3,113 research outputs found
QCD corrections to stoponium production at hadron colliders
If the lighter top squark has no kinematically allowed two-body decays that
conserve flavor, then it will live long enough to form hadronic bound states.
The observation of the diphoton decays of stoponium could then provide a
uniquely precise measurement of the top squark mass. In this paper, we
calculate the cross section for the production of stoponium in a hadron
collider at next-to-leading order (NLO) in QCD. We present numerical results
for the cross section for production of stoponium at the LHC and study the
dependence on beam energy, stoponium mass, and the renormalization and
factorization scale. The cross-section is substantially increased by the NLO
corrections, counteracting a corresponding decrease found earlier in the NLO
diphoton branching ratio.Comment: 24 page
The Feasibility of a Using a Smart Button Mobile Health System to Self-Track Medication Adherence and Deliver Tailored Short Message Service Text Message Feedback
BACKGROUND:
As many as 50% of people experience medication nonadherence, yet studies for detecting nonadherence and delivering real-time interventions to improve adherence are lacking. Mobile health (mHealth) technologies show promise to track and support medication adherence.
OBJECTIVE:
The study aimed to evaluate the feasibility and acceptability of using an mHealth system for medication adherence tracking and intervention delivery. The mHealth system comprises a smart button device to self-track medication taking, a companion smartphone app, a computer algorithm used to determine adherence and then deliver a standard or tailored SMS (short message service) text message on the basis of timing of medication taking. Standard SMS text messages indicated that the smartphone app registered the button press, whereas tailored SMS text messages encouraged habit formation and systems thinking on the basis of the timing the medications were taken.
METHODS:
A convenience sample of 5 adults with chronic kidney disease (CKD), who were prescribed antihypertensive medication, participated in a 52-day longitudinal study. The study was conducted in 3 phases, with a standard SMS text message sent in phases 1 (study days 1-14) and 3 (study days 46-52) and tailored SMS text messages sent during phase 2 (study days 15-45) in response to participant medication self-tracking. Medication adherence was measured using: (1) the smart button and (2) electronic medication monitoring caps. Concordance between these 2 methods was evaluated using percentage of measurements made on the same day and occurring within ±5 min of one another. Acceptability was evaluated using qualitative feedback from participants.
RESULTS:
A total of 5 patients with CKD, stages 1-4, were enrolled in the study, with the majority being men (60%), white (80%), and Hispanic/Latino (40%) of middle age (52.6 years, SD 22.49; range 20-70). The mHealth system was successfully initiated in the clinic setting for all enrolled participants. Of the expected 260 data points, 36.5% (n=95) were recorded with the smart button and 76.2% (n=198) with electronic monitoring. Concordant events (n=94), in which events were recorded with both the smart button and electronic monitoring, occurred 47% of the time and 58% of these events occurred within ±5 min of one another. Participant comments suggested SMS text messages were encouraging.
CONCLUSIONS:
It was feasible to recruit participants in the clinic setting for an mHealth study, and our system was successfully initiated for all enrolled participants. The smart button is an innovative way to self-report adherence data, including date and timing of medication taking, which were not previously available from measures that rely on recall of adherence. Although the selected smart button had poor concordance with electronic monitoring caps, participants were willing to use it to self-track medication adherence, and they found the mHealth system acceptable to use in most cases
Toward understanding ambulatory activity decline in Parkinson disease
BACKGROUND: Declining ambulatory activity represents an important facet of disablement in Parkinson disease (PD).
OBJECTIVE: The primary study aim was to compare the 2-year trajectory of ambulatory activity decline with concurrently evolving facets of disability in a small cohort of people with PD. The secondary aim was to identify baseline variables associated with ambulatory activity at 1- and 2-year follow-up assessments.
DESIGN: This was a prospective, longitudinal cohort study.
METHODS: Seventeen people with PD (Hoehn and Yahr stages 1-3) were recruited from 2 outpatient settings. Ambulatory activity data were collected at baseline and at 1- and 2-year annual assessments. Motor, mood, balance, gait, upper extremity function, quality of life, self-efficacy, and levodopa equivalent daily dose data and data on activities of daily living also were collected.
RESULTS: Participants displayed significant 1- and 2-year declines in the amount and intensity of ambulatory activity concurrently with increasing levodopa equivalent daily dose. Worsening motor symptoms and slowing of gait were apparent only after 2 years. Concurrent changes in the remaining clinical variables were not observed. Baseline ambulatory activity and physical performance variables had the strongest relationships with 1- and 2-year mean daily steps.
LIMITATIONS: The sample was small and homogeneous.
CONCLUSIONS: Future research that combines ambulatory activity monitoring with a broader and more balanced array of measures would further illuminate the dynamic interactions among evolving facets of disablement and help determine the extent to which sustained patterns of recommended daily physical activity might slow the rate of disablement in PD.This study was funded primarily by the Davis Phinney Foundation and the Parkinson Disease Foundation. Additional funding was provided by Boston University Building Interdisciplinary Research Careers in Women's Health (K12 HD043444), the National Institutes of Health (R01NS077959), the Utah Chapter of the American Parkinson Disease Association (APDA), the Greater St Louis Chapter of the APDA, and the APDA Center for Advanced PD Research at Washington University. (Davis Phinney Foundation; Parkinson Disease Foundation; K12 HD043444 - Boston University Building Interdisciplinary Research Careers in Women's Health; R01NS077959 - National Institutes of Health; Utah Chapter of the American Parkinson Disease Association (APDA); Greater St Louis Chapter of the APDA; APDA Center for Advanced PD Research at Washington University
Deconstructing 2 Bit Architectures Using Pedantry
The deployment of agents has investigated von Neumann machines, and current trends suggest that the emulation of the transistor will soon emerge. In fact, few researchers would disagree with the study of cache coherence, which embodies the natural principles of artificial intelligence. Pedantry, our new system for Scheme, is the solution to all of these obstacles
Balance differences in people with Parkinson disease with and without freezing of gait
Published in final edited form as:
Gait Posture. 2015 September ; 42(3): 306–309. doi:10.1016/j.gaitpost.2015.06.007.BACKGROUND:
Freezing of gait (FOG) is a relatively common and remarkably disabling impairment associated with Parkinson disease (PD). Laboratory-based measures indicate that individuals with FOG (PD+FOG) have greater balance deficits than those without FOG (PD-FOG). Whether such differences also can be detected using clinical balance tests has not been investigated. We sought to determine if balance and specific aspects of balance, measured using Balance Evaluation Systems Test (BESTest), differs between PD+FOG and PD-FOG. Furthermore, we aimed to determine if time-efficient clinical balance measures (i.e. Mini-BESTest, Berg Balance Scale (BBS)) could detect balance differences between PD+FOG and PD-FOG.
METHODS:
Balance of 78 individuals with PD, grouped as either PD+FOG (n=32) or PD-FOG (n=46), was measured using the BESTest, Mini-BESTest, and BBS. Between-groups comparisons were conducted for these measures and for the six sections of the BESTest using analysis of covariance. A PD composite score was used as a covariate.
RESULTS:
Controlling for motor sign severity, PD duration, and age, PD+FOG had worse balance than PD-FOG when measured using the BESTest (p=0.008, F=7.35) and Mini-BESTest (p=0.002, F=10.37), but not the BBS (p=0.27, F=1.26). BESTest section differences were noted between PD+FOG and PD-FOG for reactive postural responses (p<0.001, F=14.42) and stability in gait (p=0.003, F=9.18).
CONCLUSIONS:
The BESTest and Mini-BESTest, which specifically assessed reactive postural responses and stability in gait, were more likely than the BBS to detect differences in balance between PD+FOG and PD-FOG. Because it is more time efficient to administer, the Mini-BESTest may be the preferred tool for assessing balance deficits associated with FOG.This study was conducted with funding from the Davis Phinney Foundation, Parkinson's Disease Foundation, NIH R01 NS077959, NIH UL1 TR000448, Greater St. Louis American Parkinson Disease Association (APDA), APDA Center for Advanced PD Research at Washington University in St. Louis. The funding sources had no role in the study design, in the collection, analysis and interpretation of data; in the writing of the manuscript; or in the decision to submit the manuscript for publication. (Davis Phinney Foundation; Parkinson's Disease Foundation; R01 NS077959 - NIH; UL1 TR000448 - NIH; Greater St. Louis American Parkinson Disease Association (APDA); APDA Center for Advanced PD Research at Washington University in St. Louis
Two-year trajectory of fall risk in people with Parkinson disease: a latent class analysis
Published in final edited form as:
Arch Phys Med Rehabil. 2016 March ; 97(3): 372–379.e1. doi:10.1016/j.apmr.2015.10.105.OBJECTIVE: To examine fall risk trajectories occurring naturally in a sample of individuals with early to middle stage Parkinson disease (PD).
DESIGN: Latent class analysis, specifically growth mixture modeling (GMM), of longitudinal fall risk trajectories.
SETTING: Assessments were conducted at 1 of 4 universities.
PARTICIPANTS: Community-dwelling participants with PD of a longitudinal cohort study who attended at least 2 of 5 assessments over a 2-year follow-up period (N=230).
INTERVENTIONS: Not applicable.
MAIN OUTCOME MEASURES: Fall risk trajectory (low, medium, or high risk) and stability of fall risk trajectory (stable or fluctuating). Fall risk was determined at 6 monthly intervals using a simple clinical tool based on fall history, freezing of gait, and gait speed.
RESULTS: The GMM optimally grouped participants into 3 fall risk trajectories that closely mirrored baseline fall risk status (P=.001). The high fall risk trajectory was most common (42.6%) and included participants with longer and more severe disease and with higher postural instability and gait disability (PIGD) scores than the low and medium fall risk trajectories (P<.001). Fluctuating fall risk (posterior probability <0.8 of belonging to any trajectory) was found in only 22.6% of the sample, most commonly among individuals who were transitioning to PIGD predominance.
CONCLUSIONS: Regardless of their baseline characteristics, most participants had clear and stable fall risk trajectories over 2 years. Further investigation is required to determine whether interventions to improve gait and balance may improve fall risk trajectories in people with PD.Supported by the Davis Phinney Foundation, the Parkinson's Disease Foundation, National Institutes of Health (NIH) (grant nos. NIH R01 NS077959 and NIH UL1 TR000448), the Massachusetts and Utah Chapters of the American Parkinson Disease Association (APDA), the Greater St Louis Chapter of the APDA, and the APDA Center for Advanced Research at Washington University. (Davis Phinney Foundation; Parkinson's Disease Foundation; NIH R01 NS077959 - National Institutes of Health (NIH); NIH UL1 TR000448 - National Institutes of Health (NIH); Utah Chapter of the American Parkinson Disease Association (APDA); Greater St Louis Chapter of the APDA; APDA Center for Advanced Research at Washington University; Massachusetts Chapter of the American Parkinson Disease Association (APDA)
Limitations of the Standard Gravitational Perfect Fluid Paradigm
We show that the standard perfect fluid paradigm is not necessarily a valid
description of a curved space steady state gravitational source. Simply by
virtue of not being flat, curved space geometries have to possess intrinsic
length scales, and such length scales can affect the fluid structure. For modes
of wavelength of order or greater than such scales eikonalized geometrical
optics cannot apply and rays are not geodesic. Covariantizing thus entails not
only the replacing of flat space functions by covariant ones, but also the
introduction of intrinsic scales that were absent in flat space. In principle
it is thus unreliable to construct the curved space energy-momentum tensor as
the covariant generalization of a geodesic-based flat spacetime energy-momentum
tensor. By constructing the partition function as an incoherent average over a
complete set of modes of a scalar field propagating in a curved space
background, we show that for the specific case of a static, spherically
symmetric geometry, the steady state energy-momentum tensor that ensues will in
general be of the form
where the
anisotropic is a symmetric, traceless rank two tensor which
obeys . Such a type term is absent for an
incoherently averaged steady state fluid in a spacetime where there are no
intrinsic length scales, and in principle would thus be missed in a
covariantizing of a flat spacetime . While the significance of such
type terms would need to be evaluated on a case by case basis,
through the use of kinetic theory we reassuringly find that the effect of such
type terms is small for weak gravity stars where perfect fluid
sources are commonly used.Comment: Final version to appear in General Relativity and Gravitation (the
final publication is available at http://www.springerlink.com). 29 pages, 1
figur
Brief for The American Association on Intellectual and Developmental Disabilities, The Arc of the United States, The National Disability Rights Network, Disability Rights Florida, and The Bazelon Center for Mental Health Law as Amicus Curiae
Question Presented: Whether the Florida scheme for identifying mentally retarded defendants in capital cases violates Atkins v. Virginia, 536 U.S. 304 (2002). Summary of Argument: In Atkins, this Court concluded that a national consensus had developed against the execution of persons with mental retardation and that such executions violated the Eighth Amendment. The Court also stated that the national consensus suggests that some characteristics of mental retardation, such as disabilities in the areas of reasoning, judgment, and control of impulses, undermine the procedural protections of our capital punishment jurisprudence and can jeopardize the reliability and fairness of capital proceedings against defendants with mental retardation. Although the Atkins Court left to the states the task of determining whether a defendant has mental retardation, the Court noted its approval of state statutory definitions that generally conform to the clinical definitions of professional mental disability organizations, such as the American Association on Intellectual and Developmental Disabilities (AAIDD) (formerly the American Association on Mental Retardation (AAMR)) and the American Psychiatric Association (APA). In the eleven years since Atkins was decided, states have taken differing approaches to fulfilling this mandate. Many of these states have followed Atkins’ guidance and have implemented tests that, consistent with the definitions used by recognized mental disability organizations, consider assessments of both an individual’s intellectual functioning (i.e., IQ tests), including the standard margin of error or specific facts about the administration and scoring of the test, and an individual’s conceptual, social and practical skills. Florida courts, however, have adopted a test that individuals who have a raw IQ score above 70 do not have mental retardation, without consideration of the standard margin of error or factors including cognitive and behavioral impairments that are encompassed in the definitions of mental disability professionals. In doing so, Florida has erected a test with no foundation in scientifically recognized definitions that prevents an accurate assessment of whether a defendant has mental retardation and allows for the execution of individuals with mental retardation who would not be executed in states that have followed Atkins’ guidance. This, the ABA asserts, is an arbitrary and capricious application of the death penalty that denies the constitutional protection mandated by Atkins for the full range of defendants with mental retardation
The Effect of European Starlings and Ambient Air Temperature on \u3cem\u3eSalmonella enterica\u3c/em\u3e Contamination within Cattle Feed Bunks
European starlings (Sturnus vulgaris) are a known risk factor for the occurrence of microorganisms that are pathogenic to cattle and humans in concentrated animal feeding operations (CAFOs). Starling use of CAFOs is known to vary in response to weather; starling control operations on CAFOs often are timed to coincide with favorable environmental conditions to maximize take. The totality of this information suggests that disease risks in CAFOs associated with starlings may be influenced by environmental factors, such as temperature. In this study, we assessed the risk of Salmonella enterica contamination of cattle feed by modeling the interaction between starling numbers and ambient air temperatures using data previously reported from Texas CAFOs. We compared these interaction models to the previously published additive models for S. enterica contamination of cattle feed using an information-theoretic approach to model selection that ranked and weighted models in terms of their support by the data, using bias-adjusted Akaike’s Information Criterion (AICc) and Akaike weights (Wi). Our results indicate that the interaction between European starlings and ambient air temperature better explained the occurrence of S. enterica in cattle feed than any of the previously reported models. Specifically, the risk of S. enterica contamination of cattle feed by starlings was greatest when winter temperatures were highest (10°C). Thus, we conclude that the risk of S. enterica contamination of cattle feed by starlings will be worst on the few winter days when daytime high temperatures are above freezing and large numbers of birds are present. Because these conditions will be most common in the late winter and early spring, we recommend that starling control operations on feedlots and dairies be conducted as early in the winter as possible to mitigate the risks of disease created by large foraging flocks of starlings
The effect of European starlings and ambient air temperature on \u3ci\u3eSalmonella enterica\u3c/i\u3e contamination within cattle feed bunks
European starlings (Sturnus vulgaris) are a known risk factor for the occurrence of microorganisms that are pathogenic to cattle and humans in concentrated animal feeding operations (CAFOs). Starling use of CAFOs is known to vary in response to weather; starling control operations on CAFOs often are timed to coincide with favorable environmental conditions to maximize take. The totality of this information suggests that disease risks in CAFOs associated with starlings may be influenced by environmental factors, such as temperature. In this study, we assessed the risk of Salmonella enterica contamination of cattle feed by modeling the interaction between starling numbers and ambient air temperatures using data previously reported from Texas CAFOs. We compared these interaction models to the previously published additive models for S. enterica contamination of cattle feed using an information-theoretic approach to model selection that ranked and weighted models in terms of their support by the data, using bias-adjusted Akaike’s Information Criterion (AICc) and Akaike weights (Wi). Our results indicate that the interaction between European starlings and ambient air temperature better explained the occurrence of S. enterica in cattle feed than any of the previously reported models. Specifically, the risk of S. enterica contamination of cattle feed by starlings was greatest when winter temperatures were highest (10°C). Thus, we conclude that the risk of S. enterica contamination of cattle feed by starlings will be worst on the few winter days when daytime high temperatures are above freezing and large numbers of birds are present. Because these conditions will be most common in the late winter and early spring, we recommend that starling control operations on feedlots and dairies be conducted as early in the winter as possible to mitigate the risks of disease created by large foraging flocks of starlings
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