Gelechiid fauna of Baengnyeongdo,Daecheongdo, and Yeonpyeongdo in the West Sea near North Korea,with description of two new species (Lepidoptera,Gelechioidea)

In the faunistic survey on three islands (Baengnyeongdo, Decheongdo, and Yeonpyeongdo) in the northern West Sea of the Korean Peninsula, 37 species of Gelechiidae (Gelechioidea) are recognized. Of them, Anarsia asymmetrodes Park, sp. nov. and Aristotelia nesiotatos Park, sp. nov. are described as new to science and Stenolechia kodamai Okada is reported for the first time in Korea.     

Accuracy and User-Acceptability of HIV Self-Testing Using an Oral Fluid-Based HIV Rapid Test

Background

The United States FDA approved an over-the-counter HIV self-test, to facilitate increased HIV testing and earlier linkage to care. We assessed the accuracy of self-testing by untrained participants compared to healthcare worker (HCW) testing, participants’ ability to interpret sample results and user-acceptability of self-tests in Singapore.

Methodology/Principal Findings

A cross-sectional study, involving 200 known HIV-positive patients and 794 unknown HIV status at-risk participants was conducted. Participants (all without prior self-test experience) performed self-testing guided solely by visual instructions, followed by HCW testing, both using the OraQuick ADVANCE Rapid HIV 1/2 Antibody Test, with both results interpreted by the HCW. To assess ability to interpret results, participants were provided 3 sample results (positive, negative, and invalid) to interpret. Of 192 participants who tested positive on HCW testing, self-testing was positive in 186 (96.9%), negative in 5 (2.6%), and invalid in 1 (0.5%). Of 794 participants who tested negative on HCW testing, self-testing was negative in 791 (99.6%), positive in 1 (0.1%), and invalid in 2 (0.3%). Excluding invalid tests, self-testing had sensitivity of 97.4% (95% CI 95.1% to 99.7%) and specificity of 99.9% (95% CI: 99.6% to 100%). When interpreting results, 96%, 93.1% and 95.2% correctly read the positive, negative and invalid respectively. There were no significant demographic predictors for false negative self-testing or wrongly interpreting positive or invalid sample results as negative. Eighty-seven percent would purchase the kit over-the-counter; 89% preferred to take HIV tests in private. 72.5% and 74.9% felt the need for pre- and post-test counseling respectively. Only 28% would pay at least USD15 for the test.

Conclusions/Significance

Self-testing was associated with high specificity, and a small but significant number of false negatives. Incorrectly identifying model results as invalid was a major reason for incorrect result interpretation. Survey responses were supportive of making self-testing available.     

Genetic Signatures of HIV-1 Envelope-mediated Bystander Apoptosis

The envelope (Env) glycoprotein of HIV is an important determinant of viral pathogenesis. Several lines of evidence support the role of HIV-1 Env in inducing bystander apoptosis that may be a contributing factor in CD4⁺ T cell loss. However, most of the studies testing this phenomenon have been conducted with laboratory-adapted HIV-1 isolates. This raises the question of whether primary Envs derived from HIV-infected patients are capable of inducing bystander apoptosis and whether specific Env signatures are associated with this phenomenon. We developed a high throughput assay to determine the bystander apoptosis inducing activity of a panel of primary Envs. We tested 38 different Envs for bystander apoptosis, virion infectivity, neutralizing antibody sensitivity, and putative N-linked glycosylation sites along with a comprehensive sequence analysis to determine if specific sequence signatures within the viral Env are associated with bystander apoptosis. Our studies show that primary Envs vary considerably in their bystander apoptosis-inducing potential, a phenomenon that correlates inversely with putative N-linked glycosylation sites and positively with virion infectivity. By use of a novel phylogenetic analysis that avoids subtype bias coupled with structural considerations, we found specific residues like Arg-476 and Asn-425 that were associated with differences in bystander apoptosis induction. A specific role of these residues was also confirmed experimentally. These data demonstrate for the first time the potential of primary R5 Envs to mediate bystander apoptosis in CD4⁺ T cells. Furthermore, we identify specific genetic signatures within the Env that may be associated with the bystander apoptosis-inducing phenotype.     

Energy Generation from the CO Oxidation-Hydrogen Production Pathway in Rubrivivax gelatinosus

When incubated in the presence of CO gas, Rubrivivax gelatinosus CBS induces a CO oxidation-H₂ production pathway according to the stoichiometry CO + H₂O → CO₂ + H₂. Once induced, this pathway proceeds equally well in both light and darkness. When light is not present, CO can serve as the sole carbon source, supporting cell growth anaerobically with a cell doubling time of nearly 2 days. This observation suggests that the CO oxidation reaction yields energy. Indeed, new ATP synthesis was detected in darkness following CO additions to the gas phase of the culture, in contrast to the case for a control that received an inert gas such as argon. When the CO-to-H₂ activity was determined in the presence of the electron transport uncoupler carbonyl-cyanide m-chlorophenylhydrazone (CCCP), the rate of H₂ production from CO oxidation was enhanced nearly 40% compared to that of the control. Upon the addition of the ATP synthase inhibitor N,N′-dicyclohexylcarbodiimide (DCCD), we observed an inhibition of H₂ production from CO oxidation which could be reversed upon the addition of CCCP. Collectively, these data strongly suggest that the CO-to-H₂ reaction yields ATP driven by a transmembrane proton gradient, but the detailed mechanism of this reaction is not yet known. These findings encourage additional research aimed at long-term H₂ production from gas streams containing CO.     

Treatment of simulated wastewater containing toxic amides by immobilized <Emphasis Type="Italic">Rhodococcus rhodochrous</Emphasis> NHB-2 using a highly compact 5-stage plug flow reactor

Biodegradation of toxic amides by immobilized Rhodococcus rhodochrous NHB-2 has been studied to generate data for future development of reactors for the treatment of simulated wastewater containing various toxic amides. The whole resting cells were immobilized in different matrices like agar, polyacrylamide and alginate. Agar gel beads were selected for the treatment of simulated wastewater containing 100mM each acetamide, propionamide, and 10mM of acrylamide and packed in a highly compact five-stage plug flow reactor. The immobilized bacterium worked well in a broad pH range from 5 to 10, with an optimum at 8.7. The apparent K _m-value for the turnover of acetamide for the resting cells was determined to be around 40mM at pH 8.5 and 55°C, whereas the K _m-value of the purified amidase was predicted to be about 20 mM. This organism exhibited greater turnover of aliphatic amides as compared to aromatic amides. Although these cells showed maximal amide-degrading activity at 55°C, simulated wastewater treatment was carried out at 45°C, because of the greater stability of the amidase activity at that temperature. Of note, indices for overall temperature stability, based on the temperature dependence of apparent first order kinetic temperature denaturation constants, were determined to be –7.9±1.1×10^–4, and –13.7±1.3×10^–4, –14.5±0.7×10^–4, and –13.7±0.8×10^–4°Cmin, for free cells and cells immobilized in alginate, agar and polyacrylamide respectively. After 250min the reactor showed maximum degradation of acetamide, propionamide and acrylamide of about 97, 100 and 90%, respectively by using 883 enzyme activity units per reactor stage. The results of this investigation showed that R. rhodochrous NHB-2 expressing thermostable amidase could be used for the efficient treatment of wastewater containing toxic amides. Therefore, we suggest that this microbe has a very high potential for the detoxification of toxic amides from industrial effluents and other wastewaters.     

The Potential Distribution of Invading Helicoverpa armigera in North America: Is It Just a Matter of Time?

Helicoverpa armigera has recently invaded South and Central America, and appears to be spreading rapidly. We update a previously developed potential distribution model to highlight the global invasion threat, with emphasis on the risks to the United States. The continued range expansion of H. armigera in Central America is likely to change the invasion threat it poses to North America qualitatively, making natural dispersal from either the Caribbean islands or Mexico feasible. To characterise the threat posed by H. armigera, we collated the value of the major host crops in the United States growing within its modelled potential range, including that area where it could expand its range during favourable seasons. We found that the annual value of crops that would be exposed to H. armigera totalled approximately US$78 billion p.a., with US$843 million p.a. worth growing in climates that are optimal for the pest. Elsewhere, H. armigera has developed broad-spectrum pesticide resistance; meaning that if it invades the United States, protecting these crops from significant production impacts could be challenging. It may be cost-effective to undertake pre-emptive biosecurity activities such as slowing the spread of H. armigera throughout the Americas, improving the system for detecting H. armigera, and methods for rapid identification, especially distinguishing between H. armigera, H. zea and potential H. armigera x H. zea hybrids. Developing biological control programs, especially using inundative techniques with entomopathogens and parasitoids could slow the spread of H. armigera, and reduce selective pressure for pesticide resistance. The rapid spread of H. armigera through South America into Central America suggests that its spread into North America is a matter of time. The likely natural dispersal routes preclude aggressive incursion responses, emphasizing the value of preparatory communication with agricultural producers in areas suitable for invasion by H. armigera.     

Multiple rRNA variants in a single spore of the microsporidian Nosema bombi

To understand the source of the multiple DNA sequence variants of Nosema bombi ribosomal RNA (rRNA) found in a single bumble bee host, we PCR amplified, cloned, and sequenced the partial rRNA gene from 125 clones, which were derived from four out of 46 spores individually isolated from a single host by laser microdissection. At least two rRNA variants, characterized by either (GTTT)(2) or (GTTT)(3) repeat units within the internal transcribed spacer (ITS) region, were found per spore in approximately equal proportions, variants which were also found in approximately equal proportions in 55 clones of the two DNA extracts of multiple spores from the same host. Firstly, we demonstrate for the first time that DNA sequences can be obtained from single-binucleate microsporidia. Secondly, it appears that concerted evolution has not homogenized the sequences of all rRNA copies within a single N. bombi spore or even within a single nucleus. We thereby demonstrate unequivocally that two or more rRNA sequence variants exist per N. bombi spore, and urge caution in the use of multicopy rRNA genes for population genetic and phylogenetic analysis of this and other Microsporidia unless homologous copies can be reliably typed.     

Contrasting effects of a cladoceran (Daphnia galeata) and a calanoid copepod (Eodiaptomus japonicus) on algal and microbial plankton in a Japanese lake, Lake Biwa

Macrozooplankton may affect algal and microbial plankton directly through grazing or predation and indirectly through nutrient regeneration. They may also affect potential prey positively by removing alternative predators. Here, we examined the effects of a cladoceran (Daphnia) and a calanoid copepod (Eodiaptomus) on algal and microbial plankton in a Japanese lake using in situ experiments in which we manipulated the nutrient supply and biomass of these macrozooplankton. The response of algal and microbial plankton to macrozooplankton was diverse and varied depending on the level of nutrient supply. Eodiaptomus seemed to feed mainly on large algae (>20 µm) and microzooplankton, while direct grazing by Daphnia on algae, bacteria, heterotrophic nanoflagellates (HNF), and microzooplankton (ciliates, heliozoa, and rotifers) was pronounced. Trophic linkages within these microbial plankton was also suggested; bacteria were grazed by HNF and these in turn were grazed by microzooplankton. When the nutrient supply was high, both HNF and microzooplankton were exposed to higher amounts of algae and lower bacterial abundance. Moreover, nutrient regeneration by daphnids and Eodiaptomus copepods seemed to differentially stimulate the growth of algae and bacteria. The results suggest that the relationship between macrozooplankton and microbial plankton cannot be fully understood without taking into consideration not only the feeding characteristics of the macrozooplankton, but also the food web structure, the subsidized algal resource, and nutrient regeneration from the macrozooplankton.     

Anti-obesity property of the brown seaweed,Sargassum polycystum using an in vivo animal model

Obesity has reached epidemic proportions in many countries around the world. Preventing and treating obesity is becoming an increasing priority due to dissatisfaction with high costs and hazardous side effects of anti-obesity drugs. This study was designed to investigate the anti-obesity properties of the Sabah brown seaweed, Sargassum polycystum, on body weight and blood plasma levels of rats fed a high-fat diet supplemented with different doses of the seaweed powder. Male Sprague Dawley rats were divided into five groups, representing control negative (CN) group, control positive (CP) group, low dosage group (LDG), medium dosage group (MDG) and high dosage group (HDG). The study duration was 8 weeks. All groups were fed high-fat diet throughout the study except for CN group, which was fed normal rat chow. LDG, MDG and HDG were supplemented high-fat diet with 2.5, 5.0 and 10.0 % seaweed powder, respectively. By comparing with the CP group, it was found that the HDG (10.0 % seaweed treatment diet) showed the greatest effect in suppressing weight gain, followed by the MDG (5.0 % seaweed treatment diet) and LDG (2.5 % seaweed treatment diet). The HDG decreased the levels of plasma total cholesterol and triglycerides. This finding shows that S. polycystum powder treatment had a positive effect on the inhibition of weight gain and has a promising value in preventing obesity.