Time series of brightness temperature (TB) measurement obtained at various frequencies by the Advanced Microwave Scanning Radiometer–Earth Observing System (AMSR-E) are investigated to determine ice phenology parameters and ice thickness on Great Bear Lake (GBL) and Great Slave Lake (GSL), Northwest Territories, Canada. TB measurements from the 6.9, 10.7, 18.7, 23.8, 36.5, and 89.0 GHz channels (H- and V- polarization) are compared to assess their potential for detecting freeze-onset (FO)/melt-onset (MO), ice-on/ice-off dates, and ice thickness on both lakes. The sensitivity of TB measurements at 6.9, 10.7, and 18.7 GHz to ice thickness is also examined using a previously validated thermodynamic lake ice model and the most recent version of the Helsinki University of Technology (HUT) model, which accounts for the presence of a lake-ice layer under snow. This study shows that 18.7 GHz H-pol is the most suitable AMSR-E channel for detecting ice phenology events, while 18.7 GHz V-pol is preferred for estimating lake ice thickness on the two large northern lakes. These two channels therefore form the basis of new ice cover retrieval algorithms. The algorithms were applied to map monthly ice thickness products and all ice phenology parameters on GBL and GSL over seven ice seasons (2002-2009). Through application of the algorithms much was learned about the spatio-temporal dynamics of ice formation, decay and growth rate/thickness on the two lakes. Key results reveal that: 1) both FO and ice-on dates occur on average 10 days earlier on GBL than on GSL; 2) the freeze-up process or freeze duration (FO to ice-on) takes a comparable amount of time on both lakes (two to three weeks); 3) MO and ice-off dates occur on average one week and approximately four weeks later, respectively, on GBL; 4) the break-up process or melt duration (MO to ice-off) lasts for an equivalent period of time on both lakes (six to eight weeks); 5) ice cover duration is about three to four weeks longer on GBL compared to its more southern counterpart (GSL); and 6) end-of-winter ice thickness (April) on GBL tends to be on average 5-15 cm thicker than on GSL, but with both spatial variations across lakes and differences between years.

This master's essay is about seasonality in Bristols slave trade until the American Revolution 1776. The essay uses the Voyages database as the primary material. The essay's method is to study monthly distribution at different points of the slave trade – the departure from Bristol and the arrival at the American destination. The seasonality of slave purchases in Africa is primarly studied through the monthly distribution of departures from Bristol for a specific region in Africa. This methodological choice is based on the lack of coverage of African arrival dates. The theoretical groundwork in the essay is foremost based on Henri Lefebvre's concept of rhytm analysis. The results of the essay show that there usually was some seasonality in the different parts of Bristol's slave trade. The essay tries to relate this seasonality with possible explanations, like the need of provisions, trade goods, harvest cycles in Africa and America, though the essay doesn't have any pretensions of proving actual causal relations, just that the seasonality of the slave trade coincided with other seasonal cycles.

The basis of this thesis has been constructed from the following sources: 1) The British Sessional Papers (1868-1891 on Readex Cards). The Slave Trade Reports throughout this period also include valuable commercial material and political correspondance. The vast amounts of material on the slave trade or under slave trade headings has resulted in a tendency to distort the importance of Britain's anti-slave trade policy in this region. [...]

No description available.

No abstract available. / Thesis (M.A.)-University of Natal, Durban, 1973.

1. Introduction This dissertation consists of six chapters that span a very diverse set of topics. Yet, it has two unifying themes, economics and biology, that tie it together. The first four chapters present the principal findings from a project that was initiated jointly with David Cesarini and Magnus Johannesson, and that applies the twin method from behavioral genetics to economics. The last two chapters instead use a simple regression framework and evidence from biological anthropology to investigate recent claims regarding the effects of child bearing and past slave trades. 2. Genes and economics There is a small, but rapidly growing, literature studying the genetic and environmental origins of economic behavior and outcomes (Bowles et al., 2005; Beauchamp et al., 2011). Until recently, this literature focused exclusively on outcomes, and in particular income. In chapters 1-4 we instead focus on economic behavior and decision-making. Previous behavioral genetic work outside the domains of economics has changed the way that we think about a number of behavioral traits. In this literature it is typically found that i) variation is heritable ii) genetic factors are more important than family environment iii) a large fraction of variation cannot be explained by neither genes nor family environment (Turkheimer, 2000; Plomin et al., 2009). However, compared to many other disciplines, and psychology in particular, economics is lagging behind. In fact, as recently as 2009 the leading text book in behavioral genetics described economics as "still essentially untouched by genetic research" (Plomin et al., 2009, p. 353). Hopefully, the chapters in this dissertation can help to improve on this somewhat unsatisfactory state of the art. Chapters 1 and 2 study economic decision-making in the laboratory using the twin method. More specifically, we study the ultimatum and dictator games alongside risky gambles, using same-sex twin pairs as our subject pool. Given a few additional assumptions, the fact that identical twins have, in expectation, a twice as high coefficient of genetic relatedness as fraternal twins implies that we can study the genetic and environmental contributions to variation in behavior by studying twin correlations in observed choices. Chapters 3 and 4 apply the same method to actual portfolio choices associated with a far-reaching pension reform, as well as to a set of standard behavioral anomalies. Taken together, these four chapters provide strong evidence in favor of the hypothesis that genes influence economic decision-making. Thus, economic behavior does not appear to be much different from other types of behavior. 3. Economics and history The last two chapters of the dissertation turn to the past, rather than genes, in an effort to evaluate recent findings regarding two important welfare outcomes. In chapter 5 we investigate Nunn’s (2008) claim that past slave trades had a negative impact on current economic performance in Africa. By extending the sample period back in time we demonstrate that this relationship was not significant in 1960. In addition, by applying Nunn’s method to an episode of large scale slave raiding in Italy, we demonstrate that there exists a similar negative relationship across Italian regions, although it becomes insignificant when geographical controls are included. Intriguingly, going back to 1960, the coefficient on slave raids for Italy also has a similar time trend to that for Africa. Taking these facts, and our reading of the historical and anthropological literature, which is much different from that of Nunn, into account we do not find much support for the hypothesis that the African slave trades had a negative impact on current economic performance. Finally, chapter 6 investigates the large and negative relationship between giving birth to a son, rather than a daughter, and maternal longevity that was documented in a Sami hunter-gatherer population from Finland (Helle et al., 2002). Using a substantially larger sample of pre-industrial Swedish Sami we find no evidence in favor of such a relationship. 4. Brasklapp Five of the chapters in this dissertation (Ch. 1-4 &amp; 6) are slightly altered versions of previously published papers (Wallace et al., 2007; Cesarini et al., 2009 a, b; 2010; 2011). Unfortunately, the fact that earlier versions of the chapters were prepared as separate articles for five different journals means that they can at times appear both repetitive, and in terms of notation and formatting, somewhat inconsistent. I apologize to the reader for these inconveniences. / <p>Diss. Stockholm :  Stockholm School of Economics, 2011. Introduction together with 6 papers</p>

Albeit that often the only solution left to poor congregations in Africa is the practice of tentmaker ministry, this phenomenon remains problematic. There is a lack of job opportunities in the rural areas, and dividing one's time between the secular occupation and the ministry becomes increasingly complex. In the light of this situation, an (re–)evaluation of the Biblical foundations for being a tentmaker is certainly called for. Studies such as the book of Meggitt (1998), Paul, poverty and survival, stimulated renewed interest in the economic nature of Paul's ministry and the economic classes of the congregations where he ministered. Paul's offering of the gospel free of charge (1 Cor 9:18), and his sacrifice of "becoming a slave", offer interesting solutions for the poverty stricken churches in Africa, and in particular in Botswana. / Thesis (Ph.D. (New Testament))--North-West University, Potchefstroom Campus, 2011.

Albeit that often the only solution left to poor congregations in Africa is the practice of tentmaker ministry, this phenomenon remains problematic. There is a lack of job opportunities in the rural areas, and dividing one's time between the secular occupation and the ministry becomes increasingly complex. In the light of this situation, an (re–)evaluation of the Biblical foundations for being a tentmaker is certainly called for. Studies such as the book of Meggitt (1998), Paul, poverty and survival, stimulated renewed interest in the economic nature of Paul's ministry and the economic classes of the congregations where he ministered. Paul's offering of the gospel free of charge (1 Cor 9:18), and his sacrifice of "becoming a slave", offer interesting solutions for the poverty stricken churches in Africa, and in particular in Botswana. / Thesis (Ph.D. (New Testament))--North-West University, Potchefstroom Campus, 2011.

Time series of brightness temperature (TB) measurement obtained at various frequencies by the Advanced Microwave Scanning Radiometer–Earth Observing System (AMSR-E) are investigated to determine ice phenology parameters and ice thickness on Great Bear Lake (GBL) and Great Slave Lake (GSL), Northwest Territories, Canada. TB measurements from the 6.9, 10.7, 18.7, 23.8, 36.5, and 89.0 GHz channels (H- and V- polarization) are compared to assess their potential for detecting freeze-onset (FO)/melt-onset (MO), ice-on/ice-off dates, and ice thickness on both lakes. The sensitivity of TB measurements at 6.9, 10.7, and 18.7 GHz to ice thickness is also examined using a previously validated thermodynamic lake ice model and the most recent version of the Helsinki University of Technology (HUT) model, which accounts for the presence of a lake-ice layer under snow. This study shows that 18.7 GHz H-pol is the most suitable AMSR-E channel for detecting ice phenology events, while 18.7 GHz V-pol is preferred for estimating lake ice thickness on the two large northern lakes. These two channels therefore form the basis of new ice cover retrieval algorithms. The algorithms were applied to map monthly ice thickness products and all ice phenology parameters on GBL and GSL over seven ice seasons (2002-2009). Through application of the algorithms much was learned about the spatio-temporal dynamics of ice formation, decay and growth rate/thickness on the two lakes. Key results reveal that: 1) both FO and ice-on dates occur on average 10 days earlier on GBL than on GSL; 2) the freeze-up process or freeze duration (FO to ice-on) takes a comparable amount of time on both lakes (two to three weeks); 3) MO and ice-off dates occur on average one week and approximately four weeks later, respectively, on GBL; 4) the break-up process or melt duration (MO to ice-off) lasts for an equivalent period of time on both lakes (six to eight weeks); 5) ice cover duration is about three to four weeks longer on GBL compared to its more southern counterpart (GSL); and 6) end-of-winter ice thickness (April) on GBL tends to be on average 5-15 cm thicker than on GSL, but with both spatial variations across lakes and differences between years.

Issued also as Thesis (Ph. D.)--Johns Hopkins University. / Bibliography: p. 177-181.