776 research outputs found
The Quark-Gluon Plasma Equation of State and The Generalized Uncertainty Principle
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 , and 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 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
Recommended from our members
Formal and Empirical Studies of Counting Behaviour in ReLU RNNs
In recent years, the discussion about systematicity of neural network learning has gained renewed interest, in particular the formal analysis of neural network behaviour. In this paper, we investigate the capability of single-cell ReLU RNN models to demonstrate precise counting behaviour. Formally, we start by characterising the semi-Dyck-1 language and semi-Dyck-1 counter machine that can be implemented by a single Rectified Linear Unit (ReLU) cell. We define three Counter Indicator Conditions (CICs) on the weights of a ReLU cell and show that fulfilling these conditions is equivalent to accepting the semi-Dyck-1 language, i.e. to perform exact counting. Empirically, we study the ability of single-cell ReLU RNNs to learn to count by training and testing them on different datasets of Dyck-1 and semi-Dyck-1 strings. While networks that satisfy the CICs count exactly and thus correctly even on very long strings, the trained networks exhibit a wide range of results and never satisfy the CICs exactly. We investigate the effect of deviating from the CICs and find that configurations that fulfil the CICs are not at a minimum of the loss function in the most common setups. This is consistent with observations in previous research indicating that training ReLU networks for counting tasks often leads to poor results. We finally discuss implications of these results and possible avenues for improving network behaviour
Giant synovial cell sarcoma of the thorax in a 46-year-old man: a case report
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
Redox linked flavin sites in extracellular decaheme proteins involved in microbe-mineral electron transfer
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
Descriptive epidemiology of salivary gland neoplasms in Nigeria: An AOPRC multicenter tertiary hospital study
Objectives: Accurate diagnosis of salivary gland neoplasms (SGN) in many centers in
Africa is limited by poor diagnostic resources and ancillary services. Hence, we have
carried out a multicenter epidemiological study to understand the true burden of
SGN in Nigeria.
Method: In this descriptive cross‐sectional study, we have deployed resources available
to members of the African Oral Pathology Consortium (AOPRC) to examine the
burden of salivary gland lesions in Nigeria, using a multicenter approach. Data from
seven major tertiary health institutions in northern, western, and southern Nigeria
were generated using a standardized data extraction format and analyzed using the
Epi‐info software (Version 7.0, Atlanta, USA).
Result: Of the 497 cases examined across the seven centers, we observed that SGN
occurred more in females than males. Overall, pleomorphic salivary adenoma (PA)
was found to be the most common. PA was found to be the commonest benign SGN
while adenocystic carcinoma (ADCC) was the commonest malignant SGN. Regional
variations were observed for age group, diagnosis, and gender distribution. Significant statistical differences were found between males and females for malignant SGNs (p‐value=0.037).
Conclusion: We found regional variation in the pattern of distribution of SGN in
Nigeria. This is the largest multicenter study of SGN in Nigeria, and our findings are
robust and representative of the epidemiology of this neoplasm in Nigeria
Acinic cell carcinoma in pregnancy: a case report and review of the literature
<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
Allelopathic Effects of Water Hyacinth [Eichhornia crassipes]
Eichhornia crassipes (Mart) Solms is an invasive weed known to out-compete native plants and negatively affect microbes including phytoplankton. The spread and population density of E. crassipes will be favored by global warming. The aim here was to identify compounds that underlie the effects on microbes. The entire plant of E. crassipes was collected from El Zomor canal, River Nile (Egypt), washed clean, then air dried. Plant tissue was extracted three times with methanol and fractionated by thin layer chromatography (TLC). The crude methanolic extract and five fractions from TLC (A–E) were tested for antimicrobial (bacteria and fungal) and anti-algal activities (green microalgae and cyanobacteria) using paper disc diffusion bioassay. The crude extract as well as all five TLC fractions exhibited antibacterial activities against both the Gram positive bacteria; Bacillus subtilis and Streptococcus faecalis; and the Gram negative bacteria; Escherichia coli and Staphylococcus aureus. Growth of Aspergillus flavus and Aspergillus niger were not inhibited by either E. crassipes crude extract nor its five fractions. In contrast, Candida albicans (yeast) was inhibited by all. Some antialgal activity of the crude extract and its fractions was manifest against the green microalgae; Chlorella vulgaris and Dictyochloropsis splendida as well as the cyanobacteria; Spirulina platensis and Nostoc piscinale. High antialgal activity was only recorded against Chlorella vulgaris. Identifications of the active antimicrobial and antialgal compounds of the crude extract as well as the five TLC fractions were carried out using gas chromatography combined with mass spectroscopy. The analyses showed the presence of an alkaloid (fraction A) and four phthalate derivatives (Fractions B–E) that exhibited the antimicrobial and antialgal activities
Recommended from our members
Modeling the summertime evolution of sea-ice melt ponds
1] We present a mathematical model describing the summer melting of sea ice. We simulate the evolution of melt ponds and determine area coverage and total surface ablation. The model predictions are tested for sensitivity to the melt rate of unponded ice, enhanced melt rate beneath the melt ponds, vertical seepage, and horizontal permeability. The model is initialized with surface topographies derived from laser altimetry corresponding to first-year sea ice and multiyear sea ice. We predict that there are large differences in the depth of melt ponds and the area of coverage between the two types of ice. We also find that the vertical seepage rate and the melt rate of unponded ice are important in determining the total surface ablation and area covered by melt ponds
- …