bluuebunny/crossref_metadata_2025 huggingface dataset:
Conditions for the Generation of Beta Oscillations in the Subthalamic Nucleus–Globus Pallidus Network
Authors: Holgado Alejo J. Nevado , Terry John R. , Bogacz Rafal
Published: September 2010

The advance of Parkinson's disease is associated with the existence of abnormal oscillations within the basal ganglia with frequencies in the beta band (13–30 Hz). While the origin of these oscillations remains unknown, there is some evidence suggesting that oscillations observed in the basal ganglia arise due to interactions of two nuclei: the subthalamic nucleus (STN) and the globus pallidus pars externa (GPe). To investigate this hypothesis, we develop a computational model of the STN–GPe network based upon anatomical and electrophysiological studies. Significantly, our study shows that for certain parameter regimes, the model intrinsically oscillates in the beta range. Through an analytical study of the model, we identify a simple set of necessary conditions on model parameters that guarantees the existence of beta oscillations. These conditions for generation of oscillations are described by a set of simple inequalities and can be summarized as follows: (1) The excitatory connections from STN to GPe and the inhibitory connections from GPe to STN need to be sufficiently strong. (2) The time required by neurons to react to their inputs needs to be short relative to synaptic transmission delays. (3) The excitatory input from the cortex to STN needs to be high relative to the inhibition from striatum to GPe. We confirmed the validity of these conditions via numerical simulation. These conditions describe changes in parameters that are consistent with those expected as a result of the development of Parkinson's disease, and predict manipulations that could inhibit the pathological oscillations.
An Approximately Bayesian Delta-Rule Model Explains the Dynamics of Belief Updating in a Changing Environment
Authors: Nassar Matthew R. , Wilson Robert C. , Heasly Benjamin , Gold Joshua I.
Published: September 2010

Maintaining appropriate beliefs about variables needed for effective decision making can be difficult in a dynamic environment. One key issue is the amount of influence that unexpected outcomes should have on existing beliefs. In general, outcomes that are unexpected because of a fundamental change in the environment should carry more influence than outcomes that are unexpected because of persistent environmental stochasticity. Here we use a novel task to characterize how well human subjects follow these principles under a range of conditions. We show that the influence of an outcome depends on both the error made in predicting that outcome and the number of similar outcomes experienced previously. We also show that the exact nature of these tendencies varies considerably across subjects. Finally, we show that these patterns of behavior are consistent with a computationally simple reduction of an ideal-observer model. The model adjusts the influence of newly experienced outcomes according to ongoing estimates of uncertainty and the probability of a fundamental change in the process by which outcomes are generated. A prior that quantifies the expected frequency of such environmental changes accounts for individual variability, including a positive relationship between subjective certainty and the degree to which new information influences existing beliefs. The results suggest that the brain adaptively regulates the influence of decision outcomes on existing beliefs using straightforward updating rules that take into account both recent outcomes and prior expectations about higher-order environmental structure.
Molecular Anatomy of the Hair Cell's Ribbon Synapse
Authors: Uthaiah Revathy C. , Hudspeth A. J.
Published: September 2010

Hearing depends on reliable and temporally precise neurotransmission by cochlear hair cells. The wide dynamic range and high sensitivity with which these cells encode acoustic stimuli are associated with a presynaptic specialization termed the presynaptic dense body or synaptic ribbon. Apposed to the presynaptic density, this spherical or flattened structure tethers a layer of synaptic vesicles and is thought to facilitate their exocytotic fusion. Although defining the molecular constituents of the hair cell's synaptic ribbon should contribute to our understanding of neurotransmitter release at this synapse, accomplishing this task has been slowed by the difficulty of obtaining sufficient amounts of starting material for protein analysis from hair cells. We isolated synaptic material from chicken cochleas, purified synaptic ribbons with specific immunological reagents, and identified the associated proteins by tandem mass spectrometry. Purification of the ribbons revealed a predominant composition of C-terminal-binding proteins, especially ribeye, in association with the small GTPase Rab3, which is possibly involved in attaching vesicles to the ribbon. In comparison with the components of conventional synapses and of retinal ribbon synapses, we observed that certain regulatory proteins are excluded from the hair cell's synapse. Using antisera against several of the novel proteins and membrane-trafficking components that we had identified, we documented their localization in isolated hair cells. Our results indicate that the ribbon synapses of hair cells display modifications to the presynaptic machinery that are associated with the high-fidelity transmission of acoustic signals to the brain.
Protein Kinase A in the Pedunculopontine Tegmental Nucleus of Rat Contributes to Regulation of Rapid Eye Movement Sleep
Authors: Datta Subimal , Desarnaud Frank
Published: September 2010

Intracellular signaling mechanisms within the pedunculopontine tegmental (PPT) nucleus for the regulation of recovery rapid eye movement (REM) sleep following REM sleep deprivation remain unknown. This study was designed to determine the role of PPT intracellular cAMP-dependent protein kinase A (cAMP-PKA) in the regulation of recovery REM sleep in freely moving rats. The results show that a brief period (3 h) of selective REM sleep deprivation caused REM sleep rebound associated with increased PKA activity and expression of the PKA catalytic subunit protein (PKA-CU) in the PPT. Local application of a cAMP-PKA-activation-selective inhibitor, RpCAMPS (0.55, 1.1, and 2.2 nmol/100 nl;n= 8 rats/group), bilaterally into the PPT, reduced PKA activity and PKA-CU expression in the PPT, and suppressed the recovery REM sleep, in a dose-dependent manner. Regression analyses revealed significant positive relationships between: PPT levels of PKA activity and the total percentages of REM sleep recovery (Rsqr = 0.944;n= 40 rats); PPT levels of PKA-CU expression and the total percentages of REM sleep recovery (Rsqr = 0.937;n= 40 rats); PPT levels of PKA-CU expression and PKA activity (Rsqr = 0.945;n= 40 rats). Collectively, these results provide evidence that activation of intracellular PKA in the PPT contributes to REM sleep recovery following REM sleep deprivation.
Neural Correlates of Auditory Scene Analysis Based on Inharmonicity in Monkey Primary Auditory Cortex
Authors: Fishman Yonatan I. , Steinschneider Mitchell
Published: September 2010

Segregation of concurrent sounds in complex acoustic environments is a fundamental feature of auditory scene analysis. A powerful cue used by the auditory system to segregate concurrent sounds, such as speakers' voices at a cocktail party, is inharmonicity. This can be demonstrated when a component of a harmonic complex tone is perceived as a separate tone “popping out” from the complex as a whole when it is sufficiently mistuned from its harmonic value. The neural bases of perceptual “pop out” of mistuned harmonics are unclear. We recorded multiunit activity from primary auditory cortex (A1) of behaving monkeys elicited by harmonic complex tones that were either “in tune” or that contained a mistuned third harmonic set at the best frequency of the neural populations. Responses to mistuned sounds were enhanced relative to responses to “in-tune” sounds, thus correlating with the enhanced perceptual salience of the mistuned component. Consistent with human psychophysics of “pop out,” response enhancements increased with the degree of mistuning, were maximal for neural populations tuned to the frequency of the mistuned component, and were not observed under comparable stimulus conditions that do not elicit perceptual “pop out.” Mistuning was also associated with changes in neuronal temporal response patterns phase locked to “beats” in the stimuli. Intracortical auditory evoked potentials paralleled noninvasive neurophysiological correlates of perceptual “pop out” in humans, further augmenting the translational relevance of the results. Findings suggest two complementary neural mechanisms for “pop out,” based on the detection of local differences in activation level or coherence of temporal response patterns across A1.
Pathogenic Lysosomal Depletion in Parkinson's Disease
Authors: Dehay Benjamin , Bové Jordi , Rodríguez-Muela Natalia , Perier Celine , Recasens Ariadna , Boya Patricia , Vila Miquel
Published: September 2010

Mounting evidence suggests a role for autophagy dysregulation in Parkinson's disease (PD). The bulk degradation of cytoplasmic proteins (including α-synuclein) and organelles (such as mitochondria) is mediated by macroautophagy, which involves the sequestration of cytosolic components into autophagosomes (AP) and its delivery to lysosomes. Accumulation of AP occurs in postmortem brain samples from PD patients, which has been widely attributed to an induction of autophagy. However, the cause and pathogenic significance of these changes remain unknown. Here we found in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine mouse model of PD that AP accumulation and dopaminergic cell death are preceded by a marked decrease in the amount of lysosomes within dopaminergic neurons. Lysosomal depletion was secondary to the abnormal permeabilization of lysosomal membranes induced by increased mitochondrial-derived reactive oxygen species. Lysosomal permeabilization resulted in a defective clearance and subsequent accumulation of undegraded AP and contributed directly to neurodegeneration by the ectopic release of lysosomal proteases into the cytosol. Lysosomal breakdown and AP accumulation also occurred in PD brain samples, where Lewy bodies were strongly immunoreactive for AP markers. Induction of lysosomal biogenesis by genetic or pharmacological activation of lysosomal transcription factor EB restored lysosomal levels, increased AP clearance and attenuated 1-methyl-4-phenylpyridinium-induced cell death. Similarly, the autophagy-enhancer compound rapamycin attenuated PD-related dopaminergic neurodegeneration, bothin vitroandin vivo, by restoring lysosomal levels. Our results indicate that AP accumulation in PD results from defective lysosomal-mediated AP clearance secondary to lysosomal depletion. Restoration of lysosomal levels and function may thus represent a novel neuroprotective strategy in PD.
Sox1 Is Required for the Specification of a Novel p2-Derived Interneuron Subtype in the Mouse Ventral Spinal Cord
Authors: Panayi Helen , Panayiotou Elena , Orford Michael , Genethliou Nicolas , Mean Richard , Lapathitis George , Li Shengguo , Xiang Mengqing , Kessaris Nicoletta , Richardson William D. , Malas Stavros
Published: September 2010

During mouse development, the ventral spinal cord becomes organized into five progenitor domains that express different combinations of transcription factors and generate different subsets of neurons and glia. One of these domains, known as the p2 domain, generates two subtypes of interneurons, V2a and V2b. Here we have used genetic fate mapping and loss-of-function analysis to show that the transcription factor Sox1 is expressed in, and is required for, a third type of p2-derived interneuron, which we named V2c. These are close relatives of V2b interneurons, and, in the absence of Sox1, they switch to the V2b fate. In addition, we show that late-born V2a and V2b interneurons are heterogeneous, and subsets of these cells express the transcription factor Pax6. Our data demonstrate that interneuron diversification in the p2 domain is more complex than previously thought and directly implicate Sox1 in this process.
Audiovisual Synchrony Improves Motion Discrimination via Enhanced Connectivity between Early Visual and Auditory Areas
Authors: Lewis Richard , Noppeney Uta
Published: September 2010

Audiovisual synchrony enables integration of dynamic visual and auditory signals into a more robust and reliable multisensory percept. In this fMRI study, we investigated the neural mechanisms by which audiovisual synchrony facilitates shape and motion discrimination under degraded visual conditions. Subjects were presented with visual patterns that were rotated by discrete increments at irregular and unpredictable intervals while partially obscured by a dynamic noise mask. On synchronous trials, each rotation coincided with an auditory click. On asynchronous trials, clicks were noncoincident with the rotational movements (but with identical temporal statistics). Subjects discriminated shape or rotational motion profile of the partially hidden visual stimuli. Regardless of task context, synchronous signals increased activations bilaterally in (1) calcarine sulcus (CaS) extending into ventral occipitotemporal cortex and (2) Heschl's gyrus extending into planum temporale (HG/PT) compared with asynchronous signals. Adjacent to these automatic synchrony effects, synchrony-induced activations in lateral occipital (LO) regions were amplified bilaterally during shape discrimination and in the right posterior superior temporal sulcus (pSTS) during motion discrimination. Subjects' synchrony-induced benefits in motion discrimination significantly predicted blood oxygenation level-dependent synchrony effects in V5/hMT+. According to dynamic causal modeling, audiovisual synchrony increased connectivity between CaS and HG/PT bidirectionally, whereas shape and motion tasks increased forwards connectivity from CaS to LO or to pSTS, respectively. To increase the salience of partially obscured moving objects, audiovisual synchrony may amplify visual activations by increasing the connectivity between low level visual and auditory areas. These automatic synchrony-induced response amplifications may then be gated to higher order areas according to behavioral relevance and task context.
Glucocorticoid receptor gene haplotypes are not associated with birth anthropometry, blood pressure, glucose and insulin concentrations, and body composition in subjects born small for gestational age
Authors: Manenschijn L , van den Akker E L T , Ester W A , Leunissen R W J , Willemsen R H , van Rossum E F C , Koper J W , Lamberts S W J , Hokken-Koelega A C S
Published: September 2010

Objective

Smaller size at birth has been associated with an increased risk of metabolic and cardiovascular disorders in adult life. Fetal programing of the hypothalamic–pituitary–adrenal axis has been suggested as a possible explanation. Fetal glucocorticoid (GC) overexposure has effects that suggest a role of GCs in this programing. The effects of GCs are mediated through the GC receptor (GR or NR3C1). Several functional polymorphisms have been described, which are associated with relative GC resistance or hypersensitivity. Our aim is to compare frequencies of GR haplotypes, characterized by the R23K, N363S, Bcl1, or 9β polymorphisms, in subjects born small for gestational age (SGA) and associate birth anthropometry data, response to GH treatment, blood pressure, glucose and insulin concentrations, and body composition with these haplotypes.

Design

In total, 418 SGA subjects and 697 healthy controls were enrolled in this study.

Methods

Anthropometry data were obtained, as well as blood samples to determine fasting glucose and insulin concentrations. Dual energy X-ray absorptiometry scans were used to measure the amount of fat and lean mass.

Results

No differences were found between GR haplotype frequencies in SGA children compared with healthy controls. No associations were found between GR haplotypes and birth length and birth weight, growth response during GH treatment, blood pressure, glucose and insulin concentrations, and body composition.

Conclusion

GR haplotypes and their effect on GC sensitivity do not seem to play a significant role in GH-induced catch-up growth and the risk factors of developing metabolic and cardiovascular disorders in adult life of SGA children.
Extracellular matrix metalloproteinase inducer expression in the baboon endometrium: menstrual cycle and endometriosis
Authors: Braundmeier A G , Fazleabas A T , Nowak R A
Published: September 2010

Extracellular matrix metalloproteinase inducer (EMMPRIN; BSG) regulates tissue remodeling through matrix metalloproteinases (MMPs). In human and non-human primates, endometrial remodeling is important for menstruation and the pathogenesis of endometriosis. We hypothesized that as in humans, BSG and MMPs are expressed in the endometrium of cycling baboons, and their expression is hormonally regulated by ovarian hormones, but endometriosis disrupts this regulation. BSG expression was evaluated in the baboon endometrium by q-PCR and immunohistochemistry. In the endometrium of control cycling animals, BSG mRNA levels were highest in late secretory stage tissue. BSG protein localized to glandular epithelial cells during the proliferative phase; whereas, secretory stage tissues expressed BSG in glandular and luminal epithelia with weak stromal staining. Several MMPs were differentially expressed throughout the menstrual cycle with the highest levels found during menstruation. In ovariectomized animals, BSG endometrial mRNA levels were highest with treatment of both estrogen and progesterone than that with only estrogen. Estrogen alone resulted in BSG protein localization primarily in the endometrial glandular epithelia, while estrogen and progesterone treatment displayed BSG protein localization in both the glandular and stromal cells. Exogenous hormone treatment resulted in differential expression patterns of all MMPs compared with the control cycling animals. In the eutopic endometrium of endometriotic animals, BSG mRNA levels and protein were elevated early but decreased later in disease progression. Endometriosis elevated the expression of all MMPs except MMP7 compared with the control animals. In baboons, BSG and MMP endometrial expression is regulated by both ovarian hormones, and their expression patterns are dysregulated in endometriotic animals.
Reversal of Salt Preference Is Directed by the Insulin/PI3K and Gq/PKC Signaling inCaenorhabditis elegans
Authors: Adachi Takeshi , Kunitomo Hirofumi , Tomioka Masahiro , Ohno Hayao , Okochi Yoshifumi , Mori Ikue , Iino Yuichi
Published: September 2010

Animals search for foods and decide their behaviors according to previous experience. Caenorhabditis elegans detects chemicals with a limited number of sensory neurons, allowing us to dissect roles of each neuron for innate and learned behaviors. C. elegans is attracted to salt after exposure to the salt (NaCl) with food. In contrast, it learns to avoid the salt after exposure to the salt without food. In salt-attraction behavior, it is known that the ASE taste sensory neurons (ASEL and ASER) play a major role. However, little is known about mechanisms for learned salt avoidance. Here, through dissecting contributions of ASE neurons for salt chemotaxis, we show that both ASEL and ASER generate salt chemotaxis plasticity. In ASER, we have previously shown that the insulin/PI 3-kinase signaling acts for starvation-induced salt chemotaxis plasticity. This study shows that the PI 3-kinase signaling promotes aversive drive of ASER but not of ASEL. Furthermore, the Gq signaling pathway composed of Gqα EGL-30, diacylglycerol, and nPKC (novel protein kinase C) TTX-4 promotes attractive drive of ASER but not of ASEL. A putative salt receptor GCY-22 guanylyl cyclase is required in ASER for both salt attraction and avoidance. Our results suggest that ASEL and ASER use distinct molecular mechanisms to regulate salt chemotaxis plasticity.
Floral Genetic Architecture: An Examination of QTL Architecture Underlying Floral (Co)Variation Across Environments
Authors: Brock Marcus T , Dechaine Jennifer M , Iniguez-Luy Federico L , Maloof Julin N , Stinchcombe John R , Weinig Cynthia
Published: September 2010

Genetic correlations are expected to be high among functionally related traits and lower between groups of traits with distinct functions (e.g., reproductive vs. resource-acquisition traits). Here, we explore the quantitative-genetic and QTL architecture of floral organ sizes, vegetative traits, and life history in a set of Brassica rapa recombinant inbred lines within and across field and greenhouse environments. Floral organ lengths were strongly positively correlated within both environments, and analysis of standardized G-matrices indicates that the structure of genetic correlations is ∼80% conserved across environments. Consistent with these correlations, we detected a total of 19 and 21 additive-effect floral QTL in the field and the greenhouse, respectively, and individual QTL typically affected multiple organ types. Interestingly, QTL × QTL epistasis also appeared to contribute to observed genetic correlations; i.e., interactions between two QTL had similar effects on filament length and two estimates of petal size. Although floral and nonfloral traits are hypothesized to be genetically decoupled, correlations between floral organ size and both vegetative and life-history traits were highly significant in the greenhouse; G-matrices of floral and vegetative traits as well as floral and life-history traits differed across environments. Correspondingly, many QTL (45% of those mapped in the greenhouse) showed environmental interactions, including approximately even numbers of floral and nonfloral QTL. Most instances of QTL × QTL epistasis for floral traits were environment dependent.
The Role of Replication Bypass Pathways in Dicentric Chromosome Formation in Budding Yeast
Authors: Paek Andrew L , Jones Hope , Kaochar Salma , Weinert Ted
Published: September 2010

Gross chromosomal rearrangements (GCRs) are large scale changes to chromosome structure and can lead to human disease. We previously showed in Saccharomyces cerevisiae that nearby inverted repeat sequences (∼20–200 bp of homology, separated by ∼1–5 kb) frequently fuse to form unstable dicentric and acentric chromosomes. Here we analyzed inverted repeat fusion in mutants of three sets of genes. First, we show that genes in the error-free postreplication repair (PRR) pathway prevent fusion of inverted repeats, while genes in the translesion branch have no detectable role. Second, we found that siz1 mutants, which are defective for Srs2 recruitment to replication forks, and srs2 mutants had opposite effects on instability. This may reflect separate roles for Srs2 in different phases of the cell cycle. Third, we provide evidence for a faulty template switch model by studying mutants of DNA polymerases; defects in DNA pol delta (lagging strand polymerase) and Mgs1 (a pol delta interacting protein) lead to a defect in fusion events as well as allelic recombination. Pol delta and Mgs1 may collaborate either in strand annealing and/or DNA replication involved in fusion and allelic recombination events. Fourth, by studying genes implicated in suppression of GCRs in other studies, we found that inverted repeat fusion has a profile of genetic regulation distinct from these other major forms of GCR formation.
Acute atrioventricular block in chronic Lyme disease
Authors: Wagner Vince , Zima Endre , Gellér László , Merkely Béla
Published: September 2010

A Lyme-kór az egyik leggyakoribb antropozoonosis, a Borrelia kórokozója kullancs csípésével kerül az emberi szervezetbe, Magyarországon évente 10000 friss fertőzést okozva. A Lyme-kór tünetei és lefolyása változatosak, késői formában nemritkán carditist okoz. Esetünkben szerológiailag igazolt borreliosis okozott teljes atrioventricularis blokkot fiatal férfinél, aki praesyncope miatt került intézetünkbe. A blokk hátterében, a közeli kullancscsípésre való tekintettel, Lyme-carditist gyanítottunk, antibiotikum adását és monitoros obszervációt kezdtünk. A betegségre jellemző bőrtünetek nem jelentkeztek, a laborvizsgálat kórosat nem igazolt. Elektrofiziológiai vizsgálattal domináló supra-His atrioventricularis blokkot regisztráltunk. Az obszerváció másnapjától a blokk regressziót mutatott, később teljesen megjavult. Szerológiai vizsgálat egy évnél régebbi borreliosist igazolt. Terápiás ajánlás a potenciálisan reverzíbilis Lyme-carditisben egyelőre nincs. Fiataloknál rizikófaktor nélkül jelentkező ingerületvezetési zavar esetén is célszerű Lyme-carditisre gondolni, segítséget a pontos anamnézis felvétele és megfelelő labordiagnosztika jelenthet, amellyel elkerülhető a pacemakerbeültetés. Orv. Hetil., 2010, 39, 1585–1590.
Primary hyperparathyroidism and incidental multifocal metastatic papillary thyroid carcinoma in a man
Authors: Polyzos Stergios A. , Anastasilakis Athanasios D. , Iakovou Ioannis P. , Partsalidou Valassia
Published: September 2010

Co-existence of primary hyperparathyroidism (PHPT) and non-medullary thyroid carcinoma has been previously reported in sporadic case reports and some surgical series, but the majority of cases concerned women with occult papillary carcinomas without cervical lymph node involvement. We present a 71-year man with PHPT and multinodular goiter who was subjected to surgery for single parathyroid adenoma and was found to have synchronous multifocal papillary thyroid carcinoma (PTC) with cervical lymph node involvement. Review of the literature retrieved only a few similar cases. Ultrasonography of both thyroid and parathyroid glands might be considered in patients with hyperparathyroidism. Given that there are no specific guidelines for the management of patients with synchronous PHPT and PTC, they should be managed like the cases of single PTC.
As funções do Juízo final como imagem religiosa
Authors: Quírico Tamara
Published: September 2010

O uso de imagens como fonte histórica vem sendo motivo de debate há algumas décadas. O presente artigo visa a defender a sua importância uma vez que, por possuírem origem diversa das fontes escritas, as fontes visuais permitem perceber outras formas de manifestação da vida social, assim como novos atores sociais. O texto concentra a análise em representações visuais do tema do Juízo final realizadas na Idade Média, buscando um melhor entendimento não somente da religiosidade, como também da própria história das sociedades que criaram essas imagens. Neste artigo serão discutidos os modos de compreensão de pinturas sobre o Juízo final no período medieval, assim como as funções esperadas para esse tipo de imagem. A análise se concentrará particularmente nos exemplos italianos pintados entre os séculos XII e XIV.
À sombra de um mestre: Gilberto Freyre leitor de Euclides da Cunha
Authors: Nicolazzi Fernando
Published: September 2010

Este ensaio procura elaborar uma relação entre dois intelectuais atuantes em um período fundante da historiografia brasileira durante as primeiras décadas do século XX: Euclides da Cunha e Gilberto Freyre. O eixo norteador do texto é o papel de Freyre como leitor de Euclides da Cunha, analisando a forma como a obra deste foi recebida por aquele. Defende-se a hipótese que a feitura do primeiro livro do autor pernambucano, Casa-grande & senzala (1933), foi fortemente marcada pelas características do livro maior de Euclides, Os sertões (1902).
Hayden White e o pluralismo histórico
Authors: Kern Daniela
Published: September 2010

Este artigo pretende explorar a relação de Hayden White com a crítica pluralista praticada pelos participantes da Escola de Chicago, e mais especificamente o conceito de pluralismo histórico proposto pelo autor em um de seus artigos não recolhido em livro, Historical Pluralism. A fim de conduzir a análise do conceito, será recuperado, em especial, o evento que motivou o texto de White, a saber, o debate público entre os críticos Wayne Booth, Abrams e Hillis Miller, ocorrido nos anos 70.
Educação somática: limites e abrangências
Authors: Lima José Antonio de Oliveira
Published: September 2010

Este artigo faz considerações sobre as interfaces que o recente campo da educação somática mantém com as áreas da educação, da saúde e da arte e sobre a dificuldade de estabelecer seus limites, tanto pela atuação daqueles que se denominam seus "educadores", quanto pelos profissionais que a disputam como campo de trabalho. O artigo propõe, ainda, ampliação de seu conceito, em função das premissas que a sustentam.
Conceitos de genética e hereditariedade aplicados à compreensão das reabsorções dentárias durante a movimentação ortodôntica
Authors: Consolaro Alberto , Consolaro Renata Bianco , Martins-Ortiz Maria Fernanda , Freitas Patrícia Zambonato
Published: September 2010

Imagine o mundo sem telefone ou sem computador e internet. Em surtos cíclicos, os novos conhecimentos mudam nosso estilo de vida e criam necessidades. Um exemplo atual desta situação encontra-se na causa de certos fenômenos e doenças: tudo se explica a partir da genética e da hereditariedade. Deve-se tomar cuidado para evitar o exagero. As conseqüências de procedimentos clínicos, os efeitos colaterais e as iatrogenias passaram a possuir atributos genéticos, quase sempre não fundamentados em estudos experimentais. Quando o novo está amplamente difundido e não profundamente conhecido se estabelece temporariamente um poder mágico de sedução e uso. Desta forma procura-se atribuir à genética e à hereditariedade como causa primária das reabsorções dentárias na prática ortodôntica 1,10,16. A genética e hereditariedade mescladas à biologia molecular constituem um dos surtos de novos conhecimentos e tecnologias pelo qual a humanidade está passando, remetendo-nos a uma renovação conceitual ou reciclagem. Apesar das novas informações, o dia-a-dia e a necessidade de sobrevivência superpõem-se e o Profissional Clínico, mesmo consciente da importância da atualização para o seu trabalho, não tem como viabilizar no tempo e no espaço, a aquisição destes novos conceitos a partir de uma literatura fragmentada e multifacetada. Neste trabalho propusemo-nos a discorrer, com clareza e simplicidade, sobre os conceitos elementares necessários à compreensão dos mecanismos da genética, da hereditariedade e da biologia molecular. Às vezes beiramos a heresia acadêmica a favor do entendimento. Para os iniciados no assunto este artigo pode parecer muito básico, mas procuramos nos dirigir ao Profissional Clínico, especialmente aos relacionados com a prática ortodôntica e ortopédica.
Desempenho e conversão alimentar de novilhos de corte em capim-tanzânia submetido a duas intensidades de pastejo sob lotação rotativa
Authors: Difante Gelson dos Santos , Euclides Valéria Pacheco Batista , Nascimento Júnior Domicio do , Silva Sila Carneiro da , Barbosa Rodrigo Amorim , Torres Júnior Roberto Augusto de Almeida
Published: September 2010

O experimento foi realizado para avaliar o valor nutritivo da forragem, o desempenho e a conversão alimentar de novilhos em pastos de Panicum maximum Jacq. cv. Tanzânia submetidos a duas intensidades de pastejo rotativo (resíduos de 25 e 50 cm), associadas a intervalo de pastejo correspondente ao tempo necessário para que o dossel forrageiro interceptasse 95% da luz incidente durante a rebrotação. O delineamento experimental utilizado foi o de blocos completos casualizados, com duas repetições. Foram avaliados a altura do dossel pré-pastejo, os intervalos de pastejo, o ganho de peso individual, a conversão alimentar, a taxa de lotação e o ganho de peso por unidade de área. Pastos manejados com o resíduo 50 cm apresentaram maior número de ciclos de pastejo em relação àqueles manejados com resíduo de 25 cm. O maior ganho de peso médio diário foi registrado nos pastos manejados com 50 cm de resíduo (801 g/dia) em relação àqueles manejados com de 25 cm de resíduo (664 g/dia). Em contrapartida, a taxa de lotação foi mais alta nos pastos manejados com o resíduo 25 cm, fazendo com que os ganhos de peso por unidade de área fossem 601 e 559 kg/ha para os resíduos de 25 e 50 cm, respectivamente. O manejo do pasto visando altura de resíduo de 25 cm proporciona maiores ganhos de peso por unidade de área e maior uniformidade de produção e o resíduo de 50 cm promove maior ganho individual e maior número de ciclos de pastejo.
Resposta hemática de tilápias-do-nilo alimentadas com dietas suplementadas com colina e submetidas a estímulo por baixa temperatura
Authors: Fernandes Junior Ademir Calvo , Pezzato Luiz Edivaldo , Guimarães Igo Gomes , Teixeira Caroline Pelegrina , Koch João Fernando Albers , Barros Margarida Maria
Published: September 2010

Esta pesquisa foi realizada com o objetivo de avaliar a resposta hemática de tilápias-do-nilo (Oreochromis niloticus) arraçoadas com dietas suplementadas com colina e submetidas a estímulo por baixa temperatura. O período experimental foi realizado em duas etapas: a primeira, de 109 dias, e a segunda, de 7 dias. Durante a primeira etapa, foram utilizados 192 alevinos com peso médio inicial de 4 g, distribuídos em 32 tanques-rede de 200 L instalados em aquários de mil litros. As rações foram formuladas de modo a apresentar 28,0% de proteína digestível e 3.100,0 kcal ED/kg e mesma concentração de aminoácidos. O delineamento experimental foi inteiramente casualizado com oito tratamentos e quatro repetições. As rações foram suplementadas com colina (cloreto de colina 60,0%), de modo a apresentar 100,0; 200,0; 400,0; 600,0; 800,0; 1.000,0 e 1.200,0 mg/kg de ração, e avaliadas em comparação a uma ração sem suplementação. Após o período de 109 dias, foram efetuadas as análises hematológicas dos peixes. Após as análises, os peixes foram transferidos para a sala de desafio e distribuídos em 24 aquários, onde foram mantidos a 17ºC durante sete dias. Após esse período, foram feitas as mesmas análises do período anterior ao desafio. A suplementação de colina não influenciou a eritropoiese ao estímulo pelo frio. A suplementação dietética de colina não interfere na síntese de eritrócitos e leucócitos e a temperatura de 17,0ºC determina linfopenia e neutrofilia.
Production of alfalfa hay under different drying methods
Authors: Neres Marcela Abbado , Castagnara Deise Dalazen , Mesquita Eduardo Eustáquio , Zambom Maximilliane Alavarze , Souza Leiliane Cristine de , Oliveira Paulo Sérgio Rabello de , Jobim Clóves Cabreira
Published: September 2010

This trial aimed at determining the dehydration curve at nine times (0, 3, 6, 9, 24, 27, 30, 33 and 46 hours after cuting of the plants); the leaf/stem ratio and number of leaves per stem in alfalfa submitted to four managements during the drying process. It was also evaluated the bromatologic composition and in vitro digestibility of the dry matter and cell wall of alfalfa hay before storage. The drying methods applied for alfalfa were the following: drying in the field until 50% DM and drying conclusion in an airy shed; drying in the field without turning; drying with only one turning and drying with two turnings. The experimental design was completely randomized with four drying methods and five replications. Leaf dehydration was faster when compared to the stems in all drying methods. Drying in the shed promoted the lesser re-hydration of the plants at night due to dew. It was also verified that alfalfa hays that remained under the sun and were turned showed the worst quality with reduction in crude protein contents and increase in NDF, ADF, NDIN and ADIN. However, in vitro dry matter digestibility and cell wall digestibility did not suffer any alteration because of the different dehydration methods (69.79 and 41.39%, respectively). There is a market fall of leaves and a reduction on the number of leaves per stem with the turnings.
Reconhecimento de padrões: motodologias estatísticas em crédito ao consumidor
Authors: Guimarães Inácio Andruski , Chaves Neto Anselmo
Published: September 2010

A inadimplência é um dos maiores problemas, senão o maior, enfrentado pelas administradoras de cartão de crédito. No estudo deste problema foi criado o conceito de risco, que é essencialmente a probabilidade de não recebimento dos créditos por parte das administradoras de cartões. Alguns autores, Caouette et al. (2000) e Silva (1988) referem-se às técnicas estatísticas multivariadas como ferramentas poderosas na administração do risco envolvido na concessão de crédito pessoal. Este trabalho apresenta a construção e avaliação de regras de reconhecimento de padrões baseadas em duas técnicas multivariadas: a Função Discriminante Linear de Fisher e a Regressão Logística para classificação de clientes de cartão de crédito em um de dois grupos. A eficiência dos procedimentos é avaliada por meio do Método de Lachenbruch, Lachenbruch (1975).
Trinexapac-Ethyl Influences Bispyribac-Sodium Absorption and Efficacy for Annual Bluegrass (Poa annua) Control in Creeping Bentgrass (Agrostis stolonifera)
Authors: McCullough Patrick E. , Hart Stephen E.
Published: September 2010

Bispyribac-sodium selectively controls annual bluegrass in cool-season turf but efficacy may be influenced by management practices, such as plant growth regulator use. Experiments were conducted in New Jersey to investigate efficacy and absorption of bispyribac-sodium applied with trinexapac-ethyl for annual bluegrass control and turfgrass tolerance. In laboratory experiments with annual bluegrass, creeping bentgrass, and perennial ryegrass, tank-mixing trinexapac-ethyl with14C-bispyribac-sodium increased presumed foliar absorption of14C-bispyribac-sodium compared with nontrinexapac-ethyl treated; absorption increased with trinexapac-ethyl rate. Differences in14C-bispyribac-sodium absorption were not detected among emulsifiable concentration, microencapsulated concentration, and wettable powder trinexapac-ethyl formulations. In field experiments, sequential bispyribac-sodium applications controlled annual bluegrass 93%, but trinexapac-ethyl did not affect efficacy. Tank-mixing all trinexapac-ethyl formulations with bispyribac-sodium provided similar annual bluegrass control and creeping bentgrass quality compared with bispyribac-sodium alone. Applications of bispyribac-sodium reduced dollar spot cover in both years, whereas trinexapac-ethyl reduced dollar spot cover only in 2005.
Effect of Biodegradable Mulch Materials on Weed Control in Processing Tomatoes
Authors: Anzalone A. , Cirujeda A. , Aibar J. , Pardo G. , Zaragoza C.
Published: September 2010

Three years of field trials have been carried out in Zaragoza, Spain, using different biodegradable mulch materials in processing tomatoes. The aim was to evaluate weed control with several biodegradable mulches as alternatives to black polyethylene (PE) mulch. The treatments were rice straw, barley straw, maize harvest residue, absinth wormwood plants, black biodegradable plastic, brown kraft paper, PE, herbicide, manual weeding, and unweeded control. Assessments focused on weeds and on crop yield. A laboratory study showed that 1 kg/m2of organic mulch was sufficient to cover the soil for rice, barley straw, and maize harvest residue. The most abundant weed species in the field were purple nutsedge, common purslane, common lambsquarters, and large crabgrass and a change in weed composition was observed between treatments and years. Most weed species were controlled by the mulching materials except that purple nutsedge was controlled only by paper mulch. The other species were well controlled by PE and biodegradable plastic and also by some of the organic mulch treatments. Best weed control and lowest weed biomass were achieved by paper followed by PE and biodegradable plastic. The best organic mulch was rice straw and the worst weed control was from absinth wormwood. Tomato yield was highest for PE followed by paper, manual weeding, biodegradable plastic, and rice straw and was clearly related to weed control. Paper, biodegradable plastic, and rice straw are potential substitutes for PE and herbicides.
Use of a Rolled-rye Cover Crop for Weed Suppression in No-Till Soybeans
Authors: Mischler Ruth A. , Curran William S. , Duiker Sjoerd W. , Hyde Jeffrey A.
Published: September 2010

Cover crop management with a roller/crimper might reduce the need for herbicide. Weed suppression from a rolled cereal rye cover crop was compared to no cover crop with and without postemergence herbicide application in no-till soybean. The experiment was designed as a two-way factorial with rye termination and soybean planting date as the first factor and weed control treatment as the second. Cereal rye was drill-seeded in late September and managed using glyphosate followed by a roller/crimper in the spring. Soybean was no-till seeded after rolling and glyphosate was applied postemergence about 6 wk after planting to half the plots. Rye biomass doubled when delaying rye kill by 10 to 20 d. Weed density and biomass were reduced by the rye cover crop in all site–location combinations except one, but delaying rye kill and soybean planting date only reduced both weed density and biomass at a single location. The cover crop mulch provided weed control similar to the postemergence herbicide in two of four locations. Treatments did not affect soybean grain yield in 2007. In 2008, yield at Landisville with rye alone was equal to those yields receiving the postemergence herbicide, whereas at Rock Springs, it was equivalent or less. The net added cost of a rye cover crop was $123 ha−1with or $68.50 ha−1without a postemergence herbicide application. A rolled-rye cover crop sometimes provided acceptable weed control, but weed control alone did not justify the use of the cover crop. The potential for reduced herbicide use and other ecosystem services provided by a cover crop justify further refinement and research in this area.
Winter Wheat and Weed Response to Postemergence Saflufenacil Alone and in Mixtures
Authors: Frihauf John C. , Stahlman Phillip W. , Geier Patrick W.
Published: September 2010

Growth chamber experiments were conducted in the fall of 2006 and spring of 2007 to determine winter wheat, flixweed, and henbit response to POST treatments of saflufenacil at 13, 25, and 50 g ai ha−1applied alone and in combinations with bentazon at 560 g ai ha−1or 2,4-D amine at 533 g ae ha−1and nonionic surfactant (NIS) at 0.25% v/v. Mixtures of saflufenacil and 2,4-D amine were also applied without NIS. Necrosis was observed on wheat leaves within 1 d after treatment (DAT) and peaked at 5 to 7 DAT. Saflufenacil at 13, 25, or 50 g ai ha−1applied alone or in combination with 533 g ae ha−1of 2,4-D amine plus NIS caused 19 to 38% (alone) and 24 to 40% (in combination) wheat foliar necrosis, respectively. Foliar necrosis of wheat was 14% or less when saflufenacil, at any rate, was mixed with bentazon or 2,4-D amine without NIS. Combinations of saflufenacil at any of the rates tested plus bentazon and NIS did not reduce wheat dry weight. Saflufenacil plus 2,4-D amine without adjuvant resulted in similar wheat dry weights as 2,4-D amine. Saflufenacil plus 2,4-D amine without NIS provided 99% control of flixweed at 21 DAT, but henbit control ranged from 81 to 88%. In comparison, saflufenacil at 50 g ha−1mixed with bentazon and NIS controlled flixweed at 92% and henbit at 63% at 21 DAT. This research indicates saflufenacil has potential for POST use in winter wheat to control winter annual broadleaf weeds when tank-mixed with 2,4-D amine without NIS, but additional research is needed to discover ways to improve crop safety without reducing weed control.
Isoxaflutole Shifts Kochia (Kochia scoparia) Populations in Continuous Corn
Authors: Sbatella Gustavo M. , Wilson Robert G.
Published: September 2010

Kochia control in continuous corn became increasingly difficult in experimental plots where isoxaflutole was used PRE for 8 yr. Studies were conducted to determine if poor kochia control resulted from an escape mechanism based on different germination rates or from a difference in sensitivity to isoxaflutole. Germination at constant temperatures showed that the kochia population in the experimental plot had greater seed dormancy compared with populations growing in adjacent fields. Germination at 25 C for seeds collected from the isoxaflutole-treated area was near 20% after 20 d, whereas germination for the other populations was above 80%. The optimal temperatures to release seed dormancy for seeds from the experimental plot were alternating 35/25 C day/night temperatures. The kochia biotype that predominated where isoxaflutole was applied PRE had elevated levels of seed dormancy and required higher alternating temperatures to release dormancy than untreated control kochia. These characteristics were unique and not found in populations never exposed to isoxaflutole. Chlorophyll content was measured to determine if differences in sensitivity to isoxaflutole existed among biotypes. Absorption at 660 nm by photosynthetic pigments was similar among the biotypes at increasing herbicide rates, indicating no differences in sensitivity to isoxaflutole among populations. Reduced kochia control in the experimental plot was due to delayed seed germination, which allowed isoxaflutole to degrade before seeds germinated. The rapid herbicide dissipation from soil can be attributed in part to coarse soils, soil moisture, and the low isoxaflutole rate.
A Survey for Diclofop-Methyl Resistance in Italian Ryegrass from Tennessee and How To Manage Resistance in Wheat
Authors: Ellis Andrew T. , Steckel Lawrence E. , Main Christopher L. , De Melo Marcel S. C. , West Dennis R. , Mueller Thomas C.
Published: September 2010

Italian ryegrass resistance to diclofop has been documented in several countries, including the United States. The purpose of this research was to screen selected putative resistant populations of Italian ryegrass for resistance to the acetyl-CoA carboxylase (ACCase)–inhibiting herbicides diclofop and pinoxaden and the acetolactate synthase (ALS)–inhibiting herbicides imazamox, pyroxsulam, and mesosulfuron in the greenhouse and to use field experiments to develop herbicide programs for Italian ryegrass control. Resistance to diclofop was confirmed in eight populations from Tennessee. These eight populations did not show cross-resistance to pinoxaden. One additional population (R1) from Union County, North Carolina, was found to be resistant to both diclofop and pinoxaden. The level of resistance to pinoxaden of the R1 population was 15 times that of the susceptible population. No resistance was confirmed to any of the ALS-inhibiting herbicides examined in this research. Field experiments demonstrated PRE Italian ryegrass control with chlorsulfuron (71 to 94%) and flufenacet + metribuzin (84 to 96%). Italian ryegrass control with pendimethalin applied PRE or delayed preemergence (DPRE) was variable (0 to 85%). POST control of Italian ryegrass was acceptable with pinoxaden, mesosulfuron, flufenacet + metribuzin, and chlorsulfuron + flucarbazone (> 80%). Application timing and herbicide treatment had no effect on wheat yield, except for diclofop and pendimethalin treatments, in which uncontrolled Italian ryegrass reduced wheat yield.