2,349 research outputs found

    Ethnomedicine of the Kagera Region, north western Tanzania. Part 3: plants used in traditional medicine in Kikuku village, Muleba District.

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    BACKGROUND\ud \ud The Kagera region of north western Tanzania has a rich culture of traditional medicine use and practice. Traditional medicines are the mainstay of healthcare in this region and are known to support the management of many illnesses such as malaria, bacterial infections, epilepsy, gynecological problems and others. However, most of the plants being used have either not been documented or evaluated for safety and efficacy or both. This study, the sixth of an ongoing series, reports on the medicinal plants that are used at Kikuku village, Muleba District.\ud \ud METHODOLOGY\ud \ud A semi-structured questionnaire was used to collect information on the common/local names of the plants, parts of the plants used, diseases treated, methods of preparing the herbal remedies, dosage of the remedies administered, frequency and duration of treatment and toxicity of the medicines. A literature review was carried out for information on the ethnomedical uses of the reported plants.\ud \ud RESULTS\ud \ud A total of 49 plant species belonging to 47 genera and 24 plant families were documented. The family Euphorbiaceae and Asteraceae had the highest representation. The plants are used for the treatment of skin conditions (10 plants; 20%), bacterial infections and wounds (14 plants; 28.6%), malaria (14 plants; 28.6%), gastrointestinal disorders (11 plants; 22.4%), gynecological problems including infertility (8 plants; 16.3%), hypertension (5 plants; 10.2%), viral infections (7 plants; 14.3%), chest problems (5 plants; 10.2%), diabetes (3 plants; 6.1%), cancer (2 plants; 4.1%), inflammatory conditions (arthritis, rheumatism), HIV and AIDS, and hernia each treated by 1 plant (3 plants in total; 6.1%). Information obtained from the literature indicate that 25 (51.0%) of the therapeutic claims are supported by laboratory results or have similar claims of ethnomedical use from other countries.\ud \ud CONCLUSION\ud \ud Herbal remedies comprise an important and effective component of the healthcare system in Kikuku village with plants in the families Euphorbiaceae and Asteraceae comprising an important part of plants used in the indigenous healthcare management in the village. Malaria and bacterial infections dominate the list of diseases that are managed using traditional medicines

    Human Deoxycytidine Kinase Is a Valuable Biocatalyst for the Synthesis of Nucleotide Analogues

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    Natural ribonucleoside-5’-monophosphates are building blocks for nucleic acids which are used for a number of purposes, including food additives. Their analogues, additionally, are used in pharmaceutical applications. Fludarabine-5®-monophosphate, for example, is effective in treating hematological malignancies. To date, ribonucleoside-5’-monophosphates are mainly produced by chemical synthesis, but the inherent drawbacks of this approach have led to the development of enzymatic synthesis routes. In this study, we evaluated the potential of human deoxycytidine kinase (HsdCK) as suitable biocatalyst for the synthesis of natural and modified ribonucleoside-5’-monophosphates from their corresponding nucleosides. Human dCK was heterologously expressed in E. coli and immobilized onto Nickel-nitrilotriacetic acid (Ni-NTA) superflow. A screening of the substrate spectrum of soluble and immobilized biocatalyst revealed that HsdCK accepts a wide range of natural and modified nucleosides, except for thymidine and uridine derivatives. Upon optimization of the reaction conditions, HsdCK was used for the synthesis of fludarabine-5®-monophosphate using increasing substrate concentrations. While the soluble biocatalyst revealed highest product formation with the lowest substrate concentration of 0.3 mM, the product yield increased with increasing substrate concentrations in the presence of the immobilized HsdCK. Hence, the application of immobilized HsdCK is advantageous upon using high substrate concentration which is relevant in industrial applications.DFG, 392246628, Chemo-enzymatische Synthese von Selen-modifizierten Nukleosiden, Nukleotiden und OligonukleotidenTU Berlin, Open-Access-Mittel - 201

    Only a burden for females in math? Gender and domain differences in the relation between adolescents’ fixed mindsets and motivation

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    Gendered occupational and educational choices have often been traced back to gender differences in students’ domain-specific ability self-concept and intrinsic motivation. This study explored the role of believing in an “innate” math or language arts ability (i.e., having a fixed mindset) for gender differences in students’ ability self-concept and intrinsic motivation in 423 female (49%) and 447 male (51%) tenth graders from Germany (age M = 16.09 years, SD = 0.68, range: 14–18 years). In line with math-male stereotypes, believing in “innate” math ability was associated with lower ability self-concept and intrinsic motivation in female but not male students. In language arts, students’ mindsets were unrelated to their motivation. The results suggest that a fixed mindset presents an additional burden for female students in math, but not for male or female students in language arts

    Seebeck coefficients of half-metallic ferromagnets

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    In this report the Co2 based Heusler compounds are discussed as potential materials for spin voltage generation. The compounds were synthesized by arcmelting and consequent annealing. Band structure calculations were performed and revealed the compounds to be half-metallic ferromagnets. Magnetometry was performed on the samples and the Curie temperatures and the magnetic moments were determined. The Seebeck coefficients were measured from low to ambient temperatures for all compounds. For selected compounds high temperature measurements up to 900 K were performed.Comment: accepted contribution o the Special Issue "Spin Caloritronics" of Solid State Communication

    Efficient Biocatalytic Synthesis of Dihalogenated Purine Nucleoside Analogues Applying Thermodynamic Calculations

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    The enzymatic synthesis of nucleoside analogues has been shown to be a sustainable and efficient alternative to chemical synthesis routes. In this study, dihalogenated nucleoside analogues were produced by thermostable nucleoside phosphorylases in transglycosylation reactions using uridine or thymidine as sugar donors. Prior to the enzymatic process, ideal maximum product yields were calculated after the determination of equilibrium constants through monitoring the equilibrium conversion in analytical-scale reactions. Equilibrium constants for dihalogenated nucleosides were comparable to known purine nucleosides, ranging between 0.071 and 0.081. To achieve 90% product yield in the enzymatic process, an approximately five-fold excess of sugar donor was needed. Nucleoside analogues were purified by semi-preparative HPLC, and yields of purified product were approximately 50% for all target compounds. To evaluate the impact of halogen atoms in positions 2 and 6 on the antiproliferative activity in leukemic cell lines, the cytotoxic potential of dihalogenated nucleoside analogues was studied in the leukemic cell line HL-60. Interestingly, the inhibition of HL-60 cells with dihalogenated nucleoside analogues was substantially lower than with monohalogenated cladribine, which is known to show high antiproliferative activity. Taken together, we demonstrate that thermodynamic calculations and small-scale experiments can be used to produce nucleoside analogues with high yields and purity on larger scales. The procedure can be used for the generation of new libraries of nucleoside analogues for screening experiments or to replace the chemical synthesis routes of marketed nucleoside drugs by enzymatic processes.DFG, 390540038, EXC 2008: UniSysCatDFG, 414044773, Open Access Publizieren 2019 - 2020 / Technische UniversitÀt Berli

    Neural Mechanisms of Anaphoric Reference Revealed by fMRI

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    Pronouns are bound to their antecedents by matching syntactic and semantic information. The aim of this functional magnetic resonance imaging study was to localize syntactic and semantic information retrieval and integration during pronoun resolution. Especially we investigated their possible interaction with verbal working memory manipulated by distance between antecedent and pronoun. We disentangled biological and syntactic gender information using German sentences about persons (biological/syntactic gender) or things (syntactic gender) followed by congruent or incongruent pronouns. Increasing the distance between pronoun and antecedent resulted in a short and a long distance condition. Analysis revealed a language related network including inferior frontal regions bilaterally (integration), left anterior and posterior temporal regions (lexico-semantics and syntactic retrieval) and the anterior cingulate gyrus (conflict resolution) involved in pronoun resolution. Activities within the inferior frontal region were driven by Congruency (incongruent > congruent) and Distance (long > short). Temporal regions were sensitive to Distance and Congruency (but solely within long distant conditions). Furthermore, anterior temporal regions were sensitive to the antecedent type with an increased activity for person pronouns compared to thing pronouns. We suggest that activity modulations within these areas reflect the integration process of an appropriate antecedent which depends on the type of information that has to be retrieved (lexico-syntactic posterior temporal, lexico-semantics anterior temporal). It also depends on the overall syntactic and semantic complexity of long distant sentences. The results are interpreted in the context of the memory–unification-control model for sentence comprehension as proposed by Vosse and Kempen (2000), Hagoort (2005), and Snijders et al. (2009)

    Neural correlates of semantic and syntactic processes in the comprehension of case marked pronouns: Evidence from German and Dutch

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    BACKGROUND: It is well known that both semantic and syntactic information play a role in pronoun resolution in sentences. However, it is unclear what the relative contribution of these sources of information is for the establishment of a coreferential relationship between the pronoun and the antecedent in combination with a local structural case constraint on the pronoun (i.e. case assignment of a pronoun under preposition governing). In a prepositional phrase in German and Dutch, it is the preposition that assigns case to the pronoun. Furthermore, in these languages different overtly case-marked pronouns are used to refer to male and female persons. Thus, one can manipulate biological/syntactic gender features separately from case marking features. The major aim of this study was to determine what the influence of gender information in combination with a local structural case constraint is on the processing of a personal pronoun in a sentence. Event-related brain potential (ERP) experiments were performed in German and in Dutch. In a word by word sentence reading study in German and Dutch, gender congruency between the antecedent and the pronoun was manipulated and/or case assignment by the preposition was violated while ERPs of young native speakers were recorded. RESULTS: The German and the Dutch ERP data showed an enlarged negativity broadly distributed starting approximately 350 ms after onset of the pronoun followed by a late positivity for gender violations. For syntactic incongruencies without gender violations only a positivity was present. The Dutch data showed an earlier onset of the positivity in comparison to German. CONCLUSION: Finding negativities and positivities for conditions with a gender violation indicates that pronoun resolution with gender incongruency between the pronoun and the antecedent suffers from semantic as well as syntactic integration problems. The presence of a positivity for the syntactically incongruent conditions without gender violations suggests that the processing of incorrect case marking without a gender violation gives rise to syntactic but not semantic integration problems. We suggest that the more prominent case violation in Dutch caused the earlier onset of the positivity in the Dutch study. In addition, the pattern of ERP effects shows that both case and gender information are used almost immediately implying that the local structural constraint affects the resolution process with more processing activity than for a pronoun of which only one source of information is violated or incongruent

    Ethnomedicine of the Kagera Region, north western Tanzania. Part 2: The medicinal plants used in Katoro Ward, Bukoba District

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    \ud The Kagera region of north western Tanzania has a rich culture of traditional medicine use and practices. The dynamic inter-ethnic interactions of different people from the surrounding countries constitute a rich reservoir of herbal based healing practices. This study, the second in an ongoing series, reports on the medicinal plant species used in Katoro ward, Bukoba District, and tries to use the literature to establish proof of the therapeutic claims. Ethnomedical information was collected using semi-structured interviews in Kyamlaile and Kashaba villages of Katoro, and in roadside bushes on the way from Katoro to Bukoba through Kyaka. Data collected included the common/local names of the plants, parts used, the diseases treated, methods of preparation, dosage, frequency and duration of treatments. Information on toxicity and antidote were also collected. Literature was consulted to get corroborative information on similar ethnomedical claims and proven biological activities of the plants. Thirty three (33) plant species for treatment of 13 different disease categories were documented. The most frequently treated diseases were those categorized as specific diseases/conditions (23.8% of all remedies) while eye diseases were the least treated using medicinal plants (1.5% of all remedies). Literature reports support 47% of the claims including proven anti-malarial, anti-microbial and anti-inflammatory activity or similar ethnomedical uses. Leaves were the most frequently used plant part (20 species) followed by roots (13 species) while making of decoctions, pounding, squeezing, making infusions, burning and grinding to powder were the most common methods used to prepare a majority of the therapies. Therapeutic claims made on plants used in traditional medicine in Katoro ward of Bukoba district are well supported by literature, with 47% of the claims having already been reported. This study further enhances the validity of plants used in traditional medicine in this region as resources that can be relied on to provide effective, accessible and affordable basic healthcare to the local communities. The plants documented also have the potential of being used in drug development and on farm domestication initiatives.\u

    Interactive audio-tactile maps for visually impaired people

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    International audienceVisually impaired people face important challenges related to orientation and mobility. Indeed, 56% of visually impaired people in France declared having problems concerning autonomous mobility. These problems often mean that visually impaired people travel less, which influences their personal and professional life and can lead to exclusion from society. Therefore this issue presents a social challenge as well as an important research area. Accessible geographic maps are helpful for acquiring knowledge about a city's or neighborhood's configuration, as well as selecting a route to reach a destination. Traditionally, raised-line paper maps with braille text have been used. These maps have proved to be efficient for the acquisition of spatial knowledge by visually impaired people. Yet, these maps possess significant limitations. For instance, due to the specificities of the tactile sense only a limited amount of information can be displayed on a single map, which dramatically increases the number of maps that are needed. For the same reason, it is difficult to represent specific information such as distances. Finally, braille labels are used for textual descriptions but only a small percentage of the visually impaired population reads braille. In France 15% of blind people are braille readers and only 10% can read and write. In the United States, fewer than 10% of the legally blind people are braille readers and only 10% of blind children actually learn braille. Recent technological advances have enabled the design of interactive maps with the aim to overcome these limitations. Indeed, interactive maps have the potential to provide a broad spectrum of the population with spatial knowledge, irrespective of age, impairment, skill level, or other factors. To this regard, they might be an efficient means for providing visually impaired people with access to geospatial information. In this paper we give an overview of our research on making geographic maps accessible to visually impaired people
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