Population structure and genetic diversity of native and invasive populations of Solanum rostratum (Solanaceae)

Aims: We investigate native and introduced populations of Solanum rostratum, an annual, self-compatible plant that has been introduced around the globe. This study is the first to compare the genetic diversity of Solanum rostratum between native and introduced populations. We aim to (1) determine the level of genetic diversity across the studied regions; (2) explore the likely origins of invasive populations in China; and (3) investigate whether there is the evidence of multiple introductions into China. Methods: We genotyped 329 individuals at 10 microsatellite loci to determine the levels of genetic diversity and to investigate population structure of native and introduced populations of S. rostratum. We studied five populations in each of three regions across two continents: Mexico, the U.S.A. and China. Important Findings: We found the highest genetic diversity among Mexican populations of S. rostratum. Genetic diversity was significantly lower in Chinese and U.S.A. populations, but we found no regional difference in inbreeding coefficients (FIS) or population differentiation (FST). Population structure analyses indicate that Chinese and U.S.A. populations are more closely related to each other than to sampled Mexican populations, revealing that introduced populations in China share an origin with the sampled U.S.A. populations. The distinctiveness between some introduced populations indicates multiple introductions of S. rostratum into China

Effects of Mountain Pine Beetle on Fuels and Expected Fire Behavior in Lodgepole Pine Forests, Colorado, USA

In Colorado and southern Wyoming, mountain pine beetle (MPB) has affected over 1.6 million ha of predominantly lodgepole pine forests, raising concerns about effects of MPB-caused mortality on subsequent wildfire risk and behavior. Using empirical data we modeled potential fire behavior across a gradient of wind speeds and moisture scenarios in Green stands compared three stages since MPB attack (Red [1–3 yrs], Grey [4–10 yrs], and Old-MPB [∼30 yrs]). MPB killed 50% of the trees and 70% of the basal area in Red and Grey stages. Across moisture scenarios, canopy fuel moisture was one-third lower in Red and Grey stages compared to the Green stage, making active crown fire possible at lower wind speeds and less extreme moisture conditions. More-open canopies and high loads of large surface fuels due to treefall in Grey and Old-MPB stages significantly increased surface fireline intensities, facilitating active crown fire at lower wind speeds (>30–55 km/hr) across all moisture scenarios. Not accounting for low foliar moistures in Red and Grey stages, and large surface fuels in Grey and Old-MPB stages, underestimates the occurrence of active crown fire. Under extreme burning conditions, minimum wind speeds for active crown fire were 25–35 km/hr lower for Red, Grey and Old-MPB stands compared to Green. However, if transition to crown fire occurs (outside the stand, or within the stand via ladder fuels or wind gusts >65 km/hr), active crown fire would be sustained at similar wind speeds, suggesting observed fire behavior may not be qualitatively different among MPB stages under extreme burning conditions. Overall, the risk (probability) of active crown fire appears elevated in MPB-affected stands, but the predominant fire hazard (crown fire) is similar across MPB stages and is characteristic of lodgepole pine forests where extremely dry, gusty weather conditions are key factors in determining fire behavior

Low Cost Tuberculosis Vaccine Antigens in Capsules: Expression in Chloroplasts, Bio-Encapsulation, Stability and Functional Evaluation In Vitro

Tuberculosis (TB) caused by Mycobacterium tuberculosis is one of the leading fatal infectious diseases. The development of TB vaccines has been recognized as a major public health priority by the World Health Organization. In this study, three candidate antigens, ESAT-6 (6kDa early secretory antigenic target) and Mtb72F (a fusion polyprotein from two TB antigens, Mtb32 and Mtb39) fused with cholera toxin B-subunit (CTB) and LipY (a cell wall protein) were expressed in tobacco and/or lettuce chloroplasts to facilitate bioencapsulation/oral delivery. Site-specific transgene integration into the chloroplast genome was confirmed by Southern blot analysis. In transplastomic leaves, CTB fusion proteins existed in soluble monomeric or multimeric forms of expected sizes and their expression levels varied depending upon the developmental stage and time of leaf harvest, with the highest-level of accumulation in mature leaves harvested at 6PM. The CTB-ESAT6 and CTB-Mtb72F expression levels reached up to 7.5% and 1.2% of total soluble protein respectively in mature tobacco leaves. Transplastomic CTB-ESAT6 lettuce plants accumulated up to 0.75% of total leaf protein. Western blot analysis of lyophilized lettuce leaves stored at room temperature for up to six months showed that the CTB-ESAT6 fusion protein was stable and preserved proper folding, disulfide bonds and assembly into pentamers for prolonged periods. Also, antigen concentration per gram of leaf tissue was increased 22 fold after lyophilization. Hemolysis assay with purified CTB-ESAT6 protein showed partial hemolysis of red blood cells and confirmed functionality of the ESAT-6 antigen. GM1-binding assay demonstrated that the CTB-ESAT6 fusion protein formed pentamers to bind with the GM1-ganglioside receptor. The expression of functional Mycobacterium tuberculosis antigens in transplastomic plants should facilitate development of a cost-effective and orally deliverable TB booster vaccine with potential for long-term storage at room temperature. To our knowledge, this is the first report of expression of TB vaccine antigens in chloroplasts

Evaluation of the performance of different cleaning treatments in reducing microbial contamination of poultry transport crates

International audience1. The present systems for cleaning the plastic crates (drawers) used to transport live poultry to the processing plant are known to be inadequate for removing microbial contamination. 2. To investigate possible improvements, a mobile experimental rig was constructed and operated in the lairage of a poultry processing plant. The cleaning rig could simulate the conditions of commercial cleaning systems and utilise freshly emptied crates from the processing plant. 3. The aim of the study was to improve cleaning by enhancing the removal of adherent organic material on the crates and by reducing microbial contamination by at least 4 log10 units. 4. Trials showed that the most effective treatments against Campylobacter was either (a) the combination of soaking at 55oC, brushing for 90 s, washing for 15 s at 60oC, followed by the application of disinfectant (Virkon S in this study) or (b) the use of ultrasound (4 kW) at 65oC for 3 – 6 min, with or without mechanical brushing of crates. 5. Both of these treatments also achieved a 4-log10 reduction or more in the counts of Enterobacteriaceae but were less effective in reducing aerobic plate counts. 6. It was noted that here was little correlation between the visual assessment of crate cleanliness and microbiological counts. 7. It was concluded that the demonstrated enhanced cleaning could contribute significantly to overall hygiene control in poultrymeat production

Effect of ultrasonic treatment during cleaning on the microbiological condition of poultry transport crates

1. Small sections cut from commercial crates used to transport live poultry to the processing plant were artificially contaminated with effluent taken from a commercial crate-cleaning system.2. Laboratory trials, involving the immersion of these sections in an ultrasonic water bath (4 kW energy) showed that aerobic plate counts (APC) and counts of Enterobacteriaceae were progressively reduced as the immersion time was increased from 0 to 120 s and the water temperature raised from 35 to 58°C.3. In subsequent trials at a processing plant, using commercially cleaned crates, there was relatively little effect of ultrasound (or pressure washing) on the biofilm present. However, ultrasonic treatment in combination with an immersion temperature of 60°C reduced counts of Enterobacteriaceae to below the detection limit (log10 2·3 cfu) within 1 to 3 min, while APC were reduced by >2 log10 units after 3 min.4. It was concluded that ultrasonic treatment has a possible role in the crate-cleaning process, when used in conjunction with higher immersion temperatures. In this way, it could contribute significantly to hygiene control

Targeting HER2-mutant metastatic cervical cancer with neratinib: Final results from the phase 2 SUMMIT basket trial

OBJECTIVE: HER2 mutations are associated with poor prognosis and are detected in 3-6% of cervical cancers. Neratinib, an irreversible pan-HER tyrosine kinase inhibitor, had activity in several HER2-mutant cancer types in the phase 2 SUMMIT basket study. We present updated and final results from the cervical cancer cohort of SUMMIT. METHODS: Eligible patients had HER2-mutant, metastatic or recurrent cervical cancer progressing after platinum-based treatment for advanced/recurrent disease. Patients received neratinib 240 mg/day; loperamide was mandatory during cycle 1. Confirmed objective response rate (ORR) was the primary endpoint. Duration of response (DoR), clinical benefit rate (CBR), progression-free survival (PFS), and safety were secondary endpoints. RESULTS: Twenty-two patients were enrolled; 18 (81.8%) had endocervical adenocarcinoma; median two prior systemic chemotherapy regimens (range 1-4). The most common HER2 variant was S310F/Y mutation (n = 13; 59.1%). Four patients had confirmed partial responses (ORR 18.2%; 95% CI 5.2-40.3); 6 had stable disease ≥16 weeks (CBR 45.5%; 95% CI 24.4-67.8). Median DoR was 7.6 months (95% CI 5.6-12.3). Median PFS was 5.1 months (95% CI 1.7-7.2). All-grade diarrhea (90.9%), nausea (54.5%), and constipation (54.5%) were the most common adverse events. Five patients (22.7%) reported grade 3 diarrhea. There were no grade 4 adverse events, no diarrhea-related treatment discontinuations, and two grade 5 adverse events, unrelated to neratinib: dyspnea (n = 1) and embolism (n = 1). CONCLUSIONS: Neratinib resulted in durable responses and disease control in patients with HER2-mutant metastatic/recurrent cervical cancer in SUMMIT. These findings support next-generation sequencing and tailored therapy for select patients with advanced cervical cancer. All responses occurred in patients with endocervical adenocarcinoma. Further assessment of neratinib in this setting is warranted. TRIAL REGISTRATION NUMBER: NCT01953926 (ClinicalTrials.gov), 2013-002872-42 (EudraCT)