Showing papers by "University of Colorado Colorado Springs published in 2017"

Machine Learning in Radiology: Applications Beyond Image Interpretation

Abstract: Much attention has been given to machine learning and its perceived impact in radiology, particularly in light of recent success with image classification in international competitions. However, machine learning is likely to impact radiology outside of image interpretation long before a fully functional "machine radiologist" is implemented in practice. Here, we describe an overview of machine learning, its application to radiology and other domains, and many cases of use that do not involve image interpretation. We hope that better understanding of these potential applications will help radiology practices prepare for the future and realize performance improvement and efficiency gains.

Reproducible and scalable purification of extracellular vesicles using combined bind-elute and size exclusion chromatography

Abstract: Extracellular vesicles (EVs) play a pivotal role in cell-to-cell communication and have been shown to take part in several physiological and pathological processes. EVs have traditionally been purified by ultracentrifugation (UC), however UC has limitations, including resulting in, operator-dependant yields, EV aggregation and altered EV morphology, and moreover is time consuming. Here we show that commercially available bind-elute size exclusion chromatography (BE-SEC) columns purify EVs with high yield (recovery ~ 80%) in a time-efficient manner compared to current methodologies. This technique is reproducible and scalable, and surface marker analysis by bead-based flow cytometry revealed highly similar expression signatures compared with UC-purified samples. Furthermore, uptake of eGFP labelled EVs in recipient cells was comparable between BE-SEC and UC samples. Hence, the BE-SEC based EV purification method represents an important methodological advance likely to facilitate robust and reproducible studies of EV biology and therapeutic application.

Early Hearing Detection and Vocabulary of Children With Hearing Loss.

Abstract: BACKGROUND AND OBJECTIVES: To date, no studies have examined vocabulary outcomes of children meeting all 3 components of the Early Hearing Detection and Intervention (EHDI) guidelines (hearing screening by 1 month, diagnosis of hearing loss by 3 months, and intervention by 6 months of age). The primary purpose of the current study was to examine the impact of the current EHDI 1-3-6 policy on vocabulary outcomes across a wide geographic area. A secondary goal was to confirm the impact of other demographic variables previously reported to be related to language outcomes. METHODS: This was a cross-sectional study of 448 children with bilateral hearing loss between 8 and 39 months of age (mean = 25.3 months, SD = 7.5 months). The children lived in 12 different states and were participating in the National Early Childhood Assessment Project. RESULTS: The combination of 6 factors in a regression analysis accounted for 41% of the variance in vocabulary outcomes. Vocabulary quotients were significantly higher for children who met the EHDI guidelines, were younger, had no additional disabilities, had mild to moderate hearing loss, had parents who were deaf or hard of hearing, and had mothers with higher levels of education. CONCLUSIONS: Vocabulary learning may be enhanced with system improvements that increase the number of children meeting the current early identification and intervention guidelines. In addition, intervention efforts need to focus on preventing widening delays with chronological age, assisting mothers with lower levels of education, and incorporating adults who are deaf/hard-of-hearing in the intervention process.

Public Transportation: An Investigation of Barriers for People With Disabilities:

Abstract: The physical accessibility of public transportation increased nationwide following the passage of the Americans With Disabilities Act (ADA) in 1990. Despite removal of many physical barriers within...

A Survey of Stealth Malware Attacks, Mitigation Measures, and Steps Toward Autonomous Open World Solutions

Abstract: As our professional, social, and financial existences become increasingly digitized and as our government, healthcare, and military infrastructures rely more on computer technologies, they present larger and more lucrative targets for malware. Stealth malware in particular poses an increased threat because it is specifically designed to evade detection mechanisms, spreading dormant, in the wild for extended periods of time, gathering sensitive information or positioning itself for a high-impact zero-day attack. Policing the growing attack surface requires the development of efficient anti-malware solutions with improved generalization to detect novel types of malware and resolve these occurrences with as little burden on human experts as possible. In this paper, we survey malicious stealth technologies as well as existing solutions for detecting and categorizing these countermeasures autonomously. While machine learning offers promising potential for increasingly autonomous solutions with improved generalization to new malware types, both at the network level and at the host level, our findings suggest that several flawed assumptions inherent to most recognition algorithms prevent a direct mapping between the stealth malware recognition problem and a machine learning solution. The most notable of these flawed assumptions is the closed world assumption: that no sample belonging to a class outside of a static training set will appear at query time. We present a formalized adaptive open world framework for stealth malware recognition and relate it mathematically to research from other machine learning domains.

iShuffle: Improving Hadoop Performance with Shuffle-on-Write

Abstract: Hadoop is a popular implementation of the MapReduce framework for running data-intensive jobs on clusters of commodity servers. Shuffle , the all-to-all input data fetching phase between the map and reduce phase can significantly affect job performance. However, the shuffle phase and reduce phase are coupled together in Hadoop and the shuffle can only be performed by running the reduce tasks. This leaves the potential parallelism between multiple waves of map and reduce unexploited and resource wastage in multi-tenant Hadoop clusters, which significantly delays the completion of jobs in a multi-tenant Hadoop cluster. More importantly, Hadoop lacks the ability to schedule task efficiently and mitigate the data distribution skew among reduce tasks, which leads to further degradation of job performance. In this work, we propose to decouple shuffle from reduce tasks and convert it into a platform service provided by Hadoop. We present iShuffle , a user-transparent shuffle service that pro-actively pushes map output data to nodes via a novel shuffle-on-write operation and flexibly schedules reduce tasks considering workload balance. Experimental results with representative workloads and Facebook workload trace show that iShuffle reduces job completion time by as much as 29.6 and 34 percent in single-user and multi-user clusters, respectively.

How concentrated is crime at places? A systematic review from 1970 to 2015

Abstract: Despite the increasing awareness and interests about the importance of crime concentration at places, scholars have not comprehensively synthesized the body of evidence related to this thesis We conduct a systematic review and meta-analysis of the evidence that crime is concentrated among places We identified 44 studies that empirically examined crime concentration at place and provided quantitative information sufficient for analysis We organized data using visual binning and fitted logarithmic curves to the median values of the bins We examine concentration in two conditions: when all places are studied (prevalence), and when only places with at least one crime are studied (frequency) We find that crime is concentrated at a relatively few places in both conditions We also compared concentration for calls for services to reported crime incidents Calls for services appear more concentrated than crime at places Because there are several ways place is defined, we compared different units of analysis Crime is more concentrated at addresses than other units, including street segments We compared crime concentration over time and found less concentration in 2000s compared to 1980s and 1990s We also compared crime concentration between US and non-US countries and found more concentration in US Finally, violent crime is more concentrated than property crime Though we systematically reviewed a comprehensive list of studies, summarizing this literature is problematic Not only should more systematic reviews be conducted as more research becomes available, but future inquiries should examine other ways of summarizing these studies that could challenge our findings

A physical fitness profile of state highway patrol officers by gender and age

Abstract: Law enforcement officers perform physically demanding tasks that generally remain constant as they age. However, there is limited population-specific research on age, gender and normative fitness values for law enforcement officers as opposed to those of the general population. The purpose of this study was to profile the current level of fitness for highway patrol officers based on age and gender and provide percentile ranking charts unique to this population. Retrospective data for six-hundred and thirty-one state troopers (♂ = 597; mean age = 39.52 ± 8.09 yrs; mean height = 180.72 ± 7.06 cm; mean weight = 93.66 ± 15.72 kg: ♀ = 34; mean age = 36.20 ± 8.45 years; mean height = 169.62 ± 6.65 cm; mean weight = 74.02 ± 14.91 kg) collected in 2014–2015 were provided for analysis. Data included demographic (age), anthropometric (height and weight), and select fitness (VJ, push-ups, sit ups, isometric leg/back strength, isometric grip strength and 20 m shuttle run test) information. There were generally significant differences between genders for all anthropometric and fitness measures, most consistently in the 30–39 age groups. While there was a general decline in push-up and shuttle run performance in female officers, these results did not reach significance. For male officers, there were significant differences between the 20–29 year-old age group and the 30–39, 40–49 and 50–59 year-old groups with the younger group performing better in VJ, push-ups, sit ups and number of shuttle runs than the older groups. There were no differences in isometric grip strength and leg back dynamometer measures between age groups. Male officers tended to be heavier, taller and perform significantly better than female officers in all measures bar sit-ups. While there appeared to be a general decline in certain physical characteristics across genders with increasing age the notable differences were between the youngest male age group (20–29 years) and all other male age groups with a potential reason being the lack of fitness requirements once typically younger cadets leave the academy. Percentile rankings for the assessed measures were found to have elements very specific to this population when compared to the general population and those provided in this paper can be used to inform future profiling and research in this population.

Physical Fitness Characteristics of High vs. Low Performers on an Occupationally Specific Physical Agility Test for Patrol Officers.

Abstract: Law enforcement agencies frequently use physical ability tests (PATs) as a method of evaluating occupational performance. These tests are designed to replicate essential occupational tasks frequently performed by officers in the field. The purpose of this study was to determine whether significant relationships exist between the selected physical fitness tests and PAT performance and to determine which of these tests best differentiates between high and low PAT performers. Full-time highway patrol officers (n = 495) submitted self-reported anthropometric data (mean age = 39.6 + 7.7 years) along with fitness assessments taken from their organization's yearly fitness tests. All subjects completed a series of field-based fitness tests, as well as an occupationally specific PAT. Results of the study indicated that the selected tests accounted for almost 69% of the total variance on PAT performance. Overall, the 20-m meter multistage fitness test, 1-minute sit-up performance, and vertical jump height best predicted PAT performance. Furthermore, it was revealed that high performers were significantly more fit in all measures of dynamic fitness when compared with lower performers. No significant differences were discovered in static strength between groups. Strength and conditioning specialists should focus on developing aerobic capacity, trunk muscular endurance, and whole-body anaerobic power to improve PAT and occupational performance.

Improving Performance of Heterogeneous MapReduce Clusters with Adaptive Task Tuning

Abstract: Datacenter-scale clusters are evolving toward heterogeneous hardware architectures due to continuous server replacement. Meanwhile, datacenters are commonly shared by many users for quite different uses. It often exhibits significant performance heterogeneity due to multi-tenant interferences. The deployment of MapReduce on such heterogeneous clusters presents significant challenges in achieving good application performance compared to in-house dedicated clusters. As most MapReduce implementations are originally designed for homogeneous environments, heterogeneity can cause significant performance deterioration in job execution despite existing optimizations on task scheduling and load balancing. In this paper, we observe that the homogeneous configuration of tasks on heterogeneous nodes can be an important source of load imbalance and thus cause poor performance. Tasks should be customized with different configurations to match the capabilities of heterogeneous nodes. To this end, we propose a self-adaptive task tuning approach, Ant , that automatically searches the optimal configurations for individual tasks running on different nodes. In a heterogeneous cluster, Ant first divides nodes into a number of homogeneous subclusters based on their hardware configurations. It then treats each subcluster as a homogeneous cluster and independently applies the self-tuning algorithm to them. Ant finally configures tasks with randomly selected configurations and gradually improves tasks configurations by reproducing the configurations from best performing tasks and discarding poor performing configurations. To accelerate task tuning and avoid trapping in local optimum, Ant uses genetic algorithm during adaptive task configuration. Experimental results on a heterogeneous physical cluster with varying hardware capabilities show that Ant improves the average job completion time by 31, 20, and 14 percent compared to stock Hadoop (Stock), customized Hadoop with industry recommendations (Heuristic), and a profiling-based configuration approach (Starfish), respectively. Furthermore, we extend Ant to virtual MapReduce clusters in a multi-tenant private cloud. Specifically, Ant characterizes a virtual node based on two measured performance statistics: I/O rate and CPU steal time. It uses k-means clustering algorithm to classify virtual nodes into configuration groups based on the measured dynamic interference. Experimental results on virtual clusters with varying interferences show that Ant improves the average job completion time by 20, 15, and 11 percent compared to Stock, Heuristic and Starfish, respectively.

Domains of Digital Marketing Channels in the Sharing Economy

Abstract: The sharing economy has experienced major growth in a short period with little academic research that has looked into possible logistic factors that may have contributed to this phenomenon. This article explores the domains of digital marketing channels—specifically e-mail marketing, social media marketing, and search engine marketing—to understand how they can contribute to growth for organizations in the sharing economy. A detailed conceptual model of the decision spectrum necessary to coordinate digital marketing channels is presented and a special case is made for the role branded-mobile applications play in this context. In particular, branded-mobile applications leverage three embedded components to overcome common deterrents for participating in the sharing economy: trust, utility, and user experience.

Adverse childhood experiences, commitment offense, and race/ethnicity: Are the effects crime-, race-, and ethnicity-specific?

Abstract: Adverse childhood experiences are associated with an array of health, psychiatric, and behavioral problems including antisocial behavior. Criminologists have recently utilized adverse childhood experiences as an organizing research framework and shown that adverse childhood experiences are associated with delinquency, violence, and more chronic/severe criminal careers. However, much less is known about adverse childhood experiences vis-a-vis specific forms of crime and whether the effects vary across race and ethnicity. Using a sample of 2520 male confined juvenile delinquents, the current study used epidemiological tables of odds (both unadjusted and adjusted for onset, total adjudications, and total out of home placements) to evaluate the significance of the number of adverse childhood experiences on commitment for homicide, sexual assault, and serious persons/property offending. The effects of adverse childhood experiences vary considerably across racial and ethnic groups and across offense types. Adverse childhood experiences are strongly and positively associated with sexual offending, but negatively associated with homicide and serious person/property offending. Differential effects of adverse childhood experiences were also seen among African Americans, Hispanics, and whites. Suggestions for future research to clarify the mechanisms by which adverse childhood experiences manifest in specific forms of criminal behavior are offered.

Sex Trafficking and the Commercial Sexual Exploitation of Children

Abstract: In recent years, the problem of child sex trafficking has become a topic of international discussion and concern. Child sex trafficking can include many forms of commercial sexual exploitation such as prostitution, pornography, and child sex tourism. Children who fall prey to these forms of sexual exploitation are of particular concern because of their vulnerable status and the impact these experiences have on their development. This article provides a comprehensive review about what is currently known about child sex trafficking by examining definitions, estimates of the problem, child risk factors and consequences, and approaches to protection, prosecution, promotion of recovery and reintegration, and partnerships for promoting collaboration and cooperation.

Ferroelectric Nanoparticles in Liquid Crystals: Recent Progress and Current Challenges.

Abstract: The dispersion of ferroelectric nanomaterials in liquid crystals has recently emerged as a promising way for the design of advanced and tunable electro-optical materials. The goal of this paper is a broad overview of the current technology, basic physical properties, and applications of ferroelectric nanoparticle/liquid crystal colloids. By compiling a great variety of experimental data and discussing it in the framework of existing theoretical models, both scientific and technological challenges of this rapidly developing field of liquid crystal nanoscience are identified. They can be broadly categorized into the following groups: (i) the control of the size, shape, and the ferroelectricity of nanoparticles; (ii) the production of a stable and aggregate-free dispersion of relatively small (~10 nm) ferroelectric nanoparticles in liquid crystals; (iii) the selection of liquid crystal materials the most suitable for the dispersion of nanoparticles; (iv) the choice of appropriate experimental procedures and control measurements to characterize liquid crystals doped with ferroelectric nanoparticles; and (v) the development and/or modification of theoretical and computational models to account for the complexity of the system under study. Possible ways to overcome the identified challenges along with future research directions are also discussed.

Cross-Sectional and Retrospective Cohort Analysis of the Effects of Age on Flexibility, Strength Endurance, Lower-Body Power, and Aerobic Fitness in Law Enforcement Officers.

Abstract: Lockie, RG, Dawes, JJ, Kornhauser, CL, and Holmes, RJ. Cross-sectional and retrospective cohort analysis of the effects of age on flexibility, strength endurance, lower-body power, and aerobic fitness in law enforcement officers. J Strength Cond Res 33(2): 451-458, 2019-There can be a great age range in cohorts of law enforcement officers. As the tasks required of officers generally do not change with advancing age, it is important to understand how physical performance in tests that assess job-specific characteristics may be altered. Retrospective analysis of performance test data of 383 officers (362 men and 21 women) was conducted. The tests included the following: sit-and-reach to determine hamstring and lower back flexibility; maximal push-up and sit-up repetitions in 60 seconds to measure muscle endurance; vertical jump (VJ) to assess lower-body power; and 2.4-km run to ascertain aerobic capacity. Data were stratified by age into 20-29, 30-39, 40-49, and 50-59 year groups, and analyzed by sex. A 1-way analysis of variance with the Bonferroni post hoc test was used to calculate the differences between the groups. Considering the male subjects, the 40-49 and 50-59 year groups performed poorer in the VJ, sit-up test, and 2.4-km run compared with the 20-29 year group (p ≤ 0.001-0.045). For the female subjects, the 20-29 year group was superior to the 30-39 (p = 0.013) and 40-49 (p = 0.025) year groups in the push-up test. To ensure that an older officer can successfully complete occupation-specific tasks, lower-body power, abdominal strength, and aerobic training should be completed. Female officers should also attempt to maintain relative upper-body strength. Practitioners must attempt to design training programs that fit within the context of the occupational demands, and potentially using a nontraditional training design as law enforcement officers may not have the time to follow a traditional periodization model.

The Effectiveness of Emotional Freedom Techniques in the Treatment of Posttraumatic Stress Disorder: A Meta-Analysis

Abstract: Background Over the past two decades, growing numbers of clinicians have been utilizing emotional freedom techniques (EFT) in the treatment of posttraumatic stress disorder (PTSD), anxiety, and depression. Randomized controlled trials (RCTs) have shown encouraging outcomes for all three conditions. Objective To assess the efficacy of EFT in treating PTSD by conducting a meta-analysis of existing RCTs. Methods A systematic review of databases was undertaken to identify RCTs investigating EFT in the treatment of PTSD. The RCTs were evaluated for quality using evidence-based standards published by the American Psychological Association Division 12 Task Force on Empirically Validated Therapies. Those meeting the criteria were assessed using a meta-analysis that synthesized the data to determine effect sizes. While uncontrolled outcome studies were excluded, they were examined for clinical implications of treatment that can extend knowledge of this condition. Results Seven randomized controlled trials were found to meet the criteria and were included in the meta-analysis. A large treatment effect was found, with a weighted Cohen׳s d = 2.96 (95% CI: 1.96–3.97, P Conclusions The analysis of existing studies showed that a series of 4–10 EFT sessions is an efficacious treatment for PTSD with a variety of populations. The studies examined reported no adverse effects from EFT interventions and showed that it can be used both on a self-help basis and as a primary evidence-based treatment for PTSD.

Chemical Composition and Labeling of Substances Marketed as Selective Androgen Receptor Modulators and Sold via the Internet.

Abstract: Importance Recent reports have described the increasing use of nonsteroidal selective androgen receptor modulators, which have not been approved by the US Food and Drug Administration (FDA), to enhance appearance and performance. The composition and purity of such products is not known. Objective To determine the chemical identity and the amounts of ingredients in dietary supplements and products marketed and sold through the internet as selective androgen receptor modulators and compare the analyzed contents with product labels. Design and Setting Web-based searches were performed from February 18, 2016, to March 25, 2016, using the Google search engine on the Chrome and Internet Explorer web browsers to identify suppliers selling selective androgen receptor modulators. The products were purchased and the identities of the compounds and their amounts were determined from April to August 2016 using chain-of-custody and World Anti-Doping Association–approved analytical procedures. Analytical findings were compared against the label information. Exposures Products marketed and sold as selective androgen receptor modulators. Main Outcomes and Measures Chemical identities and the amount of ingredients in each product marketed and sold as selective androgen receptor modulators. Results Among 44 products marketed and sold as selective androgen receptor modulators, only 23 (52%) contained 1 or more selective androgen receptor modulators (Ostarine, LGD-4033, or Andarine). An additional 17 products (39%) contained another unapproved drug, including the growth hormone secretagogue ibutamoren, the peroxisome proliferator-activated receptor-δ agonist GW501516, and the Rev-ErbA agonist SR9009. Of the 44 tested products, no active compound was detected in 4 (9%) and substances not listed on the label were contained in 11 (25%). In only 18 of the 44 products (41%), the amount of active compound in the product matched that listed on the label. The amount of the compounds listed on the label differed substantially from that found by analysis in 26 of 44 products (59%). Conclusions and Relevance In this limited investigation involving chemical analyses of 44 products marketed as selective androgen receptor modulators and sold via the internet, most products contained unapproved drugs and substances. Only 52% contained selective androgen receptor modulators and many were inaccurately labeled.

AAPM medical physics practice guideline 8.a.: Linear accelerator performance tests

Abstract: Purpose The purpose of this guideline is to provide a list of critical performance tests in order to assist the Qualified Medical Physicist (QMP) in establishing and maintaining a safe and effective quality assurance (QA) program The performance tests on a linear accelerator (linac) should be selected to fit the clinical patterns of use of the accelerator and care should be given to perform tests which are relevant to detecting errors related to the specific use of the accelerator Methods A risk assessment was performed on tests from current task group reports on linac QA to highlight those tests that are most effective at maintaining safety and quality for the patient Recommendations are made on the acquisition of reference or baseline data, the establishment of machine isocenter on a routine basis, basing performance tests on clinical use of the linac, working with vendors to establish QA tests and performing tests after maintenance Results The recommended tests proposed in this guideline were chosen based on the results from the risk analysis and the consensus of the guideline's committee The tests are grouped together by class of test (eg, dosimetry, mechanical, etc) and clinical parameter tested Implementation notes are included for each test so that the QMP can understand the overall goal of each test Conclusion This guideline will assist the QMP in developing a comprehensive QA program for linacs in the external beam radiation therapy setting The committee sought to prioritize tests by their implication on quality and patient safety The QMP is ultimately responsible for implementing appropriate tests In the spirit of the report from American Association of Physicists in Medicine Task Group 100, individual institutions are encouraged to analyze the risks involved in their own clinical practice and determine which performance tests are relevant in their own radiotherapy clinics

In vivo expression technology and 5' end mapping of the Borrelia burgdorferi transcriptome identify novel RNAs expressed during mammalian infection.

Abstract: Borrelia burgdorferi, the bacterial pathogen responsible for Lyme disease, modulates its gene expression profile in response to the environments encountered throughout its tick-mammal infectious cycle. To begin to characterize the B. burgdorferi transcriptome during murine infection, we previously employed an in vivo expression technology-based approach (BbIVET). This identified 233 putative promoters, many of which mapped to un-annotated regions of the complex, segmented genome. Herein, we globally identify the 5' end transcriptome of B. burgdorferi grown in culture as a means to validate non-ORF associated promoters discovered through BbIVET. We demonstrate that 119 BbIVET promoters are associated with transcription start sites (TSSs) and validate novel RNA transcripts using Northern blots and luciferase promoter fusions. Strikingly, 49% of BbIVET promoters were not found to associate with TSSs. This finding suggests that these sequences may be primarily active in the mammalian host. Furthermore, characterization of the 6042 B. burgdorferi TSSs reveals a variety of RNAs including numerous antisense and intragenic transcripts, leaderless RNAs, long untranslated regions and a unique nucleotide frequency for initiating intragenic transcription. Collectively, this is the first comprehensive map of TSSs in B. burgdorferi and characterization of previously un-annotated RNA transcripts expressed by the spirochete during murine infection.

The implications of workplace spirituality for person–environment fit theory.

Abstract: Person–environment (PE) fit theory is based on the premise that people flourish in work settings that are compatible with their skills, interests, values, and other characteristics. While the premise of PE fit theory appears to be straightforward, it is actually a complex and evolving framework with

Maternal PTSD and Children's Adjustment: Parenting Stress and Emotional Availability as Proposed Mediators.

Abstract: Objectives Maternal posttraumatic stress disorder (PTSD) is a risk factor for negative child adjustment, but it is unclear whether this association is direct (e.g., a mother's PTSD symptoms are observed, learned, and internalized by children which results in behavioral and emotional problems) or indirect, through parent–child relationship difficulties or parenting stress. We hypothesized that parenting stress and maternal emotional availability would exhibit indirect effects on relationships between maternal PTSD and children's functioning. Method Participants were 52 trauma-exposed mothers and their children (aged 7–12 years). Mothers completed measures of PTSD and parenting stress and reported on their children's functioning. Emotional availability was assessed through observer-rated mother–child interactions. Results Emotional availability was not related to PTSD or child outcomes. Parenting stress had a substantial indirect effect on the relationships between maternal PTSD and child emotion regulation, internalizing, and externalizing behaviors. Conclusions Results highlight the need to target parenting stress in interventions with trauma-exposed families.

A View of Tropical Cyclones from Above: The Tropical Cyclone Intensity Experiment

Abstract: Tropical cyclone (TC) outflow and its relationship to TC intensity change and structure were investigated in the Office of Naval Research Tropical Cyclone Intensity (TCI) field program during 2015 using dropsondes deployed from the innovative new High-Definition Sounding System (HDSS) and remotely sensed observations from the Hurricane Imaging Radiometer (HIRAD), both on board the NASA WB-57 that flew in the lower stratosphere. Three noteworthy hurricanes were intensively observed with unprecedented horizontal resolution: Joaquin in the Atlantic and Marty and Patricia in the eastern North Pacific. Nearly 800 dropsondes were deployed from the WB-57 flight level of ∼60,000 ft (∼18 km), recording atmospheric conditions from the lower stratosphere to the surface, while HIRAD measured the surface winds in a 50-km-wide swath with a horizontal resolution of 2 km. Dropsonde transects with 4–10-km spacing through the inner cores of Hurricanes Patricia, Joaquin, and Marty depict the large horizontal and ver...

FLEP: Enabling Flexible and Efficient Preemption on GPUs

Abstract: GPUs are widely adopted in HPC and cloud computing platforms to accelerate general-purpose workloads. However, modern GPUs do not support flexible preemption, leading to performance and priority inversion problems in multi-tasking environments.In this paper, we propose and develop FLEP, the first software system that enables flexible kernel preemption and kernel scheduling on commodity GPUs. The FLEP compilation engine transforms the GPU program into preemptable forms, which can be interrupted during execution and yield all or part of the streaming multi-processors (SMs) in the GPU. The FLEP runtime engine intercepts all kernel invocations and determines which kernels and how those kernels should be preempted and scheduled. Experimental results on two-kernel co-runs demonstrate up to 24.2X speedup for high-priority kernels and up to 27X improvement on normalized average turnaround time for kernels with the same priority. FLEP reduces the preemption latency by up to 41% compared to yielding the whole GPU when the waiting kernels only need several SMs. With all the benefits, FLEP only introduces 2.5% runtime overhead, which is substantially lower than the kernel slicing approach.

Ravenous wolves revisited: a systematic review of offending concentration

Abstract: Numerous studies have established that crime is highly concentrated among a small group of offenders. These findings have guided the development of various crime prevention strategies. The underlying theme of these strategies is that by focusing on the few offenders who are responsible for most of the crime, we can prevent the greatest amount of crime with the fewest resources. Nevertheless, there has been no systematic review of the many studies, so it is possible that the accepted understanding among researchers and practitioners is based on a few prominent studies that are misleading. Further, we do not know how concentrated crime is among offenders, given the variety of ways researchers report their findings. This paper systematically reviews this literature and uses meta-analysis to determine how confident we can be that crime is concentrated among a few offenders. We first systematically reviewed the literature and found 73 studies on the concentration of crime among offenders. From those studies, we identified 15 studies on the prevalence of offending and 27 studies on the frequency of offending that provided data suitable for analysis. We then performed a meta-analysis of those studies to examine how crime is concentrated among the worst offenders and how that concentration varies between different types of offenders. We found that crime is highly concentrated in the population and across different types of offenders. Little variation in concentration exists between youths and adults or between American offenders and those from other countries. We found more variation between males and females in the concentration of offending, though we believe this may be due to the more limited data on female offenders. The systematic review and meta-analysis we present here is the first study of its kind on offending concentration. This is an important step in closing this gap in the crime prevention literature, but we encourage making updates to this systematic review as new literature becomes available, and using alternate methods of summarizing these studies that could challenge these findings.

Clinical interventions, implementation interventions, and the potential greyness in between -a discussion paper

Abstract: There is increasing awareness that regardless of the proven value of clinical interventions, the use of effective strategies to implement such interventions into clinical practice is necessary to ensure that patients receive the benefits. However, there is often confusion between what is the clinical intervention and what is the implementation intervention. This may be caused by a lack of conceptual clarity between ‘intervention’ and ‘implementation’, yet at other times by ambiguity in application. We suggest that both the scientific and the clinical communities would benefit from greater clarity; therefore, in this paper, we address the concepts of intervention and implementation, primarily as in clinical interventions and implementation interventions, and explore the grey area in between. To begin, we consider the similarities, differences and potential greyness between clinical interventions and implementation interventions through an overview of concepts. This is illustrated with reference to two examples of clinical interventions and implementation intervention studies, including the potential ambiguity in between. We then discuss strategies to explore the hybridity of clinical-implementation intervention studies, including the role of theories, frameworks, models, and reporting guidelines that can be applied to help clarify the clinical and implementation intervention, respectively. Semantics provide opportunities for improved precision in depicting what is ‘intervention’ and what is ‘implementation’ in health care research. Further, attention to study design, the use of theory, and adoption of reporting guidelines can assist in distinguishing between the clinical intervention and the implementation intervention. However, certain aspects may remain unclear in analyses of hybrid studies of clinical and implementation interventions. Recognizing this potential greyness can inform further discourse.

Ethics in the Sharing Economy: Creating a Legitimate Marketing Channel

Abstract: The sharing economy is a regulatory-disruptive business model in transportation, accommodation, household services, and other service sectors. In this article, we examine the ethical issues in the sharing-economy business model that depends on trust and reputation. We draw from the stakeholder, trust, and institutional theory literature to explore ways to encourage conformity of practices in the relatively infant marketing channel of the sharing economy.