101,928 research outputs found
3D-electrical resistivity tomography monitoring of salt transport in homogeneous and layered soil samples
No full textMonitoring transport of dissolved substances in soil deposits is particularly relevant where safety is concerned, as in the case of geo-environmental barriers. Geophysical methods are very appealing, since they cover a wide domain, localising possible preferential flow paths and providing reliable links between geophysical quantities and hydrological variables. This paper describes a 3D laboratory application of Electrical Resistivity Tomography (ERT) used to monitor solute transport processes. Dissolution and transport tests on both homogeneous and heterogeneous samples were conducted in an instrumented oedometer cell. ERT was used to create maps of electrical conductivity of the monitored domain at different time intervals and to estimate concentration variations within the interstitial fluid. Comparisons with finite element simulations of the transport processes were performed to check the consistency of the results. Tests confirmed that the technique can monitor salt transport, infer the hydro-chemical behaviour of heterogeneous geomaterials and evaluate the performances of clay barrier
Estimation of the hydraulic parameters of unsaturated samples by electrical resistivity tomography
No full textIn situ and laboratory experiments have shown that electrical resistivity tomography (ERT) is an effective tool to image transient phenomena in soils. However, its application in quantifying soil hydraulic parameters has been limited. In this study, experiments of water inflow in unsaturated soil samples were conducted in an oedometer equipped to perform three-dimensional electrical measurements. Reconstructions of the electrical conductivity at different times confirmed the usefulness of ERT for monitoring the evolution of water content. The tomographic reconstructions were subsequently used in conjunction with a finite-element simulation to infer the water retention curve and the unsaturated hydraulic conductivity. The parameters estimated with ERT agree satisfactorily with those determined using established techniques, hence the proposed approach shows good potential for relatively fast characterisations. Similar experiments could be carried out on site to study the hydraulic behaviour of the entire soil deposi
Assistive products and childhood neurodisability: a retrospective study on factors associated with aids/orthoses prescription
No full textBACKGROUND: Children affected by pathologies causing neurodisability go through motor, cognitive, sensory and other limitations. The selection of assistive products can influence their level of independence and quality of life. AIM: The present study investigated the possibility to assess the equipment needs of children with neurodisabilities, based on their clinical characteristics. DESIGN: A retrospective observational study. SETTING: Outpatients. POPULATION: Inclusion criteria: diagnosis of cerebral palsy or genetic/chromosomal/syndromic disorders, age range 0-18 years, intelligence quotient evaluation, medical history of positive or negative presence of epilepsy and of communication disorders, admission at our neurorehabilitation service between 2007 and 2017, and registration of all equipment prescribed to each child. METHODS: In 192 children (111 males, 57.81%) we evaluated the relationship between several independent variables (diagnosis, sex, Gross Motor Function Classification System level, intelligence quotient, history of epilepsy and communication disorders) and equipment prescription by means of logistic regression models. RESULTS: Our data showed significant correlation between the Gross Motor Function Classification System level and the equipment prescribed. A history of seizures was negatively correlated with walker prescriptions (the log odds of prescription decreases by -2.156; CI: -4.16 to -0.65) and positively with those of stroller (the log odds increases by 1.427; CI: 0.22 to 2.69). Stroller and knee-ankle-foot orthoses and hip-knee-ankle-foot orthoses prescriptions were negatively correlated with the cerebral palsy diagnosis. The prescription of foot orthoses was positively correlated with mental retardation (the log odds increases by 0.358; CI: 0.12 to 0.61). A negative correlation between communication disorders and the prescription of ankle-foot orthoses and communication/learning devices was also found (the log odds decreases by -0.833; CI -1.66 to -0.01). CONCLUSIONS: Several clinical characteristics correlate with specific equipment needs. CLINICAL REHABILITATION IMPACT: The definition of the clinical characteristics with a potential predicting value, may facilitate the task of physician on choosing what is more appropriate to prescribe, as well as the authorizing office responsible for evaluating the appropriateness of prescriptions. Furthermore, it could be possible to foresee the care needs in terms of type and number of aids/orthoses and to guarantee every disabled child the possibility to take advantage of the same opportunities. (Cite this article as: Assenza C, Cacciatore D, Manica M, Iosa M, Foti C, Gobbetti T, et al. Assistive products and childhood neurodisability: a retrospective study on factors associated with aids/orthoses prescription
On the evaluation of the horizontal forces produced by grain-like material inside silos during earthquakes
No full textThis paper presents analytical developments devoted to the evaluation of the effective behaviour of grain in flat-bottom silos during an earthquake. This research work starts from all the same basic assumptions of Eurocode 8 except for the one regarding the horizontal shear forces among consecutive grains. Only this difference leads to a new physically-based evaluation of the effective mass of the grain which horizontally pushes on the silo walls. The analyses are developed by simulating the earthquake ground motion with time constant vertical and horizontal accelerations and are carried out by means of simple dynamic equilibrium equations that take into consideration the specific mutual actions developing in the ensiled grain. The findings indicate that, in case of squat silos (characterized by low, but usual, height/diameter slenderness ratios), the portion of the grain mass that interacts with the silo walls turns out to be noticeably smaller than the total mass of the grain in the silo and the effective mass adopted by Eurocode 8
Letter, [Author unclear] to Paulina T. Merritt
No full textHandwritten letter to Paulina Merritt from an unknown author, October 1, 1876.
Invitro Cardiac-performance In Octopus-vulgaris (lam)
No full textAbstract
1. The in vitro cardiac performance of Octopus vulgaris (Lam) was studied with a new technique that allows perfusion of the ventricle via both the auricles and measurement of coronary efflux.
2. The coronary efflux increases with both preload and Δ load, while the stroke volume increases with preload up to 20 cm of water and decreases with Δ load.
3. The beat rate depends on the preload only.
4. The drugs assayed (acetylcholine, 5-hydroxytryptamine and adrenaline) affect both heart rate and pulse amplitude. The observation that high frequencies are associated with negative inotropic effects explains some results reported in vitro by others
Preliminary diagnostic guidelines for macrophage activation syndrome complicating systemic juvenile idiopathic arthritis.
No full textPRELIMINARY DIAGNOSTIC GUIDELINES FOR MACROPHAGE ACTIVATION SYNDROME COMPLICATING SYSTEMIC JUVENILE IDIOPATHIC ARTHRITIS
ANGELO RAVELLI, SILVIA MAGNI-MANZONI, ANGELA PISTORIO, CRISTINA BESANA, TIZIANA FOTI, NICOLINO RUPERTO, STEFANIA VIOLA, ALBERTO MARTINI
Objective To develop diagnostic guidelines for macrophage activation syndrome (MAS) complicating systemic juvenile idiopathic arthritis (S-JIA).
Study design We followed the classification criteria approach that is based on the comparison of patients with the index disease with patients with a ‘‘confusable’’ disease. The former group included 74 patients with S-JIA-associated MAS reported in the literature or seen by the authors; the latter group included 37 patients with S-JIA who had 51 instances of ‘‘high disease activity’’ seen by the authors. The relative power of clinical, laboratory, and histopathologic variables in discriminating patients
with MAS from patients with high disease activity was evaluated by calculating the sensitivity rate, specificity rate, area under the receiver operating characteristic curve, and diagnostic odds ratio (DOR). The combinations of variables that led to best separation between patients and control subjects were identified through ‘‘the number of criteria present’’ method.
Results The strongest clinical discriminators were hemorrhages (DOR = 67) and central nervous system dysfunction (DOR = 63); the strongest laboratory discriminators were decreased platelet count (DOR = 1092), increased aspartate aminotransferase (DOR = 247), leukopenia (DOR = 70), and hypofibrinogenemia (DOR = 165). The best separation between patients and control subjects occurred when any 2 or more laboratory criteria (DOR = 1309) were simultaneously present; the second best performance was provided by the presence of any 2, 3, or more clinical and/or laboratory criteria (DOR = 765 and 743, respectively).
Conclusion We identified preliminary diagnostic guidelines for MAS complicating S-JIA. These guidelines deserve prospective validation.
J Pediatr 2005;146:598-60
Mesoterapia antalgica versus esercizio terapeutico nel trattamento del dolore cervicale cronico
No full text- …
