Lake trout (Salvelinus namaycush) otoliths as indicators of past climate patterns and growth in Arctic lakes

Thesis (M.S.) University of Alaska Fairbanks, 2017The effects of climate change on freshwater ecosystems are amplified in high-latitude regions, however, Alaska climate data are limited due to the remote location of the Arctic. Predictions have indicated that warming temperatures owing to climate change could increase fish growth, but the magnitude and factors influencing these changes remain uncertain. Here I investigated the relationship between Lake Trout Salvelinus namaycush growth and physical and biological characteristics, fish community structure and climate patterns. I applied biochronology techniques to predict recent climate patterns from annual growth increments recorded on Lake Trout otoliths. Growth increments were also used to perform length-at-age back-calculations and to estimate the growth coefficient K, as described by a von Bertalanffy growth model. Lake Trout were captured from 13 climate-sensitive lakes in the Fish Creek watershed in Arctic Alaska during 2014 and 2015. Individual Lake Trout (N = 53) ranged from 471--903 mm fork length (FL; mean = 589.3 mm) and their readable annuli, representative of age, ranged from 9--55 annual growth increments. I constructed a growth chronology for the period 1977--2014 and used model selection to identify the best predictive model of relative Lake Trout growth (ring width index; RWI) as a function of climate descriptors. A single covariate model was the best predictor and indicated that RWI tracked mean August air temperature recorded at a local weather station from 1998--2013 (P < 0.001; R2adj = 0.55; RMSE = 0.048). Lake Trout growth (K) was subsequently modeled as a function of physical and biological characteristics, and fish community structure, using multiple linear regression. The highest ranked model included physical (i.e., depth, distance to river and coast, connectivity class, and number of stream intersections) and biological (sex) covariates. Model averaging indicated K was higher in deeper, well connected lakes, located further from the coast and was lower with increasing distance from a large river, though the relationship with depth was found to be the single significant covariate. This study demonstrated the utility of biochronology techniques to estimate past climate patterns in remote regions, and provided valuable knowledge regarding growth-environment relationships for Lake Trout. In turn, this information can be used to better understand the effects of a changing environment in sensitive Arctic lake ecosystems

The economic burden of asthma and chronic obstructive pulmonary disease and the impact of poor inhalation technique with commonly prescribed dry powder inhalers in three European countries

Contains fulltext : 171713.pdf (publisher's version ) (Open Access)BACKGROUND: Asthma and chronic obstructive pulmonary disease (COPD) are common chronic inflammatory respiratory diseases, which impose a substantial burden on healthcare systems and society. Fixed-dose combinations (FDCs) of inhaled corticosteroids (ICS) and long-acting beta2 agonists (LABA), often administered using dry powder inhalers (DPIs), are frequently prescribed to control persistent asthma and COPD. Use of DPIs has been associated with poor inhalation technique, which can lead to increased healthcare resource use and costs. METHODS: A model was developed to estimate the healthcare resource use and costs associated with asthma and COPD management in people using commonly prescribed DPIs (budesonide + formoterol Turbuhaler((R)) or fluticasone + salmeterol Accuhaler((R))) over 1 year in Spain, Sweden and the United Kingdom (UK). The model considered direct costs (inhaler acquisition costs and scheduled and unscheduled healthcare costs), indirect costs (productive days lost), and estimated the contribution of poor inhalation technique to the burden of illness. RESULTS: The direct cost burden of managing asthma and COPD for people using budesonide + formoterol Turbuhaler((R)) or fluticasone + salmeterol Accuhaler((R)) in 2015 was estimated at euro813 million, euro560 million, and euro774 million for Spain, Sweden and the UK, respectively. Poor inhalation technique comprised 2.2-7.7 % of direct costs, totalling euro105 million across the three countries. When lost productivity costs were included, total expenditure increased to euro1.4 billion, euro1.7 billion and euro3.3 billion in Spain, Sweden and the UK, respectively, with euro782 million attributable to poor inhalation technique across the three countries. Sensitivity analyses showed that the model results were most sensitive to changes in the proportion of patients prescribed ICS and LABA FDCs, and least sensitive to differences in the number of antimicrobials and oral corticosteroids prescribed. CONCLUSIONS: The cost of managing asthma and COPD using commonly prescribed DPIs is considerable. A substantial, and avoidable, contributor to this burden is poor inhalation technique. Measures that can improve inhalation technique with current DPIs, such as easier-to-use inhalers or better patient training, could offer benefits to patients and healthcare providers through improving disease outcomes and lowering costs

Fitness efficacy of vibratory exercise compared to walking in postmenopausal women

In this study, we compared the efficacy of 8 months of low-frequency vibration and a walk-based program in health-related fitness. Twenty-seven postmenopausal women were randomly assigned into two groups: whole-body vibration (WBV) group (n = 18) performed three times/week a static exercise on a vibration platform (6 sets of 1-min with 1 min of rest, with a 12.6 Hz of frequency and an amplitude of 3 mm); walk-based program (WP) group (n = 18) performed three times/week a 60-min of walk activity at 70-75% of maximal heart rate. A health-related battery of tests was applied. Maximal unilateral concentric and eccentric isokinetic torque of the knee extensors was recorded by an isokinetic dynamometer. Physical fitness was measured using the following tests: vertical jump test, chair rise test and maximal walking speed test over 4 m. Maximal unilateral isokinetic strength was measured in the knee extensors in concentric actions at 60 and 300 degrees /s, and eccentric action at 60 degrees /s. After 8 months, the WP improved the time spent to walk 4 m (20%) and to perform the chair rise test (12%) compared to the WBV group (P = 0.006, 0.002, respectively). In contrast, the comparison of the changes in vertical jump showed the higher effectiveness of the vibratory exercise in 7% (P = 0.025). None of exercise programs showed change on isokinetic measurements. These results indicate that both programs differed in the main achievements and could be complementary to prevent lower limbs muscle strength decrease as we age [ISRCTN76235671]

Effects of whole-body vibration on postural control in elderly: a systematic review and meta-analysis

<p>Abstract</p> <p>Background</p> <p>This systematic review was performed to summarize the current evidence for whole body vibration (WBV) interventions on postural control in elderly.</p> <p>Methods</p> <p>English and German language papers in Medline, PEDro, Cinahl and the Cochrane databases were searched. Two reviewers extracted data on patients' characteristics, type of WBV intervention and outcomes. Two independent reviewers rated the methodological quality of these studies. Data were pooled using random-effects meta-analysis.</p> <p>Results</p> <p>Fifteen papers reporting quantitative data were included. Results from 15 papers could be pooled for a meta-analysis. The studies involved 933 participants. In 7 studies the authors investigated the effects of vibration plates generating vertical sinusoidal vibrations (VS-WBV) and 7 papers described the use of side-alternating sinusoidal vibrations (SS-WBV). One study investigated both VS-WBV and SS-WBV.</p> <p>Weak to moderate evidence of an overall effect as a result of VS-WBV and SS-WBV was observed for (a) static balance for post-intervention values with a standardized mean difference (SMD) -0.06, 95% CI -0.31 to 0.18 and for change values SMD -0.26, 95% CI -1.09 to 0.57, and (b) dynamic balance for post-intervention-values SMD -0.34, 95% CI -0.60 to -0.08. For functional balance (c) an overall outcome for post-intervention values with SMD of 0.34, 95% CI -0.19 to 0.87 was found.</p> <p>Conclusions</p> <p>The 15 studies reviewed were of moderate methodological quality. In summary, SS-WBV seems to have a beneficial effect on dynamic balance in elderly individuals. However, the current results should be interpreted with caution because of the observed heterogeneity of training parameters and statistical methods. Future studies are warranted to evaluate the effects of WBV on postural control in an elderly population.</p

Prospecting environmental mycobacteria: combined molecular approaches reveal unprecedented diversity

Background: Environmental mycobacteria (EM) include species commonly found in various terrestrial and aquatic environments, encompassing animal and human pathogens in addition to saprophytes. Approximately 150 EM species can be separated into fast and slow growers based on sequence and copy number differences of their 16S rRNA genes. Cultivation methods are not appropriate for diversity studies; few studies have investigated EM diversity in soil despite their importance as potential reservoirs of pathogens and their hypothesized role in masking or blocking M. bovis BCG vaccine. Methods: We report here the development, optimization and validation of molecular assays targeting the 16S rRNA gene to assess diversity and prevalence of fast and slow growing EM in representative soils from semi tropical and temperate areas. New primer sets were designed also to target uniquely slow growing mycobacteria and used with PCR-DGGE, tag-encoded Titanium amplicon pyrosequencing and quantitative PCR. Results: PCR-DGGE and pyrosequencing provided a consensus of EM diversity; for example, a high abundance of pyrosequencing reads and DGGE bands corresponded to M. moriokaense, M. colombiense and M. riyadhense. As expected pyrosequencing provided more comprehensive information; additional prevalent species included M. chlorophenolicum, M. neglectum, M. gordonae, M. aemonae. Prevalence of the total Mycobacterium genus in the soil samples ranged from 2.3×107 to 2.7×108 gene targets g−1; slow growers prevalence from 2.9×105 to 1.2×107 cells g−1. Conclusions: This combined molecular approach enabled an unprecedented qualitative and quantitative assessment of EM across soil samples. Good concordance was found between methods and the bioinformatics analysis was validated by random resampling. Sequences from most pathogenic groups associated with slow growth were identified in extenso in all soils tested with a specific assay, allowing to unmask them from the Mycobacterium whole genus, in which, as minority members, they would have remained undetected