Bone marrow senescence and the microenvironment of hematological malignancies

Senescence is the irreversible arrest of cell proliferation that has now been shown to play an important role in both health and disease. With increasing age senescent cells accumulate throughout the body, including the bone marrow and this has been associated with a number of age-related pathologies including malignancies. It has been shown that the senescence associated secretory phenotype (SASP) creates a pro-tumoural environment that supports proliferation and survival of malignant cells. Understanding the role of senescent cells in tumor development better may help us to identify new treatment targets to impair tumor survival and reduce treatment resistance. In this review, we will specifically discuss the role of senescence in the aging bone marrow (BM) microenvironment. Many BM disorders are age-related diseases and highly dependent on the BM microenvironment. Despite advances in drug development the prognosis particularly for older patients remains poor and new treatment approaches are needed to improve outcomes for patients. In this review, we will focus on the relationship of senescence and hematological malignancies, how senescence promotes cancer development and how malignant cells induce senescence

BIOTECHNOLOGY AND PEST RESISTANCE: AN ECONOMIC ASSESSMENT OF REFUGES

Transgenic crops offer farmers a new and effective pest control option. However, the wide spread adoption of these crops could lead to a resistant pest population. This paper demonstrates how a pest refuge can be used to maximise the value of farm income in a dynamic model with genetic foundations.Crop Production/Industries, Research and Development/Tech Change/Emerging Technologies,

BT CORN AND INSECT RESISTANCE: AN ECONOMIC ASSESSMENT OF REFUGES

Genetically engineered crops offer farmers a new option for controlling pests. The high efficacy of these pesticidal crops, combined with the potential for widespread adoption, has raised concerns that pest resistance may prematurely diminish their value. In response to these concerns, the Environmental Protection Agency requires resistance management plans. Current resistance management plans rely on a high-dose refuge strategy. This analysis extends the current framework for evaluating high-dose refuge strategies to include a measure of agricultural productivity and conventional pesticide use. The economic tradeoff relative to agricultural productivity, conventional pesticide use, and pest resistance is assessed when Bt corn is planted to control the European corn borer.Crop Production/Industries,

Student use and instructor beliefs: Machine translation in language education

The use of machine translation (MT) tools remains controversial among language instructors, with limited integration into classroom practices. While much of the existing research into MT and language education has explored instructor perceptions, less is known about how students actually use MT or how student use compares to instructor beliefs and expectations. In response to this gap, the current article explores how students use MT while writing and how this use compares to instructor perceptions via two studies: a computer-tracking study of how 49 second semester-level language learners (French, Spanish) use MT and a qualitative survey of 165 US-based second language educators’ beliefs about MT. Findings highlight important areas of alignment (e.g., MT input at word level) and divergence (e.g., MT output analysis strategies) between student use and instructor perceptions as well as layered tensions in what mediates student use of MT tools. The article concludes with calls for more research on student use and an outline for how to approach MT tools in language education in ways that support existing student practices

Bacillus thuringiensis plants expressing Cry1Ac, Cry2Ab and Cry1F are not toxic to the assassin bug, Zelus renardii

Cotton‐ and maize‐producing insecticidal crystal (Cry) proteins from the bacterium, Bacillus thuringiensis (Bt), have been commercialized since 1996. Bt plants are subjected to environmental risk assessments for non‐target organisms, including natural enemies that suppress pest populations. Here, we used Cry1F‐resistant Spodoptera frugiperda (J.E. Smith) and Cry1Ac and Cry2Ab‐resistant Trichoplusia ni (Hübner) as prey for the assassin bug, Zelus renardii (Kolenati), a common predator in maize and cotton fields. In tritrophic studies, we assessed several fitness parameters of Z. renardii when it fed on resistant S. frugiperda that had fed on Bt maize expressing Cry1F or on resistant T. ni that had fed on Bt cotton expressing Cry1Ac and Cry2Ab. Survival, nymphal duration, adult weight, adult longevity and female fecundity of Z. renardii were not different when they were fed resistant‐prey larvae (S. frugiperda or T. ni) reared on either a Bt crop or respective non‐Bt crops. ELISA tests demonstrated that the Cry proteins were present in the plant at the highest levels, at lower levels in the prey and at the lowest levels in the predator. While Z. renardii was exposed to Cry1F and Cry1Ac and Cry2Ab when it fed on hosts that consumed Bt‐transgenic plants, the proteins did not affect important fitness parameters in this common and important predator

Biotechnology and Pest Resistance: An Economic Assessment of Refuges

Biologists now engineer transgenic crop varieties that offer farmers a new tool for effectively managing pests. Concern over pest resistance, however, has prompted the Environmental Protection Agency to require resistance management plans. This paper develops an economic model of pest management with pest resistance to estimate the constant proportion of cropland planted in refuge that maximizes farm income over a fixed planning horizon. Results indicate a clear economic tradeoff between the pest control benefits of a transgenic variety and the resistance management benefits afforded by refuge