Long Term Factors of Internet Diffusion in Sub-Saharan Africa: A Panel Co- Integration Analysis

Identifying factors that influence the diffusion of the Internet is paramount for researchers as well as policy makers in articulating strategies to improve the availability and subsequent use of the Internet. Most existing empirical studies have focused on this problem by analyzing diffusion data for countries for one fixed year and identified variables affecting the Internet diffusion. These variables, generally, come from the economic, technological, policy, culture, and human capital realms. These results have provided a good “snapshot” of what factors are important towards the diffusion of the Internet and the results tend to vary for studies conducted in different time frames. This paper also addresses, the phenomenon of cross-country dependence – the economic, political, and technological environment of one country affecting other countries- into account in their analyses. This paper, for the first time in the literature, empirically identifies long-term determinants of the Internet diffusion in sub-Saharan African (SSA) countries by considering data for the period 1997-2013. It employs a recently-developed technique named “panel co-integration analysis” to model the diffusion of the internet among the SSA countries. The analysis reveals that in SSA countries, the number of telephones, the level of per capita real gross product and the extent of ruralization (conversely, the degree of urbanization) are the key long-term drivers of the diffusion of the Internet. Finally, the paper concludes with a discussion of policy implications

Natural killer cell biology and its effect on graft versus host disease

Natural killer (NK) cells were originally described in terms of their function. NK cells are of lymphoid origin and are found in the peripheral blood, spleen, and bone marrow, as well as other tissues. These cells are large, radio-resistant and granular lymphocytes that represent an important arm of innate immunity and are thought to play a critical role in the immune surveillance against tumors and virally infected cells. Allogeneic bone marrow transplantation (BMT) has proven to be an effective treatment for hematologic malignancies and some solid tumors. One of the major challenges of allo-stem cell transplantation (SCT) is to reduce the incidence and severity of GVHD while boosting the graft-versus-leukemia (GVL) effect. In the setting of allo-SCT, the reconstitution of NK cells is of notable interest due to their known capability to induce GVL without GVHD. Clinical applications of NK cells have been inspired by recognition of their potent anticancer activity. These studies discussed a solid basis for development of future NK cell trials for cancer therapy by minimizing risks and toxicities

The Effect of Passive Smoking on Total Antioxidant Capacity of Serum and Saliva in Rats

Objective: Active and passive smoking lead to the production of a number of oxidants and antioxidants with various adverse health effects compromising the immune system. Tobacco use increases the production of free radicals as well. The purpose of this study was to determine the effects of passive smoking on total antioxidant capacity (TAC) of serum and saliva in rats.Methods: This experimental study was conducted on 18 rats with an age range of 7-11 weeks weighing 160-200 g; 9 of them were exposed to cigarette smoke 3 times daily for 8 minutes. The 9 controls were not exposed to cigarette smoke. After injection of 0.2 mg/kg midazolam and 0.5  mg/kg pilocarpine, serum and saliva samples were taken from subjects in the exposure and control groups at 0, 15 and 30 days. Serum cotinine was measured using ELISA kit. TAC of saliva and serum was measured using ferric reducing antioxidant power (FRAP) assay. TAC values at different time points were statistically analyzed in each group using Repeated Measures ANOVA and compared between the two groups using t-test.Results: At baseline, no significant difference existed between the two groups in terms of serum cotinine concentration but at days 15 and 30, cotinine serum concentration significantly increased in the exposure group. At baseline and 30 days, no significant difference existed between the two groups of passive smoker and non-smoker in terms of serum TAC values but at day 15, serum TAC values were significantly higher in the exposure group. Also, TAC of salivawas significantly higher in the passive smoker group at baseline and at day 15 but at day 30, the difference in this respect between the two groups was not statistically significant.Conclusion: Based on the obtained results, changes in TAC of serum and saliva in rats due to exposure to cigarette smoke were compensated by their immune system activity. However, further investigations are still required in this respect

Nourodevelopmental follow-up in high-risk infants: Review article

Growing and developing are influenced by genetic, social and environmental factors and it's most important and initial phase step is formed of the early life of the fetus and infant. According to the world health organization, the incidence of preterm birth and low birth weight are increasing in most countries that most of it related to developing countries. Low birth weight (LBW) and preterm birth are one the most important causes of death in the world and therefore are considered as one of the major health problems that can affect growing and developing so that it can threaten public health. Advances in medical technology in recent decades at intensive care unit, increased survival of premature infants and high-risk specialist care is needed, but failed, to reduce the complications of premature birth but it couldn’t reduce complications of preterm birth. There is also an increased recognition of the potential disconnect between perinatal outcomes and long-term outcomes. The administration of oxygen and postnatal steroids are prime examples of interventions that may have immediate positive effects but negative long-term effects. Many premature babies will be encounter with mobility problems, cognitive, neurosensory impairments, cerebral palsy, cognitive and language delays, neuromotor developmental delay, blindness and hearing loss, behavioral and psychosocial disorders, learning difficulties and dysfunction in scholastic performances in the future. These disadvantages appear to persist into adulthood and therefore have broad implications for society. Without a doubt, one of the tragedies of the world is people with physical or mental damage caused by premature birth, many of these disorders are not early diagnosed and the prediction of long term complications of infants discharged from the NICU is difficult. Although nourodevelopmental follow-up of these babies is a necessary part of the neonatal assessment but there is no standard process for it. The present review article aims to introduce the care process and tools that is used for following-up these babies, also introduces the application of screening tools for neuro-developmental care

The Role of Advanced Echocardiographic Parameters of the Left Atrial Function in the Incidence of Cryptogenic Ischemic Stroke: A Review

Stroke is one of the primary causes of morbidity and mortality worldwide, including a large proportionof cryptogenic strokes. Long-term electrocardiographic monitoring is beneficial in prospective studies fordetecting atrial fibrillation in patients with cryptogenic stroke. This review aimed to evaluate the advancedechocardiographic parameters and their roles in assessing left atrial (LA) function in the incidence ofcryptogenic and ischemic strokes. Main resources, including PubMed, Scopus, and ISI Web of Sciencedatabases, were evaluated for articles published in English from 2010 until May 2021. LA echocardiographicparameters such as LA strain and strain rate, isovolumetric relaxation time (IVRT), the mean left atrialvolume index (LAVI), LA reservoir volume, systole strain rate (SSR) of left atrial appendage, and lack ofLA function response to maximal exercise as measured by the LA ejection fraction during rest and exercisecould be considered for assessing the risk of cryptogenic strokes and ischemic strokes. The results indicatedthat increased LA volumes and reduced LA strain rate were correlated with cryptogenic stroke. Advancedparameters of LA function, measured by speckle tracking echocardiography, such as strain and strainrate values in different parts of the cardiac cycle, in addition to standard measures of LA function suchas LA ejection fraction and LAVI, will define an excellent understanding regarding LA myopathy and riskassessment of cryptogenic stroke, independent of considering conventional cardiovascular risk factors

The effect of intrathecal delivery of bone marrow stromal cells on hippocampal neurons in rat model of Alzheimer's disease.

OBJECTIVES: Intracerebral injection of bone marrow stromal cells (BMSCs) is being investigated as a therapeutic tool to prevent Alzheimer's disease (AD). Our aim was to investigate the effects of BMSCs by intrathecal injection in AD rat model. MATERIALS AND METHODS: BMSCs were obtained from the bone marrow of Wistar rat and transplanted into AD rat model via intrathecal injection. The rat model had received an injection of β amyloid into the hippocampus for histological and immunohistochemical studies. RESULTS: Histological examination of the brains in transplanted rats compared to controls demonstrated the migration of BrdU-labeled BMSCs from the site of delivery, confirmed the differentiation of BMSCs transplanted cells into the cholinergic neurons, and increased number of healthy and decreased number of dark neurons. CONCLUSION: Our results showed that BMSCs intratechal administration could be a promising method for treatment of Alzheimer's disease in rat model

Evaluation of the immunity factors (THC, TPP, PO, SOD, POD) of shrimp fed with the yeast Saccharomyces cerevisiae compared to shrimp fed without yeast

Effects of S. cerevisiae on immune parameters of the L. vannamei after 14 days of S .cerevisiae feeding were evaluated in this study. For this purpose a total of 300 pieces of shrimp with an average weight of 30 to 35 grams were selected from a pool shrimp Abadan CHOEBDEH. After making sure the health, absence of necrosis on the surface of the body, cuts antenna, shrimp were transferred to the center of BANDAR IMAM Research Station. Adaptation was carried out for 3-5 days. After the adaptation, shrimps were screened for virus (WSSV, TSV, MBV, HPV, YHV, BP, IHHNV and IMNV) and vibrio bacteria. After screening shrimps divided to two groups with three replication (including 50 pieces of shrimp in triplicate). The experimental diet has the commercial shrimp composition, but 2 g of S. cerevisiae substituted 2 g of fish meal. Shrimp of first group (T1) for 14 days with food containing nutritional yeast and shrimp in second group (T2) were fed with normal diet without yeast. After 14 days Immune Factors and survival rates in both groups were evaluated. The results showed that the relative survival rate between the two groups showed no significant difference. But Immune Factors (THC, TPP, PO, POD and SOD) in the treatment fed yeast (T1) compared to control treatment (T2) showed a significant increase. In conclusion these results suggest that the increased survival rate and resistance of shrimp after S. cerevisiae consumption occurs through immune modifications, such as increases in THC, TPP, SOD, SOP and PO activity

Immunization of cultured shrimp against WSSV by use of produced recombinant vaccine (In vitro)

Shrimp diseases, especially viral diseases are the major limiting factors of shrimp farming activities in the world. White spot disease is one of the most pernicious viral disease that lead to serious loss in all shrimps of penaeids family. In Iran during 2002 to 2004 in Khuzestan province and in 2005 in Bushehr province, the most ponds and farms infected with white spot and the entire industry faced threat of closure. Surface proteins of virus has important role in the early stages of virus with host cell interaction, because these proteins usually enumerated as a candidate to produce a subunit and recombinant vaccines. On the other hand, these proteins can use as an important virus antigen and produce virus-specific antibodies in the preparation of diagnostic kits. In several studies proteins in the form of injection or oral vaccine has shown promising results. This study was designed in order to gain these proteins for immunization of white leg shrimp. To achieve the white spot virus genome, sampling and DNA extraction of moribund shrimps with clinical signs was done from Choebdeh farms. VP28 and VP19 protein-coding gene-specific primers were selected, and after amplification and purification were cloned in E.coli TG1. Protein expression evaluated and commercial plates were coated with inactivated bacteria containing the recombinant protein. White leg shrimp post larvae (PL30) were fed with recombinant food for 7 days then two times in 9th and 23th day after beginning of plate feeding and was challenged by white spot disease virus. The results of the first exposure (end of the seventh day after the shrimp fed with recombinant plate) showed that the lowest mortality at day 14 after exposure in different groups belong to VP28 group with cumulative mortality percent %30 ± 3.84 and the highest percentage of the Group TG1 equal to %72.22±2.93, also The highest and lowest relative percent survival, belong to the group of VP28 (60.29± 5.09%) and TG1 (4.41 ± 2.94%), respectively. In terms of mortality percent and relative percent survival, VP28 and VP 28+19 has significant difference with other groups while there was no significant difference between the groups VP19, TG1 and pMal. In the second exposure experiment (21 days after end of plate feeding) results showed that the lowest cumulative mortality in different groups belong to VP28 (%50 ± 5.09) and the highest percentage was owned by Group TG1 equal to %75.55±2.22, also the highest and the lowest of relative percent survival belong to VP28 (%32.86± 6.83) and TG1 (%0.00 ± 2.98) groups respectively. Similar to the first experiment, VP28 showed significant differences in cumulative mortality and relative percentage of survival in contrast to other group. As a general conclusion it can be noted that recombinant protein VP28 in any form that delivered to shrimp was able to protect shrimp against white spot virus. On the contrary VP19 has no this ability. The survival rate is directly related to the duration of the presence of recombinant protein in the diet

Comparative impact of platelet rich plasma and transforming growth factor-β on chondrogenic differentiation of human adipose derived stem cells

Introduction: Transforming growth factor-beta (TGF-β) is known as standard chondrogenic differentiation agent, even though it comes with undesirable side effects such as early hypertrophic maturation, mineralization, and secretion of inflammatory/angiogenic factors. On the other hand, platelet-rich plasma (PRP) is found to have a chondrogenic impact on mesenchymal stem cell proliferation and differentiation, with no considerable side effects. Therefore, we compared chondrogenic impact of TGF-β and PRP on adipose-derived stem cells (ADSCs), to see if PRP could be introduced as an alternative to TGF-β. Methods: Differentiation of ADSCs was monitored using a couple of methods including glycosaminoglycan production, miRNAs expression, vascular endothelial growth factor (VEGF)/tumor necrosis factor alpha (TNFα) secretion, alkaline phosphatase (ALP) and calcium content assays. Results: Accordingly, the treatment of differentiating cells with 5% (v/v) PRP resulted in higher glycosaminoglycan production, enhanced SOX9 transcription, and lowered TNFα and VEGF secretion compared to the control and TGF-β groups. Besides, the application of PRP to the media up-regulated miR-146a and miR-199a in early and late stages of chondrogenesis, respectively. Conclusion: PRP induces in vitro chondrogenesis, as well as TGF-β with lesser inflammatory and hypertrophic side effects