240 research outputs found

    Ethnopharmacology, Ethnomedicine, and Wildlife Conservation

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    Ethnopharmacological relevance: There are longstanding traditions of animal-derived products being employed as medicines, and they continue to be important in many traditional cultural healthcare practices. However, the populations of numerous so-used animals are known to be threatened with extirpation by such practices. Ethnopharmacological studies documenting these animal-derived drug products are not only interesting from an anthropological standpoint, but they are also relevant from a wildlife conservation perspective - especially since ethnopharmacologists are intermediaries between indigenous and scientific communities, placing them at the forefront of being able to ethically access information to address these issues. Methods: Using the example of documenting culturally acceptable substitute materials for animal products (which ultimately also extends to flora), we explore the intersection of ethnopharmacology, biocultural resources, and wildlife conservation. Results: Pharmacological efficacy and symbolism are factors influencing the utilization of traditional medicines. Achieving the integration of conservation aims with ethnopharmacology requires a nuanced understanding of both factors, along with fair adjudication when conservation and cultural aims diverge. Ethnopharmacology is suitably placed for making conservation-orientated recommendations - including investigating more sustainable substitutes for animal products in the context of medical efficacy, and for engaging ethically with local communities to facilitate information generation aimed at protecting the environment and their traditions. Conclusion: We suggest an integrative approach to ethnopharmacological studies investigating medicinal bioresource use. This approach is considerate of species' conservation profiles, the substitutability and pharmacological efficacy of biocultural resources, indigenous and cultural rights, and a collaborative ethos for stakeholder engagement

    Dielectrophoresis of charged colloidal suspensions

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    We present a theoretical study of dielectrophoretic (DEP) crossover spectrum of two polarizable particles under the action of a nonuniform AC electric field. For two approaching particles, the mutual polarization interaction yields a change in their respective dipole moments, and hence, in the DEP crossover spectrum. The induced polarization effects are captured by the multiple image method. Using spectral representation theory, an analytic expression for the DEP force is derived. We find that the mutual polarization effects can change the crossover frequency at which the DEP force changes sign. The results are found to be in agreement with recent experimental observation and as they go beyond the standard theory, they help to clarify the important question of the underlying polarization mechanisms

    Validation of a 16th Century Traditional Chinese Medicine Use of Ginkgo biloba as a Topical Antimicrobial

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    In the search for new therapeutic solutions to address an increasing number of multidrug-resistant bacterial pathogens, secondary metabolites from plants have proven to be a rich source of antimicrobial compounds. Ginkgo biloba, a tree native to China, has been spread around the world as an ornamental tree. Its seeds have been used as snacks and medical materials in Traditional Chinese Medicine (TCM), while over the last century its leaf extracts emerged as a source of rising pharmaceutical commerce related to brain health in Western medicine. Besides studies on the neuro-protective effects of Ginkgo, its antibacterial activities have gained more attention from researchers in the past decades, though its leaves were the main focus. We reviewed a 16th-century Chinese text, the Ben Cao Gang Mu by Li Shi-Zhen, to investigate the ancient prescription of Ginkgo seeds for skin infections. We performed antibacterial assays on various Ginkgo seed extracts against pathogens (Staphylococcus aureus, Cutibacterium acnes, Klebsiella pneumoniae, Acinetobacter baumannii, Streptococcus pyogenes) relevant to skin and soft tissue infections (SSTIs). We demonstrate here that Ginkgo seed coats and immature seeds exhibit antibacterial activity against Gram-positive skin pathogens (C. acnes, S. aureus, and S. pyogenes), and thus validated its use in TCM. We also identified one compound tied to the antibacterial activity observed, ginkgolic acid C15:1, and examine its toxicity to human keratinocytes. These results highlight the relevance of ancient medical texts as leads for the discovery of natural products with antimicrobial activities

    Characterization of Fabric-to-Fabric Friction: Application to Medical Compression Bandages

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    Fabric-to-fabric friction is involved in the action mechanism of medical compression devices such as compression bandages or lumbar belts. To better understand the action of such devices, it is essential to characterize, in their use conditions (mainly pressure and stretch), the frictional properties of the fabrics they are composed of. A characterization method of fabric-to-fabric friction was developed. This method was based on the customization of the fourth instrument of the Kawabata Evaluation System, initially designed for fabric roughness and friction characterization. A friction contactor was developed so that the stretch of the fabric and the applied load can vary to replicate the use conditions. This methodology was implemented to measure the friction coefficient of several medical compression bandages. In the ranges of pressure and bandage stretch investigated in the study, bandage-to-bandage friction coefficient showed very little variation. This simple and reliable method, which was tested for commercially available medical compression bandages, could be used for other medical compression fabrics

    Polarimetric interferometer for nanoscale positioning applications

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    International audienceWe propose and demonstrate a displacement control method at the subnanometric scale based on a Michelson interferometer combined with a polarimeter and a phase-locked loop electronic board. Step by step displacements with a step value of 5 nm are presented. A repeatability of 0.47 nm is obtained from back and forth displacements over 1 m range. We show that a residual ellipticity of less than 10° on the polarization state leads to a positioning error of less than 1 nm. Such system could be used over millimeter range displacements in a controlled surrounding environment leading to numerous applications in nanometrology

    Compact and accurate concept of laser wavemeters based on ellipsometry

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    Common laser wavemeters are based on a scanning Michelson interferometer. Displacements of the moving mirror as long as tens of centimeters are needed to reach a relative accuracy of 1 × 10−6 (1σ) on the unknown laser wavelengths. Such a long displacement range makes the system very sensitive to mechanical vibrations and to misalignments of the laser beams. The purpose of this paper is to demonstrate a new concept of laser wavemeter based on the measurements of the ellipsometric parameters ψ and of the laser beams. Experimental results show that a 10−6 (1σ) accuracy level could be reach with a displacement range of only 4 ÎŒm. Implementations of the device are described. Comparisons between our polarimetric wavemeter and a calibrated wavemeter are presented for two lasers, an extended cavity laser diode at 656 nm and a 532 nm green line Nd:YAG laser

    Beyond the personal–anonymous divide: agency relations in powers of attorney in France in the eighteenth and nineteenth centuries

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    Powers of attorney are often interpreted as evidence of trust among the parties involved. We build a novel dataset of notarized powers of attorney, capturing a wide variety of agency relationships in four large French commercial cities in the eighteenth and nineteenth centuries, to test hypotheses on the relational basis of economic relationships. We find little support for the idea of a radical shift from personal to anonymous relationships during our period. Our results point to more nuanced transformations. The preference for proxies in the same occupation as the principal somewhat declined, while professional proxies emerged and principals used relational chains, especially involving notaries, to find proxies.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151849/1/ehr12784_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151849/2/ehr12784.pd

    Farm management factors associated with bulk tank somatic cell count in Irish dairy herds

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    The relationship between bulk tank somatic cell count (SCC) and farm management and infrastructure was examined using data from 398 randomly selected, yet representative, Irish dairy farms where the basal diet is grazed grass. Median bulk tank SCC for the farms was 282,887 cells/ml ranging from 82,209 to 773,028 cells/ml. Two questionnaires were administered through face-to-face contact with each farmer. Herd-level factors associated with bulk tank SCC were determined using linear models with annual somatic cell score (i.e., arithmetic mean of the natural logarithm of bulk tank SCC) included as the dependent variable. All herd level factors were analysed individually in separate regression models, which included an adjustment for geographical location of the farm; a multiple regression model was subsequently developed. Management practices associated with low SCC included the use of dry cow therapy, participation in a milk recording scheme and the use of teat disinfection post-milking. There was an association between low SCC and an increased level of hygiene and frequency of cleaning of the holding yard, passageways and cubicles. Herd management factors associated with bulk tank SCC in Irish grazing herds are generally in agreement with most previous studies from confinement systems of milk production

    Massive stars exploding in a He-rich circumstellar medium. I. Type Ibn (SN 2006jc-like) events

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    We present new spectroscopic and photometric data of the type Ibn supernovae 2006jc, 2000er and 2002ao. We discuss the general properties of this recently proposed supernova family, which also includes SN 1999cq. The early-time monitoring of SN 2000er traces the evolution of this class of objects during the first few days after the shock breakout. An overall similarity in the photometric and spectroscopic evolution is found among the members of this group, which would be unexpected if the energy in these core-collapse events was dominated by the interaction between supernova ejecta and circumstellar medium. Type Ibn supernovae appear to be rather normal type Ib/c supernova explosions which occur within a He-rich circumstellar environment. SNe Ibn are therefore likely produced by the explosion of Wolf-Rayet progenitors still embedded in the He-rich material lost by the star in recent mass-loss episodes, which resemble known luminous blue variable eruptions. The evolved Wolf-Rayet star could either result from the evolution of a very massive star or be the more evolved member of a massive binary system. We also suggest that there are a number of arguments in favour of a type Ibn classification for the historical SN 1885A (S-Andromedae), previously considered as an anomalous type Ia event with some resemblance to SN 1991bg.Comment: 17 pages including 12 figures and 4 tables. Slightly revised version, conclusions unchanged, 1 figure added. Accepted for publication in MNRA
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