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71.
Heidi Armbruster 《Ethnic and racial studies》2013,36(15):2680-2699
This article examines the “Syrian Vulnerable Persons Resettlement Programme” (SVPRP) as a specific British response to the “European refugee crisis”. Based on an analysis of media reporting (2014–17) and empirical evidence from agencies and volunteers tasked with implementing the programme, this essay reveals the ethical and political ambiguities at its heart. By focusing on the notion of “vulnerability” I argue that the humanitarian configuration of a refugee worthy of care is implicated in two significant practices: exceptionalising a small group of Syrians as legitimate targets for compassion and constructing compassion itself as a rationed resource in a climate of anti-immigrant hostility, austerity and Brexit. 相似文献
72.
Catherine R. Armbruster Terri S. Forster Rodney M. Donlan Heather A. O'Connell Alicia M. Shams 《Biofouling》2013,29(10):1129-1139
Water in healthcare environments can be a source for healthcare-associated infections (HAI). However, information on the exposure risk to opportunistic pathogens in potable water distribution systems (PWDS) is lacking. Laboratory studies characterizing the interaction of opportunistic pathogens with biofilms are needed to understand their role in water systems within healthcare facilities. A stable, repeatable, PWDS multi-species biofilm model comprising Sphingomonas paucimobilis, Methylobacterium sp., Delftia acidovorans, and Mycobacterium mucogenicum was developed in the CDC Biofilm Reactor (CBR), reaching 6 log10 CFU cm?2 within 6 days. The model was used to investigate the interaction of the opportunistic pathogen M. mucogenicum with the other species, and to determine the efficacy of monochloramine (NH2Cl) as a disinfectant against 2-week-old biofilms. Addition of 1 or 2 mg l?1 NH2Cl resulted in the same or an increased log density of viable M. mucogenicum in the biofilm while inactivating some of the Proteobacteria. Although M. mucogenicum preferentially resided in the biofilm, NH2Cl exposure caused release of viable M. mucogenicum from the biofilm into the water. Additional studies with this model should determine if sodium hypochlorite has a comparative effect and if other nontuberculous mycobacteria (NTM) respond to NH2Cl similarly. 相似文献
73.
74.
Zachary A. Batz Anthony J. Clemento Jens Fritzenwanker Timothy J. Ring John Carlos Garza Peter A. Armbruster 《Evolution; international journal of organic evolution》2020,74(7):1451-1465
In temperate climates, the recurring seasonal exigencies of winter represent a fundamental physiological challenge for a wide range of organisms. In response, many temperate insects enter diapause, an alternative developmental program, including developmental arrest, that allows organisms to synchronize their life cycle with seasonal environmental variation. Geographic variation in diapause phenology contributing to local climatic adaptation is well documented. However, few studies have examined how the rapid evolution of a suite of traits expressed across the diapause program may contribute to climatic adaptation on a contemporary timescale. Here, we investigate the evolution of the diapause program over the past 35 years by leveraging a “natural experiment” presented by the recent invasion of the Asian tiger mosquito, Aedes albopictus, across the eastern United States. We sampled populations from two distinct climatic regions separated by 6° of latitude (∼700 km). Using common-garden experiments, we identified regional genetic divergence in diapause-associated cold tolerance, diapause duration, and postdiapause starvation tolerance. We also found regional divergence in nondiapause thermal performance. In contrast, we observed minimal regional divergence in nondiapause larval growth traits and at neutral molecular marker loci. Our results demonstrate rapid evolution of the diapause program and imply strong selection caused by differences in winter conditions. 相似文献
75.
76.
Kusnierczyk A Winge P Midelfart H Armbruster WS Rossiter JT Bones AM 《Journal of experimental botany》2007,58(10):2537-2552
77.
Medicago truncatula NIN is essential for rhizobial-independent nodule organogenesis induced by autoactive calcium/calmodulin-dependent protein kinase
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Marsh JF Rakocevic A Mitra RM Brocard L Sun J Eschstruth A Long SR Schultze M Ratet P Oldroyd GE 《Plant physiology》2007,144(1):324-335
The symbiotic association between legumes and nitrogen-fixing bacteria collectively known as rhizobia results in the formation of a unique plant root organ called the nodule. This process is initiated following the perception of rhizobial nodulation factors by the host plant. Nod factor (NF)-stimulated plant responses, including nodulation-specific gene expression, is mediated by the NF signaling pathway. Plant mutants in this pathway are unable to nodulate. We describe here the cloning and characterization of two mutant alleles of the Medicago truncatula ortholog of the Lotus japonicus and pea (Pisum sativum) NIN gene. The Mtnin mutants undergo excessive root hair curling but are impaired in infection and fail to form nodules following inoculation with Sinorhizobium meliloti. Our investigation of early NF-induced gene expression using the reporter fusion ENOD11::GUS in the Mtnin-1 mutant demonstrates that MtNIN is not essential for early NF signaling but may negatively regulate the spatial pattern of ENOD11 expression. It was recently shown that an autoactive form of a nodulation-specific calcium/calmodulin-dependent protein kinase is sufficient to induce nodule organogenesis in the absence of rhizobia. We show here that MtNIN is essential for autoactive calcium/calmodulin-dependent protein kinase-induced nodule organogenesis. The non-nodulating hcl mutant has a similar phenotype to Mtnin, but we demonstrate that HCL is not required in this process. Based on our data, we suggest that MtNIN functions downstream of the early NF signaling pathway to coordinate and regulate the correct temporal and spatial formation of root nodules. 相似文献
78.
Gasi KM Brenesel MDj Djurendić EA Sakac MN Canadi JJ Daljev JJ Armbruster T Andrić S Sladić DM Bozić TT Novaković IT Juranić ZD 《Steroids》2007,72(1):31-40
Starting from dehydroepiandrosterone (1) 17-picolyl (2), 17-picolinylidene (7), 17-picolinylidene-16-one (10 and 11), and 17-picolyl-16-one (15) derivatives of androst-5-ene were synthesized in one, two, four and five steps respectively. By the Oppenauer oxidation or dehydration of 2, 7, 10, and 11 with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), the corresponding A and B ring modified derivatives 3, 5, 6, 8, 9, and 12-14 were obtained. The structure of 2 was unambiguously proved by the appropriate X-ray structural analysis. Compounds 3, 5, 9, 12-14 showed inhibitory activity against the enzyme aromatase. Antibacterial activity, toxicity to brine shrimp Artemia salina, antitumor activity against three tumor cell lines (human cervix carcinoma HeLa cells, human melanoma FemX cells, and human myelogenous leukemia K562 cells) and toxicity against peripheral blood mononuclear cells were evaluated. Three tested compounds, namely 11, 13, and 15, showed strong activity against all three cell lines, the IC(50) values being in the range of 4-10 microM. 相似文献
79.
The Berg hypothesis posits that, in plants with specialized pollination systems, floral characters should evolve to become
integrated with each other and decoupled from vegetative characters. We test this hypothesis by comparing serially homologous
and morphologically similar characters in leaves and involucral bracts in the Neotropical vine Dalechampia scandens, which has a specialized pollination system based on resin-collecting bees. The involucral bracts serve a number of specialized
floral functions, including signaling and protection, that may put them under stronger selection for precision than the less
specialized leaves. The homology and morphological similarity of the leaves and bracts allow us to make a sharper test of
Berg’s hypothesis than is possible in most other systems. We found support for the hypothesis in that the bracts had lower
coefficients of variation than the leaves for comparable traits. Also in support of the hypothesis, we found essentially zero
phenotypic correlations between bracts and leaves at the same time that we found moderate correlations between different leaves
and between different bracts. In contradiction to the hypothesis, however, we did not find higher correlations among traits
within bracts than within leaves, and we found no evidence of bracts being more developmentally stable than the leaves. 相似文献
80.
Keiser MJ Roth BL Armbruster BN Ernsberger P Irwin JJ Shoichet BK 《Nature biotechnology》2007,25(2):197-206
The identification of protein function based on biological information is an area of intense research. Here we consider a complementary technique that quantitatively groups and relates proteins based on the chemical similarity of their ligands. We began with 65,000 ligands annotated into sets for hundreds of drug targets. The similarity score between each set was calculated using ligand topology. A statistical model was developed to rank the significance of the resulting similarity scores, which are expressed as a minimum spanning tree to map the sets together. Although these maps are connected solely by chemical similarity, biologically sensible clusters nevertheless emerged. Links among unexpected targets also emerged, among them that methadone, emetine and loperamide (Imodium) may antagonize muscarinic M3, alpha2 adrenergic and neurokinin NK2 receptors, respectively. These predictions were subsequently confirmed experimentally. Relating receptors by ligand chemistry organizes biology to reveal unexpected relationships that may be assayed using the ligands themselves. 相似文献