Search

Understanding and quantifying migration phenology of commercially harvested Pacific salmon (Oncorhynchus spp.) is a cornerstone for managing sustainable populations. Here, we use a multidecadal data time series together with a hypothesis-driven framework to evaluate migration phenology in adult fall and winter ecotype chum salmon (O. keta) in a poorly studied but highly managed system--the South Puget Sound (SPS) of Washington State, USA. Using generalized additive mixed models that accounted for temporal autoregressive dynamics, we examined the effect of commercial harvest, climate variation, intra-specific density dependence, and predator buffering on migration timing and run duration. SPS chum salmon are migrating earlier over time, especially the winter ecotype that showed the strongest temporal shift from historical timing. Migration timing shifts were closely associated with regional marine climate regimes, local scale freshwater availability, and increasing pinniped abundance. We conclude that there is potential for the winter ecotype migration converging with that of the fall ecotype and that directional change in migration phenology may be driven by a unique combination of ecosystem factors. La comprehension et la quantification de la phenologie des migrations des saumons du Pacifique (Oncorhynchus spp.) faisant l'objet d'une exploitation commerciale constituent un des elements essentiels de la gestion de populations perennes. Nous utilisons une serie de donnees multidecennale jumelee a un cadre module par differentes hypotheses pour evaluer la phenologie de la migration de saumons ketas (O. keta) adultes des ecotypes automnal et hivernal dans un systeme peu etudie, mais faisant l'objet d'une gestion intense, le sud du Puget Sound (SPS, Etat de Washington, Etats-Unis). En utilisant des modeles mixtes additifs generalises qui tiennent compte de la dynamique autoregressive temporelle, nous examinons les effets de l'exploitation commerciale, des variations climatiques, de la dependance intraspecifique sur la densite et de la modulation par les predateurs sur le moment et la duree des migrations. Les saumons ketas du SPS migrent de plus en plus tot, en particulier ceux de l'ecotype hivernal, qui presentent le plus grand decalage temporel par rapport aux observations passees. Les changements du moment de la migration sont etroitement associes aux regimes climatiques marins regionaux, a la disponibilite locale d'eau douce et a l'augmentation de l'abondance de pinnipedes. En conclusion, il est possible que la migration de l'ecotype hivernal converge avec celle de l'ecotype automnal et que les changements directionnels de la phenologie des migrations soient modules par une combinaison unique de facteurs ecosystemiques. [Traduit par la Redaction], Introduction Predicting migratory behavior of commercially harvested salmonids is important for managing and maintaining sustainable populations. However, evaluating the underlying biotic and abiotic mechanisms that drive migration phenology remains complex, [...]

Sulfenyl dipyrroles feature two pyrroles linked via a sulfenyl bridge. The synthesis of sulfenyl dipyrroles has typically involved [SCl.sub.2] as the sulfur source. However, [SCl.sub.2] is no longer readily available within North America and Europe. Herein we report a new synthesis of sulfenyl dipyrroles using [SOCl.sub.2] as the sulfur source and reductant. Although five new sulfenyl dipyrroles were synthesized and isolated via this route, functional group tolerance proved limited. A potential mechanism for the reaction, involving reduction of a sulfinyl moiety by [SOCl.sub.2], is briefly explored. Key words: sulfur, pyrrole, organic synthesis, in-situ reduction of sulfinyl dipyrroles. Les sulfenyldipyrroles sont constituees de deux pyrroles relies par un pont sulfenyle. Dans la synthese des sulfenyldipyrroles, le [SCl.sub.2] est habituellement employe comme source de soufre. Or, le [SCl.sub.2] n'est plus facilement accessible en Amerique du Nord et en Europe. Dans cet article, nous presentons une nouvelle synthese des sulfenyldipyrroles qui fait intervenir le [SOCl.sub.2] comme source de soufre et comme agent reducteur. Bien que nous soyons parvenus a synthetiser et a isoler cinq nouveaux sulfenyldipyrroles par cette methode, la tolerance des groupes fonctionnels s'est revelee limitee. Nous avons explore un mecanisme de reaction possible, qui impliquerait la reduction d'une fraction sulfinyle par le [SOCl.sub.2]. [Traduit par la Redaction] Mots-cles : soufre, pyrrole, synthese organique, reduction in situ des sulfinyldipyrroles., Introduction The sulfenyl dipyrrolic motif, featuring two pyrroles linked via a sulfenyl bridge (1, V = S, Fig.1), has been known since the 1930s. (1) The most common application of [...]

Abstract: Mangrove forests are prevalent along tropical/subtropical coastlines and provide valuable ecosystem services including coastline stabilization, storm impact reduction, and enhanced coastal productivity. However, mangroves were absent from the Hawaiian [...]

F-BODIPYs substituted with BPin functionality have been coupled to aryl halides using a mild and efficient catalyst system involving [Pd.sub.2][(dba).sub.3] and XPhos. The methodology enables the Suzuki--Miyaura cross-coupling of electron-rich, electron-poor, and sterically encumbered BPin-substituted F-BODIPYs to aryl halides bearing various functional groups, thus presenting an opportunity for the preparation of highly functionalised F-BODIPYs without need for the corresponding aryl moiety to be available in borylated form. Key words: late-stage F-BODIPY arylation, aryl halides, BPin-substituted F-BODIPYs. Resume : Nous avons realise le couplage de F-BODIPY substitues par la fonction BPin avec des halogenures d'aryles a l'aide d'un systeme catalytique doux et efficace compose de [(dba).sub.3][(dba).sub.3] et de XPhos. Cette methode permet le couplage croise de Suzuki-Miyaura entre des F-BODIPY substitues par le groupe BPin, riches ou pauvres en electrons, ou encombres steriquement, et des halogenures d'aryles portant differents groupes fonctionnels, ce qui offre la possibilite de preparer des F-BODIPY hautement fonctionnalises sans qu'il soit necessaire d'avoir acces a la forme borylee du fragment aryle. [Traduit par la Redaction] Mots-cles: arylation par le F-BODIPY en finde synthese, halogenures d'aryles, F-BODIPY substitues par le BPin., Introduction The highly tunable photophysical properties of 4,4-difluoro-4-bora-3a,4a-diaza-s-indacenes (F-BODIPYs) have enabled extensive applications across the photoelectronics and chemical biological industries, the latter utilising F-BODIPYs as fluorescent labels. (1) However, although [...]

When competition is naturally limited, policymakers craft regulation to obtain effects similar to those that would have occurred in the presence of competition. In many instances, regulation of this type is not successful in overcoming market failures. We rely on property rights theory and transaction cost theory to predict when state-level policy statements will actually lead to a redistribution of benefits at the city level. We test this theory in the context of cable television franchise renewal agreements--a setting historically resistant to competition. We look to the language of the franchise agreements for evidence of concessions made by the cable operator to the city, and using a difference-in-difference estimator, we find that pro-competitive regulation translates into concessions to the city. However, a credible threat of competition embedded in regulation is not enough to curb opportunism associated with monopoly supply in cases of large franchisees; larger cable operators are at least 60 percent less likely to offer more favorable terms of trade. However, consistent with transaction cost predictions, asset-specific investments by the cable operator do curb opportunism; there is a 51 percent increase in the odds of a franchisee offering more concessions for a 1 standard deviation change--about 1,020 mi of the plant. These findings are important for those involved in crafting policy at all levels of government as well as for researchers interested in understanding the role of long-term contracting and the use of hybrid mechanisms such as franchise agreements in contemporary governance. KEY WORDS: competition, competition policy, contract behavior, franchising, property rights, There is widespread agreement among scholars and practitioners that introducing market competition to the delivery of public goods and services can be beneficial. Early public choice scholars, for example, argued [...]

A study was conducted to evaluate the efficacy and safety of transcatheter aortic-valve implantation (TAVI) for aortic stenosis in patients who cannot undergo surgery. Results indicated that such form of treatment was found to significantly reduce mortality, despite a higher incidence of strokes and major vascular events.

The federal government increasingly relies on nongovernmental organizations for procuring goods and services. This long-term trend presents a significant challenge for administrators because it risks the egalitarian values of democracy by further distancing administrative action from direct, participative, democratic oversight. The authors put forward a theory of representative bureaucracy as a way to reconcile democracy with the reality of the contemporary policy process in which unelected officials are the principal decision makers. The theory is tested in the domain of federal procurement, specifically within the contract award decisions of 60 federal agencies over three years. The authors argue that increased minority representation in leadership positions results in an increased proportion of federal contracts awarded to small minority-owned firms.

Interactions between a turbulent boundary layer and nonlinear mountain waves are explored using a large-eddy simulation model. Simulations of a self-induced critical layer, which develop a stagnation layer and a strong leeside surface jet, are considered. Over time, wave breaking in the stagnation region forces strong turbulence that influences the formation and structure of downstream leeside rotors. Shear production is an important source of turbulence in the stagnation zone and along the interface between the stagnation zone and surface jet, as well as along the rotor edges. Buoyancy perturbations act as a source of turbulence in the stagnation zone but are shown to inhibit turbulence generation on the edges of the stagnation zone. Surface heating is shown to have a strong influence on the strength of downslope winds and the formation of leeside rotors. In cases with no heating, a series of rotor circulations develops, capped by a region of increased winds. Weak heating disrupts this system and limits rotor formation at the base of the downslope jet. Strong heating has a much larger impact through a deepening of the upstream boundary layer and an overall decrease in the downslope winds. Rotors in this case are nonexistent. In contrast to the cases with surface warming, negative surface fluxes generate stronger downslope winds and intensified rotors due to turbulent interactions with an elevated stratified jet capping the rotors. Overall, the results suggest that for nonlinear wave systems over mountains higher than the boundary layer, strong downslope winds and rotors are favored in late afternoon and evening when surface cooling enhances the stability of the low-level air.

Sex in birds is chromosomally based, as in mammals, but the sex chromosomes are different and the mechanism of avian sex determination has been a long-standing mystery (1-3). In the [...]

Urea transporters (UTs) effect rapid flux of urea across biological membranes. In the mammalian kidney, UT activity is essential for effective urine concentration. In bacteria, UT-mediated urea uptake permits intracellular urease to degrade urea to ammonia and C[O.sub.2], a process that either buffers acid loads or provides nutrient nitrogen. We have characterized the urea transport channel protein ApUT from Actinobacillus pleuropneumoniae. Kinetic analysis of bacterial inside-out membranes enriched in ApUT showed ~28-fold increase in urea permeability (3.3 [+ or -] 0.4 x [10.sup.-4] cm/s) compared with control vesicles (0.11 [+ or -] 0.02 x [10.sup.-4] cm/s). In addition to urea, ApUT also conducts water. Urea and water transport across the channel was phloretin and mercury inhibitable, and the site of inhibition may be located on the cytoplasmic side of the protein. Glycerol and urea analogs, such as methylamine, dimethylurea, formamide, acetamide, methylurea, propanamide, and ethylamine did not permeate across ApUT. urea permeability; water permeability; bacterial vesicles; urea analogs

Facilitative urea transporters in the mammalian kidney play a vital role in the urinary concentrating mechanism. The urea transporters located in the renal inner medullary collecting duct, namely UT-A1 and UT-A3, are acutely regulated by the antidiuretic hormone vasopressin. In this study, we investigated the vasopressin regulation of the basolateral urea transporter UT-A3 using an MDCK-mUT-A3 cell line. Within 10 min, vasopressin stimulates urea flux through UT-A3 transporters already present at the plasma membrane, via a PKA-dependent process. Within 1 h, vasopressin significantly increases UT-A3 localization at the basolateral membrane, causing a further increase in urea transport. While the basic trafficking of UT-A3 to basolateral membranes involves both protein kinase C and calmodulin, its regulation by vasopressin specifically occurs through a casein kinase II-dependent pathway. In conclusion, this study details the effects of vasopressin on UT-A3 urea transporter function and hence its role in regulating urea permeability within the renal inner medullary collecting duct. arginine vasopressin; urea transport; membrane localization; casein kinase II

Public administration and management scholars have long recognized the necessity for public managers to interact with entities outside the hierarchical boundaries of their organizations (see Rainey 2003). The growing number [...]

Wyoming Basin archaeofaunas dating to the Middle/Late Holocene transition typically lack bison remains and instead suggest a focus on a wide range of smaller prey species. Excavations along the Sweetwater River at the Graham Ranch site produced an extensive assemblage of highly fragmented bison bones representing the remains of at least two bison that were intensively processed for meat, marrow, and grease. We use a patch use model, in combination with data from 49 Wyoming Basin archaeofaunas to explore the reasons why ancient butchers might expend the effort to extract hard to obtain within-bone nutrients. Our study suggests that prey abundance, possibly linked to climate driven trends in forage communities, may have been one factor that conditioned processing decisions across the Holocene in the Wyoming Basin. Keywords: bison, Wyoming Basin, bone grease processing, Marginal Value Theorem

The renal UT-A urea transporters UT-A1, UT-A2, and UT-A3 are known to play an important role in the urinary concentrating mechanism. The control of the cellular localization of UT-A transporters is therefore vital to overall renal function. In the present study, we have investigated the effect of ubiquitination on UT-A plasma membrane expression in MadinDarby canine kidney (MDCK) cell lines expressing each of the three renal UT-A transporters. Inhibition of the ubiquitin-proteasome pathway caused an increase in basal transepithelial urea flux across MDCK-rat (r)UT-A 1 and MDCK-mouse (m)UT-A2 monolayers (P < 0.01, n = 3, ANOVA) and also increased dimethyl urea-sensitive, arginine vasopressin-stimulated urea flux (P < 0.05, n = 3, ANOVA). Inhibition of the ubiquitin-proteasome pathway also increased basolateral urea flux in MDCK-mUT-A3 monolayers (P < 0.01, n = 4, ANOVA) in a concentration-dependent manner. These increases in urea flux corresponded to a significant increase in UT-A transporter expression in the plasma membrane (P < 0.05, n = 3, ANOVA). Further analysis of the MDCK-mUT-A3 cell line confirmed that vasopressin specifically increased UT-A3 expression in the plasma membrane (P < 0.05, n = 3, ANOVA). However, preliminary data suggested that vasopressin produces this effect through an alternative route to that of the ubiquitin-proteasome pathway. In conclusion, our study suggests that ubiquitination regulates the plasma membrane expression of all three major UT-A urea transporters, but that this is not the mechanism primarily used by vasopressin to produce its physiological effects. ubiquitin-proteasome pathway; urea transport; membrane localization

As public agencies become increasingly familiar with outsourcing public services, public managers face the challenge of building and maintaining contract management capacity while balancing the demands of external actors, including, but not limited to, contractors, executives, legislators, and clients. Although a great deal of recent research examines contract management capacity in the public sector, few studies have investigated consultants 'and public managers' perceptions of one another. Here, within a long-term research project working to build contract management capacity at the Georgia Department of Transportation (GDOT), we draw from in-depth interviews with private consultants to develop and test a model and hypotheses about how public managers' previous work experiences, communication patterns in working relations, and professional and social activities affect their perceptions of outsourcing and consultants. We outline a full model of the relationships between past experiences, perceptions, trust, and relational governance; however, the analysis presented here focuses on the antecedents of public managers 'perceptions of contractors and contracting. We test the model and hypotheses with data from a 2003 survey of GDOT managers' perceptions. Our analysis highlights the importance of social mechanisms in creating positive perceptions among public managers. Our findings contribute to the literature on contract management capacity and our understanding of how public agencies can use public management theory, evaluations, and consultant feedback to understand managerial perceptions. KEYWORDS: contracting out, manager perceptions, outsourcing, relational governance, trust

Urea is a small solute synthesized by many terrestrial organisms as part of the catabolism of protein. In mammals it is transported across cellular membranes by specific urea transporter (UT) proteins that are the products of two separate, but closely related genes, referred to as UT-A and UT-B. Three major UT-A isoforms are found in the kidney, namely UT-A1, UT-A2, and UT-A3. UT-A2 is found in the thin, descending limb of the loop of Henle, whereas UT-A1 and UT-A3 are concentrated in the inner medullary collecting duct. UT-A2 and UT-A3 effectively represent two halves of the whole UT-A gene and, when joined together by 73 hydrophilic amino acids, constitute UT-A1. A biophysical characterization of mouse UT-A2 and UT-A3 was undertaken by expression in Xenopus laevis oocytes and subsequent preparation of highly enriched plasma membrane vesicles for use in stopped-flow fluorometry. Both isoforms were found to be highly specific for urea, and did not permeate water, ammonia, or other molecules closely related to urea (formamide, acetamide, methylurea, and dimethylutea). Single transporter flux rates of 46,000 [+ or -] 10,000 and 59,000 [+ or -] 15,000 (means [+ or -] SE) urea molecules/s/channel for UT-A2 and UT-A3, respectively, were obtained. Overall, the UT-A2 and UT-A3 isoforms appear to have identical functional kinetics. urea analog; flux; water permeability; stopped flow; functional kinetics

A study to examine the efficacy of Rituximab in the relapse or remission of patients suffering from Multiple Sclerosis is conducted. Results conclude that Rituximab is effective in the removal of inflammatory brain lesions and relapses for 48 weeks and also confirms the contribution of B-cell in multiple sclerosis.

The article presents a comparative study of the outcomes of drug-eluting stents and coronary-artery bypass grafting (CABG) that are used for the treatment of multivessel coronary heart disease. CABG is found to lead to a lower mortality rate than the drug-eluting stents.

Chronic exposure to [Cd.sup.2+] causes renal proximal tubular (PT) damage. [Cd.sup.2+] reaches the PT mainly as cadmium-metallothionein 1 (CdMT-1) complexes that are filtered at the glomerulus and then internalized in part via endocytosis mediated by megalin and cubulin. Subsequently, [Cd.sup.2+] is thought to be released in the cytosol to activate cell death pathways. The proton-coupled divalent metal transporter DMT1 also transports [Cd.sup.2+] and is expressed exclusively in endosomes/lysosomes in rat PT cells. Using vector-based RNA interference with short-hairpin small-interfering RNAs (shRNAs) to downregulate DMT1 in the rat renal PT cell line WKPT-0293 C1.2, we tested the hypothesis that endosomal/lysosomal DMTI is involved in CdMT-1 nephrotoxicity. One out of 5 shRNAs tested (sh3) significantly reduced expression of DMTI protein detected by immunoblotting and DMT1 mRNA as determined by RT-PCR by 45.1 [+ or -] 9.6 and 36.9 [+ or -] 14.4% (n = 5-6), respectively. Similarly, sh3 reduced perinuclear DMT1 immunostaining in transfected cells. Consistent with the assumed role of DMT1 in CdMT-1 cytotoxicity, sh3, but not the empty vector or sh5, significantly attenuated cell death induced by a 24-h exposure to 14.3 [micro]M CdMT-1 by 35.6 [+ or -] 4.2% (17 = 13). In contrast, neither fluorescently labeled metallothionein-1 (MT-1) uptake nor free [Cd.sup.2+] toxicity was altered by the effective DMT1 shRNA (sh3), indicating that cellular uptake of metal-MT-1 complexes and [Cd.sup.2+]-induced cell death signaling are not affected by DMT1 knockdown. Thus we conclude that endosomal/lysosomal DMT1 plays a role in renal PT CdMT-1 toxicity. DMT1; endocytosis; heavy metals; metallothionein