Two essays in computational optimization: computing the clar number in fullerene graphs and distributing the errors in iterative interior point methods

Fullerene are cage-like hollow carbon molecules graph of pseudospherical sym- metry consisting of only pentagons and hexagons faces. It has been the object of interest for chemists and mathematicians due to its widespread application in various fields, namely including electronic and optic engineering, medical sci- ence and biotechnology. A Fullerene molecular, Γ n of n atoms has a multiplicity of isomers which increases as N iso ∼ O(n 9 ). For instance, Γ 180 has 79,538,751 isomers. The Fries and Clar numbers are stability predictors of a Fullerene molecule. These number can be computed by solving a (possibly N P -hard) combinatorial optimization problem. We propose several ILP formulation of such a problem each yielding a solution algorithm that provides the exact value of the Fries and Clar numbers. We compare the performances of the algorithm derived from the proposed ILP formulations. One of this algorithm is used to find the Clar isomers, i.e., those for which the Clar number is maximum among all isomers having a given size. We repeated this computational experiment for all sizes up to 204 atoms. In the course of the study a total of 2 649 413 774 isomers were analyzed.The second essay concerns developing an iterative primal dual infeasible path following (PDIPF) interior point (IP) algorithm for separable convex quadratic minimum cost flow network problem. In each iteration of PDIPF algorithm, the main computational effort is solving the underlying Newton search direction system. We concentrated on finding the solution of the corresponding linear system iteratively and inexactly. We assumed that all the involved inequalities can be solved inexactly and to this purpose, we focused on different approaches for distributing the error generated by iterative linear solvers such that the convergences of the PDIPF algorithm are guaranteed. As a result, we achieved theoretical bases that open the path to further interesting practical investiga- tion

WEB-BASED LANGUAGE CLUB AFFECTING EFL LEARNERS' PROFICIENCY: A CASE OF IRANIAN LEARNERS

Abstract: Language clubs have been reported to be effective in learning languages, increasing motivation and independence (Gao, 2009). The present study was an attempt to investigate the effect of a web-based language club on the language proficiency of Iranian EFL learners. A number of pre-intermediate learners form two universities (118) were selected among 154 through a test of proficiency (TOEFL PBL), then they were put into experimental and control groups. The participants in experimental group got on line and acted as a member of a virtual language club for a period of 6 months. They got involved with activities like emailing, chatting, and weblogging. Data were collected through TOEFL PBL. The analyzed data from the test of proficiency indicated the outperformance of those in experimental group. Consequently, it might be proposed that web-based language clubs can make language learning easier and more efficient.      Keywords: Web-based language club, English Proficiency, EFL learner

Production of Low-Fat Camel Milk Functional Ice creams Fortified with Camel Milk Casein and its Antioxidant Hydrolysates

 Background and objective: The objective of this study was to produce functional low-fat camel milk ice creams enriched with native camel milk casein or its antioxidant hydrolysates produced by chymotrypsin.Material and methods: Native or hydrolyzed camel milk caseins (0, 2 and 4%) were added to camel milk low-fat ice creams. Hydrolysates were characterized for molecular weights and antioxidant activities. Physical (hardness, overrun and melting resistance) and sensorial attributes of the final products were assessed.Results and conclusion: Results showed that the chymotrypsin-mediated hydrolysis significantly (P<0.05) increased 2,2′-azinobis (3-ethylbenzthiazoline-6-sulfonic acid) radical scavenging activity of the native camel milk casein. Apparent viscosity and consistency coefficient of the ice creams were increased by addition of proteins and hydrolysates due to their water holding capacity. Protein/hydrolysates-fortified samples showed higher melting resistances but lower overruns and softer textures, compared to control ice creams with no added native or hydrolyzed camel milk casein. Sensory analysis showed that only samples enriched with 2% of casein hydrolysate included sensory properties similar to those of control camel milk low-fat ice creams and other samples received lower sensory scores. Generally, this study has suggested that camel milk can be used to produce low-fat ice creams. Properties of these ice creams can be modified by adding various concentrations of native and hydrolyzed camel milk caseins.Conflict of interest: The authors declare no conflict of interest

The Fourth World and Politics of Social Identity in Margaret Atwood’s MaddAddam Trilogy

With the advent of the 21st century, the way characters and identities interact under the influence of dominant powers has brought a new world into existence, a world dubbed by Manuel Castells as the ‘Fourth World’. Within the Castellsian theoretical matrix of the Fourth World and politics of identity, the present study seeks to investigate the true nature of the futuristic world Margaret Atwood has created in the MaddAddam trilogy. The trilogy literarily reflects a global crisis that ultimately leads to dystopia and the destruction of the human race: what remains of humanity is a small group of survivors who must struggle to conserve what remains of humanity. Identity as the main determining factor in the Fourth World represents personal and public privileges, characteristics, and means of differentiating oneself from others. The Fourth World and its political peculiarities reflect contemporary powers, i.e. the power of the network society, network communication and media. Humankind, in this wheel, is just a toy in the hands of an intelligence broker. What exactly happens to human and semi-human characters in Atwood’s trilogy is the result of Fourth World structures and values, and how they shape and reconstruct identities to lead the world toward fabricated truths and values, and terminate in dystopia

Age-related alterations in functional connectivity patterns during working memory encoding of emotional items

Previous findings indicate age-related differences in frontal-amygdala connectivity during emotional processing. However, direct evidence for age differences in brain functional activation and connectivity during emotional processing and concomitant behavioral implications is lacking. In the present study, we examined the impact of aging on the neural signature of selective attention to emotional information during working memory (WM) encoding. Participants completed an emotional WM task in which they were asked to attend to emotional targets and ignore irrelevant distractors. Despite an overall reduction in accuracy for older relative to younger adults, no behavioral age effect was observed as a function of emotional valence. The functional connectivity patterns of left ventrolateral prefrontal cortex showed that younger adults recruited one network for encoding of both positive and negative emotional targets and this network contributed to higher memory accuracy in this cohort. Older adults, on the other hand, engaged two distinct networks for encoding of positive and negative targets. The functional connectivity analysis using left amygdala further demonstrated that older adults recruited one single network during encoding of positive as well as negative targets whereas younger adults recruited this network only for encoding of negative items. The engagement of amygdala functional network also contributed to higher memory performance and faster response times in older adults. Our findings provide novel insights into the differential roles of functional brain networks connected to the medial PFC and amygdala during encoding of emotionally-valenced items with advancing age

Evaluating the status of agricultural articles of Iranian researchers at the Scopus citation database based on the Hirsch index

Background and aim: Today, the use of scientometric methods to evaluate the scientific outputs of researchers in various fields has been highly regarded and the Hirsch index (h-index) is one of the most important scientometric indices due to the simultaneous measurement of quantity and quality of scientific outputs. Therefore, the aim of this study was to evaluate the status of Iranian agricultural articles at the Scopus citation database based on the h-index. Material and methods: This applied study was performed using a scientometric method. The research population consisted of 4037 agricultural articles produced by Iranian researchers from 2010 to 2016, which were extracted from Scopus. Excel software and SPSS 16 were used to draw tables and analyze the data, respectively. Moreover, the Spearman’s correlation coefficient and Pearson test were applied to answer the research hypotheses. Findings: In this period, 4037 agricultural articles of 157 Iranian researchers were indexed at Scopus, of which the largest was in 2011. The Advances in Environmental Biology Journal had the highest number of articles (237) and the Bioresource Technology Journal had the highest h-index (19). The results of Spearman's correlation coefficient showed that there was a significant relationship between the h-index and number of articles (P-value <0.05). Conclusion: Iran in the agricultural field is ranked 3rd place in the Middle East and 42th in the world based on h-index. Although Iran has been able to gain stable place in production of agricultural articles, it has not been successful in the region and world in citing its articles and h-index as well as further efforts are needed in this regard

Maxillofacial fracture epidemiology and treatment plans in the Northeast of Iran: A retrospective study

Background: The epidemiology of facial injuries varies based on lifestyle, cultural background and socioeconomic status in different countries and geographic zones. This study evaluated the epidemiology of maxillofacial fractures and treatment plans in hospitalized patients in Northeast of Iran (2015-2016). Material and Methods: In this retrospective study, the medical records of 502 hospitalized patients were evaluated in the Department of Maxillofacial Surgery in Kamyab Hospital in Mashhad, Iran. The type and cause of fractures and treatment plans were recorded in a checklist. Data were analyzed with Mann–Whitney test, chi-squared test and Fisher’s exact test, using SPSS 21. Results: The majority of patients were male (80.3%). Most subjects were in 20-30-year age range (43.2%). The fractures were mostly caused by accidents, particularly motorcycle accidents (MCAs), and the most common site of involvement was the body of the mandible. There was a significant association between the type of treatment and age. In fact, the age range of 16-59 years underwent open reduction internal fixation (ORIF) more than other age ranges (P=0.001). Also, there was a significant association between gender and fractures (P=0.002). Conclusions: It was concluded that patient age and gender and trauma significantly affected the prevalence of maxillofacial traumas, fracture types and treatment plans. This information would be useful for making better health policy strategies. Key words:Epidemiology, treatment, facial injuries, maxillofacial fractures, trauma

Variation in bioactive contents and anatomical characteristics of different fennel (<i>Foeniculum vulgare</i> Mill.) populations as affected by self-pollination

The production of self pollinated plant genotypes could be critical for improving medicinal plants. Pollination in Apiaceae family can also affect secondary metabolites. In this study, 23 fennel populations were used to assess the effect of self pollination on essential oil yield, antioxidant activity (based on three model system), total phenolic (TPC) and flavonoid content (TFC). First, some plant inflorescences were divided in two parts. Then the half was bagged and the second half was permitted for out crossing. The self and outcross pollinated seeds were sown in a randomized complete block design (RCBD) in three replicates. Results revealed that inbreeding led to increase in the secretary ducts number (9.36%) as well as essential oil yield (25.61%) in all fennel populations. Essential oil yield ranged from 2.4% to 6.4% in seeds produced via out crossing, while it varied from 3.5% to 6.5% in self pollinated ones. Furthermore, self pollination increased TPC (21.66%), TFC (49.40%) and antioxidant activity (6.23%). Among the populations derived from self pollinated seeds Tabriz showed the highest TFC (8.4 mgQUEg-1DW) and antioxidant activity (IC50=83.1μg/ml), whereas Semirom possessed the highest TPC (150 mgTAEg-1DW), respectively. In overall, self pollination can produce lead to the populations with higher amount of secondary metabolites

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Comparative toxic effect of bulk zinc oxide (ZnO) and ZnO nanoparticles on human red blood cells

Metal oxide nanoparticles (NPs) are a member of nanomaterials family that have been produced on a large scale and their toxicity affected by their high surface-to-volume ratio. The hemolytic toxic effects of metal oxide NPs may be completely different from those observed in their bulk counterparts. So, the main purpose of this research was to measure the difference between the hemolytic effects of ZnO (NPs and bulk) on isolated human red blood cells (RBCs). Hemolysis was measured after incubation of human RBCs with 0.01-1 mM of ZnO (bulk and NPs) for 6 h. For measurement of other variables, human RBCs were treated with 0.1 mM of ZnO (NPs and bulk) for 1, 2, and 3 h. Our results demonstrate that bulk ZnO did not show any toxic effects in the concentrations tested, while ZnO NPs caused toxic hemolytic effects through formation of ROS, lipid peroxidation, and glutathione depletion