3,096 research outputs found
Underdetermined blind source separation based on Fuzzy C-Means and Semi-Nonnegative Matrix Factorization
Conventional blind source separation is based on over-determined with more sensors than sources but the underdetermined is a challenging case and more convenient to actual situation. Non-negative Matrix Factorization (NMF) has been widely applied to Blind Source Separation (BSS) problems. However, the separation results are sensitive to the initialization of parameters of NMF. Avoiding the subjectivity of choosing parameters, we used the Fuzzy C-Means (FCM) clustering technique to estimate the mixing matrix and to reduce the requirement for sparsity. Also, decreasing the constraints is regarded in this paper by using Semi-NMF. In this paper we propose a new two-step algorithm in order to solve the underdetermined blind source separation. We show how to combine the FCM clustering technique with the gradient-based NMF with the multi-layer technique. The simulation results show that our proposed algorithm can separate the source signals with high signal-to-noise ratio and quite low cost time compared with some algorithms
3D printed multi-drug-loaded suppositories for acute severe ulcerative colitis
Acute severe ulcerative colitis (ASUC) is a growing health burden that often requires treatment with multiple therapeutic agents. As inflammation is localised in the rectum and colon, local drug delivery using suppositories could improve therapeutic outcomes. Three-dimensional (3D) printing is a novel manufacturing tool that permits the combination of multiple drugs in personalised dosage forms, created based on each patient's disease condition. This study, for the first time, demonstrates the feasibility of producing 3D printed suppositories with two anti-inflammatory agents, budesonide and tofacitinib citrate, for the treatment of ASUC. As both drugs are poorly water-soluble, the suppositories' ability to self-emulsify was exploited to improve their performance. The suppositories were fabricated via semi-solid extrusion (SSE) 3D printing and contained tofacitinib citrate and budesonide in varying doses (10 or 5 mg; 4 or 2 mg, respectively). The suppositories displayed similar dissolution and disintegration behaviours irrespective of their drug content, demonstrating the flexibility of the technology. Overall, this study demonstrates the feasibility of using SSE 3D printing to create multi-drug suppositories for the treatment of ASUC, with the possibility of titrating the drug doses based on the disease progression
Effects of Some Essential Oils on Aspergillus flavus Growth and Aflatoxin Production
The present study aimed at investigating the effects of some essential oils on inhibiting fungal growth of A. flavus and aflatoxin production. Clove oil was found as the best among the six different oils tested against the radial growth at the concentration of 0.05. mL/100ml. However the other oils were also significantly better than the control except the Pumpkin oil. Different concentrations (0.00, 0.01, 0.03 and 0.05 ml/100ml) of only three of the oils were tested against the radial growth of A. flavus. Clove and Cumin oils were significantly effective than the control at all these concentrations. Although Pumpkin oil was slightly more effective than the control at its higher concentration (0.05) ml/100ml), it was not effective at its lower concentrations (0.01 and 0.03 ml/100ml). Clove oil was also the best in suppressing mycelial growth at the concentration of 0.05 ml/100ml. However, the other oils were also significantly better than the control, while, Pumpkin oil was non-effective. Spore germination was also affected by the oils tested. Clove oil gave complete inhibition at its higher concentration followed by Cumin, Rehan, Garlic and Desert date, while Pumpkin oil was the least one. Aflatoxin production was highly affected by the essential oils tested. Clove and Cumin exhibited a complete inhibition, followed by Rehan; Garlic and Desert date while Pumpkin oil was non-effective
Growth performance, duodenal morphology and the caecal microbial population in female broiler chickens fed glycine-fortified low protein diets under heat stress conditions
This study was undertaken to examine the effect of feeding glycine (Gly)-fortified low protein (LP) diets on the growth performance, duodenal morphology and caecal microbial populations of broiler chickens raised under unheated, cyclic or constant heat stress environmental conditions. 2. From d 1 to 21 (starter phase), an equivalent number of birds were fed either a normal protein (NP) diet or a LP diet fortified with Gly. From d 22 to 42 (grower phase), an equivalent number of birds from each starter diet were distributed to one of the following dietary groups: (i) an NP diet during the starter and grower phases (NPNP), (ii) an NP diet during the starter phase and a LP diet during the grower phase (NPLP), (iii) an LP diet during the starter phase and an NP diet during the grower phase (LPNP) or (iv) LP diets during both phases (LPLP). 3. Commencing from d 22, an equivalent number of birds from each dietary group were exposed to (i) 23 ± 1°C throughout (unheated), (ii) 34 ± 1°C for 7 h each day from 10:00 to 17:00 (cyclic heat) or (iii) 34 ± 1°C throughout (constant heat). 4. Feeding the LP diet during the starter phase resulted in feed intake (FI), weight gain (WG), feed conversion ratios (FCR) and energy efficiency ratios (EER) similar to those for the NP diet. The birds fed the LP diet had a significantly higher protein efficiency ratio (PER) compared with the birds fed the NP diet. 5. During the grower phase, there were significant diet × temperature interactions for F, WG, FCR, PER, EER, villus height, crypt depth and caecal Clostridia. The birds fed the NPLP and LPLP diets had lower FI, WG and EER, higher FCR, shorter villus height and crypt depth and higher caecal Clostridia compared with the birds fed LPNP and NPNP diets under constant heat stress. However, feeding birds the NPLP and LPLP diets resulted in FI, WG, EER, FCR, morphology parameters and caecal Clostridia equivalent to the birds fed LPNP and NPNP diets, as well as improved PER, under unheated and cyclic heat stress conditions. 6. In conclusion, our results indicate that Gly-fortified LP diets can be fed to broilers under normal and acute heat stress environmental conditions without any adverse effects on performance. However, the use of such LP diets can be detrimental to broilers under chronic heat stress conditions
Production of Polysaccharides (Xanthan gum) by Xanthomonas campestris pv. Sesame
Many microorganisms and plants were found produce polysaccharides which are widely varying in their composition and structure. The extracellular polysaccharide produced by Xanthomonas campestris pv. campestris, is chemically analyzed and used industrially. However, only the xanthan gum which was ranking as the best among the ten polysaccharides was used commercially in large amounts. The xanthan gum has numerous applications in food and other industries. The present study was aiming to investigate the capacity of X; campestris pv. sesami for the production of xanthan gum, using culture media containing different carbon sources. The properties of the produced material were investigated (pH, viscosity, and chromatographic analysis using thin layer chromatography). The results showed that the weight of the product was increasing with time reaching about 9.8g at the tenth day compared to only 2.1g on the second day. The results of the effect of different carbon sources indicated that sucrose was the best giving 9.0 g in the 7th day compared to only 1.5g by raffinose. The pH was changing from 6.7 at the beginning of the experiment to 4.2 in the tenth day. However, the viscosity of the inoculated sucrose medium was found to increase from 2.4 unit at the second day to 9.7 units after ten days. Analysis on paper chromatography showed that the produced polysaccharide contains mannose, glucuronic acid, glucose, rhamnose but no ribose nor trehalose or fructose were detected. The results indicated that the investigated bacterium was producing large amounts of xanthan gum. Although, Xanthan gum was discovered in 1950s its substantial commercial production began in 1964 and in 1969, the USA, Food and Drug Administration authorized its use in food. Xanthan gum, now has numerous uses in food and other industries. Further studies should be carried on other isolates of the bacterium X. campestris pv. sesami and more chemical analysis are needed
Nuttier (A)dS Black Holes in Higher Dimensions
We construct new solutions of the vacuum Einstein field equations with
cosmological constant. These solutions describe spacetimes with non-trivial
topology that are asymptotically dS, AdS or flat. For a negative cosmological
constant these solutions are NUT charged generalizations of the topological
black hole solutions in higher dimensions. We also point out the existence of
such NUT charged spacetimes in odd dimensions and we explicitly construct such
spaces in 5 and 7 dimensions. The existence of such spacetimes with non-trivial
topology is closely related to the existence of the cosmological constant.
Finally, we discuss the global structure of such solutions and possible
applications in string theory.Comment: latex, 30 pages, added reference
The non-Abelian gauge theory of matrix big bangs
We study at the classical and quantum mechanical level the time-dependent
Yang-Mills theory that one obtains via the generalisation of discrete
light-cone quantisation to singular homogeneous plane waves. The non-Abelian
nature of this theory is known to be important for physics near the
singularity, at least as far as the number of degrees of freedom is concerned.
We will show that the quartic interaction is always subleading as one
approaches the singularity and that close enough to t=0 the evolution is driven
by the diverging tachyonic mass term. The evolution towards asymptotically flat
space-time also reveals some surprising features.Comment: 29 pages, 8 eps figures, v2: minor changes, references added: v3
small typographical changes
Association between polymorphisms of SLC6A3 and DRD1 genes and autism among Saudi Arabia Taif population using PCR-restriction fragment length polymorphism (PCR- RFLP)
The prevalence of autism in Saudi Arabia is 18 per 10,000, higher than the 13 per 10,000 reported in developed countries. The etiology of autism is still not completely understood. Different studies support the involvement of dopaminergic neurotransmitter system in the etiology of autism. Several lines of evidences suggest the role of some dopamine related genes, such as DRD1 and SLC6A3 in the etiology of autism. The aim of the present work was to study the possible role of rs2550936 A/C polymorphism at SLC6A3 locus as well as rs4532 A/G polymorphism at DRD1 locus in the etiology of autism among Saudi population. The polymorphisms of DRD1 and LC6A3 were genotyped in the case-control study using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. Significant association as risk factor was found between autism and GA genotype of DRD1 [OR = 3.5 CI (1.04, 12.41*)] as well as CA genotype of SLC6A3 [OR = 2.53 CI (1.03, 6.26*)], while CC genotype of SLC6A3 revealed protective effect. In conclusion, possible risk genotypes for autism in the DRD1 and SLC6A3 genes were observed. This is the first report in Saudi Arabia population and Arab world. Therefore further investigations of these markers and other SNPs of SLC6A3 and DRD1 genes are considered in large replication samples with other causal factors to enable positive identification of risk genotypes and generalize obtained results.Key words: Etiology, polymorphism, autism, genotype
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