1,721,459 research outputs found
Rock Excavation by Drilling & Blasting: Evaluation of the Performance of the Equipment in an Open Pit Limestone Quarry
No full textThe paper deals with a research carried out at an open pit quarry, to optimize the production through the analysis of the equipment. The discussion was focused on the currently available machines: excavators, dump trucks and drills. The objective was to optimize some aspects of the exploitation, making it possible to complain with the desired productivity. The excavation is performed by explosives, followed by mucking with backhoe excavators and transportation to the crushing plant through dump trucks. All data on the currently in use machines at the quarry were taken into account. Economic evaluations were carried out by analyzing the fuel consumption of each machine; then different models of machines with the same power and capacity features were examined, to evaluate cheaper alternatives. Finally, the more advantageous fleet from an economic standpoint was rated, considering the critical geometry of the quarry. The cost of an initial investment was also evaluated, in reference to the purchase of a new fleet. The cycle times of the machines were experimentally evaluated on site. The results obtained are analyzed in the light of future perspectives; the analysis revealed a reliability of the evaluation and the quarry is currently testing the solution propose
The Evolution of negative symptom constructs
No full textIntroductionNegative symptoms represent a separate dimension of schizophrenia psychopathology, distinct from positive symptoms, disorganization and cognitive impairment. It is increasingly acknowledged that negative symptoms are associated with poor functional outcome and represent an unmet need in schizophrenia treatment. Improvement in definition of their phenomenology, assessment instruments and experimental models are needed in order to improve schizophrenia prognosis.AimsThe presentation will review key aspects of the evolution of negative symptom constructs. In particular, findings concerning phenomenology, clinical assessment, association with functional outcome and brain imaging correlates will be presented.MethodsWe searched PubMed for English full-text publications with the keywordsSchizophrenia AND “negative symptoms”/“primary negative symptoms”/“deficit schizophrenia”/“persistent negative symptoms”/“affective flattening”/alogia/“expressive deficit”/apathy/asociality/“social withdrawal”/anhedonia/“anticipatory anhedonia”/avolition/neuroimaging.ResultsThe distinction between secondary negative symptoms (i.e., those due to identifiable factors, such as drug effects, psychotic symptoms or depression), and primary or persistent negative symptoms (i.e., those etiologically related to the core pathophysiology of schizophrenia) is grounded on solid research evidence and might have major implications for both treatment development and clinical care. The evidence that negative symptoms cluster in motivation- and expressive-related domains is founded on large consensus and empirical evidence and will foster pathophysiological modeling. The motivation-related domain is a stronger predictor of functional outcome than the expressive one.ConclusionsAn improved definition and assessment of negative symptoms needs to translate in large-scale studies to advance knowledge. In the short-term, the improved identification of treatable causes of secondary negative symptoms can translate into better care for people with schizophrenia.Disclosure of interestAM received honoraria or advisory board/consulting fees from the following companies: Janssen Pharmaceuticals, Otsuka, Pfizer and Pierre Fabre.SG received honoraria or advisory board/consulting fees from the following companies: Lundbeck, Janssen Pharmaceuticals, Hoffman-La Roche, Angelini-Acraf, Otsuka, Pierre Fabre and Gedeon-Richter.</jats:sec
The mechanical resistance of stone for different size specimens: the effect of petrographic characteristics
No full textFew scientific works deal with size effect on mechanical resistance in the case of stone, meanwhile for the concrete, Weibull law has been widely verified. In fact, the stone size effect is not always ruled by well known laws as Weibull because of the intrinsic complex structure and features of the materials analysed.
Concerning the mechanical behaviour, flexural strength is used to assess the mechanical resistance of stone and, if performed after accelerating tests, its durability. Besides, the results of flexural strength are well correlated with petrographic properties of stone. For this reason, to further investigate the size effect, this research analyses the variation of mechanical resistance with the shape and/or dimensions of the specimens taking into account the petrographic characteristics of different kinds of rock (voids, porosity, cracks, crystal contacts).
Flexural strength measurements on specimens in natural condition and on specimens subjected to artificial ageing cycles, microscopic observations, image analysis, porosity measurements have been executed in order to evaluate the effects of rock characteristics on the micro-scale on mechanical strength test. The results of the tests performed, analysing not only mechanical properties but even petrographic characteristics, can be useful to better explain the rock mechanical behaviour in function of dimensions and micro-scale properties
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Cognitive dysfunctions in the psychoses and their impact on patients’ social functioning
No full textIntroductionImpairment of neurocognitive functions, such as attention, memory or executive functions, as well as of social cognition, particularly of affect recognition and theory of mind, are frequently observed in people with Schizophrenia or other psychotic disorders. These dysfunctions are associated with poor real-life functioning. Social cognition deficits mediate in part the impact of neurocognitive dysfunction on functional outcome.AimsTo review literature findings on prevalence, severity and association with functional outcome of neurocognitive and social cognitive deficits in schizophrenia and other psychotic disorders.MethodsWe searched PubMed for English/Italian or French full-text publications with the keywords.schizophr*/psychosis/psychot*/AND neurocognitive/cognitive/neuropsychological/memory/attention/”executive function”/learning/”social cognition”/”theory of mind”/”affect recognition”/”acial emotion recognition”/”emotional intelligence”/”emot* recognition”. Furthermore, we manually searched the reference lists of relevant papers, systematic reviews and meta-analyses.ResultsIn people with schizophrenia, schizoaffective disorder or bipolar disorder with psychotic features, neurocognitive and social cognition deficits were observed in all phases of the disorders, even after symptom remission. Some of these deficits were observed in subjects at high-risk to develop schizophrenia before psychotic onset. In all these subjects, cognitive deficits are associated with worse psychosocial functioning and poor quality of life. Pharmacological treatments do not alleviate cognitive deficits, which can also limit the benefit of other psychological or psychosocial interventions.ConclusionsNeurocognitive and social cognition deficits need to be targeted by specific interventions to improve real-life functioning and quality of life of people with schizophrenia or psychotic disorders.Disclosure of interestAM received honoraria or advisory board/consulting fees from the following companies: Janssen Pharmaceuticals, Otsuka, Pfizer and Pierre Fabre.SG received honoraria or advisory board/consulting fees from the following companies: Lundbeck, Janssen Pharmaceuticals, Hoffman-La Roche, Angelini-Acraf, Otsuka, Pierre Fabre and Gedeon-Richter.</jats:sec
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