1,144 research outputs found
Australian agricultural resources: A national scale land capability map
Ongoing land clearing is a key driver of biodiversity loss and climate change. Effective action to halt land clearing and land degradation ultimately relies on understanding patterns of land capability for production uses, in particular agriculture, as a key driver of land use. Here we describe a national agricultural land capability map for Australia, based on harmonized state agricultural land capability datasets and modelled pastoral capability. State-level agricultural land capability datasets capture regional variations in crop selection and suitability. Hence, we reclassified these datasets to fit a nationally consistent land capability ranking scheme. For regions in which agricultural capability data was not available, we modelled agricultural and pastoral capability and mapped this to the same ranking scheme. The national land capability dataset fills an immediate knowledge need for Australia. This dataset has wide potential for utilization, such as for retrospective analysis of land use policies and prospective regional planning initiatives to ensure forward looking policies and land use plans optimize land allocation
Whole-field visual motion drives swimming in larval zebrafish via a stochastic process
Caudo-rostral whole-field visual motion elicits forward locomotion in many organisms, including larval zebrafish. Here, we investigate the dependence on the latency to initiate this forward swimming as a function of the speed of the visual motion. We show that latency is highly dependent on speed for slow speeds ( 1.5 s, which is much longer than neuronal transduction processes. What mechanisms underlie these long latencies? We propose two alternative, biologically inspired models that could account for this latency to initiate swimming: an integrate and fire model, which is history dependent, and a stochastic Poisson model, which has no history dependence. We use these models to predict the behavior of larvae when presented with whole-field motion of varying speed and find that the stochastic process shows better agreement with the experimental data. Finally, we discuss possible neuronal implementations of these models
Comparison of Coulomb Blockade Thermometers with the International Temperature Scale PLTS-2000
The operation of the primary Coulomb blockade thermometer (CBT) is based on a
measurement of bias voltage dependent conductance of arrays of tunnel junctions
between normal metal electrodes. Here we report on a comparison of a CBT with a
high accuracy realization of the PLTS-2000 temperature scale in the range from
0.008 K to 0.65 K. An overall agreement of about 1% was found for temperatures
above 0.25 K. For lower temperatures increasing differences are caused by
thermalization problems which are accounted for by numerical calculations based
on electron-phonon decoupling.Comment: 6 pages, 5 figure
Threatened fauna protections compromised by agricultural interests in Australia
Australia is a global leader in land clearing and biodiversity loss. The overwhelming majority of land clearing within Australia and, globally, is driven by agricultural conversion. The importance of agricultural lands also leads to the concentration of habitat protection in landscapes that do not support productive land uses, which might contribute to species conservation in marginal habitat. Using an integrated agricultural capability map and threatened vertebrate fauna range maps, we show that observed biases in protected area location have varied impacts at the species level. Specifically, threatened vertebrate fauna with habitat capable of supporting high-value productive lands received less protection and experienced greater habitat loss. Similarly, almost all species assessed received protection in the portions of their ranges less conducive to productive land uses. Finally, we identify regions of Australia at risk of future land clearing and the species likely to bear the brunt of the impacts. Our results demonstrate the importance of protecting land capable of supporting productive uses to conserve the most affected threatened species
Summary of achievements of the European Metrology Research Programme Project ââImplementing the new Kelvinâ (InK 1)
partially_open5sĂŹWe report a summary of the technical achievements of the European Metrology Research Programme
Project (EMRP) ââImplementing the new Kelvinâ (InK 1). In short these are:
The first determination of definitive thermodynamic temperatures for the point of inflection of the
high temperature fixed points of Re-C, Pt-C and Co-C as well as a new evaluation of the Cu freezing
point.
The first trial of the new dissemination mechanisms for thermodynamic temperature at high temperatures,
as described in the mise en pratique for the definition of the kelvin (MeP-K).
A new ultra-low uncertainty thermodynamic evaluation of T T90 from about 30 K to 303 K, with particular
emphasis on temperatures around the water triple point (273.16 K).
The first re-evaluation of T T2000 from 0.02 K to about 1 K with an uncertainty of <1%.
Taken together these results represent a significant advance in primary thermometry. We also give a
brief introduction to the successor project (InK 2) and discuss the impact of this work on the kelvin redefinition
and next version of the MeP-K (i.e. the MeP-K-19)openMachin, G.; Engert, J.; Gavioso, R.; Sadli, M.; Woolliams, E.Machin, G.; Engert, J.; Gavioso, ROBERTO MARIA; Sadli, M.; Woolliams, E
The Structure and Timescales of Heat Perception in Larval Zebrafish
SummaryAvoiding temperatures outside the physiological range is critical for animal survival, but how temperature dynamics are transformed into behavioral output is largely not understood. Here, we used an infrared laser to challenge freely swimming larval zebrafish with âwhite noiseâ heat stimuli and built quantitative models relating external sensory information and internal state to behavioral output. These models revealed that larval zebrafish integrate temperature information over a time-window of 400Â ms preceding a swim bout and that swimming is suppressed right after the end of a bout. Our results suggest that larval zebrafish compute both an integral and a derivative across heat in time to guide their next movement. Our models put important constraints on the type of computations that occur in the nervous system and reveal principles of how somatosensory temperature information is processed to guide behavioral decisions such as sensitivity to both absolute levels and changes in stimulation
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Simultaneous mapping of membrane voltage and calcium in zebrafish heart in vivo reveals chamber-specific developmental transitions in ionic currents
The cardiac action potential (AP) and the consequent cytosolic Ca2+ transient are key indicators of cardiac function. Natural developmental processes, as well as many drugs and pathologies change the waveform, propagation, or variability (between cells or over time) of these parameters. Here we apply a genetically encoded dual-function calcium and voltage reporter (CaViar) to study the development of the zebrafish heart in vivo between 1.5 and 4 days post fertilization (dpf). We developed a high-sensitivity spinning disk confocal microscope and associated software for simultaneous three-dimensional optical mapping of voltage and calcium. We produced a transgenic zebrafish line expressing CaViar under control of the heart-specific cmlc2 promoter, and applied ion channel blockers at a series of developmental stages to map the maturation of the action potential in vivo. Early in development, the AP initiated via a calcium current through L-type calcium channels. Between 90 and 102 h post fertilization (hpf), the ventricular AP switched to a sodium-driven upswing, while the atrial AP remained calcium driven. In the adult zebrafish heart, a sodium current drives the AP in both the atrium and ventricle. Simultaneous voltage and calcium imaging with genetically encoded reporters provides a new approach for monitoring cardiac development, and the effects of drugs on cardiac function
Trans-national conservation and infrastructure development in the Heart of Borneo
The Heart of Borneo initiative has promoted the integration of protected areas and sustainably-managed forests across Malaysia, Indonesia, and Brunei. Recently, however, member states of the Heart of Borneo have begun pursuing ambitious unilateral infrastructure-development schemes to accelerate economic growth, jeopardizing the underlying goal of trans-boundary integrated conservation. Focusing on Sabah, Malaysia, we highlight conflicts between its Pan-Borneo Highway scheme and the regional integration of protected areas, unprotected intact forests, and conservation-priority forests. Road developments in southern Sabah in particular would drastically reduce protected-area integration across the northern Heart of Borneo region. Such developments would separate two major clusters of protected areas that account for one-quarter of all protected areas within the Heart of Borneo complex. Sabah has proposed forest corridors and highway underpasses as means of retaining ecological connectivity in this context. Connectivity modelling identified numerous overlooked areas for connectivity rehabilitation among intact forest patches following planned road development. While such âlinear-conservation planningâ might theoretically retain up to 85% of intact-forest connectivity and integrate half of the conservation-priority forests across Sabah, in reality it is very unlikely to achieve meaningful ecological integration. Moreover, such measure would be exceedingly costly if properly implementedâapparently beyond the operating budget of relevant Malaysian authorities. Unless critical road segments are cancelled, planned infrastructure will fragment important conservation landscapes with little recourse for mitigation. This likelihood reinforces earlier calls for the legal recognition of the Heart of Borneo region for conservation planning as well as for enhanced tri-lateral coordination of both conservation and development
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