Controlling the characteristics of injected and accelerated electron bunch in corrugated plasma channel by temporally asymmetric laser pulses.

In laser-driven plasma wakefield accelerators, the accelerating electric field is orders of magnitude stronger than in conventional radio-frequency particle accelerators, but the dephasing between the ultrarelativistic electron bunch and the wakefield traveling at the group velocity of the laser pulse puts a limit on the energy gain. Quasi-phase-matching, enabled by corrugated plasma channels, is a technique for overcoming the dephasing limitation. The attainable energy and the final properties of accelerated electron beams are of utmost importance in laser wakefield acceleration (LWFA). In this work, using two-dimensional particle-in-cell simulations, the effect of the driving pulse duration on the performance of quasi-phase-matched laser wakefield acceleration (QPM-LWFA) is investigated. It is observed that for a pulse duration around half the plasma period, the maximum energy gain of the beam electrons finds its peak value. However, the results show that for a pulse of that duration the collimation of the bunch is much worse, compared to the case where the pulse duration is twice as long. Furthermore, the dynamics of the laser pulse and the evolution of the quality of the externally-injected electron bunch are studied for a symmetric pulse with sine-squared temporal profile, a positive skew pulse (i.e., one with sharp rise and slow fall), and a negative skew pulse (i.e., one with a slow rise and sharp fall). The results indicate that for a laser pulse with an appropriate pulse length compared with the plasma wavelength, the wakefield amplitude can be greatly enhanced by using a positive skew pulse, which leads to higher energy gain. Initially, this results from the stronger ponderomotive force associated with a fast rise time. Later, due to the distinct evolution of the three pulses with different initial profiles, the wakefield excited by the positive skew pulse becomes even stronger. In our simulations, the maximum energy gain for the asymmetric laser pulse with a fast rise time is almost two times larger than for the temporally symmetric laser pulse. Nevertheless, stronger focusing and defocusing fields are generated as well if a positive skew pulse is applied, which degrade the collimation of the bunch. These results should be taken into account in the design of miniature particle accelerators based on QPM-LWFA.

Quasi-phase-matched laser wakefield acceleration of electrons in an axially density-modulated plasma channel.

Quasi-phase matching in corrugated plasma channels has been proposed as a way to overcome the dephasing limitation in laser wakefield accelerators. In this study, the phase-lock dynamics of a relatively long electron bunch injected in an axially-modulated plasma waveguide is investigated by performing particle simulations. The main objective here is to obtain a better understanding of how the transverse and longitudinal components of the wakefield as well as the initial properties of the beam affect its evolution and qualities. The results indicate that the modulation of the electron beam generates trains of electron microbunches. It is shown that increasing the initial energy of the electron beam leads to a reduction in its final energy spread and produces a more collimated electron bunch. For larger bunch diameters, the final emittance of the electron beam increases due to the stronger experienced transverse forces and the larger diameter itself. Increasing the laser power improves the maximum energy gain of the electron beam. However, the stronger generated focusing and defocusing fields degrade the collimation of the bunch.

Assessment of Mouse Ileal loop Protection against Clinically Isolated Vibrio cholerae Outer Membrane Vesicles as a Vaccine Candidate.

Cholera, a life-threatening disease caused by the Gram-negative bacterium Vibrio cholera, remains a concern in developing countries. The present study investigated the immunogenicity and protective immunity of outer membrane vesicles (OMVs) and combination of OMV and killed whole cells (WC) of a local strain isolated from the last outbreak in Iran in addition to reference and local strains of V. cholerae El Tor O1 in comparison to Dukoral vaccine in mice model. The protein content, morphology, and size of extracted OMVs were evaluated by electrophoresis and microscopic analyses, respectively. The serum titers of total immunoglobulin G (IgG), IgG1, IgG2a, and immunoglobulin A (IgA) in addition to secretory IgA and total IgG in different mice groups were determined by enzyme-linked immunosorbent assay (ELISA). In addition, fluid accumulation (FA) assay regarding the resistance to live strain of V. cholerae in ligated ileal loops was carried out to determine immunogenicity by OMV or combination of OMV and WC in comparison to that reported for Dukoral vaccine. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of purified OMVs indicated protein profiles within the range of 34-52 kDa. Furthermore, transmission electron microscopy demonstrated the spherical shaped vesicles of 50-200 nm. The results of ELISA showed significant titers of systemic and mucosal immune anti-OMV IgGs in immunized BALB/c mice with different vaccine regimens. Additionally, a notable increase in the FA ratio was demonstrated in this study. The obtained results of the present study revealed that the WC-OMV combination of local strain can induce a high level of antibody response indicating more protection than OMV or WC separately. Moreover, it can be considered an effective immunogen against V. cholerae.

Genetic Population Diversity of Aedes caspius in Southern Provinces of Iran.

Aedes caspius has a wide distribution throughout the world and can transmit Chikungunya virus, West Nile Virus (WNV), Tahyna virus and the bacterium Francisella tularensis. Sequences of the mitochondrial cytochrome C-oxidase subunit 1 (COI) and cytochrome C-oxidase subunit 2 (COII) genes have been widely used to estimate phylogenetic relationships at different taxonomic levels among this species. Adult collections were carried out by human bait, Center for Deseases Control Light Traps (CDC-LT) and aspirator during February/April, June and October/December 2013-2015 from different southern provinces of Iran and then identified morphologically with reliable keys. A total of 3,570 adult mosquitoes were collected and identified as belonging to three genera, including five species of Culex, six species of Aedes and one species of Culiseta. In this study, 1,796 specimens of Aedes caspius were identified from four provinces. Based on the COI and COII sequences obtained for Ae. caspius population, 12 and 11 haplotypes were identified, respectively. The present study evidenced a high degree of intraspecific variation among these populations of Ae. caspius.

Aedes caspius largement distribué dans le monde est le vecteur du virus du chikungunya, du virus West Nile, du virus Tahyna et de la bactérie Francisella tularensis. Les séquences des gènes mitochondriaux COI et COII sont généralement utilisées pour estimer les relations phylogénétiques entre les différents niveaux taxonomiques de cette espèce. Des moustiques adultes ont été collectés sur appâts humains, à l'aide de pièges lumineux de type « CDC/light-trap ¼ et d'aspirateurs en février/avril, juin et octobre/décembre 2013­2015 dans les provinces au sud de l'Iran. Les moustiques ont ensuite été identifiés d'un point de vue morphologique. Trois mille cinq cent soixante-dix moustiques adultes ont été collectés et identifiés comme appartenant à trois genres, dont cinq espèces de Culex, six espèces d'Aedes et une espèce de Culiseta. Dans cette étude, 1 796 spécimens d'Aedes caspius ont été identifiés dans quatre provinces. Les séquences COI et COII des populations d'Ae. caspius ont permis d'identifier respectivement 12 et 11 haplotypes. Les résultats de cette étude ont démontré qu'il existe une forte variation intraspécifique dans ces populations d'Ae. caspius.

Spatial changes in the distribution of malaria vectors during the past 5 decades in Iran.

BACKGROUND: Global warming and climate change affect various aspects of mankind, including public health. Anopheles mosquitoes are of Public Health importance and can be affected by global warming and other environmental variables. Here, we studied the distribution of Anopheles vectors of malaria in relation to environmental variables in Iran. METHODS: Long-term meteorological and entomological data of about 50 years in retrospect were collected and arranged in a geo-database and analyzed using ArcGIS ver. 9.3 and exported to SPSS ver. 20 for statistical analysis. RESULTS: Distribution maps have been updated for seven species of Anopheles vectors of malaria which involved Anopheles culicifacies s.l., An. fluviatilis s.l., An. stephensi, An. dthali, An. sacharovi, An. maculipennis.l. and An. superpictus in Iran. Distribution maps of vectors were made based on district areas using Kriging model. Historical and recent records were demonstrated for each Anopheles based on climatic factors in the distribution areas of each Anopheles vectors. DISCUSSION: Iran, like other parts of the world is faced with warming and this probably affected the distribution of Anopheles vectors. Despite the warming phenomenon, the country's climate had changed during the cold season as temperatures became colder or cooler. This study shows that some vectors had migrated from the central part of Iran with dry and sunny landscape, moved towards the mountainous areas of the north or the warm and humid areas of the south. Historical records show that these anophelines have previously been distributed in lowland areas. If this process continues in the future, Anopheles mosquitoes may be seen in low lands with cold areas in central and northern parts of the country or will occupy humid and warm climates in the southern parts of the country where water is more available.

Effect of Cilia Beat Frequency on Muco-ciliary Clearance.

BACKGROUND: The airway surface liquid (ASL), which is a fluid layer coating the interior epithelial surface of the bronchi and bronchiolesis, plays an important defensive role against foreign particles and chemicals entering lungs. OBJECTIVE: Numerical investigation has been employed to solve two-layer model consisting of mucus layer as a viscoelastic fluid and periciliary liquid layer as a Newtonian fluid to study the effects of cilia beat frequency (CBF) at various amounts of mucus properties on muco-ciliary transport problem. METHODS: Hybrid finite difference-lattice Boltzmann-method (FB-LBM) has been used to solve the momentum equations and to simulate cilia forces, and also the PCL-mucus interface more accurately, immersed boundary method (IBM) has been employed. The main contribution of the current study is to use an Oldroyd-B model as the constitutive equation of mucus. RESULTS: Our results show that increasing CBF and decreasing mucus viscosity ratio have great effects on mucus flow, but the effect of viscosity ratio is more significant. The results also illustrate that the relation between cilia beat frequency and mean mucus velocity is almost linear and it has similar behavior at different values of viscosity ratio. CONCLUSION: Numerical investigation based on hybrid IB-FD-LBM has been used to study the effect of CBF at various mounts of mucus viscosity ratio on the muco-ciliary clearance. The results showed that the effect of viscosity ratio on the muco-ciliary transport process is more significant compared with CBF.

On the effect of mucus rheology on the muco-ciliary transport.

A two dimensional numerical model is used to study the muco-ciliary transport process in human respiratory tract. Here, hybrid finite difference-lattice Boltzmann method is used to model the flow physics of the transport of mucus and periciliary liquid (PCL) layer in the airway surface liquid. The immersed boundary method is also used to implement the propulsive effect of the cilia and also the effects of the interface between the mucus and PCL layers. The main contribution of this study is on elucidating the role of the viscoelastic behavior of mucus on the muco-ciliary transport and for this purpose an Oldroyd-B model is used as the constitutive equation of mucus for the first time. Results show that the viscosity and viscosity ratio of mucus have an enormous effect on the muco-ciliary transport process. It is also seen that the mucus velocity is affected by mucus relaxation time when its value is less than 0.002 s. Results also indicate that the variation of these properties on the mucus velocity at lower values of viscosity ratio is more significant.

Selective recognition of Ni2+ ion based on fluorescence enhancement chemosensor.

A new enhancing fluorescent chemosensor was introduced for selective and sensitive determination of nickel ions based on 2-(1-H-benzo[d]imidazol-2yl)-N-phenyl hydrazine carbothioamide (L). L has an intrinsic fluorescent emission which enhances in presence of nickel ions in CH3CN/H2O (70:30, v/v) solution. The fluorescence enhancement of L is attributed to a 1:1 complex formation between L and Ni2+ ion which has been used for selective detection of Ni2+ ion. At the optimum conditions, the fluorescence intensity of L at 352 nm enhances linearly by the concentration of nickel ion from 1.6×10(-5) to 1.6×10(-7) M and detection limit of 7.9×10(-8) M. The new fluorescent probe exhibited high selectivity to Ni2+ ion over the other common mono, di-and trivalent cations.

Turn-on fluorescent chemosensor for determination of lutetium ion.

A turn-on fluorescent chemosensor is introduced for the detection of Lu(3+) ion using N-[3-methyl]-2-[pyridine-2-amido] phenyl] pyridine-2-carboxamide (L) molecule. Fluorescent emission intensity of L enhances after binding to Lu(3+) ions in ethanol-water solution (1:9, v/v). The observed enhancement is the result of a strong covalent binding between Lu(3+) ion and L (the binding constant value is 2.0×10(6) mol(-1) L). The proposed optical chemosensor can be applied for the analysis of Lu(3+) ion in a linear range of 3.3×10(-7) to 1.0×10(-5) mol L(-1). The limit of detection was obtained 8.6×10(-7) mol L(-1). The probe exhibits high selectivity toward Lu(3+) ion in comparison with common metal ions. The proposed fluorescent chemosensor was successfully used in the determination of Lu(3+) ion in some water samples.

Molecular characterization of sandflies and Leishmania detection in main vector of zoonotic cutaneous leishmaniasis in Abarkouh district of Yazd province, Iran.

OBJECTIVE: To assess molecular characterization, distribution, seasonal activities of sandfly species and Leishmania parasites infecting them for this zoonotic cutaneous leishmaniasis focus. METHODS: The collections were carried out in 2009-2011 using CDC traps, Sticky Papers and manual aspirator in and around the villages in Abarkouh district. Individual sandflies were characterized by PCR amplification and sequencing of fragments of their mitochondrial cytochrome b gene. Leishmania parasite infections within sandflies were performed by targeting Cyt b, ITS-rDNA, k-DNA and microsatellite genes. RESULTS: The PCR assays detected only Leishmania major (L. major). All infections (30) were found in the abundant and widespread vector Phlebotomus papatasi (P. papatasi). Small numbers of other sandfly species were also screened for infections, but none was found. Sergentomyia sintoni and P. papatasi were the predominant members in all locations of this district and in all habitats throughout the trapping season. Only five other sandfly species were found, namely Phlebotomus ansari, Phlebotomus caucasicus, Phlebotomus sergenti, Sergentomyia dentata and Sergentomyia merviney. CONCLUSIONS: In the current survey, the only infections detected are of L. major in females of P. papatasi (30 out of 190). The rates of infection of P. papatasi by L. major are not significantly different in compare with other locations in Iran with no diversity of parasite strains. Zoonotic cutaneous leishmaniasis may have emerged only recently in Abarkouh district, and the reason may well be the instability of the transmission cycles there.

Identification of chemical constituents and larvicidal activity of Kelussia odoratissima Mozaffarian essential oil against two mosquito vectors Anopheles stephensi and Culex pipiens (Diptera: Culicidae).

The larvicidal activity of essential oil extracted from an indigenous plant, Kelussia odoratissima Mozaffarian was evaluated against two mosquito species, Anopheles stephensi and Culex pipiens. The chemical composition of the essential oil obtained by hydrodistillation from branch tips and leaf of this plant was determined by GC and GC/MS analysis. Forty-nine constituents were identified in the oil. The main constituents of the oil were Z-ligustilide (77.73%), 2-octen-1-ol acetate (6.27%), E-ligustilide (2.27%) and butylidene phthalide (1.97%). Five different logarithmic concentrations of essential oil were evaluated against the 4th instar larvae of An. Stephensi and Cx. pipiens. The LC(50) and LC(90) values against An. stephensi larvae were 4.88 and 9.60 ppm and for Cx. pipiens were 2.69 and 7.90 ppm, respectively. These properties suggest that K. odoratissima oil has potential source of valuable larvicidal compounds for mosquito larval control. This plant which causes high mortality at lower dose could be considered as a highly active plant. In this paper a guideline suggested for larvicidal activity of plant essential oils.

Larval habitats and biodiversity of anopheline mosquitoes (Diptera: Culicidae) in a malarious area of southern Iran.

BACKGROUND & OBJECTIVES: Malaria is the most important mosquito-borne disease in Iran. It is endemic in south to southeastern part of the country. Knowledge about bio-ecology of vectors will support authorities for appropriate management of the disease. Bashagard district is one of the main endemic areas for malaria in south of Iran. This study was conducted to determine anopheline fauna, diversity and affinity in the area, characterization of larval habitats, and mapping their potential distribution across the district. METHODS: The potential aquatic habitats for Anopheles larvae were extracted from Indian Remote Sensing Satellite (IRS) image and digital elevation model of the area using GIS. Surface water bodies were sampled monthly during 2009­10 for anopheline larvae, while characteristics of their physical environment were recorded and water samples were analyzed. RESULTS: A total of 4511 Anopheles larvae were found during the year with the lowest and highest frequencies in February and April, respectively. Dominant species was Anopheles culicifacies. The Shanon diversity index ranged from 0.570­0.829 at fixed collection sites, while the affinity index was significant among some vector species. CONCLUSION: Riversides and riverbeds were the main breeding places which provided sandy, rocky, and clay beds for different species. The potential breeding places as well as distribution of collected species were mapped. Knowledge about ecology of malaria vectors provides information to health sector for effective control programs.

Spatial analysis and mapping of malaria risk in an endemic area, south of Iran: a GIS based decision making for planning of control.

Bashagard district is one of the important malaria endemic areas in southern Iran. From this region a total of 16,199 indigenous cases have been reported in recent years. The aim of this study was to determine the situation of the disease and provide the risk map for the area. ArcGIS9.2 was used for mapping spatial distribution of malaria incidence. Hot spots were obtained using evidence-based weighting method for transmission risk. Environmental factors including temperature, relative humidity, altitude, slope and distance to rivers were combined by weighted multi criteria evaluation for mapping malaria hazard area at the district level. Similarly, risk map was developed by overlaying weighted hazard, land use/land cover, population density, malaria incidence, development factors and intervention methods. Our results reveal that the disease mainly occurs in north and east of the study area. Consequently the district is divided into three strata. Appropriate interventions are recommended for each stratum based on national malaria policy. Malaria hazard and risk map, stratification based on relevant information and data analyzing provide a useful method preparedness and early warning system for malaria control, although regular updating is required timely.

Entomological and epidemiological attributes for malaria transmission and implementation of vector control in southern Iran.

Bashagard is an important malaria endemic area in south of Iran. An epidemiological and entomological survey was performed during 2002-2010. The aim of study was to determine malaria situation, species composition of anopheline mosquitoes and susceptibility status of main vectors to insecticides/larvicides. A total of 13,490 malaria cases were recorded, Plasmodium vivax (99.64%), P. falciparum (0.35%) and mix cases (0.01%). The highest and lowest Annual Parasite Incidence (API) were observed in 2007 (145.72/1000) and 2009 (6.29/1000), respectively. Anopheles culicifacies, An. dthali, An. stephensi, An. superpictus, An. fluviatilis, An. moghulensis, An. turkhudi and An. apoci were collected from the area. Two peak activities occur in April and October. The first five species were confirmed as malaria vectors in Iran. No indication of sporozoite in mosquitoes using molecular method was performed. Susceptibility tests using diagnostic dose of insecticides and larvicides showed only resistance of An. stephensi to DDT. Tolerance in An. stephensi to deltamethrin and bendiocarb is reported. The same phenomenon was observed in An. culicifacies to DDT, propoxur and deltamethrin, and in An. dthali to malathion and deltamethrin. Larvae of vectors were susceptible to all larvicides, except for An. stephensi that exhibited tolerance to fenthion. In conclusion it should be emphasized that malaria transmission is a complex process in Bashagard. This event is attributed to five proven vectors with different behaviors which are active in the area. Regarding tolerance of vectors to deltamethrin, resistance management is suggested by using new insecticide with novel mode of action.

Knowledge, attitudes and practices regarding malaria control in an endemic area of southern Iran.

Iran is in the malaria pre-elimination stage. In this situation community based strategies are important for malaria control. In order to intensify elimination activities we need to have a better understanding of the knowledge, attitudes and practices (KAP) of malaria prevention in the community. We carried out a KAP study in one malaria endemic district in southern Iran in 2009 using a structured questionnaire. Five villages with indigenous malaria cases during the previous year and a high potential for anopheline mosquito breeding were selected. All the households in each village were visited and the head of the household or other responsible adult was interviewed. Data were analyzed using SPSS 11.5. A total of 494 respondents from the five villages participated. More than 33% of people in the study area were living in sheds with poor facilities. The illiteracy level of the studied population was high (44.2%) and significantly affected the knowledge and practices of the respondents about malaria control (p<0.05). Descriptive analysis showed significant differences between sex, job and history of malaria infection of the respondents and their knowledge and practices about malaria control (p<0.05). Knowledge of the respondents about the route of transmission in malaria was good; 72.1% knew mosquitoes were the vector. Most people knew at least one symptom of the disease. The practices of respondents were 59.5% for bednet use and 9.3% for screening windows. The knowledge, attitudes and practices of respondents in this survey about malaria control were good in some cases, but in general needed to be improved with educational programs.

Opium use in a rural area of the Islamic Republic of Iran.

Because of its geographic proximity to the major drug production centres, there is easy access to narcotic drugs in the Islamic Republic of Iran despite efforts by governmental and nongovernmental organizations. Using a structured questionnaire as a basis for conversation, local health workers interviewed 310 residents of a rural area in Babol province about opium use. The self-reported rate of opium use, adjusted due to a bias in the sex ratio of the sample, was 8.9%. All the 42 opium users reported opium use at least 2-3 times per week in the previous 3 months. Opium was smoked by 95.2% and taken orally by 4.8%; there was no injecting use. There was no reported use of other substances, including alcohol. There was a statistically significant relationship between opium use and male sex, unemployment and cigarette smoking.

Epidemiology of absconding from an Iranian psychiatric centre.

Absconding by psychiatric patients from acute psychiatric wards has been a significant problem for some time. This study was conducted to identify the incidence rate of absconding in a psychiatric hospital and some of the characteristics of patients who had escaped from hospital in year 2006. In this descriptive cross-sectional study, all of absconds in our centre have been registered in the period of 9 months. We assessed patients' age, gender, marital status, hospital stay, substance abuse, psychiatric diagnosis and site of absconding. A total of 43 cases of absconding have been registered in this period, attempted by 35 patients, with the incidence rate of 3% in our centre. The mean age of absconders was 31.7 years; 95.3% of absconds were made by men; 67.4% were single; 37.4% absconded through the main door; 62.8% of our absconders had bipolar mood disorder or schizophrenia; mean in hospital stay before absconding was 18.4 days; and 53.5% of absconds were attempted by substance users. Absconders utilize a significant portion of hospital resources and have an adverse effect on ward milieu. It seems that the patients who are more prone to abscond are male, young, single, addict, with the diagnosis of bipolar mood disorder or schizophrenia and patients who are admitted not long ago.

Opium use in a rural area of the Islamic Republic of Iran

Because of its geographic proximity to the major drug production centres, there is easy access to narcotic drugs in the Islamic Republic of Iran despite efforts by governmental and nongovernmental organizations. Using a structured questionnaire as a basis for conversation, local health workers interviewed 310 residents of a rural area in Babol province about opium use. The self-reported rate of opium use, adjusted due to a bias in the sex ratio of the sample, was 8.9%. All the 42 opium users reported opium use at least 2-3 times per week in the previous 3 months. Opium was smoked by 95.2% and taken orally by 4.8%; there was no injecting use. There was no reported use of other substances, including alcohol. There was a statistically significant relationship between opium use and male sex, unemployment and cigarette smoking