bluuebunny/crossref_metadata_2025 huggingface dataset:
Vaccine-Era Varicella Epidemiology and Vaccine Effectiveness in a Public Elementary School Population, 2002–2007
Authors: Lee Lore E. , Ho Hon , Lorber Eileen , Fratto Jeanne , Perkins Sara , Cieslak Paul R.
Published: June 2008

OBJECTIVE. We conducted ongoing varicella surveillance of public elementary school students to track changes in incidence from 2002 to 2007. In school year 2002–2003, we also conducted a retrospective cohort study to measure varicella vaccine effectiveness, assess relationships between risk factors for varicella in vaccine recipients (breakthrough varicella) identified in earlier studies, and assess the ability of school nurse surveillance to detect varicella cases.

PATIENTS AND METHODS. Varicella was defined as acute illness with maculo-papulo-vesicular rash without another apparent cause persisting >24 hours, regardless of previous episodes of the same or a similar illness. Using case data reported by school nurses, we described breakthrough varicella rates (percentage of vaccinated students with varicella), annual varicella-incidence rates (varicella cases per 100 public elementary school students), vaccine effectiveness, risk factors for breakthrough varicella, clinical characteristics of vaccinated and susceptible varicella patients, and sensitivity and positive predictive value of school nurse surveillance.

RESULTS. During school years 2002–2007, 502 elementary school students met the varicella case definition. Breakthrough varicella rates among exposed students ranged from 6% to 8% per school year; annual incidence rates ranged from 0.2% to 0.3% of public elementary school students; and varicella was more severe and lasted longer in susceptible than in vaccinated students. The positive predictive value of school nurse surveillance was 94%, and sensitivity was 90%. Vaccine effectiveness was 81%.

CONCLUSIONS. School nurse surveillance has both high positive predictive value and sensitivity and is a useful means of tracking varicella occurrence. Annual incidence rates of varicella are low. Vaccine effectiveness and breakthrough varicella rates are comparable to findings of other studies.
Prevalence of Vitamin D Deficiency and Insufficiency in Children With Osteopenia or Osteoporosis Referred to a Pediatric Metabolic Bone Clinic
Authors: Bowden Sasigarn A. , Robinson Renee F. , Carr Roxane , Mahan John D.
Published: June 2008

OBJECTIVES. The purpose of this work was to determine the prevalence of vitamin D deficiency and insufficiency in children with osteopenia or osteoporosis and to evaluate the relationship between serum 25-hydroxyvitamin D levels and bone parameters, including bone mineral density.

MATERIALS AND METHODS. Serum 25-hydroxyvitamin D, 1,25 dihydroxyvitamin D, parathyroid hormone, and other bone markers, as well as bone mineral density, were obtained for 85 pediatric patients with primary osteoporosis (caused by osteogenesis imperfecta or juvenile idiopathic osteoporosis) and secondary osteopenia or osteoporosis caused by various underlying chronic illnesses. Pearson's correlation was used to assess the relationship between vitamin D levels and different bone parameters.

RESULTS. Vitamin D insufficiency (defined as serum 25-hydroxyvitamin D <30 ng/mL) was observed in 80.0% of patients. Overt vitamin D deficiency (defined as serum 25-hydroxyvitamin D <10 ng/mL) was present in 3.5% of patients. Using a more recent definition for vitamin D deficiency in adults (defined as serum 25-hydroxyvitamin D <20 ng/mL), 21.1% of the patients had vitamin D deficiency. There was a significant inverse correlation between 25-hydroxyvitamin D and parathyroid hormone levels. There was a positive correlation between 1,25 dihydroxyvitamin D and parathyroid hormone, alkaline phosphatase, and urine markers for bone turnover.

CONCLUSIONS. Vitamin D insufficiency was remarkably common in pediatric patients with primary and secondary osteopenia or osteoporosis. The inverse relationship between 25-hydroxyvitamin D and parathyroid hormone levels suggests a physiologic impact of insufficient vitamin D levels that may contribute to low bone mass or worsen the primary bone disease. We suggest that monitoring and supplementation of vitamin D should be a priority in the management of pediatric patients with osteopenia or osteoporosis.
Serial Immune Markers Do Not Correlate With Clinical Exacerbations in Pediatric Autoimmune Neuropsychiatric Disorders Associated With Streptococcal Infections
Authors: Singer Harvey S. , Gause Colin , Morris Christina , Lopez Pablo ,   and the Tourette Syndrome Study Group
Published: June 2008

OBJECTIVE. Pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections is hypothesized to be a poststreptococcal autoimmune disorder. If clinical exacerbations are triggered by a streptococcal infection that activates cross-reacting antibodies against neuronal tissue or alters the production of cytokines, then a longitudinal analysis would be expected to identify a correlation between clinical symptoms and a change in autoimmune markers.

PATIENTS AND METHODS. Serial serum samples were available on 12 children with pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections participating in a prospective blinded study: 2 samples before an exacerbation point, 1 during the clinical exacerbation, and 2 after the exacerbation. Six subjects had a well-defined clinical exacerbation in association with a documented streptococcal infection, and 6 had a clinical exacerbation without an associated streptococcal infection. All of the serum samples were assayed for antibodies against human postmortem caudate, putamen, and prefrontal cortex; commercially prepared antigens; and complex sugars. Cytokines were measured by 2 different methodologies.

RESULTS. No correlation was identified between clinical exacerbations and autoimmune markers, including: enzyme-linked immunosorbent assay measures of antineuronal antibodies; Western immunoblotting with emphasis on brain region proteins located at 40, 45, and 60 kDa or their corresponding identified antigens; competitive inhibition enzyme-linked immunosorbent assay to evaluate lysoganglioside GM1 antibodies; and measures of inflammatory cytokines. No differences were identified between individuals with pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections with or without exacerbations triggered by streptococcal infections.

CONCLUSIONS. The failure of immune markers to correlate with clinical exacerbations in children with pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections raises serious concerns about the viability of autoimmunity as a pathophysiological mechanism in this disorder.
Effect of low light intensity on the VRN-H1 and VRN-H2 vernalization response loci in barley ( Hordeum vulgare L.)
Authors: Karsai I.
Published: May 2008

The flowering characteristics of a facultative × winter barley mapping population were evaluated in a series of controlled environmental tests in order to study the effect of low light intensity in association with various photoperiod regimes. Functional QTL analysis was used to determine the effect of low light intensity on the functioning of the
VRN-H1
and
VRN-H2
vernalization response genes and on the allele interactions. Low light intensity exerted the strongest modifying effect on these genes under a 12-hour photoperiod regime, which was intermediate between short and long daylengths. With this photoperiod more than 50% of the phenotypic variance in flowering was explained by the
VRN-H2
gene when high light intensity (340 μmol m
−2
s
−1
) was applied, but at low light intensity (170 μmol m
−2
s
−1
) the
VRN-H1
gene became the most important source of variation. There were also significant changes in the interaction between the alleles of the two
VRN-H
genes, implying that in addition to their role in vernalization-driven regulation, they may also participate in and be subjected to circadian-driven developmental regulation.
Evaluation of the apicultural value of sunflower hybrids
Authors: Zajácz E. , Szalai T. , Mészáros G.
Published: May 2008

Sunflower is one of the most important bee-pasture crops and the leading oil crop plant in Hungary. There are very few studies concerning the nectar production of the plant, most of which consist only of partial data that show the apicultural value of sunflower under intensive cultivation conditions.The nectar production and nectar sugar concentration of six sunflower hybrids, Arena, Alexandra, Cledor, Coriste, Hysun 321 PR and Louidor, were examined in Mezőhegyes (south-east Hungary) from 2002 to 2004. The aim was to determine the nectar production and overall apicultural value of the hybrids. In the experiment the agroecological conditions were also examined and recorded. These agroecological conditions showed a distinctive effect on the consistency of the apicultural values of the hybrids.It can be determined from the results that the nectar production and its sugar content can be modified measurably by external factors. The nectar quantity was measurably increased by abundant precipitation during flowering, while an increase in the nectar sugar content was caused by excessively low air temperature. During these three years the average nectar production of the hybrids was 0.147 mg/floret, with a sugar content of 48.8%. Significant differences were found between the hybrids in nectar production and in the nectar sugar concentration.Averaged over three years Coriste displayed the best apicultural value. Its nectar production was stable and high (0.167 mg/floret). Its high sugar content (49.1%) also proved to be attractive to honey bees (sugar value 0.082). The lowest apicultural value was displayed by the hybrid Alexandra, with a sugar value of 0.059. This suggests that the honey production value of the individual hybrids should be taken into consideration during the selection of bee pastures.
Direct and residual effects of agro-industrial wastes on a rocket salad ( Eruca sativa Mill.) — Sorghum [ Sorghum bicolor (L.) Moench] sequence
Authors: Sharma D. , Rana D. , Kaushik R. , Kumar S. , Joshi H.
Published: May 2008

A field study conducted for two years (2002–04) at New Delhi showed that the seed yield (1.80 t ha
−1
) of rocket salad (
Eruca sativa
Mill.) obtained by applying 5 t ha
−1
pressmud compost based on distillery effluent + half the recommended dose of NPKS (recommended dose: 60 kg N, 13 kg P, 25 kg K and 20 kg S ha
−1
) was on par with the seed yield (1.69 t ha
−1
) recorded with the recommended dose of NPKS. However, the seed yield recorded with the former treatment significantly exceeded that obtained with 5 t ha
−1
of a 1:1 mixture of fly ash and distillery effluent + half the recommended dose of NPKS (by 30.4%) or 5 t ha
−1
of dry
Jatropha curcas
leaves + ½ NPKS (by 24.1%). On average, distillery effluent-based pressmud compost + ½ NPKS induced a perceptible increase in the soil-available NPK, recorded after the harvest of rocket salad, compared to the initial fertility status. The uptake of NPKS in the seed and stover of rocket salad was the highest after the application of pressmud compost, closely followed by the recommended dose of NPKS, and the lowest in the control. The residual effect of treatments given to rocket salad was significant on the fodder yield of succeeding sorghum [
Sorghum bicolor
(L.) Moench]. The fodder yield recorded with pressmud compost + ½ NPKS was significantly higher than the other treatments. The application of pressmud compost alone was also significantly superior to the same rate of fly ash + effluent mixture or dry
Jatropha
leaves with respect to the seed yield of rocket salad, residual fertility after the harvest of rocket salad and the fodder yield of succeeding sorghum.
In vitro propagation of some Syrian varieties of olive ( Olea europaea L.)
Authors: Charbaji T. , Ayyoubi Z. , Karajouli I.
Published: May 2008

Five local olive varieties (
Olea europaea
L.), Dan, Sorani, Tadmury, Tiffahi and Zeiti, were collected from the field. Internode explants of each were micropropagated on modified MS and Rugini medium (olive medium).The shoot growth and dry weight of the Dan, Sorani and Zeiti varieties increased significantly on modified MS. Similar results were observed for Tiffahi in Rugini medium. Modified MS and Rugini media had similar effects on the growth and dry weight of Tadmury.Two concentrations (3 and 5 mg l
−1
) of three auxins (IAA, IBA and NAA) were used for the
in vitro
rooting stage. A higher percentage of
in vitro
rooting was observed on medium containing 5 mg l
−1
IBA.
Saccharide and fructooligosaccharide accumulation across leaf-bases during growth and bulb development of onion ( Allium cepa L.)
Authors: Shiomi N. , Benkeblia N. , Onodera S. , Takahashi N. , Fujishima M. , Nagamine T.
Published: May 2008

The accumulation of saccharides and fructooligosaccharides (FOS) in the individual leaf-bases of onion (
Allium cepa
L.) was investigated during growth and bulb development. Saccharides and FOS were analysed by means of high performance anion exchange chromatography-pulsed amperometric detection (HPAEC-PAD). The glucose content was the highest, while the content of saccharides (glucose, fructose and sucrose) increased during June, July and August and decreased slightly during September. The trisaccharides all accumulated to a similar extent, although the neokestose [
3b
, 6
G
-
β
-D fructofuranosylsucrose] content was higher than that of 1-kestose [
3a
, 1
F
-
β
-D-fructofuranosylsucrose]. Tetra-, penta- and high-DP (degree of polymerization) FOS also showed a similar pattern, though the contents of
4b
[6
G
(1-
β
-D-fructofuranosyl)
2
sucrose] and
5b
[6
G
(1-
β
-D-fructofuranosyl)
3
sucrose] were higher compared with that of other tetra-[
4a
, 1
F
(1-
β
-D-fructofuranosyl)
2
sucrose and
4c
, 1
F
, 6
G
-di-
β
-D-fructofuranosyl sucrose] and penta-saccharides [
5a
, 1
F
(1-
β
-D-fructofuranosyl)
3
sucrose]. Total FOS accumulated to a greater extent in the inner (youngest) leaf-bases than in the outer (oldest) leaf-bases, and their content was high during August. The total carbohydrates content was 6.71, 7.25, 8.10 and 6.30 g 100 g
−1
FW during June, July, August and September, respectively. During bulb formation, a balance was observed between the glucose, fructose, sucrose and FOS contents, with an average ratio of 20:10:10:60 of total carbohydrates, respectively.
Effect of seasonal variation on the copper status in a soil-plant-animal system
Authors: Khan Z. , Hussain A. , Ashraf M. , Ahmad K. , Danish M. , McDowell L.
Published: May 2008

A study was conducted on the sheep farm of the Livestock Experimental Station, located in the southwestern Punjab, Pakistan, to determine the copper nutrition status of different classes of grazing sheep during two different seasons. A complete free-choice supplement (feed) was available to all animals throughout the year. The purpose of this research was to investigate, as a function of the seasons, the transfer of Cu from soil, and dietary factors to sheep grazing in this semiarid region, in order to evaluate if the Cu requirement of grazing livestock was met or if a deficiency occurred. The final goal was to maximize the production of the animals by adopting, if necessary, adequate, balanced Cu supplementation. Soil, forage, feed and water samples, and animal samples (plasma, milk, faeces and urine from lactating ewes, plasma, faeces and urine from non-lactating ewes and plasma and faeces from male animals) were taken eight times during the year (four times in each season). Soil copper was affected by the seasonal changes and sampling intervals and was significantly higher than plant needs during both seasons, while the forage copper level did not show significant seasonal fluctuations, but was only affected by the sampling intervals. The soil and forage Cu was sufficient for the requirements of the plants and the animals grazing there on during both seasons. The copper contents of the feed and water showed no seasonal or sampling interval fluctuations. The plasma Cu was affected by seasonal variations in non-lactating ewes and in rams and by sampling intervals in the lactating ewes. Faecal and urine Cu was not affected by seasonal or sampling intervals except in non-lactating ewes, where the sampling interval had a pronounced effect on faecal Cu, while milk Cu in lactating ewes was affected by seasonal changes only. In all classes of sheep plasma Cu was higher during the winter than during the summer and remained in the normal range for ruminants during both seasons. It is concluded that a mixture with high bioavailability, containing Cu, should be continuously provided to grazing sheep in this semi-arid region in order to maintain the normal level of Cu and maximize the production potential of ruminants.
Influence of omitting irrigation and nitrogen levels on growth, yield and water use efficiency of coriander ( Coriandrum sativum L.)
Authors: Kumar A. , Singh R. , Chhillar R.
Published: May 2008

A field experiment conducted on the sandy loam soil in New Delhi during the winter season of 2003–2004 indicated that the application of three irrigations at the branching, flowering and seed formation stages gave the maximum values of growth and yield attributes (plant height and branches plant
−1
, umbels plant
−1
, umbellets umbel
−1
and seeds umbel
−1
) with the highest seed and stover yields, but was at par with omitting one irrigation at the seed formation stage. The data on the growth and yield indicated that, compared to the other stages, omitting irrigation at the flowering strage resulted in the greatest reduction. The growth and yield attributes and the seed and stover yield of coriander significantly responded to fertilization up to 80 kg N ha
−1
. The crop evapotranspiration was the highest with the application of three irrigations, but the water use efficiency remained the highest when irrigation was omitted at the seed formation stage. Nitrogen fertilization up to 120 kg and 80 kg N ha
−1
increased the water use and water use efficiency, respectively.
Legal regulation in the field of tissue engineering
Authors: Farkas Boglárka , Bárdos Tamás , Bellyei Árpád , Illés Tamás
Published: May 2008

Az utóbbi években a sejt- és szövettenyésztéssel foglalkozó biotechnológiai kutatási ágazat, valamint az erre alapuló tissue engineering technika rohamléptekkel fejlődött. E fejlődéssel párhuzamosan a kidolgozott új eljárások jogi szabályozása, annak harmonizálása is egyre sürgetőbbé vált. A szerzők a tissue engineering technika hazai és külföldi jogi kereteinek feltérképezésére és összehasonlítására vállalkoztak. Az általuk végzett széles körű jogszabályi értelmezés rávilágított arra a tényre, hogy a hazai szabályozás ezen a területen még gyermekcipőben jár, összehasonlítva a külföldi országok gyakorlatával, ahol érvényes és hatályos, bár nem egységes jogforrások szabályozzák a kérdéskört. Egy újonnan elfogadott európai uniós bizottsági rendelet azonban stabil és szigorú jogi keretet határoz meg a sejt- és szövettenyésztések alkalmazhatóságára.
Clinical aspects of hepatitis C virus infection in child-bearing aged women
Authors: Lombay jr. Béla , Gasztonyi Beáta , Szalay Ferenc
Published: May 2008

Az antivirális kezelés időzítése nehéz feladat a fogamzóképes korú, hepatitis C-vírus által fertőzött nők esetében. Bár a női nem jobb prognosztikai faktor a betegség lefolyását illetően, az egyes esetek aktivitása és a fertőzöttségi periódus jelentősen különbözhet egymástól, ami befolyásolhatja a reproduktív korúakban a terápia időzítését. Terhesség, szoptatás alatt az antivirális kezelés szigorúan ellenjavallt. Az irodalmi adatok megoszlanak azon a téren, hogy a gyermeket tervezők kezelése a modern kezelési formákkal (peginterferon + ribavirin) a terhesség(ek) előtt vagy azt követően történjen-e meg. A szülés kapcsán a fertőzés anyáról gyermekre való átvitelének valószínűsége mintegy 5% körüli, amit a leginkább az anyai viraemia befolyásol. Nem szült nők és menopauza kapcsán a prognózis a C-vírus-hepatitis lefolyását illetően rosszabb. A magzati fejlettséget, a koraszülések arányát nagy betegszámú vizsgálatokban sem befolyásolta a hepatitis C-vírus-fertőzöttség. A kombinált kezelés több nőgyógyászati és egyéb mellékhatással is járhat (vérzészavarok, libidó csökkenése, depresszió). A leginkább az ajánlható, hogy egyedi mérlegeléssel döntsünk még nem szült hepatitis C-vírus-fertőzött, gyermeket akaró nőbetegeink antivirális kezelésének időpontjáról.
Atomistic simulation of fracture in Ni3Al
Authors: Xie Hong-Xian , Wang Chong-Yu , Yu Tao
Published: June 2008

The molecular dynamics method has been used to simulate mode I cracking in Ni3Al. Close attention has been paid to the process of atomic configuration evolution of the cracks. The simulation results show that at low temperature, the Shockley partial dislocations are emitted before the initiation of the crack propagation, subsequently forming the pseudo-twins on (111) planes in crack-tip zone, and then the crack cleavage occurs. The emitting of the Shockley partial dislocations accompanies the crack cleavage during the simulation process. At the higher temperature, the blunting at the crack tip is caused by the [110] superdislocations emitted on (100) plane. The present work also shows that the dipole dislocations on (111) planes in the 1/2[110] dislocation core can be formed.
Controlled growth of highly aligned amorphous SiOx sunflower-like morphology
Authors: Zhang Xitian , Liu Zhuang , Zheng Zhi , Hark Suikong
Published: June 2008

Highly aligned nanowire bundles were controllably fabricated through the reaction of Si with oxygen, using molten Ga and Au as catalysts. Scanning electron microscopy reveals that the bundles have the ability to self-assemble into various morphologies, a few of which, including one that strikingly resembles a sunflower, were not reported before. Examinations of the bundles by transmission electron microscopy show that they contain fine, amorphous SiOx nanowires, with x ranging from 1.2 to 1.5. In the sunflower-like morphology, highly packed bundles form the disc florets and loosely packed bundles around the rim of the disc form the ray florets. We have studied the conditions under which the sunflower-like morphology could be obtained and suggest a possible mechanism for its growth. Room-temperature cathodoluminescence spectra of the nanowire bundles show that they emit an intense broad-band light covering the entire visible range.
Mechanical properties of wood-derived silicon carbide aluminum-alloy composites as a function of temperature
Authors: Wilkes T.E. , Pastor J.Y. , Llorca J. , Faber K.T.
Published: June 2008

The mechanical behavior [i.e., stiffness, strength, and toughness (KIC)] of SiC Al–Si–Mg metal–ceramic composites (50:50 by volume) was studied at temperatures ranging from 25 to 500 °C. The SiC phase was derived from wood precursors, which resulted in an interconnected anisotropic ceramic that constrained the pressure melt-infiltrated aluminum alloy. The composites were made using SiC derived from two woods (sapele and beech) and were studied in three orthogonal orientations. The mechanical properties and corresponding deformation micromechanisms were different in the longitudinal (LO) and transverse directions, but the influence of the precursor wood was small. The LO behavior was controlled by the rigid SiC preform and the load transfer from the metal to the ceramic. Moduli in this orientation were lower than the Halpin–Tsai predictions due to the nonlinear and nonparallel nature of the Al-filled pores. The LO KIC agreed with the Ashby model for the KIC contribution of ductile inclusions in a brittle ceramic.
Fabrication of spherical particles with mixed amorphous/crystalline nanostructured cores and insulating oxide shells
Authors: Hong J.I. , Parker F.T. , Solomon V.C. , Madras P. , Smith David J. , Berkowitz A.E.
Published: June 2008

By spark-eroding Fe75Si15B10 in water/ethanol mixtures, spherical particles with nanostructured cores consisting of mixed amorphous and crystalline phases were produced. The relative volume fractions of the amorphous and crystalline phases were dependent on the water/ethanol ratio. In the same process, continuous oxide layers were formed on the particle surfaces. The basic mechanisms responsible for the formation of the surface oxide layers and the core nanostructures were modeled. At frequencies ranging from 1 to 100 MHz, the combination of the core nanostructures and the insulating oxide shells yielded exceptionally low-loss magnetic behavior.
Calorimetric study of CaCu3Ti4O12, a ceramic with giant permittivity
Authors: Levchenko Andrey A. , Marchin Loïc , Moriya Yosuke , Kawaji Hitoshi , Atake Tooru , Guillemet-Fritsch Sophie , Durand Bernard , Navrotsky Alexandra
Published: June 2008

We conducted an investigation into the thermodynamic properties of two stoichiometric CaCu3Ti4O12(CCTO) samples prepared by solid-state reaction and soft chemistry methods to probe the stability of the material relative to simpler oxide constituents (e.g., CaO, CuO, and TiO2) over a wide temperature range. Thermodynamic functions (i.e., heat capacity, formation enthalpies, entropies, and Gibbs free energies) have been measured from near absolute zero to 1100 K using calorimetric methods, including drop solution, low-temperature adiabatic relaxation, and differential scanning calorimetry. In addition, the thermodynamic characteristics of the magnetic-phase transition from the antiferromagnetic to the paramagnetic state are reported. It has been shown that CCTO is very stable relative to constituent oxides and calcium titanate at room temperature and higher, independent of the synthesis route. The enthalpic factor is dominant in the thermodynamics of CCTO, with the entropic factor having almost no effect on the stability of the compound relative to other oxide assemblages. The recommended values for the standard molar enthalpy of formation from constituent oxides and from elements at 298.15 K are −122.1 ± 4.5 and −4155.7 ± 5.2 kJ/mol−1, respectively. The mean of the third law entropy at 298.15 K is 368.4 ± 0.1 J/mol−1/K−1. Based on the thermodynamic data reported, the study confirms the possibility of CCTO decomposition in a reducing atmosphere or CO2 under conditions recently observed in experiments.
Cleavage cracking across triple grain boundary junctions in freestanding silicon thin films
Authors: Chen J. , Qiao Y.
Published: June 2008

This article is focused on a fractography study of cleavage cracking at triple grain boundary junctions in freestanding silicon thin films. At a triple junction, as the crystallographic orientations of the two grains ahead of the crack are different by only a few degrees, the cleavage front advance becomes quite jerky. The crack first enters the grain of smaller boundary toughness and then turns into the other grain from the lateral direction. Consequently, the overall fracture resistance cannot be analyzed in the framework of line-average theory. The nonuniform characteristic of crack behavior can be attributed to the increase in local stress intensity. A few typical crack front advance modes are identified.
Synthesis of Ni ferrite and Co ferrite rodlike particles by superposition of a constant magnetic field
Authors: Vereda Fernando , de Vicente Juan , Hidalgo-Álvarez Roque
Published: June 2008

We report the fabrication of micron-sized rodlike particles of nonstoichiometric Co and Ni ferrites by aging coprecipitated Fe(OH)2 and M(OH)2—where M is either Ni or Co—at 90 °C in the presence of an external magnetic field (B ≈ 405 mT). Potassium nitrate was used as a mild oxidant. Resultant particles were analyzed by means of electron microscopy, x-ray powder diffraction (XRD), magnetometry, energy dispersive x-ray (EDX) spectrometry, and atomic absorption spectroscopy. Rodlike particles of both types of ferrite exhibited a relatively uniform thickness, an average aspect ratio close to 10, and have a spinel crystalline structure. EDX spectrometry and atomic absorption spectroscopy confirmed the incorporation of Ni2+ and Co2+ in the respective ferrite particles. The incorporation of Co2+ led to non-negligible remanence and coercivity. The incorporation of Ni2+ led to a lower saturation magnetization, whereas the remanence and coercivity of the Ni ferrite were very low, still typical of a soft ferrimagnetic material. The mechanism of formation of the rodlike particles was investigated by the time-dependent observation of growing Ni ferrite rods.
In situ coordination of pyridine, quinoline, and quinoxaline with copper(I) iodide at the solid–liquid interface: Formation, characterization, and function of the microcrystal films
Authors: Lv Baoqiang , Cheng Changming , Yuan Hongyan , Xiao Dan , Choi Martin M.F.
Published: June 2008

An in situ surface-reaction approach has been developed for the synthesis of microcrystals Cu4I4(C6H5N)4, Cu4I4(C9H7N)4, and Cu2I2(C8H6N2) in solid films. Microcrystals of Cu4I4(C6H5N)4, Cu4I4(C9H7N)4, and Cu2I2(C8H6N2) were easily formed on a copper substrate at the solid Cu–liquid pyridine (C6H5N),–quinoline (C9H7N), and–quinoxaline (C8H6N2) interfaces. The resulting microcrystal films were characterized by photoluminescence spectroscopy, scanning electron microscopy, transmission electron microscopy, energy dispersive x-ray spectroscopy, x-ray diffraction, and electrochemical impedance spectroscopy. The effect of ligands on the morphology of the film materials and their chemical properties were also discussed. These microcrystal films possessing reversible photocurrent and photovoltage properties were studied in detail. The photoactive and mechanically stable complex films described here may provide new strategies for fabricating photoluminescence solid films, photomodulation potential, and current films. The potential applications of the microcrystal films are for small light-induced electronic junction and photoluminescence sensors.
Adubação orgânica, manejo de irrigação e fertilização na produção de melão amarelo
Authors: Souza Jean de O , Medeiros José F de , Silva Marcelo C de C , Almeida Antônio HB de
Published: May 2008

O objetivo do trabalho foi estudar o efeito da adubação orgânica e manejo de irrigação e fertilização na produção de melão amarelo. O experimento foi realizado no período de outubro a novembro de 2001, no município de Mossoró-RN. O delineamento experimental foi em blocos inteiramente casualizados, com duas repetições e os fatores foram arranjados no esquema fatorial 3 x 4 + 1. Foram estudados três tipos de materiais orgânicos (composto Ribumim®, composto Integral® e esterco) em quatro doses (50; 100; 150 e 200% do recomendado) aplicadas no plantio, e um tratamento testemunha (sem adubo orgânico), além de 3 manejos de irrigação e fertirrigação em experimentos representados pelas áreas A1, A2 e A3. Foram avaliados: produção comercial de frutos, massa media de frutos comerciais, firmeza de polpa e sólidos solúveis totais. A adição de adubo orgânico ao solo favoreceu o incremento da produção comercial de frutos nas áreas A1 e A2 e firmeza na área A1, que receberam as maiores quantidades de adubo via fertirrigação, embora essas áreas tenham produzido menos que a Área A3, onde os materiais orgânicos não influenciaram na produção.
Desenvolvimento da espinheira-santa sob diferentes intensidades luminosas e níveis de poda
Authors: Souza José Roberto P de , Rocha Juliana N , Morais Heverly , Caramori Paulo H , Johansson Loana APS , Miranda Luís V
Published: May 2008

A espinheira-santa (Maytenus ilicifolia) possui, além de propriedades antiulcerogênica e antigástrica, um imenso potencial farmacológico e cosmético ainda pouco explorado de maneira racional. O objetivo do trabalho foi avaliar o desenvolvimento das plantas submetidas a diferentes manejos de luminosidade e poda durante o período de um ano. Foram realizados dois experimentos, um em uma área sombreada por espécies nativas e, outro, a pleno sol. O delineamento experimental utilizado foi blocos ao acaso, com 6 repetições e parcelas com duas plantas na área útil. Foram aplicados três tipos de podas, plantas sem eliminação de folhas/poda, plantas com eliminação de 30% das folhas e galhos e plantas com poda a 20 cm do solo; e foram realizadas quatro avaliações (0; 100; 211; 331 dias pós a poda (DAP)). Nas plantas que cresceram a pleno sol, a poda drásticas resultou em não desenvolvimento de folhas até a última data de avaliação. Nessa condição de irradiação, o número de folhas por ramo alterou-se em função da poda executada (variando de 11,2 a 15,7 na ausência de poda; e de 8,7 a 11,7, com poda de 30%), mas permaneceu constante ao longo do tempo. Na área sombreada, as plantas que sofreram poda drástica apresentaram o maior número de folhas por ramo (25,0 e 29,8 folhas por ramo com 100 e 211 DAP, respectivamente) e a maior área foliar (18,0; 13,9 e 15,5 cm² aos 100, 211 e 331 DAP). Numericamente, foi possível observar que o sombreamento foi mais favorável ao desenvolvimento das plantas e à produção de biomassa que a exposição ao sol, fator muito importante para estabelecimento de cultivos e definição de estratégias de manejo da espinheira-santa. Houve redução de até 2,9ºC nas temperaturas máximas diárias no ambiente sombreado em comparação com sol aberto, mas a umidade relativa do ar não se alterou, variando entre 63,3 e 79,4% nas duas condições.
Qualidade fisiológica de sementes de cebola em função do estádio de maturação das umbelas
Authors: Nascimento Warley M , Freitas Raquel A de
Published: May 2008

O trabalho teve como objetivo avaliar o efeito do estádio de maturação da umbela e da presença ou ausência de hastes sobre o potencial fisiológico das sementes. Foi utilizada a cultivar Beta Cristal, destinada à produção de picles. Por ocasião da abertura dos botões florais, foram selecionadas e identificadas, ao acaso, 200 umbelas com cerca de 70% de flores abertas. O experimento foi conduzido no delineamento inteiramente casualizado, em fatorial 2 x 5, correspondendo a dois comprimentos de haste floral (0 e 30 cm) e cinco épocas de colheita (cápsulas fechadas e 10% de sementes com tegumento preto; cápsulas fechadas e 90% de sementes com tegumento preto; cápsulas fechadas e 100% de sementes com tegumento preto; 10% de cápsulas abertas e 30% de cápsulas abertas), com intervalo semanal entre as colheitas. As sementes atingiram o grau de umidade mais adequado entre a terceira e quarta colheitas. Foi também até a quarta colheita que se verificou um acréscimo na massa das sementes (1000 sementes = 3,78 g). A colheita das umbelas com haste promoveu aumento na massa das sementes apenas até a segunda colheita, sendo prejudicial na terceira e não influenciando a partir de então. As sementes oriundas das três últimas colheitas apresentaram maior potencial germinativo, superior a 88% e maior vigor, superior a 52%, independente das umbelas terem sido colhidas com ou sem haste. No teste de envelhecimento acelerado, sementes provenientes das duas últimas colheitas apresentaram maior vigor (superior a 90%), não havendo forte influência da presença da haste floral. A emergência das plântulas em casa-de-vegetação também foi superior (acima de 90%) para sementes provenientes das duas últimas colheitas, independente da presença da haste floral. Conclui-se portanto que a época mais indicada para a colheita de sementes da cebola, cultivar Beta Cristal, foi quando 10% das cápsulas estavam abertas, não havendo benefício da presença da haste floral.
Nutrição mineral do mangarito num Latossolo Vermelho Amarelo
Authors: Costa Candido A da , Ramos Sílvio Junio , Alves Daniel S , Fernandes Luiz Arnaldo , Sampaio Regynaldo A , Martins Ernane Ronie
Published: May 2008

Com o objetivo de caracterizar as limitações nutricionais para a produção de matéria seca do mangarito [(Xanthosoma mafaffa (L.) Schott)], conduziu-se um experimento em casa de vegetação com amostras da camada de 0-20 cm de um Latossolo Vermelho Amarelo sob vegetação de cerrado, coletado no município de Montes Claros, MG. O cultivo foi realizado em vasos de 3 L de capacidade. O delineamento experimental foi inteiramente casualizado, em treze tratamentos, com três repetições. Os tratamentos foram baseados na técnica do elemento faltante (em que se omite a calagem e cada um dos macronutrientes e micronutrientes). A ordem decrescente dos tratamentos que mais afetaram a produção de matéria seca da parte aérea foi: -Calagem> -P > -S > testemunha > -B > -Calagem+Ca+Mg > -N > -K. A omissão de Ca, Mg, Zn e Cu não afetaram a produção de matéria seca da parte aérea. A ordem decrescente dos tratamentos que mais afetaram a produção de matéria seca de raízes foi: -B > -Mg > -Calagem+Ca+Mg > -K > -N > -Zn > -Calagem > -S > -Cu > -Ca > -Cu > -Ca > testemunha > -P.
Effect of extrusion-cooking in total carotenoids content in cream and orange flesh sweet potato cultivars
Authors: Fonseca Marcos José de O , Soares Antonio G , Freire Junior Murillo , Almeida Dejair L de , Ascheri José Luiz R
Published: May 2008

Sweet potato (Ipomoea batatas) is a food crop that supplies energy, minerals and vitamins C and B. Some cultivars are very rich in carotenoids (pro-vitamin A). In this study were evaluated and compared the total carotenoids content of two cultivars and the losses on the dehydrated extruded sweet potato flour. Samples from organic and conventional crops were analyzed, in the form of fresh and dehydrated extruded samples. Total carotenoids content of the fresh product, expressed on wet basis, was of 437 µg 100 g-1 for the cream cultivar and 10,12 µg 100 g-1 for the orange cultivar. After dehydration, losses of total carotenoids were of 41% and 38%, respectively. The fresh orange cultivar presented high total carotenoids content in comparison to the cream cultivar. The extruded orange sweet potato flour showed the lowest losses in total carotenoids. Therefore, the processed flour of orange sweet potato could be used to obtain pre-gelatinized extruded flour with high total carotenoids content.
Liver histological, portal flow and plasmatic nitric oxide alterations caused by biliary obstruction and drainage in rats
Authors: Dias Miguel Angel , Ceneviva Reginaldo , Elias Jr. Jorge , Zucoloto Sergio , Baldo Caroline Floreoto , Évora Paulo Roberto Barbosa
Published: May 2008

PURPOSE: To evaluate liver alterations caused by biliary obstruction and drainage. METHODS: Thirty-nine male Wistar rats were randomly distributed in 4 groups: BO (n=18) bile duct ligation for 20 days, with a periodic evaluation of liver histological alterations, Doppler echography portal flow and measurements of NO and malondialdehyde (MDA); BO/DB (n=13) bile duct occlusion for 20 days followed by biliary drainage by choledochoduodenal anastomosis, 5 days follow-up, same BO group parameters evaluations; group CED (n=4) sham operation and portal flow evaluation trough 20 days; CHB (n=4) sham operation, with hepatic biopsy on 25th day and followed-up trough 25 days, by the same parameters of group BO, with exception of portal flow. Direct bilirubin (DB) and alkaline phosphatase (AP) were evaluated in the group BO, BO/DB and CHB. RESULTS: The bile duct ligation led to an increase of DB and AP, development of liver histological alterations, reduction of portal flow and increase of plasmatic NO and of MDA levels. The bile duct clearing resulted in a reduction of DB, AP, NO, MDA histological alterations and increase of portal flow. CONCLUSION: The biliary occlusion resulted in cholestasis and portal flow reduction, besides the increase of plasmatic NO and of hepatic MDA levels, and histological liver alterations, with a tendency of normalization after the bile duct clearing.
Dry matter production and partitioning of maize hybrids and dwarf unes at four plant populations
Authors: Sangoi Luis , Salvador Ricardo
Published: May 2008

This experiment was conducted in Ames, Iowa, USA, to compare dry matter accumulation patterns of maize genotypes contrasting in height and leafiness, and to test whether reduction in plant height an leaf number through the use of dwarfing genes or earliness can improve grain dry matter allocation. Five plant genotypes were tested: a full season hybrid adapted to central lowa (NK 4525), a short season hybrid adapted to northern Minnesota (C1070), and three dwarf lines (156-A, 302-E and I17- A). The dwarves contained, respectively, the homozygous, independent, recessive dwarfing genes d3, d1 and br2. Each genotype was sown at four plant populations: 25, 50, 75 and 100.000 plants. ha-1. Hybrids had the greatest rates of decrease in total biomass and grain dry matter per plant when population was increased, though they also had larger absolute values of these variables at any given density. Hybrids produced more grain dry matter per unit of leaf area, and a higher harvest index, regardless the plant population used. Reduction in plant height or leaf number did not improve maize efficiency in producing and partitioning dry matter to the grain.
Efeito do AIB sobre o enraizamento e desenvolvimento de estacas de quivi (Actinidia deliciosa)
Authors: Manfroi Vitor , Francisconi Ana Helena Dias , Barradas Carlos Iguassu Nogueira , Seibert Eduardo
Published: May 2008

O objetivo do trabalho foi estudar o efeito do ácido 3-indoibiitirico (A/B) no enraizamento e desenvolvimento de estacas semi-lenhosas de quivi, cv. Monte. O experimento foi conduzido na Estação Experimental Agronômica da UFRGS, em Eldorado do Sul, RS, e constou de cinco tratamentos, com cinco repetições, em blocos casualizados. Usou-se 19 sacos/parcela, com duas estacas/saco plástico, plantadas em uma mistura argila: areia.-esterco (1: 1: 1): e tratadas com AIB nas concentrações de: 2000ppm, 4000ppm, 6000ppm e 8000ppm, além da testemunha (sem AIB). O AIB não influenciou na porcentagem de enraizamento das estacas, mas resultou no aumento linear do peso seco médio das raízes. Houve, da mesma forma, incrementos lineares no comprimento e no peso seco dos brotos, à medida que se elevou a concentração de AIB.
Produtividade e qualidade de sementes de flores produzidas em Santa Maria
Authors: Bellé Rogério Antônio , Spannenberg Rudimar
Published: May 2008

Com o objetivo de avaliar o potencial de produção e a qualidade de sementes, foram cultivadas 15 espécies deflores nas condições de Santa Maria (Latitude 29°41'S e Longitude 53°48'W). O experimento foi realizado a campo no delineamento blocos ao acaso com quatro repetições. A grande maioria das espécies produz rendimento médio de sementes elevado apesar da variabilidade. Nas condições de benefïciamento oferecidas, as espécies Dianthus, Eschscholtzia, Nigella e Fhlox produziram sementes com alta germinação. As espécies Anthirrinum, Gelosia, Gailiardia, Nicotina, Scabiosa e Zinnia possuem potencial de produção de sementes de melhor qualidade, desde que se melhore, principalmente, o beneficiamento.
Efeito de sistemas de manejo nas propriedades físicas de um latossolo vermelho-escuro
Authors: Secco Deonir , Da Ros Clovis Orlando , Fiorin Jackson Ernani , Pautz Carlito Veck , Pasa Luciano
Published: May 2008

Este trabalho foi realizado em 1995 na área experimental da Universidade de Cruz Alta, UNICRUZ, Cruz Alta - RS, com o objetivo de avaliar a influência de diferentes sistemas de manejo do solo nas propriedades físicas de um latossolo vermelho-escuro distrófico, bem como no rendimento de grãos da cultura da soja. O delineamento experimental utilizado foi o de blocos ao acaso com quatro repetições. Os sistemas de manejo do solo foram: (1) plantio direto contínuo -PDC; (2) plantio direto e escarificação de acordo com a necessidade (sistema dinâmico) - PDSD; (3) plantio direto no verão com escarificação no outono/inverno - PD V; (4) plantio convencional: escarificador mais grade niveladora - PCEG; e, (S) plantio convencional: arado de discos mais grade niveladora - PCAG. Determinou-se o espaço poroso (porosidade total, macro e microporosidade) e a densidade do solo. As amostras foram coletadas em dois pontos por parcela nas profundidades de 0-7, 7-14 e 14-21 cm. A densidade do solo foi maior nas profundidades de 0-7 cm e 7- l4cm para o tratamento PDC que diferiu dos demais tratamentos à exceção ao tratamento PDSD. A porosidade lote e a microporosidade foram menores nos tratamentos PDC e PDSD, nas profundidades de 0-7, 7-14 e 14-21 cm, quando comparados aos tratamentos P D V, PCEG e PCAG. Para a microporosidade, apenas na profundidade de 7-14cm encontrou-se diferença significativa entre os valores, onde o tratamento PDC diferiu com valor superior apenas do tratamento PCAG. O rendimento de grãos de soja não diferiu entre os sistemas de manejo do solo utilizados.
Variabilidade genética para teor de proteína bruta em grãos de aveia
Authors: Matiello Rodrigo Rodrigues , Sereno Maria Jane Cruz de Mello , Barbosa Neto José Fernandes , Carvalho Fernando Irajá Felix de , Taderka Ivone , Pegoraro Diego Girardi
Published: May 2008

O aumento da utilização dos grãos de aveia na alimentação humana tem estimulado os melhoristas a selecionar genótipos com alta qualidade de grãos. O presente trabalho foi realizado com o objetivo de identificar e caracterizar a variabilidade genética para o caráter teor de proteína bruta de grãos em genótipos cultivados de aveia, introduções silvestres de A. fatua L., A. sterilis L. e em populações híbridas de A. sativa L. x A. sterilis L. Os resultados revelaram uma ampla variabilidade genética para o caráter dentro dos grupos estudados. As diferenças observadas entre os genótipos cultivados parecem ocorrer devido a constituição genotípica diferenciada. O grupo silvestre de A. sterilis L. foi, em média, superior aos demais, sendo que a introdução I-325 se destacou pelo alto teor de proteína. O comportamento similar entre as introduções de A. fatua L. pode ser atribuído a coleta de introduções de apenas uma região, o que reduziu a variabilidade genética. Foram encontrados híbridos artificiais entre A. sativa L. x A. sterilis L. com alto teor de proteína e características desejáveis do grupo cultivado.
Eficácia do fembendazole no controle de nematódeos de pacu Piaractus mesopotamicus (Holmberg, 1987)
Authors: Parra Jorge Erick Garcia , Brandão Deodoro Atlante , Ceccarelli Paulo Sérgio
Published: May 2008

O presente trabalho foi realizado no Centro de Pesquisa e Treinamento em Aquicultura (CEPTA/1BAMA), município de Pirassununga, SP. Foram utilizados 60 pacus, dos viveiros da Estação de Piscicultura do CEPTA, com peso médio de 600g. Foi realizado um teste visando avaliar o efeito do Femben-dazote (adicionado no alimento em diferentes dosagens), sobre os nematódeos presentes no tubo intestinal do pacu, utilizando três tratamentos: Tl - grupo testemunha (ração sem Fembendazole), T2 - 20mg de Fembendazole/kg de ração e T3 - 40mg de Fembendazo-le/kg de ração. O delineamento foi inteiramente casualizado. A unidade experimental foi o peixe. Não houve diferença significativa (P 0,05) entre os tratamentos com anti-helmintico Fembendazole nas dosagens de 20mg/kg e 40/ng/kg de ração e o grupo testemunha.
Ocorrência de Amblyomma fuscum Neumann, 1899 e Amblyomma humerale Koch, 1844 (Acari: Ixodidae) em Bufo arenalis no estado de São Paulo, Brasil
Authors: Sinkoc Afonso Lodovico , Brum João Guilherme Werner
Published: May 2008

O objetivo deste trabalho é relatar a ocorrência do parasitismo monoespecífico de A. fuscum NEUMANN, 1899 e A. humerale KOCH, 1844 em sapos (Bufo arenalis) no Município de Rosana, Estado de São Paulo, Brasil. Este relato caracteriza um novo hospedeiro e uma nova localização geográfica para estas duas espécies de carrapatos.