复合材料Terfenol-D/PMNT的磁电和逆磁电响应

给出了Terfenol-D/PMN-PT/Terfenol-D(TD/PMNT/TD)和PMNT/TD/PMNT两种层状复合材料的磁电和逆磁电响应的测试方法和测试结果. 这两种复合结构的优化直流偏置磁场大小均为350 Oe(1 Oe=79.58 A/m). 在1 kHz频率下, 这两种复合材料的最大磁电电压系数分别为384 mV/Oe和158 mV/Oe, 最大逆磁电系数分别为118 mG/V和162 mG/V (1 G = 10^-4 T). 另外研究了这两种复合材料在谐振频率下的磁电响应. 通过对两种复合结构的比较得知, 磁致/压电/磁致复合结构具有好的磁电响应; 而压电/磁致/压电复合结构具有好的逆磁电响应. 这一结果有助于优化设计高性能压电/磁致复合磁电材料.     

The synthesis of a peptide having the structure attributed to a sound habituating material.

A peptide isolated from rats habituated to a sound stimulus has been given the structure (see article) Glu-Ala-Gly-Tyr-Ser-Lys-OH. A synthesis of this compound afforded a product that different from the natural material on the basis of chromatographic and physiological comparisons. The proposed sequence must therefore be in error.     

Forecasting Online Auctions via Self‐Exciting Point Processes

Modeling online auction prices is a popular research topic among statisticians and marketing analysts. Recent research mainly focuses on two directions: one is the functional data analysis (FDA) approach, in which the price–time relationship is modeled by a smooth curve, and the other is the point process approach, which directly models the arrival process of bidders and bids. In this paper, a novel model for the bid arrival process using a self‐exciting point process (SEPP) is proposed and applied to forecast auction prices. The FDA and point process approaches are linked together by using functional data analysis technique to describe the intensity of the bid arrival point process. Using the SEPP to model the bid arrival process, many stylized facts in online auction data can be captured. We also develop a simulation‐based forecasting procedure using the estimated SEPP intensity and historical bidding increment. In particular, prediction interval for the terminal price of merchandise can be constructed. Applications to eBay auction data of Harry Potter books and Microsoft Xbox show that the SEPP model provides more accurate and more informative forecasting results than traditional methods. Copyright © 2014 John Wiley & Sons, Ltd.     

Human Genome Variation 2006: emerging views on structural variation and large-scale SNP analysis

The eighth annual Human Genome Variation Meeting was held in September 2006 in the Hong Kong Special Administrative Region, China. The meeting highlighted recent advances in characterization of genetic variation, including genome-wide association studies and structural variation.     

Noradrenaline hyperalgesia is mediated through interaction with sympathetic postganglionic neurone terminals rather than activation of primary afferent nociceptors

In hyperalgesic states, observed commonly as a major symptom of tissue inflammation or after central or peripheral nerve injury, non-noxious stimuli produce pain and noxious stimuli are perceived as more painful than usual. The mechanisms underlying the generation of hyperalgesia are not known. In patients with causalgia (burning pain and severe hyperalgesia after a nerve injury) activation of sympathetic post-ganglionic neurones or application of noradrenaline to painful skin exacerbates pain and hyperalgesia while sympathectomy may afford complete relief. One suggestion is that noradrenaline released from sympathetic post-ganglionic neurons increases the discharge of damaged small-diameter afferents by a direct action on the primary afferents. Here we present a new model for noradrenaline-sensitive hyperalgesia and demonstrate that the site of action of noradrenaline is not on the primary afferents but rather is presynaptic on the sympathetic post-ganglionic terminals.     

Arylpyridyl-thiosemicarbazones: A new class of anti-juvenile hormones active against Lepidoptera

Summary A new class of anti-juvenile hormone agents is described. Active anti-juvenile hormone compounds were either diazine thiosemicarbazones or aryl substituted pyridyl thiosemicarbazones, synthesized from substituted benzaldehydes. While many analogs in these classes showed feeding and growth inhibition in a variety of insects, a select group caused formation of precocious pupal characteristics inAgrotis ipsilon (black cutworm) andHeliothis virescens (tobacco budworm) and black cuticle and precocious pupae inManduca sexta (tobacco hornworm). They were active only by diet incorporation. The symptoms of precocious development could be reversed by co-administration of a juvenoid. One of the active compounds was shown to inhibit juvenile hormone biosynthesis in vitro by corpora allata of the cockroachDiploptera punctata. However, none of the compounds were active inhibitors of purified chicken liver prenyl transferase.     

JOINTLESS is a MADS-box gene controlling tomato flower abscission zone development

Abscission is a universal and dynamic process in plants whereby organs such as leaves, flowers and fruit are shed, both during normal development, and in response to tissue damage and stress. Shedding occurs by separation of cells in anatomically distinct regions of the plant, called abscission zones (AZs). During abscission, the plant hormone ethylene stimulates cells to produce enzymes that degrade the middle lamella between cells in the AZ. The physiology and regulation of abscission at fully developed AZs is well known, but the molecular biology underlying their development is not. Here we report the first isolation of a gene directly involved in the development of a functional plant AZ. Tomato plants with the jointless mutation fail to develop AZs on their pedicels and so abscission of flowers or fruit does not occur normally. We identify JOINTLESS as a new MADS-box gene in a distinct phylogenetic clade separate from those functioning in floral organs. We propose that a deletion in JOINTLESS accounts for the failure of activation of pedicel AZ development in jointless tomato plants.