Gating energies and forces of the mammalian hair cell transducer channel and related hair bundle mechanics

NARCIS (Netherlands)

van Netten, SM; Kros, CJ

2000-01-01

We quantified the molecular energies and forces involved in opening and closing of mechanoelectrical transducer channels in hair cells using a novel generally applicable method. It relies on a thermodynamic description of the free energy of an ion channel in terms of its open probability. The

Hair cell regeneration in the bullfrog vestibular otolith organs following aminoglycoside toxicity

Science.gov (United States)

Baird, Richard A.; Torres, M. A.; Schuff, N. R.

1994-01-01

Adult bullfrogs were given single intraotic injections of the aminoglycoside antibiotic gentamicin sulfate and sacrificed at postinjection times ranging from 0.5 to 9 days. The saccular and utricular maculae of normal and injected animals were examined in wholemount and cross-section. Intraotic 200 (mu) M gentamicin concentrations resulted in the uniform destruction of the hair bundles and, at later times, the cell bodies of saccular hair cells. In the utriculus, striolar hair cells were selectively damaged while extrastriolar hair cells were relatively unaffected. Regenerating hair cells, identified in sectioned material by their small cell bodies and short, well-formed hair bundles, were seen in the saccular and utricular maculae as early as 24-48 h postinjection. Immature versions of mature hair cell types in both otolith organs were recognized by the presence of absence of a bulbed kinocilia and the relative lengths of their kinocilia and longest sterocilia. Utricular hair cell types with kinocilia longer than their longest stereocilia were observed at earlier times than hair cell types with shorter kinocilia. In the same sacculus, the hair bundles of gentamicin-treated animals, even at 9 days postinjection, were significantly smaller than those of normal animals. The hair bundles of utricular hair cells, on the other hand, reached full maturity within the same time period.

Auditory Mechanics of the Tectorial Membrane and the Cochlear Spiral

Science.gov (United States)

Gavara, Núria; Manoussaki, Daphne; Chadwick, Richard S.

2012-01-01

Purpose of review This review is timely and relevant since new experimental and theoretical findings suggest that cochlear mechanics from the nanoscale to the macroscale are affected by mechanical properties of the tectorial membrane and the spiral shape. Recent findings Main tectorial membrane themes covered are i) composition and morphology, ii) nanoscale mechanical interactions with the outer hair cell bundle, iii) macroscale longitudinal coupling, iv) fluid interaction with inner hair cell bundles, v) macroscale dynamics and waves. Main cochlear spiral themes are macroscale low-frequency energy focusing and microscale organ of Corti shear gain. Implications Findings from new experimental and theoretical models reveal exquisite sensitivity of cochlear mechanical performance to tectorial membrane structural organization, mechanics, and its positioning with respect to hair bundles. The cochlear spiral geometry is a major determinant of low frequency hearing. Suggestions are made for future research directions. PMID:21785353

Relativistic rotators: a quantum mechanical de Sitter bundle

International Nuclear Information System (INIS)

Boehm, A.

1976-02-01

If de Sitter fiber bundle over space time is the classical picture of hadrons then for a quantum mechanical description one has to generalize the concept of a principal fiber bundle to a bundle that contains the representation of the group of motion. This idea is related to the relativistic rotator model, and the radius of the de Sitter fiber is determined from the experimental hadron spectrum

Drive mechanisms to the inner and outer hair cell stereocilia

Science.gov (United States)

Maftoon, Nima; Motallebzadeh, Hamid; Guinan, John J.; Puria, Sunil

2018-05-01

It has been long believed that inner hair cell (IHC) stimulation can be gleaned from the classic ter-Kuile shear motion between the reticular lamina (RL) and tectorial membrane (TM). The present study explores this and other IHC stimulation mechanisms using a finite-element-model representation of an organ of Corti (OoC) cross section with fluid-structure interaction. A 3-D model of a cross section of the OoC including soft tissue and the fluid in the sub-tectorial space, tunnel of Corti and above the TM was formulated based on anatomical measurements from the gerbil apical turn. The outer hair cells (OHCs), Deiter's cells and their phalangeal processes are represented as Y-shaped building-block elements. Each of the IHC and OHC bundles is represented by a single sterocilium. Linearized Navier-Stokes equations coupled with linear-elastic equations discretized with tetrahedral elements are solved in the frequency domain. We evaluated the dynamic changes in the OoC motion including sub-tectorial gap dimensions for 0.1 to 10 kHz input frequencies. Calculations show the classic ter-Kuile motion but more importantly they show that the gap-height changes which produce oscillatory radial flow in the subtectorial space. Phase changes in the stereocilia across OHC rows and the IHC are also observed.

Mechanically Gated Ion Channels in Mammalian Hair Cells

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Xufeng Qiu

2018-04-01

Full Text Available Hair cells in the inner ear convert mechanical stimuli provided by sound waves and head movements into electrical signal. Several mechanically evoked ionic currents with different properties have been recorded in hair cells. The search for the proteins that form the underlying ion channels is still in progress. The mechanoelectrical transduction (MET channel near the tips of stereociliary in hair cells, which is responsible for sensory transduction, has been studied most extensively. Several components of the sensory mechanotransduction machinery in stereocilia have been identified, including the multi-transmembrane proteins tetraspan membrane protein in hair cell stereocilia (TMHS/LHFPL5, transmembrane inner ear (TMIE and transmembrane channel-like proteins 1 and 2 (TMC1/2. However, there remains considerable uncertainty regarding the molecules that form the channel pore. In addition to the sensory MET channel, hair cells express the mechanically gated ion channel PIEZO2, which is localized near the base of stereocilia and not essential for sensory transduction. The function of PIEZO2 in hair cells is not entirely clear but it might have a role in damage sensing and repair processes. Additional stretch-activated channels of unknown molecular identity and function have been found to localize at the basolateral membrane of hair cells. Here, we review current knowledge regarding the different mechanically gated ion channels in hair cells and discuss open questions concerning their molecular composition and function.

Motility of vestibular hair cells in the chick.

Science.gov (United States)

Ogata, Y; Sekitani, T

1993-01-01

Recent studies of the outer hair cells in cochlea have demonstrated active motilities. However, very little study has been done on the vestibular hair cells (VHCs). The present study shows the motile response of the VHCs induced by application of Ca2+/ATP promoting contraction. Reversible cell shape changes could be shown in 10 of 16 isolated type I hair cells and 9 of 15 isolated type II hair cells by applying the contraction solution. Furthermore, the sensory hair bundles in the utricular epithelium pivoted around the base and stood perpendicularly to the apical borderline of the epithelium in response to the application of the same solution. It is suggested that the contraction of the isolated VHCs may be transferred to tension which causes the sensory hair bundles to restrict their motion in normal tissue, instead of changing the cell shape.

Characterizing human vestibular sensory epithelia for experimental studies: new hair bundles on old tissue and implications for therapeutic interventions in ageing.

Science.gov (United States)

Taylor, Ruth R; Jagger, Daniel J; Saeed, Shakeel R; Axon, Patrick; Donnelly, Neil; Tysome, James; Moffatt, David; Irving, Richard; Monksfield, Peter; Coulson, Chris; Freeman, Simon R; Lloyd, Simon K; Forge, Andrew

2015-06-01

Balance disequilibrium is a significant contributor to falls in the elderly. The most common cause of balance dysfunction is loss of sensory cells from the vestibular sensory epithelia of the inner ear. However, inaccessibility of inner ear tissue in humans severely restricts possibilities for experimental manipulation to develop therapies to ameliorate this loss. We provide a structural and functional analysis of human vestibular sensory epithelia harvested at trans-labyrinthine surgery. We demonstrate the viability of the tissue and labeling with specific markers of hair cell function and of ion homeostasis in the epithelium. Samples obtained from the oldest patients revealed a significant loss of hair cells across the tissue surface, but we found immature hair bundles present in epithelia harvested from patients >60 years of age. These results suggest that the environment of the human vestibular sensory epithelium could be responsive to stimulation of developmental pathways to enhance hair cell regeneration, as has been demonstrated successfully in the vestibular organs of adult mice. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Zebrafish hair cell mechanics and physiology through the lens of noise-induced hair cell death

Science.gov (United States)

Coffin, Allison B.; Xu, Jie; Uribe, Phillip M.

2018-05-01

Hair cells are exquisitely sensitive to auditory stimuli, but also to damage from a variety of sources including noise trauma and ototoxic drugs. Mammals cannot regenerate cochlear hair cells, while non-mammalian vertebrates exhibit robust regenerative capacity. Our research group uses the lateral line system of larval zebrafish to explore the mechanisms underlying hair cell damage, identify protective therapies, and determine molecular drivers of innate regeneration. The lateral line system contains externally located sensory organs called neuromasts, each composed of ˜8-20 hair cells. Lateral line hair cells are homologous to vertebrate inner ear hair cells and share similar susceptibility to ototoxic damage. In the last decade, the lateral line has emerged as a powerful model system for understanding hair cell death mechanisms and for identifying novel protective compounds. Here we demonstrate that the lateral line is a tractable model for noise-induced hair cell death. We have developed a novel noise damage system capable of inducing over 50% loss of lateral line hair cells, with hair cell death occurring in a dose- and time-dependent manner. Cell death is greatest 72 hours post-exposure. However, early signs of hair cell damage, including changes in membrane integrity and reduced mechanotransduction, are apparent within hours of noise exposure. These features, early signs of damage followed by delayed hair cell death, are consistent with mammalian data, suggesting that noise acts similarly on zebrafish and mammalian hair cells. In our future work we will use our new model system to investigate noise damage events in real time, and to develop protective therapies for future translational research.

Mutations in ap1b1 cause mistargeting of the Na(+/K(+-ATPase pump in sensory hair cells.

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Rachel Clemens Grisham

Full Text Available The hair cells of the inner ear are polarized epithelial cells with a specialized structure at the apical surface, the mechanosensitive hair bundle. Mechanotransduction occurs within the hair bundle, whereas synaptic transmission takes place at the basolateral membrane. The molecular basis of the development and maintenance of the apical and basal compartments in sensory hair cells is poorly understood. Here we describe auditory/vestibular mutants isolated from forward genetic screens in zebrafish with lesions in the adaptor protein 1 beta subunit 1 (ap1b1 gene. Ap1b1 is a subunit of the adaptor complex AP-1, which has been implicated in the targeting of basolateral membrane proteins. In ap1b1 mutants we observed that although the overall development of the inner ear and lateral-line organ appeared normal, the sensory epithelium showed progressive signs of degeneration. Mechanically-evoked calcium transients were reduced in mutant hair cells, indicating that mechanotransduction was also compromised. To gain insight into the cellular and molecular defects in ap1b1 mutants, we examined the localization of basolateral membrane proteins in hair cells. We observed that the Na(+/K(+-ATPase pump (NKA was less abundant in the basolateral membrane and was mislocalized to apical bundles in ap1b1 mutant hair cells. Accordingly, intracellular Na(+ levels were increased in ap1b1 mutant hair cells. Our results suggest that Ap1b1 is essential for maintaining integrity and ion homeostasis in hair cells.

Repair of traumatized mammalian hair cells via sea anemone repair proteins.

Science.gov (United States)

Tang, Pei-Ciao; Smith, Karen Müller; Watson, Glen M

2016-08-01

Mammalian hair cells possess only a limited ability to repair damage after trauma. In contrast, sea anemones show a marked capability to repair damaged hair bundles by means of secreted repair proteins (RPs). Previously, it was found that recovery of traumatized hair cells in blind cavefish was enhanced by anemone-derived RPs; therefore, the ability of anemone RPs to assist recovery of damaged hair cells in mammals was tested here. After a 1 h incubation in RP-enriched culture media, uptake of FM1-43 by experimentally traumatized murine cochlear hair cells was restored to levels comparable to those exhibited by healthy controls. In addition, RP-treated explants had significantly more normally structured hair bundles than time-matched traumatized control explants. Collectively, these results indicate that anemone-derived RPs assist in restoring normal function and structure of experimentally traumatized hair cells of the mouse cochlea. © 2016. Published by The Company of Biologists Ltd.

Static length changes of cochlear outer hair cells can tune low-frequency hearing.

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Nikola Ciganović

2018-01-01

Full Text Available The cochlea not only transduces sound-induced vibration into neural spikes, it also amplifies weak sound to boost its detection. Actuators of this active process are sensory outer hair cells in the organ of Corti, whereas the inner hair cells transduce the resulting motion into electric signals that propagate via the auditory nerve to the brain. However, how the outer hair cells modulate the stimulus to the inner hair cells remains unclear. Here, we combine theoretical modeling and experimental measurements near the cochlear apex to study the way in which length changes of the outer hair cells deform the organ of Corti. We develop a geometry-based kinematic model of the apical organ of Corti that reproduces salient, yet counter-intuitive features of the organ's motion. Our analysis further uncovers a mechanism by which a static length change of the outer hair cells can sensitively tune the signal transmitted to the sensory inner hair cells. When the outer hair cells are in an elongated state, stimulation of inner hair cells is largely inhibited, whereas outer hair cell contraction leads to a substantial enhancement of sound-evoked motion near the hair bundles. This novel mechanism for regulating the sensitivity of the hearing organ applies to the low frequencies that are most important for the perception of speech and music. We suggest that the proposed mechanism might underlie frequency discrimination at low auditory frequencies, as well as our ability to selectively attend auditory signals in noisy surroundings.

Usher protein functions in hair cells and photoreceptors

OpenAIRE

Cosgrove, Dominic; Zallocchi, Marisa

2013-01-01

The 10 different genes associated with the deaf/blind disorder, Usher syndrome, encode a number of structurally and functionally distinct proteins, most expressed as multiple isoforms/protein variants. Functional characterization of these proteins suggests a role in stereocilia development in cochlear hair cells, likely owing to adhesive interactions in hair bundles. In mature hair cells, homodimers of the Usher cadherins, cadherin 23 and protocadherin 15, interact to form a structural fiber,...

Influence of Brazilian vegetable oils on mechanical resistence of hair fiber

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Maria Valéria Velasco

2015-02-01

Full Text Available Associating the global trend of incorporating active compounds and plants in cosmetic formulations and the vast Brazilian biodiversity, the present work aimed to study the incorporation of Brazilian vegetable oils in hair conditioner formulations, evaluating the mechanical resistance of hair fibers. The following oils were incorporated into base formulations at 5.0 % (w/w: babassu, buriti, andiroba and pequi. The formulations were applied to samples of Caucasian hair, followed by several washing steps, then the evaluation of mechanical strength. It was found that there was no statistically significant difference in mechanical resistance between samples treated with oils and the control between the first and seventh wash cycles. This fact can be explained by the possible low penetration of oils into the cortex, a region responsible for the mechanical properties of the hair fiber, since the grease composition disfavors its diffusion. The common effects of vegetable oils on the cuticle, such as filling in cracks or cavities, lubrication, and increased protein hydrophobicity cannot be excluded. The oils tested in this work were not able to raise or protect hair tresses. However, additional studies are required in order to establish the effects of oil treatments, particularly in damaged hair.

The Rho GTPase Cdc42 regulates hair cell planar polarity and cellular patterning in the developing cochlea

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Anna Kirjavainen

2015-03-01

Full Text Available Hair cells of the organ of Corti (OC of the cochlea exhibit distinct planar polarity, both at the tissue and cellular level. Planar polarity at tissue level is manifested as uniform orientation of the hair cell stereociliary bundles. Hair cell intrinsic polarity is defined as structural hair bundle asymmetry; positioning of the kinocilium/basal body complex at the vertex of the V-shaped bundle. Consistent with strong apical polarity, the hair cell apex displays prominent actin and microtubule cytoskeletons. The Rho GTPase Cdc42 regulates cytoskeletal dynamics and polarization of various cell types, and, thus, serves as a candidate regulator of hair cell polarity. We have here induced Cdc42 inactivation in the late-embryonic OC. We show the role of Cdc42 in the establishment of planar polarity of hair cells and in cellular patterning. Abnormal planar polarity was displayed as disturbances in hair bundle orientation and morphology and in kinocilium/basal body positioning. These defects were accompanied by a disorganized cell-surface microtubule network. Atypical protein kinase C (aPKC, a putative Cdc42 effector, colocalized with Cdc42 at the hair cell apex, and aPKC expression was altered upon Cdc42 depletion. Our data suggest that Cdc42 together with aPKC is part of the machinery establishing hair cell planar polarity and that Cdc42 acts on polarity through the cell-surface microtubule network. The data also suggest that defects in apical polarization are influenced by disturbed cellular patterning in the OC. In addition, our data demonstrates that Cdc42 is required for stereociliogenesis in the immature cochlea.

Hierarchical capillary adhesion of microcantilevers or hairs

International Nuclear Information System (INIS)

Liu Jianlin; Feng Xiqiao; Xia Re; Zhao Hongping

2007-01-01

As a result of capillary forces, animal hairs, carbon nanotubes or nanowires of a periodically or randomly distributed array often assemble into hierarchical structures. In this paper, the energy method is adopted to analyse the capillary adhesion of microsized hairs, which are modelled as clamped microcantilevers wetted by liquids. The critical conditions for capillary adhesion of two hairs, three hairs or two bundles of hairs are derived in terms of Young's contact angle, elastic modulus and geometric sizes of the beams. Then, the hierarchical capillary adhesion of hairs is addressed. It is found that for multiple hairs or microcantilevers, the system tends to take a hierarchical structure as a result of the minimization of the total potential energy of the system. The level number of structural hierarchy increases with the increase in the number of hairs if they are sufficiently long. Additionally, we performed experiments to verify our theoretical solutions for the adhesion of microbeams

The mechanosensory structure of the hair cell requires clarin-1, a protein encoded by Usher syndrome III causative gene.

Science.gov (United States)

Geng, Ruishuang; Melki, Sami; Chen, Daniel H-C; Tian, Guilian; Furness, David N; Oshima-Takago, Tomoko; Neef, Jakob; Moser, Tobias; Askew, Charles; Horwitz, Geoff; Holt, Jeffrey R; Imanishi, Yoshikazu; Alagramam, Kumar N

2012-07-11

Mutation in the clarin-1 gene (Clrn1) results in loss of hearing and vision in humans (Usher syndrome III), but the role of clarin-1 in the sensory hair cells is unknown. Clarin-1 is predicted to be a four transmembrane domain protein similar to members of the tetraspanin family. Mice carrying null mutation in the clarin-1 gene (Clrn1(-/-)) show loss of hair cell function and a possible defect in ribbon synapse. We investigated the role of clarin-1 using various in vitro and in vivo approaches. We show by immunohistochemistry and patch-clamp recordings of Ca(2+) currents and membrane capacitance from inner hair cells that clarin-1 is not essential for formation or function of ribbon synapse. However, reduced cochlear microphonic potentials, FM1-43 [N-(3-triethylammoniumpropyl)-4-(4-(dibutylamino)styryl) pyridinium dibromide] loading, and transduction currents pointed to diminished cochlear hair bundle function in Clrn1(-/-) mice. Electron microscopy of cochlear hair cells revealed loss of some tall stereocilia and gaps in the v-shaped bundle, although tip links and staircase arrangement of stereocilia were not primarily affected by Clrn1(-/-) mutation. Human clarin-1 protein expressed in transfected mouse cochlear hair cells localized to the bundle; however, the pathogenic variant p.N48K failed to localize to the bundle. The mouse model generated to study the in vivo consequence of p.N48K in clarin-1 (Clrn1(N48K)) supports our in vitro and Clrn1(-/-) mouse data and the conclusion that CLRN1 is an essential hair bundle protein. Furthermore, the ear phenotype in the Clrn1(N48K) mouse suggests that it is a valuable model for ear disease in CLRN1(N48K), the most prevalent Usher syndrome III mutation in North America.

Pairwise coupling of hair cell transducer channels links auditory sensitivity and dynamic range

NARCIS (Netherlands)

van Netten, Sietse M.; Meulenberg, Cecil J. W.; Lennan, George W. T.; Kros, Corne J.

Hair cells in the inner ear provide the basis for the exquisite hearing capabilities of mammals. These cells transduce sound-induced displacements of their mechanosensitive hair bundle into electrical currents within a fraction of a millisecond and with nanometer fidelity. Excitatory displacements

Usher protein functions in hair cells and photoreceptors.

Science.gov (United States)

Cosgrove, Dominic; Zallocchi, Marisa

2014-01-01

The 10 different genes associated with the deaf/blind disorder, Usher syndrome, encode a number of structurally and functionally distinct proteins, most expressed as multiple isoforms/protein variants. Functional characterization of these proteins suggests a role in stereocilia development in cochlear hair cells, likely owing to adhesive interactions in hair bundles. In mature hair cells, homodimers of the Usher cadherins, cadherin 23 and protocadherin 15, interact to form a structural fiber, the tip link, and the linkages that anchor the taller stereocilia's actin cytoskeleton core to the shorter adjacent stereocilia and the elusive mechanotransduction channels, explaining the deafness phenotype when these molecular interactions are perturbed. The conundrum is that photoreceptors lack a synonymous mechanotransduction apparatus, and so a common theory for Usher protein function in the two neurosensory cell types affected in Usher syndrome is lacking. Recent evidence linking photoreceptor cell dysfunction in the shaker 1 mouse model for Usher syndrome to light-induced protein translocation defects, combined with localization of an Usher protein interactome at the periciliary region of the photoreceptors suggests Usher proteins might regulate protein trafficking between the inner and outer segments of photoreceptors. A distinct Usher protein complex is trafficked to the ribbon synapses of hair cells, and synaptic defects have been reported in Usher mutants in both hair cells and photoreceptors. This review aims to clarify what is known about Usher protein function at the synaptic and apical poles of hair cells and photoreceptors and the prospects for identifying a unifying pathobiological mechanism to explain deaf/blindness in Usher syndrome. Copyright © 2013 Elsevier Ltd. All rights reserved.

Three-dimensional architecture of hair-cell linkages as revealedby electron-microscopic tomography

Energy Technology Data Exchange (ETDEWEB)

Auer, Manfred; Koster, Bram; Ziese, Ulrike; Bajaj, Chandrajit; Volkmann, Niels; Wang, Da Neng; Hudspeth, A. James

2006-07-28

The senses of hearing and balance rest upon mechanoelectrical transduction by the hair bundles of hair cells in the inner ear. Located at the apical cellular surface, each hair bundle comprises several tens of stereocilia and a single kinocilium that are interconnected by extracellular proteinaceous links. Using electron-microscopic tomography of bullfrog saccular sensory epithelia, we examined the three-dimensional structures of ankle or basal links, kinociliary links, and tip links. We observed clear differences in the dimensions and appearances of the three links. We found two distinct populations of tip links suggestive of the involvement of two proteins or splice variants. We noted auxiliary links connecting the upper portions of tip links to the taller stereocilia. Tip links and auxiliary links show a tendency to adopt a globular conformation when disconnected from the membrane surface.

The Mechanosensory Structure of the Hair Cell Requires Clarin-1, a Protein Encoded by Usher Syndrome III Causative Gene

Science.gov (United States)

Geng, Ruishuang; Melki, Sami; Chen, Daniel H.-C.; Tian, Guilian; Furness, David; Oshima-Takago, Tomoko; Neef, Jakob; Moser, Tobias; Askew, Charles; Horwitz, Geoff; Holt, Jeffrey; Imanishi, Yoshikazu; Alagramam, Kumar N.

2012-01-01

Mutation in the clarin-1 gene results in loss of hearing and vision in humans (Usher syndrome III), but the role of clarin-1 in the sensory hair cells is unknown. Clarin-1 is predicted to be a four transmembrane domain protein similar to members of the tetraspanin family. Mice carrying null mutation in the clarin-1 (Clrn1−/−) gene show loss of hair cell function and a possible defect in ribbon synapse. We investigated the role of clarin-1 using various in vitro and in vivo approaches. We show by immunohistochemistry and patch-clamp recordings of Ca2+ currents and membrane capacitance from IHCs that clarin-1 is not essential for formation or function of ribbon synapse. However, reduced cochlear microphonic potentials, FM1-43 loading and transduction currents pointed to diminished cochlear hair bundle function in Clrn1−/− mice. Electron microscopy of cochlear hair cells revealed loss of some tall stereocilia and gaps in the v-shaped bundle, although tip-links and staircase arrangement of stereocilia were not primarily affected by Clrn1−/− mutation. Human clarin-1 protein expressed in transfected mouse cochlear hair cells localized to the bundle; however, the pathogenic variant, p.N48K, failed to localize to the bundle. The mouse model generated to study the in vivo consequence of p. N48K in clarin-1 (Clrn1N48K) supports our in vitro and Clrn1−/− mouse data and the conclusion that CLRN1 is an essential hair bundle protein. Further, the ear phenotype in the Clrn1N48K mouse suggests that it is a valuable model for ear disease in CLRN1N48K, the most prevalent Usher III mutation in North America. PMID:22787034

The structural and functional differentiation of hair cells in a lizard's basilar papilla suggests an operational principle of amniote cochleas.

Science.gov (United States)

Chiappe, M Eugenia; Kozlov, Andrei S; Hudspeth, A J

2007-10-31

The hair cells in the mammalian cochlea are of two distinct types. Inner hair cells are responsible for transducing mechanical stimuli into electrical responses, which they forward to the brain through a copious afferent innervation. Outer hair cells, which are thought to mediate the active process that sensitizes and tunes the cochlea, possess a negligible afferent innervation. For every inner hair cell, there are approximately three outer hair cells, so only one-quarter of the hair cells directly deliver information to the CNS. Although this is a surprising feature for a sensory system, the occurrence of a similar innervation pattern in birds and crocodilians suggests that the arrangement has an adaptive value. Using a lizard with highly developed hearing, the tokay gecko, we demonstrate in the present study that the same principle operates in a third major group of terrestrial animals. We propose that the differentiation of hair cells into signaling and amplifying classes reflects incompatible strategies for the optimization of mechanoelectrical transduction and of an active process based on active hair-bundle motility.

Improved biolistic transfection of hair cells.

Directory of Open Access Journals (Sweden)

Hongyu Zhao

Full Text Available Transient transfection of hair cells has proven challenging. Here we describe modifications to the Bio-Rad Helios Gene Gun that, along with an optimized protocol, improve transfection of bullfrog, chick, and mouse hair cells. The increased penetrating power afforded by our method allowed us to transfect mouse hair cells from the basal side, through the basilar membrane; this configuration protects hair bundles from damage during the procedure. We characterized the efficiency of transfection of mouse hair cells with fluorescently-tagged actin fusion protein using both the optimized procedure and a published procedure; while the efficiency of the two methods was similar, the morphology of transfected hair cells was improved with the new procedure. In addition, using the improved method, we were able to transfect hair cells in the bullfrog sacculus and chick cochlea for the first time. We used fluorescent-protein fusions of harmonin b (USH1C and PMCA2 (ATP2B2; plasma-membrane Ca(2+-ATPase isoform 2 to examine protein distribution in hair cells. While PMCA2-EGFP localization was similar to endogenous PMCA2 detected with antibodies, high levels of harmonin-EGFP were found at stereocilia tapers in bullfrog and chick, but not mouse; by contrast, harmonin-EGFP was concentrated in stereocilia tips in mouse hair cells.

Mechanoelectrical transduction of adult outer hair cells studied in a gerbil hemicochlea.

Science.gov (United States)

He, David Z Z; Jia, Shuping; Dallos, Peter

2004-06-17

Sensory receptor cells of the mammalian cochlea are morphologically and functionally dichotomized. Inner hair cells transmit auditory information to the brain, whereas outer hair cells (OHC) amplify the mechanical signal, which is then transduced by inner hair cells. Amplification by OHCs is probably mediated by their somatic motility in a mechanical feedback process. OHC motility in vivo is thought to be driven by the cell's receptor potential. The first steps towards the generation of the receptor potential are the deflection of the stereociliary bundle, and the subsequent flow of transducer current through the mechanosensitive transducer channels located at their tips. Quantitative relations between transducer currents and basilar membrane displacements are lacking, as well as their variation along the cochlear length. To address this, we simultaneously recorded OHC transducer currents (or receptor potentials) and basilar membrane motion in an excised and bisected cochlea, the hemicochlea. This preparation permits recordings from adult OHCs at various cochlear locations while the basilar membrane is mechanically stimulated. Furthermore, the stereocilia are deflected by the same means of stimulation as in vivo. Here we show that asymmetrical transducer currents and receptor potentials are significantly larger than previously thought, they possess a highly restricted dynamic range and strongly depend on cochlear location.

The structural and functional differentiation of hair cells in a lizard’s basilar papilla suggests an operational principle of amniote cochleas

Science.gov (United States)

Chiappe, M. Eugenia; Kozlov, Andrei S.; Hudspeth, A. J.

2007-01-01

The hair cells in the mammalian cochlea are of two distinct types. Inner hair cells are responsible for transducing mechanical stimuli into electrical responses, which they forward to the brain through a copious afferent innervation. Outer hair cells, which are thought to mediate the active process that sensitizes and tunes the cochlea, possess a negligible afferent innervation. For every inner hair cell there are approximately three outer hair cells, so only a quarter of the hair cells directly deliver information to the central nervous system. Although this is a surprising feature for a sensory system, the occurrence of a similar innervation pattern in birds and crocodilians suggests that the arrangement has an adaptive value. Using a lizard with highly developed hearing, the tokay gecko, we demonstrate in the present study that the same principle operates in a third major group of terrestrial animals. We propose that the differentiation of hair cells into signaling and amplifying classes reflects incompatible strategies for the optimization of mechanoelectrical transduction and of an active process based on active hair-bundle motility. PMID:17978038

The acquisition of mechano-electrical transducer current adaptation in auditory hair cells requires myosin VI

NARCIS (Netherlands)

Marcotti, Walter; Corns, Laura F.; Goodyear, Richard J.; Rzadzinska, Agnieszka K.; Avraham, Karen B.; Steel, Karen P.; Richardson, Guy P.; Kros, Corne J.

2016-01-01

The transduction of sound into electrical signals occurs at the hair bundles atop sensory hair cells in the cochlea, by means of mechanosensitive ion channels, the mechano-electrical transducer (MET) channels. The MET currents decline during steady stimuli; this is termed adaptation and ensures they

Numerical simulation of the hair formation -modeling of hair cycle

Science.gov (United States)

Kajihara, Narumichi; Nagayama, Katsuya

2018-01-01

In the recent years, the fields of study of anti-aging, health and beauty, cosmetics, and hair diseases have attracted significant attention. In particular, human hair is considered to be an important aspect with regard to an attractive appearance. To this end, many workers have sought to understand the formation mechanism of the hair root. However, observing growth in the hair root is difficult, and a detailed mechanism of the process has not yet been elucidated. Hair repeats growth, retraction, and pause cycles (hair cycle) in a repetitive process. In the growth phase, hair is formed through processes of cell proliferation and differentiation (keratinization). During the retraction phase, hair growth stops, and during the resting period, hair fall occurs and new hair grows. This hair cycle is believed to affect the elongation rate, thickness, strength, and shape of hair. Therefore, in this study, we introduce a particle model as a new method to elucidate the unknown process of hair formation, and to model the hair formation process accompanying the proliferation and differentiation of the hair root cells in all three dimensions. In addition, to the growth period, the retraction and the resting periods are introduced to realize the hair cycle using this model.

Semicircular canals circumvent Brownian Motion overload of mechanoreceptor hair cells

DEFF Research Database (Denmark)

Muller, Mees; Heeck, Kier; Elemans, Coen P H

2016-01-01

Vertebrate semicircular canals (SCC) first appeared in the vertebrates (i.e. ancestral fish) over 600 million years ago. In SCC the principal mechanoreceptors are hair cells, which as compared to cochlear hair cells are distinctly longer (70 vs. 7 μm), 10 times more compliant to bending (44 vs. 500...... nN/m), and have a 100-fold higher tip displacement threshold (hair cells where the bundle is approximated as a stiff, cylindrical elastic rod subject to friction and thermal agitation. Our models suggest that the above...... differences aid SCC hair cells in circumventing the masking effects of Brownian motion noise of about 70 nm, and thereby permit transduction of very low frequency (

Biomechanics of hair cell kinocilia: experimental measurement of kinocilium shaft stiffness and base rotational stiffness with Euler–Bernoulli and Timoshenko beam analysis

Science.gov (United States)

Spoon, Corrie; Grant, Wally

2011-01-01

Vestibular hair cell bundles in the inner ear contain a single kinocilium composed of a 9+2 microtubule structure. Kinocilia play a crucial role in transmitting movement of the overlying mass, otoconial membrane or cupula to the mechanotransducing portion of the hair cell bundle. Little is known regarding the mechanical deformation properties of the kinocilium. Using a force-deflection technique, we measured two important mechanical properties of kinocilia in the utricle of a turtle, Trachemys (Pseudemys) scripta elegans. First, we measured the stiffness of kinocilia with different heights. These kinocilia were assumed to be homogenous cylindrical rods and were modeled as both isotropic Euler–Bernoulli beams and transversely isotropic Timoshenko beams. Two mechanical properties of the kinocilia were derived from the beam analysis: flexural rigidity (EI) and shear rigidity (kGA). The Timoshenko model produced a better fit to the experimental data, predicting EI=10,400 pN μm2 and kGA=247 pN. Assuming a homogenous rod, the shear modulus (G=1.9 kPa) was four orders of magnitude less than Young's modulus (E=14.1 MPa), indicating that significant shear deformation occurs within deflected kinocilia. When analyzed as an Euler–Bernoulli beam, which neglects translational shear, EI increased linearly with kinocilium height, giving underestimates of EI for shorter kinocilia. Second, we measured the rotational stiffness of the kinocilium insertion (κ) into the hair cell's apical surface. Following BAPTA treatment to break the kinocilial links, the kinocilia remained upright, and κ was measured as 177±47 pN μm rad–1. The mechanical parameters we quantified are important for understanding how forces arising from head movement are transduced and encoded by hair cells. PMID:21307074

Exploring the membrane fusion mechanism through force-induced disassembly of HIV-1 six-helix bundle

Energy Technology Data Exchange (ETDEWEB)

Gao, Kai [Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China); Beijing Key Laboratory of Noncoding RNA, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Zhang, Yong [Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China); Beijing Key Laboratory of Noncoding RNA, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China); Lou, Jizhong, E-mail: jlou@ibp.ac.cn [Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China); Beijing Key Laboratory of Noncoding RNA, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China)

2016-05-13

Enveloped virus, such as HIV-1, employs membrane fusion mechanism to invade into host cell. HIV-1 gp41 ectodomain uses six-helix bundle configuration to accomplish this process. Using molecular dynamic simulations, we confirmed the stability of this six-helix bundle by showing high occupancy of hydrogen bonds and hydrophobic interactions. Key residues and interactions important for the bundle integration were characterized by force-induced unfolding simulations of six-helix bundle, exhibiting the collapse order of these groups of interactions. Moreover, our results in some way concerted with a previous theory that the formation of coiled-coil choose a route which involved cooperative interactions between the N-terminal and C-terminal helix. -- Highlights: •Unfolding of HIV-1 gp41 six-helix bundle is studied by molecular dynamics simulations. •Specific interactions responsible for the stability of HIV-1 envelope post-fusion conformation were identified. •The gp41 six-helix bundle transition inducing membrane fusion might be a cooperative process of the three subunits.

Electro-mechanical response of a 3D nerve bundle model to mechanical loads leading to axonal injury.

Science.gov (United States)

Cinelli, I; Destrade, M; Duffy, M; McHugh, P

2018-03-01

Traumatic brain injuries and damage are major causes of death and disability. We propose a 3D fully coupled electro-mechanical model of a nerve bundle to investigate the electrophysiological impairments due to trauma at the cellular level. The coupling is based on a thermal analogy of the neural electrical activity by using the finite element software Abaqus CAE 6.13-3. The model includes a real-time coupling, modulated threshold for spiking activation, and independent alteration of the electrical properties for each 3-layer fibre within a nerve bundle as a function of strain. Results of the coupled electro-mechanical model are validated with previously published experimental results of damaged axons. Here, the cases of compression and tension are simulated to induce (mild, moderate, and severe) damage at the nerve membrane of a nerve bundle, made of 4 fibres. Changes in strain, stress distribution, and neural activity are investigated for myelinated and unmyelinated nerve fibres, by considering the cases of an intact and of a traumatised nerve membrane. A fully coupled electro-mechanical modelling approach is established to provide insights into crucial aspects of neural activity at the cellular level due to traumatic brain injury. One of the key findings is the 3D distribution of residual stresses and strains at the membrane of each fibre due to mechanically induced electrophysiological impairments, and its impact on signal transmission. Copyright © 2017 John Wiley & Sons, Ltd.

Mechanism of Cuticle Hole Development in Human Hair Due to UV-Radiation Exposure

Directory of Open Access Journals (Sweden)

Kazuhisa Maeda

2018-03-01

Full Text Available Hair is easily damaged by ultraviolet (UV radiation, bleaching agents or permanent wave treatments, and as damage progresses, hair loses its gloss, develops split ends and breaks. However, the causes of hair damage due to UV radiation have not yet been clarified. We discovered that in one mechanism facilitating damage to wet hair by UV radiation, the unsaturated fatty acids in wet hair produce hydroxy radicals upon exposure to UV radiation, and these radicals produce cuticle holes between the cuticle layers. In wet hair exposed to UV radiation, cuticle holes were produced only between the cuticle layers, whereas when human hair was immersed in a solution containing hydroxy radicals produced by Fenton’s reaction, a random production of cuticle holes was noted. It is thought that hydroxy radicals are produced only between the cuticle layers by exposure to UV radiation, and cuticle holes are formed only in this region because one of the polyunsaturated fatty acids, linoleic acid, with a bis-allyl hydrogen, is found between the cuticle layers.

ACh-induced hyperpolarization and decreased resistance in mammalian type II vestibular hair cells.

Science.gov (United States)

Poppi, Lauren A; Tabatabaee, Hessam; Drury, Hannah R; Jobling, Phillip; Callister, Robert J; Migliaccio, Americo A; Jordan, Paivi M; Holt, Joseph C; Rabbitt, Richard D; Lim, Rebecca; Brichta, Alan M

2018-01-01

efferent mechanism for altering hair cell membrane potential and decreasing membrane resistance that should reduce sensitivity to hair bundle displacements.

Collective Behavior of Hair, and Ponytail Shape and Dynamics

Science.gov (United States)

Ball, Robin

I will discuss how we can build a mathematical model of the behaviour of a bundle of hair, comparing the results with experimental studies of the shape and dynamics of human ponytails. We treat the individual fibers as elastic filaments with random intrinsic curvature, in which the balance of bending elasticity, gravity, orientational disorder and inertia is recast as a differential equation for the envelope of the fibre bundle. The static elements of this work were first reported in R.E. Goldstein, P.B. Warren and R.C. Ball, Physical Review Letters 108, 078101 (2012). The compressibility of the bundle enters through an ``equation of state'' whose empirical form is shown to arise from a Confined Helix Model, in which the constraint of the surrounding hair is on a given fibre is represented as a confining cylinder. Using this model we find the ponytail shape is well fit with only one adjustable parameter, which is the degree to which the confining cylinders over fill space. The dynamics of driven vertical ponytail motion is well reproduced provided we introduce some damping, and we find the level of damping required is consistent with that arising from viscous drag of the lateral motion of the hair fibres through the interstitial air. Most of our match with experiment is achieved by approximating the fibre density of the ponytail to to be uniform across its cross-section, and to vary only length-wise. However we show that detail near the exit from a confining clamp (aka hairband) is only captured by computing the full cross-sectional variation. The work reported is joint with RE Goldstein (Cambridge UK) and PB Warren (Unilever Research).

Animal Hairs as Water-stimulated Shape Memory Materials: Mechanism and Structural Networks in Molecular Assemblies

Science.gov (United States)

Xiao, Xueliang; Hu, Jinlian

2016-05-01

Animal hairs consisting of α-keratin biopolymers existing broadly in nature may be responsive to water for recovery to the innate shape from their fixed deformation, thus possess smart behavior, namely shape memory effect (SME). In this article, three typical animal hair fibers were first time investigated for their water-stimulated SME, and therefrom to identify the corresponding net-points and switches in their molecular and morphological structures. Experimentally, the SME manifested a good stability of high shape fixation ratio and reasonable recovery rate after many cycles of deformation programming under water stimulation. The effects of hydration on hair lateral size, recovery kinetics, dynamic mechanical behaviors and structural components (crystal, disulfide and hydrogen bonds) were then systematically studied. SME mechanisms were explored based on the variations of structural components in molecular assemblies of such smart fibers. A hybrid structural network model with single-switch and twin-net-points was thereafter proposed to interpret the water-stimulated shape memory mechanism of animal hairs. This original work is expected to provide inspiration for exploring other natural materials to reveal their smart functions and natural laws in animals including human as well as making more remarkable synthetic smart materials.

Efficacy of topical tofacitinib in promoting hair growth in non-scarring alopecia: possible mechanism via VEGF induction.

Science.gov (United States)

Meephansan, Jitlada; Thummakriengkrai, J; Ponnikorn, S; Yingmema, W; Deenonpoe, R; Suchonwanit, P

2017-11-01

Tofacitinib is a Janus kinase 3 (JAK3) inhibitor that promotes hair growth; however, the efficacy and mechanism of this effect are not yet understood. This study aimed to evaluate the efficacy and mechanism of topical tofacitinib on hair growth in mice. Eight-week-old male C57BL/6 mice were divided equally into four groups and treated topically with tofacitinib, minoxidil, or vehicle once daily for 21 days. Weekly photographs were taken to determine the area and rate of hair growth, and tissue samples were collected for histopathological evaluation. mRNA and protein expression of anagen-maintaining growth factors, including vascular endothelial growth factor (VEGF) and insulin-like growth factor-1 (IGF-1), were determined via RT-PCR and ELISA, respectively. Tofacitinib-treated mice exhibited more hair regrowth than either minoxidil-treated or control mice did between day 7 and 21 (P tofacitinib also promoted more rapid hair growth rate than topical minoxidil or control did (P tofacitinib-treated group. Hair follicles in the minoxidil- and vehicle-treated groups were more often classified as catagen and anagen. VEGF mRNA and protein expression in the tofacitinib-treated group was significantly greater than those in the other groups (P tofacitinib-treated mice. Topical tofacitinib is effective in promoting hair growth, and the possible mechanism involves increased VEGF levels and lowered inflammation. This study will help develop a new therapeutic option for non-scarring alopecia.

Espins and the actin cytoskeleton of hair cell stereocilia and sensory cell microvilli

Science.gov (United States)

Sekerková, Gabriella; Zheng, Lili; Loomis, Patricia A.; Mugnaini, Enrico; Bartles, James R.

2008-01-01

The espins are novel actin-bundling proteins that are produced in multiple isoforms from a single gene. They are present at high concentration in the parallel actin bundle of hair cell stereocilia and are the target of deafness mutations in mice and humans. Espins are also enriched in the microvilli of taste receptor cells, solitary chemoreceptor cells, vomeronasal sensory neurons and Merkel cells, suggesting that espins play important roles in the microvillar projections of vertebrate sensory cells. Espins are potent actin-bundling proteins that are not inhibited by Ca2+. In cells, they efficiently elongate parallel actin bundles and, thereby, help determine the steady-state length of microvilli and stereocilia. Espins bind actin monomer via their WH2 domain and can assemble actin bundles in cells. Certain espin isoforms can also bind phosphatidylinositol 4,5-bisphosphate, profilins or SH3 proteins. These biological activities distinguish espins from other actin-bundling proteins and may make them well-suited to sensory cells. PMID:16909209

The tip-link antigen, a protein associated with the transduction complex of sensory hair cells, is protocadherin-15.

Science.gov (United States)

Ahmed, Zubair M; Goodyear, Richard; Riazuddin, Saima; Lagziel, Ayala; Legan, P Kevin; Behra, Martine; Burgess, Shawn M; Lilley, Kathryn S; Wilcox, Edward R; Riazuddin, Sheikh; Griffith, Andrew J; Frolenkov, Gregory I; Belyantseva, Inna A; Richardson, Guy P; Friedman, Thomas B

2006-06-28

Sound and acceleration are detected by hair bundles, mechanosensory structures located at the apical pole of hair cells in the inner ear. The different elements of the hair bundle, the stereocilia and a kinocilium, are interconnected by a variety of link types. One of these links, the tip link, connects the top of a shorter stereocilium with the lateral membrane of an adjacent taller stereocilium and may gate the mechanotransducer channel of the hair cell. Mass spectrometric and Western blot analyses identify the tip-link antigen, a hitherto unidentified antigen specifically associated with the tip and kinocilial links of sensory hair bundles in the inner ear and the ciliary calyx of photoreceptors in the eye, as an avian ortholog of human protocadherin-15, a product of the gene for the deaf/blindness Usher syndrome type 1F/DFNB23 locus. Multiple protocadherin-15 transcripts are shown to be expressed in the mouse inner ear, and these define four major isoform classes, two with entirely novel, previously unidentified cytoplasmic domains. Antibodies to the three cytoplasmic domain-containing isoform classes reveal that each has a different spatiotemporal expression pattern in the developing and mature inner ear. Two isoforms are distributed in a manner compatible for association with the tip-link complex. An isoform located at the tips of stereocilia is sensitive to calcium chelation and proteolysis with subtilisin and reappears at the tips of stereocilia as transduction recovers after the removal of calcium chelators. Protocadherin-15 is therefore associated with the tip-link complex and may be an integral component of this structure and/or required for its formation.

Molecular mechanism of bundle formation by the bacterial actin ParM

Energy Technology Data Exchange (ETDEWEB)

Popp, David, E-mail: dpopp@imcb.a-star.edu.sg [ERATO ' Actin Filament Dynamics' Project, Japan Science and Technology Corporation, c/o RIKEN Harima Institute at Spring 8, 1-1-1 Kouto, Sayo, Hyogo 679-5148 (Japan); Institute of Molecular and Cell Biology, 61 Biopolis Drive, Proteos, 138673 Singapore (Singapore); Narita, Akihiro [ERATO ' Actin Filament Dynamics' Project, Japan Science and Technology Corporation, c/o RIKEN Harima Institute at Spring 8, 1-1-1 Kouto, Sayo, Hyogo 679-5148 (Japan); Nagoya University Graduate School of Science, Structural Biology Research Center and Division of Biological Sciences, Furo-cho, Chikusa-ku, Nagoya 464-8601 (Japan); Iwasa, Mitsusada [ERATO ' Actin Filament Dynamics' Project, Japan Science and Technology Corporation, c/o RIKEN Harima Institute at Spring 8, 1-1-1 Kouto, Sayo, Hyogo 679-5148 (Japan); Maeda, Yuichiro [ERATO ' Actin Filament Dynamics' Project, Japan Science and Technology Corporation, c/o RIKEN Harima Institute at Spring 8, 1-1-1 Kouto, Sayo, Hyogo 679-5148 (Japan); Nagoya University Graduate School of Science, Structural Biology Research Center and Division of Biological Sciences, Furo-cho, Chikusa-ku, Nagoya 464-8601 (Japan); Robinson, Robert C. [Institute of Molecular and Cell Biology, 61 Biopolis Drive, Proteos, 138673 Singapore (Singapore)

2010-01-22

The actin homolog ParM plays a microtubule-like role in segregating DNA prior to bacterial cell division. Fluorescence and cryo-electron microscopy have shown that ParM forms filament bundles between separating DNA plasmids in vivo. Given the lack of ParM bundling proteins it remains unknown how ParM bundles form at the molecular level. Here we show using time-lapse TIRF microscopy, under in vitro molecular crowding conditions, that ParM-bundle formation consists of two distinct phases. At the onset of polymerization bundle thickness and shape are determined in the form of nuclei of short helically disordered filaments arranged in a liquid-like lattice. These nuclei then undergo an elongation phase whereby they rapidly increase in length. At steady state, ParM bundles fuse into one single large aggregate. This behavior had been predicted by theory but has not been observed for any other cytomotive biopolymer, including F-actin. We employed electron micrographs of ParM rafts, which are 2-D analogs of 3-D bundles, to identify the main molecular interfilament contacts within these suprastructures. The interface between filaments is similar for both parallel and anti-parallel orientations and the distribution of filament polarity is random within a bundle. We suggest that the interfilament interactions are not due to the interactions of specific residues but rather to long-range, counter ion mediated, electrostatic attractive forces. A randomly oriented bundle ensures that the assembly is rigid and that DNA may be captured with equal efficiency at both ends of the bundle via the ParR binding protein.

Induction of Functional Hair-Cell-Like Cells from Mouse Cochlear Multipotent Cells

Directory of Open Access Journals (Sweden)

Quanwen Liu

2016-01-01

Full Text Available In this paper, we developed a two-step-induction method of generating functional hair cells from inner ear multipotent cells. Multipotent cells from the inner ear were established and induced initially into progenitor cells committed to the inner ear cell lineage on the poly-L-lysine substratum. Subsequently, the committed progenitor cells were cultured on the mitotically inactivated chicken utricle stromal cells and induced into hair-cell-like cells containing characteristic stereocilia bundles. The hair-cell-like cells exhibited rapid permeation of FM1-43FX. The whole-cell patch-clamp technique was used to measure the membrane currents of cells differentiated for 7 days on chicken utricle stromal cells and analyze the biophysical properties of the hair-cell-like cells by recording membrane properties of cells. The results suggested that the hair-cell-like cells derived from inner ear multipotent cells were functional following differentiation in an enabling environment.

Cotangent bundle approach to noninertial frames

International Nuclear Information System (INIS)

DeFacio, B.; Retzloff, D.

1980-01-01

The most general possible noninertial acceleration in special relativity is formulated with differential forms in the cotangent bundle. We show that the Lie derivative plays the same role in the cotangent bundle that the covariant derivative plays in the tangent bundle. We also show that a cotangent bundle analog of Fermi--Walker transport can be based upon the, ''cotangent-geodesic'' equation, L/sub u/ω=0. This gives a generalization of the work by Kiehn on classical Hamiltonian mechanics to special relativity

Boiling heat transfer on horizontal tube bundles

International Nuclear Information System (INIS)

Anon.

1987-01-01

Nucleate boiling heat transfer characteristics for a tube in a bundle differ from that for a single tube in a pool and this difference is known as 'tube bundle effect.' There exist two bundle effects, positive and negative. The positive bundle effect enhances heat transfer due to convective flow induced by rising bubbles generated from the lower tubes, while the negative bundle effect deteriorates heat transfer due to vapor blanketing caused by accumulation of bubbles. Staggered tube bundles tested and found that the upper tubes in bundles have higher heat transfer coefficients than the lower tubes. The effects of various parameters such as pressure, tube geometry and oil contamination on heat transfer have been examined. Some workers attempted to clarify the mechanism of occurrence of 'bundle effect' by testing tube arrangements of small scale. All reported only enhancement in heat transfer but results showed the symptom of heat transfer deterioration at higher heat fluxes. As mentioned above, it has not been clarified so far even whether the 'tube bundle effect' should serve as enhancement or deterioration of heat transfer in nucleate boiling. In this study, experiments are performed in detail by using bundles of small scale, and effects of heat flux distribution, pressure and tube location are clarified. Furthermore, some consideration on the mechanisms of occurrence of 'tube bundle effect' is made and a method for prediction of heat transfer rate is proposed

The physics of hearing: fluid mechanics and the active process of the inner ear.

Science.gov (United States)

Reichenbach, Tobias; Hudspeth, A J

2014-07-01

Most sounds of interest consist of complex, time-dependent admixtures of tones of diverse frequencies and variable amplitudes. To detect and process these signals, the ear employs a highly nonlinear, adaptive, real-time spectral analyzer: the cochlea. Sound excites vibration of the eardrum and the three miniscule bones of the middle ear, the last of which acts as a piston to initiate oscillatory pressure changes within the liquid-filled chambers of the cochlea. The basilar membrane, an elastic band spiraling along the cochlea between two of these chambers, responds to these pressures by conducting a largely independent traveling wave for each frequency component of the input. Because the basilar membrane is graded in mass and stiffness along its length, however, each traveling wave grows in magnitude and decreases in wavelength until it peaks at a specific, frequency-dependent position: low frequencies propagate to the cochlear apex, whereas high frequencies culminate at the base. The oscillations of the basilar membrane deflect hair bundles, the mechanically sensitive organelles of the ear's sensory receptors, the hair cells. As mechanically sensitive ion channels open and close, each hair cell responds with an electrical signal that is chemically transmitted to an afferent nerve fiber and thence into the brain. In addition to transducing mechanical inputs, hair cells amplify them by two means. Channel gating endows a hair bundle with negative stiffness, an instability that interacts with the motor protein myosin-1c to produce a mechanical amplifier and oscillator. Acting through the piezoelectric membrane protein prestin, electrical responses also cause outer hair cells to elongate and shorten, thus pumping energy into the basilar membrane's movements. The two forms of motility constitute an active process that amplifies mechanical inputs, sharpens frequency discrimination, and confers a compressive nonlinearity on responsiveness. These features arise because the

The physics of hearing: fluid mechanics and the active process of the inner ear

International Nuclear Information System (INIS)

Reichenbach, Tobias; Hudspeth, A J

2014-01-01

Most sounds of interest consist of complex, time-dependent admixtures of tones of diverse frequencies and variable amplitudes. To detect and process these signals, the ear employs a highly nonlinear, adaptive, real-time spectral analyzer: the cochlea. Sound excites vibration of the eardrum and the three miniscule bones of the middle ear, the last of which acts as a piston to initiate oscillatory pressure changes within the liquid-filled chambers of the cochlea. The basilar membrane, an elastic band spiraling along the cochlea between two of these chambers, responds to these pressures by conducting a largely independent traveling wave for each frequency component of the input. Because the basilar membrane is graded in mass and stiffness along its length, however, each traveling wave grows in magnitude and decreases in wavelength until it peaks at a specific, frequency-dependent position: low frequencies propagate to the cochlear apex, whereas high frequencies culminate at the base. The oscillations of the basilar membrane deflect hair bundles, the mechanically sensitive organelles of the ear's sensory receptors, the hair cells. As mechanically sensitive ion channels open and close, each hair cell responds with an electrical signal that is chemically transmitted to an afferent nerve fiber and thence into the brain. In addition to transducing mechanical inputs, hair cells amplify them by two means. Channel gating endows a hair bundle with negative stiffness, an instability that interacts with the motor protein myosin-1c to produce a mechanical amplifier and oscillator. Acting through the piezoelectric membrane protein prestin, electrical responses also cause outer hair cells to elongate and shorten, thus pumping energy into the basilar membrane's movements. The two forms of motility constitute an active process that amplifies mechanical inputs, sharpens frequency discrimination, and confers a compressive nonlinearity on responsiveness. These features arise

Evaluation of bundle duct interaction by out-of-pile compression test of FBR fuel pin bundles

Energy Technology Data Exchange (ETDEWEB)

Tanaka, Kosuke; Yamamoto, Yuji; Nagamine, Tsuyoshi; Maeda, Koji [Japan Nuclear Cycle Development Inst., Oarai, Ibaraki (Japan). Oarai Engineering Center

2001-06-01

Bundle duct interaction (BDI) caused by expansion of fuel pin bundle is a main factor to limit the fuel lifetime. Therefore, it is important for the design of fast reactor fuel assembly to understand the fuel pin deformation behavior under BDI condition. In order to understand the fuel pin deformation behavior under BDI condition, out-of-pile compression tests were conducted for FBR fuel pin bundle by use of X-ray CT equipment. In these compression tests, two kinds of fuel pin bundles were conducted. One was the fuel pin bundle with the short wire-pitch and the other was the fuel pin bundle with the short wire-pitch and large diameter claddings. The general discussions were also performed based on the results of out-of-pile compression tests obtained by use of X-ray CT equipment in the previous work. Following results were obtained. 1) The occurrence of the pin-to-duct contact depends on the wire-pitch. In the fuel pin bundle with large wire-pitch, the pin-to-duct contact occurred at the early stage of BDI. The reason of this result is due to the low bowing rigidity of the fuel pins with long wire-pitch. 2) The value of the ovalation stiffness strongly depends on the geometry of cladding (diameter, thickness) and especially on wire-pitch. This result in this work revealed that the occurrence of the pin-to-duct contact depends on the value of the ovalation stiffness. 3) The occurrence of wire dispersion and dispersive displacement of pins depends on the wire-pitch strongly. In the fuel pin bundle with the long wire-pitch, the occurrence of the above-mentioned suppression mechanism to BDI is remarkable. 4) The suppression mechanism to BDI of the fuel pin bundle with the long wire-pitch is elastic oval deformation of cladding, wire dispersion and dispersive displacement of pins. On the other hand, the elastic and plastic oval deformation of cladding is the major suppression mechanism to BDI in the fuel pin bundle with the short wire-pitch. 5) The appearance of

Drug testing with alternative matrices II. Mechanisms of cocaine and codeine deposition in hair.

Science.gov (United States)

Joseph, R E; Höld, K M; Wilkins, D G; Rollins, D E; Cone, E J

1999-10-01

-3 days after the last drug dose. These data may reflect removal of drug that was deposited by sweat shortly after dosing. Drug removed by washing hair collected 1-3 weeks after the last dose was minimal for cocaine but variable for codeine. Drug in these specimens was likely transferred from blood to germinative hair cells followed by emergence of drug in growing hair. These findings suggest that drug deposition in hair occurs by multiple mechanisms.

Fluid structure interaction in tube bundles

International Nuclear Information System (INIS)

Brochard, D.; Jedrzejewski, F.; Gibert, R.J.

1995-01-01

A lot of industrial components contain tube bundles immersed in a fluid. The mechanical analysis of such systems requires the study of the fluid structure interaction in the tube bundle. Simplified methods, based on homogenization methods, have been developed to analyse such phenomenon and have been validated through experimental results. Generally, these methods consider only the fluid motion in a plan normal to the bundle axis. This paper will analyse, in a first part, the fluid structure interaction in a tube bundle through a 2D finite element model representing the bundle cross section. The influence of various parameters like the bundle size, and the bundle confinement will be studied. These results will be then compared with results from homogenization methods. Finally, the influence of the 3D fluid motion will be investigated, in using simplified methods. (authors). 11 refs., 12 figs., 2 tabs

Hair curvature: a natural dialectic and review.

Science.gov (United States)

Nissimov, Joseph N; Das Chaudhuri, Asit Baran

2014-08-01

Although hair forms (straight, curly, wavy, etc.) are present in apparently infinite variations, each fibre can be reduced to a finite sequence of tandem segments of just three types: straight, bent/curly, or twisted. Hair forms can thus be regarded as resulting from genetic pathways that induce, reverse or modulate these basic curvature modes. However, physical interconversions between twists and curls demonstrate that strict one-to-one correspondences between them and their genetic causes do not exist. Current hair-curvature theories do not distinguish between bending and twisting mechanisms. We here introduce a multiple papillary centres (MPC) model which is particularly suitable to explain twisting. The model combines previously known features of hair cross-sectional morphology with partially/completely separated dermal papillae within single follicles, and requires such papillae to induce differential growth rates of hair cortical material in their immediate neighbourhoods. The MPC model can further help to explain other, poorly understood, aspects of hair growth and morphology. Separate bending and twisting mechanisms would be preferentially affected at the major or minor ellipsoidal sides of fibres, respectively, and together they exhaust the possibilities for influencing hair-form phenotypes. As such they suggest dialectic for hair-curvature development. We define a natural-dialectic (ND) which could take advantage of speculative aspects of dialectic, but would verify its input data and results by experimental methods. We use this as a top-down approach to first define routes by which hair bending or twisting may be brought about and then review evidence in support of such routes. In particular we consider the wingless (Wnt) and mammalian target of rapamycin (mTOR) pathways as paradigm pathways for molecular hair bending and twisting mechanisms, respectively. In addition to the Wnt canonical pathway, the Wnt/Ca(2+) and planar cell polarity (PCP) pathways

The effect of fibre loading and graphene on the mechanical properties of goat hair fibre epoxy composite

Science.gov (United States)

Jayaseelan, J.; Vijayakumar, K. R.; Ethiraj, N.; Sivabalan, T.; nallayan, W. Andrew

2017-12-01

Composite materials are heterogenous materials containing one or more solid phases. In recent years cost-effective composite making is an ideal task. Hence we have come out with a natural fibre composite, which contains goat hair and epoxy as a binding element, with the combination of Graphene as a main source of enhanced mechanical property. Fabrication of natural composite consists of five layers of goat hair sandwiched in epoxy matrix. These composites made are tested for mechanical properties including Tensile strength, Flexural strength, Inter laminar shear and Impact strength. The mechanical properties of the six composite sets are analyzed and reported.

Drugs and hair loss.

Science.gov (United States)

Patel, Mansi; Harrison, Shannon; Sinclair, Rodney

2013-01-01

Hair loss is a common complaint, both in men and women, and use of prescription medications is widespread. When there is a temporal association between the onset of hair loss and commencement of a medication, the medication is commonly thought to have caused the hair loss. However, hair loss and in particular telogen effluvium may occur in response to a number of triggers including fever, hemorrhage, severe illness, stress, and childbirth, and a thorough exclusion of these potential confounders is necessary before the hair loss can be blamed on the medication. Certain medications are known to cause hair loss by a variety of mechanisms including anagen arrest, telogen effluvium, or accentuation of androgenetic alopecia by androgens. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

The roles of USH1 proteins and PDZ domain-containing USH proteins in USH2 complex integrity in cochlear hair cells.

Science.gov (United States)

Zou, Junhuang; Chen, Qian; Almishaal, Ali; Mathur, Pranav Dinesh; Zheng, Tihua; Tian, Cong; Zheng, Qing Y; Yang, Jun

2017-02-01

Usher syndrome (USH) is the most common cause of inherited deaf-blindness, manifested as USH1, USH2 and USH3 clinical types. The protein products of USH2 causative and modifier genes, USH2A, ADGRV1, WHRN and PDZD7, interact to assemble a multiprotein complex at the ankle link region of the mechanosensitive stereociliary bundle in hair cells. Defects in this complex cause stereociliary bundle disorganization and hearing loss. The four USH2 proteins also interact in vitro with USH1 proteins including myosin VIIa, USH1G (SANS), CIB2 and harmonin. However, it is unclear whether the interactions between USH1 and USH2 proteins occur in vivo and whether USH1 proteins play a role in USH2 complex assembly in hair cells. In this study, we identified a novel interaction between myosin VIIa and PDZD7 by FLAG pull-down assay. We further investigated the role of the above-mentioned four USH1 proteins in the cochlear USH2 complex assembly using USH1 mutant mice. We showed that only myosin VIIa is indispensable for USH2 complex assembly at ankle links, indicating the potential transport and/or anchoring role of myosin VIIa for USH2 proteins in hair cells. However, myosin VIIa is not required for USH2 complex assembly in photoreceptors. We further showed that, while PDZ protein harmonin is not involved, its paralogous USH2 proteins, PDZD7 and whirlin, function synergistically in USH2 complex assembly in cochlear hair cells. In summary, our studies provide novel insight into the functional relationship between USH1 and USH2 proteins in the cochlea and the retina as well as the disease mechanisms underlying USH1 and USH2. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Influence of Fiber Bundle Morphology on the Mechanical and Bonding Properties of Cotton Stalk and Mulberry Branch Reconstituted Square Lumber

Directory of Open Access Journals (Sweden)

Jing Zhang

2016-08-01

Full Text Available The mechanical properties of natural fiber composites can be strengthened in the longitudinal direction if the fiber is formed in a parallel manner. Reconstituted cotton stalk lumber and mulberry branch lumber were fabricated using hot-press technology, and the effects of fiber morphology on their mechanical and bonding properties were investigated. The fiber bundle size had a great influence on the mechanical and bonding properties of the final products. The maximum specific modulus of rupture (MOR and specific modulus of elasticity (MOE of the reconstituted lumber were obtained for medium-size fiber bundles, and the maximum MOR and MOE of reconstituted cotton stalk lumber was 130.3 MPa·g-1·cm-3 and 12.9 GPa·g-1·cm-3, respectively. The maximum MOR and MOE of the mulberry branch lumber was 147.2 MPa·g-1·cm-3 and 14.7 GPa·g-1·cm-3, respectively. Mechanical interlocking structures in the lumber were observed via fluorescence microscopy, showing that phenol-formaldehyde adhesive had penetrated into several cell layers of the fiber bundle under heating and pressure. The adhesive penetration capacity was stronger when the fiber bundles were smaller in size and density. The reconstituted lumber fabricated from both materials exhibited excellent mechanical performance in the parallel direction. Therefore, reconstituted cotton stalk and mulberry branch lumber are attractive potential materials for the construction industry.

XIRP2, an Actin-Binding Protein Essential for Inner Ear Hair-Cell Stereocilia

Directory of Open Access Journals (Sweden)

Déborah I. Scheffer

2015-03-01

Full Text Available Hair cells of the inner ear are mechanoreceptors for hearing and balance, and proteins highly enriched in hair cells may have specific roles in the development and maintenance of the mechanotransduction apparatus. We identified XIRP2/mXinβ as an enriched protein likely to be essential for hair cells. We found that different isoforms of this protein are expressed and differentially located: short splice forms (also called XEPLIN are targeted more to stereocilia, whereas two long isoforms containing a XIN-repeat domain are in both stereocilia and cuticular plates. Mice lacking the Xirp2 gene developed normal stereocilia bundles, but these degenerated with time: stereocilia were lost and long membranous protrusions emanated from the nearby apical surfaces. At an ultrastructural level, the paracrystalline actin filaments became disorganized. XIRP2 is apparently involved in the maintenance of actin structures in stereocilia and cuticular plates of hair cells, and perhaps in other organs where it is expressed.

Deletion of PDZD7 disrupts the Usher syndrome type 2 protein complex in cochlear hair cells and causes hearing loss in mice.

Science.gov (United States)

Zou, Junhuang; Zheng, Tihua; Ren, Chongyu; Askew, Charles; Liu, Xiao-Ping; Pan, Bifeng; Holt, Jeffrey R; Wang, Yong; Yang, Jun

2014-05-01

Usher syndrome type 2 (USH2) is the predominant form of USH, a leading genetic cause of combined deafness and blindness. PDZD7, a paralog of two USH causative genes, USH1C and USH2D (WHRN), was recently reported to be implicated in USH2 and non-syndromic deafness. It encodes a protein with multiple PDZ domains. To understand the biological function of PDZD7 and the pathogenic mechanism caused by PDZD7 mutations, we generated and thoroughly characterized a Pdzd7 knockout mouse model. The Pdzd7 knockout mice exhibit congenital profound deafness, as assessed by auditory brainstem response, distortion product otoacoustic emission and cochlear microphonics tests, and normal vestibular function, as assessed by their behaviors. Lack of PDZD7 leads to the disorganization of stereocilia bundles and a reduction in mechanotransduction currents and sensitivity in cochlear outer hair cells. At the molecular level, PDZD7 determines the localization of the USH2 protein complex, composed of USH2A, GPR98 and WHRN, to ankle links in developing cochlear hair cells, likely through its direct interactions with these three proteins. The localization of PDZD7 to the ankle links of cochlear hair bundles also relies on USH2 proteins. In photoreceptors of Pdzd7 knockout mice, the three USH2 proteins largely remain unchanged at the periciliary membrane complex. The electroretinogram responses of both rod and cone photoreceptors are normal in knockout mice at 1 month of age. Therefore, although the organization of the USH2 complex appears different in photoreceptors, it is clear that PDZD7 plays an essential role in organizing the USH2 complex at ankle links in developing cochlear hair cells. GenBank accession numbers: KF041446, KF041447, KF041448, KF041449, KF041450, KF041451.

The function and molecular identity of inward rectifier channels in vestibular hair cells of the mouse inner ear

Science.gov (United States)

Levin, Michaela E.

2012-01-01

Inner ear hair cells respond to mechanical stimuli with graded receptor potentials. These graded responses are modulated by a host of voltage-dependent currents that flow across the basolateral membrane. Here, we examine the molecular identity and the function of a class of voltage-dependent ion channels that carries the potassium-selective inward rectifier current known as IK1. IK1 has been identified in vestibular hair cells of various species, but its molecular composition and functional contributions remain obscure. We used quantitative RT-PCR to show that the inward rectifier gene, Kir2.1, is highly expressed in mouse utricle between embryonic day 15 and adulthood. We confirmed Kir2.1 protein expression in hair cells by immunolocalization. To examine the molecular composition of IK1, we recorded voltage-dependent currents from type II hair cells in response to 50-ms steps from −124 to −54 in 10-mV increments. Wild-type cells had rapidly activating inward currents with reversal potentials close to the K+ equilibrium potential and a whole-cell conductance of 4.8 ± 1.5 nS (n = 46). In utricle hair cells from Kir2.1-deficient (Kir2.1−/−) mice, IK1 was absent at all stages examined. To identify the functional contribution of Kir2.1, we recorded membrane responses in current-clamp mode. Hair cells from Kir2.1−/− mice had significantly (P < 0.001) more depolarized resting potentials and larger, slower membrane responses than those of wild-type cells. These data suggest that Kir2.1 is required for IK1 in type II utricle hair cells and contributes to hyperpolarized resting potentials and fast, small amplitude receptor potentials in response to current inputs, such as those evoked by hair bundle deflections. PMID:22496522

Monoubiquitination Inhibits the Actin Bundling Activity of Fascin.

Science.gov (United States)

Lin, Shengchen; Lu, Shuang; Mulaj, Mentor; Fang, Bin; Keeley, Tyler; Wan, Lixin; Hao, Jihui; Muschol, Martin; Sun, Jianwei; Yang, Shengyu

2016-12-30

Fascin is an actin bundling protein that cross-links individual actin filaments into straight, compact, and stiff bundles, which are crucial for the formation of filopodia, stereocillia, and other finger-like membrane protrusions. The dysregulation of fascin has been implicated in cancer metastasis, hearing loss, and blindness. Here we identified monoubiquitination as a novel mechanism that regulates fascin bundling activity and dynamics. The monoubiquitination sites were identified to be Lys 247 and Lys 250 , two residues located in a positive charge patch at the actin binding site 2 of fascin. Using a chemical ubiquitination method, we synthesized chemically monoubiquitinated fascin and determined the effects of monoubiquitination on fascin bundling activity and dynamics. Our data demonstrated that monoubiquitination decreased the fascin bundling EC 50 , delayed the initiation of bundle assembly, and accelerated the disassembly of existing bundles. By analyzing the electrostatic properties on the solvent-accessible surface of fascin, we proposed that monoubiquitination introduced steric hindrance to interfere with the interaction between actin filaments and the positively charged patch at actin binding site 2. We also identified Smurf1 as a E3 ligase regulating the monoubiquitination of fascin. Our findings revealed a previously unidentified regulatory mechanism for fascin, which will have important implications for the understanding of actin bundle regulation under physiological and pathological conditions. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Monoubiquitination Inhibits the Actin Bundling Activity of Fascin*

Science.gov (United States)

Lin, Shengchen; Lu, Shuang; Mulaj, Mentor; Fang, Bin; Keeley, Tyler; Wan, Lixin; Hao, Jihui; Muschol, Martin; Sun, Jianwei; Yang, Shengyu

2016-01-01

Fascin is an actin bundling protein that cross-links individual actin filaments into straight, compact, and stiff bundles, which are crucial for the formation of filopodia, stereocillia, and other finger-like membrane protrusions. The dysregulation of fascin has been implicated in cancer metastasis, hearing loss, and blindness. Here we identified monoubiquitination as a novel mechanism that regulates fascin bundling activity and dynamics. The monoubiquitination sites were identified to be Lys247 and Lys250, two residues located in a positive charge patch at the actin binding site 2 of fascin. Using a chemical ubiquitination method, we synthesized chemically monoubiquitinated fascin and determined the effects of monoubiquitination on fascin bundling activity and dynamics. Our data demonstrated that monoubiquitination decreased the fascin bundling EC50, delayed the initiation of bundle assembly, and accelerated the disassembly of existing bundles. By analyzing the electrostatic properties on the solvent-accessible surface of fascin, we proposed that monoubiquitination introduced steric hindrance to interfere with the interaction between actin filaments and the positively charged patch at actin binding site 2. We also identified Smurf1 as a E3 ligase regulating the monoubiquitination of fascin. Our findings revealed a previously unidentified regulatory mechanism for fascin, which will have important implications for the understanding of actin bundle regulation under physiological and pathological conditions. PMID:27879315

Auditory hair cell defects as potential cause for sensorineural deafness in Wolf-Hirschhorn syndrome

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Mohi Ahmed

2015-09-01

Full Text Available WHSC1 is a histone methyltransferase (HMT that catalyses the addition of methyl groups to lysine 36 on histone 3. In humans, WHSC1 haploinsufficiency is associated with all known cases of Wolf-Hirschhorn syndrome (WHS. The cardinal feature of WHS is a craniofacial dysmorphism, which is accompanied by sensorineural hearing loss in 15% of individuals with WHS. Here, we show that WHSC1-deficient mice display craniofacial defects that overlap with WHS, including cochlea anomalies. Although auditory hair cells are specified normally, their stereocilia hair bundles required for sound perception fail to develop the appropriate morphology. Furthermore, the orientation and cellular organisation of cochlear hair cells and their innervation are defective. These findings identify, for the first time, the likely cause of sensorineural hearing loss in individuals with WHS.

Oxidative stress in ageing of hair.

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Trüeb, Ralph M

2009-01-01

Experimental evidence supports the hypothesis that oxidative stress plays a major role in the ageing process. Reactive oxygen species are generated by a multitude of endogenous and environmental challenges. Reactive oxygen species or free radicals are highly reactive molecules that can directly damage cellular structural membranes, lipids, proteins, and DNA. The body possesses endogenous defence mechanisms, such as antioxidative enzymes and non-enzymatic antioxidative molecules, protecting it from free radicals by reducing and neutralizing them. With age, the production of free radicals increases, while the endogenous defence mechanisms decrease. This imbalance leads to the progressive damage of cellular structures, presumably resulting in the ageing phenotype. Ageing of hair manifests as decrease of melanocyte function or graying, and decrease in hair production or alopecia. There is circumstantial evidence that oxidative stress may be a pivotal mechanism contributing to hair graying and hair loss. New insights into the role and prevention of oxidative stress could open new strategies for intervention and reversal of the hair graying process and age-dependent alopecia.

In Vitro Methodologies to Evaluate the Effects of Hair Care Products on Hair Fiber

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Robson Miranda da Gama

2017-01-01

Full Text Available Consumers use different hair care products to change the physical appearance of their hair, such as shampoos, conditioners, hair dye and hair straighteners. They expect cosmetics products to be available in the market to meet their needs in a broad and effective manner. Evaluating efficacy of hair care products in vitro involves the use of highly accurate equipment. This review aims to discuss in vitro methodologies used to evaluate the effects of hair care products on hair fiber, which can be assessed by various methods, such as Scanning Electron Microscopy, Transmission Electron Microscopy, Atomic Force Microscopy, Optical Coherence Tomography, Infrared Spectroscopy, Raman Spectroscopy, Protein Loss, Electrophoresis, color and brightness, thermal analysis and measuring mechanical resistance to combing and elasticity. The methodology used to test hair fibers must be selected according to the property being evaluated, such as sensory characteristics, determination of brightness, resistance to rupture, elasticity and integrity of hair strain and cortex, among others. If equipment is appropriate and accurate, reproducibility and ease of employment of the analytical methodology will be possible. Normally, the data set must be discussed in order to obtain conclusive answers to the test.

Pure states of general quantum-mechanical systems as Kaehler bundles

International Nuclear Information System (INIS)

Abbati, M.C.; Cirelli, R.; Lanzavecchia, P.; Mania, A.

1984-01-01

Pure states of general quantum systems in the Csup(*)-algebraic approach are endowed with a structure both of Kaehler manifold and of projective bundle with uniformity on the total space. The former structure gives a geometric interpretation of transition probabilities and Wigner theorem. The latter is a finer structure which determines Csup(*)-algebras up to sup(*)-isomorphisms. Pure states of Csup(*)-algebras with continuous trace among projective bundles with uniformity are characterized

Auditory hair cell defects as potential cause for sensorineural deafness in Wolf-Hirschhorn syndrome.

Science.gov (United States)

Ahmed, Mohi; Ura, Kiyoe; Streit, Andrea

2015-09-01

WHSC1 is a histone methyltransferase (HMT) that catalyses the addition of methyl groups to lysine 36 on histone 3. In humans, WHSC1 haploinsufficiency is associated with all known cases of Wolf-Hirschhorn syndrome (WHS). The cardinal feature of WHS is a craniofacial dysmorphism, which is accompanied by sensorineural hearing loss in 15% of individuals with WHS. Here, we show that WHSC1-deficient mice display craniofacial defects that overlap with WHS, including cochlea anomalies. Although auditory hair cells are specified normally, their stereocilia hair bundles required for sound perception fail to develop the appropriate morphology. Furthermore, the orientation and cellular organisation of cochlear hair cells and their innervation are defective. These findings identify, for the first time, the likely cause of sensorineural hearing loss in individuals with WHS. © 2015. Published by The Company of Biologists Ltd.

Biophysics of Human Hair Structural, Nanomechanical, and Nanotribological Studies

CERN Document Server

Bhushan, Bharat

2010-01-01

This book presents the biophysics of hair. It deals with the structure of hair, its mechanical properties, the nanomechanical characterization, tensile deformation, tribological characterization, the thickness distribution and binding interactions on hair surface. Another important topic of the book is the health of hair, human hair and skin, hair care, cleaning and conditioning treatments and damaging processes. It is the first book on the biophysical properties of hair.

Hair Transplantation in Migraine Headache Patients

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Safvet Ors, MD

2017-09-01

Conclusions:. This report details 6 patients who experienced abatement of migraine headache symptoms following hair transplantation. The positive effects of hair transplantation on migraine headache and potential mechanisms of action are also discussed.

Mechanical dispersion is associated with poor outcome in heart failure with a severely depressed left ventricular function and bundle branch blocks.

Science.gov (United States)

Stankovic, Ivan; Janicijevic, Aleksandra; Dimic, Aleksandra; Stefanovic, Milica; Vidakovic, Radosav; Putnikovic, Biljana; Neskovic, Aleksandar N

2018-03-01

Bundle branch blocks (BBB)-related mechanical dyssynchrony and dispersion may improve patient selection for device therapy, but their effect on the natural history of this patient population is unknown. A total of 155 patients with LVEF ≤ 35% and BBB, not treated with device therapy, were included. Mechanical dyssynchrony was defined as the presence of either septal flash or apical rocking. Contraction duration was assessed as time interval from the electrocardiographic R-(Q-)wave to peak longitudinal strain in each of 17 left ventricular segments. Mechanical dispersion was defined as either the standard deviation of all time intervals (dispersion SD ) or as the difference between the longest and shortest time intervals (dispersion delta ). Patients were followed for cardiac mortality during a median period of 33 months. Mechanical dyssynchrony was not associated with survival. More pronounced mechanical dispersion delta was found in patients with dyssynchrony than in those without. In the multivariate regression analysis, patients' functional class, diabetes mellitus and dispersion delta were independently associated with mortality. Mechanical dispersion, but not dyssynchrony, was independently associated with mortality and it may be useful for risk stratification of patients with heart failure (HF) and BBB. Key Messages Mechanical dispersion, measured by strain echocardiography, is associated with poor outcome in heart failure with a severely depressed left ventricular function and bundle branch blocks. Mechanical dispersion may be useful for risk stratification of patients with heart failure and bundle branch blocks.

Temperature dependency of cupular mechanics and hair cell frequency selectivity in the fish canal lateral line organ

NARCIS (Netherlands)

Wiersinga-Post, JEC; van Netten, SM

2000-01-01

The mechanical frequency selectivity of the cupula located in the supraorbital lateral line canal and the frequency selectivity of the hair cells driven by the cupula were measured simultaneously in vivo. Laser interferometry was used to measure cupular mechanics and extracellular receptor

Assembly mechanism for nuclear fuel bundles

International Nuclear Information System (INIS)

Long, J.W.; Flora, B.S.; Ford, K.L.

1980-01-01

The invention relates to a nuclear power reactor fuel bundle of the type wherein several rods are mounted in parallel array between two tie plates which secure the fuel rods in place and are maintained in assembled position by means of a number of tie rods secured to both of the end plates. Improved apparatus is provided for attaching the tie rods to the upper tie plate by the use of locking lugs fixed to rotatable sleeves which engage the upper tie plate. (auth)

Left bundle-branch block

DEFF Research Database (Denmark)

Risum, Niels; Strauss, David; Sogaard, Peter

2013-01-01

The relationship between myocardial electrical activation by electrocardiogram (ECG) and mechanical contraction by echocardiography in left bundle-branch block (LBBB) has never been clearly demonstrated. New strict criteria for LBBB based on a fundamental understanding of physiology have recently...

WNT and DKK Determine Hair Follicle Spacing Through a Reaction-Diffusion Mechanism

Science.gov (United States)

Sick, Stefanie; Reinker, Stefan; Timmer, Jens; Schlake, Thomas

2006-12-01

Mathematical reaction-diffusion models have been suggested to describe formation of animal pigmentation patterns and distribution of epidermal appendages. However, the crucial signals and in vivo mechanisms are still elusive. Here we identify WNT and its inhibitor DKK as primary determinants of murine hair follicle spacing, using a combined experimental and computational modeling approach. Transgenic DKK overexpression reduces overall appendage density. Moderate suppression of endogenous WNT signaling forces follicles to form clusters during an otherwise normal morphogenetic program. These results confirm predictions of a WNT/DKK-specific mathematical model and provide in vivo corroboration of the reaction-diffusion mechanism for epidermal appendage formation.

Raman spectroscopic analyses of preserved historical specimens of human hair attributed to Robert Stephenson and Sir Isaac Newton.

Science.gov (United States)

Edwards, Howell G M; Hassan, Nik F N; Wilson, Andrew S

2004-10-01

The Raman spectra of two historical specimens of human hair attributed to the engineer Robert Stephenson and scientist Sir Isaac Newton, preserved in private collections are reported. Comparisons are made with the Raman spectra of modern hair specimens and with hair from archaeological excavations. The hair spectra collected with a laser excitation of 785 nm are of a better quality than those collected using 1064 nm. The historical hair specimens are remarkably well-defined spectroscopically in terms of the amide I vibrational mode and the [small nu](SS), ascribed to a predominantly gauche-gauche-gauche CSSC conformation. The contrast with degraded hair specimens recovered from archaeological excavations is striking. The presence of a weak feature near 2590 cm(-1) in the hair samples attributed to a [small nu](SH) vibration could be indicative of a reduction process operative on the CSSC cystine keratotic linkages and a possible origin of this is bacterial biodegradation identified histologically. This study demonstrates the molecular information available from non-destructive Raman spectroscopic analysis from single hair shafts or small bundles of fibres which complements information available from histological and destructive analytical techniques for rare biological specimens subjected to conservation or curation procedures in museums or private collections.

Bundling of elastic filaments induced by hydrodynamic interactions

Science.gov (United States)

Man, Yi; Page, William; Poole, Robert J.; Lauga, Eric

2017-12-01

Peritrichous bacteria swim in viscous fluids by rotating multiple helical flagellar filaments. As the bacterium swims forward, all its flagella rotate in synchrony behind the cell in a tight helical bundle. When the bacterium changes its direction, the flagellar filaments unbundle and randomly reorient the cell for a short period of time before returning to their bundled state and resuming swimming. This rapid bundling and unbundling is, at its heart, a mechanical process whereby hydrodynamic interactions balance with elasticity to determine the time-varying deformation of the filaments. Inspired by this biophysical problem, we present in this paper what is perhaps the simplest model of bundling whereby two or more straight elastic filaments immersed in a viscous fluid rotate about their centerline, inducing rotational flows which tend to bend the filaments around each other. We derive an integrodifferential equation governing the shape of the filaments resulting from mechanical balance in a viscous fluid at low Reynolds number. We show that such equation may be evaluated asymptotically analytically in the long-wavelength limit, leading to a local partial differential equation governed by a single dimensionless bundling number. A numerical study of the dynamics predicted by the model reveals the presence of two configuration instabilities with increasing bundling numbers: first to a crossing state where filaments touch at one point and then to a bundled state where filaments wrap along each other in a helical fashion. We also consider the case of multiple filaments and the unbundling dynamics. We next provide an intuitive physical model for the crossing instability and show that it may be used to predict analytically its threshold and adapted to address the transition to a bundling state. We then use a macroscale experimental implementation of the two-filament configuration in order to validate our theoretical predictions and obtain excellent agreement. This long

Verification of the FBR fuel bundle-duct interaction analysis code BAMBOO by the out-of-pile bundle compression test with large diameter pins

Science.gov (United States)

Uwaba, Tomoyuki; Ito, Masahiro; Nemoto, Junichi; Ichikawa, Shoichi; Katsuyama, Kozo

2014-09-01

The BAMBOO computer code was verified by results for the out-of-pile bundle compression test with large diameter pin bundle deformation under the bundle-duct interaction (BDI) condition. The pin diameters of the examined test bundles were 8.5 mm and 10.4 mm, which are targeted as preliminary fuel pin diameters for the upgraded core of the prototype fast breeder reactor (FBR) and for demonstration and commercial FBRs studied in the FaCT project. In the bundle compression test, bundle cross-sectional views were obtained from X-ray computer tomography (CT) images and local parameters of bundle deformation such as pin-to-duct and pin-to-pin clearances were measured by CT image analyses. In the verification, calculation results of bundle deformation obtained by the BAMBOO code analyses were compared with the experimental results from the CT image analyses. The comparison showed that the BAMBOO code reasonably predicts deformation of large diameter pin bundles under the BDI condition by assuming that pin bowing and cladding oval distortion are the major deformation mechanisms, the same as in the case of small diameter pin bundles. In addition, the BAMBOO analysis results confirmed that cladding oval distortion effectively suppresses BDI in large diameter pin bundles as well as in small diameter pin bundles.

Thinning Hair and Hair Loss: Could it be Female Pattern Hair Loss?

Science.gov (United States)

... mcat1=de12", ]; for (var c = 0; c Thinning hair and hair loss: Could it be female pattern hair loss? Female pattern hair loss: Without treatment, female ... can I tell if I have female pattern hair loss? It’s best to make an appointment to ...

Equilibrium polyelectrolyte bundles with different multivalent counterion concentrations

Science.gov (United States)

Sayar, Mehmet; Holm, Christian

2010-09-01

We present the results of molecular-dynamics simulations on the salt concentration dependence of the formation of polyelectrolyte bundles in thermodynamic equilibrium. Extending our results on salt-free systems we investigate here deficiency or excess of trivalent counterions in solution. Our results reveal that the trivalent counterion concentration significantly alters the bundle size and size distribution. The onset of bundle formation takes place at earlier Bjerrum length values with increasing trivalent counterion concentration. For the cases of 80%, 95%, and 100% charge compensation via trivalent counterions, the net charge of the bundles decreases with increasing size. We suggest that competition among two different mechanisms, counterion condensation and merger of bundles, leads to a nonmonotonic change in line-charge density with increasing Bjerrum length. The investigated case of having an abundance of trivalent counterions by 200% prohibits such a behavior. In this case, we find that the difference in effective line-charge density of different size bundles diminishes. In fact, the system displays an isoelectric point, where all bundles become charge neutral.

Response to a pure tone in a nonlinear mechanical-electrical-acoustical model of the cochlea.

Science.gov (United States)

Meaud, Julien; Grosh, Karl

2012-03-21

In this article, a nonlinear mathematical model is developed based on the physiology of the cochlea of the guinea pig. The three-dimensional intracochlear fluid dynamics are coupled to a micromechanical model of the organ of Corti and to electrical potentials in the cochlear ducts and outer hair cells (OHC). OHC somatic electromotility is modeled by linearized piezoelectric relations whereas the OHC hair-bundle mechanoelectrical transduction current is modeled as a nonlinear function of the hair-bundle deflection. The steady-state response of the cochlea to a single tone is simulated in the frequency domain using an alternating frequency time scheme. Compressive nonlinearity, harmonic distortion, and DC shift on the basilar membrane (BM), tectorial membrane (TM), and OHC potentials are predicted using a single set of parameters. The predictions of the model are verified by comparing simulations to available in vivo experimental data for basal cochlear mechanics. In particular, the model predicts more amplification on the reticular lamina (RL) side of the cochlear partition than on the BM, which replicates recent measurements. Moreover, small harmonic distortion and DC shifts are predicted on the BM, whereas more significant harmonic distortion and DC shifts are predicted in the RL and TM displacements and in the OHC potentials. Copyright © 2012 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Plant 115-kDa actin-filament bundling protein, P-115-ABP, is a homologue of plant villin and is widely distributed in cells.

Science.gov (United States)

Yokota, Etsuo; Vidali, Luis; Tominaga, Motoki; Tahara, Hiroshi; Orii, Hidefumi; Morizane, Yosuke; Hepler, Peter K; Shimmen, Teruo

2003-10-01

In many cases, actin filaments are arranged into bundles and serve as tracks for cytoplasmic streaming in plant cells. We have isolated an actin-filament bundling protein, which is composed of 115-kDa polypeptide (P-115-ABP), from the germinating pollen of lily, Lilium longiflorum [Nakayasu et al. (1998) BIOCHEM: Biophys. Res. Commun. 249: 61]. P-115-ABP shared similar antigenicity with a plant 135-kDa actin-filament bundling protein (P-135-ABP), a plant homologue of villin. A full-length cDNA clone (ABP115; accession no. AB097407) was isolated from an expression cDNA library of lily pollen by immuno-screening using antisera against P-115-ABP and P-135-ABP. The amino acid sequence of P-115-ABP deduced from this clone showed high homology with those of P-135-ABP and four villin isoforms of Arabidopsis thaliana (AtVLN1, AtVLN2, AtVLN3 and AtVLN4), especially AtVLN4, indicating that P-115-ABP can also be classified as a plant villin. The P-115-ABP isolated biochemically from the germinating lily pollen was able to arrange F-actin filaments with uniform polarity into bundles and this bundling activity was suppressed by Ca2+-calmodulin (CaM), similar to the actin-filament bundling properties of P-135-ABP. The P-115-ABP type of plant villin was widely distributed in plant cells, from algae to land plants. In root hair cells of Hydrocharis dubia, this type of plant villin was co-localized with actin-filament bundles in the transvacuolar strands and the sub-cortical regions. Microinjection of the antiserum against P-115-ABP into living root hair cells caused the disappearance of transvaculor strands and alteration of the route of cytoplasmic streaming. In internodal cells of Chara corallina in which the P-135-ABP type of plant villin is lacking, the P-115-ABP type showed co-localization with actin-filament cables anchored on the intracellular surface of chloroplasts. These results indicated that plant villins are widely distributed and involved in the organization of actin

Higher order jet prolongations type gauge natural bundles over vector bundles

Directory of Open Access Journals (Sweden)

Jan Kurek

2004-05-01

Full Text Available Let $rgeq 3$ and $mgeq 2$ be natural numbers and $E$ be a vector bundle with $m$-dimensional basis. We find all gauge natural bundles ``similar" to the $r$-jet prolongation bundle $J^rE$ of $E$. We also find all gauge natural bundles ``similar" to the vector $r$-tangent bundle $(J^r_{fl}(E,R_0^*$ of $E$.

Idiopathic hirsutism: excessive bodily and facial hair in women.

Science.gov (United States)

Elghblawi, Ebtisam

Hirsutism is the excessive and increased bodily and facial hair growth in women in locations where hair is normally minimal or absent. It refers to the growth of hair in a pattern normally occurring only in men, and therefore primarily raises psychological, cosmetic and social concerns. Idiopathic hirsutism (IH), where the cause of excessive hair growth is unknown, is considered to be the most common form of hirsutism. It is suspected that this type of hirsutism may be familial, as there is often a family history of the condition. Women with IH will generally have normal menses and normal levels of testosterone. There are many treatment modalities that fall into two broad groups: medical and mechanical treatment. An example of a medical treatment is when an agent is used, which interferes with the synthesis of androgen at the ovarian or adrenal level, or by inhibiting the effect of androgen at the receptor level. An example of a mechanical treatment is laser hair removal, where the hair follicle is destroyed; however, much depends on the on the skill of the treating practitioner, laser type, laser spot size, skin type, hair colour, and the stage at which the hair follicles were during their hair growth cycle, and the delivered wavelength. Laser offers the fastest method of hair loss. Other mechanical treatments include electrolysis, depilatory creams, plucking and waxing. This article presents a general overview of IH, including a definition, diagnostic measures, clinical manifestations, normal and abnormal physiology, and treatment options.

Observed mechanism for the breakup of small bundles of cellulose Iα and Iβ in ionic liquids from molecular dynamics simulations.

Science.gov (United States)

Rabideau, Brooks D; Agarwal, Animesh; Ismail, Ahmed E

2013-04-04

Explicit, all-atom molecular dynamics simulations are used to study the breakup of small bundles of cellulose Iα and Iβ in the ionic liquids [BMIM]Cl, [EMIM]Ac, and [DMIM]DMP. In all cases, significant breakup of the bundles is observed with the initial breakup following a common underlying mechanism. Anions bind strongly to the hydroxyl groups of the exterior strands of the bundle, forming negatively charged complexes. Binding also weakens the intrastrand hydrogen bonds present in the cellulose strands, providing greater strand flexibility. Cations then intercalate between the individual strands, likely due to charge imbalances, providing the bulk to push the individual moieties apart and initiating the separation. The peeling of an individual strand from the main bundle is observed in [EMIM]Ac with an analysis of its hydrogen bonds with other strands showing that the chain detaches glucan by glucan from the main bundle in discrete, rapid events. Further analysis shows that the intrastrand hydrogen bonds of each glucan tend to break for a sustained period of time before the interstrand hydrogen bonds break and strand detachment occurs. Examination of similar nonpeeling strands shows that, without this intrastrand hydrogen bond breakage, the structural rigidity of the individual unit can hinder its peeling despite interstrand hydrogen bond breakage.

Distinct roles of Eps8 in the maturation of cochlear and vestibular hair cells.

Science.gov (United States)

Tavazzani, Elisa; Spaiardi, Paolo; Zampini, Valeria; Contini, Donatella; Manca, Marco; Russo, Giancarlo; Prigioni, Ivo; Marcotti, Walter; Masetto, Sergio

2016-07-22

Several genetic mutations affecting the development and function of mammalian hair cells have been shown to cause deafness but not vestibular defects, most likely because vestibular deficits are sometimes centrally compensated. The study of hair cell physiology is thus a powerful direct approach to ascertain the functional status of the vestibular end organs. Deletion of Epidermal growth factor receptor pathway substrate 8 (Eps8), a gene involved in actin remodeling, has been shown to cause deafness in mice. While both inner and outer hair cells from Eps8 knockout (KO) mice showed abnormally short stereocilia, inner hair cells (IHCs) also failed to acquire mature-type ion channels. Despite the fact that Eps8 is also expressed in vestibular hair cells, Eps8 KO mice show no vestibular deficits. In the present study we have investigated the properties of vestibular Type I and Type II hair cells in Eps8-KO mice and compared them to those of cochlear IHCs. In the absence of Eps8, vestibular hair cells show normally long kinocilia, significantly shorter stereocilia and a normal pattern of basolateral voltage-dependent ion channels. We have also found that while vestibular hair cells from Eps8 KO mice show normal voltage responses to injected sinusoidal currents, which were used to mimic the mechanoelectrical transducer current, IHCs lose their ability to synchronize their responses to the stimulus. We conclude that the absence of Eps8 produces a weaker phenotype in vestibular hair cells compared to cochlear IHCs, since it affects the hair bundle morphology but not the basolateral membrane currents. This difference is likely to explain the absence of obvious vestibular dysfunction in Eps8 KO mice. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

Hair Dye and Hair Relaxers

Science.gov (United States)

... For Consumers Consumer Information by Audience For Women Hair Dye and Hair Relaxers Share Tweet Linkedin Pin it More sharing ... products. If you have a bad reaction to hair dyes and relaxers, you should: Stop using the ...

Co-planar deformation and thermal propagation behavior in a bundle burst test

International Nuclear Information System (INIS)

Uetsuka, Hiroshi; Koizumi, Yasuo; Kawasaki, Satoru

1980-07-01

The probability of the suggested feedback mechanism which could lead to co-planar deformation in a bundle burst test was assessed by the data of test and the calculation based on simplified model. Following four points were evaluated. (1) The probability of local deformation during early heat up stage. (2) The relation between the characteristic of heater and the feedback mechanism. (3) Thermal propagation behavior between two adjacent rods during heat up stage. (4) The propagation of ballooning in a bundle. The probability of suggested feedback mechanism was denied in all the evaluation. The feedback mechanism suggested by Burman could not be a controlling mechanism in co-planar deformation in a bundle burst test. (author)

Hormonal therapy in female pattern hair loss

Directory of Open Access Journals (Sweden)

Kevin R. Brough

2017-03-01

Full Text Available Female pattern hair loss is the most common cause of hair loss in women and one of the most common problems seen by dermatologists. This hair loss is a nonscarring alopecia in which loss occurs on the vertex scalp, generally sparing the frontal hairline. Hair loss can have significant psychosocial effects on patients, and treatment can be long and difficult. The influence of hormones on the pathogenesis of female pattern hair loss is not entirely known. The purpose of this paper is to review physiology and potential hormonal mechanisms for the pathogenesis of female pattern hair loss. We also discuss the current hormonal and hormone-modifying therapies that are available to providers as they partner with patients to treat this frustrating issue.

Auditory hair cell centrioles undergo confined Brownian motion throughout the developmental migration of the kinocilium.

Science.gov (United States)

Lepelletier, Léa; de Monvel, Jacques Boutet; Buisson, Johanna; Desdouets, Chantal; Petit, Christine

2013-07-02

Planar polarization of the forming hair bundle, the mechanosensory antenna of auditory hair cells, depends on the poorly characterized center-to-edge displacement of a primary cilium, the kinocilium, at their apical surface. Taking advantage of the gradient of hair cell differentiation along the cochlea, we reconstituted a map of the kinocilia displacements in the mouse embryonic cochlea. We then developed a cochlear organotypic culture and video-microscopy approach to monitor the movements of the kinocilium basal body (mother centriole) and its daughter centriole, which we analyzed using particle tracking and modeling. We found that both hair cell centrioles undergo confined Brownian movements around their equilibrium positions, under the apparent constraint of a radial restoring force of ∼0.1 pN. This magnitude depended little on centriole position, suggesting nonlinear interactions with constraining, presumably cytoskeletal elements. The only dynamic change observed during the period of kinocilium migration was a doubling of the centrioles' confinement area taking place early in the process. It emerges from these static and dynamic observations that kinocilia migrate gradually in parallel with the organization of hair cells into rows during cochlear neuroepithelium extension. Analysis of the confined motion of hair cell centrioles under normal and pathological conditions should help determine which structures contribute to the restoring force exerting on them. Copyright © 2013 Biophysical Society. Published by Elsevier Inc. All rights reserved.

The behaviour of Phenix fuel pin bundle under irradiation

International Nuclear Information System (INIS)

Marbach, G.; Millet, P.; Blanchard, P.; Huillery, R.

1979-07-01

An entire Phenix sub-assembly has been mounted and sectioned after irradiation. The examination of cross-sections revealed the effects of mechanical interaction in the bundle (ovalisations and contacts between clads). According to analysis of the sodium channels, cooling of the pin bundle remained uniform. (author)

Bundles to prevent ventilator-associated pneumonia: how valuable are they?

Science.gov (United States)

Wip, Charity; Napolitano, Lena

2009-04-01

To review the value of care bundles to prevent ventilator-associated pneumonia (VAP). The Ventilator Bundle contains four components, elevation of the head of the bed to 30-45 degrees, daily 'sedation vacation' and daily assessment of readiness to extubate, peptic ulcer disease prophylaxis, and deep venous thrombosis prophylaxis, aimed to improve outcome in mechanically ventilated patients, but not all are associated with VAP prevention. Daily spontaneous awakening and breathing trials are associated with early liberation from mechanical ventilation and VAP reduction. Although a small prospective, randomized clinical study documented that the semirecumbent position was associated with a significant reduction in VAP, more recent studies have documented that the semirecumbent position is difficult to maintain in mechanically ventilated patients and may not impact VAP reduction. Prophylaxis for peptic ulcer disease and deep venous thrombosis do not directly impact VAP reduction. Other methods to reduce VAP, such as oral care and hygiene, chlorhexidine in the posterior pharynx, and specialized endotracheal tubes (continuous aspiration of subglottic secretions, silver-coated), should be considered for inclusion in a revised Ventilator Bundle more specifically aimed at VAP prevention. The Ventilator Bundle is an effective method to reduce VAP rates in ICUs. The ventilator bundle should be modified and expanded to include specific processes of care that have been definitively demonstrated to be effective in VAP reduction or a specific VAP bundle created to focus on VAP prevention.

Biophysics of Hair Cell Sensory Systems

NARCIS (Netherlands)

Duifhuis, Hendrikus; Horst, Johannes; van Dijk, Pim; van Netten, Sietse

1993-01-01

The last decade revealed to auditory researchers that hair cells can not only detect and process mechanical energy, but are also able to produce it. Thanks to the active hair cell, ears can produce otoacoustic emissions. This book gives the newest insights into the biophysics and physiology of

[When hair starts to fall out].

Science.gov (United States)

de Lorenzi, Caroline; Quenan, Sandrine

2018-03-28

Hair loss causes physical and psychological distress and represents a common motive of consultation both in general practice and dermatology. Causes of hair loss are highly diverse and can lead to a challenging diagnosis, which can delay its management. Knowledge of the main causes and their different mechanisms are thus necessary in order to optimize both the diagnosis and treatment. The purpose of this paper is to describe the main causes of hair loss in order to improve its diagnosis and management.

Hair dyeing, hair washing and hair cortisol concentrations among women from the healthy start study

DEFF Research Database (Denmark)

Kristensen, Sheila K.; Larsen, Sofus C.; Olsen, Nanna J.

2017-01-01

Background: Hair cortisol concentration (HCC) has been suggested as a promising marker for chronic stress. However, studies investigating the influence of hair dyeing and hair washing frequency on HCC have shown inconsistent results. Objective: To examine associations between HCC and hair dyeing...... status or weekly hair washing frequency among women. Methods: This cross-sectional study was based on data from 266 mothers participating in the Healthy Start intervention study. HCC was measured in the proximal end of the hair (1–2 cm closest to the scalp) while hair dyeing status, frequency of hair...... washing and covariates were reported by the women. Linear regression analyses were applied to assess the associations between HCC and hair dyeing or weekly frequency of hair washing. Results: No statistically significant difference (p = 0.91) in HCC was found between women who dyed hair (adjusted mean...

An operating principle of the turtle utricle to detect wide dynamic range.

Science.gov (United States)

Nam, Jong-Hoon

2018-03-01

The utricle encodes both static information such as head orientation, and dynamic information such as vibrations. It is not well understood how the utricle can encode both static and dynamic information for a wide dynamic range (from 2 times the gravitational acceleration; from DC to > 1000 Hz vibrations). Using computational models of the hair cells in the turtle utricle, this study presents an explanation on how the turtle utricle encodes stimulations over such a wide dynamic range. Two hair bundles were modeled using the finite element method-one representing the striolar hair cell (Cell S), and the other representing the medial extrastriolar hair cell (Cell E). A mechano-transduction (MET) channel model was incorporated to compute MET current (i MET ) due to hair bundle deflection. A macro-mechanical model of the utricle was used to compute otoconial motions from head accelerations (a Head ). According to known anatomical data, Cell E has a long kinocilium that is embedded into the stiff otoconial layer. Unlike Cell E, the hair bundle of Cell S falls short of the otoconial layer. Considering such difference in the mechanical connectivity between the hair cell bundle and the otoconial layer, three cases were simulated: Cell E displacement-clamped, Cell S viscously-coupled, and Cell S displacement-clamped. Head accelerations at different amplitude levels and different frequencies were simulated for the three cases. When a realistic head motion was simulated, Cell E was responsive to head orientation, while the viscously-coupled Cell S was responsive to fast head motion imitating the feeding strike of a turtle. Copyright © 2017 Elsevier B.V. All rights reserved.

Body hair transplant: An additional source of donor hair in hair restoration surgery

Directory of Open Access Journals (Sweden)

Poswal Arvind

2007-01-01

Full Text Available Androgenic alopecia (pattern baldness is a condition in which there is androgen mediated progressive miniaturization and loss of hair follicles in a genetically susceptible individual. A 47-year-old male patient with advanced degree of hair loss (Norwood 6 category wanted to go for full hair restoration surgery. Due to the limited availability of donor hair in the scalp, a small session with 700-chest hair was performed. On follow-up at eight months it was observed that chest hair grew and formed a cosmetically acceptable forelock.

CANFLEX fuel bundle cross-flow endurance test (test report)

International Nuclear Information System (INIS)

Hong, Sung Deok; Chung, C. H.; Chang, S. K.; Kim, B. D.

1997-04-01

As part of the normal refuelling sequence of CANDU nuclear reactor, both new and irradiated bundles can be parked in the cross-flow region of the liner tubes. This situation occurs normally for a few minutes. The fuel bundle which is subjected to the cross-flow should be capable of withstanding the consequences of cross flow for normal periods, and maintain its mechanical integrity. The cross-flow endurance test was conducted for CANFLEX bundle, latest developed nuclear fuel, at CANDU-Hot Test Loop. The test was carried out during 4 hours at the inlet cross-flow region. After the test, the bundle successfully met all acceptance criteria after the 4 hours cross-flow test. (author). 2 refs., 3 tabs

CANFLEX fuel bundle cross-flow endurance test (test report)

Energy Technology Data Exchange (ETDEWEB)

Hong, Sung Deok; Chung, C. H.; Chang, S. K.; Kim, B. D.

1997-04-01

As part of the normal refuelling sequence of CANDU nuclear reactor, both new and irradiated bundles can be parked in the cross-flow region of the liner tubes. This situation occurs normally for a few minutes. The fuel bundle which is subjected to the cross-flow should be capable of withstanding the consequences of cross flow for normal periods, and maintain its mechanical integrity. The cross-flow endurance test was conducted for CANFLEX bundle, latest developed nuclear fuel, at CANDU-Hot Test Loop. The test was carried out during 4 hours at the inlet cross-flow region. After the test, the bundle successfully met all acceptance criteria after the 4 hours cross-flow test. (author). 2 refs., 3 tabs.

Body Hair

Science.gov (United States)

... girlshealth.gov/ Home Body Puberty Body hair Body hair Even before you get your first period , you ... removing pubic hair Ways to get rid of hair top Removing body hair can cause skin irritation, ...

Hair cosmetics

Directory of Open Access Journals (Sweden)

Nina Madnani

2013-01-01

Full Text Available The hair cosmetic industry has undergone a revolutionary change over the last two decades. The focus has dramatically veered from merely cleaning to repair, increasing the tensile strength, reducing oxidative damage, and stimulating growth. Newer shorter procedures to make hair look naturally more lustrous, smooth, and manageable have evolved. Specialized grooming products have been formulated to cleanse, calm, and condition the hair, and are tailored for different hair-types, for example, dry, dry-damaged, oily, colored, and gray hair. Other products are formulated to alter the color or structure of the hair shaft, for example, hair dyes, perming/relaxing. Hair sprays and waxes/gels, can alter the ′lift′ of the hair-shaft. Although dermatologists are experts in managing scalp and hair diseases, the esthetic applications of newer cosmetic therapies still remain elusive. This article attempts to fill the lacunae in our knowledge of hair cosmetics and esthetic procedures relevant in today′s rapidly changing beauty-enhancing industry, with special emphasis on the Indian scenario for chemical and ′natural′ hair products.

The Atiyah bundle and connections on a principal bundle

Indian Academy of Sciences (India)

be the fiber bundle constructed as in (1.1) for the universal principal G-bundle. In a work in progress, we hope to show that the universal G-connection can be realized as a fiber bundle over C(EG). Turning this ... a G-invariant vector field on EG|U . In other words, we get a bijective linear map between. A(EG)(U) (the space of ...

Hair cell regeneration in the avian auditory epithelium.

Science.gov (United States)

Stone, Jennifer S; Cotanche, Douglas A

2007-01-01

Regeneration of sensory hair cells in the mature avian inner ear was first described just over 20 years ago. Since then, it has been shown that many other non-mammalian species either continually produce new hair cells or regenerate them in response to trauma. However, mammals exhibit limited hair cell regeneration, particularly in the auditory epithelium. In birds and other non-mammals, regenerated hair cells arise from adjacent non-sensory (supporting) cells. Hair cell regeneration was initially described as a proliferative response whereby supporting cells re-enter the mitotic cycle, forming daughter cells that differentiate into either hair cells or supporting cells and thereby restore cytoarchitecture and function in the sensory epithelium. However, further analyses of the avian auditory epithelium (and amphibian vestibular epithelium) revealed a second regenerative mechanism, direct transdifferentiation, during which supporting cells change their gene expression and convert into hair cells without dividing. In the chicken auditory epithelium, these two distinct mechanisms show unique spatial and temporal patterns, suggesting they are differentially regulated. Current efforts are aimed at identifying signals that maintain supporting cells in a quiescent state or direct them to undergo direct transdifferentiation or cell division. Here, we review current knowledge about supporting cell properties and discuss candidate signaling molecules for regulating supporting cell behavior, in quiescence and after damage. While significant advances have been made in understanding regeneration in non-mammals over the last 20 years, we have yet to determine why the mammalian auditory epithelium lacks the ability to regenerate hair cells spontaneously and whether it is even capable of significant regeneration under additional circumstances. The continued study of mechanisms controlling regeneration in the avian auditory epithelium may lead to strategies for inducing

Ingrown Hair

Science.gov (United States)

Ingrown hair Overview An ingrown hair occurs when a shaved or tweezed hair grows back into the skin. It can cause inflammation, pain and tiny bumps in the area where the hair was removed. Ingrown hair is a common condition ...

Age-related hair pigment loss.

Science.gov (United States)

Tobin, Desmond J

2015-01-01

Humans are social animals that communicate disproportionately via potent genetic signals imbued in the skin and hair, including racial, ethnic, health, gender, and age status. For the vast majority of us, age-related hair pigment loss becomes the inescapable signal of our disappearing youth. The hair follicle (HF) pigmentary unit is a wonderful tissue for studying mechanisms generally regulating aging, often before this becomes evident elsewhere in the body. Given that follicular melanocytes (unlike those in the epidermis) are regulated by the hair growth cycle, this cycle is likely to impact the process of aging in the HF pigmentary unit. The formal identification of melanocyte stem cells in the mouse skin has spurred a flurry of reports on the potential involvement of melanocyte stem cell depletion in hair graying (i.e., canities). Caution is recommended, however, against simple extrapolation of murine data to humans. Regardless, hair graying in both species is likely to involve an age-related imbalance in the tissue's oxidative stress handling that will impact not only melanogenesis but also melanocyte stem cell and melanocyte homeostasis and survival. There is some emerging evidence that the HF pigmentary unit may have regenerative potential, even after it has begun to produce white hair fibers. It may therefore be feasible to develop strategies to modulate some aging-associated changes to maintain melanin production for longer. © 2015 S. Karger AG, Basel.

Sensory Hair Cells: An Introduction to Structure and Physiology.

Science.gov (United States)

McPherson, Duane R

2018-06-18

Sensory hair cells are specialized secondary sensory cells that mediate our senses of hearing, balance, linear acceleration, and angular acceleration (head rotation). In addition, hair cells in fish and amphibians mediate sensitivity to water movement through the lateral line system, and closely related electroreceptive cells mediate sensitivity to low-voltage electric fields in the aquatic environment of many fish species and several species of amphibian.Sensory hair cells share many structural and functional features across all vertebrate groups, while at the same time they are specialized for employment in a wide variety of sensory tasks. The complexity of hair cell structure is large, and the diversity of hair cell applications in sensory systems exceeds that seen for most, if not all, sensory cell types. The intent of this review is to summarize the more significant structural features and some of the more interesting and important physiological mechanisms that have been elucidated thus far. Outside vertebrates, hair cells are only known to exist in the coronal organ of tunicates. Electrical resonance, electromotility, and their exquisite mechanical sensitivity all contribute to the attractiveness of hair cells as a research subject.

Low-level laser (light) therapy (LLLT) for treatment of hair loss.

Science.gov (United States)

Avci, Pinar; Gupta, Gaurav K; Clark, Jason; Wikonkal, Norbert; Hamblin, Michael R

2014-02-01

Alopecia is a common disorder affecting more than half of the population worldwide. Androgenetic alopecia, the most common type, affects 50% of males over the age of 40 and 75% of females over 65. Only two drugs have been approved so far (minoxidil and finasteride) and hair transplant is the other treatment alternative. This review surveys the evidence for low-level laser therapy (LLLT) applied to the scalp as a treatment for hair loss and discusses possible mechanisms of actions. Searches of PubMed and Google Scholar were carried out using keywords alopecia, hair loss, LLLT, photobiomodulation. Studies have shown that LLLT stimulated hair growth in mice subjected to chemotherapy-induced alopecia and also in alopecia areata. Controlled clinical trials demonstrated that LLLT stimulated hair growth in both men and women. Among various mechanisms, the main mechanism is hypothesized to be stimulation of epidermal stem cells in the hair follicle bulge and shifting the follicles into anagen phase. LLLT for hair growth in both men and women appears to be both safe and effective. The optimum wavelength, coherence and dosimetric parameters remain to be determined. © 2013 Wiley Periodicals, Inc.

Polyelectrolyte bundles

Energy Technology Data Exchange (ETDEWEB)

Limbach, H J; Sayar, M; Holm, C [Max-Planck-Institut fuer Polymerforschung, Ackermannweg 10, 55128 Mainz (Germany)

2004-06-09

Using extensive molecular dynamics simulations we study the behaviour of polyelectrolytes with hydrophobic side chains, which are known to form cylindrical micelles in aqueous solution. We investigate the stability of such bundles with respect to hydrophobicity, the strength of the electrostatic interaction and the bundle size. We show that for the parameter range relevant for sulfonated poly(para-phenylenes) (PPP) one finds a stable finite bundle size. In a more generic model we also show the influence of the length of the precursor oligomer on the stability of the bundles. We also point out that our model has close similarities to DNA solutions with added condensing agents, hinting at the possibility that the size of DNA aggregates is, under certain circumstances, thermodynamically limited.

Polyelectrolyte bundles

International Nuclear Information System (INIS)

Limbach, H J; Sayar, M; Holm, C

2004-01-01

Using extensive molecular dynamics simulations we study the behaviour of polyelectrolytes with hydrophobic side chains, which are known to form cylindrical micelles in aqueous solution. We investigate the stability of such bundles with respect to hydrophobicity, the strength of the electrostatic interaction and the bundle size. We show that for the parameter range relevant for sulfonated poly(para-phenylenes) (PPP) one finds a stable finite bundle size. In a more generic model we also show the influence of the length of the precursor oligomer on the stability of the bundles. We also point out that our model has close similarities to DNA solutions with added condensing agents, hinting at the possibility that the size of DNA aggregates is, under certain circumstances, thermodynamically limited

Polyelectrolyte bundles

Science.gov (United States)

Limbach, H. J.; Sayar, M.; Holm, C.

2004-06-01

Using extensive Molecular Dynamics simulations we study the behavior of polyelectrolytes with hydrophobic side chains, which are known to form cylindrical micelles in aqueous solution. We investigate the stability of such bundles with respect to hydrophobicity, the strength of the electrostatic interaction, and the bundle size. We show that for the parameter range relevant for sulfonated poly-para-phenylenes (PPP) one finds a stable finite bundle size. In a more generic model we also show the influence of the length of the precursor oligomer on the stability of the bundles. We also point out that our model has close similarities to DNA solutions with added condensing agents, hinting to the possibility that the size of DNA aggregates is under certain circumstances thermodynamically limited.

Optimization Of Bio-inspired Hair Sensor Arrays

NARCIS (Netherlands)

Jaganatharaja, R.K.; Bruinink, C.M.; Izadi, N.; Lammerink, Theodorus S.J.; Wiegerink, Remco J.; Casas, J.; Krijnen, Gijsbertus J.M.

2008-01-01

Crickets use a pair of hairy appendages on their abdomen called cerci, each of which contains numerous mechano-receptive filiform hairs. These sensitive hairs can respond even to the slightest air movements, down to 0.03 mm/s, generated by the approaching predators and initiating an escape mechanism

Quantitative anatomical basis for a model of micromechanical frequency tuning in the Tokay gecko, Gekko gecko.

Science.gov (United States)

Köppl, C; Authier, S

1995-01-01

The basilar papilla of the Tokay gecko was studied with standard light- and scanning electron microscopy methods. Several parameters thought to be of particular importance for the mechanical response properties of the system were quantitatively measured, separately for the three different hair-cell areas that are typical for this lizard family. In the basal third, papillar structure was very uniform. The apical two-thirds are subdivided into two hair-cell areas running parallel to each other along the papilla and covered by very different types of tectorial material. Both of those areas showed prominent gradients in hair-cell bundle morphology, i.e., in the height of the stereovillar bundles and the number of stereovilli per bundle, as well as in hair cell density and the size of their respective tectorial covering. Based on the direction of the observed anatomical gradients, a 'reverse' tonotopic organization is suggested, with the highest frequencies represented at the apical end.

miR-96 regulates the progression of differentiation in mammalian cochlear inner and outer hair cells.

Science.gov (United States)

Kuhn, Stephanie; Johnson, Stuart L; Furness, David N; Chen, Jing; Ingham, Neil; Hilton, Jennifer M; Steffes, Georg; Lewis, Morag A; Zampini, Valeria; Hackney, Carole M; Masetto, Sergio; Holley, Matthew C; Steel, Karen P; Marcotti, Walter

2011-02-08

MicroRNAs (miRNAs) are small noncoding RNAs able to regulate a broad range of protein-coding genes involved in many biological processes. miR-96 is a sensory organ-specific miRNA expressed in the mammalian cochlea during development. Mutations in miR-96 cause nonsyndromic progressive hearing loss in humans and mice. The mouse mutant diminuendo has a single base change in the seed region of the Mir96 gene leading to widespread changes in the expression of many genes. We have used this mutant to explore the role of miR-96 in the maturation of the auditory organ. We found that the physiological development of mutant sensory hair cells is arrested at around the day of birth, before their biophysical differentiation into inner and outer hair cells. Moreover, maturation of the hair cell stereocilia bundle and remodelling of auditory nerve connections within the cochlea fail to occur in miR-96 mutants. We conclude that miR-96 regulates the progression of the physiological and morphological differentiation of cochlear hair cells and, as such, coordinates one of the most distinctive functional refinements of the mammalian auditory system.

Strategic Aspects of Bundling

International Nuclear Information System (INIS)

Podesta, Marion

2008-01-01

The increase of bundle supply has become widespread in several sectors (for instance in telecommunications and energy fields). This paper review relates strategic aspects of bundling. The main purpose of this paper is to analyze profitability of bundling strategies according to the degree of competition and the characteristics of goods. Moreover, bundling can be used as price discrimination tool, screening device or entry barriers. In monopoly case bundling strategy is efficient to sort consumers in different categories in order to capture a maximum of surplus. However, when competition increases, the profitability on bundling strategies depends on correlation of consumers' reservations values. (author)

Nonabelian bundle 2-gerbes

OpenAIRE

Jurco, Branislav

2009-01-01

We define 2-crossed module bundle 2-gerbes related to general Lie 2-crossed modules and discuss their properties. A 2-crossed module bundle 2-gerbe over a manifold is defined in terms of a so called 2-crossed module bundle gerbe, which is a crossed module bundle gerbe equipped with an extra sructure. It is shown that string structures can be described and classified using 2-crossed module bundle 2-gerbes.

Polycation induced actin bundles.

Science.gov (United States)

Muhlrad, Andras; Grintsevich, Elena E; Reisler, Emil

2011-04-01

Three polycations, polylysine, the polyamine spermine and the polycationic protein lysozyme were used to study the formation, structure, ionic strength sensitivity and dissociation of polycation-induced actin bundles. Bundles form fast, simultaneously with the polymerization of MgATP-G-actins, upon the addition of polycations to solutions of actins at low ionic strength conditions. This indicates that nuclei and/or nascent filaments bundle due to attractive, electrostatic effect of polycations and the neutralization of repulsive interactions of negative charges on actin. The attractive forces between the filaments are strong, as shown by the low (in nanomolar range) critical concentration of their bundling at low ionic strength. These bundles are sensitive to ionic strength and disassemble partially in 100 mM NaCl, but both the dissociation and ionic strength sensitivity can be countered by higher polycation concentrations. Cys374 residues of actin monomers residing on neighboring filaments in the bundles can be cross-linked by the short span (5.4Å) MTS-1 (1,1-methanedyl bismethanethiosulfonate) cross-linker, which indicates a tight packing of filaments in the bundles. The interfilament cross-links, which connect monomers located on oppositely oriented filaments, prevent disassembly of bundles at high ionic strength. Cofilin and the polysaccharide polyanion heparin disassemble lysozyme induced actin bundles more effectively than the polylysine-induced bundles. The actin-lysozyme bundles are pathologically significant as both proteins are found in the pulmonary airways of cystic fibrosis patients. Their bundles contribute to the formation of viscous mucus, which is the main cause of breathing difficulties and eventual death in this disorder. Copyright © 2011 Elsevier B.V. All rights reserved.

Hair Transplants

Science.gov (United States)

... Search Skin Experts Skin Treatments Hair Transplants Share » HAIR TRANSPLANTS Before (left) and after (right) - front of ... transplant. Photo courtesy of N. Sadick What are hair transplants? In punch transplanting, a plug containing hair ...

From Hair in India to Hair India.

Science.gov (United States)

Trüeb, Ralph M

2017-01-01

In all cultures, human hair and hairdo have been a powerful metaphor. Tracing back the importance and significance of human hair to the dawn of civilization on the Indian subcontinent, we find that all the Vedic gods are depicted as having uncut hair in mythological stories as well as in legendary pictures. The same is true of the Hindu avatars, and the epic heroes of the Ramayana, and the Mahabharata. Finally, there are a number of hair peculiarities in India pertinent to the creed and religious practices of the Hindu, the Jain, and the Sikh. Shiva Nataraja is a depiction of the Hindu God Shiva as the cosmic dancer who performs his divine dance as creator, preserver, and destroyer of the universe and conveys the Indian conception of the never-ending cycle of time. The same principle manifests in the hair cycle, in which perpetual cycles of growth, regression, and resting underly the growth and shedding of hair. Finally, The Hair Research Society of India was founded as a nonprofit organisation dedicated to research and education in the science of hair. Notably, the HRSI reached milestones in the journey of academic pursuit with the launch of the International Journal of Trichology, and with the establishment of the Hair India conference. Ultimately, the society aims at saving the public from being taken for a ride by quackery, and at creating the awareness that the science of hair represents a subspecialty of Dermatology. In analogy again, the dwarf on which the Nataraja dances represents the demon of egotism, and thus symbolizes Shiva's, respectively, the HRSI's victory over ignorance.

Androgenetic alopecia: new insights into the pathogenesis and mechanism of hair loss

Science.gov (United States)

Sinclair, Rodney; Torkamani, Niloufar; Jones, Leslie

2015-01-01

The hair follicle is a complete mini-organ that lends itself as a model for investigation of a variety of complex biological phenomena, including stem cell biology, organ regeneration and cloning.  The arrector pili muscle inserts into the hair follicle at the level of the bulge- the epithelial stem cell niche.  The arrector pili muscle has been previously thought to be merely a bystander and not to have an active role in hair disease. Computer generated 3D reconstructions of the arrector pili muscle have helped explain why women with androgenetic alopecia (AGA) experience diffuse hair loss rather than the patterned baldness seen in men.  Loss of attachment between the bulge stem cell population and the arrector pili muscle also explains why miniaturization is irreversible in AGA but not alopecia areata. A new model for the progression of AGA is presented. PMID:26339482

Hair Removal

Science.gov (United States)

... Staying Safe Videos for Educators Search English Español Hair Removal KidsHealth / For Teens / Hair Removal What's in ... you need any of them? Different Types of Hair Before removing hair, it helps to know about ...

Your Hair

Science.gov (United States)

... Safe Videos for Educators Search English Español Your Hair KidsHealth / For Kids / Your Hair What's in this ... eyes from sweat dripping down from your forehead. Hair Comes From Where? Whether hair is growing out ...

Effects of solar radiation on hair and photoprotection.

Science.gov (United States)

Dario, Michelli F; Baby, André R; Velasco, Maria Valéria R

2015-12-01

In this paper the negative effects of solar radiation (ultraviolet, visible and infrared wavelengths) on hair properties like color, mechanical properties, luster, protein content, surface roughness, among others, will be discussed. Despite knowing that radiation damages hair, there are no consensus about the particular effect of each segment of solar radiation on the hair shaft. The hair photoprotection products are primarily targeted to dyed hair, specially auburn pigments, and gray shades. They are usually based on silicones, antioxidants and quaternary chemical UV filters that have more affinity for negatively charged hair surface and present higher efficacy. Unfortunately, there are no regulated parameters, like for skin photoprotection, for efficacy evaluation of hair care products, which makes impossible to compare the results published in the literature. Thus, it is important that researchers make an effort to apply experimental conditions similar to a real level of sun exposure, like dose, irradiance, time, temperature and relative humidity. Copyright © 2015 Elsevier B.V. All rights reserved.

Hair Removal

DEFF Research Database (Denmark)

Hædersdal, Merete

2011-01-01

Hair removal with optical devices has become a popular mainstream treatment that today is considered the most efficient method for the reduction of unwanted hair. Photothermal destruction of hair follicles constitutes the fundamental concept of hair removal with red and near-infrared wavelengths...... suitable for targeting follicular and hair shaft melanin: normal mode ruby laser (694 nm), normal mode alexandrite laser (755 nm), pulsed diode lasers (800, 810 nm), long-pulse Nd:YAG laser (1,064 nm), and intense pulsed light (IPL) sources (590-1,200 nm). The ideal patient has thick dark terminal hair......, white skin, and a normal hormonal status. Currently, no method of lifelong permanent hair eradication is available, and it is important that patients have realistic expectations. Substantial evidence has been found for short-term hair removal efficacy of up to 6 months after treatment with the available...

Hair removal

DEFF Research Database (Denmark)

Haedersdal, Merete; Haak, Christina S

2011-01-01

Hair removal with optical devices has become a popular mainstream treatment that today is considered the most efficient method for the reduction of unwanted hair. Photothermal destruction of hair follicles constitutes the fundamental concept of hair removal with red and near-infrared wavelengths...... suitable for targeting follicular and hair shaft melanin: normal mode ruby laser (694 nm), normal mode alexandrite laser (755 nm), pulsed diode lasers (800, 810 nm), long-pulse Nd:YAG laser (1,064 nm), and intense pulsed light (IPL) sources (590-1,200 nm). The ideal patient has thick dark terminal hair......, white skin, and a normal hormonal status. Currently, no method of lifelong permanent hair eradication is available, and it is important that patients have realistic expectations. Substantial evidence has been found for short-term hair removal efficacy of up to 6 months after treatment with the available...

Thymosin Beta-4 Induces Mouse Hair Growth.

Directory of Open Access Journals (Sweden)

Xiaoyu Gao

Full Text Available Thymosin beta-4 (Tβ4 is known to induce hair growth and hair follicle (HF development; however, its mechanism of action is unknown. We generated mice that overexpressed Tβ4 in the epidermis, as well as Tβ4 global knockout mice, to study the role of Tβ4 in HF development and explore the mechanism of Tβ4 on hair growth. To study Tβ4 function, we depilated control and experimental mice and made tissue sections stained with hematoxylin and eosin (H&E. To explore the effect of Tβ4 on hair growth and HF development, the mRNA and protein levels of Tβ4 and VEGF were detected by real-time PCR and western blotting in control and experimental mice. Protein expression levels and the phosphorylation of P38, ERK and AKT were also examined by western blotting. The results of depilation indicated that hair re-growth was faster in Tβ4-overexpressing mice, but slower in knockout mice. Histological examination revealed that Tβ4-overexpressing mice had a higher number of hair shafts and HFs clustered together to form groups, while the HFs of control mice and knockout mice were separate. Hair shafts in knockout mice were significantly reduced in number compared with control mice. Increased Tβ4 expression at the mRNA and protein levels was confirmed in Tβ4-overexpressing mice, which also had increased VEGF expression. On the other hand, knockout mice had reduced levels of VEGF expression. Mechanistically, Tβ4-overexpressing mice showed increased protein expression levels and phosphorylation of P38, ERK and AKT, whereas knockout mice had decreased levels of both expression and phosphorylation of these proteins. Tβ4 appears to regulate P38/ERK/AKT signaling via its effect on VEGF expression, with a resultant effect on the speed of hair growth, the pattern of HFs and the number of hair shafts.

Alternative Splice Forms Influence Functions of Whirlin in Mechanosensory Hair Cell Stereocilia

Directory of Open Access Journals (Sweden)

Seham Ebrahim

2016-05-01

Full Text Available WHRN (DFNB31 mutations cause diverse hearing disorders: profound deafness (DFNB31 or variable hearing loss in Usher syndrome type II. The known role of WHRN in stereocilia elongation does not explain these different pathophysiologies. Using spontaneous and targeted Whrn mutants, we show that the major long (WHRN-L and short (WHRN-S isoforms of WHRN have distinct localizations within stereocilia and also across hair cell types. Lack of both isoforms causes abnormally short stereocilia and profound deafness and vestibular dysfunction. WHRN-S expression, however, is sufficient to maintain stereocilia bundle morphology and function in a subset of hair cells, resulting in some auditory response and no overt vestibular dysfunction. WHRN-S interacts with EPS8, and both are required at stereocilia tips for normal length regulation. WHRN-L localizes midway along the shorter stereocilia, at the level of inter-stereociliary links. We propose that differential isoform expression underlies the variable auditory and vestibular phenotypes associated with WHRN mutations.

Investigation of hair dye deposition, hair color loss, and hair damage during multiple oxidative dyeing and shampooing cycles.

Science.gov (United States)

Zhang, Guojin; McMullen, Roger L; Kulcsar, Lidia

2016-01-01

Color fastness is a major concern for consumers and manufacturers of oxidative hair dye products. Hair dye loss results from multiple wash cycles in which the hair dye is dissolved by water and leaches from the hair shaft. In this study, we carried out a series of measurements to help us better understand the kinetics of the leaching process and pathways associated with its escape from the fiber. Hair dye leaching kinetics was measured by suspending hair in a dissolution apparatus and monitoring the dye concentration in solution (leached dye) with an ultraviolet-visible spectrophotometer. The physical state of dye deposited in hair fibers was evaluated by a reflectance light microscopy technique, based on image stacking, allowing enhanced depth of field imaging. The dye distribution within the fiber was monitored by infrared spectroscopic imaging of hair fiber cross sections. Damage to the ultrafine structure of the hair cuticle (surface, endocuticle, and cell membrane complex) and cortex (cell membrane complex) was determined in hair cross sections and on the hair fiber surface with atomic force microscopy. Using differential scanning calorimetry, we investigated how consecutive coloring and leaching processes affect the internal proteins of hair. Further, to probe the surface properties of hair we utilized contact angle measurements. This study was conducted on both pigmented and nonpigmented hair to gain insight into the influence of melanin on the hair dye deposition and leaching processes. Both types of hair were colored utilizing a commercial oxidative hair dye product based on pyrazole chemistry.

Nefness of adjoint bundles for ample vector bundles

Directory of Open Access Journals (Sweden)

Hidetoshi Maeda

1995-11-01

Full Text Available Let E be an ample vector bundle of rank >1 on a smooth complex projective variety X of dimension n. This paper gives a classification of pairs (X,E whose adjoint bundles K_X+det E are not nef in the case when  r=n-2.

Nucleate boiling heat transfer on horizontal tubes in bundles

International Nuclear Information System (INIS)

Fujital, Y.; Ohta, H.; Hidaka, S.; Nishikawa, K.

1986-01-01

In order to clarify the heat transfer mechanisms of the flooded type horizontal tube bundle evaporator, heat transfer characteristics of tube bundles of experimental scale which consist both of smooth and enhanced tubes were investigated in detail. The experiments of saturated nucleate boiling were performed by using Freon 113 under pressures 0.1 to 1 MPa, and the effects of various parameters, for example, bundle arrangement, heat flux, pressure on the characteristics of an individual tube are clarified. Experimental data is reproduced well by a proposed heat transfer model in which convective heat transfer coefficients due to rising bubbles are estimated as a function of their volumetric flow rate

Hair as an alternative matrix in bioanalysis.

Science.gov (United States)

Barbosa, Joana; Faria, Juliana; Carvalho, Félix; Pedro, Madalena; Queirós, Odília; Moreira, Roxana; Dinis-Oliveira, Ricardo Jorge

2013-04-01

Alternative matrices are steadily gaining recognition as biological samples for toxicological analyses. Hair presents many advantages over traditional matrices, such as urine and blood, since it provides retrospective information regarding drug exposure, can distinguish between chronic and acute or recent drug use by segmental analysis, is easy to obtain, and has considerable stability for long periods of time. For this reason, it has been employed in a wide variety of contexts, namely to evaluate workplace drug exposure, drug-facilitated sexual assault, pre-natal drug exposure, anti-doping control, pharmacological monitoring and alcohol abuse. In this article, issues concerning hair structure, collection, storage and analysis are reviewed. The mechanisms of drug incorporation into hair are briefly discussed. Analytical techniques for simultaneous drug quantification in hair are addressed. Finally, representative examples of drug quantification using hair are summarized, emphasizing its potentialities and limitations as an alternative biological matrix for toxicological analyses.

Preliminary Analysis of the Fuel Bundle Stiffness by ANSYS for SFR

Energy Technology Data Exchange (ETDEWEB)

Lee, Byoung Oon; Cheon, Jin Sik; Hahn, Do Hee; Lee, Chan Bock [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2008-05-15

In SFR (Sodium-cooled Fast Reactor) the temperature of the fuel pin is higher than that of the hexagonal duct, so the thermal expansion rate of the fuel bundle is higher than that of the duct. The neutron fluence and the fuel pin pressure are also increased according to the burnup. So the radial expansion and bowing of a fuel pin bundle would occur, and then fuel bundle would interact with a duct. This phenomenon is called bundle-to-duct interaction (BDI). Under the BDI condition, excess cladding strain and hot spots would occur. Therefore BDI as well as the core mechanics should be considered to evaluate the FBR fuel integrity. The analysis codes such as ETOILE, SHADOW, and MARSE, have been developed to evaluate the BDI behavior. The ANSYS based model is also being developed to analysis the bundle duct interaction for SFR in Korea. In this paper, the fuel pin/bundle model for analyzing the bending deflection and oval deformation was described. The preliminary analysis of the fuel bundle stiffness was performed by the developed model.

The electrical properties of auditory hair cells in the frog amphibian papilla.

Science.gov (United States)

Smotherman, M S; Narins, P M

1999-07-01

The amphibian papilla (AP) is the principal auditory organ of the frog. Anatomical and neurophysiological evidence suggests that this hearing organ utilizes both mechanical and electrical (hair cell-based) frequency tuning mechanisms, yet relatively little is known about the electrophysiology of AP hair cells. Using the whole-cell patch-clamp technique, we have investigated the electrical properties and ionic currents of isolated hair cells along the rostrocaudal axis of the AP. Electrical resonances were observed in the voltage response of hair cells harvested from the rostral and medial, but not caudal, regions of the AP. Two ionic currents, ICa and IK(Ca), were observed in every hair cell; however, their amplitudes varied substantially along the epithelium. Only rostral hair cells exhibited an inactivating potassium current (IA), whereas an inwardly rectifying potassium current (IK1) was identified only in caudal AP hair cells. Electrically tuned hair cells exhibited resonant frequencies from 50 to 375 Hz, which correlated well with hair cell position and the tonotopic organization of the papilla. Variations in the kinetics of the outward current contribute substantially to the determination of resonant frequency. ICa and IK(Ca) amplitudes increased with resonant frequency, reducing the membrane time constant with increasing resonant frequency. We conclude that a tonotopically organized hair cell substrate exists to support electrical tuning in the rostromedial region of the frog amphibian papilla and that the cellular mechanisms for frequency determination are very similar to those reported for another electrically tuned auditory organ, the turtle basilar papilla.

The impact of a ventilator bundle on preventing ventilator-associated pneumonia: a multicenter study.

Science.gov (United States)

Eom, Joong Sik; Lee, Mi-Suk; Chun, Hee-Kyung; Choi, Hee Jung; Jung, Sun-Young; Kim, Yeon-Sook; Yoon, Seon Jin; Kwak, Yee Gyung; Oh, Gang-Bok; Jeon, Min-Hyok; Park, Sun-Young; Koo, Hyun-Sook; Ju, Young-Su; Lee, Jin Seo

2014-01-01

For prevention of ventilator-associated pneumonia (VAP), a bundle approach was applied to patients receiving mechanical ventilation in intensive care units. The incidence of VAP and the preventive efficacy of the VAP bundle were investigated. A quasi-experimental study was conducted in adult intensive care units of 6 university hospitals with similar VAP rates. We implemented the VAP bundle between March 2011 and June 2011, then compared the rate of VAP after implementation of the VAP bundle with the rate in the previous 8 months. Our ventilator bundle included head of bed elevation, peptic ulcer disease prophylaxis, deep venous thrombosis prophylaxis, and oral decontamination with chlorhexidine 0.12%. Continuous aspiration of subglottic secretions was an option. Implementation of the VAP bundle reduced the VAP rate from a mean of 4.08 cases per 1,000 ventilator-days to 1.16 cases per 1,000 ventilator-days. The incidence density ratio (rate) was 0.28 (95% confidence interval, 0.275-0.292). Implementing the appropriate VAP bundle significantly decreased the incidence of VAP in patients with mechanical ventilation. Copyright © 2014 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

Evaluation of bundle duct interaction by out of pile compressive test of FBR bundles. FFTF type bundle

Energy Technology Data Exchange (ETDEWEB)

Tanaka, Kosuke; Yamamoto, Yuji; Nagamine, Tsuyoshi; Maeda, Koji [Japan Nuclear Cycle Development Inst., Oarai, Ibaraki (Japan). Oarai Engineering Center

2000-10-01

Bundle duct interaction (BDI) caused by expansion of fuel pin bundle becomes one of the main limiting factors for fuel life times. Then, it is important for the design of fast reactor fuel assembly to understand the BDI behavior in detail. In order to understand the BDI behavior, out of pile compressive tests were conducted for FFTF type bundle by use of X-ray CT equipment. In these compressive tests, two type bundles with different accuracy of initial wire position were conducted. The objective of this test is to evaluate the influence of the initial error from standard position of wire at the same axial position. The locations of the pins and the duct flats are analyzed from CT image data. Quantitative evaluation was performed at the CT image data and discussed the bundle deformation status under BDI condition. Following results are obtained. 1) The accuracy of initial wire position is strongly depends on the pin-to-duct contact behavior. In the case of bundle with large error from standard position, pin-to-duct contact is delayed. 2) The BDI mitigation of the bundle with small error from standard wire position is following: The elastic ovality is the dominant deformation in mild BDI condition, then the wire dispersion and pin dispersion are occurred in severe BDI condition. 3) The BDI mitigation of the bundle with large error from standard wire position is following: The elastic ovality and local bowing of pins with large error from standard wire position are occurred in mild BDI condition, then pin dispersion is occurred around pins with large error from standard wire position, finally wire dispersion is occurred in severe BDI condition. 4) The existence of pins with large error from standard wire position is effective to delay the pin-to-duct contact, but the existence of these pins is possible to contact of pin- to- pin. (author)

Mechanical and chemical cleaning of the tubes bundles of the moisture separator reheaters (GSS) of Nuclear power plants

International Nuclear Information System (INIS)

Guerra, Patrice; Ruiz, Jose T.; Ureta, Roman; Carreres, Cristina; Virginie, Le-Guerroue

2012-09-01

The cleaning operation concerns the 'GSS' system (GSS stands for moisture separator reheaters, MSR) which are classified as 'watch quality guarantee', not classified as safety facility and subjected to Pressure Equipment regulations. The follow-up of the operational GSS (steel carbon) of EDF nuclear power plants CP0 group reveals a clog rate due to a relevant magnetite deposits that could result in equipment damage, loss of availability and loss of plant productivity. The pressure drop between inlet and outlet of the heating steam is close to maximum design criterion. The service consisted in designing, developing, qualifying and carrying out a process which removes clog from the inside of GSS U-tubes bundle located in the vapor circuit and which respects the equipment integrity and ensures the process harmlessness. This cleaning has to enable the complete removal of deposits and oxides (magnetite) in order to recover a passage diameter and a surface finish equivalent to the origin, thus avoiding the replacement of the GSS and obtaining a considerable reduction of costs. To do so, LAINSA and SOLARCA designed, developed, qualified and operated on 14 GSS bundles, by carrying out the following operations: - Cartography of the GSS tubes bundles clogging state; - Pre-Mechanical cleaning to un-block the sealed tubes and release the inside tubes passing; - Isolation of the bundle and check of leaks of the system; - Chemical cleaning with the efficiency and harmlessness parameters follow-up: - Acid Phase by means of weak organic acids to eliminate all the deposits; - Passivation phase; - Final Rinsing respecting the customer criteria; - Drying; - Waste management and waste treatment. The implementation of this operation enables the elimination of the whole deposits (magnetite) and oxides located inside the GSS tube bundle and thus to recover a passage diameter inside the tubes, and a pressure drop close to a new system and therefore to enables the

Experimental and numerical investigations of BWR fuel bundle inlet flow

International Nuclear Information System (INIS)

Hoashi, E; Morooka, S; Ishitori, T; Komita, H; Endo, T; Honda, H; Yamamoto, T; Kato, T; Kawamura, S

2009-01-01

We have been studying the mechanism of the flow pattern near the fuel bundle inlet of BWR using both flow visualization test and computational fluid dynamics (CFD) simulation. In the visualization test, both single- and multi-bundle test sections were used. The former test section includes only a corner orifice facing two support beams and the latter simulates 16 bundles surrounded by four beams. An observation window is set on the side of the walls imitating the support beams upstream of the orifices in both test sections. In the CFD simulation, as well as the visualization test, the single-bundle model is composed of one bundle with a corner orifice and the multi-bundle model is a 1/4 cut of the test section that includes 4 bundles with the following four orifices: a corner orifice facing the corner of the two neighboring support beams, a center orifice at the opposite side from the corner orifice, and two side orifices. Twin-vortices were observed just upstream of the corner orifice in the multi-bundle test as well as the single-bundle test. A single-vortex and a vortex filament were observed at the side orifice inlet and no vortex was observed at the center orifice. These flow patterns were also predicted in the CFD simulation using Reynolds Stress Model as a turbulent model and the results were in good agreement with the test results mentioned above. (author)

Hair cell regeneration in sensory epithelia from the inner ear of a urodele amphibian.

Science.gov (United States)

Taylor, Ruth R; Forge, Andrew

2005-03-28

The capacity of urodele amphibians to regenerate a variety of body parts is providing insight into mechanisms of tissue regeneration in vertebrates. In this study the ability of the newt, Notophthalmus viridescens, to regenerate inner ear hair cells in vitro was examined. Intact otic capsules were maintained in organotypic culture. Incubation in 2 mM gentamicin for 48 hours resulted in ablation of all hair cells from the saccular maculae. Thus, any hair cell recovery was not due to repair of damaged hair cells. Immature hair cells were subsequently observed at approximately 12 days posttreatment. Their number increased over the following 7-14 days to reach approximately 30% of the normal number. Following incubation of damaged tissue with bromodeoxyuridine (BrdU), labeled nuclei were confined strictly within regions of hair cell loss, indicating that supporting cells entered S-phase. Double labeling of tissue with two different hair cell markers and three different antibodies to BrdU in various combinations, however, all showed that the nuclei of cells that labeled with hair cell markers did not label for BrdU. This suggested that the new hair cells were not derived from those cells that had undergone mitosis. When mitosis was blocked with aphidicolin, new hair cells were still generated. The results suggest that direct phenotypic conversion of supporting cells into hair cells without an intervening mitotic event is a major mechanism of hair cell regeneration in the newt. A similar mechanism has been proposed for the hair cell recovery phenomenon observed in the vestibular organs of mammals. Copyright 2005 Wiley-Liss, Inc.

Mechanical analysis of congestive heart failure caused by bundle branch block based on an electromechanical canine heart model

Energy Technology Data Exchange (ETDEWEB)

Dou Jianhong; Xia Ling; Zhang Yu; Shou Guofa [Department of Biomedical Engineering, Zhejiang University, Hangzhou 310027 (China); Wei Qing; Liu Feng; Crozier, Stuart [School of Information Technology and Electrical Engineering, University of Queensland, St Lucia, Brisbane, Queensland 4072 (Australia)], E-mail: xialing@zju.edu.cn

2009-01-21

Asynchronous electrical activation, induced by bundle branch block (BBB), can cause reduced ventricular function. However, the effects of BBB on the mechanical function of heart are difficult to assess experimentally. Many heart models have been developed to investigate cardiac properties during BBB but have mainly focused on the electrophysiological properties. To date, the mechanical function of BBB has not been well investigated. Based on a three-dimensional electromechanical canine heart model, the mechanical properties of complete left and right bundle branch block (LBBB and RBBB) were simulated. The anatomical model as well as the fiber orientations of a dog heart was reconstructed from magnetic resonance imaging (MRI) and diffusion tensor MRI (DT-MRI). Using the solutions of reaction-diffusion equations and with a strategy of parallel computation, the asynchronous excitation propagation and intraventricular conduction in BBB was simulated. The mechanics of myocardial tissues were computed with time-, sarcomere length-dependent uniaxial active stress initiated at the time of depolarization. The quantification of mechanical intra- and interventricular asynchrony of BBB was then investigated using the finite-element method with an eight-node isoparametric element. The simulation results show that (1) there exists inter- and intraventricular systolic dyssynchrony during BBB; (2) RBBB may have more mechanical synchrony and better systolic function of the left ventricle (LV) than LBBB; (3) the ventricles always move toward the early-activated ventricle; and (4) the septum experiences higher stress than left and right ventricular free walls in BBB. The simulation results validate clinical and experimental recordings of heart deformation and provide regional quantitative estimates of ventricular wall strain and stress. The present work suggests that an electromechanical heart model, incorporating real geometry and fiber orientations, may be helpful for better

Preliminary Analysis of the Bundle-Duct Interaction for the fuel of SFR

Energy Technology Data Exchange (ETDEWEB)

Lee, Byoung Oon; Cheon, Jin Sik; Hahn, Do Hee; Lee, Chan Bock [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2008-10-15

BDI (Bundle-Duct Interaction) occurs in the fuel of SFR (Sodium-cooled Fast Reactor) due to the radial expansion and bowing of a fuel pin bundle. Under the BDI condition, excess cladding strain and hot spots would occur. Therefore, BDI, which is the dominant deformation mechanisms in a fuel pin bundle, should be considered to evaluate the FBR fuel integrity. The analysis codes such as ETOILE and BMBOO, have been developed to evaluate the BDI behavior. The bundle duct interaction model is also being developed for SFR in Korea. This model is based on ANSYS. In this paper, the fuel pin configuration model for the BDI calculation was established. The preliminary analysis of the bundle-duct interaction was performed to evaluate the fuel design concept.

Investigations with diagnostic fuel rod bundles on Rheinsberg NPP

International Nuclear Information System (INIS)

Krauze, F.; Rudolf, G.; Shajfler, V.; Tsimke, K.

1982-01-01

In 70MW pressurized water reactor of Rheinsberg NPP diagnostic fuel rod bundles have been installed: first of DK 1 type and then of DK 2 advanced type. Three rounds of measurement were run with DK 1 bundle and one with DK 2. The diagnostic bundles are equiped with various sensors for temperature, pressure, neutron flux and mechanical stress measurements as well as with special flow rate control system which allows to reach coolant boiling within the bundle. Qualitative and quantitative description of the sensors performance during reactor operation is given. The presented experimental results are connected with: 1) working capability of the measuring devices and their calibration; 2) throttling and boiling in two regimes: a) stationary and non-stationary flow rate throbgh DK during stationary reactor operation; b) various constant levels of flow rate through DK during non-stationary reactor operation regime [ru

Falsification of the ionic channel theory of hair cell transduction.

Science.gov (United States)

Rossetto, Michelangelo

2013-11-01

The hair cell provides the transduction of mechanical vibrations in the balance and acoustic sense of all vertebrates that swim, walk, or fly. The current theory places hair cell transduction in a mechanically controlled ion channel. Although the theory of a mechanical input modulating the flow of ions through an ion pore has been a useful tool, it is falsified by experimental data in the literature and can be definitively falsified by a proposed experiment.

Feathers and fins: non-mammalian models for hair cell regeneration.

Science.gov (United States)

Brignull, Heather R; Raible, David W; Stone, Jennifer S

2009-06-24

Death of mechanosensory cells in the inner ear results in two profound disabilities: hearing loss and balance disorders. Although mammals lack the capacity to regenerate hair cells, recent studies in mice and other rodents have offered valuable insight into strategies for stimulating hair cell regeneration in mammals. Investigations of model organisms that retain the ability to form new hair cells after embryogenesis, such as fish and birds, are equally important and have provided clues as to the cellular and molecular mechanisms that may block hair cell regeneration in mammals. Here, we summarize studies on hair cell regeneration in the chicken and the zebrafish, discuss specific advantages of each model, and propose future directions for the use of non-mammalian models in understanding hair cell regeneration.

MYOCARDIAL DEFORMATION AND COMPLETE LEFT BUNDLE BRANCH BLOCK

Directory of Open Access Journals (Sweden)

E. N. Pavlyukova

2015-12-01

Full Text Available Tissue Doppler imaging is evolving as a useful echocardiographic tool for quantitative assessment of left ventricular systolic and diastolic function. Over the last 10 years, myocardial deformation imaging has become possible initially with tissue Doppler , and more recently with myocardial speckle-tracking using 2D echocardiography. Unlike simple tissue velocity measurements, deformation measurements are specific for the region of interest. Strain rate or strain measurements have been used as sensitive indicators for subclinical diseases, and it is the most widely used tool to assess mechanical dyssynchrony. Left bundle branch block is a frequent, etiologically heterogeneous, clinically hostile and diagnostically challenging entity. About 2% of patients underwent cardiac stress testing show stable or intermittent left bundle branch block. Presence of left bundle branch block is associated with a lower and slower diastolic coronary flow velocity especially during hyperemia. Stress echocardiography is the best option for the diagnosis of ischemic heart disease, albeit specificity and sensitivity reduce in patients with left bundle branch block in the territory of left anterior descending artery in presence of initial septum dyskinesia.

Assembly mechanism for nuclear fuel bundles

International Nuclear Information System (INIS)

Long, J.W.; Flora, B.S.

1977-01-01

A method of securing a fuel bundle to permit easy remote disassembly is described. Fuel rods are held loosely between end plates, each end of the rods fitting into holes in the end plates. At the upper end of each fuel rod there is a spring pressing against the end plate. Tie rods are used to hold the end plates together securely. The lower end of each tie rod is screwed into the lower end plate; the upper end of each tie rod is attached to the upper end plate by means of a locking assembly described in the patent. In order to remove the upper tie plate during the disassembly process, it is necessary only to depress the tie plate against the pressure of the springs surrounding the fuel rods and then to rotate each locking sleeve on the tie rods from its locked to its unlocked position. It is then possible to remove the tie plate without disassembling the locking assembly. (LL)

Design and verification of the 'GURI 01' bundle model

International Nuclear Information System (INIS)

Benito, G.D.

1990-01-01

This work presents a general description of the 'GURI 01' bundle model, designed by INVAP S.E., under international radioactive material transportation regulations, as a B(U) type bundle for international transportation up to a maximum of 350000 Ci of Co60. Moreover, the methodologies used and the results obtained from the structural evaluation of the mechanic essay and from the evaluation of the thermal behaviour under normal or accident conditions are briefly discussed. (Author) [es

Hair loss and hair-pulling in rhesus macaques (Macaca mulatta).

Science.gov (United States)

Lutz, Corrine K; Coleman, Kristine; Worlein, Julie; Novak, Melinda A

2013-07-01

Alopecia is a common problem in rhesus macaque colonies. A possible cause of this condition is hair-pulling; however the true relationship between hair-pulling and alopecia is unknown. The purpose of this study was to examine the relationship between hair loss and hair-pulling in 1258 rhesus macaques housed in 4 primate colonies across the United States. Alopecia levels ranged from 34.3% to 86.5% (mean, 49.3%) at the primate facilities. At facilities reporting a sex-associated difference, more female macaques were reported to exhibit alopecia than were males. In contrast, more males were reported to hair-pull. Animals reported to hair-pull were significantly more likely to have some amount of alopecia, but rates of hair-pulling were substantially lower than rates of alopecia, ranging from 0.6% to 20.5% (mean, 7.7%) of the populations. These results further demonstrate that hair-pulling plays only a small role in alopecia in rhesus macaques.

Hair Loss

Science.gov (United States)

... is why some people with eating disorders like anorexia and bulimia lose their hair: The body isn't getting enough protein, vitamins, and minerals to support hair growth. Some teens who are vegetarians also lose their hair if ...

Removing Hair Safely

Science.gov (United States)

... For Consumers Home For Consumers Consumer Updates Removing Hair Safely Share Tweet Linkedin Pin it More sharing ... related to common methods of hair removal. Laser Hair Removal In this method, a laser destroys hair ...

Hair Loss (Alopecia)

Science.gov (United States)

... care Kids’ zone Video library Find a dermatologist Hair loss Overview Hereditary hair loss: Millions of men ... of hair loss can often be successfully treated. Hair loss: Overview Also called alopecia (al-o-PEE- ...

Parietal scalp is another affected area in female pattern hair loss: an analysis of hair density and hair diameter

Directory of Open Access Journals (Sweden)

Rojhirunsakool S

2017-12-01

Full Text Available Salinee Rojhirunsakool, Poonkiat Suchonwanit Department of Medicine, Division of Dermatology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand Purpose: Female pattern hair loss (FPHL is a common hair disease. However, studies of the quantitative measurement of FPHL are still limited. The aim of this study was to investigate the characteristics of hair density and hair diameter in normal women and FPHL patients, and further correlate the quantitative measurement with the clinical presentation of FPHL.Patients and methods: An evaluation of 471 FPHL patients and 236 normal women was carried out according to the Ludwig classification, and analysis was performed by using a computerized handheld USB camera with computer-assisted software. Various areas of the scalp, including frontal, parietal, midscalp, and occipital, were analyzed for hair density, non-vellus hair diameter, and percentage of miniaturized hair.Results: The hair density in normal women was the highest and the lowest in the midscalp and parietal areas, respectively. The FPHL group revealed the lowest hair density in the parietal area. Significant differences in hair density, non-vellus hair diameter, and percentage of miniaturized hair between the normal and FPHL groups were observed, especially in the midscalp and parietal areas.Conclusion: The parietal area is another important affected area in FPHL in addition to the midscalp area. This finding provides novel important information of FPHL and will be useful for hair transplant surgeons choosing the optimal donor sites for hair transplantation in women. Keywords: androgenetic alopecia, alopecia, phototrichogram, miniaturization

Evaluating pulp stiffness from fibre bundles by ultrasound

Science.gov (United States)

Karppinen, Timo; Montonen, Risto; Määttänen, Marjo; Ekman, Axel; Myllys, Markko; Timonen, Jussi; Hæggström, Edward

2012-06-01

A non-destructive ultrasonic tester was developed to measure the stiffness of pulp bundles. The mechanical properties of pulp are important when estimating the behaviour of paper under stress. Currently available pulp tests are tedious and alter the fibres structurally and mechanically. The developed tester employs (933 ± 15) kHz tweezer-like ultrasonic transducers and time-of-flight measurement through (9.0 ± 2.5) mm long and (0.8 ± 0.1) mm thick fibre bundles kept at (19.1 ± 0.4) °C and (62 ± 1)% RH. We determined the stiffness of soft wood pulps produced by three kraft pulping modifications: standard kraft pulp, (5.2 ± 0.4) GPa, prehydrolysis kraft pulp, (4.3 ± 0.4) GPa, and alkali extracted prehydrolysis kraft pulp, (3.3 ± 0.4) GPa. Prehydrolysis and alkali extraction processes mainly lowered the hemicellulose content of the pulps, which essentially decreased the fibre-wall stiffness hence impairing the stiffness of the fibre networks. Our results indicate that the method allows ranking of pulps according to their stiffness determined from bundle-like samples taken at an early phase of the papermaking process.

Microfabricated adhesive mimicking gecko foot-hair

Science.gov (United States)

Geim, A. K.; Dubonos, S. V.; Grigorieva, I. V.; Novoselov, K. S.; Zhukov, A. A.; Shapoval, S. Yu.

2003-07-01

The amazing climbing ability of geckos has attracted the interest of philosophers and scientists alike for centuries. However, only in the past few years has progress been made in understanding the mechanism behind this ability, which relies on submicrometre keratin hairs covering the soles of geckos. Each hair produces a miniscule force ~10-7 N (due to van der Waals and/or capillary interactions) but millions of hairs acting together create a formidable adhesion of ~10 N cm-2: sufficient to keep geckos firmly on their feet, even when upside down on a glass ceiling. It is very tempting to create a new type of adhesive by mimicking the gecko mechanism. Here we report on a prototype of such 'gecko tape' made by microfabrication of dense arrays of flexible plastic pillars, the geometry of which is optimized to ensure their collective adhesion. Our approach shows a way to manufacture self-cleaning, re-attachable dry adhesives, although problems related to their durability and mass production are yet to be resolved.

Fuel bundle to pressure tube fretting in Bruce and Darlington

Energy Technology Data Exchange (ETDEWEB)

Norsworthy, A G; Ditschun, A [Atomic Energy of Canada Ltd., Mississauga, ON (Canada)

1996-12-31

As the fuel channel elongates due to creep, the fuel string moves relative to the inlet until the fuel pads at the inboard end eventually separate from the spacer sleeve, and the fuel resides on the burnish mark of the pressure tube. The bundle is then supported in a fashion which contributes to increased levels of vibration. Those pads which (due to geometric variation) have contact loads with the pressure tube within a certain range, vibrate, and cause significant fretting on the burnish mark, and further along at the midplane of the bundle. Inspection of the pressure tubes in Bruce A, Bruce B, and Darlington has revealed fret damage up to 0.55 mm at the burnish mark and slightly lower than this at the inlet bundle midplane. To date, all fret marks have been dealt with successfully without the need for tube replacement, but a program of work has been initiated to understand the mechanism and reduce the fretting. Such understanding is necessary to guide future design changes to the fuel bundle, to guide future inspection programs, to guide maintenance programs, and for longer term strategic planning. This paper discusses how the understanding of fretting has evolved and outlines a current hypothesis for the mechanism of fretting. The role of bundle geometry, excitation forces, and reactor conditions are reviewed, along with options under consideration to mitigate damage. (author). 4 refs., 2 tabs., 13 figs.

Fuel bundle to pressure tube fretting in Bruce and Darlington

International Nuclear Information System (INIS)

Norsworthy, A.G.; Ditschun, A.

1995-01-01

As the fuel channel elongates due to creep, the fuel string moves relative to the inlet until the fuel pads at the inboard end eventually separate from the spacer sleeve, and the fuel resides on the burnish mark of the pressure tube. The bundle is then supported in a fashion which contributes to increased levels of vibration. Those pads which (due to geometric variation) have contact loads with the pressure tube within a certain range, vibrate, and cause significant fretting on the burnish mark, and further along at the midplane of the bundle. Inspection of the pressure tubes in Bruce A, Bruce B, and Darlington has revealed fret damage up to 0.55 mm at the burnish mark and slightly lower than this at the inlet bundle midplane. To date, all fret marks have been dealt with successfully without the need for tube replacement, but a program of work has been initiated to understand the mechanism and reduce the fretting. Such understanding is necessary to guide future design changes to the fuel bundle, to guide future inspection programs, to guide maintenance programs, and for longer term strategic planning. This paper discusses how the understanding of fretting has evolved and outlines a current hypothesis for the mechanism of fretting. The role of bundle geometry, excitation forces, and reactor conditions are reviewed, along with options under consideration to mitigate damage. (author). 4 refs., 2 tabs., 13 figs

Hair cosmetics

OpenAIRE

Nina Madnani; Kaleem Khan

2013-01-01

The hair cosmetic industry has undergone a revolutionary change over the last two decades. The focus has dramatically veered from merely cleaning to repair, increasing the tensile strength, reducing oxidative damage, and stimulating growth. Newer shorter procedures to make hair look naturally more lustrous, smooth, and manageable have evolved. Specialized grooming products have been formulated to cleanse, calm, and condition the hair, and are tailored for different hair-types, for example, dr...

To Be or Not To Be: The Existential Issue for National Governance Bundles

NARCIS (Netherlands)

Millar-Schijf, Carla C.J.M.

2014-01-01

Research Question/Issue The article addresses the issue of whether governance bundles which include both formal and informal governance mechanisms should be classified and compared on the basis of national identity. Research Findings/Insights The governance bundle affecting each firm has formal

HCN channels are not required for mechanotransduction in sensory hair cells of the mouse inner ear.

Directory of Open Access Journals (Sweden)

Geoffrey C Horwitz

Full Text Available The molecular composition of the hair cell transduction channel has not been identified. Here we explore the novel hypothesis that hair cell transduction channels include HCN subunits. The HCN family of ion channels includes four members, HCN1-4. They were originally identified as the molecular correlates of the hyperpolarization-activated, cyclic nucleotide gated ion channels that carry currents known as If, IQ or Ih. However, based on recent evidence it has been suggested that HCN subunits may also be components of the elusive hair cell transduction channel. To investigate this hypothesis we examined expression of mRNA that encodes HCN1-4 in sensory epithelia of the mouse inner ear, immunolocalization of HCN subunits 1, 2 and 4, uptake of the transduction channel permeable dye, FM1-43 and electrophysiological measurement of mechanotransduction current. Dye uptake and transduction current were assayed in cochlear and vestibular hair cells of wildtype mice exposed to HCN channel blockers or a dominant-negative form of HCN2 that contained a pore mutation and in mutant mice that lacked HCN1, HCN2 or both. We found robust expression of HCNs 1, 2 and 4 but little evidence that localized HCN subunits in hair bundles, the site of mechanotransduction. Although high concentrations of the HCN antagonist, ZD7288, blocked 50-70% of the transduction current, we found no reduction of transduction current in either cochlear or vestibular hair cells of HCN1- or HCN2- deficient mice relative to wild-type mice. Furthermore, mice that lacked both HCN1 and HCN2 also had normal transduction currents. Lastly, we found that mice exposed to the dominant-negative mutant form of HCN2 had normal transduction currents as well. Taken together, the evidence suggests that HCN subunits are not required for mechanotransduction in hair cells of the mouse inner ear.

Bundle Branch Block

Science.gov (United States)

... known cause. Causes can include: Left bundle branch block Heart attacks (myocardial infarction) Thickened, stiffened or weakened ... myocarditis) High blood pressure (hypertension) Right bundle branch block A heart abnormality that's present at birth (congenital) — ...

Female pattern hair loss

Directory of Open Access Journals (Sweden)

Archana Singal

2013-01-01

Full Text Available Female pattern hair loss (FPHL is a common cause of hair loss in women characterized by diffuse reduction in hair density over the crown and frontal scalp with retention of the frontal hairline. Its prevalence increases with advancing age and is associated with significant psychological morbidity. The pathophysiology of FPHL is still not completely understood and seems to be multifactorial. Although androgens have been implicated, the involvement of androgen-independent mechanisms is evident from frequent lack of clinical or biochemical markers of hyperandrogenism in affected women. The role of genetic polymorphisms involving the androgen and estrogen receptors is being increasingly recognized in its causation and predicting treatment response to anti-androgens. There are different clinical patterns and classifications of FPHL, knowledge of which facilitates patient management and research. Chronic telogen effluvium remains as the most important differential diagnosis. Thorough history, clinical examination, and evaluation are essential to confirm diagnosis. Patients with clinical signs of androgen excess require assessment of biochemical parameters and imaging studies. It is prudent to screen the patients for metabolic syndrome and cardiovascular risk factors. The treatment comprises medical and/or surgical modalities. Medical treatment should be initiated early as it effectively arrests hair loss progression rather than stimulating regrowth. Minoxidil continues to be the first line therapy whereas anti-androgens form the second line of treatment. The progressive nature of FPHL mandates long-term treatment for sustained effect. Medical therapy may be supplemented with cosmetic concealment in those desirous of greater hair density. Surgery may be worthwhile in some carefully selected patients.

Demonstrating the compatibility of Canflex fuel bundles with a CANDU 6 fuelling machine

Energy Technology Data Exchange (ETDEWEB)

Alavi, P; Oldaker, I E [Atomic Energy of Canada Ltd., Mississauga, ON (Canada); Suk, H C; Choi, C B [Korea Atomic Energy Research Inst., Taejon (Korea, Republic of)

1997-12-31

CANFLEX is a new 43-element fuel bundle, designed for high operating margins. It has many small-diameter elements in its two outer rings, and large-diameter elements in its centre rings. By this means, the linear heat ratings are lower than those of standard 37-element bundles for similar power outputs. A necessary part of the out-reactor qualification program for the CANFLEX fuel bundle design, is a demonstration of the bundle`s compatibility with the mechanical components in a CANDU 6 Fuelling Machine (FM) under typical conditions of pressure, flow and temperature. The diameter of the CANFLEX bundle is the same as that of a 37-element bundle, but the smaller-diameter elements in the outer ring result in a slightly larger end-plate diameter. Therefore, to minimize any risk of unanticipated damage to the CANDU 6 FM sidestops, a series of measurements and static laboratory tests were undertaken prior to the fuelling machine tests. The tests and measurements showed that; a) the CANFLEX bundle end plate is compatible with the FM sidestops, b) all the dimensions of the CANFLEX fuel bundle are within the specified limits. (author). 3 tabs., 3 figs.

Maintained expression of the planar cell polarity molecule Vangl2 and reformation of hair cell orientation in the regenerating inner ear.

Science.gov (United States)

Warchol, Mark E; Montcouquiol, Mireille

2010-09-01

The avian inner ear possesses a remarkable ability to regenerate sensory hair cells after ototoxic injury. Regenerated hair cells possess phenotypes and innervation that are similar to those found in the undamaged ear, but little is known about the signaling pathways that guide hair cell differentiation during the regenerative process. The aim of the present study was to examine the factors that specify the orientation of hair cell stereocilia bundles during regeneration. Using organ cultures of the chick utricle, we show that hair cells are properly oriented after having regenerated entirely in vitro and that orientation is not affected by surgical removal of the striolar reversal zone. These results suggest that the orientation of regenerating stereocilia is not guided by the release of a diffusible morphogen from the striolar reversal zone but is specified locally within the regenerating sensory organ. In order to determine the nature of the reorientation cues, we examined the expression patterns of the core planar cell polarity molecule Vangl2 in the normal and regenerating utricle. We found that Vangl2 is asymmetrically expressed on cells within the sensory epithelium and that this expression pattern is maintained after ototoxic injury and throughout regeneration. Notably, treatment with a small molecule inhibitor of c-Jun-N-terminal kinase disrupted the orientation of regenerated hair cells. Both of these results are consistent with the hypothesis that noncanonical Wnt signaling guides hair cell orientation during regeneration.

Hair Interactions

OpenAIRE

Cani , Marie-Paule; Bertails , Florence

2006-01-01

International audience; Processing interactions is one of the main challenges in hair animation. Indeed, in addition to the collisions with the body, an extremely large number of contacts with high friction rates are permanently taking place between individual hair strands. Simulating the latter is essential: without hair self-interactions, strands would cross each other during motion or come to rest at the same location, yielding unrealistic behavior and a visible lack of hair volume. This c...

Nanotribological characterization of human hair and skin using atomic force microscopy

International Nuclear Information System (INIS)

LaTorre, Carmen; Bhushan, Bharat

2005-01-01

Healthy hair and skin is highly desired. Characterization of their morphological, frictional, and adhesive properties (tribological properties) is essential to enhance understanding of hair and skin and to advance the science. Literature on the tribological characterization of hair and skin is scarce to date. The paper presents nanotribological data and analysis on hair (Caucasian, Asian, and African hair at virgin, chemo-mechanically damaged, and treated conditions) and synthetic hair and skin, as well as roughness data of human skin replica. Roughness statistics are presented to characterize the vertical and spatial surface parameters. Average coefficient of friction values were determined for each ethnicity and hair type, and are discussed. The directionality dependence of friction is also discussed. Magnitude and spatial distribution of adhesive force are used to estimate thickness and distribution of the conditioner film

Organ-level quorum sensing directs regeneration in hair stem cell populations

Science.gov (United States)

Chen, Chih-Chiang; Wang, Lei; Plikus, Maksim V.; Jiang, Ting Xin; Murray, Philip J.; Ramos, Raul; Guerrero-Juarez, Christian F.; Hughes, Michael W; Lee, Oscar K.; Shi, Songtao; Widelitz, Randall B.; Lander, Arthur D.; Chuong, Cheng Ming

2015-01-01

SUMMARY Coordinated organ behavior is crucial for an effective response to environmental stimuli. By studying regeneration of hair follicles in response to patterned hair removal, we demonstrate that organ-level quorum sensing allows coordinated responses to skin injury. Removing hair at different densities leads to a regeneration of up to 5 times more neighboring, unplucked resting hairs, indicating activation of a collective decision-making process. Through data modeling, the range of the quorum signal was estimated to be on the order of 1 mm, greater than expected for a diffusible molecular cue. Molecular and genetic analysis uncovered a two-step mechanism, where release of CCL2 from injured hairs leads to recruitment of TNF-α secreting macrophages, which accumulate and signal to both plucked and unplucked follicles. By coupling immune response with regeneration, this mechanism allows skin to respond predictively to distress, disregarding mild injury, while meeting stronger injury with full-scale cooperative activation of stem cells. PMID:25860610

What is the use of elephant hair?

Directory of Open Access Journals (Sweden)

Conor L Myhrvold

Full Text Available The idea that low surface densities of hairs could be a heat loss mechanism is understood in engineering and has been postulated in some thermal studies of animals. However, its biological implications, both for thermoregulation as well as for the evolution of epidermal structures, have not yet been noted. Since early epidermal structures are poorly preserved in the fossil record, we study modern elephants to infer not only the heat transfer effect of present-day sparse hair, but also its potential evolutionary origins. Here we use a combination of theoretical and empirical approaches, and a range of hair densities determined from photographs, to test whether sparse hairs increase convective heat loss from elephant skin, thus serving an intentional evolutionary purpose. Our conclusion is that elephants are covered with hair that significantly enhances their thermoregulation ability by over 5% under all scenarios considered, and by up to 23% at low wind speeds where their thermoregulation needs are greatest. The broader biological significance of this finding suggests that maintaining a low-density hair cover can be evolutionary purposeful and beneficial, which is consistent with the fact that elephants have the greatest need for heat loss of any modern terrestrial animal because of their high body-volume to skin-surface ratio. Elephant hair is the first documented example in nature where increasing heat transfer due to a low hair density covering may be a desirable effect, and therefore raises the possibility of such a covering for similarly sized animals in the past. This elephant example dispels the widely-held assumption that in modern endotherms body hair functions exclusively as an insulator and could therefore be a first step to resolving the prior paradox of why hair was able to evolve in a world much warmer than our own.

Mechanical splitting of microtubules into protofilament bundles by surface-bound kinesin-1.

Science.gov (United States)

VanDelinder, Virginia; Adams, Peter G; Bachand, George D

2016-12-21

The fundamental biophysics of gliding microtubule (MT) motility by surface-tethered kinesin-1 motor proteins has been widely studied, as well as applied to capture and transport analytes in bioanalytical microdevices. In these systems, phenomena such as molecular wear and fracture into shorter MTs have been reported due the mechanical forces applied on the MT during transport. In the present work, we show that MTs can be split longitudinally into protofilament bundles (PFBs) by the work performed by surface-bound kinesin motors. We examine the properties of these PFBs using several techniques (e.g., fluorescence microscopy, SEM, AFM), and show that the PFBs continue to be mobile on the surface and display very high curvature compared to MT. Further, higher surface density of kinesin motors and shorter kinesin-surface tethers promote PFB formation, whereas modifying MT with GMPCPP or higher paclitaxel concentrations did not affect PFB formation.

Alternative Splice Forms Influence Functions of Whirlin in Mechanosensory Hair Cell Stereocilia.

Science.gov (United States)

Ebrahim, Seham; Ingham, Neil J; Lewis, Morag A; Rogers, Michael J C; Cui, Runjia; Kachar, Bechara; Pass, Johanna C; Steel, Karen P

2016-05-03

WHRN (DFNB31) mutations cause diverse hearing disorders: profound deafness (DFNB31) or variable hearing loss in Usher syndrome type II. The known role of WHRN in stereocilia elongation does not explain these different pathophysiologies. Using spontaneous and targeted Whrn mutants, we show that the major long (WHRN-L) and short (WHRN-S) isoforms of WHRN have distinct localizations within stereocilia and also across hair cell types. Lack of both isoforms causes abnormally short stereocilia and profound deafness and vestibular dysfunction. WHRN-S expression, however, is sufficient to maintain stereocilia bundle morphology and function in a subset of hair cells, resulting in some auditory response and no overt vestibular dysfunction. WHRN-S interacts with EPS8, and both are required at stereocilia tips for normal length regulation. WHRN-L localizes midway along the shorter stereocilia, at the level of inter-stereociliary links. We propose that differential isoform expression underlies the variable auditory and vestibular phenotypes associated with WHRN mutations. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Safety assessment for the CANFLEX-NU fuel bundles with respect to the 37-element fuel bundles

Energy Technology Data Exchange (ETDEWEB)

Suk, H. C.; Lim, H. S. [Korea Atomic Energy Research Institute, Taejon (Korea)

1999-11-01

The KAERI and AECL have jointly developed an advanced CANDU fuel, called CANFLEX-NU fuel bundle. CANFLEX 43-element bundle has some improved features of increased operating margin and enhanced safety compared to the existing 37-element bundle. Since CANFLEX fuel bundle is designed to be compatible with the CANDU-6 reactor design, the behaviour in the thermalhydraulic system will be nearly identical with 37-element bundle. But due to different element design and linear element power distribution between the two bundles, it is expected that CANFLEX fuel behaviour would be different from the behaviour of the 37-element fuel. Therefore, safety assessments on the design basis accidents which result if fuel failures are performed. For all accidents selected, it is observed that the loading of CANFLEX bundle in an existing CANDU-6 reactor would not worsen the reactor safety. It is also predicted that fission product release for CANFLEX fuel bundle generally is lower than that for 37-element bundle. 3 refs., 2 figs., 2 tabs. (Author)

A precise automatic system for the hair assessment in hair-care diagnosis applications.

Science.gov (United States)

Shih, H

2015-11-01

One emerging subject in medical image processing is to quantitatively assess the health and the properties of cranial hairs, including density, diameter, length, level of oiliness, and others. This information helps hair specialists with making a more accurate diagnosis and the therapy required. We develop a practical hair counting algorithm. This analytic system calculates the number of hairs on a scalp using a digital microscope camera, providing accurate information for both the hair specialist and the patient. Our proposed hair counting algorithm is substantially more accurate than the Hough-based one, and is robust to curls, oily scalp, noise-corruption, and overlapping hairs, under various levels of illumination. Rather than manually counting the hairs on a person's scalp, the proposed system determines the density, diameter, length, and level of oiliness of the hairs. We propose an automated system for counting the amount of hairs in the microscopy images. To reduce the effect of bright spots, we develop a robust morphological algorithm for color to smooth out the color and preserve the fidelity of the hair. Then, we utilize a modified Hough transform algorithm to detect the different hair lengths and to reduce any false detection due to noise. Our proposed system enables us to look at curved hairs as multiple pieces of straight lines. To avoid missing hairs when the thinning process is applied, we use edge information to discover any hidden or overlapping hairs. Finally, we employ a mutually associative regression method to label a group of line segments into a meaningful 'hair'. We demonstrated a novel approach for accurately computing the number of hairs, and successfully solved the three main obstacles in automated hair counting, including (i) oily and moist hairs, (ii) wavy and curly hairs, and (iii) under-estimation of the number of hairs occurs when hairs cross and occlude each other. The framework of this paper can be seen as the first step toward

Design verification of the CANFLEX fuel bundle - quality assurance requirements for mechanical flow testing

International Nuclear Information System (INIS)

Alavi, P.; Oldaker, I.E.; Chung, C.H.; Suk, H.C.

1997-01-01

As part of the design verification program for the new fuel bundle, a series of out-reactor tests was conducted on the CANFLEX 43-element fuel bundle design. These tests simulated current CANDU 6 reactor normal operating conditions of flow, temperature and pressure. This paper describes the Quality Assurance (QA) Program implemented for the tests that were run at the testing laboratories of Atomic Energy of Canada Limited (AECL) and Korea Atomic energy Research Institute (KAERI). (author)

Rescue of Outer Hair Cells with Antisense Oligonucleotides in Usher Mice Is Dependent on Age of Treatment.

Science.gov (United States)

Ponnath, Abhilash; Depreux, Frederic F; Jodelka, Francine M; Rigo, Frank; Farris, Hamilton E; Hastings, Michelle L; Lentz, Jennifer J

2018-02-01

The absence of functional outer hair cells is a component of several forms of hereditary hearing impairment, including Usher syndrome, the most common cause of concurrent hearing and vision loss. Antisense oligonucleotide (ASO) treatment of mice with the human Usher mutation, Ush1c c.216G>A, corrects gene expression and significantly improves hearing, as measured by auditory-evoked brainstem responses (ABRs), as well as inner and outer hair cell (IHC and OHC) bundle morphology. However, it is not clear whether the improvement in hearing achieved by ASO treatment involves the functional rescue of outer hair cells. Here, we show that Ush1c c.216AA mice lack OHC function as evidenced by the absence of distortion product otoacoustic emissions (DPOAEs) in response to low-, mid-, and high-frequency tone pairs. This OHC deficit is rescued by treatment with an ASO that corrects expression of Ush1c c.216G>A. Interestingly, although rescue of inner hairs cells, as measured by ABR, is achieved by ASO treatment as late as 7 days after birth, rescue of outer hair cells, measured by DPOAE, requires treatment before post-natal day 5. These results suggest that ASO-mediated rescue of both IHC and OHC function is age dependent and that the treatment window is different for the different cell types. The timing of treatment for congenital hearing disorders is of critical importance for the development of drugs such ASO-29 for hearing rescue.

Simulation of finite size effects of the fiber bundle model

Science.gov (United States)

Hao, Da-Peng; Tang, Gang; Xun, Zhi-Peng; Xia, Hui; Han, Kui

2018-01-01

In theory, the macroscopic fracture of materials should correspond with the thermodynamic limit of the fiber bundle model. However, the simulation of a fiber bundle model with an infinite size is unrealistic. To study the finite size effects of the fiber bundle model, fiber bundle models of various size are simulated in detail. The effects of system size on the constitutive behavior, critical stress, maximum avalanche size, avalanche size distribution, and increased step number of external load are explored. The simulation results imply that there is no feature size or cut size for macroscopic mechanical and statistical properties of the model. The constitutive curves near the macroscopic failure for various system size can collapse well with a simple scaling relationship. Simultaneously, the introduction of a simple extrapolation method facilitates the acquisition of more accurate simulation results in a large-limit system, which is better for comparison with theoretical results.

Reverse Engineering Applied to Red Human Hair Pheomelanin Reveals Redox-Buffering as a Pro-Oxidant Mechanism

Science.gov (United States)

Kim, Eunkyoung; Panzella, Lucia; Micillo, Raffaella; Bentley, William E.; Napolitano, Alessandra; Payne, Gregory F.

2015-01-01

Pheomelanin has been implicated in the increased susceptibility to UV-induced melanoma for people with light skin and red hair. Recent studies identified a UV-independent pathway to melanoma carcinogenesis and implicated pheomelanin’s pro-oxidant properties that act through the generation of reactive oxygen species and/or the depletion of cellular antioxidants. Here, we applied an electrochemically-based reverse engineering methodology to compare the redox properties of human hair pheomelanin with model synthetic pigments and natural eumelanin. This methodology exposes the insoluble melanin samples to complex potential (voltage) inputs and measures output response characteristics to assess redox activities. The results demonstrate that both eumelanin and pheomelanin are redox-active, they can rapidly (sec-min) and repeatedly redox-cycle between oxidized and reduced states, and pheomelanin possesses a more oxidative redox potential. This study suggests that pheomelanin’s redox-based pro-oxidant activity may contribute to sustaining a chronic oxidative stress condition through a redox-buffering mechanism. PMID:26669666

A novel Atoh1 "self-terminating" mouse model reveals the necessity of proper Atoh1 level and duration for hair cell differentiation and viability.

Directory of Open Access Journals (Sweden)

Ning Pan

Full Text Available Atonal homolog1 (Atoh1 is a bHLH transcription factor essential for inner ear hair cell differentiation. Targeted expression of Atoh1 at various stages in development can result in hair cell differentiation in the ear. However, the level and duration of Atoh1 expression required for proper hair cell differentiation and maintenance remain unknown. We generated an Atoh1 conditional knockout (CKO mouse line using Tg(Atoh1-cre, in which the cre expression is driven by an Atoh1 enhancer element that is regulated by Atoh1 protein to "self-terminate" its expression. The mutant mice show transient, limited expression of Atoh1 in all hair cells in the ear. In the organ of Corti, reduction and delayed deletion of Atoh1 result in progressive loss of almost all the inner hair cells and the majority of the outer hair cells within three weeks after birth. The remaining cells express hair cell marker Myo7a and attract nerve fibers, but do not differentiate normal stereocilia bundles. Some Myo7a-positive cells persist in the cochlea into adult stages in the position of outer hair cells, flanked by a single row of pillar cells and two to three rows of disorganized Deiters cells. Gene expression analyses of Atoh1, Barhl1 and Pou4f3, genes required for survival and maturation of hair cells, reveal earlier and higher expression levels in the inner compared to the outer hair cells. Our data show that Atoh1 is crucial for hair cell mechanotransduction development, viability, and maintenance and also suggest that Atoh1 expression level and duration may play a role in inner vs. outer hair cell development. These genetically engineered Atoh1 CKO mice provide a novel model for establishing critical conditions needed to regenerate viable and functional hair cells with Atoh1 therapy.

An ESR study on biological dosimeters: Human hair

International Nuclear Information System (INIS)

Colak, Seyda; Ozbey, Turan

2011-01-01

In the present work, characteristic features of the radicals found in untreated, gamma and UV-irradiated and mechanical damaged human hair samples were investigated by ESR spectroscopy. Heights of the resonance peaks measured with respect to the spectrum base line were used to monitor microwave power, dose-response, storage time and temperature dependent kinetic features of the radical species contributing to the formation of recorded experimental ESR spectra. Peak heights and g-values (2.0037-2.0052) determined from recorded spectra of hair were color dependent with ΔHpp-0.47 mT. The act of cutting hair samples gene rates sulfur centered radicals which are found in the a-keratin structure of hair. The variations of the peak heights with temperature were related with the water content found in the hair samples. In the 6-1100 Gy dose range, a linear + quadratic dose-response curve was recorded for hair and the mean radiation yield (G mean ) was calculated to be 0.4. The gamma radiation induced radicals were stable for a several hours at room temperature storage conditions. Based on these findings it was concluded that human hair samples could be used as biological/personnel dosimeters and that ESR spectroscopy could be successfully used as a potential technique for monitoring its dosimetric behaviours.

Constructing co-Higgs bundles on CP^2

OpenAIRE

Rayan, Steven

2013-01-01

On a complex manifold, a co-Higgs bundle is a holomorphic vector bundle with an endomorphism twisted by the tangent bundle. The notion of generalized holomorphic bundle in Hitchin's generalized geometry coincides with that of co-Higgs bundle when the generalized complex manifold is ordinary complex. Schwarzenberger's rank-2 vector bundle on the projective plane, constructed from a line bundle on the double cover CP^1 \\times CP^1 \\to CP^2, is naturally a co-Higgs bundle, with the twisted endom...

CANFLEX fuel bundle impact test

International Nuclear Information System (INIS)

Chang, Seok Kyu; Chung, C. H.; Park, J. S.; Hong, S. D.; Kim, B. D.

1997-08-01

This document outlines the test results for the impact test of the CANFLEX fuel bundle. Impact test is performed to determine and verify the amount of general bundle shape distortion and defect of the pressure tube that may occur during refuelling. The test specification requires that the fuel bundles and the pressure tube retain their integrities after the impact test under the conservative conditions (10 stationary bundles with 31kg/s flow rate) considering the pressure tube creep. The refuelling simulator operating with pneumatic force and simulated shield plug were fabricated and the velocity/displacement transducer and the high speed camera were also used in this test. The characteristics of the moving bundle (velocity, displacement, impacting force) were measured and analyzed with the impact sensor and the high speed camera system. The important test procedures and measurement results were discussed as follows. 1) Test bundle measurements and the pressure tube inspections 2) Simulated shield plug, outlet flange installation and bundle loading 3) refuelling simulator, inlet flange installation and sensors, high speed camera installation 4) Perform the impact test with operating the refuelling simulator and measure the dynamic characteristics 5) Inspections of the fuel bundles and the pressure tube. (author). 8 refs., 23 tabs., 13 figs

Characterization of aging hair and its influence in quality of life

Directory of Open Access Journals (Sweden)

Marcella A. L. Gabarra

2015-05-01

Full Text Available There are few studies that characterize the non-pigmented hair compared to pigmented hair. Furthermore, it is important to evaluate how the natural process of aging hair influences quality of life in women. For this purpose, a questionnaire was applied to evaluate the impact of greying hair and the appearance alterations on women´s self-esteem. The satisfaction level of volunteers regarding their hair structure and conditions such as shine, strength and smoothness were also evaluated. Mechanical properties, such as elasticity and traction to rupture were measured using Universal test equipment. Scanning electron microscopy (SEM was used to measure the hair surface morphological conditions. A large majority of the volunteers indicated that the beginning of greying hair can negatively influence their quality of life. They also reported that the primary changes of their hair were the frizziness, dryness and loss of shine, increased loss and breakage and thinning. Morphological evaluation showed that the non-pigmented hair cuticles were thinner than pigmented hair. The adherence of the cuticle scales was more pronounced in the non-pigmented hair .Finally, this study showed the influence of the appearance of grey hair on quality of life in women as well as the morphological alterations resulting from the greying processes.

Hair Loss Myths.

Science.gov (United States)

DiMarco, Gabriella; McMichael, Amy

2017-07-01

INTRODUCTION: Hair loss is a common complaint seen in dermatology clinics. From frustration and attempts at self-help, patients with hair loss may present to the dermatologist with false beliefs, or myths, about the causes of their condition and what treatments are effective. METHODS: We identified 12 common myths about hair loss, categorized as myths about minoxidil treatment, vitamin and mineral supplements, natural topical treatments, and hair care practices. We performed a PubMed search to find evidence to support or refute each myth. RESULTS: We found that there is little evidence to support many of these common hair loss myths. In some cases, randomized controlled trials have investigated the effects of particular therapies and point to the effectiveness of certain hair loss treatments. DISCUSSION: In many cases, there have not been sufficient randomized controlled trials to evaluate the effect of different therapies and hair care practices on hair loss. It is best to guide patients toward treatments with a long track record of efficacy and away from those where little is known scientifically. J Drugs Dermatol. 2017;16(7):690-694..

A Guide to Bundling Small-scale CDM Projects

International Nuclear Information System (INIS)

Mariyappan, J.; Bhardwaj, N.; De Coninck, H.; Van der Linden, N.

2005-07-01

Small-scale renewable energy and energy efficiency projects that fit the development needs of many developing countries, can potentially be supported via the Clean Development Mechanism (CDM), one of the Kyoto Protocol's flexible mechanisms for tackling climate change. However, there is concern that due to high transaction costs, as well as many existing barriers, very few investments will be made in small-scale projects, which are often the most suitable development option in countries such as India. In view of this, the 'bundling' together of appropriate small-scale projects on a regional basis has been proposed as a way in which funding can be leveraged from international sources and transaction costs reduced. IT Power, IT Power India and the Energy research Centre of the Netherlands (ECN) are carrying out a 2-year project to establish the capacity within India to enable individual small scale projects to be bundled as a single CDM project. Overall objectives are to develop the necessary institutional capabilities to formulate and implement small scale CDM projects in India; to provide a guide on how to bundle small scale projects under the CDM in developing countries; and to raise the awareness of the potential for investment in small scale energy projects which can gain funding through the CDM

Ethnic hair care products may increase false positives in hair drug testing.

Science.gov (United States)

Kidwell, David A; Smith, Frederick P; Shepherd, Arica R

2015-12-01

The question of why different races appear more susceptible to hair contamination by external drugs remains controversial. This research studied susceptibility of head hair to external cocaine and methamphetamine when hair products have been applied. Three different chemical classes of ethnic hair products were applied to Caucasian, Asian, and African hair. Some products increased the methamphetamine and cocaine concentrations in all hair types. A unique finding of this research is that certain ethnic hair products can replace moisture as a diffusion medium, thereby increasing the susceptibility to contamination over 100-fold compared to petroleum-based products. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Hair loss in women: medical and cosmetic approaches to increase scalp hair fullness.

Science.gov (United States)

Sinclair, R; Patel, M; Dawson, T L; Yazdabadi, A; Yip, L; Perez, A; Rufaut, N W

2011-12-01

Androgenetic alopecia affects both men and women. In men it produces male pattern hair loss with bitemporal recession and vertex baldness. In women it produces female pattern hair loss (FPHL) with diffuse alopecia over the mid-frontal scalp. FPHL occurs as a result of nonuniform hair follicle miniaturization within follicular units. Diffuse alopecia is produced by a reduction in the number of terminal fibres per follicular unit. Baldness occurs only when all hairs within the follicular units are miniaturized and is a relatively late event in women. The concepts of follicular units and primary and secondary hair follicles within follicular units are well established in comparative mammalian studies, particularly in sheep. However, discovery of these structures in the human scalp hair and investigation of the changes in follicular unit anatomy during the development of androgenetic alopecia have provided a clearer understanding of the early stages of androgenetic alopecia and how the male and female patterns of hair loss are related. FPHL is the most common cause of alopecia in women and approximately one-third of adult caucasian women experience hair loss. The impact of FPHL is predominantly psychological. While men anticipate age-related hair loss, hair loss in women is usually unexpected and unwelcome at any age. Treatment options to arrest hair loss progression and stimulate partial hair regrowth for FPHL include the androgen receptor antagonists spironolactone and cyproterone acetate, the 5α-reductase inhibitor finasteride and the androgen-independent hair growth stimulator minoxidil. These treatments appear to work best when initiated early. Hair transplantation should be considered in advanced FPHL that is resistant to medical treatments. Hair transplantation requires well-preserved hair growth over the occipital donor area. The psychological impact of FPHL may also be reduced by cosmetic products that improve the appearance of the hair. These agents work to

Polycation induced actin bundles

OpenAIRE

Muhlrad, Andras; Grintsevich, Elena E.; Reisler, Emil

2011-01-01

Three polycations, polylysine, the polyamine spermine and the polycationic protein lysozyme were used to study the formation, structure, ionic strength sensitivity and dissociation of polycation-induced actin bundles. Bundles form fast, simultaneously with the polymerization of MgATP-G-actins, upon addition of polycations to solutions of actins at low ionic strength conditions. This indicates that nuclei and/or nascent filaments bundle due to attractive, electrostatic effect of polycations an...

[Hormones and hair growth].

Science.gov (United States)

Trüeb, R M

2010-06-01

With respect to the relationship between hormones and hair growth, the role of androgens for androgenetic alopecia (AGA) and hirsutism is best acknowledged. Accordingly, therapeutic strategies that intervene in androgen metabolism have been successfully developed for treatment of these conditions. Clinical observations of hair conditions involving hormones beyond the androgen horizon have determined their role in regulation of hair growth: estrogens, prolactin, thyroid hormone, cortisone, growth hormone (GH), and melatonin. Primary GH resistance is characterized by thin hair, while acromegaly may cause hypertrichosis. Hyperprolactinemia may cause hair loss and hirsutism. Partial synchronization of the hair cycle in anagen during late pregnancy points to an estrogen effect, while aromatase inhibitors cause hair loss. Hair loss in a causal relationship to thyroid disorders is well documented. In contrast to AGA, senescent alopecia affects the hair in a diffuse manner. The question arises, whether the hypothesis that a causal relationship exists between the age-related reduction of circulating hormones and organ function also applies to hair and the aging of hair.

Hair cosmetics: dyes.

Science.gov (United States)

Guerra-Tapia, A; Gonzalez-Guerra, E

2014-11-01

Hair plays a significant role in body image, and its appearance can be changed relatively easily without resort to surgical procedures. Cosmetics and techniques have therefore been used to change hair appearance since time immemorial. The cosmetics industry has developed efficient products that can be used on healthy hair or act on concomitant diseases of the hair and scalp. Dyes embellish the hair by bleaching or coloring it briefly, for temporary periods of longer duration, or permanently, depending on the composition of a dye (oxidative or nonoxidative) and its degree of penetration of the hair shaft. The dermatologist's knowledge of dyes, their use, and their possible side effects (contact eczema, cancer, increased porosity, brittleness) can extend to an understanding of cosmetic resources that also treat hair and scalp conditions. Copyright © 2013 Elsevier España, S.L.U. and AEDV. All rights reserved.

Limited hair cell induction from human induced pluripotent stem cells using a simple stepwise method.

Science.gov (United States)

Ohnishi, Hiroe; Skerleva, Desislava; Kitajiri, Shin-ichiro; Sakamoto, Tatsunori; Yamamoto, Norio; Ito, Juichi; Nakagawa, Takayuki

2015-07-10

Disease-specific induced pluripotent stem cells (iPS) cells are expected to contribute to exploring useful tools for studying the pathophysiology of inner ear diseases and to drug discovery for treating inner ear diseases. For this purpose, stable induction methods for the differentiation of human iPS cells into inner ear hair cells are required. In the present study, we examined the efficacy of a simple induction method for inducing the differentiation of human iPS cells into hair cells. The induction of inner ear hair cell-like cells was performed using a stepwise method mimicking inner ear development. Human iPS cells were sequentially transformed into the preplacodal ectoderm, otic placode, and hair cell-like cells. As a first step, preplacodal ectoderm induction, human iPS cells were seeded on a Matrigel-coated plate and cultured in a serum free N2/B27 medium for 8 days according to a previous study that demonstrated spontaneous differentiation of human ES cells into the preplacodal ectoderm. As the second step, the cells after preplacodal ectoderm induction were treated with basic fibroblast growth factor (bFGF) for induction of differentiation into otic-placode-like cells for 15 days. As the final step, cultured cells were incubated in a serum free medium containing Matrigel for 48 days. After preplacodal ectoderm induction, over 90% of cultured cells expressed the genes that express in preplacodal ectoderm. By culture with bFGF, otic placode marker-positive cells were obtained, although their number was limited. Further 48-day culture in serum free media resulted in the induction of hair cell-like cells, which expressed a hair cell marker and had stereocilia bundle-like constructions on their apical surface. Our results indicate that hair cell-like cells are induced from human iPS cells using a simple stepwise method with only bFGF, without the use of xenogeneic cells. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Stimulation of the inner hair cell stereocilia: A sensitivity and noise analysis

Science.gov (United States)

Sasmal, Aritra; Grosh, Karl

2018-05-01

The inner hair cell (IHC) hair bundles (HBs) of the mammalian cochlea are located in a 2-6 µm wide fluid filled gap of the sub-tectorial space (STS) between the tectorial membrane (TM) and the reticular lamina (RL) and are excited by the radial flow of the viscous endolymphatic fluid. According to the fluctuation dissipation theorem, the viscosity of the STS fluid that couples the HBs to the radial motion of the TM also gives rise to mechanical fluctuations which are transduced into current noise by the mechano-electric transduction (MET) channels at the tip of the HBs. Conversely, the inherent stochasticity of the MET channels leads to fluctuations in the resting tension of the tip links and induce dissipation. In this study, we quantified the viscous and channel noise in the gerbil cochlea through an analytic model. The channel noise was found to be the dominant noise at the characteristic frequency (CF) of the apex while viscous noise was the dominant noise source at the CF of the base. The net root mean square (RMS) fluctuation of the HB motion was predicted to be at least 1.18 nm at the base and 2.72 nm at the apex, while the narrowband threshold TM radial motion was estimated to be 5 pm at the base and 0.1 nm at the apex. We studied the trade-off between sensitivity and noise on the HBs by varying the height of the HBs and predicted that the taller HBs have a lower TM shear displacement threshold in spite of experiencing higher viscous noise force.

Hair and bare skin discrimination for laser-assisted hair removal systems.

Science.gov (United States)

Cayir, Sercan; Yetik, Imam Samil

2017-07-01

Laser-assisted hair removal devices aim to remove body hair permanently. In most cases, these devices irradiate the whole area of the skin with a homogenous power density. Thus, a significant portion of the skin, where hair is not present, is burnt unnecessarily causing health risks. Therefore, methods that can distinguish hair regions automatically would be very helpful avoiding these unnecessary applications of laser. This study proposes a new system of algorithms to detect hair regions with the help of a digital camera. Unlike previous limited number of studies, our methods are very fast allowing for real-time application. Proposed methods are based on certain features derived from histograms of hair and skin regions. We compare our algorithm with competing methods in terms of localization performance and computation time and show that a much faster real-time accurate localization of hair regions is possible with the proposed method. Our results show that the algorithm we have developed is extremely fast (around 45 milliseconds) allowing for real-time application with high accuracy hair localization ( 96.48 %).

Pierced Lasso Bundles are a new class of knot-like motifs.

Directory of Open Access Journals (Sweden)

Ellinor Haglund

2014-06-01

Full Text Available A four-helix bundle is a well-characterized motif often used as a target for designed pharmaceutical therapeutics and nutritional supplements. Recently, we discovered a new structural complexity within this motif created by a disulphide bridge in the long-chain helical bundle cytokine leptin. When oxidized, leptin contains a disulphide bridge creating a covalent-loop through which part of the polypeptide chain is threaded (as seen in knotted proteins. We explored whether other proteins contain a similar intriguing knot-like structure as in leptin and discovered 11 structurally homologous proteins in the PDB. We call this new helical family class the Pierced Lasso Bundle (PLB and the knot-like threaded structural motif a Pierced Lasso (PL. In the current study, we use structure-based simulation to investigate the threading/folding mechanisms for all the PLBs along with three unthreaded homologs as the covalent loop (or lasso in leptin is important in folding dynamics and activity. We find that the presence of a small covalent loop leads to a mechanism where structural elements slipknot to thread through the covalent loop. Larger loops use a piercing mechanism where the free terminal plugs through the covalent loop. Remarkably, the position of the loop as well as its size influences the native state dynamics, which can impact receptor binding and biological activity. This previously unrecognized complexity of knot-like proteins within the helical bundle family comprises a completely new class within the knot family, and the hidden complexity we unraveled in the PLBs is expected to be found in other protein structures outside the four-helix bundles. The insights gained here provide critical new elements for future investigation of this emerging class of proteins, where function and the energetic landscape can be controlled by hidden topology, and should be take into account in ab initio predictions of newly identified protein targets.

Real-time wavelet-based inline banknote-in-bundle counting for cut-and-bundle machines

Science.gov (United States)

Petker, Denis; Lohweg, Volker; Gillich, Eugen; Türke, Thomas; Willeke, Harald; Lochmüller, Jens; Schaede, Johannes

2011-03-01

Automatic banknote sheet cut-and-bundle machines are widely used within the scope of banknote production. Beside the cutting-and-bundling, which is a mature technology, image-processing-based quality inspection for this type of machine is attractive. We present in this work a new real-time Touchless Counting and perspective cutting blade quality insurance system, based on a Color-CCD-Camera and a dual-core Computer, for cut-and-bundle applications in banknote production. The system, which applies Wavelet-based multi-scale filtering is able to count banknotes inside a 100-bundle within 200-300 ms depending on the window size.

Evaluation of Single-Bundle versus Double-Bundle PCL Reconstructions with More Than 10-Year Follow-Up

Directory of Open Access Journals (Sweden)

Masataka Deie

2015-01-01

Full Text Available Background. Posterior cruciate ligament (PCL injuries are not rare in acute knee injuries, and several recent anatomical studies of the PCL and reconstructive surgical techniques have generated improved patient results. Now, we have evaluated PCL reconstructions performed by either the single-bundle or double-bundle technique in a patient group followed up retrospectively for more than 10 years. Methods. PCL reconstructions were conducted using the single-bundle (27 cases or double-bundle (13 cases method from 1999 to 2002. The mean age at surgery was 34 years in the single-bundle group and 32 years in the double-bundle group. The mean follow-up period was 12.5 years. Patients were evaluated by Lysholm scoring, the gravity sag view, and knee arthrometry. Results. The Lysholm score after surgery was 89.1±5.6 points for the single-bundle group and 91.9±4.5 points for the double-bundle group. There was no significant difference between the methods in the side-to-side differences by gravity sag view or knee arthrometer evaluation, although several cases in both groups showed a side-to-side difference exceeding 5 mm by the latter evaluation method. Conclusions. We found no significant difference between single- and double-bundle PCL reconstructions during more than 10 years of follow-up.

Hair Pulling (Trichotillomania)

Science.gov (United States)

... for Families - Vietnamese Spanish Facts for Families Guide Hair Pulling (Trichotillomania) No. 96; Reviewed July 2013 It ... for children and adolescents to play with their hair. However, frequent or obsessive hair pulling can lead ...

Multiscalar black holes with contingent primary hair: Mechanics and stability

International Nuclear Information System (INIS)

Mignemi, Salvatore; Wiltshire, David L.

2004-01-01

We generalize a class of magnetically charged black holes nonminimally coupled to two scalar fields previously found by one of us to the case of multiple scalar fields. The black holes possess a novel type of primary scalar hair, which we call a contingent primary hair: although the solutions possess degrees of freedom which are not completely determined by the other charges of the theory, the charges necessarily vanish in the absence of the magnetic monopole. Only one constraint relates the black hole mass to the magnetic charge and scalar charges of the theory. We obtain a Smarr-type thermodynamic relation, and the first law of black hole thermodynamics for the system. We further explicitly show in the two-scalar-field case that, contrary to the case of many other hairy black holes, the black hole solutions are stable to radial perturbations

Modeling Chemotherapy-Induced Hair Loss: From Experimental Propositions toward Clinical Reality.

Science.gov (United States)

Botchkarev, Vladimir A; Sharov, Andrey A

2016-03-01

Chemotherapy-induced hair loss is one of the most devastating side effects of cancer treatment. To study the effects of chemotherapeutic agents on the hair follicle, a number of experimental models have been proposed. Yoon et al. report that transplantation of human scalp hair follicles onto chemotherapy-treated immunodeficient mice serves as an excellent in vivo model for chemotherapy-induced hair loss. Yoon et al. demonstrate that (i) the response of human hair follicles grafted onto immunodeficient mice to cyclophosphamide resembles the key features of the chemotherapy-induced hair loss seen in patients with cancer and (ii) this human in vivo model for chemotherapy-induced hair loss is closer to clinical reality than to any earlier models. Undoubtedly, this model will serve as a valuable tool for analyses of the mechanisms that underlie this devastating side effect of anti-cancer therapy. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

A Study on Scalp Hair Health and Hair Care Practices among Malaysian Medical Students.

Science.gov (United States)

Nayak, B Satheesha; Ann, Chua Yuet; Azhar, Azeldeen Bin; Ling, Emily Chan Su; Yen, Wong Hui; Aithal, P Ashwini

2017-01-01

Scalp care is essential because it determines the health and condition of the hair and prevents the diseases of scalp and hair. The objectives of our study were to correlate race and hair types, to determine the awareness of hair care among Malaysian medical students, and to distinguish the factors that affect the health of hair and scalp. It was a cross-sectional study wherein validated questionnaires were given to 240 medical undergraduate students who belonged to three ethnic races of Malaysia, i.e., Chinese, Malay, and Malaysian Indians after their informed consent. The results were then analyzed using percentage statistics. Chinese students had comparatively healthier scalp without dandruff. Most Chinese and Indians had silky type of hair while Malay had dry, rough hair. Chinese and Indians colored their hair and used various styling methods; while among the Malays, this percentage was very less. Regarding hair care practices, males used only shampoo and females used shampoo and conditioner for hair wash. Students also faced dietary and examination-related stress. Results indicate that there exist morphological differences in hair among the studied population. Since most students color their hair and employ various hairstyling methods, they should be educated regarding best hair care practices to improve their scalp hair condition and health.

AFM studies of environmental effects on nanomechanical properties and cellular structure of human hair

International Nuclear Information System (INIS)

Bhushan, Bharat; Chen, Nianhuan

2006-01-01

Characterization of cellular structure and physical and mechanical properties of hair are essential to develop better cosmetic products and advance biological and cosmetic science. Although the morphology of the cellular structure of human hair has been traditionally investigated using scanning electron microscopy and transmission electron microscopy, these techniques provide limited capability to in situ study of the physical and mechanical properties of human hair in various environments. Atomic force microscopy (AFM) overcomes these problems and can be used for characterization in ambient conditions without requiring specific sample preparations and surface treatment. In this study, film thickness, adhesive forces and effective Young's modulus of various hair surfaces were measured at different environments (humidity and temperature) using force calibration plot technique with an AFM. Torsional resonance mode phase contrast images were also taken in order to characterize the morphology and cellular structure changes of human hair at different humidity. The correlation between the nanomechanical properties and the cellular structure of hair is discussed

Artificial sensory hairs based on the flow sensitive receptor hairs of crickets

NARCIS (Netherlands)

Dijkstra, Marcel; van Baar, J.J.J.; Wiegerink, Remco J.; Lammerink, Theodorus S.J.; de Boer, J.H.; Krijnen, Gijsbertus J.M.

2005-01-01

This paper presents the modelling, design, fabrication and characterization of flow sensors based on the wind-receptor hairs of crickets. Cricket sensory hairs are highly sensitive to drag-forces exerted on the hair shaft. Artificial sensory hairs have been realized in SU-8 on suspended SixNy

Grey hair: clinical investigation into changes in hair fibres with loss of pigmentation in a photoprotected population.

Science.gov (United States)

Kaplan, P D; Polefka, T; Grove, G; Daly, S; Jumbelic, L; Harper, D; Nori, M; Evans, T; Ramaprasad, R; Bianchini, R

2011-04-01

Loss of pigmentation in hair fibres is one of the most obvious phenotypic changes with ageing and has been a topic of increasing interest in the study of follicle biology. The onset of greying brings cosmetic complaints that grey fibres are wild or difficult to manage. Of course, these perceptions may be the consequence of visual obviousness rather than underlying physical or chemical differences. Although several studies have compared pigmented and unpigmented fibres, few have tried to control genetic and ethnic difference as well as extrinsic factors such as photoexposure and chemical treatment. We have recruited subjects with salt-and-pepper hair from a population of Old Order Mennonites who, for cultural reasons, are not only prohibited from chemically treating their hair but also limit their exposure to sunlight. Hair samples were examined for elemental composition, surface energy, Young's modulus, break stress, bending modulus, shear modulus and water sorption/desorption isotherm. The parameters were evaluated statistically for global differences, individual differences and typical individual differences. Consistent with previous published literature, few global differences were found between pigmented and unpigmented hair across the population. We do find that many individual subjects had differences between pigmented and unpigmented fibres. These differences tend to be more pronounced in bulk than in surface properties. The small differences in mechanical properties and moisture uptake and loss lend support to the perception by consumers that grey hair is wilder, drier and less manageable. © 2011 TRI/Princeton. Journal compilation. © 2010 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Co-Higgs bundles on P^1

OpenAIRE

Rayan, Steven

2010-01-01

Co-Higgs bundles are Higgs bundles in the sense of Simpson, but with Higgs fields that take values in the tangent bundle instead of the cotangent bundle. Given a vector bundle on P^1, we find necessary and sufficient conditions on its Grothendieck splitting for it to admit a stable Higgs field. We characterize the rank-2, odd-degree moduli space as a universal elliptic curve with a globally-defined equation. For ranks r=2,3,4, we explicitly verify the conjectural Betti numbers emerging from t...

Hair cosmetics and camouflage technics

Directory of Open Access Journals (Sweden)

Zahide Eriş Eken

2014-06-01

Full Text Available Hair is composed of a mixture of trace elements in small quantities, proteins, lipids and water. Proteins consist of helical polypeptide amino acid molecules. In the hair cells; polypeptide chains of keratin protein would be organized in filaments. In recent years, hair cosmetics showed a significant change and development. The content of shampoos which is used to cleanse the hair has enhanced significantly. Hair conditioner, hair styling products, pomades, brilliantine, and gloss sprays, hair protective products, camouflage products are most commonly used hair cosmetics. Hair shaping procedures are frequently applied.

Nanotribological and nanomechanical characterization of human hair using a nanoscratch technique

Energy Technology Data Exchange (ETDEWEB)

Wei Guohua [Nanotribology Laboratory for Information Storage and MEMS/NEMS, Ohio State University, 650 Ackerman Road, Suite 255, Columbus, OH 43202 (United States); Bhushan, Bharat [Nanotribology Laboratory for Information Storage and MEMS/NEMS, Ohio State University, 650 Ackerman Road, Suite 255, Columbus, OH 43202 (United States)]. E-mail: bhushan.2@osu.edu

2006-06-15

Human hair ({approx}50-100 {mu}m in diameter) is a nanocomposite biological fiber with well-characterized microstructures, and is of great interest for both cosmetic science and materials science. Characterization of nanotribological and nanomechanical properties of human hair including the coefficient of friction and scratch resistance is essential to develop better shampoo and conditioner products and advance biological and cosmetic science. In this paper, the coefficient of friction and scratch resistance of Caucasian and Asian hair at virgin, chemo-mechanically damaged, and conditioner-treated conditions are measured using a nanoscratch technique with a Nano Indenter II system. The scratch tests were performed on both the single cuticle cell and multiple cuticle cells of each hair sample, and the scratch wear tracks were studied using scanning electron microscopy (SEM) after the scratch tests. The effect of soaking on the coefficient of friction, scratch resistance, hardness and Young's modulus of hair surface were also studied by performing experiments on hair samples which had been soaked in de-ionized water for 5 min. The nanotribological and nanomechanical properties of human hair as a function of hair structure (hair of different ethnicity), damage, treatment and soaking are discussed.

Nanotribological and nanomechanical characterization of human hair using a nanoscratch technique

International Nuclear Information System (INIS)

Wei Guohua; Bhushan, Bharat

2006-01-01

Human hair (∼50-100 μm in diameter) is a nanocomposite biological fiber with well-characterized microstructures, and is of great interest for both cosmetic science and materials science. Characterization of nanotribological and nanomechanical properties of human hair including the coefficient of friction and scratch resistance is essential to develop better shampoo and conditioner products and advance biological and cosmetic science. In this paper, the coefficient of friction and scratch resistance of Caucasian and Asian hair at virgin, chemo-mechanically damaged, and conditioner-treated conditions are measured using a nanoscratch technique with a Nano Indenter II system. The scratch tests were performed on both the single cuticle cell and multiple cuticle cells of each hair sample, and the scratch wear tracks were studied using scanning electron microscopy (SEM) after the scratch tests. The effect of soaking on the coefficient of friction, scratch resistance, hardness and Young's modulus of hair surface were also studied by performing experiments on hair samples which had been soaked in de-ionized water for 5 min. The nanotribological and nanomechanical properties of human hair as a function of hair structure (hair of different ethnicity), damage, treatment and soaking are discussed

Impact of bundle deformation on CHF: ASSERT-PV assessment of extended burnup Bruce B bundle G85159W

International Nuclear Information System (INIS)

Rao, Y.F.; Manzer, A.M.

2005-01-01

This paper presents a subchannel thermalhydraulic analysis of the effect on critical heat flux (CHF) of bundle deformation such as element bow and diametral creep. The bundle geometry is based on the post-irradiation examination (PIE) data of a single bundle from the Bruce B Nuclear Generating Station, Bruce B bundle G85159W, which was irradiated for more than two years in the core during reactor commissioning. The subchannel code ASSERT-PV IST is used to assess changes in CHF and dryout power due to bundle deformation, compared to the reference, undeformed bundle. (author)

Serenoa repens extracts promote hair regeneration and repair of hair loss mouse models by activating TGF-β and mitochondrial signaling pathway.

Science.gov (United States)

Zhu, H-L; Gao, Y-H; Yang, J-Q; Li, J-B; Gao, J

2018-06-01

Plenty of plant extracts have been used for treating hair loss. This study aims to investigate the effects of liposterolic extracts of Serenoa repens (LSESr) on hair cell growth and regeneration of hair, and clarify the associated mechanisms. Human keratinocyte cells (HACAT) were cultured, incubated with dihydrotestosterone (DHT) and treated with LSESr. Cell viability was examined by using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H- tetrazolium bromide (MTT) assay. Hair loss C57BL/6 mouse model was established by inducing with DHT. Hair growth, density, and thickness were evaluated. Back skin samples were collected and stained with hematoxylin and eosin (HE) assay. B-cell lymphoma-2 (Bcl-2), Bcl-2 associated protein X (Bax), cleaved caspase 3 and transforming growth factor β2 (TGF-β2) were examined using Western blot assay. LSESr treatment significantly increased HACAT cell viabilities compared to DHT-only treated cells (p<0.05). LSESr treatment post injection of DHT significantly converted skin color from pink to gray and increased hair density, weight and thickness compared to DHT-only treated mice (p<0.05). LSESr treatment significantly triggered follicle growth and decreased inflammatory response. LSESr treatment significantly decreased TGF-β2 and cleaved caspase 3 expression of hair loss mouse models compared to that of DHT treated mice (p<0.05). LSESr treatment significantly enhanced Bcl-2 expression and reduced Bax expression compared to that of DHT treated mice (p<0.05). Meanwhile, effects of LSESr were substantial even achieving to the potential of finasteride. LSESr promoted the hair regeneration and repair of hair loss mouse models by activating TGF-β signaling and mitochondrial signaling pathway.

Inside black holes with synchronized hair

Energy Technology Data Exchange (ETDEWEB)

Brihaye, Yves, E-mail: yves.brihaye@umons.ac.be [Physique-Mathématique, Universite de Mons-Hainaut, Mons (Belgium); Herdeiro, Carlos; Radu, Eugen [Departamento de Física da Universidade de Aveiro and Centre for Research and Development in Mathematics and Applications (CIDMA), Campus de Santiago, 3810-183 Aveiro (Portugal)

2016-09-10

Recently, various examples of asymptotically flat, rotating black holes (BHs) with synchronized hair have been explicitly constructed, including Kerr BHs with scalar or Proca hair, and Myers–Perry BHs with scalar hair and a mass gap, showing there is a general mechanism at work. All these solutions have been found numerically, integrating the fully non-linear field equations of motion from the event horizon outwards. Here, we address the spacetime geometry of these solutions inside the event horizon. Firstly, we provide arguments, within linear theory, that there is no regular inner horizon for these solutions. Then, we address this question fully non-linearly, using as a tractable model five dimensional, equal spinning, Myers–Perry hairy BHs. We find that, for non-extremal solutions: (1) the inside spacetime geometry in the vicinity of the event horizon is smooth and the equations of motion can be integrated inwards; (2) before an inner horizon is reached, the spacetime curvature grows (apparently) without bound. In all cases, our results suggest the absence of a smooth Cauchy horizon, beyond which the metric can be extended, for hairy BHs with synchronized hair.

Inside black holes with synchronized hair

International Nuclear Information System (INIS)

Brihaye, Yves; Herdeiro, Carlos; Radu, Eugen

2016-01-01

Recently, various examples of asymptotically flat, rotating black holes (BHs) with synchronized hair have been explicitly constructed, including Kerr BHs with scalar or Proca hair, and Myers–Perry BHs with scalar hair and a mass gap, showing there is a general mechanism at work. All these solutions have been found numerically, integrating the fully non-linear field equations of motion from the event horizon outwards. Here, we address the spacetime geometry of these solutions inside the event horizon. Firstly, we provide arguments, within linear theory, that there is no regular inner horizon for these solutions. Then, we address this question fully non-linearly, using as a tractable model five dimensional, equal spinning, Myers–Perry hairy BHs. We find that, for non-extremal solutions: (1) the inside spacetime geometry in the vicinity of the event horizon is smooth and the equations of motion can be integrated inwards; (2) before an inner horizon is reached, the spacetime curvature grows (apparently) without bound. In all cases, our results suggest the absence of a smooth Cauchy horizon, beyond which the metric can be extended, for hairy BHs with synchronized hair.

Inside black holes with synchronized hair

Directory of Open Access Journals (Sweden)

Yves Brihaye

2016-09-01

Full Text Available Recently, various examples of asymptotically flat, rotating black holes (BHs with synchronized hair have been explicitly constructed, including Kerr BHs with scalar or Proca hair, and Myers–Perry BHs with scalar hair and a mass gap, showing there is a general mechanism at work. All these solutions have been found numerically, integrating the fully non-linear field equations of motion from the event horizon outwards. Here, we address the spacetime geometry of these solutions inside the event horizon. Firstly, we provide arguments, within linear theory, that there is no regular inner horizon for these solutions. Then, we address this question fully non-linearly, using as a tractable model five dimensional, equal spinning, Myers–Perry hairy BHs. We find that, for non-extremal solutions: (1 the inside spacetime geometry in the vicinity of the event horizon is smooth and the equations of motion can be integrated inwards; (2 before an inner horizon is reached, the spacetime curvature grows (apparently without bound. In all cases, our results suggest the absence of a smooth Cauchy horizon, beyond which the metric can be extended, for hairy BHs with synchronized hair.

Hair restoration.

Science.gov (United States)

Rawnsley, Jeffrey D

2008-08-01

The impact of male hair loss as a personal and social marker of aging is tremendous and its persistence as a human concern throughout recorded history places it in the forefront of male concern about the physical signs of aging. Restoration of the frontal hairline has the visual effect of re-establishing facial symmetry and turning back time. Follicular unit transplantation has revolutionized hair restoration, with its focus on redistributing large numbers of genetically stable hair to balding scalp in a natural distribution. Follicular unit hair restoration surgery is a powerful tool for the facial plastic surgeon in male aesthetic facial rejuvenation because it offers high-impact, natural-appearing results with minimal downtime and risk for adverse outcome.

Diversification of Root Hair Development Genes in Vascular Plants.

Science.gov (United States)

Huang, Ling; Shi, Xinhui; Wang, Wenjia; Ryu, Kook Hui; Schiefelbein, John

2017-07-01

The molecular genetic program for root hair development has been studied intensively in Arabidopsis ( Arabidopsis thaliana ). To understand the extent to which this program might operate in other plants, we conducted a large-scale comparative analysis of root hair development genes from diverse vascular plants, including eudicots, monocots, and a lycophyte. Combining phylogenetics and transcriptomics, we discovered conservation of a core set of root hair genes across all vascular plants, which may derive from an ancient program for unidirectional cell growth coopted for root hair development during vascular plant evolution. Interestingly, we also discovered preferential diversification in the structure and expression of root hair development genes, relative to other root hair- and root-expressed genes, among these species. These differences enabled the definition of sets of genes and gene functions that were acquired or lost in specific lineages during vascular plant evolution. In particular, we found substantial divergence in the structure and expression of genes used for root hair patterning, suggesting that the Arabidopsis transcriptional regulatory mechanism is not shared by other species. To our knowledge, this study provides the first comprehensive view of gene expression in a single plant cell type across multiple species. © 2017 American Society of Plant Biologists. All Rights Reserved.

How does high-frequency sound or vibration activate vestibular receptors?

Science.gov (United States)

Curthoys, I S; Grant, J W

2015-03-01

The mechanism by which vestibular neural phase locking occurs and how it relates to classical otolith mechanics is unclear. Here, we put forward the hypothesis that sound and vibration both cause fluid pressure waves in the inner ear and that it is these pressure waves which displace the hair bundles on vestibular receptor hair cells and result in activation of type I receptor hair cells and phase locking of the action potentials in the irregular vestibular afferents, which synapse on type I receptors. This idea has been suggested since the early neural recordings and recent results give it greater credibility.

Entropy for frame bundle systems and Grassmann bundle systems induced by a diffeomorphism

Institute of Scientific and Technical Information of China (English)

SUN; Weniang(孙文祥)

2002-01-01

ALiao hyperbolic diffeomorphism has equal measure entropy and topological entropy to that ofits induced systems on frame bundles and Grassmann bundles. This solves a problem Liao posed in 1996 forLiao hyperbolic diffeomorphisms.

Tube bundle vibrations due to cross flow under the influence of turbulence

Energy Technology Data Exchange (ETDEWEB)

Popp, K.; Romberg, O. [Institute of Mechanics, University of Hannover (Germany)

1998-10-01

Tube bundles are often used in heat exchangers and chemical reactors. Besides of large heat transfer capacities and small pressure drops in the apparatus a safe design against vibration damages is demanded. For many years extensive investigations concerning the dynamical behaviour of tube bundles subjected to cross-flow have been carried out in the wind tunnel of the Institute of Mechanics at the University of Hannover. In the last years the investigations were concentrated on the experimental investigations of different flow excitation mechanisms in a fully flexible bundle as well as in a bundle with one single flexibly mounted tube in an otherwise fixed array with variable geometry and changing equilibrium position. The aim of the studies was the determination of the stability boundaries, i.e. the critical reduced fluid velocity depending on the reduced damping coefficient in a wide parameter region. Theoretical investigations of the stability behaviour on the basis of an one dimensional flow model as well as experimental investigations of the influence of turbulence on the stability boundaries have been carried out. Here, for certain tube bundle configurations an increased turbulence has a stabilizing effect and leads to a shift of the stability boundaries to higher velocities. The change of the turbulence was realised by using turbulence grids at the inlet of the bundles or thin Prandtl-tripwires at the tube surfaces. Flow visualization studies at the original experimental set-up under relevant Reynolds numbers give an impression of the flow pattern. At this time an investigation of the exciting fluid forces is carried out using a flexibly mounted pressure test tube. A survey about some recent investigations is given. (orig.)

Collagen-based mechanical anisotropy of the tectorial membrane: implications for inter-row coupling of outer hair cell bundles.

Directory of Open Access Journals (Sweden)

Núria Gavara

Full Text Available The tectorial membrane (TM in the mammalian cochlea displays anisotropy, where mechanical or structural properties differ along varying directions. The anisotropy arises from the presence of collagen fibrils organized in fibers of approximately 1 microm diameter that run radially across the TM. Mechanical coupling between the TM and the sensory epithelia is required for normal hearing. However, the lack of a suitable technique to measure mechanical anisotropy at the microscale level has hindered understanding of the TM's precise role.Here we report values of the three elastic moduli that characterize the anisotropic mechanical properties of the TM. Our novel technique combined Atomic Force Microscopy (AFM, modeling, and optical tracking of microspheres to determine the elastic moduli. We found that the TM's large mechanical anisotropy results in a marked transmission of deformations along the direction that maximizes sensory cell excitation, whereas in the perpendicular direction the transmission is greatly reduced.Computational results, based on our values of elastic moduli, suggest that the TM facilitates the directional cooperativity of sensory cells in the cochlea, and that mechanical properties of the TM are tuned to guarantee that the magnitude of sound-induced tip-link stretching remains similar along the length of the cochlea. Furthermore, we anticipate our assay to be a starting point for other studies of biological tissues that require directional functionality.

Viking Age Hair

Directory of Open Access Journals (Sweden)

Elisabeth Arwill-Nordbladh

2016-11-01

Full Text Available A study of hair in the Viking Age. The article draws on medieval Icelandic and Scandinavian texts for interpretation. Further information is taken from pictoral representations of viking hair styles and decoration, hairdressing artefacts, figurines and actual remains of hair.

Stem cell plasticity enables hair regeneration following Lgr5+ cell loss.

Science.gov (United States)

Hoeck, Joerg D; Biehs, Brian; Kurtova, Antonina V; Kljavin, Noelyn M; de Sousa E Melo, Felipe; Alicke, Bruno; Koeppen, Hartmut; Modrusan, Zora; Piskol, Robert; de Sauvage, Frederic J

2017-06-01

Under injury conditions, dedicated stem cell populations govern tissue regeneration. However, the molecular mechanisms that induce stem cell regeneration and enable plasticity are poorly understood. Here, we investigate stem cell recovery in the context of the hair follicle to understand how two molecularly distinct stem cell populations are integrated. Utilizing diphtheria-toxin-mediated cell ablation of Lgr5 + (leucine-rich repeat-containing G-protein-coupled receptor 5) stem cells, we show that killing of Lgr5 + cells in mice abrogates hair regeneration but this is reversible. During recovery, CD34 + (CD34 antigen) stem cells activate inflammatory response programs and start dividing. Pharmacological attenuation of inflammation inhibits CD34 + cell proliferation. Subsequently, the Wnt pathway controls the recovery of Lgr5 + cells and inhibition of Wnt signalling prevents Lgr5 + cell and hair germ recovery. Thus, our study uncovers a compensatory relationship between two stem cell populations and the underlying molecular mechanisms that enable hair follicle regeneration.

Myc and Fgf Are Required for Zebrafish Neuromast Hair Cell Regeneration.

Science.gov (United States)

Lee, Sang Goo; Huang, Mingqian; Obholzer, Nikolaus D; Sun, Shan; Li, Wenyan; Petrillo, Marco; Dai, Pu; Zhou, Yi; Cotanche, Douglas A; Megason, Sean G; Li, Huawei; Chen, Zheng-Yi

2016-01-01

Unlike mammals, the non-mammalian vertebrate inner ear can regenerate the sensory cells, hair cells, either spontaneously or through induction after hair cell loss, leading to hearing recovery. The mechanisms underlying the regeneration are poorly understood. By microarray analysis on a chick model, we show that chick hair cell regeneration involves the activation of proliferation genes and downregulation of differentiation genes. Both MYC and FGF are activated in chick hair cell regeneration. Using a zebrafish lateral line neuromast hair cell regeneration model, we show that the specific inhibition of Myc or Fgf suppresses hair cell regeneration, demonstrating that both pathways are essential to the process. Rapid upregulation of Myc and delayed Fgf activation during regeneration suggest a role of Myc in proliferation and Fgf in differentiation. The dorsal-ventral pattern of fgfr1a in the neuromasts overlaps with the distribution of hair cell precursors. By laser ablation, we show that the fgfr1a-positive supporting cells are likely the hair cell precursors that directly give rise to new hair cells; whereas the anterior-posterior fgfr1a-negative supporting cells have heightened proliferation capacity, likely to serve as more primitive progenitor cells to replenish lost precursors after hair cell loss. Thus fgfr1a is likely to mark compartmentalized supporting cell subtypes with different capacities in renewal proliferation and hair cell regeneration. Manipulation of c-MYC and FGF pathways could be explored for mammalian hair cell regeneration.

Pre-analytical and analytical variation of drug determination in segmented hair using ultra-performance liquid chromatography-tandem mass spectrometry.

Science.gov (United States)

Nielsen, Marie Katrine Klose; Johansen, Sys Stybe; Linnet, Kristian

2014-01-01

Assessment of total uncertainty of analytical methods for the measurements of drugs in human hair has mainly been derived from the analytical variation. However, in hair analysis several other sources of uncertainty will contribute to the total uncertainty. Particularly, in segmental hair analysis pre-analytical variations associated with the sampling and segmentation may be significant factors in the assessment of the total uncertainty budget. The aim of this study was to develop and validate a method for the analysis of 31 common drugs in hair using ultra-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) with focus on the assessment of both the analytical and pre-analytical sampling variations. The validated method was specific, accurate (80-120%), and precise (CV≤20%) across a wide linear concentration range from 0.025-25 ng/mg for most compounds. The analytical variation was estimated to be less than 15% for almost all compounds. The method was successfully applied to 25 segmented hair specimens from deceased drug addicts showing a broad pattern of poly-drug use. The pre-analytical sampling variation was estimated from the genuine duplicate measurements of two bundles of hair collected from each subject after subtraction of the analytical component. For the most frequently detected analytes, the pre-analytical variation was estimated to be 26-69%. Thus, the pre-analytical variation was 3-7 folds larger than the analytical variation (7-13%) and hence the dominant component in the total variation (29-70%). The present study demonstrated the importance of including the pre-analytical variation in the assessment of the total uncertainty budget and in the setting of the 95%-uncertainty interval (±2CVT). Excluding the pre-analytical sampling variation could significantly affect the interpretation of results from segmental hair analysis. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Hair follicle stem cell proliferation, Akt and Wnt signaling activation in TPA-induced hair regeneration.

Science.gov (United States)

Qiu, Weiming; Lei, Mingxing; Zhou, Ling; Bai, Xiufeng; Lai, Xiangdong; Yu, Yu; Yang, Tian; Lian, Xiaohua

2017-06-01

Regeneration of hair follicles relies on activation of hair follicle stem cells during telogen to anagen transition process in hair cycle. This process is rigorously controlled by intrinsic and environmental factors. 12-o-tetradecanoylphorbol-13-acetate (TPA), a tumor promoter, accelerates reentry of hair follicles into anagen phase. However, it is unclear that how TPA promotes the hair regeneration. In the present study, we topically applied TPA onto the dorsal skin of 2-month-old C57BL/6 female mice to examine the activity of hair follicle stem cells and alteration of signaling pathways during hair regeneration. We found that refractory telogen hair follicles entered anagen prematurely after TPA treatment, with the enhanced proliferation of CD34-positive hair follicle stem cells. Meanwhile, we observed Akt signaling was activated in epidermis, hair infundibulum, bulge and hair bulb, and Wnt signaling was also activated after hair follicle stem cells proliferation. Importantly, after overexpression of DKK1, a specific Wnt signaling inhibitor, the accelerated reentry of hair follicles into anagen induced by TPA was abolished. Our data indicated that TPA-induced hair follicle regeneration is associated with activation of Akt and Wnt/β-catenin signaling.

Hair loss in infancy.

Science.gov (United States)

Moreno-Romero, J A; Grimalt, R

2014-02-01

Hair diseases represent a significant portion of cases seen by pediatric dermatologists although hair has always been a secondary aspect in pediatricians and dermatologists training, on the erroneous basis that there is not much information extractable from it. Dermatologists are in the enviable situation of being able to study many disorders with simple diagnostic techniques. The hair is easily accessible to examination but, paradoxically, this approach is often disregarded by non-dermatologist. This paper has been written on the purpose of trying to serve in the diagnostic process of daily practice, and trying to help, for example, to distinguish between certain acquired and some genetically determined hair diseases. We will focus on all the data that can be obtained from our patients' hair and try to help on using the messages given by hair for each patient. Quite often it is extremely hard to distinguish between abnormality and normality in neonatal hair aspects. We will specially focus in the most common physiological changes that may mislead to an incorrect diagnosis. Specific treatment for those hair diseases that do have one, and basic general approach to improve the cosmetic appearance of hair, will be also be discussed for those hair disturbances that do not have a specific treatment.

Bundled payment fails to gain a foothold In California: the experience of the IHA bundled payment demonstration.

Science.gov (United States)

Ridgely, M Susan; de Vries, David; Bozic, Kevin J; Hussey, Peter S

2014-08-01

To determine whether bundled payment could be an effective payment model for California, the Integrated Healthcare Association convened a group of stakeholders (health plans, hospitals, ambulatory surgery centers, physician organizations, and vendors) to develop, through a consensus process, the methods and means of implementing bundled payment. In spite of a high level of enthusiasm and effort, the pilot did not succeed in its goal to implement bundled payment for orthopedic procedures across multiple payers and hospital-physician partners. An evaluation of the pilot documented a number of barriers, such as administrative burden, state regulatory uncertainty, and disagreements about bundle definition and assumption of risk. Ultimately, few contracts were signed, which resulted in insufficient volume to test hypotheses about the impact of bundled payment on quality and costs. Although bundled payment failed to gain a foothold in California, the evaluation provides lessons for future bundled payment initiatives. Project HOPE—The People-to-People Health Foundation, Inc.

Hair loss in women.

Science.gov (United States)

Harfmann, Katya L; Bechtel, Mark A

2015-03-01

Hair loss is a common cause of morbidity for many women. As a key member of the woman's health care team, the obstetrician/gynecologist may be the first person to evaluate the complaint of hair loss. Common types of nonscarring hair loss, including female pattern hair loss and telogen effluvium, may be diagnosed and managed by the obstetrician/gynecologist. A systematic approach to diagnosis and management of these common forms of hair loss is presented.

Hair casts

OpenAIRE

Sweta S Parmar; Kirti S Parmar; Bela J Shah

2014-01-01

Hair casts or pseudonits are circumferential concretions, which cover the hair shaft in such a way that, it could be easily removed. They are thin, cylindrical, and elongated in length. We present an unusual case of an 8-year-old girl presenting with hair casts. Occurrence of these is unusual, and they may have varied associations. This patient was suffering from developmental delay. It is commonly misdiagnosed as and very important to differentiate from pediculosis capitis.

Molybdenum-99-producing 37-element fuel bundle neutronically and thermal-hydraulically equivalent to a standard CANDU fuel bundle

Energy Technology Data Exchange (ETDEWEB)

Nichita, E., E-mail: Eleodor.Nichita@uoit.ca; Haroon, J., E-mail: Jawad.Haroon@uoit.ca

2016-10-15

Highlights: • A 37-element fuel bundle modified for {sup 99}Mo production in CANDU reactors is presented. • The modified bundle is neutronically and thermal-hydraulically equivalent to the standard bundle. • The modified bundle satisfies all safety criteria satisfied by the standard bundle. - Abstract: {sup 99m}Tc, the most commonly used radioisotope in diagnostic nuclear medicine, results from the radioactive decay of {sup 99}Mo which is currently being produced at various research reactors around the globe. In this study, the potential use of CANDU power reactors for the production of {sup 99}Mo is investigated. A modified 37-element fuel bundle, suitable for the production of {sup 99}Mo in existing CANDU-type reactors is proposed. The new bundle is specifically designed to be neutronically and thermal-hydraulically equivalent to the standard 37-element CANDU fuel bundle in normal, steady-state operation and, at the same time, be able to produce significant quantities of {sup 99}Mo when irradiated in a CANDU reactor. The proposed bundle design uses fuel pins consisting of a depleted-uranium centre surrounded by a thin layer of low-enriched uranium. The new molybdenum-producing bundle is analyzed using the lattice transport code DRAGON and the diffusion code DONJON. The proposed design is shown to produce 4081 six-day Curies of {sup 99}Mo activity per bundle when irradiated in the peak-power channel of a CANDU core, while maintaining the necessary reactivity and power rating limits. The calculated {sup 99}Mo yield corresponds to approximately one third of the world weekly demand. A production rate of ∼3 bundles per week can meet the global demand of {sup 99}Mo.

Hair removal in adolescence

Directory of Open Access Journals (Sweden)

Sandra Pereira

2015-06-01

Full Text Available Introduction: Due to hormonal stimulation during puberty, changes occur in hair type and distribution. In both sexes, body and facial unwanted hair may have a negative psychological impact on the teenager. There are several available methods of hair removal, but the choice of the most suitable one for each individual can raise doubts. Objective: To review the main methods of hair removal and clarify their indications, advantages and disadvantages. Development: There are several removal methods currently available. Shaving and depilation with chemicals products are temporary methods, that need frequent repetition, because hair removal is next to the cutaneous surface. The epilating methods in which there is full hair extraction include: epilation with wax, thread, tweezers, epilating machines, laser, intense pulsed light, and electrolysis. Conclusions: The age of beginning hair removal and the method choice must be individualized and take into consideration the skin and hair type, location, dermatological and endocrine problems, removal frequency, cost and personal preferences.

Role of peptide growth factors in the rhythm of change hair

Directory of Open Access Journals (Sweden)

A. A. Kubanov

2015-01-01

Full Text Available The article presents current data on the role growth factors play in hair physiology. Based on a review of literature, the authors described the role growth factors play for initiating, suppressing the growth and differentiating hair follicles. According to them, each morphologic development stage of hair follicles is characterized by its own factor expression pattern. Referring to experimental and clinical studies, the authors describe the role some growth factors play for mechanisms promoting the development of androgynous and focal alopecia.

Fluorine-induced apoptosis and lipid peroxidation in human hair follicles in vitro.

Science.gov (United States)

Wang, Zheng-hui; Li, Xiao-li; Yang, Zhuang-qun; Xu, Min

2010-12-01

Fluoride is an essential trace element for human body; however, exposure to high amounts of fluoride has been documented to be correlated with an increasing risk of hair loss. To date, little is known about the mechanism(s) of how fluoride affects hair follicles. Here, we demonstrated that middle (1.0 mmol/L) and high (10.0 mmol/L) concentrations of sodium fluoride (NaF) significantly inhibited hair follicle elongation in vitro, but low NaF (0.1 mmol/L) showed little influence. Moreover, treatment with high levels of NaF resulted in a marked increase in terminal dUTP nick end labeling-positive cells in the outer layer of the outer root sheath, the dermal sheath, and the lower bulb matrix surrounding dermal papilla. Furthermore, the enhanced apoptosis was coupled with an increased oxidative stress manifested as higher malondialdehyde content. Additionally, the presence of selenium considerably antagonized the effects of middle NaF on hair follicles, with regard to either the suppression of hair growth or the induction of oxidative stress and apoptosis. In conclusion, exposure to high levels of fluoride compromises hair follicle growth and accelerate cell apoptosis in vitro. The toxicity of fluoride can be reduced by selenium, at least partially via the suppression of intracellular oxidative stress.

Bundling of harvesting residues and whole-trees and the treatment of bundles; Hakkuutaehteiden ja kokopuiden niputus ja nippujen kaesittely

Energy Technology Data Exchange (ETDEWEB)

Kaipainen, H; Seppaenen, V; Rinne, S

1997-12-31

The conditions on which the bundling of the harvesting residues from spruce regeneration fellings would become profitable were studied. The calculations showed that one of the most important features was sufficient compaction of the bundle, so that the portion of the wood in the unit volume of the bundle has to be more than 40 %. The tests showed that the timber grab loader of farm tractor was insufficient for production of dense bundles. The feeding and compression device of the prototype bundler was constructed in the research and with this device the required density was obtained.The rate of compaction of the dry spruce felling residues was about 40 % and that of the fresh residues was more than 50 %. The comparison between the bundles showed that the calorific value of the fresh bundle per unit volume was nearly 30 % higher than that of the dry bundle. This means that the treatment of the bundles should be done of fresh felling residues. Drying of the bundles succeeded well, and the crushing and chipping tests showed that the processing of the bundles at the plant is possible. The treatability of the bundles was also excellent. By using the prototype, developed in the research, it was possible to produce a bundle of the fresh spruce harvesting residues, the diameter of which was about 50 cm and the length about 3 m, and the rate of compaction over 50 %. By these values the reduction target of the costs is obtainable

Bundling of harvesting residues and whole-trees and the treatment of bundles; Hakkuutaehteiden ja kokopuiden niputus ja nippujen kaesittely

Energy Technology Data Exchange (ETDEWEB)

Kaipainen, H.; Seppaenen, V.; Rinne, S.

1996-12-31

The conditions on which the bundling of the harvesting residues from spruce regeneration fellings would become profitable were studied. The calculations showed that one of the most important features was sufficient compaction of the bundle, so that the portion of the wood in the unit volume of the bundle has to be more than 40 %. The tests showed that the timber grab loader of farm tractor was insufficient for production of dense bundles. The feeding and compression device of the prototype bundler was constructed in the research and with this device the required density was obtained.The rate of compaction of the dry spruce felling residues was about 40 % and that of the fresh residues was more than 50 %. The comparison between the bundles showed that the calorific value of the fresh bundle per unit volume was nearly 30 % higher than that of the dry bundle. This means that the treatment of the bundles should be done of fresh felling residues. Drying of the bundles succeeded well, and the crushing and chipping tests showed that the processing of the bundles at the plant is possible. The treatability of the bundles was also excellent. By using the prototype, developed in the research, it was possible to produce a bundle of the fresh spruce harvesting residues, the diameter of which was about 50 cm and the length about 3 m, and the rate of compaction over 50 %. By these values the reduction target of the costs is obtainable

Expression and localization of VEGFR-2 in hair follicles during induced hair growth in mice.

Science.gov (United States)

Wu, Xian-Jie; Jing, Jing; Lu, Zhong-Fa; Zheng, Min

2018-06-16

Recently, VEGFR-2 has been detected not only in vascular and lymphatic endothelial cells but also in some non-vascular endothelial cells, particularly human hair follicles, sebaceous glands, and sweat glands. In addition, VEGFR-2 has been confirmed to play direct roles in hair follicle keratinocyte regulation beyond simply angiogenesis. To elucidate whether VEGFR-2 activation plays a role in hair follicle cycling regulation, immunofluorescence of VEGFR-2 expression was performed during hair cycling of the dorsum of the mouse induced by hair plucking. We observed that staining for VEGFR-2 in hair follicles during anagen II and IV was much stronger than during anagen VI, catagen and telogen. During anagen II, intense staining for VEGFR-2 was observed on the keratinocyte strands of the hair follicle. Subsequently, we detected intense staining for VEGFR-2 in the ORS, IRS and hair bulb during anagen IV. Moderate staining for VEGFR-2 was detected in the ORS and hair bulb, but staining was most intense in IRS during anagen VI. During catagen, staining for VEGFR-2 in the IRS remained intense, while staining in the ORS and hair bulb was significantly weakened and was negative in the dermal papilla. During telogen, we detected VEGFR-2 in germ cells, cap, and club hair adjoining the epidermis. In conclusion, VEGFR-2 was expressed on the hair follicles of the dorsum of the mouse and varied in expression on the mouse hair follicles during hair cycling, suggesting that VEGFR-2 may exert roles in hair cycle regulation in hair follicles on the dorsum of mice.

Vibration of fuel bundles

International Nuclear Information System (INIS)

Chen, S.S.

1975-06-01

Several mathematical models have been proposed for calculating fuel rod responses in axial flows based on a single rod consideration. The spacing between fuel rods in liquid metal fast breeder reactors is small; hence fuel rods will interact with one another due to fluid coupling. The objective of this paper is to study the coupled vibration of fuel bundles. To account for the fluid coupling, a computer code, AMASS, is developed to calculate added mass coefficients for a group of circular cylinders based on the potential flow theory. The equations of motion for rod bundles are then derived including hydrodynamic forces, drag forces, fluid pressure, gravity effect, axial tension, and damping. Based on the equations, a method of analysis is presented to study the free and forced vibrations of rod bundles. Finally, the method is applied to a typical LMFBR fuel bundle consisting of seven rods

Microtubule bundling plays a role in ethylene-mediated cortical microtubule reorientation in etiolated Arabidopsis hypocotyls.

Science.gov (United States)

Ma, Qianqian; Sun, Jingbo; Mao, Tonglin

2016-05-15

The gaseous hormone ethylene is known to regulate plant growth under etiolated conditions (the 'triple response'). Although organization of cortical microtubules is essential for cell elongation, the underlying mechanisms that regulate microtubule organization by hormone signaling, including ethylene, are ambiguous. In the present study, we demonstrate that ethylene signaling participates in regulation of cortical microtubule reorientation. In particular, regulation of microtubule bundling is important for this process in etiolated hypocotyls. Time-lapse analysis indicated that selective stabilization of microtubule-bundling structures formed in various arrays is related to ethylene-mediated microtubule orientation. Bundling events and bundle growth lifetimes were significantly increased in oblique and longitudinal arrays, but decreased in transverse arrays in wild-type cells in response to ethylene. However, the effects of ethylene on microtubule bundling were partially suppressed in a microtubule-bundling protein WDL5 knockout mutant (wdl5-1). This study suggests that modulation of microtubule bundles that have formed in certain orientations plays a role in reorienting microtubule arrays in response to ethylene-mediated etiolated hypocotyl cell elongation. © 2016. Published by The Company of Biologists Ltd.

Principal noncommutative torus bundles

DEFF Research Database (Denmark)

Echterhoff, Siegfried; Nest, Ryszard; Oyono-Oyono, Herve

2008-01-01

of bivariant K-theory (denoted RKK-theory) due to Kasparov. Using earlier results of Echterhoff and Williams, we shall give a complete classification of principal non-commutative torus bundles up to equivariant Morita equivalence. We then study these bundles as topological fibrations (forgetting the group...

COMPARATIVE STUDY OF ARTHROSCOPIC SINGLE BUNDLE ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION AND NON-ANATOMICAL DOUBLE BUNDLE WITH SINGLE TIBIAL TUNNEL ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION WITH SEMITENDINOSUS ± GRACILIS AUTOGRAFTS USING LAXOMETRY

Directory of Open Access Journals (Sweden)

Sivananda

2016-01-01

Full Text Available BACKGROUND The knee joint is the most commonly injured of all joints and the ACL is the most commonly injured ligament. Arthroscopic reconstruction of ACL has become gold standard in treating these injuries. AIM 1. To compare the short-term results of ACL reconstruction using single bundle (one Tibial + one Femoral tunnel and non-anatomical double-bundle (one Tibial + two Femoral tunnels techniques using Hamstrings (Semitendinosus ± Gracilis graft. 2. To evaluate ACL graft reconstruction stability measured by laxometry and to find out an association with clinical findings. MATERIAL & METHODS We performed a prospective study between 2014-2015 of 20 case of ACL injuries & compared single bundle reconstruction with Non – anatomical double Bundle reconstruction with semitendinosus ± Gracilis, Autograft using laxometry. CONCLUSION Arthroscopic Non-anatomical double ACL Reconstruction is Bio-mechanically stable reconstruction resembling anatomy of the ACL.

The Analysis of SBWR Critical Power Bundle Using Cobrag Code

Directory of Open Access Journals (Sweden)

Yohannes Sardjono

2013-03-01

Full Text Available The coolant mechanism of SBWR is similar with the Dodewaard Nuclear Power Plant (NPP in the Netherlands that first went critical in 1968. The similarity of both NPP is cooled by natural convection system. These coolant concept is very related with same parameters on fuel bundle design especially fuel bundle length, core pressure drop and core flow rate as well as critical power bundle. The analysis was carried out by using COBRAG computer code. COBRAG computer code is GE Company proprietary. Basically COBRAG computer code is a tool to solve compressible three-dimensional, two fluid, three field equations for two phase flow. The three fields are the vapor field, the continuous liquid field, and the liquid drop field. This code has been applied to analyses model flow and heat transfer within the reactor core. This volume describes the finitevolume equations and the numerical solution methods used to solve these equations. This analysis of same parameters has been done i.e.; inlet sub cooling 20 BTU/lbm and 40 BTU/lbm, 1000 psi pressure and R-factor is 1.038, mass flux are 0.5 Mlb/hr.ft2, 0.75 Mlb/hr.ft2, 1.00 Mlb/hr.ft2 and 1.25 Mlb/hr.ft2. Those conditions based on history operation of some type of the cell fuel bundle line at GE Nuclear Energy. According to the results, it can be concluded that SBWR critical power bundle is 10.5 % less than current BWR critical power bundle with length reduction of 12 ft to 9 ft.

"I think gorilla-like back effusions of hair are rather a turn-off": 'Excessive hair' and male body hair (removal) discourse.

Science.gov (United States)

Terry, Gareth; Braun, Virginia

2016-06-01

Men's hair removal practices are becoming mainstream, seen as a consequence of changing masculine norms and men's relationships to their bodies. This is often presented as a straightforward 'shift' from men's ideal bodies as naturally hairy, to increased hairlessness, and the consequence on men's body concerns as inevitable. This paper analyses qualitative survey data from Aotearoa/New Zealand using critical thematic analysis, and describes three themes. Two themes capture contradictory ideas: that men's body hair is natural, and that men's body hair is unpleasant. A third theme introduces the concept of 'excess' hair, which allowed sense-making of this contradiction, mandating men's grooming of 'excessive' hair. However its vagueness as a concept may provoke anxiety for men resulting in hair removal. This paper adds to a body of research demonstrating a cultural transition: the ways changing masculinities, increased commodification of male bodies, and shifting gender roles impact on men's hair removal practices. Copyright © 2016 Elsevier Ltd. All rights reserved.

Low density of membrane particles in auditory hair cells of lizards and birds suggests an absence of somatic motility.

Science.gov (United States)

Köppl, Christine; Forge, Andrew; Manley, Geoffrey A

2004-11-08

Hair cells are the mechanoreceptive cells of the vertebrate lateral line and inner ear. In addition to their sensory function, hair cells display motility and thus themselves generate mechanical energy, which is thought to enhance sensitivity. Two principal cellular mechanism are known that can mediate hair-cell motility in vitro. One of these is based on voltage-dependent changes of an intramembrane protein and has so far been demonstrated only in outer hair cells of the mammalian cochlea. Correlated with this, the cell membranes of outer hair cells carry an extreme density of embedded particles, as revealed by freeze fracturing. The present study explored the possibility of membrane-based motility in hair cells of nonmammals, by determining their density of intramembrane particles. Replicas of freeze-fractured membrane were prepared from auditory hair cells of a lizard, the Tokay gecko, and a bird, the barn owl. These species were chosen because of independent evidence for active cochlear mechanics, in the form of spontaneous otoacoustic emissions. For quantitative comparison, mammalian inner and outer hair cells, as well as vestibular hair, cells were reevaluated. Lizard and bird hair cells displayed median densities of 2,360 and 1,880 intramembrane particles/microm2, respectively. This was not significantly different from the densities in vestibular and mammalian inner hair cells; however, it was about half the density in of mammalian outer hair cells. This suggests that nonmammalian hair cells do not possess high densities of motor protein in their membranes and are thus unlikely to be capable of somatic motility. 2004 Wiley-Liss, Inc.

Hair dye contact allergy

DEFF Research Database (Denmark)

Søsted, Heidi; Rastogi, Suresh Chandra; Andersen, Klaus Ejner

2004-01-01

Colouring of hair can cause severe allergic contact dermatitis. The most frequently reported hair dye allergens are p-phenylenediamine (PPD) and toluene-2,5-diamine, which are included in, respectively, the patch test standard series and the hairdressers series. The aim of the present study...... was to identify dye precursors and couplers in hair dyeing products causing clinical hair dye dermatitis and to compare the data with the contents of these compounds in a randomly selected set of similar products. The patient material comprised 9 cases of characteristic clinical allergic hair dye reaction, where...... exposure history and patch testing had identified a specific hair dye product as the cause of the reaction. The 9 products used by the patients were subjected to chemical analysis. 8 hair dye products contained toluene-2,5-diamine (0.18 to 0.98%). PPD (0.27%) was found in 1 product, and m-aminophenol (0...

Hair cycle in dogs with different hair types in a tropical region of Brazil.

Science.gov (United States)

Favarato, Evandro S; Conceição, Lissandro Gonçalves

2008-02-01

Hair cycle activity has been extensively studied in humans, sheep and laboratory animals, but there is a lack of information in dogs. Besides varying according to species, breed, sex and general health, hair growth is mainly affected by climatic variations. The aim of the study was to evaluate the follicle activity in three breeds of dogs with different hair types, in the city of Viçosa, Minas Gerais (latitude 20 degrees 45'S), Brazil. Twenty-one male dogs of boxer, labrador and schnauzer breeds were trichographically analysed monthly over 12 consecutive months. Hair percentage of telogen and anagen hairs at the different stages of the hair cycle in boxers and labradors was not significantly different, but both differed from the schnauzers. A significant correlation between hair follicle cycle and environmental temperature and photoperiod was noted in the boxers and labradors. In these breeds, a larger number of telogen hairs were observed during the hottest months of the year, and an increase in anagen hairs during the coldest months. The mean percentage of telogen hairs was 93, 90 and 55.3% for boxer, labrador and schnauzer, respectively.

Drug-induced hair loss.

Science.gov (United States)

2016-05-01

Hair loss can have major psychological consequences. It can be due to a wide variety of causes, including hormonal disorders, dietary factors, infections, inflammation, trauma, emotional factors, and cancer. Drugs can also induce hair loss, by interacting with the hair growth cycle. Drug-induced hair loss may be immediate or delayed, sudden or gradual, and diffuse or localised. It is usually reversible after drug discontinuation. The drugs most often implicated in hair loss are anticancer agents, interferon, azole antifungals, lithium, immunosuppressants, and many other drugs belonging to a variety of pharmacological classes.

Loose anagen hair syndrome with diffuse woolly hair phenotype: A rare association

Directory of Open Access Journals (Sweden)

Arshdeep

2016-01-01

Full Text Available Loose anagen hair syndrome (LAHS is an underestimated cause of noncicatricial alopecia among children, manifesting as thin, sparse or fine hair. We report a case of LAHS clinically presenting as diffuse woolly hair, an association rarely described in the literature. In addition, we review the clinical as well as genetic link between these two enigmatic hair disorders and hypothesize that both may be associated in a yet unknown manner.

Optical hair removal.

Science.gov (United States)

Ort, R J; Anderson, R R

1999-06-01

Traditional methods of hair removal have proven unsatisfactory for many individuals with excessive or unwanted hair. In the last few years, several lasers and xenon flashlamps have been developed that promise to fulfill the need for a practical, safe, and long-lasting method of hair removal. Aggressive marketing of these has contributed to their popularity among patients and physicians. However, significant controversy and confusion surrounds this field. This article provides a detailed explanation of the scientific underpinnings for optical hair removal and explores the advantages and disadvantages of the various devices currently available (Nd:YAG, ruby, alexandrite, diode lasers, and xenon flashlamp). Treatment and safety guidelines are provided to assist the practitioner in the use of these devices. Although the field of optical hair removal is still in its infancy, initial reports of long-term efficacy are encouraging.

Influence of Bundle Diameter and Attachment Point on Kinematic Behavior in Double Bundle Anterior Cruciate Ligament Reconstruction Using Computational Model

Directory of Open Access Journals (Sweden)

Oh Soo Kwon

2014-01-01

Full Text Available A protocol to choose the graft diameter attachment point of each bundle has not yet been determined since they are usually dependent on a surgeon’s preference. Therefore, the influence of bundle diameters and attachment points on the kinematics of the knee joint needs to be quantitatively analyzed. A three-dimensional knee model was reconstructed with computed tomography images of a 26-year-old man. Based on the model, models of double bundle anterior cruciate ligament (ACL reconstruction were developed. The anterior tibial translations for the anterior drawer test and the internal tibial rotation for the pivot shift test were investigated according to variation of bundle diameters and attachment points. For the model in this study, the knee kinematics after the double bundle ACL reconstruction were dependent on the attachment point and not much influenced by the bundle diameter although larger sized anterior-medial bundles provided increased stability in the knee joint. Therefore, in the clinical setting, the bundle attachment point needs to be considered prior to the bundle diameter, and the current selection method of graft diameters for both bundles appears justified.

Interplay between microtubule bundling and sorting factors ensures acentriolar spindle stability during C. elegans oocyte meiosis.

Directory of Open Access Journals (Sweden)

Timothy J Mullen

2017-09-01

Full Text Available In many species, oocyte meiosis is carried out in the absence of centrioles. As a result, microtubule organization, spindle assembly, and chromosome segregation proceed by unique mechanisms. Here, we report insights into the principles underlying this specialized form of cell division, through studies of C. elegans KLP-15 and KLP-16, two highly homologous members of the kinesin-14 family of minus-end-directed kinesins. These proteins localize to the acentriolar oocyte spindle and promote microtubule bundling during spindle assembly; following KLP-15/16 depletion, microtubule bundles form but then collapse into a disorganized array. Surprisingly, despite this defect we found that during anaphase, microtubules are able to reorganize into a bundled array that facilitates chromosome segregation. This phenotype therefore enabled us to identify factors promoting microtubule organization during anaphase, whose contributions are normally undetectable in wild-type worms; we found that SPD-1 (PRC1 bundles microtubules and KLP-18 (kinesin-12 likely sorts those bundles into a functional orientation capable of mediating chromosome segregation. Therefore, our studies have revealed an interplay between distinct mechanisms that together promote spindle formation and chromosome segregation in the absence of structural cues such as centrioles.

Hair camouflage: A comprehensive review.

Science.gov (United States)

Saed, Stephanie; Ibrahim, Omer; Bergfeld, Wilma F

2017-03-01

Hair is venerated, cherished, and desired in societies throughout the world. Both women and men express their individual identities through their hairstyles. Healthy hair contributes to successful social assimilation, employment, and overall quality of life. Therefore, hair loss can have detrimental effects on almost every aspect of a person's life. In this review, we discuss the myriad of options that aid in concealing and camouflaging hair loss to facilitate a healthier-appearing scalp. Camouflage options for patients who suffer from hair loss include full or partial wigs, hair extensions, concealing powders and sprays, surgical tattoos, and hair transplants. We describe these modalities in detail and discuss their respective advantages and disadvantages.

Artificial Hair: By the Dawn to Automatic Biofibre® Hair Implant

Directory of Open Access Journals (Sweden)

Maria Roccia

2017-12-01

In 1995 the European Union (UE recognised the artificial hair implant as a legitimate medical treatment and outlined the rules related to that procedure. In 1996, biocompatible fibres (Biofibre® produced by Medicap® Italy were approved by the UE Authorities and by the Australian Therapeutic Goods Administration (TGA as medical devices for hair implant. An effective medical protocol was developed during the following years to provide correct guidelines for appropriate treatment, and to reduce possible related complications. Automatic Biofibre® hair implant represents the last achievement in this hair restoration technique with significant advantages for the patients.

Reinforcement of single-walled carbon nanotube bundles by intertube bridging

Science.gov (United States)

Kis, A.; Csányi, G.; Salvetat, J.-P.; Lee, Thien-Nga; Couteau, E.; Kulik, A. J.; Benoit, W.; Brugger, J.; Forró, L.

2004-03-01

During their production, single-walled carbon nanotubes form bundles. Owing to the weak van der Waals interaction that holds them together in the bundle, the tubes can easily slide on each other, resulting in a shear modulus comparable to that of graphite. This low shear modulus is also a major obstacle in the fabrication of macroscopic fibres composed of carbon nanotubes. Here, we have introduced stable links between neighbouring carbon nanotubes within bundles, using moderate electron-beam irradiation inside a transmission electron microscope. Concurrent measurements of the mechanical properties using an atomic force microscope show a 30-fold increase of the bending modulus, due to the formation of stable crosslinks that effectively eliminate sliding between the nanotubes. Crosslinks were modelled using first-principles calculations, showing that interstitial carbon atoms formed during irradiation in addition to carboxyl groups, can independently lead to bridge formation between neighbouring nanotubes.

Modeling of fuel bundle vibration and the associated fretting wear in a CANDU fuel channel

International Nuclear Information System (INIS)

Mohany, A.; Hassan, M.

2011-01-01

In this paper a numerical model is developed to predict the vibration response of a CANDU® fuel bundle and the associated fretting wear in the surrounding pressure tube. One excitation mechanism is considered in this model; turbulence-induced excitation caused by coolant flow inside the fuel channel. The numerical model can be easily adapted to include the effects of seismic events, fuel bundle impact during refuelling and start-up of the reactor, and the acoustic pressure pulsations caused by the primary heat transport (PHT) pumps. The simulation is performed for a typical CANDU fuel bundle with 37 fuel elements. The clearances between the buttons of the inner fuel elements, and between the bearing pads of the outer fuel elements and the pressure tube were measured from an actual fuel bundle. Some variability among the measured clearance values was observed. Therefore, probability density functions of the measured clearance values were established and the simulation was performed for the probabilistic distribution of the clearance values. The contact between the fuel bundle and the pressure tube is modeled using pseudo-force contact method. The proposed modelling technique can be used in future CANDU reactors to avoid fuel and pressure tube fretting damage due to the aforementioned excitation mechanisms. (author)

Nanotube bundle oscillators: Carbon and boron nitride nanostructures

International Nuclear Information System (INIS)

Thamwattana, Ngamta; Hill, James M.

2009-01-01

In this paper, we investigate the oscillation of a fullerene that is moving within the centre of a bundle of nanotubes. In particular, certain fullerene-nanotube bundle oscillators, namely C 60 -carbon nanotube bundle, C 60 -boron nitride nanotube bundle, B 36 N 36 -carbon nanotube bundle and B 36 N 36 -boron nitride nanotube bundle are studied using the Lennard-Jones potential and the continuum approach which assumes a uniform distribution of atoms on the surface of each molecule. We address issues regarding the maximal suction energies of the fullerenes which lead to the generation of the maximum oscillation frequency. Since bundles are also found to comprise double-walled nanotubes, this paper also examines the oscillation of a fullerene inside a double-walled nanotube bundle. Our results show that the frequencies obtained for the oscillation within double-walled nanotube bundles are slightly higher compared to those of single-walled nanotube bundle oscillators. Our primary purpose here is to extend a number of established results for carbon to the boron nitride nanostructures.

Gold thread implantation promotes hair growth in human and mice

Science.gov (United States)

Kim, Jong-Hwan; Cho, Eun-Young; Kwon, Euna; Kim, Woo-Ho; Park, Jin-Sung; Lee, Yong-Soon

2017-01-01

Thread-embedding therapy has been widely applied for cosmetic purposes such as wrinkle reduction and skin tightening. Particularly, gold thread was reported to support connective tissue regeneration, but, its role in hair biology remains largely unknown due to lack of investigation. When we implanted gold thread and Happy Lift™ in human patient for facial lifting, we unexpectedly found an increase of hair regrowth in spite of no use of hair growth medications. When embedded into the depilated dorsal skin of mice, gold thread or polyglycolic acid (PGA) thread, similarly to 5% minoxidil, significantly increased the number of hair follicles on day 14 after implantation. And, hair re-growth promotion in the gold threadimplanted mice were significantly higher than that in PGA thread group on day 11 after depilation. In particular, the skin tissue of gold thread-implanted mice showed stronger PCNA staining and higher collagen density compared with control mice. These results indicate that gold thread implantation can be an effective way to promote hair re-growth although further confirmatory study is needed for more information on therapeutic mechanisms and long-term safety. PMID:29399026

Microscopy of the hair and trichogram

Directory of Open Access Journals (Sweden)

Özlem Dicle

2014-06-01

Full Text Available Hair microscopy is a fast and simple method for the diagnosis of various disorders affecting the hair in daily practice. For the microscopy of the hair, samples are collected by either clipping or plucking. The trichogram technique which the hair sample is collected by a standardized plucking method is used for the diagnosis of hair shedding and of alopecia via hair root pattern. In this review, the examination techniques and details are discussed and the most common indications for the hair microscopy including hair abnormalities as a part of genodermatosis and, infections and infestations affecting the hair are highlighted.

Usher syndrome (sensorineural deafness and retinitis pigmentosa): pathogenesis, molecular diagnosis and therapeutic approaches.

Science.gov (United States)

Bonnet, Crystel; El-Amraoui, Aziz

2012-02-01

Usher syndrome (USH) is the most prevalent cause of hereditary deafness-blindness in humans. In this review, we pinpoint new insights regarding the molecular mechanisms defective in this syndrome, its molecular diagnosis and prospective therapies. Animal models wherein USH proteins were targeted at different maturation stages of the auditory hair cells have been engineered, shedding new light on the development and functioning of the hair bundle, the sound receptive structure. Improved protocols and guidelines for early molecular diagnosis of USH (USH genotyping microarrays, otochips and complete Sanger sequencing of the 366 coding exons of identified USH genes) have been developed. Approaches to alleviate or cure hearing and visual impairments have been initiated, leading to various degrees of functional rescuing. Whereas the mechanisms underlying hearing impairment in USH patients are being unraveled, showing in particular that USH1 proteins are involved in the shaping of the hair bundle and the functioning of the mechanoelectrical transduction machinery, the mechanisms underlying the retinal defects are still unclear. Efforts to improve clinical diagnosis have been successful. Yet, despite some encouraging results, further development of therapeutic approaches is necessary to ultimately treat this dual sensory defect.

Telogen Effluvium Hair Loss

Science.gov (United States)

... Category: Share: Yes No, Keep Private Telogen Effluvium Hair Loss Share | It is normal to lose up to ... months after the "shock". This sudden increase in hair loss, usually described as the hair coming out in ...

Taking Care of Your Hair

Science.gov (United States)

... Educators Search English Español Taking Care of Your Hair KidsHealth / For Teens / Taking Care of Your Hair ... role in how healthy it looks. Caring for Hair How you take care of your hair depends ...

Sonic Hedgehog Initiates Cochlear Hair Cell Regeneration through Downregulation of Retinoblastoma Protein

Science.gov (United States)

Lu, Na; Chen, Yan; Wang, Zhengmin; Chen, Guoling; Lin, Qin; Chen, Zheng-Yi; Li, Huawei

2013-01-01

Cell cycle re-entry by cochlear supporting cells and/or hair cells is considered one of the best approaches for restoring hearing loss as a result of hair cell damage. To identify mechanisms that can be modulated to initiate cell cycle re-entry and hair cell regeneration, we studied the effect of activating the sonic hedgehog (Shh) pathway. We show that Shh signaling in postnatal rat cochleae damaged by neomycin leads to renewed proliferation of supporting cells and hair cells. Further, proliferating supporting cells are likely to transdifferentiate into hair cells. Shh treatment leads to inhibition of retinoblastoma protein (pRb) by increasing phosphorylated pRb and reducing retinoblastoma gene transcription. This results in upregulation of cyclins B1, D2, and D3, and CDK1. These results suggest that Shh signaling induces cell cycle re-entry in cochlear sensory epithelium and the production of new hair cells, in part by attenuating pRb function. This study provides an additional route to modulate pRb function with important implications in mammalian hair cell regeneration. PMID:23211596

Holomorphic bundles over elliptic manifolds

International Nuclear Information System (INIS)

Morgan, J.W.

2000-01-01

In this lecture we shall examine holomorphic bundles over compact elliptically fibered manifolds. We shall examine constructions of such bundles as well as (duality) relations between such bundles and other geometric objects, namely K3-surfaces and del Pezzo surfaces. We shall be dealing throughout with holomorphic principal bundles with structure group GC where G is a compact, simple (usually simply connected) Lie group and GC is the associated complex simple algebraic group. Of course, in the special case G = SU(n) and hence GC = SLn(C), we are considering holomorphic vector bundles with trivial determinant. In the other cases of classical groups, G SO(n) or G = Sympl(2n) we are considering holomorphic vector bundles with trivial determinant equipped with a non-degenerate symmetric, or skew symmetric pairing. In addition to these classical cases there are the finite number of exceptional groups. Amazingly enough, motivated by questions in physics, much interest centres around the group E8 and its subgroups. For these applications it does not suffice to consider only the classical groups. Thus, while often first doing the case of SU(n) or more generally of the classical groups, we shall extend our discussions to the general semi-simple group. Also, we shall spend a good deal of time considering elliptically fibered manifolds of the simplest type, namely, elliptic curves

Muon bundles from the Universe

Directory of Open Access Journals (Sweden)

Kankiewicz P.

2018-01-01

Full Text Available Recently the CERN ALICE experiment, in its dedicated cosmic ray run, observed muon bundles of very high multiplicities, thereby confirming similar findings from the LEP era at CERN (in the CosmoLEP project. Significant evidence for anisotropy of arrival directions of the observed high multiplicity muonic bundles is found. Estimated directionality suggests their possible extragalactic provenance. We argue that muonic bundles of highest multiplicity are produced by strangelets, hypothetical stable lumps of strange quark matter infiltrating our Universe.

Infinitesimal bundles and projective relativity

International Nuclear Information System (INIS)

Evans, G.T.

1973-01-01

An intrinsic and global presentation of five-dimensional relativity theory is developed, in which special coordinate conditions are replaced by conditions of Lie invariance. The notion of an infinitesimal bundle is introduced, and the theory of connexions on principal bundles is extended to infinitesimal bundles. Global aspects of projective relativity are studied: it is shown that projective relativity can describe almost any space-time. In particular, it is not necessary to assume that the electromagnetic field have a global potential. (author)

CANFLEX fuel bundle strength tests (test report)

International Nuclear Information System (INIS)

Chang, Seok Kyu; Chung, C. H.; Kim, B. D.

1997-08-01

This document outlines the test results for the strength tests of the CANFLEX fuel bundle. Strength tests are performed to determine and verify the amount of the bundle shape distortion which is against the side-stops when the bundles are refuelling. There are two cases of strength test; one is the double side-stop test which simulates the normal bundle refuelling and the other is the single side-stop test which simulates the abnormal refuelling. the strength test specification requires that the fuel bundle against the side-stop(s) simulators for this test were fabricated and the flow rates were controlled to provide the required conservative hydraulic forces. The test rig conditions of 120 deg C, 11.2 MPa were retained for 15 minutes after the flow rate was controlled during the test in two cases, respectively. The bundle loading angles of number 13- number 15 among the 15 bundles were 67.5 deg CCW and others were loaded randomly. After the tests, the bundle shapes against the side-stops were measured and inspected carefully. The important test procedures and measurements were discussed as follows. (author). 5 refs., 22 tabs., 5 figs

Design and Characterization of a Novel Bio-inspired Hair Flow Sensor Based on Resonant Sensing

Science.gov (United States)

Guo, X.; Yang, B.; Wang, Q. H.; Lu, C. F.; Hu, D.

2018-03-01

Flow sensors inspired by the natural hair sensing mechanism have great prospect in the research of micro-autonomous system and technology (MAST) for the three-dimensional structure characteristics with high spatial and quality utilization. A novel bio-inspired hair flow sensor (BHFS) based on resonant sensing with a unique asymmetric design is presented in this paper. A hair transducer and a signal detector which is constituted of a two-stage micro-leverage mechanism and two symmetrical resonators (double ended tuning fork, DETF) are adopted to realize the high sensitivity to air flow. The sensitivity of the proposed BHFS is improved significantly than the published ones due to the high sensitivity of resonators and the higher amplification factor possessed by the two-stage micro-leverage mechanism. The standard deep dry silicon on glass (DDSOG) process is chosen to fabricate the proposed BHFS. The experiment result demonstrates that the fabricated BHFS has a mechanical sensitivity of 5.26 Hz/(m/s)2 at a resonant frequency of 22 kHz with the hair height of 6 mm.

Gender differences in scalp hair growth rates are maintained but reduced in pattern hair loss compared to controls.

Science.gov (United States)

Van Neste, D J J; Rushton, D H

2016-08-01

Hair loss is related to follicular density, programmed regrowth and hair productivity. The dissatisfaction with hair growth in patients experiencing hair loss might be due to slower linear hair growth rate (LHGR). LHGR and hair diameter was evaluated in Caucasian controls and patients with patterned hair loss employing the validated non-invasive, contrast-enhanced-phototrichogram with exogen collection. We evaluated 59,765 anagen hairs (controls 24,609, patients 35,156) and found thinner hairs grew slower than thicker hairs. LHGR in normal women was generally higher than in normal men. LHGR correlates with hair diameter (P hair of equal thickness in controls, subjects affected with patterned hair loss showed reduced hair growth rates, an observation found in both male and female patients. Males with pattern hair loss showed further reduction in growth rates as clinical severity worsened. However, sample size limitations prevented statistical evaluation of LHGR in severely affected females. Caucasian ethnicity. In pattern hair loss, LHGR significantly contributes to the apparent decrease in hair volume in affected areas. In early onset, LHRG might have a prognostic value in females but not in males. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The Comparison Analysis of Thermalhydraulic Behavior Between A Reference 37-element Bundle and A Modified 37-element Bundle

International Nuclear Information System (INIS)

Ryu, Eui-Seung; You, Sung-Chang

2014-01-01

As pressure tube diameter creep increase, the coolant flows through some of the interior subchannels of the fuel bundle are reduced and consequently reduces the Critical Heat Flux (CHF). For this reason, Canadian Utilities have performed the project that developing the new fuel design (modified 37-element bundle) to increase critical heat flux. The modified 37-element (37M) bundle has the same overall geometry as the reference 37-element (37R) bundle that is using in the Wolsong units now but the center element diameter has been reduced from 13.06mm to 11.5mm. The reduction in center element diameter of the 37M bundle design increase the flow of center areas to improve the cooling and thus to enhance CHF. The CHF experiments with 37M bundle string simulator in un-crept and crept (3.3%, 5.1% peak creep) flow channels were completed at Stern Laboratories in 2008. A substantially large increase in dryout-power was observed for the 37M bundle compared to the 37R bundle, particularly in the 5.1% crept channel. As a result of the experiments, Ontario Power Generation (OPG) and Bruce Power (BP) have increased the operational margin with this CHF correlation and has fully refueled the 37M fuel on some units or almost done on the other units. KHNP also has performed the project to refuel the 37M bundle which is the same design with OPG and BP recently. This paper summarizes the comparison assessment of Thermalhydraulic (T/H) behavior for 37M bundle and 37R bundle with their own correlations and geometry parameters. This analysis performed with the thermal hydraulic code (NUCIRC) and the site measured data at the Wolsong Unit2. Tests to evaluate the CHF performance with the 37M fuel bundle have been conducted in 2008 using the un-crept, 3.3% crept and 5.1% crept flow channels in the CHF Test facility at Stern Laboratories. In addition pressure drop tests have been performed at the same time. The changes of geometry from 37R bundle to 37M bundle reduced the center element

Help! It's Hair Loss!

Science.gov (United States)

... Staying Safe Videos for Educators Search English Español Hair Loss KidsHealth / For Kids / Hair Loss What's in this ... head are in the resting phase. What Causes Hair Loss? Men, especially older men, are the ones who ...

Skin, Hair, and Nails

Science.gov (United States)

... Safe Videos for Educators Search English Español Skin, Hair, and Nails KidsHealth / For Parents / Skin, Hair, and ... piel, el cabello y las uñas About Skin, Hair and Nails Skin is our largest organ. If ...

The amazing miniorgan: Hair follicle

Directory of Open Access Journals (Sweden)

Çiler Çelik Özenci

2014-06-01

Full Text Available Hair is a primary characteristic of mammals, and exerts a wide range of functions including thermoregulation, physical protection, sensory activity, and social interactions. The hair shaft consists of terminally differentiated keratinocytes that are produced by the hair follicle. Hair follicle development takes place during fetal skin development and relies on tightly regulated ectodermal–mesodermal interactions. Hair follicles form during embryonic development and, after birth, undergo recurrent cycling of growth (anagen, apoptosis-driven regression (catagen, and relative quiescence (telogen. As a functional mini-organ, the hair follicle develops in an environment with dynamic and alternating changes of diverse molecular signals. Our molecular understanding of hair follicle biology relies heavily on genetically engineered mouse models with abnormalities in hair structure, growth, and/or pigmentation and significant advances have been made toward the identification of key signaling pathways and the regulatory genes involved. In this review, the basic concepts of hair follicle, a mini-complex organ, biology will be presented and its importance in clinical applications will be summarized.

Twisted Vector Bundles on Pointed Nodal Curves

Indian Academy of Sciences (India)

Abstract. Motivated by the quest for a good compactification of the moduli space of -bundles on a nodal curve we establish a striking relationship between Abramovich's and Vistoli's twisted bundles and Gieseker vector bundles.

Hair dye poisoning

Science.gov (United States)

Hair tint poisoning ... Different types of hair dye contain different harmful ingredients. The harmful ingredients in permanent dyes are: Naphthylamine Other aromatic amino compounds Phenylenediamines Toluene ...

Design of Sb2S3 nanorod-bundles: imperfect oriented attachment

Science.gov (United States)

Lu, Qifei; Zeng, Haibo; Wang, Zhenyang; Cao, Xueli; Zhang, Lide

2006-05-01

The large scale formation of uniform Sb2S3 nanorod-bundles has been achieved via a simple and mild hydrothermal approach with the assistance of polyvinylpyrrolidone. By closely inspecting the growth process and the crystallographic analysis of as-synthesized products, conclusive evidence has been provided to show that the growth mechanism of such nanorod-bundles is imperfect oriented attachment. The anisotropic adsorption of polyvinylpyrrolidone at the different surfaces of Sb2S3 nanocrystals assists the one-dimensional preferential growth; it is just the misorientations that result in the nanorod-based superstructures. Moreover, the hydrothermal treatment time plays a crucial role, and can be used as the parameter to control the size and morphology of the bundles. This simple approach promises future large-scale controlled synthesis of various nanobody-based superstructures for many important applications in nanotechnology.

Wolff-Parkinson-White syndrome type B and left bundle-branch block: electrophysiologic and radionuclide study

Energy Technology Data Exchange (ETDEWEB)

Rakovec, P.; Kranjec, I.; Fettich, J.J.; Jakopin, J.; Fidler, V.; Turk, J.

1985-01-01

Coinciding left bundle-branch block and Wolff-Parkinson-White syndrome type B, a very rare electrocardiographic occurrence, was found in a patient with dilated cardiomyopathy. Electrophysiologic study revealed eccentric retrograde atrial activation during ventricular pacing, suggesting right-sided accessory pathway. At programmed atrial pacing, effective refractory period of the accessory pathway was 310 ms; at shorter pacing coupling intervals, normal atrioventricular conduction with left bundle-branch block was seen. Left bundle-branch block was seen also with His bundle pacing. Radionuclide phase imaging demonstrated right ventricular phase advance and left ventricular phase delay; both right and left ventricular phase images revealed broad phase distribution histograms. Combined electrophysiologic and radionuclide investigations are useful to disclose complex conduction abnormalities and their mechanical correlates.

Wolff-Parkinson-White syndrome type B and left bundle-branch block: electrophysiologic and radionuclide study

International Nuclear Information System (INIS)

Rakovec, P.; Kranjec, I.; Fettich, J.J.; Jakopin, J.; Fidler, V.; Turk, J.

1985-01-01

Coinciding left bundle-branch block and Wolff-Parkinson-White syndrome type B, a very rare electrocardiographic occurrence, was found in a patient with dilated cardiomyopathy. Electrophysiologic study revealed eccentric retrograde atrial activation during ventricular pacing, suggesting right-sided accessory pathway. At programmed atrial pacing, effective refractory period of the accessory pathway was 310 ms; at shorter pacing coupling intervals, normal atrioventricular conduction with left bundle-branch block was seen. Left bundle-branch block was seen also with His bundle pacing. Radionuclide phase imaging demonstrated right ventricular phase advance and left ventricular phase delay; both right and left ventricular phase images revealed broad phase distribution histograms. Combined electrophysiologic and radionuclide investigations are useful to disclose complex conduction abnormalities and their mechanical correlates

Effect of hair care and hair cosmetics on the concentrations of fatty acid ethyl esters in hair as markers of chronically elevated alcohol consumption.

Science.gov (United States)

Hartwig, Sven; Auwärter, Volker; Pragst, Fritz

2003-01-28

Fatty acid ethyl esters (FAEE) can be used as alcohol markers in hair. It was investigated in this study whether this diagnostic method is disturbed by hair care and hair cosmetics. Traces of ethyl myristate, ethyl palmitate, ethyl oleate and ethyl stearate were detected in all of 49 frequently applied hair care products by headspace solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS). The highest concentration was 0.003% in a hair wax. From experiments with separated hair samples of alcoholics as well as from the evaluation of the FAEE concentrations and the data about hair care of 75 volunteers (alcoholics, social drinkers and teetotalers) follows that usual shampooing, permanent wave, dyeing, bleaching or shading are of minor importance as compared to the drinking amount and other individual features. However, false positive results were found after daily treatment with a hair lotion containing 62.5% ethanol, with a deodorant and with a hair spray. As an explanation, it is assumed that FAEE are formed in the sebum glands also after regular topical application of products with a higher ethanol content.

Essential of Hair Care Cosmetics

Directory of Open Access Journals (Sweden)

Aurora Alessandrini

2016-09-01

Full Text Available Nowadays, hair care and style play a very important role in people’s physical aspect and self-perception. Hair cosmetics can be distinguished into two main categories: cosmetics with temporary effect on the hair, for example shampoos, conditioners, sprays, and temporary colors; and cosmetics with permanent effect on the hair, such as permanent waves, relaxers, bleaches and permanent colors. These cosmetic procedures may induce hair abnormalities. We provide an overview on the most important characteristics of these procedures, analyzing components and effects on the hair. Finally, we evaluated new camouflage techniques and tattoo scalp.

Development of a smart, anti-water polyurethane polymer hair coating for style setting.

Science.gov (United States)

Liu, Y; Liu, Y J; Hu, J; Ji, F L; Lv, J; Chen, S J; Zhu, Y

2016-06-01

The goal of this work was to develop a novel polyurethane polymer coating for the surface of the hair that could be used for style setting via the shape memory effect (SME). The features of the films are in accordance with conventional hair styling methods used in the laboratory. In this study, a new polyurethane polymer was synthesized; the morphology and mechanical behaviour of the coated hair were systematically investigated using a scanning electron microscope (SEM) and an Instron 5566 (with a temperature oven). The SME of the hair was tested using a 35-g weight and over five washing and drying cycles. The experimental result shows that the polyurethane polymer has effects on the mechanical behaviour of the hair. It indicates that the fixed shape (at 22°C) and recover rate (at 60°C) of different casted thickness films are similar. And the stress of the film becomes larger with increasing film thickness. Furthermore, the shape memory ability could be endowed with the hair styling using this polymer; the hair fibre could recover to the 65% of its original shape after five cycle deformation by 35 g mass under the heat-treated condition; it could recover its original setting styling even after 5th water washing and drying. The SEM results indicated that the microsurface of the hair is coated with the polymer membrane; it contributes to the shape memory ability of the coated hair to keep and recover to the original setting styling. The styling hair can return to the original hair because the polyurethane polymer can be washed out by water with suitable strength and shampoo totally which does not leave any flake. The polyurethane polymer-based hair setting agent has been developed successfully, and it could be coated evenly on the human hair with good hand feeling and SMEs. The SME is highly related to the quantity of polyurethane polymer solution, and the effect could be improved by increasing the solution quantity. The maximum deformation of the coated hair could

Preliminary report: NIF laser bundle review

International Nuclear Information System (INIS)

Tietbohl, G.L.; Larson, D.W.; Erlandson, A.C.

1995-01-01

As requested in the guidance memo 1 , this committe determined whether there are compelling reasons to recommend a change from the NIF CDR baseline laser. The baseline bundle design based on a tradeoff between cost and technical risk, which is replicated four times to create the required 192 beams. The baseline amplifier design uses bottom loading 1x4 slab and flashlamp cassettes for amplifier maintenance and large vacuum enclosures (2.5m high x 7m wide in cross-section for each of the two spatial filters in each of the four bundles. The laser beams are arranged in two laser bays configured in a u-shape around the target area. The entire bundle review effort was performed in a very short time (six weeks) and with limited resources (15 personnel part-time). This should be compared to the effort that produced the CDR design (12 months, 50 to 100 personnel). This committee considered three alternate bundle configurations (2x2, 4x2, and 4x4 bundles), and evaluated each bundle against the baseline design using the seven requested issues in the guidance memo: Cost; schedule; performance risk; maintainability/operability; hardware failure cost exposure; activation; and design flexibility. The issues were reviewed to identify differences between each alternate bundle configuration and the baseline

Structural and photoluminescence properties of Si-based nanosheet bundles rooted on Si substrates

Science.gov (United States)

Yuan, Peiling; Tamaki, Ryo; Kusazaki, Shinya; Atsumi, Nanae; Saito, Yuya; Kumazawa, Yuki; Ahsan, Nazmul; Okada, Yoshitaka; Ishida, Akihiro; Tatsuoka, Hirokazu

2018-04-01

Si-based nanosheet bundles were synthesized by the extraction of Ca atoms from CaSi2 microwalls grown on Si substrates by inositol hexakisphosphate solution or thermal treatment in FeCl2 vapor. The structural and photoluminescence properties of the Si-based nanosheet bundles were examined. The photoluminescence emissions in the visible region were clearly observed, and the temperature and excitation intensity dependences of the emissions were characterized. The observed Si-based nanosheets consist of thin Si layers, and a superlattice-like layered structural model is proposed to describe the Si-based nanosheet bundle structures and their photoluminescence property. The photoluminescence property of the nanosheets significantly depends on their treatment process. The luminescence mechanism of the nanosheets was discussed.

Warps, grids and curvature in triple vector bundles

Science.gov (United States)

Flari, Magdalini K.; Mackenzie, Kirill

2018-06-01

A triple vector bundle is a cube of vector bundle structures which commute in the (strict) categorical sense. A grid in a triple vector bundle is a collection of sections of each bundle structure with certain linearity properties. A grid provides two routes around each face of the triple vector bundle, and six routes from the base manifold to the total manifold; the warps measure the lack of commutativity of these routes. In this paper we first prove that the sum of the warps in a triple vector bundle is zero. The proof we give is intrinsic and, we believe, clearer than the proof using decompositions given earlier by one of us. We apply this result to the triple tangent bundle T^3M of a manifold and deduce (as earlier) the Jacobi identity. We further apply the result to the triple vector bundle T^2A for a vector bundle A using a connection in A to define a grid in T^2A . In this case the curvature emerges from the warp theorem.

Air Trapping Mechanism in Artificial Salvinia-Like Micro-Hairs Fabricated via Direct Laser Lithography

Directory of Open Access Journals (Sweden)

Omar Tricinci

2017-12-01

Full Text Available Salvinia leaves represent an extraordinary example of how nature found a strategy for the long term retainment of air, and thus oxygen, on a surface, the so-called ‘Salvinia effect’, thanks to the peculiar three-dimensional and hierarchical shape of the hairs covering the leaves. Here, starting from the natural model, we have microfabricated hairs inspired by those present on the Salvinia molesta leaves, by means of direct laser lithography. Artificial hairs, like their natural counterpart, are composed of a stalk and a crown-like head, and have been reproduced in the microscale since this ensures, if using a proper design, an air-retaining behavior even if the bulk structural material is hydrophilic. We have investigated the capability of air retainment inside the heads of the hairs that can last up to 100 h, demonstrating the stability of the phenomenon. For a given dimension of the head, the greater the number of filaments, the greater the amount of air that can be trapped inside the heads since the increase in the number of solid–air interfaces able to pin the liquid phase. For this reason, such type of pattern could be used for the fabrication of surfaces for controlled gas retainment and gas release in liquid phases. The range of applications would be quite large, including industrial, medical, and biological fields.

Noncommutative generalization of SU(n)-principal fiber bundles: a review

International Nuclear Information System (INIS)

Masson, T

2008-01-01

This is an extended version of a communication made at the international conference 'Noncommutative Geometry and Physics' held at Orsay in april 2007. In this proceeding, we make a review of some noncommutative constructions connected to the ordinary fiber bundle theory. The noncommutative algebra is the endomorphism algebra of a SU(n)-vector bundle, and its differential calculus is based on its Lie algebra of derivations. It is shown that this noncommutative geometry contains some of the most important constructions introduced and used in the theory of connections on vector bundles, in particular, what is needed to introduce gauge models in physics, and it also contains naturally the essential aspects of the Higgs fields and its associated mechanics of mass generation. It permits one also to extend some previous constructions, as for instance symmetric reduction of (here noncommutative) connections. From a mathematical point of view, these geometrico-algebraic considerations highlight some new point on view, in particular we introduce a new construction of the Chern characteristic classes

Bundling ecosystem services in Denmark

DEFF Research Database (Denmark)

Turner, Katrine Grace; Odgaard, Mette Vestergaard; Bøcher, Peder Klith

2014-01-01

We made a spatial analysis of 11 ecosystem services at a 10 km × 10 km grid scale covering most of Denmark. Our objective was to describe their spatial distribution and interactions and also to analyze whether they formed specific bundle types on a regional scale in the Danish cultural landscape....... We found clustered distribution patterns of ecosystem services across the country. There was a significant tendency for trade-offs between on the one hand cultural and regulating services and on the other provisioning services, and we also found the potential of regulating and cultural services...... to form synergies. We identified six distinct ecosystem service bundle types, indicating multiple interactions at a landscape level. The bundle types showed specialized areas of agricultural production, high provision of cultural services at the coasts, multifunctional mixed-use bundle types around urban...

The new vestibular stimuli: sound and vibration-anatomical, physiological and clinical evidence.

Science.gov (United States)

Curthoys, Ian S

2017-04-01

The classical view of the otoliths-as flat plates of fairly uniform receptors activated by linear acceleration dragging on otoconia and so deflecting the receptor hair bundles-has been replaced by new anatomical and physiological evidence which shows that the maculae are much more complex. There is anatomical spatial differentiation across the macula in terms of receptor types, hair bundle heights, stiffness and attachment to the overlying otolithic membrane. This anatomical spatial differentiation corresponds to the neural spatial differentiation of response dynamics from the receptors and afferents from different regions of the otolithic maculae. Specifically, receptors in a specialized band of cells, the striola, are predominantly type I receptors, with short, stiff hair bundles and looser attachment to the overlying otoconial membrane than extrastriolar receptors. At the striola the hair bundles project into holes in the otolithic membrane, allowing for fluid displacement to deflect the hair bundles and activate the cell. This review shows the anatomical and physiological evidence supporting the hypothesis that fluid displacement, generated by sound or vibration, deflects the short stiff hair bundles of type I receptors at the striola, resulting in neural activation of the irregular afferents innervating them. So these afferents are activated by sound or vibration and show phase-locking to individual cycles of the sound or vibration stimulus up to frequencies above 2000 Hz, underpinning the use of sound and vibration for clinical tests of vestibular function.

Evaluation of droplet deposition in rod bundle

International Nuclear Information System (INIS)

Ji, W.; Gu, C.Y.; Anglart, H.

1997-01-01

Deposition model for droplets in gas droplet two-phase flow in rod bundle is developed in this work using the Lagrangian method. The model is evaluated in a 9-rod bundle geometry. The deposition coefficient in the bundle geometry are compared with that in round tube. The influences of the droplet size and gas mass flow rate on deposition coefficient are investigated. Furthermore, the droplet motion is studied in more detail by dividing the bundle channel into sub-channels. The results show that the overall deposition coefficient in the bundle geometry is close to that in the round tube with the diameter equal to the bundle hydraulic diameter. The calculated deposition coefficient is found to be higher for higher gas mass flux and smaller droplets. The study in the sub-channels show that the ratio between the local deposition coefficient for a sub-channel and the averaged value for the whole bundle is close to a constant value, deviations from the mean value for all the calculated cases being within the range of ±13%. (author)

No Correlates for Somatic Motility in Freeze-Fractured Hair-Cell Membranes of Lizards and Birds

Science.gov (United States)

Köppl, C.; Forge, A.; Manley, G. A.

2003-02-01

It is not known whether active processes in mammals and non-mammals are due to the same underlying mechanism. To address this, we studied the size and density of particles in hair-cell membranes in mammals, in a lizard, the Tokay gecko, and in a bird, the barn owl. We surmised that if the prominent particles described in mammalian outer-hair-cell membranes are responsible for cochlear motility, a similar occurrence in non-mammalian hair cells would argue for similar mechanisms. Particle densities differed, however, substantially from those of mammals, suggesting that non-mammals have no membrane-based motility.

Functional anatomy of the hair follicle: The Secondary Hair Germ.

Science.gov (United States)

Panteleyev, Andrey A

2018-07-01

The secondary hair germ (SHG)-a transitory structure in the lower portion of the mouse telogen hair follicle (HF)-is directly involved in anagen induction and eventual HF regrowth. Some crucial aspects of SHG functioning and ontogenetic relations with other HF parts, however, remain undefined. According to recent evidence (in contrast to previous bulge-centric views), the SHG is the primary target of anagen-inducing signalling and a source of both the outer root sheath (ORS) and ascending HF layers during the initial (morphogenetic) anagen subphase. The SHG is comprised of two functionally distinct cell populations. Its lower portion (originating from lower HF cells that survived catagen) forms all ascending HF layers, while the upper SHG (formed by bulge-derived cells) builds up the ORS. The predetermination of SHG cells to a specific morphogenetic fate contradicts their attribution to the "stem cell" category and supports SHG designation as a "germinative" or a "founder" cell population. The mechanisms of this predetermination driving transition of the SHG from "refractory" to the "competent" state during the telogen remain unknown. Functionally, the SHG serves as a barrier, protecting the quiescent bulge stem cell niche from the extensive follicular papilla/SHG signalling milieu. The formation of the SHG is a prerequisite for efficient "precommitment" of these cells and provides for easier sensing and a faster response to anagen-inducing signals. In general, the formation of the SHG is an evolutionary adaptation, which allowed the ancestors of modern Muridae to acquire a specific, highly synchronized pattern of hair cycling. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Tau can switch microtubule network organizations: from random networks to dynamic and stable bundles.

Science.gov (United States)

Prezel, Elea; Elie, Auréliane; Delaroche, Julie; Stoppin-Mellet, Virginie; Bosc, Christophe; Serre, Laurence; Fourest-Lieuvin, Anne; Andrieux, Annie; Vantard, Marylin; Arnal, Isabelle

2018-01-15

In neurons, microtubule networks alternate between single filaments and bundled arrays under the influence of effectors controlling their dynamics and organization. Tau is a microtubule bundler that stabilizes microtubules by stimulating growth and inhibiting shrinkage. The mechanisms by which tau organizes microtubule networks remain poorly understood. Here, we studied the self-organization of microtubules growing in the presence of tau isoforms and mutants. The results show that tau's ability to induce stable microtubule bundles requires two hexapeptides located in its microtubule-binding domain and is modulated by its projection domain. Site-specific pseudophosphorylation of tau promotes distinct microtubule organizations: stable single microtubules, stable bundles, or dynamic bundles. Disease-related tau mutations increase the formation of highly dynamic bundles. Finally, cryo-electron microscopy experiments indicate that tau and its variants similarly change the microtubule lattice structure by increasing both the protofilament number and lattice defects. Overall, our results uncover novel phosphodependent mechanisms governing tau's ability to trigger microtubule organization and reveal that disease-related modifications of tau promote specific microtubule organizations that may have a deleterious impact during neurodegeneration. © 2018 Prezel, Elie, et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Bundle Security Protocol for ION

Science.gov (United States)

Burleigh, Scott C.; Birrane, Edward J.; Krupiarz, Christopher

2011-01-01

This software implements bundle authentication, conforming to the Delay-Tolerant Networking (DTN) Internet Draft on Bundle Security Protocol (BSP), for the Interplanetary Overlay Network (ION) implementation of DTN. This is the only implementation of BSP that is integrated with ION.

Connections on discrete fibre bundles

International Nuclear Information System (INIS)

Manton, N.S.; Cambridge Univ.

1987-01-01

A new approach to gauge fields on a discrete space-time is proposed, in which the fundamental object is a discrete version of a principal fibre bundle. If the bundle is twisted, the gauge fields are topologically non-trivial automatically. (orig.)

Deformation quantization of principal fibre bundles

International Nuclear Information System (INIS)

Weiss, S.

2007-01-01

Deformation quantization is an algebraic but still geometrical way to define noncommutative spacetimes. In order to investigate corresponding gauge theories on such spaces, the geometrical formulation in terms of principal fibre bundles yields the appropriate framework. In this talk I will explain what should be understood by a deformation quantization of principal fibre bundles and how associated vector bundles arise in this context. (author)

Measurement of arsenic in sectioned hair samples by instrumental neutron activation analysis

International Nuclear Information System (INIS)

Guinn, V.P.; Gavrilas-Guinn, M.; Demiralp, R.

1994-01-01

In a recent Texas murder case, bundles of head hair from the female victim (aligned with all root ends together) were washed, cut into 7 mm sections, air-dried and weighed, activated in a nuclear reactor neutron flux, and then counted with a Ge(Li) detector/4096-channel gamma-ray spectrometer. In each of the 15 samples, the 559 keV gamma-ray peak of 26.3 hour 76 As was measured. In the section closest to the scalp, an arsenic concentration of 107 ppm was found (cf. a 'normal' level of about 1 ppm As). Barium ingestion was also possible so Ba was looked for, but not found. The victim's husband was found guilty of murder by chronic arsenic poisoning. (author) 2 refs.; 1 fig.; 1 tab

Deformations of the generalised Picard bundle

International Nuclear Information System (INIS)

Biswas, I.; Brambila-Paz, L.; Newstead, P.E.

2004-08-01

Let X be a nonsingular algebraic curve of genus g ≥ 3, and let Mξ denote the moduli space of stable vector bundles of rank n ≥ 2 and degree d with fixed determinant ξ over X such that n and d are coprime. We assume that if g = 3 then n ≥ 4 and if g = 4 then n ≥ 3, and suppose further that n 0 , d 0 are integers such that n 0 ≥ 1 and nd 0 + n 0 d > nn 0 (2g - 2). Let E be a semistable vector bundle over X of rank n 0 and degree d 0 . The generalised Picard bundle W ξ (E) is by definition the vector bundle over M ξ defined by the direct image p M ξ *(U ξ x p X * E) where U ξ is a universal vector bundle over X x M ξ . We obtain an inversion formula allowing us to recover E from W ξ (E) and show that the space of infinitesimal deformations of W ξ (E) is isomorphic to H 1 (X, End(E)). This construction gives a locally complete family of vector bundles over M ξ parametrised by the moduli space M(n 0 ,d 0 ) of stable bundles of rank n 0 and degree d 0 over X. If (n 0 ,d 0 ) = 1 and W ξ (E) is stable for all E is an element of M(n 0 ,d 0 ), the construction determines an isomorphism from M(n 0 ,d 0 ) to a connected component M 0 of a moduli space of stable sheaves over M ξ . This applies in particular when n 0 = 1, in which case M 0 is isomorphic to the Jacobian J of X as a polarised variety. The paper as a whole is a generalisation of results of Kempf and Mukai on Picard bundles over J, and is also related to a paper of Tyurin on the geometry of moduli of vector bundles. (author)

Exogenous and endogenous lipids of human hair.

Science.gov (United States)

Coderch, L; Oliver, M A; Martínez, V; Manich, A M; Rubio, L; Martí, M

2017-11-01

The aim of this study was to characterize the external and internal lipids of Caucasian hair and their influence in different hair properties such as moisture content, hydrophobic character, and mechanical properties. Lipid extraction and their analysis by thin layer chromatography with flame ionization detector were carried out. Lipid rearrangement and water sorption and desorption evaluation of these fibers with and without lipids will also be determined using different techniques such as differential scanning calorimetry, thermogravimetric analysis and dynamic vapor sorption, mainly to evaluate permeation changes of these hair fibers possibly related to the fluidity of the lipids extracted. Caucasian fibers were found to be well hydrated, and moisture diminution was observed mainly for the external lipid extracted fibers. Unexpectedly, the lipid extraction promoted an increase in the break tenacity of the Caucasian fibers. The hydrophobic character of the fiber surfaces indicates the marked hydrophobicity of all fibers. Delipidization promotes only a slight diminution of their hydrophobic properties. Water uptake and desorption studies indicate an important water regain for Caucasian fibers. The external extracted hair fibers presented a diminution of maximum water regain, which surprisingly increases with the following internal lipid extraction. This can be due to a higher water desorption found only for external extracted fibers. The relationship between fluidity of lipids extracted and hair fiber water diffusion were established. Extraction of internal lipids of Caucasian fibers, which have a higher unsaturated lipid content than external lipids of the same hair fiber, leads to a lower water permeability of the fiber. On the capillar formulations should be considered the importance of lipid fluidity to modify the permeability of the fiber. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Hair straightener poisoning

Science.gov (United States)

... this page: //medlineplus.gov/ency/article/002706.htm Hair straightener poisoning To use the sharing features on this page, please enable JavaScript. Hair straightener poisoning occurs when someone swallows products that ...

Hair spray poisoning

Science.gov (United States)

... this page: //medlineplus.gov/ency/article/002705.htm Hair spray poisoning To use the sharing features on this page, please enable JavaScript. Hair spray poisoning occurs when someone breathes in (inhales) ...

Stability of Picard bundle over moduli space of stable vector bundles ...

Indian Academy of Sciences (India)

Springer Verlag Heidelberg #4 2048 1996 Dec 15 10:16:45

Since the morphism ϕ is given by the universal property of the moduli space, the pullback of the universal bundle E on X × M to X × P by the map idX × ϕ is isomorphic (up to a twist by a line bundle coming from P) to ˜E. In other words, there is an integer k such that. 0 −→ (idX × ϕ)∗E −→ W ⊠ OP (k) −→ Ox×P (k + 1) −→ 0.

Characteristics of CANDU fuel bundles that caused pressure tube fretting at the bundle midplane

Energy Technology Data Exchange (ETDEWEB)

Dennier, D; Manzer, A M [Atomic Energy of Canada Ltd., Mississauga, ON (Canada); Koehn, E [Ontario Hydro, Toronto, ON (Canada)

1996-12-31

Detailed measurements on new bundles, and those that caused fretting during in- and out-reactor tests, have given insight into the factors responsible for fretting at the midplane of the inlet bundle. Bottom fuel elements that were attached near radial endplate spokes and had inboard bearing pads in the rolled joint cavity produced a significant portion of the observed fret marks. These elements are influenced by several driving forces that deflect the centre bearing pads towards the pressure tube surface. The evidence suggests that slight changes in bundle design may be possible to reduce pressure tube fretting. (author). 4 refs., 3 tabs., 8 figs.

Diseases that turn African hair silky.

Science.gov (United States)

Ajose, Frances O A

2012-11-01

African hair in its natural state poses tenacious grooming challenges; consequently a large portion of the African cosmetic industry is focused on means to relax the tight curls of African hair to make the hair more manageable. In malnourished and hypoproteinemic states, African hair straightens in an uncomplimentary manner. Recently, we observed that in certain diseases African hair changes to a desirable silky wavy texture. To identify the diseases that turn African hair silky and their parameters we examined 5612 dermatology patients at a tertiary hospital in Nigeria. We then studied the clinical and basic laboratory parameters of those patients whose diseases were accompanied by the silky hair change. Silky hair change similar to the hair of the African neonatal child was observed in five diseases, namely AIDS, rheumatoid arthritis, systemic lupus erythematosus, pulmonary tuberculosis with cachexia, and Behçet's disease. Our study identified retrogression of African hair to the neonatal structure in five diseases. Anemia of chronic illness, high erythrocyte sedimentation rate, and mild hypocalcemia were significant laboratory parameters. This is an important observation, which should excite and advance research into the nature and structure of African hair. The causes of structural hair changes should include these five diseases. © 2012 The International Society of Dermatology.

Analysis of sequential hair segments reflects changes in the metabolome across the trimesters of pregnancy

DEFF Research Database (Denmark)

Delplancke, Thibaut D J; de Seymour, Jamie V; Tong, Chao

2018-01-01

The hair metabolome has been recognized as a valuable source of information in pregnancy research, as it provides stable metabolite information that could assist with studying biomarkers or metabolic mechanisms of pregnancy and its complications. We tested the hypothesis that hair segments could...... mellitus (p metabolome during pregnancy, as well as highlight the potential of the maternal hair metabolome to differentiate pregnancy complications from healthy pregnancies....

A new Theory for frequencies computation of overhead lines with bundle conductors.

OpenAIRE

dubois, Hervé; Dal Maso, Filipo; Lilien, Jean-Louis

1991-01-01

Vertical, horizontal and torsional mechanical frequencies are studies for both single and bundle conductor lines. Models and tests are presented. These data are of particular impact on galloping phenomenon. Peer reviewed

Elevated temperature triggers human respiratory syncytial virus F protein six-helix bundle formation

International Nuclear Information System (INIS)

Yunus, Abdul S.; Jackson, Trent P.; Crisafi, Katherine; Burimski, Irina; Kilgore, Nicole R.; Zoumplis, Dorian; Allaway, Graham P.; Wild, Carl T.; Salzwedel, Karl

2010-01-01

Human respiratory syncytial virus (RSV) is a major cause of severe lower respiratory tract infection in infants, immunocompromised patients, and the elderly. The RSV fusion (F) protein mediates fusion of the viral envelope with the target cell membrane during virus entry and is a primary target for antiviral drug and vaccine development. The F protein contains two heptad repeat regions, HR1 and HR2. Peptides corresponding to these regions form a six-helix bundle structure that is thought to play a critical role in membrane fusion. However, characterization of six-helix bundle formation in native RSV F protein has been hindered by the fact that a trigger for F protein conformational change has yet to be identified. Here we demonstrate that RSV F protein on the surface of infected cells undergoes a conformational change following exposure to elevated temperature, resulting in the formation of the six-helix bundle structure. We first generated and characterized six-helix bundle-specific antibodies raised against recombinant peptides modeling the RSV F protein six-helix bundle structure. We then used these antibodies as probes to monitor RSV F protein six-helix bundle formation in response to a diverse array of potential triggers of conformational changes. We found that exposure of 'membrane-anchored' RSV F protein to elevated temperature (45-55 deg. C) was sufficient to trigger six-helix bundle formation. Antibody binding to the six-helix bundle conformation was detected by both flow cytometry and cell-surface immunoprecipitation of the RSV F protein. None of the other treatments, including interaction with a number of potential receptors, resulted in significant binding by six-helix bundle-specific antibodies. We conclude that native, untriggered RSV F protein exists in a metastable state that can be converted in vitro to the more stable, fusogenic six-helix bundle conformation by an increase in thermal energy. These findings help to better define the mechanism of

Study of fuel bundle geometry on inter subchannel flow in a 19 pin wire wrapped bundle

International Nuclear Information System (INIS)

Naveen Raj, M.; Velusamy, D.K.

2015-01-01

In typical sodium cooled fast reactor (SFR) fuel pin bundle, gap between the pins is maintained by helically wound wire wrap around each pin. The presence of wire induces large inter-subchannel transverse flow, eventually promoting mixing and heat transfer. The magnitude of the transverse flow is highly dependent on the various pin-bundle dimensions. Appropriate modeling of these transverse flows in subchannel codes is necessary to predict realistic temperature distribution in pin bundle. Hence, detailed parametric study of transverse flow on pin-bundle geometric parameters has been conducted. The parameters taken for the present study are pin diameter, wire diameter, helical wire pitch and edge gap. Towards this 3-D computational fluid dynamic analysis on a structured mesh of 19 pin bundle is carried out using k-epsilon turbulence model. Periodic oscillations along the primacy flow direction were found in subchannel transverse flow and peripheral pin clad temperatures with periodicity over one pitch length. Based on parametric studies, correlations for transverse flow in central subchannels are proposed. (author)

Systemic causes of hair loss.

Science.gov (United States)

Lin, Richard L; Garibyan, Lilit; Kimball, Alexandra B; Drake, Lynn A

2016-09-01

Hair loss is both a common chief complaint by patients and a clinical challenge for physicians, especially general practitioners, yet few dermatological problems yield as much patient satisfaction when resolved as hair loss. The diagnosis is often attributed to androgen-related hair loss, while other causes, some of which are life-threatening but treatable, are overlooked. We searched for relevant literature on hair loss and supported these findings with our clinical experience to identify seven major systemic etiologies of hair loss, ranging from infectious agents to consumption of unsafe supplements. Many causes are only described in the literature through case studies, though some original articles and meta-analyses are available. Careful history taking, proper examination techniques, and judicious use of laboratory tests are essential to reach at the correct diagnosis in a cost-effective manner when performing patient work-up. Such methodical evaluation of hair loss can result in the appropriate treatment plan and provide significant patient satisfaction. Key messages Hair loss is a common chief complaint and a difficult challenge for both general practitioners and dermatology consultants. We identified seven major categories of systemic hair loss etiology and present a framework for their clinical evaluation. A methodical approach to hair loss can result in the appropriate treatment plan and provide significant patient satisfaction.

Managing hair loss in midlife women.

Science.gov (United States)

Mirmirani, Paradi

2013-02-01

Hair is considered one of the most defining aspects of human appearance. Hair loss, or alopecia in women is often met with significant emotional distress and anxiety. In midlife, women may encounter various hormonal and age-related physiologic changes that can lead to alterations in hair texture and growth. The most significant hormonal alteration is the onset of menopause in which there is a cessation of ovarian estrogen production. This decrease in estrogen is known to have deleterious effects on the skin and cutaneous appendages. As our understanding of the molecular and hormonal controls on the hair follicle has grown, there has been increased interest in the various modulators of hair growth, including the potential role of estrogen. Further study of hair changes in midlife women provides an important opportunity for identification of the complex regulation of hair growth as well as identification of treatment targets that may specifically benefit women. In this review, management of hair loss in midlife women is discussed with a focus on three most commonly encountered clinical conditions: female pattern hair loss, hair shaft alterations due to hair care, and telogen effluvium. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Hydraulic characteristics of HANARO fuel bundles

Energy Technology Data Exchange (ETDEWEB)

Cho, S; Chung, H J; Chun, S Y; Yang, S K; Chung, M K [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1998-12-31

This paper presents the hydraulic characteristics measured by using LDV (Laser Doppler Velocimetry) in subchannels of HANARO, KAERI research reactor, fuel bundle. The fuel bundle consists of 18 axially finned rods with 3 spacer grids, which are arranged in cylindrical configuration. The effects of the spacer grids on the turbulent flow were investigated by the experimental results. Pressure drops for each component of the fuel bundle were measured, and the friction factors of fuel bundle and loss coefficients for the spacer grids were estimated from the measured pressure drops. Implications regarding the turbulent thermal mixing were discussed. Vibration test results measured by using laser vibrometer were presented. 9 refs., 12 figs. (Author)

Hydraulic characteristics of HANARO fuel bundles

Energy Technology Data Exchange (ETDEWEB)

Cho, S.; Chung, H. J.; Chun, S. Y.; Yang, S. K.; Chung, M. K. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1997-12-31

This paper presents the hydraulic characteristics measured by using LDV (Laser Doppler Velocimetry) in subchannels of HANARO, KAERI research reactor, fuel bundle. The fuel bundle consists of 18 axially finned rods with 3 spacer grids, which are arranged in cylindrical configuration. The effects of the spacer grids on the turbulent flow were investigated by the experimental results. Pressure drops for each component of the fuel bundle were measured, and the friction factors of fuel bundle and loss coefficients for the spacer grids were estimated from the measured pressure drops. Implications regarding the turbulent thermal mixing were discussed. Vibration test results measured by using laser vibrometer were presented. 9 refs., 12 figs. (Author)

In-pool damaged fuel bundle recovery

International Nuclear Information System (INIS)

Piascik, T.G.; Patenaude, R.S.

1988-01-01

While preparing to rerack the Oyster Creek Nuclear Generating Station, GPU Nuclear had need to move a damaged fuel bundle. This bundle had no upper tie plate and could not be moved in the normal manner. GPU Nuclear formed a small, dedicated project team to disassemble, package and move this damaged bundle. The team was composed of key personnel from GPU Nuclear Fuels Projects, OCNGS Operations and Proto-Power / Bisco, a specialty contractor who has fuel bundle reconstitution and rod consolidation experience, remote tooling, underwater video systems and experienced technicians. Proven tooling, clear procedures and a simple approach were important, but the key element was the spirit of teamwork and leadership exhibited by the people involved

The Effects of Urethane on Rat Outer Hair Cells

Directory of Open Access Journals (Sweden)

Mingyu Fu

2016-01-01

Full Text Available The cochlea converts sound vibration into electrical impulses and amplifies the low-level sound signal. Urethane, a widely used anesthetic in animal research, has been shown to reduce the neural responses to auditory stimuli. However, the effects of urethane on cochlea, especially on the function of outer hair cells, remain largely unknown. In the present study, we compared the cochlear microphonic responses between awake and urethane-anesthetized rats. The results revealed that the amplitude of the cochlear microphonic was decreased by urethane, resulting in an increase in the threshold at all of the sound frequencies examined. To deduce the possible mechanism underlying the urethane-induced decrease in cochlear sensitivity, we examined the electrical response properties of isolated outer hair cells using whole-cell patch-clamp recording. We found that urethane hyperpolarizes the outer hair cell membrane potential in a dose-dependent manner and elicits larger outward current. This urethane-induced outward current was blocked by strychnine, an antagonist of the α9 subunit of the nicotinic acetylcholine receptor. Meanwhile, the function of the outer hair cell motor protein, prestin, was not affected. These results suggest that urethane anesthesia is expected to decrease the responses of outer hair cells, whereas the frequency selectivity of cochlea remains unchanged.

Anatomic Double-bundle ACL Reconstruction

NARCIS (Netherlands)

Schreiber, Verena M.; van Eck, Carola F.; Fu, Freddie H.

2010-01-01

Rupture of the anterior cruciate ligament (ACL) is one of the most frequent forms of knee trauma. The traditional surgical treatment for ACL rupture is single-bundle reconstruction. However, during the past few years there has been a shift in interest toward double-bundle reconstruction to closely

Output commitment through product bundling : Experimental evidence

NARCIS (Netherlands)

Hinloopen, Jeroen; Mueller, Wieland; Normann, Hans-Theo

We analyze the impact of product bundling in experimental markets. One firm has monopoly power in a first market but competes with another firm la Cournot in a second market. We compare treatments where the multi-product firm (i) always bundles, (ii) never bundles, and (iii) chooses whether to

Hair-on-hair static friction coefficient can be determined by tying a knot.

Science.gov (United States)

Chevalier, Nicolas R

2017-11-01

Characterizing the tribological properties of the hair-hair interface is important to quantify the manageability of hair and to assess the performance of hair care products. Audoly et al. (Phys. Rev. Lett. 99, 164301, 2007) derived an equation relating the self-friction coefficient of an elastic fiber to the dimensions of a simple, relaxed overhand knot made from this fiber. I experimentally tested and validated their equation using nylon thread and an independent measurement of its self-friction coefficient. I show that this methodology can be applied to provide high-throughput data on the static self-friction coefficient of single hair fibers in various conditions and to quantitatively assess how hair care treatments (conditioner, relaxant) alter frictional properties. I find that treatment of hair with 1M sodium hydroxide leads to a quick, irreversible self-friction coefficient increase; the resulting fine frictional fibers can be used to form very small knots for microsurgical vessel and organ ligature in medicine or embryology. The relaxed overhand knot method can more generally be used to measure the self-friction coefficients of a wide range of elastic fibers from the nano- (e.g. proteins, nanotubes) to the macro-scale (e.g. textile fiber, fiberglass). Copyright © 2017 Elsevier B.V. All rights reserved.

ACM Bundles on Del Pezzo surfaces

Directory of Open Access Journals (Sweden)

Joan Pons-Llopis

2009-11-01

Full Text Available ACM rank 1 bundles on del Pezzo surfaces are classified in terms of the rational normal curves that they contain. A complete list of ACM line bundles is provided. Moreover, for any del Pezzo surface X of degree less or equal than six and for any n ≥ 2 we construct a family of dimension ≥ n − 1 of non-isomorphic simple ACM bundles of rank n on X.

Bundling and mergers in energy markets

International Nuclear Information System (INIS)

Granier, Laurent; Podesta, Marion

2010-01-01

Does bundling trigger mergers in energy industries? We observe mergers between firms belonging to various energy markets, for instance between gas and electricity providers. These mergers enable firms to bundle. We consider two horizontally differentiated markets. In this framework, we show that bundling strategies in energy markets create incentives to form multi-market firms in order to supply bi-energy packages. Moreover, we find that this type of merger is detrimental to social welfare. (author)

Safety analysis report of the irradiation test of Type-B bundle

Energy Technology Data Exchange (ETDEWEB)

Lee, Choong Sung; Lim, I. C.; Lee, B. C.; Ryu, J. S.; Kim, H. R

2000-06-01

The HANARO fuel, U{sub 3}Si-A1, has been developed by AECL and tested in NRU reactor. In the course of the fuel qualification tests, only one case was performed under the higher power condition than maximum linear power which was expected in the design stage. The Korea regulatory body, KINS imposed that HANARO shall be operated at the power level less than 24MW which is 80% of the design full power until HANARO shows the repetitive performance of the fuel at the power condition abov e 112.8KW/m. To resolve this imposition, KAERI designed two types of special test bundles: two non-instrumented(Type-A) and one instrumented(Type-B) test bundles. Two Type-A bundles were irradiated in HANARO: one of them has finished PIE and the other is under PIE. Type-B bundle was loaded in the core during 1.32 day at 1996, but outstanding FIV(flow induced vibration) was observed at the pool top because of long guide tube attached to the top of the bundle. The successful installation of the chimney fastener to fix the guide tube resulted in conducting the irradiation test of Type-B bundle again. The test will start at mid- July, 2000. In order to safely do the Type-B irradiation test, the safety analysis for the nuclear, mechanical and thermal-hydraulic aspects was performed. The reactivity worth and the maximum 1 near power predicted by VENTURE are 6.3mk/k and 121.6kW/m, respectively. Thermal margins for normal and transient conditions using MATRA-h, are assessed to satisfy the safety criteria.

Black Hole's 1/N Hair

CERN Document Server

Dvali, Gia

2013-01-01

According to the standard view classically black holes carry no hair, whereas quantum hair is at best exponentially weak. We show that suppression of hair is an artifact of the semi-classical treatment and that in the quantum picture hair appears as an inverse mass-square effect. Such hair is predicted in the microscopic quantum description in which a black hole represents a self-sustained leaky Bose-condensate of N soft gravitons. In this picture the Hawking radiation is the quantum depletion of the condensate. Within this picture we show that quantum black hole physics is fully compatible with continuous global symmetries and that global hair appears with the strength B/N, where B is the global charge swallowed by the black hole. For large charge this hair has dramatic effect on black hole dynamics. Our findings can have interesting astrophysical consequences, such as existence of black holes with large detectable baryonic and leptonic numbers.

Hair Regenerative Mechanisms of Red Ginseng Oil and Its Major Components in the Testosterone-Induced Delay of Anagen Entry in C57BL/6 Mice.

Science.gov (United States)

Truong, Van-Long; Bak, Min Ji; Lee, Changook; Jun, Mira; Jeong, Woo-Sik

2017-09-08

Hair loss (alopecia) is a universal problem for numerous people in the world. The present study was conducted to investigate the effects of red ginseng oil (RGO) and its major components on hair re-growth using testosterone (TES)-induced delay of anagen entry in C57BL/6 mice and their mechanisms of action. Seven-week-old C57BL/6 mice were daily treated with TES for 1 h prior to topical application of 10% RGO, 1% linoleic acid (LA), 1% β-sitosterol (SITOS), or 1% bicyclo(10.1.0)tridec-1-ene (BICYCLO) once a day for 28 days. Hair regenerative capacity was significantly restored by treatment of RGO and its major compounds in the TES-treated mice. Histological analysis showed that RGO along with LA and SITOS but not BICYCLO promoted hair growth through early inducing anagen phase that was delayed by TES in mice. Treatment of mice with RGO, LA, or SITOS up-regulated Wnt/β-catenin and Shh/Gli pathways-mediated expression of genes such as β-catenin, Lef-1, Sonic hedgehog, Smoothened, Gli-1, Cyclin D1, and Cyclin E in the TES-treated mice. In addition, RGO and its major components reduced the protein level of TGF-β but enhanced the expression of anti-apoptotic protein Bcl-2. These results suggest that RGO is a potent novel therapeutic natural product for treatment of androgenic alopecia possibly through hair re-growth activity of its major components such as LA and SITOS.

Grey Hair Evlsion Technique For Evaluating the Effect of Drugs For the Treatment of Premature Grey Hairs

Directory of Open Access Journals (Sweden)

J S Pasricha

1985-01-01

Full Text Available An improved method for evaluating the effect of treatment for premature grey hairs is described. The method consists of pulling out all the grey hairs in a patient and counting the number removed. Simultaneously, the converted hairs are also snipped at the grey-black junction and counted. After a gap of 3 months, the survey is repeated to count the number of hairs which have regrowing as grey hairs, the hairs which have become grey and also the hairs which have got converted into black during this period. Such surveys are repeated at 3 months intervals over a period of several years to see the progress of greying of hair in an individual and to evaluate the effect of various therapeutic procedures.

Computational imaging through a fiber-optic bundle

Science.gov (United States)

Lodhi, Muhammad A.; Dumas, John Paul; Pierce, Mark C.; Bajwa, Waheed U.

2017-05-01

Compressive sensing (CS) has proven to be a viable method for reconstructing high-resolution signals using low-resolution measurements. Integrating CS principles into an optical system allows for higher-resolution imaging using lower-resolution sensor arrays. In contrast to prior works on CS-based imaging, our focus in this paper is on imaging through fiber-optic bundles, in which manufacturing constraints limit individual fiber spacing to around 2 μm. This limitation essentially renders fiber-optic bundles as low-resolution sensors with relatively few resolvable points per unit area. These fiber bundles are often used in minimally invasive medical instruments for viewing tissue at macro and microscopic levels. While the compact nature and flexibility of fiber bundles allow for excellent tissue access in-vivo, imaging through fiber bundles does not provide the fine details of tissue features that is demanded in some medical situations. Our hypothesis is that adapting existing CS principles to fiber bundle-based optical systems will overcome the resolution limitation inherent in fiber-bundle imaging. In a previous paper we examined the practical challenges involved in implementing a highly parallel version of the single-pixel camera while focusing on synthetic objects. This paper extends the same architecture for fiber-bundle imaging under incoherent illumination and addresses some practical issues associated with imaging physical objects. Additionally, we model the optical non-idealities in the system to get lower modelling errors.

Sonic hedgehog initiates cochlear hair cell regeneration through downregulation of retinoblastoma protein

International Nuclear Information System (INIS)

Lu, Na; Chen, Yan; Wang, Zhengmin; Chen, Guoling; Lin, Qin; Chen, Zheng-Yi; Li, Huawei

2013-01-01

Highlights: ► Shh activation in neonatal cochleae enhances sensory cell proliferation. ► Proliferating supporting cells can transdifferentiate into hair cells. ► Shh promotes proliferation by transiently modulating pRb activity. ► Shh inhibits pRb by inhibiting transcription and increasing phosphorylation of pRb. -- Abstract: Cell cycle re-entry by cochlear supporting cells and/or hair cells is considered one of the best approaches for restoring hearing loss as a result of hair cell damage. To identify mechanisms that can be modulated to initiate cell cycle re-entry and hair cell regeneration, we studied the effect of activating the sonic hedgehog (Shh) pathway. We show that Shh signaling in postnatal rat cochleae damaged by neomycin leads to renewed proliferation of supporting cells and hair cells. Further, proliferating supporting cells are likely to transdifferentiate into hair cells. Shh treatment leads to inhibition of retinoblastoma protein (pRb) by increasing phosphorylated pRb and reducing retinoblastoma gene transcription. This results in upregulation of cyclins B1, D2, and D3, and CDK1. These results suggest that Shh signaling induces cell cycle re-entry in cochlear sensory epithelium and the production of new hair cells, in part by attenuating pRb function. This study provides an additional route to modulate pRb function with important implications in mammalian hair cell regeneration.

Associated quantum vector bundles and symplectic structure on a quantum space

International Nuclear Information System (INIS)

Coquereaux, R.; Garcia, A.O.; Trinchero, R.

2000-01-01

We define a quantum generalization of the algebra of functions over an associated vector bundle of a principal bundle. Here the role of a quantum principal bundle is played by a Hopf-Galois extension. Smash products of an algebra times a Hopf algebra H are particular instances of these extensions, and in these cases we are able to define a differential calculus over their associated vector bundles without requiring the use of a (bicovariant) differential structure over H. Moreover, if H is coquasitriangular, it coacts naturally on the associated bundle, and the differential structure is covariant. We apply this construction to the case of the finite quotient of the SL q (2) function Hopf algebra at a root of unity (q 3 = 1) as the structure group, and a reduced 2-dimensional quantum plane as both the 'base manifold' and fibre, getting an algebra which generalizes the notion of classical phase space for this quantum space. We also build explicitly a differential complex for this phase space algebra, and find that levels 0 and 2 support a (co)representation of the quantum symplectic group. On this phase space we define vector fields, and with the help of the Sp q structure we introduce a symplectic form relating 1-forms to vector fields. This leads naturally to the introduction of Poisson brackets, a necessary step to do 'classical' mechanics on a quantum space, the quantum plane. (author)

Greying of the human hair: a worldwide survey, revisiting the '50' rule of thumb.

Science.gov (United States)

Panhard, S; Lozano, I; Loussouarn, G

2012-10-01

While numerous papers have reported on the biological mechanisms of human hair pigmentation and greying, epidemiological descriptions of both natural hair colour and the greying process, worldwide, remain scarce. To assess hair colour and greying in a large world sample of human subjects, and to revisit the validity of the 50/50/50 rule of thumb, which states that 'at age 50 years, 50% of the population has at least 50% grey hair'. The natural hair colour of 4192 healthy male and female volunteers was assessed using a sensorial expert evaluation through the comparison of each volunteer's hair with standard swatches. Hair colour was studied according to age, gender and ethnic or geographical origin. Overall we observed that between 45 and 65 years of age, 74% of people were affected by grey hair with a mean intensity of 27%. Men harboured significantly more grey hair than women. Both age at onset and rate of greying with age appeared to be clearly linked to ethnic/geographical origin. Subjects of Asian and African descent showed less grey hair than those of caucasian origin, at comparable ages, confirming previously reported data. Calculating the percentage of people showing at least 50% grey hair coverage at age 50 years leads to a global range of 6-23%, according to ethnic/geographical origin and natural hair colour: well below that expressed by the '50' rule of thumb. © 2012 The Authors. BJD © 2012 British Association of Dermatologists.

Photodynamic therapy for hair removal

Directory of Open Access Journals (Sweden)

Mohamed H. M. Ali

2013-05-01

Full Text Available Background: Unwanted hair is one of the most common medical problems affecting women of reproductive age inducing a lot of psychological stress and threatening their femininity and self-esteem. Old methods of removing unwanted hair include shaving, waxing, chemical depilation, and electrolysis, all of which have temporary results. However laser-assisted hair removal is the most efficient method of long-term hair removal currently available. It is desirable to develop a reduced cost photodynamic therapy (PDT system whose properties should include high efficiency and low side-effects. Method: Mice skin tissues were used in this study and divided into six groups such as controls, free methylene blue (MB incubation, liposome methylene blue (MB incubation, laser without methylene blue (MB, free methylene blue (MB for 3 and 4 hrs and laser, liposome methylene blue (MB for 3 hrs and laser. Methylene blue (MBwas applied to wax epilated areas. The areas were irradiated with CW He-Ne laser system that emits orange-red light with wavelength 632.8 nm and 10 mW at energy density of 5 J/ cm2 for 10 minutes. The UV-visible absorption spectrum was collected by Cary spectrophotometer. Results: Methylene blue (MB is selectively absorbed by actively growing hair follicles due to its cationic property. Methylene blue (MBuntreated sections showed that hair follicle and sebaceous gland are intact and there is no change due to the laser exposure. Free methylene blue (MB sections incubated for 3 hrs showed that He:Ne laser induced destruction in hair follicles, leaving an intact epidermis. Treated section with free methylene blue (MB for 4 hrs showed degeneration and necrosis in hair follicle, leaving an intact epidermis. Liposomal methylene blue (MB sections incubated for 3 hrs showed He:Ne laser induced destruction in hair follicles with intradermal leucocytic infiltration. Conclusions: Low power CW He:Ne laser and methylene blue (MB offered a successful PDT system

Standard-model bundles

CERN Document Server

Donagi, Ron; Pantev, Tony; Waldram, Dan; Donagi, Ron; Ovrut, Burt; Pantev, Tony; Waldram, Dan

2002-01-01

We describe a family of genus one fibered Calabi-Yau threefolds with fundamental group ${\\mathbb Z}/2$. On each Calabi-Yau $Z$ in the family we exhibit a positive dimensional family of Mumford stable bundles whose symmetry group is the Standard Model group $SU(3)\\times SU(2)\\times U(1)$ and which have $c_{3} = 6$. We also show that for each bundle $V$ in our family, $c_{2}(Z) - c_{2}(V)$ is the class of an effective curve on $Z$. These conditions ensure that $Z$ and $V$ can be used for a phenomenologically relevant compactification of Heterotic M-theory.

An in vitro biomechanical comparison of anterior cruciate ligament reconstruction: single bundle versus anatomical double bundle techniques

Directory of Open Access Journals (Sweden)

Sandra Umeda Sasaki

2008-01-01

Full Text Available INTRODUCTION: Anterior cruciate ligament ruptures are frequent, especially in sports. Surgical reconstruction with autologous grafts is widely employed in the international literature. Controversies remain with respect to technique variations as continuous research for improvement takes place. One of these variations is the anatomical double bundle technique, which is performed instead of the conventional single bundle technique. More recently, there has been a tendency towards positioning the two bundles through double bone tunnels in the femur and tibia (anatomical reconstruction. OBJECTIVES: To compare, through biomechanical tests, the practice of anatomical double bundle anterior cruciate ligament reconstruction with a patellar graft to conventional single bundle reconstruction with the same amount of patellar graft in a paired experimental cadaver study. METHODS: Nine pairs of male cadaver knees ranging in age from 44 to 63 years were randomized into two groups: group A (single bundle and group B (anatomical reconstruction. Each knee was biomechanically tested under three conditions: intact anterior cruciate ligament, reconstructed anterior cruciate ligament, and injured anterior cruciate ligament. Maximum anterior dislocation, rigidity, and passive internal tibia rotation were recorded with knees submitted to a 100 N horizontal anterior dislocation force applied to the tibia with the knees at 30, 60 and 90 degrees of flexion. RESULTS: There were no differences between the two techniques for any of the measurements by ANOVA tests. CONCLUSION: The technique of anatomical double bundle reconstruction of the anterior cruciate ligament with bone-patellar tendon-bone graft has a similar biomechanical behavior with regard to anterior tibial dislocation, rigidity, and passive internal tibial rotation.

Reduction of symplectic principal R-bundles

International Nuclear Information System (INIS)

Lacirasella, Ignazio; Marrero, Juan Carlos; Padrón, Edith

2012-01-01

We describe a reduction process for symplectic principal R-bundles in the presence of a momentum map. These types of structures play an important role in the geometric formulation of non-autonomous Hamiltonian systems. We apply this procedure to the standard symplectic principal R-bundle associated with a fibration π:M→R. Moreover, we show a reduction process for non-autonomous Hamiltonian systems on symplectic principal R-bundles. We apply these reduction processes to several examples. (paper)

Bundles of C*-categories and duality

OpenAIRE

Vasselli, Ezio

2005-01-01

We introduce the notions of multiplier C*-category and continuous bundle of C*-categories, as the categorical analogues of the corresponding C*-algebraic notions. Every symmetric tensor C*-category with conjugates is a continuous bundle of C*-categories, with base space the spectrum of the C*-algebra associated with the identity object. We classify tensor C*-categories with fibre the dual of a compact Lie group in terms of suitable principal bundles. This also provides a classification for ce...

Evaluating big deal journal bundles.

Science.gov (United States)

Bergstrom, Theodore C; Courant, Paul N; McAfee, R Preston; Williams, Michael A

2014-07-01

Large commercial publishers sell bundled online subscriptions to their entire list of academic journals at prices significantly lower than the sum of their á la carte prices. Bundle prices differ drastically between institutions, but they are not publicly posted. The data that we have collected enable us to compare the bundle prices charged by commercial publishers with those of nonprofit societies and to examine the types of price discrimination practiced by commercial and nonprofit journal publishers. This information is of interest to economists who study monopolist pricing, librarians interested in making efficient use of library budgets, and scholars who are interested in the availability of the work that they publish.

Dimensional measurement of fresh fuel bundle for CANDU reactor

International Nuclear Information System (INIS)

Jo, Chang Keun; Cho, Moon Sung; Suk, Ho Chun; Koo, Dae Seo; Jun, Ji Su; Jung, Jong Yeob

2005-01-01

This report describes the results of the dimensional measurement of fresh fuel bundles for the CANDU reactor in order to estimate the integrity of fuel bundle in two-phase flow in the CANDU-6 fuel channel. The dimensional measurements of fuel bundles are performed by using the 'CANDU Fuel In-Bay Inspection and Dimensional Measurement System', which was developed by this project. The dimensional measurements are done from February 2004 to March 2004 in the CANDU fuel storage of KNFC for the 36 fresh fuel bundles, which are produced by KNFC and are waiting for the delivery to the Wolsong-3 plant. The detail items of dimensional measurements are included fuel rod and bearing pad profiles of the outer ring in fuel bundle, diameter of fuel bundle, bowing of fuel bundle, fuel rod length, and surface profile of end plate profile. The measurement data will be compared with those of the post-irradiated bundles cooled in Wolsong-3 NPP spent fuel pool by using the same bundles and In-Bay Measurement System. So, this analysis of data will be applied for the evaluation of fuel bundle integrity in two-phase flow of the CANDU-6 fuel channel

Sasakian and Parabolic Higgs Bundles

Science.gov (United States)

Biswas, Indranil; Mj, Mahan

2018-03-01

Let M be a quasi-regular compact connected Sasakian manifold, and let N = M/ S 1 be the base projective variety. We establish an equivalence between the class of Sasakian G-Higgs bundles over M and the class of parabolic (or equivalently, ramified) G-Higgs bundles over the base N.

Fuel bundle movement due to reverse flow

Energy Technology Data Exchange (ETDEWEB)

Wahba, N N; Akalin, O [Ontario Hydro, Toronto, ON (Canada)

1996-12-31

When a break occurs in the inlet feeder or inlet header, the rapid depressurization will cause the channel flow to reverse forcing the string of bundles to accelerate and impact with upstream shield plug. A model has been developed to predict the bundle motion due to the channel flow reversal. The model accounts for various forces acting on the bundle. A series of five reverse flow, bundle acceleration experiments have been conducted simulating a break in the inlet feeder of a CANDU fuel channel. The model has been validated against the experiments. The predicted impact velocities are in good agreement with the measured values. It is demonstrated that the model may be successfully used in predicting bundle relocation timing following a large LOCA (loss of coolant). (author). 7 refs., 3 tabs., 11 figs.

Bundles over Quantum RealWeighted Projective Spaces

Directory of Open Access Journals (Sweden)

Tomasz Brzeziński

2012-09-01

Full Text Available The algebraic approach to bundles in non-commutative geometry and the definition of quantum real weighted projective spaces are reviewed. Principal U(1-bundles over quantum real weighted projective spaces are constructed. As the spaces in question fall into two separate classes, the negative or odd class that generalises quantum real projective planes and the positive or even class that generalises the quantum disc, so do the constructed principal bundles. In the negative case the principal bundle is proven to be non-trivial and associated projective modules are described. In the positive case the principal bundles turn out to be trivial, and so all the associated modules are free. It is also shown that the circle (coactions on the quantum Seifert manifold that define quantum real weighted projective spaces are almost free.

Automatic hair detection in the wild

DEFF Research Database (Denmark)

Julian, Pauline; Dehais, Christophe; Lauze, Francois Bernard

2010-01-01

This paper presents an algorithm for segmenting the hair region in uncontrolled, real life conditions images. Our method is based on a simple statistical hair shape model representing the upper hair part. We detect this region by minimizing an energy which uses active shape and active contour....... The upper hair region then allows us to learn the hair appearance parameters (color and texture) for the image considered. Finally, those parameters drive a pixel-wise segmentation technique that yields the desired (complete) hair region. We demonstrate the applicability of our method on several real images....

Damping in heat exchanger tube bundles. A review

International Nuclear Information System (INIS)

Iqbal, Qamar; Khushnood, Shahab; Ghalban, Ali Roheim El; Sheikh, Nadeem Ahmed; Malik, Muhammad Afzaal; Arastu, Asif

2007-01-01

Damping is a major concern in the design and operation of tube bundles with loosely supported tubes in baffles for process shell and tube heat exchangers and steam generators which are used in nuclear, process and power generation industries. System damping has a strong influence on the amplitude of vibration. Damping depends upon the mechanical properties of the tube material, geometry of intermediate supports and the physical properties of shell-side fluid. Type of tube motion, number of supports, tube frequency, vibration amplitude, tube mass or diameter, side loads, support thickness, higher modes, shell-side temperature etc., affect damping in tube bundles. The importance of damping is further highlighted due to current trend of larger exchangers with increased shell-side velocities in modern units. Various damping mechanisms have been identified (Friction damping, Viscous damping, Squeeze film damping, Support damping. Two-Phase damping, and very recent-Thermal damping), which affect the performance of process exchangers and steam generators with respect to flow induced vibration design, including standard design guidelines. Damping in two-phase flow is very complex and highly void fraction, and flow-regime dependent. The current paper focuses on the various known damping mechanisms subjected to both single and two-phase cross-flow in process heat exchangers and steam generators and formulates the design guidelines for safer design. (author)

Dynamic behaviour of FBR fuel pin bundles

International Nuclear Information System (INIS)

Martin, P.H.; Van Dorsselaere, J.P.; Ravenet, A.

1990-01-01

A programme of shock tests on a fast neutron reactor subassembly model (SPX1 geometry) including a complete bundle of fuel pins (dummy elements) is being carried out in the BELIER test facility at Cadarache. The purpose of these tests is: to determine the distribution of dynamic forces applied to the fuel rod clads under the impact conditions encountered in a reactor during a earthquake; to reduce as much as possible the conservatism of the methods presently used for the calculation of those forces. The test programme, now being completed, consists of the following steps: impacts on the mock-up in air with an non-compact bundle (situation of the subassembly at beginning of life (BOL) with clearances within the bundle); impacts under the same conditions but with fluid (water) in the subassembly; impacts on the mock-up in air and with a compacted bundle (simulating the conditions of an end-of-life (EOL) bundle with no clearance within the bundle). The accelerations studied in these tests cover the range encountered in design calculations for the subassembly frequencies in beam mode. (author)

Side Effects: Hair Loss (Alopecia)

Science.gov (United States)

Hair loss, also called alopecia, is a side effect of cancer treatments, such as chemotherapy and radiation therapy. Learn how to cope with and manage hair loss. Listen to tips from others who have experienced hair loss.

Topical Valproate Solution for Hair Growth

Directory of Open Access Journals (Sweden)

Anil Kakunje

2018-05-01

Full Text Available Valproate is used regularly in the treatment of various seizure disorders, bipolar disorder, migraine prophylaxis and off label in many other conditions. Alopecia or hair loss is cosmetic side effect of oral valproate administration. Hair loss with valproate is diffused, non-scarring and dose related. A large number of drugs may interfere with the hair cycle and produce hair loss. We have only a few drugs like Minoxidil, Finasteride used for hair regeneration and both have its own side effects and limitations. In contrast to oral ingestions of valproate causing hair loss, early experiments with topical Valproic acid cream showed hair regeneration. Valproic acid cream is currently unavailable in the market, alternatively, we do have valproate and divalproex solutions available in various strengths which have a potential to be used topically for hair regeneration. The side effects and cost of topical valproate solution could be much less than the available options in the market. Valproate solution topically has the potential to be used for hair growth.

Fuel temperature characteristics of the 37-element and CANFLEX fuel bundle

International Nuclear Information System (INIS)

Bae, Jun Ho; Rho, Gyu Hong; Park, Joo Hwan

2009-10-01

This report describes the fuel temperature characteristics of CANFLEX fuel bundles and 37-element fuel bundles for a different burnup of fuel. The program was consisted for seeking the fuel temperature of fuel bundles of CANFLEX fuel bundles and 37-element fuel bundles by using the method in NUCIRC. Fuel temperature has an increasing pattern with the burnup of fuel for CANFLEX fuel bundles and 37-element fuel bundles. For all the case of burnup, the fuel temperature of CANFLEX fuel bundles has a lower value than that of 37-element fuel bundles. Especially, for the high power channel, the CANFLEX fuel bundles show a lower fuel temperature as much as about 75 degree, and the core averaged fuel temperature has a lower fuel temperature of about 50 degree than that of 37-element fuel bundles. The lower fuel temperature of CANFLEX fuel bundles is expected to enhance the safety by reducing the fuel temperature coefficient. Finally, for each burnup of CANFLEX fuel bundles and 37-element fuel bundles, the equation was present for predicting the fuel temperature of a bundle in terms of a coolant temperature and bundle power

Abscisic Acid Regulates Auxin Homeostasis in Rice Root Tips to Promote Root Hair Elongation

Directory of Open Access Journals (Sweden)

Tao Wang

2017-06-01

Full Text Available Abscisic acid (ABA plays an essential role in root hair elongation in plants, but the regulatory mechanism remains to be elucidated. In this study, we found that exogenous ABA can promote rice root hair elongation. Transgenic rice overexpressing SAPK10 (Stress/ABA-activated protein kinase 10 had longer root hairs; rice plants overexpressing OsABIL2 (OsABI-Like 2 had attenuated ABA signaling and shorter root hairs, suggesting that the effect of ABA on root hair elongation depends on the conserved PYR/PP2C/SnRK2 ABA signaling module. Treatment of the DR5-GUS and OsPIN-GUS lines with ABA and an auxin efflux inhibitor showed that ABA-induced root hair elongation depends on polar auxin transport. To examine the transcriptional response to ABA, we divided rice root tips into three regions: short root hair, long root hair and root tip zones; and conducted RNA-seq analysis with or without ABA treatment. Examination of genes involved in auxin transport, biosynthesis and metabolism indicated that ABA promotes auxin biosynthesis and polar auxin transport in the root tip, which may lead to auxin accumulation in the long root hair zone. Our findings shed light on how ABA regulates root hair elongation through crosstalk with auxin biosynthesis and transport to orchestrate plant development.

ROOT HAIR DEFECTIVE SIX-LIKE Class I Genes Promote Root Hair Development in the Grass Brachypodium distachyon.

Directory of Open Access Journals (Sweden)

Chul Min Kim

2016-08-01

Full Text Available Genes encoding ROOT HAIR DEFECTIVE SIX-LIKE (RSL class I basic helix loop helix proteins are expressed in future root hair cells of the Arabidopsis thaliana root meristem where they positively regulate root hair cell development. Here we show that there are three RSL class I protein coding genes in the Brachypodium distachyon genome, BdRSL1, BdRSL2 and BdRSL3, and each is expressed in developing root hair cells after the asymmetric cell division that forms root hair cells and hairless epidermal cells. Expression of BdRSL class I genes is sufficient for root hair cell development: ectopic overexpression of any of the three RSL class I genes induces the development of root hairs in every cell of the root epidermis. Expression of BdRSL class I genes in root hairless Arabidopsis thaliana root hair defective 6 (Atrhd6 Atrsl1 double mutants, devoid of RSL class I function, restores root hair development indicating that the function of these proteins has been conserved. However, neither AtRSL nor BdRSL class I genes is sufficient for root hair development in A. thaliana. These data demonstrate that the spatial pattern of class I RSL activity can account for the pattern of root hair cell differentiation in B. distachyon. However, the spatial pattern of class I RSL activity cannot account for the spatial pattern of root hair cells in A. thaliana. Taken together these data indicate that that the functions of RSL class I proteins have been conserved among most angiosperms-monocots and eudicots-despite the dramatically different patterns of root hair cell development.

Olivocochlear efferent vs. middle-ear contributions to the alteration of otoacoustic emissions by contralateral noise

NARCIS (Netherlands)

Buki, B; Wit, HP; Avan, P

2000-01-01

The medial olivocochlear efferent bundle is the key element of a bilateral efferent reflex activated by sound in either ear and acting directly on cochlear outer hair cells (OHC) via numerous cholinegic synapses. It probably contributes to regulating the mechanical activity of the cochlea

Laser-assisted hair removal for facial hirsutism in women: A review of evidence.

Science.gov (United States)

Lee, Chun-Man

2018-06-01

Poly cystic ovarian syndrome (PCOS) has been described as the common diagnosis for hirsutism in women. Facial hirsutism is by far the most distressing symptom of hyperandrogenism in women with PCOS. A statistically significant improvement in psychological well-being has been reported in patients with PCOS allocated for laser-assisted hair removal. The theory of selective photothermolysis has revolutionized laser hair removal in that it is effective and safe, when operated by sufficiently trained and experienced professionals. Long-pulsed ruby (694 nm), long-pulsed alexandrite (755 nm), diode (800-980 nm), and long-pulsed Nd:YAG (1064 nm) are commercially available laser devices for hair removal most widely studied. This article will introduce the fundamentals and mechanism of action of lasers in hair removal, in a contemporary literature review looking at medium to long term efficacy and safety profiles of various laser hair removal modalities most widely commercially available to date.

A toddler with hair fascination.

Science.gov (United States)

Kao, Patricia; Needlman, Robert D; Stein, Martin T

2010-04-01

Joseph is a 24-months old boy referred by his pediatrician because of an "obsession" with pulling and eating hair. When Joseph was 14 months old, he enjoyed touching and twirling his mother's long hair. She observed that it seemed to provide comfort to him. At 18 months, he initiated pulling out and eating his own hair, twirling his mother's hair around his thumb and then sucking on it. Currently, he searches the carpet or a hard floor and looks for hair to eat. The identical behavior is observed at daycare. Joseph's teacher commented, "He pulled hair from a girl who has the longest hair of all the children. We try to distract him from this habit, but he is not distracted for long." Less frequently, Joseph has also eaten sand, chalk, and crayons at daycare. Joseph's mother describes him as a "happy and outgoing" child who interacts with his peers and has a best friend at the daycare. There have not been recent changes or stressful events in his life. Joseph separates from his mother with ease and he sleeps comfortably through the night in his own bed. There have been no episodes of nausea, vomiting, abdominal pain, or constipation. Strands of hair are occasionally seen in the stool. Prenatal and perinatal history was unremarkable. Joseph was breast-fed for 11 months, described as an "easy" baby, achieved motor, social, and language developmental milestones at the usual time, and has been in excellent health. He lives with his mother and maternal grandparents; the biological father has never been involved in his care. At 20 months, Joseph's pediatrician suggested cutting his hair. After several haircuts, Joseph stopped pulling his own hair. However, he continued to search the floor for hair. Hemoglobin and a blood lead level were normal. Joseph appeared pleasant and friendly with normal growth parameters and facial features. He was sitting comfortably on his mother's lap, sucking on his thumb. Social interactions with his mother were appropriate and reciprocal. He

Episodic payments (bundling): PART I.

Science.gov (United States)

Jacofsky, D J

2017-10-01

Episodic, or bundled payments, is a concept now familiar to most in the healthcare arena, but the models are often misunderstood. Under a traditional fee-for-service model, each provider bills separately for their services which creates financial incentives to maximise volumes. Under a bundled payment, a single entity, often referred to as a convener (maybe the hospital, the physician group, or a third party) assumes the risk through a payer contract for all services provided within a defined episode of care, and receives a single (bundled) payment for all services provided for that episode. The time frame around the intervention is variable, but defined in advance, as are included and excluded costs. Timing of the actual payment in a bundle may either be before the episode occurs (prospective payment model), or after the end of the episode through a reconciliation (retrospective payment model). In either case, the defined costs over the defined time frame are borne by the convener. Cite this article: Bone Joint J 2017;99-B:1280-5. ©2017 The British Editorial Society of Bone & Joint Surgery.

Mutations in Three Genes Encoding Proteins Involved in Hair Shaft Formation Cause Uncombable Hair Syndrome

DEFF Research Database (Denmark)

Ü Basmanav, F Buket; Cau, Laura; Tafazzoli, Aylar

2016-01-01

Uncombable hair syndrome (UHS), also known as "spun glass hair syndrome," "pili trianguli et canaliculi," or "cheveux incoiffables" is a rare anomaly of the hair shaft that occurs in children and improves with age. UHS is characterized by dry, frizzy, spangly, and often fair hair that is resistant...... in the majority of UHS case subjects. The two enzymes PADI3 and TGM3, responsible for posttranslational protein modifications, and their target structural protein TCHH are all involved in hair shaft formation. Elucidation of the molecular outcomes of the disease-causing mutations by cell culture experiments...... and tridimensional protein models demonstrated clear differences in the structural organization and activity of mutant and wild-type proteins. Scanning electron microscopy observations revealed morphological alterations in hair coat of Padi3 knockout mice. All together, these findings elucidate the molecular genetic...

Missing Strands? Dealing with Hair Loss

Science.gov (United States)

... 2017 Print this issue Missing Strands? Dealing with Hair Loss En español Send us your comments Hair loss is often associated with men and aging, but ... or their treatments, and many other things cause hair loss. The most common type of hair loss is ...

Direct hair transplantation: A modified follicular unit extraction technique

Directory of Open Access Journals (Sweden)

Pradeep Sethi

2013-01-01

Full Text Available Background: In hair transplantation, the survival rate of harvested grafts depends upon many factors like maintenance of hydration, cold temperature, reduced mechanical handling and asepsis. All these factors are favourably improved if time out of body is reduced significantly. We have tried a modification called direct hair transplantation in the existing follicular unit extraction technique, in which the follicular unit grafts are implanted as soon as they are harvested. In this article, we have described the detailed methodology and a series of 29 patients who underwent direct hair transplantation. Aim: To evaluate the efficacy and feasibility of direct hair transplantation. Subjects and Methods: The patients willing to undergo hair transplantation by the technique of follicular unit extraction were enrolled for the surgery. After administration of local anaesthesia, the recipient sites were created. Thereafter, the processes of scoring the skin with a motorized punch, graft extraction and implantation were performed simultaneously. These patients were followed up to look for the time period of initiation of hair growth, the growth achieved at the end of 6-8 months and any adverse events. The results of patients with noticeable improvement in the photographs and reduction in baldness grade were taken as ′good′, whereas, in other patients, it was classified as ′poor′. Results: All patients were males with age ranging from 21 to 66 years (median 30 years. Twenty-six patients had androgenetic alopecia, 1 patient had traction alopecia and 2 patients had scarring alopecia. Twenty-seven patients showed ′good′ results, whereas 2 patients showed ′poor′ results. Conclusion: Direct hair transplantation is a simple and feasible modification in the follicular unit extraction technique. It is an efficacious surgical treatment modality for baldness.

Hair transplantation: Standard guidelines of care

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Patwardhan Narendra

2008-03-01

Full Text Available Hair transplantation is a surgical method of hair restoration. Physician qualification : The physician performing hair transplantation should have completed post graduation training in dermatology; he should have adequate background training in dermatosurgery at a centre that provides education training in cutaneous surgery. In addition, he should obtain specific hair transplantation training or experience at the surgical table(hands on under the supervision of an appropriately trained and experienced hair transplant surgeon. In addition to the surgical technique, training should include instruction in local anesthesia and emergency resuscitation and care. Facility : Hair transplantation can be performed safely in an outpatient day case dermatosurgical facility. The day case theatre should be equipped with facilities for monitoring and handling emergencies. A plan for handling emergencies should be in place and all nursing staff should be familiar with the emergency plan. It is preferable, but not mandatory to have a standby anesthetist. Indication for hair transplantation is pattern hair loss in males and also in females. In female pattern hair loss, investigations to rule out any underlying cause for hair loss such as anemia and thyroid deficiency should be carried out. Hair transplantation can also be performed in selected cases of scarring alopecia, eyebrows and eye lashes, by experienced surgeons. Preoperative counseling and informed consent :Detailed consent form listing details about the procedure and possible complications should be signed by the patient. The consent form should specifically state the limitations of the procedure and if more procedures are needed for proper results, it should be clearly mentioned. Patient should be provided with adequate opportunity to seek information through brochures, computer presentations, and personal discussions. Need for concomitant medical therapy should be emphasized. Patients should understand

Hair Shaft Abnormality in Children: a Narrative Review

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Ghasem Rahmatpour Rokni

2017-08-01

Full Text Available Background Hair is an ectodermal structure, and its formation is regulated by master genes important in embryology. Hair shaft consists of three major regions: the medulla, cortex and cuticle. Hair shaft abnormality will divide structural hair abnormalities into two broad categories - those associated with increased hair fragility and those not associated with increased hair fragility. We conducted a review study to assess hair shaft abnormality in children. Materials and Methods We conducted a review of all papers published on hair shaft abnormalities. A literature search was performed using PubMed, Scopus and Google Scholar on papers publish from 1990 to 2016. The search terms were: hair shaft abnormality, Hair loss, Hair fragility. All abstracts and full text English-language articles were studied. Results While common developmental and structural features are shared in hair follicles and hair shafts. Anomalies of the hair shaft are separated into those with and those without increased hair fragility. Conclusion Although hair has no vital function, it may serve as an indicator for human health. Clinical and morphological hair abnormalities can be clues to specific complex disorders. Hair shaft abnormalities can be inherited or acquired, can reflect a local problem or a systemic disease.

Diagnosis of Hair Loss: Clinical features of common causes of hair loss

OpenAIRE

Coupe, Robert L.M.

1992-01-01

Common causes of hair loss include androgenic hair loss, alopecia areata, trichotillomania, tinea capitis, telogen effluvium, and traction alopecia. The author discusses their distinguishing clinical features and those of less common alopecias.

Hair analysis using PIXE

International Nuclear Information System (INIS)

Li Hongkou.

1983-10-01

A simple new technique for examining single hair strands to obtain linear mass densities, longitudinal profiles and transverse distribution of each trace element is described. It is primarily based upon the PIXE technique, in combination with proton back- scattering. The three main components of this technique are: 1) An accurate way of using an interpolation method to evaluate the magnitude of the correction factor accounting for the proton energy loss and X-ray absorption in the bulk of the hair is formulated; 2) A simple method to qualitatively determine the transverse distribution of each trace element in a hair is in- troduced and proved to be effective; 3) Proton back-scattering is proved to be capable of providing an ideal linear measure of the geometric hair diameter, one of the most important parameters in quantifying the results of PIXE measurements in mass concentrations. Using the technique, a PIXE system designed and constructed for routine longitudinal scanning of single hair strands is also described. (Author)

Microwave-assisted hydrothermal synthesis of Bi2S3 nanorods in flower-shaped bundles

International Nuclear Information System (INIS)

Thongtem, Titipun; Pilapong, Chalermchai; Kavinchan, Jutarat; Phuruangrat, Anukorn; Thongtem, Somchai

2010-01-01

Bi 2 S 3 nanorods in flower-shaped bundles were successfully synthesized from the decomposition of Bi-thiourea complexes under the microwave-assisted hydrothermal process. X-ray powder diffraction (XRD) patterns and field emission scanning electron microscopy (FE-SEM) show that Bi 2 S 3 has the orthorhombic phase and appears as nanorods in flower-shaped bundles. A transmission electron microscopic (TEM) study reveals the independent single Bi 2 S 3 nanorods with their growth along the [0 0 1] direction. A possible formation mechanism of Bi 2 S 3 nanorods in flower-shaped bundles is also proposed and discussed. Their UV-vis spectrum shows the absorbance at 596 nm, with its direct energy band gap of 1.82 eV.

Hair: what is new in diagnosis and management? Female pattern hair loss update: diagnosis and treatment.

Science.gov (United States)

Atanaskova Mesinkovska, Natasha; Bergfeld, Wilma F

2013-01-01

Female pattern hair loss (FPHL) is the most common cause of alopecia in women. FPHL is characterized histologically with increased numbers of miniaturized, velluslike hair follicles. The goal of treatment of FPHL is to arrest hair loss progression and stimulate hair regrowth. The treatments for FPHL can be divided into androgen-dependent and androgen-independent. There is an important adjuvant role for nutritional supplements, light therapy, and hair transplants. All treatments work best when initiated early. Combinations of treatments tend to be more efficacious. Copyright © 2013 Elsevier Inc. All rights reserved.

Hair Regenerative Mechanisms of Red Ginseng Oil and Its Major Components in the Testosterone-Induced Delay of Anagen Entry in C57BL/6 Mice

Directory of Open Access Journals (Sweden)

Van-Long Truong

2017-09-01

Full Text Available Hair loss (alopecia is a universal problem for numerous people in the world. The present study was conducted to investigate the effects of red ginseng oil (RGO and its major components on hair re-growth using testosterone (TES-induced delay of anagen entry in C57BL/6 mice and their mechanisms of action. Seven-week-old C57BL/6 mice were daily treated with TES for 1 h prior to topical application of 10% RGO, 1% linoleic acid (LA, 1% β-sitosterol (SITOS, or 1% bicyclo(10.1.0tridec-1-ene (BICYCLO once a day for 28 days. Hair regenerative capacity was significantly restored by treatment of RGO and its major compounds in the TES-treated mice. Histological analysis showed that RGO along with LA and SITOS but not BICYCLO promoted hair growth through early inducing anagen phase that was delayed by TES in mice. Treatment of mice with RGO, LA, or SITOS up-regulated Wnt/β-catenin and Shh/Gli pathways-mediated expression of genes such as β-catenin, Lef-1, Sonic hedgehog, Smoothened, Gli-1, Cyclin D1, and Cyclin E in the TES-treated mice. In addition, RGO and its major components reduced the protein level of TGF-β but enhanced the expression of anti-apoptotic protein Bcl-2. These results suggest that RGO is a potent novel therapeutic natural product for treatment of androgenic alopecia possibly through hair re-growth activity of its major components such as LA and SITOS.

The application of safeguards design principles to the spent fuel bundle counter for 600 MW

International Nuclear Information System (INIS)

Stirling, A.J.; Allen, V.H.

1978-10-01

The irradiated fuel bundle counters for CANDU 600 MW reactors provide the IAEA with a secure and independent means of estimating the inventory of the spent fuel storage bay at each inspection. Their function is straightforward: to count the bundles entering the storage area through the normal transfer ports. However, location, reliability, security and operating requirements make them highly ΣintelligentΣ instruments which have required a major development program. Moreover, the bundle counters incorporate principles which apply to many unattended safeguards instruments. For example, concealing the operating status from potential diverters eases reliability specifications, continuous self-checking gives the inspector confidence in the readout, independence from continuous station services improves tamper resistance, and the detailed data display provides tamper indication and a high level of credibility. Each irradiated fuel bundle counter uses four Geiger counters to detect the passage of fuel bundles as they pass sequentially through the field-of-view. A Microprocessor analyzes the sequence of the Geiger counter signals and determines the number and direction of bundles transferred. The readout for IAEA inspectors includes both a tally and a printed log. The printer is also used to alert the inspector to abnomal fuel movements, tampering, Geiger counter failures and contamination of the fuel transfer mechanism. (author)

Hair Loss: Common Causes and Treatment.

Science.gov (United States)

Phillips, T Grant; Slomiany, W Paul; Allison, Robert

2017-09-15

Hair loss is often distressing and can have a significant effect on the patient's quality of life. Patients may present to their family physician first with diffuse or patchy hair loss. Scarring alopecia is best evaluated by a dermatologist. Nonscarring alopecias can be readily diagnosed and treated in the family physician's office. Androgenetic alopecia can be diagnosed clinically and treated with minoxidil. Alopecia areata is diagnosed by typical patches of hair loss and is self-limited. Tinea capitis causes patches of alopecia that may be erythematous and scaly and must be treated systemically. Telogen effluvium is a nonscarring, noninflammatory alopecia of relatively sudden onset caused by physiologic or emotional stress. Once the precipitating cause is removed, the hair typically will regrow. Trichotillomania is an impulse-control disorder; treatment is aimed at controlling the underlying psychiatric condition. Trichorrhexis nodosa occurs when hairs break secondary to trauma and is often a result of hair styling or overuse of hair products. Anagen effluvium is the abnormal diffuse loss of hair during the growth phase caused by an event that impairs the mitotic activity of the hair follicle, most commonly chemotherapy. Physician support is especially important for patients in this situation.

Sonic hedgehog initiates cochlear hair cell regeneration through downregulation of retinoblastoma protein

Energy Technology Data Exchange (ETDEWEB)

Lu, Na [Otology Skull Base Surgery Department, Hearing Research Institute, Eye and ENT Hospital of Shanghai Medical School, Fudan University, Shanghai 200031 (China); Department of Otolaryngology and Program in Neuroscience, Harvard Medical School and Eaton Peabody Laboratory, Massachusetts Eye and Ear Infirmary, Boston, MA 02114 (United States); Chen, Yan [Central Laboratory, Hearing Research Institute, Eye and ENT Hospital of Shanghai Medical School, Fudan University, Shanghai 200031 (China); Wang, Zhengmin [Otology Skull Base Surgery Department, Hearing Research Institute, Eye and ENT Hospital of Shanghai Medical School, Fudan University, Shanghai 200031 (China); Institute of Biomedical Sciences, Fudan University, Shanghai 200032 (China); Chen, Guoling [Otology Skull Base Surgery Department, Hearing Research Institute, Eye and ENT Hospital of Shanghai Medical School, Fudan University, Shanghai 200031 (China); Lin, Qin [Otology Skull Base Surgery Department, Hearing Research Institute, Eye and ENT Hospital of Shanghai Medical School, Fudan University, Shanghai 200031 (China); Department of Otolaryngology, First Affiliated Hospital of Fujian Medical University, Otolaryngology Institute of Fujian Province, Fuzhou (China); Chen, Zheng-Yi, E-mail: Zheng-yi_chen@meei.harvard.edu [Department of Otolaryngology and Program in Neuroscience, Harvard Medical School and Eaton Peabody Laboratory, Massachusetts Eye and Ear Infirmary, Boston, MA 02114 (United States); Li, Huawei, E-mail: hwli@shmu.edu.cn [Otology Skull Base Surgery Department, Hearing Research Institute, Eye and ENT Hospital of Shanghai Medical School, Fudan University, Shanghai 200031 (China); Institute of Biomedical Sciences, Fudan University, Shanghai 200032 (China)

2013-01-11

Highlights: Black-Right-Pointing-Pointer Shh activation in neonatal cochleae enhances sensory cell proliferation. Black-Right-Pointing-Pointer Proliferating supporting cells can transdifferentiate into hair cells. Black-Right-Pointing-Pointer Shh promotes proliferation by transiently modulating pRb activity. Black-Right-Pointing-Pointer Shh inhibits pRb by inhibiting transcription and increasing phosphorylation of pRb. -- Abstract: Cell cycle re-entry by cochlear supporting cells and/or hair cells is considered one of the best approaches for restoring hearing loss as a result of hair cell damage. To identify mechanisms that can be modulated to initiate cell cycle re-entry and hair cell regeneration, we studied the effect of activating the sonic hedgehog (Shh) pathway. We show that Shh signaling in postnatal rat cochleae damaged by neomycin leads to renewed proliferation of supporting cells and hair cells. Further, proliferating supporting cells are likely to transdifferentiate into hair cells. Shh treatment leads to inhibition of retinoblastoma protein (pRb) by increasing phosphorylated pRb and reducing retinoblastoma gene transcription. This results in upregulation of cyclins B1, D2, and D3, and CDK1. These results suggest that Shh signaling induces cell cycle re-entry in cochlear sensory epithelium and the production of new hair cells, in part by attenuating pRb function. This study provides an additional route to modulate pRb function with important implications in mammalian hair cell regeneration.

Hair dosimetry following neutron irradiation.

Science.gov (United States)

Lebaron-Jacobs, L; Gaillard-Lecanu, E; Briot, F; Distinguin, S; Boisson, P; Exmelin, L; Racine, Y; Berard, P; Flüry-Herard, A; Miele, A; Fottorino, R

2007-05-01

Use of hair as a biological dosimeter of neutron exposure was proposed a few years ago. To date, the (32)S(n,p)(32)P reaction in hair with a threshold of 2.5 MeV is the best choice to determine the fast neutron dose using body activation. This information is essential with regards to the heterogeneity of the neutron transfer to the organism. This is a very important parameter for individual dose reconstruction from the surface to the deeper tissues. This evaluation is essential to the adapted management of irradiated victims by specialized medical staff. Comparison exercises between clinical biochemistry laboratories from French sites (the CEA and COGEMA) and from the IRSN were carried out to validate the measurement of (32)P activity in hair and to improve the techniques used to perform this examination. Hair was placed on a phantom and was irradiated at different doses in the SILENE reactor (Valduc, France). Different parameters were tested: variation of hair type, minimum weight of hair sample, hair wash before measurement, delivery period of results, and different irradiation configurations. The results obtained in these comparison exercises by the different laboratories showed an excellent correlation. This allowed the assessment of a dose-activity relationship and confirmed the feasibility and the interest of (32)P measurement in hair following fast neutron irradiation.

Annular burnout data from rod-bundle experiments

International Nuclear Information System (INIS)

Yoder, G.L.; Morris, D.G.; Mullins, C.B.

1983-01-01

Burnout data for annular flow in a rod bundle are presented for both transient and steady-state conditions. Tests were performed at the Oak Ridge National Laboratory in the Thermal Hydraulic Test Facility (THTF), a pressurized-water loop containing an electrically heated 64-rod bundle. The bundle configuration is typical of later generation pressurized-water reactors with 17 x 17 fuel arrays. Both axial and radial power profiles are flat. All experiments were carried out in upflow with subcooled inlet conditions, insuring accurate flow measurement. Conditions within the bundle were typical of those which could be encountered during a nuclear reactor loss-of-coolant accident

Reversal of the hair loss phenotype by modulating the estradiol-ANGPT2 axis in the mouse model of female pattern hair loss.

Science.gov (United States)

Endo, Yujiro; Obayashi, Yuko; Ono, Tomoji; Serizawa, Tetsushi; Murakoshi, Michiaki; Ohyama, Manabu

2018-07-01

Despite high demand for a remedy, the treatment options for female pattern hair loss (FPHL) are limited. FPHL is frequent in postmenopausal women. In ovariectomized (OVX) mice, which lack β-estradiol (E2) and manifest hair loss mimicking FPHL, E2 supplementation has been shown to increase hair density. However, the mechanism by which E2 exhibits its biological activity remains elusive. To identify the downstream targets of E2 in the context of FPHL pathophysiology and discover a potential therapeutic agent for the E2-dependent subtype of FPHL. Human dermal papilla cells (hDPCs) were cultured with E2, and a microarray analysis was performed to identify the genes regulated by E2. Using OVX mice, the identified gene product was intradermally administered and then quantitative image analysis of hair density was conducted. In silico analysis to link E2 and the identified gene was performed. Global gene expression and bioinformatics analyses revealed that the genes associated with the angiopoietin-2 (ANGPT2) pathway were upregulated by E2 in hDPCs. ANGPT2 was significantly downregulated in OVX mice than in sham-operated mice (P < 0.01). Importantly, hair density was higher in OVX mice treated with ANGPT2 than in control mice (P < 0.05). In silico analysis showed DNA sequences with high possibility of estrogen receptor binding in the promoter region of ANGPT2. The E2-ANGPT2 axis is present in hair follicles. ANGPT2 provides a strategy for the management of E2-dependent and postmenopausal subsets of FPHL. Copyright © 2018 Japanese Society for Investigative Dermatology. Published by Elsevier B.V. All rights reserved.

Heat Transfer Analysis in Wire Bundles for Aerospace Vehicles

Science.gov (United States)

Rickman, S. L.; Iamello, C. J.

2016-01-01

Design of wiring for aerospace vehicles relies on an understanding of "ampacity" which refers to the current carrying capacity of wires, either, individually or in wire bundles. Designers rely on standards to derate allowable current flow to prevent exceedance of wire temperature limits due to resistive heat dissipation within the wires or wire bundles. These standards often add considerable margin and are based on empirical data. Commercial providers are taking an aggressive approach to wire sizing which challenges the conventional wisdom of the established standards. Thermal modelling of wire bundles may offer significant mass reduction in a system if the technique can be generalized to produce reliable temperature predictions for arbitrary bundle configurations. Thermal analysis has been applied to the problem of wire bundles wherein any or all of the wires within the bundle may carry current. Wire bundles present analytical challenges because the heat transfer path from conductors internal to the bundle is tortuous, relying on internal radiation and thermal interface conductance to move the heat from within the bundle to the external jacket where it can be carried away by convective and radiative heat transfer. The problem is further complicated by the dependence of wire electrical resistivity on temperature. Reduced heat transfer out of the bundle leads to higher conductor temperatures and, hence, increased resistive heat dissipation. Development of a generalized wire bundle thermal model is presented and compared with test data. The steady state heat balance for a single wire is derived and extended to the bundle configuration. The generalized model includes the effects of temperature varying resistance, internal radiation and thermal interface conductance, external radiation and temperature varying convective relief from the free surface. The sensitivity of the response to uncertainties in key model parameters is explored using Monte Carlo analysis.

Hair Loss Following The Topiramate Treatment

Directory of Open Access Journals (Sweden)

I Ghafoor

2017-02-01

Full Text Available BACKGROUND AND OBJECTIVE: Genetics, hormone profiles and other physiologic factors can cause hair loss. Medication induced hair loss is an occasional side effect of many psychopharmaceuticals. It can reduce medication compliance if not discovered and treated. We present a 18 year old female with migraine headache who developed hair loss after 3 months of receiving topiramate treatment. CASE REPORT: 18 year old female had been suffering from headache visited in psychiatric clinic. She agreed to a treatment with topiramate (50mg per day for Migraine headache. 3 months later, the patient complained of significant hair loss. Topiramate tapered to 25 mg/day and stopped. Hair loss stopped after topiramate withdrawal. Two weeks after reintroduction of topiramate, hair loss developed again. The medication was stopped and hair loss stopped again. CONCLUSION: Topiramate can cause hair loss. Although the condition is not life-threatening, a decrease in medication compliance can cause recurrence of the underlying disease. It is necessary to ask the patient at visits about it.

Single-phase convective heat transfer in rod bundles

International Nuclear Information System (INIS)

Holloway, Mary V.; Beasley, Donald E.; Conner, Michael E.

2008-01-01

The convective heat transfer for turbulent flow through rod bundles representative of nuclear fuel rods used in pressurized water reactors is examined. The rod bundles consist of a square array of parallel rods that are held on a constant pitch by support grids spaced axially along the rod bundle. Split-vane pair support grids, which create swirling flow in the rod bundle, as well as disc and standard support grids are investigated. Single-phase convective heat transfer coefficients are measured for flow downstream of support grids in a rod bundle. The rods are heated using direct resistance heating, and a bulk axial flow of air is used to cool the rods in the rod bundle. Air is used as the working fluid instead of water to reduce the power required to heat the rod bundle. Results indicate heat transfer enhancement for up to 10 hydraulic diameters downstream of the support grids. A general correlation is developed to predict the heat transfer development downstream of support grids. In addition, circumferential variations in heat transfer coefficients result in hot streaks that develop on the rods downstream of split-vane pair support grids

Single-phase convective heat transfer in rod bundles

Energy Technology Data Exchange (ETDEWEB)

Holloway, Mary V. [Mechanical Engineering Department, United States Naval Academy, 590 Holloway Rd., Annapolis, MD 21402 (United States)], E-mail: holloway@usna.edu; Beasley, Donald E. [Mechanical Engineering Department, Clemson University, Clemson, SC 29634 (United States); Conner, Michael E. [Westinghouse Nuclear Fuel, 5801 Bluff Road, Columbia, SC 29250 (United States)

2008-04-15

The convective heat transfer for turbulent flow through rod bundles representative of nuclear fuel rods used in pressurized water reactors is examined. The rod bundles consist of a square array of parallel rods that are held on a constant pitch by support grids spaced axially along the rod bundle. Split-vane pair support grids, which create swirling flow in the rod bundle, as well as disc and standard support grids are investigated. Single-phase convective heat transfer coefficients are measured for flow downstream of support grids in a rod bundle. The rods are heated using direct resistance heating, and a bulk axial flow of air is used to cool the rods in the rod bundle. Air is used as the working fluid instead of water to reduce the power required to heat the rod bundle. Results indicate heat transfer enhancement for up to 10 hydraulic diameters downstream of the support grids. A general correlation is developed to predict the heat transfer development downstream of support grids. In addition, circumferential variations in heat transfer coefficients result in hot streaks that develop on the rods downstream of split-vane pair support grids.

Synthesis and Characterization of Flower-Like Bundles of ZnO Nanosheets by a Surfactant-Free Hydrothermal Process

Directory of Open Access Journals (Sweden)

Jijun Qiu

2014-01-01

Full Text Available Flower-like bundles of ZnO nanosheets have been prepared by using preheating hydrothermal process without any surfactants. The flower-like bundles consist of many thin and uniform hexagonal-structured ZnO nanosheets, with a thickness of 50 nm. The selected area electronic diffraction (SAED and high-resolution transmission electron microscope (HRTEM images indicate that the ZnO nanosheets are single crystal in nature. The growth mechanism of the flower-like bundles of ZnO nanosheets is discussed based on the morphology evolution with growth times and reaction conditions. It is believed that the formation of flower-like bundles of ZnO nanosheets is related to the shielding effect of OH− ions and the self-assembly process, which is dominated by a preheating time. Room temperature photoluminescence spectra results show that the annealing atmosphere strongly affects the visible emission band, which is sensitive to intrinsic and surface defects, especially oxygen interstitials, in flower-like bundles of ZnO nanosheets.

The density and length of root hairs are enhanced in response to cadmium and arsenic by modulating gene expressions involved in fate determination and morphogenesis of root hairs in Arabidopsis

Directory of Open Access Journals (Sweden)

Ramin Bahmani

2016-11-01

Full Text Available Root hairs are tubular outgrowths that originate from epidermal cells. Exposure of Arabidopsis to cadmium (Cd and arsenic [arsenite, As(III] increases root hair density and length. To examine the underlying mechanism, we measured the expression of genes involved in fate determination and morphogenesis of root hairs. Cd and As(III downregulated TTG1 and GL2 (negative regulators of fate determination and upregulated GEM (positive regulator, suggesting that root hair fate determination is stimulated by Cd and As(III. Cd and As(III increased the transcript levels of genes involved in root hair initiation (RHD6 and AXR2 and root hair elongation (AUX1, AXR1, ETR1, and EIN2 except CTR1. DR5::GUS transgenic Arabidopsis showed a higher DR5 expression in the root tip, suggesting that Cd and As(III increased the auxin content in the root tip. Knockdown of TTG1 in Arabidopsis resulted in increased root hair density and decreased root hair length compared with the control (Col-0 on 1/2 MS media. This phenotype may be attributed to the downregulation of GL2 and CTR1 and upregulation of RHD6. By contrast, gem mutant plants displayed a decrease in root hair density and length with reduced expression of RHD6, AXR2, AUX1, AXR1, ETR1, CTR1, and EIN2. Taken together, our results indicate that fate determination, initiation, and elongation of root hairs are stimulated in response to Cd and As(III through the modulation of the expression of genes involved in these processes in Arabidopsis.

Cost-effectiveness of a central venous catheter care bundle.

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Kate A Halton

Full Text Available BACKGROUND: A bundled approach to central venous catheter care is currently being promoted as an effective way of preventing catheter-related bloodstream infection (CR-BSI. Consumables used in the bundled approach are relatively inexpensive which may lead to the conclusion that the bundle is cost-effective. However, this fails to consider the nontrivial costs of the monitoring and education activities required to implement the bundle, or that alternative strategies are available to prevent CR-BSI. We evaluated the cost-effectiveness of a bundle to prevent CR-BSI in Australian intensive care patients. METHODS AND FINDINGS: A Markov decision model was used to evaluate the cost-effectiveness of the bundle relative to remaining with current practice (a non-bundled approach to catheter care and uncoated catheters, or use of antimicrobial catheters. We assumed the bundle reduced relative risk of CR-BSI to 0.34. Given uncertainty about the cost of the bundle, threshold analyses were used to determine the maximum cost at which the bundle remained cost-effective relative to the other approaches to infection control. Sensitivity analyses explored how this threshold alters under different assumptions about the economic value placed on bed-days and health benefits gained by preventing infection. If clinicians are prepared to use antimicrobial catheters, the bundle is cost-effective if national 18-month implementation costs are below $1.1 million. If antimicrobial catheters are not an option the bundle must cost less than $4.3 million. If decision makers are only interested in obtaining cash-savings for the unit, and place no economic value on either the bed-days or the health benefits gained through preventing infection, these cost thresholds are reduced by two-thirds. CONCLUSIONS: A catheter care bundle has the potential to be cost-effective in the Australian intensive care setting. Rather than anticipating cash-savings from this intervention, decision

Genetics and other factors in the aetiology of female pattern hair loss.

Science.gov (United States)

Redler, Silke; Messenger, Andrew G; Betz, Regina C

2017-06-01

Pattern hair loss is the most common form of hair loss in both women and men. Male pattern hair loss, also termed male androgenetic alopecia (M-AGA), is an androgen-dependent trait that is predominantly genetically determined. Androgen-mediated mechanisms are probably involved in female pattern hair loss (FPHL) in some women but the evidence is less strong than in M-AGA; other non-androgenic pathways, including environmental influences, may contribute to the aetiology. Genome-wide association studies have identified several genetic loci for M-AGA and have provided better insight into the underlying biology. However, the role of heritable factors in Female Pattern Hair Loss (FPHL) is largely unknown. Recently published studies have been restricted to candidate gene approaches and could not clearly identify any susceptibility locus/gene for FPHL but suggest that the aetiology differs substantially from that of M-AGA. Hypotheses about possible pathomechanisms of FPHL as well as the results of the genetic studies performed to date are summarized. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Can an "Aesthetic" Intervention (Braided Hair Coil) Cause Hair Loss After an Aesthetic Operation?

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Dionyssopoulos, Alexander; Papaconstantinou, Antony; Stoltidou, Alexandra; Spyropoulou, Georgia-Alexandra

2014-07-01

Postoperative pressure alopecia (PPA), defined as hair loss caused by prolonged pressure on the patient's scalp during surgery, is an uncommon condition after aesthetic surgery. Originally, it was described for patients who underwent lengthy cardiovascular and gynecologic operations. The authors present a rare case, in which hair loss occurred after secondary breast augmentation (replacement of breast implants). The PPA appeared in the occipitoparietal region of the patient's scalp approximately 2 weeks after surgery. The operation was completed in less than 3 hours, without any fluctuations in the patient's blood pressure or any unusual blood loss. There were no other precipitating factors such as anemia or coagulopathies. The probable cause of this unexpected result was the patient's braided hair coil, which had not been noted before the operation. The patient habitually, and on the day of her operation, combed her hair into a braided coil, which placed extra pressure on the occipitoparietal region. The hair loss was temporary, and hair regrowth was complete within 2 months. This incident may have been avoided if the braided hair coil had been noted by nursing or other medical staff preoperatively. Repositioning the head every 30 minutes and providing adequate head padding during surgery are advised to protect the patient and prevent such incidents. 5. © 2014 The American Society for Aesthetic Plastic Surgery, Inc.

Pollution Damage and Protection of Asian Hair

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Xin Qu

2018-02-01

Full Text Available Cigarette smoke was used to simulate a polluted environment and an experiment was performed to reveal how virgin and bleached hair are damaged by a polluted environment. The dry/wet combability, surface contact angle, tryptophan content, and cuticle morphology of the smoke exposed hair were evaluated, and compared to unexposed virgin hair. The results showed that pollution exposure can cause significant chemical damage to hair. In particular, virgin hair exposure to pollution can cause damage to the hair cuticles (higher wet/dry combing, protein degradation, and a more hydrophilic hair surface. The experiment also demonstrated that the styling polymer, polyimide-1 (isobutylene/dimethyl amino propyl maleimide/ethoxylated maleimide/maleic acid copolymer, can provide effective protection against such hair damage.

Mercury in human hair

International Nuclear Information System (INIS)

Kapauan, P.A.; Cruz, C.C.; Verceluz, F.P.

1980-10-01

The analysis of mercury (Hg) in scalp hair obtained from individuals residing in five different localities in the Philippines - Metro Manila, Naga City in Bicol, Bataan, Oriental Mindoro, and Palawan is presented. An overall mean of 1.46 ug/g of hair was obtained for all samples excluding those from Palawan and represents a baseline value.'' In terms of the mercury levels found in hair, the Honda Bay area in Palawan is, relatively, a ''contaminated area.'' (author)

In-pool damaged fuel bundle recovery

International Nuclear Information System (INIS)

Piascik, T.G.; Patenaude, R.S.

1988-01-01

While preparing to rerack the Oyster Creek Nuclear Generating Station, GPU Nuclear had need to move a damaged fuel bundle. This bundle had no upper tie plate and could not be moved in the normal manner. GPU Nuclear formed a small, dedicated project team to disassemble, package, and move this damaged bundle. The team was composed of key personnel from GPU Nuclear Fuels Projects, OCNGS Operations and Proto-Power/Bisco, a specialty contractor who has fuel bundle reconstitution and rod consolidation experience, remote tooling, underwater video systems and experienced technicians. Proven tooling, clear procedures and a simple approach were important, but the key element was the spirit of teamwork and leadership exhibited by the people involved. In spite of several emergent problems which a task of this nature presents, this small, close knit utility/vendor team completed the work on schedule and within the exposure and cost budgets

The Current Status of Microscopical Hair Comparisons

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Walter F. Rowe

2001-01-01

Full Text Available Although the microscopical comparison of human hairs has been accepted in courts of law for over a century, recent advances in DNA technology have called this type of forensic examination into question. In a number of cases, post-conviction DNA testing has exonerated defendants who were convicted in part on the results of microscopical hair comparisons. A federal judge has held a Daubert hearing on the microscopical comparison of human hairs and has concluded that this type of examination does not meet the criteria for admission of scientific evidence in federal courts. A review of the available scientific literature on microscopical hair comparisons (including studies conducted by the Royal Canadian Mounted Police and the Federal Bureau of Investigation leads to three conclusions: (1 microscopical comparisons of human hairs can yield scientifically defensible conclusions that can contribute to criminal investigations and criminal prosecutions, (2 the reliability of microscopical hair comparisons is strongly affected by the training of the forensic hair examiner, (3 forensic hair examiners cannot offer estimates of the probability of a match of a questioned hair with a hair from a randomly selected person. In order for microscopical hair examinations to survive challenges under the U.S. Supreme Court’s Daubert decision, hair microscopists must be better trained and undergo frequent proficiency testing. More research on the error rates of microscopical hair comparisons should be undertaken, and guidelines for the permissible interpretations of such comparisons should be established. Until these issues have been addressed and satisfactorily resolved, microscopical hair comparisons should be regarded by law enforcement agencies and courts of law as merely presumptive in nature, and all microscopical hair comparisons should be confirmed by nuclear DNA profiling or mitochondrial DNA sequencing.

"Castor Oil" - The Culprit of Acute Hair Felting.

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Maduri, V Ramya; Vedachalam, Ahalya; Kiruthika, S

2017-01-01

Acute hair felting is a rare disorder of scalp hair. In this condition, the hair becomes twisted, entangled as a hard stony mass resembling a bird's nest. Sudden hair matting has been reported earlier in the literature after vigorous use of chemical and herbal shampoos. Plica polonica is a patchy area of hair matting occurring in due course of time in neglected hair or underlying psychiatric illness. This case is interesting as the whole scalp hair matted immediately after using coconut oil and castor oil following washing. Growing long hair and taking oil bath are cultural and religious customs in South India. The high viscosity of castor oil and long hair had contributed to sudden felting of hair. This disorder of hair is irreversible and the hair should be cut off. Acute nature of this disorder will result in a serious psychological impact on the patient and the family.

Use of ventilator associated pneumonia bundle and statistical process control chart to decrease VAP rate in Syria.

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Alsadat, Reem; Al-Bardan, Hussam; Mazloum, Mona N; Shamah, Asem A; Eltayeb, Mohamed F E; Marie, Ali; Dakkak, Abdulrahman; Naes, Ola; Esber, Faten; Betelmal, Ibrahim; Kherallah, Mazen

2012-10-01

Implementation of ventilator associated pneumonia (VAP) bundle as a performance improvement project in the critical care units for all mechanically ventilated patients aiming to decrease the VAP rates. VAP bundle was implemented in 4 teaching hospitals after educational sessions and compliance rates along with VAP rates were monitored using statistical process control charts. VAP bundle compliance rates were steadily increasing from 33 to 80% in hospital 1, from 33 to 86% in hospital 2 and from 83 to 100% in hospital 3 during the study period. The VAP bundle was not applied in hospital 4 therefore no data was available. A target level of 95% was reached only in hospital 3. This correlated with a decrease in VAP rates from 30 to 6.4 per 1000 ventilator days in hospital 1, from 12 to 4.9 per 1000 ventilator days in hospital 3, whereas VAP rate failed to decrease in hospital 2 (despite better compliance) and it remained high around 33 per 1000 ventilator days in hospital 4 where VAP bundle was not implemented. VAP bundle has performed differently in different hospitals in our study. Prevention of VAP requires a multidimensional strategy that includes strict infection control interventions, VAP bundle implementation, process and outcome surveillance and education.

Characterization of hairless (Hr) and FGF5 genes provides insights into the molecular basis of hair loss in cetaceans.

Science.gov (United States)

Chen, Zhuo; Wang, Zhengfei; Xu, Shixia; Zhou, Kaiya; Yang, Guang

2013-02-09

Hair is one of the main distinguishing characteristics of mammals and it has many important biological functions. Cetaceans originated from terrestrial mammals and they have evolved a series of adaptations to aquatic environments, which are of evolutionary significance. However, the molecular mechanisms underlying their aquatic adaptations have not been well explored. This study provided insights into the evolution of hair loss during the transition from land to water by investigating and comparing two essential regulators of hair follicle development and hair follicle cycling, i.e., the Hairless (Hr) and FGF5 genes, in representative cetaceans and their terrestrial relatives. The full open reading frame sequences of the Hr and FGF5 genes were characterized in seven cetaceans. The sequence characteristics and evolutionary analyses suggested the functional loss of the Hr gene in cetaceans, which supports the loss of hair during their full adaptation to aquatic habitats. By contrast, positive selection for the FGF5 gene was found in cetaceans where a series of positively selected amino acid residues were identified. This is the first study to investigate the molecular basis of the hair loss in cetaceans. Our investigation of Hr and FGF5, two indispensable regulators of the hair cycle, provide some new insights into the molecular basis of hair loss in cetaceans. The results suggest that positive selection for the FGF5 gene might have promoted the termination of hair growth and early entry into the catagen stage of hair follicle cycling. Consequently, the hair follicle cycle was disrupted and the hair was lost completely due to the loss of the Hr gene function in cetaceans. This suggests that cetaceans have evolved an effective and complex mechanism for hair loss.

Scanning electron microscopy of the vestibular end organs. [morphological indexes of inner ear anatomy and microstructure

Science.gov (United States)

Lindeman, H. H.; Ades, H. W.; West, R. W.

1973-01-01

The vestibular end organs, after chemical fixation, were freeze dried, coated with gold and palladium, and studied in the scanning microscope. Scanning microscopy gives a good three dimensional view of the sensory areas and allows study of both gross anatomy and microstructures. Cross anatomical features of the structure of the ampullae are demonstrated. The form of the statoconia in different species of animals is shown. New aspects of the structure of the sensory hairs are revealed. The hair bundles in the central areas of the cristae and in the striola of the maculae differ structurally from the hair bundles at the periphery of the sensory regions. Furthermore, some hair bundles consisting of very short stereocilia were observed. The relationship between the cupula and the statoconial membrane to the epithelial surface is discussed.

Nanotechnology-Based Cosmetics for Hair Care

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Jamie Rosen

2015-07-01

Full Text Available Hair is a significant indicator of health and can have a major impact on an individual’s cosmetic appearance. Research within the cosmetics industry has revealed that when nanomaterials are engineered into hair care, they can enhance the benefits of active ingredients in order to improve hair cosmesis. Within the cosmetics arena, the unique size and intrinsic properties of nanoparticles can be tailored to target the hair follicle and shaft. This review aims to provide an overview of cosmetic nanocarriers that can be employed to improve the appearance of hair.

Optimal Nonlinear Pricing, Bundling Commodities and Contingent Services

International Nuclear Information System (INIS)

Podesta, Marion; Poudou, Jean-Christophe

2008-01-01

In this paper, we propose to analyze optimal nonlinear pricing when a firm offers in a bundle a commodity and a contingent service. The paper studies a mechanism design where all private information can be captured in a single scalar variable in a monopoly context. We show that to propose the package for commodity and service is less costly for the consumer, the firm has lower consumers' rent than the situation where it sells their good and contingent service under an independent pricing strategy. In fact, the possibility to use price discrimination via the supply of package is dominated by the fact that it is costly for the consumer to sign two contracts. Bundling energy and a contingent service is a profitable strategy for a energetician monopoly practising optimal nonlinear tariff. We show that the rates of the energy and the contingent service depend to the optional character of the contingent service and depend to the degree of complementarity between commodities and services. (authors)

Why Does Hair Turn Gray?

Science.gov (United States)

... out, but people with naturally lighter hair are just as likely to go gray. From the time a person notices a few gray hairs, it may take more than 10 years for all of that person's hair to turn ... really believe that this happens. Just in case, try not to freak out your ...

Comparison of ASSERT subchannel code with Marviken bundle data

International Nuclear Information System (INIS)

Tahir, A.; Carver, M.B.

1984-04-01

In this paper ASSERT predictions are compared with the Marviken 6-rod bundle and 36+1 rod bundle. The predictions are presented for two experiments in the 6-rod bundle and four experiments in the 36+1 rod bundle. For low inlet subcooling, the void predictions are in good agreement with the experimental data. For high inlet subcooling, however, the agreement is not as good. This is attributed to the fact that in the high inlet subcooling experiments, single phase turbulent mixing plays a more important role in determining flow conditions in the bundle

Hair Transplantation in Migraine Headache Patients.

Science.gov (United States)

Ors, Safvet

2017-09-01

improvement each patient experienced was dramatic ( P < 0.001). Overall, the mean intensity of headaches declined from 6.6 ± 1.47 to 0, on an analog scale of 1-10 ( P < 0.001); and mean headache frequency was reduced from 5.83 ± 1.03/month to 0/month ( P < 0.001). Likewise, the migraine pain index fell from a mean of 149.33 ± 19.21/month to mean of 0/month ( P < 0.001). This report details 6 patients who experienced abatement of migraine headache symptoms following hair transplantation. The positive effects of hair transplantation on migraine headache and potential mechanisms of action are also discussed.

Investigation of scale effects and directionality dependence on friction and adhesion of human hair using AFM and macroscale friction test apparatus

International Nuclear Information System (INIS)

LaTorre, Carmen; Bhushan, Bharat

2006-01-01

Macroscale testing of human hair tribological properties has been widely used to aid in the development of better shampoos and conditioners. Recently, literature has focused on using the atomic force microscope (AFM) to study surface roughness, coefficient of friction, adhesive force, and wear (tribological properties) on the nanoscale in order to increase understanding about how shampoos and conditioners interact with the hair cuticle. Since there are both similarities and differences when comparing the tribological trends at both scales, it is thus recognized that scale effects are an important aspect of studying the tribology of hair. However, no microscale tribological data for hair exists in literature. This is unfortunate because many interactions between hair-skin, hair-comb, and hair-hair contact takes place at microasperities ranging from a few μm to hundreds of μm. Thus, to bridge the gap between the macro- and nanoscale data, as well as to gain a full understanding of the mechanisms behind the trends, it is now worthwhile to look at hair tribology on the microscale. Presented in this paper are coefficient of friction and adhesive force data on various scales for virgin and chemically damaged hair, both with and without conditioner treatment. Macroscale coefficient of friction was determined using a traditional friction test apparatus. Microscale and nanoscale tribological characterization was performed with AFM tips of various radii. The nano-, micro-, and macroscale trends are compared and the mechanisms behind the scale effects are discussed. Since the coefficient of friction changes drastically (on any scale) depending on whether the direction of motion is along or against the cuticle scales, the directionality dependence and responsible mechanisms are discussed

Exposure to nickel by hair mineral analysis.

Science.gov (United States)

Michalak, Izabela; Mikulewicz, Marcin; Chojnacka, Katarzyna; Wołowiec, Paulina; Saeid, Agnieszka; Górecki, Henryk

2012-11-01

The aim of the present work was to investigate the exposure to nickel from various sources by investigation of mineral composition of human scalp hair. The research was carried out on hair sampled from subjects, including 87 males and 178 females (22 ± 2 years). The samples of hair were analyzed by ICP-OES. The effect of several factors on nickel content in hair was examined: lifestyle habits (e.g. hair coloring, hair spray, hair straighteners, hair drier, drugs); dietary factors (e.g. yoghurts, blue cheese, lettuce, lemon, mushroom, egg, butter); other (e.g. solarium, cigarette smoking, tap water pipes, tinned food, PVC foil, photocopier, amalgam filling). These outcomes were reached by linking the results of nickel level in hair with the results of questionnaire survey. Basing on the results it can be concluded that exposure to nickel ions can occur from different sources: lifestyle, eating habits and environmental exposure. Copyright © 2012 Elsevier B.V. All rights reserved.

Excessive or unwanted hair in women

Science.gov (United States)

Hypertrichosis; Hirsutism; Hair - excessive (women); Excessive hair in women; Hair - women - excessive or unwanted ... Women normally produce low levels of male hormones (androgens). If your body makes too much of this ...

Female pattern hair loss

Directory of Open Access Journals (Sweden)

İdil Ünal

2014-06-01

Full Text Available Female androgenetic alopecia is the commonest cause of hair loss in women. It is characterized by a diffuse reduction in hair density over the crown and frontal scalp with retention of the frontal hairline and a characteristic pattern distribution in genetically predisposed women. Because of the uncertain relationship with the androgens Female Pattern Hair Loss (FPHL is the most preferred definition of the condition. This review has been focused on the clinical features, diagnosis and treatment alternatives of FPHL.

One stage revision single-bundle anterior cruciate ligament reconstruction with impacted morselized bone graft following a failed double-bundle reconstruction

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Ho Jong Ra

2017-01-01

Full Text Available Although double-bundle anterior cruciate ligament (ACL reconstruction has theoretical benefits such as more accurate reproduction of ACL anatomy, it is technically more demanding surgery. This report describes the case of a one stage revision single-bundle ACL reconstruction after primary double-bundle ACL reconstruction. A professional dancer had an ACL previously reconstructed with a double-bundle technique, but the femoral tunnels were malpositioned resulting in residual laxity and rotational instability. The previous femoral tunnel positions were vertical and widened. The previous vertical tunnels were filled with impacted bone graft and a revision single-bundle ACL reconstruction was performed via the new femoral tunnel with a 2 O'clock position between the previous two tunnels. After 10 months of postoperative rehabilitation, the patient returned to professional dancing with sound bony union and without any residual instability.

Alterations in Hair Follicle Dynamics in Women

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Claudine Piérard-Franchimont

2013-01-01

Full Text Available Endocrine changes supervening after parturition and menopause participate in the control of sebum production and hair growth modulation. The ensuing conditions include some peculiar aspects of hair loss (effluvium, alopecia, and facial hirsutism. The hair cycling is of major clinical relevance because most hair growth disorders result from disturbances in this chronobiological feature. Of note, any correlation between a biologic abnormality and hair cycling disturbance does not prove a relationship of causality. The proportion of postmenopausal women is rising in the overall population. Therefore, the prevalence of these hair follicle disturbances is globally on the rise. Current therapies aim at correcting the underlying hormonal imbalances, and at improving the overall cosmetic appearance. However, in absence of pathogenic diagnosis and causality criteria, chances are low that a treatment given by the whims of fate will adequately control hair effluvium. The risk and frequency of therapeutic inertia are further increased. When the hair loss is not controlled and/or compensated by growth of new hairs, several clinical aspects of alopecia inexorably develop. Currently, there is little evidence supporting any specific treatment for these endocrine hair disorders in post-partum and postmenopausal women. Current hair treatment strategies are symptomatic and nonspecific so current researchers aim at developing new, targeted methods.

Trichotillomania (Hair-Pulling Disorder)

Science.gov (United States)

... pulling Biting, chewing or eating pulled-out hair Playing with pulled-out hair or rubbing it across ... of trichotillomania: Family history. Genetics may play a role in the development of trichotillomania, and the disorder ...

Boiling on a tube bundle: heat transfer, pressure drop and flow patterns

International Nuclear Information System (INIS)

Royen Van, E.

2011-11-01

The complexity of two-phase flow boiling on a tube bundle presents many challenges to the understanding of the physical phenomena taking place. It is important to quantify these numerous heat flow mechanisms in order to better describe the performance of tube bundles as a function of the operational conditions. In the present study, the bundle boiling facility at the Laboratory of Heat and Mass Transfer (LTCM) was modified to obtain high-speed videos to characterise the two-phase regimes and some bubble dynamics of the boiling process. It was then used to measure heat transfer on single tubes and in bundle boiling conditions. Pressure drop measurements were also made during adiabatic and diabatic bundle conditions. New enhanced boiling tubes from Wolverine Tube Inc. (Turbo-B5) and the Wieland-Werke AG (Gewa-B5) were investigated using R134a and R236fa as test fluids. The tests were carried out at saturation temperatures T sat of 5 °C and 15 °C, mass flow rates from 4 to 35 kg/m 2 s and heat fluxes from 15 to 70 kW/m 2 , typical of actual operating conditions. The flow pattern investigation was conducted using visual observations from a borescope inserted in the middle of the bundle. Measurements of the light attenuation of a laser beam through the intertube two-phase flow and local pressure fluctuations with piezo-electric pressure transducers were also taken to further help in characterising the complex flow. Pressure drop measurements and data reduction procedures were revised and used to develop new, improved frictional pressure drop prediction methods for adiabatic and diabatic two-phase conditions. The physical phenomena governing the enhanced tube evaporation process and their effects on the performance of tube bundles were investigated and insight gained. A new method based on a theoretical analysis of thin film evaporation was used to propose a new correlating parameter. A large new database of local heat transfer coefficients were obtained and then

Bio-inspired flow sensor from printed PEDOT:PSS micro-hairs

International Nuclear Information System (INIS)

Devaraj, Harish; Sharma, Rajnish; Aw, Kean C; Travas-Sejdic, Jadranka; Aydemir, Nihan; Williams, David; Haemmerle, Enrico

2015-01-01

This paper reports on the creation of a low-cost, disposable sensor for low flow velocities, constructed from extruded micro-sized ‘hair’ of conducting polymer PEDOT. These microstructures are inspired by hair strands found in many arthropods and chordates, which play a prime role in sensing air flows. The paper describes the fabrication techniques and the initial prototype testing results toward employing this sensing mechanism in applications requiring sensing of low flow rates such as a flow sensor in neonatal resuscitators. The fabricated 1000 μm long, 6 μm diameter micro-hairs mimic the bending movement of tactile hair strands to sense the velocity of air flow. The prototype sensor developed is a four-level direct digital-output sensor and is capable of detecting flow velocities of up to 0.97 m s −1 . (paper)

Managing Chemotherapy Side Effects: Hair Loss (Alopecia)

Science.gov (United States)

... C ancer I nstitute Managing Chemotherapy Side Effects Hair Loss (Alopecia) “Losing my hair was hard at first. ... and anywhere on your body may fall out. Hair loss is called alopecia. When will my hair start ...

Boiling on a tube bundle: heat transfer, pressure drop and flow patterns

International Nuclear Information System (INIS)

Agostini, F.

2008-07-01

The complexity of the two-phase flow in a tube bundle presents important problems in the design and understanding of the physical phenomena taking place. The working conditions of an evaporator depend largely on the dynamics of the two-phase flow that in turn influence the heat exchange and the pressure drop of the system. A characterization of the flow dynamics, and possibly the identification of the flow pattern in the tube bundle, is thus expected to lead to a better understanding of the phenomena and to reveal on the mechanisms governing the tube bundle. Therefore, the present study aims at providing further insights into two-phase bundle flow through a new visualization system able to provide for the first time a view of the flow in the core of a tube bundle. In addition, the measurement of the light attenuation of a laser beam through the two-phase flow and measurement of the high frequency pressure fluctuations with a piezo-electric pressure transducer are used to characterize the flow. The design and the validation of this new instrumentation also provided a method for the detection of dry-out in tube bundles. This was achieved by a laser attenuation technique, flow visualization, and estimation of the power spectrum of the pressure fluctuation. The current investigation includes results for two different refrigerants, R134a and R236fa, three saturations temperatures T sat = 5, 10 and 15 °C, mass velocities ranging from 4 to 40 kg/sm² in adiabatic and diabatic conditions (several heat fluxes). Measurement of the local heat transfer coefficient and two-phase frictional pressure drop were obtained and utilized to improve the current prediction methods. The heat transfer and pressure drop data were supported by extensive characterization of the two-phase flow, which was to improve the understanding of the two-phase flow occurring in tube bundles. (author)

The use of human hair as biodosimeter

International Nuclear Information System (INIS)

Tepe Çam, S.; Polat, M.; Seyhan, N.

2014-01-01

The potential use of human hair samples as biologic dosimeter was investigated by electron spin resonance (ESR) spectroscopy. The hair samples were obtained from female volunteers and classified according to the color, age and whether they are natural or dyed. Natural black, brown, red, blonde and dyed black hair samples were irradiated at low doses (5–50 Gy) and high doses (75–750 Gy) by gamma source giving the dose rate of 0.25 Gy/s in The Sarayköy Establishment of Turkish Atomic Energy Authority. While the peak heights and g-values (2.0021–2.0023) determined from recorded spectra of hair were color dependent, the peak-to-peak line widths were varied according to natural or dyed hair (ΔH pp : 0.522–0.744 mT). In all samples, the linear dose–response curves at low doses saturated after ∼300 Gy. In black hair samples taken from different individuals, differences in the structure of the spectrum and signal intensities were not observed. The EPR signal intensities of samples stored at room temperature for 22 days fell to their half-values in 44 h in black hair, 41 h in blonde and brown hairs, 35 h in dyed black hair and in 17 h in red hair. The activation energies of samples annealed at high temperatures for different periods of time were correlated well with those obtained in the literature. In conclusion, hair samples can be used as a biological dosimeter considering the limitations showed in this study. - Highlights: • Applied electron spin resonance spectroscopy to human hair used in biodosimetry. • Showed the limitations of hair samples using as a biological dosimeter. • Provided more systematic information on radiation-induced radicals in hair. • Found at least 3 different contributions in the RIS. That is the major finding of this work

PDS4 Bundle Creation Governance Using BPMN

Science.gov (United States)

Radulescu, C.; Levoe, S. R.; Algermissen, S. S.; Rye, E. D.; Hardman, S. H.

2015-06-01

The AMMOS-PDS Pipeline Service (APPS) provides a Bundle Builder tool, which governs the process of creating, and ultimately generates, PDS4 bundles incrementally, as science products are being generated.

Elution behaviors of elements from the hair

International Nuclear Information System (INIS)

Akashi, Junko; Fukushima, Ichiro; Imahori, Akira

1981-01-01

The elution of the neutron activated elements out of hair soaked in some organic solvents and EDTA solution was studied. Soakage of the hair sample, which was washed with water and acetone in advance as IAEA's proposal, in ether and acetone for 30 minutes each resulted in no elution of Hg, Zn, Co and Se. Elution of Zn and Co from the powdered hair sample soaked in 0.1 M EDTA solution was rapid, while Zn did not elute out from the cut hair (2 -- 3 mm length) on the same condition. Hg, Se and Au were not eluted out by 0.1 M EDTA solution in the both case of cut hair and of powdered hair. Br was removed by 0.1 M EDTA solution from the cut hair and from the powdered hair with equal ease. (author)

Application of safeguards design principles to the spent-fuel bundle counters for 600-MW CANDU reactors

International Nuclear Information System (INIS)

Stirling, A.J.; Allen, V.H.

1979-01-01

The irradiated fuel bundle counters for CANDU 600-MW reactors provide the IAEA with a secure and independent means of estimating the inventory of the spent-fuel storage bay at each inspection. Their function is straightforward - to count the bundles entering the storage area through the normal transfer ports. However, location, reliability, security and operating requirements make them highly ''intelligent'' instruments which have required a major development programme. Moreover, the bundle counters incorporate principles which apply to many unattended safeguards instruments. For example, concealing the operating status from potential diverters eases reliability specifications, continuous self-checking gives the inspector confidence in the readout, independence from continuous station services improves tamper-resistance, and the detailed data display provides tamper indication and a high level of credibility. Each irradiated fuel-bundle counter uses four Geiger counters to detect the passage of fuel bundles as they pass sequentially through the field-of-view. A microprocessor analyses the sequence of the Geiger counter signals and determines the number and direction of bundles transferred. The readout for IAEA inspectors includes both a tally and a printed log. The printer is also used to alert the inspector to abnormal fuel movements, tampering, Geiger counter failures and contamination of the fuel transfer mechanism. (author)

Drug discovery for alopecia: gone today, hair tomorrow.

Science.gov (United States)

Santos, Zenildo; Avci, Pinar; Hamblin, Michael R

2015-03-01

Hair loss or alopecia affects the majority of the population at some time in their life, and increasingly, sufferers are demanding treatment. Three main types of alopecia (androgenic [AGA], areata [AA] and chemotherapy-induced [CIA]) are very different, and have their own laboratory models and separate drug-discovery efforts. In this article, the authors review the biology of hair, hair follicle (HF) cycling, stem cells and signaling pathways. AGA, due to dihydrotesterone, is treated by 5-α reductase inhibitors, androgen receptor blockers and ATP-sensitive potassium channel-openers. AA, which involves attack by CD8(+)NK group 2D-positive (NKG2D(+)) T cells, is treated with immunosuppressives, biologics and JAK inhibitors. Meanwhile, CIA is treated by apoptosis inhibitors, cytokines and topical immunotherapy. The desire to treat alopecia with an easy topical preparation is expected to grow with time, particularly with an increasing aging population. The discovery of epidermal stem cells in the HF has given new life to the search for a cure for baldness. Drug discovery efforts are being increasingly centered on these stem cells, boosting the hair cycle and reversing miniaturization of HF. Better understanding of the molecular mechanisms underlying the immune attack in AA will yield new drugs. New discoveries in HF neogenesis and low-level light therapy will undoubtedly have a role to play.

Enthalpy and void distributions in subchannels of PHWR fuel bundles

Energy Technology Data Exchange (ETDEWEB)

Park, J W; Choi, H; Rhee, B W [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1999-12-31

Two different types of the CANDU fuel bundles have been modeled for the ASSERT-IV code subchannel analysis. From calculated values of mixture enthalpy and void fraction distribution in the fuel bundles, it is found that net buoyancy effect is pronounced in the central region of the DUPIC fuel bundle when compared with the standard CANDU fuel bundle. It is also found that the central region of the DUPIC fuel bundle can be cooled more efficiently than that of the standard fuel bundle. From the calculated mixture enthalpy distribution at the exit of the fuel channel, it is found that the mixture enthalpy and void fraction can be highest in the peripheral region of the DUPIC fuel bundle. On the other hand, the enthalpy and the void fraction were found to be highest in the central region of the standard CANDU fuel bundle at the exit of the fuel channel. This study shows that the subchannel analysis is very useful in assessing thermal behavior of the fuel bundle that could be used in CANDU reactors. 10 refs., 4 figs., 2 tabs. (Author)

Enthalpy and void distributions in subchannels of PHWR fuel bundles

Energy Technology Data Exchange (ETDEWEB)

Park, J. W.; Choi, H.; Rhee, B. W. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1998-12-31

Two different types of the CANDU fuel bundles have been modeled for the ASSERT-IV code subchannel analysis. From calculated values of mixture enthalpy and void fraction distribution in the fuel bundles, it is found that net buoyancy effect is pronounced in the central region of the DUPIC fuel bundle when compared with the standard CANDU fuel bundle. It is also found that the central region of the DUPIC fuel bundle can be cooled more efficiently than that of the standard fuel bundle. From the calculated mixture enthalpy distribution at the exit of the fuel channel, it is found that the mixture enthalpy and void fraction can be highest in the peripheral region of the DUPIC fuel bundle. On the other hand, the enthalpy and the void fraction were found to be highest in the central region of the standard CANDU fuel bundle at the exit of the fuel channel. This study shows that the subchannel analysis is very useful in assessing thermal behavior of the fuel bundle that could be used in CANDU reactors. 10 refs., 4 figs., 2 tabs. (Author)

Protection of oxidative hair color fading from shampoo washing by hydrophobically modified cationic polymers.

Science.gov (United States)

Zhou, Y; Foltis, L; Moore, D J; Rigoletto, R

2009-01-01

regimen significantly outperforms commercial products that were tested containing a color protection claim. The proposed mechanism for the anti-fading action of hydrophobically modified polymers includes a cationic charge-reinforced hydrophobic barrier. This model is supported by evaluating the color fastness effect of several different polymer chemistries and by measuring hair surface hydrophobicity changes.

CANFLEX fuel bundle junction pressure drop

International Nuclear Information System (INIS)

Chung, H. J.; Chung, C. H.; Jun, J. S.; Hong, S. D.; Chang, S. K.; Kim, B. D.

1996-11-01

This report describes the junction pressure drop test results which are to used to determine the alignment angle between bundles to achieve the most probable fuel string pressure drop for randomly aligned bundles for use in the fuel string total pressure drop test. (author). 4 tabs., 17 figs