Magnetotactic bacteria are a morphologically, metabolically and phylogenetically disparate array of bacteria united by the ability to biomineralize membrane-encased, single-magnetic-domain mineral crystals (magnetosomes) that cause the cell to orient along the Earth's geomagnetic field lines. The most commonly observed type of magnetotactic bacteria is the ubiquitous magnetotactic cocci, which comprise their own phylogenetic group. Strain MC-1, a member of this group, was isolated from water collected from the oxic-anoxic interface of the Pettaquamscutt Estuary in Rhode Island, USA, and cultivated in axenic culture. Cells of strain MC-1 are roughly spherical with two sheathed bundles of flagella at a single pole (bilophotrichous). Strain MC-1 uses polar magnetotaxis, and has a single chain of magnetite crystals per cell. Cells grow chemolithoautotrophically with thiosulfate or sulfide as the electron donors, and chemoorganoheterotrophically on acetate. During autotrophic growth, strain MC-1 relies on the reductive tricarboxylic acid cycle for CO2 fixation. The G + C content is 54.2 mol %. The name Magnetococcus marinus gen. nov., sp. nov.is proposed for strain MC-1, which is nominated as the type strain (=ATCC BAA-1437T = JCM 17883T). A new order (Magnetococcales ord. nov.) and family (Magnetococcaceae fam. nov.) are proposed for the reception of Magnetococcus and related magnetotactic cocci, which are provisionally included in the Alphaproteobacteria as the most basal known lineage of this class.

Antarctic surface oceans are well-studied during summer when irradiance levels are high, sea ice is melting and primary productivity is at a maximum. Coincident with this timing, the bacterioplankton respond with significant increases in secondary productivity. Little is known about bacterioplankton in winter when darkness and sea-ice cover inhibit photoautotrophic primary production. We report here an environmental genomic and small subunit ribosomal RNA (SSU rRNA) analysis of winter and summer Antarctic Peninsula coastal seawater bacterioplankton. Intense inter-seasonal differences were reflected through shifts in community composition and functional capacities encoded in winter and summer environmental genomes with significantly higher phylogenetic and functional diversity in winter. In general, inferred metabolisms of summer bacterioplankton were characterized by chemoheterotrophy, photoheterotrophy and aerobic anoxygenic photosynthesis while the winter community included the capacity for bacterial and archaeal chemolithoautotrophy. Chemolithoautotrophic pathways were dominant in winter and were similar to those recently reported in global 'dark ocean' mesopelagic waters. If chemolithoautotrophy is widespread in the Southern Ocean in winter, this process may be a previously unaccounted carbon sink and may help account for the unexplained anomalies in surface inorganic nitrogen content.The ISME Journal advance online publication, 26 April 2012; doi:10.1038/ismej.2012.31.

A metaproteomic survey of surface coastal waters near Palmer Station on the Antarctic Peninsula, West Antarctica, was performed, revealing marked differences in the functional capacity of summer and winter communities of bacterioplankton. Proteins from Flavobacteria were more abundant in the summer metaproteome, whereas winter was characterized by proteins from ammonia-oxidizing Marine Group I Crenarchaeota. Proteins prevalent in both seasons were from SAR11 and Rhodobacterales clades of Alphaproteobacteria, as well as many lineages of Gammaproteobacteria. The metaproteome data were used to elucidate the main metabolic and energy generation pathways and transport processes occurring at the microbial level in each season. In summer, autotrophic carbon assimilation appears to be driven by oxygenic photoautotrophy, consistent with high light availability and intensity. In contrast, during the dark polar winter, the metaproteome supported the occurrence of chemolithoautotrophy via the 3-hydroxypropionate/4-hydroxybutyrate cycle and the reverse tricarboxylic acid cycle of ammonia-oxidizing archaea and nitrite-oxidizing bacteria, respectively. Proteins involved in nitrification were also detected in the metaproteome. Taurine appears to be an important source of carbon and nitrogen for heterotrophs (especially SAR11), with transporters and enzymes for taurine uptake and degradation abundant in the metaproteome. Divergent heterotrophic strategies for Alphaproteobacteria and Flavobacteria were indicated by the metaproteome data, with Alphaproteobacteria capturing (by high-affinity transport) and processing labile solutes, and Flavobacteria expressing outer membrane receptors for particle adhesion to facilitate the exploitation of non-labile substrates. TonB-dependent receptors from Gammaproteobacteria and Flavobacteria (particularly in summer) were abundant, indicating that scavenging of substrates was likely an important strategy for these clades of Southern Ocean bacteria. This study provides the first insight into differences in functional processes occurring between summer and winter microbial communities in coastal Antarctic waters, and particularly highlights the important role that 'dark' carbon fixation has in winter.

AimThe impact of cardiac dysfunction on the liver is known as cardiac hepatopathy. In certain instances this can result in significant hepatic fibrosis or cirrhosis. The validity of non-invasive tools to assess hepatic fibrosis, such as FibroScan(®) which measures liver stiffness (LSM), has not been established in this setting. We examined the impact of cardiac dysfunction on LSM using FibroScan(®) and the influence of volume changes on LSM. METHODS AND RESULTS: A prospective, cross-sectional study examined the use of FibroScan(®) in subjects with left-sided heart failure (LHF, n = 32), right-sided heart failure (RHF, n = 9), and acute decompensated heart failure (ADHF, n = 8). The impact of volume changes upon LSM was further examined in the ADHF group (pre- and post-diuresis) and in a haemodialysis group (HD, n = 12), pre- and post-ultrafiltration on dialysis. Compared with healthy controls [n = 55, LSM = median 4.4 (25th percentile 3.6, 75th percentile 5.1) kPa], LSM was increased in all the cardiac dysfunction subgroups [LHF, 4.7 (4.0, 8.7) kPa, P = 0.04; RHF, 9.7 (5.0, 10.8) kPa, P < 0.001; ADHF, 11.2 (6.7, 14.3) kPa, P < 0.001]. Alteration in volume status via diuresis did not change the baseline LSM in ADHF [11.2 (6.7, 14.3) to 9.5 (7.3, 21.6) kPa, P > 0.05] with mean diuresis 5051 ± 1585 mL, or ultrafiltration in HD [6.0 (3.6, 5.1) vs. 5.7 (4.8, 7.0) kPa, P > 0.05] with mean diuresis 1962 ± 233 mL. CONCLUSION: Our findings support the concept of increased LSM in the cardiac failure population. LSM was not altered to a statistically significant level with acute volume changes.

Chronic obstructive pulmonary disease (COPD) is a major cause of mortality and morbidity worldwide and is often complicated by the development of pulmonary hypertension (PHT). The presence of PHT in COPD subjects is associated with increased mortality, morbidity and use of health-care resources. Thus, there has been significant effort to treat PHT in COPD patients to achieve improved clinical outcomes, but with only minimal success. There is renewed interest in understanding the mechanisms contributing to PHT in COPD as the basis for exploring new therapeutic strategies. In this study we review the evidence supporting the postulated mechanisms contributing to PHT in COPD. Hypoxia plays a pivotal role in the development of COPD-associated PHT. However, other mechanisms are also likely involved in the pathogenesis of increased pulmonary vascular resistance in this cohort, including acidemia, dynamic pulmonary hyperinflation, parenchymal destruction, pulmonary vascular remodeling, endothelial dysfunction and inflammation. These mechanisms are interdependent, modulated by genetic factors, and may be confounded by comorbidities such as sleep-disordered breathing, left heart failure and pulmonary thromboembolism. Despite significant research in recent decades, there is surprisingly little evidence of a causal relationship between many of these factors and the development of COPD-associated PHT. The pathogenesis of PHT in COPD is complex and multifaceted. Ultimately, as we obtain better information on COPD phenotypes, we may be able to more precisely account for the varied pathologic mechanisms of PHT occurring in various COPD patients. This may ultimately enable targeted PHT therapy for each COPD phenotype.

An electrochemical approach for the preparation of copper(i) N-heterocyclic carbene complexes has been developed to include a diverse range of ligand precursors. Importantly, the method is effective for a ligand precursor that contains several acidic protons and for which traditional methods of carbene formation are not suitable.

Opioids play a critical role in hippocampally dependent behavior and plasticity. In the hippocampal formation, mu opioid receptors (MOR) are prominent in parvalbumin (PARV) containing interneurons. Previously we found that gonadal hormones modulate the trafficking of MORs in PARV interneurons. Although sex differences in response to stress are well documented, the point at which opioids, sex and stress interact to influence hippocampal function remains elusive. Thus, we used quantitative immunocytochemistry in combination with light and electron microscopy for the phosphorylated MOR at the SER375 carboxy-terminal residue (pMOR) in male and female rats to assess these interactions. In both sexes, pMOR-immunoreactivity (ir) was prominent in axons and terminals and in a few neuronal somata and dendrites, some of which contained PARV in the mossy fiber pathway region of the dentate gyrus (DG) hilus and CA3 stratum lucidum. In unstressed rats, the levels of pMOR-ir in the DG or CA3 were not affected by sex or estrous cycle stage. However, immediately following 30 minutes of acute immobilization stress (AIS), males had higher levels of pMOR-ir whereas females at proestrus and estrus (high estrogen stages) had lower levels of pMOR-ir within the DG. In contrast, the number and types of neuronal profiles with pMOR-ir were not altered by AIS in either males or proestrus females. These data demonstrate that although gonadal steroids do not affect pMOR levels at resting conditions, they are differentially activated both pre- and post-synaptic MORs following stress. These interactions may contribute to the reported sex differences in hippocampally dependent behaviors in stressed animals.

We report herein convenient, aerobic conditions for the oxidation of thiazolines to thiazoles and data regarding the oxidation mechanism. These reactions feature operationally simple and environmentally benign conditions and proceed in good yield to afford the corresponding azoles, thus enabling the inexpensive preparation of valuable molecular building blocks. Incorporation of a novel diimine-ligated copper catalyst,[((Mes)DAB(Me))Cu(II)(OH(2))(3)](2+)[(-)OTf](2), provides increased reaction efficiency in many cases. In other cases copper-free conditions involving a stoichiometric quantity of base affords superior results.

High-T(c) cuprates, iron pnictides, organic BEDT and TMTSF, alkali-doped C(60), and heavy-fermion systems have superconducting states adjacent to competing states exhibiting static antiferromagnetic or spin density wave order. This feature has promoted pictures for their superconducting pairing mediated by spin fluctuations. Sr(2)RuO(4) is another unconventional superconductor which almost certainly has a p-wave pairing. The absence of known signatures of static magnetism in the Sr-rich side of the (Ca, Sr) substitution space, however, has led to a prevailing view that the superconducting state in Sr(2)RuO(4) emerges from a surrounding Fermi-liquid metallic state. Using muon spin relaxation and magnetic susceptibility measurements, we demonstrate here that (Sr,Ca)(2)RuO(4) has a ground state with static magnetic order over nearly the entire range of (Ca, Sr) substitution, with spin-glass behaviour in Sr(1.5)Ca(0.5)RuO(4) and Ca(1.5)Sr(0.5)RuO(4). The resulting new magnetic phase diagram establishes the proximity of superconductivity in Sr(2)RuO(4) to competing static magnetic order.

PURPOSE: The aim was to examine the interaction of lactoferrin with gram-negative bacteria isolated from ocular adverse responses. METHODS: Strains representing the species Pseudomonas aeruginosa (six strains), Aeromonas hydrophila, Escherichia coli, Stenotrophomonas maltophilia, and Haemophilus influenza were tested. A modified enzyme-linked immunosorbent assay was used to measure the binding of the strains to native and deglycosylated lactoferrin. The effect on the viability of strains was measured by incubating strains in media containing lactoferrin as the sole carbon and nitrogen source. Siderophore production by strains was measured using an established assay. RESULTS: All the strains except the single strain of E. coli (Ecol8) were capable of binding to lactoferrin. The ocular isolate of H. influenzae showed strong affinity for lactoferrin. The P. aeruginosa strains and the strain of S. maltophilia showed significantly reduced (80%-100% reduction; P<0.05) binding to lactoferrin that had been enzymatically deglycosylated, whereas deglycosylation had no effect on the binding of other strains/species tested. Most strains were able to grow and produce siderophores in the presence of lactoferrin as the sole carbon and nitrogen source. CONCLUSIONS: The ability to bind to and grow on lactoferrin can be important for gram-negative pathogens that colonize the ocular environment, because this could allow bacteria to survive and propagate in the presence of tear fluid.