1,024 research outputs found
Swimming Efficiency of Bacterium Escherichia Coli
We use in vivo measurements of swimming bacteria in an optical trap to
determine fundamental properties of bacterial propulsion. In particular, we
determine the propulsion matrix, which relates the angular velocity of the
flagellum to the torques and forces propelling the bacterium. From the
propulsion matrix dynamical properties such as forces, torques, swimming speed
and power can be obtained from measurements of the angular velocity of the
motor. We find significant heterogeneities among different individuals even
though all bacteria started from a single colony. The propulsive efficiency,
defined as the ratio of the propulsive power output to the rotary power input
provided by the motors, is found to be 0.2%.Comment: 6 page
Assessment of dietary intakes, nutritional risk and whole grain behaviors of community-residing adults age 60+ years
Older adults (OA) are not meeting MyPlate recommendations. Tailored lifestyle intervention programs have the potential to improve nutrition-related knowledge and dietary behaviors. Study 1 assessed the nutritional risk and dietary intake frequencies (DIF) of community-residing OA electing to participate in lifestyle intervention programs and sociodemographic characteristics influencing these behaviors. It was a cross-sectional study consisting of participants from three states who completed the Dietary Screening Tool (DST). Study 2 evaluated to what extent a three-week whole grain (WG) education program is able to impact WG behaviors. The program incorporated discussion, hands-on activities and taste-testing among OA. Participants were assigned to PowerPoint classes (n=13 sites) or discussion-based classes (n=12 sites). The DST and a non-validated WG questionnaire were completed pre and post.
Study 1 participants (n=352) were mostly college-educated, white females, age 60-70 years classified as at nutritional risk or at possible nutritional risk. Participants had low DIF of dairy, lean protein and processed meat. Participants also had moderate DIF of added fats, sugars and sweets, total and WG, vegetables and whole fruit and juice. Whole fruit and juice DIF were influenced by state (p≤.001). Vegetable DIF were influenced by state (p=.021) and gender (p=.022). Processed meat DIF were influenced by gender (p=.033) and age (p=.001). Finally, nutritional risk was influenced by gender (p=.006). Study 2 participants (n=157) were mostly white, high-income females. Significant increases in WG knowledge were observed (p≤.001). DST total grain and WG DIF increased (p≤.001), with a positive correlation between post WG knowledge and DST WG DIF (p=.027). At post, more participants reported liking the taste of WG foods (p=0.019) and knew how to use a product\u27s package to determine WG content (p≤.001). About 59.2% had a strong intention to eat more WG foods at post. A positive association between post intention to eat more WG foods and DST WG DIF was observed (p≤.001). Furthermore, WG knowledge was higher among those in the PowerPoint-based classes (p=0.002). These findings suggest community-residing OA are at nutritional risk. Additionally, a WG education program may be an effective strategy for increasing WG knowledge and encouraging improvements in WG intake among OA
The role of body rotation in bacterial flagellar bundling
In bacterial chemotaxis, E. coli cells drift up chemical gradients by a
series of runs and tumbles. Runs are periods of directed swimming, and tumbles
are abrupt changes in swimming direction. Near the beginning of each run, the
rotating helical flagellar filaments which propel the cell form a bundle. Using
resistive-force theory, we show that the counter-rotation of the cell body
necessary for torque balance is sufficient to wrap the filaments into a bundle,
even in the absence of the swirling flows produced by each individual filament
Twirling Elastica: Kinks, Viscous Drag, and Torsional Stress
Biological filaments such as DNA or bacterial flagella are typically curved
in their natural states. To elucidate the interplay of viscous drag, twisting,
and bending in the overdamped dynamics of such filaments, we compute the
steady-state torsional stress and shape of a rotating rod with a kink. Drag
deforms the rod, ultimately extending or folding it depending on the kink
angle. For certain kink angles and kink locations, both states are possible at
high rotation rates. The agreement between our macroscopic experiments and the
theory is good, with no adjustable parameters.Comment: 4 pages, 4 figure
Film support and the challenge of ‘sustainability’: on wing design, wax and feathers, and bolts from the blue
In recognition of the importance of film in generating both economic and cultural value, the UK Labour government set up a new agency – the United Kingdom Film Council (UKFC) – in 2000 with a remit to build a sustainable film industry. But, reflecting a plethora of differing expectations in relation to the purposes behind public support for film, the UKFC's agenda shifted and broadened over the organisation's lifetime (2000–11). Apparently unconvinced by the UKFC's achievements, the Coalition government which came to power in May 2010 announced the Council's abolition and reassigned its responsibilities as part of a general cost-cutting strategy. Based on original empirical research, this article examines how the UKFC's sense of strategic direction was determined, how and why the balance of objectives it pursued changed over time and what these shifts tell us about the nature of film policy and the challenges facing bodies that are charged with enacting it in the twenty-first century
Statistical methods for multivariate meta-analysis of diagnostic tests: An overview and tutorial
In this article, we present an overview and tutorial of statistical methods for meta-analysis of diagnostic tests under two scenarios: 1) when the reference test can be considered a gold standard; and 2) when the reference test cannot be considered a gold standard. In the first scenario, we first review the conventional summary receiver operating characteristics (ROC) approach and a bivariate approach using linear mixed models (BLMM). Both approaches require direct calculations of study-specific sensitivities and specificities. We next discuss the hierarchical summary ROC curve approach for jointly modeling positivity criteria and accuracy parameters, and the bivariate generalized linear mixed models (GLMM) for jointly modeling sensitivities and specificities. We further discuss the trivariate GLMM for jointly modeling prevalence, sensitivities and specificities, which allows us to assess the correlations among the three parameters. These approaches are based on the exact binomial distribution and thus do not require an ad hoc continuity correction. Last, we discuss a latent class random effects model for meta-analysis of diagnostic tests when the reference test itself is imperfect for the second scenario. A number of case studies with detailed annotated SAS code in procedures MIXED and NLMIXED are presented to facilitate the implementation of these approaches
Spectroscopy 19 (2005) 207-212 207 IOS Press Clinical NIRS of the urinary bladder - A demonstration case report
Abstract. Urinary incontinence is a common affliction among people of all ages throughout the world. There are many causes of incontinence, treatment options are determined by the cause, and current diagnostic methods require urodynamic assessment, which involves urethral and rectal catheterization, which are uncomfortable and distasteful for patients. Since clinical near infrared spectrophotometry (NIRS) is a non-invasive, rapid means of measuring tissue oxygenation status at the bedside, we examined whether NIRS could be useful as a diagnostic tool for bladder dysfunction. An adult patient attending an incontinence clinic for routine urodynamic testing also had NIRS data collection during the standard bladder filling regimen. NIRS optodes were placed on the skin of the intact abdomen over the supra pubic region. Changes in oxy and de-oxy hemoglobin concentration and changes in cytochrome c oxidase net redox status via NIRS were collected at 6 Hz. The magnitudes of change that occurred during NIRS data collection are on the order of 0.5 µmol/l and the moments of change correspond to the subject's reported sensations of bladder filling and emptying, and with conventional urodynamics. These observations suggest that NIRS may be a disruptive technology with a role to play in non-invasive evaluation of bladder dysfunction in humans
Disappeared persons and homicide in El Salvador
During 2012–2013, the homicide rate in El Salvador came down from 69.9 to 42.2 per 100,000 population following a government brokered truce between the leaders of the two major gangs, Mara Salvatrucha and Barrio 18. But despite the apparent successes of the truce, it was speculated that the drop in murders could have been due to the killers simply hid the bodies of their victims. This paper aims at determining whether gangs effectively disappeared their victims to cut down the official counts of murders, or they committed these crimes for other reasons. The results from this study suggest that Salvadoran gangs had been using disappearance as a method to gain sustained social control among residents of already gang-dominated areas, that together with homicide, disappearance is part of a process of territorial spread and strategic strengthening by which these groups are enhancing their capabilities to interfere in the alliances of Mexican drug trafficking organizations with Central American criminal organizations specializing in the trans-shipment of drugs and in providing access to local markets to distribute and sell drugs. Our findings show that the risk for disappearance has been large even before the truce was in place and that actually, it continues as such and going through a process of geographic expansion
Predictors of recurrence and reoperation for prosthetic valve endocarditis after valve replacement surgery for native valve endocarditis
ObjectiveSurgical treatment of native valve endocarditis remains challenging, especially in cases with paravalvular destruction. Basic principles include complete debridement and reconstruction. This study is designed to evaluate the outcomes of surgical reconstruction of complex annular endocarditis using standard techniques and materials, including autologous and bovine pericardium.MethodsFrom 1975 to 2000, 358 cases (357 patients, mean age 49 ± 16 years, range 18–88 years) of native valve endocarditis were surgically managed. Bioprosthetic valves were implanted in 189 cases, and mechanical prostheses were implanted in 169 cases. A total of 78 cases of paravalvular destruction were identified: 62 annular abscesses, 8 fistulas, and 8 combined abscesses/fistulas. These were managed with 46 pericardial patches and 32 isolated suture reconstructions after radical debridement and prosthetic valve replacement.ResultsThe overall early mortality was 8.4% (n = 30). The mortality with paravalvular destruction was 17.9%, and the mortality with simple leaflet infection was 5.7% (P = .001). The unadjusted survival at 20 years was 26.4% ± 4.9% for bioprosthetic valves and 56.5% ± 8.1% for mechanical prostheses (P = .007). The freedom from recurrent prosthetic valve endocarditis was 78.9% ± 4.4% at 15 years. The freedom from reoperation for recurrent prosthetic valve endocarditis was 85.8% ± 4.2% at 15 years. The freedom from reoperation after reconstruction for paravalvular destruction was 88.2% ± 6.9% at 15 years. The freedom from mortality for recurrent prosthetic valve endocarditis was 92.7% ± 3.4% at 15 years. The independent predictors of reoperation were age (hazard ratio 0.930, P = .005) and intravenous drug use/human immunodeficiency virus plus surgical technique (hazard ratio 12.8, P = .003 for patch reconstruction plus valve and hazard ratio 3.6, P = .038 for valve replacement only). Prosthesis type was not predictive when separated from intravenous drug use/human immunodeficiency virus (hazard ratio 3.268, P = .088).ConclusionParavalvular destruction is associated with a higher operative mortality. Native valve endocarditis can be managed with reasonable long-term survival and low rates of reinfection with radical debridement and pericardial reconstruction with bioprostheses and mechanical prostheses. The type of prosthesis implanted does not influence long-term outcome. Patients with a history of intravenous drug use and human immunodeficiency virus are at increased risk for recurrent infection and reoperation
Exile Vol. XV No. 1
POETRY
Haiku by John Anderson 2
It\u27s the looking in the mirror by Larry Faso 3
There is a voice in me by Larry Faso 15
We fight along time by Tracy Mac Nab 8
During the night by Tracy Mac Nab 8
Illusion by Phil Cockerille 10
Mexico City \u2759 by Keith McWalter 12
Summer Correspondence II by Lauren Shakely 13
America Sings to Herself and Doesn\u27t Hear by Lauren Shakely 15
eatin crawdads by Bob Martin 14
G. [unattributed*] 16
Finis Coronant Opus [unattributed*] 17
The Droplet Sea by Jeffrey R. Smith 17
The surrounding dismal forest by P. F. Galbraith 18
FICTION
The Shadow in his mind by Cem Mehmet Kozlu 4-7
An Excerpt from a Novel in Progress by Dick Devine 19-22
ARTWORK AND ILLUSTRATIONS
by Tom Robinson 2, 12, 16, 18
by Bob Tauber 3, 8, 15
by Tom King 7, 9, 13
by Ted Hall 11, 24
by Clare Conrad 14
Mislabeled Fall 196
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