184 research outputs found

    Cube law, condition factor and weight-length relationships: history, meta-analysis and recommendations

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    This study presents a historical review, a meta-analysis, and recommendations for users about weight–length relationships, condition factors and relative weight equations. The historical review traces the developments of the respective concepts. The meta-analysis explores 3929 weight–length relationships of the type W = aLb for 1773 species of fishes. It shows that 82% of the variance in a plot of log a over b can be explained by allometric versus isometric growth patterns and by different body shapes of the respective species. Across species median b = 3.03 is significantly larger than 3.0, thus indicating a tendency towards slightly positive-allometric growth (increase in relative body thickness or plumpness) in most fishes. The expected range of 2.5 < b < 3.5 is confirmed. Mean estimates of b outside this range are often based on only one or two weight–length relationships per species. However, true cases of strong allometric growth do exist and three examples are given. Within species, a plot of log a vs b can be used to detect outliers in weight–length relationships. An equation to calculate mean condition factors from weight–length relationships is given as Kmean = 100aLb−3. Relative weight Wrm = 100W/(amLbm) can be used for comparing the condition of individuals across populations, where am is the geometric mean of a and bm is the mean of b across all available weight–length relationships for a given species. Twelve recommendations for proper use and presentation of weight–length relationships, condition factors and relative weight are given

    Novel nomograms for survival and progression in HPV+ and HPV- oropharyngeal cancer:a population-based study of 1,542 consecutive patients

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    BACKGROUND: No study has combined tumour and clinical covariates for survival to construct an individual risk-profile for overall survival (OS), time to progression (TTP), and survival after progression (SAP) in patients with HPV+ and HPV– oropharyngeal squamous cell carcinoma (OPSCC). Based on the largest-to-date, unselected, population-based cohort of patients diagnosed with OPSCC, we performed a comprehensive analysis of long-term OS, TTP, and SAP and constructed novel nomograms to evaluate patients' prognoses. RESULTS: At a median follow-up of 4.0 years (range: 0.8–15.8 yrs.), 690 deaths were recorded. The 5-year OS, TTP, and SAP for the HPV+/p16+ subgroup were 77%, 82%, and 33, vs. 30%, 66%, and 6% for the HPV–/p16– group (P < 0.01). 376 patients failed to maintain disease control with a median TTP of 13 months in the HPV+/p16+ subgroup vs. 8.5 months in the HPV–/p16– subgroup (P < 0.05). HPV combined with p16 status remained one of the most informative covariates in the final Cox regression model for OS, TTP, and SAP. METHODS: We included all patients diagnosed with OPSCC (n = 1,542) between 2000–2014 in Eastern Denmark. Survival rates were estimated by the Kaplan-Meier method. A multivariate Cox regression model was used to construct predictive, internally validated nomograms. CONCLUSION: The HPV+/p16+ subgroup had improved OS, TTP, and SAP compared with other combinations of HPV and p16 after adjusting for covariates. Nomograms were constructed for 1-, 5- and 10-year survival probability. Models may aid patients and clinicians in their clinical decision making as well as in counselling, research, and trial design

    Consumption Dynamics of the Adult Piscivorous Fish Community in Spirit Lake, Iowa

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    At Spirit Lake, one of Iowa’s most important fisheries, walleye Sander vitreus (formerly Stizostedion vitreum) is one of the most popular species with anglers. Despite a century of walleye stocking and management in Spirit Lake, walleye growth rate, size structure, and angler harvest continue to decline. Our purpose was to determine the magnitude and dynamics of walleye population consumption relative to those of other piscivorous species in Spirit Lake, which would allow managers to judge the feasibility of increasing the abundance, growth rate, and size structure of the walleye population.We quantified food consumption by the adult piscivorous fish community in Spirit Lake over a 3-year period. Data on population dynamics, diet, energy density, and water temperature from 1995 to 1997 were used in bioenergetics models to estimate total consumption by walleye, yellow perch Perca flavescens, smallmouth bass Micropterus dolomieu, largemouth bass Micropterus salmoides, black crappie Pomoxis nigromaculatus, and northern pike Esox lucius. Estimated annual consumption by the piscivorous community varied roughly fourfold, ranging from 154,752 kg in 1995 to 662,776 kg in 1997. Walleyes dominated total consumption, accounting for 68, 73, and 90% (1995–1997, respectively) of total food consumption. Walleyes were also the dominant consumers of fish, accounting for 76, 86, and 97% of piscivorous consumption; yellow perch followed, accounting for 16% of piscivorous consumption in 1995 and 12% in 1996. Yellow perch were the predominant fish prey species in all 3 years, accounting for 68, 52, and 36% of the total prey consumed. Natural reproduction is weak, so high walleye densities are maintained by intensive stocking. Walleye stocking drives piscivorous consumption in Spirit Lake, and yearly variation in the cannibalism of stocked walleye fry may be an important determinant of walleye year-class strength and angler success. Reducing walleye stocking intensity, varying stocking intensity from year to year, and attempting to match stocking intensity with the abundance of prey species other than walleye may improve the walleye fishery in Spirit Lake

    Clinical and Prognostic Differences in Oropharyngeal Squamous Cell Carcinoma in USA and Denmark, Two HPV High-Prevalence Areas

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    BACKGROUND: Uncertainty persists regarding clinical and treatment variations crucial to consider when comparing high human papillomavirus (HPV)-prevalence oropharyngeal squamous cell carcinoma (OPSCC) cohorts for accurate patient stratification and replicability of clinical trials across different geographical areas. METHODS: OPSCC patients were included from The University of Texas MD Anderson Cancer Center (UTMDACC), USA and from The University Hospital of Copenhagen, Denmark from 2015-2020, (n = 2484). Outcomes were 3-year overall survival (OS) and recurrence-free interval (RFI). Subgroup analyses were made for low-risk OPSCC patients (T1-2N0M0) and high-risk patients (UICC8 III-IV). RESULTS: There were significantly more HPV-positive (88.2 % vs. 63.1 %), males (89.4 % vs. 74.1 %), never-smokers (52.1 % vs. 23.7 %), lower UICC8-stage (I/II: 79.3 % vs. 68 %), and fewer patients treated with radiotherapy (RT) alone (14.8 % vs. 30.3 %) in the UTMDACC cohort. No difference in the adjusted OS was observed (hazard ratio [HR] 1.21, p = 0.23), but a significantly increased RFI HR was observed for the Copenhagen cohort (HR: 1.74, p = 0.003). Subgroup analyses of low- and high-risk patients revealed significant clinical and treatment differences. No difference in prognosis was observed for low-risk patients, but the prognosis for high-risk patients in the Copenhagen cohort was worse (OS HR 2.20, p = 0.004, RFI HR 2.80, p = 0.002). CONCLUSIONS: We identified significant differences in clinical characteristics, treatment modalities, and prognosis between a Northern European and Northern American OPSCC population. These differences are important to consider when comparing outcomes and for patient stratification in clinical trials, as reproducibility might be challenging

    Low Vitamin D in Narcolepsy with Cataplexy

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    Narcolepsy with cataplexy (NC) is currently thought to be an autoimmune-mediated disorder in which environmental risk factors make a significant contribution to its development. It was proposed that vitamin D deficiency plays a role in autoimmune diseases. Here we investigated whether NC can be associated with 25-hydroxyvitamin D (25(OH)D) level deficiency in patients with NC compared with gender- and age-matched normal controls.Serum level of 25 (OH)D was determined in 51 European patients with typical NC compared to 55 age-, gender-, and ethnicity-matched healthy controls. Demographic and clinical data (age at onset, duration and severity of disease at baseline, and treatment intake at time of study) and season of blood sampling were collected to control for confounding variables.Serum 25(OH)D concentration was lower in NC compared to controls (median, 59.45 nmol/l [extreme values 24.05-124.03] vs. 74.73 nmol/l [26.88-167.48] p = 0.0039). Patients with NC had significantly greater vitamin D deficiency (<75 nmol/l) than controls (72.5% vs 50.9%, p = 0.0238). Division into quartiles of the whole sample revealed that the risk of being affected with NC increased with lower 25(OH)D level, with a 5.34 OR [1.65-17.27] for the lowest quartile (p = 0.0051). Further adjustment for BMI did not modify the strength of the association (OR: 3.63, 95% CI = 1.06-12.46, p = 0.0191). No between BMI and 25(OH)D interaction, and no correlation between 25(OH)D level and disease duration or severity or treatment intake were found in NC.We found a higher frequency of vitamin D deficiency in NC. Further studies are needed to assess the contribution of hypovitaminosis D to the risk of developing narcolepsy, and to focus on the utility of assessing vitamin D status to correct potential deficiency

    Growth Rate Responses of Missouri and Lower Yellowstone River Fishes to a Latitudinal Gradient

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    Notropis atherinoides, freshwater drums Aplodinotus grunniens, river carpsuckers Carpiodes carpio and saugers Stizostedion canadense collected in 1996-1998 from nine river sections of the Missouri and lower Yellowstone rivers at two life-stages (young-of-the-year and age 1+ years) were significantly different among sections. However, they showed no river-wide latitudinal trend except for age 1+ years emerald shiners that did show a weak negative relation between growth and both latitude and length of growing season. The results suggest growth rates of fishes along the Missouri River system are complex and could be of significance in the management and conservation of fish communities in this altered system

    No effect of the turmeric root phenol curcumin on prednisolone-induced glucometabolic perturbations in men with overweight or obesity

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    Objectives: Preclinically, curcumin has been shown to protect against glucocorticoid-induced insulin resistance. We evaluated the effect of curcumin administered with prednisolone in healthy overweight or obese men. Methods: In a double-blind, parallel-group trial, 24 overweight/obese non-diabetic men were randomised to one of three intervention groups (A) prednisolone placebo+curcumin placebo, (B) prednisolone (50 mg/day)+curcumin placebo or (C) prednisolone and curcumin (400 mg/day). Curcumin or curcumin placebo treatment started 1 day prior to 10-day prednisolone or prednisolone placebo treatment. The primary endpoint was change in prednisolone-induced insulin resistance assessed by homeostatic model assessment of insulin resistance (HOMA2-IR). Other endpoints included anthropometric measurements, magnetic resonance spectroscopy-assessed hepatic fat content, blood pressure, circulating metabolic markers and continuous glucose monitoring measures. Results: Baseline characteristics (mean ± s.d): age 44.2 ± 13.7 years, BMI 30.1 ± 3.5 kg/m2, HbAlc 33.3 ± 3.2 mmol/mol, HOMA2-IR 1.10 ± 0.45 and fasting plasma glucose 5.2 ± 0.4 mmol/L. Prednisolone significantly increased HOMA2-IR (estimated treatment difference 0.36 (95% CI 0.16; 0.57)). Co-treatment with curcumin had no effect on HOMA2-IR (estimated treatment difference 0.08 (95% CI −0.13; 0.39)). Prednisolone increased HbAlc, insulin, C-peptide, glucagon, blood pressure, mean interstitial glucose, time spent in hyperglycaemia and glucose variability, but no protective effect of curcumin on any of these measures was observed. Conclusions: In this double-blind, placebo-controlled parallel-group study involving 24 overweight or obese men randomised to one of three treatment arms, curcumin treatment had no protective effect on prednisolone-induced insul in resistance or other glucometabolic perturbations

    Standard methods for sampling freshwater fishes: opportunities for international collaboration

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    With publication of Standard Methods for Sampling North American Freshwater Fishes in 2009, the American Fisheries Society (AFS) recommended standard procedures for North America. To explore interest in standardizing at intercontinental scales, a symposium attended by international specialists in freshwater fish sampling was convened at the 145th Annual AFS Meeting in Portland, Oregon, in August 2015. Participants represented all continents except Australia and Antarctica and were employed by state and federal agencies, universities, nongovernmental organizations, and consulting businesses. Currently, standardization is practiced mostly in North America and Europe. Participants described how standardization has been important for management of long-term data sets, promoting fundamental scientific understanding, and assessing efficacy of large spatial scale management strategies. Academics indicated that standardization has been useful in fisheries education because time previously used to teach how sampling methods are developed is now more devoted to diagnosis and treatment of problem fish communities. Researchers reported that standardization allowed increased sample size for method validation and calibration. Group consensus was to retain continental standards where they currently exist but to further explore international and intercontinental standardization, specifically identifying where synergies and bridges exist, and identify means to collaborate with scientists where standardization is limited but interest and need occur

    Could sound be used as a strategy for reducing symptoms of perceived motion sickness?

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    <p>Abstract</p> <p>Background</p> <p>Working while exposed to motions, physically and psychologically affects a person. Traditionally, motion sickness symptom reduction has implied use of medication, which can lead to detrimental effects on performance. Non-pharmaceutical strategies, in turn, often require cognitive and perceptual attention. Hence, for people working in high demand environments where it is impossible to reallocate focus of attention, other strategies are called upon. The aim of the study was to investigate possible impact of a mitigation strategy on perceived motion sickness and psychophysiological responses, based on an artificial sound horizon compared with a non-positioned sound source.</p> <p>Methods</p> <p>Twenty-three healthy subjects were seated on a motion platform in an artificial sound horizon or in non-positioned sound, in random order with one week interval between the trials. Perceived motion sickness (Mal), maximum duration of exposure (ST), skin conductance, blood volume pulse, temperature, respiration rate, eye movements and heart rate were measured continuously throughout the trials.</p> <p>Results</p> <p>Mal scores increased over time in both sound conditions, but the artificial sound horizon, applied as a mitigation strategy for perceived motion sickness, showed no significant effect on Mal scores or ST. The number of fixations increased with time in the non-positioned sound condition. Moreover, fixation time was longer in the non-positioned sound condition compared with sound horizon, indicating that the subjects used more time to fixate and, hence, assumingly made fewer saccades.</p> <p>Conclusion</p> <p>A subliminally presented artificial sound horizon did not significantly affect perceived motion sickness, psychophysiological variables or the time the subjects endured the motion sickness triggering stimuli. The number of fixations and fixation times increased over time in the non-positioned sound condition.</p

    Four aspects of self-image close to death at home

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    Living close to death means an inevitable confrontation with one's own existential limitation. In this article, we argue that everyday life close to death embodies an identity work in progress. We used a narrative approach and a holistic-content reading to analyze 12 interviews conducted with three persons close to death. By illuminating the unique stories and identifying patterns among the participants’ narratives, we found four themes exemplifying important aspects of the identity work related to everyday life close to death. Two of the themes, named “Inside and outside of me” and “Searching for togetherness,” represented the core of the self-image and were framed by the other themes, “My place in space” and “My death and my time.” Our findings elucidate the way the individual stories moved between the past, the present, and the future. This study challenges the idea that everyday life close to impending death primarily means limitations. The findings show that the search for meaning, new knowledge, and community can form a part of a conscious and ongoing identity work close to death
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