Neural and Neuroendocrine Processing of a Non-Photic Cue in an Opportunistically Breeding Songbird

Recent studies of the onset of breeding in long-day photoperiodic breeders have focused on the roles of type 2 and 3 iodothyronine deiodinases (DIO2 and DIO3) in the conversion of thyroxine (T4) to triiodothyronine (T3) and subsequent activation of the reproductive axis. It has been hypothesized that an increase in DIO2 and a reciprocal decrease in DIO3 causes the release of gonadotropinreleasing hormone (GnRH) from the hypothalamus, setting off a reproductive cascade, and that this DIO mechanism for GnRH release is conserved across vertebrate taxa. We sought to test whether social cues that are known to stimulate reproductive behaviors can activate the DIO system to initiate reproduction in a non-photoperiodic bird, the zebra finch (Taeniopygia guttata). Isolation of males and subsequent presentation of females did not increase DIO2 or GnRH expression in the hypothalamus, nor did it decrease gonadotropin-inhibitory hormone (GnIH) or DIO3. Males receiving a female stimulus showed significantly higher mRNA expression and immunoreactive cell count of the immediate-early gene early growth response protein 1 (EGR-1) than isolated males, indicating hypothalamic activation in response to a female. Cells immunoreactive for EGR-1 were not co-localized with those immunoreactive for GnRH. Reproductive behaviors (singing, copulation attempts and overall activity) were significantly higher in males receiving a female stimulus. This study presents a social effect on behavior and EGR-1 expression in the hypothalamus of males in response to females, but more research is needed to determine whether the DIO2 system and the GnRH system are responsive to social stimulation in this species

Peripheral and central mechanisms involved in hormonal control of male and female reproduction

Reproduction involves the integration of hormonal signals acting across multiple systems togenerate a synchronized physiological output. A critical component of reproduction is the luteinizinghormone (LH) surge, which is mediated by estradiol (E2) and neuroprogesterone interacting tostimulate kisspeptin release in the rostral periventricular nucleus of the third ventricle in rats. Recentevidence has shown that both classical and membrane E2 and progesterone signaling is involved inthis pathway. A metabolite of gonadotropin-releasing hormone (GnRH), GnRH-(1-5), has been shownto stimulate GnRH expression, secretion, and has a role in the regulation of lordosis. Additionally,gonadotropin-inhibitory hormone (GnIH) projects to and influences the activity of GnRH neurons inbirds. Stress-induced changes in GnIH have been shown to alter breeding behaviors in birds,demonstrating another molecular control of reproduction. Peripherally, paracrine and autocrineactions within the gonad have been suggested as therapeutic targets for infertility in both males andfemales. Dysfunction of testicular prostaglandin synthesis is a possible cause of idiopathic maleinfertility. Indeed, local production of melatonin and corticotropin-releasing hormone (CRH) couldinfluence spermatogenesis via immune pathways in the gonad. In females, vascular endothelialgrowth factor A (VEGF-A) has been implicated in an angiogenic process that mediates developmentof the corpus luteum and thus fertility via the Notch signaling pathway. Age-induced decreases infertility involve ovarian kisspeptin and its regulation of ovarian sympathetic innervation. Finally,morphological changes in the arcuate nucleus of the hypothalamus influence female sexualreceptivity in rats. The processes mediating these morphological changes have been shown toinvolve rapid effects of E2 controlling synaptogenesis in this hypothalamic nucleus. Together, thisreview highlights new research in these areas, focusing on recent findings in the molecularmechanisms of central and peripheral hormonal control of reproduction.Fil: Rudolph, L. M.. University of California at Los Angeles; Estados UnidosFil: Bentley, G. E.. University of California Berkeley; Estados UnidosFil: Calandra, Ricardo Saul. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Paredes, A. H.. Universidad de Chile; ChileFil: Tesone, Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Wu, T. J.. Uniformed Services University; Estados UnidosFil: Micevych, P. E.. University of California at Los Angeles; Estados Unido

Hormonal regulation of female reproduction

Reproduction is an event that requires the coordination of peripheral organs with the nervous system to ensure that the internal and external environments are optimal for successful procreation of the species. This is accomplished by the hypothalamic-pituitary-gonadal axis that coordinates reproductive behavior with ovulation. The primary signal from the central nervous system is gonadotropin-releasing hormone (GnRH), which modulates the activity of anterior pituitary gonadotropes regulating follicle stimulating hormone (FSH) and luteinizing hormone (LH) release. As ovarian follicles develop they release estradiol, which negatively regulates further release of GnRH and FSH. As estradiol concentrations peak they trigger the surge release of GnRH, which leads to LH release inducing ovulation. Release of GnRH within the central nervous system helps modulate reproductive behaviors providing a node at which control of reproduction is regulated. To address these issues, this review focuses on several critical questions. How is the HPG axis regulated in species with different reproductive strategies? What internal and external conditions modulate the synthesis and release of GnRH? How does GnRH modulate reproductive behavior within the hypothalamus? How does disease shift the activity of the HPG axis.Fil: Christensen, A.. University of California at Los Angeles; Estados UnidosFil: Bentley, G. E.. University of California at Berkeley; Estados UnidosFil: Cabrera Kreiker, Ricardo Jorge. Universidad de Mendoza; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Ortega, Hugo Hector. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Litoral; ArgentinaFil: Perfito, N.. University of California at Berkeley; Estados UnidosFil: Wu, T. J.. Uniformed Services University Of The Health Sciences; Estados UnidosFil: Micevych, P.. University of California at Los Angeles; Estados Unido

Kinetic and Spectroscopic Characterisation of Highly Reactive Methanesulfonates. Leaving Group Effects for Solvolyses and Comments on Geminal Electronic Effects Influencing SN_N1 Reactivity

Highly reactive methanesulfonates (mesylates, ROMs) have been prepared from 1-phenylethanol. cyclohex-2-en-1-ol, diphenylmethanol and p-methoxybenzyl alcohol by treatment with methanesulfonyl chloride and triethylamine in dichloro- or trichloro-methane at - 20 to 0 °C. The mesylates. characterised in solution by $^1$H and $^{13}$C NMR at -20 °C, were obtained in satisfactory purity (ca. 95%) in cold solutions but they decomposed by reaction with chloride, triethylamine or the parent alcohol. Rate constants for solvolyses in aqueous acetone and aqueous ethanol have been determined by a fast response conductimetric method. Product selectivities for solvolyses of pmethoxybenzyl mesylate in aqueous ethanol and methanol at 0 °C have been determined by HPLC. From additional new or Iiterature kinetic data for solvolyses of corresponding bromides. chlorides and p-nitrobenzoates (OPNB). Br/CI. OMs/Br and OMs/OPNB rate ratios were calculated; the results are consistent with electronic effects stabilising the carbocationic transition states and increasing OMs/Br rate ratios for these SN 1 solvolyses; none of the evidence supports a geminal electronic effect on Br/CI rate ratios (e.g. caused by stabilisation of the initial state in pmethoxybenzyl chloride). Steric effects on ester /halide rate ratios for solvolyses of tertiary substrates are confirmed. Relative rates over a 10$^{16}$ range for ester and halide leaving groups are evaluated for solvolyses of 1-phenylethyl substrates in 80% ethanol-water. updating previous work by Noyce et al. (1972)

On Beneficial Vehicle-to-Grid (V2G) Services

A number of studies have investigated the possibility of extending Electric Vehicle (EV) Lithium-ion battery life by deliberately choosing to store the battery at a low to moderate state of charge. Recently, there has been considerable interest shown in the scheme of a deliberate discharge and subsequent recharge of a battery to yield an overall reduction in battery degradation whilst carrying out Vehicle-to-Grid (V2G) services (so-called `beneficial V2G'). This paper presents an investigation of the conditions permitting successful operation of this method by examining incremental time variation of the relevant parameters for two types of cells from results of the same physical size and chemistry, and similar capacity. These two types of cells are found in this present analysis to offer differing degrees of suitability for beneficial V2G

The energetics of the gradual phase

Reseachers compare results with those in the chapter by Moore et al. (1980), who reached five main conclusions about the gradual phase: (1) the typical density of the soft X-ray emitting plasma is between 10 to the 11th power and 10 to the 12th power cm-3 for compact flares and between 10 to the 10th power and 10 to the 11th power cm-3 for a large-area flare; (2) cooling is by conduction and radiation in roughly equal proportions; (3) continual heating is needed in the decay phase of two-ribbon flares; (4) continual heating is probably not needed in compact events; (5) most of the soft-X-ray-emitting plasma results from chromospheric evaporation. The goal was to reexamine these problems with the data from the Solar Maximum Mission (SMM) and other supporting instruments as well as to take advantage of recent theoretical advances. SMM is capable of measuring coronal temperatures more accurately and with a better cadence than has been possible before. The SMM data set is also unique in that the complete transit of an active region was observed, with soft X-ray and UV images being taken every few minutes. Researcher's were therefore able to establish the pre-flare conditions of the region and see whether anything has changed as a result of the flare. The assumptions made in attempting to determine the required plasma parameters are described. The derived parameters for the five prime flares are presented, and the role of numerical simulations is discussed

Das bandkeramische Gräberfeld vom „Viesenhäuser Hof“ bei Stuttgart-Mühlhausen: Neue Untersuchungsergebnisse zum Migrationsverhalten im frühen Neolithikum

Einleitung: Gegenstand des vorliegenden Beitrags ist die Rolle der Mobilität im Leben der frühen Ackerbauern und Viehzüchter in Südwestdeutschland. Seit Jahrzehnten werden wissenschaftliche Auseinandersetzungen über die Bedeutung von Wanderungsbewegungen bei der Ausbreitung der produzierenden Wirtschaftsweise in Europa zwischen 7000 und 4000 v. Chr. geführt. Dabei gehen traditionelle Überlegungen davon aus, dass die ersten Ackerbauern in Mitteleuropa Zuwanderer waren, die ein ‚Paket‘ neuer Errungenschaften und Ideen mit sich führten, das u. a. Haustiere, dauerhafte Siedlungen, Keramik und den Ackerbau enthielt.1 Neuere Untersuchungen und Überlegungen gestehen dagegen der einheimischen Bevölkerung eine maßgebliche Bedeutung bei der Übernahme der neolithischen Wirtschaftsweise zu.2 Die Mobilität des Menschen ist aber nicht nur für die Erklärung des Neolithisierungsprozesses, sondern auch für das Verständnis der Lebens- und Wirtschaftsweise der Menschen in den mittleren und späteren Abschnitten der Linearbandkeramik von höchstem Interesse. Die bisherige Forschungsdiskussion basierte in diesem Zusammenhang überwiegend auf indirekten Argumenten, d. h. auf Artefakten, die auch getauscht oder gestohlen worden sein konnten, aber nicht auf den Überresten der potenziellen Zuwanderer selbst, die in Form von Knochen und Zähnen erhalten sind. Die vorliegende Studie bedient sich der direkten Analyse menschlicher Skelettreste der bandkeramischen Gräber vom ‚Viesenhäuser Hof‘, Stuttgart-Mühlhausen, mittels anthropologischer Untersuchungen und Strontiumisotopenanalysen. Nachfolgend werden der Fundplatz in seinem archäologischen Kontext der Linearbandkeramik sowie die Ergebnisse der anthropologischen Untersuchungen und Strontiumisotopenanalysen vorgestellt und dann die Rolle der Mobilität im Leben der frühen Ackerbauern und Viehzüchter sowie für die Ausbreitung der neolithischen Wirtschaftsweise diskutiert. Stuttgart-Mühlhausen ist eines der ältesten bandkeramischen Gräberfelder, die bislang für derartige Untersuchungen zur Verfügung standen

A well-separated pairs decomposition algorithm for k-d trees implemented on multi-core architectures

Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.Variations of k-d trees represent a fundamental data structure used in Computational Geometry with numerous applications in science. For example particle track tting in the software of the LHC experiments, and in simulations of N-body systems in the study of dynamics of interacting galaxies, particle beam physics, and molecular dynamics in biochemistry. The many-body tree methods devised by Barnes and Hutt in the 1980s and the Fast Multipole Method introduced in 1987 by Greengard and Rokhlin use variants of k-d trees to reduce the computation time upper bounds to O(n log n) and even O(n) from O(n2). We present an algorithm that uses the principle of well-separated pairs decomposition to always produce compressed trees in O(n log n) work. We present and evaluate parallel implementations for the algorithm that can take advantage of multi-core architectures.The Science and Technology Facilities Council, UK