A parallel algorithm for global optimization problems in a distributed computing environment

The problem of finding a global minimum of a real function on a set S of Rn occurs in many real world problems. Since its computational complexity is exponential, its solution can be a very expensive computational task. In this paper, we introduce a parallel algorithm that exploits the latest computers in the market equipped with more than one processor, and used in clusters of computers. The algorithm belongs to the improvement of local minima algorithm family, and carries on local minimum searches iteratively but trying not to find an already found local optimizer. Numerical experiments have been carried out on two computers equipped with four and six processors; fourteen configurations of the computing resources have been investigated. To evaluate the algorithm performances the speedup and the efficiency are reported for each configuration

Protective effects of carbonic anhydrase inhibition in brain ischaemia in vitro and in vivo models

Ischaemic stroke is a leading cause of death and disability. One of the major pathogenic mechanisms after ischaemia includes the switch to the glycolytic pathway, leading to tissue acidification. Carbonic anhydrase (CA) contributes to pH regulation. A new generation of CA inhibitors, AN11-740 and AN6-277 and the reference compound acetazolamide (ACTZ) were investigated in two models of brain ischaemia: in rat hippocampal acute slices exposed to severe oxygen, glucose deprivation (OGD) and in an in vivo model of focal cerebral ischaemia induced by permanent occlusion of the middle cerebral artery (pMCAo) in the rat. In vitro, the application of selective CAIs significantly delayed the appearance of anoxic depolarisation induced by OGD. In vivo, sub-chronic systemic treatment with AN11-740 and ACTZ significantly reduced the neurological deficit and decreased the infarct volume after pMCAo. CAIs counteracted neuronal loss, reduced microglia activation and partially counteracted astrocytes degeneration inducing protection from functional and tissue damage

Characterization of the Sos Enattos site for the Einstein Telescope

In this work we report the ongoing characterization of the Sos Enattos former mine (Sardinia, Italy), one of the two candidate sites for the Einstein Telescope (ET), the European third-generation underground interferometric detector of Gravitational Waves. The Sos Enattos site lies on a crystalline basement, made of rocks with good geomechanical properties, characterized by negligible groundwater. In addition, the site has a very low seismic background noise due to the absence of active tectonics involving Sardinia. Finally, the area has a low population density, resulting in a reduced anthropic noise even at the ground level. This location was already studied in 2012-2014 as a promising site for an underground detector. More recently, in March 2019, we deployed a new network of surface and underground seismometers at the site, that is currently monitoring the local seismic noise. Most of the energy carried by the seismic waves is due to the microseisms below 1 Hz, showing a significant correlation with the waves of the west Mediterranean sea. Above 1 Hz the seismic noise in the underground levels of the mine approaches the Peterson's low noise model. Exploiting mine blasting works into the former mine, we were also able to perform active seismic measurements to evaluate the seismic waves propagation across the area. In conclusion we also give a first assessment about the acoustic and magnetic noise in this underground site

Mineralogical-petrographic and physical-mechanical features of the construction stones in punic and roman temples of antas (Sw sardinia, italy): Provenance of the raw materials and conservation state

The Antas site (SW Sardinia, Italy) is of fundamental cultural importance because it testifies the presence of Nuragic, Punic and Roman civilizations from the second millennium to the third century BC. This work focuses on the Punic and the Roman temples and aims to define their conservation state and provenance of construction materials through their minero-petrographic and physical-mechanical characterization. In addition, artificial geomaterials used in restoration works comprising a partial anastylosis and a consolidation intervention on the monument, were investigated to evaluate the aesthetic, petrographic and petrophysical compatibility with the original materials. The results indicate that Punic builders preferred to use a porous sandstone coming from at least few kilometres away from the site. By contrast, Roman builders opted for the use of the less porous and harder local metadolostones, more difficult to quarry and to hew but promptly available in the surrounding area. The Roman temple still preserves decorative architectural elements (as the Pronao threshold and the mosaic tesserae) whose source is definitely not local, suggesting the import of these materials. As regards artificial materials, a new material was found within the Punic temple consisting of a sandstone-like rock (i.e., lime based sandy-conglomeratic geomaterial) and characterized by higher mechanical strength and lower porosity

Measuring depression with questions about well-being: A study on psychiatric outpatients

SUMMARY. Background. Most depression rating scales are characterized by negatively-phrased questions, exploring the presence of various symptoms. Questions such as those regarding suicidal ideation or painful experiences may reduce acceptability or even lead the reader to withdraw participation in the study. Although positively-worded items may be useful, it should be acknowledged that without formal testing they cannot be assumed to be equivalent to negatively-worded ones. The aim of the present study was to test the reliability and validity of a depression rating scale including only positively-phrased items. Methods. Two groups were enrolled in the study: the first comprised 104 adult psychiatric outpatients, the second 88 undergraduate students. All participants completed the depression scale of the Patient Health Questionnaire, the Zung Self- Rating Depression Scale, and the Positively-phrased Depression Scale (PDS), a 10-item self-report instrument in which the items are phrased in a positive way to reflect the absence of symptoms. Psychiatric outpatients also were rated by their clinician on the Hamilton Depression Rating Scale. Results. The internal consistency of the PDS was satisfactory. The correlations between scores on the PDS and on the other depression scales were moderate to high. Mean PDS scores of patients with a diagnosis of depressive disorder were significantly higher than those of patients with other mental disorders. Conclusions. Despite some limitations, this study suggests that the PDS a valid and reliable instrument which might prove particularly useful for the assessment of depressive symptoms in studies where issues of acceptability are important, such as studies on non-clinical populations, occupational samples, and patients drawn from non-psychiatric settings. © Il Pensiero Scientifico Editore