Genomic Features Of A Bumble Bee Symbiont Reflect Its Host Environment

Here, we report the genome of one gammaproteobacterial member of the gut microbiota, for which we propose the name >Candidatus Schmidhempelia bombi,> that was inadvertently sequenced alongside the genome of its host, the bumble bee, Bombus impatiens. This symbiont is a member of the recently described bacterial order Orbales, which has been collected from the guts of diverse insect species; however, >Ca. Schmidhempelia> has been identified exclusively with bumble bees. Metabolic reconstruction reveals that >Ca. Schmidhempelia> lacks many genes for a functioning NADH dehydrogenase I, all genes for the high-oxygen cytochrome o, and most genes in the tricarboxylic acid (TCA) cycle. >Ca. Schmidhempelia> has retained NADH dehydrogenase II, the low-oxygen specific cytochrome bd, anaerobic nitrate respiration, mixed-acid fermentation pathways, and citrate fermentation, which may be important for survival in low-oxygen or anaerobic environments found in the bee hindgut. Additionally, a type 6 secretion system, a Flp pilus, and many antibiotic/multidrug transporters suggest complex interactions with its host and other gut commensals or pathogens. This genome has signatures of reduction (2.0 megabase pairs) and rearrangement, as previously observed for genomes of host-associated bacteria. A survey of wild and laboratory B. impatiens revealed that >Ca. Schmidhempelia> is present in 90% of individuals and, therefore, may provide benefits to its host.Center for Insect Science (University of Arizona)National Science Foundation NSF 1046153NIH Director's Pioneer 1DP1OD006416-01NIH R01-HG006677Swiss National Science Foundation 140157, 147881Integrative Biolog

Exploring the southern ocean response to climate change

The purpose of this project was to couple a regional (Southern Ocean) ocean/sea ice model to the existing Goddard Institute for Space Science (GISS) atmospheric general circulation model (GCM). This modification recognizes: the relative isolation of the Southern Ocean; the need to account, prognostically, for the significant air/sea/ice interaction through all involved components; and the advantage of translating the atmospheric lower boundary (typically the rapidly changing ocean surface) to a level that is consistent with the physical response times governing the system evolution (that is, to the base of the fast responding ocean surface layer). The deeper ocean beneath this layer varies on time scales several orders of magnitude slower than the atmosphere and surface ocean, and therefore the boundary between the upper and deep ocean represents a more reasonable fixed boundary condition

Two Decades Of Pelagic Ecology Of The Western Antarctic Peninsula

Significant strides in our understanding of the marine pelagic ecosystem of the Western Antarctic Peninsula (WAP) region have been made over the past two decades, resulting from research conducted aboard ARSV Laurence M. Gould and RVIB Nathaniel B. Palmer. These advances range from an understanding of the physical forcing on biology, to food web ecology (from microbes to top predators), to biogeochemical cycling, often in the larger context of rapid climate warming in the region. The proximity of the WAP to the Antarctic Circumpolar Current and WAP continental shelf bathymetry affects the hydrography and helps structure the biological community. Seasonal, spatial, and interannual variability at all levels of the food web, as well as the mechanisms supporting their production, are now more clearly understood. New tools and technologies employed in the region were critical for making this research possible. As a result, our knowledge of the WAP pelagic ecosystem during a time of rapid climate change has vastly improved

Modeling and Validation of a Navy A6-Intruder Actively Controlled Landing Gear System

Concepts for long-range air travel are characterized by airframe designs with long, slender, relatively flexible fuselages. One aspect often overlooked is ground-induced vibration of these aircraft. This paper presents an analytical and experimental study of reducing ground-induced aircraft vibration loads by using actively controlled landing gear. A facility has been developed to test various active landing gear control concepts and their performance, The facility uses a Navy A6 Intruder landing gear fitted with an auxiliary hydraulic supply electronically controlled by servo valves. An analytical model of the gear is presented, including modifications to actuate the gear externally, and test data are used to validate the model. The control design is described and closed-loop test and analysis comparisons are presented

Transport of warm Upper Circumpolar Deep Water onto the western Antarctic Peninsula continental shelf

Five thermistor moorings were placed on the continental shelf of the western Antarctic Peninsula (between 2007 and 2010) in an effort to identify the mechanism(s) responsible for delivering warm Upper Circumpolar Deep Water (UCDW) onto the broad continental shelf from the Antarctic Circumpolar Current (ACC) flowing over the adjacent continental slope. Historically, four mechanisms have been suggested: (1) eddies shed from the ACC, (2) flow into the cross-shelf-cutting canyons with overflow onto the nominal shelf, (3) general upwelling, and (4) episodic advective diversions of the ACC onto the shelf. The mooring array showed that for the years of deployment, the dominant mechanism is eddies; upwelling may also contribute but to an unknown extent. Mechanism 2 played no role, though the canyons have been shown previously to channel UCDW across the shelf into Marguerite Bay. Mechanism 4 played no role independently, though eddies may be advected within a greater intrusion of the background flow

Effect of air-sea-ice interaction on winter 1996 Southern Ocean subpolar storm distribution

Air-sea-ice interaction processes in the Southern Ocean are investigated utilizing space-observed surface winds, sea ice concentration, and sea surface temperature (SST) from September through December, 1996. The sea ice edge (SIE) shows three ice-extent maxima around the Antarctic during September and October when sea ice coverage is maximum. They are located in the central Indian Ocean, east of the Ross Sea, and in the eastern Weddell Gyre. During September and October, most of the strong and long lasting storms initiate northeast of the three sea ice maxima. Such spatial distributions of storms and sea ice reflect coupling processes of the air-sea-ice interaction. A relatively stable, wave number 3 atmospheric circulation pattern that is believed to be fixed by the land-ocean distribution prevails during the ice maximum season. The ice-extent maxima coincide with strong southerlies and divergent wind fields associated with this pattern, which suggests that the mean atmospheric circulation determines the ice distribution. The ice-extent maxima can enhance the regional meridional surface pressure gradient and therefore strengthen the westerly winds north of the ice edge. The decreasing ice extent east of the ice maxima creates a local zonal thermal gradient which enhances local southerlies. This positive feedback between the wave pattern in the mean atmospheric circulation and ice distribution partially causes the eastward propagation of the ice maxima and also provides a favorable condition for cyclogenesis northeast of the ice-extent maxima. The mechanism of the cyclogenesis is the baroclinic instability caused by the cold air blown from the ice pack to the warm open-ocean waters. Where the SST is warmest off the SIE and the southerlies are the strongest, the potential for cyclogenesis is most likely. This is consistent with the observations

A new approach to physical activity maintenance: Rationale, design, and baseline data from the Keep Active Minnesota trial

<p>Abstract</p> <p>Background</p> <p>Since many individuals who initiate physical activity programs are highly likely to return to a sedentary lifestyle, innovative strategies to efforts to increase the number of physically active older adults who successfully <it>maintain </it>beneficial levels of PA for a substantial length of time are needed.</p> <p>Methods/Design</p> <p>The Keep Active Minnesota Trial is a randomized controlled trial of an interactive phone- and mail-based intervention to help 50–70 year old adults who have recently increased their physical activity level, maintain that activity level over a 24-month period in comparison to usual care. Baseline, 6, 12, and 24 month measurement occurred via phone surveys with kilocalories expended per week in total and moderate-to-vigorous physical activity (CHAMPS Questionnaire) as the primary outcome measures. Secondary outcomes include hypothesized mediators of physical activity change (e.g., physical activity enjoyment, self-efficacy, physical activity self-concept), body mass index, and depression. Seven day accelerometry data were collected on a sub-sample of participants at baseline and 24-month follow-up.</p> <p>Discussion</p> <p>The Keep Active Minnesota study offers an innovative approach to the perennial problem of physical activity relapse; by focusing explicitly on physical activity maintenance, the intervention holds considerable promise for modifying the typical relapse curve. Moreover, if shown to be efficacious, the use of phone- and mail-based intervention delivery offers potential for widespread dissemination.</p> <p>Trial registration</p> <p>ClinicalTrials.gov Identifier: NCT00283452.</p