The nitric oxide-cGMP pathway may mediate communication between sensory afferents and projection neurons in the antennal lobe of Manduca sexta

The nitric oxide (NO)-cGMP signaling system is thought to play important roles in the function of the olfactory system in both vertebrates and invertebrates. One way of studying the role of NO in the nervous system is to study the distribution and properties of NO synthase (NOS), as well as the soluble guanylyl cyclases (sGCs), which are the best characterized targets of NO. We study NOS and sGC in the relatively simple and well characterized insect olfactory system of the hawkmoth, Manduca sexta. We have cloned Manduca sexta nitric oxide synthase (MsNOS) and two sGCs (MsGCalpha1 and MsGCbeta1), characterized their basic biochemical properties, and studied their expression in the olfactory system. The sequences of the Manduca genes are highly similar to their mammalian homologs and show similar biochemical properties when expressed in COS-7 cells. In particular, we find that MsGC functions as an obligate heterodimer that is stimulated significantly by NO. We also find that MsNOS has a Ca2+-sensitive NO-producing activity similar to that of mammalian neuronal NOS. Northern and in situ hybridization analyses show that MsNOS and the MsGCs are expressed in a complementary pattern, with MsNOS expressed at high levels in the antennae and the MsGCs expressed at high levels in a subset of antennal lobe neurons. The expression patterns of these genes suggest that the NO-sGC signaling system may play a role in mediating communication between olfactory receptor neurons and projection neurons in the glomeruli of the antennal lobe.     

Electroantennographic and behavioral responses of the sphinx moth Manduca sexta to host plant headspace volatiles

Coupled gas chromatography with electroantennographic detection (GC-EAD) using antennae of adult female Manduca sexta was employed to screen for olfactory stimulants present in headspace collections from four species of larval host plants belonging to two families: Solanaceae—Lycopersicon esculentum (tomato), Capiscum annuum (bell pepper), and Datura wrightii; and Martyniaceae—Proboscidea parviflora. Headspace volatiles were collected from undamaged foliage of potted, living plants. GC–EAD revealed 23 EAD-active compounds, of which 15 were identified by GC-mass spectrometry. Identified compounds included aliphatic, aromatic, and terpenoid compounds bearing a range of functional groups. Nine EAD-active compounds were common to all four host plant species: (Z)-3-hexenyl acetate, nonanal, decanal, phenylacetaldehyde, methyl salicylate, benzyl alcohol, geranyl acetone, (E)-nerolidol, and one unidentified compound. Behavioral responses of female moths to an eight-component synthetic blend of selected tomato headspace volatiles were tested in a laboratory wind tunnel. Females were attracted to the blend. A comparison of responses from antennae of males and females to bell pepper headspace volatiles revealed that males responded to the same suite of volatiles as females, except for (Z)-3-hexenyl benzoate. EAD responses of males also were lower for (Z)- and (E)-nerolidol and one unidentified compound. Electroantennogram EAG dose–response curves for the 15 identified EAD-active volatiles were recorded. At the higher test doses (10–100 g), female antennae yielded larger EAG responses to terpenoids and to aliphatic and aromatic esters. Male antennae did respond to the higher doses of (Z)-3-hexenyl benzoate, indicating that they can detect this compound. On the basis of ubiquity of the EAD-active volatiles identified to date in host plant headspace collections, we suggest that M. sexta uses a suite of volatiles to locate and identify appropriate host plants.     

Near surface flaw detection by ultrasonic critical angle imaging

Acoustic critical angle measurements usually involve broad beam or global isonification of a water-solid interface. In order to obtain local interface data, it is convenient to use a focused acoustic source with lens axis at incident angle and point-receiver at specular reflection angle . By scanning this combination at various critical angles (=_crit), interface waves are generated locally near the lens focus. These waves penetrate the solid to a depth of approximately one shear wavelength _T and are modulated by discontinuities such as flaws, inclusions, and debonds that may be present there. A radiated longitudinal wave in water accompanies these modulated interface waves and carries information on subsurface flaws to the point-detector along the direction of a specularly reflected wave. By scanning the focus-receiver combination along the interface, the receiver output may be used to form images of local subsurface detail. We show that in anisotropic materials, such as crystals, there are generally two different _crit where a radiating interface wave provides subsurface information. We also discuss special problems associated with the use of a focused acoustic source including nonlinear effects (generation of harmonics) in the water.     

Initiation of tantalum oxide pores grown on tantalum by potentiodynamic anodic oxidation

The initiation and growth of porous oxide on Ta was investigated in mixed H₂SO₄/HF electrolytes. Under selected potentiodynamic anodic oxidation conditions the formation of nearly uniform porous Ta₂O₅ layer was observed. The porous Ta₂O₅ layers consist of self-organized pore arrays with single pore diameters ranging from 2 to 10 nm. The morphology and the thickness of the layer depend strongly on the applied potential, the scan rate and on HF presence. The composition of the porous oxide layer is Ta₂O₅.     

A review on assessment of fatigue strength in welded studs

Welding is one of the most important and highly developed joining methods; nevertheless unwanted side effects occur like thermal strains and altering of certain material properties induced by heating and melting. These effects lead to distortions and high residual stresses which should be kept to a minimum. To minimize distortion, various strategies are being developed. Stud welding is widely used in steel structures, power plants, and ship buildings due to the significantly technology including highest quality of production processes by continuous electrical control and the efficiency of such a process. Therefore, varying the heat input typically will affect the material properties including yield strength, tensile strength, hardness, and notch toughness in the stud arc welding. Well-defined heat sources offer a reproduced heat input into a highly localized area. The fatigue strength of stud welding has been investigated by performing welding process and microstructural observations. This paper is going to discuss the influence of heat input on the structural changes in stud arc welding.     

Turning wine (waste) into water: Toward technological advances in the use of constructed wetlands for winery effluent treatment

The research presented in this article describes an investigation into the use of vegetated submerged reedbeds (VSR) as a practicable alternative for effluent treatment for small‐scale wine producers. In this study, we found that the hydraulic processes occurring within the VSR display significantly nonideal behavior. If the feed to the VSR was located on the surface the dead volume accounted for approximately 25% of the nonideal behavior of the system and bypass accounted for a further 6%. A preferential flow pattern was found within the VSR with the greatest flow occurring closest the surface and in the center, and the least at the sidewalls. We propose that the flow profile can be conceptualized as being hull shaped and found that this profile was the same for irregularly shaped gravel and for spherically shaped gelatinous beads. We, therefore, hypothesize that it is not dependent on the geometry of the VSR or the packing medium. © 2013 American Institute of Chemical Engineers AIChE J 60: 420–431, 2014     

Chromatographische Untersuchungen zur Polydispersität von Hydroxyethylstärke

Chromatographic Studies on the Polydispersity of Hydroxyethyl Starch. A representative sample of clinically used hydroxyethyl starch was separated by semipreparative HPSEC into narrow fractions in the range of approx. 3.000 to 800.000 D. The original sample and selected fractions were characterised by gaschromatographic methylation analysis according to their substitution degrees MS and DS, which were differentiated by the substitution positions at C2, C3 and C6 of the anhydroglucoses and their kind of glycosidic bonding α-1, α-1,4 or α-1,4,6, respectively. Furthermore, polydispersity in relations to the degree of branching was determined. Mark-Houwink and molecular weight distribution parameters determined by multi-detection HPSEC are reported. The presented data demonstrate a extensive homogeneity of the original sample. The clinical relevance is discussed.     

Measurements of density and viscosity of one- and two-phase fluids with torsional waveguides

The continuing need for in-situ measurements of physical properties of wastes contained within many high level radioactive waste tanks within the Hanford Site has initiated experimental and theoretical investigations of candidate measurement methods. This paper describes experiments performed with acoustic waveguide sensors. This technology has potential application at the Hanford Site for in-situ measurements of density, viscosity, and temperature of liquid wastes. Waveguides of both circular and rectangular geometry were used in these studies for determination of the densities and viscosities of various fluids. The flight time of a torsional pulse through the sensing region of the waveguide forms the measured quantity. The flight time depends on the velocity of the wave through the sensing region of the waveguide, and this velocity in turn depends upon the properties of the fluid in contact with the waveguide. We performed experiments with 15 different fluids, most of which were single-phase Newtonian fluids. However, three of the fluids were particle-liquid mixtures, and one of these Newtonian in behavior. Most of the wastes held in Hanford tanks contain high solids content. The results of our experiments showed that acoustic waveguides were well suited for measurements in most Newtonian fluids, in agreement with earlier research presented in the literature. However, results for two-phase Newtonian fluids containing particles indicate that, in our case, the waveguides responded primarily to the background fluid rather than the mixture. Very poor results were obtained with the non-Newtonian fluid. In addition, there was a class of fluids, which serve the community as viscosity standards, for which viscosities determined with torsional waveguides were in disagreement with viscosities obtained with standard viscometers.