A new operational matrix based on Bernoulli polynomials

In this research, the Bernoulli polynomials are introduced. The properties of these polynomials are employed to construct the operational matrices of integration together with the derivative and product. These properties are then utilized to transform the differential equation to a matrix equation which corresponds to a system of algebraic equations with unknown Bernoulli coefficients. This method can be used for many problems such as differential equations, integral equations and so on. Numerical examples show the method is computationally simple and also illustrate the efficiency and accuracy of the method

Overexpression of microRNA-16 declines cellular growth, proliferation and induces apoptosis in human breast cancer cells

MicroRNAs (miRNA) are a large family of small single-stranded RNA molecules found in all multicellular organisms. Early studies have been shown that miRNA are involved in cancer development and progression, and this role can be done by working as an oncogenes and tumor suppressor genes, so manipulation of this molecules can be a promising approach in cancer therapy, and experimental results represented that the modification in breast cancer phenotype is possible by miRNA expression alteration. miR-16, which is located in 13q14 chromosome, plays critical roles as a tumor suppressor by targeting several oncogenes which regulate cell cycle and apoptosis. Hence, in the present study, we investigated whether miR-16 could decline growth and survival of MCF-7 cell line as model of human breast cancer. MCF-7 cell line was infected with lentiviruses containing miR-16 precursor sequence. The effects of ectopic expression of miR-16 on breast cancer phenotype were examined by cell cycle analysis and apoptosis assays. miR-16 cytotoxicity effect was measured by the MTT assay. We showed that the miR-16 overexpression reduces Cyclin D1 and BCL2 at messenger RNA (mRNA) and protein levels in MCF-7 cell line. In addition, this is found that enforced expression of miR-16 decreases cell growth and proliferation and induces apoptosis in MCF-7 cells. In conclusion, our results revealed that upregulation of miR-16 would be a potential approach for breast cancer therapy. © 2015, The Society for In Vitro Biology

Susceptibility of Leishmania major to Veronica persica Poir. extracts - In vitro and in vivo assays

Leishmania major is an intracellular parasite generally responsible for cutaneous leishmaniasis (CL), one of the most encountered skin diseases especially in Pakistan, Iran, Iraq, and Saudi Arabia. Current treatment options are not ideal, due to unwanted side effects and increasing resistance and availability is often limited in developing countries. Medicinal plants continue to attract attention because of their beneficial effects in the prevention or/and accelerating the healing process of various diseases. In this study, in vitro and in vivo susceptibility of L. major to Veronica persica Poir. extract, a medicinal plant with many applications, has been evaluated. Antileishmanial activity of plant extract was investigated both on cultured L. major promastigotes and in mice challenged with L. major. Animals were divided into three groups including control (without any treatment), test (treated with plant extract) and glucantime (the reference drug) treated groups. After treatments, skin lesion sizes and body weights of animals were checked during 4 weeks. The potential of the plant extract in decreasing the number of parasites in spleen cells of animals as well as inducing the nitric oxide (NO) production by macrophage cells was also investigated. In vitro tests showed that the plant extract was able to reduce the survival time of promastigotes in a concentration-dependent manner. In vivo experiments also revealed a significant influence of V. persica extracts on accelerating the healing process as well as reducing the overall disease burden in animal model by inducing NO production in macrophage cells. Our findings indicated the promising potential of V. persica extract as an ideal candidate in the treatment of CL caused by L. major

Topological Measure Locating the Effective Crossover between Segregation and Integration in a Modular Network

We introduce an easily computable topological measure which locates the effective crossover between segregation and integration in a modular network. Segregation corresponds to the degree of network modularity, while integration is expressed in terms of the algebraic connectivity of an associated hyper-graph. The rigorous treatment of the simplified case of cliques of equal size that are gradually rewired until they become completely merged, allows us to show that this topological crossover can be made to coincide with a dynamical crossover from cluster to global synchronization of a system of coupled phase oscillators. The dynamical crossover is signaled by a peak in the product of the measures of intra-cluster and global synchronization, which we propose as a dynamical measure of complexity. This quantity is much easier to compute than the entropy (of the average frequencies of the oscillators), and displays a behavior which closely mimics that of the dynamical complexity index based on the latter. The proposed toplogical measure simultaneously provides information on the dynamical behavior, sheds light on the interplay between modularity vs total integration and shows how this affects the capability of the network to perform both local and distributed dynamical tasks

Short sales constraints and price adjustment to earnings announcements

This study looks at how short sales constraints affect the stock price adjustment to the release of public information in the Hong Kong Stock Exchange for a sample of 4,757 firm-event observations over the period 1994-2011. Using a unique feature of this market that allows us to directly investigate the impact of the imposition of short sales restriction, we find following results. First, nonshortable stocks react more strongly to negative information than shortable stocks. Second, nonshortable stocks are overpriced before the negative earnings announcement. Hence, part of the strong market reaction of nonshortable stocks on announcement day could be due to the correction of such overpricing. Third, prices of nonshortable stocks reverse following the announcement of negative information, suggesting that investors overreact to the negative information on the announcement day. Fourth, it takes longer time for the prices of nonshortable stocks to fully adjust to the negative earnings information. On the whole, our results are supportive of the stream of research that finds the imposition of short sales restrictions reduce the efficiency of stock markets

In vitro and in vivo assessment of free radical scavenging and antioxidant activities of Veronica persica Poir

With the appearance of new disorders along with inability of some conventional therapies for the treatment of diseases without any side effects, the discovery of safe and efficient therapeutic agents is of utmost importance in the medical area. In this context, medicinal plants as promising therapeutic candidates can provide a reliable and efficient profile. Since free radicals are at the center of various disorder pathways, reducing their production or complete removal of these chemical species could be advantageous for prevention and treatment of many diseases. In this experiment, free radical scavenging and antioxidant activities of Veronica persica Poir., a known medicinal plant, were evaluated using in vitro and in vivo assays. Chemical characterization results showed a high phenolic content in the V. persica methanol extract. In addition, in vitro assays including DPPH radical-scavenging assay, nitric oxide-scavenging activity assay, hydrogen peroxide scavenging test and bleomycin-dependent DNA damage test revealed significant antioxidant power and radical scavenging capacity of this plant. In accordance, in vivo experiments showed inhibitory effects of the methanol extract on lipid peroxidation, a main cause of cell damage. Our findings revealed the promising potential of this plant in reducing free radicals through different pathways. Moreover, our data suggested a correlation between the high phenolic content of the V. persica extract and its free radical scavenging and antioxidant activities

Pullulan gum production from low-quality fig syrup using Aureobasidium pullulans

Pullulan is an important polysaccharide with several potential applications in food science, pharmaceutical and cosmetic industries, but high costs of pullulan production are the main limitation for commercial utilization. Therefore, a cost-effective process for pullulan production was developed using fig syrup as an exclusive nutrient source. In particular, the feasibility of using low quality fig syrup as a supplemental substrate for pullulan gum production by Aureobasidium pullulans was investigated. Fermentation was carried out over a range of fig syrup and sucrose degrees Brix (5-15%). Maximum pullulan gum production was observed after 96h using 12.5% fig syrup, yielding approximately14.06 g/L. This value of pullulan production (14.06 g/L) was higher than the amount of pullulan produced using sucrose as substrate (5.01 g/L). In conclusion, fig syrup was an effective substrate for pullulan production by Aureobasidium pullulans, and, therefore, this byproduct deserves attention for the cost-effective and environmentally friendly pullulan production

Foodborne Listeriosis

Abstract: Foodborne listeriosis is a rare and very dangerous disease which is caused by Listeria monocytogenes. This bacterium is found in the nature in very high population, but can cause disease only in certain groups of people. Listeriosis usually happens after consumption of unpasteurized dairy products especially soft and unripe cheeses and ready to eat meat products like hot dog by susceptible people. In general, pregnant women, infants, elderly people and immuno deficient patients are susceptible to this disease. Listeria monocytogenes is able to produce septicemia, meningitis and abortion in human. The important characteristic of this bacterium is its ability to live inside the cells of immune system and by this way, it is able to distribute through body easily. In order to prevent listeriosis, susceptible people should avoid eating unpasteurized dairy products and ready to eat meats. Keywords: Foodborne disease, Listeria infections, Listeria monocytogene