The evolutionary fate and consequences of duplicate genes

Gene duplication has generally been viewed as a necessary source of material for the origin of evolutionary novelties, but it is unclear how often gene duplicates arise and how frequently they evolve new functions. Observations from the genomic databases for several eukaryotic species suggest that duplicate genes arise at a very high rate, on average 0.01 per gene per million years. Most duplicated genes experience a brief period of relaxed selection early in their history, with a moderate fraction of them evolving in an effectively neutral manner during this period. However, the vast majority of gene duplicates are silenced within a few million years, with the few survivors subsequently experiencing strong purifying selection. Although duplicate genes may only rarely evolve new functions, the stochastic silencing of such genes may play a significant role in the passive origin of new species.     

The exploitation of volatile oil

Rose is a kind of favorite ornamental plant. This article briefly introduced the cultivation and the use of rose around the world both in ancient time and nowadays. Today, volatile oil becomes the mainstream of the rose industry. People pay attention to the effect of volatile oil; meanwhile, they speed up their research on extracting volatile oil and the ingredients.     

久效磷在环境中的行为与归趋

运用同位素示踪技术研究了久效磷在农业生态环境中的行为。结果表明,久效磷进入生态环境后将降解为可溶态和结合态残留物;土壤微生物能显著地加速久效磷的降解与消失;在水灌农作物及水生生态系中,久效磷在水中消失较快,易被系统内动植物吸收;久效磷用于水稻,一次喷药0.45kg/hm~2,间隔31天,糙米中的残留浓度低于最大残留限量,若二次、三次用药,则安全间隔期为52天和67天。久效磷在所论各系统中的可溶态降解物主要为磷酸三酯。     

The intracellular fate of Salmonella depends on the recruitment of kinesin

Salmonella enterica causes a variety of diseases, including gastroenteritis and typhoid fever. The success of this pathogen depends on its capacity to proliferate within host cells in a membrane-bound compartment. We found that the Salmonella-containing vacuole recruited the plus-end-directed motor kinesin. Bacterial effector proteins translocated into the host cell by a type III secretion system antagonistically regulated this event. Among these effectors, SifA targeted SKIP, a host protein that down-regulated the recruitment of kinesin on the bacterial vacuole and, in turn, controlled vacuolar membrane dynamics.     

Stochasticity and cell fate

Fundamental to living cells is the capacity to differentiate into subtypes with specialized attributes. Understanding the way cells acquire their fates is a major challenge in developmental biology. How cells adopt a particular fate is usually thought of as being deterministic, and in the large majority of cases it is. That is, cells acquire their fate by virtue of their lineage or their proximity to an inductive signal from another cell. In some cases, however, and in organisms ranging from bacteria to humans, cells choose one or another pathway of differentiation stochastically, without apparent regard to environment or history. Stochasticity has important mechanistic requirements. We speculate on why stochasticity is advantageous-and even critical in some circumstances-to the individual, the colony, or the species.     

高油花生新品种郑农花7号的选育

郑农花7号是郑州市农林科学研究所于1995年以8636-96M作母本,以82105-2-4作父本,进行有性杂交,采用系谱选择的方法,历经10余年育成的高油分、高产、大果花生新品种,2007年3月通过河南省农作物品种审定委员会审定.     

关于液压油液若干问题的研究

液压系统能否可靠地工作，在很大程度上取决于系统中所使用的液压油液。本文从液压油的选用，污染及在使用过程中丰承的问题进行分析。并提出了预防污染和防止在使用中油温过高的各项举措。     

Farming and the fate of wild nature

World food demand is expected to more than double by 2050. Decisions about how to meet this challenge will have profound effects on wild species and habitats. We show that farming is already the greatest extinction threat to birds (the best known taxon), and its adverse impacts look set to increase, especially in developing countries. Two competing solutions have been proposed: wildlife-friendly farming (which boosts densities of wild populations on farmland but may decrease agricultural yields) and land sparing (which minimizes demand for farmland by increasing yield). We present a model that identifies how to resolve the trade-off between these approaches. This shows that the best type of farming for species persistence depends on the demand for agricultural products and on how the population densities of different species on farmland change with agricultural yield. Empirical data on such density-yield functions are sparse, but evidence from a range of taxa in developing countries suggests that high-yield farming may allow more species to persist.     

我国主要油料作物及植物油的起源与发展史

油料作物和植物油作为农业和手工业的重要组成部分,在中国古代经济社会中占有一席之地。中国古代油料作物的种植历史可以追溯到秦汉以前,油料作物(包括脂麻、油菜、花生等)和植物油(包括菜油、花生油、豆油等)的出现、加工、生产、使用及商品化,先后经历了从无到有(包括引进)由小面积种植到大范围普种、由自食自用到进入市场的过程。     

油葵（向日葵）栽培管理技术要点

本文简述了油葵的经济价值与用途,提出了油葵栽培管理技术要点。     

p53 dynamics control cell fate

Cells transmit information through molecular signals that often show complex dynamical patterns. The dynamic behavior of the tumor suppressor p53 varies depending on the stimulus; in response to double-strand DNA breaks, it shows a series of repeated pulses. Using a computational model, we identified a sequence of precisely timed drug additions that alter p53 pulses to instead produce a sustained p53 response. This leads to the expression of a different set of downstream genes and also alters cell fate: Cells that experience p53 pulses recover from DNA damage, whereas cells exposed to sustained p53 signaling frequently undergo senescence. Our results show that protein dynamics can be an important part of a signal, directly influencing cellular fate decisions.