1,399 research outputs found
Environmental stress and genetics influence night-time leaf conductance in the C4 grass Distichlis spicata
Growing awareness of night-time leaf conductance (gnight) in many species, as well as genetic variation in gnight within several species, has raised questions about how genetic variation and environmental stress interact to influence the magnitude of gnight. The objective of this study was to investigate how genotype salt tolerance and salinity stress affect gnight for saltgrass [Distichlis spicata (L.) Greene]. Across genotypes and treatments, night-time water loss rates were 5–20% of daytime rates. Despite growth declining 37–87% in the high salinity treatments (300 mM and 600 mM NaCl), neither treatment had any effect on gnight in four of the six genotypes compared with the control treatment (7 mM NaCl). Daytime leaf conductance (gday) also was not affected by salinity treatment in three of the six genotypes. There was no evidence that more salt tolerant genotypes (assessed as ability to maintain growth with increasing salinity) had a greater capacity to maintain gnight or gday at high salinity. In addition, gnight as a percentage of gday was unaffected by treatment in the three most salt tolerant genotypes. Although gnight in the 7 mM treatment was always highest or not different compared with the 300 mM and 600 mM treatments, gday was generally highest in the 300 mM treatment, indicating separate regulation of gnight and gday in response to an environmental stress. Thus, it is clear that genetics and environment both influence the magnitude of gnight for this species. Combined effects of genetic and environmental factors are likely to impact our interpretation of variation of gnight in natural populations
South Loup River Valley Floristics: A Survey of Selected Sites in Buffalo County, Nebraska
Originating in the Nebraska Sand Hills, the South Loup River flows 30 km north of Kearney, Nebraska and traverses the northern edge of Buffalo County as it flows eastward to its confluence with the Middle Loup River in southwestern Howard County. Several diverse plant communities are associated with the South Loup Valley, including wet-meadows, wetland/oxbows, sand prairie, and riparian forest. Over a period of 6 years (2006-2012), we surveyed representative wet meadow, wetland, and sand prairie communities. We compiled an annotated vascular plant checklist that included 324 vascular plant species of which 11 were new county records. Three species of scouring rushes (Equisetophyta) were also listed. Approximately 84.1% (276 species) were native and 15.9% (52) were exotics. The mean coefficient of conservatism (Cm) values for the wet meadow, sand prairie, and wetland sites were 3.51, 3.61, and 4.25 respectively. The floristic quality indices (FQI) were 52.42 for the wet meadow, 32.49 for the sand prairie, and 34.26 for the wetland/oxbow. Several noteworthy sedge species collected in this study were bristly sedge (Carex comosa), shoreline sedge (C. hyalinolepis), ripgut sedge (C. lacustris), and smoothcane sedge (C. laeviconica). Forbs at the west edge of their range included Sullivant’s milkweed (Asclepias sullivantii) and three-seeded mercury (Acalypha rhomboidea). A major objective of our study was to substantiate the significance of the South Loup River Valley to the species richness and flora of Nebraska and the Great Plains
Variability in water column respiration in Salish Sea waters and implications for coastal and ocean acidification
Water column respiration is a key driver of carbon cycling, ocean acidification, and oxygen dynamics in marine ecosystems. However, empirical estimates of the range and variability of respiration and its relative contribution to ocean acidification are seldom measured. In 2014, we began measuring respiration rates at multiple sites in the central Salish Sea (San Juan Islands, Bellingham Bay) and then initiated routine monitoring of water column respiration at multiple sites in Padilla Bay National Estuarine Research Reserve (NERR). Measurements in Padilla Bay were integrated into the well-established NERR System Wide Monitoring Program (SWMP). Our investigation revealed that 1) rates of respiration vary seasonally and appear to be associated with changes in organic matter supply and, to a lesser extent, temperature, and 2) incoming deeper waters of marine origin are characterized by relatively low rates of respiration (i.e. ~5ugO2/L/h). To further explore underlying mechanisms, we conducted a series of manipulative experiments to investigate the direct effect of increasing ocean temperature and organic matter supply on rates of respiration. These experiments revealed that respiration can more than triple in response to increases in organic carbon supply and that this response may be influenced by seasonal changes in the export of organic matter and detritus from the extensive eelgrass meadows of Padilla Bay. Our field sampling and manipulative experiments have produced empirical estimates of respiration that can be included in models and projections of water quality and ocean acidification for the Puget Sound, and provide insight into the response of inland marine waters of the Pacific Northwest to a warmer, more acidified ocean
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Measurement and calculation of PZT thin film longitudinal piezoelectric coefficients.
The ferroelectric and piezoelectric properties of 2000 {angstrom} thick chemical solution deposited Pb(Zr{sub x}Ti{sub 1{minus}x})O{sub 3} (PZT) thin films were investigated. Several Zr/Ti ratios were studied: 30/70, 50/50 and 65/35, which correspond to tetragonal, near-morphotropic, and rhombohedral symmetries. In all samples, a {l_brace}111{r_brace}-texture is predominant. Longitudinal piezoelectric coefficients and their dc field dependence were measured using the contact AFM method. The expected trend of a maximum piezoelectric coefficient at or near to the MPB was not observed. The composition dependence was small, with the maximum d{sub 33} occurring in the tetragonal material. To explain the results, crystallographic texture and film thickness effects are suggested. Using a modified phenomenological approach, derived electrostrictive coefficients, and experimental data, d{sub 33} values were calculated. Qualitative agreement was observed between the measured and calculated coefficients. Justifications of modifications to the calculations are discussed
Student’s Perceptions of Spiritual Preparedness and Contribution to their Community Following An Emergency Preparedness Interprofessional Collaborative Practice Simulation
This presentation highlights findings from a study exploring student perceptions of spirituality and contributing to their community after participating in an emergency preparedness interprofessional simulation. Mixed methods were utilized and an online survey was emailed to a convenience sample (N=338). The majority self-reported they can better contribute to their community
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Analysis of PETT Images in Psychiatric Disorders
A quantitative method is presented for studying the pattern of metabolic activity in a set of Positron Emission Transaxial Tomography (PETT) images. Using complex Fourier coefficients as a feature vector for each image, cluster, principal components, and discriminant function analyses are used to empirically describe metabolic differences between control subjects and patients with DSM III diagnosis for schizophrenia or endogenous depression. We also present data on the effects of neuroleptic treatment on the local cerebral metabolic rate of glucose utilization (LCMRGI) in a group of chronic schizophrenics using the region of interest approach. 15 references, 4 figures, 3 tables
Replication of genome-wide association studies (GWAS) loci for fasting plasma glucose in African-Americans
Operationalizing the Reciprocal Engagement Model of Genetic Counseling Practice: a Framework for the Scalable Delivery of Genomic Counseling and Testing
With the advent of widespread genomic testing for diagnostic indications and disease risk assessment, there is increased need to optimize genetic counseling services to support the scalable delivery of precision medicine. Here, we describe how we operationalized the reciprocal engagement model of genetic counseling practice to develop a framework of counseling components and strategies for the delivery of genomic results. This framework was constructed based upon qualitative research with patients receiving genomic counseling following online receipt of potentially actionable complex disease and pharmacogenomics reports. Consultation with a transdisciplinary group of investigators, including practicing genetic counselors, was sought to ensure broad scope and applicability of these strategies for use with any large‐scale genomic testing effort. We preserve the provision of pre‐test education and informed consent as established in Mendelian/single‐gene disease genetic counseling practice. Following receipt of genomic results, patients are afforded the opportunity to tailor the counseling agenda by selecting the specific test results they wish to discuss, specifying questions for discussion, and indicating their preference for counseling modality. The genetic counselor uses these patient preferences to set the genomic counseling session and to personalize result communication and risk reduction recommendations. Tailored visual aids and result summary reports divide areas of risk (genetic variant, family history, lifestyle) for each disease to facilitate discussion of multiple disease risks. Post‐counseling, session summary reports are actively routed to both the patient and their physician team to encourage review and follow‐up. Given the breadth of genomic information potentially resulting from genomic testing, this framework is put forth as a starting point to meet the need for scalable genetic counseling services in the delivery of precision medicine.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147027/1/jgc41111.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147027/2/jgc41111-sup-0001.pd
Facilitate Insight by Non-Invasive Brain Stimulation
Our experiences can blind us. Once we have learned to solve problems by one method, we often have difficulties in generating solutions involving a different kind of insight. Yet there is evidence that people with brain lesions are sometimes more resistant to this so-called mental set effect. This inspired us to investigate whether the mental set effect can be reduced by non-invasive brain stimulation. 60 healthy right-handed participants were asked to take an insight problem solving task while receiving transcranial direct current stimulation (tDCS) to the anterior temporal lobes (ATL). Only 20% of participants solved an insight problem with sham stimulation (control), whereas 3 times as many participants did so (p = 0.011) with cathodal stimulation (decreased excitability) of the left ATL together with anodal stimulation (increased excitability) of the right ATL. We found hemispheric differences in that a stimulation montage involving the opposite polarities did not facilitate performance. Our findings are consistent with the theory that inhibition to the left ATL can lead to a cognitive style that is less influenced by mental templates and that the right ATL may be associated with insight or novel meaning. Further studies including neurophysiological imaging are needed to elucidate the specific mechanisms leading to the enhancement
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