Genetic Requirements for Intra-Chromosomal Deletions

Chromosomal deletions are one of the most dangerous types of DNA damage and often arise as a result of inappropriately repaired DNA double strand breaks (DSB). These breaks are usually formed either in an induced manner from exogenous damage such as radiation, or more commonly caused from spontaneous replication errors. If there is a single strand break during replication and it is not repaired properly, as the replication fork progresses it can lead to the formation of a DSB. When there is a DSB present, there is the opportunity for a chromosomal deletion to occur. If the break is in between non-tandem direct repeats, the DNA repair machinery will degrade what is between the direct repeats through a process called Single Strand Annealing (SSA). This massive loss of DNA is what is known as a chromosomal deletion. Using an assay that in Schizosaccharomyces pombe, we can detect DSBs and determine DNA repair pathways through a selection screen of yeast cells with inactivated DNA repair genes. We generated an in vivo assay that reports exclusively SSA. We validated the assay by showing its dependence on rad52+ and independence rad51+. However, we show that earlier events epistatic to rad52+ and rad51+ have differential requirements for deletions vs. other forms of repair. Here, we delineate a more detailed epistatic pathway for intrachromosomal deletions.No embargoAcademic Major: Biolog

Current issues in empirical trade estimation

The study of empirical trade estimation has been a staple in international economics literature since the early 1960s. I focus on three current topics in empirical trade estimation. In chapter 1, I use a time-series approach and in the context of the effect of exchange-rate volatility on trade, provide both theoretical and empirical explanations for positive volatility effects. My results show a clear pattern; when the effect of exchange-rate uncertainty on trade volume is positive [negative] for importers, the effect for exporters is negative [positive]. In addition, the U.K. provides evidence that trade balance is an important factor in determining the effect of volatility. If changes in the sign of trade balance are not taken into account, the effect of volatility may go undetected. Finally, the sensitivity of imports and exports to exchange-rate volatility is affected similarly by changes in market conditions; trade is more sensitive to volatility when the trade terms are expected to improve. In chapter 2, I turn to cross-sectional analysis and following a growing trend in the literature, I examine the impact of adding nonstandard variables, ones that measure cultural or ideological differences, to the basic gravity model. In the context of United States trade with Latin America, I show that in the case of Brazil, Nicaragua, and El Salvador, as the number of foreign-born peoples in the United States increases, U.S. exports to their country of origin increases. This finding sheds important light on the fact that the determinants of trade may go beyond standard economic and descriptive variables. In Chapter 3 I compare the Hausman-Taylor method for estimating the unrealized US-Cuban trade potential to the OLS, fixed-effects, and random-effects methods using the out-of-sample approach. The Hausman Taylor method is ideal because it allows for the inclusion of time-invariant variables in trade projections and circumvents the problem of an ad hoc estimation of the country-specific dummy variable needed for a projection based on the fixed-effects estimator. In addition, it removes the correlation between the error term and included variables which often plagues random-effects estimation

Are Hospital Pharmacies More Efficient if They Employ Nurses?

This paper assesses the efficiency of utilizing nurses in Washington State hospital pharmacies. We take the perspective of a pharmacy department manager and model an input oriented hospital pharmacy production process. Data envelopment analysis (DEA) is used to examine both scale efficiency and technical efficiency, and differences across hospital pharmacies that use and do not use nurse staffing are analyzed using cross-tabulations and nonparametric hypothesis tests. The results indicate that the use of nurse staffing does not significantly impact either scale or technical efficiency. Thus, permitting nurses to play a greater role in hospital pharmacies does not adversely affect efficiency. This paper has important policy implications for hospital administrators and pharmacists.

“Shake ‘n Bake” Route to Functionalized Zr-UiO-66 Metal–Organic Frameworks

We report a novel synthetic procedure for the high-yield synthesis of metal-organic frameworks (MOFs) with topology with a UiO-66-like structure starting from a range of commercial Zr precursors and various substituted dicarboxylic linkers. The syntheses are carried out by grinding in a ball mill the starting reagents, namely, Zr salts and the dicarboxylic linkers, in the presence of a small amount of acetic acid and water (1 mL total volume for 1 mmol of each reagent), followed by incubation at either room temperature or 120 °C. Such a simple "shake 'n bake" procedure, inspired by the solid-state reaction of inorganic materials, such as oxides, avoids the use of large amounts of solvents generally used for the syntheses of Zr-MOF. Acidity of the linkers and the amount of water are found to be crucial factors in affording materials of quality comparable to that of products obtained under solvo- or hydrothermal conditions

The Effects of Government Reimbursement on Hospital Costs:Some Empirical Evidence from Washington State

We use a panel of hospitals from Washington state to examine the impact of government reimbursement on a provider’s costs. We find that providers change their relative patient mix when Medicare and Medicaid lower reimbursement rates. On a percentage change basis, the magnitudes of these changes are small; however, the overall economic impacts are quite large. Additionally, our findings indicate that a number of other factors significantly influence a provider’s costs, including patient demographics, initial illness severity and input market conditions facing the firm. We thank two anonymous reviewers for their helpful comments. We also thank William Greene for valuable econometric advice when making revisions to this manuscript. Remaining errors are our own

Determinants of Demand for HIV Testing: Evidence from California Outpatients Clinics

This paper provides an initial empirical analysis of the impact of changing epidemiological, economic and sociological conditions on the amount of HIV testing in primary care, outpatient clinics. Particular attention is paid to examining whether changes in HIV/AIDS prevalence impact the amount of testing these clinics perform, and also how financial constraints impact this relationship. Using a sample of California clinics, we find that changing epidemiological conditions do impact the demand for HIV testing. Additionally, certain clinic characteristics, such as the type of practitioners providing care and the socio-economic characteristics of patients treated at each clinic also affect the demand for testing. However, we find little evidence supporting increased government or private grants, contracts and donations as a means of enhancing the demand for HIV testing

Re Dartmouth (City of) and Dartmouth Police Association, Local 101

Employee Grievance alleging improper refusal of leave of absence in lieu of statutory holiday. There was no dispute about any of the essential facts. The practice in the Dartmouth Police Department is for a leave calendar to be circulated at the start of each year. Each man writes in his preferred vacation leave in accordance with an order of priorities not here in issue. Thereafter as requests are made and granted for leave for statutory holidays, time off in lieu of overtime and compassionate leave and as members of the department go on training courses, those facts are noted on the leave calendar. Staff Sergeant John Friis has responsibility under art. 12(2)(a) of the collective agreement for coordinating leaves but in fact the maintenance of the leave calendar has been delegated to platoon NCO\u27s, and in the case here relevant to Sergeant Binns and Corporal Lowe of C Platoon

Interplay between oxygen doping and ultra-microporosity improves the CO2/N2 separation performance of carbons derived from aromatic polycarboxylates

Microporous carbons were prepared starting from a series of benzene polycarboxylic acids following two strategies: (i) activation- and template-free pyrolysis and (ii) ion-exchange pyrolysis. The proposed synthetic strategies are facile approaches to produce highly microporous carbons that avoid the use of large amounts of corrosive and expensive chemical activators or templates. By varying the number of carboxylic acid groups, the charge balancing species and the degree of deprotonation of the precursors, microporous carbons with diverse morphologies, textural properties and oxygen contents were obtained and their CO2 and N2 sorption properties were assessed. The abundant micropores made the materials suitable for CO2 adsorption at low pressure and ambient temperature, achieving CO2 uptake as high as 4.4 mmol/g at 25 °C and 1 bar, competitive with those reported for porous carbons produced using large excess of alkali metal based activating agents. It was found that high performance, in terms of CO2 uptake and CO2/N2 selectivity, was linked to the simultaneous presence of large ultra-micropore volume and high oxygen content in the sorbents. This suggests that the interplay of ultra-microporosity and oxygen doping matters more than the two features taken singularly in determining the CO2/N2 separation properties of porous carbons at low pressure

Operator-assisted harvesting of protein crystals using a universal micromanipulation robot

The prototype of a universal micromanipulation robot for crystal harvesting is presented, and a robotically harvested trypsin crystal yields a high-resolution structure demonstrating the feasibility of robotic protein crystal harvesting