Dogs cloned from adult somatic cells

Several mammals--including sheep, mice, cows, goats, pigs, rabbits, cats, a mule, a horse and a litter of three rats--have been cloned by transfer of a nucleus from a somatic cell into an egg cell (oocyte) that has had its nucleus removed. This technology has not so far been successful in dogs because of the difficulty of maturing canine oocytes in vitro. Here we describe the cloning of two Afghan hounds by nuclear transfer from adult skin cells into oocytes that had matured in vivo. Together with detailed sequence information generated by the canine-genome project, the ability to clone dogs by somatic-cell nuclear transfer should help to determine genetic and environmental contributions to the diverse biological and behavioural traits associated with the many different canine breeds.     

Preface — special issue on complex data processing methods and their applications to economic systems

This special issue of Journal of Systems Science ＆ Complexity [JSSC） includes papers selected from the 1st International Conference on Forecasting Economic ＆： Financial Systems （FEFS-2012） and the 5th InternatioIlal Workshop on Singular Spectrum Analysis ＆ its Appli- cations （SSA-2012）, held in Beijing, China, May 17-20, 2012.     

添加Co3O4纳米颗粒引起的残余结构应变对粉末冶金制备的Al/Co3O4纳米复合材料的结构、硬度和磁性能的影响

Al composites are of interest due to their appropriate ratio of strength to weight. In our research, an Al/Co₃O₄ nanocomposite was generated using a sintering technique. The powders of Al with various Co₃O₄ nanoparticle contents (0wt%, 0.5wt%, 1.0wt%, 1.5wt%, 2.0wt%, and 2.5wt%) were first blended using planetary milling for 30 min, and compressed in a cylindrical steel mold with a diameter of 1 cm and a height of 5 cm at a pressure of 80 MPa. The samples were evaluated with X-ray diffractometry (XRD), scanning electron microscopy (SEM), Vickers hardness, and a vibrating sample magnetometer (VSM). Although the crystallite size of the Al particles remained constant at 7–10 nm, the accumulation of nanoparticles in the Al particle interspace increased the structural tensile strain from 0.0045 to 0.0063, the hardness from HV 28 to HV 52 and the magnetic saturation from 0.044 to 0.404 emu/g with an increase in Co₃O₄ nanoparticle content from 0wt% to 2.5wt%.     

A data-mining approach to biomarker identification from protein profiles using discrete stationary wavelet transform

Objective： To develop a new bioinformatic tool based on a data-mining approach for extraction of the most informative proteins that could be used to find the potential biomarkers for the detection of cancer. Methods： Two independent datasets from serum samples of 253 ovarian cancer and 167 breast cancer patients were used. The samples were examined by surfaceenhanced laser desorption/ionization time-of-flight mass spectrometry （SELDI-TOF MS）. The datasets were used to extract the informative proteins using a data-mining method in the discrete stationary wavelet transform domain. As a dimensionality reduction procedure, the hard thresholding method was applied to reduce the number of wavelet coefficients. Also, a distance measure was used to select the most discriminative coefficients. To find the potential biomarkers using the selected wavelet coefficients, we applied the inverse discrete stationary wavelet transform combined with a two-sided t-test. Results： From the ovarian cancer dataset, a set of five proteins were detected as potential biomarkers that could be used to identify the cancer patients from the healthy cases with accuracy, sensitivity, and specificity of 100%. Also, from the breast cancer dataset, a set of eight proteins were found as the potential biomarkers that could separate the healthy cases from the cancer patients with accuracy of 98.26%, sensitivity of 100%, and specificity of 95.6%. Conclusion： The results have shown that the new bioinformatic tool can be used in combination with the high-throughput proteomic data such as SELDI-TOF MS to find the potential biomarkers with high discriminative power.     

Culture of a new medicinal leech: growth,survival and reproduction of Hirudo orientalis Utevsky and Trontelj, 2005 under laboratory conditions

The increasing demands for medicinal leeches around the world has increased the need for new sources of leeches. To assess the feasibility of culturing a new medicinal leech species, growth, survival and reproduction of Hirudo orientalis was investigated under laboratory conditions (28°C; 9.5D:14.5L light regime; monthly feeding by sheep blood) from hatching until sexual maturity. Several interesting results emerged from this study. (1) The first copulation was observed in 5.5-month-old leeches and cocoon deposition started by six months. (2) Cocoon length and diameter did not differ significantly between six- and nine-month-old leeches, but the percentage of leeches depositing cocoons was significantly higher in the nine-month old group. (3) The growth curve was saltatory, similar to other sanguivorous species. The mean (±SE) wet weight of 6-month-old individuals was 4.70 (±0.86) g. (4) Weight gain rate decreased with increasing age. (5) Mortality only occurred in the one-, seven- and eight-month age groups at the rate of 5.7%, 23.1% and 14.3%, respectively.     

Synthesis of a NiTi_2–AlNi–Al_2O_3 nanocomposite by mechanical alloying and heat treatment of Al–TiO_2–NiO

The aim of the present study was to investigate the phases formed during ball milling of Al–TiO_2–NiO. For this purpose, a mixture of Al–TiO_2–NiO with a molar ratio of 6:1:1 was used. Characterization of the milled powders by X-ray diffraction, differential thermal analysis, field-emission scanning electron microscopy, and transmission electron microscopy showed the formation of nanocrystalline NiTi_2 along with AlNi. A thermodynamical investigation confirmed that NiO was reduced by Al during ball milling, which consequently promoted TiO_2 reduction and the formation of NiTi_2. Al is capable of reducing NiO either during ball milling or at temperatures above the melting point of Al; by contrast, TiO_2 can be reduced by Al only by milling.     

A common CFH haplotype, with deletion of CFHR1 and CFHR3, is associated with lower risk of age-related macular degeneration

Age-related macular degeneration (AMD; OMIM #603075) is the most frequent cause of visual impairment in the elderly population, with severe disease affecting nearly 10% of individuals of European descent over the age of 75 years. It is a complex disease in which genetic and environmental factors contribute to susceptibility. Complement factor H (CFH) has recently been identified as a major AMD susceptibility gene, and the Y402H polymorphism has been proposed as the likely causative factor. We genotyped polymorphisms spanning the cluster of CFH and five CFH-related genes on chromosome 1q23 in 173 individuals with severe neovascular AMD and 170 elderly controls with no signs of AMD. Detailed analysis showed a common haplotype associated with decreased risk of AMD that was present on 20% of chromosomes of controls and 8% of chromosomes of individuals with AMD. We found that this haplotype carried a deletion of CFHR1 and CFHR3, and the proteins encoded by these genes were absent in serum of homozygotes. The protective effect of the deletion haplotype cannot be attributed to linkage disequilibrium with Y402H and was replicated in an independent sample.     

Multistage interband cascade photovoltaic devices with a bandgapof 0.23 eV operating above room temperature

Interband cascade （IC） photovoltaic （PV）device structures, consisting of multiple discrete InAs/GaSb superlattice absorbers sandwiched between electronand hole barriers, were grown by molecular beam epitaxy.Details of the molecular beam epitaxy growth and materialcharacterization of the structures are presented. The dis-crete absorber architecture enables certain advantages, suchas high open-circuit voltage, high collection efficiency,high operating temperature, and smooth integration ofcascade stages with different bandgaps. The two- andthree-stage ICPV devices presented in this article operate atroom temperature with substantial open-circuit voltages ata cutoff wavelength of 5.3 μm （corresponding to a bandgapof 0.23 eV）, the longest ever reported for room temperaturePV devices. The device characteristics indicate a high levelof current matching and demonstrate the advantages of theinterband cascade approach in thermophotovoltaic celldesign.     

The Importance of the Macroeconomic Variables in Forecasting Stock Return Variance: A GARCH‐MIDAS Approach

This paper applies the GARCH‐MIDAS (mixed data sampling) model to examine whether information contained in macroeconomic variables can help to predict short‐term and long‐term components of the return variance. A principal component analysis is used to incorporate the information contained in different variables. Our results show that including low‐frequency macroeconomic information in the GARCH‐MIDAS model improves the prediction ability of the model, particularly for the long‐term variance component. Moreover, the GARCH‐MIDAS model augmented with the first principal component outperforms all other specifications, indicating that the constructed principal component can be considered as a good proxy of the business cycle. Copyright © 2013 John Wiley & Sons, Ltd.     

含过量Fe和Si的铸态Al–Cu合金的拉伸性能和热裂敏感性

This study was undertaken to investigate the tensile properties and hot tearing susceptibility of cast Al–Cu alloys containing excess Fe (up to 1.5wt%) and Si (up to 2.5wt%). According to the results, the optimum tensile properties and hot tearing resistance were achieved at Fe/Si mass ratio of 1, where the α-Fe phase was the dominant Fe compound. Increasing the Fe/Si mass ratio above unity increased the amounts of detrimental β-CuFe platelets in the microstructure, deteriorating the tensile properties and hot tearing resistance. Decreasing the mass ratio below unity increased the size and fraction of Si needles and micropores in the microstructure, also impairing the tensile properties and hot tearing resistance. The investigation of hot-torn surfaces revealed that the β-CuFe platelets disrupted the tear healing phenomenon by blocking interdendritic feeding channels, while the α-Fe intermetallics improved the hot tearing resistivity due to their compact morphology and high melting point.