Combining sediment fingerprinting with age-dating sediment using fallout radionuclides for an agricultural stream,Walnut Creek,Iowa, USA

Journal of Soils and Sediments - The main purpose of this study was to demonstrate the utility of the sediment fingerprinting approach to apportion surface-derived sediment, and then age date that...     

Characterization of serum immunoglobulin M of grouper and cDNA cloning of its heavy chain

Immunoglobulin M (IgM) from the whole serum of grouper fish, Epinephelus coioides was purified by affinity chromatography using protein A-Sepharose column. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) under reducing conditions revealed that the relative molecular masses (Mr) of the equimolar heavy and light chains of IgM were 78,000 and 27,000, respectively. The cDNAs encoding IgM heavy chain comprising its variable (VH) and constant (CH) regions have been cloned and sequenced from a grouper kidney cDNA library by antibody screening method. Five VH (130-142 amino acids) and four CH (450-454 amino acids) families were identified. The variable and constant regions were conserved with their putative domains. All the four constant region domains (CH1-CH2-CH3-CH4) contained each three conserved cysteine residues, which are considered to form the inter- and intra-chain disulfide bridges. There were three carbohydrate acceptor sites in the constant region. In general, the pattern of IgM gene organization seems to resemble that of other teleosts. Moreover, the CH genes in grouper IgM occur as multifamily as reported in Atlantic salmon and common carp.     

Fall in Earth's magnetic field is erratic

Earth's magnetic field has decayed by about 5% per century since measurements began in 1840. Directional measurements predate those of intensity by more than 250 years, and we combined the global model of directions with paleomagnetic intensity measurements to estimate the fall in strength for this earlier period (1590 to 1840 A.D.). We found that magnetic field strength was nearly constant throughout this time, in contrast to the later period. Extrapolating to the core surface showed that the fall in strength originated in patches of reverse magnetic flux in the Southern Hemisphere. These patches were detectable by directional data alone; the pre-1840 model showed little or no evidence of them, supporting the conclusion of a steady dipole up to 1840.     

Use of infrared spectroscopy for diagnosis of traumatic arthritis in horses

OBJECTIVE: To evaluate use of infrared spectroscopy for diagnosis of traumatic arthritis in horses. ANIMALS: 48 horses with traumatic arthritis and 5 clinically and radiographically normal horses. PROCEDURES: Synovial fluid samples were collected from 77 joints in 48 horses with traumatic arthritis. Paired samples (affected and control joints) from 29 horses and independent samples from an affected (n = 12) or control (7) joint from 19 horses were collected for model calibration. A second set of 20 normal validation samples was collected from 5 clinically and radiographically normal horses. Fourier transform infrared spectra of synovial fluids were acquired and manipulated, and data from affected joints were compared with controls to identify spectroscopic features that differed significantly between groups. A classification model that used linear discriminant analysis was developed. Performance of the model was determined by use of the 2 validation datasets. RESULTS: A classification model based on 3 infrared regions classified spectra from the calibration dataset with overall accuracy of 97% (sensitivity, 93%; specificity, 100%). The model, with cost-adjusted prior probabilities of 0.60:0.40, yielded overall accuracy of 89% (sensitivity, 83%; specificity, 100%) for the first validation sample dataset and 100% correct classification of the second set of independent normal control joints. CONCLUSIONS AND CLINICAL RELEVANCE: The infrared spectroscopic patterns of fluid from joints with traumatic arthritis differed significantly from the corresponding patterns for controls. These alterations in absorption patterns may be used via an appropriate classification algorithm to differentiate the spectra of affected joints from those of controls.     

Development and evaluation of a rapid immunomagnetic bead assay for the detection of classical swine fever virus antigen

Classical swine fever (CSF) is a highly contagious and severe viral disease of swine resulting in substantial production losses in different farming systems in many regions of the world. The accurate and rapid detection of CSF outbreaks is reliant on sensitive and specific laboratory testing and is a key component of disease control. Specific detection of CSF virus can be achieved by virus isolation in tissue culture, antigen capture or the detection of viral RNA using molecular techniques. In order to reduce the time taken to achieve a diagnostic result and simplify testing methods, an antigen capture ELISA using immunomagnetic beads (IMB) as the solid phase was developed and compared to a microplate-based antigen capture (AC)-ELISA. The IMB-ELISA has up to 64-fold greater analytical sensitivity than the AC-ELISA and initial estimates of diagnostic sensitivity and specificity are 100%. The IMB-ELISA has a highly robust, rapid and stable test format and is simpler to perform than the AC-ELISA. The IMB-ELISA has the added advantage that a result can be sensitively and specifically determined by eye, lending it to the possibility of adaptation to a near-to-field test with minimal equipment or expertise needed.