Volunteering at Catholic Charities of Southern Nevada

Catholic Charities provides services for the homeless and needy, family programs, and adoption services.https://digitalscholarship.unlv.edu/educ_sys_202/1053/thumbnail.jp

Understanding N-nitrosodimethylamine Formation in Water: Chloramine Chemistry, Kinetics, and A Proposed Reaction Pathway

The formation of N-nitrosodimethylamine (NDMA) in drinking water systems is a concern because of its potential carcinogenicity and occurrence at toxicologically relevant levels. The postulated mechanism for NDMA formation involves a substitution between dichloramine and amine-based precursors to form an unsymmetrical dimethylhydrazine (UDMH), which is then oxidized by ground-state molecular oxygen to form NDMA. However, this latter reaction is spin forbidden, thus likely occurs at a slow rate. It is hypothesized that the reaction between monochloramine and hydroxylamine (a nitrification product) may form an intermediate, which is involved in the NDMA formation pathway. This intermediate may also be generated from dichloramine decay, in the absence of hydroxylamine. In this study, a series of batch kinetic experiments were conducted to investigate the decomposition of chloramine species at pH 8.0 to 10.0 and the concomitant formation of NDMA. Chloramine species were quantified using UV/Vis spectroscopy (Direct UV) and colorimetric methods (Hach) and compared to simulations from the unified chloramine model. NDMA was quantified using GC-MS following liquid-liquid extraction. The model captured the decay of monochloramine and dichloramine adequately, with the exception of monochloramine at pH 10.0, possibly due to an interference from a previously reported unidentified chloramine decomposition compound (UC1). NDMA formation was pH dependent with the maximum yields at pH 9.0 and the fastest kinetics at pH 10.0. A second unidentified compound (UC2), with a mass spectrum identified as UDMH, was detected only at pH 9.0 and 10.0 in batch reactors with DMA and dichloramine. Importantly, NDMA formation appeared to be insensitive to the presence or absence of UC2, suggesting UC2 was not involved in NDMA formation. Hydroxylamine accelerates the decomposition of monochloramine. The reaction between DMA and hydroxylamine formed a third unidentified compound (UC3), preliminarily identified as acetoxime, which was not observed in the presence of monochloramine. Upon addition of hydroxylamine, NDMA yields decreased by more than half in batch reactors with DMA and monochloramine. On balance, the findings suggest the existence of a NDMA formation pathway that may not involve UDMH, and points to the need for studies with scavengers and donors of short-lived species from chloramine decay

High Time for Medical Marijuana or Buzz-Kill?: The Controlled Substances Act and the Sherman Antitrust Act May Cause Florida\u27s Compassionate Medical Cannabis Act to Go Up in Smoke

Florida is the latest state to jump into the arena of medical marijuana with the passage of SBI030 on June 16, 2014. The law, named The Compassionate Medical Cannabis Act of 2014,\u27 allows low-THC cannabis to be prescribed to patients suffering from cancer or physical medical conditions that chronically produce symptoms of seizures or severe and persistent muscle spasms

The time to shut down

At each time, a firm facing uncertainty over future market conditions have to make a decision whether they should continue to produce or stop the process? As the traditional principle, the firm will go out of production when the price of the typical unit does not cover the average variable cost that it must incur to produce the typical unit. In reality the firm can suffer losses today however it can get more gains tomorrow that is enough to make up the losses. It means that this rule seems not be suitable absolutely in an uncertainty environment. And it leads to a rule that the firm only stop producing if average variable costs of unit exceed the price of unit by a positive amount. This paper expects to find this exceeding amount and when a firm will stop producing. Under uncertainty, the price of unit and the average variables cost are assumed to follow a continuous time stochastic process. We wish to apply the optimal stopping time approach in order to solve it.

Soft power and the United States' strategic "rebalancing" to the Asia-Pacific region

Power in international relations can be defined in several different ways. Power can be understood as a goal of states or leaders involving a measure of influence or control over outcomes, events, actors and issues; achieving victory in conflict and the attainment of security; control over resources and capabilities; or status, which some states or actors possess and other do not. Modern discourse in international relations generally speaks in terms of state power, indicating both economic and military power. The capabilities to handle those above functions are different from state to state and can be measured in different ways as well as with respect to different dimensions, among which “hard” and “soft” power can be taken into consideration. In the policy-making process of any states, hard power and soft power strategies are rarely separated but they are, in fact, closely related. The relationship between hard power and soft power has become an increasingly popular topic both inside and outside the USA in considering how to strengthen its status in the world arena, particularly in the Asia-Pacific region. American politicians, businessmen and scholars have constantly stressed the need and the opportunities of using soft power instead of hard power to manage the USA’s international relations, especially in this important region. The policy of the U.S. government towards this region is reflected through its strategic rebalance towards the Asia-Pacific region, which was announced by the Obama Administration in 2010. Since it came into being, this strategy has been described by several names including “return”, “pivot” or “rebalancing to Asia”. Although the strategy may be referred to by different names, it aims at describing the new prioritization in the foreign and national security policy of the United States. In order to examine the importance of both “hard” and “soft” power in international relations, American soft power and the implementation of its soft power in the “rebalancing” strategy, four research questions come to mind. They are: 1. What are the definitions soft power and hard power in international relations? 2. How does the US make use of both hard and soft power in building its capabilities and position in the region of Asia-Pacific? 3. What are the US’s intentions in its announced shift in focus to the Asia-Pacific region? 4. What are the regional responses to the US’ policy including by Vietnam? 5. What ensures the future success of the rebalance in the region? Due to the US’s growing emphasis on the use of soft power, the research will focus specifically on two questions; what are the soft power strategies of the US in this region; and what are Vietnam’s attitudes towards these strategies. If one can distinguish soft power elements in this policy shift, it is still important to consider the role of hard power elements and what larger regional role the US will play if its policy shift is successful. The focus of the research is on US actions and will exclude the effects of the policy on domestic policies in the Asia-Pacific, with the exception of briefly summarizing the changing stance of regional countries, thereby, showing the effects of American soft power on the region and on the US itself. Before examining the research questions, a theoretical framework will be provided in the first section of this paper discussing the content of hard power and soft power as described by several political analysts and theorists. This aims at giving an idea of the numerous definitions attached to hard and soft power as well as to lay out the analytical tools for the third section in which the “pivot” in the US’s Asia-Pacific policy will be examined. In the next section, regional attitudes towards the US’ “rebalancing” strategy, especially Vietnam’s, will be surveyed. The thesis will conclude with a discussion on whether these strategies are in line with the US’s use of soft power with their policies in other parts of the world and why the use of soft power, which can help to ensure the successes of this policy direction, does not yet seem to have received adequate attention. The significance of the study will be to enhance understanding of the role of hard and soft power in building the US’s status in the world arena, especially in realizing its “return to Asia” strategy. Moreover, this study may interest those whose work is closely related to the US and its policies, especially in the Asia-Pacific region, enabling them to have more understanding, which they can use to initiate appropriate strategies in their work. It is obvious from the broad audiences above that a census is not feasible for this study. Accordingly, the research approach includes informal interviews in which a sample from the target population of interested parties is used for the study. In total, a sample of 20 was selected. First, the target population was divided into political leadership, governmental officials and other relevant peoples in the Asia-Pacific region. Then they were grouped into those who are experienced, non-experienced and little experienced in working with the US. This ensured a fair representation of each group since their understanding and experiences are significantly different. The focus of the study is on personal attitudes and perceptions and the importance of primary data cannot be over-emphasized. Before the collection of actual data, the researcher sent introductory letters from the Vietnam Union of Friendship Organizations to the sampled offices and institutions. The initial visit to the selected offices and institutions was therefore to introduce the researcher, obtain familiarity with those offices and institutions as well as seek their consent for the study. The researcher collected data by administering a questionnaire. The questionnaire used open questions, consisting of five questions seeking to answer research questions related to soft power and the U.S. rebalance to the Asia-Pacific. The results of the study should provide interested parties with a panorama of the US’s “return to Asia” strategy, its contributions to development in relations between the US and the region’s countries and Vietnam’s responses to it with specific respect to its soft power elements. In particular, the insights yielded by the study into the role of soft power should tell much about the likely success of this policy and its implications for those in the region who interact with the US. Although this research was carefully prepared, it still has some limitations. First, the research was conducted in such a short time that it was not possible for the researcher to read all the materials related to the topic. Therefore, the thesis cannot reflect all aspects of the issue. Second, the population of the sample population was small, only 20. In addition, since the researcher conducted the interviews herself, it is unavoidable that a certain degree of subjectivity can be found in this study

Formation of Reactive Nitrogen Species During Dichloramine Decay and Their Impact on N Nitrosodimethylamine Formation Under Drinking Water Conditions

NDMA occurrence and formation pathways in drinking water systems are reviewed and NDMA yields are compared on the basis of disinfectant type, water chemistry, and precursor category. In chloramination, despite monochloramine being the predominant species between pH 7-9, evidence suggests that dichloramine is the primary species involved in NDMA formation. This is somewhat confounding as NDMA yields are maximal at pH 9, yet at pH 9 dichloramine decays faster than it forms and hence is present at trace levels; additionally, the proposed mechanism involves a spin-forbidden incorporation of dissolved oxygen as a triplet, which is presumably kinetically slow. This review reveals that kinetic data for NDMA formation is lacking, and its influence on chloramine chemistry has not been carefully considered. In pH 7-10 waters amended with 10 μM total dimethylamine and 800 μeq Cl2.L–1 dichloramine (NHCl2), NDMA, nitrous oxide (N2O), dissolved oxygen (DO), NHCl2, and monochloramine (NH2Cl) were kinetically quantified. NHCl2, N2O, and DO profiles indicated reactive nitrogen species (RNS) formed during NHCl2 decomposition, including nitroxyl/nitroxyl anion (HNO/NO−) and peroxynitrous acid/peroxynitrite anion (ONOOH/ONOO–). Experiments with uric acid (an ONOOH/ONOO– scavenger) implicated ONOOH/ONOO– as a central node for NDMA formation, which was further supported by concomitant N-nitrodimethylamine formation. A kinetic model accurately simulated NHCl2, NH2Cl, NDMA, and DO concentrations and included (1) the unified model of chloramine chemistry revised with HNO as a direct product of NHCl2 hydrolysis, (2) HNO/NO− then reacting with (i) HNO to form N2O, (ii) DO to form ONOOH/ONOO–, or (iii) NHCl2 or NH2Cl to form nitrogen gas, and (3) NDMA formation via ONOOH/ONOO– or their decomposition products reacting with (i) dimethylamine (DMA) and/or (ii) chlorinated unsymmetrical dimethylhydrazine (UDMH-Cl), the product of NHCl2 and DMA. The role of DO was further examined at pH 9 by assessing kinetic profiles of NHCl2 and NDMA under ambient DO (~280 μM) and low-DO (\u3c 20 μM) conditions in the presence and absence of 10 μM TOTDMA. Uric acid completely shut down NDMA formation under the low-DO condition, validating ONOOH/ONOO− as the central node in NDMA formation. Yield experiments with initial NHCl2 of 200-, 400-, and 800 μeq Cl2.L–1 tracked the formation of NH3/NH4+, NH2Cl, N2O, N2, NO2−, and NO3−. NH3/NH4+ yields were 20–40% greater under the low-DO condition, implying a reaction occurred between NH3/NH4+ and ONOOH/ONOO− or its decomposition products. NH2Cl yields were 16–20% lower under the low-DO condition, revealing a previously unknown NH2Cl formation reaction. Under ambient DO conditions, about 80% of the nitrogen was accounted for compared to the low-DO conditions in which nitrogen recoveries were 90- and 100% in the absence and presence of 10 μM TOTDMA, respectively. An existing mechanistic model accurately predicted NH3/NH4+, NH2Cl, and N2 under ambient conditions but underpredicted N2O and overpredicted NO2− and NO3−. The results provide a framework to guide future experiments with ONOOH/ONOO− generators and revise the mechanistic model to better capture the nitrogenous end-products

Penalized Spline Joint Models for Longitudinal and Time-To-Event Data

The joint models for longitudinal data and time-to-event data have recently received numerous attention in clinical and epidemiologic studies. Our interest is in modeling the relationship between event time outcomes and internal time-dependent covariates. In practice, the longitudinal responses often show non-linear and fluctuated curves. Therefore, the main aim of this chapter is to use penalized splines with a truncated polynomial basis to parameterize the non-linear longitudinal process. Then, the linear mixed effects model is applied to subject-specific curves and to control the smoothing. The association between the dropout process and longitudinal outcomes is modeled through a proportional hazard model. Two types of baseline risk functions are considered, namely a Gompertz distribution and a piecewise constant model. The resulting models are referred to as penalized spline joint models; an extension of the standard linear joint models