The Contribution of the Pineal Gland on Daily Rhythms and Masking in Diurnal Grass Rats, Arvicanthis niloticus

Melatonin is a hormone rhythmically secreted at night by the pineal gland in vertebrates. In diurnal mammals, melatonin is present during the inactive phase of the rest/activity cycle, and in primates it directly facilitates sleep and decreases body temperature. However, the role of the pineal gland for the promotion of sleep at night has not yet been studied in non-primate diurnal mammalian species. Here, the authors directly examined the hypothesis that the pineal gland contributes to diurnality in Nile grass rats by decreasing activity and increasing sleep at night, and that this could occur via effects on circadian mechanisms or masking, or both. Removing the pineal gland had no effect on the hourly distribution of activity across a 12:12 light-dark (LD) cycle or on the patterns of sleep-like behavior at night. Masking effects of light at night on activity were also not significantly different in pinealectomized and control grass rats, as 1h pulses of light stimulated increases in activity of sham and pinealectomized animals to a similar extent. In addition, the circadian regulation of activity was unaffected by the surgical condition of the animals. Our results suggest that the pineal gland does not contribute to diurnality in the grass rat, thus highlighting the complexity of temporal niche transitions. The current data raise interesting questions about how and why genetic and neural mechanisms linking melatonin to sleep regulatory systems might vary among mammals that reached a diurnal niche via parallel and independent pathways

Economic analysis of usable potential solar energy in field of residential services

Tato práce se zabývá potenciálem solární energie v oblasti bytových služeb. První část práce je věnována významu energií pro civilizaci, přičemž jsou zdroje energie rozděleny na obnovitelné a neobnovitelné. Dále je práce zaměřena na solární energii a její možné využití v oblasti bytových služeb. Druhá část práce popisuje postup výpočtu potřeby tepla pro objekty k bydlení, faktory ovlivňující ekonomiku solárních fototermických systémů a jejich ekonomickou analýzu. Práce obsahuje vyčíslení předpokládané doby návratnosti realizovaných solárních termických systémů, možné pokrytí potřeby tepla a roční úspory.This work deals with the potential of solar energy in housing services. The first part of the work is devoted to the importance of energy for civilization, while energy sources are divided into renewable and non-renewable. Furthermore, the work is focused on solar energy and its possible use in apartment services. The second part describes the procedure of calculating the heat demand for residential buildings, factors affecting the economics of solar photothermal systems, and their economic analysis. The work contains a quantification of the expected payback period of implemented solar thermal systems, possible coverage of heat demand, and annual savingsFakulta ekonomicko-správníStudent přednesl téma své DP ''Analýza ekonomicky využitelného potenciálu solární energie v oblasti poskytování'', otázka vedoucího práce: 1. Jak hodnotíte vypočítaný výsledek potenciální úspory energie pro bytové domy z hlediska celkového dosažitelného objemu potenciálně uspořitelné energie? Otázky a náměty z rozpravy: Jak jste určoval parametr ''r'' v modelu? Kdo financoval tyto projekty? Snižuje se výkon těchto kolektorů v čase? Započítal jste do modelu provozní náklady a náklady na likvidaci? Student otázky zodpověděl.Dokončená práce s úspěšnou obhajobo

Mortgage and consumer credits providing in the Czech Republic

Tato práce se zabývá legislativními změnami v poskytování spotřebitelských a hypotečních úvěrů v České republice, které nabyly platnosti 1.12.2016 přijetím zákona č. 257/2016 Sb. Budou zhodnoceny změny podmínek pro žadatele o úvěry a poskytovatele úvěrů. Následně budou zkoumány dopady na finanční sektor zejména na počty nebankovních poskytovatelů či vývoj objemů poskytnutých spotřebitelských úvěrů v bankovní a nebankovní sféře.This thesis deals with legislative changes in a provision of consumer and mortgage loans in the Czech Republic. These changes came into force on December 1st, 2016 by accepting a novel No. 257/2016 Coll. Changes in conditions for loan applicants and lenders will be assessed. Furthermore, impacts on a financial sector will be examined, especially a number of non-banking providers and a development of a volu me of provided consumer loans in a banking and non-banking sectors.Fakulta ekonomicko-správníPrvní část obhajoby byla věnována prezentaci studenta, který představil svou bakalářskou práci na téma Poskytování hypotečních a spotřebitelských úvěrů v České republice.Cílem práce bylo zhodnotit dopad novely o spotřebitelských úvěrech č. 257/2016 na poskytování hypotečních a spotřebitelských úvěrů v České republice. Následně student reagoval na otázka vedoucí práce z posudku: Jaký dopad má zpřísnění podmínek pro poskytování hypotečních a spotřebitelských úvěrů na obchodní banky a na domácnosti Českou národní bankou, např. LTV, DTI či DTSI

Sex differences in circadian rhythms: Effects of gonadal hormones in <italic>Octodon degus</italic>.

Sex differences have been identified in a variety of circadian rhythms, including free-running rhythms, light-induced phase shifts, sleep patterns, hormonal fluctuations, and rates of reentrainment. In the precocious, diurnal rodent, Octodon degus, sex differences have been found in length of free-running rhythm (tau), phase response curves, rates of reentrainment, and in the use of social cues to facilitate reentrainment. This thesis examines the effects of gonadal hormones on a number of sex differences in juvenile and adult degus. The author concludes that adult gonadal steroids are not responsible for the sex differences in endogenous circadian mechanisms of O. degus (tau, PRC), although they influence activity level and phase angle of entrainment. This is most likely due to masking properties of testosterone, similar to the activity-increasing effects of estrogen during estrus in O. degus females. Interestingly, juvenile and pubertal degus do not exhibit a sex difference in tau. Chapter 7 concludes that adult sex differences in period length are the result of organizational effects of testicular hormones between 6 and 12 months of age. It was previously reported that Octodon degus display a robust sex difference in the ability to use social cues to facilitate reentrainment following a phase advance of the light cycle. Adult females housed with a female social cue donor reentrained 25--40% faster than females reentraining alone. However, reentrainment rates of males were unaffected by exposure to female social cues during reentrainment. Through several experiments, it is reported that adult gonadal hormones are responsible for the observed sex differences in rate-accelerating responsiveness. Testosterone suppresses responsiveness in both males and females, whereas ovariectomized (OVX) females become unresponsive to the accelerating effects of olfactory social cues and a combination of estrogen and progesterone reinstates responsiveness in OVX females. In addition, the sex difference observed in adults is not evident in juveniles; both males and females respond to a single olfactory cue donor with accelerated reentrainment after a 6-hour phase-advance of the Light:Dark cycle. Furthermore, the only effective olfactory cues capable of accelerating degu reentrainment after a phase advance of the LD cycle are from conspecifics.Ph.D.Physiological psychologyPsychologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/123204/2/3068893.pd

Incorporating Monte Carlo Analysis into Techno-Economic Assessment of Corn Stover to Ethanol

Presentation at the 2003 AIChE Annual Meeting, 20 November 2003, San Francisco, California

Thermochemical ethanol via indirect gasification and mixed alcohol synthesis of lignocellulosic biomass

This process design and technoeconomic evaluation addresses the conversion of biomass to ethanol via thermochemical pathways that are expected to be demonstrated at the pilot level by 2012

Pubertal Development of Sex Differences in Circadian Function: An Animal Model

The development of adult circadian function, particularly sexual dimorphism of function, has been well studied only in rapidly developed rodents. In such species development is complete by weaning. Data from adolescent humans suggest that significant development occurs during the pubertal period. We hypothesized that a more slowly developing rodent might better mimic the changes in circadian function around puberty in humans and allow us to determine the underlying neural changes. Entrained and free-running circadian rhythms were analyzed and correlated with pubertal development in male and female Octodon degus (degu) that remained gonadally intact or were gonadectomized at weaning. Brains were collected during development to measure androgen and estrogen receptors in the suprachiasmatic nuclei (SCN) Adult circadian period does not develop until 10-12 months of age in degus, long after the onset of gonadal maturation (3-5 months). The timing of circadian period maturation correlates with the appearance of steroid receptors in the SCN. Changes in free-running rhythms only occurred in gonadally intact degus. Adult phase angles of activity onset develop between 2 and 3 months of age (comparing results of two experiments), soon after the onset of pubertal changes. Conclusion: The development of sexually dimorphic adult circadian period occurs after gonadal puberty is complete and requires the presence of gonadal steroids. The delay in development until after gonadal puberty is likely due to the delayed appearance of steroid receptors in the SCN. Phase is not sexually dimorphic and changes in the absence of steroid hormones.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73107/1/annals.1308.031.pd

Daytime Naps in Night-Migrating Birds: Behavioural Adaptation to Seasonal Sleep Deprivation in the Swainson\u27s Thrush, \u3ci\u3eCatharus ustulatus\u3c/i\u3e

Many typically diurnal songbird species are routinely subjected to severe sleep deprivation during their seasonal, nocturnal migrations, yet they seem to suffer few of the negative consequences so obvious in sleep-deprived mammals. Studying the Swainson\u27s thrush, a Nearctic-Neotropical long-distance migrant, we investigated seasonal changes in behaviour as possible adaptations to naturally occurring sleep loss during the migratory season. We found that captive Swainson\u27s thrushes substantially change their daytime behaviour in response to significant loss of night-time sleep during migration, engaging in numerous episodes of daytime sleep, unilateral eye closure and drowsiness. Our observations suggest that brief episodes of sleep and sleep-like behaviour during the day, including lateralized naps in the form of unihemispheric sleep, enable migratory birds to compensate for extended periods of nocturnal sleep loss. Although episodes of daytime sleep and unilateral eye closure rarely exceed 30 s, these brief episodes, considering the short sleep cycle of birds, appear sufficiently long to provide recuperative opportunities without stretching a migrant\u27s time budget. Importantly, the temporal structure of the daytime rest and sleep behaviour would not preclude migrants from foraging and replenishing fat deposits during a large portion of the day. (c) 2006 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved