558 research outputs found
Recommended from our members
Automated pre-processing strategies for species occurrence data used in biodiversity modelling
To construct Biodiversity richness maps from Environmental Niche Models (ENMs) of thousands of species is time consuming. A separate species occurrence data pre-processing phase enables the experimenter to control test AUC score variance due to species dataset size.
Besides, removing duplicate occurrences and points with missing environmental data, we discuss the need for coordinate precision, wide dispersion, temporal and synonymity filters. After species data filtering, the
final task of a pre-processing phase should be the automatic generation of species occurrence datasets which can then be directly ’plugged-in’ to the ENM. A software application capable of carrying out all these tasks will
be a valuable time-saver particularly for large scale biodiversity studies
Recommended from our members
The complete plastome of Hyacinthoides non-scripta (L.) Chouard ex Rothm. (Asparagaceae)
The whole plastome sequence ofHyacinthoides non-scripta, was assembled and annotated in this study.This is the first complete plastid genome for the genusHyacinthoides. The plastome is 155,035 bp longand consists of a large single-copy (LSC) region spanning 83,947 bp, a small single-copy (SSC) regionspanning 18,496bp, and two inverted repeat (IR) regions, each of which is 26,296bp in length. Thereare 132 genes annotated in the plastome, of which the protein-coding geneinfAhas pseudogenized
Recommended from our members
Can the Iberian floristic diversity withstand near-future climate change?
We assess how effectively the current network of protected areas (PAs) across the Iberian Peninsula will conserve plant diversity under near-future (2020) climate change. We computed 3267 MAXENT environmental niche models (ENMs) at 1-km spatial resolution for known Iberian plant species under two climate scenarios (1950-2000 baseline & 2020). To predict near-future species distributions across the network of Iberian and Balearics PAs, we combined projections of species’ ENMs with simulations of propagule dispersal by using six scenarios of annual dispersal rates (no dispersal, 0.1 km, 0.5 km, 1 km, 2 km and unlimited). Mined PA grid cell values for each species were then analyzed. We forecast 3% overall floristic diversity richness loss by 2020. The habitat of regionally extant species will contract on average by 13.14%. Niche movement exceeds 1 km per annum for 30% of extant species. While the southerly range margin of northern plant species retracts northward at 8.9 km per decade, overall niche movement is more easterly and westerly than northerly. There is little expansion of the northern range margin of southern plant species even under unlimited dispersal. Regardless of propagule dispersal rate, altitudinal niche movement of +25 m per decade is strongest for northern species. Pyrenees flora is most vulnerable to near-future climate change with many northern plant species responding by shifting their range westerly and easterly rather than northerly. Northern humid habitats will be particularly vulnerable to near-future climate change. Andalusian National Parks will become important southern biodiversity refuges. With limited human intervention (particularly in the Pyrenees), we conclude that floristic diversity in Iberian PAs should withstand near-future climate change
Home Program of Hip Abductor Exercises: Effect on Knee Joint Loading, Strength, Function and Pain in Persons with Knee Osteoarthritis
Background Hip abductor muscle weakness may result in impaired frontal-plane pelvic control during gait, leading to greater medial compartment loading in people with knee osteoarthritis (OA). Objective This study investigated the effect of an 8-week home strengthening program for the hip abductor muscles on knee joint loading (measured by the external knee adduction moment during gait), strength (force-generating capacity), and function and pain in individuals with medial knee OA. Design The study design was a nonequivalent, pretest-posttest, control group design. Setting Testing was conducted in a motor performance laboratory. Patients An a priori sample size calculation was performed. Forty participants with knee OA were matched for age and sex with a control group of participants without knee OA. Intervention Participants with knee OA completed a home hip abductor strengthening program. Measurements Three-dimensional gait analysis was performed to obtain peak knee adduction moments in the first 50% of the stance phase. Isokinetic concentric strength of the hip abductor muscles was measured using an isokinetic dynamometer. The Five-Times-Sit-to-Stand Test was used to evaluate functional performance. Knee pain was assessed with the Western Ontario and McMaster Universities Osteoarthritis Index questionnaire. Results Following the intervention, the OA group demonstrated significant improvement in hip abductor strength, but not in the knee adduction moment. Functional performance on the sit-to-stand test improved in the OA group compared with the control group. The OA group reported decreased knee pain after the intervention. Limitations Gait strategies that may have affected the knee adduction moment, including lateral trunk lean, were not evaluated in this study. Conclusions Hip abductor strengthening did not reduce knee joint loading but did improve function and reduce pain in a group with medial knee OA
IMECE2005-79902 CONVECTIVE HEAT TRANSFER OF LAMINAR, SINGLE-PHASE FLOW IN RANDOMLY ROUGH MICROTUBES
Abstract Convective heat transfer of laminar, single-phase flow in rough microtubes is studied. Wall roughness and slope are assumed to possess Gaussian, isotropic distributions. Fractal concepts are used to model the rough microtube. It is shown that due to the existence of wall roughness, both cross-sectional and inside surface areas are increased. A new concept is defined as a figure of merit for assessing thermal performance of rough microtubes. As a result of increasing roughness, an enhancement is observed in the thermal performance of microtubes. The present model can be extended to analyze other geometries such as rectangular and trapezoidal microchannels. 1 Post-Doctoral Fellow. Mem. ASME. Corresponding author. Email: [email protected]. 2 Distinguished Professor Emeritus. Fellow ASME. 3 Associate Professor and Director of MHTL. Mem. ASME
Thermal contact resistance at low contact pressure: effect of elastic deformation
Abstract Existing models over-predict the thermal contact resistance of conforming rough joints at low contact pressures. However, the applicable pressure range in some applications such as microelectronics cooling is low. A new model is developed which is more suitable for low pressures. The effect of elastic deformations beneath the plastically deformed microcontacts is determined by superimposing normal deformations due to self and neighboring contact spots in an elastic half-space. A parametric study reveals that the elastic deformation effect is an important phenomenon at low contact pressures. The model is compared with data and good agreement is observed at low contact pressures
IMECE2005-79902 CONVECTIVE HEAT TRANSFER OF LAMINAR, SINGLE-PHASE FLOW IN RANDOMLY ROUGH MICROTUBES
Abstract Convective heat transfer of laminar, single-phase flow in rough microtubes is studied. Wall roughness and slope are assumed to possess Gaussian, isotropic distributions. Fractal concepts are used to model the rough microtube. It is shown that due to the existence of wall roughness, both cross-sectional and inside surface areas are increased. A new concept is defined as a figure of merit for assessing thermal performance of rough microtubes. As a result of increasing roughness, an enhancement is observed in the thermal performance of microtubes. The present model can be extended to analyze other geometries such as rectangular and trapezoidal microchannels. 1 Post-Doctoral Fellow. Mem. ASME. Corresponding author. Email: [email protected]. 2 Distinguished Professor Emeritus. Fellow ASME. 3 Associate Professor and Director of MHTL. Mem. ASME
Synthesis and Luminescence Modulation of Pyrazine-Based Gold(III) Pincer Complexes
The first examples of pyrazine-based gold(III) pincer complexes have been synthesized; their intense photoemissions can be modified by interactions with the non-coordinating pyrazine-N atom. Luminescence modulation is possible without the need for altering the ligand framework. Emissions shift from red (77 K) to blue (298 K) due to thermally activated delayed fluorescence (TADF
Fluid Flow Around and Heat Transfer from Elliptical Cylinders: Analytical Approach
An integral method of boundary-layer analysis is employed to derive closed-form expressions for the calculation of total drag and average heat transfer for flow across an elliptical cylinder under isothermal and isoflux thermal boundary conditions. The Von Kármán-Pohlhausen integral method is used to solve the momentum and energy equations for both thermal boundary conditions. A fourth-order velocity profile in the hydrodynamic boundary layer and a third-order temperature profile in the thermal boundary layer are used. The present results are in good agreement with existing experimental/numerical data and, in the limiting cases, can be used for circular cylinders and finite plates. = complete elliptic integral of second kind e = eccentricity
- …