15 research outputs found
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Long-term and persistent vocal plasticity in adult bats.
Bats exhibit a diverse and complex vocabulary of social communication calls some of which are believed to be learned during development. This ability to produce learned, species-specific vocalizations - a rare trait in the animal kingdom - requires a high-degree of vocal plasticity. Bats live extremely long lives in highly complex and dynamic social environments, which suggests that they might also retain a high degree of vocal plasticity in adulthood, much as humans do. Here, we report persistent vocal plasticity in adult bats (Rousettus aegyptiacus) following exposure to broad-band, acoustic perturbation. Our results show that adult bats can not only modify distinct parameters of their vocalizations, but that these changes persist even after noise cessation - in some cases lasting several weeks or months. Combined, these findings underscore the potential importance of bats as a model organism for studies of vocal plasticity, including in adulthood
Let’s Visit Harford County
Final project for INST710: User Research Methods (Fall 2018).
University of Maryland, College Park.Harford Count
Transactivation and signaling functions of Tat are not correlated: biological and immunological characterization of HIV-1 subtype-C Tat protein
BACKGROUND: Of the diverse subtypes of Human Immunodeficiency Virus Type-1 (HIV-1), subtype-C strains cause a large majority of infections worldwide. The reasons for the global dominance of HIV-1 subtype-C infections are not completely understood. Tat, being critical for viral infectivity and pathogenesis, may differentially modulate pathogenic properties of the viral subtypes. Biochemical studies on Tat are hampered by the limitations of the current purification protocols. Tat purified using standard protocols often is competent for transactivation activity but defective for a variety of other biological functions. Keeping this limitation in view, we developed an efficient protein purification strategy for Tat. RESULTS: Tat proteins obtained using the novel strategy described here were free of contaminants and retained biological functions as evaluated in a range of assays including the induction of cytokines, upregulation of chemokine coreceptor, transactivation of the viral promoter and rescue of a Tat-defective virus. Given the highly unstable nature of Tat, we evaluated the effect of the storage conditions on the biological function of Tat following purification. Tat stored in a lyophilized form retained complete biological activity regardless of the storage temperature. To understand if variations in the primary structure of Tat could influence the secondary structure of the protein and consequently its biological functions, we determined the CD spectra of subtype-C and -B Tat proteins. We demonstrate that subtype-C Tat may have a relatively higher ordered structure and be less flexible than subtype-B Tat. We show that subtype-C Tat as a protein, but not as a DNA expression vector, was consistently inferior to subtype-B Tat in a variety of biological assays. Furthermore, using ELISA, we evaluated the anti-Tat antibody titers in a large number of primary clinical samples (n = 200) collected from all four southern Indian states. Our analysis of the Indian populations demonstrated that Tat is non-immunodominant and that a large variation exists in the antigen-specific antibody titers. CONCLUSION: Our report not only describes a simple protein purification strategy for Tat but also demonstrates important structural and functional differences between subtype-B and -C Tat proteins. Furthermore, this is the first report of protein purification and characterization of subtype-C Tat
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Phase 1 doseâ finding study of metformin in combination with concurrent cisplatin and radiotherapy in patients with locally advanced head and neck squamous cell cancer
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153201/1/cncr32539.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/153201/2/cncr32539_am.pd
Comparative Effect of Atorvastatin and Trigonella foenum graecum L. Seeds in the Postmenopausal Hyperlipidemia
Trigonella foenum graecum L. (Fabaceae) seeds have been extensively used in Ayurveda and Unani medicine. It has been used as a traditional medicine for a household remedy against various human ailments. The seeds have been shown to possess hypoglycemic, hypocholesterolaemic and antioxidant activity. The present study is to evaluate whether ovariectomised (OVX) Wistar rats could form an experimental model of postmenopausal hyperlipidemia and to evaluate the antihyperlipidemic potential of Atorvastatin (AT) and Ethyl acetate extract of Trigonella foenum graecum L. Seeds (ET) in OVX Wistar rats and toxicity associated with it. Ovariectomy was performed to mimic the postmenopausal hyperlipidemic condition in Wistar rats. The effects of AT and ET on body weight, weight of uterus and the levels of total cholesterol (TC), triglycerides (TG), high density lipoproteins (HDL), low density lipoproteins (LDL), very low density lipoprotein (VLDL) were also evaluated. The rats in OVX control group showed 51% weight gain when compared with vehicle control group. The serum TC, TG, LDL, VLDL of OVX control group was found to be increased significantly; serum HDL level was reduced and atrophy of uterus was observed in comparison with vehicle control group. The ET showed the significant (P<0.05, P<0.01) antihyperlipidemic potency when compared with AT & proportional antihyperlipidemic potency in comparison with Estradiol benzoate (EB). These findings confirm the bilateral OVX Wistar rats as a model of postmenopausal hypercholesterolemia. The significant antihyperlipidemic activity of ET thus lends pharmacological credence to the suggested use of the plant as a safe natural remedy in the treatment of postmenopausal hyperlipidemia
Comparative Effect of Atorvastatin and Trigonella foenum graecum L. Seeds in the Postmenopausal Hyperlipidemia
Trigonella foenum graecum L. (Fabaceae) seeds have been extensively used in Ayurveda and Unani medicine. It has been used as a traditional medicine for a household remedy against various human ailments. The seeds have been shown to possess hypoglycemic, hypocholesterolaemic and antioxidant activity. The present study is to evaluate whether ovariectomised (OVX) Wistar rats could form an experimental model of postmenopausal hyperlipidemia and to evaluate the antihyperlipidemic potential of Atorvastatin (AT) and Ethyl acetate extract of Trigonella foenum graecum L. Seeds (ET) in OVX Wistar rats and toxicity associated with it. Ovariectomy was performed to mimic the postmenopausal hyperlipidemic condition in Wistar rats. The effects of AT and ET on body weight, weight of uterus and the levels of total cholesterol (TC), triglycerides (TG), high density lipoproteins (HDL), low density lipoproteins (LDL), very low density lipoprotein (VLDL) were also evaluated. The rats in OVX control group showed 51% weight gain when compared with vehicle control group. The serum TC, TG, LDL, VLDL of OVX control group was found to be increased significantly; serum HDL level was reduced and atrophy of uterus was observed in comparison with vehicle control group. The ET showed the significant (P<0.05, P<0.01) antihyperlipidemic potency when compared with AT & proportional antihyperlipidemic potency in comparison with Estradiol benzoate (EB). These findings confirm the bilateral OVX Wistar rats as a model of postmenopausal hypercholesterolemia. The significant antihyperlipidemic activity of ET thus lends pharmacological credence to the suggested use of the plant as a safe natural remedy in the treatment of postmenopausal hyperlipidemia