Prevalence of a Chytrid Pathogen (Batrachochytrium dendrobatidis) in Eastern Hellbender Salamanders in New York and Pennsylvania

Amphibian populations are currently declining globally. There are many possible causes for these declines, among which an emerging infectious disease, chytridiomycosis, has been implicated. Chytridiomycosis in the U.S.A. is mainly caused by the Batrachochytrium dendrobatidis. In this study, I used qPCR assays to detect the existence of this pathogen in the Eastern Hellbender (Cryptobranchus alleganiensis alleganiensis) populations in the Allegheny and Susquehanna River drainages of New York and Pennsylvania. Chytrid is most often tested by using skin swabs, but in this study, tail clips, dorsal skin, blood and eggs were tested as well. Batrachochytrium dendrobatidis was detected in tail clips in this study, although the tail clip samples seemed to have lower Bd detection sensitivities and concentrations compared with swab samples. Only three out of 41 samples that had tested positive for swabs also tested positive for tail clips, and very small tail clip samples did not result in chytrid positives, despite a relatively high known rate of infection in Pennsylvania. Batrachochytrium dendrobatidis was detected in 8.5% of NY and 2.4% of PA tail clip samples (out of 124 total) and from tail clips taken as early as 2004 in the NY Allegheny River drainage. This shows that archival samples, often available for genetic testing, may also be used for Bd detection. The Bd positive rate from swab samples (25 in total) was 56.0% in NY

SiX2 (X = S, Se) Single Chains and (Si–Ge)X2 Quaternary Alloys

Layered or chain materials have received significant research attention owing to their interesting physical properties, which can dramatically change when the material is thinned from bulk (three-dimensional) to thin two-dimensional sheet or one-dimensional (1D) chain form. Materials with the stoichiometry AX2 with A = Si or Ge and X = S or Se form an especially intriguing semiconducting class. For example, bulk silicon dichalcogenides (SiX2) consist of 1D chains held together by van der Waals forces. Although this structural configuration has the potential to reveal interesting physical phenomena within the 1D limit, obtaining SiX2 single chains has been challenging. We here examine experimentally and theoretically SiX2 materials in the low chain number limit. Carbon nanotubes serve as growth templates and stabilize and protect the structures, and atomic-resolution scanning transmission electron microscopy directly identifies the atomic structure. Two distinct chain structures are observed for SiX2. SixGe1-xS2(1-y)Se2y quaternary alloy chains are also synthesized and characterized, demonstrating tunable semiconducting properties at the atomic-chain level. Density functional theory calculations reveal that the band gap of these alloy chains can be widely tuned through composition engineering. This work offers the possibilities for synthesizing and controlling semiconductor compositions at the single-chain limit to tailor material properties

Establishing adherence–concentration–efficacy thresholds of TDF–FTC pre-exposure prophylaxis for HIV prevention in African women: a protocol for the Women TDF–FTC Benchmark Study

BackgroundOral pre-exposure prophylaxis (PrEP) using co-formulated emtricitabine (FTC) and tenofovir disoproxil fumarate (TDF) is a potent HIV prevention method for men and women, with its efficacy highly dependent on adherence. A pivotal HIV efficacy study combined with a directly observed pharmacological study defined the thresholds for HIV protection in men who have sex with men (MSM), which are the keys to PrEP promotion and development of new PrEP agents. For African women at risk for HIV and belonging to a priority group considered due to disproportionately high incident HIV infections, the variable adherence in PrEP clinical trials and the limited pharmacologic data have resulted in a lack of clarity about the PrEP adherence required for HIV protection. We propose a study to quantify the adherence–concentration–efficacy thresholds of TDF/FTC PrEP among African cisgender women to inform decisions about optimal PrEP dosing and adherence for HIV protection.MethodsWe randomized 45 low-risk HIV-uninfected African women, aged 18–30 years old, to directly observe the TDF/FTC PrEP of two, four, or seven doses per week for 8 weeks. A complementary age-matched pregnant women cohort at high risk of HIV, who will receive seven doses per week, was recruited (N = 15) with the primary aim of establishing benchmark concentrations in dried blood spots and peripheral blood mononuclear cells. Plasma, whole blood (WB), urine, hair, vaginal fluid, and vaginal tissue (non-pregnant women only) were archived for future testing. Drug concentrations were measured using methods validated for each biological matrix. Pharmacokinetic models were fitted to drug concentrations to quantify concentration–adherence thresholds. To define the drug concentrations associated with HIV protection, we applied the newly defined thresholds from the primary pharmacologic trial to the subset of women randomized to TDF/FTC or TDF in the Partners PrEP Study with the drug concentration assessed in plasma and WB samples. Multiple imputation was used to construct a data set with drug concentrations at each visit when an HIV test was performed for the entire cohort, replicating the work for MSM.DiscussionThe proposed study generated the first African women-specific TDF–PrEP adherence–concentration–efficacy thresholds essential for guiding the accurate interpretation of TDF/FTC PrEP programs and clinical trials of novel HIV prevention products using TDF/FTC as an active control. Clinical Trial RegistrationClinicalTrials.gov, identifier (NCT05057858)

Association of sexual relationship power with PrEP persistence and other sexual health outcomes among adolescent and young women in Kenya and South Africa

IntroductionGendered power inequalities impact adolescent girls’ and young women's (AGYW) sexual and reproductive health (SRH) outcomes. We investigated the influence of sexual relationship power on AGYW's SRH outcomes, including HIV pre-exposure prophylaxis (PrEP) persistence.MethodsThe POWER study in Kisumu, Kenya, and Cape Town and Johannesburg, South Africa provided PrEP to 2,550 AGYW (aged 16–25). AGYW's perceived power in their primary sexual relationship was measured among the first 596 participants enrolled using the Sexual Relationship Power Scale's (SRPS) relationship control sub-scale. Multivariable regression was used to test for (1) key sociodemographic and relationship characteristics associated with relationship power; and (2) the association of relationship power with SRH outcomes including PrEP persistence.ResultsIn this cohort, the mean SRPS score was 2.56 (0.49), 542 (90.9%) initiated PrEP; 192 (35.4%) persisted with PrEP at 1 month of which 46 (24.0% of 192) persisted at 6 months. SRPS were significantly lower among AGYW who cohabited with their sex partner (−0.14, 95% CI: −0.24 to −0.04, p = 0.01), or had ≥1 sex partner (−0.10, 95% CI: −0.19 to −0.00, p = 0.05). AGYW with lower SRPS were more likely to not know their partner's HIV status (aOR 2.05, 95% CI: 1.27 to 3.33, p < 0.01), but SRPS was not associated with PrEP persistence, STI infection, condom, or hormonal contraception use.DiscussionAGYW's reasons for initiating PrEP and reasons for continuously using PrEP may be different. While low relationship power was associated with perceived HIV vulnerability, AGYW's PrEP persistence may be influenced by more than relationship power

Circ_0000520 interacts with miR-512-5p to upregulate KIAA0100 to promote malignant behaviors in lung cancer

Background. CircRNAs function as pivotal molecules to regulate the malignant development of lung cancer. This study was designed to research the functional role and how it acted in lung cancer progression. Methods. Circ_0000520, microRNA-512-5p (miR512-5p) and Breast cancer-overexpressed gene 1 (KIAA0100) levels were measured through reverse transcription-quantitative polymerase chain reaction assay. Cell Counting Kit-8 assay and EdU assay were used to examine cell proliferation. Cell cycle and apoptosis were evaluated via flow cytometry. The protein levels were determined using western blot. Cell migration and invasion were assessed by wound healing assay and transwell assay. The circ_0000520 function in vivo was explored by tumor xenograft assay. The molecular interaction was analyzed via Dual-luciferase reporter assay. Results. Circ_0000520 was obviously upregulated in lung cancer tissues and cells. Silence of circ_0000520 inhibited proliferation, cell cycle progression, migration, invasion and angiogenesis but promoted cell apoptosis. Circ_0000520 downregulation reduced tumor growth of lung cancer in vivo. Circ_0000520 served as a miR-512- 5p sponge. The oncogenic function of circ_0000520 was partly achieved by sponging miR-512-5p in lung cancer. KIAA0100 was a target of miR-512-5p and miR-512-5p inhibited the malignant behaviors of lung cancer cells via downregulating KIAA0100. Circ_0000520 targeted miR-512-5p to regulate the level of KIAA0100. Conclusion. All these data demonstrated that circ_0000520 was able to drive the progression of lung cancer via the mediation of miR-512-5p/KIAA0100 axis. Circ_0000520 might be a potential biomarker for lung cancer

Distribution Characteristics of Microbial Residues within Aggregates of Fluvo-Aquic Soil under Biochar Application

The use of biochar as a soil amendment has substantial potential to enhance soil quality and carbon sequestration. However, the responses to the addition of biochar based on soil microbial residues are not well understood, particularly at the aggregate level. Herein, a two-year field experiment investigated the characteristics of distribution of microbial residues in calcareous fluvo-aquic soil aggregates (SA) in Henan Province, China. Four treatments were established as follows: no fertilizer (CK), chemical fertilizer (NPK), biochar (BC), and biochar combined with chemical fertilizer (NPK + BC). The results showed that the effects of particle size substantially impacted the microbial residues with 2–0.25 mm SA having the largest contents of amino sugars and microbial residual carbon (MRC), followed by >2 mm SA. Compared with the CK, the NPK treatment markedly enhanced the levels of glucosamine (GluN), galactosamine (GalN), muramic acid (MurA), total amino sugar (TAS), and MRC in the 2–0.25 mm SA by 26.69%, 24.0%, 23.62%, 25.11%, and 24.82%, respectively. The NPK + BC treatment significantly increased the contents of GluN, GalN, TAS, and MRC in the bulk soil and 0.25–0.053 mm SA compared with the NPK treatment. Bacterial biomass and the activity of N-acetyl-glucosaminidase in the bulk soil and SA markedly and positively affected the content of carbon in the amino sugars and microbial residues. Overall, the 2–0.25 mm SA were microenvironments with the largest accumulation of soil microbial residues, and the combined application of NPK + BC was more effective at increasing the accumulation of microbial residues in the SA, which provides an ideal fertilization strategy to improve the soil microenvironment and enhance soil quality

Distribution Characteristics of Microbial Residues within Aggregates of Fluvo-Aquic Soil under Biochar Application

The use of biochar as a soil amendment has substantial potential to enhance soil quality and carbon sequestration. However, the responses to the addition of biochar based on soil microbial residues are not well understood, particularly at the aggregate level. Herein, a two-year field experiment investigated the characteristics of distribution of microbial residues in calcareous fluvo-aquic soil aggregates (SA) in Henan Province, China. Four treatments were established as follows: no fertilizer (CK), chemical fertilizer (NPK), biochar (BC), and biochar combined with chemical fertilizer (NPK + BC). The results showed that the effects of particle size substantially impacted the microbial residues with 2–0.25 mm SA having the largest contents of amino sugars and microbial residual carbon (MRC), followed by >2 mm SA. Compared with the CK, the NPK treatment markedly enhanced the levels of glucosamine (GluN), galactosamine (GalN), muramic acid (MurA), total amino sugar (TAS), and MRC in the 2–0.25 mm SA by 26.69%, 24.0%, 23.62%, 25.11%, and 24.82%, respectively. The NPK + BC treatment significantly increased the contents of GluN, GalN, TAS, and MRC in the bulk soil and 0.25–0.053 mm SA compared with the NPK treatment. Bacterial biomass and the activity of N-acetyl-glucosaminidase in the bulk soil and SA markedly and positively affected the content of carbon in the amino sugars and microbial residues. Overall, the 2–0.25 mm SA were microenvironments with the largest accumulation of soil microbial residues, and the combined application of NPK + BC was more effective at increasing the accumulation of microbial residues in the SA, which provides an ideal fertilization strategy to improve the soil microenvironment and enhance soil quality

RNA-Seq and Genome-Wide Association Studies Reveal Potential Genes for Rice Seed Shattering

The loss of the shattering ability is one of the key events in rice domestication. The strength of the seed shattering ability is closely related to the harvest yield and the adaptability of modern mechanical harvesting methods. In this study, using a population of 587 natural rice cultivars, quantitative trait loci associated with seed shattering were detected by genome-wide association studies (GWASs). We consider the quantitative trait loci (QTLs) qBTS1 and qBTS3 to be the key loci for seed shattering in rice. Additionally, the abscission zone (AZ) and nonabscission zone (NAZ) of materials with a loss of shattering (DZ129) and easy shattering (W517) were subjected to RNA-Seq, and high-quality differential expression profiles were obtained. The AZ-specific differentially expressed genes (DEGs) of W517 were significantly enriched in plant hormone signal transduction, while the AZ-specific DEGs of DZ129 were enriched in phenylpropanoid biosynthesis. We identified candidate genes for the lignin-associated laccase precursor protein (LOC_Os01g63180) and the glycoside hydrolase family (LOC_Os03g14210) in the QTLs qBTS1 (chromosome 1) and qBTS3 (chromosome 3), respectively. In summary, our findings lay the foundation for the further cloning of qBTS1 and qBTS3, which would provide new insights into seed shattering in rice