573 research outputs found
Connections between Interglacial Variation and Lithological Variability within Midland Basin Permian Shale Rocks in Martin County, Texas
The Upper Pennsylvanian (323.2–289.9 Ma) and Lower Permian (289.9-251 Ma), (Wolfcamp and Spraberry formations) interval of the Midland Basin, West Texas, contains a mixed succession of shale, carbonate, and siltstone/sandstone lithofacies that accumulated in a deep-water marine environment under variable hydrographic restrictions. The heterogenous stratigraphy found in the Wolfcamp and Spraberry formation was formed in response to variations in sea level and a transition from a glacial to an interglacial climate during the Early Permian. These fluctuations left behind alternating beds of mudstone and carbonate, interwoven with thin sandstone beds. Because the Wolfcamp and Spraberry formations are highly heterolithic, it is critical to understand how the stratigraphic and lateral variability in lithology changes if they are to be exploited as hydrocarbon reservoirs. A highly-resolved (5-cm vertical) X-Ray fluorescence (XRF)-based chemostratigraphic study was undertaken on eleven wells from Martin Co., Texas. The study incorporates data from cuttings and cores from intervals of the Wolfcamp and Spraberry formations. Major and trace elements compositions were measured on cuttings and slabbed cores using XRF methods. Correlation of the geochemical data across the wells was undertaken in order to correlate known changes in climate with changes in lithology. After correlation of chemofacies across the eleven wells was completed, a sequence stratigraphy analysis was conducted in order to assign general basin conditions to each major sea level change
Nutritional Requirements for Space Station Freedom Crews
The purpose of this report was to set preliminary nutritional requirements for crewmembers flying from 90 to 180 day missions on Space Station Freedom. Specific recommendations included providing crewmembers with in flight feedback on nutritional intake, weight and strength, and incorporating issues of energy intake, body weight, body composition, strength, and protein intake in the flight medicine program. Exercise must be considered an integral part of any plan to maintain nutritional status, especially those modes that stress the skeleton and maintain body weight. Nutrient intake, amount of exercise, and drugs ingested must be recorded daily; high priority should be given to development of fully automated record systems that minimize astronauts' effort. A system of nutritional supplements should be developed to provide a method for reducing intake deficits that become apparent. Finally, post flight monitoring should include bone density, muscle mass and function, and iron status at three and six months after landing
Design and Development of Laboratory Single-Axis PV Module Tracker
Solar energy is an integral part of the renewable energy industry. Advanced solar farms actively track solar movement and update solar panel angles to maximize the system’s output power. Cal Poly boasts its own Solar Farm that features a single-axis tracking system. Single-axis tracking aims to get panels as close to perpendicular as possible given the panel arrangements and given the time of year. Single-axis tracking is a more robust measurement and tracking option. Single-axis tracking systems usually only have East-West panel arc movement, following the sun’s rotation. Dual-axis trackers have both East-West and North-South panel arc movements. Dual-axis systems have the ability to shift their North-South angle to better face the sun as the seasons change, based on GPS location. Solar panels generate the most power when receiving the highest light intensity. Single-axis systems generally cost less than Dual-axis. One less axis of motion translates to fewer mechanical parts, fewer motor controllers, and ultimately a more durable system. To account for the inability to directly face the sun year round, students will study how to eliminate inter-row shading between panels to maximize power production.
To observe and improve the single-axis tracking system, a laboratory model of the solar farm will be created. Identical solar panels to the Cal Poly panels will be integrated with a solar tracking embedded system. The system will be tested on available test panels in conjunction with a specialized angle tracking measurement network. Students will alter and study the system, accommodating for variables that are not accounted for in the current static algorithm. The new testing system will allow students to study the issues present in the farm and to develop a proposal to improve the power production performance at the farm. In addition, students will learn the fundamentals of single-axis tracking. The laboratory model will be adaptable regardless of the location and terrain of the solar farm, and will tilt the panels in the most optimal angle for the network of arrays in a typical farm
Enhanced survival but not amplification of Francisella spp. in the presence of free-living amoebae
Transmission of Francisella tularensis, the etiologic agent of tularemia, has been associated with various water sources. Survival of many waterborne pathogens within free-living amoeba (FLA) is well documented; however, the role of amoebae in the environmental persistence of F. tularensis is unclear. In this study, axenic FLA cultures of Acanthamoeba castellanii, Acanthamoeba polyphaga, and Vermamoeba vermiformis were each inoculated with virulent strains of F. tularensis (Types A and B), the attenuated live vaccine strain, and Francisella novicida. Experimental parameters included low and high multiplicity of infection and incubation temperatures of 25 and 30 °C for 0–10 days. Francisella spp. survival was enhanced by the presence of FLA; however, bacterial growth and protozoa infectivity were not observed. In contrast, co-infections of A. polyphaga and Legionella pneumophila, used as an amoeba pathogen control, resulted in bacterial proliferation, cytopathic effects, and amoebal lysis. Collectively, even though short-term incubation with FLA was beneficial, the long-term effects on Francisella survival are unknown, especially given the expenditure of available amoebal derived nutrients and the fastidious nature of Francisella spp. These factors have clear implications for the role of FLA in Francisella environmental persistence
Nutrition Research: Basis for Station Requirements
Prior to the Shuttle program, all understanding of nutritional needs in space came from Skylab metabolic research. Because Shuttle flights were short, most less than 14 days, research focused on major nutritional issues: energy (calories), protein and amino acids, water and electrotypes, with some more general physiology studies that related to iron and calcium. Using stable isotope tracer studies and diet intake records, we found that astronauts typically did not consume adequate calories to meet energy expenditure. To monitor energy and nutrient intake status and provide feedback to the flight surgeon and the astronauts, the International Space Station (ISS) program implemented a weekly food frequency questionnaire and routine body mass measurements. Other Shuttle investigations found that protein turnover was higher during flight, suggesting there was increased protein degradation and probably concurrent increase in protein synthesis, and this occurred even in cases of adequate protein and caloric intake. These results may partially explain some of the loss of leg muscle mass. Fluid and electrolyte flight studies demonstrated that water intake, like energy intake, was lower than required. However, sodium intakes were elevated during flight and likely related to other concerns such as calcium turnover and other health-related issues. NASA is making efforts to have tasty foods with much lower salt levels to reduce sodium intake and to promote fluid intake on orbit. Red blood cell studies conducted on the Shuttle found decreased erythrogenesis and increased serum ferritin levels. Given that the diet is high in iron there may be iron storage health concerns, especially related to the role of iron in oxidative damage, complicated by the stress and radiation. The Shuttle nutrition research lead to new monitoring and research on ISS. These data will be valuable for future NASA and commercial crewed missions
Revealing the dynamic modulations that underpin a resilient neural network for semantic cognition:An fMRI investigation in patients with anterior temporal lobe resection
Metal catalyzed rearrangement of a 2,2'-bipyridine Schiff-base ligand to a quaterpyridine-type complex
Tense marking in children with autism
A recent large-scale study identified a subgroup of children with autism who had a language profile similar to that found among children with specific language impairment (SLI). including difficulties with nonsense word repetition, an ability that has been implicated as one clinical marker for SLI. A second clinical marker for English-speaking children with SLI is high rates of omission of grammatical morphemes that mark tense in obligatory contexts. This study used experimental probes designed to elicit third person and past tense morphology with a large heterogeneous sample of children with autism. The subgroup of children with autism who were language impaired showed high rates of omission of tense marking on the experimental tasks. in addition, some of the children with autism made performance errors that were specific to the autistic population, such as echolalia. These findings further refine the characteristics of language impairment found in a subgroup of children with autism
Defining Spoken Language Benchmarks and Selecting Measures of Expressive Language Development for Young Children with Autism Spectrum Disorders
Purpose: The aims of this article are twofold: (a) to offer a set of recommended measures that can be used for evaluating the efficacy of interventions that target spoken language acquisition as part of treatment research studies or for use in applied settings and (b) to propose and define a common terminology for describing levels of spoken language ability in the expressive modality and to set benchmarks for determining a child\u27s language level in order to establish a framework for comparing outcomes across intervention studies.Method: The National Institute on Deafness and Other Communication Disorders assembled a group of researchers with interests and experience in the study of language development and disorders in young children with autism spectrum disorders. The group worked for 18 months through a series of conference calls and correspondence, culminating in a meeting held in December 2007 to achieve consensus on these aims.Results: The authors recommend moving away from using the term functional speech, replacing it with a developmental framework. Rather, they recommend multiple sources of information to define language phases, including natural language samples, parent report, and standardized measures. They also provide guidelines and objective criteria for defining children\u27s spoken language expression in three major phases that correspond to developmental levels between 12 and 48 months of age
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