Heat transfer from horizontal cylinders to liquids: Combined effects of natural and forced convection

Heat transfer rates have been measured from electrically heated cylinders to liquid flowing perpendicular to the axes of the cylinders. Results have been expressed as a Nusselt group as a function of Reynolds and Prandtl numbers. Natural convection exerts a significant influence when Grashof number divided by the square of the Reynolds number exceeds about 0.2.     

Influence of Host-Plant Surface Chemicals on the Oviposition of the Cereal Stemborer Busseola Fusca

The chemical composition of plant surfaces plays a role in selection of host plants by herbivorous insects. Once the insect reaches the plant, these cues determine host acceptance. Laboratory studies have shown that the stem borer Busseola fusca (Lepidoptera: Noctuidae), an important pest of sorghum and maize in sub-Saharan Africa, is able to differentiate between host and non-host plant species. However, no information is available on the cues used by this insect to seek and accept the host plant. Thus, the role of surface phytochemical stimuli on host selection and oviposition by B. fusca was studied in the laboratory using two host plants, sorghum, Sorghum bicolor, and maize, Zea mays, and one non-host plant, Napier grass, Pennisetum purpureum. The numbers of eggs and egg masses deposited on the three plant species were compared first under no-choice and choice conditions. In both cases, more eggs and egg masses were laid on maize and sorghum than on the non-host. Artificial surrogate stems treated with a water or chloroform surface extract of each plant were then compared with surrogate stems treated with, respectively, water or chloroform as controls, under similar conditions. Surrogate stems treated with plant water extracts did not show an increase in oviposition when compared to controls, indicating that the major compounds in these extracts, i.e., simple sugars and free amino acids, are not significantly responsible for the oviposition preference. By contrast, a chloroform extract of sorghum enhanced oviposition on the surrogate stems compared to the control, while those of maize and Napier grass showed no significant effects. Analysis of the chloroform extract of sorghum showed higher amounts of α-amyrin, ß-amyrin, and n-nonacosane compared to those of maize and Napier grass. A blend of the three chemicals significantly increased oviposition compared to the chloroform-treated control, indicating that these compounds are part of the surface chemical signature of the plant responsible for host recognition and oviposition by B. fusca.     

Management of Gliricidia (Gliricidia sepium) residues for improved sweet corn yield in an ultisol

The nitrogen contribution from Gliricidia (G. sepium) leaves and roots in a Gliricidia alley cropping with sweet corn was quantified by the 15N isotope dilution technique over 3 cropping seasons. Below-ground competition in the third crop was assessed using ³²P radioisotope. Leaf prunings, roots and their mixture were compared in the presence or absence of hedgerows in a randomized complete block design. The combination of leaf prunings and roots resulted in highest N uptake, plant N concentration, and dry matter yield of corn. The Gliricidia leaf prunings decomposed fast and provided nutrients to the corn crop when applied at 21 and 45 days after planting. By contrast, roots decomposed slowly and did not become an important nutrient source to the corn crop. Below-ground competition was observed between hedgerows and corn at 1.7 m distance under conditions of low nutrient availability. However, the competition was masked when the supply of plant available nutrient increased.     

Pecan (Carya illinoinensis) oil consumer hedonic rating,sensory characteristic,satiating and energizing effect,and drivers of overall acceptance

With increasing global health and wellness product needs, pecan oil is getting popular in recent years. Although considered a gourmet oil because of its unique sensory and nutritional values, there is no publication focusing on consumer attitude toward pecan oil. This study, for the first time, investigated consumer acceptance, sensory quality, and emotional response to five pecan oils from native and improved varieties, with a comparison to an olive oil. All five pecan oils had positive hedonic ratings (>5, with a 9-point hedonic scale) for overall acceptance and the acceptance of oil flavor, raw-nut flavor, and thickness, while the olive oil was rated slightly lower than 5 for these attributes. Pecan oils had higher intensities in raw-nut flavor, but lower in overall oil flavor, fatty flavor, astringency, and thickness compared to olive oil. Off-flavor was not perceived in pecan oils, whereas it was perceived in olive oil. The six oils did not show significant differences in satiating effects; however, olive oil was rated lower in energizing effects than pecan oils, which showed a significant variety difference (p ≤ 0.05). Consumer overall acceptance was significantly, positively driven by energizing effects, followed by the acceptability of raw-nut flavor, thickness, and oil flavor; off-flavors were negative drivers. Results obtained from this study add direct pecan oil consumer insight: an asset for pecan growers, pecan processing industry, and pecan oil marketers.     

Insulin Signal Transduction Perturbations in Insulin Resistance

Type 2 diabetes mellitus is a widespread medical condition, characterized by high blood glucose and inadequate insulin action, which leads to insulin resistance. Insulin resistance in insulin-responsive tissues precedes the onset of pancreatic β-cell dysfunction. Multiple molecular and pathophysiological mechanisms are involved in insulin resistance. Insulin resistance is a consequence of a complex combination of metabolic disorders, lipotoxicity, glucotoxicity, and inflammation. There is ample evidence linking different mechanistic approaches as the cause of insulin resistance, but no central mechanism is yet described as an underlying reason behind this condition. This review combines and interlinks the defects in the insulin signal transduction pathway of the insulin resistance state with special emphasis on the AGE-RAGE-NF-κB axis. Here, we describe important factors that play a crucial role in the pathogenesis of insulin resistance to provide directionality for the events. The interplay of inflammation and oxidative stress that leads to β-cell decline through the IAPP-RAGE induced β-cell toxicity is also addressed. Overall, by generating a comprehensive overview of the plethora of mechanisms involved in insulin resistance, we focus on the establishment of unifying mechanisms to provide new insights for the future interventions of type 2 diabetes mellitus.     

Magnetic resonance imaging of the UroLume urethral stent

We discuss the use of magnetic resonance imaging of the pelvis in a patient with the UroLume urethral stent. This case demonstrates that magnetic resonance imaging is a safe and effective modality for imaging tissue surrounding the stent.     

α-Amylase Mediates Host Acceptance in the Braconid Parasitoid <Emphasis Type="Italic">Cotesia flavipes</Emphasis>

Foraging parasitoids use chemical signals in host recognition and selection processes. Although, the volatiles play a relevant role in the localization by parasitoids of their hosts feeding on plants, the host identification process for acceptance occurs mainly during contact between the parasitoid and its host where host products related to feeding activities, fecal pellets and oral secretions, play a crucial role. The purpose of this study was to identify the nature of the contact kairomone(s) that mediate the acceptance for oviposition of the parasitoid Cotesia flavipes Cameron (Hymenoptera, Braconidae), which was released in Kenya in 1993 to control the invasive crambid Chilo partellus (Swinhoe). Using host and non-hosts of C. flavipes, we showed that it is mainly the oral secretions of the larvae that harbour the active compound(s) that mediate host acceptance for oviposition by C. flavipes. Using an integration of behavioral observations and biochemical approaches, the active compound of the oral secretions was identified as an α-amylase. Using synthetized α-amylases from Drosophila melanogaster (an insect model for which syntheses of active and inactive α-amylases are available), we observed that the conformation of the enzyme rather than its catalytic site as well as its substrate and its degradation product is responsible for host acceptance and oviposition mediation of C. flavipes females. The results suggest that the α-amylase from oral secretions of the caterpillar host is a good candidate for an evolutionary solution to host acceptance for oviposition in C. flavipes.     

Electrophoretic Deposition of TiO2/Nb2O5 Composite Electrode Thin Films for Photovoltaic Application

Nano sized powders of TiO2 （titanium dioxide） and Nb2O5 （Niobium （V） oxide） were used to fabricate TiO2/Nb2O5 composites thin films by EPD （electrophoretic deposition） technique. The metal oxide powders, together with magnesium nitrate hexahydrate pellets, were suspended in propan-2-ol inside an EPD cell. The electrodes, placed 1.2 cm apart, were partially immersed in the suspension and a DC potential applied across them. Key EPD process parameters, which include applied DC electric field, deposition time and solid concentration in suspension, were optimized through visual inspection and from UV-Vis-NIR spectrophotometer spectra. The highest （55%） transmittance was obtained for films with deposition time of 90 s, powder concentration of 0.01 g/40 mL, and 35 V DC （direct current） voltage. XRD micrographs confirmed that TiO2 and Nb2O5 particles were presented in the composite film. SEM （scanning electron microscope） micrographs of the composite electrode thin films showed that porous films of high quality with well controlled morphology were deposited by using the EPD technique.