The effects of climate warming on the migratory status of early summer populations of Mythimna separata (Walker) moths: A case‐study of enhanced corn damage in central‐northern China, 1980–2016

Mythimna separata (Walker) moths captured in light traps were monitored in Luohe, central‐northern China, from 1980 to 2016. Annual average temperature recorded an increase of 0.298°C/10 years in this region in the period. Our results indicate that a rising April and May average temperature and earlier occurrences of days recording the highest day temperature (30°C) caused an advanced peak and increasing proportion of high ovarian development levels of first‐generation females in earlier summers. Results using Johnson's formulation of “oogenesis‐flight syndrome” indicate that increasing sexual maturity proportion has resulted in more emigrant individuals in the local first‐generation moth becoming residents, and then increased individuals rapidly in the local second‐generation moth since 2006. Consequences of this action have a boom in corn damage since 2007 in this region. Advanced peak dates of the first and second‐generation moth revealed the same response to increasing average monthly temperatures in the monitoring period. Increasing temperatures, the average May temperature exceeds or equal to 22°C, during the early 2000's may represent a physiological threshold for M. separata development. Our results suggest that climate warming may impact M. separata migratory status and cause a problem of crop production in this region.     

On the Applicability of Temperature and Precipitation Data from CMIP3 for China

Global Circulation Models (GCMs) contributed to the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) and are widely used in global change research. This paper assesses the performance of the AR4 GCMs in simulating precipitation and temperature in China from 1960 to 1999 by comparison with observed data, using system bias (B), root-mean-square error (RMSE), Pearson correlation coefficient (R) and Nash-Sutcliffe model efficiency (E) metrics. Probability density functions (PDFs) are also fitted to the outputs of each model. It is shown that the performance of each GCM varies to different degrees across China. Based on the skill score derived from the four metrics, it is suggested that GCM 15 (ipsl_cm4) and GCM 3 (cccma_cgcm_t63) provide the best representations of temperature and precipitation, respectively, in terms of spatial distribution and trend over 10 years. The results also indicate that users should apply carefully the results of annual precipitation and annual temperature generated by AR4 GCMs in China due to poor performance. At a finer scale, the four metrics are also used to obtain best fit scores for ten river basins covering mainland China. Further research is proposed to improve the simulation accuracy of the AR4 GCMs regarding China.     

Lysosomotropic Properties of Weakly Basic Anticancer Agents Promote Cancer Cell Selectivity In Vitro

Drug distribution in cells is a fundamentally important, yet often overlooked, variable in drug efficacy. Many weakly basic anticancer agents accumulate extensively in the acidic lysosomes of normal cells through ion trapping. Lysosomal trapping reduces the activity of anticancer drugs, since anticancer drug targets are often localized in the cell cytosol or nucleus. Some cancer cells have defective acidification of lysosomes, which causes a redistribution of trapped drugs from the lysosomes to the cytosol. We have previously established that such differences in drug localization between normal and cancer cells can contribute to the apparent selectivity of weakly basic drugs to cancer cells in vitro. In this work, we tested whether this intracellular distribution-based drug selectivity could be optimized based on the acid dissociation constant (pKa) of the drug, which is one of the determinants of lysosomal sequestration capacity. We synthesized seven weakly basic structural analogs of the Hsp90 inhibitor geldanamycin (GDA) with pKa values ranging from 5 to 12. The selectivity of each analog was expressed by taking ratios of anti-proliferative IC₅₀ values of the inhibitors in normal fibroblasts to the IC₅₀ values in human leukemic HL-60 cells. Similar selectivity assessments were performed in a pair of cancer cell lines that differed in lysosomal pH as a result of siRNA-mediated alteration of vacuolar proton ATPase subunit expression. Optimal selectivity was observed for analogs with pKa values near 8. Similar trends were observed with commercial anticancer agents with varying weakly basic pKa values. These evaluations advance our understanding of how weakly basic properties can be optimized to achieve maximum anticancer drug selectivity towards cancer cells with defective lysosomal acidification in vitro. Additional in vivo studies are needed to examine the utility of this approach for enhancing selectivity.     

Ready player one? Autophagy shapes resistance to photodynamic therapy in cancers

Photodynamic therapy (PDT) is a procedure used in cancer therapy that has been shown to be useful for certain indications. Considerable evidence suggests that PDT might be superior to conventional modalities for some indications. In this report, we examine the relationship between PDT responsiveness and autophagy, which can exert a cytoprotective effect. Autophagy is an essential physiological process that maintains cellular homeostasis by degrading dysfunctional or impaired cellular components and organelles via a lysosome-based pathway. Autophagy, which includes macroautophagy and microautophagy, can be a factor that decreases or abolishes responses to various therapeutic protocols. We systematically discuss the mechanisms underlying cell-fate decisions elicited by PDT; analyse the principles of PDT-induced autophagy, macroautophagy and microautophagy; and present evidence to support the notion that autophagy is a critical mechanism in resistance to PDT. A combined strategy involving autophagy inhibitors may be able to further enhance PDT efficacy. Finally, we provide suggestions for future studies, note where our understanding of the relevant molecular regulators is deficient, and discuss the correlations among PDT-induced resistance and autophagy, especially microautophagy.     

Quantifying the Impact of Woodpecker Predation on Population Dynamics of the Emerald Ash Borer (Agrilus planipennis)

The emerald ash borer (EAB), Agrilus planipennis, is an invasive beetle that has killed millions of ash trees (Fraxinus spp.) since it was accidentally introduced to North America in the 1990s. Understanding how predators such as woodpeckers (Picidae) affect the population dynamics of EAB should enable us to more effectively manage the spread of this beetle, and toward this end we combined two experimental approaches to elucidate the relative importance of woodpecker predation on EAB populations. First, we examined wild populations of EAB in ash trees in New York, with each tree having a section screened to exclude woodpeckers. Second, we established experimental cohorts of EAB in ash trees in Maryland, and the cohorts on half of these trees were caged to exclude woodpeckers. The following spring these trees were debarked and the fates of the EAB larvae were determined. We found that trees from which woodpeckers were excluded consistently had significantly lower levels of predation, and that woodpecker predation comprised a greater source of mortality at sites with a more established wild infestation of EAB. Additionally, there was a considerable difference between New York and Maryland in the effect that woodpecker predation had on EAB population growth, suggesting that predation alone may not be a substantial factor in controlling EAB. In our experimental cohorts we also observed that trees from which woodpeckers were excluded had a significantly higher level of parasitism. The lower level of parasitism on EAB larvae found when exposed to woodpeckers has implications for EAB biological control, suggesting that it might be prudent to exclude woodpeckers from trees when attempting to establish parasitoid populations. Future studies may include utilizing EAB larval cohorts with a range of densities to explore the functional response of woodpeckers.     

Dendrobium shixingense sp. nov. (Orchidaceae) from Guangdong,China

Dendrobium shixingense Z.‐L. Chen, S.‐J. Zeng et J. Duan sp. nov. (Orchidaceae), is described and illustrated from Guangdong, China; it is compared with its nearest allies, D. scoriarum, D. flexicaule and D. officinale.     

Effect of storage conditions on the survival of two potential biocontrol agents of nematodes,the fungi Paecilomyces lilacinus and Pochonia chlamydosporia

The nematophagous fungi Paecilomyces lilacinus and Pochonia chlamydosporia have been extensively studied as biological control agents for plant-parasitic nematodes. This study describes the formulation of alginate pellets containing mycelia of these fungi and also describes the effect of storage conditions on shelf-life of the pellets. The shelf-lives of P. lilacinus and P. chlamydosporia, which were measured monthly for 6 months, were significantly improved at low temperatures and low water activity (a _w) values (<0.33). Vacuum did not affect the viability of the formulated P. lilacinus but increased the viability of P. chlamydosporia. Carbon dioxide reduced the activity of P. lilacinus as compared to ambient air but increased the activity of P. chlamydosporia. Nitrogen, however, significantly improved the viability of both fungi. The optimal parameters of each factor for our formulation of P. lilacinus and P. chlamydosporia included a temperature range of 4 to ?20°C, a _w=0.12, and a nitrogen-filled atmosphere.