Plant volatiles and density-dependent conspecific female odors are used by Asian citrus psyllid to evaluate host suitability on a spatial scale

We investigated how chemical cues derived from female Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae) and their host plants affect host acceptance choices by conspecifics. In four-choice cage and two-choice olfactometer assays, female psyllids avoided conspecific female cues in a density-dependent manner. However, odors from citrus plants actively damaged by psyllid feeding were attractive to conspecific females. When odors from feeding-damaged plants were presented simultaneously with odors from female D. citri, attraction of female conspecifics was no longer observed as compared with a clean air control in olfactometer assays. In subsequent experiments, D. citri females were released within arenas that contained actively feeding-damaged or non-damaged (control) citrus plants, each with previously psyllid-infested and uninfested young leaves. D. citri development is linked to the presence of these newly emerging leaves which is the only site of nymphal development. Female D. citri were initially attracted by the actively damaged plants as compared with non-damaged controls. After acceptance of plants that were actively damaged by feeding, D. citri females preferentially chose and settled on uninfested young leaves as compared with previously infested young leaves. A herbivore-induced plant volatile attractant and a female-specific odor repellent appear to be complementary foraging cues providing psyllids with information at two spatial scales: (1) the whole plant level for choosing a plant potentially harboring male conspecifics for mating, and (2) the within plant level to reduce intra-conspecific competition by identifying previously exploited resources.     

Role of Genetic Variants of Autophagy Genes in Susceptibility for Non-Medullary Thyroid Cancer and Patients Outcome

Autophagy is a central process in regulation of cell survival, cell death and proliferation and plays an important role in carcinogenesis, including thyroid carcinoma. Genetic variation in autophagy components has been demonstrated to influence the capacity to execute autophagy and is associated with disease susceptibility, progression and outcome. In the present study, we assessed whether genetic variation in autophagy genes contributes to susceptibility to develop thyroid carcinoma, disease progression and/or patient outcome. The results indicate that patients carrying the ATG5 single nucleotide polymorphisms rs2245214 have a higher probability to develop thyroid carcinoma (OR 1.85 (95% CI 1.04–3.23), P = 0.042). In contrast, no significant differences could be observed for the other genetic variants studied in terms of thyroid carcinoma susceptibility. Furthermore, none of the selected genetic variants were associated with clinical parameters of disease progression and outcome. In conclusion, genetic variation in ATG5, a central player in the autophagy process, is found to be associated with increased susceptibility for thyroid carcinoma, indicating a role for autophagy in thyroid carcinogenesis.     

Novel method to label solid lipid nanoparticles with 64cu for positron emission tomography imaging

Solid lipid nanoparticles (SLNs) are submicrometer (1-1000 nm) colloidal carriers developed in the past decade as an alternative system to traditional carriers (emulsions, liposomes, and polymeric nanoparticles) for intravenous applications. Because of their potential as drug carriers, there is much interest in understanding the in vivo biodistribution of SLNs following intravenous (i.v.) injection. Positron emission tomography (PET) is an attractive method for investigating biodistribution but requires a radiolabeled compound. In this work, we describe a method to radiolabel SLN for in vivo PET studies. A copper specific chelator, 6-[p-(bromoacetamido)benzyl]-1,4,8,11-tetraazacyclotetradecane-N,N',N',N'-tetraacetic acid (BAT), conjugated with a synthetic lipid, was incorporated into the SLN. Following incubation with (64)CuCl(2) for 1 h at 25 °C in 0.1 M NH(4)OAc buffer (pH 5.5), the SLNs (～150 nm) were successfully radiolabeled with (64)Cu (66.5% radiolabeling yield), exhibiting >95% radiolabeled particles following purification. The (64)Cu-SLNs were delivered intravenously to mice and imaged with PET at 0.5, 3, 20, and 48 h post injection. Gamma counting was utilized post imaging to confirm organ distributions. Tissue radioactivity (% injected dose/gram, %ID/g), obtained by quantitative analysis of the images, suggests that the (64)Cu-SLNs are circulating in the bloodstream after 3 h (blood half-life ～1.4 h), but are almost entirely cleared by 48 h. PET and gamma counting demonstrate that approximately 5-7%ID/g (64)Cu-SLNs remain in the liver at 48 h post injection. Stability assays confirm that copper remains associated with the SLN over the 48 h time period and that the biodistribution patterns observed are not from free, dissociated copper. Our results indicate that SLNs can be radiolabeled with (64)Cu, and their biodistribution can be quantitatively evaluated by in vivo PET imaging and ex vivo gamma counting.     

Chemical disinfection of high-consequence transboundary animal disease viruses on nonporous surfaces

Disinfection is a critical part of the response to transboundary animal disease virus (TADV) outbreaks by inactivating viruses on fomites to help control infection. To model the inactivation of TADV on fomites, we tested selected chemicals to inactivate Foot and Mouth Disease virus (FMDV), African Swine Fever virus (ASFV), and Classical Swine Fever virus (CSFV) dried on steel and plastic surfaces. For each of these viruses, we observed a 2 to 3 log reduction of infectivity due to drying alone. We applied a modified surface disinfection method to determine the efficacy of selected disinfectants to inactivate surface-dried high-titer stocks of these three structurally different TADV. ASFV and FMDV were susceptible to sodium hypochlorite (500 and 1000 ppm, respectively) and citric acid (1%) resulting in complete disinfection. Sodium carbonate (4%), while able to reduce FMDV infectivity by greater than 4-log units, only reduced ASFV by 3 logs. Citric acid (2%) did not totally inactivate dried CSFV, suggesting it may not be completely effective for disinfection in the field. Based on these data we recommend disinfectants be formulated with a minimum of 1000 ppm sodium hypochlorite for ASFV and CSFV disinfection, and a minimum of 1% citric acid for FMDV disinfection.     

Diversity Arrays Technology effectively reveals DNA polymorphism in a large and complex genome of sugarcane

Diversity Arrays Technology (DArT) provides whole genome profiling for hundreds to thousands of polymorphic markers in a single assay using a high-throughput microarray platform. The presented work aimed to establish DArT genotyping for the genetically challenging genome of sugarcane. Due to the genome complexity of this sugar-producing crop of high economic importance, an application of DArT genotyping to this species required extensive testing and optimization. As the method of genome complexity reduction determines the efficiency of polymorphism identification in DArT, various approaches and several methods were tested, in order to establish the most optimal. The sugarcane DArT markers generated with these established methods identified high genetic differentiation of sugarcane ancestral species from modern cultivars, in agreement with the data available for other types of molecular markers for this crop. The majority of sugarcane DArT markers segregated in a Mendelian fashion and were readily incorporated into the framework genetic map. As the DArT markers are sequence-ready genomic clones, we sequenced 384 clones and found that one-third of sequenced markers came from the transcribed portion of the sugarcane genome. The presented results further validate the potential of DArT technology in providing cost-effective genetic profiles for plants, irrespective of their genome complexity, for effective applications in molecular-assisted breeding, diversity analysis or genetic identity testing.     

An automated paradigm for Drosophila visual psychophysics

Background

Mutations that cause learning and memory defects in Drosophila melanogaster have been found to also compromise visual responsiveness and attention. A better understanding of attention-like defects in such Drosophila mutants therefore requires a more detailed characterization of visual responsiveness across a range of visual parameters.

Methodology/Principal Findings

We designed an automated behavioral paradigm for efficiently dissecting visual responsiveness in Drosophila. Populations of flies walk through multiplexed serial choice mazes while being exposed to moving visuals displayed on computer monitors, and infra-red fly counters at the end of each maze automatically score the responsiveness of a strain. To test our new design, we performed a detailed comparison between wild-type flies and a learning and memory mutant, dunce ¹. We first confirmed that the learning mutant dunce ¹ displays increased responsiveness to a black/green moving grating compared to wild type in this new design. We then extended this result to explore responses to a wide range of psychophysical parameters for moving gratings (e.g., luminosity, contrast, spatial frequency, velocity) as well as to a different stimulus, moving dots. Finally, we combined these visuals (gratings versus dots) in competition to investigate how dunce ¹ and wild-type flies respond to more complex and conflicting motion effects.

Conclusions/Significance

We found that dunce ¹ responds more strongly than wild type to high contrast and highly structured motion. This effect was found for simple gratings, dots, and combinations of both stimuli presented in competition.     

The Sugarcane Genome Challenge: Strategies for Sequencing a Highly Complex Genome

Sugarcane cultivars derive from interspecific hybrids obtained by crossing Saccharum officinarum and Saccharum spontaneum and provide feedstock used worldwide for sugar and biofuel production. The importance of sugarcane as a bioenergy feedstock has increased interest in the generation of new cultivars optimised for energy production. Cultivar improvement has relied largely on traditional breeding methods, which may be limited by the complexity of inheritance in interspecific polyploid hybrids, and the time-consuming process of selection of plants with desired agronomic traits. In this sense, molecular genetics can assist in the process of developing improved cultivars by generating molecular markers that can be used in the breeding process or by introducing new genes into the sugarcane genome. For meeting each of these, and additional goals, biotechnologists would benefit from a reference genome sequence of a sugarcane cultivar. The sugarcane genome poses challenges that have not been addressed in any prior sequencing project, due to its highly polyploid and aneuploid genome structure with a complete set of homeologous genes predicted to range from 10 to 12 copies (alleles) and to include representatives from each of two different species. Although sugarcane’s monoploid genome is about 1 Gb, its highly polymorphic nature represents another significant challenge for obtaining a genuine assembled monoploid genome. With a rich resource of expressed-sequence tag (EST) data in the public domain, the present article describes tools and strategies that may aid in the generation of a reference genome sequence.     

Longevity Relatives Count score identifies heritable longevity carriers and suggests case improvement in genetic studies

Loci associated with longevity are likely to harbor genes coding for key players of molecular pathways involved in a lifelong decreased mortality and decreased/compressed morbidity. However, identifying such loci is challenging. One of the most plausible reasons is the uncertainty in defining long‐lived cases with the heritable longevity trait among long‐living phenocopies. To avoid phenocopies, family selection scores have been constructed, but these have not yet been adopted as state of the art in longevity research. Here, we aim to identify individuals with the heritable longevity trait by using current insights and a novel family score based on these insights. We use a unique dataset connecting living study participants to their deceased ancestors covering 37,825 persons from 1,326 five‐generational families, living between 1788 and 2019. Our main finding suggests that longevity is transmitted for at least two subsequent generations only when at least 20% of all relatives are long‐lived. This proves the importance of family data to avoid phenocopies in genetic studies.     

United States Acculturation and Cancer Patients’ End-of-Life Care

Background

Culture shapes how people understand illness and death, but few studies examine whether acculturation influences patients’ end-of-life treatment preferences and medical care.

Methods and Findings

In this multi-site, prospective, longitudinal cohort study of terminally-ill cancer patients and their caregivers (n = 171 dyads), trained interviewers administered the United States Acculturation Scale (USAS). The USAS is a 19-item scale developed to assess the degree of “Americanization” in first generation or non-US born caregivers of terminally-ill cancer patients. We evaluated the internal consistency, concurrent, criterion, and content validity of the USAS. We also examined whether caregivers’ USAS scores predicted patients’ communication, treatment preferences, and end-of-life medical care in multivariable models that corrected for significant confounding influences (e.g. education, country of origin, English proficiency). The USAS measure was internally consistent (Cronbach α = 0.98); and significantly associated with US birthplace (r = 0.66, P<0.0001). USAS scores were predictive of patients’ preferences for prognostic information (AOR = 1.31, 95% CI:1.00–1.72), but not comfort asking physicians’ questions about care (AOR 1.23, 95% CI:0.87–1.73). They predicted patients’ preferences for feeding tubes (AOR = 0.68, 95% CI:0.49–0.99) and wish to avoid dying in an intensive care unit (AOR = 1.36, 95% CI:1.05–1.76). Scores indicating greater acculturation were also associated with increased odds of patient participation in clinical trials (AOR = 2.20, 95% CI:1.28–3.78), compared with lower USAS scores, and greater odds of patients receiving chemotherapy (AOR = 1.59, 95% CI:1.20–2.12).

Conclusion

The USAS is a reliable and valid measure of “Americanization” associated with advanced cancer patients’ end-of-life preferences and care. USAS scores indicating greater caregiver acculturation were associated with increased odds of patient participation in cancer treatment (chemotherapy, clinical trials) compared with lower scores. Future studies should examine the effects of acculturation on end-of-life care to identify patient and provider factors that explain these effects and targets for future interventions to improve care (e.g., by designing more culturally-competent health education materials).