Localization of primordial germ cells or their precursors in stage X blastoderm of chickens and their ability to differentiate into functional gametes in opposite-sex recipient gonads

This study was performed to determine the distribution of primordial germ cells and their precursors in stage X blastoderm of chickens. The blastoderm (Barred Plymouth Rock chickens) isolated from the yolk was separated into three portions: the central disc, the marginal zone and the area opaca. The dissociated blastodermal cells derived from the central disc, marginal zone and area opaca were transferred into a recipient blastoderm (White Leghorn chicken) from which a cell cluster was removed from the centre of the central disc. The manipulated embryos were cultured in host eggshells until hatching. The chicks were raised until sexual maturity and test mated with Barred Plymouth Rock chickens to assess the donor cell contribution to the recipient germline. Germline chimaeric chickens were produced efficiently (46.7%, 7/15) when the blastodermal cells derived from the central disc were transferred into recipient embryos of the same sex, whereas no germline chimaeric chickens were produced when the blastodermal cells derived from the marginal zone or area opaca were transferred into recipient embryos of the same sex (0/12). Germline chimaeric chickens were also produced by transfer of blastodermal cells derived from the central disc (6.7%, 1/15), marginal zone (10.0%, 1/10) or area opaca (11.1%, 1/9) into recipient embryos of the opposite sex. It is concluded that primordial germ cells are induced during or shortly after stage X and that the cells derived from the central disc have the highest potential to give rise to germ cells. Cells derived from the marginal zone and area opaca can also give rise to germ cells, although the frequency is low.     

Exploring overlapping clusters using dynamic re-scaling and sampling

Until recently, the aim of most text-mining work has been to understand major topics and clusters. Minor topics and clusters have been relatively neglected even though they may represent important information on rare events. We present a novel method for exploring overlapping clusters of heterogeneous sizes, which is based on vector space modeling, covariance matrix analysis, random sampling, and dynamic re-weighting of document vectors in massive databases. Our system addresses a combination of difficult issues in database analysis, such as synonymy and polysemy, identification of minor clusters, accommodation of cluster overlap, automatic labeling of clusters based on their document contents, and the user-controlled trade-off between speed of computation and quality of results. We conducted implementation studies with new articles from the Reuters and LA Times TREC data sets and artificially generated data with a known cluster structure to demonstrate the effectiveness of our system. Mei Kobayashi received a Bachelors degree in Chemistry from Princeton and Masters and Ph.D. degrees in Pure and Applied Mathematics from UC Berkeley. She was a student intern in Frick Chemical Laboratory at Princeton, the Biochemical and Math-Physics divisions of Lawrence Berkeley Laboratories, and IBM Research. She has been a Researcher at IBM since 1988 and has been involved in projects ranging from inverse problems, airflow simulation and graphics to speech signal analysis using wavelets. Her most recent work has been on information retrieval, data mining, and unstructured information management. She has served on the Editorial Board of the Bulletin of Japan SIAM and Technical Program Committees of the SIAM Data Mining Conference, SIAM Text Mining Workshops, and Symposiums on Wavelets sponsored by the Japanese Ministry of Education. From 1996 to 1999, she was a Visiting Associate Professor at the Graduate School for Mathematical Sciences of the University of Tokyo. Masaki Aono received Bachelors and Masters in Science degrees in Information Science from the University of Tokyo and a Ph.D. in Computer Science from Rensselaer Polytechnic Institute. He worked for IBM Research, Tokyo Research Laboratory from 1984 to 2003. He is currently a Professor in the Information and Computer Sciences. Department at the Toyohashi University of Technology, where he is teaching object-oriented programming, logic circuit, computer architecture, and knowledge data engineering. His current research interests include text and data mining, information extraction, semantic web, and information visualization. His most recent work on time series data mining from human body bio-signals obtained by microsensors, was been selected to be part of the 21st century Center Of Excellence Program sponsored by Japanese government. He has been a Japanese delegate of the ISO/IEC JTC1 SC24 Standard Committee since 1996.     

Anomalous Mixing State in Room-Temperature Ionic Liquid-Water Mixtures: <Emphasis Type="Italic">N,N</Emphasis>-diethyl-<Emphasis Type="Italic">N</Emphasis>-methyl-<Emphasis Type="Italic">N</Emphasis>-(2-methoxyethyl) Ammonium Tetrafluoroborate

The mixing states of room-temperature ionic liquid (RTIL) H₂O mixtures (x = 0.0 mol pct to 99.5 mol pct H₂O) were investigated using wide-angle X-ray scattering (WAXS), small-angle X-ray scattering (SAXS), and optical absorption in an ultraviolet and visible (UV-vis) region. The RTIL is N, N-diethyl-N-methyl-N-(2-methoxyethyl) ammonium tetrafluoroborate, [DEME][BF₄]. In a “prepeak” region of the WAXS, the scattered intensities increased at 85 mol pct to 95 mol pct. A medium-range order (MRO) in the liquid structure as observed in network-forming materials developed markedly. In the SAXS experiments, we can detect nanoscale fluctuations relating to polar and nonpolar regions. At 65 mol pct to 85 mol pct, the SAXS intensity increased unexpectedly. Furthermore, entirely different optical absorption spectra in the UV-vis region were observed as a macroscopic property from 90 mol pct to 95 mol pct. We suppose that these anomalies relate to the MRO of the liquid structure. All anomalies probably are induced by an intrinsic property in [DEME][BF₄]-H₂O mixtures.     

Transactional support for adaptive indexing

Adaptive indexing initializes and optimizes indexes incrementally, as a side effect of query processing. The goal is to achieve the benefits of indexes while hiding or minimizing the costs of index creation. However, index-optimizing side effects seem to turn read-only queries into update transactions that might, for example, create lock contention. This paper studies concurrency control and recovery in the context of adaptive indexing. We show that the design and implementation of adaptive indexing rigorously separates index structures from index contents; this relaxes constraints and requirements during adaptive indexing compared to those of traditional index updates. Our design adapts to the fact that an adaptive index is refined continuously and exploits any concurrency opportunities in a dynamic way. A detailed experimental analysis demonstrates that (a) adaptive indexing maintains its adaptive properties even when running concurrent queries, (b) adaptive indexing can exploit the opportunity for parallelism due to concurrent queries, (c) the number of concurrency conflicts and any concurrency administration overheads follow an adaptive behavior, decreasing as the workload evolves and adapting to the workload needs.     

Tunable morphology from 2D to 3D in the formation of hierarchical architectures from a self-assembling dipeptide: thermal-induced morphological transition to 1D nanostructures

Construction of complex three-dimensional (3D) architectures through hierarchical self-assembly of peptide molecules has become an attractive approach of fabricating multifunctional advanced materials due to their various potential applications in bionanotechnology. This paper describes the tunable formation of flower-like 3D hierarchical architectures of intricate morphology from a simple self-assembling dipeptide phenylalanine–tyrosine with a facile preparative method by applying a range of voltages through a drop of peptide solution. The fine-tuning of voltages and their application time enable to produce morphological changes of the microstructures from 2D to 3D and also control their formation. The morphology has been characterized by the gradual change in the height-to-diameter ratio of the microstructures with change in the applied voltages. Moreover, these microstructures show significant thermal stability over a wide range of temperatures, whereas adequately high temperature promotes the morphological transformation of the microstructures into different types of ultrathin 1D nanostructures such as nanowires, nanofibrils, etc. Furthermore, we have suggested a possible growth model for the fabrication of unique hierarchical architectures through diffusion-limited aggregation mechanism.     

Infrared Aluminum Metamaterial Perfect Absorbers for Plasmon‐Enhanced Infrared Spectroscopy

Matured surface chemistry and excellent chemical stability have enabled gold to become the material‐of‐choice for plasmonic sensing in both visible and infrared wavelength range. Here, successful surface functionalization of metamaterials made from a low‐cost abundant plasmonic material, aluminum, with phosphonic acid and subsequent detection of the C?O vibration mode via surface‐enhanced infrared absorption spectroscopy is demonstrated. The metamaterial consists of infrared perfect absorbers fabricated by colloidal lithography. Near perfect absorption is achieved at resonance wavelengths, which can be readily tuned by changing the diameters of the Al disk resonators, enabling excellent overlapping with the molecular vibration. Separately, the detection of a physically adsorbed protein layer on the Al metamaterial is also demonstrated. Surface functionalization with phosphonic acid provides various functional groups to the Al surfaces. Combined with tunable metamaterials, the work herein opens up great opportunities for Al‐based plasmonic nanostructures for biochemical sensing applications.     

High hydrostatic pressure treatment impairs AcrAB-TolC pump resulting in differential loss of deoxycholate tolerance in Escherichia coli

We reported previously that high hydrostatic pressure-injured stationary phase cells of Escherichia coli K-12 lost their intrinsic deoxycholate tolerance. The AcrAB-TolC multi-drug resistance pump driven by proton motive force has been argued to be responsible for the tolerance to deoxycholate. In this report, we tested the sensitivity of the AcrAB-TolC (three components) pump to high hydrostatic pressure treatment (HPT). E. coli K-12 treated with HPT became sensitive to AcrAB-TolC-specific drugs such as ethidium bromide, but not to tetracycline which is pumped out by a one-component transporter, Tet. Only E. coli K-12 overproducing both AcrAB and TolC exhibited restored tolerance to deoxycholate after HPT but not E. coli overproducing either TolC or AcrAB. These observations strongly suggest that three-component pumps such as AcrAB-TolC are more susceptible to HPT than one-component pumps such as Tet, resulting in the differential loss of deoxycholate tolerance in high hydrostatic pressure-injured E. coli cells.     

Pu and 137Cs in the Yangtze River estuary sediments: distribution and source identification

Pu isotopes and (137)Cs were analyzed using sector field ICP-MS and γ spectrometry, respectively, in surface sediment and core sediment samples from the Yangtze River estuary. (239+240)Pu activity and (240)Pu/(239)Pu atom ratios (>0.18) shows a generally increasing trend from land to sea and from north to south in the estuary. This spatial distribution pattern indicates that the Pacific Proving Grounds (PPG) source Pu transported by ocean currents was intensively scavenged into the suspended sediment under favorable conditions, and mixed with riverine sediment as the water circulated in the estuary. This process is the main control for the distribution of Pu in the estuary. Moreover, Pu is also an important indicator for monitoring the changes of environmental radioactivity in the estuary as the river basin is currently the site of extensive human activities and the sea level is rising because of global climate changes. For core sediment samples the maximum peak of (239+240)Pu activity was observed at a depth of 172 cm. The sedimentation rate was estimated on the basis of the Pu maximum deposition peak in 1963-1964 to be 4.1 cm/a. The contributions of the PPG close-in fallout Pu (44%) and the riverine Pu (45%) in Yangtze River estuary sediments are equally important for the total Pu deposition in the estuary, which challenges the current hypothesis that the riverine Pu input was the major source of Pu budget in this area.     

Searching for noble Ni–Nb–Zr thin film amorphous alloys for optical glass device molding die materials

This paper presents a search for Ni–Nb–Zr thin film amorphous alloys for use as optical glass device molding die materials. To efficiently search for candidate materials, we used a combinatorial method to evaluate thermal stability. First, compositionally spread Ni–Nb–Zr libraries were fabricated by combinatorial arc plasma deposition (CAPD). To evaluate thermal stability, the Ni–Nb–Zr amorphous CAPD samples in the libraries were annealed in vacuum at 723 K, representing the molding temperature for glass devices, for various time periods. The phases of the annealed CAPD samples were identified using X-ray diffractometry (XRD). From XRD identification, candidate amorphous compositions with high thermal stabilities were screened. Sputter-deposited samples with the same candidate amorphous compositions were subsequently fabricated. Other desired properties for optical glass device molding die materials, including mechanical strength, linear expansion coefficient, oxidation resistance, machinability and anti-sticking properties to molten glass, were evaluated. The investigation revealed Ni₃₆Nb₃₉Zr₂₅ to be a suitable composition for a new glass lens molding die material. This material exhibited a high fracture stress, σ_f, of 1.3 GPa, good heat resistance, good oxidation resistance, similar linear expansion coefficient as glass, good machinability, and excellent anti-sticking properties to molten glass.