An experimental study was carried out to identify effective advisory and alarm stimuli to be used in a drowsy driver detection system. The envisioned system has three stages. In the first stage, previously developed detection algorithms would compute online drowsiness levels. If a driver's drowsiness level exceeds a predetermined threshold the system would proceed to stage two. At this point an initial advisory tone and a voice message would be played. If the driver does not respond, he or she would experience a realerting alarm. The third stage of the system would give the driver an option of using a drowsiness countermeasure to help maintain the re-alerted state. The goal of the present research was to determine the effectiveness of possible stimuli to be used in the second and third stages of the envisioned system. Eight initial advisory tones, two voice messages, eight alarm sounds, and five peripheral stimuli were investigated as part of stage two. In addition, six drowsiness countermeasures to be used in stage three were investigated. Eight graduate students in the Human Factors Engineering program at Virginia Tech volunteered as subjects. Subjects drove the automobile simulator throughout the experimental session. Data were collected using subjective opinion, paired comparisons, and effectiveness ratings. This study succeeded in answering many question regarding stimuli to be used in a drowsy driver detection, advising, and alerting system. The results of the study indicated very effective stimuli to be used in the advising and alerting stages of the envisioned system. / Master of Science

I measured habitat characteristics at 21 barred owl, 30 northern goshawk. and 17 redshouldered hawk nest areas, and at 49 random areas within a 780 km2 area in northwest Connecticut. Measurements were taken at a macro ground level and from 1:12,000 and 1:40,000 black and white and 1:58,000 and 1:126,000 color infrared aerial photography. Among-species nest area analyses at the ground level indicated that higher beech and red maple densities were associated with red-shouldered hawk nest areas than with nest areas of barred owls or northern goshawks. Analyses between species and random areas indicated that barred owl nest areas had higher sugar maple density and basal area than random areas. Denser canopy, greater tree density and basal area, a greater percentage of forested land, and greater hemlock density were associated with nest areas of both northern goshawks and red-sl1ouldered hawks. Northern goshawk nest areas had higher red maple and conifer densities and were found farther from human activity and forest openings than random (available) habitat. Red-shouldered hawk nest areas had higher beech and deciduous tree densities and basal areas than expected based on available habitat. Six of 21 habitat characteristics measured from 4 scales of aerial photography were significantly different either among species nest areas or between species and random areas. Northern goshawks nested in areas with little open water. Red-shouldered hawks had higher percentages of open water near nest sites and were significantly closer to water than available habitat. Four variables related to contiguity of the forest were Significant in the analyses. The greatest number of cover type patches generally was associated with random areas followed by barred owl then redshouldered hawk nest areas. Red-shouldered hawks and northern goshawk nest areas were in relatively contiguous tracts of forested land and farthest from forest openings. The highest percentages of agricultural and non-forested land were found at random areas and barred owl nest areas, with lowest percentages at red-shouldered hawk and northern goshawk nest areas. The percentage of open water and swamp were most easily identified and measured from 1:58,000 color infrared aerial photography. Distance to water was most consistently measured from 1:58,000 CIR or 1:40,000 B&W aerial photography. The distance to opening was measured most consistently from the 1:12,000 scale. The 1:40,000 and 1:12,000 scales of aerial photography provided the most consistent measurements of the percentages of agricultural and non-forested land. / Master of Science

The results of deoxyribonucleic acid homology experiments with the type strains of Azospirillum lipoferum, Azospirillum brasilense, and Azospirillum amazonense, and 19 additional strains of A. amazonense, confirmed that A. amazonense is a distinct new species. The description of the genus Azospirillum is emended to accommodate A. amazonense. Ribosomal RNA (rRNA) homology studies indicated 90 to 96% homology between Azospirillum lipoferum and Azospirillum brasilense, and 64 to 70% homology between these species and Azospirillum amazonense. This supports the inclusion of these three species in the genus Azospirillum. In contrast, "Azospirillum seropedicae" had very little homology with the other Azospirillum species (<22% RNA homology) and should not be considered a member of the genus. The taxonomic placement of "A. seropedicae" is uncertain. The nearest relatives of the genus Azospirillum were Aquaspirillum itersonii and Rhodospirillum rubrum (>65% RNA homology); Gluconobacter oxydans and Beijerinckia indica exhibited 30 to 60% RNA homology with Azospirillum species. Deoxyribonucleic acid (DNA) studies indicated that Conglomeromonas largomobilis subsp. largomobilis was related to Azospirillum lipoferum by >45% DNA homology and by 99% RNA homology; moreover, it was found to be a microaerophilic nitrogen fixer. Thus C. largomobilis subsp. largomobilis is a subjective synonym of A. lipoferum. In contrast, DNA homology studies indicated that Conglomeromonas largomobilis subspecies parooensis was unrelated to C. largomobilis or A. lipoferum, or to any other species tested, and its taxonomic position is uncertain. Several strains of azospirilla which form unique star-shaped colonies were identified as A. lipoferum by DNA homology. / Master of Science

Yes / Seasonal or photoperiodically sensitive animals respond to altered day length with changes in physiology (growth, food intake and reproductive status) and behaviour to adapt to predictable yearly changes in the climate. Typically, different species of hamsters, voles and sheep are the most studied animal models of photoperiodism. Although laboratory rats are generally considered nonphotoperiodic, one rat strain, the inbred Fischer 344 (F344) rat, has been shown to be sensitive to the length of daylight exposure by changing its physiological phenotype and reproductive status according to the season. The present study aimed to better understand the nature of the photoperiodic response in the F344 rat. We examined the effects of five different photoperiods on the physiological and neuroendocrine responses. Young male F344 rats were held under light schedules ranging from 8 h of light/day to 16 h of light/day, and then body weight, including fat and lean mass, food intake, testes weights and hypothalamic gene expression were compared. We found that rats held under photoperiods of ≥ 12 h of light/day showed increased growth and food intake relative to rats held under photoperiods of ≤ 10 h of light/day. Magnetic resonance imaging analysis confirmed that these changes were mainly the result of a change in lean body mass. The same pattern was evident for reproductive status, with higher paired testes weight in photoperiods of ≥ 12 h of light/day. Accompanying the changes in physiological status were major changes in hypothalamic thyroid hormone (Dio2 and Dio3), retinoic acid (Crabp1 and Stra6) and Wnt/b-Catenin signalling genes (sFrp2 and Mfrp). Our data demonstrate that a photoperiod schedule of 12 h of light/day is interpreted as a stimulatory photoperiod by the neuroendocrine system of young male F344 rats.

Despite the overwhelming evidence for atrophy of the NGF-dependant Basal Forebrain Cholinergic neurons during aging, there is no persuasive evidence towards a decrease in NGF and/or NGF mRNA content in the brain of aged animals. Previous experiments from our laboratory have shown that NGF is released as a precursor protein and cleaved into the mature form in the extracellular space under the influence of a complex protease cascade. These recent findings have lead us to propose that any alterations in levels and/or activity of this maturation/degradation cascade might affect NGF's biological activity and perhaps lead to cognitive impairments in a subset of aged rats. To investigate this possibility, we measured protein and mRNA levels of the protease cascade players (NGF, pro-NGF, tPA, plasminogen, plasmin, MMP-9, neuroserpin). We found significantly decreased levels of both pro-NGF protein and NGF mRNA, but no difference in the remaining elements of the protease cascade, when comparing aged impaired (Al) to the aged unimpaired (AU) animals. Our second objective was to investigate whether animals trained in the Morris Water Maze would preserve their cognitive status in two additional behavioral paradigms, the Novel Object Location (NOL, spatial memory) and Novel Object Recognition (NOR, nonspatial memory) tasks. We found that both AU and AI animals in the MWM were impaired in the NOL when compared to the young controls, with the AI animals performing significantly worse than the AU in this particular task. In the NOR tasks, AI animals performed significantly worse compared to both young and AU animals. In conclusion, further experiments are required to better understand the implication of the complex protease cascade involved in NGF's maturation and degradation as well as its effect on memory of aged animals. In addition, because the segregation of animals (aged impaired/unimpaired) is a crucial step in aging research, we now have additional behavioral paradigms (NOL/NOR) that confirm the cognitive status of these animals.

No description available.

Yes / In many species, seasonal changes in day length (photoperiod) have profound effects on physiology and behavior. In humans, these include cognitive function and mood. Here we investigated the effect of photoperiod and high fat diets on cognitive deficits, as measured by novel object recognition, in the photoperiod-sensitive F344 rat, which exhibits marked natural changes in growth, body weight and food intake in response to photoperiod. 32 male juvenile F344 rats were housed in either long or short photoperiod and fed either a high fat or nutrient-matched chow diet. Rats were tested in the novel object recognition test before photoperiod and diet intervention and re-tested 28 days after intervention. In both tests during the acquisition trials there was no significant difference in exploration levels of the left and right objects in the groups. Before intervention, all groups showed a significant increase in exploration of the novel object compared to the familiar object. However, following the photoperiod and diet interventions the retention trial revealed that only rats in the long photoperiod-chow group explored the novel object significantly more than the familiar object, whereas all other groups showed no significant preference. These results suggest that changing rats to short photoperiod impairs their memory regardless of diet. The cognitive performance of rats on long photoperiod-chow remained intact, whereas the high fat diet in the long photoperiod group induced a memory impairment. These findings suggest that rats exposed to long photoperiod have different cognitive responses to rats exposed to short photoperiod and high fat diet.

Estudos com células tronco mesenquimais (CTm) têm despertado grande interesse devido a seu promissor potencial terapêutico e representam uma alternativa para o tratamento de diversas patologias em diferentes órgãos, inclusive em transplante renal. A rejeição crônica é um dos maiores desafios no transplante tardio e se caracteriza por perda progressiva da função renal causado pela intensa fibrogênese no aloenxerto. Os tratamentos convencionais com imunossupressores, apesar de reduzirem significativamente as crises de rejeição aguda, não interferem na sobrevida do enxerto a longo prazo. A compreensão dos processos fisiopatológicos da doença depende de seu estudo em modelos experimentais, que são de grande importância pois também propiciam uma melhor compreensão dos possíveis tratamentos. O presente estudo teve como objetivo analisar a terapia com células-tronco mesenquimais derivadas de tecido adiposo (CTmTA) no modelo experimental de transplante renal em ratos, para estudar seu efeito na rejeição crônica e avaliar seu potencial efeito imunomodulador. O modelo foi estabelecido com ratos das linhagens isogênicas Fisher (doador) e Lewis (receptor) e os animais transplantados foram divididos em três grupos: ISO (transplante isogênico de Lewis para Lewis, n=6), ALO (transplante alogênico de Fisher para Lewis, n=6) e ALO+CTmTA (transplante alogênico, tratado com CTmTA, n=6). As CTmTA foram caracterizadas por aderência ao plástico, diferenciação nas linhagens adipogênica, condrogênicas e osteogênicas e por citometria de fluxo. Foram inoculadas 1 x 106 células na região subcapsular renal no dia da realização da nefrectomia unilateral direita (10 dias pós-transplante). Após 6 meses foram realizadas análises dos parâmetros clínicos e laboratoriais, além de análise histológica, imunohistoquímica e PCR em tempo real. As CTmTA foram eficientes em prevenir significativamente a elevação da ureia e da creatinina séricas, manter clearence de creatinina em níveis normais, e prevenir a elevação da fração de excreção de Na+ e K+. Além disso, impediram o desenvolvimento de proteinúria e da hipertensão arterial. A análise histológica mostrou uma redução significativa do infiltrado inflamatório de macrófagos e linfócitos T, além de uma diminuição da fibrose intersticial no grupo ALO+CTmTA. O tratamento com CTmTA reduziu significativamente a expressão relativa dos fatores e citocinas pró-inflamatórios tais como INF-y, TNF-alfa, IL1beta e IL-6, além de aumento importante na expressão de IL-4 e IL-10, conhecidas por seu potencial antiinflamatório. Em conclusão, o tratamento com ADMSC em um modelo experimental de transplante renal pode trazer uma nova abordagem terapêutica para controle da rejeição crônica do enxerto. A aparente modulação da resposta imune observada neste trabalho, pode estar associada a uma possível polarização de macrófagos e células T. Outros estudos pré-clínicos e clínicos são necessários para confirmar nossos resultados / Studies involving mesenchymal stem cells (MSCs) have aroused great interest due to their promising therapeutic potential representing an alternative for the treatment of several pathologies in different organs, including renal transplantation. Chronic rejection is one of the major challenges in late transplantation and is characterized by progressive loss of renal function caused by intense fibrogenesis in the allograft. Conventional immunosuppressive treatments, while significantly reducing acute rejection crises, do not interfere with long-term graft survival. Animal model of kidney transplantation can provide a better understanding of the pathophysiological processes and bring a new path to treat chronic rejection. The aim of this project was to analyze the therapy with mesenchymal stem cells derived from adipose tissue (ADMSCs) in the experimental model of kidney transplantation in rats, focus on chronic rejection and evaluate its potential immunomodulatory effect. The model was established with rats of isogenic strains Fisher (donor) and Lewis (recipient), and the transplanted animals were divided into three groups: ISO (isogenic transplantation from Lewis to Lewis, n = 6), ALO (allogenic transplant from Fisher to Lewis, n = 6) and ALO + ADMSCs (allogenic transplantation, treated with ADMSCs, n = 6). ADMSCs were characterized by adhesion to plastic, differentiation in adipogenic, condrogenic and osteogenic lines and by flow cytometry. One million of cells were inoculated under the renal capsule on the day of the right unilateral nephrectomy (10 days after transplantation). After 6 months, clinical and laboratory parameters were analyzed, as well as histological analysis, immunohistochemistry and real-time PCR. ADMSCs were effective in preventing elevation of serum urea and creatinine, elevation of the Na + and K + excretion fraction as well as maintained creatinine clearence at normal levels. Furthermore, the treatment also prevented the development of proteinuria and preserved blood pressure. Histological analysis showed a significant reduction of macrophages and T cells infiltrate, associated to a decreased of interstitial fibrosis in the ALO + ADMSCs group. In the presence of ADMSCs, there was a significant decrease in the relative expression of INF-y, TNF-alpha, IL1beta and IL-6 factors and pro-inflammatory cytokines, as well as a significant increase in the relative expression of anti-inflammatory cytokines as IL-4 and IL-10. In conclusion, treatment with ADMSC in a transplantation model could open a new approach to control chronic rejection. This apparent modulation of the immune response may be associated with a possible polarization of macrophages and T cells. Further pre-clinical and clinical studies are needed to confirm our findings

Estudos com células tronco mesenquimais (CTm) têm despertado grande interesse devido a seu promissor potencial terapêutico e representam uma alternativa para o tratamento de diversas patologias em diferentes órgãos, inclusive em transplante renal. A rejeição crônica é um dos maiores desafios no transplante tardio e se caracteriza por perda progressiva da função renal causado pela intensa fibrogênese no aloenxerto. Os tratamentos convencionais com imunossupressores, apesar de reduzirem significativamente as crises de rejeição aguda, não interferem na sobrevida do enxerto a longo prazo. A compreensão dos processos fisiopatológicos da doença depende de seu estudo em modelos experimentais, que são de grande importância pois também propiciam uma melhor compreensão dos possíveis tratamentos. O presente estudo teve como objetivo analisar a terapia com células-tronco mesenquimais derivadas de tecido adiposo (CTmTA) no modelo experimental de transplante renal em ratos, para estudar seu efeito na rejeição crônica e avaliar seu potencial efeito imunomodulador. O modelo foi estabelecido com ratos das linhagens isogênicas Fisher (doador) e Lewis (receptor) e os animais transplantados foram divididos em três grupos: ISO (transplante isogênico de Lewis para Lewis, n=6), ALO (transplante alogênico de Fisher para Lewis, n=6) e ALO+CTmTA (transplante alogênico, tratado com CTmTA, n=6). As CTmTA foram caracterizadas por aderência ao plástico, diferenciação nas linhagens adipogênica, condrogênicas e osteogênicas e por citometria de fluxo. Foram inoculadas 1 x 106 células na região subcapsular renal no dia da realização da nefrectomia unilateral direita (10 dias pós-transplante). Após 6 meses foram realizadas análises dos parâmetros clínicos e laboratoriais, além de análise histológica, imunohistoquímica e PCR em tempo real. As CTmTA foram eficientes em prevenir significativamente a elevação da ureia e da creatinina séricas, manter clearence de creatinina em níveis normais, e prevenir a elevação da fração de excreção de Na+ e K+. Além disso, impediram o desenvolvimento de proteinúria e da hipertensão arterial. A análise histológica mostrou uma redução significativa do infiltrado inflamatório de macrófagos e linfócitos T, além de uma diminuição da fibrose intersticial no grupo ALO+CTmTA. O tratamento com CTmTA reduziu significativamente a expressão relativa dos fatores e citocinas pró-inflamatórios tais como INF-y, TNF-alfa, IL1beta e IL-6, além de aumento importante na expressão de IL-4 e IL-10, conhecidas por seu potencial antiinflamatório. Em conclusão, o tratamento com ADMSC em um modelo experimental de transplante renal pode trazer uma nova abordagem terapêutica para controle da rejeição crônica do enxerto. A aparente modulação da resposta imune observada neste trabalho, pode estar associada a uma possível polarização de macrófagos e células T. Outros estudos pré-clínicos e clínicos são necessários para confirmar nossos resultados / Studies involving mesenchymal stem cells (MSCs) have aroused great interest due to their promising therapeutic potential representing an alternative for the treatment of several pathologies in different organs, including renal transplantation. Chronic rejection is one of the major challenges in late transplantation and is characterized by progressive loss of renal function caused by intense fibrogenesis in the allograft. Conventional immunosuppressive treatments, while significantly reducing acute rejection crises, do not interfere with long-term graft survival. Animal model of kidney transplantation can provide a better understanding of the pathophysiological processes and bring a new path to treat chronic rejection. The aim of this project was to analyze the therapy with mesenchymal stem cells derived from adipose tissue (ADMSCs) in the experimental model of kidney transplantation in rats, focus on chronic rejection and evaluate its potential immunomodulatory effect. The model was established with rats of isogenic strains Fisher (donor) and Lewis (recipient), and the transplanted animals were divided into three groups: ISO (isogenic transplantation from Lewis to Lewis, n = 6), ALO (allogenic transplant from Fisher to Lewis, n = 6) and ALO + ADMSCs (allogenic transplantation, treated with ADMSCs, n = 6). ADMSCs were characterized by adhesion to plastic, differentiation in adipogenic, condrogenic and osteogenic lines and by flow cytometry. One million of cells were inoculated under the renal capsule on the day of the right unilateral nephrectomy (10 days after transplantation). After 6 months, clinical and laboratory parameters were analyzed, as well as histological analysis, immunohistochemistry and real-time PCR. ADMSCs were effective in preventing elevation of serum urea and creatinine, elevation of the Na + and K + excretion fraction as well as maintained creatinine clearence at normal levels. Furthermore, the treatment also prevented the development of proteinuria and preserved blood pressure. Histological analysis showed a significant reduction of macrophages and T cells infiltrate, associated to a decreased of interstitial fibrosis in the ALO + ADMSCs group. In the presence of ADMSCs, there was a significant decrease in the relative expression of INF-y, TNF-alpha, IL1beta and IL-6 factors and pro-inflammatory cytokines, as well as a significant increase in the relative expression of anti-inflammatory cytokines as IL-4 and IL-10. In conclusion, treatment with ADMSC in a transplantation model could open a new approach to control chronic rejection. This apparent modulation of the immune response may be associated with a possible polarization of macrophages and T cells. Further pre-clinical and clinical studies are needed to confirm our findings

Dissertation (Ph.D.)--University of South Florida, 2007. / Includes vita. Includes bibliographical references (leaves 109-141). Also available online.