Generalized minimizers of convex integral functionals, Bregman distance, Pythagorean identities

Integral functionals based on convex normal integrands are minimized subject to finitely many moment constraints. The integrands are finite on the positive and infinite on the negative numbers, strictly convex but not necessarily differentiable. The minimization is viewed as a primal problem and studied together with a dual one in the framework of convex duality. The effective domain of the value function is described by a conic core, a modification of the earlier concept of convex core. Minimizers and generalized minimizers are explicitly constructed from solutions of modified dual problems, not assuming the primal constraint qualification. A generalized Pythagorean identity is presented using Bregman distance and a correction term for lack of essential smoothness in integrands. Results are applied to minimization of Bregman distances. Existence of a generalized dual solution is established whenever the dual value is finite, assuming the dual constraint qualification. Examples of `irregular' situations are included, pointing to the limitations of generality of certain key results

Current Approaches to HR Strategies: Inside-Out vs. Outside-In

In an effort to determine the best practices with regard to Human Resource (HR) strategies, we conducted interviews with HR executives knowledgeable about their HR strategies from 20 companies, and gathered archival materials such as the HR strategy documents from 9 of the companies. We found that the content, process, and evaluation of the HR strategies can each be classified as focusing primarily on the HR function, the people of the firm, or the business. We provide some examples of ways that firms can move from an HR focused to a business-focused HR strategy

Collisionless shocks in plasmas

Collisionless shocks in plasmas, dissipation and dispersion in determining shock structur

Analysis of permanent magnets as elasmobranch bycatch reduction devices in hook-and-line and longline trials

Previous studies indicate that elasmobranch fishes (sharks, skates and rays) detect the Earth’s geomagnetic field by indirect magnetoreception through electromagnetic induction, using their ampullae of Lorenzini. Applying this concept, we evaluated the capture of elasmobranchs in the presence of permanent magnets in hook-and-line and inshore longline fishing experiments. Hooks with neodymium-iron-boron magnets significantly reduced the capture of elasmobranchs overall in comparison with control and procedural control hooks in the hook-and-line experiment. Catches of Atlantic sharpnose shark (Rhizoprionodon terraenovae) and smooth dogfish (Mustelus canis) were signif icantly reduced with magnetic hook-and-line treatments, whereas catches of spiny dogfish (Squalus acanthias) and clearnose skate (Raja eglanteria) were not. Longline hooks with barium-ferrite magnets significantly reduced total elasmobranch capture when compared with control hooks. In the longline study, capture of blacktip sharks (Carcharhinus limbatus) and southern stingrays (Dasyatis americana) was reduced on magnetic hooks, whereas capture of sandbar shark (Carcharhinus plumbeus) was not affected. Teleosts, such as red drum (Sciaenops ocellatus), Atlantic croaker (Micropogonias undulatus), oyster toadfish (Opsanus tau), black sea bass (Centropristis striata), and the bluefish (Pomatomas saltatrix), showed no hook preference in either hook-and-line or longline studies. These results indicate that permanent magnets, although eliciting species-specific capture trends, warrant further investigation in commercial longline and recreational fisheries, where bycatch mortality is a leading contributor to declines in elasmobranch populations

An estimate of the uptake of atmospheric methyl bromide by agricultural soils

Published estimates of removal of atmospheric methyl bromide (CH3Br) by agricultural soils are 2.7 Gg yr−1 (Gg = 109 g) [Shorter et al., 1995] and 65.8 Gg yr−1 [Serça et al., 1998]. The Serça et al. estimate, if correct, would suggest that the current value for total removal of atmospheric CH3Br by all sinks of 206 Gg yr−1 (based on Shorter et al., 1995) would be 30% too low. We have calculated a new rate of global agricultural soil uptake of atmospheric CH3Br from a larger sampling of cultivated soils collected from 40 sites located in the United States, Costa Rica, and Germany. First order reaction rates were measured during static laboratory incubations. These data were combined with uptake measurements we reported earlier based on field and laboratory experiments [Shorter et al. 1995]. Tropical (10.2°–10.4°N) and northern (45°–61°N) soils averaged lower reaction rate constants than temperate soils probably due to differing physical and chemical characteristics as well as microbial populations. Our revised global estimate for the uptake of ambient CH3Br by cultivated soils is 7.47±0.63 Gg yr−1, almost three times the value that we reported in 1995

Controls on the seasonal exchange of CH3Br in temperate peatlands

Measurements of CH3Br exchange at two New Hampshire peatlands (Sallie\u27s Fen and Angie\u27s Bog) indicate that net flux from these ecosystems is the sum of competing production and consumption processes. Net CH3Br fluxes were highly variable and ranged from net emission to net uptake between locations within a single peatland. At Sallie\u27s Fen, net CH3Br flux exhibited positive correlations with peat temperature and air temperature during all seasons sampled, but these relationships were not observed at Angie\u27s Bog where flux varied according to microtopography. The major CH3Br production process at Sallie\u27s Fen appeared dependent on aerobic conditions within the peat, while CH3Br production at Angie\u27s Bog was favored by anaerobic conditions. There was evidence of aerobic microbial consumption of CH3Br within the peat at both sites. In a vegetation removal experiment conducted at Sallie\u27s Fen with dynamic chambers, all collars exhibited net consumption of CH3Br. Net CH3Br flux had a negative correlation with surface temperature and a positive correlation with water level in collars with all vegetation clipped consistent with aerobic microbial consumption. Vegetated collars showed positive correlations between net CH3Br flux and air temperature. A positive correlation between net CH3Br flux and surface temperature was also observed in collars in which all vegetation except Sphagnum spp. were clipped. These correlations are consistent with seasonal relationships observed in 1998, 1999, and 2000 and suggest that plants and/or fungi are possible sources of CH3Br in peatlands. Estimates of production and consumption made on two occasions at Sallie\u27s Fen suggest that peatlands have lower rates of CH3Br consumption compared to upland ecosystems, but a close balance between production and consumption rates may allow these wetlands to act as either a net source or sink for this gas

Muscle Fatigue from the Perspective of a Single Crossbridge

The repeated intense stimulation of skeletal muscle rapidly decreases its force- and motion-generating capacity. This type of fatigue can be temporally correlated with the accumulation of metabolic by-products, including phosphate (Pi) and protons (H+). Experiments on skinned single muscle fibers demonstrate that elevated concentrations of these ions can reduce maximal isometric force, unloaded shortening velocity, and peak power, providing strong evidence for a causative role in the fatigue process. This seems to be due, in part, to their direct effect on muscle’s molecular motor, myosin, because in assays using isolated proteins, these ions directly inhibit myosin’s ability to move actin. Indeed, recent work using a single molecule laser trap assay has revealed the specific steps in the crossbridge cycle affected by these ions. In addition to their direct effects, these ions also indirectly affect myosin by decreasing the sensitivity of the myofilaments to calcium, primarily by altering the ability of the muscle regulatory proteins, troponin and tropomyosin, to govern myosin binding to actin. This effect seems to be partially due to fatigue-dependent alterations in the structure and function of specific subunits of troponin. Parallel efforts to understand the molecular basis of muscle contraction are providing new technological approaches that will allow us to gain unprecedented molecular detail of the fatigue process. This will be crucial to fully understand this ubiquitous phenomenon and develop appropriately targeted therapies to attenuate the debilitating effects of fatigue in clinical populations

Thermodynamic properties of extremely diluted symmetric Q-Ising neural networks

Using the replica-symmetric mean-field theory approach the thermodynamic and retrieval properties of extremely diluted {\it symmetric} $Q$-Ising neural networks are studied. In particular, capacity-gain parameter and capacity-temperature phase diagrams are derived for $Q=3, 4$ and $Q=\infty$. The zero-temperature results are compared with those obtained from a study of the dynamics of the model. Furthermore, the de Almeida-Thouless line is determined. Where appropriate, the difference with other $Q$-Ising architectures is outlined.Comment: 16 pages Latex including 6 eps-figures. Corrections, also in most of the figures have been mad

Production of methyl bromide in a temperate forest soil

Field enclosure measurements of a temperate forest soil show net uptake of ambient methyl bromide (CH3Br), an important trace gas in both tropospheric and stratospheric ozone cycling. The net flux for 1999 was estimated to be −168 ± 72 μg CH3Br m−2 (negative indicates loss from the atmosphere). Individual enclosure flux measurements ranged from −4.0 to +3.3 μg CH3Br m−2 d−1. Soil consumption of CH3Br was estimated from laboratory soil incubations. Production of CH3Br was calculated as the difference between net flux and predicted consumption. Fungi could be responsible for the production of CH3Br in this temperate forest soil