Mechanisms of vascular smooth muscle contraction and the basis for pharmacologic treatment of smooth muscle disorders

The smooth muscle cell directly drives the contraction of the vascular wall and hence regulates the size of the blood vessel lumen. We review here the current understanding of the molecular mechanisms by which agonists, therapeutics, and diseases regulate contractility of the vascular smooth muscle cell and we place this within the context of whole body function. We also discuss the implications for personalized medicine and highlight specific potential target molecules that may provide opportunities for the future development of new therapeutics to regulate vascular function.Accepted manuscrip

Electroweak Theory Without Higgs Bosons

A perturbative SU(2)_L X U(1)_Y electroweak theory containing W, Z, photon, ghost, lepton and quark fields, but no Higgs or other fields, gives masses to W, Z and the non-neutrino fermions by means of an unconventional choice for the unperturbed Lagrangian and a novel method of renormalisation. The renormalisation extends to all orders. The masses emerge on renormalisation to one loop. To one loop the neutrinos are massless, the A -> Z transition drops out of the theory, the d quark is unstable and S-matrix elements are independent of the gauge parameter xi.Comment: 27 pages, LaTex, no figures; revised for publication; accepted by Int. J. Mod. Phys. A; includes biographical note on A. F. Nicholso

Livestock, Land Use Change, and Environmental Outcomes in the Developing World

No Abstrac

Using System Dynamics Modelling Approach to Develop Management Tools for Animal Production with Emphasis on Small Ruminants

Small ruminants are important assets in several regions of the world. They account for more than half of the domesticated ruminants. Despite the growth in goat production in the world (more than 2% per year), research related to goat production is less than desired. One underused but potentially valuable approach for research on small ruminants is simulation modelling. Models of the components of small ruminant systems can enhance the financial returns and reduce negative environmental impacts. These models can be used to assess many dimensions of small ruminant production, from rumen dynamics to economic policies designed to support small ruminant production. Understanding the nutrition, production, and economic policy feedback signals and planning ahead is crucial to build a robust and integrated production activity that can be managed under different production scenarios. System Dynamics (SD) is a computer-aided modelling methodology that can be used to perform policy analysis and decision support system (DSS) applied to dynamic problems arising in complex social, managerial, economic, or ecological dynamic systems characterized by interdependence, mutual interaction, information feedback, and circular causality. SD can be used as a modelling tool to aggregate knowledge to solve different types of problems that have a limited scope to a specific location or have broad trends of applications across locations and areas of science. Important issues of broad application include the bearings of animal production in the climate change and the impacts of climate change in animal production, alternative production scenarios of animal and crop integration, associations between animal production and business (economics, marketing). The trend of increasing small ruminants in tropical and subtropical regions and an increasing pressure on tropical and subtropical livestock systems to produce food, to feed livestock, and to produce energy crops warrants the development of DSS to address issues such as what is the “real” benefits of livestock, the negative impacts livestock can have on greenhouse-gas emissions and the environment, and the effects of climate change on livestock systems

Constraints on small-scale cosmological perturbations from gamma-ray searches for dark matter

Events like inflation or phase transitions can produce large density perturbations on very small scales in the early Universe. Probes of small scales are therefore useful for e.g. discriminating between inflationary models. Until recently, the only such constraint came from non-observation of primordial black holes (PBHs), associated with the largest perturbations. Moderate-amplitude perturbations can collapse shortly after matter-radiation equality to form ultracompact minihalos (UCMHs) of dark matter, in far greater abundance than PBHs. If dark matter self-annihilates, UCMHs become excellent targets for indirect detection. Here we discuss the gamma-ray fluxes expected from UCMHs, the prospects of observing them with gamma-ray telescopes, and limits upon the primordial power spectrum derived from their non-observation by the Fermi Large Area Space Telescope.Comment: 4 pages, 3 figures. To appear in J Phys Conf Series (Proceedings of TAUP 2011, Munich

RELATIONSHIP BETWEEN GROUND REACTION FORCE AND THROWING ARM KINETICS IN HIGH SCHOOL AND COLLEGIATE BASEBALL PITCHERS

The purpose of this study was to examine the relationship of ground reaction force (GRF) of the drive and stride leg and kinetics of the throwing arm in high school and collegiate baseball pitchers. Several studies have examined the relationship between GRF and ball velocity, but no one has examined the effect of GRF on maximum shoulder rotation torque (MERT) and maximum elbow valgus torque (MEVT). Understanding this relationship will be important to both enhancing performance and avoiding injury. Data that were previously collected during a pitching evaluation were analyzed. Twenty-two high school pitchers and 13 collegiate pitchers had received a pitching evaluation. Multiple regression analysis was used to examine the relationships between variables. Only the drive leg medial force (β = .372, p = .015) and stride leg braking force (β = .401, p = .009) were significant predictors of MERT

Nutrient status of cattle grazing systems in the western brazilian Amazon.

Low-input cultivated pastures to feed cattle have dominated land use after forest clearing for decades in the western Brazilian Amazon. This study was undertaken to help understand the inherent nutrient supply dynamics underwriting cattle performance on three farms in the state of Acre. We assessed soil chemical and physical properties associated over time with different land uses following forest clearing. This information permitted specifying a conceptual model of nutrient stocks and flows under the observed grazing system, which produced insights about the dynamics of soil nutrient degradation. Above ground forage mass, topsoil nutrient concentrations and soil bulk density were measured. Land covers were Brachiaria spp. grasses, a grass-Pueraria phaseoloides mix, cropland and forest. Most soil nutrient parameters initially decreased after clearing, gradually recovering over time with grass-only pastures; however, 20 yr-old pastures had 20% less forage mass. Most pasture system nutrients on these farms resided in topsoil and roots, where large stocks of mature forage supported soil fertility with recycled nutrients from litter. Estimates of partial topsoil nutrient balances were negative. This suggested that corresponding nutrient stocks and the accumulation of forage mass were probably maintained primarily through the sum of inflows from cattle excreta, the subsoil, soil organic matter, and litter mineralization with scant input of commercial fertilizer. Therefore, herd management to increase animal system productivity via higher stocking rates on vegetatively younger forage requires monitoring of nutrient stocks and flows and fertilization that assures replenishment of the nutrients extracted. Otherwise, rapid depletion of soil nutrient stocks will lead to system degradation and failure