A cis-acting regulatory mutation causes premature hair graying and susceptibility to melanoma in the horse

In horses, graying with age is an autosomal dominant trait associated with a high incidence of melanoma and vitiligo-like depigmentation. Here we show that the Gray phenotype is caused by a 4.6-kb duplication in intron 6 of STX17 (syntaxin-17) that constitutes a cis-acting regulatory mutation. Both STX17 and the neighboring NR4A3 gene are overexpressed in melanomas from Gray horses. Gray horses carrying a loss-of-function mutation in ASIP (agouti signaling protein) had a higher incidence of melanoma, implying that increased melanocortin-1 receptor signaling promotes melanoma development in Gray horses. The Gray horse provides a notable example of how humans have cherry-picked mutations with favorable phenotypic effects in domestic animals.     

Dopamine-β-hydroxylase,adrenaline, noradrenaline and dopamine in the venous blood of adrenal gland of man: A comparison with levels in the periphery of the circulation

Summary In 10 human subjects plasma dopamine--hydroxylase activity was found in the adrenal vein blood to be as high as in the periphery of the circulation. Adrenaline concentration in the adrenal vein blood was in the mean 170 times, noradrenaline concentration 11 times and dopamine concentration little higher than levels in the periphery.This study was supported by the Deutsche Forschungsgemeinschaft.     

Lateralization of magnetic compass orientation in a migratory bird

Lateralization of brain functions, once believed to be a human characteristic, has now been found to be widespread among vertebrates. In birds, asymmetries of visual functions are well studied, with each hemisphere being specialized for different tasks. Here we report lateralized functions of the birds' visual system associated with magnetoperception, resulting in an extreme asymmetry of sensing the direction of the magnetic field. We found that captive migrants tested in cages with the magnetic field as the only available orientation cue were well oriented in their appropriate migratory direction when using their right eye only, but failed to show a significant directional preference when using their left eye. This implies that magnetoreception for compass orientation, assumed to take place in the eyes alongside the visual processes, is strongly lateralized, with a marked dominance of the right eye/left brain hemisphere.     

New observations on the karyotype of the Djungarian hamster,Phodopus sungorus

Summary In this paper, the C-banding pattern of the karyotype of Phodopus sungorus is presented and polymorphism is taken into consideration.     

Resonance effects indicate a radical-pair mechanism for avian magnetic compass

Migratory birds are known to use the geomagnetic field as a source of compass information. There are two competing hypotheses for the primary process underlying the avian magnetic compass, one involving magnetite, the other a magnetically sensitive chemical reaction. Here we show that oscillating magnetic fields disrupt the magnetic orientation behaviour of migratory birds. Robins were disoriented when exposed to a vertically aligned broadband (0.1-10 MHz) or a single-frequency (7-MHz) field in addition to the geomagnetic field. Moreover, in the 7-MHz oscillating field, this effect depended on the angle between the oscillating and the geomagnetic fields. The birds exhibited seasonally appropriate migratory orientation when the oscillating field was parallel to the geomagnetic field, but were disoriented when it was presented at a 24 degrees or 48 degrees angle. These results are consistent with a resonance effect on singlet-triplet transitions and suggest a magnetic compass based on a radical-pair mechanism.     

重构全钒液流电池碳毡力学仿真及孔尺度模拟

为探究全钒液流电池(VRFB)碳毡微观尺度下承受压力的位移变形并量化其对传输特性的影响,应用X射线断层扫描(XCT)微观重构技术、有限元方法(FEM)和孔尺度模拟技术(PSM),考虑碳纤维间受压缩的接触摩擦及挤压弯曲,重构碳纤维微观结构,研究了碳纤维不同压缩比3D(X,Y和Z方向)位移分布,并量化位移变形对微结构传输特性的影响。结果表明:随着压缩比增大到30%,Z方向位移变化最为明显,计算域A位移变化为:-59～+5μm,计算域B位移变化为:-145～+16μm,钒离子XY方向扩散系数减小15.4%,Z方向扩散系数减小24.2%,XY方向电导率升高112.5%,Z方向电导率增大113.3%,模拟结果与实验结果趋势较吻合,可以较好模拟预测碳毡电导率计算域尺寸为:X/Y=300～400μm,Z=200～400μm。     

高温质子交换膜燃料电池催化层孔尺度模拟

为了研究磷酸在高温质子交换膜燃料电池催化层中再分布对电极性能的影响,使用聚焦离子束电子扫描显微镜对自制的扩散电极成像,重构得到了三维的催化层几何模型;采用多弛豫时间格子玻尔兹曼模型对磷酸在催化层的迁移行为进行仿真,模拟得到递减型和准均匀型2种不同的磷酸分布形式;采用孔尺度模型求解不同条件下的电极传输性质。结果表明在磷酸含量较低时,准均匀型的磷酸分布具有稍优的电化学活性表面积和稍差的氧气和水蒸气有效扩散系数;在磷酸含量较高时,2种分布的电化学活性表面积相似,但是准均匀型分布具有更好的氧气和水蒸气有效扩散系数。