Search results for "Hair"

Sex and MC1R variants in human pigmentation: Differences in tanning ability and sensitivity to sunlight between sexes

2016

‘It’s not a part of me, but it is what it is’: the struggle of becoming en-wheeled after spinal cord injury

2019

Many people who experience spinal cord injury become long-term wheelchair users. This article addresses the process of becoming en-wheeled through the case example of a disabled man called Patrick.An intrinsic case study informed by posthumanist developments was used. Within this design, Patrick and his manual wheelchair were the entangled participants of the inquiry.Interviews and fieldwork observation with Patrick were conducted. Qualitative data were analysed using the posthumanist notion of 'assemblages'.The results illuminate Patrick's struggle of negotiating a new embodied selfhood that includes the wheelchair. Patrick engaged in ableist rehabilitation after spinal cord injury to recu…

Histochemical localization of calcium ATPase in the cochlea of the guinea pig

1992

The activity of Ca(2+)-ATPase in the inner ear of the guinea pig was studied ultracytochemically by the lead citrate reaction. The electron-dense reaction products as an expression of Ca(2+)-ATPase activity were localized in endolymphatic cells of Reissner's membrane, in outer and inner hair cells and in some supporting cells. The main finding was the difference in the localization of Ca(2+)-ATPase in outer and inner hair cells. In the latter cells the activity sites were mainly intracellular and in apical membrane specializations, whereas in the outer hair cells the enzyme was localized in the apical membrane specializations and the basolateral plasma membrane.

Coverage intervals for trace elements in human scalp hair are site specific.

2014

Coverage intervals for trace elements in human scalp hair commonly provide the basis for interpreting laboratory results and also in comparative decision-making processes regarding exposure risk assessment. This short communication documents, by some examples, that those computed for human hair are to be considered site specific, as they reflect local environmental conditions; also each geographic area has a typical profile of hair elemental composition of its inhabitants. Therefore, the levels of trace elements in hair are not strictly comparable between different areas of the world. This issue is particularly relevant when identification of anomalous environmental exposures are requested …

Concentration and reference interval of trace elements in human hair from students living in Palermo, Sicily (Italy).

2010

Trace element contents in specimens of hair collected from 137 children aged 11–13 years old, living in Palermo (Sicily, Italy) were determined by ICP-MS. This work reports analytical data for the following 19 elements: Al, As, Ba, Cd, Co, Cr, Cu, Li, Mn, Mo, Ni, Pb, Rb, Sb, Se, Sr, U, V and Zn. The most abundant chemical elements were zinc and copper (Zn > Cu), with concentrations exceeding 10microg/g (Zn = 189.2microg/g; Cu= 22.9microg/g). Other elements with concentrations greater than 1microg/g were, in order of abundance, Al > Sr > Ba > Pb. The remaining elements were all below 1microg/g. The average elemental concentrations in hair were statistically compared by Kolmogorov–Smirnov’s t…

Trace elements in scalp hair of children living in differing environmental contexts in Sicily (Italy)

2012

We present here data about trace elements in human scalp hair samples to test whether they are valuable to reflect environmental exposure and contamination by trace elements. The study compares contents of trace elements in scalp hair from a total of 336 children, aged 11–13 years old, living in various geographical areas of Sicily (southern Italy) characterized by differing environmental conditions. Nineteen elements (Al, As, Ba, Cd, Co, Cr, Cu, Li, Mn, Mo, Ni, Pb, Rb, Sb, Se, Sr, U, V and Zn) were determined by inductively coupled plasma mass spectrometry (ICP-MS). Coverage intervals (CI) formulated by the elemental composition of hair samples from the Palermo subjects were compared with …

Investigating individual stress reactivity: High hair cortisol predicts lower acute stress responses

2020

Identifying individual differences in stress reactivity is of particular interest in the context of stress-related disorders and resilience. Previous studies already identified several factors mediating the individual stress response of the hypothalamus-pituitary-adrenal axis (HPA). However, the impact of long-term HPA axis activity on acute stress reactivity remains inconclusive. To investigate associations between long-term HPA axis variation and individual acute stress reactivity, we tested 40 healthy volunteers for affective, endocrine, physiological, and neural reactions to a modified, compact version of the established in-MR stress paradigm ScanSTRESS (ScanSTRESS-C). Hair cortisol con…

Increased radiation from Chernobyl decreases the expression of red colouration in natural populations of bank voles (Myodes glareolus)

2014

AbstractPheomelanin is a pink to red version of melanin pigment deposited in skin and hair. Due to its bright colour, pheomelanin plays a crucial function in signalling, in particular sexual signalling. However, production of pheomelanin, as opposed to its dark alternative, eumelanin, bears costs in terms of consumption of antioxidants important for protection of DNA against naturally produced reactive oxidative species. Therefore, decreased expression of pheomelanin is expected in organisms exposed to severe oxidative stress such as that caused by exposure to chronic ionizing radiation. We tested if variable exposure to radiation among natural populations of bank voles Myodes glareolus in …

Penalized linear discriminant analysis and Discrete AdaBoost to distinguish human hair metal profiles: The case of adolescents residing near Mt. Etna

2016

The research focus of the present paper was twofold. First, we tried to document that human intake of trace elements is influenced by geological factors of the place of residence. Second, we showed that the elemental composition of human hair is a useful screening tool for assessing people's exposure to potentially toxic substances. For this purpose, we used samples of human hair from adolescents and applied two robust statistical approaches. Samples from two distinct geological and environmental sites were collected: the first one was characterized by the presence of the active volcano Mt. Etna (ETNA group) and the second one lithologically made up of sedimentary rocks (SIC group). Chemica…

Trace elements in scalp hair of children chronically exposed to volcanic activity (Mt. Etna, Italy)

2014

Abstract The aim of this survey was to use scalp hair as a biomonitor to evaluate the environmental exposure to metals and metalloids of schoolchildren living around the Mt. Etna area, and to verify whether the degree of human exposure to trace elements is subject to changes in local environmental factors. Twenty trace elements were determined in 376 samples of scalp hair from schoolboys (11–13 years old) of both genders, living in ten towns located around the volcanic area of Mt. Etna (Sicily). The results were compared with those (215 samples) from children living in areas of Sicily characterized by a different geological setting (reference site). As, U and V showed much higher concentrat…