875 research outputs found

    The Quark-Gluon Plasma Equation of State and The Generalized Uncertainty Principle

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    The quark-gluon plasma (QGP) equation of state within a minimal length scenario or Generalized Uncertainty Principle (GUP) is studied. The Generalized Uncertainty Principle is implemented on deriving the thermodynamics of ideal QGP at a vanishing chemical potential. We find a significant effect for the GUP term. The main features of QCD lattice results were quantitatively achieved in case of nf=0n_{f}=0, nf=2n_{f}=2 and nf=2+1n_{f}=2+1 flavors for the energy density, the pressure and the interaction measure. The exciting point is the large value of bag pressure especially in case of nf=2+1n_{f}=2+1 flavor which reflects the strong correlation between quarks in this bag which is already expected. One can notice that, the asymptotic behavior which is characterized by Stephan-Boltzmann limit would be satisfied.Comment: 9 Pages, 8 figure

    Transport of N-acetylaspartate via murine sodium/dicarboxylate cotransporter NaDC3 and expression of this transporter and aspartoacylase II in ocular tissues in mouse

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    AbstractCanavan disease is a genetic disorder associated with optic neuropathy and the metabolism of N-acetylaspartate is defective in this disorder due to mutations in the gene coding for the enzyme aspartoacylase II. Here we show that the plasma membrane transporter NaDC3, a Na+-coupled transporter for dicarboxylates, is able to transport N-acetylaspartate, suggesting that the transporter may function in concert with aspartoacylase II in the metabolism of N-acetylaspartate. Since Canavan disease is associated with ocular complications, we investigated the expression pattern of NaDC3 and aspartoacylase II in ocular tissues in mouse by in situ hybridization. These studies show that NaDC3 mRNA is expressed in the optic nerve, most layers of the retina, retinal pigment epithelium, ciliary body, iris, and lens. Aspartoacylase II mRNA is coexpressed in most of these cell types. We conclude that transport of N-acetylaspartate into ocular tissues via NaDC3 and its subsequent hydrolysis by aspartoacylase II play an essential role in the maintenance of visual function

    Assessing the Impacts of Different Initiatives on the Rehabilitation of Pastoral and Silvopastoral Ecosystems: Big Data Oriented Approach

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    Moroccan forests, through the provision of goods and ecosystem services, underpins benefits to local communities and play a crucial role for rural area development. The legal framework recognizes to people, living near public forests, the right to graze their domestic livestock. Over the years, the grazing pressure is at levels far beyond the forestland’s carrying capacity throughout the country. Such pressure has been demonstrated as the main cause of forest cover loss and land degradation in Morocco and still threatening the sustainability of forests. To reduce the heavy grazing pressure on forest ecosystems and ensure their regeneration, several initiatives have been conducted such as the program of compensation for forest areas closed to grazing (CFCG), initiated by Moroccan forestry department. Socio-economic impact assessment of this mechanism was presented within several studies but its effectiveness for forest rangeland rehabilitation remains scarce and very spatially limited. To deal with this concern and to assess vegetation dynamics through various spatial and temporal scales, parcels concerned by CFCG and others within similar conditions was chosen. Time series of remotely sensed spectral indices at each parcel was used for vegetation cover dynamics assessment. Google Earth Engine platform (GEE) was used as computing plateform. As result, the spectral indices trends shown a long-lasting degradation tendency in areas planted without compensation compared to those concerned by CFCG. Such results were also verified using aerial images covering the analyzed parcels. As conclusion, within comparable conditions, CFCG improved vegetation cover trends. The use of GEE Platform simplified the process of treatment of remote sensed imagery and made it easy to assess the state of the vegetation and will be of great use in assessing the impacts of different programs and initiatives on the restoration of pastoral and silvopastoral ecosystems

    Redox linked flavin sites in extracellular decaheme proteins involved in microbe-mineral electron transfer

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    Extracellular microbe-mineral electron transfer is a major driving force for the oxidation of organic carbon in many subsurface environments. Extracellular multi-heme cytochromes of the Shewenella genus play a major role in this process but the mechanism of electron exchange at the interface between cytochrome and acceptor is widely debated. The 1.8 Å x-ray crystal structure of the decaheme MtrC revealed a highly conserved CX8C disulfide that, when substituted for AX8A, severely compromised the ability of S. oneidensis to grow under aerobic conditions. Reductive cleavage of the disulfide in the presence of flavin mononucleotide (FMN) resulted in the reversible formation of a stable flavocytochrome. Similar results were also observed with other decaheme cytochromes, OmcA, MtrF and UndA. The data suggest that these decaheme cytochromes can transition between highly reactive flavocytochromes or less reactive cytochromes, and that this transition is controlled by a redox active disulfide that responds to the presence of oxygen

    Giant synovial cell sarcoma of the thorax in a 46-year-old man: a case report

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    Background:Although synovial cell sarcoma is a common tumor of the extremities, its occurrence in the thorax has been less frequently documented. Case Presentation: A 46-year-old Pakistani man presented with a 2 month history of progressively increasing cough and left lower chest pain. Initial evaluation was done using a chest x-ray, the Patient was found to have a large mass involving the lower portion of the left chest. A computed tomography scan was performed next which showed a large mass involving the left chest wall with invasion into the pericardium and left hemidiaphragm. En bloc surgical resection of the tumor was undertaken. Final pathology showed synovial cell sarcoma of the thorax. At one-year follow-up, the Patient has shown no recurrence of the disease. Conclusions: We have described a rare case of a large synovial cell sarcoma of the thorax. Surgical resection appears an appropriate modus operandi for managing giant synovial cell sarcomas of the thorax. However, there is a need to clearly define post-operative strategies for cases with extensive involvement of surrounding structures

    Oval Domes: History, Geometry and Mechanics

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    An oval dome may be defined as a dome whose plan or profile (or both) has an oval form. The word Aoval@ comes from the latin Aovum@, egg. Then, an oval dome has an egg-shaped geometry. The first buildings with oval plans were built without a predetermined form, just trying to close an space in the most economical form. Eventually, the geometry was defined by using arcs of circle with common tangents in the points of change of curvature. Later the oval acquired a more regular form with two axis of symmetry. Therefore, an “oval” may be defined as an egg-shaped form, doubly symmetric, constructed with arcs of circle; an oval needs a minimum of four centres, but it is possible also to build polycentric ovals. The above definition corresponds with the origin and the use of oval forms in building and may be applied without problem until, say, the XVIIIth century. Since then, the teaching of conics in the elementary courses of geometry made the cultivated people to define the oval as an approximation to the ellipse, an “imperfect ellipse”: an oval was, then, a curve formed with arcs of circles which tries to approximate to the ellipse of the same axes. As we shall see, the ellipse has very rarely been used in building. Finally, in modern geometrical textbooks an oval is defined as a smooth closed convex curve, a more general definition which embraces the two previous, but which is of no particular use in the study of the employment of oval forms in building. The present paper contains the following parts: 1) an outline the origin and application of the oval in historical architecture; 2) a discussion of the spatial geometry of oval domes, i. e., the different methods employed to trace them; 3) a brief exposition of the mechanics of oval arches and domes; and 4) a final discussion of the role of Geometry in oval arch and dome design

    Acinic cell carcinoma in pregnancy: a case report and review of the literature

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    <p>Abstract</p> <p>Introduction</p> <p>We report an observational study on the etiology and recurrence of acinic cell carcinoma of the parotid gland that seemed to be related to pregnancy. The medical literature has never reported such an association; therefore, our case report is probably the first to mention this observation.</p> <p>Case presentation</p> <p>This report is of a 25-year-old Arabic female patient from the United Arab Emirates, who, during her first pregnancy, developed acinic cell carcinoma of the right parotid gland that was managed with surgical excision in the form of superficial parotidectomy. During her second pregnancy, which occurred four years later, she had a recurrence of the same malignant neoplasm associated with ipsilateral malignant cervical lymphadenopathy. The patient was managed with total parotidectomy and neck dissection, as well as postoperative adjuvant radiotherapy. Our observation on this particular case of acinic cell carcinoma is that the initial onset of her neoplasm was during her first pregnancy, and the recurrence of the same malignant disease was during a subsequent pregnancy. This chronologic association raised our suspicion that there might be a possible etiologic effect of pregnancy or its associated hormonal or physiologic changes or both on the pathogenesis or etiology of acinic cell carcinoma.</p> <p>Conclusion</p> <p>Some association might exist between pregnancy and the pathogenesis or etiology of acinic cell carcinoma.</p
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