244 research outputs found
Annual Forage Legume Response to Herbicides Labelled for Lucerne Establishment
Weed competition reduces stand establishment, thus lowering forage production and quality. However, there are no herbicides labelled for annual legume establishment, despite several labelled for the establishment of lucerne (Medicago sativa). Some of these may be useful in the establishment and production of annual forage legumes. Lucerne herbicides have greater potential for use on other legumes, since they have grazing and feeding clearance. The objective of this paper is to summarize annual legume yield response trials to herbicides labelled for lucerne establishment
Catalytic cyclization and competitive deactivation with Ru(P\u3csup\u3eR\u3c/sup\u3e2N\u3csup\u3eR′\u3c/sup\u3e2) complexes
The first successful use of the PR2NR′2 (1,5-R′-3,7-R-1,5-diaza-3,7-diphosphacyclooctane) ligand family toward an organic synthesis is described. The precatalysts [Ru(Cp)(PR2NBn2)(MeCN)]PF6 are active toward cyclization of 2-ethynylbenzyl alcohol at low catalyst loading and mild temperatures. Catalyst performance however is limited by both low conscription and by competitive deactivation
A phosphorus-rich polymer as a homogeneous catalyst scavenger
© The Royal Society of Chemistry 2017. A soft polymer network prepared through a phosphane-ene reaction successfully sequestered Rh and Ru from hydrogenation and ring closing metathesis reactions, respectively. Scavenging effectively quenches catalytic activity and ultimately removes \u3e98% of the metal
Design and optimization of a nanoprobe comprising amphiphilic chitosan colloids and Au-nanorods: Sensitive detection of human serum albumin in simulated urine
Metallic nanoparticles have been utilized as analytical tools to detect a wide range of organic analytes. In most reports, gold (Au)-based nanosensors have been modified with ligands to introduce selectivity towards a specific target molecule. However, in a recent study a new concept was presented where bare Au-nanorods on self-assembled carboxymethyl-hexanoyl chitosan (CHC) nanocarriers achieved sensitive and selective detection of human serum albumin (HSA) after manipulation of the solution pH. Here this concept was further advanced through optimization of the ratio between Au-nanorods and CHC nanocarriers to create a nanotechnology-based sensor (termed CHC-AuNR nanoprobe) with an outstanding lower detection limit (LDL) for HSA. The CHC-AuNR nanoprobe was evaluated in simulated urine solution and a LDL as low as 1.5 pM was achieved at an estimated AuNR/CHC ratio of 2. Elemental mapping and protein adsorption kinetics over three orders of magnitude in HSA concentration confirmed accumulation of HSA on the nanorods and revealed the adsorption to be completed within 15 min for all investigated concentrations. The results suggest that the CHC-AuNR nanoprobe has potential to be utilized for cost-effective detection of analytes in complex liquids
Native Texas Ornamental Bunchgrass Performance Under Water Restrictions
Growing human populations and increasing drought conditions compete with ornamental grassland landscapes for freshwater resources. With outdoor use as the largest consumer of municipal water, irrigation restrictions will likely be increasingly implemented, restricting ornamental municipal grasslands. Substituting irrigation-dependent exotic grasses with drought-adapted native bunchgrasses could help mitigate this problem. Greenhouse (GH) trials revealed exotic ornamental bunchgrasses declined faster than natives under progressive water stress, with natives performing best under moderate water with maximum water treatments decreasing aesthetic quality. There was wide variability among accessions, indicating promising genetic diversity from which to select drought resistance for ornamentals. Native grasses performed best in field trials with supplemental irrigation during warm-season growth and restricted irrigation during the cool season. In northcentral Texas, native little bluestem (LBS; Schizachyrium scoparium L.) accessions outperformed exotics in health and aesthetics across environments. Most response variables were species as well as accession dependent. Select LBS accessions are recommended for commercialization for municipal grasslands due to superior field performance under water restrictions. Replacing favored water-intensive exotic grasses with adapted native grasses could help reduce irrigation water use
Transitioning to Multiple-use Polyculture Grassland-derived Bioenergy Feedstock Systems
We argue that research and development of grassland-derived bioenergy feedstock (GBF) has focused unduly on dedicated monospecific biomass systems to the detriment of more stable multiple-use multispecies grasslands. This has retarded GBF adoption as a viable, sustainable contribution to renewable energy production in North America. We hypothesize that focusing on multiple-use GBFs will foster greater feedstock availability for nascent renewable energy generation while minimizing financial risk to grassland husbandry during market transitions from current grazing systems to more flexible business models. Our hypothesis is that source and demand are more likely to develop simultaneously under less risky multiple-use grassland management. We review what little research exists detailing such multiple-use systems that include GBF as a major component. We propose that more federal and private sector research funding should focus on perennial forage legumes and bunchgrasses for multiple uses including forage, bioenergy, grassland restoration, wildlife, and ecosystems services such as hydrology, carbon capture and biodiversity. These data cover both native and introduced species in cultivated pastures as well as managed rangeland and native grassland. We conclude that more research effort should be focused on multiple-use GBF in order to identify individual species, mixtures and ecosystems that provide flexibility in the face of unpredictable grassland environments and volatile energy markets
Foreign policy beliefs and support for Stephen Harper and the Conservative Party
Similar to other recent Canadian elections, foreign policy did not feature prominently in the 2011 federal election campaign. In fact, many doubt Canadian public opinion on international affairs is linked to the actions taken by recent Governments. In this paper, we examine Canadian public opinion toward a range of foreign policy issues and argue that the survey questions measure two latent dimensions —militarism and internationalism. Our survey evidence indicates the existence of an “issue public” which is prepared to endorse military action and is skeptical of human rights and overseas aid programs, and this group is far more supportive of Prime Minister Harper and the Conservative Party than other Canadians. The absence of an elite discussion, either among politicians or between media elites, about the direction of Canadian foreign policy does not prevent the Canadian voter from thinking coherently about questions pertaining to this issue domain and employing these beliefs to support or oppose political parties and their leaders
Localization of P-gp (Abcb1) and Mrp2 (Abcc2) in Freshly Isolated Rat Hepatocytes
Freshly isolated hepatocytes are widely accepted as the “gold standard” for providing reliable data on drug uptake across the sinusoidal (basolateral) membrane. However, the suitability of freshly isolated hepatocytes in suspension to assess efflux by canalicular (apical) proteins or predict biliary excretion in the intact organ is unclear. After collagenase digestion, hepatocytes rapidly lose polarity, but localization of canalicular transport proteins in the first few hours after isolation has not been well characterized. In this study, immunostaining and confocal microscopy have provided, for the first time, a detailed examination of canalicular transport protein localization in freshly isolated rat hepatocytes fixed within 1 h of isolation and in cells cultured for 1 h. Organic anion transporting polypeptide 1a1 (Oatp1a1) was expressed in all hepatocytes and distributed evenly across the basolateral membrane; there was no evidence for colocalization of Oatp1a1 with P-glycoprotein (P-gp) or multidrug resistance-associated protein 2 (Mrp2). In contrast, P-gp and Mrp2 expression was lower than Oatp1a1 and confined to junctions between adjacent cells, intracellular compartments, and “legacy” network structures at or near the cell surface. P-gp and Mrp2 staining was more predominant in regions adjacent to former canalicular spaces, identified by zonula occludens-1 staining. Functional analysis of rat hepatocytes cultured for 1 h demonstrated that the fluorescent anion and Mrp2 substrate, 5-(and-6)-carboxy-2′,7′-dichlorofluorescein (CDF), accumulated in cellular compartments; compartmental accumulation of CDF was sensitive to (E)-3-[[[3-[2-(7-chloro-2-quinolinyl)ethenyl]phenyl]-[[3-dimethylamino)-3-oxopropyl]thio]methyl]thio]-propanoic acid (MK571, Mrp inhibitor) and was not observed in hepatocytes isolated from Mrp2-deficient rats. Drug efflux from freshly isolated hepatocytes as an estimate of apical efflux/biliary excretion would give an inaccurate assessment of true apical elimination and, as such, should not be used to make in vivo extrapolations
Singular regional brightening events on Titan as seen by Cassini/VIMS
Titan, the largest satellite of Saturn, is the only satellite in the solar system with a dense atmosphere. The close and continuous observations of Titan by the Cassini spacecraft, in orbit around Saturn since July 2004, bring us evidences that Titan tropo-sphere and low stratosphere experience an exotic, but complete meteorological cycle similar to the Earth hy-drological cycle, with hydrocarbons evaporation, con-densation in clouds, and rainfall. Cassini monitoring campaigns also demonstrate that Titan’s cloud cover-age and climate vary with latitude. Titan’s tropics, with globally weak meteorological activity and widespread dune fields, seem to be slightly more arid than the poles, where extensive and numerous liquid reservoirs and sustained cloud activity were discovered.
Only a few tropospheric clouds have been observed at Titan’s tropics during the southern summer [2-4]. As equinox was approaching (in August 2009), they oc-curred more frequently and appeared to grow in strength and size [5-7]
Defining Responses to Therapy and Study Outcomes in Clinical Trials of Invasive Fungal Diseases: Mycoses Study Group and European Organization for Research and Treatment of Cancer Consensus Criteria
Invasive fungal diseases (IFDs) have become major causes of morbidity and mortality among highly immunocompromised patients. Authoritative consensus criteria to diagnose IFD have been useful in establishing eligibility criteria for antifungal trials. There is an important need for generation of consensus definitions of outcomes of IFD that will form a standard for evaluating treatment success and failure in clinical trials. Therefore, an expert international panel consisting of the Mycoses Study Group and the European Organization for Research and Treatment of Cancer was convened to propose guidelines for assessing treatment responses in clinical trials of IFDs and for defining study outcomes. Major fungal diseases that are discussed include invasive disease due to Candida species, Aspergillus species and other molds, Cryptococcus neoformans, Histoplasma capsulatum, and Coccidioides immitis. We also discuss potential pitfalls in assessing outcome, such as conflicting clinical, radiological, and/or mycological data and gaps in knowledg
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