The relationship between leadership practices of principals and student achievement

This study sought to determine if a significant relationship existed between the leadership practices of school principals and student achievement in mathematics and reading. The leadership practices of principals were measured using Kouzes’and Posner’s Leadership Practices Inventory (LPI) which measures leadership practices in five distinct areas: modeling the way, inspiring a shared vision, challenging the process, enabling others to act and encouraging the heart. Student achievement in reading and mathematics was determined using the percentage of students proficient in reading and mathematics as measured by the state of West Virginia’s standardized exam, the West Virginia Educational Standards Test (WESTEST) for the 2003-2004 and 2004-2005 school years. This study also considered the relationship of four selected demographic variables (per-pupil expenditure, principals’ years of experience, school size and socioeconomic status) and the interaction of the leadership practices of principals and student achievement in both mathematics and reading. The study’s population consisted of West Virginia’s school principals who had served as the principal of their schools for a minimum period of three years and whose schools contained some portion of grades three through eight (N=350). When examining the relationship between the leadership practices of principals and student achievement, a significant relationship was found between the leadership practice modeling the way and individual cases of student achievement in reading. Seven additional significant relationships were found when considering the relationship between selected demographic variables and the interaction of the leadership practices of principals and student achievement in mathematics and reading. The seven significant relationships existed when principals’ years of experience, school size and socioeconomic status were considered. No significant relationships were found when examining per-pupil expenditure

THREE-DIMENSIONAL ANALYSIS OF COLOUR DOPPLER ULTRASOUND IMAGES: THE RELATIONSHIP OF VASCULAR FLOW TO OVARIAN STRUCTURES AND THEIR FUNCTION IN BUFFALO COWS AND BEEF CALVES

The main objective of this thesis was to develop a three-dimensional method to assess ovarian structures and relate their vascularity to their function (i.e. hormone production, oocyte quality, ovulatory capacity, etc.). This novel method uses video segments recorded after free-hand movement of the routine linear-array transducer, obtained vascularity index values are independent of speed of transducer movement, and the method does not require a-priori operator selection of images, i.e. is an objective method. In Study 1, colour Doppler ultrasonography was used to assess the ovaries of water buffalo (Bubalus bubalis) who were induced to ovulate using a gonadotropin releasing hormone analogue. Ultrasonographic examinations were performed daily to assess ovulation and subsequent corpus luteum (CL) development. Recorded cineloops were exported from the ultrasound machine and analyzed on a personal computer equipped with imaging software from two sources, Fiji (ImageJ) and Imaris. Fiji was used to perform conventional two-dimensional image analysis and Imaris was used to develop a new three-dimensional analysis method that does not require operator selection of images (i.e. objective method). Verification of the three-dimensional method was performed using two-dimensional data. Buffalo that did not ovulate within 24 hours of artificial insemination (40h from time of gonadotrophin releasing hormone analogue treatment) (n=3) tended to have lower change in vascular flow (P=0.06) to their preovulatory follicles when compared to those that ovulated (n=13) using the three-dimensional analysis method. In Study 2, power Doppler ultrasonography was used to assess the ovaries of 4-month-old prepubertal beef heifers (Bos taurus) who were superstimulated using two follicle stimulating hormone (FSH) protocols. Ultrasonographic scans were performed on the day of luteinizing hormone (LH) treatment, the day of oocyte collection, and the third and seventh day following follicular aspiration. The three-dimensional method developed in Study 1 was used to calculate vascularity indices for the four time points. Ovarian vascularity was then related to the expansion of the cumulus-oocyte-complexes that were retrieved, as well as the subsequent luteal tissue that developed following follicle aspiration. Luteal vascularity index measured at three days following follicular aspiration were related to the rise in plasma progesterone concentration over time (from 24 h following LH to day seven after aspiration) (r=0.65, P<0.01). Prepubertal calves demonstrated an increase in ovarian vascularity index under the influence of exogenous LH that was similar to adult animals. Additionally, an increased duration of superstimulation (seven days instead of four) was important for calves in the development of luteal tissue on day seven, luteal vascularity and progesterone production. In conclusion, three-dimensional image analysis of colour Doppler ultrasound images was superior to two-dimensional in detecting follicles that did not ovulate. This method using power Doppler ultrasound images was also applied to prepubertal calves undergoing superstimulation and found that luteal vascular flow was related to progesterone production following follicular aspiration

Environmental and Societal Impacts in New England Following a Potential Yellowstone Eruption

Yellowstone National Park is famously known for its history of “super-volcano” eruptions. From the evidence of volcanic deposits, scientists know that the ash cloud that erupted from Yellowstone covered most of the western U.S. states, but until recently, models have not shown the ash could also have reached eastern states. The scope of this investigation is to determine what would happen to New England if Yellowstone were to erupt today in terms of health, agriculture, transportation, relocation, economy, and climate. In order to do so, three significant eruptions during human history are considered as case studies in order to compare their impacts to those of a potential Yellowstone eruption. In addition, ash fall models are created to predict the amount of ash that could reach New England. These models suggest that 0-30 mm of ash could cover New England and global temperatures could decrease by 3-5°C. This would have devastating impacts on agriculture in New England, leading to starvation and other issues that could ricochet across the globe. Although Yellowstone is unlikely to erupt during the 21st century, there are numerous other less closely-monitored caldera systems on the planet that could erupt, and therefore it is important to have mitigation strategies in place to decrease the harmful effects of potential volcanic cataclysms

La presidenza russa del G20

Analisi degli obiettivi e delle prospettive della presidenza russa del G2