1,578 research outputs found
Liquid actuated gravity experiments
We describe a new actuation technique for gravity experiments based on a
liquid field mass. The Characterizing idea is to modulate the gravity force
acting on a test mass by controlling the level of a liquid in a suitable
container. This allows to obtain a periodical gravity force without moving
parts (except the liquid level) close to the TM. We describe in detail the most
relevant aspects of the liquid actuator and discuss how it can be used in
gravity experiments. In particular we analyse an application to test the
inverse square law in the mm to cm distance region
Lower urinary tract symptoms and benign prostatic hyperplasia and their impact on quality of life
LUTS is an acronym that refers to symptoms affecting the lower urinary tract, which are very common in elderly subjects (between 60 and 70%), and often associated with, but not always caused by, benign prostatic hypertrophy (BPH). BPH is a chronic condition characterized by an increase in the number of cells, particularly in the transition area of the prostate. BPH involves a compression of the surrounding tissues, consequently obstructing vescical voiding. Nycturia and urgency represent the most prevalent symptoms and those with the greatest impact on quality of life measured as urinary-specific health-related quality. The prevalence of BPH is directly proportional to age; therefore, the absolute number of subjects affected is growing throughout the world. BPH is one of the most common medical conditions affecting those over 50. The overall cost for the diagnosis and treatment of BPH-related LUTS, in the US, has been estimated at approximately 1.1 billion US$/year, compared to total annual expenditure for urological conditions of some 9 billion and this cost continues to increase. The quick prostate test, which was developed by the Italian Urology Society (SIU), is an easy to use instrument that can be utilized in first-level screening for evaluation of the male population with LUTS. This test can be used both in patients not on pharmacological treatment and as a therapy-monitoring instrument. A positive response to one of the questions is sufficient for requesting a more in-depth investigation, which may provide indications on the therapeutic strategy to be taken
Design criteria and 3D FEM modeling of air hole photonic crystal
This work presents a detailed numerical Finite Element Method FEM modeling for passive optical components such as photonic crystals (PhCs). The accurate modeling characterizes the PhCs structures by considering the field resonance and the radiation behavior of the periodic pattern. The frequency responses at each side of the photonic crystal are evaluated by considering the 3D periodic structure enclosed in a black box with six input/output ports. This scattering matrix approach (SMA) is useful in order to evaluate in plane and vertical PhCs the resonance of the photonic crystal. Through the analysis of all the frequency responses we characterize the passband regions and the stopband regions of the PhC slab
The Emerging Role of Altered D-Aspartate Metabolism in Schizophrenia: New Insights From Preclinical Models and Human Studies
Besides D-serine, another D-amino acid with endogenous occurrence in the mammalian brain, D-aspartate, has been recently shown to influence NMDA receptor (NMDAR)-mediated transmission. D-aspartate is present in the brain at extracellular level in nanomolar concentrations, binds to the agonist site of NMDARs and activates this subclass of glutamate receptors. Along with its direct effect on NMDARs, D-aspartate can also evoke considerable L-glutamate release in specific brain areas through the presynaptic activation of NMDA, AMPA/kainate and mGlu5 receptors. D-aspartate is enriched in the embryonic brain of rodents and humans and its concentration strongly decreases after birth, due to the post-natal expression of the catabolising enzyme D-aspartate oxidase (DDO). Based on the hypothesis of NMDAR hypofunction in schizophrenia pathogenesis, recent preclinical and clinical studies suggested a relationship between perturbation of D-aspartate metabolism and this psychiatric disorder. Consistently, neurophysiological and behavioral characterization of Ddo knockout (Ddo−/−) and D-aspartate-treated mice highlighted that abnormally higher endogenous D-aspartate levels significantly increase NMDAR-mediated synaptic plasticity, neuronal spine density and memory. Remarkably, increased D-aspartate levels influence schizophrenia-like phenotypes in rodents, as indicated by improved fronto-hippocampal connectivity, attenuated prepulse inhibition deficits and reduced activation of neuronal circuitry induced by phencyclidine exposure. In healthy humans, a genetic polymorphism associated with reduced prefrontal DDO gene expression predicts changes in prefrontal phenotypes including greater gray matter volume and enhanced functional activity during working memory. Moreover, neurochemical detections in post-mortem brain of schizophrenia-affected patients have shown significantly reduced D-aspartate content in prefrontal regions, associated with increased DDO mRNA expression or DDO enzymatic activity. Overall, these findings suggest a possible involvement of dysregulated embryonic D-aspartate metabolism in schizophrenia pathophysiology and, in turn, highlight the potential use of free D-aspartate supplementation as a new add-on therapy for treating the cognitive symptoms of this mental illness
The comparative analysis of Mediterranean coastal communities: six case studies
The aim of this study is to promote cooperation and actions for the benefit of coastal communities on the Southern and Eastern shores of the Mediterranean region by adopting an approach that integrates environmental, economic and social dimensions. These areas are traditionally based on Fisheries, especially small-scale fisheries (SSFs), which contribute to strengthen social cohesion, in that the seafood value chains still represent the backbone of the coastal economy. The six coastal communities analysed in this paper are located in Algiers port - Casbah (Algeria), Marsa Matrouh (Egypt), Tricase (Italy), Tyre (Lebanon), Nador Lagoon (Morocco), Zarzis (Tunisia). Conclusions emphasise the need to develop a comprehensive reference system for dialogue, cooperation and capacity building both at national and regional level. The cluster approach can help create a favourable cooperation and competition environment, generating income and employment opportunities for local communities.Le but de cette \ue9tude est de promouvoir la coop\ue9ration et des actions en faveur des communaut\ue9s c\uf4ti\ue8res sur les rives Sud et Est de la M\ue9diterran\ue9e, en adoptant une approche qui int\ue8gre les dimensions environnementale, \ue9conomique et sociale. Cette r\ue9gion est traditionnellement ax\ue9e sur la p\ueache, et notamment la petite p\ueache, qui contribue \ue0 renforcer la coh\ue9sion sociale, car les cha\ueenes de valeur des produits de la mer constituent encore la colonne vert\ue9brale de l\u2019\ue9conomie c\uf4ti\ue8re. Les six communaut\ue9s c\uf4ti\ue8res examin\ue9es dans ce travail sont situ\ue9es \ue0 la Casbah- port d\u2019Alger (Alg\ue9rie), \ue0 Marsa Matrouh (Egypte), \ue0 Tricase (Italie), Tyre (Liban), dans la lagune de Nador (Maroc) et \ue0 Zarzis (Tunisie). Dans les conclusions, l\u2019accent est mis sur l\u2019importance de structurer un syst\ue8me de r\ue9f\ue9rence global pour encourager le dialogue, la coop\ue9ration et le d\ue9veloppement des capacit\ue9s \ue0 l\u2019\ue9chelle nationale et r\ue9gionale. Le mod\ue8le du cluster pourrait contribuer \ue0 cr\ue9er un environnement de coop\ue9ration et comp\ue9tition favorable, g\ue9n\ue9rant des revenus et des emplois au niveau des communaut\ue9s locales
Decreased Rhes mRNA levels in the brain of patients with Parkinson's disease and MPTP-treated macaques
In rodent and human brains, the small GTP-binding protein Rhes is highly expressed in virtually all dopaminoceptive striatal GABAergic medium spiny neurons, as well as in large aspiny cholinergic interneurons, where it is thought to modulate dopamine-dependent signaling. Consistent with this knowledge, and considering that dopaminergic neurotransmission is altered in neurological and psychiatric disorders, here we sought to investigate whether Rhes mRNA expression is altered in brain regions of patients with Parkinsonâ\u80\u99s disease (PD), Schizophrenia (SCZ), and Bipolar Disorder (BD), when compared to healthy controls (about 200 post-mortem samples). Moreover, we performed the same analysis in the putamen of non-human primate Macaca Mulatta, lesioned with the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Overall, our data indicated comparable Rhes mRNA levels in the brain of patients with SCZ and BD, and their respective healthy controls. In sharp contrast, the putamen of patients suffering from PD showed a significant 35% reduction of this transcript, compared to healthy subjects. Interestingly, in line with observations obtained in humans, we found 27% decrease in Rhes mRNA levels in the putamen of MPTP-treated primates. Based on the established inhibitory influence of Rhes on dopamine-related responses, we hypothesize that its striatal downregulation in PD patients and animal models of PD might represent an adaptive event of the dopaminergic system to functionally counteract the reduced nigrostriatal innervation
Dysfunctional dopaminergic neurotransmission in asocial BTBR mice
Autism spectrum disorders (ASD) are neurodevelopmental conditions characterized by pronounced social and communication deficits and stereotyped behaviours. Recent psychosocial and neuroimaging studies have highlighted reward-processing deficits and reduced dopamine (DA) mesolimbic circuit reactivity in ASD patients. However, the neurobiological and molecular determinants of these deficits remain undetermined. Mouse models recapitulating ASD-like phenotypes could help generate hypotheses about the origin and neurophysiological underpinnings of clinically relevant traits. Here we used functional magnetic resonance imaging (fMRI), behavioural and molecular readouts to probe dopamine neurotransmission responsivity in BTBR T+ Itpr3tf/J mice (BTBR), an inbred mouse line widely used to model ASD-like symptoms owing to its robust social and communication deficits, and high level of repetitive stereotyped behaviours. C57BL/6J (B6) mice were used as normosocial reference comparators. DA reuptake inhibition with GBR 12909 produced significant striatal DA release in both strains, but failed to elicit fMRI activation in widespread forebrain areas of BTBR mice, including mesolimbic reward and striatal terminals. In addition, BTBR mice exhibited no appreciable motor responses to GBR 12909. DA D1 receptor-dependent behavioural and signalling responses were found to be unaltered in BTBR mice, whereas dramatic reductions in pre- and postsynaptic DA D2 and adenosine A2A receptor function was observed in these animals. Overall these results document profoundly compromised DA D2-mediated neurotransmission in BTBR mice, a finding that is likely to have a role in the distinctive social and behavioural deficits exhibited by these mice. Our results call for a deeper investigation of the role of dopaminergic dysfunction in mouse lines exhibiting ASD-like phenotypes, and possibly in ASD patient populations
D-aspartate oxidase gene duplication induces social recognition memory deficit in mice and intellectual disabilities in humans
The D-aspartate oxidase (DDO) gene encodes the enzyme responsible for the catabolism of D-aspartate, an atypical amino acid enriched in the mammalian brain and acting as an endogenous NMDA receptor agonist. Considering the key role of NMDA receptors in neurodevelopmental disorders, recent findings suggest a link between D-aspartate dysmetabolism and schizophrenia. To clarify the role of D-aspartate on brain development and functioning, we used a mouse model with constitutive Ddo overexpression and D-aspartate depletion. In these mice, we found reduced number of BrdU-positive dorsal pallium neurons during corticogenesis, and decreased cortical and striatal gray matter volume at adulthood. Brain abnormalities were associated with social recognition memory deficit at juvenile phase, suggesting that early D-aspartate occurrence influences neurodevelopmental related phenotypes. We corroborated this hypothesis by reporting the first clinical case of a young patient with severe intellectual disability, thought disorders and autism spectrum disorder symptomatology, harboring a duplication of a chromosome 6 region, including the entire DDO gene
Measurement of gravitational and thermal effects in a liquid-actuated torsion pendulum
We describe a proof-of-principle experiment aiming to investigate the inverse-square law of gravitation at the centimeter scale. The sensor is a two-stage torsion pendulum, while actuation is accomplished by a variable liquid mass. The time-varying gravitational force is related to the level of the circulating fluid in one or two containers at a short distance from the test mass, with all moving mechanical parts positioned at a large distance. We provide a description of the apparatus and present the first results. We identified a systematic effect of thermal origin, producing offsets of few fNm in torque and of about 10 pN in force. When this effect is neutralized, the measurements agree well with the predictions of simulations. We also discuss the upcoming instrument upgradations and the expected sensitivity improvement that will allow us to perform measurements with adequate accuracy to investigate the unexplored regions of the α−λ parameter space of a Yukawa-like deviation from the Newtonian potential
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