Search results for " aqueduct"
showing 10 items of 12 documents
Spatial resolution of fMRI in the human parasylvian cortex: Comparison of somatosensory and auditory activation
2005
Abstract In spite of its outstanding spatial resolution, the biological resolution of functional MRI may be worse because it depends on the vascular architecture of the brain. Here, we compared the activation patterns of the secondary somatosensory and parietal ventral cortex (SII/PV) with that of the primary auditory cortex and adjacent areas (AI/AII). These two brain regions are located immediately adjacent to each other on opposite banks of the Sylvian fissure, and are anatomically and functionally distinct. In 12 healthy subjects, SII/PV was activated by pneumatic tactile stimuli applied to the index finger (0.5 cm 2 contact area, 4 bar pressure), and AI/AII by amplitude-modulated tones…
Abnormal BAEP and internal auditory canal MRI in intracranial hypotension
2017
Intracranial hypotension (IH) is a treatable condition due to cerebrospinal fluid leak, characterised by variable clinical and MRI findings.1 Positional headache, neck stiffness, hearing changes with subdural fluid collection, enhancement of meninges, engorgement of venous structures and brain sagging are among the most frequent clinical and MRI findings. Typical abnormalities are found in 68%–85% of patients1. Hearing alterations (ranging from misperception to severe hearing loss) are known clinical symptoms of IH.1 The mechanism involves secondary perilymph depression due to patency of the cochlear aqueduct, inducing a compensatory expansion of the endolymphatic compartment, decreasing ba…
Endoscopic aqueductoplasty through a tailored craniocervical approach.
2005
Object. Neuroendoscopy has an essential role in the management of occlusive hydrocephalus due to a membranous obstruction of the sylvian aqueduct. Well-known endoscopic methods include endoscopic third ventriculostomy (ETV) and endoscopic aqueductoplasty through a frontal burr hole. Building on their experience in the endoscopic management of hydrocephalus, the authors realized that not all of their patients with aqueductal obstruction were eligible for the aforementioned lines of treatment. Certain anatomical situations made it impossible to perform ETV or endoscopic aqueductoplasty through a frontal burr hole. Long-term complications of the shunt system led the authors to seek an alternat…
Intrafamilial variability of the deafness and goiter phenotype in Pendred syndrome caused by a T416P mutation in the SLC26A4 gene.
2004
AbstractPendred syndrome (PS) is the most common cause of syndromic deafness, accounting for more than 5% of all autosomal-recessive hearing loss cases. It is characterized by bilateral sensorineural hearing loss and by goiter with or without hypothyroidism. Mutations in the SLC26A4 gene cause both classical PS and deafness associated with an enlarged vestibular aqueduct without goiter.To investigate a possible genotype-phenotype correlation in PS, we performed a detailed clinical and genetic study in three adult German sibs with typical PS caused by a common homozygous SLC26A4 mutation, T416P. An audiological long-term follow-up of 23 yr showed that the mutation T416P is associated with a …
Carbonates from the ancient world's longest aqueduct:A testament of Byzantine water management
2021
The fourth‐ and fifth‐century aqueduct system of Constantinople is, at 426 km, the longest water supply line of the ancient world. Carbonate deposits in the aqueduct system provide an archive of both archaeological developments and palaeo‐environmental conditions during the depositional period. The 246‐km‐long aqueduct line from the fourth century used springs from a small aquifer, whereas a 180‐km‐long fifth‐century extension to the west tapped a larger aquifer. Although historical records testify at least 700 years of aqueduct activity, carbonate deposits in the aqueduct system display less than 27 years of operation. This implies that the entire system must have been cleaned of carbonate…
Inter-basin water transfer conflicts. The case of the Tagus-Segura Aqueduct (Spain)
2020
Since its inauguration in 1979, the Tagus-Segura Aqueduct has become one of the hydraulic infrastructures that have given rise to the highest number of inter-regional conflicts in Spain during recent decades. The aim of this paper is to analyse the political, social, environmental and economic conflicts presented in the donor (Tagus) and recipient (Segura) basins of this infrastructure. To this end, through the holding of interviews with the main stakeholders and an analysis of the regulations, an assessment has been made of the results (for and against) of those who defend maintaining this infrastructure, owing to its far-reaching social and economic impact, and those who advocate its imme…
Laminated carbonate deposits in Roman aqueducts: Origin, processes and implications
2013
Carbonate deposits in Roman aqueducts of Patara and Aspendos (southern Turkey) were studied to analyse the nature of their regular layering. Optical microscopy and electron-backscattered diffraction results show an alternation of dense, coarsely crystalline, translucent laminae composed of bundles and fans of elongate calcite crystals with their c-axes parallel to the long axis, and porous, fine-grained laminae with crystals at near-random orientation. The ?18O and ?13C data show a strong cyclicity and anti-correlation, whereby high and low ?18O values correspond to dense columnar and porous fine-grained laminae, respectively. Geochemical analyses show similar cyclic changes in carbonate co…
Long-Term Follow-Up of Repeat Endoscopic Third Ventriculostomy in Obstructive Hydrocephalus.
2017
Endoscopic third ventriculostomy (ETV) is a safe and less-invasive treatment strategy for patients with obstructive hydrocephalus and provides excellent outcome. Nevertheless, repeat ETV in cases of ETV failure is a controversial issue.Between 1993 and 1999, 113 patients underwent a total of 126 ETVs at the Department of Neurosurgery, Mainz University Hospital. Obstructive hydrocephalus was the causative pathology in all cases. A very long-term follow-up of up to 16 years could be achieved. All medical reports of patients who received ETV were reviewed and analyzed with focus on ETV failure with following repeat ETV and its initial as well as very long-term success.Thirty-one events of ETV …
Characterization of mortars from ancient and traditional water supply systems in Sicily
2008
Long aged mortars from ancient hydraulic constructions of Sicily, i.e. the Roman aqueduct of Thermae and the Punic cisterns and traditional water supply systems in Pantelleria, have been characterised by means of XRD analysis, optical microscopy and simultaneous thermal analysis to correlate the hydraulic properties to the texture and to their different role in the construction, i.e. lining, covering, roofing and joint mortars. According to a procedure proposed in the literature all of the samples, but two air hardening ones, show high hydraulicity, which somehow can be related to the characteristics of aggregates.
Le risorse idriche nel territorio di Alesa
2022
The contribution examines the complex archaeological data produced by the survey carried out in the region of Alesa, in an attempt to recognise the essential elements of the system of collection and distribution of water in rural settlements. The archaeological data are integrated with what can be obtained from the well-known ‘Table of Alesa’, and with other toponymical, environmental, morphological, and geological information. The results are compared with known data in areas with similar characteristics along the northern coast of Sicily.