bluuebunny/crossref_metadata_2025 huggingface dataset:
Nutritional evaluation of winter foods of wild turkeys
Authors: Decker Scott R. , Pekins Peter J. , Mautz William W.
Published: August 2008

Red oak acorns (Quercus rubra), fruits of multiflora rose (Rosa multiflora), common juniper (Juniper communis), winterberry holly (Ilex verticillata), and barberry (Berberis spp.), fertile fronds of sensitive fern (Onoclea sensibilis), corn, and apples were fed as mixed rations to eight eastern wild turkeys (Meleagris gallopavo silvestris). Crude protein content of the foods ranged from 2 (apples) to 19% (sensitive fern). Red oak acorns and juniper berries were 14% fat; other foods were 1–7% fat. Apples were lowest in gross energy content (3.9 kcal/g dry matter (1 cal = 4.1868 J)), and sensitive fern was highest (5.5 kcal/g). Little variation existed in nutrient composition and energy content of the mixed diets. Metabolizable energy values of the diets ranged from 65 to 84% of gross energy intake and from 3.1 to 4.0 kcal/g. Solution of simultaneous equations based on the mixed-diet data yielded metabolizable energy values of individual foods; juniper had the highest metabolizable energy (4.6 kcal/g) and sensitive fern the lowest (2.1 kcal/g); other foods ranged from 3.3 to 4.1 kcal/g. Acorns, corn, and shrubs with persistent fruits (juniper, winterberry, barberry, and multiflora rose) were the most nutritious foods. Metabolizable energy intake of the mixed diets, excluding the juniper-dominated diet, approximated or exceeded the predicted daily energy expenditure of wild turkeys.
Life history and larval morphology of Chrysolampus (Hymenoptera: Chalcidoidea: Chrysolampinae) in western North America
Authors: Darling D. Christopher , Miller Terry D.
Published: August 2008

Species of Chrysolampus are widely distributed in arid regions of western North America and parasitize tychiine weevils that infest the seed pods of legumes. Detailed host information is presented for the first time: Chrysolampus sisymbrii parasitizes Tychius tectus in Astragalus inflexus and Chrysolampus schwarzi parasitizes Tychius lineellus in Lupinus leucophyllus. Data are presented on phenology, sex ratio, mating and oviposition behaviour of adults, and behaviour and development of larvae and pupae. Ovipositional promiscuity (i.e., eggs are equally likely to be laid in pods infested or uninfested with weevil larvae) is documented in both species of Chrysolampus and discussed from a historical perspective. The immature stages of C. sisymbrii and C. schwarzi are described and illustrated using both light and scanning electron microscopy, and hypermetamorphic development is documented; the first-instar larva is morphologically distinct from the remaining larval instars. On the basis of both life history and morphology it is appropriate to refer to the first-instar larvae as planidia. The first-instar larva is sclerotized, mobile, and actively involved in host location and attack, and it is regarded as homologous to the planidia of the Eucharitidae and Perilampidae. Previous phylogenetic hypotheses regarding Chrysolampus, the Eucharitidae, and the Perilampidae are reevaluated and discussed in light of these new morphological, behavioural, and ecological data.
Host effects on the development and fecundity of gypsy moth, Lymantria dispar L., reared under field conditions
Authors: Hamilton Diana J. , Lechowicz Martin J.
Published: August 2008

We reared gypsy moth larvae outdoors under natural temperature and photoperiod regimes on red oak (Quercus rubra L.) and sugar maple (Acer saccharum Marsh). Initiation of the experiment coincident with the peak hatch of the local gypsy moth population assured normal synchrony between foliage quality and larval development. Compared with larvae reared on oak foliage, the mortality of maple-fed larvae is greatest and development slowest in the first instar. Overall, the larvae reared on sugar maple have higher mortality, extended development time, lower pupal weights, and lower fecundity relative to larvae reared on red oak. The mean diameter of individual eggs did not differ between oak- and maple-fed larvae, nor was the rate of increase in egg mass weight with female pupal weight host dependent. The egg masses from oak-fed moths hatched more completely than did those from moths reared on maple. In the interaction between these two abundant potential hosts and gypsy moths, the interspecific differences between the hosts are more important than any effects of seasonal asynchrony between larvae and foliar development. Gypsy moth larval success is much greater on red oak, and survival and reproduction on sugar maple under field conditions are likely to be marginal at best.
Histopathological changes in the olfactory organ of rainbow trout (Oncorhynchus mykiss) induced by early chronic exposure to a sublethal copper concentration
Authors: Saucier D. , Astic L. , Rioux P. , Godinot F.
Published: August 2008

Sequential histopathological changes related to a long-term sublethal copper exposure were investigated in the olfactory organ of rainbow trout, Oncorhynchus mykiss (formerly Salmo gairdneri Richardson, 1836). Fish were continuously exposed to an average copper level of 22 μg/L from the 14th day after fertilization (embryo group) or from hatching (alevin group) for a period of 41 and 37 weeks, respectively. A control group was reared in well water. Specimens of the exposed and the control groups were sacrificed every month for histological examination by light microscopy. Morphological alterations were identical in both embryo and alevin groups and appeared at the same posthatching periods. The first change, noted from the 8th week posthatch, was an increase in goblet cells. Epithelial lesions, which looked like patches of necrotic tissue randomly distributed in the olfactory sheet, were reported from the 28th week posthatch. From the 32nd week, cellular shrinkage related to degeneration and necrosis of individual cells led to a pattern of loose epithelium in many olfactory areas. These sequential histopathological changes suggest an initial increased mucus production which, however, does not appear effective enough to ensure long-term protection of the olfactory rosette. Stopping the copper exposure led to some morphological restoration. Ten weeks after copper removal, a few epithelial lesions and shrinkage were still noted. The delay between morphological and functional recoveries supports the concept of an anatomical redundancy of the epithelium-to-bulb connections.
Primary setae and pores on the cephalic capsule and head appendages of larval Hydroporinae (Coleoptera: Dytiscidae: Hydroporinae)
Authors: Alarie Y.
Published: August 2008

Through an analysis of the primary setae and pores of first-instar larvae of 30 Nearctic species of Hydroporinae (Coleoptera: Dytiscidae), 6 species belonging to other dytiscid subfamilies, and 1 species each of Amphizoidae, Gyrinidae, Haliplidae, Noteridae, and Hygrobiidae, the ancestral system of primary setae and pores of the cephalic capsule and head appendages of the Hydroporinae is deduced. Homology of setae and pores among larval Adephaga is attempted for all structures except the maxilla. Sixty-two setae and 39 pores have been assigned to the generalized hydroporine larva: 28 setae and 16 pores on the cephalic capsule, 5 setae and 8 pores on the antenna, 1 seta and 4 pores on the mandible, 15 setae and 3 pores on the labium, and 13 setae and 8 pores on the maxilla. Generic differences among the Hydroporinae are discussed in a phylogenetic perspective. Laccornis Des Gozis and Desmopachria Babington are confirmed as the first offshoot and the most derived lineage of Hydroporinae, respectively. Comparison of Desmopachria convexa with the Palaearctic Hyphydrus aubei Ganglbauer shows that they are closely similar, which suggests that Desmopachria convexa should remain a member of the Hyphydrini. There is much conflicting evidence suggestive of a more derived condition for Hygrotus Stephens (compared with Hydroporus Clairville). Oreodytes Seidlitz and Potamonectes Zimmermann share with Liodessus affinis (Say) and Desmopachria convexa a unique feature within the Hydroporinae: the absence of a maxillary cardo and insertion of seta 1 of the maxilla on the maxillary stipes. This feature might indicate a more derived condition for Oreodytes and Potamonectes within the Hydroporini.
Intraspecific genome size variation in a turtle (Trachemys scripta) exhibiting temperature-dependent sex determination
Authors: Lockwood Samuel F. , Holland Brenden S. , Bickham John W. , Hanks Brian G. , Bull James J.
Published: August 2008

Variation in genome size within and among populations of the pond slider, Trachemys scripta, a species with temperature-dependent sex determination, was investigated. Because genome size has been shown to affect developmental rate in various organisms, as does incubation temperature, it was hypothesized that genome size could influence sex determination in species with environmental sex determination. Significant variation in DNA content was found between geographic populations and among clutches. No significant differences in mean genome size were observed among samples incubated at different temperatures or between sexes of turtles hatched at a temperature that yields a mixed sex ratio. Thus, it appears that sex determination in T. scripta is accomplished in the absence of sex-specific and incubation-temperature-specific differences in genome size. Preliminary data from two populations, however, suggest that genome size may be significantly correlated with the threshold incubation temperature at which a mixed sex ratio is produced.
Ecology of Red-winged Blackbird parasitism by haematozoa
Authors: Weatherhead Patrick J. , Bennett Gordon F.
Published: August 2008

We sampled haematozoa in Red-winged Blackbirds (Agelaius phoeniceus) over three consecutive breeding seasons in eastern Ontario to identify factors that affect the reliability of quantifying parasites as this pertains to testing Hamilton and Zuk's hypothesis of sexual selection. Parasite prevalence and intensity varied seasonally, indicating that for samples to be reliable they should not be taken either early or late in the breeding season, and analysis should be limited to prevalence (presence versus absence). Among males (but not females), parasite prevalence increased with age, indicating that all individuals are not exposed to parasites early in life, and therefore tests of the "parasite" hypothesis of sexual selection are best restricted to older individuals. Resampling of known individuals within and between years showed that some individuals changed from positive to negative. Prevalence estimates also varied by year, indicating that reliable estimates of prevalence for a species, necessary for interspecific tests of the parasite hypothesis, will require extensive sampling. Overall, parasite prevalence did not vary with habitat. Parasites were detectable in only 1 of 119 nestlings sampled, indicating either lack of exposure or inadequate time for infections to reach detectable intensities. In either case, it is not possible to test the assumption that parasite resistance is heritable using blood samples from nestlings. Although males and females were parasitized by the same array of parasites, the distribution of specific parasites differed significantly (males were more heavily parasitized by leucocytozoids). If males and females generally differ in either exposure or resistance to specific parasites, the coevolutionary dynamics between host and parasite and the implications for sexual selection will require reassessment.
The number of fibers and range of fiber diameters in the cochlear nerve of three odontocete species
Authors: Guofu Gao , Kaiya Zhou
Published: August 2008

The total number of fibers and the range of fiber diameters in the cochlear nerve of three species of toothed whales were determined. There are 90 672 fibers in Lipotes vexillifer, 82 570 in Neophocaena phocaenoides, and 77 171 in Sousa chinensis. In Lipotes the fiber diameters range from 0.4 to 25.8 μm, with a modal diameter of 9.5 μm, and the largest fiber measures 35.2 μm; in Neophocaena, the diameter ranges from 0.6 to 36.0 μm, with a mode of 9.5 μm, and the largest fiber measures 54.9 μm; in Sousa the diameter ranges from 0.3 to 39.7 μm, with a mode of 8.5 μm and the largest fiber measures 50.3 μm. In Lipotes, Neophocaena, and Sousa, 1.5, 8.5, and 14.2%, respectively, of the cochlear fibers are ≥ 20 μm in diameter. Almost all the fibers are myelinated, and the ratio of the diameter of the axis cylinder to the outer diameter of the fiber in each species averages between 0.6 and 0.7. The high percentage of large fibers and the very wide range of fiber diameters indicate that the odontocete cochlear nerve is specialized for high-speed communication with the brain. The maximum diameters of the myelinated fibers of the cochlear nerve reported in this paper are the largest diameters recorded for the cranial nerve, or any other nerve, among the vertebrates.
The prenatal molt and its ecological significance in hooded and harbor seals
Authors: Oftedal Olav T. , Bowen W. Don , Widdowson Elsie M. , Boness Daryl J.
Published: August 2008

Hooded and harbor seals are unique among true seals (family Phocidae) in that the lanugo (fetal pelage) is typically shed in utero. Shedding had occurred in all newborn hooded seals examined off the Labrador coast (n = 62) and in 94% of newborn harbor seals on Sable Island, Nova Scotia (n = 110), although in one-fifth of the latter the molt was incomplete. In hooded seals the shed hair in the amniotic sac was organized into tightly woven disks, whereas in harbor seals the shed hair formed a loose mat with no evident structure. We examined hair masses in the intestines of pups of both species but could find no evidence that the intestines were involved in hair disk formation. We argue that fetal shedding, like prenatal blubber deposition, is an adaptation enabling newborn pups to enter cold water without adverse consequences. This ability allows the use of pupping substrates that are unstable or regularly inundated with water.
Female-biased sex ratio of immature loggerhead sea turtles inhabiting the Atlantic coastal waters of Florida
Authors: Wibbels Thane , Martin R. Erik , Owens David W. , Amoss Jr. Max S.
Published: August 2008

The sex ratio of immature loggerhead sea turtles, Caretta caretta, inhabiting the Atlantic coastal waters of Florida was investigated. Blood samples were obtained from 223 turtles that were captured in the intake channel of a power plant on Hutchinson Island. A serum androgen sexing technique was utilized to sex individual turtles. The sex ratio of the turtles (2.1 female: 1.0 male) differed significantly from 1:1 and thus appears to differ from predictions of sex allocation theory. These observations are consistent with those of a previous study, and collectively the results suggest that the sex ratio of immature C. caretta inhabiting the Atlantic coastal waters of the United States is significantly female biased: approximately two females per male.
The termination of spring display by male spruce grouse, and commencement of egg laying by females
Authors: Keppie Daniel M.
Published: August 2008

Whether the ability of males to attract renesting females (female attraction) adequately explains the termination, or the persistence, of display by male grouse in late spring was evaluated. In 7 of 8 years and (or) locations, advertising display (fluttering) by male spruce grouse (Dendragapus canadensis) at dawn ceased or became sporadic soon (≤9 days) after the median date on which females were estimated to have commenced laying eggs. Early cessation of display is consistent with the proposal that there is little reproductive gain for males in continuing to display if nesting success is high; hence, female nesting chronology drives the pattern of display by males in spring. Male–male interactions and colonizing effort, and the risk of display and the probability of survival to the next year, could also determine the timing of the cessation of display, and these factors are discussed, along with the female-attraction hypothesis.
Citrate synthase in the rainbow trout heart: regulation by pH, temperature, and metabolite levels
Authors: Ferguson R. A. , Storey K. B.
Published: August 2008

Crude homogenates of rainbow trout (Oncorhynchus mykiss) hearts have high citrate synthase activity (30 units per gram wet weight at 20 °C), reflecting the aerobic nature of this organ. Citrate synthase was purified 70-fold by polyethylene glycol fractionation followed by ion-exchange separation on phosphocellulose and DEAE columns. At 20 °C the partially purified enzyme displayed hyperbolic Michaelis–Menton-type substrate kinetics and an activity maximum at pH 8.5. The Km values for oxaloacetic acid and acetylcoenzyme A were 1.65 and 3.91 μM, respectively. Competitive inhibition with respect to oxaloacetic acid was seen with citrate (Ki = 8.80 mM) and α-ketoglutarate (Ki = 13.95 mM). Noncompetitive inhibition by ATP (Ki = 1.04 mM) with respect to oxaloacetic acid was observed. ATP (Ki = 0.382 mM) and NADH (Ki = 0.451 mM) were competitive inhibitors for acetylcoenzyme A. Citrate synthase activity is both pH- and temperate-dependent. Indeed, the temperature dependence (0–25 °C) is modified by pH. This is reflected by a decrease in the activation energy from 15.7 to 10.6 kcal/mol (65.63 to 44.30 kJ/mol) as the pH of the medium is increased from 7.05 to 7.80. These findings are discussed with respect to trout heart citrate synthase function in vivo.
Cells with affinity for periodic acid – Schiff are present in the pars intermedia of Atlantic salmon
Authors: Komourdjian Martin P. , Saunders Richard L.
Published: August 2008

Examination of pituitaries from two populations of Atlantic salmon (Salmo salar) parr held under natural photoperiods revealed at least two histologically distinct cell types. One type has fine granules with affinity for lead hematoxylin (PIPbH). Another type, hitherto believed to be absent in salmonids, has larger granules which are Schiff-positive (PIPAS). These cells are significantly (P < 0.05) shorter and narrower and have significantly smaller nuclei (P < 0.05) than the PIPbH type. No evidence was found for ascribing to the PIPAS cells the functions assigned to them in other species: melanophore control and reproduction. However, PIPAS granules became evident only during fall-winter, when the smolting process begins. The incidence of these cells rose and then declined sharply during this period, suggesting a possible role in some aspect of smoltification. While the role of these PIPAS cells deserves further study, their presence is in itself important from an evolutionary point of view.
Description of Isospora schlegeli sp.nov. (Apicomplexa: Eimeriidae) from gekkonid lizards in the South Pacific
Authors: Upton Steve J. , Hanley Kathy , Case Ted J. , McAllister Chris T.
Published: August 2008

A new species of coccidian was recovered from feces of Hemidactylus frenatus (type host) and Lepidodactylus lugubris from the South Pacific. Oocysts of Isospora schlegeli sp.nov. are subspherical, 17.8 × 15.8 (13.6–20.0 × 12.8–18.0) μm; shape index 1.13 (1.06–1.25). Micropyle and oocyst residuum absent, polar granule present. Sporocysts ovoidal, 10.0 × 7.5 (8.8–11.8 × 6.6–9.0) μm, with Stieda and substieda bodies; shape index 1.33 (1.20–1.51). Sporozoites each with anterior and posterior refractile bodies. In addition, oocysts of Eimeria furmani, Eimeria dixoni, and Isospora frenatus were collected from both the above hosts and an unnamed elongate Eimeria sp. of Yamamoto (K. Yamamoto. 1933. Fukuoka Igaku Zasshi. 26: 40–43) were seen in H. frenatus.
IMPURITY EFFECTS ON THE ENTANGLEMENT OF SPIN-ONE HEISENBERG MODEL
Authors: HU MING-LIANG
Published: August 2008

The entanglement characteristics of the three-qutrit spin-one Heisenberg chain in the presence of one impurity site is investigated by using the concept of negativity. The results show that the existence of impurity can lead to an enhancement of both bipartite and pairwise entanglement for certain ranges of the impurity parameter, and the amount of entanglement can be controlled and tuned by varying the impurity parameter J1. The results also show that the thermal fluctuations always suppress the entanglement and as a result there exists a threshold temperature Tth after which the entanglement vanishes. Tth increases as J1 increases except the case for that of the pairwise negativity [Formula: see text] which measures entanglement between the two norm spins in the chain.
Influence of the Drain Bias and Gate Length of Partially Depleted SOI MOSFETs on the ZTC Biasing Point
Authors: Camillo Luciano M. , Martino João A. , Simoen Eddy , Claeys Cor
Published: August 2008

This paper presents the influence of the drain bias and gate length of partially depleted SOI MOSFETs on the Zero Temperature Coefficient (ZTC) for devices operating at high temperatures (from room temperature up to 573K). The analysis takes into account temperature dependent model parameters such as threshold voltage and mobility. The analytical predictions are in very close agreement with experimental results in spite of the simplification used for the VZTC model as a function of temperature in the linear and the saturation region.
High-k Gate-Dielectrics Based on Titanium-Aluminum for Sub-32 Nm CMOS Technology
Authors: Miyoshi Juliana , Wada Ricardo , De Barros Angélica D. , Von Zuben A. A. , Cavarsan F. A. , Doi Ioshiaki , Diniz José A.
Published: August 2008

High k insulators for the next generation (sub-32 nm CMOS (complementary metal-oxide-semiconductor) technology), such as titanium-aluminum oxynitride (TiwAlxOyNz) and titanium-aluminum oxide (TiwAlxOy), have been obtained by Ti/Al e-beam evaporation, with additional electron cyclotron resonance (ECR) plasma oxynitridation and oxidation on Si substrates, respectively. The physical thickness values between 5.7 nm and 6.3 nm were determined by ellipsometry. These films have been used as gate insulators in MOS capacitors, which were fabricated with Al electrodes and final sintering time at 4500C for 10 min in forming gas. These capacitors were used to obtain capacitance-voltage (C-V) measurements. A relative dielectric constant of 3.9 was adopted to extract the Equivalent Oxide Thickness of films from C-V curves under strong accumulation condition, resulting in values between 1.9 and 1.7 nm, and the effective charge densities of about 1011 cm-2. These results indicate that the obtained TiwAlxOyNz and TiwAlxOy films are suitable gate insulators for the next generation (MOS) devices.
Local Anodic Oxidation Induced by Electric Fields of MV/cm at AFM Silicon Nitride Tips on Silicon Surfaces
Authors: Pinto Diego K. , Dos Santos Filho Sebastião G.
Published: August 2008

Local anodic oxidation of silicon using Atomic Force Microscopy (AFM) was investigated by applying a negative voltage between a silicon nitride tip and p+doped Si (111) surfaces. Numerical simulations of the electric field at the silicon nitride tip apex on the silicon presented values next to 1x106 V/cm, which is ten times lower than that obtained from conductive tips. In addition, a last ammonium-based cleaning known as standard cleaning 1 (SC1) was a necessary pre-conditioning for anodic oxidation to occur using negative applied potentials (Vtip) ranging from -15 to -22.5V. The anodic oxidation was performed from 0 to 144 hours after SC1. Localized squares patterns of oxide, 0.25 μm2 in area, were formed by growing parallel lines with constant interlinear spacing and length and several scans in the same area. It was noteworthy that oxide thickness increased with the applied negative voltage, number of scans and interval of time after SC1. As a result, the high hydrophilic characteristic of the SC1-last cleaning allowed establishing a local oxidation process assisted by lower electric fields (1x106 V/cm) and by diffusion of ionic species generated from adsorbed water after SC1.
A Computer Based Optimization Method for Quantum Dots Growth
Authors: Singulani Anderson , Vilela Neto Omar P. , Pacheco Marco Aurélio C. , Pires Mauricio P. , Souza Patricia L.
Published: August 2008

We apply two computational intelligence techniques, namely, Artificial Neural Network and Genetic Algorithm to the growth of self-assembled quantum dots. The method relies on an existing database of growth parameters with a resulting quantum dot characteristic to be able to later obtain the growth parameters needed to reach a specific value for such a quantum dot characteristic. The computational techniques were used to associate the growth input parameters with the mean height of the deposited quantum dots.
Evidence for an Intraband Auger Effect in InAs/InGaAlAs/InP Quantum Dot Structures
Authors: Gebhard Thomas , Alvarenga Deborah , Souza Patricia L. , Guimarães Paulo Sergio S. , Unterrainer Karl , Pires Mauricio P. , Vieira Gustavo S. , Villas-Boas José Maria
Published: August 2008

InAs quantum dots grown on InGaAlAs lattice matched to InP have been investigated for use in quantum dot infrared photodetectors. Intraband photocurrent of samples with different doping levels have been measured and with the help of a 3D effective mass calculation, the main absorption peak has been identified. Moreover, the reported results strongly suggest that an Auger process plays a fundamental role in generating the observed intraband photocurrent.
Towards 21% Efficiency Silicon Solar Cells with Rear Passivation in Non-Ultra Clean Facilities: the Development of a Simplified Fabrication Process Achieving 670mV/ 660mV Open-Circuit Voltages using FZ and Cz Silicon Wafers
Authors: Stem Nair , Cid Manuel , Ramos Carlos Alberto S.
Published: August 2008

The development of a simple fabrication process of silicon solar cells n+p with rear passivation is presented. Each optimized step was monitored by the photoconductive decay technique. The starting materials presented thickness about 300micron and low resistivity: FZ (0.5Ohm.cm), Cz - type 1 (2.5Ohm.cm) and Cz - type 2 (3.3Ohm.cm). The Gaussian profile emitters were optimized with sheet resistance between 55Ohm/sq and 100Ohm/sq. After alneal, the maximum effective lifetimes measured at the excess carrier concentration corresponding to 1 Sun operation point at open-circuit condition were approximately 0.09ms, 0.25ms and 0.35ms for FZ, Cz-type 1 and Cz-type 2, accordingly. Excellent implied open-circuit voltages of 670.8mV, 652.5mV and 662.6mV, respectively could be associated to these measured lifetimes, representing solar cell efficiencies up to 20% if a low cost anti-reflection coating system random pyramids and SiO2 layer is considered, even if a typical industrial wafer (Cz silicon with low resistivity) is use
Diffractive Optical Elements Based in Brand Glass
Authors: Sparvoli Marina , Mansano Ronaldo D. , Chubaci José Fernando D.
Published: August 2008

A Diffractive Optical Element (DOE) based in optical glass substrate was developed in this work. DOEs are lighter, occupy a relatively smaller volume and they can be fabricated using microelectronic processes. These devices had been built by glass etching: first, glass substrate was submitted to a cleanness process; after it was carried through a process of evaporation of an aluminum mask, which will be used to format the device. Before the etching process, a small layer of photo resist was deposited on aluminum, a lithographic process and wet process defines a pattern on the aluminum layer. Plasma etching was made by RIE (Reactive Ion Etching) equipment, remaining the diffractive patterns. The characterizations of these devices are performed by optical analyzes with a 633 nm HeNe laser. The roughness and etch rate of materials after etch process were obtained by Atomic Force Microscopy and high step meter.
Thermal Oxide Passivation by Corona Charges
Authors: Ramos Carlos Alberto S. , Sánchez Manuel C. , Onmori Roberto K. , Stem Nair
Published: August 2008

High quality oxidation, following the same steps usually employed in the fabrication of high efficiency silicon solar cells in open tube furnaces (tube pre-cleaning, ramps at low temperatures, oxidation in TCA ambient, etc.), were produced on high quality FZ and Cz, p-type, silicon samples in order to investigate the passivation effect of corona charges deposited over their front and rear surfaces. The samples were characterized, before and after this passivation process, by means of lifetime measurements, using the WCT-100 lifetime tester apparatus, in a wide range of injection levels (from 0 to 1000 suns), allowing the extraction of recombination parameters and bulk properties of the wafers. We have not found any significant difference in results when compared to other, more complex and expensive, passivation schemes, like forming gas annealing (FG annealing) and aluminum annealing (alneal).
Design of Disc-Shaped Tool in Electrochemical Removal of Displays' Color Filter Reclaim Process
Authors: Pa P.S.
Published: August 2008

A new design system using a disc-shaped cathode as a tool electrode and electrochemical removal as a precision reclaiming process of ITO thin-film removal from optoelectronic flat panel displays' color filter surface is presented. The electrochemical machining just needs quite a short time to remove the ITO film easily and cleanly. In the current experiment, a large major axis of the disc-shaped cathode or a small minor axis of the disc-shaped cathode corre-sponds to a higher removal rate for the ITO thin-film. A large flow rate of the electrolyte, a higher temperature, a high rotational speed of the electrodes, or a higher concentration of the electrolyte corresponds to a higher removal rate for ITO thin-film. Pulsed direct current can improve the effect of dreg discharge and is advantageous to be associated with the fast feed rate of the workpiece, but this raises the current rating. A higher feed rate of displays' color filter combined with enough electric power produces fast electrochemical removal. Through the ultra-precise removal of thin film microstructure, the semiconductor optoelectronic industry can effectively recycle defective products, reducing production costs.
Waferlevel Vacuum Packaging: Essential for Microscanners in Mobile Applications
Authors: Oldsen Marten , Hofmann Ulrich , Quenzer Hans-Joachim , Reinert Wolfgang , Wagner Bernd
Published: August 2008

MEMS scanning mirrors are a key part of miniaturized laser based display systems. Due to their small outline and high performance these systems are supposed to be integrated into next generation mobile devices such as cellular phones or PDAs. But mobile applications demand for ruggedness against harsh environmental conditions, which can only be guaranteed by a hermetic package. Packaging of MEMS is an important expense factor within the production costs and to ensure mass producibility the packaging has to be done on a wafer level. While for inertial MEMS this is state of the art, it has not yet been reported for MOEMS. Therefore, Fraunhofer ISIT has developed a complete process technology for the manufacturing of wafer level vacuum packaged MEMS scanning mirrors. It allows the fabrication of vertical stacked combdrives for quasistatic mirror operation and a low damping environment for the reduction of needed driving signals. It has been achieved that scan angles of above 50 deg can be reached even at a low driving voltage of below 6 V.
Ether-linked diglycerides inhibit vascular smooth muscle cell growth via decreased MAPK and PI3K/Akt signaling
Authors: Houck Kristy L. , Fox Todd E. , Sandirasegarane Lakshman , Kester Mark
Published: August 2008

Diglycerides (DGs) are phospholipid-derived second messengers that regulate PKC-dependent signaling pathways. Distinct species of DGs are generated from inflammatory cytokines and growth factors. Growth factors increase diacyl- but not ether-linked DG species, whereas inflammatory cytokines predominately generate alkyl, acyl- and alkenyl, acyl-linked DG species in rat mesenchymal cells. These DG species have been shown to differentially regulate protein kinase C (PKC) isotypes. Ester-linked diacylglycerols activate PKC-ε and cellular proliferation in contrast to ether-linked DGs, which lead to growth arrest through the inactivation of PKC-ε. It is now hypothesized that ether-linked DGs inhibit mitogenesis through the inactivation of ERK and/or Akt signaling cascades. We demonstrate that cell-permeable ether-linked DGs reduce vascular smooth muscle cell growth by inhibiting platelet-derived growth factor-stimulated ERK in a PKC-ε-dependent manner. This inhibition is specific to the ERK pathway, since ether-linked DGs do not affect growth factor-induced activation of other family members of the MAPKs, including p38 MAPK and c-Jun NH2-terminal kinases. We also demonstrate that ether-linked DGs reduce prosurvival phosphatidylinositol 3-kinase (PI3K)/Akt signaling, independent of PKC-ε, by diminishing an interaction between the subunits of PI3K and not by affecting protein phosphatase 2A or lipid (phosphatase and tensin homologue deleted in chromosome 10) phosphatases. Taken together, our studies identify ether-linked DGs as potential adjuvant therapies to limit vascular smooth muscle migration and mitogenesis in atherosclerotic and restenotic models.
Embryonic stem cells attenuate myocardial dysfunction and inflammation after surgical global ischemia via paracrine actions
Authors: Crisostomo Paul R. , Abarbanell Aaron M. , Wang Meijing , Lahm Tim , Wang Yue , Meldrum Daniel R.
Published: August 2008

Stem cell treatment may positively influence recovery and inflammation after shock by multiple mechanisms, including the paracrine release of protective growth factors. Embryonic stem cells (ESCs) are understudied and may have greater protective power than adult bone marrow stem cells (BMSCs). We hypothesized that ESC paracrine protective mechanisms in the heart (decreased injury by enhanced growth factor-mediated reduction of proinflammatory cytokines) would be superior to the paracrine protective mechanisms of the adult stem cell population in a model of surgically induced global ischemia. Adult Sprague-Dawley rat hearts were isolated and perfused via Langendorff model. Hearts were subjected to 25 min of warm global ischemia and 40 min of reperfusion and were randomly assigned into one of four groups: 1) vehicle treated; 2) BMSC or ESC preischemic treatment; 3) BMSC or ESC postischemic treatment; and 4) BMSC- or ESC-conditioned media treatment. Myocardial function was recorded, and hearts were analyzed for expression of tissue cytokines and growth factors (ELISA). Additionally, ESCs and BMSCs in culture were assessed for growth factor production (ELISA). ESC-treated hearts demonstrated significantly greater postischemic recovery of function (left ventricular developed pressure, end-diastolic pressure, and maximal positive and negative values of the first derivative of pressure) than BMSC-treated hearts or controls at end reperfusion. ESC-conditioned media (without cells) also conferred cardioprotection at end reperfusion. ESC-infused hearts demonstrated increased VEGF and IL-10 production compared with BMSC hearts. ESC hearts also exhibited decreased proinflammatory cytokine expression compared with MSC hearts. Moreover, ESCs in cell culture demonstrated greater pluripotency than MSCs. ESC paracrine protective mechanisms in surgical ischemia are superior to those of adult stem cells.
The ubiquitin ligase Nedd4 mediates oxidized low-density lipoprotein-induced downregulation of insulin-like growth factor-1 receptor
Authors: Higashi Yusuke , Sukhanov Sergiy , Parthasarathy Sampath , Delafontaine Patrice
Published: August 2008

Oxidized low-density lipoprotein (LDL) is proatherogenic and induces smooth muscle cell apoptosis, which contributes to atherosclerotic plaque destabilization. We showed previously that oxidized LDL downregulates insulin-like growth factor-1 receptor in human smooth muscle cells and that this is critical for induction of apoptosis. To identify mechanisms, we exposed smooth muscle cells to 60 μg/ml oxidized LDL or native LDL and assessed insulin-like growth factor-1 receptor mRNA levels, protein synthesis rate, and receptor protein stability. Oxidized LDL decreased insulin-like growth factor-1 receptor mRNA levels by 30% at 8 h compared with native LDL, and this decrease was maintained for up to 20 h. However, insulin-like growth factor-1 receptor protein synthesis rate was not altered by oxidized LDL. Pulse-chase labeling experiments revealed that oxidized LDL reduced insulin-like growth factor-1 receptor protein half-life to 12.2 ± 1.7 h from 24.4 ± 4.7 h with native LDL. This destabilization of insulin-like growth factor-1 receptor protein was accompanied by enhanced receptor ubiquitination. Overexpression of dominant-negative Nedd4 prevented oxidized LDL-induced downregulation of insulin-like growth factor-1 receptor, suggesting that Nedd4 was the ubiquitin ligase that mediated receptor downregulation. However, the proteasome inhibitors lactacystin, MG-132, and proteasome inhibitor-1 failed to block oxidized LDL-induced downregulation of insulin-like growth factor-1 receptor. Thus oxidized LDL downregulates insulin-like growth factor-1 receptor by destabilizing the protein via Nedd4-enhanced ubiquitination, leading to degradation via a proteasome-independent pathway. This finding provides novel insights into oxidized LDL-triggered oxidant signaling and mechanisms of smooth muscle cell depletion that contribute to plaque destabilization and coronary events.
Inhibition of vascular smooth muscle G protein-coupled receptor kinase 2 enhances α1D-adrenergic receptor constriction
Authors: Cohn Heather Irina , Harris David M. , Pesant Stephanie , Pfeiffer Michael , Zhou Rui-Hai , Koch Walter J. , Dorn Gerald W. , Eckhart Andrea D.
Published: August 2008

G protein-coupled receptor kinase 2 (GRK2) is a serine/theorinine kinase that phosphorylates and desensitizes agonist-bound G protein-coupled receptors. GRK2 is increased in expression and activity in lymphocytes and vascular smooth muscle (VSM) in human hypertension and animal models of the disease. Inhibition of GRK2 using the carboxyl-terminal portion of the protein (GRK2ct) has been an effective tool to restore compromised β-adrenergic receptor (AR) function in heart failure and improve outcome. A well-characterized dysfunction in hypertension is attenuation of βAR-mediated vasodilation. Therefore, we tested the role of inhibition of GRK2 using GRK2ct or VSM-selective GRK2 gene ablation in a renal artery stenosis model of elevated blood pressure (BP) [the two-kidney, one-clip (2K1C) model]. Use of the 2K1C model resulted in a 30% increase in conscious BP, a threefold increase in plasma norepinephrine levels, and a 50% increase in VSM GRK2 mRNA levels. BP remained increased despite VSM-specific GRK2 inhibition by either GRK2 knockout (GRK2KO) or peptide inhibition (GRK2ct). Although βAR-mediated dilation in vivo and in situ was enhanced, α1AR-mediated vasoconstriction was also increased. Further pharmacological experiments using α1AR antagonists revealed that GRK2 inhibition of expression (GRK2KO) or activity (GRK2ct) enhanced α1DAR vasoconstriction. This is the first study to suggest that VSM α1DARs are a GRK2 substrate in vivo.
Mice expressing BMPR2R899X transgene in smooth muscle develop pulmonary vascular lesions
Authors: West James , Harral Julie , Lane Kirk , Deng Yupu , Ickes Brian , Crona Daniel , Albu Sebastian , Stewart Duncan , Fagan Karen
Published: August 2008

Familial pulmonary arterial hypertension (PAH) is associated with mutations in bone morphogenetic protein type II receptor (BMPR2). Many of these mutations occur in the BMPR2 tail domain, leaving the SMAD functions intact. To determine the in vivo consequences of BMPR2 tail domain mutation, we created a smooth muscle-specific doxycycline-inducible BMPR2 mutation with an arginine to termination mutation at amino acid 899. When these SM22-rtTA x TetO7-BMPR2R899X mice had transgene induced for 9 wk, starting at 4 wk of age, they universally developed pulmonary vascular pruning as assessed by fluorescent microangiography. Approximately one-third of the time, the induced animals developed elevated right ventricular systolic pressures (RVSP), associated with extensive pruning, muscularization of small pulmonary vessels, and development of large structural pulmonary vascular changes. These lesions included large numbers of macrophages and T cells in their adventitial compartment as well as CD133-positive cells in the lumen. Small vessels filled with CD45-positive and sometimes CD3-positive cells were a common feature in all SM22-rtTA x TetO7-BMPR2R899X mice. Gene array experiments show changes in stress response, muscle organization and function, proliferation, and apoptosis and developmental pathways before RVSP increases. Our results show that the primary phenotypic result of BMPR2 tail domain mutation in smooth muscle is pulmonary vascular pruning leading to elevated RVSP, associated with early dysregulation in multiple pathways with clear relevance to PAH. This model should be useful to the research community in examining early molecular and physical events in the development of PAH and as a platform to validate potential treatments.
AICAR decreases the activity of two distinct amiloride-sensitive Na+-permeable channels in H441 human lung epithelial cell monolayers
Authors: Albert A. P. , Woollhead A. M. , Mace O. J. , Baines D. L.
Published: August 2008

Transepithelial transport of Na+ across the lung epithelium via amiloride-sensitive Na+ channels (ENaC) regulates fluid volume in the lung lumen. Activators of AMP-activated protein kinase (AMPK), the adenosine monophosphate mimetic AICAR, and the biguanide metformin decreased amiloride-sensitive apical Na+ conductance (GNa+) in human H441 airway epithelial cell monolayers. Cell-attached patch-clamp recordings identified two distinct constitutively active cation channels in the apical membrane that were likely to contribute to GNa+: a 5-pS highly Na+ selective ENaC-like channel (HSC) and an 18-pS nonselective cation channel (NSC). Substituting NaCl with NMDG-Cl in the patch pipette solution shifted the reversal potentials of HSC and NSC, respectively, from +23 mV to −38 mV and 0 mV to −35 mV. Amiloride at 1 μM inhibited HSC activity and 56% of short-circuit current ( Isc), whereas 10 μM amiloride partially reduced NSC activity and inhibited a further 30% of Isc. Neither conductance was associated with CNG channels as there was no effect of 10 μM pimoside on Isc, HSC, or NSC activity, and 8-bromo-cGMP (0.3–0.1 mM) did not induce or increase HSC or NSC activity. Pretreatment of H441 monolayers with 2 mM AICAR inhibited HSC/NSC activity by 90%, and this effect was reversed by the AMPK inhibitor Compound C. All three ENaC proteins were identified in the apical membrane of H441 monolayers, but no change in their abundance was detected after treatment with AICAR. In conclusion, activation of AMPK with AICAR in H441 cell monolayers is associated with inhibition of two distinct amiloride-sensitive Na+-permeable channels by a mechanism that likely reduces channel open probability.
Adenoviral endoplasmic reticulum–targeted mda-7/interleukin-24 vector enhances human cancer cell killing
Authors: Pataer Abujiang , Hu Wenxian , Xiaolin Lu , Chada Sunil , Roth Jack A. , Hunt Kelly K. , Swisher Stephen G.
Published: August 2008

We developed several adenoviral vectors designed to target MDA-7 expression to different subcellular compartments [endoplasmic reticulum (ER), mitochondria, nucleus, and cytosol] and evaluated their ability to enhance apoptosis. Adenoviral ER-targeted mda-7/interleukin-24 vector (Ad-ER-mda7) selectively and effectively inhibited the growth and proliferation of lung (A549 and H1299) and esophageal (Seg1 and Bic1) cancer cells by enhancing cell killing. Both Ad-mda7 and Ad-ER-mda7 activated a novel pathway of ER stress-induced apoptosis characterized by unregulated expression of phosphorylated JNK, phosphorylated c-Jun, and phosphorylated RNA-dependent protein kinase. Caspase-4 activation mediated Ad-mda7- and Ad-ER-mda7-induced cell death. In addition, Ad-mda7- and Ad-ER-mda7-mediated growth inhibition correlated with activation of ER molecular markers RNA-dependent protein kinase and JNK both in vitro (in Ad-mda7- or Ad-ER-mda7-treated lung cancer cells) and in vivo. These findings suggest that vectors targeting the ER (Ad-ER-mda7) may be more effective in cancer gene therapy possibly through more effective induction or ER stress pathways. [Mol Cancer Ther 2008;7(8):2528–35]
Z3, a novel Jak2 tyrosine kinase small-molecule inhibitor that suppresses Jak2-mediated pathologic cell growth
Authors: Sayyah Jacqueline , Magis Andrew , Ostrov David A. , Allan Robert W. , Braylan Raul C. , Sayeski Peter P.
Published: August 2008

Jak2 tyrosine kinase is essential for animal development and hyperkinetic Jak2 function has been linked to a host of human diseases. Control of this pathway using Jak2-specific inhibitors would therefore potentially serve as a useful research tool and/or therapeutic agent. Here, we used a high-throughput program called DOCK to predict the ability of 20,000 small molecules to interact with a structural pocket adjacent to the ATP-binding site of murine Jak2. One small molecule, 2-methyl-1-phenyl-4-pyridin-2-yl-2-(2-pyridin-2-ylethyl)butan-1-one (herein designated as Z3), bound to Jak2 with a favorable energy score. Z3 inhibited Jak2-V617F and Jak2-WT autophosphorylation in a dose-dependent manner but was not cytotoxic to cells at concentrations that inhibited kinase activity. Z3 selectively inhibited Jak2 kinase function with no effect on Tyk2 or c-Src kinase function. Z3 significantly inhibited proliferation of the Jak2-V617F-expressing, human erythroleukemia cell line, HEL 92.1.7. The Z3-mediated reduction in cell proliferation correlated with reduced Jak2 and STAT3 tyrosine phosphorylation levels as well as marked cell cycle arrest. Finally, Z3 inhibited the growth of hematopoietic progenitor cells isolated from the bone marrow of an essential thrombocythemia patient harboring the Jak2-V617F mutation and a polycythemia vera patient carrying a Jak2-F537I mutation. Collectively, the data suggest that Z3 is a novel specific inhibitor of Jak2 tyrosine kinase. [Mol Cancer Ther 2008;7(8):2308–18]