Inflammatory modulation of exercise salience: using hormesis to return to a healthy lifestyle

Most of the human population in the western world has access to unlimited calories and leads an increasingly sedentary lifestyle. The propensity to undertake voluntary exercise or indulge in spontaneous physical exercise, which might be termed "exercise salience", is drawing increased scientific attention. Despite its genetic aspects, this complex behaviour is clearly modulated by the environment and influenced by physiological states. Inflammation is often overlooked as one of these conditions even though it is known to induce a state of reduced mobility. Chronic subclinical inflammation is associated with the metabolic syndrome; a largely lifestyle-induced disease which can lead to decreased exercise salience. The result is a vicious cycle that increases oxidative stress and reduces metabolic flexibility and perpetuates the disease state. In contrast, hormetic stimuli can induce an anti-inflammatory phenotype, thereby enhancing exercise salience, leading to greater biological fitness and improved functional longevity. One general consequence of hormesis is upregulation of mitochondrial function and resistance to oxidative stress. Examples of hormetic factors include calorie restriction, extreme environmental temperatures, physical activity and polyphenols. The hormetic modulation of inflammation, and thus, exercise salience, may help to explain the highly heterogeneous expression of voluntary exercise behaviour and therefore body composition phenotypes of humans living in similar obesogenic environments

An Aboriginal Perspective on the Remediation of Mid-Canada Radar Line Sites in the Subarctic: A Partnership Evaluation

The Mid-Canada Radar Line (MCRL) was built during the 1950s in response to the perceived threat of a Soviet nuclear attack over the Arctic. The MCRL was an entirely Canadian project, consisting of 98 radar stations that stretched across the 55th parallel from Dawson Creek, British Columbia, to Hopedale, Labrador. Seventeen MCRL sites were located in Ontario, and by 1965, all had been closed for strategic and economic reasons. Since these sites were improperly decommissioned, they have become point sources of contaminants in northern Canada. In 2001, MCRL Site 050 was remediated. The Fort Albany First Nation (located near Site 050), the Department of National Defence, and the Ontario Ministry of Natural Resources had formed a “partnership” to undertake this. We determined that from an Aboriginal perspective, a true partnership (as we define it) did exist between these organizations; a partnership based on the essential elements of respect, equity, and empowerment. We show that these cornerstones of a true partnership were present in the initial documents that discussed remediation of this site. This evaluation will provide insight, guidance, and a potential framework to benefit future partnership endeavours, helping to foster stronger collaborative relationships between Aboriginal organizations and governments at all levels, especially with respect to the remediation of abandoned radar line sites.Le réseau mitoyen d’alerte radar du Canada a été aménagé dans les années 1950 en réaction à une menace perçue d’attaque nucléaire soviétique qui passerait par l’Arctique. Ce réseau mitoyen était un projet entièrement canadien. Il consistait en 98 postes de radar répartis à la hauteur du 55e parallèle, de Dawson Creek, en Colombie-Britannique, à Hopedale, au Labrador. Dix-sept postes de radar avaient été installés en Ontario, et vers 1965, ils avaient tous fermé leurs portes et ce, pour des raisons stratégiques et économiques. Puisque ces postes n’ont pas été désaffectés dans les règles de l’art, ils sont devenus des sources ponctuelles de contaminants dans le nord du Canada. En 2001, le poste 050 du réseau mitoyen a fait l’objet d’une biorestauration. La Première Nation de Fort Albany (située près du poste 050), le ministère de la Défense nationale et le ministère des Richesses naturelles de l’Ontario avaient formé un « partenariat » pour s’acquitter de cette tâche. Nous avons déterminé que du point de vue des Autochtones, un vrai partenariat (comme nous le définissons) a existé entre ces organismes. Il s’agissait d’un partenariat reposant sur des éléments essentiels de respect, d’équité et d’habilitation. Nous montrons que ces éléments essentiels d’un vrai partenariat étaient présents dans les premiers documents ayant trait aux efforts de biorestauration de ce poste de radar. La présente évaluation a pour but de fournir une perspective, une orientation et un cadre de référence éventuel pouvant servir de modèles à d’autres partenariats et ce, dans le but de favoriser des relations de collaboration plus étroites entre les organismes autochtones et les gouvernements de tous les échelons, surtout en ce qui a trait aux travaux de biorestauration des postes de radar abandonnés

The mass insertion approximation without squark degeneracy

We study the applicability of the mass insertion approximation (MIA) for calculations of neutral meson mixing when squark masses are not degenerate and, in particular, in models of alignment. We show that the MIA can give results that are much better than an order of magnitude estimate as long as the masses are not strongly hierarchical. We argue that, in an effective two-squark framework, m_q=(m_1+m_2)/2 is the best choice for the MIA expansion point, rather than, for example, m_q^2=(m_1^2+m_2^2)/2.Comment: 7 pages, revtex

Longevity hedge effectiveness: A decomposition

We use a case study of a pension plan wishing to hedge the longevity risk in its pension liabilities at a future date. The plan has the choice of using either a customised hedge or an index hedge, with the degree of hedge effectiveness being closely related to the correlation between the value of the hedge and the value of the pension liability. The key contribution of this paper is to show how correlation and, therefore, hedge effectiveness can be broken down into contributions from a number of distinct types of risk factors. Our decomposition of the correlation indicates that population basis risk has a significant influence on the correlation. But recalibration risk as well as the length of the recalibration window are also important, as is cohort effect uncertainty. Having accounted for recalibration risk, additional parameter uncertainty has only a marginal impact on hedge effectiveness. Finally, the inclusion of Poisson risk only starts to become significant when the smaller population falls below about 10,000 members over age 50. Our case study shows that, at least for medium and large pension plans, longevity risk can be substantially hedged using index hedges as an alternative to customised longevity hedges. As a consequence, when the hedger's population involves more than about 10,000 members over age 50, index longevity hedges (in conjunction with the other components of an ALM strategy) can provide an effective and lower cost alternative to both a full buy-out of pension liabilities or even to a strategy using customised longevity hedges

Probing the time dependence of dark energy

A new method to investigate a possible time-dependence of the dark energy equation of state $w$ is proposed. We apply this methodology to two of the most recent data sets of type Ia supernova (Union2 and SDSS) and the baryon acoustic oscillation peak at $z = 0.35$. For some combinations of these data, we show that there is a clear departure from the standard $\Lambda$CDM model at intermediary redshifts, although a non-evolving dark energy component ($dw/dz = 0$) cannot be ruled out by these data. The approach developed here may be useful to probe a possible evolving dark energy component when applied to upcoming observational data.Comment: 6 pages, 3 figures, LaTe

Anthropogenic resource subsidies determine space use by Australian arid zone dingoes: an improved resource selection modelling approach

Dingoes (Canis lupus dingo) were introduced to Australia and became feral at least 4,000 years ago. We hypothesized that dingoes, being of domestic origin, would be adaptable to anthropogenic resource subsidies and that their space use would be affected by the dispersion of those resources. We tested this by analyzing Resource Selection Functions (RSFs) developed from GPS fixes (locations) of dingoes in arid central Australia. Using Generalized Linear Mixed-effect Models (GLMMs), we investigated resource relationships for dingoes that had access to abundant food near mine facilities, and for those that did not. From these models, we predicted the probability of dingo occurrence in relation to anthropogenic resource subsidies and other habitat characteristics over ∼ 18,000 km(2). Very small standard errors and subsequent pervasively high P-values of results will become more important as the size of data sets, such as our GPS tracking logs, increases. Therefore, we also investigated methods to minimize the effects of serial and spatio-temporal correlation among samples and unbalanced study designs. Using GLMMs, we accounted for some of the correlation structure of GPS animal tracking data; however, parameter standard errors remained very small and all predictors were highly significant. Consequently, we developed an alternative approach that allowed us to review effect sizes at different spatial scales and determine which predictors were sufficiently ecologically meaningful to include in final RSF models. We determined that the most important predictor for dingo occurrence around mine sites was distance to the refuse facility. Away from mine sites, close proximity to human-provided watering points was predictive of dingo dispersion as were other landscape factors including palaeochannels, rocky rises and elevated drainage depressions. Our models demonstrate that anthropogenically supplemented food and water can alter dingo-resource relationships. The spatial distribution of such resources is therefore critical for the conservation and management of dingoes and other top predators

Cloning and characterization of Trypanosoma congolense and T. vivax nucleoside transporters reveal the potential of P1-type carriers for the discovery of broad-spectrum nucleoside-based therapeutics against Animal African trypanosomiasis

African Animal Trypanosomiasis (AAT), caused predominantly by Trypanosoma brucei brucei, T. vivax and T. congolense, is a fatal livestock disease throughout Sub-Saharan Africa. Treatment options are very limited and threatened by resistance. Tubercidin (7-deazaadenosine) analogs have shown activity against individual parasites but viable chemotherapy must be active against all three species. Divergence in sensitivity to nucleoside antimetabolites could be caused by differences in nucleoside transporters. Having previously characterized the T. brucei nucleoside carriers, we here report the functional expression and characterization of the main adenosine transporters of T. vivax (TvxNT3) and T. congolense (TcoAT1/NT10), in a Leishmania mexicana cell line (‘SUPKO’) lacking adenosine uptake. Both carriers were similar to the T. brucei P1-type transporters and bind adenosine mostly through interactions with N3, N7 and 3′-OH. Expression of TvxNT3 and TcoAT1 sensitized SUPKO cells to various 7-substituted tubercidins and other nucleoside analogs although tubercidin itself is a poor substrate for P1-type transporters. Individual nucleoside EC50s were similar for T. b. brucei, T. congolense, T. evansi and T. equiperdum but correlated less well with T. vivax. However, multiple nucleosides including 7-halogentubercidines displayed pEC50>7 for all species and, based on transporter and anti-parasite SAR analyses, we conclude that nucleoside chemotherapy for AAT is viable

Can we save large carnivores without losing large carnivore science?

Large carnivores are depicted to shape entire ecosystems through top-down processes. Studies describing these processes are often used to support interventionist wildlife management practices, including carnivore reintroduction or lethal control programs. Unfortunately, there is an increasing tendency to ignore, disregard or devalue fundamental principles of the scientific method when communicating the reliability of current evidence for the ecological roles that large carnivores may play, eroding public confidence in large carnivore science and scientists. Here, we discuss six interrelated issues that currently undermine the reliability of the available literature on the ecological roles of large carnivores: (1) the overall paucity of available data, (2) reliability of carnivore population sampling techniques, (3) general disregard for alternative hypotheses to top-down forcing, (4) lack of applied science studies, (5) frequent use of logical fallacies, and (6) generalisation of results from relatively pristine systems to those substantially altered by humans. We first describe how widespread these issues are, and given this, show, for example, that evidence for the roles of wolves (Canis lupus) and dingoes (Canis lupus dingo) in initiating trophic cascades is not as strong as is often claimed. Managers and policy makers should exercise caution when relying on this literature to inform wildlife management decisions. We emphasise the value of manipulative experiments, and discuss the role of scientific knowledge in the decision-making process. We hope that the issues we raise here prompt deeper consideration of actual evidence, leading towards an improvement in both the rigour and communication of large carnivore science

Large carnivore science: non-experimental studies are useful, but experiments are better

1. Response to Bruskotter and colleagues We recently described the following six interrelated issues that justify questioning some of the discourse about the reliability of the literature on the ecological roles of large carnivores (Allen et al., in press): 1. The overall paucity of available data, 2. The reliability of carnivore population sampling techniques, 3. The general disregard for alternative hypotheses to top-down forcing, 4. The lack of applied science studies, 5. The frequent use of logical fallacies, 6. The generalisation of results from relatively pristine systems to those substantially altered by humans. We thank Bruskotter et al. (2017) for responding to our concerns and engaging with this important issue. We agree completely that nonexperimental studies can and do often have great value, and we recognize that in many (most) cases these types of studies may provide the only data that are available. We acknowledge the many challenges of working on large, cryptic, dangerous, and highly-mobile animals in the wild. However, the absence of more robust data and the reality of these challenges do not excuse weak inference or overstating conclusions – a practice apparent in many studies (and communication of those studies) adopting only observational or correlative methods to infer the roles of large carnivores (reviewed in Allen et al., in press)

The Physics of Cluster Mergers

Clusters of galaxies generally form by the gravitational merger of smaller clusters and groups. Major cluster mergers are the most energetic events in the Universe since the Big Bang. Some of the basic physical properties of mergers will be discussed, with an emphasis on simple analytic arguments rather than numerical simulations. Semi-analytic estimates of merger rates are reviewed, and a simple treatment of the kinematics of binary mergers is given. Mergers drive shocks into the intracluster medium, and these shocks heat the gas and should also accelerate nonthermal relativistic particles. X-ray observations of shocks can be used to determine the geometry and kinematics of the merger. Many clusters contain cooling flow cores; the hydrodynamical interactions of these cores with the hotter, less dense gas during mergers are discussed. As a result of particle acceleration in shocks, clusters of galaxies should contain very large populations of relativistic electrons and ions. Electrons with Lorentz factors gamma~300 (energies E = gamma m_e c^2 ~ 150 MeV) are expected to be particularly common. Observations and models for the radio, extreme ultraviolet, hard X-ray, and gamma-ray emission from nonthermal particles accelerated in these mergers are described.Comment: 38 pages with 9 embedded Postscript figures. To appear in Merging Processes in Clusters of Galaxies, edited by L. Feretti, I. M. Gioia, and G. Giovannini (Dordrecht: Kluwer), in press (2001