Various semantic technologies such as ontologies, machine learning, or artificial intelligence-based are being used today with data science for the purpose of explaining the meaning of data, and ...making this explanation exploitable by computer processing. Although some quick and brief reports do exist, to the best of our knowledge, the literature lacks a detailed study reporting why, when and how semantic technologies are used with data science. This paper is a theoretical review aiming at providing an insight into data science with semantic technologies. We characterize this research topic through a framework called DS2T helping to understand data science with semantic technologies and giving a comprehensive overview of the field through different, but complementary views. The proposed framework may be used to position research studies integrating semantic technologies with data science, compare them, understand new trends, and identify opportunities and open issues related to a given application domain. Software development processes are used as illustration domain.
•A detailed numerical 2-D model of a CPV/T system has been developed.•Thermal and electrical investigations have been performed.•An evaluation of the CPV/T power generation has been carried out under ...Chambery and Tunisia conditions.•A comprehensive economic analysis study of the system has also been done.
Concentrated photovoltaic thermal (CPV/T) solar collector systems are designed to provide simultaneously thermal and electrical energies. This paper analyzes a numerical model of a photovoltaic thermal collector in order to evaluate its performances from energy and economic viewpoints. Therefore, a two dimensional numerical model has been developed and applied in this study. This electrical/thermal model is based on the energy balance of the CPV/T receiver in order to calculate the net thermal and electrical output energy. A comparison between the numerical results and those obtained by experimental studies is presented in order to prove the viability of our developed model. The results show that the output power predicted by the numerical model has a good agreement with the experimental data with low mean percentage errors. Indeed, the effects of several parameters on the performance of the system were examined and discussed in details. The simulation process has allowed evaluating the power generation of the CPV/T system and performing a comprehensive economic analysis study under Chambery and Tunisia conditions. The CPV/T system has proven its viability and feasibility especially in regions with high solar radiation.
Presented in this paper was an overview on research works on solar radiation basics and photovoltaic generation. Also, a complete PV modeling and investigation on the effect of using multi-axes ...sun-tracking systems on the electrical generation was carried out to evaluate its performance using the case study of the Monastir city, Tunisia. The effects of azimuth and tilt angles on the output power of a photovoltaic module were investigated. The instantaneous increments of the output power generated by a photovoltaic module mounted on a single and dual-axis tracking system relative to a traditional fixed panel were estimated. The results show that the yearly optimal tilt angle of a fixed panel faced due to the south is close to 0.9 times Monastir latitude. The gain made by the module mounted on a single-axis tracking panel relative to a traditional fixed panel was analyzed. The monthly increments of the gain are more noticeable for two critical periods which correspond to those surrounding the summer and the winter solstice dates. It reaches the value of 10.34% and 15% in the summer and winter solstice periods, respectively. However, the yearly gain relative to a fixed panel installed with the yearly optimal tilt angle is 5.76%. In some applications, covering loads at early morning or late afternoon hours and in order to more optimize the solar systems exploitation suggest the adjustment of the PV panel orientation to azimuth angles different from the south direction by using a dual-axis tracking installation. The gain made by this recommendation relative to a traditional fixed panel is evaluated. This gain reaches 30% and 44% respectively in the winter and summer solstice days.
•Many technical challenges are encountered when manufacturing Stirling machines.•Variety of Stirling configurations represents a barrier against technology spread.•Regenerator characteristics have ...the greatest impact on engine performances.•Working gas leakage is a major difficulty when engine operates under high pressure.•Optimum rotation speed must be respected to ensure the machine proper functioning.
The Stirling engines are being carried out worldwide, used for divers’ application such as solar generator, micro cogeneration and cryogenic uses. The present paper is an over view of Stirling technologies researches. Several possibilities of resolving technical challenges encountered when manufacturing or using Stirling machines will be discussed. The most appropriate models and optimizations strategies are reported. Stirling engine performances are derived as function of geometric parameters (swept volumes, dead volumes, heat exchange areas, compression ratio…) for several working conditions (speed, mean pressure, temperature difference and working fluid). The effect of each parameter on the Stirling performances when using numerical and/or experimental approaches are presented. It is concluded that multi-objective optimizations methods are useful for predicting geometric and working parameters that corresponding to the optimal performances of the Stirling engine.
Technology and Poultry Welfare Ben Sassi, Neila; Averós, Xavier; Estevez, Inma
Animals,
10/2016, Letnik:
6, Številka:
10
Journal Article, Book Review
Recenzirano
Odprti dostop
Consideration of animal welfare is essential to address the consumers' demands and for the long term sustainability of commercial poultry. However, assessing welfare in large poultry flocks, to be ...able to detect potential welfare risks and to control or minimize its impact is difficult. Current developments in technology and mathematical modelling open new possibilities for real-time automatic monitoring of animal welfare and health. New technological innovations potentially adaptable to commercial poultry are appearing, although their practical implementation is still being defined. In this paper, we review the latest technological developments with potential to be applied to poultry welfare, especially for broiler chickens and laying hens. Some of the examples that are presented and discussed include the following: sensors for farm environmental monitoring, movement, or physiological parameters; imaging technologies such as optical flow to detect gait problems and feather pecking; infrared technologies to evaluate birds' thermoregulatory features and metabolism changes, that may be indicative of welfare, health and management problems. All these technologies have the potential to be implemented at the commercial level to improve birds' welfare and to optimize flock management, therefore, improving the efficiency of the system in terms of use of resources and, thus, long term sustainability.
The variant named rs3115534-G, which is in the non-coding region of GBA1 (the gene encoding the lysosomal enzyme glucocerebrosidase), is reported as a new common risk factor for Parkinson's disease ...in African people. ...common non-coding variants within the GBA1 locus have been identified as potential modifiers of age at onset, with haplotypes based on three of these variants delaying disease onset by 5 years.6 There are some limitations to the study by Rizig and colleagues, including potential bias due to ethnically unmatched cases and controls, and shortcomings of the principal components method that was used to correct for subpopulation stratification. ...according to 1000 Genomes, rs3115534-G frequencies were found to vary across populations of African or African admixed ancestry, ranging from 0·11 in African Americans to 0·3 in Nigerians, the latter being comparable to the frequency of 0·33 in African cases, which was observed by the authors. SBS declares research grant and travel support from the Michael J Fox Foundation, honoraria for educational courses and travel support from the International Parkinson and Movement Disorder Society (MDS), and is treasurer of the MDS Africa section.
This study presents an important view to the predictive capacity of COVID-19 for the correlation between Chinese stock market and 9 international stock market in Asia, Europe, and North America ...regions. In this paper, we try to investigate the spillover impacts of China's stock market on the selected stock markets using an econometric methodology based on DCC-GARCH models during the period from May 01, 2019 to May 30, 2020. Our results show a strong significant DCC among China's stock market index and selected international stock market indices especially in the outbreak of COVID-19. We find that the results related to the degree of the persistence of volatility, are sensitive to the existence of the COVID-19 surprises into the DCC-GARCH (1) model. We remark that that COVID-19 has a short-term impact on international stock market indices volatilities. Finally, we can conclude that COVID-19 explain the spillover impacts of China's stock market index on selected countries using DCC-GARCH models. This paper gives an important framework to the investors to choose their portfolios in the financial markets especially in the crisis period. This paper contributes to the literature on assessing the impact of COVID-19 confirmed cases surprises on the correlation between China's stock market index and selected international stock market in Asia, Europe, and North America regions.
At the beginning of the coronavirus virus (COVID-19) pandemic, the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV2) was thought to cause mainly respiratory symptoms, largely sparing the ...brain and the rest of the nervous system. However, as the knowledge about COVID-19 infection progresses and the number of COVID19-related neurological manifestations reports increases, neurotropism and neuroinvasion were finally recognized as major features of the SARS-CoV-2. Neurological manifestations involving the central nervous system are sparse, ranging from headaches, drowsiness, and neurovascular attacks to seizures and encephalitis 1. Thus far, several cases of non-epileptic myoclonus were reported in critical patients 2,3. Here, we report the first case of myoclonus status as the inaugural and sole symptom of COVID-19 in a conscious patient.
A 60-year-old man with unknown family history and no medical issues other than smoking one cigarette packet a day over the span of 25 years. The patient presented with 5 days of abnormal movements in bilateral arms following the COVID vaccination. They were described as brief, involuntary jerking, like in sleep starts, in the proximal part of their upper members, and his face with a regular tremor in his arms exacerbated by movements and emotion. His movement disorder worsened the second day, and he developed an abnormal gait with slurred speech, concomitantly with diarrhea. Seven days following the symptoms onset, the patient was alert. His neurological exam revealed multifocal myoclonic jerks affecting four limbs predominantly proximal, the face, and the trunk (video 1). The myoclonic jerks were sensitive to tactile and auditory stimuli, without enhanced startle response or hyperekplexia. His gait was unsteady due to severe myoclonus, without cerebellar ataxia (video 2) and he had mild dysarthria. No dysmetria at the finger-to-nose and heel-to-shin tests were found. Examination of eye movements revealed paralysis of Down-Gaze and no opsoclonus was detected. Physical exam was unremarkable, including lack of fever and meningitis signs. The electroencephalogram (EEG) did not show any abnormalities concomitant with myoclonic jerks (Fig.1). The cerebral Magnetic Resonance Imaging (MRI) was normal (Fig. 2). An extensive biological work-up including a complete blood count, a comprehensive metabolic panel, an arterial blood gas analysis, a urine drug screen, a thyroid function test, a vitamin B12, folate, and ammonia level, and HIV and syphilis serologies were inconclusive. Testing for autoimmune and paraneoplastic antineuronal antibodies including anti-NMDA-R was negative. The cerebrospinal fluid (CSF) study was unremarkable (0.3 g/l of proteinorachia, 1 white blood cell). Polymerase chain reaction (PCR) for herpes simplex virus, varicella-zoster virus, and SARS-CoV-2 in CSF was negative. However, the patient tested positive for COVID-19 through PCR for viral RNA from the nasopharyngeal swab. After the administration of 12mg/day of Dexamethasone for 3 days, along with clonazepam and levetiracetam, the patient's symptoms started improving on day 3 and he displayed a very slow but progressive recovery.
Our patient presented with acute isolated multifocal myoclonus status without cognitive impairment. These movements were prominent, spontaneous, worsened by action, and sensitive to touch and sound. The anatomical source of this myoclonus could be cortical or subcortical despite the absence of evident EEG discharges. Several diseases can cause acute myoclonus such as severe hypoxia, metabolic disturbances, and paraneoplastic syndromes. these diagnoses were ruled out in our patient. Post-vaccinal origin was also suggested, but its accountability was not proven. Thus, the two hypothetic etiologies raised were either para-infectious or infectious mechanisms in relation to SARS-Cov 2 infection. HIV, VZV, HSV, and syphilis infections were eliminated and the patient tested positive for SARS-Cov2 infection. In the literature, COVID-19-related myoclonus was reported as a complication of an already-known SARS-CoV-2 infection in about 50 patients so far. It generally occurs between 6 days and 26 days following the SARS-CoV-2 infection 2–5, and affects critical illness patients with cognitive decline, mainly from the intensive care unit 3,4. Yet, our patient did not display any symptoms of COVID-19 infection before the occurrence of these abnormal movements. Furthermore, he had a relatively good general condition and no cognitive impairment. Several pathophysiological mechanisms were suggested regarding the COVID-19-related myoclonus. Either central nervous invasion by SARS-Cov 2 after transneuronal spread and/or auto-immune cross-reactivity reaction, are likely incriminated in the pathophysiology of most of the cases 6. We believe that there is an inflammatory process involved with increased levels of proinflammatory cytokines and systemic inflammation, including cytokine storm or cytokine release syndrome targeting the brain and more specifically the cortex and basal ganglia 6. Data collection in clinical registries is needed to increase our knowledge of the prevalence of neurological symptoms in patients with COVID-19 and will hopefully clarify the causal relationship between SARS-CoV-2 infection and post-COVID-19 myoclonic syndrome.
Introduction
cocaine is a widely used illegal drug, known for its fast ability to induce euphoria and arousal. However, cocaine exposure can contribute to several mental and physical effects. Cocaine ...induced brain damage can be divided into 3 mechanisms: direct effect leading to toxic encephalopathy, secondary to vascular damage causing vasculitis, stroke and vasospasm, and tertiary effect due to hypoxia through a cardiovascular collapse.
Objectives
Here, we report 2 young men who developed a subacute encephalopathy with different clinical and radiological presentation after a cocaine overdose
Methods
a case serie
Results
we present two men aged respectively of 28 (P1) and 42 years-old (P2). Both had a history of alcohol consumption and toxicomania (mainly cocaine) during the past year. They manifested, 2 weeks following a cocaine overdose, with gait disorder and confusion. On examination, P1 was apathic and confused. He had a subcortical frontal syndrome with gait apraxia and grasping reflex, along with a quadri-pyramidal syndrome. While patient P2 developed a cognitive decline, parkinsonism with dystonic posture of the trunk and the right limbs, and a pseudobulbar syndrome. Brain MRI was performed in both patients and showed a bilateral multifocal leukoencephalopathy (P1) and the presence of bilateral hyper T2 and FLAIR weighted images affecting basal ganglia, the mesencephalon and the periventricular cerebral white matter. Cerebrospinal fluid (CSF) analysis showed no pleocytosis and normal proteinorrachia. Electroencephalogram was also normal. Infectious differential diagnosis including Human Immunodeficiency Virus (HIV) and syphilis were excluded and metabolic screening including copper analysis, serum and CSF lactate were normal. The urine toxic screening, performed 20 days following the drug overdose, was negative. Both patients were treated with benzodiazepine and fluids without significative improvement. They were discharged with major cognitive and motor impairment.
Conclusions
cocaine toxicity is associated with high morbidity and mortality. Usually, cocaine abuse can lead to cardio-vascular, pulmonary and nervous complication. Neuropsychiatric sequelae are uncommon with less recovery potential. To date, there is no drug to prevent or cure cocaine addiction. The key is to educate the patient when he or she presents to the emergency department. Patients should be urged to seek drug counseling.
Disclosure of Interest
None Declared
Heat waves, defined as events associating high temperatures with severe drought, are expected to become increasingly recurrent. Research has focused heavily on the impacts of drought and temperature ...increase on soil functioning and microbial diversity, but little attention has been paid to soil microbial community responses to combined heat−drought stresses. Heat waves, which combine heat and drought stresses, may induce different microbial responses to those observed in studies focusing on heat or drought alone. Microbial recovery strategies to with-stand heat−drought conditions, along with patterns of microbial functional redundancy and complex interactions with the soil physical−chemical−biological interface may have marked effects on soil ecosystem functioning, particularly in agroecosystems through the rhizosphere. To better understand how heat waves affect soil ecosystem functioning, we advocate the development of mechanistic approaches integrating individual to community level and biophysicochemical studies on the indirect effects of combined heat−drought stresses in microbial communities, observed through soil environment parameters in experimental and field studies. The challenge will be to define trait-based functional indicators of the microbial community response to heat waves, particularly the potential interrelatedness between the traits responsible for tolerance to drought and heat.
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