887 research outputs found
Novel Method for Improving the Capacity of Optical MIMO System Using MGDM
In current local area networks, multimode fibers (MMFs), primarily graded index (GI) MMFs, are the main types of fibers employed for data communications. Due to their enormous bandwidth, it is considered that they are the main channel medium that can offer broadband multiservices using optical multiplexing techniques. Amongst these, mode group diversity multiplexing (MGDM) has been proposed as a way to integrate various services over an MMF network by exciting different groups of modes that can be used as independent and parallel communication channels. In this paper, we study optical multiple-inputâmultiple-output (O-MIMO) systems using MGDM techniques while also optimizing the launching conditions of light at the fiber inputs and the spot size, radial offset, angular offset, wavelength, and the radii of the segment areas of the detectors. We propose a new approach based on the optimization of launching and detection conditions in order to increase the capacity of an O-MIMO link using the MGDM technique. We propose a (3 3) O-MIMO system, where our simulation results show significant improvement in GI MMFs' capacity compared with existing O-MIMO systems.
Optical multiple-input-multiple-output multiplexing of parallel communication multichannels over a single multimode fiber network. Optical multiple-input-multiple-output multiplexing of parallel communication multichannels over a single multimode fiber network
Water status and yield response to deficit irrigation and fertilization of three olive oil cultivars under the semi-arid conditions of Tunisia
Sustainability of olive production is possible by adopting the modern techniques of irrigation and fertilization. In Tunisia, olive trees are usually cultivated in poor soils, under semi-arid conditions characterized by water scarcity. This study investigated the effects of different water supply and fertilization on leaf water status and crop yield of three different olive oil varieties cultivated in central Tunisia, during four experimental seasons (2014-2017). Three treatments were examined: trees conducted under rainfed conditions (TRF), which represented the control treatment, trees irrigated with 50% ETc (T50) and, finally, trees irrigated with 50% ETc and with additional fertilization (T50F). Leaf water content and potential, yield and water use efficiency have been monitored on three different varieties, Chetoui, Chemlali, and Koroneiki, which are quite typical in the considered region. For all the growing seasons, midday leaf water potentials were measured from April to September. Midday leaf water potentials (MLWP) were generally higher for the two irrigated treatments (T50 and T50F) than for non-irrigated trees (TRF). As the season proceeded, MLWPs tended to decrease during summer for all the treatments and varieties. The lowest values were observed for the non-irrigated trees, varying between -3.25 MPa to -4.75 MPa. Relative leaf water content followed the same trends of midday leaf water potentials. Chetoui showed the lowest yield, which did not exceed 1530 Kg/(ha year), even for irrigated and fertilized trees. On the other hand, the yields of Chemlali and Koroneiki, cumulated in the four years, reached the maximum value of about 20 tons/ha. For these two varieties, the cumulated yield obtained in the control treatment (TRF) resulted significantly lower than the corresponding of the other two treatments (T50 and T50F). The highest irrigation water use efficiency (WUE) was estimated for Chemlali (T50) and (TRF). WUE was equal to 1.22 Kg/m3 for Koroneiki under fertigated treatment (T50F). Application of the only water supply (50% ETc) or associated with fertilizer improved the tree water status and increased the productivity of Chemlali and Koroneiki varieties
Prise en charge des complications de la chirurgie partielle du larynx
Introduction : Le cancer du larynx est un cancer frĂ©quent occupant la premiĂšre place des cancers des voies aĂ©ro-digestives chez lâhomme en Tunisie. Le tabac est le principal facteur favorisant surtout sâil est associĂ© Ă lâĂ©thylisme chronique. Il sâagit le plus souvent dâun carcinome Ă©pidermoĂŻde plus ou moins diffĂ©renciĂ©. Son pronostic est gĂ©nĂ©ralement bon, en raison de son dĂ©veloppement dans un tube rigide bien limitĂ© et dâun traitement chirurgical actuellement bien codifiĂ©. La chirurgie partielle du cancer du larynx est une chirurgie Ă risque de complications postopĂ©ratoires nĂ©cessitant une prise en charge adĂ©quate.Patients et mĂ©thodes : Notre sĂ©rie comprend 54 patients ayant bĂ©nĂ©ficiĂ© dâune chirurgie partielle du larynx au sein du service de chirurgie carcinologique de lâinstitut Salah Azaiez sur une pĂ©riode de 15 ans (1997-2011).But : PrĂ©senter notre expĂ©rience en matiĂšre de prise en charge des complications de la chirurgie partielle du larynx.RĂ©sultats : La moyenne dâĂąge de nos patients Ă©tait de 54,9 ans avec des extrĂȘmes allant de 33 Ă 69 ans. La prĂ©dominance masculine était nette avec un sex-ratio de 26. La consommation tabagique Ă©tait notĂ©e dans 92,6% des cas et la dysphonie Ă©tait prĂ©sente chez 40 patients porteurs dâune tumeur Ă localisation glottique. Six types dâinterventions ont Ă©tĂ© pratiquĂ©s: cordectomie (9 cas), laryngectomie fronto-latĂ©rale (4 cas), laryngectomie frontale antĂ©rieure reconstructive type Tucker (10 cas), laryngectomie partielle supra-cricoĂŻdienne avec crico-hyoĂŻdopexie (CHP) (4 cas), laryngectomie partielle supra-cricoĂŻdienne avec crico-hyoĂŻdo-Ă©piglottopexie (CHEP) (24 cas) et laryngectomie horizontale supra-glottique (3 cas). Une antibioprophylaxie Ă©tait administrĂ©e chez 79,6% des patients pour une durĂ©e moyenne de 7 jours. Les complications postopĂ©ratoires ont Ă©tĂ© analysĂ©es et discutĂ©es en fonction du type de la chirurgie partielle pratiquĂ©e et du type dâantibiothĂ©rapie utilisĂ©e. Ces complications Ă©taient les suivantes: infection du trachĂ©ostome (20,4%), infection de paroi (5 cas), complications respiratoires (29,6%), emphysĂšme sous cutanĂ© (7,4%), fistule salivaire (1 cas) et pancrĂ©atite aigĂŒe (1 cas).Conclusion : Cette Ă©tude montre dans lâensemble des bons rĂ©sultats tant sur le plan infectieux que respiratoires, justifiant ainsi lâimportance de la prise en charge des complications de la chirurgie partielle du cancer du larynx.Introduction : Laryngeal cancer is a common cancer occurring mainly in men. Smoking is the main risk factor especially if associated with chronic alcoholism. Squamous cell carcinoma is the most common histologic type. Prognosis is generally good, due to the development of the tumor in a very limited rigid tube and to a well-codified surgical treatment. Partial surgery of laryngeal cancer is characterized by postoperative complications requiring an adequate management.Methods : Our series includes 54 cases of laryngeal cancer treated with partial laryngectomy in the ENT department of Salah Azaiez Institute over a period of 15 years from 1997 to 2011.Objective : To present our experience in the management of partial laryngeal surgery complications.Results : Average age of our patients was 54.9 years ranging from 33 to 69 years. Male predominance was marked with a sex ratio of 26. Tobacco abuse was found in 92.6%. Dysphonia was the most common symptom found in 40 patients with glottic cancer. Six varieties of partial laryngectomy were performed: cordectomy (9 cases), fronto-lateral laryngectomy (4 cases), fronto-anterior reconstructive laryngectomy (10 cases), partial supra-cricoid laryngectomy with CHP (4 cases), partial supra-cricoid laryngectomy with CHEP (24 cases) and supra glottic horizontal laryngectomy (3 cases). 79.6 % of our patients received prophylactic antibiotics for an average of 7 days. Postoperative complications were analyzed and discussed in terms of the type of surgery performed and the antibiotic used. Complications observed were: infection of the tracheostoma (20.4%), parietal infection (5 cases), respiratory complications (29.6%), subcutaneous emphysema (7.4%), salivary fistula (1 case) and acute pancreatitis (1 case).Conclusion : This study shows overall good results for partial laryngeal cancer surgery with minimal post-operative complications and oncologic failure justifying the importance of an early management of these complications
(E)-1-(1,3-Benzodioxol-5-yl)-4,4-diÂmethylÂpent-1-en-3-one
In the molÂecule of the title compound, C14H16O3, all non-H atoms except for one methyl C atom lie on a crystallographic mirror plane. The conformation with respect to the C=C bond [1.3465â
(12)â
Ă
] is trans. In the crystal, molÂecules are linked via CâHâŻO hydrogen bonds into C(5) chains propagating along [100]
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âLike a part of a puzzle which is missingâ: The impact on families of a relative missing in migration across the Mediterranean
Diversity of Coronaviruses with Particular Attention to the Interspecies Transmission of SARS-CoV-2
In December 2019, the outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was reported in China with serious impacts on global health and economy that is still ongoing. Although interspecies transmission of coronaviruses is common and well documented, each coronavirus has a narrowly restricted host range. Coronaviruses utilize different receptors to mediate membrane fusion and replication in the cell cytoplasm. The interplay between the receptor-binding domain (RBD) of coronaviruses and their coevolution are determinants for host susceptibility. The recently emerged SARS-CoV-2 caused the coronavirus disease 2019 (COVID-19) pandemic and has also been reported in domestic and wild animals, raising the question about the responsibility of animals in virus evolution. Additionally, the COVID-19 pandemic might also substantially have an impact on animal production for a long time. In the present review, we discussed the diversity of coronaviruses in animals and thus the diversity of their receptors. Moreover, the determinants of the susceptibility of SARS-CoV-2 in several animals, with special reference to the current evidence of SARS-CoV-2 in animals, were highlighted. Finally, we shed light on the urgent demand for the implementation of the One Health concept as a collaborative global approach to mitigate the threat for both humans and animals
Artificially decreasing cortical tension generates aneuploidy in mouse oocytes
Human and mouse oocytesâ developmental potential can be predicted by their mechanical
properties. Their development into blastocysts requires a specific stiffness window. In this
study, we combine live-cell and computational imaging, laser ablation, and biophysical
measurements to investigate how deregulation of cortex tension in the oocyte contributes to
early developmental failure. We focus on extra-soft cells, the most common defect in a
natural population. Using two independent tools to artificially decrease cortical tension, we
show that chromosome alignment is impaired in extra-soft mouse oocytes, despite normal
spindle morphogenesis and dynamics, inducing aneuploidy. The main cause is a cytoplasmic
increase in myosin-II activity that could sterically hinder chromosome capture. We describe
here an original mode of generation of aneuploidies that could be very common in oocytes
and could contribute to the high aneuploidy rate observed during female meiosis, a leading
cause of infertility and congenital disorders
Thrombolysis ImPlementation in Stroke (TIPS): evaluating the effectiveness of a strategy to increase the adoption of best evidence practice â protocol for a cluster randomised controlled trial in acute stroke care
BACKGROUND: Stroke is a leading cause of death and disability internationally. One of the three effective interventions in the acute phase of stroke care is thrombolytic therapy with tissue plasminogen activator (tPA), if given within 4.5Â hours of onset to appropriate cases of ischaemic stroke. OBJECTIVES: To test the effectiveness of a multi-component multidisciplinary collaborative approach compared to usual care as a strategy for increasing thrombolysis rates for all stroke patients at intervention hospitals, while maintaining accepted benchmarks for low rates of intracranial haemorrhage and high rates of functional outcomes for both groups at three months. METHODS AND DESIGN: A cluster randomised controlled trial of 20 hospitals across 3 Australian states with 2 groups: multi- component multidisciplinary collaborative intervention as the experimental group and usual care as the control group. The intervention is based on behavioural theory and analysis of the steps, roles and barriers relating to rapid assessment for thrombolysis eligibility; it involves a comprehensive range of strategies addressing individual-level and system-level change at each site. The primary outcome is the difference in tPA rates between the two groups post-intervention. The secondary outcome is the proportion of tPA treated patients in both groups with good functional outcomes (modified Rankin Score (mRS <2) and the proportion with intracranial haemorrhage (mRS â„2), compared to international benchmarks. DISCUSSION: TIPS will trial a comprehensive, multi-component and multidisciplinary collaborative approach to improving thrombolysis rates at multiple sites. The trial has the potential to identify methods for optimal care which can be implemented for stroke patients during the acute phase. Study findings will include barriers and solutions to effective thrombolysis implementation and trial outcomes will be published whether significant or not. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry: ACTRN1261300093979
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