Complex Oscillations and Limit Cycles in Autonomous Two-Component Incommensurate Fractional Dynamical Systems

MSC 2010: 26A33, 34D05, 37C25

Igazolható-e az üzleti ciklus az iparágak viselkedésével? = Can business cycles be proved with the behavior of enterprises?

A dolgozat alapja egy olyan Leontief-típusú gazdaság, ahol minden egyes ágazatban egy vállalat termel, tehát monopóliumokból áll a gazdaság. A vállalatok termelnek, és a termékeiket a piacon értékesítik. A gazdaság mozgásegyenleteit a vállalati mérleg összefüggések, valamint a piaci csere után a gazdaságban, a termékek készletváltozása írja le. Az így létrejött mozgásegyenletekből arra következtethetünk, hogy a ciklusok egy ilyen modellben szükségszerűen kialakulnak, tehát az üzleti ciklus a gazdaság működéséhez hozzátartozik. Journal of Economic Literature (JEL) kód: D46, E32. = The aim of the paper is to analyze a Leontief-type economy, i.e. all firms produce only one product and only one technology. The firms sell the products on a monopolistic market. The move of this economy is controlled by the balance sheet expressions and the inventory level fluctuations. The differential equations of the move of this economy show a cyclical movement of the economy along the balanced growth path. Journal of Economic Literature (JEL) kód: D46, E32.

Bródy András gazdaságiciklus-elmélete (András Bródy's theory of economic cycles)

Bródy András kutatásainak egyik központi témaköre a gazdasági mozgás vizsgálata volt. Írásunkban Bródy elméletét kívánjuk röviden áttekinteni és összefoglalni. A termelés sokszektoros leírása egyben árelméletét (értékelméletét, méréselméletét) is keretbe foglalja. Ebben a keretben a gazdasági mozgás összetett ingadozása technológiai alapon elemezhető. Bródy megközelítésében a gazdasági ciklust nem külső megrázkódások magyarázzák, hanem a termelési rendszer belső arányai és kapcsolatai. A termelési struktúrát az árak és a volumenek egyformán alakítják, ezek között nincsen kitüntetett vagy domináns tényező. Az árak és a volumenek a köztük lévő duális kapcsolatban alakulnak ki. A gazdaság mozgásegyenleteit technológiai mérlegösszefüggések, valamint a piaci csere útján a gazdaságban újraelosztásra (újratermelésre) kerülő termékek felhasználása és az eszközlekötés változása írja le. Az így meghatározott mozgásegyenletek a gazdaság természetes mozgását ciklusmozgás alakjában írják le. A technológia vagy az értékviszonyok megváltozása (sokkok) a gazdaság ciklikus mozgásának megváltozásában tükröződik. Bródy munkáiban technológiai megalapozást nyer a történelemből ismert számos jellegzetes gazdasági ciklus. / === / Economic motion and dynamics are at the heart of Andras Brody's creative output. This paper attempts a bird's-eye view of his theory of economic cycles. Brody's multi-sector modelling of production has provided a framework for price theory (the theory of value and measurement). His theory of economic motion with cyclical characteristics is technology driven. It argues that the complex web of economic cycles is determined by the proportions and interrelationships of the system of production, not by arbitrary external shocks. The structure's behaviour are driven by prices and proportions, with the duality of prices and proportions as a dominant feature. These are features in common with the Leontief models, which Brody extended to economic cycles. Brody saw economic cycles as natural motions of economic systems with accumulated assets (time lags) and market exchange of goods (demand and supply adjustment). Changes in technology or valuations (shocks) are reflected in changing patterns of motion. His model of the economy is a fine instrument that enabled him to show how the technological parameters of its system determine the frequency and other characteristics of various economic cycles identified in economic history.

Konjunktúraingadozások az Egyesült Államokban 1970-2010 - Értelmezési nehézségek = Business cycles and recession patterns in the US economy and in the G7

Lehet-e beszélni a 2011-ig felgyülemlett empirikus tapasztalatok tükrében egy egységes válságlefolyásról, amely a fejlett ipari országok egészére általában jellemző, és a meghatározó országok esetében is megragadható? Megállapíthatók-e olyan univerzális változások a kibocsátás, a munkapiacok, a fogyasztás, valamint a beruházás tekintetében, amelyek jól illeszkednek a korábbi tapasztalatokhoz, nem kevésbé az ismert makromodellek predikcióihoz? A válasz – legalábbis jelen sorok írásakor – nemleges: sem a válság lefolyásának jellegzetességeiben és a makrogazdasági teljesítmények romlásának ütemében, sem a visszacsúszás mértékében és időbeli kiterjedésében sincsenek jól azonosítható közös jegyek, olyanok, amelyek a meglévő elméleti keretekbe jól beilleszthetők. A tanulmány áttekinti a válsággal és a makrogazdasági sokkokkal foglalkozó empirikus irodalom – a pénzügyi globalizáció értelmezései nyomán – relevánsnak tartott munkáit. Ezt követően egy 60 év távlatát átfogó vizsgálatban próbáljuk megítélni a recessziós időszakokban az amerikai gazdaság teljesítményét azzal a célkitűzéssel, hogy az elmúlt válság súlyosságának megítélése kellően objektív lehessen, legalább a fontosabb makrováltozók elmozdulásának nagyságrendje tekintetében. / === / Based on the empirical evidence accumulated until 2011, using official statistics from the OECD data bank and the US Commerce Department, the article addresses the question whether one can, or cannot, speak about generally observable recession/crisis patterns, such that were to be universally recognized in all major industrial countries (the G7). The answer to this question is a firm no. Changes and volatility in most major macroeconomic indicators such as output-gap, labor market distortions and large deviations from trend in consumption and in investment did all, respectively, exhibit wide differences in depth and width across the G7 countries. The large deviations in output-gaps and especially strong distortions in labor market inputs and hours per capita worked over the crisis months can hardly be explained by the existing model classes of DSGE and those of the real business cycle. Especially bothering are the difficulties in fitting the data into any established model whether business cycle or some other types, in which financial distress reduces economic activity. It is argued that standard business cycle models with financial market imperfections have no mechanism for generating deviation from standard theory, thus they do not shed light on the key factors underlying the 2007–2009 recession. That does not imply that the financial crisis is unimportant in understanding the recession, but it does indicate however, that we do not fully understand the channels through which financial distress reduced labor input. Long historical trends on the privately held portion of the federal debt in the US economy indicate that the standard macro proposition of public debt crowding out private investment and thus inhibiting growth, can be strongly challenged in so far as this ratio is neither a direct indicator of growth slowing down, nor for recession.

Cumulative live birth rates after one or more complete cycles of IVF : a population-based study of linked cycle data from 178 898 women

© The Author 2016. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Cycles of passive versus active diapirism recorded along an exposed salt wall

Acknowledgements GIA is grateful for funding from the Carnegie Trust for the Universities of Scotland that enabled fieldwork for this project. RW was supported by the Israel Science Foundation (ISF grant No. 1245/11). SM was supported by the Israel Science Foundation (ISF grant No. 1436/14). We would like to thank Chris Talbot and Yohann Poprawski for careful and constructive reviews. The authors appreciate the help of Nicolas Waldmann in precisely locating the positons of dated unconformities.

Policewomen on duty at Women's Liberation rally

Inscriptions: Verso: [stamped] Photograph by Freda Leinwand. [463 West Street, Studio 229G, New York, NY 10014].

The Burden of Burnout: An Assessment of Burnout Among Internal Medicine Residents After the 2011 Duty Hour Changes.

This study sought to determine burnout prevalence and factors associated with burnout in internal medicine residents after introduction of the 2011 ACGME duty hour rules. Burnout was evaluated using an anonymized, abbreviated version of the Maslach Burnout Inventory. Surveys were collected biweekly for 48 weeks during the 2013-2014 academic year. Burnout severity was compared across subgroups and time. A score of 3 or higher signified burnout. Overall, 944 of 3936 (24%) surveys were completed. The mean burnout score across all surveys was 2.8. Categorical residents had higher burnout severity than noncategorical residents (2.9 vs 2.7, P = .005). Postgraduate year 2 residents had the highest burnout severity by year (3.1, P < .001). Residents on inpatient rotations had higher burnout severity than residents on outpatient or consultation rotations (3.1 vs 2.2 vs 2.2, P < .001). Night float rotations had the highest severity (3.8). Burnout remains a significant problem even with recent duty hour modifications.

Aspects of Motives: Finite-dimensionality, Chow-Kunneth Decompositions and Intersections of Cycles

This thesis analyzes the Chow motives of 3 types of smooth projective varieties: the desingularized elliptic self fiber product, the Fano surface of lines on a cubic threefold and an ample hypersurface of an Abelian variety. For the desingularized elliptic self fiber product, we use an isotypic decomposition of the motive to deduce the Murre conjectures. We also prove a result about the intersection product. For the Fano surface of lines, we prove the finite-dimensionality of the Chow motive. Finally, we prove that an ample hypersurface on an Abelian variety possesses a Chow-Kunneth decomposition for which a motivic version of the Lefschetz hyperplane theorem holds.

(Table S1) Diatom abundance according to ice cycles in ANDRILL AND1-1B drill core

The influence of Antarctica and the Southern Ocean on Late Pliocene global climate reconstructions has remained ambiguous due to a lack of well-dated Antarctic-proximal, paleoenvironmental records. Here we present ice sheet, sea-surface temperature, and sea ice reconstructions from the ANDRILL AND-1B sediment core recovered from beneath the Ross Ice Shelf. We provide evidence for a major expansion of an ice sheet in the Ross Sea that began at ~3.3 Ma, followed by a coastal sea surface temperature cooling of ~2.5°C, a stepwise expansion of sea ice, and polynya-style deep mixing in the Ross Sea between 3.3 and 2.5 Ma. The intensification of Antarctic cooling resulted in strengthened westerly winds and invigorated ocean circulation. The associated northward migration of Southern Ocean fronts has been linked with reduced Atlantic Meridional Overturning Circulation by restricting surface water connectivity between the ocean basins, with implications for heat transport to the high latitudes of the North Atlantic. While our results do not exclude low-latitude mechanisms as drivers for Pliocene cooling, they indicate an additional role played by southern high-latitude cooling during development of the bipolar world.

Diatom-bound N isotope records over the last two glacial cycles in sediment core PS75/072-4

In a sediment core from the Pacific sector of the Antarctic Zone (AZ) of the Southern Ocean, we report diatom-bound N isotope (d15Ndb) records for total recoverable diatoms and two distinct diatom assemblages (pennate and centric rich). These data indicate tight coupling between the degree of nitrate consumption and Antarctic climate across the last two glacial cycles, with d15Ndb (and thus the degree of nitrate consumption) increasing at each major Antarctic cooling event. Coupled with evidence from opal- and barium-based proxies for reduced export production during ice ages, the d15Ndb increases point to ice age reductions in the supply of deep ocean-sourced nitrate to the AZ surface. The two diatom assemblages and species abundance data indicate that the d15Ndb changes are not the result of changing species composition. The pennate and centric assemblage d15Ndb records indicate similar changes but with a significant decline in their difference during peak ice ages. A tentative seasonality-based interpretation of the centric-to-pennate d15Ndb difference suggests that late summer surface waters became nitrate free during the peak glacials.

Analysis of testosterone pulsatility in women with ovulatory menstrual cycles

Objetivo: Avaliar o padrão pulsátil da secreção da testosterona em mulheres normais. Métodos: Oito mulheres saudáveis com ciclos ovulatórios foram selecionadas. Amostras sanguíneas foram coletadas a cada dez minutos durante seis horas, começando entre 7 e 8 h da manhã, após dez horas de jejum, nas três fases do ciclo menstrual: folicular média (Dia 7), folicular tardia (Dia 12) e lútea (Dia 21). Foram mensurados: testosterona, LH e, no basal, também SHBG. Resultados: A frequência dos pulsos de testosterona, média da amplitude do pulso, porcentagem do incremento da amplitude, duração e intervalos dos pulsos foram similares nas três fases (p > 0,05). A pulsatilidade do LH foi estatisticamente diferente entre as três fases (p < 0,001), caracterizando padrão característico do ciclo ovulatório normal. Conclusões: Esses dados aumentam o conhecimento sobre o padrão de secreção da testosterona no ciclo menstrual humano e representam uma contribuição para a investigação clínica, tanto no hiperandrogenismo como na síndrome de insuficiência androgênica __________________________________________________ ABSTRACT Objective: To evaluate the pattern of the pulsatile secretion of testosterone in normal menstrual cycle. Methods: Eight healthy women with ovulatory menstrual cycles were enrolled. Blood samples were collected at ten-minute intervals for six hours, starting between 7 and 8 am, after a ten-hour fasting, in three phases: mid-follicular (Day 7), late follicular (Day 12) and mid-luteal phase (Day 21). Samples were assayed for testosterone, LH and the baseline also for SHBG. Results: Testosterone pulse frequency, mean amplitude pulse, percentage of increment in pulse amplitude, mean duration of pulses and pulse interval were similar in the three phases. LH pulsatility was statistically different among the three phases (p < 0.001) representing normal ovulatory cycles. Conclusions: These data increase the knowledge about the testosterone secretion profile in the human menstrual cycle and can be used as a contribution to clinical investigation in both hyperandrogenism and androgen insufficiency syndrome

Étude communicationnelle des pratiques culturelles au Québec: analyses des enquêtes ministérielles (1979-2009). Facteurs et prédicteurs, générations et cycles de vie, et découpages territoriaux

Cette thèse porte sur les pratiques culturelles des Québécois et des Québécoises et, plus spécifiquement dans un premier temps, sur les facteurs qui les influencent. Elle traite ensuite des comparaisons entre les individus selon les générations et les cycles de vie. Finalement, elle porte sur les découpages territoriaux régionaux sur le plan des pratiques culturelles et sur les questions liées au territoire. Tous les résultats sont tirés des enquêtes sur les pratiques culturelles au Québec menées à tous les cinq ans depuis 1979 par les ministères en charge de la culture. Les deux principaux référents théoriques sont la théorie de la légitimité de Bourdieu et la figure de l’omnivore de Peterson. Dans la première partie, cette thèse a cherché à savoir si les usages d’Internet sont associés à une ouverture culturelle ou à un confinement. Les résultats montrent que l’âge, la scolarité et les usages culturels que l’on fait d’Internet sont des prédicteurs importants des visites des lieux culturels et des sorties au spectacle. Les modèles qui incluent les usages d’Internet et des variables sociodémographiques sont plus performants que ceux ne considérant que ces dernières. Dans la deuxième partie, les quasi-cohortes à l’étude ont été comparées afin de voir si leurs comportements culturels diffèrent selon les cycles de vie et si leur parcours culturel a varié dans le temps. Finalement, la diversification des pratiques des quasi-cohortes a été étudiée afin d’estimer si elles deviennent plus omnivores avec le temps et d’une quasi-cohorte à l’autre. Le modèle explicatif créé affiche des différences dans le parcours culturel selon les cycles de vie, de même qu’au fil du temps. Il met également en lumière des différences d’une génération à l’autre, de même que des différences entre les générations lorsqu’elles traversent un même cycle de vie. À la différence de ceux de Peterson (2004), les résultats ne permettent pas de conclure que les quasi-cohortes plus âgées sont plus omnivores qu’avant ni que les jeunes sont plus omnivores que leurs aînés. La troisième partie de ce travail avait un objectif comparatif : il s’agissait de voir si les régions administratives du Québec, lorsqu’elles sont étudiées sous l’angle des pratiques culturelles, se regroupent conformément à la typologie des espaces culturels régionaux développée par Harvey et Fortin (1995) sur la base de l’offre culturelle. Les résultats montrent que les regroupements ne sont pas toujours conformes à la typologie et que les pratiques sont très hétérogènes, ce qui permet difficilement d’établir une constance dans les regroupements. Aussi semble-t-il indiqué de fonder la comparaison des territoires sur la prise en compte de l’objet (p. ex. offre ou pratique culturelle), de l’échelle territoriale (p. ex. bibliothèque municipale ou musée national) et de la nature du produit ou de la pratique (p. ex. mobile ou immobile). En conclusion, la pertinence d’élargir l’horizon des pratiques culturelles mesurées dans les enquêtes et d’y inclure des phénomènes transcendants, comme les valeurs, les contraintes et la motivation a été remise en question. À titre d’exemple, l’étude de la motivation pourrait permettre de préciser la figure de l’omnivore au Québec. Il est également apparu pertinent de poursuivre la réflexion en étudiant la manière dont les pratiques culturelles sont consommées afin de voir si, et comment, le cas échéant, s’opère la distinction.

Analysis of testosterone pulsatility in women with ovulatory menstrual cycles

Objetivo: Avaliar o padrão pulsátil da secreção da testosterona em mulheres normais. Métodos: Oito mulheres saudáveis com ciclos ovulatórios foram selecionadas. Amostras sanguíneas foram coletadas a cada dez minutos durante seis horas, começando entre 7 e 8 h da manhã, após dez horas de jejum, nas três fases do ciclo menstrual: folicular média (Dia 7), folicular tardia (Dia 12) e lútea (Dia 21). Foram mensurados: testosterona, LH e, no basal, também SHBG. Resultados: A frequência dos pulsos de testosterona, média da amplitude do pulso, porcentagem do incremento da amplitude, duração e intervalos dos pulsos foram similares nas três fases (p > 0,05). A pulsatilidade do LH foi estatisticamente diferente entre as três fases (p < 0,001), caracterizando padrão característico do ciclo ovulatório normal. Conclusões: Esses dados aumentam o conhecimento sobre o padrão de secreção da testosterona no ciclo menstrual humano e representam uma contribuição para a investigação clínica, tanto no hiperandrogenismo como na síndrome de insuficiência androgênica __________________________________________________ ABSTRACT Objective: To evaluate the pattern of the pulsatile secretion of testosterone in normal menstrual cycle. Methods: Eight healthy women with ovulatory menstrual cycles were enrolled. Blood samples were collected at ten-minute intervals for six hours, starting between 7 and 8 am, after a ten-hour fasting, in three phases: mid-follicular (Day 7), late follicular (Day 12) and mid-luteal phase (Day 21). Samples were assayed for testosterone, LH and the baseline also for SHBG. Results: Testosterone pulse frequency, mean amplitude pulse, percentage of increment in pulse amplitude, mean duration of pulses and pulse interval were similar in the three phases. LH pulsatility was statistically different among the three phases (p < 0.001) representing normal ovulatory cycles. Conclusions: These data increase the knowledge about the testosterone secretion profile in the human menstrual cycle and can be used as a contribution to clinical investigation in both hyperandrogenism and androgen insufficiency syndrome