Calcite Reinforced Silica–Silica Joints in the Biocomposite Skeleton of Deep‐Sea Glass Sponges

The hierarchically structured glass sponge Caulophacus species uses the first known example of a silica and calcite biocomposite to join the spicules of its skeleton together. In the stalk and body skeleton of this poorly known deep‐sea glass sponge siliceous spicules are modified by the addition of conical calcite seeds, which then form the basis for further silica secretion to form a spinose region. Spinose regions on adjacent spicules are then joined by siliceous crosslinks, leading to unusually strong cross‐spicule linkages. In addition to the biomaterials implications it is now clear, from this first record of a biomineral other than silica, that the hexactinellid sponges are capable of synthesizing calcite, the ancestral skeletal material. We propose that, while the low concentrations of calcium in deep sea waters drove the evolution of silica skeletons, the brittleness of silica has led to retention of the more resilient calcite in very low concentrations at the skeletal joints.     

“To Catch or Not to Catch”: Microcapsule‐Based Sandwich Assay for Detection of Proteins and Nucleic Acids

The development of new assays that specifically detect intermediate or final products of biotechnological processes or multiple analytes in biomedical research is important for diagnostics and biotechnology. This study presents a microcapsule‐based sandwich assay for detection of proteins and nucleic acids using flow cytometry as an optical readout. The main component of the assay are robust chemically cross‐linked microcapsules that are coated with adaptor proteins such as protein A or streptavidin. In the first approach, the ability of detecting the blood cancer biomarker beta‐2 microglobulin in the fM to pM concentration range with the help of protein A‐coated capsules is demonstrated. In the second approach, streptavidin‐coated capsules are used for detection of nucleic acids in the nM concentration range. The developed assay allows rapid quantitative analyte measurement, while providing high sensitivity and selectivity at very small sample quantities. In the future, protein A‐ and streptavidin‐coated microcapsules can be used as universal tools for detection of a broad range of analytes.     

Comparison of Holstein and Jersey innate immune responses to Escherichia coli intramammary infection

Mastitis is one of the most prevalent diseases in cattle and remains among the most costly diseases to the dairy industry. Various surveys have indicated a greater prevalence of and risk for mastitis in Holstein cows than in Jersey cows. The innate immune system comprises the immediate host defense mechanisms that respond to infection, and differences in the magnitude and rapidity of this response are known to influence susceptibility to and clearance of infectious pathogens. The reported differences in the prevalence of mastitis between Holstein and Jersey cows may suggest the occurrence of breed-dependent differences in the innate immune response to intramammary infection. The objective of the current study was to compare the acute phase and cytokine responses of Holstein and Jersey cows following intramammary infection by the bacterial pathogen Escherichia coli, a leading cause of clinical mastitis. All cows in the study were in similar stages of lactation, of the same parity, subjected to the same housing and management conditions, and experimentally infected on the same day with the same inoculum preparation. Before and after infection, the following innate immune parameters were monitored: bacterial clearance; febrile response; induction of the acute phase proteins serum amyloid A and lipopolysaccharide-binding protein; alterations in total and differential white blood cell counts; changes in milk somatic cell counts and mammary vascular permeability; and induction of the cytokines IFN-γ, IL-1β, IL-8, IL-12, and tumor necrosis factor-α. Overall innate immune responses were similar between the 2 breeds; however, temporal differences in the onset, cessation, and duration of several responses were detected. Despite these differences, intramammary clearance of E. coli was comparable between the breeds. Together, these data demonstrate a highly conserved innate immune response of Holstein and Jersey cows to E. coli intramammary infection.     

采用MEMS技术高选择性、电子调谐式低温滤波器

描述了一种使用HTS/AuMEMS 开关电容器阵的低插损电子调谐式滤波器。同步将每个谐振器的电容值以相同变化量变化,两极滤波器就得到调谐。单极谐振器在3500～5000之间的K 系数得到了证明。在77K 平均Q 值为7000 时的总调谐范围大约为25%。     

Elastic properties of random-linked cis-PB networks: A characterization and gel point study

cis-Polybutadiene networks with microstructure 98% cis, cross-linked in the bulk state by gamma irradiation, were characterized in terms of their mechanical properties. Data from stress-strain analyses, swelling degrees, stress relaxation, and random-linking theory are in accordance and the estimated gel points practically coincide. Trapped entanglements lead to a 30% increase in the network modulus, from which also the plateau modulus, 0.71 ± 0.09 MPa, was determined. The tensile data were obtained from Mooney-Rivlin representations without junction constrained corrections. Preliminary stress-relaxation experiments indicated a slow relaxation at room temperature. It can be concluded that the assumption of additive contributions from chemical and entanglement cross-link densities in the Langley theory works well in the range of doses investigated here. © 1993 John Wiley & Sons, Inc.     

Estimating the value of electricity storage in PJM: Arbitrage and some welfare effects

Significant increases in prices and price volatility of natural gas and electricity have raised interest in the potential economic opportunities for electricity storage. In this paper, we analyze the arbitrage value of a price-taking storage device in PJM during the six-year period from 2002 to 2007, to understand the impact of fuel prices, transmission constraints, efficiency, storage capacity, and fuel mix. The impact of load-shifting for larger amounts of storage, where reductions in arbitrage are offset by shifts in consumer and producer surplus as well as increases in social welfare from a variety of sources, is also considered.     

Upper bound risk estimates for mixtures of carcinogens

The excess cancer risk that might result from exposure to a mixture of chemical carcinogens usually is estimated with data from experiments conducted on individual chemicals. An upper bound on the total excess risk is estimated commonly by summing individual upper bound risk estimates. The degree to which this approach might overstate the true risk associated with the mixture has not been evaluated previously. This paper reports the results of a Monte Carlo simulation study on the degree of reduction in conservation that might be achieved using alternative methods for calculating mixture upper bounds. An unexpected finding is that for chemicals that exhibit strongly linear dose-response relationships, the summing of multistage-model-based upper bounds on excess risk can be anti-conservative, that is, it can provide less than the nominal 100(1-alpha)% coverage.     

The Arabidopsis LATERAL ORGAN BOUNDARIES-domain gene ASYMMETRIC LEAVES2 functions in the repression of KNOX gene expression and in adaxial-abaxial patterning

The normal development of lateral organs of the shoot requires the simultaneous repression of meristem-specific genes and the activation of organ-specific genes. ASYMMETRIC LEAVES2 (AS2) is required for the development of normal leaf shape and for the repression of KNOX genes in the leaf. AS2 is a member of the recently identified, plant-specific LATERAL ORGAN BOUNDARIES (LOB)-domain gene family. Expression of AS2 at high levels resulted in repression of the KNOX homeobox genes BREVIPEDICELLUS, KNAT2, and KNAT6 but not of the related SHOOT MERISTEMLESS gene. Overexpression of AS2 also led to a perturbation of normal adaxial-abaxial asymmetry in lateral organs, resulting in the replacement of abaxial cell types with adaxial cell types. These results indicate that AS2 is sufficient to induce adaxial cell fate and repress KNOX gene expression.