294 research outputs found
Assessment and visualization of threshold exceedance probabilities in complex space-time settings: A case study of air quality in Northern Italy
A Study of the Aspects of Vocational Agriculture Teacher Travel in South Dakota
Travel outside the area is vital to the success of vocational agriculture programs. It enables the instructor to improve professionally through his attendance at conferences, conventions, and other meetings held for purposes of in-service improvement. An integral portion of the vocational agriculture teacher’s responsibilities also entails visiting students and their parents on their home farms. Travel benefits students as well. Students in vocational agriculture classes “learn by doing”. Without travel some of the effectiveness of the vocational agriculture programs could be lost, since the home farm, as well as industries related to agriculture, serve as the laboratory. The purpose of this research problem is to determine the average number of miles traveled by vocational agriculture teachers in South Dakota; the methods by which they are reimbursed for the cost of such travel each year; the extent of travel in terms of purposes for which the travel is used; and whether any relationship exists between travel allowances and the possibilities teachers have in carrying out sound programs of instruction. In delimiting the purposes of such travel this study also purposes to ascertain (1) the number of miles traveled in supervised farming instruction (2) the number of schools providing the instructor with means of transportation other than the use of his own vehicle, and (3) the proportion of vocation agriculture instructors who receive reimbursement for expenses incurred when away from home on vocational agriculture work
Morphometric analysis of corpus callosum in relation to brain size in fetuses of South Indian population
Background: The corpus callosum (CC) comprises axons connecting the cortices of the two cerebral hemispheres and is the principal white matter fiber bundle in the brain Morphological characteristics of fetal corpus callosum are of value from embryologic and diagnostic points of view. Knowledge of fetal callosal size is an essential prerequisite for the study of its changes during infancy and childhood. Methods: The study included twenty four formalin fixed fetuses ranging from 25 to 40 weeks obtained from department of Anatomy, Kasturba Medical College. The measurements taken were; frontal pole to occipital pole, anterior most point to posterior most point of CC, frontal pole of brain to anterior most point of CC, occipital pole of brain to posterior most point of CC, anterior edge of splenium to superior most point of superior colliculus and thickness of body of CC.Results: Spearman’s correlation test was used to determine the correlation between different parameters. A strong positive correlation was found between the length and gestational age (r=0.69), between thickness and gestational age (r=0.4) and between length and thickness of corpus callosum (r=0.5).Conclusions: Length and thickness of corpus callosum was found to increase proportionally to gestational age but it was not statistically significant. The growth of CC was proportional to the growth of brain. The precise anatomical knowledge regarding the morphology and growth of corpus callosum will provide baseline data for the diagnosis and assessment of progression of a disease affecting it.
Correlation of placental histomorphology with doppler velocimetry in preeclampsia and IUGR and their perinatal outcome
Background: Though numerous placental ischemic changes are described in relation to placental insufficiency, universally accepted criteria are unavailable till date leading to under or over reporting. Present study is an attempt to define standardized grading system for placental dysmorphology and correlate it with Doppler changes. The objective was to study placental histomorphology in preeclampsia and IUGR (Intrauterine Growth Restriction), to correlate the placental histomorphology with multivessel Doppler findings and their perinatal outcome in preeclampsia and IUGR.Methods: Prospective study was done over 2 years, 64 antenatal women with preeclampsia and/or IUGR were recruited, their multivessel Doppler measurements were recorded and placental histomorphological changes were studied post-delivery which were graded as either low or high grade placentas considering degree and number of ischemic changes observed.Results: Out of 64 cases, 33 (51.5%) cases had low grade changes and 31 (48.5%) had high grade changes. Out of 33 patients with low grade placentas 24 (73%) had normal Doppler, 20 (65%) out of 31 high grade placenta had abnormal Doppler. Placental histomorphology correlated well with Doppler abnormality (Coefficient of Kappa test). Syncytial knots>50%, presence of hypermature villi, infarcts, fibrin deposits were significantly associated with abnormal Doppler. High grade placenta group had significantly poor perinatal outcome (Chi square test).Conclusions: We formulated a grading system of placental dysmorphology in preeclampsia and IUGR which correlated well with clinical Doppler abnormality and perinatal outcome. Further studies are warranted to develop preventive strategies aimed at specific high grade placental changes seen in pregnancies with abnormal Doppler and develop strategies to improve perinatal outcome.
Assessment of the present and potential role of weather modification in agricultural production
August 1975.Includes bibliographical references.The Workshop for an Assessment of the Present and Potential Role of Weather Modification in Agricultural Production, Colorado State University, 1975, was held at CSU, July 15-18, 1975.Sponsored by RANN, NSF
Microbial Communities on Seafloor Basalts at Dorado Outcrop Reflect Level of Alteration and Highlight Global Lithic Clades
Areas of exposed basalt along mid-ocean ridges and at seafloor outcrops serve as conduits of fluid flux into and out of a subsurface ocean, and microbe-mineral interactions can influence alteration reactions at the rock-water interface. Located on the eastern flank of the East Pacific Rise, Dorado Outcrop is a site of low-temperature (<20°C) hydrothermal venting and represents a new end-member in the current survey of seafloor basalt biomes. Consistent with prior studies, a survey of 16S rRNA gene sequence diversity using universal primers targeting the V4 hypervariable region revealed much greater richness and diversity on seafloor rocks than in surrounding seawater. Overall, Gamma-, Alpha-, and Deltaproteobacteria, and Thaumarchaeota dominated the sequenced communities, together making up over half of the observed diversity, though bacterial sequences were more abundant than archaeal in all samples. The most abundant bacterial reads were closely related to the obligate chemolithoautotrophic, sulfur-oxidizing Thioprofundum lithotrophicum, suggesting carbon and sulfur cycling as dominant metabolic pathways in this system. Representatives of Thaumarchaeota were detected in relatively high abundance on the basalts in comparison to bottom water, possibly indicating ammonia oxidation. In comparison to other sequence datasets from globally distributed seafloor basalts, this study reveals many overlapping and cosmopolitan phylogenetic groups and also suggests that substrate age correlates with community structure
Evidence for microbial mediation of subseafloor nitrogen redox processes at Loihi Seamount, Hawaii
© The Author(s), 2016. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Geochimica et Cosmochimica Acta 198 (2017): 131-150, doi:10.1016/j.gca.2016.10.029.The role of nitrogen cycling in submarine hydrothermal systems is far less studied than
that of other biologically reactive elements such as sulfur and iron. In order to address
this knowledge gap, we investigated nitrogen redox processes at Loihi Seamount,
Hawaii, using a combination of biogeochemical and isotopic measurements,
bioenergetic calculations and analysis of the prokaryotic community composition in
venting fluids sampled during four cruises in 2006, 2008, 2009 and 2013.
Concentrations of NH4+ were positively correlated to dissolved Si and negatively
correlated to NO3-+NO2-, while NO2- was not correlated to NO3-+NO2-, dissolved Si or
NH4+. This is indicative of hydrothermal input of NH4+ and biological mediation
influencing NO2- concentrations. The stable isotope ratios of NO3- (d15N and d18O) was
elevated with respect to background seawater, with d18O values exhibiting larger
changes than corresponding d15N values, reflecting the occurrence of both production
and reduction of NO3- by an active microbial community. d15N-NH4+ values ranged from
0‰ to +16.7‰, suggesting fractionation during consumption and potentially N-fixation
as well. Bioenergetic calculations reveal that several catabolic strategies involving the
reduction of NO3- and NO2- coupled to sulfide and iron oxidation could provide energy to
microbes in Loihi fluids, while 16S rRNA gene sequencing of Archaea and Bacteria in
the fluids reveals groups known to participate in denitrification and N-fixation. Taken
together, our data support the hypothesis that microbes are mediating N-based redox
processes in venting hydrothermal fluids at Loihi Seamount.This work
was supported by the NSF Microbial Observatories program (MCB 0653265), the
Gordon and Betty Moore Foundation (GBMF1609), NSF-OCE 0648287, the Center for
Dark Energy Biosphere Investigations (C-DEBI) and the NASA Astrobiology Institute — Life Underground (NAI-LU). Sequence data was generated as part of the Alfred P.
Sloan Foundation's ICoMM field project and the W. M. Keck Foundation
Dynamic p-enrichment schemes for multicomponent reactive flows
We present a family of p-enrichment schemes. These schemes may be separated
into two basic classes: the first, called \emph{fixed tolerance schemes}, rely
on setting global scalar tolerances on the local regularity of the solution,
and the second, called \emph{dioristic schemes}, rely on time-evolving bounds
on the local variation in the solution. Each class of -enrichment scheme is
further divided into two basic types. The first type (the Type I schemes)
enrich along lines of maximal variation, striving to enhance stable solutions
in "areas of highest interest." The second type (the Type II schemes) enrich
along lines of maximal regularity in order to maximize the stability of the
enrichment process. Each of these schemes are tested over a pair of model
problems arising in coastal hydrology. The first is a contaminant transport
model, which addresses a declinature problem for a contaminant plume with
respect to a bay inlet setting. The second is a multicomponent chemically
reactive flow model of estuary eutrophication arising in the Gulf of Mexico.Comment: 29 pages, 7 figures, 3 table
Investigating Perceptual Congruence Between Data and Display Dimensions in Sonification
The relationships between sounds and their perceived meaning and connotations are complex, making auditory perception an important factor to consider when designing sonification systems. Listeners often have a mental model of how a data variable should sound during sonification and this model is not considered in most data:sound mappings. This can lead to mappings that are difficult to use and can cause confusion. To investigate this issue, we conducted a magnitude estimation experiment to map how roughness, noise and pitch relate to the perceived magnitude of stress, error and danger. These parameters were chosen due to previous findings which suggest perceptual congruency between these auditory sensations and conceptual variables. Results from this experiment show that polarity and scaling preference are dependent on the data:sound mapping. This work provides polarity and scaling values that may be directly utilised by sonification designers to improve auditory displays in areas such as accessible and mobile computing, process-monitoring and biofeedback
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