem of class imbalance that was thoroughly studied within machine learning. For regression tasks, where the target variable is continuous, few works exist addressing this type of problem. Still, important applications involve forecasting rare extreme values of a continuous target variable. This paper describes a contribution to this type of tasks. Namely, we propose to address such tasks by resampling approaches that change the distribution of the given data set to decrease the problem of imbalance between the rare target cases and the most frequent ones. We present two modifications of well‐known resampling strategies for classification tasks: the under‐sampling and the synthetic minority over‐sampling technique (SMOTE) methods. These modifications allow the use of these strategies on regression tasks where the goal is to forecast rare extreme values of the target variable. In an extensive set of experiments, we provide empirical evidence for the superiority of our proposals for these particular regression tasks. The proposed resampling methods can be used with any existing regression algorithm, which means that they are general tools for addressing problems of forecasting rare extreme values of a continuous target variable.
A belief‐desire‐intention agent architecture for partner selection in peer‐to‐peer live video streaming applications
Authors: Yildirim Suleyman , Sayit Muge , Kardas Geylani 
Published: August 2014

AbstractIn peer‐to‐peer (P2P) video streaming systems, one of the most challenging parts is to schedule video data dissemination, that is, each peer should carefully select the partner(s) it receives video from and the partner(s) it sends data to. We believe that an agent‐based partner selection approach may improve the quality of streaming by taking both autonomy and dynamic plan selection into account in a goal‐oriented manner. In this study, a Belief‐Desire‐Intention agent architecture for partner selection in P2P video streaming systems is introduced. The major concern of our study is to exhibit how to select the best partner during video streaming session whilst maximizing the quality of video and minimizing delay and hop count. The effects and comparative results of executing proposed agent behaviours are evaluated in the study. The proposed autonomous agent‐based approach also provides an infrastructure in which the best plan for the achievement of optimum streaming goal can be dynamically determined and executed at runtime. Experimental results of the implementation have revealed to us that both of the partner selection methods (with or without agents) manage to increase the video quality. However, the agent‐based approach performs better in terms of received bitrate, delay and hop count during streaming.
Gross changes in reconstructions of historic land cover/use for Europe between 1900 and 2010
Authors: Fuchs Richard , Herold Martin , Verburg Peter H. , Clevers Jan G.P.W. , Eberle Jonas 
Published: August 2014

AbstractHistoric land‐cover/use change is important for studies on climate change, soil carbon, and biodiversity assessments. Available reconstructions focus on the net area difference between two time steps (net changes) instead of accounting for all area gains and losses (gross changes). This leads to a serious underestimation of land‐cover/use dynamics with impacts on the biogeochemical and environmental assessments based on these reconstructions. In this study, we quantified to what extent land‐cover/use reconstructions underestimate land‐cover/use changes in Europe for the 1900–2010 period by accounting for net changes only. We empirically analyzed available historic land‐change data, quantified their uncertainty, corrected for spatial‐temporal effects and identified underlying processes causing differences between gross and net changes. Gross changes varied for different land classes (largest for forest and grassland) and led to two to four times the amount of net changes. We applied the empirical results of gross change quantities in a spatially explicit reconstruction of historic land change to reconstruct gross changes for the EU27 plus Switzerland at 1 km spatial resolution between 1950 and 2010. In addition, the reconstruction was extended back to 1900 to explore the effects of accounting for gross changes on longer time scales. We created a land‐change reconstruction that only accounted for net changes for comparison. Our two model outputs were compared with five commonly used global reconstructions for the same period and area. In our reconstruction, gross changes led in total to a 56% area change (ca. 0.5% yr−1) between 1900 and 2010 and cover twice the area of net changes. All global reconstructions used for comparison estimated fewer changes than our gross change reconstruction. Main land‐change processes were cropland/grassland dynamics and afforestation, and also deforestation and urbanization.
Surficial gains and subsoil losses of soil carbon and nitrogen during secondary forest development
Authors: Mobley Megan L. , Lajtha Kate , Kramer Marc G. , Bacon Allan R. , Heine Paul R. , Richter Daniel Deb 
Published: August 2014

AbstractReforestation of formerly cultivated land is widely understood to accumulate above‐ and belowground detrital organic matter pools, including soil organic matter. However, during 40 years of study of reforestation in the subtropical southeastern USA, repeated observations of above‐ and belowground carbon documented that significant gains in soil organic matter (SOM) in surface soils (0–7.5 cm) were offset by significant SOM losses in subsoils (35–60 cm). Here, we extended the observation period in this long‐term experiment by an additional decade, and used soil fractionation and stable isotopes and radioisotopes to explore changes in soil organic carbon and soil nitrogen that accompanied nearly 50 years of loblolly pine secondary forest development. We observed that accumulations of mineral soil C and N from 0 to 7.5 cm were almost entirely due to accumulations of light‐fraction SOM. Meanwhile, losses of soil C and N from mineral soils at 35 to 60 cm were from SOM associated with silt and clay‐sized particles. Isotopic signatures showed relatively large accumulations of forest‐derived carbon in surface soils, and little to no accumulation of forest‐derived carbon in subsoils. We argue that the land use change from old field to secondary forest drove biogeochemical and hydrological changes throughout the soil profile that enhanced microbial activity and SOM decomposition in subsoils. However, when the pine stands aged and began to transition to mixed pines and hardwoods, demands on soil organic matter for nutrients to support aboveground growth eased due to pine mortality, and subsoil organic matter levels stabilized. This study emphasizes the importance of long‐term experiments and deep measurements when characterizing soil C and N responses to land use change and the remarkable paucity of such long‐term soil data deeper than 30 cm.
Spatial variability and temporal trends in water‐use efficiency of European forests
Authors: Saurer Matthias , Spahni Renato , Frank David C. , Joos Fortunat , Leuenberger Markus , Loader Neil J. , McCarroll Danny , Gagen Mary , Poulter Ben , Siegwolf Rolf T.W. , Andreu‐Hayles Laia , Boettger Tatjana , Dorado Liñán Isabel , Fairchild Ian J. , Friedrich Michael , Gutierrez Emilia , Haupt Marika , Hilasvuori Emmi , Heinrich Ingo , Helle Gerd , Grudd Håkan , Jalkanen Risto , Levanič Tom , Linderholm Hans W. , Robertson Iain , Sonninen Eloni , Treydte Kerstin , Waterhouse John S. , Woodley Ewan J. , Wynn Peter M. , Young Giles H.F. 
Published: August 2014

AbstractThe increasing carbon dioxide (CO2) concentration in the atmosphere in combination with climatic changes throughout the last century are likely to have had a profound effect on the physiology of trees: altering the carbon and water fluxes passing through the stomatal pores. However, the magnitude and spatial patterns of such changes in natural forests remain highly uncertain. Here, stable carbon isotope ratios from a network of 35 tree‐ring sites located across Europe are investigated to determine the intrinsic water‐use efficiency (iWUE), the ratio of photosynthesis to stomatal conductance from 1901 to 2000. The results were compared with simulations of a dynamic vegetation model (LPX‐Bern 1.0) that integrates numerous ecosystem and land–atmosphere exchange processes in a theoretical framework. The spatial pattern of tree‐ring derived iWUE of the investigated coniferous and deciduous species and the model results agreed significantly with a clear south‐to‐north gradient, as well as a general increase in iWUE over the 20th century. The magnitude of the iWUE increase was not spatially uniform, with the strongest increase observed and modelled for temperate forests in Central Europe, a region where summer soil‐water availability decreased over the last century. We were able to demonstrate that the combined effects of increasing CO2 and climate change leading to soil drying have resulted in an accelerated increase in iWUE. These findings will help to reduce uncertainties in the land surface schemes of global climate models, where vegetation–climate feedbacks are currently still poorly constrained by observational data.