Search results for "Hair"
showing 10 items of 348 documents
Direct evidence for positive selection of skin, hair, and eye pigmentation in Europeans during the last 5,000 y
2014
Significance Eye, hair, and skin pigmentation are highly variable in humans, particularly in western Eurasian populations. This diversity may be explained by population history, the relaxation of selection pressures, or positive selection. To investigate whether positive natural selection is responsible for depigmentation within Europe, we estimated the strength of selection acting on three genes known to have significant effects on human pigmentation. In a direct approach, these estimates were made using ancient DNA from prehistoric Europeans and computer simulations. This allowed us to determine selection coefficients for a precisely bounded period in the deep past. Our results indicate t…
Genome-wide association analysis on normal hearing function identifies PCDH20 and SLC28A3 as candidates for hearing function and loss.
2015
Hearing loss and individual differences in normal hearing both have a substantial genetic basis. Although many new genes contributing to deafness have been identified, very little is known about genes/variants modulating the normal range of hearing ability. To fill this gap, we performed a two-stage meta-analysis on hearing thresholds (tested at 0.25, 0.5, 1, 2, 4, 8 kHz) and on pure-tone averages (low-, medium-and high-frequency thresholds grouped) in several isolated populations from Italy and Central Asia (total N = 2636). Here, we detected two genome-wide significant loci close to PCDH20 and SLC28A3 (top hits: rs78043697, P = 4.71E-10 and rs7032430, P = 2.39E-09, respectively). For both…
Histological and electron microscopical observations on the effects of lead on gills and midgut gland ofProcambarus clarkii
1991
Adult intermolt specimen of Procambarus clarkii (Crustacea, Decapoda) have been treated for 96 hours in aquaria with 100mg/l of lead. The gills and midgut gland were processed and studied in the electron microscope. The gill filament shows important changes in the ultrastructure of the epithelial cells and the cuticle. The hepatopancreatic cells studied (i.e. the vacuolated and dark cells) do not show noticeable structural changes but accumulate lead (electrondense precipitates) mainly in lysosomes.
Adhesive root hairs facilitate Posidonia oceanica seedling settlement on rocky substrates
2015
Posidonia oceanica, the dominant Mediterranean seagrass, has been historically described as a species typically growing on mobile substrates whose development requires precursor communities. During more than 10 years of direct observations, we noticed that P. oceanica seedlings were often firmly anchored to rocky reefs, even at exposed sites. Thus, we analysed the ultrastructural features of seedling root systems to identify specific traits that may represent adaptations for early seedling anchorage on rocky bottoms. Subapical sections of adventitious roots were obtained from 2-3 months old specimens collected in the field and were observed at SEM revealing an extensive coverage of adhesive…
Trace elements in hair of urban schoolboys: a diagnostic tool in environmental risk assessment.
2011
Hair analysis may represent a means to quantify the relationship between human exposure to metal contamination and the environmental conditions of workplaces or residence sites. Hair are stable and their composition does not change over short time period. Furthermore, sampling procedure is very easy, requires no specific professional skills, is painless and non-invasive. 334 hair samples were collected from Caucasian children 11-13 years old, of both genders, without colored or treated hair, living in several Sicilian towns characterized by different geochemical environments: urban (Palermo), volcanic (Etna), mining area (Antillo-Fiumedinisi), industrial site (Pace del Mela), uncontamined a…
�ber Ver�nderungen im Hautbindegewebe w�hrend des Haarwachstumscyclus bei der Maus
1959
Es wird uber das Verhalten der interfibrillaren Grundsubstanz wahrend des Haarcyclus bei der weisen Albinomaus berichtet. Der Gehalt an Hale-reaktivem interfibrillarem Material im Corium ist gering wahrend der Ruhephase (Telogen) und nimmt deutlich zu mit Beginn der Phase des aktiven Haarwachstums (Anagen). Strukturveranderungen des Hale-reaktiven Materials lassen eine Anderung des Polymerisationsgrades der interfibrillaren Grundsubstanz vermuten. Auffallig ist der Reichtum Hale-reaktiver Substanzen zwischen den Fettzellen des subcutanen Fettgewebes wahrend der Anagenperiode. Auch im morphologischen Verhalten der cutanen Kollagenfasern konnen Anderungen wahrend des Haarcyclus festgestellt w…
Coverage intervals for trace elements in human scalp hair are site and also gender-specific
2015
Hair analysis is a powerful tool for assessing human exposure to metals and metalloids (MM). The basis for interpreting laboratory results lie on the use of coverage intervals (CI), computed between the 0.025 and 0.975 fractiles, from a well-defined group of reference individuals reflecting normal and healthy people. A critical point in efficient use of CI, when used for comparative decision-making processes, forensic and clinic considerations, is constituted by confounding factors as the specific living site of study population and gender of participants. Our study aims to demonstrate that hair levels of trace elements are site specific and also gender specific. We have taken into account …
Sovereign Debt Litigation in Argentina: Implications of the Pari Passu Default
2015
On 31 July 2014, Argentina defaulted on its sovereign bonds for the second time in the 21st century. It was also its eighth default since independence1; at such frequency, this was perhaps not an especially noteworthy event. What made it so extraordinary was not that another domestic financial crisis triggered the payment default, but rather an injunction handed down by a federal district court in New York. However, despite public outrage, the wider impact of this decision is likely to be limited. That is even more so if reforms that have already started continue to be implemented. The case dates back to Christmas Eve 2001, when the interim Saa administration declared a payment suspension o…
Oral leukoplakia; a proposal for simplification and consistency of the clinical classification and terminology
2019
There is a distinct lack of uniformity in the definitions and clinical terminologies related to oral leukoplakia and leukoplakialike lesions and disorders. Proposals have been put forward to subclassify leukoplakia into a homogeneous and a non-homogeneous type based on color only, being either predominantly white or mixed white-and-red, respectively, irrespective of the texture of the lesion. In this proposal there is no need anymore to regard the poorly defined proliferative verrucous leukoplakia as a separate entity. Since keratosis is primarily a histopathological term, its clinical use is discouraged. Alternative terminology for these so-called keratotic lesions and disorders has been p…
Knowledge, attitudes and risk of HIV, HBV and HCV infections in hairdressers of Palermo city (South Italy)
2009
Background: The hairdressing trade may potentially expose its practitioners and their customers to blood-borne infections. Methods: Knowledge, attitudes and behaviours towards occupational risk of HIV, HBV and HCV infections were evaluated in a cross-sectional survey, conducted during spring 2008, in 105 out of 112 randomly selected hairdressers of Palermo. Participants were queried by answering to an anonymous questionnaire. Results: Most of hairdressers (93.3%) knew that HIV and hepatitis are transmitted through parenteral route and could also be transmitted by razors. The availability of gloves was inadequate, up to 30% of the participants never used them and up to 50% usually reused the…