6,806 research outputs found
LINKAGES BETWEEN AGRICULTURAL TRADE AND RESOURCE QUALITY: A CONCEPTUAL OVERVIEW
International Relations/Trade, Resource /Energy Economics and Policy,
Resilience of Hierarchical Critical Infrastructure Networks
Concern over the resilience of critical infrastructure networks has increased dramatically over the last decade due to a
number of well documented failures and the significant disruption associated with these. This has led to a large body of
research that has adopted graph-theoretic based analysis in order to try and improve our understanding of infrastructure
network resilience. Many studies have asserted that infrastructure networks possess a scale-free topology which is
robust to random failures but sensitive to targeted attacks at highly connected hubs. However, many studies have
ignored that many networks in addition to their topological connectivity may be organised either logically or spatially
in a hierarchical system which may significantly change their response to perturbations. In this paper we explore if
hierarchical network models exhibit significantly different higher-order topological characteristics compared to other
network structures and how this impacts on their resilience to a number of different failure types. This is achieved by
investigating a suite of synthetic networks as well as a suite of ‘real world’ spatial infrastructure networks
Coagulation kinetics beyond mean field theory using an optimised Poisson representation
Binary particle coagulation can be modelled as the repeated random process of
the combination of two particles to form a third. The kinetics can be
represented by population rate equations based on a mean field assumption,
according to which the rate of aggregation is taken to be proportional to the
product of the mean populations of the two participants. This can be a poor
approximation when the mean populations are small. However, using the Poisson
representation it is possible to derive a set of rate equations that go beyond
mean field theory, describing pseudo-populations that are continuous, noisy and
complex, but where averaging over the noise and initial conditions gives the
mean of the physical population. Such an approach is explored for the simple
case of a size-independent rate of coagulation between particles. Analytical
results are compared with numerical computations and with results derived by
other means. In the numerical work we encounter instabilities that can be
eliminated using a suitable 'gauge' transformation of the problem [P. D.
Drummond, Eur. Phys. J. B38, 617 (2004)] which we show to be equivalent to the
application of the Cameron-Martin-Girsanov formula describing a shift in a
probability measure. The cost of such a procedure is to introduce additional
statistical noise into the numerical results, but we identify an optimised
gauge transformation where this difficulty is minimal for the main properties
of interest. For more complicated systems, such an approach is likely to be
computationally cheaper than Monte Carlo simulation
Robust designs for Poisson regression models
We consider the problem of how to construct robust designs for Poisson regression models. An analytical expression is derived for robust designs for first-order Poisson regression models where uncertainty exists in the prior parameter estimates. Given certain constraints in the methodology, it may be necessary to extend the robust designs for implementation in practical experiments. With these extensions, our methodology constructs designs which perform similarly, in terms of estimation, to current techniques, and offers the solution in a more timely manner. We further apply this analytic result to cases where uncertainty exists in the linear predictor. The application of this methodology to practical design problems such as screening experiments is explored. Given the minimal prior knowledge that is usually available when conducting such experiments, it is recommended to derive designs robust across a variety of systems. However, incorporating such uncertainty into the design process can be a computationally intense exercise. Hence, our analytic approach is explored as an alternative
The Athletic Profile of Fast Bowling in Cricket : A Review
Cricket is a global sport played in over 100 countries with elite performers attracting multimillion dollar contracts. Therefore, performers maintaining optimum physical fitness and remaining injury free is important. Fast bowlers have a vital position in a cricket team, and there is an increasing body of scientific literature that has reviewed this role over the past decade. Previous research on fast bowlers has tended to focus on biomechanical analysis and injury prevention in performers. However, this review aims to critically analyze the emerging contribution of physiological-based literature linked to fast bowling in cricket, highlight the current evidence related to simulated and competitive in-match performance, and relate this practically to the conditioning coach. Furthermore, the review considers limitations with past research and possible avenues for future investigation. It is clear with the advent of new applied mobile monitoring technology that there is scope for more ecologically valid and longitudinal exploration capturing in-match data, providing quantification of physiological workloads, and analysis of the physical demands across the differing formats of the game. Currently, strength and conditioning specialists do not have a critical academic resource with which to shape professional practice, and this review aims to provide a starting point for evidence in the specific areaPeer reviewedFinal Accepted Versio
A Rapid Technic for Demonstrating Melanin in Fresh Tissue11From the Scott and White Clinic and the Temple Division of the University of Texas Postgraduate School of Medicine, Temple, Texas.
Recommended from our members
Covalent targeting of the vacuolar H+-ATPase activates autophagy via mTORC1 inhibition.
Autophagy is a lysosomal degradation pathway that eliminates aggregated proteins and damaged organelles to maintain cellular homeostasis. A major route for activating autophagy involves inhibition of the mTORC1 kinase, but current mTORC1-targeting compounds do not allow complete and selective mTORC1 blockade. Here, we have coupled screening of a covalent ligand library with activity-based protein profiling to discover EN6, a small-molecule in vivo activator of autophagy that covalently targets cysteine 277 in the ATP6V1A subunit of the lysosomal v-ATPase, which activates mTORC1 via the Rag guanosine triphosphatases. EN6-mediated ATP6V1A modification decouples the v-ATPase from the Rags, leading to inhibition of mTORC1 signaling, increased lysosomal acidification and activation of autophagy. Consistently, EN6 clears TDP-43 aggregates, a causative agent in frontotemporal dementia, in a lysosome-dependent manner. Our results provide insight into how the v-ATPase regulates mTORC1, and reveal a unique approach for enhancing cellular clearance based on covalent inhibition of lysosomal mTORC1 signaling
Networks and the epidemiology of infectious disease
The science of networks has revolutionised research into the dynamics of interacting elements. It could be argued that epidemiology in particular has embraced the potential of network theory more than any other discipline. Here we review the growing body of research concerning the spread of infectious diseases on networks, focusing on the interplay between network theory and epidemiology. The review is split into four main sections, which examine: the types of network relevant to epidemiology; the multitude of ways these networks can be characterised; the statistical methods that can be applied to infer the epidemiological parameters on a realised network; and finally simulation and analytical methods to determine epidemic dynamics on a given network. Given the breadth of areas covered and the ever-expanding number of publications, a comprehensive review of all work is impossible. Instead, we provide a personalised overview into the areas of network epidemiology that have seen the greatest progress in recent years or have the greatest potential to provide novel insights. As such, considerable importance is placed on analytical approaches and statistical methods which are both rapidly expanding fields. Throughout this review we restrict our attention to epidemiological issues
Preserving Innocence: Ending Perceived Adultification and Toxic Masculinity Toward Black Boys
As early as the age of ten, Black boys are viewed as older, guilty until proven innocent by law enforcement (including school resource officers), and encounter a myriad of adverse racialized academic and social experiences (e.g., explicit and implicit biases) (Goff et al., 2014; Noguera, 2008). Dancy (2014) noted how Trayvon Martin, a Black male teen murdered for essentially being seen as threatening and intimidating, was viewed as adult-aged, deviant, troubled, and shiftless. Moreover, Black boys are expected to express minimum “signs” of weakness, vulnerability, and/or sensitivity. The aforementioned social persona may contribute to young Black men and boys not feeling comfortable talking about their feelings and emotional distresses or even seeking professional help, when needed. Generally speaking, many young Black men and boys struggle with emotional vulnerability and choose to avoid or resist any attempts to examine their emotional experiences. Thus, it is important to note that the absence of healthy emotional support channels to process and disclose their feelings may lead to negative life outcomes, such as depression, cardiac arrest, and a shorter lifespan (Ford, 2020). In this article, we discuss the historical and contemporary contexts of adultification of young Black boys; present two vignettes to show examples of how boys are adultified; examine how toxic masculinity may prevent healthy relationships and emotional expressions for Black boys; and offer specific recommendations to educators and families
- …