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The article presents information on the growing popularity of digital X-ray along with advantages and disadvantages of digital X-ray. The advent of digital X-ray is stated to created a revolution on chiropractic imaging. There are several forms of digital receptors including direct radiography (DE) and computed radiography.

The article provides a brief overview of the advantages and disadvantages of the most common types of digital X-ray systems seen in the chiropractic market. Topics discussed include the misconceptions associated with digital X-ray such as that the X-ray itself is not digital and that one cannot take a bad X-ray with digital and the questions a chiropractor should consider when evaluating the viewing software prior to purchase such whether he can enhance the image and annotate easily.

Abstract—Ink‐jet‐printing technology for displays has been making rapid progress and is now nearing production. This paper will go through the developments that have been carried out at CDT, Ltd., to achieve this status. The ink‐jet head and machine development that underpin the capability of the RGB printing process to manufacture P‐OLEDs at high speed with high reliability and with the film‐forming properties to achieve the appropriate device performance will be described. The important contribution made by the availability of flexible metrological tools will be discussed.

In the work reported herein, we have combined a short-lived femtosecond laser-induced plasma (LIP) and a longer-lived nanosecond LIP in a collinear pulse configuration to examine the source(s) of atomic emission and signal-to-noise enhancement in dual-pulse laser-induced breakdown spectroscopy (LIBS). Initial studies indicate that the primary source of dual-pulse LIBS enhancement in the collinear configuration may in large part be a matter of pulse focus; focusing on the sample surface, for example, yields atomic emission enhancements whose lifetime correlates reasonably well with the femtosecond LIP emissive lifetime, suggesting that plasma–plasma coupling may play an important role at that pulse focus. At a second “optimal” focal position above the sample surface, alternatively, atomic emission and signal-to-noise enhancements correlate quite well with the nitrogen and oxygen atomic emission reductions previously seen following use of a femtosecond air spark and a nanosecond ablative pulse in the orthogonal dual-pulse configuration, suggesting that pressure or number density reductions due to femtosecond LIP formation in air may be significant at that pulse focus.

Amino acid derivatives bearing an alkyne (AA-CCH) at either the N- or C-terminus readily react with W(CO)3(S2CNMe2)2 to replace the carbon monoxides and form the novel bis-alkyne complexes W(AA-CCH)2(S2CNMe2)2; the solution behavior of these complexes shows that only the alkyne, and not the other functional groups on the amino acid, bonds to the tungsten.

C. elegans embryogenesis begins with a stereotyped sequence of asymmetric cell divisions that are largely responsible for establishing the nematode body plan. These early asymmetries are specified after fertilization by the widely conserved, cortically enriched PAR and PKC-3 proteins, which include three kinases and two PDZ domain proteins. During asymmetric cell divisions in the early embryo, centrosome pairs initially are positioned on transverse axes but then rotate to align with the anteroposterior embryonic axis. We show that rotation of the centrosomal/nuclear complex in an embryonic cell called P(1) requires a maternally expressed gene we name spn-4. The predicted SPN-4 protein contains a single RNA recognition motif (RRM), and belongs to a small subfamily of RRM proteins that includes one Drosophila and two human family members. Remarkably, in mutant embryos lacking spn-4 function the transversely oriented 'P(1)' mitotic spindle appears to re-specify the axis of cell polarity, and the division remains asymmetric. spn-4 also is required for other developmental processes, including the specification of mesendoderm, the restriction of mesectoderm fate to P(1) descendants, and germline quiescence during embryogenesis. We suggest that SPN-4 post-transcriptionally regulates the expression of multiple developmental regulators. Such SPN-4 targets might then act more specifically to generate a subset of the anterior-posterior asymmetries initially specified after fertilization by the more generally required PAR and PKC-3 proteins.

A maternally expressed Caenorhabditis elegans gene called cyk-1 is required for polar body extrusion during meiosis and for a late step in cytokinesis during embryonic mitosis. Other microfilament- and microtubule-dependent processes appear normal in cyk-1 mutant embryos, indicating that cyk-1 regulates a specific subset of cytoskeletal functions. Because cytokinesis initiates normally and cleavage furrows ingress extensively in cyk-1 mutant embryos, we propose that the wild-type cyk-1 gene is required for a late step in cytokinesis. Cleavage furrows regress after completion of mitosis in cyk-1 mutants, leaving multiple nuclei in a single cell. Positional cloning and sequence analysis of the cyk-1 gene reveal that it encodes an FH protein, a newly defined family of proteins that appear to interact with the cytoskeleton during cytokinesis and in the regulation of cell polarity. Consistent with cyk-1 function being required for a late step in embryonic cytokinesis, we show that the CYK-1 protein co-localizes with actin microfilaments as a ring at the leading edge of the cleavage furrow, but only after extensive furrow ingression. We discuss our findings in the context of other studies suggesting that FH genes in yeast and insects function early in cytokinesis to assemble a cleavage furrow.

Twelve young (average age — 4 days) male Holstein calves fed either whole milk or whole milk supplemented with 15 ppm manganese (Mn) were given either an oral or intravenous (iv) tracer 54Mn dose. Manganese-supplemented calves excreted more (P< .01) 54Mn in the feces than controls. Feeding supplemental Mn reduced 54Mn retention, as measured directly, by 73% (60.1 vs.16.3%) in iv-dosed animals and by 88% (18.2 vs.2.2%) in orally-dosed animals. Liver and small intestinal 54Mn were most affected by dietary Mn intake. Supplemental Mn reduced liver 54Mn from over half of the total body content to less than one-tenth. The added Mn caused a twofold increase in liver Mn (11.5 vs.22.1 ppm) and gall bladder (5.8 vs. 11.6 ppm), a 30-fold increase in bile (1.3 vs. 39.4 ppm), but no significant increase in other tissues. Manganese absorption by controls was far greater than generally reported in any species. The data indicate that both variable excretion and absorption play important roles in Mn homeostasis, and that iv-administered Mn is metabolized quite differently from that absorbed.

Twelve Mile Bay is a long (about 16 km), narrow bay within Georgian Bay, Lake Huron, without a significant tributary and not strongly affected by cultural eutrophication. The Moon River Basin, immediately to the north, is also lightly inhabited, but has a significant input of soft water from a tributary draining the Canadian Shield. A strong gradient in zooplankton community structure exists at Twelve-Mile Bay. At the nearshore end of the bay, the zooplankton community is dominated by Rotifera, small Cladocera, and Cyclopoida. Rotifera decline in importance toward the entrance of the bay, and larger Cladocera, Daphnia and Holopedium, increase in relative importance. The highest biomass of Daphnia and Holopedium is attained midway along the length of the bay. Towards the entrance to the bay, Calanoida dominate the community. Ciliophora are a relatively stable, but smaller, component of zooplankton biomass. This gradient is accompanied by an increase in secchi depth, and a decline in total phosphorus, chlorophyll, and chlorophyll to TP ratio, toward the offshore end of the bay. Phytoplankton biomass and species composition also change. Flagellated nanoplankton were a relatively constant component of the community, but other groups, including Cyanophyta and non-motile Chlorophyta, decreased along the length of the bay. These changes are consistent with the hypothesis of a greater abundance of grazing-resistant nanoplankton in the microzooplankton-dominated upper bay. Close to the outlet of the Moon River, the zooplankton community is quite different from that at the upper end of Twelve Mile Bay, suggesting an important role of the river in modifying the zooplankton community.

Five stations on the lower Saint John River, a complex multibasin estuary, were sampled semiquantitatively for zooplankton at biweekly intervals for one year, and qualitatively over a 4-year period. Planktonic Crustacea were dominated by the true estuarine copepods,Acartia tonsaandEurytemora affinisand the euryhaline marine copepodsOithona similisandPseudocalanus minutus. Atypical estuarine forms, confined to a lower fiord-like basin with salinity of 20‰, were the amphipod,Parathemisto abyssorumand the mysidErythrops erythrophthalma. River flows were highly variable from year to year. Certain basins function as lakes in some years and estuaries in other years, causing extreme zooplankton community fluctuations, and succession patterns dependent on salinity rather than season. On occasion freshwater zooplankters maintained viable populations at unusually high salinities (ca. 5‰). Vertical and horizontal distributions of zooplankters indicate that the estuary in fact comprises two systems: a true estuary in the upper reaches and the surface waters at the lower end, and a fiord in a subsidiary basin in the lower end.

We measured the emission of water vapor at a wavelength of 1.35 centimeters from nine sources with the 120-foot (36.5-meter) Haystack antenna. Eight sources lie within 30 seconds of arc of the hydroxyl sources of 18 centimeters but not all hydroxyl sources produced detectable emission of water vapor. All sources are smaller than 30 seconds of arc in angular diameter, but we resolved at least three separate sources in the Orion Nebula. We do not find that the known hyperfine components are present with the equilibrium intensity distribution.

The distribution and limnetic density of five species of Chaoborus larvae were determined in 26 lakes of the Matamek River System, Québec. The distribution of C. americanus is closely related to the absence of fish while C. punctipennis is associated with fish populations. The distributions of C. trivittatus and C. flavicans appear independent of the presence or absence of fish, but C. flavicans reaches its greatest density in the three lakes with the largest individual basins. A probable new species or subspecies of the subgenus Scadanophasma was found in three lakes. The standing crop of limnetic Chaoborus larvae is higher in lakes without fish than with fish.

The Stokes parameters were measured as a function of frequency for the anomalous 1665-megacycles-per-second OH emission originating near the thermal radio source W3. The emission is highly polarized, and the polarization parameters vary rapidly with frequency. The observed polarization can be described in terms of narrow, roughly Gaussian, emission features, all with uniform polarization but with several features overlapping without coherence near the center of the spectrum. Most of the individual features may be 100-percent polarized. Detailed examination of the brightest features suggest that they are not exactly Gaussian in shape.

Competition among members of the microflora leads the investigator into many strange and diverse by-paths. Microorganisms in their metabolism give off by-products, many of which are inhibitory in nature; some have stimulatory effects. These products and activities properly controlled will give us much insight into the proper care of cultures, a natural and effective method of controlling some diseases and, possibly, chemical products of economic value.

This note reports on the noise of CMOS devices. It is shown experimentally that a weak boron threshold implant (~1012 cm-3) can influence the 1/f noise levels. For wafers with threshold adjustment the p-channel noise decreases whilst the n-channel noise increases. The changes in the n/p noise ratio with/without threshold implantation are predicted using a simple model in conjunction with carrier profile simulations.

WE report here the first results of a nearly complete, high-sensitivity, water vapour survey of galactic H II regions situated in the Southern Hemisphere.

An upper limit of 0.02 second of arc has been determined for a hydroxyl radical (OH) emission region associated with the radio source W3, with the use of a Michelson interferometer consisting of two radio telescopes 845 kilometers apart. Timing was provided at the stations by independent atomic frequency standards. The 1665-megahertz radiation was translated to video frequency and recorded digitally on magnetic tapes which were later processed by computer, yielding fringe phase and amplitude as a function of frequency over the received bandwidth.