• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 36
  • 33
  • 13
  • 7
  • 5
  • 2
  • 1
  • 1
  • 1
  • Tagged with
  • 117
  • 21
  • 18
  • 13
  • 11
  • 10
  • 9
  • 9
  • 9
  • 9
  • 8
  • 8
  • 8
  • 8
  • 8
  • 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.
21

Nocturnal light and temperature influences on necrophagous, carrion-associating blow fly species (Diptera: Calliphoridae) of forensic importance in Central Texas

Kirkpatrick, Ryan Scott 15 November 2004 (has links)
It is commonly thought that blow flies are nocturnally inactive. Blowflies are often important in helping to estimate post mortem intervals (PMI) for corpses found at death scenes. If blow flies oviposit during nocturnal hours, there could possibly be up to 12-hour discrepancies for estimates of PMI. Two blow fly species, Phaenicia eximia (Wiedemann) and Cochliomyia macellaria (F.), oviposited nocturnally on ground beef baits in 2003, during the onset of low-atmospheric pressure (an air mass with lower atmospheric pressure than that of the air surrounding it) at rural study sites near Snook (Burleson County), Texas, under artificial lighting of at least 1500 footcandles when temperatures were at 26?C or higher. Trials conducted under similar conditions during the same year without a low-pressure system moving into the area resulted in no nocturnal blow fly oviposition. Nocturnal blow fly oviposition went undetected once low-atmospheric pressure systems settled into the study area, irrespective of temperature and lighting conditions. Thus, this study illustrates that there is a connection between the onset of low-atmospheric pressure and nocturnal blow fly oviposition on baits under artificial lighting of 1500 footcandles or more when temperatures are 26 ?C or above. After concluding 2003 experiments, statistical analyses supplied evidence that woodland habitat was more favorable for blow fly oviposition than prairieland habitat throughout the 2003 study, irrespective of species or time of year. Furthermore, statistical analyses conducted on nocturnal and diurnal temperature ranges furnished evidence to support the hypothesis that 2003 nocturnal temperatures had more of an effect on daily ovipositing than diurnal temperatures for P. eximia and Cynomyopsis cadaverina (Robineau-Desvoidy).
22

Efeito dos acordares na monitorização ambulatorial da pressão arterial

Lenz, Maria do Carmo Sfreddo January 2006 (has links)
Objetivo: Investigar o efeito de se distinguir a pressão arterial noturna da pressão arterial no sono pelo registro simultâneo da monitorização ambulatorial da pressão arterial e da polissonografia. Métodos: Recrutaram-se 36 pacientes, 29 homens e 7 mulheres, com suspeita de síndrome das apnéias e hipopnéias obstrutivas do sono (SAHOS), encaminhados à clínica do sono para investigação diagnóstica e que concordaram usar o monitor ambulatorial de pressão arterial (MAPA) Spacelabs 90207 ABP durante a polissonografia (PSG). A média de idade dos indivíduos era 45 ± 11 anos; o índice de massa corporal (IMC), 30,8 ± 5,4 Kg/m2; o índice de apnéias e hipopnéias, 35 ± 29 AH/h. Um microfone acoplado ao monitor ambulatorial de PA registrou os sons característicos de sua atividade em um canal da polissonografia e permitiu determinar, de modo eletrográfico, se a PA foi medida em sono (e-sono) ou vigília (e-vigília).Resultados: Os pacientes encontravam-se dormindo durante (média+DP) 61+24% (variando de 0 a 100%), das 14+1 medidas de pressão arterial durante a noite. Leituras de pressão sistólica e diastólica na MAPA foram significativamente maiores durante o evigília (121 + 12 / 73 + 9 mm Hg) que durante o total do período noturno (119 + 11 / 70 + 8 mmHg) e e-sono (116 + 13 / 68 + 9 mm Hg). Baseado nas medidas do período noturno, 22 pacientes (61%) tinham hipertensão noturna; baseado nas medidas do período de e-sono, 12 pacientes tinham hipertensão noturna (33%; qui-quadrado= 5,54; p= 0,018). Um modelo de regressão linear múltipla mostrou que a percentagem de medidas feitas durante o e-sono foi a única variável que explicou significantemente a diferença entre os valores de PA noturna e PA em e-sono, controlando para gênero, idade, IMC, IAH, e SaO2 mínima. Conclusão: Durante a MAPA as leituras de PA noturnas são mais altas que as leituras durante e-sono. / Objective: Investigate the effect of distinguishing nighttime and sleep on nocturnal blood pressure results in ambulatory blood pressure monitoring (ABPM). Methods: We recruited 36 patients, 28 male, with suspected OSAHS attending a sleep clinic for diagnostic polysomnography (PSG) and who agreed to wear a Spacelabs 90207 ABP monitor during PSG. Their mean age was 45±11 years; body mass index (BMI), 30.8±5.4 kg/m2; apnea-hypopnea index (AHI), 35±29 AH/h; 13 had history of hypertension. A microphone attached to the ABP monitor recorded its sounds in the polygraph and allowed to classify each ABPM measurement as being made in electrographically-determined wake (e-wake) or sleep state (e-sleep). Results: Patients were asleep during (mean±SD) 61±24% (range 0 to 100%) of the 14±1 nighttime BP measurements. Systolic and diastolic ABPM readings were significantly higher during e-wake (121±12 / 73±9 mm Hg) than during total nighttime (119±11/70±8 m Hg) and e-sleep (116±13 / 68±9 mm Hg). Based on nighttime measurements 22 patients (61%) had nocturnal hypertension. Based on measurements made during e-sleep, nocturnal hypertension was diagnosed in 12 patients (33%; chisquare= 5.54; p= 0.018). A multiple linear regression model showed that the percentage of measurements made in e-sleep was the only variable that significantly explained the difference between nighttime and e-sleep BP figures, when controlling for gender, age, BMI, AHI, and lowest SaO2. Conclusion: During ABPM, nighttime BP readings are higher than during e-sleep and this changes dipping and nocturnal hypertension classification.
23

Efeito dos acordares na monitorização ambulatorial da pressão arterial

Lenz, Maria do Carmo Sfreddo January 2006 (has links)
Objetivo: Investigar o efeito de se distinguir a pressão arterial noturna da pressão arterial no sono pelo registro simultâneo da monitorização ambulatorial da pressão arterial e da polissonografia. Métodos: Recrutaram-se 36 pacientes, 29 homens e 7 mulheres, com suspeita de síndrome das apnéias e hipopnéias obstrutivas do sono (SAHOS), encaminhados à clínica do sono para investigação diagnóstica e que concordaram usar o monitor ambulatorial de pressão arterial (MAPA) Spacelabs 90207 ABP durante a polissonografia (PSG). A média de idade dos indivíduos era 45 ± 11 anos; o índice de massa corporal (IMC), 30,8 ± 5,4 Kg/m2; o índice de apnéias e hipopnéias, 35 ± 29 AH/h. Um microfone acoplado ao monitor ambulatorial de PA registrou os sons característicos de sua atividade em um canal da polissonografia e permitiu determinar, de modo eletrográfico, se a PA foi medida em sono (e-sono) ou vigília (e-vigília).Resultados: Os pacientes encontravam-se dormindo durante (média+DP) 61+24% (variando de 0 a 100%), das 14+1 medidas de pressão arterial durante a noite. Leituras de pressão sistólica e diastólica na MAPA foram significativamente maiores durante o evigília (121 + 12 / 73 + 9 mm Hg) que durante o total do período noturno (119 + 11 / 70 + 8 mmHg) e e-sono (116 + 13 / 68 + 9 mm Hg). Baseado nas medidas do período noturno, 22 pacientes (61%) tinham hipertensão noturna; baseado nas medidas do período de e-sono, 12 pacientes tinham hipertensão noturna (33%; qui-quadrado= 5,54; p= 0,018). Um modelo de regressão linear múltipla mostrou que a percentagem de medidas feitas durante o e-sono foi a única variável que explicou significantemente a diferença entre os valores de PA noturna e PA em e-sono, controlando para gênero, idade, IMC, IAH, e SaO2 mínima. Conclusão: Durante a MAPA as leituras de PA noturnas são mais altas que as leituras durante e-sono. / Objective: Investigate the effect of distinguishing nighttime and sleep on nocturnal blood pressure results in ambulatory blood pressure monitoring (ABPM). Methods: We recruited 36 patients, 28 male, with suspected OSAHS attending a sleep clinic for diagnostic polysomnography (PSG) and who agreed to wear a Spacelabs 90207 ABP monitor during PSG. Their mean age was 45±11 years; body mass index (BMI), 30.8±5.4 kg/m2; apnea-hypopnea index (AHI), 35±29 AH/h; 13 had history of hypertension. A microphone attached to the ABP monitor recorded its sounds in the polygraph and allowed to classify each ABPM measurement as being made in electrographically-determined wake (e-wake) or sleep state (e-sleep). Results: Patients were asleep during (mean±SD) 61±24% (range 0 to 100%) of the 14±1 nighttime BP measurements. Systolic and diastolic ABPM readings were significantly higher during e-wake (121±12 / 73±9 mm Hg) than during total nighttime (119±11/70±8 m Hg) and e-sleep (116±13 / 68±9 mm Hg). Based on nighttime measurements 22 patients (61%) had nocturnal hypertension. Based on measurements made during e-sleep, nocturnal hypertension was diagnosed in 12 patients (33%; chisquare= 5.54; p= 0.018). A multiple linear regression model showed that the percentage of measurements made in e-sleep was the only variable that significantly explained the difference between nighttime and e-sleep BP figures, when controlling for gender, age, BMI, AHI, and lowest SaO2. Conclusion: During ABPM, nighttime BP readings are higher than during e-sleep and this changes dipping and nocturnal hypertension classification.
24

Abelhas crepusculares/ noturnas: adaptações morfológicas e interações com plantas / Crepuscular bees: morphological adaptations and interactions with plants

Carolina de Almeida Caetano 13 June 2016 (has links)
As abelhas utilizam sinais visuais e olfatórios para encontrar plantas das quais utilizam recursos florais. Algumas abelhas adquiriram hábitos crepuscular ou noturno e forrageiam durante períodos de pouca luminosidade. Algumas espécies de abelhas noturnas são conhecidas por possuírem adaptações morfológicas do sistema visual que lhes permitem o voo noturno, e assim facilitam o encontro de plantas que podem ser utilizadas como recursos. No presente estudo investigamos se espécies crepusculares Megalopta sodalis, Megommation insigne e Ptiloglossa latecalcarata, que utilizam Campomanesia phaea como recurso, e possuem adaptações na morfologia externa do sistema visual. A hipótese principal é que seriam encontrados olhos compostos, omatídeos e ocelos maiores, assim como menor quantidade de omatídeos nos olhos compostos quando comparadas às abelhas diurnas. Para tanto, medimos o comprimento, área e número de omatídeos dos olhos compostos, assim como o diâmetro dos omatídeos e ocelos. A distância intertegular foi medida para ter um controle do tamanho corporal. Além das abelhas crepusculares acima citadas, utilizamos as abelhas diurnas Bombus brasiliensis, Bombus morio, Melipona bicolor e Euglossa cordata para comparação. Para a medida dos olhos fizemos um molde de esmalte e a partir deste obtivemos imagens que foram analisadas utilizando-se o software ImageJ e Matlab. Para as outras medidas, foram obtidas imagens em estereomicroscopio que foram analizadas com o ImageJ. Utilizamos a análise estatística de permutação para ver se havia diferença entre as abelhas crepusculares e diurnas, e correlação de Spearman para ver se a medida estava correlacionada à distância intertegular. Foi realizado um levantamento das espécies com registro de interação com abelhas crepusculares e noturnas e de suas características florais com uma respectiva análise descritiva. As abelhas crepusculares deste estudo possuem o diâmetro dos ocelos e omatídeos maiores e olhos compostos com maior comprimento e área, e menor número de omatídeos. Algumas variáveis estão correlacionadas com a distância intertegular. As flores visitadas por abelhas noturnas possuem em sua maioria cores claras, perfume acentuado e são odoríferas. As abelhas crepusculares deste estudo possuem adaptações na morfologia externa, o que lhes permite o voo no período de pouca luminosidade. Algumas espécies de abelhas que forrageiam em período de pouca luminosidade visitaram flores de cores fortes e uma não odorífera, isso pode estar relacionado à capacidade de reconhecer cores em ambientes pouco iluminados. Algumas espécies de abelhas forrageiam durante o dia e a noite, essa plasticidade do comportamento pode ser um caminho pelo qual caracteres vantajosos para esse ambiente sejam selecionados. Para as plantas, ter as abelhas noturnas como polinizadoras pode ser vantojoso. Então plantas que possuem sinais reconhecidos pelas abelhas noturnas podem se beneficiar com a polinização noturna, evitando o disperdício de pólen com as abelhas diurnas. A maioria das abelhas foi generalista na utlilização do recurso, mas parece haver preferência por certas espécies de plantas / The bees use visual cues and olfactory to find plants which own floral resources. Some bees acquired crepuscular or nocturnal habits and foraging during periods of low light. Some nocturnal bees species are recognized to possess morphological adaptations of the visual system that enable them to practice the night flight, and thus facilitate the matching of plants that can be used as resources. In the present study we investigated whether crepuscular species Megalopta sodalis, Megommation insigne e Ptiloglossa latecalcarata, using Campomanesia phaea as a resource, have adaptations in the external morphology of the visual system. The main hypothesis was that the eyes were composed of ommatidia and larger ocelli as well as lower amount of ommatidia in the compound eyes when compared to daytime bees. Therefore, we measure the length, the area and number of ommatidia of the compound eye and also the diameter of the ommatidia, ocelli, and intertegular distance to have a control of body size. In addition to the crepuscular bees mentioned above, we used the diurnal bees Bombus brasiliensis, Bombus morio, Euglossa cordata, and Melipona bicolor for comparison. For the measurement of eyes, we made a nail polish mold and from this mold was obtained images which were analyzed using ImageJ and Matlab software. For other measures, we obtained images in stereomicroscope that were analyzed only using ImageJ. We use the statistical analysis of permutation to observe if there was any difference between the crepuscular and diurnal bees, and Spearman correlation to see if the measure was correlated with distance intertegular. In addition, we conducted a survey of species interaction with record crepuscular and nocturnal bees and their floral characteristics with a descriptive analisys. The crepuscular bees in this research have lager diameter of omatidea and ocelli, and larger area and length of compound eyes, and less number of omatidea per eye. Most of the flowers visited by nocturnal bees have pale color, scent and nocturnal anthesis. Some bee species that forage in low light visit flowers with strong color, and one bee visited flower without scent, this can be related with capacibility to recoginized colors in environments with low light. Some bees forage during day and night, this phenotypic plasticity of behavior can be a way that advantageous characters for this environment are selected. For plants can be advantageous. Then plants that posses sinals recognized by nocturnal and crepuscular bees can be benefited through nocturnal pollination, avoiding daylight bees waste their polen. The most of bees were generalists in their utilization of flower resource but seems to have preference for some plant species
25

Efeito dos acordares na monitorização ambulatorial da pressão arterial

Lenz, Maria do Carmo Sfreddo January 2006 (has links)
Objetivo: Investigar o efeito de se distinguir a pressão arterial noturna da pressão arterial no sono pelo registro simultâneo da monitorização ambulatorial da pressão arterial e da polissonografia. Métodos: Recrutaram-se 36 pacientes, 29 homens e 7 mulheres, com suspeita de síndrome das apnéias e hipopnéias obstrutivas do sono (SAHOS), encaminhados à clínica do sono para investigação diagnóstica e que concordaram usar o monitor ambulatorial de pressão arterial (MAPA) Spacelabs 90207 ABP durante a polissonografia (PSG). A média de idade dos indivíduos era 45 ± 11 anos; o índice de massa corporal (IMC), 30,8 ± 5,4 Kg/m2; o índice de apnéias e hipopnéias, 35 ± 29 AH/h. Um microfone acoplado ao monitor ambulatorial de PA registrou os sons característicos de sua atividade em um canal da polissonografia e permitiu determinar, de modo eletrográfico, se a PA foi medida em sono (e-sono) ou vigília (e-vigília).Resultados: Os pacientes encontravam-se dormindo durante (média+DP) 61+24% (variando de 0 a 100%), das 14+1 medidas de pressão arterial durante a noite. Leituras de pressão sistólica e diastólica na MAPA foram significativamente maiores durante o evigília (121 + 12 / 73 + 9 mm Hg) que durante o total do período noturno (119 + 11 / 70 + 8 mmHg) e e-sono (116 + 13 / 68 + 9 mm Hg). Baseado nas medidas do período noturno, 22 pacientes (61%) tinham hipertensão noturna; baseado nas medidas do período de e-sono, 12 pacientes tinham hipertensão noturna (33%; qui-quadrado= 5,54; p= 0,018). Um modelo de regressão linear múltipla mostrou que a percentagem de medidas feitas durante o e-sono foi a única variável que explicou significantemente a diferença entre os valores de PA noturna e PA em e-sono, controlando para gênero, idade, IMC, IAH, e SaO2 mínima. Conclusão: Durante a MAPA as leituras de PA noturnas são mais altas que as leituras durante e-sono. / Objective: Investigate the effect of distinguishing nighttime and sleep on nocturnal blood pressure results in ambulatory blood pressure monitoring (ABPM). Methods: We recruited 36 patients, 28 male, with suspected OSAHS attending a sleep clinic for diagnostic polysomnography (PSG) and who agreed to wear a Spacelabs 90207 ABP monitor during PSG. Their mean age was 45±11 years; body mass index (BMI), 30.8±5.4 kg/m2; apnea-hypopnea index (AHI), 35±29 AH/h; 13 had history of hypertension. A microphone attached to the ABP monitor recorded its sounds in the polygraph and allowed to classify each ABPM measurement as being made in electrographically-determined wake (e-wake) or sleep state (e-sleep). Results: Patients were asleep during (mean±SD) 61±24% (range 0 to 100%) of the 14±1 nighttime BP measurements. Systolic and diastolic ABPM readings were significantly higher during e-wake (121±12 / 73±9 mm Hg) than during total nighttime (119±11/70±8 m Hg) and e-sleep (116±13 / 68±9 mm Hg). Based on nighttime measurements 22 patients (61%) had nocturnal hypertension. Based on measurements made during e-sleep, nocturnal hypertension was diagnosed in 12 patients (33%; chisquare= 5.54; p= 0.018). A multiple linear regression model showed that the percentage of measurements made in e-sleep was the only variable that significantly explained the difference between nighttime and e-sleep BP figures, when controlling for gender, age, BMI, AHI, and lowest SaO2. Conclusion: During ABPM, nighttime BP readings are higher than during e-sleep and this changes dipping and nocturnal hypertension classification.
26

Analysis of Nocturnal op. 70 by Benjamin Britten

Frackenpohl, David J. (David John) 12 1900 (has links)
Nocturnal op. 70 is one of the most important large-scale works written for guitar in the twentieth century. Brief biographical data and some background information on Nocturnal show how it exemplifies Britten's compositional approach. The focus of the analysis is on three structural aspects: the rhythmic, the intervallic, and the aspect of underlying pitch patterns. The rhythmic analysis discusses the distortion of rhythmic patterns by the use of compression, expansion, elisions, syncopation, and rhythmic dissonance. The pitch set analysis discusses the intervallic character of the work, identifying and correlating set types as they form networks of relationship. The reductive analysis discusses the underlying connections of focal pitches in the linear material of Nocturnal. The conclusion then correlates the results of the preceding analyses, discussing the large-scale unfolding of the form in Nocturnal.
27

Night and day: distinct retinohypothalamic innervation patterns predict the development of nocturnality and diurnality in two murid rodent species

Todd, William David 01 May 2012 (has links)
How does the brain develop differently to support nocturnality in some mammals, but diurnality in others? To answer this question, one might look to the suprachiasmatic nucleus (SCN), the pacemaker of the mammalian brain, which is required for all circadian biological and behavioral rhythms. Light arriving at the retina entrains the SCN to the daily light-dark cycle via the retinohypothalamic tract (RHT). However, in all mammals studied thus far, whether nocturnal or diurnal, the SCN exhibits a rhythm of increased activity during the day and decreased activity at night. Therefore, structures downstream of the SCN are likely to determine whether a species is nocturnal or diurnal. From an evolutionary perspective, nocturnality appears to be the primitive condition in mammals, with diurnality having reemerged independently in some lineages. However, it is unclear what mechanisms underlie the development of one or the other circadian phase preference. In adult Norway rats (Rattus norvegicus), which are nocturnal, the RHT also projects to the ventral subparaventricular zone (vSPVZ), an adjacent region that expresses an in-phase pattern of SCN-vSPVZ neuronal activity (in other words, activity in the SCN and vSPVZ increase and decrease together). In contrast, in adult Nile grass rats (Arvicanthis niloticus), a diurnal species that is closely related to Norway rats, an anti-phase pattern of SCN-vSPVZ neuronal activity is expressed (in other words, activity in the SCN increases as activity in the vSPVZ decreases, and vice versa). We hypothesized that these species differences in activity pattern result in part from a weak or absent RHT-to-vSPVZ projection in grass rats. Using a developmental comparative approach, we assessed differences in behavior, hypothalamic activity, and RHT and SCN connectivity to the vSPVZ between these two species. We report that a robust retina-to-vSPVZ projection develops in Norway rats around the end of the second postnatal week when nocturnal wakefulness and the in-phase pattern of SCN-vSPVZ activity emerge. In grass rats, however, such a projection does not develop and the emergence of the anti-phase SCN-vSPVZ activity pattern during the second postnatal week is accompanied by increased diurnal wakefulness. When considered within the context of previously published reports on RHT projections in a variety of other nocturnal and diurnal species, our current findings suggest that how and when the retina connects to the hypothalamus differentially shapes brain and behavior to produce animals that occupy opposing temporal niches.
28

Linking dynamics of the near-surface flow to deeper boundary layer forcing in the nocturnal boundary layer

Smoot, Alexander R. 01 June 2012 (has links)
Weak-wind flow in the nocturnal boundary is one of the most poorly understood problems in the field of meteorology. The understanding of weak-wind flows is essential for the improvement of regulatory dispersion models which are currently rendered invalid under weak-wind conditions and stable stratification. Recently there have been increased efforts directed towards improving the understanding nocturnal boundary layer dynamics. The results of these studies have shown that nocturnal boundary layer flows are often dominated by intermittent turbulence and motions occurring on horizontal scales ranging from hundreds of meters to several kilometers and on time scales of 1 minute to 1 hour. We refer to these scales as sub-meso. This connection has led to the hypothesis that intermittent turbulence generation may be the result of sub-meso motions that are subject to external forcing originating in the deeper boundary layer. However, these processes have proven difficult to measure as traditional sensor networks have failed to provide the vertical and horizontal coverage necessary to observe the driving forces on these scales. This study sought to close this knowledge gap using SOund Detection And Ranging (SODAR). SODAR is a ground based acoustic remote sensing technology that is capable of measuring wind and turbulence at multiple heights in the boundary layer. Data were collected with a pair of SODAR systems with sequentially increasing separation distance at the Oregon State University Botany and Plant Pathology lab during the summer of 2010. The data have indicated that motion occurring on time scales of 2 minutes to 32 minutes are isolated to the lowest 50 meters of the nocturnal boundary layer. Surface-layer measurements were collected using a pair of sonic anemometers placed at heights of 1.5 and 7 meters above ground level. Comparisons of surface-layer measurements and deeper boundary layer measurements have shown that when the surface layer stratification is stable, processes within the surface layer are not likely to be influenced by external forcing from aloft. In contrast external forcing from the deeper boundary layer may still have an influence on weak, nocturnal surface flows when the surface layer is weakly stratified as is shown for the case of low-level jets. / Graduation date: 2013
29

Effects of removal on movements within populations of nocturnal desert rodents

Courtney, Mark William, 1949- January 1971 (has links)
No description available.
30

NOCTURNALISM IN THREE SPECIES OF DESERT RODENTS

Justice, Keith Evans, 1930- January 1960 (has links)
No description available.

Page generated in 0.0451 seconds