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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
391

Central Control Of Body Fat And Thermoregulation Through Shared And Separate Sympathetic Circuitries And Sensory Feedback

Nguyen, Ngoc Ly 10 May 2017 (has links)
More than 30% of the population suffers from obesity, which increases the risk of death and secondary health problems. Body fat [white adipose tissue (WAT) and brown adipose tissue (BAT)] are innervated and regulated by the sympathetic nervous system (SNS). WAT stores energy, while BAT generates heat for thermoregulation. Fat also has sensory innervations, but the roles of sensory nerves are still being elucidated. Hence, understanding the neuroanatomy of the SNS innervations of fat and the neural regulation of fat metabolism will be valuable for advancing obesity treatment. Using trans-synaptic tract tracers with unique fluorescent proteins, we defined and compared the SNS innervations of visceral fat [mesenteric WAT (MWAT)] and subcutaneous fat [inguinal WAT (IWAT)] and of IWAT and interscapular BAT (IBAT) in Siberian hamsters. MWAT and IWAT have moderately shared SNS innervations within the hindbrain, but separate SNS innervations in rostral regions. In contrast, IWAT and IBAT have relatively separate SNS circuitries throughout the brain yet some overlap in SNS nuclei known to regulate thermogenesis. We tested for the presence of functional coordination between IWAT and IBAT defined by overlap in IWAT SNS and IBAT SNS innervations. When IBAT function was impaired by SNS denervation, IWAT SNS drive, thermogenic activity, and beige adipocyte recruitment increased in cold exposed hamsters likely through coordination with IWAT SNS pathways. Conversely, we found that only SNS drive to IWAT increased during acute food deprivation suggesting that populations of SNS neurons singly innervating each fat depot may contribute to differential SNS drive to fat. Lastly, we demonstrated that IWAT sensory nerves mediate the functional coordination between IWAT and IBAT and the regulation of SNS drive to fat. The absence of IWAT sensory feedback via sensory denervation differentially decreased SNS drive to IBAT and IWAT itself, but not to MWAT, retroperitoneal WAT, and epididymal WAT in cold exposed hamsters. Collectively, the studies in this dissertation provide neuroanatomical evidence of separate and shared SNS brain sites likely receiving sensory signaling and regulating SNS drive to fat, and direct evidence of the roles of SNS and sensory nerves innervating fat to energetic homeostasis and thermoregulation.
392

Search for Close Binary Evolved Stars

Saffer, R. A., Liebert, J. 10 1900 (has links)
We report on a search for short -period binary systems composed of pairs of evolved stars. The search is being carried out concurrently with a program to characterize the kinematical properties of two different samples of stars. Each sample has produced one close binary candidate for which further spectroscopic observations are planned. We also recapitulate the discovery of a close detached binary system composed of two cool DA white dwarfs, and we discuss the null results of Ha observations of the suspected white dwarf /brown dwarf system G 29-38.
393

High Dispersion Observations of H alpha in the Suspected Brown Dwarf, White Dwarf Binary System G29-38

Liebert, J., Saffer, R. A., Pilachowski, C. A. 10 1900 (has links)
We report on high dispersion spectroscopy of the Ha absorption line of the cool DA white dwarf G 29 -38. This is the star for which a recently detected infrared excess has been suggested to be due to a possible brown dwarf companion by Zuckerman and Becklin (1986, 1987). Three echelle spectra obtained at the Multiple Mirror Telescope and at the Kitt Peak Mayall 4m telescope in 1987 December show no evidence for radial velocity variations larger than -'1.1 ± 8.7 km s -1 and are used to derive a weighted heliocentric radial velocity Vr = 33.7 ± 4.3 km s -1 for the white dwarf. No emission component from the hypothesized secondary star is detected. These negative results do not constitute strong evidence against the companion hypothesis, since the expected orbital velocity of the white dwarf component could be quite small, and the companion's line emission could be too faint to be detected. However, the observation of a sharp absorption line core restricts the possible rotation of the white dwarf to < 40 km s -1 and ensures that any surface magnetic field has a strength < 105 gauss. These results make it unlikely that the DA white dwarf has previously been in a cataclysmic variable accretion phase.
394

A STEEPER THAN LINEAR DISK MASS–STELLAR MASS SCALING RELATION

Pascucci, I., Testi, L., Herczeg, G. J., Long, F., Manara, C. F., Hendler, N., Mulders, G. D., Krijt, S., Ciesla, F., Henning, Th., Mohanty, S., Drabek-Maunder, E., Apai, D., Szűcs, L., Sacco, G., Olofsson, J. 02 November 2016 (has links)
The disk mass is among the most important input parameter for every planet formation model to determine the number and masses of the planets that can form. We present an ALMA 887 mu m survey of the disk population around objects from similar to 2 to 0.03 M-circle dot in the nearby similar to 2 Myr old Chamaeleon I star-forming region. We detect thermal dust emission from 66 out of 93 disks, spatially resolve 34 of them, and identify two disks with large dust cavities of about 45 au in radius. Assuming isothermal and optically thin emission, we convert the 887 mu m flux densities into dust disk masses, hereafter M-dust. We find that the M-dust-M* relation is steeper than linear and of the form M-dust proportional to (M*)(1.3-1.9), where the range in the power-law index reflects two extremes of the possible relation between the average dust temperature and stellar luminosity. By reanalyzing all millimeter data available for nearby regions in a self-consistent way, we show that the 1-3 Myr old regions of Taurus, Lupus, and Chamaeleon. I share the same M-dust-M* relation, while the 10 Myr old Upper. Sco association has a steeper relation. Theoretical models of grain growth, drift, and fragmentation reproduce this trend and suggest that disks are in the fragmentation-limited regime. In this regime millimeter grains will be located closer in around lower-mass stars, a prediction that can be tested with deeper and higher spatial resolution ALMA observations.
395

You Gotta Crack A Few Begs To Make An Honest

Brown, Jonathan Alexander 16 December 2016 (has links)
This thesis explores childhood, relationships, teaching, and god.
396

Baptists and Racial and Ethnic Minorities in Texas

McLeod, Joseph Alpha, 1921- 12 1900 (has links)
This study examines the relations of white Baptists with racial and ethnic minorities in Texas from the beginning of organized Baptist work in Texas in the mid-nineteenth century, through the United States Supreme Court decision in the Brown v. Topeka case in 1954, Emphasizing the role of attitudes in forming actions, it examines the ideas of various leaders of the chief Baptist bodies in Texas: the artist General Convention of Texas, the Baptist Missionary Association of Texas and the American Baptist Convention. The minorities included in the work are the Negroes, the Mexican-Americans, non-Anglo-Saxon Europeans, American Indians, Orientals, and Jews. Several factors tend to justify a study of this subject. First, there is the prominence of race relations in the nation which has aroused interest in the effect which race relations have had upon affairs in Texas, Second, the widespread changes which have taken place in Texas during, the last two decades suggest the feasibility of a study of that phenomenon, and the fact that many consider the race problem to be a moral and religious issue indicates the relevance of the churches' relationships to these changes. As the largest religious denomination in the state, the Baptists offer a viable subject for study. Finally, since to date no study specifically relating to the Baptists of Texas and their role in race relations in the state has been made, it is felt that such a study will contribute to an understanding of the situation. The scope of this study, in point of time, extends from about 1850 to the early 1960's, in order to consider the reactions of Texas Baptists to the Brown decision of the United States Supreme Court. From the standpoint of subject, the study has been limited to leaders of the Baptist denomination. Their statements on the race issue as well as actions which may or may not have supported their statements have been studied,
397

Virginia's Pupil Placement Board and the Massive Resistance Movement, 1956-1966

Eskridge, Sara Kathryn 01 January 2006 (has links)
Virginia's Pupil Placement Board was the most enduring vestige of the state's "massive resistance" movement in the 1950s. Following the example of other Southern states, the state's General Assembly passed the Pupil Placement Act in 1956 as part of a package of legislation designed to counteract the Supreme Court desegregation ruling. The Act, and the Pupil Placement Board that enforced it, lasted a decade, much longer than any of the other legislative initiatives born during that session, longer than the massive resistance movement itself.Whites, including many of Virginia's leaders, considered the Board to be ineffective at stemming the onslaught of integration, while African-Americans felt that the agency breeched their constitutional rights. From its inception to its dissolution in 1966, the Pupil Placement Board had to defend itself in a slew of desegregation cases all over Virginia, and the General Assembly changed the law several times to comply with court orders. Despite this adversity, the Board was consistently effective in stemming desegregation in Virginia throughout its tenure.
398

Weather on Other Worlds. IV. H alpha Emission and Photometric Variability Are Not Correlated in L0-T8 Dwarfs

Miles-Paez, Paulo A., Metchev, Stanimir A., Heinze, Aren, Apai, Daniel 10 May 2017 (has links)
Recent photometric studies have revealed that surface spots that produce flux variations are present on virtually all L and T dwarfs. Their likely magnetic or dusty nature has been a much-debated problem, the resolution to which has been hindered by paucity of diagnostic multi-wavelength observations. To test for a correlation between magnetic activity and photometric variability, we searched for Ha emission among eight L3-T2 ultra-cool dwarfs with extensive previous photometric monitoring, some of which are known to be variable at 3.6 mu m or 4.5 mu m. We detected Ha only in the non-variable T2 dwarf 2MASS J12545393-0122474. The remaining seven objects do not show Ha emission, even though six of them are known to vary photometrically. Combining our results with those for 86 other L and T dwarfs from the literature show that the detection rate of Ha emission is very high (94%) for spectral types between L0 and L3.5 and much smaller (20%) for spectral types. >= L4, while the detection rate of photometric variability is approximately constant (30%-55%) from L0 to T8 dwarfs. We conclude that chromospheric activity, as evidenced by H alpha emission, and large-amplitude photometric variability are not correlated. Consequently, dust clouds are the dominant driver of the observed variability of ultra-cool dwarfs at spectral types, at least as early as L0.
399

Sukcese vegetace a vývoj půd na výsypkách po těžbě hnědého uhlí / Vegetation succession and soil development on heaps from brown coal mining

Veselý, Martin January 2012 (has links)
Plant diversity and selected soil parameters from 36 sites placed on brown coal mining spoil heaps were analyzed and compared. Spontaneously revegetated or technically reclaimed spoil heaps of different age were situated in brown coal mining district of eastern Most basin in north western part of the Czech republic. Samples were sorted in groups according to vegetation growth and type. Plant diversity increases during succession development and is higher on non-reclaimed sites than reclaimed sites, where diversity decreases with time. Soil bulk density decreases during succession on all sites. Soil pH is decreasing too and this process is faster on spontaneously revegetated sites. Old successional forest type sites have very acid soils probably due to properties of original mineral matrix. Thickness of organic horizon and A horizon is increasing during succession and they appear in mid-aged sites first. Content of soil organic carbon is increasing continuously. Non-reclaimed sites reach higher contents, mainly because of higher content of fossil organic matter in spoil mineral matrix. Keywords: vegetation succession, soil development, reclamation, brown coal mining heaps
400

Prostorová aktivita medvěda hnědého (Ursus arctos Linnaeus, 1758) v zoologické zahradě / Home range activity of the Brown Bear (Ursus arctos) in ZOO

Vojáčková, Jana January 2012 (has links)
This dissertation deals with monitoring of European brown bears behavior (Ursus arctos arctos), namely of males Pišta, Miky and Honzík and of female Eliška in zoological garden in Plzen in spring 2012. Behaviour of all European brown bears is for better clarity presented in the form of tables and graphs. The dissertation includes overview of all kinds of ursine (size, environment, food and reproduction). Key words: bear, hibernation, bears activity

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