Re-Patterning Sleep Architecture in Drosophila through Gustatory Perception and Nutritional Quality

Organisms perceive changes in their dietary environment and enact a suite of behavioral and metabolic adaptations that can impact motivational behavior, disease resistance, and longevity. However, the precise nature and mechanism of these dietary responses is not known. We have uncovered a novel link between dietary factors and sleep behavior in Drosophila melanogaster. Dietary sugar rapidly altered sleep behavior by modulating the number of sleep episodes during both the light and dark phase of the circadian period, independent of an intact circadian rhythm and without affecting total sleep, latency to sleep, or waking activity. The effect of sugar on sleep episode number was consistent with a change in arousal threshold for waking. Dietary protein had no significant effect on sleep or wakefulness. Gustatory perception of sugar was necessary and sufficient to increase the number of sleep episodes, and this effect was blocked by activation of bitter-sensing neurons. Further addition of sugar to the diet blocked the effects of sweet gustatory perception through a gustatory-independent mechanism. However, gustatory perception was not required for diet-induced fat accumulation, indicating that sleep and energy storage are mechanistically separable. We propose a two-component model where gustatory and metabolic cues interact to regulate sleep architecture in response to the quantity of sugar available from dietary sources. Reduced arousal threshold in response to low dietary availability may have evolved to provide increased responsiveness to cues associated with alternative nutrient-dense feeding sites. These results provide evidence that gustatory perception can alter arousal thresholds for sleep behavior in response to dietary cues and provide a mechanism by which organisms tune their behavior and physiology to environmental cues

Second Order Perturbations in the Randall-Sundrum Infinite Brane-World Model

We discuss the non-linear gravitational interactions in the Randall-Sundrum single brane model. If we naively write down the 4-dimensional effective action integrating over the fifth dimension with the aid of the decomposition with respect to eigen modes of 4-dimensional d'Alembertian, the Kaluza-Klein mode coupling seems to be ill-defined. We carefully analyze second order perturbations of the gravitational field induced on the 3-brane under the assumption of the static and axial-symmetric 5-dimensional metric. It is shown that there remains no pathological feature in the Kaluza-Klein mode coupling after the summation over all different mass modes. Furthermore, the leading Kaluza-Klein corrections are shown to be sufficiently suppressed in comparison with the leading order term which is obtained by the zero mode truncation. We confirm that the 4-dimensional Einstein gravity is approximately recovered on the 3-brane up to second order perturbations.Comment: 15 pages, 2 figures, comment and reference added, typos correcte

Can Sustainable Withdrawal Rates be Enhanced by Trend Following?

We examine the consequences of alternative popular investment strategies for the decumulation of funds invested for retirement through a defined contribution pension scheme. We examine in detail the viability of specific ‘safe’ withdrawal rates including the ‘4%-rule’ of Bengen (1994). We find two powerful conclusions. First that smoothing the returns on individual assets by simple trend following techniques is a potent tool to enhance withdrawal rates. Second, we show that while diversification across asset classes does lead to higher withdrawal rates than simple equity/bond portfolios, “smoothing” returns in itself is far more powerful a tool for raising withdrawal rates. In fact, smoothing the popular equity/bond portfolios (such as the 60/40 portfolio) is in itself an excellent and simple solution to constructing a retirement portfolio. Alternatively, trend following enables portfolios to contain more risky assets, and the greater upside they offer, for the same level of overall risk compared to standard portfolios

Developing country applications of molecular farming: case studies in South Africa and Argentina.

Molecular farming is a technology that is very well suited to being applied in developing countries, given the reasonably high level of expertise in recombinant plant development in many centers. In addition, there is an urgent need for products such as inexpensive vaccines and therapeutics for livestock and for some human diseases – and especially those that do not occur or are rare in developed regions. South Africa and Argentina have been at the fore in this area among developing nations, as researchers have been able to use plants to produce experimental therapeutics such as nanoantibodies against rotavirus and vaccines against a wide variety of diseases, including Rabbit haemorrhagic disease virus, Foot and mouth disease virus, Bovine viral diarrhoea virus, bovine rotaviruses, Newcastle disease virus, rabbit and human papillomaviruses, Bluetongue virus, and Beak and feather disease virus of psittacines. A combination of fortuitous scientific expertise in both places, coupled with association with veterinary and human disease research centers, has enabled the growth of research groups that have managed to compete successfully with others in Europe and the USA and elsewhere, to advance this field. This review will cover relevant work from both South Africa and Argentina, as well as a discussion about the perspectives in this field for developing nations.Fil: Rybicki, Edward P.. University of Cape Town; Estados UnidosFil: Hitzeroth, Inga I.. University of Cape Town; Estados UnidosFil: Meyers, Ann. University of Cape Town; Estados UnidosFil: Dus Santos, María José. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Wigdorovitz, Andrés. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Influence of peculiarities and trends of Russian socio-dynamics on economy

Специфика и тренды экономики РФ определяются в зависимости от социальных процессов, характерных для России как страны многоукладной. Социальная динамика рассматривается необходимым условием развития страны, кардинально влияя на управление. Система факторов социально-экономического роста России разворачивается с применением аппарата теории динамических информационных систем (ТДИС). Такая система позволяет учитывать взаимные влияния внутренних и внешних социальных и экономических изменений, и она доступна дальнейшим детализациям и преобразованиям. Тема модернизации и инновационной стратегии РФ связывается с перспективами развития поселений, миграционными потоками.Peculiarities and trends of the Russian economy are defined in connection with social processes characteristic for Russia as a heterogeneous culture. Socio-dynamics is seen as a prerequisite for the development of the country exercising great influence on its management. The system of factors of socio-economic growth of Russia is developed by means of the theory of dynamic information systems. Such system makes it possible to consider interaction of internal and external social and economic changes and is subject to further expansion and modifications. The issue of modernization and innovational strategies of the Russian Federation is connected with the prospects of development of settlements and migration flows

Accurate detection of Bovine Leukemia Virus using recombinant p24-ELISA and PCR

ACCURATE DETECTION OF BOVINE LEUKEMIA VIRUS USING RECOMBINANT P24-ELISA AND PCR Gutierrez, Geronimo; Dus Santos, Maria Jose; Alvarez, Irene; Lomonaco, Marina; Politzki, Romina; Rodríguez, Sabrina; Trono, Karina Introduction: Diagnosis of Bovine leukemia virus (BLV) infection is currently carried out by agar gel immunodiffusion (AGID) and ELISA (1). Even when both tests are approved by the OIE for trade purposes, several factors can contribute to yield conflicting results that need to be confirmed. In this work, ELISA and PCR were used as complementary tools to confirm the real sanitary status for specific situations as breeding or commercialization. The performance characteristics of an in-house developed recombinant ELISA (rp24-ELISA) were evaluated according to international guidelines (2,3). Material & methods: The BLV p24 major capsid protein was expressed as a recombinant thioredoxin-6xHis fusion protein in Escherichia coli in our laboratory. The purified rp24 was used as antigen for the ELISA test (rp24-ELISA) to detect antibodies to BLV. To assess the performance characteristics of this test 710 field serum samples were analyzed by rp24-ELISA and a commercial AGID test (UNLP AGID). Amplification of the envelope gene by nested PCR (nPCR) (4) and an in-house Western Blot assay were used to confirm discordant results on a well-characterized herd. Results: rp24-ELISA and AGID showed a 90.5% of concordance when the 710 field serum samples were analyzed on the accuracy trial. rp24-ELISA could detect 269 positives samples while AGID only detected 210. When nPCR was carried out 18 out of 22 samples that were declared as positive by rp24-ELISA were positive by nPCR. In addition, the rp24-ELISA was able to detect 5 out of 21 infected animals that were not detected by AGID. Five out of 8 samples that were not declared as positives by AGID were detected by WB and rp24-ELISA. Complementary, the rp24-ELISA demonstrated to be a precise assay with excellent repeatability, reproducibility and better analytical sensitivity than AGID Discussions & conclusions Taking these results into account, the rp24-ELISA could be adopted as an official test method for diagnosis and control of BLV in Argentina, and together with the nested-PCR assay could be considered as complementary tools for confirmatory situations. References 1- World Organization for Animal Health (OIE). 2004. Manual of Diagnostic Test and Vaccines for Terrestrial Animals (mammals, birds and bees). Chapter 2.3.4. Enzootic bovine leukosis 2- World Organization for Animal Health (OIE). 2004. Manual of Diagnostic Test and Vaccines for Terrestrial Animals (mammals, birds and bees). Chapter 1.1.3. Principles of validation and of diagnostic assays for infectious diseases. 3- International Committee of Harmonisation. Tripartite Guidelina Q2A: Text on Validation of Analytical Procedures, 1994, and Tripartite Guideline Q2B: Validation of Analytical Procedures: Methodology, 1996. 4-Lew, AE; Bock, RE; Molloy, JB; Minchin, CM; Robinson, SJ; Steer, P. Sensitive and specific detection of proviral bovine leukemia virus by 5´Taq nuclease PCR using a 3´ minor groove binder fluorogenic probe. J Virol Methods, 2004 Feb;115(2):167-7