23 research outputs found

    Functional, Morphological, and Evolutionary Characterization of Hearing in Subterranean, Eusocial African Mole-Rats

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    Naked mole-rats are highly vocal, eusocial, subterranean rodents with, counterintuitively, poor hearing. The causes underlying their altered hearing are unknown. Moreover, whether altered hearing is degenerate or adaptive to their unique lifestyles is controversial. We used various methods to identify the factors contributing to altered hearing in naked and the related Damaraland mole-rats and to examine whether these alterations result from relaxed or adaptive selection. Remarkably, we found that cochlear amplification was absent from both species despite normal prestin function in outer hair cells isolated from naked mole-rats. Instead, loss of cochlear amplification appears to result from abnormal hair bundle morphologies observed in both species. By exploiting a well-curated deafness phenotype-genotype database, we identified amino acid substitutions consistent with abnormal hair bundle morphology and reduced hearing sensitivity. Amino acid substitutions were found in unique groups of six hair bundle link proteins. Molecular evolutionary analyses revealed shifts in selection pressure at both the gene and the codon level for five of these six hair bundle link proteins. Substitutions in three of these proteins are associated exclusively with altered hearing. Altogether, our findings identify the likely mechanism of altered hearing in African mole-rats, making them the only identified mammals naturally lacking cochlear amplification. Moreover, our findings suggest that altered hearing in African mole-rats is adaptive, perhaps tailoring hearing to eusocial and subterranean lifestyles. Finally, our work reveals multiple, unique evolutionary trajectories in African mole-rat hearing and establishes species members as naturally occurring disease models to investigate human hearing loss

    Association between obesity profile and non-alcoholic fatty liver by race/ethnicity

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    NAFLD is characterized by accumulation of fat in the liver that can lead to health complications. Previous studies have found the obesity phenotype and its components to be risk factors for the development of NAFLD. This study aims to examine the relationship between the obesity phenotype and NAFLD among each racial-ethnic group. We analyzed data from the NHANES III survey (1988-1994). The obesity phenotype was defined based on BMI and metabolic syndrome. NAFLD was defined by abdominal ultrasounds among non-alcoholics with no infection or taking drugs affecting the liver. A higher prevalence of NAFLD was found among the metabolically unhealthy obese group (43.1%) and the metabolically unhealthy overweight (29.4%) than the metabolically unhealthy normal weight (11.8%). Mexicans-Americans had higher odds of NAFLD relative to whites (adjusted odds ratio (AOR) = 1.3, 95% confidence interval (CI) = 1.01-1.9, p = 0.04). The metabolically healthy obese phenotype was associated with NAFLD (p > 0.05) in the overall sample and in Whites. The metabolically healthy overweight was associated with NAFLD only among Mexican-American (p < 0.05). Metabolically unhealthy overweight or obese had higher odds of NAFLD relative to the metabolically healthy normal weight and this relation is consistent in all the racial/ethnic groups (p < 0.05). Metabolically healthy overweight and obese individuals had a high chance of NAFLD and it varied by race/ethnicity. Healthcare providers should pay more attention to care for those who are part of the metabolically healthy overweight or obese group especially among the Mexican-American population

    Data supporting "Nonlinear processing of a multicomponent communication signal by combination‑sensitive neurons in the anuran inferior colliculus"

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    This submission is a supplement to the paper entitled "Nonlinear processing of a multicomponent communication signal by combination-sensitive neurons in the anuran inferior colliculus" by Lee et al. (2017) published in the Journal of Comparative Physiology A. We investigated how female green treefrogs (Hyla cinerea) integrate multiple spectral components present in male advertisement calls. Typical calls have a bimodal spectrum consisting of low-frequency (0.9 kHz) and high-frequency (2.7 kHz) components that are transduced by different sensory organs in the inner ear. In behavioral experiments, only bimodal calls reliably elicited phonotaxis in no-choice tests, and they were selectively chosen over unimodal calls in two-alternative choice experiments. Single-unit recordings from the inferior colliculus of awake, passively listening subjects were classified as combination-insensitive (27.9%) or combination-sensitive units (72.1%) based on patterns of relative responses to the same bimodal and unimodal calls. Combination-insensitive units responded similarly to the bimodal call and one or both unimodal calls. In contrast, combination-sensitive units exhibited both linear responses and, more commonly, nonlinear responses to the spectral combination in the bimodal calls. Nonlinearities play potentially critical roles in spectral integration and in the neural processing of multicomponent communication signals. This submission includes source data used in generating the figures presented in the paper.National Science Foundation (NSF IOS-1452831

    Dietary quality, food security and glycemic control among adults with diabetes

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    Background and aimsNutritionally adequate diets can slow the progression of diabetes, but adherence to recommended dietary choices can be hindered by food insecurity. We examined the relationship between dietary quality, food insecurity, and glycemic control among adults with Type 2 Diabetes.MethodsWe analyzed data from the National Health and Nutrition Examination Survey (2011-2016) for 1682 adults =>20 years old with Type 2 diabetes. Glycemic control was measured by HbA1c. Dietary quality was computed using the Healthy Eating Index 2015 score. Food security was assessed by a questionnaire. We analyzed the data using multinomial regression models.ResultsAbout 16% of the population had an HbA1c â‰Ą 9; 31.8% had food insecurity; 68.3% consumed a poor quality diet. About 24% consumed a poor quality diet and had food insecurity. In the multinomial model, an HbA1c of 8-<9% was associated with poor diet quality (adjusted odds ratio (AOR) = 5.2, 95% confidence interval (CI) = 1.4-19.2, p = 0.01) and food insecurity (AOR = 8.5, 95% CI = 1.4-52.0, p = 0.02). Those with both factors had higher odds of both an HbA1c 8-<9% (AOR = 6.1, 95% CI = 1.5-24.8, p = 0.01) and HbA1c â‰Ą 9% (AOR = 6.7, 95% CI = 2.0-22.2, p < 0.01). Other risk factors for poor glycemic control were being Black or Hispanic, having no regular source of care, and ever having visited a diabetes specialist (p < 0.05).ConclusionsPoor glycemic control among adults with diabetes was associated with poor quality of diet and/or food insecurity, being Black, Hispanic, and lacking a regular source of care. There is a need for policies that improve access to healthy food in patients with type 2 diabetes, particularly among minority populations

    Sex bias in basic and preclinical age-related hearing loss research

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    Abstract Objectives This study aims to determine if there is sex bias in basic and preclinical research on age-related hearing loss for the 10-year period of 2006–2015, prior to the NIH mandate of including sex as a biological variable in 2016. Design Manuscripts were identified in PubMed for the query “age-related hearing loss” for the 10-year period of 2006 to 2015. Manuscripts were included if they were original research (not reviews or meta-analyses), written in English, contained an abstract, used animals, and were primarily on age-related hearing loss. These criteria yielded 231 unique manuscripts for inclusion in the study analysis. The text of each manuscript was screened for the sex of the animals, the number of male and female animals, the discussion of sex-based results, the study site (US or international), and the year of publication. Results Only two thirds of manuscripts reported the sex of animals used in the experiments, and of these, 54% used both sexes, 34% used males only, and 13% used females only. In papers reporting sex and number of animals used, 67% were males and 33% were females. Over twice as many internationally based studies used males only compared to US-based studies. Only 15% of all manuscripts discussed sex-based results. Conclusions Sex bias is present in basic and preclinical age-related hearing loss research for the manuscripts screened in the 10-year period. Equal inclusion of both males and females in basic and preclinical age-related hearing loss research is critical for understanding sex-based differences in mechanisms and for effective treatment options

    Data supporting "Vocal sacs do not act as visual cues in acoustically guided courtship in Cope’s gray treefrog (Hyla chrysoscelis)"

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    Components in multiple sensory modalities are present in many animal signals, which provides opportunities for receivers to use them as complementary cues in communication, especially in noisy environments that impose difficulty on signal perception. In frogs, it has been suspected that females use the visual byproduct of call production - the inflation of vocal sacs - as a cue in finding individual calling males in loud choruses. This mate recognition and selection behavior was traditionally considered as acoustically guided but recently there has been rising discussion on whether it was a multimodal process. We investigated whether female Cope’s gray treefrog (Hyla chrysoscelis) use visual cues in the context of sexual communication to find and select males. We performed playback experiments in a field setting under natural light using robotic frog models as visual stimuli and examined females’ responses. Acoustic stimuli were played back in quiet, in noise, and with ambiguous acoustic features. Despite the various acoustic conditions tested in a realistic lighting environment, we did not find any evidence that females use visual cues in the context of sexual communication. We review previous reports on the use of vocal sacs as visual cues in nocturnal anurans and discuss potential reasons for the stark contrast between those reports and this research

    Racial/ethnic and gender disparity in the severity of NAFLD among people with diabetes or prediabetes

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    Aim: Non-alcoholic fatty liver disease (NAFLD) exhibits a racial disparity. We examined the prevalence and the association between race, gender, and NAFLD among prediabetes and diabetes populations among adults in the United States. Methods: We analyzed data for 3,190 individuals ≥18 years old from the National Health and Nutrition Examination Survey (NHANES) 2017–2018. NAFLD was diagnosed by FibroScan® using controlled attenuation parameter (CAP) values: S0 (none) \u3c 238, S1 (mild) = 238–259, S2 (moderate) = 260–290, S3 (severe) \u3e 290. Data were analyzed using Chi-square test and multinomial logistic regression, adjusting for confounding variables and considering the design and sample weights. Results: Of the 3,190 subjects, the prevalence of NAFLD was 82.6%, 56.4%, and 30.5% (p \u3c 0.0001) among diabetes, prediabetes and normoglycemia populations respectively. Mexican American males with prediabetes or diabetes had the highest prevalence of severe NAFLD relative to other racial/ethnic groups (p \u3c 0.05). In the adjusted model, among the total, prediabetes, and diabetes populations, a one unit increase in HbA1c was associated with higher odds of severe NAFLD [adjusted odds ratio (AOR) = 1.8, 95% confidence level (CI) = 1.4–2.3, p \u3c 0.0001; AOR = 2.2, 95% CI = 1.1–4.4, p = 0.033; and AOR = 1.5, 95% CI = 1.1–1.9, p = 0.003 respectively]. Conclusion: We found that prediabetes and diabetes populations had a high prevalence and higher odds of NAFLD relative to the normoglycemic population and HbA1c is an independent predictor of NAFLD severity in prediabetes and diabetes populations. Healthcare providers should screen prediabetes and diabetes populations for early detection of NAFLD and initiate treatments including lifestyle modification to prevent the progression to non-alcoholic steatohepatitis or liver cancer
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