Voltage-current and voltage-flux characteristics of asymmetric high TC DC SQUIDs

We report measurements of transfer functions and flux shifts of 20 on-chip high T$_C$ DC SQUIDs half of which were made purposely geometrically asymmetric. All of these SQUIDs were fabricated using standard high T$_C$ thin film technology and they were single layer ones, having 140 nm thickness of YBa$_2$Cu$_3$O$_{7-x}$ film deposited by laser ablation onto MgO bicrystal substrates with 24$^0$ misorientation angle. For every SQUID the parameters of its intrinsic asymmetry, i. e., the density of critical current and resistivity of every junction, were measured directly and independently. We showed that the main reason for the on-chip spreading of SQUIDs' voltage-current and voltage-flux characteristics was the intrinsic asymmetry. We found that for SQUIDs with a relative large inductance ($L>120$ pH) both the voltage modulation and the transfer function were not very sensitive to the junctions asymmetry, whereas SQUIDs with smaller inductance ($L\simeq 65-75$ pH) were more sensitive. The results obtained in the paper are important for the implementation in the sensitive instruments based on high T$_C$ SQUID arrays and gratings.Comment: 11 pages, 4 tables, 17 figures This version is substantially modified. The Introduction and Section 2 are completely rewritten, while experimental part is mainly the same as in previous versio

Scale morphology and specialized dorsal scales of a new teleosteomorph fish from the Aptian of West Gondwana

Scales of a new species of Teleosteomorpha from the continental Aptian of the south of South America are studied. These neopterygians are from the La Cantera Formation in central Argentina, and were previously identified as Pholidophoriformes. They present ganoid scales; most of them are rhombic with well-developed peg-and-socket articulations and possessing a smooth surface. They have a straight posterior margin, but occasionally, some scales of the flank have a sinuous posterior margin with one or two serrations. The shape of the scales varies along the body from large, rectangular and deeper than long scales behind the head to the preanal region to smaller and rhomboidal scales in the caudal region. There are a few horizontal rows along the flank and about 32 lateral line scales. Thick, round ganoid scales are present in the prepelvic region close to the ventral margin. The round and rhombic scales present growth lines, which form concentric ridges on the external side. A characteristic row of deep scales forms the dorsal margin on each side of the body; a row of median ridge scales is not present. This is a unique feature of the studied fishes. Scutes covered with unornamented ganoine precede the pelvic, dorsal, and anal fins, as well as the dorsal and ventral margins of the caudal fin. The posterior margin of the dorsal lobe of the caudal fin is formed by a single line of scales, which continues and covers the base of the first principal caudal ray. Histological studies reveal a lepisosteoid-scale type with multiple ganoine layers, lack of dentine, and the presence of canaliculi of Williamson. The macro- and micromorphology of the scales shows features that are found in other teleosteomorphs, but also in other neopterygians

Meat Juice serology underestimates prevalence of Salmonella in pig herds

Salmonella serology is used for classifying pig herds in risk categories in several national quality programs. Meat juice is used as test matrix in most of these programs. Two studies were done to compare the salmonella ELISA test results from meat juice with blood serum as a reference. Pig blood and meat samples for these studies were collected in one slaughterhouse. ELISA tests were done with a commonly applied commercial test. In the first study paired blood serum and meat juice samples from 182 pigs were collected and tested in two different laboratories. In the second study meat and blood samples were collected from 470 herds, over 20.000 samples for each matrix

Clearing confusion in Stylosanthes taxonomy. 2. S. macrocephala MB Ferreira & Sousa Costa vs. S. capitata Vogel and S. bracteata Vogel

Stylosanthes macrocephala was described as a new species in 1977 and has become an economically important pasture legume. It has recently been claimed to be conspecific with S. capitata, also an economically important species. This paper refutes this synonymization and summarizes morphological descriptions as well as genetic studies and cytological evidence indicating that diploid S. macrocephala should be considered a separate species, even being a likely progenitor of tetraploid S. capitata. Early confusion with S. bracteata is also discussed