2,076 research outputs found
The Repatriation & Reintegration Dilemma: How states manage the return of foreign terrorist fighters & their families
This study analyzes the interplay of factors which drive states’ approaches to the repatriation and reintegration of Foreign Terrorist Fighters (FTFs) and their family members. The literature is dominated by descriptive studies of state policies that tend to explain states’ failure to repatriate and reintegrate citizens as the result of deference to governments’ national security decisions. Our study builds on these foundations to offer the scholarly and policy fields both a framework to explain why governments adopt distinct policy postures, and a means to enable these same actors to engage in more systematic analysis and development of repatriation and reintegration policy. This study argues that a balance of four considerations are crucial for explaining state behavior in this policy context: (i.) the scope of the issue, including the number of citizens considered FTFs or affiliated persons, geographic proximity, and access to the conflict, (ii.) existing legal basis for repatriation and reintegration, (iii.) instrumentalization for institution building, and (iv.) programming strategy for repatriation and reintegration. As a pilot study, this paper applies the framework to assess cases of the United States, the Netherlands, Kosovo, and Iraq. As FTF management issues are not a relic of the recent past but a persistent policy concern that warrants more nuanced and forward-looking attention, this study also considers the continued application of the framework to explore the different ways in which states may balance these four considerations in policy design and practice in the future
Impact of a novel surgical wound protection device on observed versus expected surgical site infection rates after colectomy using the National Surgical Quality Improvement Program Risk Calculator
Surgical site infection (SSI) remains a persistent and morbid problem in colorectal surgery. A novel surgical device that combines barrier surgical wound protection and continuous surgical wound irrigation was evaluated in a cohort of elective colorectal surgery patients. A retrospective analysis was performed comparing rates of SSI observed in a prospective cohort study with the predicted rate of SSI using the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) Risk Calculator.A prospective multi-center study of colectomy patients was conducted using a study device for surgical site retraction and protection, as well as irrigation of the incision. Patients were followed for 30 days after the surgical procedure to assess for SSI. After completion of the study, patients' characteristics were inserted into the ACS-NSQIP Risk Calculator to determine the predicted rate of SSI for the given patient population and compared with the observed rate in the study.A total of 108 subjects were enrolled in the study. The observed rate of SSI in the prospective study using the novel device was 3.7% (4/108). The predicted rate of SSI in the same patient population utilizing the ACS-NSQIP Risk Calculator was estimated to be 9.5%. This demonstrated a 61% difference (3.7% vs. 9.5%, p = 0.04) in SSI from the NSQIP predicted rate with the use of the irrigating surgical wound protection and retraction device.These data suggest the use of a novel surgical wound protection device seems to reduce the rate of SSIs in colorectal surgery
Residence Time Statistics for Normal and Fractional Diffusion in a Force Field
We investigate statistics of occupation times for an over-damped Brownian
particle in an external force field. A backward Fokker-Planck equation
introduced by
Majumdar and Comtet describing the distribution of occupation times is
solved. The solution gives a general relation between occupation time
statistics and probability currents which are found from solutions of the
corresponding problem of first passage time. This general relationship between
occupation times and first passage times, is valid for normal Markovian
diffusion and for non-Markovian sub-diffusion, the latter modeled using the
fractional Fokker-Planck equation. For binding potential fields we find in the
long time limit ergodic behavior for normal diffusion, while for the fractional
framework weak ergodicity breaking is found, in agreement with previous results
of Bel and Barkai on the continuous time random walk on a lattice. For
non-binding potential rich physical behaviors are obtained, and classification
of occupation time statistics is made possible according to whether or not the
underlying random walk is recurrent and the averaged first return time to the
origin is finite. Our work establishes a link between fractional calculus and
ergodicity breaking.Comment: 12 page
Weakly non-ergodic Statistical Physics
We find a general formula for the distribution of time averaged observables
for weakly non-ergodic systems. Such type of ergodicity breaking is known to
describe certain systems which exhibit anomalous fluctuations, e.g. blinking
quantum dots and the sub-diffusive continuous time random walk model. When the
fluctuations become normal we recover usual ergodic statistical mechanics.
Examples of a particle undergoing fractional dynamics in a binding force field
are worked out in detail. We briefly discuss possible physical applications in
single particle experiments
The melanoma-specific graded prognostic assessment does not adequately discriminate prognosis in a modern population with brain metastases from malignant melanoma
The melanoma-specific graded prognostic assessment (msGPA) assigns patients with brain metastases from malignant melanoma to 1 of 4 prognostic groups. It was largely derived using clinical data from patients treated in the era that preceded the development of newer therapies such as BRAF, MEK and immune checkpoint inhibitors. Therefore, its current relevance to patients diagnosed with brain metastases from malignant melanoma is unclear. This study is an external validation of the msGPA in two temporally distinct British populations.Performance of the msGPA was assessed in Cohort I (1997-2008, n=231) and Cohort II (2008-2013, n=162) using Kaplan-Meier methods and Harrell's c-index of concordance. Cox regression was used to explore additional factors that may have prognostic relevance.The msGPA does not perform well as a prognostic score outside of the derivation cohort, with suboptimal statistical calibration and discrimination, particularly in those patients with an intermediate prognosis. Extra-cerebral metastases, leptomeningeal disease, age and potential use of novel targeted agents after brain metastases are diagnosed, should be incorporated into future prognostic models.An improved prognostic score is required to underpin high-quality randomised controlled trials in an area with a wide disparity in clinical care
Perfusion Assessment in Laparoscopic Left-Sided/Anterior Resection (PILLAR II): A Multi-Institutional Study
BackgroundOur primary objective was to demonstrate the utility and feasibility of the intraoperative assessment of colon and rectal perfusion using fluorescence angiography (FA) during left-sided colectomy and anterior resection. Anastomotic leak (AL) after colorectal resection increases morbidity, mortality, and, in cancer cases, recurrence rates. Inadequate perfusion may contribute to AL. The PINPOINT Endoscopic Fluorescence Imaging System allows for intraoperative assessment of anastomotic perfusion.Study DesignThis is a prospective, multicenter, open-label, clinical trial that assessed the feasibility and utility of FA for intraoperative perfusion assessment during left-sided colectomy and anterior resection at 11 centers in the United States.ResultsA total of 147 patients were enrolled, of whom 139 were eligible for analysis. Diverticulitis (44%), rectal cancer (25%), and colon cancer (21%) were the most prevalent indications for surgery. The mean level of anastomosis was 10 ± 4 cm from the anal verge. Splenic-flexure mobilization was performed in 81% and high ligation of the inferior mesenteric artery in 61.9% of patients. There was a 99% success rate for FA, and FA changed surgical plans in 11 (8%) patients, with the majority of changes occurring at the time of transection of the proximal margin (7%). Overall morbidity rates were 17%. The anastomotic leak rate was 1.4% (n = 2). There were no anastomotic leaks in the 11 patients who had a change in surgical plan based on intraoperative perfusion assessment with FA.ConclusionsPINPOINT is a safe and feasible tool for intraoperative assessment of tissue perfusion during colorectal resection. There were no anastomotic leaks in patients in whom the anastomosis was revised based on inadequate perfusion with FA
Reintegration of Foreign Terrorist Fighter Families: A Framework of Best Practices for the U.S.
This report outlines a comprehensive framework of best practices in the reintegration of foreign terrorist fighter spouses and children (i.e., “the FTF family”). It collates and synthesizes a suite of interlocking principles to guide reintegration policy and implementation, covering practical challenges and programmatic objectives, the organizational structure and process of reintegration management in the U.S. context, the role of strategic communications and trauma-informed care, and the use of specialized risk assessment tools. Drawing on original work conducted in previous investigative streams, this report combines scholarly analyses from both theory and practice, interviews with practitioners and stakeholders, case study investigations, and the authors’ collective experiences in the field. Four key findings are central to this report. First, overarching policy and programmatic planning must take into account a suite of core objectives that are central to the reintegration of FTF families. Four main categories of objectives emerge within which are a range of policy and programmatic goals: align domestic policy and programmatic responses with the scope and nature of the returnee problem, develop a strategically guided approach to reintegration, integrate existing legal bases and systems of reintegration, and consider how FTF management may be instrumentalized towards broader policy objectives. These core objectives provide a compass for guiding how policymakers and practitioners navigate through the complex and interrelated challenges associated with reintegration work. Moreover, in order to achieve the goals and objectives outlined above, this report has identified a set of best practices relating to the formal structures and roles and responsibilities assigned to the reintegration mission community in the U.S. Second, we argue that the coordination and efficacy of reintegration activities can be improved with a greater focus on the role of strategic communications at the overarching planning and management level. It is broadly recognized that reintegration efforts should not be stovepiped. Less acknowledged is the role that a robust and integrated approach to strategic communications can play in helping to improve the sequencing and synchronicity of standard programming activities. This coordination issue also extends to how the age, gender and psychosocial needs of FTF returnees and their families are addressed. Third, we highlight the need for better incorporation of gender, age, and trauma-informed considerations at the program and case levels. The synthesis of trauma-informed approaches during the repatriation and reintegration process is vital and case managers must be appropriately equipped to develop tailored plans that harness gender, age, and familial factors too. Together, the coherent integration of compatible reintegration efforts and supporting activities will enable a more strategically focused approach. Finally, this report presents the broad parameters of a risk assessment tool for assessing FTF returnees and their families based on the project’s multidisciplinary and multisectoral findings. The framework is underpinned by a rigorous methodology and an evidence-based theory of change. However, it also seeks to be accessible and adaptable to ensure usability. The development and further refinement of this risk assessment instrument presents a promising avenue for future applied research
Reverse Engineering Gene Networks with ANN: Variability in Network Inference Algorithms
Motivation :Reconstructing the topology of a gene regulatory network is one
of the key tasks in systems biology. Despite of the wide variety of proposed
methods, very little work has been dedicated to the assessment of their
stability properties. Here we present a methodical comparison of the
performance of a novel method (RegnANN) for gene network inference based on
multilayer perceptrons with three reference algorithms (ARACNE, CLR, KELLER),
focussing our analysis on the prediction variability induced by both the
network intrinsic structure and the available data.
Results: The extensive evaluation on both synthetic data and a selection of
gene modules of "Escherichia coli" indicates that all the algorithms suffer of
instability and variability issues with regards to the reconstruction of the
topology of the network. This instability makes objectively very hard the task
of establishing which method performs best. Nevertheless, RegnANN shows MCC
scores that compare very favorably with all the other inference methods tested.
Availability: The software for the RegnANN inference algorithm is distributed
under GPL3 and it is available at the corresponding author home page
(http://mpba.fbk.eu/grimaldi/regnann-supmat
Complete structure of the chemosensory array core signalling unit in an E. coli 1 minicell strain
Motile bacteria sense chemical gradients with transmembrane receptors organised in supramolecular signalling arrays. Understanding stimulus detection and transmission at the molecular level requires precise structural characterisation of the array building block known as a core signalling unit. Here we introduce an Escherichia coli strain that forms small minicells possessing extended and highly ordered chemosensory arrays. We use cryo-electron tomography and subtomogram averaging to provide a three-dimensional map of a complete core signalling unit, with visible densities corresponding to the HAMP and periplasmic domains. This map, combined with previously determined high resolution structures and molecular dynamics simulations, yields a molecular model of the transmembrane core signalling unit and enables spatial localisation of its individual domains. Our work thus offers a solid structural basis for the interpretation of a wide range of existing data and the design of further experiments to elucidate signalling mechanisms within the core signalling unit and larger array
Stochastic pump effect and geometric phases in dissipative and stochastic systems
The success of Berry phases in quantum mechanics stimulated the study of
similar phenomena in other areas of physics, including the theory of living
cell locomotion and motion of patterns in nonlinear media. More recently,
geometric phases have been applied to systems operating in a strongly
stochastic environment, such as molecular motors. We discuss such geometric
effects in purely classical dissipative stochastic systems and their role in
the theory of the stochastic pump effect (SPE).Comment: Review. 35 pages. J. Phys. A: Math, Theor. (in press
- …