664 research outputs found
Influence of Motivational Text Messages on Adherence to Continuous Positive Airway Pressure Therapy
Obstructive sleep apnea (OSA) is a condition affecting an estimated 22% of men and 17% of women. Individuals with OSA have periodic bouts of apneas and hypopneas while sleeping that negatively impacts their sleep quality and neurohormonal function. As a result, individuals with OSA are at increased risk for diseases including diabetes, cancer, stroke, myocardial infarction, and depression. Continuous positive airway pressure (CPAP) therapy is an effective treatment for but adherence rates are low at an estimated 60%.The purpose of this pilot study was to examine the effects of a four-week text message-based intervention on an individual\u27s CPAP device adherence, OSA symptom management, and outcome expectations when compared to participants receiving generic text messages. Participants were randomized to an experimental group (EG) (n=29) or to a control group (CG) (n=28). The EG received one motivational text message every week for four weeks based on concepts derived from the theory of planned behavior (TPB). The CG received one text message every week for four weeks with objective information (average use in hours per week). Total mask-on time and CPAP adherence status were measured using CPAP device real-time data. Symptom management and CPAP use expectations were evaluated using Apnea Belief Scale (ABS), Epworth Sleepiness Scale (ESS), and Functional Outcomes of Sleep Questionnaire-10 (FOSQ-10).There was no significant difference in total mask-on time between the two groups (p=.64). The proportion of participants classified as adherent did not differ between the two groups (p=.17). Differences in ABS, ESS, and FOSQ-10 scores between groups were also not significant (ANOVA, ABS: p =.47; ESS: p =.81; FOSQ: p =0.97).The pilot study identified trends toward improved CPAP adherence with use of TPB-based text messages. For example, the experimental group’s adherence rate was 14.8% higher than control group’s adherence rate. The lack of significance in the 3 instruments may have occurred because they measured actual behavior (CPAP use) and not what effect the intervention had on changing the behavior. More research is needed to elucidate the impact of TPB-based text messages on improving CPAP adherence and outcomes for individuals with OSA
A study of jet impingment on curved surfaces followed by oblique introduction into a freestream flow
Technology of thrust reversers with particular application to STOL aircraf
On the Use of Surrogate Functions for Mixed Variable Optimization of Simulated Systems
This research considers the efficient numerical solution of linearly constrained mixed variable programming (MVP) problems, in which the objective function is a black-box stochastic simulation, function evaluations may be computationally expensive, and derivative information is typically not available. MVP problems are those with a mixture of continuous, integer, and categorical variables, the latter of which may take on values only from a predefined list and may even be non-numeric. Mixed Variable Generalized Pattern Search with Ranking and Selection (MGPS-RS) is the only existing, provably convergent algorithm that can be applied to this class of problems. Present in this algorithm is an optional framework for constructing and managing less expensive surrogate functions as a means to reduce the number of true function evaluations that are required to find approximate solutions. In this research, the NOMADm software package, an implementation of pattern search for deterministic MVP problems, is modified to incorporate a sequential selection with memory (SSM) ranking and selection procedure for handling stochastic problems. In doing so, the underlying algorithm is modified to make the application of surrogates more efficient. A second class of surrogates based on the Nadaraya-Watson kernel regression estimator is also added to the software. Preliminary computational testing of the modified software is performed to characterize the relative efficiency of selected surrogate functions for mixed variable optimization in simulated systems
A number or a person?: perspectives on credit scoring and fair mortgage lending: article four in a five-part series
This fourth article in a five-part series on credit scoring showcases three different perspectives. Up for debate is how lenders can ensure fair treatment to all mortgage applicants and how consumers can be educated about the effect their credit score has on loan pricing.Mortgage loans
Feral swine management for conservation of an imperiled wetland habitat: Florida’s vanishing seepage slopes
Only 1% of the original extent of Florida’s seepage slope habitat remains, with Eglin Air Force Base containing some of the largest tracts. Feral swine damage is one of the greatest threats to this wetland habitat.We conducted a multi-year study to evaluate the impacts of sport hunting and supplemental swine removal on damage to seepage slopes. Prior to initiation of removal in 2003, swine damage to seepage slopes in the portion of the base closed to hunting averaged 25.0%, over twice the 10.9% losses in the portion open to hunting. After less than one year of supplemental removal, damage in the closed-to-hunting area dropped to 7.2%. Although supplemental removal was not applied in the open hunting area, damage dropped significantly to 5.6%, statistically indistinguishable from the swine-controlled (closed) portion. After another year of removal, average damage in the closed hunting area dropped further to 5.6%, while the open hunting area dropped to 4.3%, again statistically indistinguishable. Even though removal was only applied to the area closed to hunting, it also produced damage reductions in the open hunting area, as swine were free to move among areas. Declines in damage following implementation of removal corresponded with large drops in swine population indices for the base. Economic valuations of seepage slope damage losses demonstrated substantial benefit–cost ratios for application of removal. Prior to removal, the combined value of swine damage to seepage slopes in areas open and closed to hunting was estimated at 4 million to $1.5 million. The benefit–cost ratio over the 1.7 years of removal was an impressive 27.5. Moreover, the economic benefits of removal exceeded the costs 55.2-fold for the first year, when management impact would be greatest
Feral swine management for conservation of an imperiled wetland habitat: Florida’s vanishing seepage slopes
Only 1% of the original extent of Florida’s seepage slope habitat remains, with Eglin Air Force Base containing some of the largest tracts. Feral swine damage is one of the greatest threats to this wetland habitat.We conducted a multi-year study to evaluate the impacts of sport hunting and supplemental swine removal on damage to seepage slopes. Prior to initiation of removal in 2003, swine damage to seepage slopes in the portion of the base closed to hunting averaged 25.0%, over twice the 10.9% losses in the portion open to hunting. After less than one year of supplemental removal, damage in the closed-to-hunting area dropped to 7.2%. Although supplemental removal was not applied in the open hunting area, damage dropped significantly to 5.6%, statistically indistinguishable from the swine-controlled (closed) portion. After another year of removal, average damage in the closed hunting area dropped further to 5.6%, while the open hunting area dropped to 4.3%, again statistically indistinguishable. Even though removal was only applied to the area closed to hunting, it also produced damage reductions in the open hunting area, as swine were free to move among areas. Declines in damage following implementation of removal corresponded with large drops in swine population indices for the base. Economic valuations of seepage slope damage losses demonstrated substantial benefit–cost ratios for application of removal. Prior to removal, the combined value of swine damage to seepage slopes in areas open and closed to hunting was estimated at 4 million to $1.5 million. The benefit–cost ratio over the 1.7 years of removal was an impressive 27.5. Moreover, the economic benefits of removal exceeded the costs 55.2-fold for the first year, when management impact would be greatest
Evolution and diversification of a sexually dimorphic luminescent system in ponyfishes (Teleostei: Leiognathidae), including diagnoses for two new genera
A phylogeny was generated for Leiognathidae, an assemblage of bioluminescent, Indo-Pacific schooling fishes, using 6175 characters derived from seven mitochondrial genes ( 16S , COI , ND4 , ND5 , tRNA-His , tRNA-Ser , tRNA-Leu ), two nuclear genes ( 28S , histone H3 ), and 15 morphological transformations corresponding to features of the fishes' sexually dimorphic light-organ system (LOS; e.g., circumesophageal light organ, lateral lining of the gas bladder, transparent flank and opercular patches). Leiognathidae comprises three genera, Gazza , Leiognathus , and Secutor . Our results demonstrate that Leiognathidae, Gazza , and Secutor are monophyletic, whereas Leiognathus is not. The recovered pattern of relationships reveals that a structurally complex, strongly sexually dimorphic and highly variable species-specific light organ is derived from a comparatively simple non-dimorphic structure, and that evolution of other sexually dimorphic internal and external features of the male LOS are closely linked with these light-organ modifications. Our results demonstrate the utility of LOS features, both for recovering phylogeny and resolving taxonomic issues in a clade whose members otherwise exhibit little morphological variation. We diagnose two new leiognathid genera, Photopectoralis and Photoplagios , on the basis of these apomorphic LOS features and also present derived features of the LOS to diagnose several additional leiognathid clades, including Gazza and Secutor . Furthermore, we show that five distinct and highly specialized morphologies for male-specific lateral luminescence signaling, which exhibit species-specific variation in structure, have evolved in these otherwise outwardly conservative fishes. Leiognathids inhabit turbid coastal waters with poor visibility and are often captured in mixed assemblages of several species. We hypothesize that the species-specific, sexually dimorphic internal and external modifications of the leiognathid LOS provide compelling evidence for an assortative mating scheme in which males use species-specific patterns of lateral luminescence signaling to attract mates, and that this system functions to maintain reproductive isolation in these turbid coastal environments. © The Willi Hennig Society 2005.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72092/1/j.1096-0031.2005.00067.x.pd
Investigations on the Surface Chemistry of Colloidal Quantum Dots Towards Fluorescent Biological Probes
Colloidal semiconductor quantum dots (QDs) have garnered significant interest as promising materials for biological applications due to their improved photostability and narrow, tunable photoluminescence properties compared to organic fluorophores. To facilitate their utility as fluorescent bioimaging probes, QDs must undergo post-synthetic modifications to exchange their native hydrophobic ligands from synthesis with hydrophilic ones that enable colloidal dispersions in aqueous environments. Many examples exist that demonstrate surface modifications for water-soluble QDs and their efficacy in biological systems, however, there is a need to develop a more thorough understanding of how hydrophilic ligands coordinate to QD surfaces in order to develop more robust QD systems. The central themes of this dissertation are to describe how hydrophilic ligands bind to QD surfaces, what types of ligands lead to the formation of robust surface coatings, and how to identify properties of ligands that lead to stronger binding. I will begin by introducing the general applications of QDs and the necessary considerations regarding their synthesis, purification, and ligand exchange chemistry. Then, I will describe the first direct comparison of the influence of block and random copolymer ligands on QD stability in the presence of an endogenous competitor ligand. Finally, I will demonstrate the relative binding strength of molecular ligands in water as a function of ligand chain length and binding denticity. Through these systematic investigations, I aim to improve upon our understanding of ligand-QD interactions towards the development of stable and robust fluorescent QD bioimaging probes
Morphology and ploidy level determination of Pteris vittata callus during induction and regeneration
Background: Morphological and ploidy changes of the arsenic hyperaccumulator, Chinese brake fern (Pteris vittata) callus tissue are described here to provide insight into fern life cycle biology and for possible biotechnology applications. Pteris vittata callus was studied using transmission and scanning electron microscopy, and flow cytometry.
Results: Callus induction occurred both in light and dark culture conditions from prothallus tissues, whereas rhizoid formation occurred only in dark culture conditions. Callus tissues contained two types of cells: one actively dividing and the other containing a single large vacuole undergoing exocytosis. Sporophytes regenerated from callus asynchronously form clusters of cells in a manner apparently analogous to direct organogenesis. Extracellular matrices were observed in actively-growing callus and at the base of regenerating sporophytes. Callus tissue nuclei were found to be primarily diploid at induction and throughout maintenance of cultures indicating that callus cell fate is determined at induction, which closely follows apogamous sporophyte development. Presence of a dense extracellular matrix in conjunction with sporophyte development suggests a link between the suspensor-like activity of the embryonic foot during normal fern embryo development and the suspected functions of extracellular matrices in angiosperms.
Conclusions: Further investigation could lead to a better understanding of genes involved in P. vittata embryo development and apogamous sporophyte development. The methodology could be useful for in vitro propagation of rare and valuable fern germplasm
- …