Praxis: An Editorial Statement

Praxis: An Editorial Statemen

The Double Dividend of a Joint Tariff and VAT Reform: Evidence from Iran

Abstract A rich theoretical literature discusses whether replacing tariffs with value added tax (VAT) improves efficiency. We provide empirical evidence on a novel complementarity between VAT and trade taxes. Downstream domestic firms require VAT receipts from importers to claim purchases VAT increasing incentives for honest reporting of imports. We use the trade gap, the difference between mirror and domestic trade reports in Iran at 6-digit HS disaggregation, to measure this complementarity. Iran introduced VAT in 2008 and increased its rate from 3 to 9 percent since then. Difference-in-differences estimations show that a 1 percentage point increase in the VAT rate reduces the trade gap by 6.7 percent. Consistent with the compliance mechanisms of VAT, we observe a smaller effect for the consumer products that have a shorter value chain. Our results suggest that replacing tariffs with VAT results in a double dividend. Tax revenue could increase due to better tariff compliance and a broader VAT base

The effect of bilingualism on the processing of clustering and switching in verbal fluency tasks

Background: This study examined the effect of bilingualism on the processing of clustering and switching in verbal fluency tasks in Farsi-Balochi bilinguals. Methods: Ninety participants entered this study, including 45 Farsi monolinguals and 45 Farsi-Balochi bilinguals. All participants were male university students between the ages of 18 to 24 years. Verbal fluency tests were performed and the clustering and switching scores were calculated. Data was analyzed in SPSS-16 software. Results: The monolingual group obtained a score of 32.84 in the total semantic fluency task and 24.13 in the phonemic fluency task, while the bilingual group obtained 30.70 in the semantic task and 29.37 in the phonemic task. The number of switches between the clusters and the mean cluster size were 35.82 and 2.6 in the monolingual group and 38.65 and 2.26 in the bilingual group, respectively. The difference between groups in phonemic fluency, phonemic switching, and semantic clustering was significant (p˂0.05). Discussion: The bilingual group performed better in phonemic fluency and switched more between the clusters. Meanwhile, the monolinguals produced more words in each cluster than the bilinguals

Comparison of Phonemic Fluency Test Results Using Different Letters among Persian Speakers

Background: The purpose of this study was to compare the results obtained from phonemic fluency test using “F”1 , “A”2 , “S”3 and “L”4 , “T”5 ,”M”6 among Persian Speakers aged between 20 and 30 years. Methods: In this applied study, 76 subjects were randomly chosen. The data was analyzed separately for each subject according to the three letters: “F”, “A”, and “S” by using the routine phonemic fluency subtest of verbal fluency test and then phonemic fluency performance was gathered by using the three letters: “L”, “T” and “M” and after scoring according to Troyer method, the resultant numbers were reported after statistical analyses. For statistical analysis using SPSS 19, the distribution of data was firstly evaluated. Due to the fact that the data distribution was normal, Bonferroni test was used to compare the scores of the letters. Results: No significant gender and educational level effects were found and therefore, all further analyses were conducted without taking gender and educational level into account. Also, when the results of the three letters: “F”, “A” and “S” as a group for phonemic fluency performance and “L”, “T” and “M” letters as a different group, were integrated, a significant difference was found between the mean cluster size and switching between these two groups, while there was no significant difference between the average cluster size and cluster number. Conclusion: Based on the findings of this research, it can be concluded that the results of phonemic fluency test in each of the six letters are significantly different. Therefore, when using the special letters in the Persian language, it is necessary to examine all the letters for phonological sub-tests and use the simplest letters to study this function

Overexpression of miR-490-5p/miR-490-3p Potentially Induces IL-17-Producing T Cells in Patients With Breast Cancer

Objective: Breast cancer (BC) is the most prevalent female cancer globally and this is also true in Iranian women. Alteration in circulating microRNAs affects the fate of immune cells, affecting immunological response to neoplasia. Materials and Methods: We investigated the expression of miR-490-5p and miR-490-3p in peripheral blood mononuclear cells (PBMCs) and plasma of patients with BC. Moreover, the correlation of these microRNAs with the expression levels of CD3d, interleukin 2 (IL-2), IL-2 receptor chain alpha (IL-2RA), forkhead box O1 (FOXO1) and nuclear factor of activated T cells 5 (NFAT5) were investigated. Results: Two groups, including 42 patients with BC, aged 22-75 years with stage I, II, III disease without administration of immunosuppressive chemotherapy regimens/radiotherapy and 40 healthy controls aged 27-70 years, participated. Overexpression and higher circulation levels of miR-490-5p and miR-490-3p were found in the patients with consequent down-regulation of all targets investigated in PBMCs. Furthermore, there was a significant negative correlation between the overexpression of these microRNAs and a reduction in levels of CD3d, IL-2, and IL-2RA in patients with BC. Conclusion: These results suggest that down-regulation of the target genes by miR-490 may predispose and facilitate the production of Th17 lymphocytes and IL-17-producing Tregs. The variation in miR-490-5p/-3p and the investigated targets in the PBMCs of BC patients may be used as non-invasive diagnostic markers

Evaluation of anti-biofilm activity of Lactobacillus rhamnosus GG and Nisin on the expression of aap, ica-A and ica-D as biofilm-associated genes of Staphylococcus epidermidis

Background and Objectives: In the present study, the anti-biofilm activity of Lactobacillus rhamnosus GG and Nisin was investigated on biofilm-forming abilities of Staphylococcus epidermidis strains and the expression of the biofilm-associated genes. Materials and Methods: In this study, the standard strain of L. rhamnosus GG (ATCC 53103) and Nisin were used to assess their anti-microbial and anti-biofilm effects on S. epidermidis (RP62A). Results: The MIC and MBC analysis showed that Nisin at 256 μg/mL and 512 μg/mL, and L. rhamnosus GG at 1×107 CFU/mL and 1×108 CFU/mL have anti-microbial activity compared to the negative control respectively. L. rhamnosus GG bacteria and Nisin inhibited the biofilm formation of S. epidermidis based on optical density of at 570 nm (P 0.05). In addition, the relative expression of aap and icaA genes, but not icaD (P>0.05), was significantly lower than the negative control (0.62 and 0.7 fold, respectively) (P>0.05), after exposure to the sub MIC of L. rhamnosus GG. Conclusion: Nisin and L. rhamnosus GG exhibit potent activity against biofilm-forming abilities of S. epidermidis and these agents could be utilized as an anti-biofilm agents against S. epidermidis infections

The synergic effects of presynaptic calcium channel antagonists purified from spiders on memory elimination of glutamate-induced excitotoxicity in the rat hippocampus trisynaptic circuit

The hippocampus is a complex area of the mammalian brain and is responsible for learning and memory. The trisynaptic circuit engages with explicit memory. Hippocampal neurons express two types of presynaptic voltage-gated calcium channels (VGCCs) comprising N and P/Q-types. These VGCCs play a vital role in the release of neurotransmitters from presynaptic neurons. The chief excitatory neurotransmitter at these synapses is glutamate. Glutamate has an essential function in learning and memory under normal conditions. The release of neurotransmitters depends on the activity of presynaptic VGCCs. Excessive glutamate activity, due to either excessive release or insufficient uptake from the synapse, leads to a condition called excitotoxicity. This pathological state is common among all neurodegenerative disorders, such as Alzheimer’s and Parkinson’s diseases. Under these conditions, glutamate adversely affects the trisynaptic circuitry, leading to synaptic destruction and loss of memory and learning performance. This study attempts to clarify the role of presynaptic VGCCs in memory performance and reveals that modulating the activity of presynaptic calcium channels in the trisynaptic pathway can regulate the excitotoxic state and consequently prevent the elimination of neurons and synaptic degradation. All of these can lead to an improvement in learning and memory function. In the current study, two calcium channel blockers—omega-agatoxin-Aa2a and omega-Lsp-IA—were extracted, purified, and identified from spiders (Agelena orientalis and Hogna radiata) and used to modulate N and P/Q VGCCs. The effect of omega-agatoxin-Aa2a and omega-Lsp-IA on glutamate-induced excitotoxicity in rats was evaluated using the Morris water maze task as a behavioral test. The local expression of synaptophysin (SYN) was visualized for synaptic quantification using an immunofluorescence assay. The electrophysiological amplitudes of the field excitatory postsynaptic potentials (fEPSPs) in the input-output and LTP curves of the mossy fiber and Schaffer collateral circuits were recorded. The results of our study demonstrated that N and P/Q VGCC modulation in the hippocampus trisynaptic circuit of rats with glutamate-induced excitotoxicity dysfunction could prevent the destructive consequences of excitotoxicity in synapses and improve memory function and performance

Ameliorative effects of omega-lycotoxin-Gsp2671e purified from the spider venom of Lycosa praegrandis on memory deficits of glutamate-induced excitotoxicity rat model

Memory impairment is one of the main complications of Alzheimer’s disease (AD). This condition can be induced by hyper-stimulation of N-Methyl-D-aspartate receptors (NMDARs) of glutamate in the hippocampus, which ends up to pyramidal neurons determination. The release of neurotransmitters relies on voltage-gated calcium channels (VGCCs) such as P/Q-types. Omega-lycotoxin-Gsp2671e (OLG1e) is a P/Q-type VGCC modulator with high affinity and selectivity. This bio-active small protein was purified and identified from the Lycosa praegrandis venom. The effect of this state-dependent low molecular weight P/Q-type calcium modulator on rats was investigated via glutamate-induced excitotoxicity by N-Methyl-D-aspartate. Also, Electrophysiological amplitude of field excitatory postsynaptic potentials (fEPSPs) in the input–output and Long-term potentiation (LTP) curves were recorded in mossy fiber and the amount of synaptophysin (SYN), synaptosomal-associated protein, 25 kDa (SNAP-25), and synaptotagmin 1(SYT1) genes expression were measured using Real-time PCR technique for synaptic quantification. The outcomes of the current study suggest that OLG1e as a P/Q-type VGCC modulator has an ameliorative effect on excitotoxicity-induced memory defects and prevents the impairment of pyramidal neurons in the rat hippocampus

Staging the Invisible: Gorgio Strehler and Luigi Pirandello

Staging the Invisible: Gorgio Strehler and Luigi Pirandell