16,245 research outputs found
RV Knorr Cruise KN200-4, 13 Apr-03 May 2011. RAPID Mooring Cruise
This report describes the mooring operations conducted during RV Knorr cruise KN200-4 between 13 April and 3 May 2011.
These mooring operations were completed as part of the United Kingdom Natural Environment Research Council (NERC) funded RAPID-WATCH Programme to monitor the Atlantic Meridional Overturning Circulation (MOC) at 26.5°N. The primary purpose on this cruise for the UK team was to service the RAPID Western Boundary moorings while the US teams worked on the Western Boundary Time Series project and the RAPID-MOCHA Western Boundary moorings.
Cruise KN200-4 was from Port Everglades, Florida to Port Everglades, Florida and covered the Western Boundary moorings deployed on RB0901 and OC459. This cruise was the ninth annual refurbishment of the Western Boundary section of an array of moorings deployed across the Atlantic in order to continuously observe the MOC. This array will be further refined and refurbished during subsequent years.
The instruments deployed on the array consist of a variety of current meters, bottom pressure recorders, and CTD loggers, which, combined with time series measurements of the Florida Straits Current and wind stress estimates, will be used to determine the strength and structure of the MOC at 26.5°N.
(http://www.noc.soton.ac.uk/rapid
Eddy Impacts on the Florida Current
The Gulf Stream in the Atlantic carries warm water northwards and forms both the return closure of the subtropical gyre as well as the upper limb of the meridional overturning circulation. Recent time series recorded east of the Bahamas at 26°N indicate that from May 2009 to April 2011, in contrast with past observations, the northward flowing Antilles Current covaried with the Gulf Stream in the Florida Straitsâthe Florida Currentâeven though the Florida and Antilles Currents are separated by banks and islands spanning 150?km. The peak-to-trough amplitude of transport variations during this period was 15?Ă?106?m3?s?1 for the Florida Current and 12?Ă?106?m3?s?1 for the Antilles Current, at time scales of 50?days to a year. From satellite observations, we show that the fluctuations in both the Florida and Antilles Currents between May 2009 and April 2011 are driven by eddy activity east of the Bahamas. Since the Florida Current time series is a critical time series for the state of the oceans, and often compared to climate models, this newly identified source of variability needs careful consideration when attributing the variability of the Florida Current to changes in the larger-scale circulations (e.g., gyre and overturning) or wind forcing.<br/
Some Food Reactions of Snails
The following work was done at the University of Chicago Zoological Laboratory under the supervision of Dr. W. J. Crozier to investigate primarily the method of innervation of the food reflex. For the studies, various forms of common snails were experimented with, but the domestic snail known as the Singapore was used for most of this work because of its ready availability and suitableness for the work due to its large size, activity and omniverousness. The main objection to them is that they do not swim on the surface of the water as do many forms. In order to obviate this difficulty they were studied by placing the snail to be observed in a Petri dish on the stand of a dissecting microscope and watching its movements along the bottom of the dish with the aid of the reflecting mirror. It was found that the snails varied considerably in physiological activity, so that during the experiments it was often necessary to discard an animal because of inactivity, necessitating work with a considerable number of individuals in order to get approximately accurate results
The Somatic Methods Survey: Investigating LICSWsâ Training in Physically Based Interventions
This clinical research project investigates how and when Licensed Independent Clinical Social Workers (LICSW) in the State of Minnesota received training in somatic methods of helping. As a Masters of Social Work (MSW) student examples of somatic methods permeate class lecture, training videos, and observations made in the field. Though ubiquitous in clinical practice, methods of engaging clients somatically are not typically part of the core social work curriculum. This paradox laid the foundation for the Somatic Methods Survey which provided insight into how and when LICSWs develop skills in somatic methods of helping.
The Somatic Methods Survey was completed by N=28 LICSWs licensed in the state of Minnesota. Of N=28 respondents, N=25 (89%) of respondents indicated they use somatic methods with their clients. Respondents who use somatic methods identified a wide range of physically based methods used with clients, and indicated an average of N=2 somatic methods may be used in their clinical practice. This dedication to the use of somatic methods by clinical social workers is notable, and has implications for the future of social work education
The Somatic Methods Survey: Investigating LICSWsâ Training in Physically Based Interventions
This clinical research project investigates how and when Licensed Independent Clinical Social Workers (LICSW) in the State of Minnesota received training in somatic methods of helping. As a Masters of Social Work (MSW) student examples of somatic methods permeate class lecture, training videos, and observations made in the field. Though ubiquitous in clinical practice, methods of engaging clients somatically are not typically part of the core social work curriculum. This paradox laid the foundation for the Somatic Methods Survey which provided insight into how and when LICSWs develop skills in somatic methods of helping.
The Somatic Methods Survey was completed by N=28 LICSWs licensed in the state of Minnesota. Of N=28 respondents, N=25 (89%) of respondents indicated they use somatic methods with their clients. Respondents who use somatic methods identified a wide range of physically based methods used with clients, and indicated an average of N=2 somatic methods may be used in their clinical practice. This dedication to the use of somatic methods by clinical social workers is notable, and has implications for the future of social work education
Conceptual design and analysis of orbital cryogenic liquid storage and supply systems
A wide variety of orbital cryogenic liquid storage and supply systems are defined in NASA and DOD long-range plans. These systems include small cooling applications, large chemical and electrical orbit transfer vehicles and supply tankers. All have the common requirements of low-g fluid management to accomplish gas-free liquid expulsion and efficient thermal control to manage heat leak and tank pressure. A preliminary design study was performed to evaluate tanks ranging from 0.6 to 37.4 cu m (22 to 1320 cu ft). Liquids of interest were hydrogen, oxygen, methane, argon and helium. Conceptual designs were generated for each tank system and fluid dynamic, thermal and structural analyses were performed for Shuttle compatible operations. Design trades considered the paradox of conservative support structure and minimum thermal input. Orbital performance and weight data were developed, and a technology evaluation was completed
The Staining Effect of the Hydrochloric Acid-Chromate Trioxide Solution on the Minerals of the Chalcocite-Stibnite-Galena Ternary System.
The object of this work has been to devise a method by which the different phases in the chalcocite-stibnite-galena ternary system may be identified. As the mineralogists have no precise methods for the identification of these phases, a hydrochloric acid-chromate trioxide staining solution was employed
From ecophysiology to ecoregions: Integrating patterns in waterfowl reproductive success across multiple scales
Variation in avian reproductive success (RS) can be influenced by intrinsic traits (e.g., individual quality, physiology and experience) or extrinsic factors (e.g., weather, habitat use, or landscape composition) which can act across multiple scales. Determining how these two factors affect RS â and how they interact â represent significant challenges for ecologists and conservationists. Thus, I evaluated these two main hypotheses using information obtained for northern pintail (Anas acuta) and mallard (Anas platyrhynchos) breeding in the Canadian prairies. I integrated data from laboratory experiments, field-based observational studies and existing long-term datasets to determine the relative importance of intrinsic (past and current metrics of individual quality) and extrinsic (landscape composition) factors in contributing to variation in RS for prairie-breeding ducks at multiple scales. I also validated and used feather biomarkers to investigate evidence of energetic carry-over effects on reproductive performance in both species.
To verify that an individualâs feather corticosterone (CORTf) levels are related to energy expenditure, I manipulated work rates of mallard ducklings in the laboratory. Ducklings experiencing higher workloads had lower body mass, slower growth rates, greater daily energy expenditure and higher CORTf. These patterns were repeatable and CORTf reflected current energetic demands during feather replacement.
Using CORTf and stable isotopes in feathers, I provided new insights regarding the consequences of migratory origins of adult female pintails breeding in southern Saskatchewan, and found no evidence of strong carry-over effects on pre-breeding body condition or reproductive investment. However, late-nesting females were typically from coastal wintering regions and had higher CORTf in body feathers grown during winter-spring, suggesting that energetic challenges during body moult during late winter or early spring migration delayed timing of breeding.
I investigated maternal influences on RS and found that pintail duckling survival was higher among breeding females with lower late-incubation body mass, those that hatched nests somewhat later in the season or behaved more cautiously during brood rearing. Extrinsic landscape conditions drove most variation in duckling survival. Duckling survival was higher in grassland-dominated landscapes and, in agricultural landscapes, broods hatching from winter wheat had similar survival to perennial cover, double the estimates in spring-seeded cropland. Ducklings raised in local environments with higher amounts of perennial cover and seasonal wetlands, but lower amounts of wetland edge, had higher survival. On balance, the benefits of higher nest survival in winter wheat were not completely superseded by lower duckling survival for broods raised in intensive agricultural areas.
Using unique data sets composed of individually-marked adult female mallards, I did not find any consistent indication that CORTf was correlated with either reproductive effort or success, or local weather and wetland conditions, in the same year as feather growth. Counter to initial predictions, I found that current RS was unrelated to CORTf levels in feathers grown the previous summer-fall. Path analyses of mallard breeding decisions revealed that lighter females were less likely to breed but experienced higher hatching and fledging success; female age had no direct effects on the decision to breed nor directly influenced fledging success. As expected, greater nesting effort and investment occurred on sites with a higher pond abundance and above-average regional pond conditions.
For breeding mallards, heavier females were more likely to settle in areas with above-average pond conditions, nested earlier and re-nested more often while females that had lower CORTf in wing feathers tended to re-nest more often but experienced higher nest success. Older birds, and those that settled in areas with more grassland, had larger clutch sizes. As expected, nest success was higher on sites with a higher abundance of ponds and above-average regional pond conditions but lower for early and re-nests, with the number of hatched young smaller for late or re-nests. Overall, fledging success was higher in late-hatched or larger broods and of successful nests, more ducklings fledged if it was a re-nest but there were trade-offs with pond abundance and egg production.
Overall, in pintails and mallards, local environmental factors and landscape composition had consistently strong effects on RS whereas measurements of individual quality were generally weaker or more variable. Through integration of intrinsic and extrinsic factors, I bridged our understanding of variation in energetic conditions and RS across ecological, spatial and temporal scales. Further study is required to evaluate the roles of carry-over effects on prairie-breeding ducks, as this would more clearly reveal putative linkages between conditions on non-breeding areas and subsequent RS
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