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No full textContrasting responses of large carnivores to land use management across an Asian montane landscape in Iran
No full textLand-use change has led to substantial range contractions for many species. Such contractions are particularly acute for wide-ranging large carnivores in Asia’s high altitude areas, which are marked by high spatiotemporal variability in resources. Current conservation planning for human-dominated landscapes often takes one of two main approaches: a “coexistence” (land sharing) approach or a “separation” (land sparing) approach. In this study, we evaluated the effects of land-use management on a guild of large carnivores in a montane ecosystem located in northeastern Iran. We used interview surveys to collect data on Persian leopard Panthera pardus saxicolor and grey wolf Canis lupus and modeled the areas occupied by these species in a Bayesian framework. After accounting for imperfect detection, we found that wolves had a higher probability of occupying the study area than leopards (82%; 95% CI: 73-90% vs. 63%; 95% CI: 53-73%). Importantly, each predator showed contrasting response to land-use management. National Parks (i.e. human-free areas) had a positive association with leopard occupancy (αNational Park = 2.56, 95% CI 0.22 to 5.77), in contrast to wolves, which displayed a negative association with National Parks (αNational Park = -1.62, 95% CI -2.29 to 0.31). An opposite pattern was observed for human-dominated areas (i.e. Protected Areas and Communal Lands), where occupancy was higher for wolves but lower for leopards. Our study suggests that to protect these large carnivores, a combination of land sharing and land sparing approaches is desirable within Iran montane landscapes. Any recovery program for big cats in Iranian mountains, and likely similar mountainous landscapes in west Asia, should take into account other sympatric carnivores and how they can affect adjacent human communities. For example, conflict mitigation and compensation efforts are required to include the guild of large carnivores, instead of solely targeting the charismatic big cats
Inference of brain networks with approximate Bayesian computation – assessing face validity with an example application in Parkinsonism
No full textThis paper describes and validates a novel framework using the Approximate Bayesian Computation (ABC) algorithm for parameter estimation and model selection in models of mesoscale brain network activity. We provide a proof of principle, first pass validation of this framework using a set of neural mass models of the cortico-basal ganglia thalamic circuit inverted upon spectral features from experimental, in vivo recordings. This optimization scheme relaxes an assumption of fixed-form posteriors (i.e. the Laplace approximation) taken in previous approaches to inverse modelling of spectral features. This enables the exploration of model dynamics beyond that approximated from local linearity assumptions and so fit to explicit, numerical solutions of the underlying non-linear system of equations. In this first paper, we establish a face validation of the optimization procedures in terms of: (i) the ability to approximate posterior densities over parameters that are plausible given the known causes of the data; (ii) the ability of the model comparison procedures to yield posterior model probabilities that can identify the model structure known to generate the data; and (iii) the robustness of these procedures to local minima in the face of different starting conditions. Finally, as an illustrative application we show (iv) that model comparison can yield plausible conclusions given the known neurobiology of the cortico-basal ganglia-thalamic circuit in Parkinsonism. These results lay the groundwork for future studies utilizing highly nonlinear or brittle models that can explain time dependant dynamics, such as oscillatory bursts, in terms of the underlying neural circuits
Electrospun rhodamine@MOF/polymer luminescent fibers with a quantum yield of over 90%
No full textTailored luminescent guest@metal-organic framework (Guest@MOF) materials with outstanding photophysical properties are enabling materials for emergent technologies in smart sensors and optoelectronics. However, the practical utility of Guest@MOF currently is impaired by its poor stability and difficult-to-handle powder form. Here, we combine a luminescent-sensing Guest@MOF system with a non-luminescent polymer matrix and, for the first time, demonstrated the easy-to-apply electrospinning of luminescent fibers comprising nanocrystals of RhB@ZIF-71 (rhodamine B@zeolitic imidazolate framework-71) homogeneously dispersed in a polyvinylidene difluoride (PVDF) matrix. The luminescence of RhB@ZIF-71/PVDF fiber is tunable and exhibits a quantum yield exceeding 90%. Compared with RhB fluorophore in PVDF fiber, the ZIF-71 (host) protects the nanoconfined RhB guest molecules (especially the J-aggregates of RhB), giving the composite fiber its unique thermofluorochromic response and enhanced thermal stability to 200°C. Our results reveal the exciting opportunities for implementing electrospun luminescent fibers functionalized with bespoke Guest@MOF nanocrystals for multifunctional device applications
Experimental study of extended timescale dynamics of a plasma wakefield driven by a self-modulated proton bunch
No full textPlasma wakefield dynamics over timescales up to 800 ps, approximately 100 plasma periods, are studied experimentally at the Advanced Wakefield Experiment (AWAKE). The development of the longitudinal wakefield amplitude driven by a self-modulated proton bunch is measured using the external injection of witness electrons that sample the fields. In simulation, resonant excitation of the wakefield causes plasma electron trajectory crossing, resulting in the development of a potential outside the plasma boundary as electrons are transversely ejected. Trends consistent with the presence of this potential are experimentally measured and their dependence on wakefield amplitude are studied via seed laser timing scans and electron injection delay scans
Summarising good practice guidelines for data extraction for systematic reviews and meta-analysis
No full textLearning probabilistic termination proofs
No full textWe present the first machine learning approach to the termination analysis
of probabilistic programs. Ranking supermartingales (RSMs) prove that
probabilistic programs halt, in expectation, within a finite number of steps.
While previously RSMs were directly synthesised from source code,
our method learns them from sampled execution traces.
We introduce the neural ranking supermartingale:
we let a neural network fit
an RSM over execution traces and then we
verify it over the source code using satisfiability modulo theories (SMT);
if the latter step produces a counterexample, we generate from it
new sample traces and repeat learning in a
counterexample-guided inductive synthesis loop,
until the SMT solver confirms the validity of the RSM.
The result is thus a sound witness of probabilistic termination.
Our learning strategy is agnostic to the source code and its
verification counterpart supports the widest range of probabilistic
single-loop programs that any existing tool can handle to date.
We demonstrate the efficacy of our method over a range of benchmarks that
include linear and polynomial programs with discrete, continuous, state-dependent,
multi-variate, hierarchical distributions, and distributions with
undefined moments
Sidgwick and Rawls on distributive justice and desert
No full textThis article explores, comparatively and critically, Sidgwick’s and Rawls’s reasons for
rejecting desert as a principle of distributive justice. Their ethical methods, though not
identical, each require giving weight to common sense convictions about justice as well as
higher-level principles. Both men, therefore, need to find a substitute for desert that
captures some of its content – in Sidgwick’s case ‘quasi-desert’ takes the form of an
incentive principle, and in Rawls’s case a principle of legitimate entitlement. However their
reasons for rejecting desert are unclear, and at points appear to rest on contestable
conceptual or metaphysical claims that their methodological commitments are meant to
rule out. To clarify matters, the article distinguishes between three levels at which antidesert arguments may operate: 1) Those purporting to reveal some fundamental defect in
the idea of desert itself; 2) Those purporting to show that we cannot find a coherent basis
for desert, at least for purposes of social justice; 3) Those purporting to show that it is
impossible for social institutions to reward people according to their deserts, no matter
which basis is chosen. At each level, the arguments put forward by Sidgwick and by Rawls
are shown to be unsound
Competitive binding of MatP and topoisomerase IV to the MukB hinge domain
No full textStructural Maintenance of Chromosomes (SMC) complexes have ubiquitous roles in compacting DNA linearly, thereby promoting chromosome organization-segregation. Interaction between the Escherichia coli SMC complex, MukBEF, and matS-bound MatP in the chromosome replication termination region, ter, results in depletion of MukBEF from ter, a process essential for efficient daughter chromosome individualization and for preferential association of MukBEF with the replication origin region. Chromosome-associated MukBEF complexes also interact with topoisomerase IV (ParC2E2), so that their chromosome distribution mirrors that of MukBEF. We demonstrate that MatP and ParC have an overlapping binding interface on the MukB hinge, leading to their mutually exclusive binding, which occurs with the same dimer to dimer stoichiometry. Furthermore, we show that matS DNA competes with the MukB hinge for MatP binding. Cells expressing MukBEF complexes that are mutated at the ParC/MatP binding interface are impaired in ParC binding and have a mild defect in MukBEF function. These data highlight competitive binding as a means of globally regulating MukBEF-topoisomerase IV activity in space and time
Constructing a representative in-silico population for pediatric simulations: application to HIV positive African children
No full textAims: Simulations are an essential tool for investigating scenarios in pharmacokinetics-pharmacodynamics. The models used during simulation often include the effect of highly correlated covariates such as weight, height, and sex and for children also age, which complicates the construction of an in-silico population. For this reason, a suitable and representative patient population is crucial for the simulations to produce meaningful results. For simulation in pediatric patients, international growth charts from the WHO and CDC provide a reference, but these may not always be representative for specific populations, such as malnourished children with HIV, or acutely unwell children.
Methods: We present a workflow to construct a virtual pediatric patient population using WHO and CDC growth charts, suggest piecewise linear functions to adjust the median of the growth charts by sex and age, and suggest visual diagnostics to compare with the target population. We applied this workflow in a population of 1,206 HIV-positive African children, consisting of 19,742 observations with weight ranging from 3.8 to 79.7 kg, height from 55.5 to 180 cm, and an age between 0.40 and 18 years.
Results: Before adjustment, the WHO and CDC charts produced weights and heights higher compared to the observed data. After applying our methodology, we could simulate weight, height, sex and age combinations in good agreement with the observed data.
Conclusion: The methodology presented here is flexible and may be applied to other scenarios where WHO and CDC growth standards might not be appropriate, in addition we provide R scripts and a large ready-to-use pediatric population