scholarly journals Dynamical feature extraction at the sensory periphery guides chemotaxis

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Aljoscha Schulze ◽  
Alex Gomez-Marin ◽  
Vani G Rajendran ◽  
Gus Lott ◽  
Marco Musy ◽  
...  
Keyword(s):  
Sensory Neurons ◽  
Generalized Linear Model ◽  
Activity Levels ◽  
Behavioral Strategies ◽  
Dynamical Feature ◽  
First Order ◽  
Olfactory Stimuli ◽  
Drosophila Larva ◽  
Integral Feedback ◽  
Low Activity

Behavioral strategies employed for chemotaxis have been described across phyla, but the sensorimotor basis of this phenomenon has seldom been studied in naturalistic contexts. Here, we examine how signals experienced during free olfactory behaviors are processed by first-order olfactory sensory neurons (OSNs) of the Drosophila larva. We find that OSNs can act as differentiators that transiently normalize stimulus intensity—a property potentially derived from a combination of integral feedback and feed-forward regulation of olfactory transduction. In olfactory virtual reality experiments, we report that high activity levels of the OSN suppress turning, whereas low activity levels facilitate turning. Using a generalized linear model, we explain how peripheral encoding of olfactory stimuli modulates the probability of switching from a run to a turn. Our work clarifies the link between computations carried out at the sensory periphery and action selection underlying navigation in odor gradients.

scholarly journals High-Efficiency Production of Radiopharmaceuticals via Droplet Radiochemistry: A Review of Recent Progress

2020 ◽  
Vol 19 ◽  
pp. 153601212097309
Author(s):  
Jia Wang ◽  
R. Michael van Dam
Keyword(s):  
High Efficiency ◽  
State Of The Art ◽  
System Size ◽  
Scaling Up ◽  
Activity Levels ◽  
Synthesis Time ◽  
Molar Activity ◽  
Reagent Consumption ◽  
Prosthetic Groups ◽  
Low Activity

New platforms are enabling radiochemistry to be carried out in tiny, microliter-scale volumes, and this capability has enormous benefits for the production of radiopharmaceuticals. These droplet-based technologies can achieve comparable or better yields compared to conventional methods, but with vastly reduced reagent consumption, shorter synthesis time, higher molar activity (even for low activity batches), faster purification, and ultra-compact system size. We review here the state of the art of this emerging direction, summarize the radiotracers and prosthetic groups that have been synthesized in droplet format, describe recent achievements in scaling up activity levels, and discuss advantages and limitations and the future outlook of these innovative devices.

scholarly journals Ambulatory Physical Activity Performance in Youth With Cerebral Palsy and Youth Who Are Developing Typically

2007 ◽  
Vol 87 (3) ◽  
pp. 248-257 ◽  
Author(s):  
Kristie F Bjornson ◽  
Basia Belza ◽  
Deborah Kartin ◽  
Rebecca Logsdon ◽  
John F McLaughlin
Keyword(s):  
Cerebral Palsy ◽  
Activity Levels ◽  
Ambulatory Activity ◽  
Cross Sectional ◽  
Walking Activity ◽  
Activity Performance ◽  
Cross Sectional Design ◽  
Low Activity ◽  
Gmfcs Level ◽  
Daily Total

Background and Purpose Assessment of walking activity in youth with cerebral palsy (CP) has traditionally been “capacity-based.” The purpose of this study was to describe the day-to-day ambulatory activity “performance” of youth with CP compared with youth who were developing typically. Subjects Eighty-one youth with CP, aged 10 to 13 years, who were categorized as being in Gross Motor Function Classification System (GMFCS) levels I to III and 30 age-matched youth who were developing typically were recruited. Methods Using a cross-sectional design, participants wore the StepWatch monitor for 7 days while documenting average daily total step counts, percentage of time they were active, ratio of medium to low activity levels, and percentage of time at high activity levels. Results The youth with CP demonstrated significantly lower levels of all outcomes than the comparison group. Discussion and Conclusion Daily walking activity and variability decreased as functional walking level (GMFCS level) decreased. Ambulatory activity performance within the context of the daily life for youth with CP appears valid and feasible as an outcome for mobility interventions in CP.

Brown pigmentation in Serratia marcescens cultures associated with tyrosine metabolism

1989 ◽  
Vol 35 (11) ◽  
pp. 1037-1042 ◽  
Author(s):  
Joaquim Trias ◽  
Miquel Viñas ◽  
Jesus Guinea ◽  
José G. Lorèn
Keyword(s):  
Serratia Marcescens ◽  
Minimal Medium ◽  
Brown Pigment ◽  
Activity Levels ◽  
Amino Acid Catabolism ◽  
Catabolic Pathway ◽  
Tyrosine Metabolism ◽  
High Concentrations ◽  
Low Activity ◽  
Production Conditions

Serratia marcescens produced a brown pigment when grown in minimal medium in the presence of tyrosine and high concentrations of copper(II) ion. The pigment was not related to the melanin pigments, but was similar to the pigment produced by autooxidation and polymerization of 3,4-dihydroxyphenylacetate, which is synthesized in S. marcescens from tyrosine through the 3,4-dihydroxyphenylacetate catabolic pathway. The enzymes of this pathway were induced under pigment production conditions; however, 3,4-dihydroxyphenylacetate 2,3-dioxygenase remained at low activity levels, permitting the accumulation and excretion of the substrate. Mutants unable to use tyrosine as a sole carbon and energy source were able to produce brown pigments only if the step blocked by the mutation was after the synthesis of 3,4-dihydroxyphenylacetate. The ability to produce brown pigments was common to all the S. marcescens strains tested.Key words: brown pigment, 3,4-dihydroxyphenylacetate 2,3-dioxygenase, Serratia marcescens, tyrosine, aromatic amino acid catabolism.

Neural networks with low activity levels

1992 ◽  
Vol 86 (2) ◽  
pp. 309-315 ◽  
Author(s):  
Bruce M. Forrest ◽  
Andrea Loettgers
Keyword(s):  
Neural Networks ◽  
Activity Levels ◽  
Low Activity

scholarly journals Efficacy of an Online Physical Activity Intervention Coordinated With Routine Clinical Care: Protocol for a Pilot Randomized Controlled Trial

10.2196/18891 ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. e18891
Author(s):  
Bonny Rockette-Wagner ◽  
Gary S Fischer ◽  
Andrea M Kriska ◽  
Molly B Conroy ◽  
David Dunstan ◽  
...  
Keyword(s):  
Physical Activity ◽  
Physical Activity Intervention ◽  
Controlled Trial ◽  
Clinical Care ◽  
Online Intervention ◽  
Activity Levels ◽  
Randomized Controlled ◽  
Low Activity ◽  
Pilot Randomized Controlled Trial ◽  
Clinical Referral

Background Most adults are not achieving recommended levels of physical activity (150 minutes/week, moderate-to-vigorous intensity). Inadequate activity levels are associated with numerous poor health outcomes, and clinical recommendations endorse physical activity in the front-line treatment of obesity, diabetes, dyslipidemia, and hypertension. A framework for physical activity prescription and referral has been developed, but has not been widely implemented. This may be due, in part, to the lack of feasible and effective physical activity intervention programs designed to coordinate with clinical care delivery. Objective This manuscript describes the protocol for a pilot randomized controlled trial (RCT) that tests the efficacy of a 13-week online intervention for increasing physical activity in adult primary care patients (aged 21-70 years) reporting inadequate activity levels. The feasibility of implementing specific components of a physical activity clinical referral program, including screening for low activity levels and reporting patient program success to referring physicians, will also be examined. Analyses will include participant perspectives on maintaining physical activity. Methods This pilot study includes a 3-month wait-listed control RCT (1:1 ratio within age strata 21-54 and 55-70 years). After the RCT primary end point at 3 months, wait-listed participants are offered the full intervention and all participants are followed to 6 months after starting the intervention program. Primary RCT outcomes include differences across randomized groups in average step count, moderate-to-vigorous physical activity, and sedentary behavior (minutes/day) derived from accelerometers. Maintenance of physical activity changes will be examined for all participants at 6 months after the intervention start. Results Recruitment took place between October 2018 and May 2019 (79 participants were randomized). Data collection was completed in February 2020. Primary data analyses are ongoing. Conclusions The results of this study will inform the development of a clinical referral program for physical activity improvement that combines an online intervention with clinical screening for low activity levels, support for postintervention behavior maintenance, and feedback to the referring physician. Trial Registration ClinicalTrials.gov NCT03695016; https://clinicaltrials.gov/ct2/show/NCT03695016. International Registered Report Identifier (IRRID) DERR1-10.2196/18891

scholarly journals Bioassay and alpha spectrometry in indirect monitoring of Spanish workers exposed to enriched uranium

2019 ◽  
Vol 70 (3) ◽  
pp. 201-206
Author(s):  
Inmaculada Sierra ◽  
Carolina Hernández ◽  
Paula Albendea ◽  
Maria Antonia López
Keyword(s):  
Alpha Spectrometry ◽  
Internal Exposure ◽  
Internal Dosimetry ◽  
Activity Levels ◽  
Risk Of Exposure ◽  
Enriched Uranium ◽  
The Individual ◽  
Fuel Elements ◽  
Low Activity

AbstractWorkers at risk of exposure to uranium compounds should be monitored and their internal exposure quantified in terms of committed effective dose E(50) in mSv. In vitro bioassay methods can quantify uranium in urine and faeces at low activity levels. Alpha spectrometry (AS) is the most common method used for monitoring alpha-emitting radionuclides in internal dosimetry services. It provides isotopic information and low minimum detectable activity (MDA) values (≤0.50 mBq per sample). This study reports the results of a five-year monitoring of workers exposed to uranium at a Spanish Juzbado facility, which produces nuclear fuel elements enriched with up to 5 % of 235U. Monitoring included about 100 workers per year, most of whom had worked at the facility for more than 10 years before the individual monitoring programme was established. We analysed nearly 550 samples of more than 200 workers over five years. The obtained results indicate that workers were adequately protected from uranium exposure through inhalation and had an acceptably low chronic intake at the facility.

scholarly journals Soft X-ray coronal spectra at low activity levels observed by RESIK

2010 ◽  
Vol 514 ◽  
pp. A82 ◽  
Author(s):  
B. Sylwester ◽  
J. Sylwester ◽  
K. J. H. Phillips
Keyword(s):  
Activity Levels ◽  
X Ray ◽  
Low Activity

Effect of temperature and clothing thermal resistance on human sweat at low activity levels

2020 ◽  
Vol 183 ◽  
pp. 107117 ◽  
Author(s):  
Wu Qingqing ◽  
Liu Jianhua ◽  
Zhang Liang ◽  
Zhang Jiawen ◽  
Jiang Linlin
Keyword(s):  
Thermal Resistance ◽  
Effect Of Temperature ◽  
Activity Levels ◽  
Human Sweat ◽  
Low Activity

scholarly journals Accelerometer-measured physical activity and functional behaviours among people on dialysis

2020 ◽  
Author(s):  
Khizr A Nawab ◽  
Benjamin C Storey ◽  
Natalie Staplin ◽  
Rosemary Walmsley ◽  
Richard Haynes ◽  
...  
Keyword(s):  
Physical Activity ◽  
Moderate Intensity ◽  
Activity Levels ◽  
Uk Biobank ◽  
Control Groups ◽  
Leg Weakness ◽  
Moderate Intensity Activity ◽  
Low Activity ◽  
Population Controls ◽  
Apparently Healthy

Abstract Background The feasibility of wrist-worn accelerometers, and the patterns and determinants of physical activity, among people on dialysis are uncertain. Methods People on maintenance dialysis were fitted with a wrist-worn AxivityAX3 accelerometer. Subsets also wore a 14-day electrocardiograph patch (Zio®PatchXT) and wearable cameras. Age-, sex- and season-matched UK Biobank control groups were derived for comparison. Results Median (interquartile range) accelerometer wear time for the 101 recruits was 12.5 (10.4–13.5) days, of which 73 participants (mean age 66.5 years) had excellent wear on both dialysis and non-dialysis days. Mean (standard error) overall physical activity levels were 15.5 (0.7) milligravity units (mg), 14.8 (0.7) mg on dialysis days versus 16.2 (0.8) mg on non-dialysis days. This compared with 28.1 (0.5) mg for apparently healthy controls, 23.4 (0.4) mg for controls with prior cardiovascular disease (CVD) and/or diabetes mellitus and 22.9 (0.6) mg for heart failure controls. Each day, we estimated that those on dialysis spent an average of about 1 hour (h/day) walking, 0.6 h/day engaging in moderate-intensity activity, 0.7 h/day on light tasks, 13.2 h/day sedentary and 8.6 h/day asleep. Older age and self-reported leg weakness were associated with decreased levels of physical activity, but the presence of prior CVD, arrhythmias and listing for transplantation were not. Conclusions Wrist-worn accelerometers are an acceptable and reliable method to measure physical activity in people on dialysis and may also be used to estimate functional behaviours. Among people on dialysis, who are broadly half as active as general population controls, age and leg weakness appear to be more important determinants of low activity levels than CVD.

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