Variability of the Pulsed Radio Emission from the Large Magellanic Cloud Pulsar PSR J0529-6652

We have studied the variability of PSR J0529-6652, a radio pulsar in the LMC, using observations conducted at 1390 MHz with the Parkes 64-m telescope. PSR J0529-6652 is detectable as a single pulse emitter, with amplitudes that classify the pulses as giant pulses. This makes PSR J0529-6652 the second known giant pulse emitter in the LMC, after PSR B0540-69. The fraction of the emitted pulses detectable from PSR J0529-6652 at this frequency is roughly two orders of magnitude greater than it is for either PSR B0540-69 or the Crab pulsar (if the latter were located in the LMC). We have measured a pulse nulling fraction of 83.3 \pm 1.5% and an intrinsic modulation index of 4.07 \pm 0.29 for PSR J0529-6652. The modulation index is significantly larger than values previously measured for typical radio pulsars but is comparable to values reported for members of several other neutron star classes. The large modulation index, giant pulses, and large nulling fraction suggest that this pulsar is phenomenologically more similar to these other, more variable sources, despite having spin and physical characteristics that are typical of the unrecycled radio pulsar population. The large modulation index also does not appear to be consistent with the small value predicted for this pulsar by a model of polar cap emission outlined by Gil & Sendyk (2000). This conclusion depends to some extent on the assumption that PSR J0529-6652 is exhibiting core emission, as suggested by its simple profile morphology, narrow profile width, and previously measured profile polarization characteristics.Comment: 24 pages, including 7 figures and 2 tables. Accepted to the Astrophysical Journa

Real-time image-based feedback for microfluidic applications

The field of microfluidics has been solving problems on the micro-scale for decades, but many in-flow analysis techniques only take single dimensional measurements. In this thesis, multi-dimensional, real-time image analysis has been used to improve and expand upon current microfluidic techniques in several microfluidic areas. Microdroplets within microfluidics are a promising technique for creating microscopic vessels for chemical and biochemical experiments, however accurately controlling such tiny objects can be difficult. The use of real-time image feedback has dramatically improved the monodispersity (coefficient of variation of 0.32%) and accurate loading of the contents of droplets. Beyond this, using these techniques, real-time analysis on the morphology of living cells can be carried out and used to isolate cells of interest. Machine learning algorithms have provided a rapid method to identify the cell populations based on quantitative parameters extracted from transmission or fluorescent images of the cells. By integrating fast piezo-based fluid manipulation, highly selective and accurate cell sorting can be performed within a lab-on-a-chip device for the isolation of subpopulations of cells based on their morphological features. Using this method, K562 cells have been sorted from a mixed population with an efficiency of 91.3% and a purity of 99.4%

Nuclear Structure Calculations with Coupled Cluster Methods from Quantum Chemistry

We present several coupled-cluster calculations of ground and excited states of 4He and 16O employing methods from quantum chemistry. A comparison of coupled cluster results with the results of exact diagonalization of the hamiltonian in the same model space and other truncated shell-model calculations shows that the quantum chemistry inspired coupled cluster approximations provide an excellent description of ground and excited states of nuclei, with much less computational effort than traditional large-scale shell-model approaches. Unless truncations are made, for nuclei like 16O, full-fledged shell-model calculations with four or more major shells are not possible. However, these and even larger systems can be studied with the coupled cluster methods due to the polynomial rather than factorial scaling inherent in standard shell-model studies. This makes the coupled cluster approaches, developed in quantum chemistry, viable methods for describing weakly bound systems of interest for future nuclear facilities.Comment: 10 pages, Elsevier latex style, Invited contribution to INPC04 proceedings, to appear in Nuclear Physics

Mobilising Uncertainty and the Making of Responsible Sovereigns

The past few decades have witnessed a fundamental change in the perception of threats to the security of states and individuals. Issues of security are no longer primarily framed in terms of threats posed by an identifiable, conventional enemy. Instead, post-Cold War security policies have emphasised the global and radically uncertain nature of threats such as environmental degradation, terrorism and financial risks. What are the implications of this transformation for one of the constitutive principles of international society: state sovereignty? Existing literature has provided two possible answers to this question. The first focuses on the alleged need for states to seek international cooperation and to relax claims of national sovereignty. In Ulrich Beck's terminology, this would amount to a transformation of sovereign states into cosmopolitan states. The second takes the opposite position: in response to uncertain threats states rely on their sovereign prerogatives to take exceptional measures and set aside provisions of positive law. In Beck's terminology, this would amount to the creation of a surveillance state. None of these two answers, however, does justice to the complex relation between sovereignty, power and (international) law. As this article will show, the invocation of radical uncertainty has led to a transformation in sovereignty that cannot be captured in terms of the cosmopolitan/surveillance dichotomy. What is at stake is a more fundamental transformation of the way in which sovereignty is used to counter threats. Based on a study of the UN Counterterrorism Committee, this article demonstrates how state sovereignty is used as a governmental technology that aims to create proactive, responsible subjects. © 2011 British International Studies Association

Coupled cluster calculations of ground and excited states of nuclei

The standard and renormalized coupled cluster methods with singles, doubles, and noniterative triples and their generalizations to excited states, based on the equation of motion coupled cluster approach, are applied to the He-4 and O-16 nuclei. A comparison of coupled cluster results with the results of the exact diagonalization of the Hamiltonian in the same model space shows that the quantum chemistry inspired coupled cluster approximations provide an excellent description of ground and excited states of nuclei. The bulk of the correlation effects is obtained at the coupled cluster singles and doubles level. Triples, treated noniteratively, provide the virtually exact description

Levels of Analysis in Comprehensive River Basin Planning

Since nearly every water resource managment choice has two or more sides, differences must be resolved in decision making. Equitable resolution requires an understanding of the reasons for the differences. These reasons originate in the implemented plans have physical-environmental, economic, social, cultural, and political impacts at levels ranging from local to national or international in scope. Decisions are made by individuals and groups impacted in all of these dimensions and at all of these levels; the decisions generate additional impacts; and the entire interactive process changes water management practice in ways outside the control of any one decision point or even dicision dimension. The objective of this study is to conceptualize this process in a way that will help in establishing institutional mechanisms for reconciling differences among levels of analysis. The conceptualization used viewed differences in choices being made at the various levels of analysis as associated with perspective differences having value, jurisdiction, action, and temporal elements. The possible combinations of differences within and between these elements were used to identify ten categories of institutional obstacles to efficient water planning (differences in values, conflicts between value and jurisdiction, etc.). The history of water resources planning on the Colorado River basin was then examined to identify 17 specific institutional obstacles, and a computerized policy simulation was applied to levels of analysis in the Uintah basin of Utah to identify three more. These 20 obstacles were shown to be broadly distributed over the ten categories, and the nature of the obstacles defined provides valuable insight into the common characteristics of the major institutional obstacles to water management. The priciples of logic as applicable to rationality in decision making were then used to identify two root causes of levels\u27 conflicts. If alternatives are evaluated from a single perspective, the ostensible causal relationships commonly used lead to estimates of the sum of the consequences from the parts of a water management program being far more than the total consequences of the entire program. Looked at another way, since available water resources planning tools do not properly allocate consequences from interactive processes to individual causal sources, decisions made to acheive a desired impact are not based on reliable information. In fact, different decisions made over time from a single perspective have conflicting impacts. When multiple perspectices are considered, one finds that individual values do not aggregate linearly in forming social values, many actions are not efficient in achieving preferred values, and decision makers are not able to implement their plans as desired. Real world situations combine interacting perspectives and partial contributions. Nine recommendations are made on what to do next in improving water resources planning in an interactive, nonlinear world

Circulating proteolytic signatures of chemotherapy-induced cell death in humans discovered by N-terminal labeling

It is known that many chemotherapeutics induce cellular apoptosis over hours to days. During apoptosis, numerous cellular proteases are activated, most canonically the caspases. We speculated that detection of proteolytic fragments released from apoptotic cells into the peripheral blood may serve as a unique indicator of chemotherapy-induced cell death. Here we used an enzymatic labeling process to positively enrich free peptide α-amines in the plasma of hematologic malignancy patients soon after beginning treatment. This N-terminomic approach largely avoids interference by high-abundance proteins that complicate traditional plasma proteomic analyses. Significantly, by mass spectrometry methods, we found strong biological signatures of apoptosis directly in the postchemotherapy plasma, including numerous caspase-cleaved peptides as well as relevant peptides from apoptotic and cell-stress proteins second mitochondria-derived activator of caspases, HtrA serine peptidase 2, and activating transcription factor 6. We also treated hematologic cancer cell lines with clinically relevant chemotherapeutics and monitored proteolytic fragments released into the media. Remarkably, many of these peptides coincided with those found in patient samples. Overall, we identified 153 proteolytic peptides in postchemotherapy patient plasma as potential indicators of cellular apoptosis. Through targeted quantitative proteomics, we verified that many of these peptides were indeed increased post- vs. prechemotherapy in additional patients. Our findings reveal that numerous proteolytic fragments are released from dying tumor cells. Monitoring posttreatment proteolysis may lead to a novel class of inexpensive, rapid biomarkers of cell death

Brief intervention for alcohol misuse in people attending sexual health clinics: study protocol for a randomized controlled trial.

BACKGROUND: Over the last 30  years the number of people who drink alcohol at harmful levels has increased in many countries. There have also been large increases in rates of sexually transmitted infections. Available evidence suggests that excessive alcohol consumption and poor sexual health may be linked. The prevalence of harmful alcohol use is higher among people attending sexual health clinics than in the general population, and a third of those attending clinics state that alcohol use affects whether they have unprotected sex. Previous research has demonstrated that brief intervention for alcohol misuse in other medical settings can lead to behavioral change, but the clinical- and cost-effectiveness of this intervention on sexual behavior have not been examined. METHODS: We will conduct a two parallel-arm, randomized trial. A consecutive sample of people attending three sexual health clinics in London and willing to participate in the study will be screened for excessive alcohol consumption. Participants identified as drinking excessively will then be allocated to either active treatment (Brief Advice and referral for Brief Intervention) or control treatment (a leaflet on healthy living). Randomization will be via an independent and remote telephone randomization service and will be stratified by study clinic. Brief Advice will comprise feedback on the possible health consequences of excessive alcohol consumption, written information about alcohol and the offer of an appointment for further assessment and Brief Intervention. Follow-up data on alcohol use, sexual behavior, health related quality of life and service use will be collected by a researcher masked to allocation status six months later. The primary outcome for the study is mean weekly alcohol consumption during the previous three months, and the main secondary outcome is the proportion of participants who report unprotected sex during this period. DISCUSSION: Opportunistic intervention for excessive alcohol use has been shown to be effective in a range of medical settings. The SHEAR study will examine whether delivering such interventions in sexual health clinics results in reductions in alcohol consumption and will explore whether this is associated with changes in sexual behavior.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

Social capital and HIV/AIDS in the United States: Knowledge, gaps, and future directions

Purpose Social capital is a well-established predictor of several behavioral health outcomes. However, we know less about the relationship with prevention, transmission, and treatment of HIV/AIDS outcomes in the United States (US). Methods In 2017, we conducted a scoping review of empirical studies investigating the relationships between social capital and HIV/AIDS in the US by searching PubMed, Embase, PsycINFO, Web of Science, and Sociological Abstracts with no restriction on publication date, for articles in English language. Sample search terms included: HIV infections OR HIV OR AIDS OR acquired immunodeficiency syndrome OR human immunodeficiency virus AND social capital OR social control, informal OR social participation OR social cohesion OR generalized trust OR social trust OR collective efficacy OR community mob* OR civic participation. Results We identified 1581 unique manuscripts and reviewed 13 based on eligibility criteria. The earliest eligible study was published in 2003. More than half (n=7/13) focused on HIV or AIDS diagnosis, then prescribing ART and/or adherence (n=5/13), then linkage and or engagement in HIV care (n=4/13). Fifty eight percent (58%) documented a protective association between at least one social capital measure and an HIV/AIDS outcome. Seven studies used validated social capital scales, however there was substantial variation in conceptual/operational definitions and measures used. Most studies were based on samples from the Northeast. Three studies directly focused on or stratified analyses among subgroups or key populations. Studies were cross-sectional, so causal inference is unknown. Conclusion Our review suggests that social capital may be an important determinant of HIV/AIDS prevention, transmission, and treatment outcomes. We recommend future research assess these associations using qualitative and mixed-methods approaches, longitudinally, examine differences across subgroups and geographic region, include a wider range of social capital constructs, and examine indicators beyond HIV diagnosis, as well as how mechanisms like stigma link social capital to HIV/AIDS

Preferences under ignorance

A decision maker (DM) makes choices from different sets of alternatives. The DM is initially ignorant of the payoff associated with each alternative, and learns these payoffs only after a large number of choices have been made. We show that, in the presence of an outside option, once payoffs are learned, the optimal choice rule from sets of alternatives can be rationalized by a DM with strict preferences over all alternatives. Under this model, the DM has preferences for preferences while being ignorant of what preferences are “right”