While crystal methamphetamine use by gay, bisexual, and other men who have sex with men (GBM) is associated with increased risk for sexually transmitted infection (STI) transmission, less is ...understood about the causal pathways between crystal methamphetamine use and STIs. We examined whether the association between greater crystal methamphetamine risk and prevalent bacterial STI diagnosis among GBM was mediated by two types of attitudinal variables: attitudes toward condoms, and sexual escape motives, defined as the use of substances to escape self-awareness during sex, and by sexual behaviors.
We used computer-assisted self-interview questionnaires from 2449 sexually active GBM (18% living with HIV; median age = 33, interquartile range, 27–45) recruited via respondent-driven sampling in Vancouver, Toronto, and Montreal, Canada. Using the baseline data from the Engage cohort study, we fit a series of structural mediation models of the associations between greater crystal methamphetamine risk and bacterial STI (syphilis, gonorrhea, and chlamydia) diagnosis. We estimated indirect paths from greater crystal methamphetamine risk, attitudes toward condoms, sexual escape motives, and sexual risk behaviors, adjusting for self-reported demographic variables.
In the mediated model, the direct association between greater crystal methamphetamine risk and bacterial STI diagnosis was non-significant; however, five indirect paths were significant. Greater crystal methamphetamine risk was associated with bacterial STIs via condom use attitudes and escape motives, which in turn were associated with number of male anal sex partners, condomless anal sex, and oral sex.
Public health and counselling interventions for GBM who use crystal methamphetamine and who are at higher risk for STIs should target evidence-based causal paths that consider sexual attitudes and sexual practices.
•Crystal methamphetamine (CM) risk is associated with STIs in sexual minority men (SMM).•Indirect paths from CM risk to STIs via attitudinal variables and sexual behaviors.•Targeted psychosocial STI prevention interventions are needed for SMM who use CM.
We study the reaction mechanism of
ϕ
-meson photoproduction on the nucleon and
4
He targets by using a dynamical model based on a Hamiltonian. In addition to the dominant contribution of the Pomeron ...exchange, various meson exchanges are considered in the
t
channel to describe the CLAS data in the low energy region
s
=
(
1.97
-
2.84
)
GeV. The direct
ϕ
radiations are taken into account in the
s
- and
u
-channels. The backward structures at
s
≈
2.1
and 2.3 GeV are well reproduced by the inclusion of the
s
-channel
N
(
2000
,
5
/
2
+
)
and
N
(
2300
,
1
/
2
+
)
resonances, respectively. We also consider the final
ϕ
N
interactions by the gluon exchange, the direct
ϕ
N
interactions, and the box diagrams arising from the couplings with the
π
N
,
ρ
N
,
K
Λ
, and
K
Σ
channels. The effects of the final state interactions are found to be very weak. Then the resulting Hamiltonian is used to study the coherent
γ
4
He
→
ϕ
4
He
reaction within the distorted-weave impulse approximation. The calculated differential cross sections account for the LEPS data quite well.
Summary
We have produced 22 090 primary transgenic rice plants that carry a T‐DNA insertion, which has resulted in 18 358 fertile lines. Genomic DNA gel‐blot and PCR analyses have shown that ...approximately 65% of the population contains more than one copy of the inserted T‐DNA. Hygromycin resistance tests revealed that transgenic plants contain an average of 1.4 loci of T‐DNA inserts. Therefore, it can be estimated that approximately 25 700 taggings have been generated. The binary vector used in the insertion contained the promoterless β‐glucuronidase (GUS) reporter gene with an intron and multiple splicing donors and acceptors immediately next to the right border. Therefore, this gene trap vector is able to detect a gene fusion between GUS and an endogenous gene, which is tagged by T‐DNA. Histochemical GUS assays were carried out in the leaves and roots from 5353 lines, mature flowers from 7026 lines, and developing seeds from 1948 lines. The data revealed that 1.6–2.1% of tested organs were GUS‐positive in the tested organs, and that their GUS expression patterns were organ‐ or tissue‐specific or ubiquitous in all parts of the plant. The large population of T‐DNA‐tagged lines will be useful for identifying insertional mutants in various genes and for discovering new genes in rice.
The fabrication of Pt‐coated, vertically aligned, nanoporous gold‐nanorod arrays (see figure, left panel) that display electrocatalytically active large surface areas is described. Epitaxial platinum ...coatings only 1–2 monolayers thick are prepared by the spontaneous replacement of an electrochemically deposited copper layer with platinum metal. Electrochemical characterization of the resulting nanoporous nanorod arrays (see figure, right panel) is carried out as a method for probing catalytic behavior.
Biodegradable polymeric micelles, self-assembled from a di-block copolymer of poly(
d,
l-lactic-co-glycolic acid) (PLGA) and poly(ethylene glycol) (PEG), were prepared to achieve folate receptor ...targeted delivery of doxorubicin (DOX). In the di-block copolymer structure of PLGA–
b-PEG, DOX was chemically conjugated to a terminal end of PLGA to produce DOX–PLGA–mPEG, and folate was separately conjugated to a terminal end of PEG to produce PLGA–PEG–FOL. The two di-block copolymers with different functional moieties at their chains ends were physically mixed with free base DOX in an aqueous solution to form mixed micelles. It was expected that folate moieties were exposed on the micellar surface, while DOX was physically and chemically entrapped in the core of micelles. Flow cytometry and confocal image analysis revealed that folate conjugated mixed micelles exhibited far greater extent of cellular uptake than folate unconjugated micelles against KB cells over-expressing folate receptors on the surface. They also showed higher cytotoxicity than DOX, suggesting that folate receptor medicated endocytosis of the micelles played an important role in transporting an increased amount of DOX within cells. In vivo animal experiments, using a nude mice xenograft model, demonstrated that when systemically administered, tumor volume was significantly regressed. Biodistribution studies also indicated that an increased amount of DOX was accumulated in the tumor tissue.
It may be challenging to differentiate primary CNS lymphomas, especially primary CNS lymphomas with atypical MR features, from tumefactive demyelinating lesions by the use of conventional MR. This ...study aimed to investigate the usefulness of (1)H-MR spectroscopy for making this discrimination.
Forty-four patients with primary CNS lymphomas and 21 with tumefactive demyelinating lesions were enrolled. Single-voxel (TE = 144 ms) (1)H-MR spectroscopy scans with the use of the point-resolved spectroscopy sequence were retrospectively analyzed. The Cho/Cr and Cho/NAA area ratios were calculated. The lipid and/or lactate peak was visually categorized into 5 grades on the basis of comparison with the height of the Cr peak. The (1)H-MR spectroscopy findings were compared in all of the primary CNS lymphomas and the tumefactive demyelinating lesions and in the subgroup of atypical primary CNS lymphomas and tumefactive demyelinating lesions. The thresholds and added value of (1)H-MR spectroscopy to conventional MR were calculated by use of receiver operating characteristic curves.
Discrepancies between all of the primary CNS lymphomas and tumefactive demyelinating lesions were found in the Cho/Cr ratio (P = .000), Cho/NAA ratio (P = .000), and the lipid and/or lactate peak grade (P = .000). Lymphoma rather than tumefactive demyelinating lesions was suggested when the Cho/Cr ratio was >2.58, the Cho/NAA ratio was >1.73, and a high lipid and/or lactate peak grade (grade >3) was seen. Higher Cho/Cr ratios, Cho/NAA ratios, and lipid and/or lactate peak grades were found in atypical primary CNS lymphomas when compared with those of tumefactive demyelinating lesions. The area under the receiver operating characteristic curve of conventional MR was improved from 0.827 to 0.870 when Cho/NAA ratio was added in the uncertain cases.
(1)H-MR spectroscopy may be useful for differentiating primary CNS lymphomas from tumefactive demyelinating lesions. Cho/NAA ratio could provide added value to conventional MR imaging.
Polygonatum odoratum var. pluriflorum, called "Dunggulle", is cultivated in East Asia to obtain rhizomes. In Korea and China, these rhizomes are used in traditional teas, health beverages, and herbal ...medicines (Zhao and Li, 2015). In 2019, Dunggulle was cultivated in 47 hectares, with an annual output of 120M/T in Korea. In November 2020, Dunggulle rhizomes with symptoms of blue mold rot were observed at a Dunggulle farm storage (36°06'01''N, 127°29'20''E) in Geuman, Korea, where the temperature ranged from 9 to 13°C, with an average humidity of 70%. The disease incidence was 2 to 3% out of 200 rhizomes across all markets surveyed. The disease begins with a greenish blue mold covering the rhizome surface (30 to 60%), followed by rhizome rot with a dark brown color as the disease progresses. Leading edges of the rotten rhizome pieces were sterilized with 1% NaOCl and 70% ethanol and placed on MEA (Malt Extract Agar) with penicillin G and streptomycin (both 50 µg/mL). After 7 days of incubation at 25°C, greenish-blue colonies appeared, from which a monospore was isolated. A representative isolated strain was deposited in the Korean Agricultural Culture Collection (KACC, Wanju, Korea) with Acc. No. KACC 49832. The strain grew slowly on MEA at 25°C (8 to 18 mm diam. after 7 days), producing greenish blue conidia. The conidiophores were hyaline and mostly terverticillate; the branches were appressed against the main axis; the stipes were smooth-walled; and the metulae were cylindrical, 10 to 13 × 2.7 to 3.2 µm, with 6 to 10 flask-shaped phialides, measured 9 to 12 × 2.7 to 3.1 µm. The conidia were globose or subglobose and 2.8 to 4.1 µm diam. These morphological characteristics fit well with the description of Penicillium expansum (Frisvad & Samson, 2004). Genomic DNA was extracted from the mycelia of the KACC 49832 MEA plate. ITS rDNA, beta-tubulin (BenA), and calmodulin (CaM) gene regions were sequenced for identification (Houbraken et al., 2020), and the rsulting sequences were deposited in GenBank (Acc. Nos. MZ189258, MZ226688, and MZ226689, respectively). Comparison with the GenBank sequences revealed that the Korean isolate was highly similar to P. expansum (ITS rDNA 99.8%, BenA 98.6%, and CaM 97.8%). Phylogenetic results based on the maximum-likelihood analysis revealed that KACC 49832 was grouped with P. expansum. To demonstrate pathogenicity, 10 µL of conidial suspension (1.3 × 105 conidia/mL) was dropped on the surface of three Dunggulle rhizomes scratched with a syringe needle. For the control, sterile water was applied on three control rhizomes. All rhizomes were surface-sterilized as referred above before being sprayed and dried. All inoculated and control rhizomes were kept in incubator at 25°C and 90-95% relative humidity. After a week, the inoculated points showed symptoms similar to those of the initial infection, whereas controls remained symptomless. The re-isolated fungus matched KACC 49832 based on morphological and sequence analyses, thereby fulfilling Koch's postulates. The experiment was performed three times. To our knowledge, this is the first report of P. expansum as a Dunggulle rhizome pathogen in Korea. As this pathogen is known to produce patulin, a carcinogenic fungal metabolite, further studies on the mycotoxicity of the infected rhizomes are required. This report might help manage the storage conditions of Dunggulle rhizomes to prevent the blue mold rot.
Asian Citrus Psyllid (ACP), Diaphorina citri, is a key vector transmitting the causative agent of Huanglongbing (HLB) disease. Population growth of ACP is evident after feeding on plant flush shoots, ...as they only oviposit here. However, the underlying mechanism as to why flush shoots govern oviposition is unclear. This study compares the fecundity and ovarian morphology of ACP between young flush and mature leaves. Furthermore, the transcriptome of mated females infesting Murraya paniculata was analysed. Finally, the gene of the key Target of Rapamycin (TOR) signalling pathway was silenced by RNAi. Results indicated that flush shoot feeding activated the development of the psyllids ovary and therefore induced oviposition. A total of 126 and 2794 differentially expressed genes were detected at 1 and 5 days, respectively, after pest infestation of flush shoots compared to mature leaves. Many genes are involved in protein metabolism, Mitogen‐Activated Protein Kinase (MAPK) signalling pathway, hormone synthesis, and TOR signalling pathway: all thought to activate reproduction. Silencing of the positive regulator gene DcRheb in the TOR pathway resulted in lower levels of ecdysone and juvenile hormone and decreased vitellogenin synthesis, further disrupting reproductive ability. This study enhances understanding of the molecular mechanism underlying ACP's reproductive strategy.
Asian Citrus Psyllid (ACP) only oviposits on flush shoots.
Protein metabolism, Mitogen‐Activated Protein Kinase (MAPK) signalling, hormone synthesis and Target of Rapamycin (TOR) signalling in ACP are involved in activating reproduction following feeding on flush shoots.
TOR signalling plays important role via transferring and inducing hormone synthesis and vitellogenesis.
Objectives
The last Canadian biobehavioural surveillance study of HIV and other sexually transmitted and blood-borne infections (STBBI) among gay, bisexual and other men who have sex with men (GBM) ...was conducted in 2010. We designed a study to measure STBBI prevalence among GBM in metropolitan Montreal, Toronto and Vancouver and to document related preventive and risk behaviours.
Methods
The Engage Cohort Study used respondent-driven sampling (RDS) to recruit GBM who reported sex with another man in the past 6 months. At baseline, we examined recruitment characteristics of the samples, and the RDS-II-adjusted distributions of socio-demographics, laboratory-confirmed HIV and other STBBI prevalence, and related behaviours, with a focus on univariate differences among cities.
Results
A total of 2449 GBM were recruited from February 2017 to August 2019. HIV prevalence was lower in Montreal (14.2%) than in Toronto (22.2%) or Vancouver (20.4%). History of syphilis infection was similar across cities (14–16%). Vancouver had more HIV-negative/unknown participants who reported never being HIV tested (18.6%) than Toronto (12.9%) or Montreal (11.5%). Both Montreal (74.9%) and Vancouver (78.8%) had higher proportions of men who tested for another STBBI in the past 6 months than Toronto (67.4%). Vancouver had a higher proportion of men who used pre-exposure prophylaxis (PrEP) in the past 6 months (18.9%) than Toronto (11.1%) or Montreal (9.6%).
Conclusion
The three largest cities of Canada differed in HIV prevalence, STBBI testing and PrEP use among GBM. Our findings also suggest the need for scale-up of both PrEP and STI testing among GBM in Canada.
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