• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 706
  • 479
  • 221
  • 137
  • 89
  • 27
  • 22
  • 19
  • 16
  • 14
  • 14
  • 14
  • 14
  • 14
  • 14
  • Tagged with
  • 2044
  • 600
  • 409
  • 229
  • 200
  • 199
  • 141
  • 133
  • 127
  • 117
  • 115
  • 113
  • 108
  • 96
  • 95
  • 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.
381

Composted societal organic wastes for sustainable wheat (Triticum aestivum) production

Rodrigues, Mario Sergio January 1996 (has links)
No description available.
382

Essays in the economics of crime and corruption

Papadopoulou, Vea Genovefa January 2012 (has links)
The purpose of the thesis is to offer an examination of the economics of crime and corruption. By stressing the importance of Becker's seminal paper, we show how criminal behaviour is no longer considered the result of mental illness, but a decision largely based on a cost-benefit comparison from the possible legal and illegal actions. The puzzle that countries, with seemingly identical characteristics, display different corruption levels can be explained by considering the role of social stigma in the decision-making process. Additionally, we also examine the way that corruption is practised, by assuming that two regimes are possible, namely, collusive corruption and non-collusive corruption regimes. In the second part of the thesis, we examine the interrelationships between crime, fertility and economic growth. We link these variables of interest with the probability of avoiding apprehension, which is considered as one of the most important deterrence factors in crime decisions. In line with current literature, results show that a higher probability of avoiding apprehension increases crime rates, has a non-monotonic effect on fertility rates and an ambiguous impact on growth. The contribution of the model is that the relationship between the probability of avoiding apprehension and crime is not linear, but becomes positive after a threshold value of the parameter. In the subsequent part we provide an econometric analysis that examines these empirical regularities. We find that there exists a positive relationship between the probability of escaping apprehension, the rates of crime and fertility. The relationship is not linear but is subject to threshold effects. The finding of a positive impact of the probability of escaping arrest on both crime and fertility implies that the positive link between fertility and crime is an equilibrium outcome, rather than a causal one running from fertility to crime. In addition, we find that the probability of escaping apprehension has a negative effect on economic growth, an effect that becomes more notable when the probability exceeds a threshold value. Lastly, we consider the interrelationships among the three endogenous variables of crime, fertility and growth. In accordance with the theoretical section, we find that the probability of avoiding detection has a positive effect on both crime and fertility. In addition, these two variables negatively affect economic growth.
383

Parametros reprodutivos masculinos e fertilidade de ratos adultos expostos ao inseticida fenvalerato / Male reproductive parameters and fertility of adult rats exposed to fenvalerate

Arena, Arielle Cristina 10 November 2006 (has links)
Orientador: Wilma de Grava Kempinas / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-07T11:02:16Z (GMT). No. of bitstreams: 1 Arena_ArielleCristina_D.pdf: 6263469 bytes, checksum: 65be2ee6efd96baa2f00b966ad068e99 (MD5) Previous issue date: 2006 / Resumo: O fenvalerato é um inseticida piretróide sintético amplamente utilizado na agricultura para o controle de pragas. Embora seja considerado de baixa toxicidade para os mamíferos, trabalhos têm demonstrado que certos piretróides podem apresentar atividade estrogênica e atuar como desreguladores endócrinos, acarretando disfunções reprodutivas importantes no sexo masculino. Está documentado na literatura que a exposição de ratas prenhes ao fenvalerato reduziu os níveis plasmáticos de testosterona e os pesos da vesícula seminal e do ducto deferente dos filhotes machos na idade adulta, além de alterações no comportamento sexual desses animais. Também foi observado que ratos adultos expostos à formulação de fenvalerato, por inalação, exibiram uma redução significativa no peso dos testículos e na contagem espermática no epidídimo. Até o momento pouco se sabe sobre os mecanismos pelos quais o fenvalerato exerce sua ação na reprodução, assim, o objetivo do presente trabalho foi investigar a atividade estrogênica e os efeitos do inseticida piretróide fenvalerato sobre o sistema reprodutor masculino e fertilidade de ratos machos adultos. Para tanto, ratos machos adultos (90 dias de idade) receberam durante 30 dias consecutivos, por gavage (via oral), 40 mg/kg/dia de fenvalerato (grau técnico; 96,8% de pureza). O grupo controle recebeu apenas o veículo (óleo de milho), segundo o mesmo protocolo experimental. No final do tratamento, foram avaliados os seguintes parâmetros: peso corporal; peso absoluto de órgãos da reprodução, fígado e rins; níveis plasmáticos de testosterona; contagem de células germinativas no testículo e no epidídimo; morfologia espermática; estudo da fertilidade através de cruzamentos naturais e inseminação artificial in utero; contagem de espermatozóides ejaculados no útero; avaliação do comportamento sexual; análises do testículo e epidídimo em nível de microscopia óptica e eletrônica e avaliação da possível atividade estrogênica de diferentes doses do fenvalerato (0,4; 1,0; 4,0; 8,0 e 40 mg/kg) através do teste uterotrófico. A quantificação de resíduos de fenvalerato por Cromatografia Líquida de Alta Precisão (HPLC) em órgãos reprodutores e vitais e análises de proteínas espermáticas e epididimárias também foram realizadas. Os resultados foram comparados pelos testes ¿t¿ de Student e Mann-Whitney, dependendo da natureza da distribuição dos dados, enquanto os resultados do teste uterotrófico comparados pela ANOVA seguida pelo teste de Tukey. Os resultados da quantificação de fenvalerato revelaram que o piretróide foi retido em órgãos reprodutores (testículo e epidídimo) e vitais (cérebro e fígado). O tratamento com fenvalerato reduziu os pesos absolutos do testículo e do epidídimo. Além disso, o tratamento não provocou diminuição nos níveis plasmáticos de testosterona. Verificou-se também que os ratos tratados apresentaram redução na produção espermática no testículo e no número de espermatozóides no epidídimo. No entanto, não foi observado comprometimento na fertilidade desses machos quando acasalados com fêmeas controles. As análises morfológicas do testículo e epidídimo assim como as análises de proteínas espermáticas e epididimárias não mostraram alterações. Além disso, o fenvalerato, nas doses testadas, não apresentou atividade estrogênica in vivo. Concluiu-se que o fenvalerato, nestas condições experimentais, foi retido em órgãos reprodutores e vitais. O fenvalerato foi espermatotóxico, visto que reduziu tanto a produção quanto as reservas espermáticas dos animais tratados. No entanto, apesar dessa alteração, a fertilidade dos animais tratados não foi comprometida, uma vez que o rato tem uma grande eficiência reprodutiva, diferentemente do que acontece com o ser humano / Abstract: Fenvalerate is a synthetic pyrethroid insecticide widely used in agriculture to control a variety of insects. Although it is considered to be of low acute toxicity to mammals, studies have showed that pyrethroids can have estrogenic activity and can act as endocrine disruptors, causing important reproductive impairment in males. It is documented in the literature that the exposure of pregnant rats to fenvalerate decreased plasma testosterone levels and weights of seminal vesicle and vas deferens in male pups during adult life, besides alterations in their sexual behavior. It was also observed that adult rats exposed to formulated fenvalerate,by inhalation, exhibited a significant reduction in the testis weight and epididymal sperm count. Little is known about the mechanisms by which fenvalerate exerts its action on reproduction; thus, the objective of the present study was to investigate the estrogenic activity and the effects of fenvalerate on the reproductive system and fertility of adult male rats. For this, adult male rats (aged 90 days) received, for 30 consecutive days, by oral gavage, 40 mg/kg/day of fenvalerate (technical grade; 96.8% purity). The control group received only the vehicle (corn oil), in the same experimental conditions. At the end of the treatment, the following parameters were analyzed: body weight; absolute weight of reproductive organs, liver and kidneys; plasma testosterone levels; germ cell count in the testis and epididymis; sperm morphology; fertility tests by natural matings and artificial insemination in utero; ejaculated sperm counts in uterus; sexual behavior; analysis of testis and epididymis at the optical and electron microscopic levels, and evaluation of possible estrogenic activity of different doses (0.4; 1.0; 4.0; 8.0 and 40 mg/kg) of fenvalerate by the uterotrophic test. Fenvalerate residues were quantified using High Performance Liquid Chromatography (HPLC) in reproductive and vital organs; sperm and epididymal protein were also realized. The results were compared by Student-t and Mann-Whitney tests, according to the characteristics of each variable, while the results of the uterotrophic test were compared by ANOVA followed by the Tukey test. The results of fenvalerate quantification revealed that the pyrethroid was retained in reproductive (testis and epididymis) and vital organs (brain and liver). The treatment with fenvalerate decreased the absolute weights of testis and epididymis. Furthermore, the treatment did not provoke reduction of plasma testosterone levels. It was also verified that the treated rats presented a reduction in daily sperm production and in epididymal sperm number. The fertility tests did not reveal differences related to the treatment. The results of the fenvalerate quantification revealed high concentrations of insecticide residues in the epididymis, testis, brain and liver. The histopathology of the testis and epididymis as well as analysis of sperm and epididymal proteins did not show alterations. Moreover, fenvalerate, at the tested doses, did not present estrogenic activity in vivo. It was concluded that fenvalerate, in these experimental conditions, was retained in reproductive organs and was spermatotoxic, since it reduced sperm production and storage, but this alteration was not sufficient to compromise fertility by virtue of the high reproductive efficiency of rodents in contrast with humans / Doutorado / Biologia Celular / Doutor em Biologia Celular e Estrutural
384

Fertilizer Management Strategies of Soybean (Glycine Max, L. Merrill) in Northcentral and Northwestern North Dakota

Augustin, Christopher Lee January 2019 (has links)
Soybean (Glycine max L. Merrill) is a new cash crop for north central and northwestern North Dakota producers. Soils and climate in these new soybean areas differ from those regions where the current fertilizer recommendations were based. Northcentral and northwestern North Dakota is more undulating, drier, cooler, and has differencing soils than eastern North Dakota and Minnesota. A three-year study to evaluate soybean best management practices was conducted during the 2016 to 2018 growing seasons. Each year, the study consisted of two sites and 12 treatments. By design, one site was on acidic (pH < 6) soil while the other was on alkaline (pH > 7.3) soil. Both site treatments were: untreated check, inoculated with rhizobia (B. japonicum L.), broadcast urea (55 kg ha-1), broadcast MAP (monoammonium phosphate, 11-52-0) (110 kg ha-1), in-furrow 10-34-0 (28 L ha-1), in-furrow 6-24-6 (28 L ha-1), foliar 3-18-18 (28 L ha-1) at V5 and R2 growth stages, and foliar 3-18-18 (28 L ha-1) with sulfate (1.1 kg ha-1) at V5 and R2. The acidic sites alone included two treatments of sugar beet (Beta vulgaris L.) waste lime (4.4 Mg ha-1 and 8.8 Mg ha-1). The alkaline sites alone received treatments of iron ortho-ortho-EDDHA (1.8% Fe) (7.1 L ha-1), and sodium (naked- without Fe) ortho-ortho-EDDHA (7.1 L ha-1). Treatments did not impact soybean yield, protein content or oil content at the 95% significance level. Sugar beet waste lime surface applied at planting at rates of 4.4 Mg ha-1 and 8.8 Mg ha-1 increased soil pH to a depth of 10 cm over the course of the growing season. / North Dakota Soybean Council
385

Can Hematocrit Levels at Estrus in Dairy Cows and Sheep Be an Indicator for Pregnancy Success?

Kelany, Khaled Elaraby January 2019 (has links)
Despite the major reproductive advances in the livestock industry, prenatal embryonic loss is still one of the major issues that causes substantial economic loss. While there are many tests available to determine pregnancy soon after maternal recognition of pregnancy, most of the prenatal losses are undetectable because it occurs before then. Based on previous research we hypothesized that increased plasma volume around the time of estrus will increase the survivability of the embryo at early stages of gestation. However, our findings indicate that hematocrit levels are not a consistent measurement in determining successful pregnancies.
386

Childhood cancer fertility preservation decision aid: development and field testing

Grasso, Jessica 10 October 2019 (has links)
There is an increased number of childhood cancer survivors living into adulthood. As more survivors live into adulthood, researchers have been able to study and better understand the late effects of cancer treatment. A well-known late effect of cancer treatment is the risk of infertility. Cancer-related infertility is a source of distress to cancer survivors. There have been many advances to fertility preservation over the last few years and there are now multiple options available for both men and women. Despite the improved understanding of the risk of cancer-related infertility and advances to fertility preservation treatment, these services remain underutilized by cancer patients. It is known that discussing fertility preservation options with newly diagnosed cancer patients improves survivors’ long-term quality of life and reduces decisional regret, regardless of if they pursue fertility preservation treatment. Survivors often report that the risk of treatment-related infertility and/or available fertility preservation options was often inadequately or not discussed with them at the time of diagnosis. The use of fertility preservation decision aids for adult patients newly diagnosed with cancer have been proven to be effective at improving participants’ knowledge surrounding fertility preservation, reducing decisional conflict, and reducing long term decisional regret. A fertility preservation decision aid has not yet been developed for use by adolescents newly diagnosed with childhood cancer. This study aims to engage survivors and providers to develop a fertility preservation decision aid to improve the decision quality of adolescents newly diagnosed with childhood cancer who are determining their preferences on accepting a referral to a fertility specialist. This study then proposes to field test the decision aid with newly diagnosed patients. The use of a decision aid will lead adolescents with childhood cancer to have increased knowledge on the risk of infertility and the fertility preservation options available. This study also aims to lower participants’ levels of decisional conflict about their fertility preferences. There is a need to incorporate the use of a fertility preservation decision aid into childhood cancer treatment. If this decision aid proves effective, referral to the fertility preservation decision aid may become common practice at the time of initial diagnosis. If the decision aid is effect at improving decision quality and reducing decisional conflict, survivors may experience long-term benefits including improved quality of life and reduced levels of decisional regret.
387

Improving referral rate of female cancer patients to reproductive endocrinology

Riemer, Rebecca 11 October 2019 (has links)
BACKGROUND: There are currently an estimated 250,000 female cancer survivors of reproductive age living in the US. Loss of fertility is an issue many cancer survivors face after treatment, as all forms of cancer therapy can cause infertility. Methods to preserve fertility can be initiated prior to cancer therapy. These methods include embryo cryopreservation, oocyte cryopreservation, fertility sparing surgery, ovarian tissue cryopreservation, ovarian transposition, and medical therapy. LITERATURE REVIEW: Although the clinical guidelines state that oncologists should discuss the risk of infertility with every patient of reproductive age and should refer every patient who is interested in or ambivalent towards fertility preservation to reproductive endocrinologists, studies have shown that a significant proportion of female cancer patients report never receiving information about fertility. Even fewer female cancer patients are referred to reproductive endocrinologists for further discussion and/or potential treatment. PROPOSED PROJECT: Oncologists at Boston Medical Center will be recruited to participate in a study that measures the effect of an educational intervention on referral rate to reproductive endocrinology. The knowledge gained from the intervention will be assessed with a pre- and post-test. The proportion of female patients age 18-45 referred to reproductive endocrinology will be evaluated through the Electronic Medical Record System. The correlation between knowledge gain and change in referral rates will also be assessed. CONCLUSION: Fertility after cancer treatment is an essential issue to consider for young cancer survivors. These patients benefit from being referred to reproductive endocrinologists so that they can get information about fertility preservation and undergo treatment in a timely fashion. Improving and/or reinforcing oncologist knowledge about this topic will increase the rate at which they initiate this conversation and therefore the number of female patients who are referred to reproductive endocrinology. SIGNIFICANCE: Providing female cancer patients with information about and opportunities to undergo fertility preservation will maximize their options. This will lead to a higher quality of life after cancer therapy.
388

Ethnic differentiation of fertility in Kazakhstan

Abuov, Anas January 2010 (has links)
Ethnic differentiation of fertility in Kazakhstan Abstract This paper examines ethnic differentials in fertility in Kazakhstan using data from the Statistical Agency of Kazakhstan from 1999 to 2006. The study focuses on four major ethnic groups including Kazakhs, Russians, Ukrainians and Uzbeks which account for 90% of the country's population. The paper lays emphasis on comparison and determination of differences in fertility trends among the chosen ethnic groups. In order to describe the main reasons of differences in fertility trends in greater detail, the author analyzed birth orders in fertility in the groups. At the same time, the paper presents ethnic structure of Kazakhstan's population and within each ethnicity it shows age structure which also determines fertility trends. Keywords: Ethnicity, ethnic groups, fertility, differentiation, Kazakhstan.
389

Essays in Applied Microeconomics

El Kattan, Lamis 27 May 2022 (has links)
This dissertation includes three essays in applied microeconomics. The first two chapters focus on gender and female labor force participation. The third chapter examines the strategic behavior in politics. The first chapter examines the impact of male casualties due to World War II on fertility and female employment in the United States. We rely on the number of casualties at the county-level and use a differences-in-differences strategy. While most counties in the U.S. experienced a Baby Boom following the war, we find that the increase in fertility was lower in high casualty rate counties than in low casualty rate counties. Analyzing the channels through which male casualties could have decreased fertility, we provide evidence that county male casualties are positively related to 1950s female employment and household income. The second chapter examines the impact of gender focused labor legislation on women's labor force participation and economic empowerment. We rely on historical acts passed by state legislatures and exploit whether or not states passed regulatory laws regulating overall and industry specific employment and work conditions for women, night work laws and labor laws requiring provision of seats for working women. We exploit the fact that not all states enacted these laws as well as the variation in the timing of enactment of such laws. Our results show that women in comparison to men in treated states are more likely to be in the labor force after the introduction of seating and night work laws relative to control states. We also document the effect of industry-specific labor policies on women's likelihood to be employed in the affected industry and in higher-wage occupations within the industry of interest. Policy implications of our findings endorse the adoption of labor laws in favor of women to further their empowerment through a higher involvement in the labor market and financial independence. The third chapter examines strategic timing in the appearance of scandals about elected officials in the United States. In order to minimize negative publicity, politicians may strategically manipulate the timing of uncovering their own unpopular actions to coincide with other important events that are crowding the media and distracting the public. I start by developing a simple voting model to better understand the different mechanisms behind the timing of scandals' appearance. A forward-looking strategy implies that predictable news events may be used by politicians to distort public opinion. Using a novel data set of misconduct episodes from 1970 to 2020 and an instrumental variable strategy, I show that scandals are more likely to appear simultaneously with other foreseeable newsworthy events. I also examine the heterogeneity of different types of scandals and potentially different behavior across political parties. My findings suggest that Republican politicians are behaving especially strategically in timing the revelation of sexual and political misconducts.
390

Environment, fertility, structural change, and growth / 環境、出生、構造変化と成長

Wu, Chen 23 March 2021 (has links)
京都大学 / 新制・課程博士 / 博士(経済学) / 甲第22958号 / 経博第633号 / 新制||経||296(附属図書館) / 京都大学大学院経済学研究科経済学専攻 / (主査)准教授 遊喜 一洋, 教授 柴田 章久, 准教授 安井 大真 / 学位規則第4条第1項該当 / Doctor of Economics / Kyoto University / DFAM

Page generated in 0.033 seconds