bluuebunny/crossref_metadata_2025 huggingface dataset:
Relationship with Family of Origin Scale (REFAMOS)
Authors: Hill Jonathan , Mackie Erica , Banner Linda , Kondryn Helena , Blair Val
Published: October 2008

Background

Family relationships in the transition from childhood to adult life may be important mediators of risk and resilience for adult psychopathology.

Aims

To develop a reliable and valid measure of the quality of relationships with each parent in young adults.

Method

Interrater reliability of the Relationship with Family of Origin Scale (REFAMOS) was assessed from audio-taped interviews with 59 subjects. Age-related trends and associations with recalled childhood relationships were examined in survivors of childhood cancer and their controls (n=178).

Results

Intraclass correlation coefficients were in the range 0.69–0.95, and κ values 0.80–0.82. Indices of current closeness to mothers were negatively correlated with age of subject and positively correlated with recalled maternal care in childhood. Negative qualities in current relationships were correlated with recalled overprotection.

Conclusions

The REFAMOS has good interrater reliability, and shows the predicted age-related trends in scores and associations with recalled childhood relationships.
Cognitive therapy or imaginal exposure in the treatment of post-traumatic stress disorder
Authors: Tarrier Nicholas , Sommerfeld Claire , Pilgrim Hazel , Humphreys Lloyd
Published: October 2008

Background

Previously reported results have demonstrated the efficacy of exposure and cognitive therapy in the treatment of chronic post-traumatic stress disorder (PTSD), but have not shown one to be superior to the other.

Aims

To investigate whether treatment benefits and equivalence are maintained at 12-month follow-up in patients with chronic PTSD treated with either imaginai exposure or cognitive therapy.

Method

Twelve-month follow-up of a randomised clinical trial.

Results

Fifty-four subjects (87% of the sample) were available to follow-up. They did not significantly differ clinically from drop-outs. There was significant clinical improvement at 12 months compared with pre-treatment. However, 39% of those followed-up still met criteria for PTSD. There were no significant differences between the two treatments. Victims of crime displayed higher levels of symptoms at follow-up than victims of accidents.

Conclusions

Clinical benefits for exposure or cognitive therapy were maintained.
High-Dose Yttrium-90–Ibritumomab Tiuxetan With Tandem Stem-Cell Reinfusion: An Outpatient Preparative Regimen for Autologous Hematopoietic Cell Transplantation
Authors: Devizzi Liliana , Guidetti Anna , Tarella Corrado , Magni Michele , Matteucci Paola , Seregni Ettore , Chiesa Carlo , Bombardieri Emilio , Di Nicola Massimo , Carlo-Stella Carmelo , Gianni Alessandro M.
Published: October 2008

Purpose

To develop high-dose myeloablative therapy for CD20+ non-Hodgkin's lymphoma (NHL) as a safe and widely applicable regimen.

Patients and Methods

Patients with relapsed/refractory (n = 25) or de novo high-risk (n = 5) NHL received one myeloablative dose of yttrium-90 (90Y)–ibritumomab tiuxetan after five chemotherapy courses, including three cycles of anthracycline- or platinum-containing regimens, one cycle of cyclophosphamide (4 to 7 g/m2), and one cycle of cytarabine (12 to 24 g/m2). The only exclusion criteria were CNS lymphoma and Eastern Cooperative Oncology Group performance status of more than 3. Primary end points were overall survival (OS) and event-free survival (EFS). Secondary end points included safety and applicability of high-dose 90Y-ibritumomab tiuxetan. To minimize hematologic toxicity, stem cells were reinfused at days 7 and 14 after 90Y-ibritumomab tiuxetan.

Results

Thirteen patients received 90Y-ibritumomab tiuxetan 0.8 mCi/kg, and 17 patients received 1.2 mCi/kg. At 1.2 mCi/kg, the radiation absorbed by critical nonhematologic organs approached the protocol-defined upper safety limit, defining this as the recommended dose for subsequent studies. Hematologic toxicity was mild to moderate and of short duration. Infections occurred in 27% of patients (none had a severity grade greater than 3). After a median observation time of 30 months (range, 22 to 48 months), no myeloid secondary malignancy or chromosomal abnormality was observed, the OS rate was 87%, and the EFS rate was 69%.

Conclusion

High-dose 90Y-ibritumomab tiuxetan seems to be an innovative myeloablative regimen with unprecedented short-term toxicity and wide applicability. Further studies are required to assess its long-term safety and role in the management of CD20+ NHL.
Glucocorticoid Receptor Gene Variant in the 3′ Untranslated Region Is Associated with Multiple Measures of Blood Pressure
Authors: Chung Charles C. , Shimmin Lawrence , Natarajan Sivamani , Hanis Craig L. , Boerwinkle Eric , Hixson James E.
Published: October 2008

Context: The glucocorticoid receptor (GR) is a key hormone in the hypothalamus-pituitary-adrenal axis that regulates many pathways including blood pressure homeostasis. Thus, GR gene variation may influence interindividual differences in blood pressure in human populations.

Objective: We resequenced individual GR alleles for comprehensive discovery of GR variants and their chromosomal phase in three major American ethnic groups. We examined the influence of GR variants on blood pressure in large numbers of families using family-based association methods.

Design and Participants: For association studies, we genotyped GR variants in family members from the Genetic Epidemiology Network of Arteriopathy (GENOA) study that were measured for multiple blood pressure traits. The GENOA families consisted of African-Americans, Mexican-Americans, and European-Americans.

Main Measurements: The blood pressure measurements for association studies included systolic blood pressure, diastolic blood pressure, mean arterial pressure, and pulse pressure.

Results: Single-nucleotide polymorphisms (SNPs) identified by resequencing were tested for associations with blood pressure measures in GENOA families. Analysis of individual SNPs identified significant associations of rs6198 A/G in exon 9β with multiple blood pressure measures in European-Americans. Analysis of GR haplotypes found significant associations of a haplotype that is distinguished by rs6198 A/G.

Conclusions: Significant associations of blood pressure with rs6198 A/G likely reflect allelic effects on GR signaling. This SNP disrupts a 3′ untranslated region sequence element in exon 9β that destabilizes mRNA, resulting in increased production of the inactive GRβ isoform. Excess heterodimerization with the active GRα isoform may reduce GR signaling with subsequent physiological effects on blood pressure regulation.
OTX2 Loss of Function Mutation Causes Anophthalmia and Combined Pituitary Hormone Deficiency with a Small Anterior and Ectopic Posterior Pituitary
Authors: Tajima Toshihiro , Ohtake Akira , Hoshino Masaya , Amemiya Shin , Sasaki Nozomu , Ishizu Katsura , Fujieda Kenji
Published: October 2008

Context: Orthodenticle homeobox 2 (OTX2) is a transcription factor necessary for ocular and forebrain development. In humans, heterozygous mutations of OTX2 cause severe ocular malformations. However, whether mutations of OTX2 cause pituitary structural abnormalities or combined pituitary hormone deficiency (CPHD) has not been clarified.

Objectives: We surveyed the functional consequences of a novel OTX2 mutation that was detected in a patient with anophthalmia and CPHD.

Patient: We examined a Japanese patient with growth disturbance, anophthalamia, and severe developmental delay. He showed deficiencies in GH, TSH, LH, FSH, and ACTH. Brain magnetic resonance imaging revealed a small anterior pituitary gland, invisible stalk, ectopic posterior lobe, and Chiari malformation.

Results: Sequence analysis of OTX2 demonstrated a heterozygous two bases insertion [S136fsX178 (c.576-577insCT)] in exon 3. The mutant Otx2 protein localized to the nucleus, but did not activate the promoter of the HESX1 and POU1F1 gene, indicating a loss of function mutation. No dominant negative effect in the presence of wild-type Otx2 was observed.

Conclusion: This case indicates that the OTX2 mutation is a cause of CPHD. Further study of more patients with OTX2 defects is necessary to clarify the clinical phenotypes and endocrine defects caused by OTX2 mutations.
Lay perceptions of current and future health, the causes of illness, and the nature of recovery: Explaining health and illness in Malaysia
Authors: Swami Viren , Arteche Adriane , Chamorro‐Premuzic Tomas , Maakip Ismail , Stanistreet Debbi , Furnham Adrian
Published: October 2008

This study examined beliefs about the causes and determinants of health, illness, and recovery in an opportunistic sample from Malaysia. In all, 371 women and 350 men completed the Health and Illness Scale, a 124‐item scale that examined beliefs about current and future health, and beliefs about the causes of illness and recovery. Each of the four subscales of the Health Illness Scale were factor analysed to reveal the underlying structure. Results showed the emergence of a number of distinct factors in the case of each subscale, of which environmental, life‐style, psychological, religious, and fate‐related factors were fairly stable across subscales. Results also showed a number of differences in beliefs between religious groups, and that religiosity and sex were the strongest predictors of beliefs across the four subscales. The results are discussed in terms of the available cross‐cultural literature on lay beliefs about health.
Peer Interactions and Academic Engagement of Youth With Developmental Disabilities in Inclusive Middle and High School Classrooms
Authors: Carter Erik W. , Sisco Lynn G. , Brown Lissa , Brickham Dana , Al-Khabbaz Zainab A.
Published: October 2008

We examined the peer interactions and academic engagement of 23 middle and high school students with developmental disabilities within inclusive academic and elective classrooms. The extent to which students with and without disabilities interacted socially was highly variable and influenced by instructional format, the proximity of general and special educators, and curricular area. Peer interactions occurred more often within small group instructional formats, when students were not receiving direct support from a paraprofessional or special educator, and in elective courses. Academic engagement also varied, with higher levels evidenced during one-to-one or small group instruction and when in proximity of general or special educators. Implications for designing effective support strategies for students with autism and/or intellectual disability within general education classrooms are discussed.
Epigenetic Regulation ofbdnfGene Transcription in the Consolidation of Fear Memory
Authors: Lubin Farah D. , Roth Tania L. , Sweatt J. David
Published: October 2008

Long-term memory formation requires selective changes in gene expression. Here, we determined the contribution of chromatin remodeling to learning-induced changes in brain-derived neurotrophic factor (bdnf) gene expression in the adult hippocampus. Contextual fear learning induced differential regulation of exon-specificbdnfmRNAs (I, IV, VI, IX) that was associated with changes inbdnfDNA methylation and altered local chromatin structure. Infusions of zebularine (a DNA methyltransferase inhibitor) significantly alteredbdnfDNA methylation and triggered changes in exon-specificbdnfmRNA levels, indicating that altered DNA methylation is sufficient to drive differentialbdnftranscript regulation in the hippocampus. In addition, NMDA receptor blockade prevented memory-associated alterations inbdnfDNA methylation, resulting in a block of alteredbdnfgene expression in hippocampus and a deficit in memory formation. These results suggest epigenetic modification of thebdnfgene as a mechanism for isoform-specific gene readout during memory consolidation.
Striate Cortical Lesions Affect Deliberate Decision and Control of Saccade: Implication for Blindsight
Authors: Yoshida Masatoshi , Takaura Kana , Kato Rikako , Ikeda Takuro , Isa Tadashi
Published: October 2008

Monkeys with unilateral lesions of the primary visual cortex (V1) can make saccades to visual stimuli in their contralateral (“affected”) hemifield, but their sensitivity to luminance contrast is reduced. We examined whether the effects of V1 lesions were restricted to vision or included later stages of visual–oculomotor processing. Monkeys with unilateral V1 lesions were tested with a visually guided saccade task with stimuli in various spatial positions and of various luminance contrasts. Saccades to the stimuli in the affected hemifield were compared with those to the near-threshold stimuli in the normal hemifield so that the performances of localization were similar. Scatter in the end points of saccades to the affected hemifield was much larger than that of saccades to the near-threshold stimuli in the normal hemifield. Additional analysis revealed that this was because the initial directional error was not as sufficiently compensated as it was in the normal hemifield. The distribution of saccadic reaction times in the affected hemifield tended to be narrow. We modeled the distribution of saccadic reaction times by a modified diffusion model and obtained evidence that the decision threshold for initiation of saccades to the affected hemifield was lower than that for saccades to the normal hemifield. These results suggest that the geniculostriate pathway is crucial for on-line compensatory mechanisms of saccadic control and for decision processes. We propose that these results reflect deficits in deliberate control of visual–oculomotor processing after V1 lesions, which may parallel loss of visual awareness in human blindsight patients.
Mechanisms of Potentiation of Mossy Fiber EPSCs in the Cerebellar Nuclei by Coincident Synaptic Excitation and Inhibition
Authors: Pugh Jason R. , Raman Indira M.
Published: October 2008

Neurons of the cerebellar nuclei receive synaptic excitation from cerebellar mossy fibers. Unlike in many principal neurons, coincident presynaptic activity and postsynaptic depolarization do not generate long-term potentiation at these synapses. Instead, EPSCs are potentiated by high-frequency trains of presynaptic activity applied with postsynaptic hyperpolarization, in patterns resembling mossy-fiber-mediated excitation and Purkinje-cell-mediated inhibition that are predicted to occur during delay eyelid conditioning. Here, we have used electrophysiology and Ca imaging to test how synaptic excitation and inhibition interact to generate long-lasting synaptic plasticity in nuclear cells in cerebellar slices. We find that the extent of plasticity varies with the relative timing of synaptic excitation and hyperpolarization. Potentiation is most effective when synaptic stimuli precede the postinhibitory rebound by ∼400 ms, whereas with longer intervals, or with a reverse sequence, EPSCs tend to depress. When basal intracellular Ca is raised by spontaneous firing or reduced by voltage clamping at subthreshold potentials, potentiation is induced as long as the synaptic-rebound temporal sequence is maintained, suggesting that plasticity does not require Ca levels to exceed a threshold or attain a specific concentration. Although rebound and spike-dependent Ca influx are global, potentiation is synapse specific, and is disrupted by inhibitors of calcineurin or Ca-calmodulin-dependent protein kinase II, but not PKC. When IPSPs replace the hyperpolarizing step in the induction protocol, potentiation proceeds normally. These results lead us to propose that synaptic and inhibitory/rebound stimuli initiate separate processes, with local NMDA receptor-mediated Ca influx “priming” synapses, and Ca changes from the inhibition and rebound “triggering” potentiation at recently activated synapses.
Distinct Roles of PDE4 and PDE10A in the Regulation of cAMP/PKA Signaling in the Striatum
Authors: Nishi Akinori , Kuroiwa Mahomi , Miller Diane B. , O'Callaghan James P. , Bateup Helen S. , Shuto Takahide , Sotogaku Naoki , Fukuda Takaichi , Heintz Nathaniel , Greengard Paul , Snyder Gretchen L.
Published: October 2008

Phosphodiesterase (PDE) is a critical regulator of cAMP/protein kinase A (PKA) signaling in cells. Multiple PDEs with different substrate specificities and subcellular localization are expressed in neurons. Dopamine plays a central role in the regulation of motor and cognitive functions. The effect of dopamine is largely mediated through the cAMP/PKA signaling cascade, and therefore controlled by PDE activity. We usedin vitroandin vivobiochemical techniques to dissect the roles of PDE4 and PDE10A in dopaminergic neurotransmission in mouse striatum by monitoring the ability of selective PDE inhibitors to regulate phosphorylation of presynaptic [e.g., tyrosine hydroxylase (TH)] and postsynaptic [e.g., dopamine- and cAMP-regulated phosphoprotein of Mr32 kDa (DARPP-32)] PKA substrates. The PDE4 inhibitor, rolipram, induced a large increase in TH Ser40 phosphorylation at dopaminergic terminals that was associated with a commensurate increase in dopamine synthesis and turnover in striatumin vivo. Rolipram induced a small increase in DARPP-32 Thr34 phosphorylation preferentially in striatopallidal neurons by activating adenosine A2Areceptor signaling in striatum. In contrast, the PDE10A inhibitor, papaverine, had no effect on TH phosphorylation or dopamine turnover, but instead robustly increased DARPP-32 Thr34 and GluR1 Ser845 phosphorylation in striatal neurons. Inhibition of PDE10A by papaverine activated cAMP/PKA signaling in both striatonigral and striatopallidal neurons, resulting in potentiation of dopamine D1receptor signaling and inhibition of dopamine D2receptor signaling. These biochemical results are supported by immunohistochemical data demonstrating differential localization of PDE10A and PDE4 in striatum. These data underscore the importance of individual brain-enriched cyclic-nucleotide PDE isoforms as therapeutic targets for neuropsychiatric and neurodegenerative disorders affecting dopamine neurotransmission.
Loss of Inhibitory Neuron AMPA Receptors Contributes to Ataxia and Epilepsy inStargazerMice
Authors: Menuz Karen , Nicoll Roger A.
Published: October 2008

Stargazermice are characterized by ataxia and seizures, which resemble the human disorder absence epilepsy. Stargazin, the protein mutated instargazermice, promotes the expression and function of neuronal AMPA receptors (AMPARs). However, it is unclear how decreased expression of excitatory AMPARs generatesstargazerseizures, given that seizures often result from increased neuronal excitability. Additionally, althoughstargazerataxia has been attributed to loss of AMPARs from cerebellar granule cells, other cerebellar neurons have not been examined. To examine the role of AMPAR dysfunction in these behavioral phenotypes, electrophysiological recordings were used to probe AMPAR regulation in relevant brain regions. We found that both cerebellar Purkinje cells and inhibitory thalamic reticular nucleus neurons have strongly reduced synaptic AMPAR function instargazermice. Together, our data suggest that impaired AMPAR regulation in multiple neuron populations may contribute to the behavioral phenotypes of absence seizures and ataxia seen instargazermice and imply that an understanding of human genetic disorders will require knowledge of both the genes that are mutated as well as their precise cellular expression pattern.
Exercise-Induced Synaptogenesis in the Hippocampus Is Dependent on UCP2-Regulated Mitochondrial Adaptation
Authors: Dietrich Marcelo O. , Andrews Zane B. , Horvath Tamas L.
Published: October 2008

Mitochondria are essential organelles in neurons providing appropriate energetic needs to maintain resting and action potentials as well as to modulate synaptic plasticity. Although neuronal events underlie various behavioral events, the behavior itself, such as voluntary exercise, feeds back to affect neuronal morphology and function as well as glial morphology and function. The hippocampal formation is a main site of synaptic plasticity induced by voluntary exercise. Here we show that voluntary exercise induces uncoupling protein 2 (UCP2) mRNA expression and mitochondrial oxygen consumption in coupled as well as uncoupled respiratory states in the hippocampus. These changes in mitochondrial metabolism coincided with an increase in mitochondrial number and dendritic spine synapses in granule cells of the dentate gyrus and the stratum radiatum of the CA1 region and were dependent on UCP2 expression, because in UCP2 knock-out mice such changes were not observed. Together, these observations reveal that a mitochondrial mechanism related to UCP2 function is essential for appropriate bioenergetic adaptation of neurons to increased neuronal activity and synaptic plasticity in response to exercise.
Explaining Enhanced Logical Consistency during Decision Making in Autism
Authors: De Martino Benedetto , Harrison Neil A. , Knafo Steven , Bird Geoff , Dolan Raymond J.
Published: October 2008

The emotional responses elicited by the way options are framed often results in lack of logical consistency in human decision making. In this study, we investigated subjects with autism spectrum disorder (ASD) using a financial task in which the monetary prospects were presented as either loss or gain. We report both behavioral evidence that ASD subjects show a reduced susceptibility to the framing effect and psycho-physiological evidence that they fail to incorporate emotional context into the decision-making process. On this basis, we suggest that this insensitivity to contextual frame, although enhancing choice consistency in ASD, may also underpin core deficits in this disorder. These data highlight both benefits and costs arising from multiple decision processes in human cognition.
Correlations between Groups of Premotor Neurons Carry Information about Prehension
Authors: Stark Eran , Globerson Amir , Asher Itay , Abeles Moshe
Published: October 2008

How distinct parameters are bound together in brain activity is unknown. Combination coding by interneuronal interactions is one possibility, but, to coordinate parameters, interactions between neuronal pairs must carry information about them. To address this issue, we recorded neural activity from multiple sites in the premotor cortices of monkeys that memorized reach direction and grasp type followed by actual prehension. We found that correlations between individual spiking neurons are generally weak and carry little information about prehension. In contrast, correlations and synchronous interactions between small groups of neurons, quantified by multiunit activity (MUA), are an order of magnitude stronger. A substantial fraction of the information carried by pairwise interactions between MUAs is about combinations of reach and grasp. This contrasts with the information carried by individual neurons and individual MUAs, which is mainly about reach and/or grasp but much less about their combinations. The main contribution of pairwise interactions to the coding of reach–grasp combinations is when animals memorize prehension parameters, consistent with an internal composite representation. The informative interactions between neuronal groups may facilitate the coordination of reach and grasp into coherent prehension.
Noradrenergic Induction of Odor-Specific Neural Habituation and Olfactory Memories
Authors: Shea Stephen D. , Katz Lawrence C. , Mooney Richard
Published: October 2008

For many mammals, individual recognition of conspecifics relies on olfactory cues. Certain individual recognition memories are thought to be stored when conspecific odor cues coincide with surges of noradrenaline (NA) triggered by intensely arousing social events. Such familiar stimuli elicit reduced behavioral responses, a change likely related to NA-dependent plasticity in the olfactory bulb (OB). In addition to its role in these ethological memories, NA signaling in the OB appears to be relevant for the discrimination of more arbitrary odorants as well. Nonetheless, no NA-gated mechanism of long-term plasticity in the OB has ever been directly observedin vivo. Here, we report that NA release from locus ceruleus (LC), when coupled to odor presentation, acts locally in the main OB to cause a specific long-lasting suppression of responses to paired odors. These effects were observed for both food odors and urine, an important social recognition cue. Moreover, in subsequent behavioral tests, mice exhibited habituation to paired urine stimuli, suggesting that this LC-mediated olfactory neural plasticity, induced under anesthesia, can store an individual recognition memory that is observable after recovery.
Shared Internal Models for Feedforward and Feedback Control
Authors: Wagner Mark J. , Smith Maurice A.
Published: October 2008

A child often learns to ride a bicycle in the driveway, free of unforeseen obstacles. Yet when she first rides in the street, we hope that if a car suddenly pulls out in front of her, she will combine her innate goal of avoiding an accident with her learned knowledge of the bicycle, and steer away or brake. In general, when we train to perform a new motor task, our learning is most robust if it updates the rules of online error correction to reflect the rules and goals of the new task. Here we provide direct evidence that, after a new feedforward motor adaptation, motor feedback responses to unanticipated errors become precisely task appropriate, even when such errors were never experienced during training. To study this ability, we asked how, if at all, do online responses to occasional, unanticipated force pulses during reaching arm movements change after adapting to altered arm dynamics? Specifically, do they change in a task-appropriate manner? In our task, subjects learned novel velocity-dependent dynamics. However, occasional force-pulse perturbations produced unanticipated changes in velocity. Therefore, after adaptation, task-appropriate responses to unanticipated pulses should compensate corresponding changes in velocity-dependent dynamics. We found that after adaptation, pulse responses precisely compensated these changes, although they were never trained to do so. These results provide evidence for a smart feedback controller which automatically produces responses specific to the learned dynamics of the current task. To accomplish this, the neural processes underlying feedback control must (1) be capable of accurate real-time state prediction for velocity via a forward model and (2) have access to recently learned changes in internal models of limb dynamics.
Surviving the Bottleneck: Transmission Mutants and the Evolution of Microbial Populations
Authors: Handel Andreas , Bennett Matthew R
Published: October 2008

The ability of microbial populations to increase fitness through fixation of mutants with an increased growth rate has been well described. In experimental studies, this is often the only way fitness can be increased. In natural settings, however, fitness can also be improved by increasing the ability of the microbe to transmit from one host to the next. For many pathogens, transmission includes a phase outside the host during which they need to survive before the chance of reinfecting a new host occurs. In such a situation, a reduced death rate during this phase will lead to improved fitness. Here, we compute the fixation probability of mutants that better survive the transmission bottleneck during the evolution of microbial populations. We derive analytical results that show that transmission mutants are often likely to occur and that their importance relative to growth mutants increases as the population decline during the transmission phase increases. We confirm our theoretical results with numerical simulations and suggest specific experiments that can be done to test our predictions.
O pensamento dos militares em política internacional (1961-1989)
Authors: Garcia Eugênio Vargas
Published: October 2008

O artigo trata de questões relacionadas à evolução do pensamento dos militares brasileiros, no período 1961-1989, em matéria de relações internacionais e Política Externa. Levanta algumas das limitações da interpretação crítica tradicional e analisa a concepção de política internacional prevalecente na doutrina das Forças Armadas. Procura destacar, por fim, traços distintivos que marcaram o pensamento dos militares sobre o assunto, incluindo sua vinculação com as grandes tendências históricas da diplomacia brasileira.
Uso de lodo de esgoto na reestruturação de solo degradado
Authors: Campos Fabiana da Silva de , Alves Marlene Cristina
Published: October 2008

O uso do solo nem sempre dá lugar a um novo sistema ecológico sustentável, seja de lavouras, seja de pastagens. Com isso, solos utilizados intensamente e de forma inadequada são levados à degradação. Nesse sentido, este trabalho teve como objetivo estudar a influência do lodo de esgoto na recuperação de propriedades físicas de um Latossolo Vermelho degradado, cultivado há 2,5 anos com eucalipto (Eucalyptus citriodora Hook) e braquiária (Brachiaria decumbens) no município de Selvíria, MS. O delineamento experimental utilizado foi em blocos casualizados com seis tratamentos e quatro repetições. Os tratamentos foram: 1-vegetação de Cerrado; 2-solo exposto sem tratamento para recuperação; 3-solo cultivado com eucalipto e braquiária sem uso do lodo de esgoto e adubação mineral; 4-solo cultivado com eucalipto e braquiária com adubação mineral; 5-solo cultivado com eucalipto e braquiária com uso de 30 Mg ha-1 de lodo de esgoto; e 6-solo cultivado com eucalipto e braquiária com uso de 60 Mg ha-1 de lodo de esgoto. Nas camadas do solo de 0,00-0,05; 0,05-0,10; 0,10-0,20; e 0,20-0,30 m, foram estudadas as propriedades físicas do solo: macroporosidade, microporosidade; porosidade; e densidade do solo. Na braquiária foram avaliadas as matérias verde e seca e, no eucalipto, a altura média de planta e o DAP (diâmetro à altura do peito). Concluiu-se que o solo estudado está sendo recuperado por meio dos tratamentos estabelecidos. Dentre eles, destacam-se os tratamentos com a utilização do lodo, que influenciaram as propriedades físicas do solo, proporcionaram mais rendimentos de matérias verde e seca da braquiária e promoveram maior crescimento das plantas de eucalipto. O crescimento vegetal, a densidade do solo, a porosidade total e a macroporosidade foram os melhores indicadores da recuperação do solo.
Pressão de preconsolidação e intervalo hídrico ótimo como indicadores de alterações estruturais de um latossolo e de um cambissolo sob cana-de-açúcar
Authors: Severiano Eduardo da Costa , Oliveira Geraldo César de , Dias Júnior Moacir de Souza , Oliveira Luiz Fernando Coutinho de , Castro Matheus Bornelli de
Published: October 2008

A identificação dos impactos da colheita mecanizada da cultura da cana-de-açúcar sobre a estrutura do solo em diferentes classes pode-se tornar uma importante estratégia de manejo para a minimização dos efeitos da compactação. O objetivo deste trabalho foi avaliar as alterações estruturais, a pressão de preconsolidação e o intervalo hídrico ótimo (IHO) em um Latossolo Vermelho-Amarelo (LVA) e um Cambissolo Háplico (CX), em conseqüência das operações de colheita da cana-de-açúcar em diferentes épocas de safra. Coletaram-se amostras indeformadas de solo na profundidade de 0 a 0,05 m para determinar a pressão de preconsolidação, a densidade, a porosidade do solo, a agregação e o IHO, bem como amostras deformadas para a caracterização química e física do solo. O CX apresentou maior resistência à compactação que o LVA. O conteúdo de água no solo durante a colheita da cana-de-açúcar variou na ordem: agosto de 2006 < novembro de 2005 < março de 2006 e CX > LVA em cada época. A densidade do solo na pressão de preconsolidação foi sensível à ocorrência de alterações estruturais no solo. A macroporosidade limitante apresentou restrições ao crescimento das plantas em níveis de compactação inferiores à densidade do solo crítica do IHO. A colheita mecanizada da cana-de-açúcar realizada em solo com 0,16 e 0,21 kg kg-1 de água, para LVA e CX, respectivamente, não promoveu compactação excessiva.
Porosidade e retenção de água em um argissolo sob manejos convencional e direto submetido a compressões unidimensionais
Authors: Bortoluzzi Edson Campanhola , Silva Vanderlei Rodrigues da , Petry Claudia , Cecchetti Dileta
Published: October 2008

A dinâmica da ocupação do espaço poroso pela água e ar em solos sujeitos ao estresse mecânico ainda é pouco conhecida, principalmente quando as pressões situam-se sobre a reta de pré-consolidação. Assim, este trabalho foi realizado com o intuito de quantificar as mudanças no espaço poroso de um Argissolo sob dois sistemas de preparo, submetido a compressões unidimensionais, dando-se ênfase à densidade do solo e ao conteúdo de água retida em dois potenciais. Foram coletadas amostras sob os sistemas plantio convencional (SPC) e plantio direto (SPD), em triplicata e com estrutura preservada, do horizonte superficial Ap (0-0,075 m) de um Argissolo Vermelho-Amarelo distrófico abrúptico, do campus da Universidade Federal de Santa Maria, Rio Grande do Sul. Uniformizou-se o conteúdo de água das amostras a -32 kPa sobre placa porosa em membrana de Richards (panela de pressão), sendo submetidas, em célula odométrica com dreno aberto, às pressões uniaxiais finais de zero, 50, 100 e 200 kPa. Após o ensaio, torrões foram separados com as mãos por tração e submetidos, em quadruplicata, a dois potenciais de água (-1.600 e -100 kPa), utilizando-se membrana de Richards (célula). O volume das amostras e o teor de água gravimétrica foram determinados por pesagens sob empuxo e após secagem em estufa a 105 °C. Aplicou-se a análise de variância nos resultados, e uma análise de regressão foi aplicada quando necessária. A densidade do solo respondeu linearmente para o SPD e de forma quadrática para o SPD com o aumento das pressões. O conteúdo de água variou de forma quadrática com o aumento das pressões aplicadas em ambos os sistemas de preparo do solo. Explica-se 85 % da retenção de água do solo pela variação da pressão unidimensional aplicada, sendo a resposta positiva para o SPC e negativa para o SPD. As mudanças na densidade do solo e no conteúdo de água gravimétrica foram importantes em ambos os sistemas de preparo no potencial de água de -100 kPa. Pode-se inferir que o solo sob sistema de preparo convencional foi mais sensível ao estresse mecânico que aquele sob plantio direto, evidenciando a diminuição da porosidade e consequentemente da proporção de ar.
Fertilizer 15N balance in a coffee cropping system: a case study in Brazil
Authors: Fenilli Tatiele Anete Bergamo , Reichardt Klaus , Favarin José Laércio , Bacchi Osny Oliveira Santos , Silva Adriana Lúcia , Timm Luis Carlos
Published: October 2008

Knowledge about the fate of fertilizer nitrogen in agricultural systems is essential for the improvement of management practices in order to maximize nitrogen (N) recovery by the crop and reduce N losses from the system to a minimum. This study involves fertilizer management practices using the 15N isotope label applied in a single rate to determine the fertilizer-N balance in a particular soil-coffee-atmosphere system and to deepen the understanding of N plant dynamics. Five replicates consisting of plots of about 120 plants each were randomly defined within a 0.2 ha coffee plantation planted in 2001, in Piracicaba, SP, Brazil. Nine plants of each plot were separated in sub-plots for the 15N balance studies and treated with N rates of 280 and 350 kg ha-1 during 2003/2004 and 2004/2005, respectively, both of them as ammonium sulfate enriched to a 15N abundance of 2.072 atom %. Plant shoots were considered as separate parts: the orthotropic central branch, productive branches, leaves of productive branches, vegetative branches, leaves of vegetative branches and fruit. Litter, consisting of dead leaves accumulated below the plant canopy, was measured by the difference between leaves at harvest and at the beginning of the following flowering. Roots and soil were sampled down to a depth of 1.0 at intervals of 0.2 m. Samples from the isotopic sub-plots were used to evaluate total N and 15N, and plants outside sub-plots were used to evaluate dry matter. Volatilization losses of NH3 were estimated using special collectors. Leaching of fertilizer-N was estimated from deep drainage water fluxes and 15N concentrations of the soil solution at 1 m soil depth. At the end of the 2-year evaluation, the recovery of 15N applied as ammonium sulfate was 19.1 % in aerial plant parts, 9.4 % in the roots, 23.8 % in the litter, 26.3 % in the fruit and 12.6 % remaining in the 0_1.0 m soil profile. Annual leaching and volatilization losses were very small (2.0 % and 0.9 %, respectively). After two years, only 6.2 % N were missing in the balance (100 %) which can be attributed to other non-estimated compartments and experimental errors. Results show that an enrichment of only 2 % atom 15N allows the study of the partition of fertilizer-N in a perennial crop such as coffee during a period of two years.
Comunidades microbianas, atividade enzimática e fungos micorrízicos em solo rizosférico de "Landfarming" de resíduos petroquímicos
Authors: Nakatani André Shigueyoshi , Siqueira José Oswaldo , Soares Cláudio Roberto Fonsêca Sousa , Lambais Marcio Rodrigues
Published: October 2008

As raízes das plantas podem estimular a microbiota do solo, a qual pode contribuir para o aumento da eficiência do processo de remediação. Assim, avaliar a magnitude dos efeitos das raízes sobre a microbiota do solo é de grande interesse e de relevância prática e ecológica. Neste trabalho, avaliaram-se a densidade microbiana, a atividade enzimática, a estrutura da comunidade bacteriana e a presença de fungos micorrízicos arbusculares (FMAs) na rizosfera de plantas de ocorrência espontânea em solo de sistema de "landfarming" de resíduos petroquímicos. Avaliaram-se também solos rizosféricos de cinco plantas e solo-controle sem planta por meio de contagens de microrganismos em placas, eletroforese em gel com gradiente desnaturante (DGGE) de fragmentos do gene rRNA 16S, seqüenciamento genético, atividades enzimáticas, percentagem de colonização radicular e contagem e identificação de esporos de FMAs. As plantas estimularam a densidade microbiana total e da população de degradadores de antraceno, com contagens médias de 1,5 x 10(6) e 2,2 x 10(6) UFC g-1 no solo seco, respectivamente, enquanto, no solo sem planta, essas contagens foram de 5,7 x 10(5) e 2,9 x 10(5) UFC g-1 no solo seco para os respectivos grupos microbianos. As espécies de maior efeito foram Bidens pilosa e Eclipta alba. Entretanto, esses efeitos estimulantes não foram verificados para a atividade enzimática do solo. A colonização micorrízica das raízes (em torno de 40 %) e a densidade de esporos nos solos rizosféricos foram elevadas (entre 900 e 4.800 esporos por 50 cm³ de solo), sendo maior na Brachiaria decumbens. Foram identificadas quatro espécies de FMAs: Acaulospora morrowiae, Glomus intraradices, Paraglomus occultum e Archaeospora trappei. Com exceção de G. intraradices, essas espécies não foram observadas em áreas contaminadas por hidrocarbonetos de petróleo. A análise por DGGE revelou que os solos rizosféricos apresentaram comunidades bacteriana diferente do solo sem plantas. As bactérias degradadoras de antraceno isoladas apresentaram relação filogenética com os gêneros Streptomyces, Nocardioides, Arthrobacter, Pseudoxanthomonas e com gêneros não identificados das famílias Cellulomonadaceae, Xanthomonadaceae e Rhodobacteraceae, sendo quatro destes isolados pertencentes aos actinomicetos. Apenas Nocardioides e o gênero relacionado com a família Cellulomonadaceae foram relatados em áreas brasileiras contaminadas com hidrocarbonetos de petróleo. Conclui-se que as plantas estimulam o aumento da densidade de células bacterianas e alteram a comunidade microbiana do solo de "landfarming" de resíduo petroquímico.
Características químicas do lixiviado na fase de enraizamento de estacas de cacau em substratos adubados com fósforo
Authors: Souza Júnior José Olimpio de , Carmello Quirino Augusto de Camargo , Faria José Cláudio
Published: October 2008

Para a produção de mudas em substratos, é intenso o uso de fertilizante e de irrigação, o que pode gerar perdas elevadas de nutrientes. O P é muito utilizado na preparação de substratos, mas estudos modelando suas perdas ainda são escassos. Este trabalho objetivou avaliar atributos químicos do lixiviado na fase de enraizamento de estacas de cacaueiro cultivadas sob irrigação intermitente em diferentes substratos e doses de P. O delineamento experimental foi em blocos casualizados com três repetições, em esquema fatorial 5 x 5: cinco substratos (misturas, em volume, de 20, 35, 50, 65 e 80 % de fibra de coco - FC, complementadas com Plantmax®) e cinco doses de superfosfato triplo - SFT (P2O5 = 0; 0,23; 0,46; 0,92; e 1,84 g dm-3). A parcela foi formada por dois tubetes (288 cm³), com uma estaca herbácea de cacau por tubete. O total do lixiviado de 28 dias foi coletado e medido, sendo a condutividade elétrica (CE) e o pH analisados em três amostras semanais. Os nutrientes P, Ca, Mg e K foram quantificados em amostras médias semanais. Os resultados foram submetidos à análise de regressão. Com o decorrer dos dias, o pH do lixiviado aumentou e a CE diminuiu, alcançando valores próximos aos da água de irrigação. O incremento de SFT diminuiu o pH e aumentou a CE do lixiviado. As variações de pH e CE foram mais rápidas e maiores quanto maior foi a proporção de FC no substrato. O teor e o conteúdo dos nutrientes no lixiviado decresceram rapidamente com o tempo, independente do substrato. O fornecimento de SFT aumentou a lixiviação de todos os nutrientes analisados. As perdas de Ca, Mg e K foram proporcionais à riqueza desses nutrientes no substrato. A lixiviação do P aplicado variou de 39 a 74 % e foi inversamente proporcional à capacidade de adsorção de fosfato do substrato.
Effect of fertilizer-N application and seed coating with rhizobial inoculants on soybean yield in eastern Paraguay
Authors: Kubota Aki , Hoshiba Kent , Bordon Jorge
Published: October 2008

Nitrogen removal in soybean grains at harvest may exceed biological N2 fixation, particularly if grain yields are as high as typically achieved on "Terra Rossa" soils of Eastern Paraguay. Applying N fertilizer or coating seeds with rhizobial inoculants that enhance nodulation may represent a way of balancing the N budget. However, the effects of such treatments appear to be highly site-specific. The objective of this study was to examine the effects of N application (N) and rhizobial inoculation (I) on nodulation, N accumulation and soybean yields in Eastern Paraguay. Field experiments were conducted in two consecutive soybean seasons. Dry conditions in the first year delayed sowing and reduced plant number m-2 and pod number plant-1. Grain yields were generally below 2 t ha-1 but the +N+I treatment increased yields by about 75%. In the second year favorable conditions resulted in yields of around 4 t ha-1 and the treatments had no effect. Nitrogen accumulation was higher in the first year and could therefore not explain the observed yield differences between years and treatment combinations. The positive effect of the +N+I treatment in year one was associated with a more rapid root growth which could have reduced susceptibility to intermittent drought stress. Nodule biomass decreased between flowering and pod setting stages in the +I treatment whereas further increases in nodule biomass in the -I treatment may have led to competition for assimilates between nodules and developing pods. Based on these preliminary results we conclude that N application and seed inoculation can offer short-term benefits in unfavorable years without negative effects on yield in favorable years.
Modelagem da recomendação de corretivos e fertilizantes para a cultura da soja
Authors: Santos Flavia Cristina dos , Neves Julio Cesar Lima , Novais Roberto Ferreira , Alvarez V. Víctor Hugo , Sediyama Carlos Sigueyuki
Published: October 2008

A recomendação de adubação para as culturas agrícolas, no Brasil, é feita com base em tabelas que relacionam a classe de disponibilidade do nutriente no solo com a dose a ser aplicada. Este trabalho apresenta uma alternativa para recomendar corretivos e fertilizantes para a cultura da soja, o SIRSo (sistema de recomendação de corretivos e fertilizantes para a cultura da soja). O princípio desse sistema é o balanço nutricional, ou seja, a recomendação se faz a partir da diferença entre o requerimento de nutrientes pela planta e o suprimento de nutrientes pelo solo, por resíduos orgânicos, por fertilizantes e pela calagem. O sistema considera ainda o fator sustentabilidade, visando manter uma quantidade de nutriente no solo capaz de garantir produtividade mínima em cultivos subseqüentes. Para recomendar calagem, o sistema considera dois métodos: a neutralização do Al3+ e a elevação dos teores de Ca2+ + Mg2+, ou a saturação por bases. O requerimento de nutrientes varia com a produtividade esperada de grãos, com as características do solo e com a taxa de recuperação pela planta do nutriente aplicado ao solo. O suprimento pelo solo depende da disponibilidade do nutriente, estimada a partir da análise de solo e da taxa de recuperação pelo extrator do nutriente aplicado. As comparações entre as recomendações geradas pelo SIRSo e aquelas oriundas das tabelas em uso no País mostram, em geral, que o SIRSo recomenda maior quantidade de nutrientes, principalmente de P e K quando consideradas as maiores produtividades, fato confirmado pela análise de sensibilidade, que mostrou grande variação da dose a ser recomendada desses nutrientes com a produtividade de grãos. Esse fato pode ser considerado como vantagem do SIRSo em relação às tabelas, muitas das quais apresentam pouca ou nenhuma variabilidade das doses em relação à produtividade.
Influência de nitrogênio e potássio, via fertirrigação, em atributos do solo, níveis críticos foliares e produção do coqueiro-anão
Authors: Sobral Lafayette Franco , Nogueira Luis Carlos
Published: October 2008

O plantio de coqueiro-anão irrigado, com o objetivo de produzir coco para aproveitamento de água, tem se expandido muito no Brasil. As maiores produtividades, obtidas sob irrigação, influenciam nas quantidades de N e de K requeridas pela planta, o que altera as relações entre os seus teores no solo e na planta. Um experimento com plantas de coqueiro-anão, irrigado por microaspersão, foi conduzido em um Argissolo Amarelo da unidade de paisagem dos tabuleiros costeiros no Nordeste do Brasil. Foi utilizada a matriz Pan Puebla III em blocos ao acaso, com quatro repetições. Os tratamentos de fertirrigação foram dez combinações de N e K, utilizando uréia e cloreto de potássio como fontes dos nutrientes, aplicados semanalmente durante 52 meses. Amostras de solo foram coletadas na zona de influência do microaspersor e amostras de folhas foram coletadas nas posições 9 e 14. A aplicação de uréia reduziu o pH e os teores de Ca2+ e Mg2+ no solo. O maior valor de condutividade elétrica do extrato de saturação do solo foi de 0,65 dS m-1, na profundidade 0_5 cm, e decresceu com a profundidade. Os coeficientes de correlação entre os teores de K na folha e no solo, nas profundidades 0_5, 0_20 e 20_40 cm, foram similares, indicando que a amostragem de solo para fertilidade na cultura do coqueiro-anão fertirrigado pode ser feita na profundidade de 0_20 cm. Maior quantidade de massa do fruto e mais volume do albúmen líquido foram obtidos com a menor dose de N, dado o menor número de frutos por árvore. Os tratamentos de N e K não influenciaram o valor do pH da água do coco, porém alteraram o valor do brix. O teor de K na água do coco aumentou com a quantidade de K aplicada e do teor de K na folha. Os níveis críticos de N e K nas folhas 9 e 14 foram 19,2, 20,5, 12,1 e 9,4 g kg-1, respectivamente. O nível crítico de K no solo pelo Mehlich-1, na profundidade 0_20 cm, foi 45 mg dm-3.