850 research outputs found
Gentrification : assessing the causes and effects / Winnipeg's municipal conflict of interest guidelines : problems and solutions
iii, 18 p
Harvesting Freedom: African American Agrarianism in Civil War Era South Carolina
Pursuit of property Policies frustrated freed slaves\u27 quest for land The Reconstruction era continues to fascinate scholars around the world. In 1928, French statesman Georges Clemenceau published his History of American Reconstruction, and it is not unlikely that his par...
Neonatal androgenization of hypogonadal (hpg) male mice does not abolish estradiol-induced FSH production and spermatogenesis
BACKGROUND: Testicular development is arrested in the hypogonadal (hpg) mouse due to a congenital deficiency in hypothalamic gonadotropin-releasing hormone (GnRH) synthesis. Chronic treatment of male hpg mice with estradiol induces FSH synthesis and secretion, and causes testicular maturation and qualitatively normal spermatogenesis. As estradiol negative feedback normally inhibits FSH production in the male, this study tested whether this paradoxical response to estradiol in the male hpg mouse might be due to inadequate masculinisation or incomplete defeminization in the neonatal period. Previous studies have demonstrated that treatment of hpg mice with testosterone propionate in the immediate neonatal period is necessary to allow full reproductive behaviors to be expressed following suitable endocrine stimulation at adult ages. METHODS: Hpg mice were treated with 100 μg testosterone propionate or vehicle on postnatal day 2. At 35 days of age, subgroups of these mice were treated with silastic implants containing estradiol or cholesterol. Reproductive behavior was scored in tests with steroid-primed female mice, then testicular development was assessed histologically, and measures of pituitary FSH content made at 85 days of age. RESULTS: The neonatal testosterone propionate treatment successfully defeminized female litter mates, as revealed by impaired vaginal opening and deficiencies in lordosis behavior, and it allowed appropriate male reproductive behavior to be expressed in a proportion of the hpg males when tested at an adult age. However, neonatal androgen supplementation did not block or even reduce the subsequent actions of estradiol in increasing pituitary FSH content, nor did it affect the ability of estradiol to induce qualitatively normal spermatogenesis. CONCLUSION: The ability of the hpg male to show a "female" neuroendocrine response to estradiol is not a result of inadequate androgenization during neonatal development, and thus the actions of estradiol revealed in this rodent model are not an artefact of incomplete sexual differentiation, but reflect a physiological role of estradiol occurring during a specific early temporal window of male reproductive development
Undecalcified Bone Preparation for Histology, Histomorphometry and Fluorochrome Analysis
Undecalcified bone histology demonstrates the micro-architecture of bone. It shows both the mineralised and cellular components of bone, which provides vital information on bone turnover or bone formation and resorption. This has tremendous importance in a variety of clinical and research applications. It yields beautiful images1 and allows for techniques such as fluorochrome assessment and histomorphometry2. Fluorochrome analysis is a technique where fluorescent dyes that bind to calcium are injected at a particular time point, which allows for quantification of the amount of mineralisation at that given time. Histomorphometry is a process of bone quantification at the microscopic level
Exploring corporate governance structures and practices in Jamaica : towards policy reform
This study explores corporate governance (CG) structures and practices in Jamaica to fill theoretical, practical and public policy gaps. The study is organized into four parts and nine chapters. Part one is an introduction to the thesis and the contextual setting. Part two explores the theoretical and methodological framework via an in-depth review of the social science literature on CG and sets out the research strategy and methodology. Part three analyses and discusses the findings from the fieldwork, and part four examines gaps, proposes recommendations for reform, discusses conclusions, limitations of the study, and suggestions for future research. The study assumes a two-fold hypothesis of a CG problem and public policy problem. The CG problem is characterised by a dearth of empirical literature, a lack of CG awareness, and inadequate and poor CG practices among public bodies. The public policy problem is defined by a weak regulatory framework, systemic weaknesses in the financial sector, and pervasive corporate and political corruption. In seeking solution to the problems under review, the study adapts the interviewer’s administered survey method supported by three in-depth case studies and two focus groups. The views of about 100 respondents were sought and an additional unspecified number of informal informants. This multi-technique approach ensured that the weaknesses of a given technique were compensated for by the counterbalancing strengths of other techniques. The key themes of focus were regulation, corruption, ownership and control, stakeholder relations, perceptions and role of institutional investors, board characteristics and processes and the board’s role in strategic decision-making and corporate disclosures. The findings revealed that while Jamaica has implemented several laws and regulations, there are still gaps in coverage, content and effectiveness of implementation. Corruption is still rampant in spite of evidence of a reduction since 2006 (TI 2008 Report). Ownership and control of Jamaican firms are highly concentrated and mainly by oligarchic groups giving way to such problems as an under-developed new issues market, a high degree of insider boards, inadequate minority protection, poor information disclosure, and incentives are aligned to dominant shareholders. There is a lack of representation and voice of employee and trade union representatives in the Jamaican boardrooms and institutional investors (II), while controlling approximately 75% of listed companies, are not interested in promoting CG reform over and above the extent to which such efforts would redound to their self-interest. IIs play influential roles in financing Jamaican politics and control large distribution channels, and determine who gets large private sector contracts. While much is being done internationally to achieve gender balance in the boardroom, the mean number of females on Jamaican corporate boards is 1.8 (or 19.8%) with an average board size of 9.1 Directors. Cross-tabulation analyses were conducted and tests for relationships between and within groups of key variables (board size, Chair/CEO duality, NEDs vs. EDs, number of female Directors with listed and unlisted firms and dominant ownership dispersed vs. closely held) and nothing of significance was found. The study has concluded that reform is needed in several areas. These include increase of coverage and content of legislation and enforcement mechanisms to improve CG and fight corruption; reform of corporate boards - director selection and appointments, board’s role and conduct of Directors, training and board performance evaluation. Future research is directed at more emphasis on CG in developing countries, SMEs, public bodies and non-profit organizations, the role and contribution of employees and trade unions, the board’s role in influencing strategy, and the role of risk management. The study seeks to contribute to the growing body of international literature on emerging CG and targets primarily academics, practitioners and policymakers.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Self-Supervised Visuo-Tactile Pretraining to Locate and Follow Garment Features
Humans make extensive use of vision and touch as complementary senses, with
vision providing global information about the scene and touch measuring local
information during manipulation without suffering from occlusions. While prior
work demonstrates the efficacy of tactile sensing for precise manipulation of
deformables, they typically rely on supervised, human-labeled datasets. We
propose Self-Supervised Visuo-Tactile Pretraining (SSVTP), a framework for
learning multi-task visuo-tactile representations in a self-supervised manner
through cross-modal supervision. We design a mechanism that enables a robot to
autonomously collect precisely spatially-aligned visual and tactile image
pairs, then train visual and tactile encoders to embed these pairs into a
shared latent space using cross-modal contrastive loss. We apply this latent
space to downstream perception and control of deformable garments on flat
surfaces, and evaluate the flexibility of the learned representations without
fine-tuning on 5 tasks: feature classification, contact localization, anomaly
detection, feature search from a visual query (e.g., garment feature
localization under occlusion), and edge following along cloth edges. The
pretrained representations achieve a 73-100% success rate on these 5 tasks.Comment: RSS 2023, site: https://sites.google.com/berkeley.edu/ssvt
Fast Large-Tip-Angle Multidimensional and Parallel RF Pulse Design in MRI
Large-tip-angle multidimensional radio-frequency (RF) pulse design is a difficult problem, due to the nonlinear response of magnetization to applied RF at large tip-angles. In parallel excitation, multidimensional RF pulse design is further complicated by the possibility for transmit field patterns to change between subjects, requiring pulses to be designed rapidly while a subject lies in the scanner. To accelerate pulse design, we introduce a fast version of the optimal control method for large-tip-angle parallel excitation. The new method is based on a novel approach to analytically linearizing the Bloch equation about a large-tip-angle RF pulse, which results in an approximate linear model for the perturbations created by adding a small-tip-angle pulse to a large-tip-angle pulse. The linear model can be evaluated rapidly using nonuniform fast Fourier transforms, and we apply it iteratively to produce a sequence of pulse updates that improve excitation accuracy. We achieve drastic reductions in design time and memory requirements compared to conventional optimal control, while producing pulses of similar accuracy. The new method can also compensate for nonidealities such as main field inhomogeneties.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/86004/1/Fessler12.pd
SMOS L1C and L2 Validation in Australia
Extensive airborne field campaigns (Australian Airborne Cal/val Experiments for SMOS - AACES) were undertaken during the 2010 summer and winter seasons of the southern hemisphere. The purpose of those campaigns was the validation of the Level 1c (brightness temperature) and Level 2 (soil moisture) products of the ESA-led Soil Moisture and Ocean Salinity (SMOS) mission. As SMOS is the first satellite to globally map L-band (1.4GHz) emissions from the Earth?s surface, and the first 2-dimensional interferometric microwave radiometer used for Earth observation, large scale and long-term validation campaigns have been conducted world-wide, of which AACES is the most extensive. AACES combined large scale medium-resolution airborne L-band and spectral observations, along with high-resolution in-situ measurements of soil moisture across a 50,000km2 area of the Murrumbidgee River catchment, located in south-eastern Australia. This paper presents a qualitative assessment of the SMOS brightness temperature and soil moisture products
Duration of adjuvant chemotherapy for stage III colon cancer
BACKGROUND
Since 2004, a regimen of 6 months of treatment with oxaliplatin plus a fluoropyrimidine has been standard adjuvant therapy in patients with stage III colon cancer. However, since oxaliplatin is associated with cumulative neurotoxicity, a shorter duration of therapy could spare toxic effects and health expenditures.
METHODS
We performed a prospective, preplanned, pooled analysis of six randomized, phase 3 trials that were conducted concurrently to evaluate the noninferiority of adjuvant therapy with either FOLFOX (fluorouracil, leucovorin, and oxaliplatin) or CAPOX (capecitabine and oxaliplatin) administered for 3 months, as compared with 6 months. The primary end point was the rate of disease-free survival at 3 years. Noninferiority of 3 months versus 6 months of therapy could be claimed if the upper limit of the two-sided 95% confidence interval of the hazard ratio did not exceed 1.12.
RESULTS
After 3263 events of disease recurrence or death had been reported in 12,834 patients, the noninferiority of 3 months of treatment versus 6 months was not confirmed in the overall study population (hazard ratio, 1.07; 95% confidence interval [CI], 1.00 to 1.15). Noninferiority of the shorter regimen was seen for CAPOX (hazard ratio, 0.95; 95% CI, 0.85 to 1.06) but not for FOLFOX (hazard ratio, 1.16; 95% CI, 1.06 to 1.26). In an exploratory analysis of the combined regimens, among the patients with T1, T2, or T3 and N1 cancers, 3 months of therapy was noninferior to 6 months, with a 3-year rate of disease-free survival of 83.1% and 83.3%, respectively (hazard ratio, 1.01; 95% CI, 0.90 to 1.12). Among patients with cancers that were classified as T4, N2, or both, the disease-free survival rate for a 6-month duration of therapy was superior to that for a 3-month duration (64.4% vs. 62.7%) for the combined treatments (hazard ratio, 1.12; 95% CI, 1.03 to 1.23; P=0.01 for superiority).
CONCLUSIONS
Among patients with stage III colon cancer receiving adjuvant therapy with FOLFOX or CAPOX, noninferiority of 3 months of therapy, as compared with 6 months, was not confirmed in the overall population. However, in patients treated with CAPOX, 3 months of therapy was as effective as 6 months, particularly in the lower-risk subgroup. (Funded by the National Cancer Institute and others.
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