1,460 research outputs found

    The somatotopy of the spinal cord: a comprehensive descrption.

    Get PDF
    For the benefit of medical students, in this paper we examine the somatotopic organization of the spinal cord, which shows a similar organization in mammalians. The dorsal horn is comprised of sensory nuclei with deutoneurons; the lateral horn contains preganglionic visceral motoneurons; the ventral horn is subdivided into a medial column innervating the paravertebral muscles, a central column, C3-C6, innervating the diaphragm, and a lateral column innervating the limb muscles. In the lateral column of the ventral horn, the dorsal motoneuron groups innervate the intrinsc arm muscles; the dorsal posterior motoneuron groups innervate hand muscles; the lateroventral motoneuron groups innervate the shoulder. Furthermore, the rostral and caudal motoneuron groups innervate the proximal and the distal muscles, respectively. In cat spinal cord, the medial columns 1-2 innervate the paravertebral muscles, and columns 3-6 are divisible into groups, each innervating specific muscle groups. In human spinal cord, 11 motor columns have been identified: column 1 is located in the medial part and columns 2-11 in the lateral part of the ventral horn. Columns 1-2 extend to S3, while columns 3-8 are confined to the cervical and T1 segments, and columns 9-11 are situated in the lumbosacral segments

    Atrial natriuretic peptide (ANP) and oxytocin-expression in the adult and mouse cerebellum

    Get PDF
    Abstract Background: Many studies are in the literature on the ANP and oxytocin-presence in the brain, but very few studies with controversial results are reported on the presence of these peptides in the cerebellum. This immunohistochemical study investigates on the ANP and oxytocin-presence in the cerebellum of the adult rat and mouse rodents. Results: This study, firstly, evidences the ANP- immunopositivity in cerebellar cortex of both rat and mouse rodents. In rat the molecular layer presents some few immunopositive fibers, but no neuron resulted immunopositive; the granular and Purkinje cells are immunopositive. In mouse the cerebellar cortex ANP-immunopositivity is present in all layers. The oxytocin-presence in the rat the afferent fibers are immunopositive are in the granular layer; in mouse the OT-immunopositivity is in the molecular layer only. Conclusions: This study, firstly, shows that ANP and OT are present in the cerebellar cortex both in rat and mouse rodents. In the mouse cerebellar cortex ANP-presence is more diffuse and OT- localization differences in the two species

    SOMATOTOPIC ORGANIZATION OF THE CRANIAL NERVE NUCLEI INVOLVED IN EYE MOVEMENTS: III, IV, VI.

    Get PDF
    The oculomotor nucleus is divided into: 1. somatic medial column innervating the superior rectus muscle and somatic lateral column, further subdivided into a lateral column innervating the inferior rectus, inferior oblique and medial rectus muscles; 2. central nucleus innervating the levator palpebrae superioris muscle; 3. visceral nucleus innervating the pupillary sphincter muscle, consisting of the following two groups of neurons: cholinergic, preganglionic neurons supplying the ciliary ganglion, termed the Edinger- Westphal preganglionic (EWpg) neuron population, and the centrally projecting, peptidergic neurons, termed the Edinger-Westphal centrally projecting (EWcp) population. A detailed understanding of the position of both nuclei and their subgroups supplying the individual muscles is an essential prerequisite for eye movement assessment, offering a simple clinical method for diagnosing eventual dysfunctions of eye movement generation pathways

    Oxytocin and vasopressin expression in the turbinates of patients with chronic sinusitis

    Get PDF
    Many peptides are present in the nasal mucosa, but few studies have investigated the presence or absence of the oxytocin and vasopressin peptides. This immunohistochemical study on the inferior turbinates of patients affected by chronic sinusitis shows, for the first time, that these peptides are present in the epithelium of both nasal mucosa and glands. Their presence could be related to the presence of atrial natriuretic peptide (ANP), like previously demonstrated in other organs such as heart and prostate, since in some circumstances they play in antagonism

    A hierarchical scheduling model for component-based real-time systems

    Get PDF
    In this paper, we propose a methodology for developing component-based real-time systems based on the concept of hierarchical scheduling. Recently, much work has been devoted to the schedulability analysis of hierarchical scheduling systems, in which real-time tasks are grouped into components, and it is possible to specify a different scheduling policy for each component. Until now, only independent components have been considered. In this paper, we extend this model to tasks that interact through remote procedure calls. We introduce the concept of abstract computing platform on which each component is executed. Then, we transform the system specification into a set of real-time transactions and present a schedulability analysis algorithm. Our analysis is a generalization of the holistic analysis to the case of abstract computing platforms. We demonstrate the use of our methodology on a simple example

    AQuoSA - adaptive quality of service architecture

    Get PDF
    This paper presents an architecture for quality of service (QoS) control of time-sensitive applications in multi-programmed embedded systems. In such systems, tasks must receive appropriate timeliness guarantees from the operating system independently from one another; otherwise, the QoS experienced by the users may decrease. Moreover, fluctuations in time of the workloads make a static partitioning of the central processing unit (CPU) that is neither appropriate nor convenient, whereas an adaptive allocation based on an on-line monitoring of the application behaviour leads to an optimum design. By combining a resource reservation scheduler and a feedback-based mechanism, we allow applications to meet their QoS requirements with the minimum possible impact on CPU occupation. We implemented the framework in AQuoSA (Adaptive Quality of Service Architecture (AQuoSA). http://aquosa.sourceforge.net), a software architecture that runs on top of the Linux kernel. We provide extensive experimental validation of our results and offer an evaluation of the introduced overhead, which is perfectly sustainable in the class of addressed applications

    Indagini briologiche in aree urbane: diversità briofitica dei centri abitati di Erice (Trapani) e Belmonte Mezzagno (Palermo).

    Get PDF
    Bryologic surveys in urban areas: bryophyte diversity of the population centers of Erice (province of Trapani) and Belmonte Mezzagno ((province of Palermo). The bryophytic flora of the towns of Erice (Trapani) and Belmonte Mezzagno (Palermo) have been studied. The first consists of 53 taxa (42 mosses and 11 liverwort), two of which are new for the province of Trapani, the second of 40 taxa (38 mosses and 2 liverworts), one of which new for the province of Palermo. A comparison between the studied bryofloras and those of other Sicilian urban areas shows that Erice’s bryophytic flora is, given its size, rich in species and families

    Determining the sign of Δ31\Delta_{31} at long baseline neutrino experiments

    Full text link
    Recently it is advocated that high intensity and low energy (Eν2GeV)(E_\nu \sim 2 GeV) neutrino beams should be built to probe the (13)(13) mixing angle ϕ\phi to a level of a few parts in 10410^4. Experiments using such beams will have better signal to background ratio in searches for νμνe\nu_\mu \to \nu_e oscillations. We propose that such experiments can also determine the sign of Δ31\Delta_{31} even if the beam consists of {\it neutrinos} only. By measuring the νμνe\nu_\mu \to \nu_e transitions in two different energy ranges, the effects due to propagation of neutrinos through earth's crust can be isolated and the sign of Δ31\Delta_{31} can be determined. If the sensitivity of an experiment to ϕ\phi is ϵ\epsilon, then the same experiment is automatically sensitive to matter effects and the sign of Δ31\Delta_{31} for values of ϕ2ϵ\phi \geq 2 \epsilon.Comment: Title changed and paper rewritten. 4 pages, 1 figure, revte

    Matter effects in long baseline experiments, the flavor content of the heaviest (or lightest) neutrino and the sign of Delta m^2

    Full text link
    The neutrinos of long baseline beams travel inside the Earth's crust where the density is approximately rho = 2.8 g cm^-3. If electron neutrinos participate in the oscillations, matter effects will modify the oscillation probabilities with respect to the vacuum case. Depending on the sign of Delta m^2 an MSW resonance will exist for neutrinos or anti-neutrinos with energy approximately E_nu(res) = 4.7 |\Delta m^2|/(10^-3 eV^2) GeV. For Delta m^2 in the interval indicated by the Super-Kamiokande experiment this energy range is important for the proposed long baseline experiments. For positive Delta m^2 the most important effects of matter are a 9% (25%) enhancement of the transition probability P(nu_mu -> nu_e) for the KEK to Kamioka (Fermilab to Minos and CERN to Gran Sasso) beam(s) in the energy region where the probability has its first maximum, and an approximately equal suppression of P(antinu_mu -> antinu_e). For negative Delta m^2 the effects for neutrinos and anti-neutrinos are interchanged. Producing beams of neutrinos and antineutrinos and measuring the oscillation probabilities for both (nu_mu -> nu_e) and (antinu_mu -> antinu_e) transitions can solve the sign ambiguity in the determination of Delta m^2.Comment: Latex, 28 pages, 12 postscript figure

    Atmospheric neutrino flux supported by recent muon experiments

    Get PDF
    We present a new one-dimensional calculation of low and intermediate energy atmospheric muon and neutrino fluxes, using up-to-date data on primary cosmic rays and hadronic interactions. We study several sources of uncertainties relevant to our calculations. A comparison with the muon fluxes and charge ratios measured in several modern balloon-borne experiments suggests that the atmospheric neutrino flux is essentially lower than one used for the standard analyses of the sub-GeV and multi-GeV neutrino induced events in underground detectors.Comment: 23 pages, 7 figures, 2 tables. Typos corrected, figure layout improved, references added. Final version accepted for publication in PL
    corecore