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Tallulah, LA, United States

Baggarly S.A.,University of Louisiana at Monroe | Kemp R.J.,University of Louisiana at Monroe | Wang X.,University of Louisiana at Monroe | Magoun A.D.,Applied Research and Analysis Inc.
Research in Social and Administrative Pharmacy

Background: Non-adherence with antihypertensive therapy is a significant problem. Prior research has generally focused upon one drug or one drug class. Current information across multiple antihypertensive drug classes is limited. Objectives: To describe the initial treatment of recipients of Louisiana Medicaid with newly-diagnosed hypertension; evaluate differences in adherence and persistence rates among multiple antihypertensive drug classes; and test the association of drug classes, race, gender, age and comorbidity with adherence and persistence to drug therapy. Methods: In a retrospective analysis of administrative claims data, initial therapy was described by type and drug class for 4544 Medicaid recipients with newly-diagnosed hypertension. Recipients were placed into cohorts based upon drug classes (diuretics, beta-blockers, angiotensin-II receptor blockers, angiotensin converting enzyme inhibitors, and calcium channel blockers). Persistence with drug therapy and Medication Possession Ratios (MPR) were calculated for 6-month and 12-month periods following diagnosis. Drug class and demographic variables were used as predictor variables in logistic regression analyses of persistence and MPR. Results: Recipients in the study group were primarily female (66%) and Black (65%). Recipients initially were treated with monotherapy (33%), multiple drugs (11%), fixed combinations (8%) or no drugs (48%). After one year, 62% of recipients were not receiving drug therapy. Persistence rates by cohort ranged from 26% to 42% at 6-months following diagnosis, and 14%-28% at 12-months. The proportion of recipients by cohort with MPRs of 0.8 or above ranged from 43% to 60% at 6-months and 25%-42% at 12-months. Race, comorbidities, and initial drug therapy were significant predictors of both persistence and MPR. Conclusions: Within this study group, adherence and persistence to medication therapy were less than optimal. Future efforts to improve compliance with medication therapy could be focused upon specific groups having poor adherence and/or persistence within the drug class cohorts analyzed in this study. © 2014 Elsevier Inc. Source

Ailstock M.S.,Anne Arundel Community College | Shafer D.J.,Engineer Research and Development Center | Magoun A.D.,Applied Research and Analysis Inc.
Restoration Ecology

Protocols are now available for seed harvest, storage and germination of several mesohaline and polyhaline species; however, low seedling survival rates point to the need for an increased understanding of factors affecting seedling establishment. Depth of seed burial in sediments and initial seedling growth rates are shown to be limiting factors for photosynthetic competency of Ruppia maritima and Potamogeton perfoliatus. Seedling emergence is inversely proportional to planting depth on sediments ranging in grain size from coarse sands (850 μm) to silt (63 μm). Less than 6% of the seeds of either species emerged when buried to a depth of 3 cm in test sediments. Germination was greatest for seeds placed on the surface of sediments; however, these seedlings were subject to displacement because of the weak and fragile roots produced during early growth. Fine sediments may be more favorable for R. maritima seedling establishment, because seedling emergence and height decreased with increasing sediment grain size. Potamogeton perfoliatus seedlings seem to be more tolerant of a wider range of sediment grain sizes than R. maritima as indicated by the lack of an effect of sediment grain size on P. perfoliatus seed emergence, seedling height, and biomass. Increasing nutrients stimulated seedlings of both species; however, even at the highest concentrations tested, growth, as determined by shoot elongation and leaf and root formation, slowed within 7-10 days. This suggests factors other than mineral nutrients and light limit growth or that growth shifts from aboveground biomass production to belowground vegetative spread. © 2010 Society for Ecological Restoration International. Source

Ailstock M.S.,Anne Arundel Community College | Shafer D.J.,Engineer Research and Development Center | Magoun A.D.,Applied Research and Analysis Inc.
Restoration Ecology

Restoration of submerged aquatic vegetation from seed has been hampered by a lack of information on the appropriate conditions for collecting, processing, and storing seeds prior to dispersal. Seeds must be processed and stored under conditions that maintain seed viability, meet dormancy requirements, and prevent premature germination. This study examined the effects of collection date, processing technique, aeration, storage and induction temperature and salinity, and storage period on seed germination of two mesohaline aquatic species, Potamogeton perfoliatus and Ruppia maritima. Collection date and processing technique were significant factors affecting seed yield from donor populations. Seeds of both species remained viable and germinated best when stored at 4°C, and then exposed to freshwater induction conditions. However, their responses to other factors differed. Aeration during storage was necessary in order to maintain viability of P. perfoliatus seeds, whereas it was unnecessary for R. maritima seeds. Storage in freshwater at 4°C prevented germination of P. perfoliatus seeds, while high salinity during cold storage was necessary to minimize premature germination of R. maritima. Mean germination time of P. perfoliatus was dependent on storage salinity; in contrast, mean germination time of R. maritima seeds was dependent on induction salinity. These differences indicate that the methods required to produce large quantities of underwater plant seed amenable to large-scale restoration efforts must be tailored to the specific requirements of individual species and must consider the range of processes from initial harvest through seed testing prior to field establishment. © 2010 Society for Ecological Restoration International. Source

Koch E.W.,University of Cambridge | Koch E.W.,Anne Arundel Community College | Ailstock M.S.,Engineer Research and Development Center | Booth D.M.,University of Cambridge | And 2 more authors.
Restoration Ecology

We tested the hypothesis that currents, waves, and sediment grain size affect the dispersal of seeds and seedlings of the submersed angiosperms Ruppia maritima, Potamogeton perfoliatus and Stuckenia pectinata. Seed settling velocities and initiation of motion of seeds and seedlings and distance transported were quantified on four sediment types under a range of currents and waves in a flume. The rapid settling velocities of R. maritima and S. pectinata seeds and the increased settling velocity of P. perfoliatus in currents above 8 cm/second suggest that primary dispersal of these species is localized to the general area colonized by their parents. Once settled within a bed, seeds are exposed to weak currents and waves, and are likely to be subject to sediment deposition which may further limit dispersal. In contrast, in restoration projects, the absence of vegetation is likely to make seeds more vulnerable to grazing and transport, and may contribute to the lack of plant establishment. If seeds germinate without being buried, they are susceptible to secondary dispersal at relatively low current velocities and small wave heights due to the drag exerted on the cotyledon. Sand grains tend to stick to the seed coat and rootlet of P. perfoliatus seedlings, perhaps a mechanism to reduce the chances of being displaced following germination. These data reveal the close links between sediment, water flow, and submersed angiosperm seedling establishment; these parameters should be considered when using seeds for restoration of submersed angiosperms. © 2010 Society for Ecological Restoration International. Source

Kaldy J.E.,US Ecology | Shafer D.J.,U.S. Army | Dale Magoun A.,Applied Research and Analysis Inc.
Journal of Experimental Marine Biology and Ecology

At least two seagrass congeners in the genus Zostera are found along the Pacific Coast of North America: native Zostera marina L. and the non-native Zostera japonica Aschers. & Graebn. Efforts to understand the drivers behind the expanding colonization of Z. japonica have led to interest in the biology and ecology of this species. In most locations where they co-occur, these species exhibit a disjunct vertical zonation. We experimentally consider the influence of pulsed temperature effects on Z. japonica growth as a driver of vertical zonation. In mesocosm tanks seagrass planting units were cycled from ambient to treatment temperatures (8, 20, 32. °C) of variable duration (2, 6, 12, 24. h) each day for 10. d and then growth was assessed. Leaf elongation and growth rates exhibited strong, statistically significant relationships with increasing duration of exposure to 20. °C. Plants exposed to continuous 20. °C temperatures grew 2.5 times faster than plants exposed to 20. °C for 2. h. Likewise, plants exposed to continuous 8. °C temperatures grew 2.5 times slower than plants at 8. °C for 2. h. Plants exposed to 32. °C maintained fairly constant growth and elongation rates regardless of the duration of exposure. Field data indicate that Z. japonica and Z. marina experience different thermal regimes in the same estuary. We suggest that intertidal zonation patterns of Z. japonica in North America are predominantly driven by seagrass temperature responses; increased duration of exposure to cold water temperatures appears to limit expansion of the Z. japonica bed lower boundary to the mid-intertidal. Additionally, we recognize characteristics that may be useful to identifying systems susceptible to colonization. © 2014. Source

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