Poly-(γ-glutamic acid) Production and Optimization from Agro-Industrial Bioresources as Renewable Substrates by Bacillus sp. FBL-2 through Response Surface Methodology

We optimized culture conditions using Bacillus sp. FBL-2 as a poly-(γ-glutamic acid) (PGA) producing strain isolated from cheonggukjang. All experiments were performed under aerobic conditions using a laboratory scale 2.5 L fermentor. We investigated the effects of fermentation parameters (temperature, pH, agitation, and aeration) and medium components (glutamic acid, citric acid, and yeast extract) on poly-(γ-glutamic acid) production, viscosity, and dry cell mass. A non-optimized fermentation method (1.5 vvm, 350 rpm, and 37 °C) yielded PGA, viscosity, and dry cell mass at levels of 100.7 g/L, 483.2 cP, and 3.4 g/L, respectively. L-glutamic acid, citric acid, and yeast extract supplementation enhanced poly-(γ-glutamic acid) production to 175.9 g/L. Additionally, the production of poly-(γ-glutamic acid) from rice bran and wheat bran was assessed using response surface methodology (central composite rotatable design). Agricultural by-products (rice bran and wheat bran) and H2SO4 were selected as factors, and experiments were performed by combining various component concentrations to determine optimal component concentrations. Our experimentally-derived optimal parameters included 38.6 g/L of rice bran, 0.42% of H2SO4, 28.0 g/L of wheat bran, and 0.32% of H2SO4. Under optimum conditions, rice bran medium facilitated poly-(γ-glutamic acid) production of up to 22.64 g/L, and the use of wheat bran medium yielded up to 14.6 g/L. Based on a validity test using the optimized culture conditions, poly-(γ-glutamic acid) was produced at 47.6 g/L and 36.4 g/L from these respective mediums, and both results were higher than statistically predicted. This study suggests that rice bran can be used as a potential alternative substrate for poly-(γ-glutamic acid) production

An Initial Value Technique using Exponentially Fitted Non Standard Finite Difference Method for Singularly Perturbed Differential-Difference Equations

In this paper, an exponentially fitted non standard finite difference method is proposed to solve singularly perturbed differential-difference equations with boundary layer on left and right sides of the interval. In this method, the original second order differential difference equation is replaced by an asymptotically equivalent singularly perturbed problem and in turn the problem is replaced by an asymptotically equivalent first order problem. This initial value problem is solve by using exponential fitting with non standard finite differences. To validate the applicability of the method, several model examples have been solved by taking different values for the delay parameter δ , advanced parameter η and the perturbation parameter ε . Comparison of the results is shown to justify the method. The effect of the small shifts on the boundary layer solutions has been investigated and presented in figures. The convergence of the scheme has also been investigated

Green Tea Consumption Reduces Oxidative Stress in Parkinson’s Disease Patients

Oxidative stress is one of the underlying causes of Parkinson’s disease (PD). Because of its antioxidant effect, we hypothesize that green tea consumption (3 cups daily for 3 months) would improve antioxidant status and reduces oxidative damage in Parkinson’s disease. Fifteen subjects who were within the first five years of PD, on stable PD medication, and not regular green tea consumers were recruited. Iron status, oxidative stress and PD status were evaluated before and after 3 months of green tea consumption. Hemoglobin, serum iron, iron saturation and ferritin concentrations were used to assess iron status. Antioxidant enzymes including catalase, superoxide dismutase (SOD), and glutathione peroxidase (GPx) were measured to determine antioxidant status. Lipid peroxidation and protein carbonyls were measured as oxidative damage markers. There were no changes in total motor scores of the Unified Parkinson’s Disease Rating Scale (UPDRS), PDQ-39 total scores and various iron status markers after 3 months. Catalase (p \u3c 0.05) and SOD activities (p \u3c 0.005) were increased significantly indicating an improvement of antioxidant status. Both lipid peroxidation and protein carbonyls decreased by ~52% (p \u3c 0.01) with green tea consumption, indicating less oxidative stress. In conclusion, 3 cups of green tea consumption for 3 months can improve antioxidant status and reduce oxidative damage in PD patients. Further studies are needed to determine if these changes result in slowing the disease progression

A case of human parvo virus B 19 infection with erythroid hypoplasia and Idiopathic thrombocytopenic purpura in an immunocompetent child: a case report

Human parvo virus B19 (B19V) is a small (5.5kb) single stranded DNA (deoxy ribo nucleic acid) virus with known tropism and cytotoxicity for erythroid progenitors. Human parvovirus B19 infection is associated with various hematological disorders like aplastic crisis, erythroid hypoplasia and idiopathic thrombocytopenic purpura. Here we are presenting a rare case of parvo virus B19 infection with erythroid hypoplasia and idiopathic thrombocytopenic purpura occurring simultaneously in a 13year old girl who presented with fever and bleeding manifestations. A 13 year old girl presented with fever of 5 days duration, epistaxis and bleeding gums spontaneously of one day duration. On admission she had pancytopenia. Her B12 and folate levels were within normal range. Bone marrow aspiration suggestive of normal cellularity with paucity of erythroid precursors, myeloid: erythroid ratio 9:1 and gaint basophilic pronormoblasts with intra-nuclear inclusions, with no further maturation, as well as increased megakaryocytes with few hypolobate forms suggestive of erythroid hypoplasia and idiopathic thrombocytopenic purpura. Parvo virus B19 DNA PCR by nested polymerase chain reaction was detected in serum. She was treated with blood component support and with steroids for idiopathic thrombocytopenic purpura. She recovered and her cell counts are improved. This case highlights the morphology of Human parvo virus B19 inclusions and its association with simultaneous presentation of erythroid hypoplasia and idiopathic thrombocytopenic purpura in immunocompetent child, which is very rare

Validation of Molecular Markers Genetically Linked to S-Cytoplasm and Restoration-of-fertility (Rf) Loci in Hot Pepper (Capsicum annuum L.)

Existence of CGMS system in hot pepper is due to the rearrangements in the mitochondrial genome and is largely used in economized and pure F 1 hybrid seed production around the world. The orf456, a new ORF present at flanking region of the coxII gene at the 3’ end, was distinguished male sterile cytoplasm in hot peppers along with atp6-2gene. In the current study, eighteen pepper genotypes (nine each of A and corresponding B lines) of varied origin were used to validate with two male sterile cytoplasm (S-cytoplasm) specific sequence characterised amplified region (SCAR) markers viz., atp6-2 (875 bp) and orf456 (456 bp) and one restoration-of-fertility (Rf) locus specific marker, CRF (550 bp). The results clearly showed that the presence of CMS-S-cytoplasm and absence of restoration-of-fertility (Rf) gene in the pepper genotypes studied and is comparable with the phenotypic data. In view of the outcomes it has been reasoned that the accessible S and Rf markers available in the public domain are reproducible and can be promptly utilized for marker assisted selection (MAS) in hot pepper crop improvement program

Experimental Evidence of Time Delay Induced Death in Coupled Limit Cycle Oscillators

Experimental observations of time delay induced amplitude death in a pair of coupled nonlinear electronic circuits that are individually capable of exhibiting limit cycle oscillations are described. In particular, the existence of multiply connected death islands in the parameter space of the coupling strength and the time delay parameter for coupled identical oscillators is established. The existence of such regions was predicted earlier on theoretical grounds in [Phys. Rev. Lett. 80, 5109 (1998); Physica 129D, 15 (1999)]. The experiments also reveal the occurrence of multiple frequency states, frequency suppression of oscillations with increased time delay and the onset of both in-phase and anti-phase collective oscillations.Comment: 4 aps formatted RevTeX pages; 6 figures; to appear in Phys. Rev. Let

Parameterized Inapproximability of Target Set Selection and Generalizations

In this paper, we consider the Target Set Selection problem: given a graph and a threshold value $thr(v)$ for any vertex $v$ of the graph, find a minimum size vertex-subset to "activate" s.t. all the vertices of the graph are activated at the end of the propagation process. A vertex $v$ is activated during the propagation process if at least $thr(v)$ of its neighbors are activated. This problem models several practical issues like faults in distributed networks or word-to-mouth recommendations in social networks. We show that for any functions $f$ and $\rho$ this problem cannot be approximated within a factor of $\rho(k)$ in $f(k) \cdot n^{O(1)}$ time, unless FPT = W[P], even for restricted thresholds (namely constant and majority thresholds). We also study the cardinality constraint maximization and minimization versions of the problem for which we prove similar hardness results