We employed an island biogeographic approach to determine whether small fragments of the shrub habitats coastal sage scrub and chaparral, isolated by urbanization, are capable of supporting viable populations of native rodent species. The distribution of native rodents in 25 urban habitat fragments was assessed by live‐trapping. Over half of the fragments surveyed (13 of 25) did not support populations of native rodents. Fragments supported fewer species than equivalently sized plots in large expanses of unfragmented habitat, and older fragments (fragments that had been isolated for a longer period of time) supported fewer species. Both results implied that local extinctions occurred in the fragments following insularization. Stepwise multiple polychotomous logistic regression was used to determine which biogeographic variables were the best predictors of species number across fragments. The area of shrub habitat in each fragment was the most significant predictor of species diversity; age of a fragment was also significant and was negatively correlated with species number, but the isolation distance of a fragment had no relationship to species diversity. We found a negative relationship between extinction vulnerability of native rodent species and relative abundance: species that were more abundant in unfragmented habitat persisted in more habitat fragments. Random environmental and demographic fluctuations (island effects) and edge effects associated with fragmentation are proposed as causes of these local extinctions.

All 18 species of gibbons are considered threatened with extinction and listed on the IUCN Red List of Threatened Species. Because gibbons (Hylobatidae) are one of the most threatened primate families, a great need exists to determine and monitor their status effectively. To meet this need, we employed distance sampling methods to estimate the density and number of gibbon groups. We focused on southern yellow-cheeked crested gibbon in the Nam Cat Tien sector of Cat Tien National Park, Vietnam, from July to October, 2016. We used an auditory point count method at 48 listening posts to detect gibbon groups. We estimated our detection probability of calling groups of gibbons within 1,200 m of a listening post was 0.63 (95% CI: 0.54-0.74). In addition, we estimated the daily calling probability of a gibbon group to be 0.46 (95% CI: 0.33-0.59) and interpreted this as the probability that a group was available to be detected. We adjusted our group density and abundance estimates by both detection and availability probabilities. Ultimately we estimated 325 (95% CI: 232-455) gibbon groups in the Nam Cat Tien sector. Our results suggest that Cat Tien National Park contains one of the largest populations of southern yellow-cheeked crested gibbon in Vietnam. Our methods are one way of avoiding underestimation of gibbon group density and abundance by incorporating uncertainty in gibbon group availability and detection.

Background: The BRAF V600E gene encodes for the mutant BRAF V600E protein, which triggers downstream oncogenic signaling in thyroid cancer. Since most currently available methods have focused on detecting BRAF V600E mutations in tumor DNA, there is limited information about the level of BRAF V600E mRNA in primary tumors of thyroid cancer, and the diagnostic relevance of these RNA mutations is not known. Methods: Sixty-two patients with thyroid cancer and non-malignant thyroid disease were included in the study. Armed with an ultrasensitive technique for mRNA-based mutation analysis based on a two step RT-qPCR method, we analysed the expression levels of the mutated BRAF V600E mRNA in formalin-fixed paraffin-embedded samples of thyroid tissues. Sanger sequencing for detection of BRAF V600E DNA was performed in parallel for comparison and normalization of BRAF V600E mRNA expression levels. Results: The mRNA-based mutation detection assay enables detection of the BRAF V600E mRNA transcripts in a 10, 000-fold excess of wildtype BRAF counterparts. While BRAF V600E mutations could be detected by Sanger sequencing in 13 out of 32 malignant thyroid cancer FFPE tissue samples, the mRNA-based assay detected mutations in additionally 5 cases, improving the detection rate from 40.6 to 56.3%. Furthermore, we observed a surprisingly large, 3-log variability, in the expression level of the BRAF V600E mRNA in FFPE samples of thyroid cancer tissue. Conclusions: The expression levels of BRAF V600E mRNA was characterized in the primary tumors of thyroid cancer using an ultrasensitive mRNA-based mutation assay. Our data inspires further studies on the prognostic and diagnostic relevance of the BRAF V600E mRNA levels as a molecular biomarker for the diagnosis and monitoring of various genetic and malignant diseases.

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Objectives To determine DNA‐HPV transition rates and related factors in HPV‐infected women 18–69 years of age in Can Tho City from 2013 to 2018. Methods Both a retrospective and a prospective cohort study were done. Interviews, gynaecological examinations and HPV testing by PCR (cervical fluid) were used to collect data. The results were recorded and compared with those of HPV in 2013 to assess the development of HPV over time. Transition was defined as conversion to HPV‐positive state in 2018 from a negative state in 2013. No transition was defined as clearance of HPV when the positive 2013 result was negative in 2018 or when the result remained negative or positive in 2013 and 2018. Factors related to the change were analysed. Results Among a sample size of 204 cases, the average age of participants was 48.9 ± 10.4 years. Women >45 comprised 63.2% of participants; 82.8% lived with their husbands, 6.4% were divorced, and 2.9% lived apart from their husbands due to work. After 5 years of observation, 16.2% of DNA‐HPV cases had converted to HPV‐positive state and 66.2% of DNA‐HPV cases had cleared to HPV‐negative state. Factors related to conversion to HPV‐positive state were age ≤ 45 years (3.14 times higher risk of transition than in the >45 age group (95% CI: 1.12–8.8)); change of sexual partner (OR = 3.75 (95% CI: 1.15–12.2)); change of sexual partner by husband (OR = 3.69 (95% CI: 1.20–11.3); sexually transmitted diseases (OR = 5.19 (95% CI: 1.09–24.8)); and a history of vacuum aspiration or dilation and evacuation abortion (OR = 1.4 (95% CI: 0.29–6.4)). Conclusions 16.2% of women with DNA‐HPV transition converted to HPV‐positive state. Changes in sexual habits increase the risk of developing HPV positivity.