Spelling suggestions: "subject:"grown,"" "subject:"broad,""
231 |
Regulation of mouse UCP2 and UCP3 gene expressionKim, Dongho, n/a January 2006 (has links)
Uncoupling protein, UCP, present in the inner mitochondrial membrane of brown adipose tissue (BAT) contributes to adaptive thermogenesis. UCP functions as a proton pore and can dissipate the proton electrochemical gradient established by the respiratory chain during fuel oxidation, and thus generates heat without producing ATP. However, the brown adipose tissue thermogenesis is not likely to be a major mechanism in controlling energy expenditure for humans because adults have only residual amounts of the tissue.
Two new members of the UCP family have been identified based on their high sequence homology to UCP in BAT and named UCP2 and UCP3. The original UCP was renamed UCP1. At the amino acid level, human UCP2 and UCP3 are 59% and 57% identical to UCP1, respectively. In contrast to UCP1, UCP2 is expressed in many tissues such as brown adipose tissue, white adipose tissue, muscle, spleen and macrophages. UCP3 is expressed preferentially in skeletal muscle in humans, and brown adipose tissue and skeletal muscle in rodents. Since their identification many functional studies, including transgenic animals and ectopic expression of UCP2 or UCP3 in yeast, showed uncoupling activity of UCP2 and UCP3. A number of studies have been done that show increased expression of UCP2 and UCP3 by fasting, high-fat diets and suckling of newborn mice. A common characteristic of these circumstances is an associated increase in plasma free fatty acid levels. This study aimed to investigate effects of fatty acids, peroxisome proliferator-activated receptors (PPARs) and other transcription factors on UCP2 and UCP3 gene expression and to explore the molecular mechanism of their regulation through analysis of the promoter of the UCP2 and UCP3 genes.
The 3.1 kb and 3.2 kb 5�-flanking regions of the mouse UCP2 and UCP3 genes, respectively, were cloned and used to construct promoter reporter gene (firefly luciferase) plasmids. The cloned region of the UCP2 and UCP3 genes contained putative binding motifs for several transcription factors, including PPAR, myogenin, and MyoD. Luciferase assays of both constructs showed basal promoter activity with 20~190-fold induction for the UCP2 promoter and 1.3~23-fold induction for the UCP3 promoter in several transfected cell lines, including 3T3-L1, C2C12, L6, COS7 and HepG2. Oleic acid (0.3 mM) up-regulated endogenous UCP2 mRNA by 2.3-fold in 3T3-L1 preadipocytes but not in C2C12 myotubes, and UCP3 mRNA by 2.5-fold in C2C12 myotubes. Responsiveness of the cloned promoter to oleic acid reflected the tissue-specific responsiveness of their endogenous genes but with less fold induction, 1.4-fold for UCP2 promoter in 3T3-L1 preadipocytes and 1.5-fold for UCP3 promoter in C2C12 myotubes.
Forced expression of PPAR isotypes (PPARα, PPAR[delta] and PPARγ) showed tissue and isotype-specific activation of the UCP2 promoter. UCP2 promoter activity was induced by 2-fold by PPARγ in 3T3-L1 and by 2.8-fold by PPAR[delta] in C2C12. Treatment of oleic acid (0.3 mM) brought about further induction of the UCP2 promoter activity only in 3T3-L1. In contrast, all three isotypes induced activation of the UCP3 promoter in 3T3-L1, C2C12 and HepG2 cells. Treatment with oleic acid (0.3 mM) or isotype-specific agonist (10 [mu]M) resulted in further increased activity of the UCP3 promoter in 3T3-L1 and HepG2 cells. In particular, rosiglitazone (10 [mu]M) induced a 41-fold increase in UCP3 promoter activity in PPARγ transfected HepG2 cells, and this induction returned to basal level by treatment with bisphenol A diglycidyl ether (BADGE) (50 [mu]M), an antagonist for PPARγ.
In addition, UCP3 promoter activity increased up to 20-fold 4 days after induction of C2C12 myoblasts differentiation, whereas UCP2 promoter activity increased only up to 2-fold. Forced expression of myogenin and MyoD in C2C12 myoblasts to mimic differentiation, induced UCP3 promoter activity in an additive manner, consistent with UCP3 being regulated by muscle differentiation.
In the present study, it has been shown that UCP2 and UCP3 genes are regulated differently by fatty acids. The tissue-type dependence in regulation of endogenous UCP2 and UCP3 paralleled the cell type-specific effect of oleic acid on the promoter-reporter constructs, suggesting that fatty acid effects are at the transcriptional level. UCP2 and UCP3 promoters showed differences in their response to PPARs. Mediation of the fatty acid effect through PPARs has been also demonstrated, but direct binding of PPARs and particular regulatory motifs on the cloned promoter region have not yet been investigated.
|
232 |
Transforming sectionalism to unity through narrative in John Brown Gordon's "The last days of the Confederacy"Acklin, David R. 11 June 1993 (has links)
John Brown Gordon was committed to the mission of national reconciliation.
He knew that the South would have to embrace the North to repair the devastation of
the Civil War. Driven by dedication to public service after the war, he worked
through his positions in governmental offices to help the South. As his public life
slowed he began work on a lecture aimed at making him a peacemaker, a missionary
for reconciliation. His purpose was to provide a broad, nationalistic perspective
which created a common vantage point that would allow both Northerners and
Southerners to derive pride and honor from their participation in the Civil War. The
lecture, "The Last Days of the Confederacy," became very popular in a short period of
time, and made Gordon one of the most requested speakers of the Southern Lyceum
Program and Slayton Lyceum Program.
The purpose of this critical interpretation of Gordon's lecture is to account for
the effectiveness of the rhetorical elements and strategies in the work. The analysis
will be based on Walter Fisher's narrative paradigm. Narratives dominate the content
and structure of speech; narratives provide a way of ordering and presenting a view of
the world through descriptions of a situation - -the act of storytellingthe format
Gordon chose in creating the lecture. After drawing conclusions from application of
the narrative paradigm I will focus on identifying and evaluating Gordon's rhetorical
vision, which is based in Ernest Bormann's fantasy-theme theory. Finally, due to the
synecdochal nature of the narratives I will use Kenneth Burke's four master tropes
literature to fully interpret the various aspects of the narrative, which complements
the initial mission of narrative criticism.
In "The Last Days of the Confederacy," Gordon masterfully uses anecdotes
from his experiences in the Civil War to create narrative sequences, which construct a
strategy of transformative discourse. A typical sequence would start with an
ingratiary tactic in which Gordon, in his eloquent manner, would describe a Northern
character, scene, or theme and juxtapose it to another story from the South. The
purpose of this sequence is to generate irony, creating a dialectic between the two
stories, which, at the surface, seem to be opposed. His third step, then, was to use that
dialectic to point to the commonalities between the North and the South. This he
would do by illustrating an American trait, skill, or value. The result would be a
major theme demonstrating a national value or belief to add strength to his existing
compendium of themes, such as unity, fraternity, and brotherhood - -all tools to salve
the process of reconciliation of conflict with face-saving for both. / Graduation date: 1994
|
233 |
Effekt av födotillgång på smoltifieringsprocessen hos öring / Effect of food availability on the smoltification process in brown troutGottmarsson, Monica January 2007 (has links)
Populationer av öring består av både migrerande och stationära individer, och det tycks vara både genetiska och miljömässiga faktorer som påverkar en individs beslut att vandra eller ej. Syftet med denna studie var att testa vilken effekt tillgång på föda har på tillväxt och smoltifieringsprocess hos öring (Salmo trutta). Min hypotes var att öring med hög tillförsel av mat växer bättre och smoltifieras därmed inte till samma grad som öring med låg tillförsel av mat. Som en konsekvens av skillnader i mattillgång förväntades att ATPas-aktiviteten, vilken indikerar smoltstatus, var lägre vid god tillförsel av mat än vid låg tillförsel. Experimentet utfördes från november 2003 till april 2004 vid fiskeodlingen i Brattfors, Värmland, där 2+ Klarälvsöringar utsattes för tre olika födonivåer, med fyra replikat av varje födonivå. Var 4-5 vecka fångades fisken för att vägas och mätas och slutligen togs biopsi på öringens gälar för en analys av Na+,K+ -ATPas aktivitet. I slutet av experimentet klassificerades fiskarna som parr eller smolt. Parr hade en signifikant lägre Na+, K+ -ATPas aktivitet än smolt i de tre olika födonivåerna. Na+, K+ -ATPas aktiviteten visade dock ingen signifikant skillnad mellan födonivåerna. Parr hade ökat sin vikt och längd mest i samtliga födonivåer och störst skillnad var det i den lägsta födonivån, parr hade ökat i genomsnitt 17 g och 3,5 mm mer än smolt. Av de två högsta födonivåerna var andelen klassificerade som smolt 37 % och vid den lägsta födonivån var andelen smolt 76 %. / Populations of brown trout consist of both migratory and resident individuals, and it is likely that both genetic and environmental factors influence the decision to migrate. The purpose of this study was to test the effect of food availability on growth and the smolting process in brown trout (Salmo trutta). My hypothesis was that brown trout subjected to a high food supply grows better and smoltifies to a lesser degree than brown trout subjected to a low food supply. As a consequence of differences in food supply I expected that ATPase-activity, which indicates smoltification status, would be lower with a high food supply than with a low supply. The experiment was run from November 2003 until April 2004 in a fish hatchery in Brattfors, Värmland, where 2+ brown trout from the river Klarälven were exposed to three food levels, each replicated four times. Every 4-5 weeks the fish were weighed and measured and a biopsy was taken from the gills for analysis of Na+, K+ -ATPase activity at the end of the experiment. At the end of the experiment the fish were classified as parr or smolt. Parr had a significantly lower Na+, K+ -ATPase activity than smolt for the three different food treatments. Na+, K+ -ATPase activity did not differ significantly between food levels. Parr grew faster (both weight and length) than smolt at all food levels, and the largest difference between parr and smolt was observed at the lowest food level, where parr increased on average 17 g and 3,5 mm more than smolt. At the two highest food levels the proportion classified as smolt was 37 % and at the lowest foodlevel the proportion of smolt was 76 %.
|
234 |
Role of caveolin-1 in brown adipose tissueMattsson, Charlotte L. January 2010 (has links)
Caveolae are 50-100 nm invaginations in the plasma membrane. Caveolae and the protein caveolin-1 (Cav1) have been shown to be important in many signaling pathways in different cell types; however, in some cell types caveolae and Cav1 do not seem to affect the investigated signaling pathways. In my thesis, I have investigated the role of caveolin-1 (Cav1) in metabolism and b3-adrenergic, LPA-, EGF- and PDGF-receptor signaling in brown adipocytes. Brown adipose tissue is responsible for nonshivering thermogenesis. Recent studies have shown that not only infants but also adult man can have brown adipose tissue and that the presence is negatively correlated with both obesity and age. By understanding how signaling for proliferation and differentiation in brown adipocytes is regulated, it could be possible in the future to activate brown adipose tissue to combat obesity and the metabolic syndrome. In brown adipocytes, both epidermal growth factor (EGF) and platelet-derived growth factor (PDGF) were able to induce proliferation, which was dependent on Erk1/2 activation. However, EGF and PDGF utilized different pathways to activate Erk1/2, with EGF signaling partially occurring via a Src-pathway (not involving PI3K/PKC) and PDGF via a PI3K/PKC/Src-pathway. Furthermore, LPA receptors were able to activate Erk1/2 via two pathways, one Gi/PKC/Src-pathway and one PI3K-pathway. For these receptors, Cav1-ablation did not affect the agonist-induced Erk1/2 activation. Cav1 was, however, required for proper b3-adrenergic receptor (b3-AR) signaling to cAMP and for adenylyl cyclase activity. In Cav1-ablated mice, the adrenergic receptors are desensitized. However, this desensitization could be overcome physiologically, and the Cav1-ablated mice were therefore able to survive in prolonged cold by nonshivering thermogenesis. In conclusion, ablation of Cav1 affected certain signaling pathways in brown adipocytes, while other pathways were not affected or could be physiologically rescued. / At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 1: Manuscript. Paper 3: Manuscript. Paper 4: Manuscript.
|
235 |
Regulatory Factors that Reveal Three Distinct Adipocytes : The Brown, the White and the BriteWaldén, Tomas B January 2010 (has links)
Adipose tissues have long been considered to derive from a common origin. Even the functionally different brown and white adipose tissues were generalized to share a common origin. Brown adipose tissue is a highly innervated and vascularised tissue containing multilocular and multimitochondrial brown adipocytes. Brown adipose tissue expends energy through sympathetic nervous system-mediated non-shivering thermogenesis, where uncoupling protein 1 (UCP1) is the key player. In contrast, white adipose tissue consists of unilocular white adipocytes with a main role to store energy in the form of the lipid droplet. We know today that this generalisation is exaggerated since adipocytes can derive from more than one origin and not only be brown or white. We and others have demonstrated that the brown adipocyte has a dermomyotomal origin and derives from the adipomyocyte, the precursor cell that can also become a myocyte, whereas white adipocytes are suggested to derive from pericytes, cells that are embedded within the vascular vessel walls. For a long time there has been evidence that energy-expending adipocytes reside within certain white adipose tissues, based on the fact that cold exposure, by switching on the sympathetic nervous system, leads to levels of UCP1 that are not detectable in mice housed at thermoneutrality. We demonstrated that these cells have a molecular signature that is distinct from brown and white adipocytes. Since these energy-expending cells reside within certain white adipose tissues, we chose to name them brite (brown in white) adipocytes. Moreover, we also identified regulatory factors that were specifically expressed in each adipocyte type, thus, facilitating the possibility to identify the three adipocytes: the brown, the white and the brite. / At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 4: Manuscript. Paper 5: Manuscript.
|
236 |
Mitochondrial form and function in pancreatic β-cells and brown adipocytesWikström, Jakob D January 2010 (has links)
This thesis is focused on the role of mitochondria in pancreatic β-cells and brown adipose tissue (BAT). Two main aspects of mitochondria were explored; mitochondrial functional efficiency and the interrelationship between mitochondrial shape and function. Mitochondria in β-cells were found to exhibit heterogeneity in mitochondrial membrane potential. This functional diversity decreased when cells were challenged with glucose stimuli, suggesting that at higher fuel levels low-activity mitochondria are recruited into a pool of high-activity mitochondria. Glucolipotoxic conditions increased the functional diversity suggesting that this may be of importance for diabetes pathophysiology. To examine mitochondrial efficiency in intact islets a high throughput islet respirometry method was developed. Due to increased uncoupling, islets from a diabetic animal model exhibit lower respiratory efficiency. Glucose, free fatty acids and amino acids all decreased respiratory efficiency. A large portion of the respiratory efficiency was mediated by reactive oxygen species and the adenine nucleotide translocase. In β-cells mitochondria were found to undergo cycles of fusion and fission. During glucolipotoxicity mitochondria fragmented and lost their fusion ability. Knock down of the fission protein Fis1 rescued the β-cells from glucolipotoxic induced cell death. BAT mitochondria also showed fusion and fission. The mitochondrial dynamics proteins Mfn2 and Drp1 were shown to strongly affect BAT mitochondrial morphology. In response to a combination of adrenergic and free fatty acid stimuli mitochondria drastically changed from long filamentous structures to fragmented spheres. Inhibiting fission by the negative form of Drp1 decreased BAT response to adrenergic stimuli by half. In conclusion, mitochondrial efficiency may be of importance for normal as well as compromised β-cell and islet function. Mitochondrial morphology appears critical for mitochondrial function in β-cells and BAT. / At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Manuscript. Paper 4: Manuscript.
|
237 |
The Culinary BrownsBrown, Phoebe A. 01 December 2009 (has links)
The Culinary Browns is an experimental documentary that traces four generations of the Brown family beginning with Bob Brown, my great-grandfather, a writer of pulp fiction, modern poetry, cookbooks and social commentary. This documentary is not a linear history or purely factual document, but instead, uses personal experience as a means to generate more universal connections to the inherently dysfunctional dynamics of family, the fragmentary quality of memory, and to ultimately remind the viewer that history is relative.
|
238 |
Effect of resident epiphytic fungi development of brown rot blossom blight of stone fruitsWittig, Hans P. P. 14 January 1992 (has links)
Antagonistic effects of Epicoccum purpurascens,
Aureobasidium pullulans, Trichoderma spp., and Botrytis
cinerea on establishment of Monilinia fructicola infections
in cherry and peach blossoms were assessed in field and mist
chamber studies. Conidia of each fungus were applied to
blossoms that were subsequently inoculated with conidia of
M fructicola. Mist chamber experiments on forced cherry
blossoms demonstrated that recovery of M. fructicola was
significantly reduced (P=.05) when spores of E. purpurascens
and B.cinerea had been applied 24 hr prior to inoculation
with M. fructicola. Reduction in recovery of M. fructicola
was comparable to that obtained with the fungicide benomyl.
In field trials done in 1990 and 1991, applications of
E. purpurascens and A. pullulans reduced cherry blossom
blight relative to nontreated blossoms by 47 to 65 and 54 to
58%, respectively, compared to reductions of 80 to 96 and 84
to 97% with the fungicides benomyl and iprodione,
respectively. Twig blight in peach, an indicator of blossom
blight infection, was reduced by 37% relative to nontreated
blossoms with applications of E. purpurascens, compared to
54 and 51% reductions with benomyl and iprodione,
respectively.
Analysis of the influence of antagonistic fungi
sprayed onto blossoms on fruit set indicated that B.cinerea
was a weak pathogen of stone fruit blossoms. Significant
reductions (P=.05 and P=.10) were obtained in fruit set
compared with the nontreated control when conidia of B. cinerea
were applied to both cherry and peach blossoms in
1991.
Latent Monilinia infections were evaluated by dipping
green cherries in the herbicide paraquat. Applications of
E. purpurascens and A. pullulans to blossoms caused
reductions in the number of latent Monilinia infections in
green cherries by 18 and 49%, respectively in 1990, and 61
and 66% respectively in 1991. This compares with reductions
of 98 and 92% in 1990 and 1991, respectively, with the
fungicide iprodione. It was observed that the antagonists
E. purpurascens and B. cinerea also became established as
latent infections. These fungi were recovered at a
significantly (P=.05) higher percentage on green cherries
where they had been applied as antagonists to blossoms.
No meaningful differences were detected in the amount
of brown rot that developed on fruit due to the influence of
fungal treatments on blossoms. / Graduation date: 1992
|
239 |
Thermoresponsiveness of ventromedial hypothalamic (VMH) neurons to peripheral (scrotal) thermal stimulationLi, Qiang 01 January 1996 (has links)
The ventromedial hypothalamic nucleus (VMH) is an important central effector site involved in activating brown adipose tissue (BAT) or non-shivering thermogenesis. VMH neurons have previously been shown to be thermally responsive to changes in local temperature of the preoptic area/anterior hypothalamus (PO/AH). However, the thermoresponsiveness of VMH neurons of room temperature acclimatized and cold acclimatized rats to peripheral thermal stimulation has not been tested. In this thesis, a series of studies was designed to determine the thermoresponsiveness of VMH neurons to peripheral (scrotal) thermal stimulation of rats. Extracelluiar VMH neuronal activity was recorded from urethane anaesthetized male Sprague-Dawley rats, which were acclimatized either to room temperature (21°C for 4 weeks) or to cold (4°C for 4 weeks) prior to testing, during scrotal cooling and heating with glass-micropipettes filled with 0.5 M sodium acetate containing 2% pontamine sky blue. The rats' colonic temperatures were kept at normothermia (37°C), or hypothermia (33-35°C) during scrotal thermal stimulation. In the room temperature acclimatized rats, VMH neurons were temperature responsive to scrotal heating and cooling and were classified as warm responsive (WRN), cold responsive (CRN) and temperature non-responsive neurons (TNRN), based on their thermal coefficients. The ratio of VMH WRNs and CRNs was similar to that of thermoresponsive neurons observed in other brain regions (eg, the PO/AH and thalamus). VMH WRNs and CRNs were further classified as biphasic or monophasic in nature according to their thermal responses to scrotal heating and cooling. VMH neurons sustained their thermoresponsiveness to repeated trials of scrotal thermal stimulation with colonic temperatures maintained at 37°C or when colonic temperatures were acutely lowered from 37°C to 35°C and 33°C. In addition, scrotal thermal signals specifically altered neuronal activity of VMH thermoresponsive neurons, as changes in EEG activity did not occur with changes in VMH neuronal activity. Scrotal thermal inputs were functionally shown to be transmitted via the medial preoptic nucleus (MPO) prior to reaching the VMH nucleus because thermoresponsive VMH neuronal activity was blocked with the pretreatment of lidocaine into the MPO. Scrotal heating or cooling to 21°C-acclimatized rats did not increase IBAT temperatures, inferring that scrotal cooling had not evoked IBAT thermogenesis in this group. In cold acclimatized (CA) rats, prolonged (over 2 hours) and transient localized scrotal cooling caused IBAT temperatures to increase, inferring that scrotal cooling activated BAT thermogenesis. Mean basal firing rates of all recorded VMH neurons of CA-groups significantly increased, compared to those of VMH neurons observed in room temperature acclimatized (RA) groups. More VMH CRNs than WRNs were recorded in the CA-group and the thermoresponsiveness (ie, thermal coefficient) of VMH CRNs significantly increased during localized scrotal cooling in the cold acclimatized group, compared to thermal coefficients of VMH CRNs of the RA-groups. (Abstract shortened by UMI.)
|
240 |
Facies architecture of the upper Calvert Bluff Formation exposed in the highwall of Big Brown Mine, Fairfield, TexasSturdy, Michael Dale 30 October 2006 (has links)
The facies architecture and geometry of stratigraphic surfaces within a lignite
bearing interval of the Paleocene upper Calvert Bluff Formation is mapped on a
photomosaic of the 150 ft (50 m) high and 12,000 ft (4km) long âÂÂCâ area highwall of
Big Brown Mine, near Fairfield, Texas. Observed bedding and facies architecture are
interpreted in terms of temporal changes, depositional environments and sequence
stratigraphic setting. A three dimensional grid of 89 subsurface logs is correlated to this
photomosaic to characterize log response patterns of facies. Six facies are observed: 1)
lignite, 2) interdistributary bay mud, 3) prograding delta, 4) delta top mud, 5)
distributary channels, and 6) incised valley fill. The six facies were defined by a
combination of mapped photomosaic observations and subsurface log correlations. The
lignite deposit formed in a low depositional energy, low sediment input, high-organic
productivity interchannel basin. Overlying mud records overbank flooding followed by
avulsion and progradation of delta deposits. Tidal-flat deposits overlying prograding
delta deposits record fluctuating energy conditions on the emerging delta top. Channel
deposits cutting into the delta top record lateral channel migration across delta top floodplains. These regressive delta deposits are capped by a local incised sequence
boundary overlain by fluvial channel deposits inferred to have allowed sediment to
bypass further basinward during lowstand. A sheet of channel deposits capping this
highwall exposure records more recent erosion, followed by development of modern soil
horizons.
The Big Brown Mine highwall exposes a relatively complete high-frequency
Paleocene stratigraphic sequence developed in an area landward of the shoreline position
during maximum transgression, that progresses upsection from: 1) highstand alluvial
flood basin coals, 2) a thin condensed maximum flooding interdistributary shale, 3) a
thick succession of regressive deltaic strata, and 4) a high-relief, sequence-bounding
erosion surface overlain by a lowstand to transgressive fill of channel deposits.
Correlations with regional Wilcox Group stratigraphic studies spanning coeval shoreline
and shelf strata indicate that this high-frequency sequence is within the transgressive
systems tract of a 3rd order stratigraphic sequence. It appears that high-frequency
sequences of sub-regional extent control the complex distribution of coal seams within
central Texas.
|
Page generated in 5.1406 seconds