74201 research outputs found
Sort by
From Pee to Potable: Steering from Day Zero through Urban Wastewater Recycling
No full textAbstract: With urban populations burgeoning, water demand growing in the agricultural, energy and industrial sectors, and climate change intensifying droughts, water-scarce cities are challenged with maintaining a water secure future. Through a self-developed Water Security Index (WSI), this paper evaluated the role of wastewater reuse in defining city water portfolios. The index was then applied to four water scarce cities to evaluate the different components of a resilient water system and the potential of wastewater reuse in boosting water security. Data gathered showed that wastewater reuse contributed small percentages to water portfolios. The index suggested that wastewater reuse (toilet to tap) has potential to increase a city's potable supplies and that cities with diversified water portfolios scored higher in the WSI. Thus, this paper concluded that the adoption of wastewater recycling and reuse is essential in adding to diversity of water sources to build a resilient water system.Thesis (M.S.)--Tufts University, 2018.Submitted to the Dept. of Urban and Environmental Policy and Planning.Advisor: Ann Rappaport.Committee: Mary Davis.Keywords: Water resources management, Urban planning, and Sustainability
Reporting animal cruelty : the role of the veterinarian : establishing protocols to identify and report suspected animal cruelty in Massachusetts.
No full text1 online resource (179 pages) : color illustration
Criterial learning is not enough: Retrieval practice is necessary for improving post-stress memory accessibility.
No full textIn a recent study, having participants make three retrieval attempts (i.e., retrieval practice) when learning information strengthened memory against the detrimental effects of psychological stress. We aimed to determine whether learning to criterion, in which only one successful retrieval attempt is made, would similarly buffer memory against stress, or whether multiple retrieval attempts are necessary to achieve that effect. In Experiment 1, participants learned to criterion and then engaged in additional restudying (CLS) or retrieval practice (CLR) Twenty-four hours later, stress was induced and stress-related increases in cortisol were observed. However, no differences in recall performance were observed between any of the groups. Experiment 2 was similar but introduced a 1-week delay between encoding and retrieval. Recall performance was impaired for both groups under stress, but recall for those in the CLR group was still better than either pre- or post-stress performance for those in the CLS group. Thus, criterial learning may protect memory against stress in the short-term, but additional retrieval practice is more beneficial for achieving this effect in the long-term. (c) American Psychological Association, 2018
Retraction Note: detangling PPI networks to uncover functionally meaningful clusters.
No full textSpringer Open
Probing the role of the Epa1p tandem repeat region in Candida glabrata adhesion.
No full textThe aim in this project was the identification of function associated with variation in the repetitive cell surface adhesin Epa1p. Epa1p is responsible for the binding of the fungal pathogen Candida glabrata to host epithelial cells, a process necessary for infection. Submitted in partial fulfillment of the grant requirement of the Tufts Summer Scholars Program
Hemodialysis patient characteristics associated with better experience as measured by the In-center Hemodialysis Consumer Assessment of Healthcare Providers and Systems (ICH CAHPS) survey.
No full textBackground: Patient experience in hemodialysis (HD) is measured twice yearly in all in-center HD patients in the United States using the In-Center Hemodialysis Consumer Assessment of Healthcare Providers and Systems (ICH CAHPS) survey. Survey scores are publically available and incorporated into the dialysis payment system. Despite its importance, little is known about factors associated with better experience scores. We studied the association between patient-level characteristics and experience scores in a large real-world cohort of HD patients.Keywords: ICH CAHPS, CAHPS, Dialysis, Patient experience.Springer Open
Association between dietary habits and physical activity pattern with overweight and obesity amongst women in an urban community in Lalitpur.
No full textThis poster shows the association between dietary behaviors, physical activity patterns with body mass index, waist hip ratio and west conference
School of Dental Medicine, Postgraduate Bulletin, Spring 2018
No full textSchool of Dental Medicine, Postgraduate Bulletin, Spring 201
Cellular Networks Performance Under User-Assisted Relaying
No full textAbstract: User-assisted relaying is a promising technology to help cellular user equipments (UEs) achieve the envisioned seamless experience especially needed near the cell edge. In user-assisted relaying, the base station (BS) serves a UE using an adaptive direct and relaying transmission scheme according to a cooperation strategy. In case of relaying transmission, the active (served) UE selects an idle UE based on the cooperation strategy to act as a relay. In this thesis, we evaluate the performance of user-assisted relaying in single and multiple antenna networks with a focus on cell edge UEs. Using stochastic geometry and Poisson point processes as tools to model locations of network nodes, UEs and BSs, we first propose practical cooperation strategies, which determine how to select the relaying UE and when to perform relaying transmission, and derive their probabilities. These in turn are used in the development of a statistical inter-cell interference power model to facilitate network performance evaluation. For single antenna networks, {\color{blue}the} Gamma distribution provides a good model for the interference power by analytically matching the first two moments. For multiple-input multiple-output (MIMO) cellular networks, a mixture of inverse Gaussian and inverse Weibull distributions models the interference power using a combination of moment matching and maximum likelihood estimation (MLE). Using the proposed cooperation strategies and interference models, we evaluate the performance of user-assisted relaying in single antenna and MIMO networks using as metrics the average transmission rate and outage probabilities. For single antenna networks, results show that user-assisted relaying can significantly improve per-user transmission rate and outage probability despite the increased inter-cell interference. The transmission rate gain is significant for active users near the cell edge and further increases with higher idle users' density, supporting user-assisted relaying as a viable solution to crowded population areas. For MIMO networks, we implemented a simple transmit beamforming scheme and two optimized receive combining schemes depending on interference awareness. Provided sufficient density of potential relay UEs, results illustrate user-assisted relaying most beneficial for improving the reliability for cell edge UEs when these UEs are equipped with multiple antenna elements and their signals propagate in relatively high shadowing environments.Thesis (Ph.D.)--Tufts University, 2018.Submitted to the Dept. of Electrical Engineering.Advisor: Mai Vu.Committee: Eric Miller, Misha Kilmer, and Alexander Wyglinski.Keyword: Electrical engineering
The Strategic Choice of Violence in Islamist Groups
No full textAbstract: EXECUTIVE SUMMARY In this dissertation, I study the causes behind Islamist groups' strategic choice of violent contention against states in pursuit of their political objectives. I seek to understand why an Islamist group, that has political goals, engages in violent action against a state to meet its objectives, or, alternatively, why it would only use nonviolent means for the same purpose. My main research question, therefore, is: Why do some Islamist groups engage in anti-state violence while others use nonviolent methods of contention in pursuit of their objectives? What make(s) established nonviolent Islamist groups to turn into violent organizations, and what lead(s) organized violent Islamist groups to shun violence, even if temporarily, and cooperate with the state? As implied in the research question(s), the focus of this dissertation is on Islamist groups that have a national agenda and operate within the geographical boundaries of a state; not transnational Islamist organizations with a global focus and trans-border operations, i.e., al-Qaeda and the Islamic State. Most traditional studies of Islamism focus on the centrality of ideology as a driving force behind Islamist groups' choice of the method of contention. The general argument in these studies posits that Islamism as an ideology sanctions the use of violence to promote itself. As a result, the degree of an Islamist group's ideological orthodoxy determines its course of action. The stronger the group's belief in Islamist ideology, the more prone to violence it is; and vice versa. In contrast to the traditional approaches, I utilize Political Process Theory (PPT), which privileges structural factors as determinants of Islamist groups' methods of contention. I argue that Islamist groups are not very different from other social movement organizations when making strategic choices. Therefore, I reject the "Islamic exceptionalism" of the traditional studies, which view Islamist groups as ideology-driven, fanatic, even irrational actors. Instead, I treat Islamist groups as rational actors, which make strategic choices based on cost-benefit calculations, and choose a method of contention that maximizes returns on their efforts. I argue that an Islamist group's choice of the method of contention is a function of its motivations and capabilities at any given time. The convergence of a group's motivations and capabilities determines whether a violent or a nonviolent strategy would maximize returns for the group, leading the group to choose the most cost-effective option. A group's motivations and capabilities are, in turn, determined by the confluence of three main factors: (1) the degree of a group's relative access to political power; (2) the nature of government repression of the group; and (3) the degree of a group's access to war-making resources. The causal mechanism for these arguments will be fully explained in the theory chapter, but here the summary of the argument suffices: For the first variable (the degree of a group's relative access to political power), initially, the more access a group gains to political power, i.e., influence over public policymaking, the less prone to anti-state violence it is likely to become; and vice versa. But there is a threshold to this access to political power. Once that threshold is hit, i.e., the group gains too much control over public policymaking, it is likely to become more prone to anti-state violence. Thus, a group's propensity to anti-state violence vis-à-vis its degree of access to political power follows a U-shaped graph. The movement along this U curve follows four stages - deficient access, moderate access, optimal access, and hyped access -, each describing specific levels of access to political power by a given Islamist group, and causing a commensurate effect on its strategic stance. The second variable (the nature of government repression of the group) takes two forms - effective government repression (rapid and decisive), and ineffective government repression (sluggish and lenient). For the former, the argument is that state repression and anti-state violence are correlated in a curvilinear way. Initially, the more the government represses an Islamist group, the more likely the Islamist group is to engage in anti-state violence in reaction; and vice versa. But this entails a threshold. Once state repression reaches a high peak at a fast pace, it is likely that anti-state violence decreases because the repression campaign possibly defeats the Islamist oppositions and takes the group, more or less, out of the contest. In this situation, a group's propensity to anti-state violence vis-à-vis state repression of the group follows an upright V-curve. Thus, in the face of effective government repression, Islamist groups have a low propensity for violence. Ineffective government repression, on the other hand, is weak and lethargic, likely causing the first effect - the upward slope -, increasing the group's anti-state violence propensity, but never reaches the needed threshold to cause the second effect - the downward slope -, to decrease the group's anti-state violence propensity. This is likely to cause prolonged anti-state violence. In the face of this, Islamist groups are likely to have a high propensity for violence in what can graphically be shown as an S-curve. For the third variable (the degree of a group's access to war-making resources), war-making resources include fighters, money, weapons, sanctuaries, supply routes, combat skills, intelligence capabilities, etc.; essentially the elements needed for the manifestation of violent activities. The argument is intuitive and straight forward - the more access a group has to such resources, the more prone to anti-state violence it is likely to be; and vice versa. This access is measured at three levels - no access, insufficient access, and sufficient access -, each describing specific amounts of access to war-making resources by a given Islamist group. It is critical to take the model at its entirety, i.e., the three above-mentioned variables together, and not separately, in order to draw a reasonably sufficient picture of an Islamist group's strategic inclinations. This is because the independent variables interact with each other, and collectively affect the dependent variable. Interaction among the three independent variables means the effect of one of the variables on the dependent variable is not constant within the integrated model - the effect differs at different values of the other variables in the model. In other words, the impact of each independent variable on the dependent variable is different in a standalone form than while mixed with other independent variables. As a result, variations within the variables impact each other, leading to different outcomes than when they are in effect on their own. Thus, while each of the variables has sufficient explanatory power in a standalone approach, the thesis in this dissertation is based on an integrated model of the three independent variables. Given the integration of the independent variables, the model specifies four possible scenarios for an Islamist group on the use of violence as a method of contention. These are: (1) motivated, but incapable of fighting; (2) unmotivated and incapable of fighting; (3) unmotivated, but capable of fighting; and (4) motivated and capable of fighting. Scenarios 1, 2, and 3 are likely to yield no probability of violence, as a group lacks the motivation, the capability, or both, for violence in any of those scenarios. Probability of violence exists only in scenario 4, as a group has both the motivation and capability to engage in violence. In that scenario, three levels of probability of violence - low, medium, and high - are estimated. In the empirical part of the dissertation, I use a case study method, tracing the evolution of political Islam in Afghanistan since the second half of the 1800s, but focus mainly on the activities of the Afghan Islamist groups over the past seventy years. This entails reviewing the inception of political Islam as a result of King Abdur Rahman Khan's state-building efforts in the 1880s through the first half of the 1900s, and showing how the centuries-long social Islam in Afghanistan gradually became political. The formal case-studies for the test of the theory starts with the emergence of formalized Islamist groups in country, i.e., with the Shia Union Party in the late 1940s, moving onto the development of the Afghan Muslim Youth Organization (MYO) in the 1960s, following the latter's evolution after the abolishment of the monarchy and the establishment of the republic in the early 1970s, continuing onto the jihad in the Soviet war era in the 1980s and concluding with the ongoing Taliban's war against the current Afghan regime and its Western supporters. I test the proposed theoretical framework against the empirical facts on the strategic conduct of the various Afghan Islamist groups in each of these four periods - four cases for the empirical test of the model. The cases I study share similar backgrounds and characteristics, but differ on the study variables - the dependent and independent variables. In other words, the statuses of the three independent variables discussed earlier, as well as that of the dependent variable (violent or nonviolent Islamism) entail sufficient variation across the four cases. This allows me to conduct multiple tests of the theory through the test techniques Process Tracing and Congruence Procedure, making theory testing harder, hence, the theoretical argument empirically stronger. I utilize multiple sources to gather data on the empirical side of this research. These include: (1) library research on secondary sources in English, Dari and Pashto; (2) primary source research in the form of over 40,000 pages of newspapers and magazines published by the Afghan mujahideen groups in the 1980s and 1990s, as well as, books and articles written by individuals involved at the highest ranks of decision-making within the groups studied; and (3) in-depth interviews with various stakeholders in the field. The interviewees include former insurgents who have surrendered to the government over the past decade, members of the High Peace Council, mosque mullahs (clerics), as well as, persons from various professional backgrounds in multiple provinces across Afghanistan. I conclude by suggesting that studying the ideology of Islamism and its various types and interpretations is necessary, but insufficient in providing a complete understanding of Islamist groups' choice of violent contention. Hence, other structural factors must be taken into account in order to provide a fuller and more accurate explanation of why Islamist groups engage in violence and otherwise. This research has four main objectives. The first and the primary one is to develop a theoretical model that would enhance our understanding of Islamism and how Islamist groups make strategic choices in their repertoire of contention. This will help us to better appreciate the causes behind anti-state Islamist violence, and prepare more suitable recommendations on how to prevent, decrease or cope with it. The second objective is to provide a succinct historical analysis of political Islam in Afghanistan and the development of the Afghan Islamist movement; a phenomenon that is seriously under-studied in the existing literature on Islamism and on Afghanistan. The third objective is to expand the empirical frontiers of Social Movement Theory to include Islamist groups, particularly Afghan ones, into its traditional constituency of mostly secular or non-religious movements and groups. Finally, the fourth objective is to draw a set of policy recommendations, based on the theoretical framework and the empirical evidence, that could potentially help guide the Afghan government's and its international partners' approach in pushing the current war to a potential end. It is important to note that this research is built upon the works of many scholars, namely David Snow, Susan Marshal, Rhys Williams, Quintan Wiktorowicz, Mohammad Hafez, Omar Ashor, John Foran, Meriem Verges, Anthony Shadid, Carrie R. Wickham, Henry Munson Jr., Edward Schatz, and others who have used various frameworks within Social Movement Theory to explain Islamist activism in various parts of the world. This trend, however, is relatively new and further theoretical and empirical research is needed to develop better frameworks that would provide more accurate explanations of Islamism.Thesis (Ph.D.)--Tufts University, 2018.Submitted to the Dept. of Diplomacy, History, and Politics.Advisor: Robert Pfaltzgraff.Committee: Andrew Hess, and Richard Shultz.Keywords: International relations, and Southeast Asian studies