Maine Horseshoe Crab (Limulus polyphemus) Spawning Surveys, 2003

Maine spawning surveys of horseshoe crabs (Limulus polyphemus) continued for a third season in 2003. Survey sites were located in Yarmouth, Brunswick (2 sites), Woolwich, Nobleboro, Damariscotta, Sedgwick, Franklin and Sullivan. The purpose of this project is to establish quantitative baseline data on horseshoe crab populations in Maine as a basis for management of this species. The 2003 season recorded cooler than normal water temperatures through the end of May, which resulted in negligible activity during the initial historical May spawning period. Warmer water temperatures in June supported normal levels of spawning activity, as documented by the June counts. The tagging study on Taunton Bay in Franklin continued for a third year, with more observations (1255) and more individuals observed (900) than in 2002 (1119 and 741, respectively), but fewer than in 2001 (2273 and 1292 respectively). The overall data indicate that horseshoe crab populations are declining at all but two of the sites, both of which are in Brunswick

Feeding, Respiration and Excretion of the Copepod Calanus hyperboreus from Baffin Bay, Including Waters Contaminated by Oil Seeps

Metabolic processes in eastern arctic copepods Calanus hyperboreus were analyzed during the post-bloom period (August-September). Mixed adult and subadult copepods were collected from 12 stations in Baffin Bay (Davis Strait to Lancaster Sound) by trawling from 0-300 m. Measurements were made of clearance rate, O2-consumption and NH3 excretion. The cruise track included 6 stations in oil-seep contaminated waters of Scott Inlet and Buchan Gulf. Physiological parameters for populations of C. hyperboreus from the latter stations were compared with those from non-seep stations. Mean O2 consumption rates (0.309 - 0.907 µl O2 / mg dry wt / h) for all stations were similar to those described for Antarctic calanoid species but were higher than reported for more northern arctic waters. Mean ammonia excretion rates (0.023 - 0.071 µg N / mg dry wt / h) were somewhat lower than reported for comparable Antarctic species and were similar to values from other eastern arctic studies. O:N ratios for 11 of the 12 stations occupied ranged between 8.4 and 22.1, indicative of protein-based metabolism. The single exception was a High Arctic station with O:N ratio 43.6. Clearance rates were low to nonexistant for all stations. Most of the non-feeding values came from the Scott Inlet-Buchan Gulf region of western Baffin Bay. At those stations in this region a strong negative correlation (P<.01) exists between clearance rate and hydrocarbon contamination. This suggests that in the oil-seep region of Baffin Bay feeding may be suppressed in Calanus hyperboreus by low concentrations of petroleum hydrocarbons derived from sub-sea seepage.Key words: zooplankton, Calanus hyperboreus, Arctic, metabolism, oil seep, petroleum, hydrocarbons, oil pollutionMots clés: zooplancton, Calanus hyperboreus, Arctique, métabolisme, suitements de pétrole, pétrole, hydrocarbures, pollution par les hydrocarbure

Renal tubular triglyercide accumulation following endotoxic, toxic, and ischemic injury

Renal tubular triglyercide accumulation following endotoxic, toxic, and ischemic injury.BackgroundCholesterol accumulates in renal cortical proximal tubules in response to diverse forms of injury or physiologic stress. However, the fate of triglycerides after acute renal insults is poorly defined. This study sought new insights into this issue.MethodsCD-1 mice were subjected to three diverse models of renal stress: (1) endotoxemia [Escherichia coli lipopolysaccharide (LPS), injection]; (2) ischemia/reperfusion (I/R); or (3) glycerol-induced rhabdomyolysis. Renal cortical, or isolated proximal tubule, triglyceride levels were measured ∼18 hours later. To gain mechanistic insights, triglyceride levels were determined in (1) proximal tubules following exogenous phospholipase A2 (PLA2) treatment; (2) cultured HK-2 cells after mitochondrial blockade (antimycin A) ± serum; or (3) HK-2 cells following “septic” (post-LPS) serum, or exogenous fatty acid (oleate) addition.ResultsEach form of in vivo injury evoked three-to fourfold triglyceride increases in renal cortex and/or proximal tubules. PLA2 treatment of proximal tubules evoked acute, dose-dependent, triglyceride formation. HK-2 cell triglyceride levels rose with antimycin A. With serum present, antimycin A induced an exaggerated triglyceride loading state (vs. serum alone or antimycin A alone). “Septic” serum stimulated HK-2 triglyceride formation (compared to control serum). Oleate addition caused striking HK-2 cell triglyceride accumulation. Following oleate washout, HK-2 cells were sensitized to adenosine triphosphate (ATP) depletion or oxidant attack.ConclusionDiverse forms of renal injury induce dramatic triglyceride loading in proximal tubules/renal cortex, suggesting that this is a component of a cell stress response. PLA2 activity, increased triglyceride/triglyceride substrate (e.g., fatty acid) uptake, and possible systemic cytokine (e.g., from LPS) stimulation, may each contribute to this result. Finally, in addition to being a marker of prior cell injury, accumulation of triglyceride (or of its constituent fatty acids) may predispose tubules to superimposed ATP depletion or oxidant attack

Maine Horseshoe Crab (Limulus polyphemus) Spawning Surveys, 2004

The Maine Horseshoe Crab Surveys were begun in 2001 to establish quantitative baseline data and determine whether horseshoe crab (Limulus polyphemus) populations are stable or declining. Spawning counts were conducted at sites from Casco Bay (southern Maine) to Frenchman’s Bay (downeast), to establish an index of relative abundance. Few (relatively) abundant populations remain in Maine at Middle Bay (Harpswell/Brunswick), Thomas Point (Brunswick), and in the Damariscotta River. Healthy but less abundant populations persist in the Bagaduce River (Brooksville/ Sedgwick) and in Taunton Bay (Hancock/Franklin/Sullivan). An intensive tagging study has been conducted on Taunton Bay, which offers a natural population with no known history of harvest, and which is effectively closed to immigration and emigration by the physical characteristics of the Bay. During four field seasons, 6176 observations have been logged on 3883 individuals (2595 males, 1288 females; 66.8%, 33.2%). Returns by the 2001 tag year class have varied between 8.7 and 7.5 % in subsequent years. Females comprised 28% (of 116) of the returning 2001 tagged animals in 2002, and 33% (of 113) in 2003, but declined to only 13% (of 100) returning in 2004—just 1% of the original 2001 tag year class of 1333 (individuals). A cause has not yet been attributed, but adult molting is suspected. However, unless adult molting is confirmed, mortality must be assumed instead. Return rates of individuals tagged in 2001 were analyzed to evaluate spawning site fidelity. While return rates from year to year did not exceed 8.7% of the original tag year class of 1333 individuals, 22% of the individuals were observed again in the years from 2002 to 2004. Similarly, observations for 2004 were analyzed to determine the ratio of new individuals to those observed that had been tagged in the three prior years. In 2004, there were 1384 observations of 915 individuals (592 males, 323 females) at the tagging site, of which 25% had been tagged in prior field seasons. This suggests that a significant number of the adult horseshoe crabs in the vicinity of Shipyard Point may now be tagged, and each additional season of data will increase the value of the existing data for understanding the population dynamics of horseshoe crabs in Taunton Bay, and other sites in Maine

A Prospective Surveillance Study of Candidaemia : Epidemiology, Risk Factors, Antifungal Treatment and Outcome in Hospitalized Patients

Funding This work was supported by the Wellcome Trust Strategic Award for Medical Mycology and Fungal Immunology 097377/Z/11/Z. Data collection was supported by a grant from Pfizer. GR was also supported by a research fellowship grant from Gilead Sciences. The collection of the isolates was funded by a Gilead Fellowship to GR. Acknowledgments We are grateful to microbiology colleagues throughout Scotland for submitting isolates. Antimicrobial sensitivity testing was performed by the Mycology Reference Laboratory, Public Health England, Bristol.Peer reviewedPublisher PD

Canonical Formulation of A Bosonic Matter Field in 1+1 Dimensional Curved Space

We study a Bosonic scalar in 1+1 dimensional curved space that is coupled to a dynamical metric field. This metric, along with the affine connection, also appears in the Einstein-Hilbert action when written in first order form. After illustrating the Dirac constraint analysis in Yang-Mills theory, we apply this formulation to the Einstein-Hilbert action and the action of the Bosonic scalar field, first separately and then together. Only in the latter case does a dynamical degree of freedom emerge.Comment: 21 page

Biofilm formation is a risk factor for mortality in patients with Candida albicans bloodstream infection-Scotland, 2012-2013

Acknowledgements This work was supported by the Wellcome Trust Strategic Award for Medical Mycology and Fungal Immunology 097377/Z/11/Z. Data collection was supported by a grant from Pfizer. G. Ramage was also supported by a research fellowship grant from Gilead Sciences. We are grateful to microbiology colleagues throughout Scotland for submitting isolates.Peer reviewedPublisher PD

Disks in the Arches cluster -- survival in a starburst environment

Deep Keck/NIRC2 HK'L' observations of the Arches cluster near the Galactic center reveal a significant population of near-infrared excess sources. We combine the L'-band excess observations with K'-band proper motions, to confirm cluster membership of excess sources in a starburst cluster for the first time. The robust removal of field contamination provides a reliable disk fraction down to our completeness limit of H=19 mag, or about 5 Msun at the distance of the Arches. Of the 24 identified sources with K'-L' > 2.0 mag, 21 have reliable proper motion measurements, all of which are proper motion members of the Arches cluster. VLT/SINFONI K'-band spectroscopy of three excess sources reveals strong CO bandhead emission, which we interpret as the signature of dense circumstellar disks. The detection of strong disk emission from the Arches stars is surprising in view of the high mass of the B-type main sequence host stars of the disks and the intense starburst environment. We find a disk fraction of 6 +/- 2% among B-type stars in the Arches cluster. A radial increase in the disk fraction from 3 to 10% suggests rapid disk destruction in the immediate vicinity of numerous O-type stars in the cluster core. A comparison between the Arches and other high- and low-mass star-forming regions provides strong indication that disk depletion is significantly more rapid in compact starburst clusters than in moderate star-forming environments.Comment: 51 pages preprint2 style, 22 figures, accepted by Ap

Influenza D Virus Infection in Feral Swine Populations, United States

Influenza D virus (IDV) has been identified in domestic cattle, swine, camelid, and small ruminant populations across North America, Europe, Asia, South America, and Africa. Our study investigated seroprevalence and transmissibility of IDV in feral swine. During 2012–2013, we evaluated feral swine populations in 4 US states; of 256 swine tested, 57 (19.1%) were IDV seropositive. Among 96 archived influenza A virus–seropositive feral swine samples collected from 16 US states during 2010–2013, 41 (42.7%) were IDV seropositive. Infection studies demonstrated that IDV-inoculated feral swine shed virus 3–5 days postinoculation and seroconverted at 21 days postinoculation; 50% of in-contact naive feral swine shed virus, seroconverted, or both. Immunohistochemical staining showed viral antigen within epithelial cells of the respiratory tract, including trachea, soft palate, and lungs. Our findings suggest that feral swine might serve an important role in the ecology of IDV

Stars and brown dwarfs in the sigma Orionis cluster. II. A proper motion study

Aims: I seek to fully know the stellar and substellar populations in the young sigma Orionis open cluster, which is a benchmark for star-forming studies. Because of the very low proper motion of the cluster, late-type dwarfs with appreciable proper motion in the foreground of sigma Orionis can be easily discarded for expensive spectroscopic follow-up. Methods: I use the Aladin sky atlas, USNO-B1, public astrometric catalogues, and photographic plate digitisations to identify stars with proper motions inconsistent with cluster membership in a circular area of radius 30 arcmin centred on the early-type multiple system sigma Ori. Mostly due to the long time baseline, of more than half a century, the errors in the measured proper motions are lower than 2 mas/a. Results: Of the 42 stars selected for astrometric follow-up, 37 of them are proper-motion cluster interlopers. Some USNO-B1 measurements were affected by partially resolved (visual) multiplicity and target faintness. Because of their late spectral types and, hence, red colours, 24 contaminants had been considered as sigma Orionis members at some moment. I discuss how contamination may have affected previous works (especially related to disc frequencies) and the curious presence of lithium absorption in three M-dwarf proper-motion contaminants. Finally, I classify the bright star HD 294297 as a late-F field dwarf unrelated to the cluster based on a new proper motion measurement. Conclusions: Although proper motions cannot be used to confirm membership in sigma Orionis, they can be used instead to discard a number of cluster member candidates without spectroscopy.Comment: A&A, in press (v2: language edited