Full and reduced models for yield trials

Summary Empirical results routinely demonstrate that the reduced Additive Main effects and Multiplicative Interaction (AMMI) model achieves better predictive accuracy for yield trials than does the full treatment means model. It may seem mysterious that treatment means are not the most accurate estimates, but rather that the AMMI model is often more accurate than its data. The statistical explanation involves the Stein effect, whereby a small sacrifice in bias can produce a large gain in accuracy. The corresponding agricultural explanation is somewhat complex, beginning with a yield trial's design and ending with its research purposes and applications. In essence, AMMI selectively recovers pattern related to the treatment design in its model, while selectively relegating noise related to the experimental design in its discarded residual. For estimating the yield of a particular genotype in a particular environment, the AMMI model uses the entire yield trial, rather than only the several replications of this particular trial, as in the treatment means model. This use of more information is the source of AMMI's gain in accuracy.This research was supported by the Rhizobotany Project of the USDA-ARS     

The impact of food quantity on UV-B tolerance and recovery from UV-B damage in Daphnia pulex

UV-B (290 nm) tolerance of Daphnia pulex, conditioned to four different food levels (Chlorophyta), was tested under standardized conditions with an artificial radiation source. Parameters measured were survival, percentage of egg bearing Daphnia and the number of juveniles produced after irradiation. UV-B tolerance of Daphnia pulex was found to be significantly improved with increasing food concentrations at all three parameters. The impact of the four different food concentrations on the photoreactivation system was tested with simultanous UV-B and white-light irradiation of Daphnia. Survival rate improved significantly with increasing food levels compared to solely UV-B irradiation. Photoreactivation had no effect on the reproductive parameters.     

Evaluation of Drugs for Treating Obesity

Criteria for the evaluation of new drugs to treat obesity are important as guides for designing clinical trials to test these agents. These criteria must be developed in relation to the realities of obesity, which is a chronic disease associated with morbidity and mortality that is increased by visceral fat deposits. The observation that patients regain weight after stopping drug treatment for obesity argues for the proposition that drugs work only when taken and NOT that the drugs are ineffective. The analogy between the development of treatments for obesity to those for the treatment of hypertension is used to highlight potential areas for new developments. Several features of an ideal drug for the treatment of obesity are suggested. Criteria for evaluating new drugs include both primary and secondary endpoints. The primary endpoint for an anti-obesity drug should be weight loss, possibly by category of success. Losses of total body fat or visceral fat might be alternative primary endpoints. Secondary endpoints include reduction in risk factors for associated diseases and improvement in the quality of life. In trials where vigorous placebo designs including highly aggressive behavior modification or very-low-calorie diets were used, it may be difficult or impossible to detect a response to a drug.     

Friend or Foe? Implication of the autophagy-lysosome pathway in SARS-CoV-2 infection and COVID-19

There is increasing amount of evidence indicating the close interplays between the replication cycle of SARS-CoV-2 and the autophagy-lysosome pathway in the host cells. While autophagy machinery is known to either assist or inhibit the viral replication process, the reciprocal effects of the SARS-CoV-2 on the autophagy-lysosome pathway have also been increasingly appreciated. More importantly, despite the disappointing results from the clinical trials of chloroquine and hydroxychloroquine in treatment of COVID-19, there is still ongoing effort in discovering new therapeutics targeting the autophagy-lysosome pathway. In this review, we provide an update-to-date summary of the interplays between the autophagy-lysosome pathway in the host cells and the pathogen SARS-CoV-2 at the molecular level, to highlight the prognostic value of autophagy markers in COVID-19 patients and to discuss the potential of developing novel therapeutic strategies for COVID-19 by targeting the autophagy-lysosome pathway. Thus, understanding the nature of such interactions between SARS-CoV-2 and the autophagy-lysosome pathway in the host cells is expected to provide novel strategies in battling against this global pandemic.     

新型疫苗佐剂的研究进展

与传统的灭活或活体疫苗相比,由基因工程重组抗原或化学合成多肽组成的现代疫苗往往存在免疫原性弱等问题,需要新型的免疫佐剂来增强其作用。尽管传统的铝盐佐剂是目前唯一全球公认的人用佐剂,但存在激发细胞免疫应答能力差等不足,因此,需要研发更为安全有效的人用新型佐剂,尤其是安全无毒、能够刺激较强细胞免疫应答的佐剂,以及适合粘膜疫苗、DNA疫苗和癌症疫苗的免疫佐剂。分析阐述了新型佐剂研究状况和佐剂发展方向,并进一步对新型佐剂的临床前和临床试验研究以及已批准上市的新型疫苗佐剂进行了综述。     

Retroviral vectors

The majority of clinical trials for gene therapy currently employ retroviral-mediated gene delivery. This is because the life cycle of the retrovirus is well understood and can be effectively manipulated to generate vectors that can be efficiently and safely packaged. Here, we review the molecular technology behind the generation of recombinant retroviral vectors. We also highlight the problems associated with the use of these viruses as gene therapy vehicles and discuss future developments that will be necessary to maintain retroviral vectors at the forefront of gene transfer technology.