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Scientific Reports Nov 2022Many processes in nature are the result of many coupled individual subsystems (like population dynamics or neurosystems). Not always such systems exhibit simple stable...
Many processes in nature are the result of many coupled individual subsystems (like population dynamics or neurosystems). Not always such systems exhibit simple stable behaviors that in the past science has mostly focused on. Often, these systems are characterized by bursts of seemingly stochastic activity, interrupted by quieter periods. The hypothesis is that the presence of a strong deterministic ingredient is often obscured by the stochastic features. We test this by modeling classically stochastic considered real-world data from both, the stochastic as well as the deterministic approaches to find that the deterministic approach's results level with those from the stochastic side. Moreover, the deterministic approach is shown to reveal the full dynamical systems landscape, which can be exploited for steering the dynamics into a desired regime.
Topics: Stochastic Processes; Population Dynamics
PubMed: 36400910
DOI: 10.1038/s41598-022-23212-x -
Digestive Diseases (Basel, Switzerland) 2014Modern medical therapies for gastroesophageal reflux disease (GERD) are totally dedicated to the control of the acid component of the refluxate. In chronic erosive GERD,... (Review)
Review
UNLABELLED
Modern medical therapies for gastroesophageal reflux disease (GERD) are totally dedicated to the control of the acid component of the refluxate. In chronic erosive GERD, antireflux surgery has proven to be very efficacious and superior to traditional medical therapies, such as H2 blockers. The introduction of proton pump inhibitors (PPIs), however, substantially improved medical therapy. Still, treatment failures are inevitable regardless of which of these two effective therapies is chosen. Some recent reports have presented conflicting results from trials comparing antireflux surgery and PPIs. This may be due to differences in trial designs as well as in the structure and content of the therapeutic strategies that are compared. The study with the longest clinical follow-up by far is the SOPRAN study comparing open antireflux surgery and omeprazole. The protocol provides for a follow-up period of more than a decade and the clinical outcomes have recently been published. There has always been concern about the long-term effectiveness of reflux prevention whether by surgery or PPI therapy. It is likely that a marker for an emerging risk for recurrence of GERD is abnormal acid reflux as assessed by ambulatory 24-hour pH-metry. The LOTUS trial compared maintenance therapy provided by esomeprazole (dose-adjusted when required) with standardized laparoscopic antireflux surgery in patients with good response to acid suppressive therapy. An operation is suitable when symptoms are poorly controlled despite medication, especially for patients who suffer large-volume regurgitation and those who wake at night coughing and choking and who regurgitate acidic fluid or food into their throat and airways. Regurgitation into the throat upon stooping or exercising can limit a patient's ability to work, play sports or even do simple housework. A few patients cannot tolerate medical treatment. If surgery is to be a good option, it must be ensured that the right surgeon performs a standardized operation for the right indications on the right patient and provides good preoperative counseling and testing along with postoperative support. When a patient is refractory to medical treatment, the diagnosis of GERD should be reconsidered before surgery is advised; extradigestive manifestations should be accounted for with care.
CONCLUSIONS
Laparoscopic fundoplication (LF) substantially improves GERD symptoms, although in some individuals symptoms return and acid-suppressive medication use increases. Limited data suggest that LF is less effective at reducing symptoms in partial responders to medical therapy than in complete responders. This may affect cost arguments for using fundoplication surgery rather than acid-suppressive medications, as data are based largely on complete responders.
Topics: Digestive System Surgical Procedures; Gastroesophageal Reflux; Humans; Obesity, Morbid; Patient Selection; Postoperative Complications; Preoperative Care; Quality Assurance, Health Care
PubMed: 24603401
DOI: 10.1159/000357182 -
Journal of the Experimental Analysis of... Jul 2022Contingency management (CM) interventions are the most effective psychosocial interventions for substance use disorders. However, further investigation is needed to... (Clinical Trial)
Clinical Trial
Contingency management (CM) interventions are the most effective psychosocial interventions for substance use disorders. However, further investigation is needed to create the most robust intervention possible. This study investigated the effects of 1) reinforcer magnitude; and 2) fixed and escalating and resetting incentives on cocaine abstinence in an outpatient trial. In this analysis, 34 treatment-seeking individuals with Cocaine Use Disorder received either high or low value incentives for providing a benzoylecgonine-negative urine sample or were in a control condition and received incentives for providing a urine sample regardless of the results. Participants received either escalating and resetting incentives, wherein the value of each incentive increased with consecutive negative samples and reset to the initial level upon a positive sample (Experiment 1), or fixed incentives, wherein they received the same value incentive for each negative urine sample they provided (Experiment 2). Large incentives produced more abstinence, although escalating and resetting reinforcer values did not have a differential effect. Large, fixed incentives promoted abstinence faster than other reinforcers, whereas smaller incentives resulted in poor abstinence and took many visits to achieve initial abstinence. Future research comparing different schedules on cocaine abstinence in a randomized control trial with a larger sample size is required.
Topics: Behavior Therapy; Cocaine; Cocaine-Related Disorders; Humans; Motivation; Substance-Related Disorders
PubMed: 35538731
DOI: 10.1002/jeab.770 -
Pharmacology, Biochemistry, and Behavior Nov 2015Individuals with cocaine use disorder chronically self-administer cocaine to the detriment of other rewarding activities, a phenomenon best modeled in laboratory... (Review)
Review
Individuals with cocaine use disorder chronically self-administer cocaine to the detriment of other rewarding activities, a phenomenon best modeled in laboratory drug-choice procedures. These procedures can evaluate the reinforcing effects of drugs versus comparably valuable alternatives under multiple behavioral arrangements and schedules of reinforcement. However, assessing drug-choice in treatment-seeking or abstaining humans poses unique challenges: for ethical reasons, these populations typically cannot receive active drugs during research studies. Researchers have thus needed to rely on alternative approaches that approximate drug-choice behavior or assess more general forms of decision-making, but whether these alternatives have relevance to real-world drug-taking that can inform clinical trials is not well-understood. In this mini-review, we (A) summarize several important modulatory variables that influence cocaine choice in nonhuman animals and non-treatment seeking humans; (B) discuss some of the ethical considerations that could arise if treatment-seekers are enrolled in drug-choice studies; (C) consider the efficacy of alternative procedures, including non-drug-related decision-making and 'simulated' drug-choice (a choice is made, but no drug is administered) to approximate drug choice; and (D) suggest opportunities for new translational work to bridge the current divide between preclinical and clinical research.
Topics: Animals; Choice Behavior; Cocaine; Cocaine-Related Disorders; Delay Discounting; Humans; Neuropsychological Tests; Patient Acceptance of Health Care
PubMed: 26432174
DOI: 10.1016/j.pbb.2015.09.020 -
Journal of Biomechanics May 2020The number one cause of disability in the world is low-back pain, with mechanical loading as one of the major risk factors. To reduce mechanical loading, exoskeletons...
The number one cause of disability in the world is low-back pain, with mechanical loading as one of the major risk factors. To reduce mechanical loading, exoskeletons have been introduced in the workplace. Substantial reductions in back muscle activity were found when using the exoskeleton during static bending and manual materials handling. However, most exoskeletons only have one joint at hip level, resulting in loss of range of motion and shifting of the exoskeleton relative to the body. To address these issues, a new exoskeleton design has been developed and tested. The present study investigated the effect of the SPEXOR passive exoskeleton on compression forces, moments, muscle activity and kinematics during static bending at six hand heights and during lifting of a box of 10 kg from around ankle height using three techniques: Free, Squat and Stoop. For static bending, the exoskeleton reduced the compression force by 13-21% depending on bending angle. Another effect of the exoskeleton was that participants substantially reduced lumbar flexion. While lifting, the exoskeleton reduced the peak compression force, on average, by 14%. Lifting technique did not modify the effect of the exoskeleton such that the reduction in compression force was similar. In conclusion, substantial reductions in compression forces were found as a result of the support generated by the exoskeleton and changes in behavior when wearing the exoskeleton. For static bending, lumbar flexion was reduced with the exoskeleton, indicating reduced passive tissue strain. In addition, the reduced peak compression force could reduce the risk of compression induced tissue failure during lifting.
Topics: Back Muscles; Biomechanical Phenomena; Electromyography; Exoskeleton Device; Humans; Lifting
PubMed: 32423541
DOI: 10.1016/j.jbiomech.2020.109795 -
Scientific Reports Feb 2022We ask whether empirical finance market data (Financial Stress Index, swap and equity, emerging and developed, corporate and government, short and long maturity), with...
We ask whether empirical finance market data (Financial Stress Index, swap and equity, emerging and developed, corporate and government, short and long maturity), with their recently observed alternations between calm periods and financial turmoil, could be described by a low-dimensional deterministic model, or whether this requests a stochastic approach. We find that a deterministic model performs at least as well as one of the best stochastic models, but may offer additional insight into the essential mechanisms that drive financial markets.
PubMed: 35105929
DOI: 10.1038/s41598-022-05765-z -
Molecular Systems Biology Jun 2021The ability to switch a gene from off to on and monitor dynamic changes provides a powerful approach for probing gene function and elucidating causal regulatory...
The ability to switch a gene from off to on and monitor dynamic changes provides a powerful approach for probing gene function and elucidating causal regulatory relationships. Here, we developed and characterized YETI (Yeast Estradiol strains with Titratable Induction), a collection in which > 5,600 yeast genes are engineered for transcriptional inducibility with single-gene precision at their native loci and without plasmids. Each strain contains SGA screening markers and a unique barcode, enabling high-throughput genetics. We characterized YETI using growth phenotyping and BAR-seq screens, and we used a YETI allele to identify the regulon of Rof1, showing that it acts to repress transcription. We observed that strains with inducible essential genes that have low native expression can often grow without inducer. Analysis of data from eukaryotic and prokaryotic systems shows that native expression is a variable that can bias promoter-perturbing screens, including CRISPRi. We engineered a second expression system, Z EB42, that gives lower expression than Z EV, a feature enabling conditional activation and repression of lowly expressed essential genes that grow without inducer in the YETI library.
Topics: Gene Library; Genes, Essential; Plasmids; Promoter Regions, Genetic; Saccharomyces cerevisiae
PubMed: 34096681
DOI: 10.15252/msb.202110207 -
Nature Communications Mar 2024The presence of a companion can reduce fear, but the neural mechanisms underlying this social buffering of fear are incompletely known. We studied social buffering of...
The presence of a companion can reduce fear, but the neural mechanisms underlying this social buffering of fear are incompletely known. We studied social buffering of fear in male and female, and its encoding in the amygdala of male, auditory fear-conditioned rats. Pharmacological, opto,- and/or chemogenetic interventions showed that oxytocin signaling from hypothalamus-to-central amygdala projections underlied fear reduction acutely with a companion and social buffering retention 24 h later without a companion. Single-unit recordings with optetrodes in the central amygdala revealed fear-encoding neurons (showing increased conditioned stimulus-responses after fear conditioning) inhibited by social buffering and blue light-stimulated oxytocinergic hypothalamic projections. Other central amygdala neurons showed baseline activity enhanced by blue light and companion exposure, with increased conditioned stimulus responses that persisted without the companion. Social buffering of fear thus switches the conditioned stimulus from encoding "fear" to "safety" by oxytocin-mediated recruitment of a distinct group of central amygdala "buffer neurons".
Topics: Rats; Male; Female; Animals; Conditioning, Psychological; Oxytocin; Central Amygdaloid Nucleus; Rats, Wistar; Fear; Neurons
PubMed: 38453902
DOI: 10.1038/s41467-024-45626-z -
The Journals of Gerontology. Series A,... Aug 2013Downward reaching may lead to falls in older adults, but the underlying mechanisms are poorly understood. This study assessed differences between younger and older...
BACKGROUND
Downward reaching may lead to falls in older adults, but the underlying mechanisms are poorly understood. This study assessed differences between younger and older adults in postural control and losses of balance when performing a forward reach to the floor in 2 possible real-world situations, with and without full foot contact with the floor.
METHODS
Healthy younger (n = 13) and older (n = 12) women reached as fast as possible to a target placed at their maximal forward reaching distance on floor, either standing on their whole foot or on the shortest base of support (BOS) that they were willing to perform a toe touch with.
RESULTS
Compared with younger women, older women used a 50% larger BOS when stooping down to touch their toes and had 22% less maximal forward reaching distance on the floor. Older women were twice as likely to lose their balance as younger women while performing a rapid forward floor reach (χ(2)(2) = 3.9; p < .05; relative risk = 1.91; 95% CI = 0.99-3.72). Postural sway, measured as center of pressure excursions and center of pressure root mean square error, did not differ between younger and older women anteriorly, but posteriorly, older women decreased their sway in full foot BOS and increased their sway in forefoot BOS (Age × BOS, p < .05). Leg strength was reduced in older versus younger women and was correlated with maximal reach distance (r = .65-.71).
CONCLUSIONS
Healthy older women performing a rapid maximum forward reach on the floor, particularly when using their forefoot for support, are at an increased risk for losing their balance.
Topics: Accidental Falls; Adolescent; Adult; Age Factors; Aged; Aging; Biomechanical Phenomena; Female; Humans; Postural Balance; Risk Factors; Young Adult
PubMed: 23292289
DOI: 10.1093/gerona/gls260 -
Dental Research Journal Jan 2012Dental professionals are predisposed to a number of occupational hazards. These include exposure to infections (including Human Immunodeficiency Virus and viral...
Dental professionals are predisposed to a number of occupational hazards. These include exposure to infections (including Human Immunodeficiency Virus and viral hepatitis); percutaneous exposure incidents, dental materials, radiation, and noise; musculoskeletal disorders; psychological problems and dermatitis; respiratory disorders; and eye insults. Percutaneous exposure incidents remain a main concern, as exposure to serious infectious agents is a virtual risk. Minimizing percutaneous exposure incidents and their consequences should continue to be considered, including sound infection control practices, continuing education, and hepatitis B vaccination. Basically, for any infection control strategies, dentists should be aware of individual protective measures and appropriate sterilization or other high-level disinfection utilities. Strained posture at work disturbs the musculoskeletal alignment and leads to stooped spine. The stooped posture also involved certain groups of muscles and joints. This may lead to diseases of the musculoskeletal system. Continuous educating and appropriate intervention studies are needed to reduce the complication of these hazards. So, it is important for dentists to remain constantly up-to-date about measures on how to deal with newer strategies and dental materials, and implicates the need for special medical care for this professional group.
PubMed: 22363355
DOI: 10.4103/1735-3327.92919