An opiate binding site in the rat brain is highly selective for 4,5-epoxymorphinans

In vitro binding studies have demonstrated the existence of multiple opiate receptor types. An additional site in the rat brain (termed the lambda site) is distinct from the established types by its selectivity for 4,5-epoxymorphinans (such as naloxone and morphine). While the lambda site displays a high affinity for naloxone in vivo and in vitro in fresh brain membrane homogenates, these sites rapidly convert in vitro to a state of low affinity. The regional distribution of the lambda site in the brain is strikingly different from that of the classic opiate receptor types.     

Bias in Peer Review of Organic Farming Grant Applications

Peer reviews of 84 organic farming grant applications from Sweden were analyzed to determine whether the reviewers’ affiliation to one of two types of agriculture (i.e., organic and conventional) influenced their reviews. Fifteen reviewers were divided into three groups: (1) scientists with experience in organic farming research; (2) scientists with no experience in organic farming research; and (3) users of organic farming research. The two groups of scientists assessed the societal relevance and scientific quality of the grant applications based on three criteria (i.e., presentation, methodology, qualifications), whereas the user group only assessed societal relevance. The analysis showed that the two groups of scientists provided very different reviews. Scientist reviewers with experience in organic farming research agreed more with the user group on research relevance than did scientist reviewers without such experience, and the assessment of relevance was closely correlated to the assessment of scientific quality within both scientific groups. As both scientific groups did not clearly distinguish between societal relevance and scientific quality, the idea of an objective science is challenged. The contextual values associated with the norms of good agriculture were not clearly distinguished from the constitutive values of science associated with the traditional norms of good science. This raises the question of whether organic and conventional grant applications should be mixed for review regardless of the reviewers.     

农业分析实验课考试办法及标准

根据农业分析实验课的特点及内容提出了考试的办法，考试和考核的积分情况，制定了评分的标准以及有关扣分的说明。     

Progression of vertebrate limb development through SHH-mediated counteraction of GLI3

Distal limb development and specification of digit identities in tetrapods are under the control of a mesenchymal organizer called the polarizing region. Sonic Hedgehog (SHH) is the morphogenetic signal produced by the polarizing region in the posterior limb bud. Ectopic anterior SHH signaling induces digit duplications and has been suspected as a major cause underlying congenital malformations that result in digit polydactyly. Here, we report that the polydactyly of Gli3-deficient mice arises independently of SHH signaling. Disruption of one or both Gli3 alleles in mouse embryos lacking Shh progressively restores limb distal development and digit formation. Our genetic analysis indicates that SHH signaling counteracts GLI3-mediated repression of key regulator genes, cell survival, and distal progression of limb bud development.     

Mutations in dynein link motor neuron degeneration to defects in retrograde transport

Degenerative disorders of motor neurons include a range of progressive fatal diseases such as amyotrophic lateral sclerosis (ALS), spinal-bulbar muscular atrophy (SBMA), and spinal muscular atrophy (SMA). Although the causative genetic alterations are known for some cases, the molecular basis of many SMA and SBMA-like syndromes and most ALS cases is unknown. Here we show that missense point mutations in the cytoplasmic dynein heavy chain result in progressive motor neuron degeneration in heterozygous mice, and in homozygotes this is accompanied by the formation of Lewy-like inclusion bodies, thus resembling key features of human pathology. These mutations exclusively perturb neuron-specific functions of dynein.     

镉在土壤中释放的动力学特征研究

采用间歇法研究了镉在不同土壤中释放的动力学特征。结果表明 ,酸性土壤镉释放速率大于石灰性土壤 ;随温度升高 ,石灰性土壤镉平均释放速率下降 ,而酸性土壤镉平均释放速率增加 ;不同温度下土壤镉释放速率 V与时间 t最优模型为 ln V=A+ Bt;不同土壤镉释放量 S与时间 t的较优模型为 ln S=A+ k/ t     

Mechanism of the selective catalytic reduction of nitric oxide by ammonia elucidated by in situ on-line fourier transform infrared spectroscopy

The selective catalytic reduction reaction of nitric oxide bv ammonia over vanadia-titania catalysts is one of the methods of removing NOx pollution. In the present study, it has been possible to identify the reaction mechanism and the nature of the active sites in these catalysts by combining transient or steady-state in situ (Fourier transform infrared spectroscopy) experiments directly with on-line activity studies. The results suggest a catalytic cycle that consists of both acid and redox reactions and involves both surface V-OH (Br?nsted acid sites) and V=O species. A fundamental microkinetic model is proposed, which accounts for the observed industrial kinetics performance.     

Microinjection of a conserved peptide sequence of p34cdc2 induces a Ca2+ transient in oocytes

The product of the yeast cell cycle control gene cdc2, and its homologs in higher eukaryotes (p34cdc2), all contain a perfectly conserved sequence of 16 amino acids that has not been found in any other protein sequence. Microinjection of this peptide triggers a specific increase in the concentration of intracellular free Ca2+ that originates from intracellular stores in both starfish and Xenopus oocytes. Thus, p34cdc2 might interact through its conserved peptide domain with some component of the Ca2(+)-regulatory system.