bluuebunny/crossref_metadata_2025 huggingface dataset:
On the elastic effects in power-law indentation creep with sharp conical indenters
Authors: Alkorta Jon , Martínez-Esnaola José Manuel , Sevillano Javier Gil
Published: March 2008

The elastic deformation contribution can significantly affect the measurement of the strain-rate sensitivity (SRS) of the plastic flow stress by indentation methods. In this paper, the effect of such elastic contribution is critically analyzed using an extension of a previous treatment developed by the authors for the elastic effects on the indentation of strain-hardening materials [J. Alkorta et al., J. Mater. Res.20, 432 (2005)]. The analytical model is calibrated and validated through finite element calculations. The results show that when the elastic contribution to the total deformation is not negligible then the measured SRS is significantly lower than the real one. A satisfactory correction factor for the apparent SRS exponent is proposed based on parameters directly accessible to instrumented indentation test results.
Determination of the effective zero point of contact for spherical nanoindentation
Authors: Moseson Alexander J. , Basu Sandip , Barsoum Michel W.
Published: March 2008

Accurate determination of the “zero point,” the first contact between an indenter tip and sample surface, has to date remained elusive. In this article, we outline a relatively simple, objective procedure by which an effective zero point can be determined accurately and reproducibly using a nanoindenter equipped with a continuous stiffness measurement option and a spherical tip. The method relies on applying a data shift, which ensures that curves of stiffness versus contact radius are linear and go through the origin. The method was applied to fused silica, sapphire single crystals, and polycrystalline iron with various indenter sizes to a zero-point resolution of ≈2 nm. Errors of even a few nanometers can drastically alter plots and calculations that use the data, including curves of stress versus strain.
Polymorphism in the negative thermal expansion material magnesium hafnium tungstate
Authors: Gindhart Amy M. , Lind Cora , Green Mark
Published: March 2008

Magnesium hafnium tungstate [MgHf(WO4)3] was synthesized by high-energy ball milling followed by calcination. The material was characterized by variable- temperature neutron and x-ray diffraction. It crystallized in space group P21/a below 400 K and transformed to an orthorhombic structure at higher temperatures. The orthorhombic polymorph adopted space group Pnma, instead of the Pnca structure commonly observed for other A2(MO4)3 materials (A = trivalent metal, M = Mo, W). In contrast, the monoclinic polymorphs appeared to be isostructural. Negative thermal expansion was observed in the orthorhombic phase with αa = −5.2 × 10−6 K−1, αb = 4.4 × 10−6 K−1, αc = −2.9 × 10−6 K−1, αV = −3.7 × 10−6 K−1, and αl = −1.2 × 10−6 K−1. The monoclinic to orthorhombic phase transition was accompanied by a smooth change in unit-cell volume, indicative of a second-order phase transition.
Inhibition of interfacial embrittlement at SnBi/Cu single crystal by electrodeposited Ag film
Authors: Zhu Q.S. , Zhang Z.F. , Wang Z.G. , Shang J.K.
Published: March 2008

Electrodeposited Ag film was explored as a potential interfacial barrier to Bi segregation for suppressing the interfacial embrittlement of Cu/SnBi interconnects. The presence of Ag film introduced Ag3Sn intermetallic layer at the interface, which effectively prevented Bi from reaching the Cu/intermetallic interface. When the persistent slip bands (PSBs) in the Cu single crystal were driven to impinge the Cu/Cu3Sn interface, interfacial cracking was averted and instead superceded by cracking of intermetallic compounds (IMCs) at the interface.
Phase identification from electronic structures by Auger electron spectroscopy
Authors: Xu Fuchun , Cai Duanjun , Kang Junyong
Published: March 2008

A technique of phase identification from the characteristics of electronic structures is established by Auger electron spectroscopy. GaN epilayers in wurtzite and zinc-blende polytypes are used for practical investigations. Auger spectra show phase-dependent energetic shifts and peak intensity variations. Simulation of theoretical spectra reveals the substantial correlation of the Auger line shape with the bonding electronic states. This approach demonstrates the correspondence between electronic structure and atomic structure and hence provides criteria for phase identification.
Transmission electron microscopy microstructural characterization of Ti–Si–C–N coatings
Authors: Guo Yan , Ma Shengli , Xu Kewei , Bell Tom , Li Xiaoying , Dong Hanshan
Published: March 2008

A new type of Ti–Si–C–N coatings deposited on high-speed steel substrate by means of pulsed direct current (dc) plasma-enhanced chemical vapor deposition was investigated. The as-deposited coatings were characterized systematically by using energy-dispersive x-ray spectroscopy, x-ray diffraction (XRD), transmission electron microscopy (TEM), and microhardness with particular attention paid to the microstructure of the coatings. It has been shown that C content has a profound effect on the microstructure and hardness of coatings. TEM and XRD analyses revealed that these coatings consist of the dominate Ti(C, N) with a silicide (TiSi2, Si3N4, or SiC, depending on the C content in the coatings). The crystallite sizes are in the range of 8–35 nm, which decrease with increasing C content. The Ti–Si–C–N coatings with high C content (25.2–38.6 at.%) possess superhardness (41–48 GPa). This can be attributed to the grain refinement/grain boundary hardening and dispersion hardening of the hard, nanosized crystalline Si3N4 or SiC formed in the deposition.
Analysis of macroscopic crack branching patterns in chemically strengthened glass
Authors: Kooi J.E. , Tandon R. , Glass S.J. , Mecholsky J.J.
Published: March 2008

Residual stress profiles were introduced in sodium aluminosilicate glass disks using an ion-exchange process. They were fractured in two loading conditions: indentation and biaxial flexure. The fractal dimension of the macroscopic crack branching pattern called the crack branching coefficient (CBC), as well as the number of fragments (NOF) were used to quantify the crack patterns. The fracture surfaces were analyzed to determine the stresses responsible for the crack branching patterns. The total strain energy in the body was calculated. The CBC was a good measure of the NOF. They are directly related to the tensile strain energy due to the residual stress profile for fractures due to indentation loading. However, in general for materials with residual stresses, CBC (or NOF) is not related to the strength or the stress at fracture, or even to the total stored tensile strain energy. Instead, the CBC appears to be related, in a complex manner, to the distribution of stresses in the body. Therefore, in general, the characterization of the CBC of fractured materials cannot be used to ascertain the prior stress distribution.
Effects of Zr/Ti ratio and post-annealing temperature on the electrical properties of lead zirconate titanate (PZT) thick films fabricated by aerosol deposition
Authors: Hahn Byung-Dong , Park Dong-Soo , Choi Jong-Jin , Yoon Woon-Ha , Ryu Jungho , Kim Doh-Yeon
Published: March 2008

The effects of the Zr/Ti ratio on the electrical properties of lead zirconate titanate (PZT) thick films prepared by the aerosol deposition (AD) process were investigated to optimize the electrical properties of the thick film. The Zr/Ti ratio was varied among 45/55, 52/48, and 60/40, and the post-annealing temperature was varied from 500 to 900 °C. Microscopic examination of the as-deposited films revealed crack-free and dense microstructures with a thickness of 10 μm. The annealed films showed markedly improved electrical properties in comparison with the as-deposited films with increasing post-annealing temperature. With increasing Zr/Ti ratio, the remnant polarization and coercive field decreased. The dielectric constant and piezoelectric coefficient,d33, were highest for the PZT 52/48 film. This film annealed at 900 °C exhibited the best overall combination of electrical properties, with a dielectric constant, remnant polarization, and piezoelectric coefficient of 1320, 31.1 μC/cm2, and 150 pC/N, respectively.
Propagation of shear bands in a Cu47.5Zr47.5Al5 bulk metallic glass
Authors: Kim K.B. , Das J. , Lee M.H. , Yi S. , Fleury E. , Zhang Z.F. , Wang W.H. , Eckert J.
Published: March 2008

We report a novel finding of slither propagation of shear bands on the fracture surface of a Cu47.5Zr47.5Al5 bulk metallic glass (BMG). The nanoscale heterogeneities in the as-cast state are aggregated along shear bands with irregular morphology. Such heterogeneities create a fluctuating stress field during shear band propagation leading to a slither propagation mode. The slither propagation of 10 to 15 nm wide shear bands is effective to improve both the plasticity and the “work-hardening-like” behavior of BMGs if the size, the morphology, and the elastic properties of the heterogeneities are intimately intercalated during solidification.
Tilted domain growth of metalorganic chemical vapor (MOCVD)-grown ZnO(0001) on α-Al2O3(0001)
Authors: Wang C.M. , Saraf L.V. , Hubler T.L. , Nachimuthu P.
Published: March 2008

ZnO grown on α-Al2O3(0001) generally possesses an orientation such that α-Al2O3(0001) is parallel to ZnO(0001) and two in-plane domains nucleate, so that α-Al2O3[11¯20] is parallel to ZnO[11¯20] and/or α-Al2O3[11¯20] is parallel to ZnO[10¯10]. In this paper, we report a new growth mode for ZnO grown on α-Al2O3(0001) using metalorganic chemical vapor deposition (MOCVD). We find that α-Al2O3[11¯20] is parallel to ZnO[10¯10], but the (0001) plane of ZnO is tilted relative to the (0001) plane of α-Al2O3 such that ZnO(0001) is almost parallel to the α-Al2O3(¯1104) plane. This orientation reduces the extent of lattice mismatch. The interface between ZnO and α-Al2O3 is abrupt and possesses periodic dislocations.
Synthesis and characterization of nitrides of iridium and palladium
Authors: Crowhurst Jonathan C. , Goncharov Alexander F. , Sadigh B. , Zaug J.M. , Aberg D. , Meng Yue , Prakapenka Vitali B.
Published: March 2008

We describe the synthesis of nitrides of iridium and palladium using the laser-heated diamond anvil cell. We have used the in situ techniques of x-ray powder diffraction and Raman scattering to characterize these compounds and have compared our experimental findings where possible to the results of first-principles theoretical calculations. We suggest that palladium nitride is isostructural with pyrite, while iridium nitride has a monoclinic symmetry and is isostructural with baddeleyite.
Molybdenum polyoxometalate impregnated amino- functionalized mesoporous silica thin films as multifunctional materials for photochromic and electrochemical applications
Authors: Zhang Xueao , Wu Wenjian , Wang Jianfang , Liu Changli , Qian Siwen
Published: March 2008

Molybdenum polyoxometalate (PMo)/silica mesoporous composite thin films, which can be applied as multifunctional materials for photochromic and electrochemical applications, were prepared by impregnating PMo into amino-functionalized mesoporous silica thin films. The composite thin films possess excellent reversible photochromic properties and change from colorless to blue under ultraviolet (UV) irradiation. It is shown in the study that intervalence charge transfer and ligand-to-metal charge transfer are the main reasons for photochromism. After UV irradiation, the charge transfer occurs by the reduction of heteropolyanions accompanying the formation of heteropolyblues with multivalence Mo (+6, +5), and the bleaching process of composite thin films is closely related to the presence of oxygen. Moreover, the composite thin films deposited on the indium tin oxide (ITO) substrate can be used as the electrode and have many advantages, including simple fabrication, fast response, and good stability. The modified ITO electrode retains the electrochemical properties of PMo, can catalyze the electroreduction of the BrO3−, and may be used as the current sensor for the BrO3−.
The mechanical properties of a surface-modified layer on polydimethylsiloxane
Authors: Mills K.L. , Zhu Xiaoyue , Takayama Shuichi , Thouless M.D.
Published: March 2008

Surface modification of the elastomer polydimethylsiloxane (PDMS) by exposure to oxygen plasma for four minutes creates a thin, stiff film. In this study, the thickness and mechanical properties of this surface-modified layer were determined. Using the phase image capabilities of a tapping-mode atomic force microscope (AFM), the surface-modified region was distinguished from the bulk PDMS; specifically, it suggested a graded surface layer to a depth of about 200 nm. Load-displacement data for elastic indentation using a compliant AFM cantilever was analyzed as a plate bending on an elastic foundation to determine the elastic modulus of the surface (37 MPa). An applied uniaxial strain generated a series of parallel nanocracks with spacing on the order of a few microns. Numerical analyses of this cracking phenomenon showed that the depth of these cracks was in the range of 300–600 nm and that the surface layer was extremely brittle, with toughness in the range of 0.1– 0.3 J/m2.
Contact damage evolution in diamondlike carbon coatings on ductile substrates
Authors: Singh Rajnish K. , Tilbrook M.T. , Xie Z.H. , Bendavid A. , Martin P.J. , Munroe P. , Hoffman M.
Published: March 2008

A diamondlike carbon (DLC) thin film was deposited onto a stainless steel substrate using a plasma-enhanced chemical vapor deposition (PECVD) process. Nanoindentation, coupled with focused-ion-beam (FIB) milling, was used to investigate contact-induced deformation and fracture in this coating system. Following initial elastic contact between the coating and the indenter and apparent plastic yield of the substrate, pop-ins were observed in the load–displacement curve, indicative of coating fracture. However, FIB cross-sectional images of indentations revealed the presence of ring, radial, and lateral cracks at loads much lower than the critical load for the first observed pop-ins. Finite element modeling was used, and the properties of the substrate and the film were calibrated by fitting the simulated load–displacement curves to experimental data. Then, based upon the experimental observations of damage evolution in this coating system, the stress distributions relevant to initiate ring, radial, and lateral cracks in the coating were ascertained. Furthermore, the effects of substrate yield stress and coating residual stress on the formation of these cracks were investigated.
Electromigration behavior of the Cu/Au/SnAgCu/Cu solder combination
Authors: Chiu Tsung-Chieh , Lin Kwang-Lung
Published: March 2008

The electromigration behavior of the Cu/Au/SnAgCu/Cu combination was investigated under 103 A/cm2 of current stressing at ambient temperature. The Au layer, when it acts as a cathode, was consumed continuously, and no significant compound was found at the interface. Meanwhile, Cu6Sn5 was formed at the anodic Cu layer, and the thickness of the compound increased with increasing time. The Au atoms were found to be trapped in Cu6Sn5 within the solder matrix. The AuSn4 compound precipitated while attaching to Cu6Sn5 at the Cu6Sn5/solder interface. The thermomigration effect was found to be insignificant in this work as no obvious reaction occurred at the cathode/anode sides or in the solder matrix without current stressing.
Enhanced electrochromic properties of heat treated nanostructured tungsten trioxide thin films
Authors: Beydaghyan Gisia , Renaud Jean-Luc M. , Bader Georges , Ashrit P.V.
Published: March 2008

Nanostructured tungsten trioxide films were fabricated with the technique of glancing angle deposition (GLAD) in a thermal evaporation chamber with a base pressure of 1.3 × 10−4 Pa. Films were deposited at vapor incidence angles of 0°, 20°, 40°, and 50° with film thickness varying between 160 and 200 nm, as determined by spectroscopic ellipsometry. After deposition, samples were heated for 1 h in air at 400 °C and were subsequently intercalated with small amounts (5 to 15 nm) of lithium by dry lithiation, a technique developed in our laboratory. Compared with our previous work on as-deposited nanostructured films, these samples showed significantly enhanced coloration in the infrared region. It was found that the films exhibited an absorption- based coloration in the lower wavelengths as well as an increased reflection in the infrared region. Morphological investigation by atomic force microscopy (AFM) showed grain agglomeration and increased surface roughness upon heating. Our studies further indicate that grain agglomeration significantly contributes to the superior coloration properties of the films.
Vertical Transmission of Ovipleistophora ovariae (Microspora) within the Eggs of the Golden Shiner
Authors: Phelps Nicholas B. D. , Goodwin Andrew E.
Published: March 2008

Fertilized eggs collected from broodfish infected by Ovipleistophora ovariae were tested by quantitative polymerase chain reaction (PCR) and found to be positive for the O. ovariae genome at 7.77 × 102 to 3.26 × 107 copies per microgram of host DNA. Fry hatched from these eggs contained from 1.37 × 102 to 9.89 × 106 copies of the O. ovariae genome per microgram of host DNA. Surface treatments of fertilized eggs with 150 mg formalin/L (used by farms as a fungicide) or a 1.5% solution of sodium sulfite (which removes the adhesive egg matrix) did not reduce vertical transmission to fry. Treatment of eggs with a 10% solution of bleach or a proprietary commercial DNA denaturant did not reduce the number of egg-associated copies of the O. ovariae genome. Histology of ovaries of infected fish demonstrated spores within the oocytes. However, no spores were observed by histology in positive fry hatched from infected eggs. The PCR and histological demonstration of the presence of O. ovariae spores in oocytes and fry, and the failure of strong DNA denaturants to reduce egg-associated copies, give evidence that O. ovariae is vertically transmitted within eggs.
Annual Run Size and Genetic Characteristics of Atlantic Sturgeon in the Altamaha River, Georgia
Authors: Peterson Douglas L. , Schueller Paul , DeVries Rob , Fleming Joel , Grunwald Cheryl , Wirgin Isaac
Published: March 2008

Although the Altamaha River, Georgia, once supported one of the largest fisheries for Atlantic sturgeon Acipenser oxyrinchus in U.S. waters, the fishery was closed in 1997 because of severe overfishing. Since then, no studies have been conducted and population trends have remained unknown. The objective of this study was to estimate annual run size and age structure of the spring spawning migration and to determine genetic relatedness between this population and other Georgia populations. In spring of 2004 and 2005, we sampled the annual spawning run of Atlantic sturgeon in the lower 30 km of the Altamaha River using large‐mesh gill nets. Captured fish were marked with passive integrated transponder tags and released to facilitate a run estimate using a simple Schnabel mark‐recapture estimator. Over the 2 years of the study, we captured 213 individuals, yielding mark‐recapture run estimates of 324 (95% confidence interval [CI] = 143‐667) in 2004 and 386 (95% CI = 216‐787) in 2005. Catch curve analysis yielded annual mortality rates of 17.3% in 2004 and 21.3% in 2005. Genetic analysis showed that the Altamaha River population is distinct from neighboring populations in the Ogeechee and Savannah rivers. The results of this study suggest that after 10 years of federal protection, the Altamaha River population of Atlantic sturgeon appears to be in the early stages of recovery; however, the genetic diversity of the population is surprisingly low. Future studies are needed to monitor population dynamics and genetic structure of the stock to ensure complete recovery.
Tissue‐Specific Sampling for the Estimation of Striped Bass Whole‐Body Proximate Composition
Authors: Jacobs John M. , Rhodes Matt R. , Martin Brandon , McIntosh Dennis , Van Heukelem William F. , Harrell Reginal M.
Published: March 2008

The need for precise estimates of chemical components of fish is common among the fields of aquaculture, fish health, and bioenergetics in fisheries management. Proximate composition is a widely used tool for obtaining this level of information but is time consuming and requires homogenization of the entire fish, limiting the ability to obtain additional information from the same individual. Exploratory chemical component analysis of differing body regions of age‐1 (215‐290‐mm) striped bass Morone saxatilis suggests that the abdominal wall (belly flap) is an appropriate surrogate for estimating whole‐body proximate composition. Belly flaps showed strong linear relationships with total lipid composition (R2 = 0.91) and moisture (R2 = 0.82) but were more variable with respect to protein (R2 = 0.22) and ash (R2 = 0.26). Equations derived from these linear relationships allowed for accurate estimation of total‐body energy, water, lipid, dry mass, fat‐free dry mass, and protein (R2 > 0.89). Strong linear relationships were also found for belly flap lipid and moisture and the same components measured in fillets (lipid: R2 = 0.82; moisture: R2 = 0.73). We conclude that sampling an otherwise unused portion of the fish can provide precise chemical compositional information without sacrificing product and can allow for additional information to be obtained from the same organism.
The effect of antioxidant properties of aqueous garlic extract and Nigella sativa as anti-schistosomiasis agents in mice
Authors: EL Shenawy Nahla S. , Soliman Maha F. M. , Reyad Shimaa I.
Published: March 2008

The aim of this study was to assess the antioxidant and anti-schistosomal activities of the garlic extract (AGE) and Nigella sativa oil (NSO) on normal and Schistosoma mansoni-infected mice. AGE (125 mg kg-1, i.p.) and NSO (0.2 mg kg-1, i.p.) were administrated separately or in combination for successive 28 days, starting from the 1st day post infection (pi). All mice were sacrificed at weeks 7 pi. Hematological and biochemical parameters including liver and kidney functions were measured to assess the progress of anemia, and the possibility of the tissue damage. Serum total protein level, albumin, globulin and cholesterol were also determined. Malondialdehyde (MDA) and glutathione (GSH) levels were determined in the liver tissues as biomarkers for oxidative and reducing status, respectively. The possible effect of the treatment regimens on Schistosoma worms was evaluated by recording percentage of the recovered worms, tissue egg and oogram pattern. Result showed that, protection with AGE and NSO prevented most of the hematological and biochemical changes and markedly improved the antioxidant capacity of schistosomiasis mice compared to the infected-untreated ones. In addition, remarkable reduction in worms, tissue eggs and alteration in oogram pattern were recorded in all the treated groups. The antioxidant and antischistosomal action of AGE and NSO was greatly diverse according to treatment regimens. These data point to these compounds as promising agents to complement schistosomiasis specific treatment.
Comparison of direct immunofluorescence, conventional cell culture and polymerase chain reaction techniques for detecting respiratory syncytial virus in nasopharyngeal aspirates from infants
Authors: Reis Alexanda Dias , Fink Maria Cristina Domingues , Machado Clarisse Martins , Paz Jr. José de Paula , Oliveira Renato Reis , Tateno Adriana Fumie , Machado Adriana Freire , Cardoso Maria Regina , Pannuti Claudio Sérgio
Published: March 2008

A total of 316 samples of nasopharyngeal aspirate from infants up to two years of age with acute respiratory-tract illnesses were processed for detection of respiratory syncytial virus (RSV) using three different techniques: viral isolation, direct immunofluorescence, and PCR. Of the samples, 36 (11.4%) were positive for RSV, considering the three techniques. PCR was the most sensitive technique, providing positive findings in 35/316 (11.1%) of the samples, followed by direct immunofluorescence (25/316, 7.9%) and viral isolation (20/315, 6.3%) (p < 0.001). A sample was positive by immunofluorescence and negative by PCR, and 11 (31.4%) were positive only by RT-PCR. We conclude that RT-PCR is more sensitive than IF and viral isolation to detect RSV in nasopharyngeal aspirate specimens in newborn and infants.
Cystic echinococcosis in southern Brazil
Authors: de La Rue Mario L.
Published: March 2008

Cystic echinococcosis (CE) is very common in the southern part of Rio Grande do Sul State where sheep and cattle raising is the most important economical activity. Prevalence in intermediate hosts is well known due to reports in slaughterhouses while human reports are of discussed value. This is due to underreporting of cases and few epidemiological studies make it difficult to assess the situation of echinococcosis in the population. Whereas cattle infection rate is more or less stable around 12% of the slaughter animals, in sheep there has been an increasing number in the last five years. Some efforts have been done to control the zoonosis but no effective results were obtained so far. Probably educational efforts to change human practices (feeding dogs with raw viscera), periodic treatment of dogs with praziquantel and joined actions with slaughterhouses could bring more attention to improve some control measures.
Optimization of the Sybr Green real time PCR for the detection of Human Herpes Virus type 6 (HHV-6)
Authors: Canto Cynthia Liliane Motta do , Sumita Laura Massami , Machado Adriana Freire , Tateno Adriana , Cunha Eveline Vieira da , Machado Clarisse Martins
Published: March 2008

HHV-6 is the etiological agent of Exanthem subitum which is considered the sixth most frequent disease in infancy. In immuno-compromised hosts, reactivation of latent HHV-6 infection may cause severe acute disease. We developed a Sybr Green Real Time PCR for HHV-6 and compared the results with nested conventional PCR. A 214 pb PCR derived fragment was cloned using pGEM-T easy from Promega system. Subsequently, serial dilutions were made in a pool of negative leucocytes from 10-6 ng/µL (equivalent to 2465.8 molecules/µL) to 10-9 (equivalent to 2.46 molecules/µL). Dilutions of the plasmid were amplified by Sybr Green Real Time PCR, using primers HHV3 (5' TTG TGC GGG TCC GTT CCC ATC ATA 3)'and HHV4 (5' TCG GGA TAG AAA AAC CTA ATC CCT 3') and by conventional nested PCR using primers HHV1 (outer): 5'CAA TGC TTT TCT AGC CGC CTC TTC 3'; HHV2 (outer): 5' ACA TCT ATA ATT TTA GAC GAT CCC 3'; HHV3 (inner) and HHV4 (inner) 3'. The detection threshold was determined by plasmid serial dilutions. Threshold for Sybr Green real time PCR was 24.6 molecules/µL and for the nested PCR was 2.46 molecules/µL. We chose the Real Time PCR for diagnosing and quantifying HHV-6 DNA from samples using the new Sybr Green chemistry due to its sensitivity and lower risk of contamination.
Biomass accumulation, photochemical efficiency of photosystem II, nutrient contents and nitrate reductase activity in young rosewood plants (Aniba rosaeodora Ducke) submitted to different NO3-:NH4+ ratios
Authors: Barreto Denize Caranhas de Sousa , Gonçalves José Francisco de Carvalho , Santos Júnior Ulysses Moreira dos , Fernandes Andreia Varmes , Bariani Adriana , Sampaio Paulo de Tarso Barbosa
Published: March 2008

The rosewood (Aniba rosaeodora Ducke) is a native tree species of Amazon rainforest growing naturally in acidic forest soils with reduced redox potential. However, this species can also been found growing in forest gaps containing oxide soils. Variations in the forms of mineral nitrogen (NO3- or NH4+) may be predicted in these different edaphic conditions. Considering that possibility, an experiment was carried out to analyze the effects of different NO3-:NH4+ ratios on the growth performance, mineral composition, chloroplastid pigment contents, photochemical efficiency photosystem II (PSII), and nitrate redutase activity (RN, E.C.1.6.6.1) on A. rosaeodora seedlings. Nine-month-old seedlings were grown in pots with a washed sand capacity of 7.5 kg and submitted to different NO3-:NH4+ ratios (T1 = 0:100%, T2 = 25:75%, T3 = 50:50%, T4 = 75:25%, and T5 = 100:0%). The lowest relative growth rate was observed when the NO3-:NH4+ ratio was equal to 0:100%. In general, high concentrations of NO3- rather than NH4+ favored a greater nutrient accumulation in different parts of the plant. For the chloroplastid pigment, the highest Chl a, Chl b, Chl tot, Chl a/b and Chl tot/Cx+c contents were found in the treatment with 75:25% of NO3-:NH4+, and for Chl b and Cx+c it was observed no difference. In addition, there was a higher photochemical efficiency of PSII (Fv/Fm) when high NO3- concentrations were used. A linear and positive response for the nitrate reductase activity was recorded when the nitrate content increased on the culture substrate. Our results suggest that A. rosaeodora seedlings have a better growth performance when the NO3- concentrations in the culture substrate were higher than the NH4+ concentrations.
Sistemas agroflorestais em áreas de agricultores familiares em Igarapé-Açu, Pará: caracterização florística, implantação e manejo
Authors: Vieira Thiago Almeida , Rosa Leonilde dos Santos , Vasconcelos Paulo César Silva , Santos Mônica Mota dos , Modesto Rozi da Silva
Published: March 2008

Este trabalho objetivou avaliar os Sistemas Agroflorestais-SAF comerciais multiestratificados de agricultores familiares de Igarapé-Açu, bem como identificar as espécies que compõem os sistemas agroflorestais. A partir de entrevistas foram catalogadas as espécies de maior interesse dos agricultores familiares e por meio de inventário florístico foram avaliados os SAF produtivos. Os cultivos de pimenta-do-reino, mandioca, feijão, cupuaçu, caju, açaí, pupunha, mogno e o nim indiano foram os mais freqüentes pelos agricultores. Os SAF são manejados na sua maioria de forma tradicional.
Comunidades de morcegos em hábitats de uma Mata Amazônica remanescente na Ilha de São Luís, Maranhão
Authors: Cruz Leonardo Dominici , Martínez Carlos , Fernandes Fernanda Rodrigues
Published: March 2008

Estudos com comunidades de morcegos são escassos no Brasil, não sendo encontrado nenhum no Maranhão. Este estudo teve como objetivo investigar a composição de espécies da comunidade de morcegos do Parque Estadual do Bacanga (PEB), São Luís - MA, além de contribuir para o levantamento da fauna de morcegos do estado. Os morcegos foram capturados com três redes neblina de maio a agosto de 2004 em quatro diferentes hábitats (mata de capoeira, mata de terra firme, mata de várzea e mangue). A diversidade e similaridade entre hábitats foram calculadas, bem como a amplitude e sobreposição dos nichos das espécies consideradas comuns na área. Foram registradas 24 espécies de morcegos, sendo a maior diversidade encontrada na mata de várzea. A baixa similaridade constatada entre o hábitat de mangue e os demais hábitats indica a existência de dois conjuntos de espécies de morcegos distintos, o que é reforçado pelas sobreposições de nicho espacial das espécies mais comuns.
Ciclo de vida y aspectos poblacionales de Edessa aff. aulacosterna Stal, 1872 (Heteroptera: Pentatomidae) chinche del fruto del camu camu (Myrtaceae) en zona de restinga, Ucayali, Perú
Authors: Iannacone José , Perez Diana , Tueros Alfredo
Published: March 2008

El camu camu es uno de los frutales nativos con gran potencial económico para la agroindustria y agro exportación. Edessa es una de las plagas del camu camu que provoca sequedad en los brotes, y en los frutos una mancha decolorada con círculos concéntricos bien marcados y un punto central al alimentarse. El objetivo del presente trabajo fue determinar el ciclo biológico bajo condiciones de laboratorio y la fluctuación poblacional de Edessa aff. aulacosterna "Chinche del fruto del camu camu" durante enero a noviembre del 2004 en el cultivo de camu camu, en parcelas en desarrollo y producción ubicadas en áreas de restinga inundables en Pucallpa, Ucayali, Perú. Se colectaron huevos, ninfas y adultos procedentes del distrito de Yarinacocha, Pucallpa, Ucayali, Perú para iniciar la crianza artificial. El tiempo de duración del huevo al I estadio ninfal fue 5,1 días. Se encontró un 94,6% de eclosión de los huevos, variando entre 12 hasta 14 huevos por postura. El tiempo transcurrido desde el huevo hasta II estadío fue de 37,3 días y del III al V estadío ninfal fue de 81,9 días. El porcentaje de mortalidad del primer estadio ninfal a adulto fue de 98,1%. Los adultos colectados se localizaron preferentemente sobre las ramas y el tallo de la planta, mientras que las ninfas se encontraron en los brotes tiernos. Con relación a su fluctuación poblacional, solo se registró posturas a lo largo del año en parcelas en producción. No se encontraron diferencias entre ninfas I a V, y adultos de Edessa aff. aulacosterna, entre plantaciones en producción y desarrollo de camu camu. Solo se encontró diferencias entre la época seca y lluviosa en las ninfas de III a V estadio en las plantas de camu camu en desarrollo. Edessa aff. aulacosterna presentó mayormente una distribución contagiosa. El adecuado conocimiento de la bioecología nos permite mejorar la estrategia de control de esta plaga.
Aquatic and semiaquatic Heteroptera (Insecta) from Pitinga, Amazonas, Brazil
Authors: Pereira Domingos L. V. , Melo Alan Lane de
Published: March 2008

A list of aquatic and semiaquatic Heteroptera from a collecting trip to Pitinga, a village in a mining area in the County of Presidente Figueiredo in the Central Amazon is presented. Identified were fifty five species of Heteroptera, distributed in 13 families. Among the insects collected, some are new records for this Amazonian region and in addition 3 apparently undescribed species of Microvelia and one of Paravelia remain for further study.
Diversidade de espécies dos gêneros de Crematogaster, Gnamptogenys e Pachycondyla (Hymenoptera: Formicidae) e complementaridade dos métodos de coleta durante a estação seca numa estação ecológica no estado do Pará, Brasil
Authors: Souza Jorge Luiz Pereira , Moura C.A.R. , Harada Ana Y. , Franklin Elizabeth
Published: March 2008

As formigas são muito usadas em programas de inventários e monitoramentos, resultando em grande quantidade de material coletado com vários métodos, limitações financeiras e na falta de taxonomos para vários táxons. Para contribuir na elaboração de protocolos alternativos, analisamos a complementaridade de dois métodos de amostragem na detecção da riqueza de espécies. Em seis parcelas de 1 km² distribuídas em 33.000 ha de floresta primária, investigamos a diversidade e a freqüência das espécies de Crematogaster,Gnamptogenys e Pachycondyla, como parte do protocolo de formigas de serapilheira do Projeto TEAM. Em cada parcela, quatro transectos de 100 m foram instalados. Dez sub-amostras foram efetuadas por transecto, usando extrator de Winkler e armadilha de fosso. Registramos 36 espécies, sendo 15 novos registros para o Pará e 29 para a área de estudo. Dezessete espécies foram comuns aos dois métodos, onze foram capturadas com armadilhas de fosso e oito com Winkler. As proporções de espécies representadas por um indivíduo ("singletons") foram altas para ambos os métodos (> 0,4). Dezenove espécies foram coletadas por apenas um método e três foram representadas por apenas um indivíduo em cada método. A análise de ordenação (escalonamento multidimensional semi-híbrido) revelou diferenças na estrutura das comunidades de formigas obtidas pelos dois métodos de amostragem. Houve um efeito de complementaridade entre os dois métodos para a obtenção de um levantamento mais completo da riqueza de espécies, significando que ambos devem ser usados no protocolo. Outros recursos, como a rarefação e/ou diluição das amostras são recursos a serem avaliados em futuras investigações.
O cuidar do enfermeiro especialista em reabilitação físico-motora
Authors: Leite Valéria Barreto Esteves , Faro Ana Cristina Mancussi e
Published: March 2008

O processo de reabilitação físico-motora tem por objetivo principal a adaptação das pessoas com deficiência física às novas condições de vida. Este trabalho tem por objetivo descrever as atividades desenvolvidas pelo enfermeiro de reabilitação em uma unidade de internação de pacientes em reabilitação físico-motora e destacar sua importância frente à equipe de reabilitação. Dentre as principais atividades desenvolvidas destacamos a manutenção das necessidades fisiológicas, onde a equipe de Enfermagem executa, orienta, demonstra, supervisiona e reavalia as condições de autocuidado destes pacientes. O enfermeiro atua, também, na prevenção de possíveis complicações que podem ocorrer frente à suscetibilidade peculiar desta clientela.
Sexualidade no período climatérico: situações vivenciadas pela mulher
Authors: Fernandez Márcia Rodrigues , Gir Elucir , Hayashida Miyeko
Published: March 2008

Estudo de caráter descritivo,com o objetivo de identificar os aspectos que as mulheres atendidas em um Serviço de Ginecologia e Obstetrícia consideram como positivos e negativos no exercício de sua sexualidade, na fase do climatério. Os dados foram coletados através de entrevista individual, utilizando-se da técnica de incidentes críticos. As 45 mulheres entrevistadas mencionaram 86 situações, sendo 41 (47,7%) consideradas positivas e 45 (52,3%) negativas. As situações foram classificadas em três categorias: relacionamento a dois, ato sexual e mulher - ser social. Os resultados evidenciaram que elas priorizam a valorização da qualidade do relacionamento e da manifestação da emoção no contexto romântico. Destacaram a insatisfação com a auto-imagem e a presença da dominação sexual do homem sobre a mulher. O estudo possibilitou uma compre-ensão mais abrangente sobre o climatério, oferecendo subsídios para a assistência à saúde da mulher contemplando a dimensão sexual.
Crises hipertensivas em portadores de hipertensão arterial em tratamento ambulatorial
Authors: Guedes Nirla Gomes , Costa Francisca Bertília Chaves , Moreira Rafaella Pessoa , Moreira Tahissa Frota , Chaves Emília Soares , Araújo Thelma Leite de
Published: March 2008

O presente estudo avaliou as características sociodemográficas e de adesão terapêutica de 27 portadores de hipertensão arterial em tratamento ambulatorial que apresentaram crises de urgências ou emergências hipertensivas e haviam sido atendidos em uma unidade de leito-dia e em uma unidade de emergência da cidade de Fortaleza-Ceará, no período de outubro de 2002 a maio de 2003. A maioria era mulher, com idade de 50 a 60 anos, pouca escolaridade, tempo de tratamento inferior a cinco anos e tempo de diagnóstico entre cinco e dez anos. O uso dos remédios foi o tratamento mais referido, seguido pela redução do consumo de sal e comparecimento às consultas. No entanto, o fato de comparecerem às consultas e receberem orientação parece não modificar o comportamento, uma vez que a maioria dos entrevistados não praticava exercícios físicos e demonstrava deficiência no conhecimento sobre a doença, atribuindo a elevação da pressão arterial a fatores emocionais.
A mulher japonesa vivenciando o câncer cérvico-uterino: um estudo de caso com abordagem da fenomenologia social
Authors: Chubaci Rosa Yuka Sato , Merighi Miriam Aparecida Barbosa , Yasumori Yumi
Published: March 2008

Trata-se de estudo sobre a experiência de uma mulher japonesa, com câncer cérvico-uterino, realizado em um hospital da cidade de Osaka-Japão, no qual se utilizou o "estudo de caso" com abordagem da Fenomenologia Social de Alfred Schütz. Objetivou-se conhecer o significado da doença e da hospitalização para essa mulher, buscando compreender os motivos que envolvem a sua ação. Por meio da análise dos dados, foi possível compreender que o processo da hospitalização deve ser visto respeitando, além da característica individual, o mundo cultural que nos remete às ações humanas e que exerce influência importante no comportamento e atitude em relação à doença e hospitalização.
Therapeutic intervention scoring system-28 (TISS-28): diretrizes para aplicação
Authors: Padilha Katia Grillo , Sousa Regina Marcia Cardoso de , Miyadahira Ana Maria Kazue , Cruz Diná de Almeida Lopes Monteiro da , Vattimo Maria de Fátima Fernandes , Kimura Miako , Grossi Sonia Aurora Alves , Silva Maria Claudia Moreira da , Cruz Valéria Ferraz , Ducci Adriana Janzanti
Published: March 2008

O Therapeutic Intervention Scoring System-28 (TISS-28) é um instrumento que permite dimensionar carga de trabalho de enfermagem em Unidade de Terapia Intensiva e estimar gravidade da doença. Apresenta-se nesta publicação as definições operacionais para sua aplicação, proposta por um grupo de especialistas na área, com vistas a uniformizar o significado de cada um dos itens e evitar vieses de interpretação.
Diferentes suplementos no cultivo in vitro de embriões de pinhão-manso
Authors: Nunes Claudinéia Ferreira , Pasqual Moacir , Santos Dalilhia Nazaré dos , Custódio Telde Natel , Araujo Aparecida Gomes de
Published: March 2008

O objetivo deste trabalho foi avaliar a influência do estádio de maturação dos frutos, no desenvolvimento de embriões de pinhão-manso (Jatropha curcas), cultivados em meio MS com diferentes suplementos: sacarose, água de coco e carvão ativado. Os frutos foram coletados, e os embriões de suas sementes extraídos assepticamente. Utilizaram-se duas condições experimentais: embriões oriundos de frutos em três estádios de desenvolvimento (imaturo, maduro e seco), colocados em meio de cultivo MS acrescido de sacarose (0, 15, 30 e 60 g L-1); embriões oriundos de frutos secos, colocados em meio MS acrescido de: 30 g L-1de sacarose, carvão ativado (0, 1, 2 e 3 g L-1) e de água de coco (0, 50, 100, 150, 200 e 250 mL L-1). O material foi mantido por 30 dias em sala de crescimento, sob condições ambientais controladas. Apenas os embriões zigóticos provenientes de frutos imaturos necessitam da suplementação de sacarose para sustentar sua germinação. O melhor desenvolvimento de embriões ocorre em meio MS suplementado com 60 g L-1 de sacarose. A associação de carvão ativado e água de coco proporcionam melhor crescimento de plântulas oriundas de embriões de sementes retiradas de frutos secos.
Controle genético da qualidade da vagem em cruzamento de feijão-vagem e feijão-comum
Authors: Mariguele Keny Henrique , Maluf Wilson Roberto , Gomes Luiz Antônio Augusto , Lopes Marcus José Conceição , Melo Osvânder David de
Published: March 2008

O objetivo deste trabalho foi determinar os tipos principais de ações gênicas responsáveis pela expressão fenotípica de alguns caracteres de qualidade da vagem, em cruzamento de feijão-vagem e feijão-comum. Foram avaliadas duas populações segregantes (F2 e F2:3), além das linhagens parentais. Como genitora feminina, utilizou-se a cultivar de feijão-vagem Conquista Rasteiro e, como genitora masculina, a linhagem de feijão-comum H126. Foram avaliados: comprimento da vagem, largura entre as suturas, largura das valvas, formato da vagem e teor de fibra da vagem . Os efeitos não-aditivos destacaram-se em todas as características avaliadas. Embora tenha ocorrido predominância dos efeitos genéticos sobre os ambientais, nas características comprimento e formato da vagem e teor de fibra, a eficiência da seleção em plantas individuais tendeu a ser bastante baixa nas gerações segregantes pouco avançadas, em razão dos baixos valores da herdabilidade no sentido restrito, exceto para formato da vagem. O predomínio dos efeitos genéticos sobre os ambientais em todas as características em nível de família, associado a valores de herdabilidade no sentido restrito em famílias F2:3, indica a alta eficiência para a seleção de famílias nas gerações segregantes pouco avançadas, com relação a todas as características, exceto para comprimento e teor de fibra.
Correlações genéticas e fenotípicas entre características reprodutivas e produtivas de touros da raça Nelore
Authors: Dias Juliano Cesar , Andrade Venício José de , Martins Jorge André Matias , Emerick Lucas Luz , Vale Filho Vicente Ribeiro do
Published: March 2008

O objetivo deste trabalho foi estimar correlações genéticas e fenotípicas de características reprodutivas e ponderais em 579 touros Nelore, em criação extensiva. As características reprodutivas estudadas foram: circunferência escrotal, consistência, volume e forma testiculares, comprimento dos testículos esquerdo e direito, largura dos testículos esquerdo e direito, motilidade e vigor espermáticos, defeitos espermáticos maiores, menores e totais e classificação andrológica por pontos. As características foram analisadas pelo método de máxima verossimilhança restrita, com algoritmos livres de derivadas, sob modelo animal, com inclusão da matriz de numeradores dos coeficientes de parentesco entre os animais e seus ascendentes. As correlações genéticas entre circunferência escrotal e as características peso corporal, volume testicular, motilidade espermática, vigor espermático, defeitos espermáticos menores, defeitos espermáticos totais e classificação andrológica por pontos foram, respectivamente, 0,72, 0,99, 0,72, 0,60, -0,67, -0,12 e 0,64. As maiores correlações fenotípicas encontradas entre peso e circunferência escrotal, características físicas e morfológicas do sêmen, quando comparadas às correlações entre idade e as mesmas características, são indicativas de que o peso tem maior influência na condição reprodutiva. As correlações genéticas entre classificação andrológica por pontos e as características: peso, circunferência escrotal, volume testicular, defeitos espermáticos maiores e defeitos espermáticos totais foram, respectivamente, 0,19, 0,64, 0,71, -0,47 e -0,58.
Parâmetros genéticos em café Conilon
Authors: Ferrão Romário Gava , Cruz Cosme Damião , Ferreira Adésio , Cecon Paulo Roberto , Ferrão Maria Amélia Gava , Fonseca Aymbiré Francisco Almeida da , Carneiro Pedro Crescêncio de Souza , Silva Marcia Flores da
Published: March 2008

O objetivo deste trabalho foi avaliar a produtividade e obter as estimativas de parâmetros genéticos e não genéticos de 40 materiais genéticos do programa de melhoramento genético de café Conilon do Incaper, no Estado do Espírito Santo. Foram analisados dados de dois experimentos, nos municípios de Marilândia e Sooretama, ES, nas safras de 1996, 1997, 1998, 1999, 2000, 2001 e 2002, em que se avaliaram 16 características. Realizou-se, inicialmente, a análise de variância individual, por local em cada ano, com base na média de parcelas, em blocos ao acaso. Posteriormente foi feita a análise de variância conjunta. Os genótipos apresentaram grande variabilidade genética para a maioria das características avaliadas. Os elevados coeficientes de determinação genotípico e coeficientes de variação genéticos, associados às altas produtividades e à variabilidade genética indicam a possibilidade de obtenção de êxitos em programas de melhoramento genético para diferentes características avaliadas nos dois municípios.