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Respostas de curto período das características fotossintéticas da alga vermelha Batrachospermum delicatulum a temperatura e irradiância /Kusakariba, Thiago. January 2007 (has links)
Orientador: Orlando Necchi Júnior / Banca: Ricardo Moreira Chaloub / Banca: Gustavo Habermann / Resumo: Respostas de curto período das características fotossintéticas a temperatura e irradiância foram avaliadas na rodófita Batrachospermum delicatulum em condições naturais e em laboratório. A variação diária dos parâmetros fotossintéticos por fluorescência da clorofila foi amostrada em duas épocas (junho, período frio e seco; outubro, quente e chuvoso) em um riacho da região noroeste do Estado de São Paulo (20o4324-S, 49o1821-W). Os valores de RQE e RQP (rendimento quântico efetivo e potencial, respectivamente) apresentaram correlação negativa com a irradiância nas duas épocas e valores similares no início e final do dia, indicando respectivamente alta pressão de excitação sobre o fotossistema II (FSII) e boa capacidade de recuperação e ausência de fotodano ao aparato fotossintético. Os valores de NPQ (extinção não-fotoquímica) também apresentaram correlação negativa com irradiância (significativa apenas em junho), o que possivelmente indica baixa capacidade de dissipação da energia absorvida pelos centros de reação. Sob temperatura e irradiância fixas a variação diária para fotossíntese líquida foi caracterizada por dois picos: o primeiro (maior) durante a manhã e o segundo (menor) durante a tarde. Os valores de ETR (taxa de transporte de elétrons) também apresentaram padrão semelhante, o que demonstra a ocorrência de ritmos endógenos que controlam as taxas fotossintéticas. Curvas de fotossíntese-irradiância e de indução escuro/luz foram testadas em laboratório (sob condições de baixa e alta irradiância) e em campo sob luz natural (não-sombreada) e artificialmente sombreada em duas épocas (junho e novembro). O isolado em cultura e as plantas em condições naturais (novembro) tiveram maiores valores de fotossíntese máxima (Fmax), eficiência fotossintética ( ) e rendimento quântico em baixa irradiância... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Short-term responses of photosynthetic characteristics to temperature and irradiance were analyzed in the rhodophyte Batrachospermum delicatulum under natural and laboratory conditions. The diurnal variation of photosynthetic parameters by chlorophyll fluorescence was sampled in two seasons (June, cool and dry season; October, warm and rainy season) in a stream of northwest region of São Paulo state (20o4324S, 49o1821W). Values of EQY and PQY (effective and potential quantum yield, respectively) were negatively correlated with irradiance in both seasons and had similar values at the beginning and end of the day, indicating, respectively high excitation pressure on photosystem II (PSII) and good recovery capacity and lack of photodamage to the photosynthetic apparatus. Values of NPQ (non-photochemical quenching) were also negatively correlated with irradiance (significantly only in June) possibly indicating low dissipation capacity of absorbed energy by reaction centres. The diurnal variation of net photosynthesis under fixed conditions of temperature and irradiance was characterized by two peaks the first (higher) in the morning and the second (lower) in the afternoon. ETR (electron transport rate) values also presented a similar pattern, suggesting the occurrence of endogenous rhythm that controls photosynthetic rates. Photosynthesis-irradiance and dark/light (induction) curves were tested in laboratory (under low and high irradiance conditions) and in field under natural light (unshaded) and artificially shaded in two seasons (June and November). Specimens from culture isolate and in natural conditions (November) had higher values of maximum photosynthesis (Pmax) photosynthetic efficiency ( ) and EQY at low irradiance, whereas at high irradiance (laboratory and field), values of were significantly higher than at low irradiance. A positive correlation between of ETR with NPQ... (Complete abstract click electronic access below) / Mestre
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Diurnal and subdiurnal variability in the Mars Pathfinder Presidential meteorology sessionsBennett, Scott 28 April 2003 (has links)
The Mars Pathfinder (MPF) arrived on the Martian surface on 4 July
1997 to become only the third successful landed mission to Mars, recording
surface meteorological data intermittently over a period of 83 Martian days
("sols"). The in situ observations made by the MPF meteorology (MET) experiment
were recorded at much greater precision than those of the previous
missions, Viking Landers 1 and 2. These observations have been analyzed,
focusing primarily upon the four so-called "Presidential" sessions, which each
covered a complete diurnal cycle.
The signature of very strong convective activity was seen in the temperature
data, beginning soon after sunrise with temperatures changing as much
as 14.39 K over the four-second interval between observations, and ceasing in
late afternoon at the collapse of the boundary layer. Less extreme variability
occurred at most other times of day and night.
Examination of the first ten tidal pressure harmonic amplitudes for each
Presidential session revealed strong diurnal and semidiurnal amplitudes and
smaller, yet significant, amplitudes at the higher tidal frequencies. The normalized
diurnal amplitude was slightly more than 1.7% for one session and
averaged ~2.5% for the other three sessions. The semidiurnal amplitude averaged
~1.3%. A pattern in the tidal pressure harmonic amplitudes exists, in
which odd-numbered harmonics (excluding the diurnal frequency) have smaller
amplitudes than those of the next lower and next higher, even-numbered harmonics.
Wind direction data for one Presidential session show very high variability
throughout most of the diurnal cycle, the most intense activity occurring
during the daytime convective period. A generally clockwise rotation of the
mean wind direction was observed throughout the session.
Temperature and wind data were examined closely for evidence of contamination
of the temperature data by thermal effects of the lander itself. No
evidence was found for such "lander interference" in the morning, but lander
interference may have occurred in the afternoon of the session examined.
A study of a numerical simulation by the NASA Ames Mars General
Circulation Model (MGCM) showed prominent minima and maxima, resembling
those observed by MPF, in the diurnal pressure cycles of simulated sols
corresponding to the Presidential sessions. Also well simulated in each sol is the
very rapid increase in surface pressure immediately after the daily minimum.
Maps of diurnal and semidiurnal tidal amplitudes for the simulated Presidential
sols show that tidal harmonic amplitudes are very spatially dependent, and
that large changes in the harmonic amplitudes at any given location are likely
to result if the global amplitude pattern for one or more frequencies undergoes
small shifts in areographic location.
Simulated temperature has a classic "red" power spectrum, while simulated
pressure power is concentrated in the tidal frequency range. These spectral
shapes are roughly consistent with those computed from the MPF Presidential
sessions. The ratios of simulated to observed temperature power spectral estimates
for frequencies from 1 to 50 cycles/sol show that the MGCM's simulated
temperature variability is too low at all frequencies and especially so at higher
frequencies. / Graduation date: 2003
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Evaluation of Land-Atmosphere Interactions in Models of the North American MonsoonKelly, Patrick 01 January 2008 (has links)
Improving diurnal errors in surface-based heating processes in models might be a promising step towards improved seasonal simulation of the North American Monsoon (NAM). This study isolates model errors in the surface energy budget and examines diurnal heating implications for seasonal development of the NAM 500hPa anticyclone and 850-500hPa thickness ridge using observations and multi-model output. Field data from the 2004 North American Monsoon Experiment (NAME) and satellite estimates are used to evaluate land-atmosphere interactions in regional and global models as part of the North American Monsoon Model Assessment Project 2 (NAMAP2). Several key findings about heating in the NAM emerge: ? Models exhibit considerable differences in surface radiation of the NAM, beginning with albedo (Fig. 3.1). All models have highly-biased albedo throughout summer (Fig. 3.2). ? Observed net surface radiation is around 125 Wm-2 over land in the NAM region in summer (Table 3.5). Models overestimate it by an average of about 20 Wm-2, despite their high albedo, apparently due to deficiencies in cloud radiative forcing. ? Partitioning of this net radiation into latent and sensible fluxes to the atmosphere differs substantially among models. Sensitivity of this partitioning to rainfall also varies widely among models, and appears clearly excessive in some models relative to observations (Fig. 4.10). ? Total sensible heating exceeds latent heating in the NAM (Table 4.1), since it covers a much larger area than the rainy core region (Fig. 4.11). ? Inter-model differences in sensible heating can be traced consistently from surface heat flux (Table 5.1), to PBL diurnal evolution (Fig. 5.1), to diurnal thickening of the lower troposphere (Fig. 5.2). ? Seasonal biases in the NAM?s synoptic structure correspond well to diurnal heating biases (Fig. 5.3, Fig. 5.5), suggesting that diurnal cycle studies from a single field season may suffice to inform physical process improvements that could impact seasonal simulation and forecasting. These NAMAP2 results highlight the range of uncertainty and errors in contemporary models, including those defining US national weather forecasting capability. Model experimentation will be necessary to fully interpret the lessons and harvest the fruits of this offline inter-comparison exercise.
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The Plant Transcriptome and Its Response to Envrionmental StimuliWilkins, Olivia 02 September 2010 (has links)
The relationship between an organism’s genome, developmental stage, and environment is complex. The aim of the research presented herein was to provide experimental evidence to contribute to the annotation of the P. trichocarpa genome and to test two major hypotheses addressing the interaction between drought and time of day in A. thaliana and in two hybrid Populus clones. In order to generate data to address these aims, three separate experiments were undertaken.
First, all members of the R2R3-MYB family of transcription factors in the P. trichocarpa genome were characterised by phylogenetic analysis and their transcript accumulation patterns across a range of tissues and organs were assessed using whole genome poplar microarrays. Results of this analysis indicated that expansion and diversification of the R2R3-MYB family may have contributed to phenotypic innovation in the Populus lineage.
Second, drought-responsive transcriptome adjustments of two hybrid poplar clones, DN34 (P. deltoides X P. nigra) and NM6 (P. nigra X P. maxiomowiczii) were assessed for time-of-day and genotype dependent patterns. For each genotype, each of four time points was characterised by discrete sets of drought-responsive genes. Furthermore, while a number of genes were identified that were responsive to drought in both genotypes, a much larger number of genotype-dependent, drought-responsive transcriptome changes were detected.
Finally, the drought-responsive transcriptome adjustments A. thaliana plants were assessed for time-of-day dependent accumulation patterns. Results of this analysis indicate that time-of-day-dependent differences in the drought response were manifest as changes of different magnitudes for a conserved set of genes across the four time points measured. These results emphasise the complex interplay of a plant’s genome, developmental stage, and environment in shaping the observed transcriptome.
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Monitoring and modelling diurnal and seasonal odour and gas emission profiles for swine grower/finisher roomsSun, Gang 22 March 2006
To address odour and gas problems generated by livestock facilities, air dispersion models have been used to determine reasonable science-based setback distances between the livestock operations and the neighbouring residences. However, none of the existing models consider diurnal, seasonal and climate variations of odour and gas (ammonia, hydrogen sulphide, carbon dioxide) concentrations and emission rates (OGCER), which may result in great uncertainties in setback distance calculations. Thus, the purpose of this project was to monitor and model diurnal and seasonal OGCER from swine grower/finisher rooms. Specifically, this research was conducted to: 1) characterize diurnal OGCER between two different flooring systems (fully and partially slatted floorings) under three different weather conditions (August, October and February); 2) identify seasonal OGCER over a 12-month measuring period; and 3) develop mathematical models to predict the OGCER. <p>A two-factorial strip-block experiment was designed for measuring diurnal OGCER in two grower/finisher rooms. It was found that: 1) the diurnal OGCER in the fully slatted flooring system was 27.6 to 39.5% higher than that in the partially slatted flooring system; however, no significant differences in the diurnal OGCER were found between the two rooms, except for the NH3 concentrations in August, the NH3 and H2S concentrations and emissions in October, and odour concentrations and emissions in February (P > 0.05), and 2) significant diurnal variations in the OGCER (except for the odour concentrations and H2S emissions) have been observed in August (P < 0.05); only gas emissions showed significant fluctuation patterns in October (P < 0.05); no significant variations in the OGCER (except for the CO2 concentrations and emissions) were found in February (P > 0.05). <p>A repeated measurement method was used to monitor seasonal OGCER in four grower/finisher rooms over a period of 12 months. It was found that: 1) the seasonal OGCER from the fully slatted flooring system was 2.9 to 40.6% higher than that from the partially slatted flooring system; however, the seasonal OGCER (except for the NH3 concentrations in October, November and January; the CO2 concentrations in August and the CO2 emissions in December) between the two different floors for each measuring month did not differ significantly (P > 0.05); and 2) the seasonal OGCER was significantly affected by the sampling month (P < 0.05), and no specific seasonal pattern was observed. <p> The statistical models developed for each type of the flooring system determined the OGCER based on the room and ambient temperatures, the ventilation rates and the animal units. The predicted results showed good agreement with measured values for most of OGCER (r2: 0.67-0.95). In order to improve odour and gas prediction models, animal activity and dirtiness of pens should be further investigated.
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The Behavioral Neuroendocrinology of Fish Sex Change: The Role of Steroids and MonoaminesLorenzi, Varenka 02 July 2009 (has links)
Social status influences reproductive physiology in many species, and sex change in marine teleost fishes provides an excellent model to understand how an organism can modulate its reproductive system in response to social stimuli. The series of experiments presented in this dissertation has focused on the proximate mechanisms underlying sex change and, in particular, the neuroendocrine factors that might translate social information into physiological changes. The bluebanded goby (Lythrypnus dalli) is a sexually plastic fish, and the dominant female typically changes sex when the male is removed from the social group. The direct physical interactions between the male and the females were found to be the main sensory cues that inhibit sex change. Sex steroids can both modulate and be modulated by behavior, and as a result they have been the most obvious candidates for a key role in the regulation of sex change. Males and females showed similar diurnal patterns for steroid hormones, but females had significantly higher water-borne estrogen levels. Concentrations of estradiol, testosterone and 11-ketotestosterone presented sex and tissue differences in brain, gonad and muscle, and they varied in complex ways in different tissues during sex change. The neurotransmitter serotonin (5-HT) has been suggested to be involved in the inhibition of socially regulated sex change because of its role in the modulation of both reproductive and aggressive behavior. None of the pharmacological manipulations performed in L. dalli to alter serotonergic activity was able to overcome the input from the social environment and affect sex change. Neither monoamine levels nor the area or number of 5-HT immunoreactive neurons were different between males, females and sex changers or between dominant and subordinate females. The results do not support the hypothesis of a serotonergic inhibition on sex change in L. dalli, but show that rapid changes in brain androgen levels might be implicated in inducing behavioral or morphological changes associated with sex reversal. Also, steroids respond to changes in the social environment in different ways in different tissues so local steroid synthesis should receive greater attention, and caution is required when using circulating levels to understand behavioral regulation.
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The Plant Transcriptome and Its Response to Envrionmental StimuliWilkins, Olivia 02 September 2010 (has links)
The relationship between an organism’s genome, developmental stage, and environment is complex. The aim of the research presented herein was to provide experimental evidence to contribute to the annotation of the P. trichocarpa genome and to test two major hypotheses addressing the interaction between drought and time of day in A. thaliana and in two hybrid Populus clones. In order to generate data to address these aims, three separate experiments were undertaken.
First, all members of the R2R3-MYB family of transcription factors in the P. trichocarpa genome were characterised by phylogenetic analysis and their transcript accumulation patterns across a range of tissues and organs were assessed using whole genome poplar microarrays. Results of this analysis indicated that expansion and diversification of the R2R3-MYB family may have contributed to phenotypic innovation in the Populus lineage.
Second, drought-responsive transcriptome adjustments of two hybrid poplar clones, DN34 (P. deltoides X P. nigra) and NM6 (P. nigra X P. maxiomowiczii) were assessed for time-of-day and genotype dependent patterns. For each genotype, each of four time points was characterised by discrete sets of drought-responsive genes. Furthermore, while a number of genes were identified that were responsive to drought in both genotypes, a much larger number of genotype-dependent, drought-responsive transcriptome changes were detected.
Finally, the drought-responsive transcriptome adjustments A. thaliana plants were assessed for time-of-day dependent accumulation patterns. Results of this analysis indicate that time-of-day-dependent differences in the drought response were manifest as changes of different magnitudes for a conserved set of genes across the four time points measured. These results emphasise the complex interplay of a plant’s genome, developmental stage, and environment in shaping the observed transcriptome.
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Förändringar av tårfilmens osmolaritet mellan morgon och kväll hos personer utan symptom på torra ögonCsobod, Sylvia January 2013 (has links)
Syfte: Syftet med studien var att utvärdera om det fanns någon variation av tårfilmens osmolariet, morgon och kväll hos personer utan symptom av torra ögon. Metod: Tårfilmens osmolaritet mättes på totalt 30 patienter, två gånger på en dag; morgon och kväll. Mätningarna utfördes med TearLabTM osmolarity system. Både höger och vänster öga mättes på varje patient. Samtliga deltagande ombads fylla i en symptomenkät vid namn TERTC-DEQ. Endast personer utan symptom på torra ögon tilläts delta i studien. Alltså personer med totalt 17 poäng på TERTC-DEQ. Resultat: Ingen statistisk signifikant skillnad kunde iakttas hos personernas osmolaritet mellan morgon och kväll (P > 0.05). Slutsats: I studien kunde ingen skillnad på osmolaritet i tårfilmen iakttas mellan morgon och kväll hos personer utan symptom på torra ögon. Därmed tros tårfunktionen hos dessa personer fungera korrekt. Tårfilmens osmolaritet upprätthåller rätt balans och förändras därför inte från morgon till kväll. / Aim: The aim of this study was to determine if there is an diurnal variation in tear osmolarity among healty non dry-eye subjects. Method: The osmolarity of the tearfilm was measured in a total of 30 subjects twice a day; morning and evening, using the TearLabTM osmolarity system. Measurements were performed on both right and left eye in all the subjects. All subjects were asked to fill in a symptom questionnaire named TERTC-DEQ and only those with a total score of 17 points were allowed to participate in the study. Subjects below this score had therefore no symptoms of dry eye. Results: There was no statistical significant difference between the subjects tear osmolarity comparing the morning and evening values (P>0,05). Conclusion: This study did not show any difference in the subjects tear osmolarity, comparing morning and evening measurements. None of the individuals had any symptoms of dry eye. Therefore it is believed that in subjects with no symptoms of dry eye, the tear osmolarity remains stable between morning and evening.
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Processing Techniques of Aeromagnetic Data. Case Studies from the Precambrian of MozambiqueMagaia, Luis January 2009 (has links)
During 2002-2006 geological field work were carried out in Mozambique. The purpose was to check the preliminary geological interpretations and also to resolve the problems that arose during the compilation of preliminary geological maps and collect samples for laboratory studies. In parallel, airborne geophysical data were collected in many parts of the country to support the geological interpretation and compilation of geophysical maps. In the present work the aeromagnetic data collected in 2004 and 2005 in two small areas northwest of Niassa province and another one in eastern part of Tete province is analysed using GeosoftTM. The processing of aeromagnetic data began with the removal of diurnal variations and corrections for IGRF model of the Earth in the data set. The study of the effect of height variations on recorded magnetic field, levelling and interpolation techniques were also studied. La Porte interpolation showed to be a good tool for interpolation of aeromagnetic data using measured horizontal gradient. Depth estimation techniques are also used to obtain semi-quantitative interpretation of geological bodies. It was showed that many features in the study areas are located at shallow depth (less than 500 m) and few geological features are located at depths greater than 1000 m. This interpretation could be used to draw conclusions about the geology or be incorporated into further investigations in these areas.
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Monitoring and modelling diurnal and seasonal odour and gas emission profiles for swine grower/finisher roomsSun, Gang 22 March 2006 (has links)
To address odour and gas problems generated by livestock facilities, air dispersion models have been used to determine reasonable science-based setback distances between the livestock operations and the neighbouring residences. However, none of the existing models consider diurnal, seasonal and climate variations of odour and gas (ammonia, hydrogen sulphide, carbon dioxide) concentrations and emission rates (OGCER), which may result in great uncertainties in setback distance calculations. Thus, the purpose of this project was to monitor and model diurnal and seasonal OGCER from swine grower/finisher rooms. Specifically, this research was conducted to: 1) characterize diurnal OGCER between two different flooring systems (fully and partially slatted floorings) under three different weather conditions (August, October and February); 2) identify seasonal OGCER over a 12-month measuring period; and 3) develop mathematical models to predict the OGCER. <p>A two-factorial strip-block experiment was designed for measuring diurnal OGCER in two grower/finisher rooms. It was found that: 1) the diurnal OGCER in the fully slatted flooring system was 27.6 to 39.5% higher than that in the partially slatted flooring system; however, no significant differences in the diurnal OGCER were found between the two rooms, except for the NH3 concentrations in August, the NH3 and H2S concentrations and emissions in October, and odour concentrations and emissions in February (P > 0.05), and 2) significant diurnal variations in the OGCER (except for the odour concentrations and H2S emissions) have been observed in August (P < 0.05); only gas emissions showed significant fluctuation patterns in October (P < 0.05); no significant variations in the OGCER (except for the CO2 concentrations and emissions) were found in February (P > 0.05). <p>A repeated measurement method was used to monitor seasonal OGCER in four grower/finisher rooms over a period of 12 months. It was found that: 1) the seasonal OGCER from the fully slatted flooring system was 2.9 to 40.6% higher than that from the partially slatted flooring system; however, the seasonal OGCER (except for the NH3 concentrations in October, November and January; the CO2 concentrations in August and the CO2 emissions in December) between the two different floors for each measuring month did not differ significantly (P > 0.05); and 2) the seasonal OGCER was significantly affected by the sampling month (P < 0.05), and no specific seasonal pattern was observed. <p> The statistical models developed for each type of the flooring system determined the OGCER based on the room and ambient temperatures, the ventilation rates and the animal units. The predicted results showed good agreement with measured values for most of OGCER (r2: 0.67-0.95). In order to improve odour and gas prediction models, animal activity and dirtiness of pens should be further investigated.
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