Controlled replication of ‘Candidatus Liberibacter asiaticus‘ DNA in citrus leaf discs

‘Candidatus Liberibacter asiaticus’ is a fastidious bacterium and a putative agent of citrus greening disease (a.k.a., huanglongbing, HLB), a significant agricultural disease that affects citrus fruit quality and tree health. In citrus, ‘Ca. L. asiaticus’ is phloem limited. Lack of culture tools to study ‘Ca. L. asiaticus’ complicates analysis of this important organism. To improve understanding of ‘Ca. L. asiaticus’–host interactions including parameters that affect ‘Ca. L. asiaticus’ replication, methods suitable for screening pathogen responses to physicochemical and nutritional variables are needed. We describe a leaf disc-based culture assay that allows highly selective measurement of changes in ‘Ca. L. asiaticus’ DNA within plant tissue incubated under specific physicochemical and nutritional conditions. qPCR analysis targeting the hypothetical gene CD16-00155 (strain A4) allowed selective quantification of ‘Ca. L. asiaticus’ DNA content within infected tissue. ‘Ca. L. asiaticus’ DNA replication was observed in response to glucose exclusively under microaerobic conditions, and the antibiotic amikacin further enhanced ‘Ca. L. asiaticus’ DNA replication. Metabolite profiling revealed a moderate impact of ‘Ca. L. asiaticus’ on the ability of leaf tissue to metabolize and respond to glucose.     

Circuit Model of Fano Resonance on Tetramers,Pentamers, and Broken Symmetry Pentamers

This paper presents the representation circuit model for Fano resonance of plasmonic nanoparticles in the optical domain. An intuitive explanation is provided for the physical nature of Fano resonance based on the three-level quantum system, and the Fano resonance effects of three basic nanoparticle arrangements, namely tetramer, pentamer, and symmetry broke pentamer are discussed. A coupling capacitor is calculated as an equivalent component in the proposed circuit model in order to describe the coupling effect between subradiant and superradiant mode in the Fano resonance. The circuit impedances of tetramer, pentamer, and broken symmetry pentamer are simulated, with resultant circuit models in agreement with the calculated results based on S-parameters.     

A new podapolipid species (Acari) on Scarabaeus (Scarabaeus) acuticollis (Insecta: Coleoptera: Scarabaeidae) from Iran

A new species of mites of the genus Tarsopolipus (Acari: Prostigmata: Podapolipidae) is described from southern Iran. Tarsopolipus husbandi Mortazavi and Hajiqanbar n. sp. is a sub-elytral ectoparasite of the scarabaeid beetle, Scarabaeus (Scarabaeus) acuticollis. The new species is closely related to Tarsopolipus corrugatus Berlese 1911, but is distinguished from it by the following characters. Adult female: presence of vestigial setae v(2) and shorter setae sc(2). Adult male: presence of setae v' on tibia IV and shorter setae sc(2) and c(2). Larval female: shorter cheliceral stylets and longer distance between setae v(1) and ch. Species of Tarsopolipus are currently distributed in Afro-tropical, Palaearctic, and Oriental regions and parasitize species in 3 genera of scarabaeid beetles, i.e., Scarabaeus , Kheper, and Drepanopodes, all belonging to the tribe Scarabaeini.     

A chemiluminescent metalloimmunoassay based on copper‐enhanced gold nanoparticles for quantification of human growth hormone

A chemiluminescence (CL) immunoassay was developed to determine human growth hormone (hGH) based on copper‐enhanced gold nanoparticles. In this method, gold nanoparticles were deposited on polystyrene wells for adsorption of human growth antibodies as well as catalyst for reducing of copper ions from the copper enhancer solution. The reduction of copper ions was prevented where the gold nanoparticles were covered by the antibody–antigen immunocomplex. The deposited copper on Au nanoparticles was then dissolved in HNO₃ solution and quantified using the CL method. The CL intensity response was logarithmically dependent on the hGH concentrations over the range 0.2–50 ng/mL, with a detection limit (3σ) of 0.036 ng/mL. Copyright © 2012 John Wiley & Sons, Ltd.     

HIV among People Who Inject Drugs in the Middle East and North Africa: Systematic Review and Data Synthesis

Background

It is perceived that little is known about the epidemiology of HIV infection among people who inject drugs (PWID) in the Middle East and North Africa (MENA). The primary objective of this study was to assess the status of the HIV epidemic among PWID in MENA by describing HIV prevalence and incidence. Secondary objectives were to describe the risk behavior environment and the HIV epidemic potential among PWID, and to estimate the prevalence of injecting drug use in MENA.

Methods and Findings

This was a systematic review following the PRISMA guidelines and covering 23 MENA countries. PubMed, Embase, regional and international databases, as well as country-level reports were searched up to December 16, 2013. Primary studies reporting (1) the prevalence/incidence of HIV, other sexually transmitted infections, or hepatitis C virus (HCV) among PWIDs; or (2) the prevalence of injecting or sexual risk behaviors, or HIV knowledge among PWID; or (3) the number/proportion of PWID in MENA countries, were eligible for inclusion. The quality, quantity, and geographic coverage of the data were assessed at country level. Risk of bias in predefined quality domains was described to assess the quality of available HIV prevalence measures. After multiple level screening, 192 eligible reports were included in the review. There were 197 HIV prevalence measures on a total of 58,241 PWID extracted from reports, and an additional 226 HIV prevalence measures extracted from the databases.We estimated that there are 626,000 PWID in MENA (range: 335,000–1,635,000, prevalence of 0.24 per 100 adults). We found evidence of HIV epidemics among PWID in at least one-third of MENA countries, most of which are emerging concentrated epidemics and with HIV prevalence overall in the range of 10%–15%. Some of the epidemics have however already reached considerable levels including some of the highest HIV prevalence among PWID globally (87.1% in Tripoli, Libya). The relatively high prevalence of sharing needles/syringes (18%–28% in the last injection), the low levels of condom use (20%–54% ever condom use), the high levels of having sex with sex workers and of men having sex with men (15%–30% and 2%–10% in the last year, respectively), and of selling sex (5%–29% in the last year), indicate a high injecting and sexual risk environment. The prevalence of HCV (31%–64%) and of sexually transmitted infections suggest high levels of risk behavior indicative of the potential for more and larger HIV epidemics.

Conclusions

Our study identified a large volume of HIV-related biological and behavioral data among PWID in the MENA region. The coverage and quality of the data varied between countries. There is robust evidence for HIV epidemics among PWID in multiple countries, most of which have emerged within the last decade and continue to grow. The lack of sufficient evidence in some MENA countries does not preclude the possibility of hidden epidemics among PWID in these settings. With the HIV epidemic among PWID in overall a relatively early phase, there is a window of opportunity for prevention that should not be missed through the provision of comprehensive programs, including scale-up of harm reduction services and expansion of surveillance systems. Please see later in the article for the Editors'' Summary     

Investigating the effect of age and gender of users on improving spirituality by using EEG

The current study aims to examine the effect of age and gender of users on spirituality by using an experiment. Literature believes that age and gender have a huge effect on increased or decreased spirituality. The current study aims to examine these theories by a scientific and rational method and using cognitive neuroscience (recording electroencephalograph). In order to do this, an electroencephalograph was recorded for 45 users. Findings show that there is a significant relationship between age and gender of users and spirituality (F = 4.1, p < 0.05) (F = 3.8, p < 0.05). Results showed that users at older ages reached spirituality sooner. Thus, it can be said in regard to the relationship between age and formation/improvement of spirituality that users at older ages reach spirituality sooner than users at younger ages. Results of data analysis showed that alpha and theta brain signals increased in male students at the 30–35 age range; while this increase was slower at the 20–29 age range.