Search results for " head"
showing 10 items of 503 documents
Biochemical Factors and Mechanisms of Secondary Brain Damage in Cerebral Ischemia and Trauma
1992
A distinction between primary and secondary manifestations of brain damage from acute insults, such as trauma, or ischemia is not only of scientific interest but also of the highest clinical significance. After all, prevention of secondary brain damage in patients with severe head injury or cerebral ischemia is the ultimate purpose of treatment, including the measures of emergency care. It can be assumed that the secondary sequelae of head injury are as important for the outcome as the primary insult is. Therefore, it is obvious that development of more effective forms of treatment requires a better understanding of the mechanisms underlying secondary brain damage. Manifestations of seconda…
Occiput-spine relationship: shoulders are more important than head.
2017
BACKGROUND:To understand the role of fetal spine position in determining a fetal head position at the time of birth and modality of delivery. PATIENTS AND METHODS: This was a multicenter prospective observational study. Fetal occiput and spine position were evaluated by intrapartum ultrasound. Eighty-six women were eligible for inclusion in the study. Occiput rotational movements and modality of delivery in relation to the fetal spine position were investigated. RESULTS: At the beginning of labor, fetal occiput was in a posterior position in 52.3% of cases and, in 81.5% of cases the spine was in an anterior transverse position. At birth, occiput and spine were both in an anterior position i…
An enhanced random walk algorithm for delineation of head and neck cancers in PET studies
2017
An algorithm for delineating complex head and neck cancers in positron emission tomography (PET) images is presented in this article. An enhanced random walk (RW) algorithm with automatic seed detection is proposed and used to make the segmentation process feasible in the event of inhomogeneous lesions with bifurcations. In addition, an adaptive probability threshold and a k-means based clustering technique have been integrated in the proposed enhanced RW algorithm. The new threshold is capable of following the intensity changes between adjacent slices along the whole cancer volume, leading to an operator-independent algorithm. Validation experiments were first conducted on phantom studies:…
An assessment of the Beerkan method for determining the hydraulic properties of a sandy loam soil
2014
Abstract Establishing the ability of the Beerkan Estimation of Soil Transfer parameters (BEST) procedure to reproduce soil properties is necessary for specific soil types. In this investigation, the BEST predictions for a sandy loam soil were compared with water retention data obtained by a standard laboratory method and with the saturated soil hydraulic conductivity, K s , obtained by both the Wu et al. (1999) method, applied to the BEST infiltration data, and the Simplified Falling Head (SFH) technique. When the original BEST-slope algorithm with the infiltration constants fixed at β = 1.9 and γ = 0.79 was applied, the agreement between the predicted and the measured retention data was sa…
A test of the Beerkan Estimation of Soil Transfer parameters (BEST) procedure
2014
Abstract The Beerkan Estimation of Soil Transfer parameters (BEST) procedure is attractive for a simple soil hydraulic characterization but testing the ability of this procedure to estimate soil properties is necessary. The BEST predictions were compared with soil water retention and hydraulic conductivity data measured in the laboratory and the field, respectively, at ten Sicilian field sites. Provided that BEST yielded physically possible scale parameters of the soil characteristic curves in most of the four replicated infiltration runs at a site, the measured water retention was satisfactorily predicted (i.e., not statistically significant differences between measurements and predictions…
Internalizing problems are related to sleep patterns disordered in children affected by primary headache
2017
Introduction: Migraine is a common disorder in children and adolescents, associated with various disorders such as emotions, behavioral problems, and sleep disturbances. Aim of the study is to verify the relationship between psychological problems of cephalalgic patients and sleep disturbances. Materials and methods: 64 subjects (27 females), aged 8-12 years (mean 9.4 years, SD ± 1.03) with primary headache were enrolled. CBCL 6-18 scale and the SDSC scale were used for behavioral screening and for assessing sleep habits. Results: According to the ICHD-III criteria, the distribution of the headache subtype was as follows: headaches without aura (71.87%), headache episodes typical of tensio…
Advances in designing drip irrigation laterals
2018
It is known that using paired laterals, in which two distribution pipes extend in opposite directions from a common manifold, contribute to increasing water use efficiency (WUE). Recently, an analytical procedure to optimally design paired drip laterals on uniform slopes was proposed. More recently, this design procedure was simplified by deriving simple explicit relationships, as a function of 16 calibration constants, with relative errors that were less than 2%. In this paper, further simple design relationships are derived that require only 3 calibration constants, thus more readily obtainable results are produced and the influence of the flow rate and diameter exponents of resistance eq…
New-stage discharge relationships for free and submerged sluice gates
2012
Abstract The flow movement through a sluice gate is investigated for both free and submerged flow conditions. For free flow condition, the current dimensionless formula, indicated acceptable accuracy; while for submerged flow condition it was modified especially for low submerged condition. In this regard, Buckingham theorem along with the Incomplete Self-Similarity concept was employed and a new stage–discharge relationship was developed accordingly. Also, to achieve a suitable formula for submerged flow condition being accurate in low submergence, the maximum tailwater depth allowing the free flow condition and head loss factor were identified as missing parameters in the functional dimen…
Hydropower Potential in Water Distribution Networks: Pressure Control by PATs
2014
Pressure control is one of the main techniques to control leakages in Water Distribution Networks (WDNs) and to prevent pipe damage, improving the delivery standards of a water supply systems. Pressure reducing stations (PRSs) equipped by either pressure reducing valves or motor driven regulating valves are commonly used to dissipate excess hydraulic head in WDNs. An integrated new technical solution with economic and system flexibility benefits is presented which replaces PRSs with pumps used as turbines (PATs). Optimal PAT performance is obtained by a Variable Operating Strategy (VOS), recently developed for the design of small hydropower plants on the basis of valve time operation, and n…
Manual packing and soil reuse effects on determination of saturated hydraulic conductivity of a loam soil
2022
Abstract Performing laboratory measurement of saturated hydraulic conductivity, Ks, of sieved soil is important for many scientific purposes such as testing theories and methods to determine Ks. A given soil mass can be used only once or it can be reused after a previous use. Little is known on the dependence of the Ks measurements on both the applied packing method and the reuse of the same soil mass. This lack of knowledge makes comparisons among different investigations more or less uncertain. Four packing methods were tested on an initially dry loam soil by measuring Ks with the simplified falling head (SFH) technique. The four methods differed by the used compacting procedure (dropping…