bluuebunny/crossref_metadata_2025 huggingface dataset:
Supplemental Instruction in Introductory Biology I: Enhancing the Performance and Retention of Underrepresented Minority Students
Authors: Rath Kenneth A. , Peterfreund Alan R. , Xenos Samuel P. , Bayliss Frank , Carnal Nancy
Published: November 2007

Supplemental instruction classes have been shown in many studies to enhance performance in the supported courses and even to improve graduation rates. Generally, there has been little evidence of a differential impact on students from different ethnic/racial backgrounds. At San Francisco State University, however, supplemental instruction in the Introductory Biology I class is associated with even more dramatic gains among students from underrepresented minority populations than the gains found among their peers. These gains do not seem to be the product of better students availing themselves of supplemental instruction or other outside factors. The Introductory Biology I class consists of a team-taught lecture component, taught in a large lecture classroom, and a laboratory component where students participate in smaller lab sections. Students are expected to master an understanding of basic concepts, content, and vocabulary in biology as well as gain laboratory investigation skills and experience applying scientific methodology. In this context, supplemental instruction classes are cooperative learning environments where students participate in learning activities that complement the course material, focusing on student misconceptions and difficulties, construction of a scaffolded knowledge base, applications involving problem solving, and articulation of constructs with peers.
A Faculty Team Works to Create Content Linkages among Various Courses to Increase Meaningful Learning of Targeted Concepts of Microbiology
Authors: Marbach-Ad Gili , Briken Volker , Frauwirth Kenneth , Gao Lian-Yong , Hutcheson Steven W. , Joseph Sam W. , Mosser David , Parent Beth , Shields Patricia , Song Wenxia , Stein Daniel C. , Swanson Karen , Thompson Katerina V. , Yuan Robert , Smith Ann C.
Published: November 2007

As research faculty with expertise in the area of host–pathogen interactions (HPI), we used a research group model to effect our professional development as scientific educators. We have established a working hypothesis: The implementation of a curriculum that forms bridges between our seven HPI courses allows our students to achieve deep and meaningful learning of HPI concepts. Working collaboratively, we identified common learning goals, and we chose two microorganisms to serve as anchors for student learning. We instituted variations of published active-learning methods to engage students in research-oriented learning. In parallel, we are developing an assessment tool. The value of this work is in the development of a teaching model that successfully allowed faculty who already work collaboratively in the research area of HPI to apply a “research group approach” to further scientific teaching initiatives at a research university. We achieved results that could not be accomplished by even the most dedicated instructor working in isolation.
A Connectionist Model of English Past Tense and Plural Morphology
Authors: Plunkett Kim , Juola Patrick
Published: November 2007

The acquisition of English noun and verb morphology is modeled using a single‐system connectionist network. The network is trained to produce the plurals and past tense forms of a large corpus of monosyllabic English nouns and verbs. The developmental trajectory of network performance is analyzed in detail and is shown to mimic a number of important features of the acquisition of English noun and verb morphology in young children. These include an initial error‐free period of performance on both nouns and verbs followed by a period of intermittent over‐regularization of irregular nouns and verbs. Errors in the model show evidence of phonological conditioning and frequency effects. Furthermore, the network demonstrates a strong tendency to regularize denominal verbs and deverbal nouns and masters the principles of voicing assimilation. Despite their incorporation into a single‐system network, nouns and verbs exhibit some important differences in their profiles of acquisition. Most importantly, noun inflections are acquired earlier than verb inflections. The simulations generate several empirical predictions that can be used to evaluate further the suitability of this type of cognitive architecture in the domain of inflectional morphology.
Dynamical Models of Sentence Processing
Authors: Tabor Whitney , Tanenhaus Michael K.
Published: November 2007

We suggest that the theory of dynamical systems provides a revealing general framework for modeling the representations and mechanism underlying syntactic processing. We show how a particular dynamical model, the Visitation Set Gravitation model of Tabor, Juliano, and Tanenhaus (1997), develops syntactic representations and models a set of contingent frequency effects in parsing that are problematic for other models. We also present new simulations showing how the model accounts for semantic effects in parsing, and propose a new account of the distinction between syntactic and semantic incongruity. The results show how symbolic structures useful in parsing arise as emergent properties of connectionist dynamical systems.
Connectionist Models of Language Production: Lexical Access and Grammatical Encoding
Authors: Dell Gary S. , Chang Franklin , Griffin Zenzi M.
Published: November 2007

Theories of language production have long been expressed as connectionist models. We outline the issues and challenges that must be addressed by connectionist models of lexical access and grammatical encoding, and review three recent models. The models illustrate the value of an interactive activation approach to lexical access in production, the need for sequential output in both phonological and grammatical encoding, and the potential for accounting for structural effects on errors and structural priming from learning.
The Ste20-like kinase SvkA ofDictyostelium discoideumis essential for late stages of cytokinesis
Authors: Rohlfs Meino , Arasada Rajesh , Batsios Petros , Janzen Julia , Schleicher Michael
Published: November 2007

The genome of the social amoeba Dictyostelium discoideum encodes ∼285 kinases, which represents ∼2.6% of the total genome and suggests a signaling complexity similar to that of yeasts and humans. The behavior of D. discoideum as an amoeba and during development relies heavily on fast rearrangements of the actin cytoskeleton. Here, we describe the knockout phenotype of the svkA gene encoding severin kinase, a homolog of the human MST3, MST4 and YSK1 kinases. SvkA-knockout cells show drastic defects in cytokinesis, development and directed slug movement. The defect in cytokinesis is most prominent, leading to multinucleated cells sometimes with >30 nuclei. The defect arises from the frequent inability of svkA-knockout cells to maintain symmetry during formation of the cleavage furrow and to sever the last cytosolic connection. We demonstrate that GFP-SvkA is enriched at the centrosome and localizes to the midzone during the final stage of cell division. This distribution is mediated by the C-terminal half of the kinase, whereas a rescue of the phenotypic changes requires the active N-terminal kinase domain as well. The data suggest that SvkA is part of a regulatory pathway from the centrosome to the midzone, thus regulating the completion of cell division.
Direct interaction of tyrosinase with Tyrp1 to form heterodimeric complexes in vivo
Authors: Kobayashi Takeshi , Hearing Vincent J.
Published: November 2007

Mutations of the critical and rate-limiting melanogenic enzyme tyrosinase (Tyr) result in hypopigmentation of the hair, skin and eyes. Two other related enzymes, Tyrp1 and Dct, catalyze distinct post-Tyr reactions in melanin biosynthesis. Tyr, Tyrp1 and Dct have been proposed to interact with and stabilize each other in multi-enzyme complexes, and in vitro, Tyr activity is more stable in the presence of Tyrp1 and/or Dct. We recently reported that Tyr is degraded more quickly in mutant Tyrp1 mouse melanocytes than in wild-type Tyrp1 melanocytes, and that decreased stability of Tyr can be partly rescued by infection with wild-type Tyrp1. Although interactions between Tyr and Tyrp1 have been demonstrated in vitro, there is no direct evidence for Tyr interaction with Tyrp1 in vivo. In this study, we use in vivo chemical crosslinking to stabilize the association of Tyr with other cellular proteins. Western blot analysis revealed that Tyrp1, but not Dct, associates with Tyr in murine melanocytes in vivo, and more specifically, in melanosomes. Two-dimensional SDS-PAGE analysis detected heterodimeric species of Tyr and Tyrp1. Taken together, these data demonstrate that Tyrp1 interacts directly with Tyr in vivo, which may regulate the stability and trafficking of melanogenic enzymes and thus pigment synthesis.
Stage One Digitization Project Report: Part 2
Authors: Ewbank Lynn
Published: November 2007

On 14 March 2002, at the Arkansas Museum Association annual meeting, I spoke on the choices we made and the lessons we learned during the Stage One Digitization (SOD) grant project at the Arkansas History Commission (AHC). As SOD included three elements:
Lack of Self-Administration of Cocaine in Dopamine D1Receptor Knock-Out Mice
Authors: Caine S. Barak , Thomsen Morgane , Gabriel Kara I. , Berkowitz Jill S. , Gold Lisa H. , Koob George F. , Tonegawa Susumu , Zhang Jianhua , Xu Ming
Published: November 2007

Evidence suggests a critical role for dopamine in the reinforcing effects of cocaine in rats and primates. However, self-administration has been less often studied in the mouse species, and, to date, “knock-out” of individual dopamine-related genes in mice has not been reported to reduce the reinforcing effects of cocaine. We studied the dopamine D1receptor and cocaine self-administration in mice using a combination of gene-targeted mutation and pharmacological tools. Two cohorts with varied breeding and experimental histories were tested, and, in both cohorts, there was a significant decrease in the number of D1receptor knock-out mice that met criteria for acquisition of cocaine self-administration (2 of 23) relative to wild-type mice (27 of 32). After extinction of responding with saline self-administration, dose–response studies showed that cocaine reliably and dose dependently maintained responding greater than saline in all wild-type mice but in none of the D1receptor knock-out mice. The D1-like agonist SKF 82958 (2,3,4,5,-tetrahydro-6-chloro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine hydrobromide) and the D2-like agonist quinelorane both functioned as positive reinforcers in wild-type mice but not in D1receptor mutant mice, whereas food and intravenous injections of the opioid agonist remifentanil functioned as positive reinforcers in both genotypes. Finally, pretreatment with the D1-like antagonist SCH 23390 [R-(+)-8-chloro-2,3,4,5-tetrahydro-3-methyl-5-phenyl-1H-3-benzazepine-7-01] produced surmountable antagonism of the reinforcing effects of cocaine in the commonly used strain C57BL/6J. We conclude that D1receptor knock-out mice do not reliably self-administer cocaine and that the D1receptor is critical for the reinforcing effects of cocaine and other dopamine agonists, but not food or opioids, in mice.
Progesterone and Estrogen Regulate Alzheimer-Like Neuropathology in Female 3xTg-AD Mice
Authors: Carroll Jenna C. , Rosario Emily R. , Chang Lilly , Stanczyk Frank Z. , Oddo Salvatore , LaFerla Frank M. , Pike Christian J.
Published: November 2007

Estrogen depletion in postmenopausal women is a significant risk factor for the development of Alzheimer's disease (AD), and estrogen-based hormone therapy may reduce this risk. However, the effects of progesterone both alone and in combination with estrogen on AD neuropathology remain unknown. In this study, we used the triple transgenic mouse model of AD (3xTg-AD) to investigate the individual and combined effects of estrogen and progesterone on β-amyloid (Aβ) accumulation, tau hyperphosphorylation, and hippocampal-dependent behavioral impairments. In gonadally intact female 3xTg-AD mice, AD-like neuropathology was apparent by 3 months of age and progressively increased through age 12 months, a time course that was paralleled by behavioral impairment. Ovariectomy-induced depletion of sex steroid hormones in adult female 3xTg-AD mice significantly increased Aβ accumulation and worsened memory performance. Treatment of ovariectomized 3xTg-AD mice with estrogen, but not progesterone, prevented these effects. When estrogen and progesterone were administered in combination, progesterone blocked the beneficial effect of estrogen on Aβ accumulation but not on behavioral performance. Interestingly, progesterone significantly reduced tau hyperphosphorylation when administered both alone and in combination with estrogen. These results demonstrate that estrogen and progesterone independently and interactively regulate AD-like neuropathology and suggest that an optimized hormone therapy may be useful in reducing the risk of AD in postmenopausal women.
Spatial Properties and Functional Organization of Small Bistratified Ganglion Cells in Primate Retina
Authors: Field Greg D. , Sher Alexander , Gauthier Jeffrey L. , Greschner Martin , Shlens Jonathon , Litke Alan M. , Chichilnisky E. J.
Published: November 2007

The primate visual system consists of parallel pathways initiated by distinct cell types in the retina that encode different features of the visual scene. Small bistratified cells (SBCs), which form a major projection to the thalamus, exhibit blue-ON/yellow-OFF [S-ON/(L+M)-OFF] light responses thought to be important for high-acuity color vision. However, the spatial processing properties of individual SBCs and their spatial arrangement across the visual field are poorly understood. The present study of peripheral primate retina reveals that contrary to previous suggestions, SBCs exhibit center-surround spatial structure, with the (L+M)-OFF component of the receptive field ∼50% larger in diameter than the S-ON component. Analysis of response kinetics shows that the (L+M)-OFF response in SBCs is slower than the S-ON response and significantly less transient than that of simultaneously recorded OFF-parasol cells. The (L+M)-OFF response in SBCs was eliminated by bath application of the metabotropic glutamate receptor agonistl-APB. These observations indicate that the (L+M)-OFF response of SBCs is not formed by OFF-bipolar cell input as has been suspected and suggest that it arises from horizontal cell feedback. Finally, the receptive fields of SBCs form orderly mosaics, with overlap and regularity similar to those of ON-parasol cells. Thus, despite their distinctive morphology and chromatic properties, SBCs exhibit two features of other retinal ganglion cell types: center-surround antagonism and regular mosaic sampling of visual space.
Bradykinin-Induced Microglial Migration Mediated by B1-Bradykinin Receptors Depends on Ca2+Influx via Reverse-Mode Activity of the Na+/Ca2+Exchanger
Authors: Ifuku Masataka , Färber Katrin , Okuno Yuko , Yamakawa Yukiko , Miyamoto Taiki , Nolte Christiane , Merrino Vanessa F. , Kita Satomi , Iwamoto Takahiro , Komuro Issei , Wang Bing , Cheung Giselle , Ishikawa Eiichi , Ooboshi Hiroaki , Bader Michael , Wada Keiji , Kettenmann Helmut , Noda Mami
Published: November 2007

Bradykinin (BK) is produced and acts at the site of injury and inflammation. In the CNS, migration of microglia toward the lesion site plays an important role pathologically. In the present study, we investigated the effect of BK on microglial migration. Increased motility of cultured microglia was mimicked by B1receptor agonists and markedly inhibited by a B1antagonist,but not by a B2receptor antagonist. BK induced chemotaxis in microglia isolated from wild-type and B2-knock-out mice but not from B1-knock-out mice. BK-induced motility was not blocked by pertussis toxin but was blocked by chelating intracellular Ca2+or by low extracellular Ca2+, implying that Ca2+influx is prerequisite. Blocking the reverse mode of Na+/Ca2+exchanger (NCX) completely inhibited BK-induced migration. The involvement of NCX was further confirmed by using NCX+/−mice; B1-agonist-induced motility and chemotaxis was decreased compared with that in NCX+/+mice. Activation of NCX seemed to be dependent on protein kinase C and phosphoinositide 3-kinase, and resultant activation of intermediate-conductance (IK-type) Ca2+-dependent K+currents (IK(Ca)) was activated. Despite these effects, BK did not activate microglia, as judged from OX6 staining. Usingin vivolesion models and pharmacological injection to the brain, it was shown that microglial accumulation around the lesion was also dependent on B1receptors andIK(Ca). These observations support the view that BK functions as a chemoattractant by using the distinct signal pathways in the brain and, thus, attracts microglia to the lesion sitein vivo.
Differential Effects of Serotonin and Dopamine on Human 5-HT3AReceptor Kinetics: Interpretation within an Allosteric Kinetic Model
Authors: Solt Ken , Ruesch Dirk , Forman Stuart A. , Davies Paul A. , Raines Douglas E.
Published: November 2007

Serotonin type 3 (5-HT3) receptors are members of the pentameric Cys-loop superfamily of receptors that modulate synaptic neurotransmission. In response to agonist binding and unbinding, members of this superfamily undergo a series of conformational transitions that define their functional properties. In this study, we report the results of electrophysiological studies using rapid solution exchange designed to characterize and compare the actions of the high-efficacy agonist serotonin and the low-efficacy agonist dopamine on human 5-HT3Areceptors expressed in human embryonic kidney HEK293 cells. In the case of serotonin, receptor activation rates varied with agonist concentration, and deactivation occurred as a single-exponential process with a rate that was similar to the maximal rate of desensitization. Receptors recovered slowly from long desensitizing pulses of serotonin with a sigmoidal time course. In the case of dopamine, receptor activation rates were independent of agonist concentration, receptor deactivation occurred as a complex process that was significantly faster than the maximal rate of desensitization, and recovery from desensitization occurred more quickly than with 5-HT and its time course was not sigmoidal. We developed an allosteric kinetic model for 5-HT3Areceptor activation, deactivation, desensitization, and resensitization. Interpretation of our results within the context of this model indicated that the distinct modulatory actions of serotonin versus dopamine are largely attributable to the vastly different rates with which these two agonists induce channel opening and dissociate from open and desensitized states.
Functional Compartmentalization of Endosomal Trafficking for the Synaptic Delivery of AMPA Receptors during Long-Term Potentiation
Authors: Brown Tyler C. , Correia Susana S. , Petrok Cortney N. , Esteban José A.
Published: November 2007

Endosomal membrane trafficking in dendritic spines is important for proper synaptic function and plasticity. However, little is known about the molecular identity and functional compartmentalization of the membrane trafficking machinery operating at the postsynaptic terminal. Here we report that the transport of AMPA-type glutamate receptors into synapses occurs in two discrete steps, and we identify the specific endosomal functions that control this process during long-term potentiation. We found that Rab11-dependent endosomes translocate AMPA receptors from the dendritic shaft into spines. Subsequently, an additional endosomal trafficking step, controlled by Rab8, drives receptor insertion into the synaptic membrane. Separate from this receptor delivery route, we show that Rab4 mediates a constitutive endosomal recycling within the spine. This Rab4-dependent cycling is critical for maintaining spine size but does not influence receptor transport. Therefore, our data reveal a highly compartmentalized endosomal network within the spine and identify the molecular components and functional organization of the membrane organelles that mediate AMPA receptor synaptic delivery during plasticity.
Echtzeit-Implementierung eines algebraischen Ableitungsschätzverfahrens (Realtime Implementation of an Algebraic Derivative Estimation Scheme)
Authors: Zehetner Josef , Reger Johann , Horn Martin
Published: November 2007

In der vorliegenden Arbeit wird die Echtzeitimplementierung eines algebraischen Verfahrens zur Schätzung von Zeitableitungen gemessener Signale vorgestellt. Ausgehend von einer Taylorreihendarstellung des betrachteten Signals werden mit Methoden der Operatorenrechnung Berechnungsvorschriften für Zeitableitungen beliebiger Ordnung hergeleitet. Diese können effizient in Echtzeit ausgewertet werden. Im vorliegenden Fall wird Matlab/Simulink als Werkzeug eingesetzt. Mit Hilfe eines Codegenerators und eines Target-Compilers können die Echtzeitroutinen mühelos auf verschiedene Zielplattformen übertragen werden. An Hand eines praktischen Anwendungsbeispiels wird die Leistungsfähigkeit des Ansatzes demonstriert.
Studies of the growth parameters for silver nanoparticle synthesis by inert gas condensation
Authors: Raffi M. , Rumaiz Abdul K. , Hasan M.M. , Shah S. Ismat
Published: November 2007

Silver nanoparticles were synthesized by an inert gas condensation method using flowing helium in the process chamber. Nucleation, growth mechanism, and the kinetics of nanoparticle formation in vapor phase are studied. Effect of process parameters, such as evaporation temperature and inert gas pressure, on the particle crystallinity, morphology, and size distribution are examined. Particles were synthesized at evaporation temperatures of 1123, 1273, and 1423 K and at helium pressures of 0.5, 1, 5, 50, and 100 Torr. Synthesized silver nanoparticles were characterized by x-ray diffraction (XRD) and transmission electron microscopy (TEM). The particle size ranged from 9 to 32 nm, depending on the growth conditions. At lower evaporation temperature and inert gas pressure, smaller particles with spherical shape showing less agglomeration are formed. Based on the experimental results and theoretical model of surface free energy and undercooling as a function of evaporation temperature and inert gas pressure, particle formation is analyzed. A simple operating map for nanoparticle synthesis is presented. The theoretical model is well supported by the experimental data.
Nanoindentation investigation of the mechanical behaviors of nanoscale Ag/Cu multilayers
Authors: Wen S.P. , Zong R.L. , Zeng F. , Gao Y. , Pan F.
Published: November 2007

The microstructure, hardness, elastic modulus, and indentation creep of Ag/Cu multilayers prepared by magnetron sputtering were investigated by x-ray diffraction, transmission electron microscopy, and nanoindentation. The hardness values obey the Hall–Petch relationship as the periodicity decreases to 20 nm. For multilayers with periodicity smaller than 20 nm, the Hall–Petch relationship breaks down and the hardness values saturate at about 4.6 GPa; moreover, there are shear bands formed around their indents and strain bursts occurring during the load-holding process of indentation creep. These results imply that there is a transition of the deformation mechanism in the region where the periodicity is equal to 20 nm. This transition of the deformation mechanism can be ascribed to grain-size-dependent competition between the dislocations-mediated plasticity and grain-boundary sliding-mediated plasticity.
Preparation and characteristics of novel poly-L-lactide/β-calcium metaphosphate fracture fixation composite rods
Authors: Liao Li , Chen Lin , Chen Ai-Zheng , Pu Xi-Ming , Kang Yun-Qing , Yao Ya-Dong , Liao Xiao-Ming , Huang Zhong-bing , Yin Guang-Fu
Published: November 2007

A kind of novel poly-L-lactide (PLLA)/β-calcium metaphosphate (β-CMP) fracture-fixation composite rod was prepared by a two-step compression-molding method. The in vitro bioactivity of the composite rod was evaluated by investigating the effects of dissolved products from the composite rod on osteoblasts. In addition, the in vitro biocompatibility of the composite rod was evaluated by an osteoblast adhesion-and-proliferation assay. The products from composite rod dissolution significantly promoted cell growth. Furthermore, osteoblasts adhered and spread well on the rod. This PLLA/β-CMP composite rod has potential applications for clinical use following the assessment of adaptation during in vivo studies.
Association between Helicobacter pylori concentration and the combining frequency of histopathological findings in gastric biopsies specimens
Authors: Nai Gisele Alborghetti , Parizi Ana Carolina Gomes , Barbosa Ricardo Luís
Published: November 2007

BACKGROUND: Helicobacter pylori is the most prevalent infectious agent worldwide. About 90% of patients with chronic gastritis are infected with this bacterium. Some studies have shown a association between the H. pylori concentration and the scores of gastritis activity and severity. AIM: To evaluate the association between H. pylori concentration and the combining frequency of findings on histopathological examination. METHODS: Two hundred consecutive gastric endoscopic biopsies diagnosed as chronic gastritis were retrospectively investigated. The Warthin-Starry silver stain was used to study H. pylori and the following parameters were assessed (according to the Sydney system): 1. infiltration by polymorphonuclear cells in chorio and epithelium (activity) graded as mild, moderate and marked; 2. presence of lymphoid follicles; 3. presence of intestinal metaplasia; 4. presence of regenerative cell atypias, graded as mild, moderate and marked; and 5. H. pylori concentration on the mucous covering the foveolar epithelium. RESULTS: The most frequent association was chronic gastritis and activity, regardless of H. pylori concentration. The association of five histopathological findings in the same biopsy has not occurred in the cases of higher concentration of H. pylori. CONCLUSION: Our study has not revealed any association between H. pylori concentration and an increasing in the number of histopathological findings found in the gastric mucosa. Since referring to its presence is much more important than to its concentration.
Melhoramento do trigo: XVIII. Comportamento de linhagens em cinco regiões paulistas
Authors: Camargo Carlos Eduardo de Oliveira , Felício João Carlos , Ferreira Filho Antonio Wilson Penteado , Freitas José Guilherme de , Barros Benedito De Camargo , Castro Jairo Lopes de , Pettinelli Júnior Armando , Rocha Júnior Laércio Soares
Published: November 2007

Avaliaram-se vinte e duas linhagens e três cultivares de trigo em ensaios instalados em cinco regiões paulistas, em 1984-86, analisando-se os seguintes parâmetros: rendimento de grãos, altura de plantas, ciclo, em dias, da emergência ao florescimento e da emergência à maturação, porcentagem de plantas acamadas, comprimento da espiga, número de grãos por espiga e por espigueta, número de espiguetas por espiga, peso de cem grãos, resistência à ferrugem-do-colmo e da-folha em condições de campo e de casa de vegetação, resistência à helmintosporiose e ao oídio em condições de campo. Em laboratório, foram realizados estudos da tolerância ao alumínio, em soluções nutritivas. Em sequeiro, nos ensaios conduzidos em Capão Bonito e no Vale do Paranapanema (Maracaí e Cruzália), destacaram-se, quanto à produção de grãos, respectivamente, o cultivar BH-1146 e a linhagem 12. As linhagens 4, 9 e 13, em Campinas, e a 8, em Tatuí, evidenciaram alta produção de grãos em condição de irrigação por aspersão. Na média de nove experimentos, destacaram-se em produção de grãos, por ordem decrescente, o cultivar BH-1146 e as linhagens 13, 20 e 14. As linhagens 2, 7, 8, 17 e 18 e o 'Alondra-S-46' mostraram plantas significativamente mais baixas que o 'BH-1146' e 'IAC-5'. As linhagens 7 e 8 e o cultivar Alondra-S-46 mostraram resistência às seis raças e as linhagens 17 e 18 a cinco raças testadas do agente causal de ferrugem-do-colmo em estádio de plântula, em casa de vegetação. Em campo, no estádio de planta adulta, apresentaram menor área infectada por essa doença as linhagens 1, 2, 7, 8, 12 e 17 e o cultivar Alondra-S-46. Nas mesmas condições, as linhagens 1, 5, 8 e 18 exibiram menor área infectada por ferrugem-da-folha. As linhagens 11, 12, 13, 19, 20 e 21 e o cultivar BH-1146 mostraram tolerância à presença de 10mg/litro de Al3+ na solução nutritiva.
Deficiência de boro em soja
Authors: Mascarenhas Hipólito Assunção Antonio , Miranda Manoel Albino Coelho de , Bataglia Ondino Cleante , Pereira José Carlos Vila Nova Alves , Tanaka Roberto Tetsuo
Published: November 2007

A deficiência de boro é rara na cultura da soja no Brasil. A deficiência aqui descrita ocorreu em Guaíra, SP, numa várzea onde houve excessiva aplicação de calcário, elevando a saturação por bases a valores próximos de 90%. Nas áreas deficientes, o teor de boro no solo foi de 0,06 ppm e nas áreas aparentemente sem sintomas, 0,11 ppm. Nas folhas das plantas com sintomas, a concentração era de 10 ppm de boro e nas sem sintomas, de 19 ppm. Nas plantas deficientes, as folhas primárias eram coriáceas e espessas, e houve morte da gema apical, com brotamento de gemas laterais, nanismo, poucas flores e pequeno pegamento de vagens, com sensível redução na produtividade.
Melhoramento do trigo: XX. Herdabilidades e correlações entre os componentes de produção em populações híbridas envolvendo fontes de nanismo
Authors: Camargo Carlos Eduardo de Oliveira
Published: November 2007

Foram estimados os valores da herdabilidade em sentido restrito para a produção de grãos, altura das plantas, número de espigas por planta e de grãos por espiga e peso de cem grãos, bem como as correlações entre esses parâmetros através de cruzamentos em forma dialética entre os cultivares BH-1146, Atlas-66, Tordo e Siete Cerros. Plantas representando os pais, as gerações F1 e F2 e os retrocruzamentos para ambos os pais foram estudadas em um ensaio em blocos ao acaso, com cinco repetições, na Estação Experimental de Hyslop, da Universidade Estadual de Oregon, EUA, em 1978. Os valores da herdabilidade em sentido restrito para altura das plantas foram moderadamente altos para os cruzamentos BH-1146 x Atlas-66 (0,55), BH-1146 x Siete Cerros (0,60) e Atlas-66 x Siete Cerros (0,74); moderados para os cruzamentos Atlas-66 x Tordo (0,43) e Tordo x Siete Cerros (0,41), e baixo para o BH-1146 x Tordo (0,24). Foram estimados valores médios da herdabilidade em sentido restrito para número de espigas por planta variando de 0,43 a 0,58 para todos os cruzamentos, com exceção do BH-1146 x Atlas-66 e Atlas-66 x Tordo, que apresentaram valores baixos. Para o caráter peso de cem grãos, os indices da herdabilidade foram baixos para todos os cruzamentos, à exceção do BH-1146 x Atlas-66 e BH-1146 x Siete Cerros, que foram médios (0,40 e 0,45 respectivamente). Os valores da herdabilidade para produção de grãos foram baixos, à exceção dos verificados para os cruzamentos BH-1146 x Tordo (0,73) e BH-1146 x Siete Cerros (0,62). As correlações fenotípicas entre a produção de grãos e o número de espigas por planta, a altura das plantas, o número de grãos por espiga e o peso de cem grãos foram positivas e altamente significativas (com exceção da correlação produção de grãos e peso de cem grãos para a população BH-1146 x Atlas-66, que foi não-significativa). Os resultados sugerem ser possível selecionar somente plantas de porte semi-anão, com elevado potencial produtivo, alto número de grãos por espiga e de espigas por planta e elevado peso de cem grãos, desde que grandes populações segregantes sejam conduzidas para favorecer a identificação dos genótipos desejáveis originários das eventuais recombinações genéticas. Tal procedimento vem sendo adotado na seleção de cultivares de porte semi-anão para o Estado de São Paulo.
Tabagismo: conhecimentos, atitudes, hábitos e grau de dependência de jovens fumantes em Salvador
Authors: Almeida Aline Farias de , Mussi Fernanda Carneiro
Published: November 2007

O estudo objetivou avaliar o grau de dependência ao cigarro e caracterizar dados sócio-demográficos, conhecimentos, hábitos e atitudes de jovens fumantes. Responderam um questionário 102 estudantes de Salvador, sendo 11 tabagistas. A idade média dos fumantes foi 18,2 anos e de experimentação do cigarro 13,4 anos. Houve predomínio de homens, jovens no 1.º ano colegial, de cor parda e entes próximos fumantes. A maioria recebeu orientação familiar e escolar sobre os prejuízos do fumo, mas poucos sabiam dos benefícios de parar de fumar. Quase metade fumava há mais de três anos e iniciou o hábito por curiosidade. Mais da metade fumava um cigarro por dia, com baixo teor de nicotina, comprava o cigarro em lojas, desejava parar de fumar, já fez tentativas, mas nunca parou. O grau de dependência foi baixo para a maioria dos jovens. O estudo oferece pistas para enfermeiras atuarem junto aos jovens no controle do tabagismo.
Erros de medicação: tipos, fatores causais e providências tomadas em quatro hospitais brasileiros
Authors: Miasso Adriana Inocenti , Grou Cris Renata , Cassiani Silvia Helena De Bortoli , Silva Ana Elisa Bauer de Camargo , Fakih Flávio Trevisan
Published: November 2007

Este estudo analisou, em quatro hospitais brasileiros, tipos, causas, providências administrativas tomadas e sugestões, em relação aos erros na medicação, na perspectiva dos profissionais envol-vidos no sistema de medicação. Trata-se de um estudo multicêntrico, do tipo survey exploratório. A amostra constou de profissionais de clínica médica e farmácia, dos referidos hospitais. Para coleta de dados, utilizou-se a técnica de entrevista semi-estruturada. Os resultados evidenciaram que os tipos de erros mais citados pelos profissionais foram aqueles relacionados à prescrição/transcrição dos medicamentos. A falta de atenção, falhas individuais e problemas na administração dos serviços constituíram importantes atributos das causas dos erros. Relatórios foram as prin-cipais providências tomadas ante os erros e mudanças nas atitudes individuais as mais citadas como forma de prevení-los.
Baixo peso ao nascer e condições maternas no pré-natal
Authors: Minagawa Áurea Tamami , Biagoline Rosângela Elaine Minéo , Fujimori Elizabeth , Oliveira Ida Maria Vianna de , Moreira Ana Paula de Campos Araújo , Ortega Luiza Dolores Saldaña
Published: November 2007

Para verificar como o peso ao nascer se relaciona às condições maternas de trabalho, pré-natal, nutricionais (altura, peso inicial, final e ganho na gestação) e sócio-econômico-demográficas (idade, situação conjugal, escolaridade, renda familiar), o presente estudo foi realizado na área de abrangência do Hospital Universitário da Universidade de São Paulo e a amostra foi constituída por 101 crianças. A ocorrência de baixo peso ao nascer (BPN) foi de 5,1% e não se associou com o trabalho materno, nem com o pré-natal, porém mostrou associação significativa com as seguintes variáveis maternas: ganho de peso na gestação inferior a 7 kg, idade menor que 20 anos e não ter companheiro. Apesar da baixa ocorrência de BPN, os resultados evidenciaram a importância do pré-natal para reduzir a ocorrência de BPN, especialmente por meio do controle do ganho de peso na gestação, controle da gestação na adolescência e também priorizando a atenção das mulheres sem companheiro.
Investigação de áreas de risco como metodologia complementar ao controle da leishmaniose visceral canina
Authors: Julião Fred S. , Souza Bárbara M.P.S. , Freitas Daniela S. , Oliveira Lídia S. , Larangeira Daniela F. , Dias-Lima Artur G. , Souza Verena M.M. , Barrouin-Melo Stella M. , Moreira Jr Edson D. , Paule Bruno J.A. , Franke Carlos R.
Published: November 2007

Foram investigadas áreas de risco de leishmaniose visceral canina no município de Camaçari, Bahia. Um total de 278 cães distribuídos em 141 residências, pertencentes a 20 áreas de risco investigadas, foi examinado sorologicamente (ELISA). A soroprevalência geral foi 21,7% (56/258) depois da exclusão dos 20 cães usados no início do estudo para delimitar a área. Os resultados respectivos das análises univariada e multivariada dos fatores relacionados à infecção do cão por Leishmania chagasi, a captura e distribuição do vetor na área e a metodologia usada para localizar os focos caninos são discutidos.
Diatomáceas indicadoras de paleoambientes do Quaternário de Dois Irmãos, Recife, PE, Brasil
Authors: Souza Giane Soares de , Koening Maria Luise , Leça Enide Eskinazi , Coêlho Maria de Pompéia Correia de A.
Published: November 2007

O trabalho apresenta o levantamento da diatomoflórula identificada em sedimentos do Quaternário da Lagoa das Diatomáceas (Dois Irmãos, Recife), baseado em um testemunho de sondagem com 4,5 m, tendo sido analisadas amostras com intervalos de 10 em 10 cm. Foram identificados 46 táxons, distribuídos em 19 gêneros, 40 espécies e seis variedades. A coluna estratigráfica esteve composta por gêneros epífitos (Actinella, Amphora, Cocconeis Eunotia, Fragilaria, Frustulia, Gomphonema e Rhopalodia), bentônicos (Navicula, Neidium, Nitzschia e Surirella) e planctônicos (Aulacoseira, Cyclotella e Skeletonema). A maioria das espécies é oligoalóbia e litoral, destacando-se em termos de freqüência e abundância: Actinella brasiliensis, Anomoeoneis serians, Eunotia pectinalis, Frustulia rhomboides, sugerindo uma deposição de sedimentos em ambiente limnético. O predomínio de espécies epífitas em determinadas profundidades confirma a presença de macrófitas durante uma parte do período de deposição. Das espécies identificadas sete são consideradas de ambiente marinho: Cocconeis heteroidea, Cocconeis scutellum, Diploneis decipiens, Nitzschia scalaris, Nitzschia sigma, Skeletonema costatum e Surirella heideni as quais ocorreram de forma esporádica.
Species of Hypholoma (Fr.) P. Kumm. (Strophariaceae, Agaricales) in Rio Grande do Sul State, Brazil
Authors: Cortez Vagner Gularte , Silveira Rosa Mara Borges da
Published: November 2007

Detailed descriptions, illustrations, discussions and a key for identification of the known species of the genus Hypholoma (Fr.) P. Kumm. in Rio Grande do Sul state are presented, as well as a revision of the Hypholoma specimens deposited in the Fungi Rickiani collection. Based on the authors' collections and the herbarium revision, the following species were recognized: H. aurantiacum (Cooke) Faus, H. ericaeum (Pers.: Fr.) Kühner, and H. subviride (Berk. & M.A. Curtis) Dennis.
Palinotaxonomia de espécies de Chrysolaena H. Rob., Echinocoryne H. Rob. e Stenocephalum Sch. Bip. (Vernonieae-Compositae) ocorrentes no sudeste do Brasil
Authors: Mendonça Cláudia Barbieri Ferrreira , Souza Mariana Albuquerque de , Gonçalves-Esteves Vania , Esteves Roberto Lourenço
Published: November 2007

Realizou-se o estudo polínico de 11 espécies distribuídas em três gêneros, Chrysolaena H. Rob., Echinocoryne H. Rob. e Stenocephalum Sch. Bip., pertencentes à subtribo Vernoniinae, com o objetivo de contribuir para a caracterização polínica dessas espécies e avaliar sua posição taxonômica. Os grãos de pólen foram acetolisados, analisados e fotomicrografados sob microscopia de luz. Para observar detalhes da superfície e abertura, grãos de pólen não acetolisados foram analisados em microscópio eletrônico de varredura e de transmissão. Os gêneros foram separados, em uma chave palinológica, em dois grandes grupos utilizando-se o número total e a organização das lacunas que formam o padrão lofado. No primeiro grupo foram reunidas espécies de Echinocoryne H. Rob. que possuem grãos de pólen com 30 lacunas. No segundo grupo, espécies de Chrysolaena H. Rob. e Stenocephalum Sch. Bip., com 29 lacunas. As espécies de Echinocoryne são palinologicamente homogêneas, afastando-se apenas Echinocoryne holosericea (Mart. ex DC.) H. Rob. e Echinocoryne schwenkiaefolia (Mart. ex DC.) H. Rob. de Echinocoryne pungens (Gardn.) H. Rob. e Echinocoryne stricta (Gardn.) H. Rob. Estas duas últimas não puderam ser separadas pelas características polínicas. Considera-se, após o estudo aqui realizado, que as características polínicas isoladamente não são suficientes para definir os três gêneros aqui analisados.
Variação temporal de características morfológicas de folhas em dez espécies do Parque Nacional da Restinga de Jurubatiba, Macaé, RJ, Brasil
Authors: Rosado Bruno Henrique Pimentel , Mattos Eduardo Arcoverde de
Published: November 2007

Ordenar espécies em relação a um contínuo de variação de características foliares pode ser útil para inferir sobre a suscetibilidade de uma comunidade a alterações na disponibilidade de recursos e/ou condições ambientais ao longo do tempo. Dez espécies lenhosas de restinga foram acompanhadas quanto à variação temporal de atributos morfológicos foliares. Folhas de dez espécies de restinga foram coletadas nos meses de fevereiro, abril e agosto ao longo de três anos para caracterização da variação temporal da massa de folha por unidade de área (MFA), suculência (SUC), espessura (ESP) e densidade (DEN). As espécies apresentaram uma tendência de valores mais elevados para as características estudadas nos meses mais secos. A partir da comparação sazonal e interanual da MFA, SUC, ESP e DEN sugerimos que a natureza das respostas das plantas à heterogeneidade temporal na disponibilidade de água foi convergente, independentemente do padrão fenológico de produção foliar e filogenia. Portanto, a similaridade observada entre as espécies na dinâmica temporal dos atributos foliares indica a disponibilidade hídrica como um fator determinante para o sucesso na ocupação das planícies arenosas costeiras do norte fluminense.
Conhecimento de pediatras e nutricionistas sobre o tratamento da alergia ao leite de vaca no lactente
Authors: Cortez Ana Paula B. , Medeiros Lilian Cristiane da S. , Speridião Patrícia da Graça L. , Mattar Regina Helena G. M. , Fagundes Neto Ulysses , Morais Mauro Batista de
Published: November 2007

OBJETIVO: Avaliar o conhecimento de pediatras e nutricionistas sobre a dieta de exclusão do leite de vaca e seus derivados, com ênfase em questões relacionadas à nutrição da criança. MÉTODOS: Estudo transversal descritivo, do qual participaram pediatras (n=53) e nutricionistas (n=29), vinculados a hospitais públicos do Município de São Paulo, no ano de 2005. Os dados foram coletados por questionário auto-administrado. RESULTADOS: A idade dos profissionais variou de 21 a 50 anos. Quanto ao tempo de graduação, 41,2% eram formados a menos de cinco anos e 91,6% possuíam especialização, mestrado e/ou doutorado. A maioria (97,5%) afirmou avaliar a dieta de crianças submetidas à exclusão do leite de vaca, entretanto, somente 48% o faziam de forma mais detalhadas, incluindo o cálculo da ingestão alimentar. Apenas 38,7% comparam a ingestão alimentar da criança com algum padrão de recomendação. A recomendação diária da ingestão de cálcio para crianças com até 36 meses foi corretamente assinalada por 22% dos pediatras e 60,7% dos nutricionistas (p=0,001). Produtos não adequados como substitutos do leite de vaca seriam recomendados por 66% dos pediatras e 48,3% dos nutricionistas. Com relação à leitura de rótulos de produtos industrializados, 81,6% dos pediatras e 96,4% dos nutricionistas orientam os pais a ler todos os termos que indicam a presença das proteínas do leite de vaca. CONCLUSÕES: Os pediatras e nutricionista demonstraram erro conceitual no que se refere às principais recomendações terapêuticas na alergia às proteínas do leite de vaca.
Estabilidade do reposicionamento anterior da maxila através de análise cefalométrica lateral
Authors: Tavares Rodrygo Nunes , Passeri Luis Augusto
Published: November 2007

Este estudo cefalométrico retrospectivo foi proposto objetivando analisar a estabilidade do reposicionamento anterior da maxila, utilizando-se a osteotomia Le Fort I. A amostra consistiu de 30 telerradiografias de dez pacientes submetidos a um avanço cirúrgico da maxila, sem segmentação desta ou associação com qualquer cirurgia na mandíbula, realizado pela Área de Cirurgia Buco-Maxilo-Facial da Faculdade de Odontologia de Piracicaba - Unicamp. A mesma técnica de fixação interna rígida foi utilizada para todos os pacientes, e nenhum enxerto ou substituto ósseo foi usado. Três radiografias cefalométricas laterais foram realizadas para cada paciente, nos períodos pré e pós-operatórios imediatos, e com, no mínimo, seis meses após a cirurgia. Sobre estas radiografias foram feitas linhas de referência horizontal e vertical. Os pontos cefalométricos utilizados para calcular as mudanças de posição da maxila foram tanto esqueléticos, quanto dentários. A análise estatística (teste t de student pareado) não demonstrou diferença estatística significante entre os intervalos pós-operatórios imediato e com no mínimo seis meses. Concluímos que o reposicionamento anterior da maxila, utilizando-se a osteotomia Le Fort I, com fixação interna rígida e sem o uso de enxertos autógenos ou qualquer substituto ósseo, é um procedimento estável.
Fibras reforçadas por resina (FRC) em Ortodontia. Versatilidade clínica: parte 2
Authors: Ianni Filho Daniel , Strinta Lylian Tsai , Miyahira Yasushi Inoue , Serpa Eduardo
Published: November 2007

As fibras de vidro e de polietileno podem ser utilizadas na prática ortodôntica em diversas situações clínicas, nos casos com ou sem extrações dentárias. Este artigo tem como objetivo mostrar algumas das aplicações clínicas nas quais as fibras contribuíram de forma significativa para a realização dos tratamentos ortodônticos, simplificando-os e aumentando a eficiência clínica. As fibras foram utilizadas principalmente em segmentos de ancoragem e na substituição da banda pela colagem da associação fibra/tubo nos molares.
Nitrogen forms, pH and total carbon in a soil incubated with treated sewage effluent
Authors: Fonseca Adriel Ferreira da , Herpin Uwe , Dias Carlos Tadeu dos Santos , Melfi Adolpho José
Published: November 2007

In this study, an experiment under controlled conditions was carried out to determine the effects of secondary-treated sewage effluent (STSE) application on soil nitrogen concentrations (mineral and total), total carbon and soil pH. The soil and STSE used were collected at Lins, São Paulo State, Brazil. A completely randomized design was used, in completed factorial 4x11 (weekly application rates of 0, 100, 150 and 200 mL STSE per kg soil; and, eleven soil incubation periods from 0 to 10 weeks) with four replicates. The STSE was applied simulating common surface irrigation. Seven days after each incubation period, ammonium and nitrate contents were determined. Additionally, pH and total carbon and nitrogen contents were measured in the soil after 10 weeks. STSE application increased the nitrogen content (total and mineral - mainly as nitrate) and soil pH. For the total carbon content no differences were observed.
Glycogen levels and energy status of the liver of fasting rats with diabetes types 1 and 2
Authors: Oliveira Denise Silva de , Amado Ciomar Aparecida Bersani , Martini Mirian Carvalho , Suzuki-Kemmelmeier Fumie , Bracht Adelar
Published: November 2007

Glycogen levels and the energy status of livers from fasting rats with diabetes types 1 and 2 were measured. After a 24 h fast, the hepatic glycogen levels of rats with diabetes1 and diabetes2 were, 18.7 and 2.6 times higher, respectively, than those of livers from the normal rats. In diabetes1 rats, the glycogen levels decreased when the fasting period was extended to 48 and 72 h. The opposite occurred with the control and diabetes2 rats. Consistently, glucose release by the perfused livers from diabetes1 rats was considerably higher during at least 60 minutes after initiating perfusion. The hepatic ATP content of diabetes1 rats was similar to that of the control rats; in diabetes2 rats, the hepatic ATP content was increased. It could be concluded that regulation of glycogen deposition and degradation in rats with diabetes1 differed markedly from that of rats with diabetes2 which, in turn, behaved similarly to normal healthy rats.