513 research outputs found
Sensory Measurements: Coordination and Standardization
Do sensory measurements deserve the label of “measurement”? We argue that they do. They fit with an epistemological view of measurement held in current philosophy of science, and they face the same kinds of epistemological challenges as physical measurements do: the problem of coordination and the problem of standardization. These problems are addressed through the process of “epistemic iteration,” for all measurements. We also argue for distinguishing the problem of standardization from the problem of coordination. To exemplify our claims, we draw on olfactory performance tests, especially studies linking olfactory decline to neurodegenerative disorders
Results from the dissemination of an evidence-based telephone-delivered intervention for healthy lifestyle and weight loss: the Optimal Health Program
Despite proven efficacy, there are few published evaluations of telephone-delivered interventions targeting physical activity, healthy eating, and weight loss in community dissemination contexts. This study aims to evaluate participant and program outcomes from the Optimal Health Program, a telephone-delivered healthy lifestyle and weight loss program provided by a primary health care organization. Dissemination study used a single-group, repeated measures design; outcomes were assessed at 6-month (mid-program; n = 166) and 12-month (end of program; n = 88) using paired analyses. The program reached a representative sample of at-risk, primary care patients, with 56 % withdrawing before program completion. Among completers, a statistically significant improvement between baseline and end of program was observed for weight [mean change (SE) −5.4 (7.0) kg] and waist circumference [−4.8 (9.7) cm], underpinned by significant physical activity and dietary change. Findings suggest that telephone-delivered weight loss and healthy lifestyle programs can provide an effective model for use in primary care settings, but participant retention remains a challenge
Attachment, infidelity, and loneliness in college students involved in a romantic relationship: the role of relationship satisfaction, morbidity and prayer for partner
This study examined the mediating effects of relationship satisfaction, prayer
for a partner, and morbidity in the relationship between attachment and loneliness, infidelity
and loneliness, and psychological morbidity and loneliness, in college students
involved in a romantic relationship. Participants were students in an introductory course on
family development. This study examined only students (n = 345) who were involved in a
romantic relationship. The average age of participants was 19.46 (SD = 1.92) and 25 %
were males. Short-form UCLA Loneliness Scale (ULS-8), (Hays and DiMatteo in J Pers
Assess 51:69–81, doi:10.1207/s15327752jpa5101_6, 1987); Relationship Satisfaction
Scale (Funk and Rogge in J Fam Psychol 21:572–583, doi:10.1037/0893-3200.21.4.572,
2007); Rotterdam Symptom Checklist (De Haes et al. in Measuring the quality of life of
cancer patients with the Rotterdam Symptom Checklist (RSCL): a manual, Northern
Centre for Healthcare Research, Groningen, 1996); Prayer for Partner Scale, (Fincham
et al. in J Pers Soc Psychol 99:649–659, doi:10.1037/a0019628, 2010); Infidelity Scale,
(Drigotas et al. in J Pers Soc Psychol 77:509–524, doi:10.1037/0022-3514.77.3.509, 1999);
and the Experiences in Close Relationship Scale-short form (Wei et al. in J Couns Psychol
52(4):602–614, doi:10.1037/0022-0167.52.4.602, 2005). Results showed that relationship
satisfaction mediated the relationship between avoidance attachment and loneliness and
between infidelity and loneliness. Physical morbidity mediated the relationship between
anxious attachment and psychological morbidity. Psychological morbidity mediated the
relationship between anxious attachment and physical morbidity. The present results
expand the literature on attachment by presenting evidence that anxious and avoidant partners experience loneliness differently. Implications for couple’s therapy are addressed.
Future research should replicate these results with older samples and married couples.Acknowledgments This research was supported by Grant Number 90FE0022 from the United States
Department of Health and Human Services awarded to the last author
FEniCS-HPC: Automated predictive high-performance finite element computing with applications in aerodynamics
Developing multiphysics finite element methods (FEM) and scalable HPC implementations can be very challenging in terms of software complexity and performance, even more so with the addition of goal-oriented adaptive mesh refinement. To manage the complexity we in this work present general adaptive stabilized methods with automated implementation in the FEniCS-HPC automated open source software framework. This allows taking the weak form of a partial differential equation (PDE) as input in near-mathematical notation and automatically generating the low-level implementation source code and auxiliary equations and quantities necessary for the adaptivity. We demonstrate new optimal strong scaling results for the whole adaptive framework applied to turbulent flow on massively parallel architectures down to 25000 vertices per core with ca. 5000 cores with the MPI-based PETSc backend and for assembly down to 500 vertices per core with ca. 20000 cores with the PGAS-based JANPACK backend. As a demonstration of the power of the combination of the scalability together with the adaptive methodology allowing prediction of gross quantities in turbulent flow we present an application in aerodynamics of a full DLR-F11 aircraft in connection with the HiLift-PW2 benchmarking workshop with good match to experiments
Balancing repair and tolerance of DNA damage caused by alkylating agents
Alkylating agents constitute a major class of frontline chemotherapeutic drugs that inflict cytotoxic DNA damage as their main mode of action, in addition to collateral mutagenic damage. Numerous cellular pathways, including direct DNA damage reversal, base excision repair (BER) and mismatch repair (MMR), respond to alkylation damage to defend against alkylation-induced cell death or mutation. However, maintaining a proper balance of activity both within and between these pathways is crucial for a favourable response of an organism to alkylating agents. Furthermore, the response of an individual to alkylating agents can vary considerably from tissue to tissue and from person to person, pointing to genetic and epigenetic mechanisms that modulate alkylating agent toxicity
New Pharmacological Agents to Aid Smoking Cessation and Tobacco Harm Reduction: What has been Investigated and What is in the Pipeline?
A wide range of support is available to help smokers to quit and aid attempts at harm reduction, including three first-line smoking cessation medications: nicotine replacement therapy, varenicline and bupropion. Despite the efficacy of these, there is a continual need to diversify the range of medications so that the needs of tobacco users are met. This paper compares the first-line smoking cessation medications to: 1) two variants of these existing products: new galenic formulations of varenicline and novel nicotine delivery devices; and 2) twenty-four alternative products: cytisine (novel outside of central and eastern Europe), nortriptyline, other tricyclic antidepressants, electronic cigarettes, clonidine (an anxiolytic), other anxiolytics (e.g. buspirone), selective 5-hydroxytryptamine (5-HT) reuptake inhibitors, supplements (e.g. St John’s wort), silver acetate, nicobrevin, modafinil, venlafaxine, monoamine oxidase inhibitors (MAOI), opioid antagonist, nicotinic acetylcholine receptors (nAChR) antagonists, glucose tablets, selective cannabinoid type 1 receptor antagonists, nicotine vaccines, drugs that affect gamma-aminobutyric acid (GABA) transmission, drugs that affect N-methyl-D-aspartate receptors (NMDA), dopamine agonists (e.g. levodopa), pioglitazone (Actos; OMS405), noradrenaline reuptake inhibitors, and the weight management drug lorcaserin. Six criteria are used: relative efficacy, relative safety, relative cost, relative use (overall impact of effective medication use), relative scope (ability to serve new groups of patients), and relative ease of use (ESCUSE). Many of these products are in the early stages of clinical trials, however, cytisine looks most promising in having established efficacy and safety and being of low cost. Electronic cigarettes have become very popular, appear to be efficacious and are safer than smoking, but issues of continued dependence and possible harms need to be considered
An overview of harms associated with β-lactam antimicrobials: where do the carbapenems fit in?
The US Institute of Medicine's focus on patient safety has motivated hospital administrators to facilitate a culture of safety. As a result, subcommittees of the pharmacy and therapeutics committee have emerged in many hospitals to focus on adverse events and patient safety. Antimicrobial harms have gained the attention of practicing clinicians and hospital formulary committees, because they top the list of drugs that are associated with adverse events and because of certain serious harms that have ultimately led to the withdrawal of some antimicrobial agents. In the near future, several antimicrobials in the late phase of development will become available for clinical use (ceftobiprole, ceftaroline, and telavancin), and others (doripenem and dalbavancin) have recently joined the armamentarium. Because new antimicrobials will become part of the treatment armamentarium, it is important to discuss our current understanding of antimicrobial harms in general. Although not thought of as traditional adverse events, Clostridium difficile infection and development of resistance during therapy are adverse events that occur as a result of antimicrobial exposure and therefore are discussed. In addition, a distillation of our current understanding of β-lactam specific adverse events will be provided. Finally, new methods of administration are being evaluated that may influence peak concentration-related antimicrobial adverse events
Self-assisted Amoeboid Navigation in Complex Environments
Background: Living cells of many types need to move in response to external
stimuli in order to accomplish their functional tasks; these tasks range from
wound healing to immune response to fertilization. While the directional motion
is typically dictated by an external signal, the actual motility is also
restricted by physical constraints, such as the presence of other cells and the
extracellular matrix. The ability to successfully navigate in the presence of
obstacles is not only essential for organisms, but might prove relevant in the
study of autonomous robotic motion.
Methodology/principal findings: We study a computational model of amoeboid
chemotactic navigation under differing conditions, from motion in an
obstacle-free environment to navigation between obstacles and finally to moving
in a maze. We use the maze as a simple stand-in for a motion task with severe
constraints, as might be expected in dense extracellular matrix. Whereas agents
using simple chemotaxis can successfully navigate around small obstacles, the
presence of large barriers can often lead to agent trapping. We further show
that employing a simple memory mechanism, namely secretion of a repulsive
chemical by the agent, helps the agent escape from such trapping.
Conclusions/significance: Our main conclusion is that cells employing simple
chemotactic strategies will often be unable to navigate through maze-like
geometries, but a simple chemical marker mechanism (which we refer to as
"self-assistance") significantly improves success rates. This realization
provides important insights into mechanisms that might be employed by real
cells migrating in complex environments as well as clues for the design of
robotic navigation strategies. The results can be extended to more complicated
multi-cellular systems and can be used in the study of mammalian cell migration
and cancer metastasis
Molecular Dynamics Analysis Reveals Structural Insights into Mechanism of Nicotine N-Demethylation Catalyzed by Tobacco Cytochrome P450 Mono-Oxygenase
CYP82E4, a cytochrome P450 monooxygenase, has nicotine N-demethylase (NND) activity, which mediates the bioconversion of nicotine into nornicotine in senescing tobacco leaves. Nornicotine is a precursor of the carcinogen, tobacco-specific nitrosamine. CYP82E3 is an ortholog of CYP82E4 with 95% sequence identity, but it lacks NND activity. A recent site-directed mutagenesis study revealed that a single amino acid substitution, i.e., cysteine to tryptophan at the 330 position in the middle of protein, restores the NND activity of CYP82E3 entirely. However, the same amino acid change caused the loss of the NND activity of CYP82E4. To determine the mechanism of the functional turnover of the two molecules, four 3D structures, i.e., the two molecules and their corresponding cys–trp mutants were modeled. The resulting structures exhibited that the mutation site is far from the active site, which suggests that no direct interaction occurs between the two sites. Simulation studies in different biological scenarios revealed that the mutation introduces a conformation drift with the largest change at the F-G loop. The dynamics trajectories analysis using principal component analysis and covariance analysis suggests that the single amino acid change causes the opening and closing of the transfer channels of the substrates, products, and water by altering the motion of the F-G and B-C loops. The motion of helix I is also correlated with the motion of both the F-G loop and the B-C loop and; the single amino acid mutation resulted in the curvature of helix I. These results suggest that the single amino acid mutation outside the active site region may have indirectly mediated the flexibility of the F-G and B-C loops through helix I, causing a functional turnover of the P450 monooxygenase
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