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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
331

Testing the Atlantic ice hypothesis : the blade manufacturing of Clovis, Solutrean and the broader technological aspects of production in the Upper Palaeolithic

Williams, Thomas Joseph January 2014 (has links)
The origins of Clovis technology and the nature and timing of the first populations to reach the Western Hemisphere is one of the most contentious issues in American archaeology. With the rejection of “Clovis-first”, many scholars consider that all colonising migrations followed a route out of Asia and across Beringia into North America. However, none of the technologies present in the far northeast of Asia or Beringia exhibit the manufacturing processes that were used in Clovis. To address this enigma, Stanford and Bradley proposed a radical alternative for the origins of Clovis. They argue that a small pioneering group of Solutreans crossed the Atlantic ice sheets of the LGM and reached the shores of North America. The basis for this argument stems from technological similarities between Clovis and the Solutrean, as well as from climatic, oceanographic, and ethnographic data. Biface manufacture is at the centre of their technological analysis, specifically comparing the reduction sequences of the distinctive Solutrean laurel leaf points and comparing them to Clovis points. This thesis tests the assumption of Stanford and Bradley that the blade manufacturing technologies of Clovis and Solutrean were “virtually identical”. By analysing the blade manufacturing processes from the Solutrean assemblage at Laugerie-Haute and the Clovis assemblage from the Gault site and comparing them to the broader technological patterns present across Eurasia between ~30,000 BP and 11,000 BP; this thesis supports the findings of Stanford and Bradley with the amendment that Clovis specifically intended to produce curved blades but did not use blades to produce projectile points. While convergence cannot be completely ruled out, there is a lack of evidence that would explain the number of similarities in the manufacturing processes. Thus it remains highly likely that interaction across the ice-edge corridor of the Atlantic may have occurred during the LGM.
332

Positiv avkastning är en kostnad : En eventstudie om svenska och norska målföretags runup och dess påverkan på premien vid företagsförvärv / Positive return is a cost : An event study on swedish and norwegian target companies’runup and its impact on the takeover premium in mergers and acquisitions

Axelsson, Viktor, Söderberg, Sebastian January 2017 (has links)
Syfte: Syftet med denna studie är att undersöka hur målföretags runup påverkar den premie sombetalas vid företagsförvärv utifrån substitutions- och markup-prissättningshypotesen. Metod: Studien har en deduktiv ansats där en eventstudie har tillämpats för att samla in relevant sekundärdata från databaserna Thomson Reuters Eikon och Zephyr. För att studera sambandet mellan förvärvspremie och målföretagets runup har en enkel regressionsanalys genomförts och för att studera förklarande variablers påverkan på runup har en multipel regressionsanalys tillämpats. Resultat & slutsats: Studiens resultat visar att det förekommer ett samband mellan runup och den förvärvspremie som betalas vid företagsförvärv. Utifrån substitutions- och markup-prissättningshypotesen visar studien att om runup ökar med 1 % ökar förvärvspremien med 0,879% vilket innebär att en ökning av målföretagets runup är en kostnad för det förvärvande företaget. Förslag till fortsatt forskning: Förslag på vidare forskning är att studera fler förklarande variabler för ett målföretags runup samt att studera volymskillnader i handel av målföretagets aktier dagarna före offentliggörande av bud på exempelvis den svenska marknaden för att se huruvida resultatet skiljer sig från tidigare forskning och andra marknader. Uppsatsens bidrag: Studiens resultat bidrar med kunskap som kan förklara den variation i förvärvspremier som förekommer samt kunskap om att ett målföretags runup är en förvärvskostnad för det förvärvande företaget. / Aim: The purpose of this study is to investigate how the target companies’ runup affects thetakeover premium in mergers and acquisitions based on the substitution and markup pricing hypothesis. Method: The study has a deductive approach in which an event study has been applied to collectrelevant secondary data from the databases Thomson Reuters Eikon and Zephyr. To study the relationship between the acquisition premium and the target company’s runup a simple regression analysis has been conducted and to study the influence of explanatory variables on runup a multiple regression analysis has been applied. Result & Conclusions: The study’s results show that there is a relationship between runup and the takeover premiums. Based on the substitution and markup pricing hypothesis, the study shows that if runup increases by 1 % the takeover premium increases by 0.879 % which means that an increase in the target company's runup is a cost to the acquiring company. Suggestions for future research: Suggestions for further research are to study more explanatory variables for a target company's runup and study volume differences in trading of the target company's shares the days prior to bid announcement on the Swedish market to see if the results differ from previous research and other markets. Contribution of the thesis: The study’s results contribute knowledge that can explain the variation in takeover premiums and knowledge that a target company’s runup in an acquisition is a cost for the acquiring company.
333

Prenatal Pathways to Early Puberty: Testing the Thrifty Phenotype and Fetal Overnutrition Hypotheses

Olivia C Robertson (11647522) 08 November 2021 (has links)
<p>This thesis outlined a novel operationalization and extension of the thrifty phenotype and fetal overnutrition hypotheses, two evolutionary developmental hypotheses stemming from the developmental origins of health and disease perspective, for developmental pathways from prenatal risk through child growth to early puberty. Support has accumulated for both, but previous studies have not clearly determined which hypothesis better predicts early puberty. Using the Fragile Families and Child Wellbeing Study (<i>n</i>=4898), the thrifty phenotype and fetal overnutrition pathways were tested against each other, separately by sex, and race/ethnicity for adrenal, and gonadal pubertal markers. Results indicated that in general, both hypotheses were supported. Contrary to hypotheses, the thrifty phenotype pathway did not predict perceived pubertal timing better in boys and the fetal overnutrition pathway did not predict perceived pubertal timing best in girls. Instead, both pathways predicted puberty equally well between girls and boys and the fetal overnutrition pathway stemming from maternal gestational weight gain was stronger than the pre-pregnancy BMI pathway. Individual paths of the hypothesized pathways were generally supported when analyzed by race/ethnicity group separately, but support for the entire pathways were sparse. Implications of this work are that pubertal timing may be similarly programmed by restrictive and overnutrition prenatal risks, both should be prioritized, and that interventions for maternal gestational weight should be prioritized over interventions for pre-pregnancy BMI for reducing rates of early puberty. </p>
334

Evolutionary Theories of Menopause

Hägg, Fanny January 2020 (has links)
Menopause, the cessation of female reproduction well before death, is a puzzling phenomenon, because evolutionary theory suggests there should be no selection for survival when reproduction has ended. Nevertheless, menopause does exist in a limited number of species, and besides humans it has predominately evolved among toothed whales (Odontoceti). The aim of this thesis is to review both adaptive and non-adaptive theories. Of the latter, the most prominent proposes that menopause is a product of a physiological trade-offs between reproductive benefits early in life and negative late-life reproduction. Among the adaptive theories the grandmother hypothesis is the most acknowledged. This theory is based on inclusive fitness benefits gained from increasing the reproductive success of kin at an advanced age, when prospects of successfully raising additional offspring is reduced. Alternatively, the mother hypothesis suggests that increased investment in already produced offspring at late life explains menopause. There are support for both the care of mothers and grandmothers, but whether this is enough to compensate for repressed reproduction is debated. The reproductive conflict hypothesis provides a complementary explanation, and suggests that inter-generational conflict between either in-laws or kin selects the older female to shift investment into the younger female’s offspring due to asymmetries in how older and younger females are related to one another’s offspring. The evolution of menopause is a complex issue, containing many factors, kinship dynamics among the most important. Theories apply unequally to various species and populations, meaning an integrated approach is necessary for decrypting the evolution of menopause.
335

The role of copulatory wound infliction on fitness in Drosophila melanogaster / Betydelsen av kopulationsskador och dess inverkan på fitness hos Drosophila melanogaster

Leandersson, Dennis January 2021 (has links)
One of the more fascinating Darwinian puzzles in sexual selection is that of copulatory wounding. For those taxa displaying this behavior, and that does not engage in traumatic insemination, the function of wound infliction during copulation remains unknown. In this study, the intention was to evaluate the purpose of copulatory wounding in Drosophila melanogaster and the consequences it might have for male and female fecundity. The present study measured the size and number of wounds that males from different stocks of Darwinian fitness imposed on females, as well as the copulation duration and the resulting fecundity. The number of wounds and the total wound size showed no apparent correlation to fecundity, but a significant difference in variation of the number of wounds inflicted on females was observed between males from two different lines of fitness. Wounded females were also considerably more common than non-wounded females, as were wounds that were paired compared to non-paired copulatory wounds. The results suggests that wounding might be an adaptive male trait and a copulatory courtship interpretable to females, implying a possible case of cryptic female choice. Since most wounds were paired, this implies that a bilaterally symmetrical organ is causing these wounds. Also, wounding was not as important for fecundity as previously thought. / Ett av de mer fascinerande Darwinistiska pusslen inom sexuell selektion är skadande under kopulationen. För de taxa som uppvisar detta beteende, och inte engagerar sig i traumatisk insemination, så är funktionen av kopulationsskador okänd. I denna studie så var avsikten att utvärdera syftet av kopulationsskador hos Drosophila melanogaster och de konsekvenser beteendet kan ha för det resulterande antalet avkomma. Denna studie uppmätte storleken och antalet skador som hanar av olika Darwinistisk fitness vållade honor, samt kopulationstiden och antalet avkomma. Antalet skador och den totala storleken av skador visade ingen signifikant korrelation till antalet avkommor, däremot uppvisades signifikanta variationsskillnader mellan hanar av två olika fitnessnivåer. Skadade honor visade sig också vara betydligt vanligare än icke skadade honor och parade skador var även vanligare än icke parade skador. Resultaten indikerade att kopulationsskador kan vara en adaptiv egenskap hos hanar och en form av uppvaktning som honorna kan tyda, vilket kan antyda ett möjligt fall av ”kryptiskt honligt val”. Eftersom de flesta skador var parade, så antyder detta att ett bilateralt symmetriskt organ orsakar skadorna. Kopulationsskador visade sig heller inte vara så viktiga som man tidigare antagit.
336

The Performance of Serial Acquirers : Evidence from the Nordic market

Gionis, Mattias, Stugemo, Jesper January 2022 (has links)
This thesis examines the performance of serial acquirers in the Nordic market between 2006-2016. We investigate how serial acquirers perform in the short-term and long-term and if serial acquirers are affected by hubris, or if they learn by experience. The payment method is examined to determine if cash-financed deals outperform equity-financed deals. The short-term performance study is measured by the Cumulative Abnormal Return (CAR) and the long-term performance study is measured by the Calendar-Time Portfolio (CTP) combined with the Fama-French Four-Factor model. The main findings show that serial acquirers underperform relative to single acquirers only in the short term. No significant results are found for the hubris and learning hypotheses. In addition, we find that acquirer size and the deal size have a significant effect on the short-term post-M&amp;A performance.
337

This Time It’s Different: Speculative Asset Bubbles & Adaptive Expectations

Sheehy, Conor January 2019 (has links)
Thesis advisor: Harold Petersen / Using insights from Hyman Minsky’s Financial Instability Hypothesis (FIH), we develop a theoretical framework for how speculative bubbles may materialize in securities markets. Our model and empirical analysis show that agents place undue emphasis on recent experience of risk and returns when developing future expectations. We use the aggregate investor allocation to equities (aggregate total market capitalization of equities divided by the price of all real liabilities outstanding), Tobin’s Q (the aggregate market price of equities divided by the replacement cost of nonfinancial firms’ assets), Shiller Total Return Cyclically Adjusted Price to Earnings Ratio (TR CAPE), and Shiller Cyclically Adjusted Price to Earnings Ratio (CAPE) as proxy variables for bubbles. We find statistically significant, negative relationships between all four of these proxy variables and two dependent variables, Subsequent Ten-Year Annualized Cumulative Equity Market Returns (Nominal and Real), and also Subsequent 10-year Average Losses, thereby providing evidence against the Efficient Market Hypothesis and suggesting the possibility of speculative bubbles. / Thesis (BS) — Boston College, 2019. / Submitted to: Boston College. Carroll School of Management. / Discipline: Departmental Honors. / Discipline: Economics.
338

A Cross-Cultural Examination of the Contextual Effects of Gender Inequality on Child Sexual Abuse

LeSuer, Will Monroe, II January 2016 (has links)
No description available.
339

Functional evidence for cone-specific connectivity in the human retina

Whitaker, David J., McGraw, Paul V., McKeefry, Declan J., Vakrou, Chara 09 June 2009 (has links)
No / Physiological studies of colour vision have not yet resolved the controversial issue of how chromatic opponency is constructed at a neuronal level. Two competing theories, the cone-selective hypothesis and the random-wiring hypothesis, are currently equivocal to the architecture of the primate retina. In central vision, both schemes are capable of producing colour opponency due to the fact that receptive field centres receive input from a single bipolar cell ¿ the so called `private line arrangement¿. However, in peripheral vision this single-cone input to the receptive field centre is lost, so that any random cone connectivity would result in a predictable reduction in the quality of colour vision. Behavioural studies thus far have indeed suggested a selective loss of chromatic sensitivity in peripheral vision. We investigated chromatic sensitivity as a function of eccentricity for the cardinal chromatic (L/M and S/(L + M)) and achromatic (L + M) pathways, adopting stimulus size as the critical variable. Results show that performance can be equated across the visual field simply by a change of scale (size). In other words, there exists no qualitative loss of chromatic sensitivity across the visual field. Critically, however, the quantitative nature of size dependency for each of the cardinal chromatic and achromatic mechanisms is very specific, reinforcing their independence in terms of anatomy and genetics. Our data provide clear evidence for a physiological model of primate colour vision that retains chromatic quality in peripheral vision, thus supporting the cone-selective hypothesis.
340

上市上櫃公司股票買回宣告對股價影響之比較研究

費騏葳, Fei ,Chi-wei Unknown Date (has links)
庫藏股制度於國外已經行之有年,特別是美國,早在1960年代即有庫藏股交易。我國上市上櫃股票可合法買回自己公司股票制度始於2000年所通過的上市上櫃公司買回本公司股份辦法,除了希望藉以提振東南亞金融危機中不振的股市表現,也賦予企業多一種能向投資人傳遞訊息的管道。本研究基於股票買回的各項假說,希望探究公司股票買回宣告的動機還有事件宣告後對於公司股價的影響效果,最後並檢視公司的宣告決策是否會受到前次購回宣告的表現所影響。 在假說驗證方面,以2000至2004年上市公司832家、上櫃公司236家曾經宣告買回自家股票的公司為研究樣本,輔以選出與買回樣本同時間的相同數量「未買回樣本」,透過1-way ANOVA測試與鑑別分析探討影響公司宣告股票買回的因素符合哪些假說的推論結果。此外,依據各項假說,進ㄧ步利用1-way ANOVA測試和複迴歸分析找出與公司事件宣告後股價異常報酬率之間的關係,接著以1-way ANOVA檢視最後一部份研究主題。經由上述的實證分析,本研究獲得以下主要結論: 1.公司買回自家的股票平均而言對於股價有正面的影響效果。 2.以上市公司而言,影響公司宣告股票買回的假說包括了:自由現金流量假說、個人所得稅節稅假說與財務槓桿假說。以上櫃公司而言則包括:自由現金流量假說、個人所得稅節稅假說與資訊信號假說。 3.以上市公司而言,股票買回宣告後,股價的正向異常報酬與:自由現金流量假說、管理者的誘因假說呈現相關關係。上櫃公司則包括:自由現金流量假說。 4.本次是否再度宣告股票買回會受前次買回的正向累積異常報酬率所影響。 / Stock price reactions on stock repurchase announcements among publicly traded corporations have been widely studied over 40 years in United States. Several hypothesizes were established and provide logical reasons for why corporations buy back their own stocks. References show large proportion of positive effect on post-announcement stock price after stock repurchase announcements from empirical researches. It is since 2000 that corporations are allowed to repurchase their own stocks legally in Taiwan. Although many efforts were put in surveying the post-announcement stock price reactions, few focused on examining how corporations’ repurchase decision would be influenced by different hypothesizes. Moreover, whether or not previous repurchase outcome may affect future repurchase judgments met contradict conclusion from recent studies. This research aims on exploring the two main topics which form 7 hypothesize. Data collecting from Taiwan Economic Journal (TEJ) database, Commercial Times and Economic Daily News contains publicly traded corporations had ever made stock repurchase announcement except financial and government institutions. The period of the study was from Aug. 6, 2000 to Jul. 31, 2004 and total number of announced corporations included was 832 listed on the Taiwan Security Exchange with 236 listed on the OTC separately. Hypothesis 1 to 6 were tested both from individual model using 1-way ANOVA Analysis and integrated model using Discriminate Analysis on Hypothesis 1 to 5, Event Study Analysis on Hypothesis 6. Hypothesis 7 was also verified with 1-way ANOVA Analysis. The empirical results show supports in several hypothesize which reflect corporations did concern free cash flow amount, leverage level, stock underpriced and dividend payout level issues when making repurchase announcement. The stock price after announcement has certain degree of moving correlation toward the same direction as free cash flow level and managerial stockholding level. Finally, previous repurchase outcome was found holding opposite relation with future repurchase judgments.

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