bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantitative analysis of time-lapse seismic monitoring data at the Sleipner CO2 storage operation
Authors: Chadwick Andy , Williams Gareth , Delepine Nicolas , Clochard Vincent , Labat Karine , Sturton Susan , Buddensiek Maike-L , Dillen Menno , Nickel Michael , Lima Anne Louise , Arts Rob , Neele Filip , Rossi Giuliana
Published: February 2010

The [Formula: see text] storage operation at Sleipner in the Norwegian North Sea provides an excellent demonstration of the application of time-lapse surface seismic methods to [Formula: see text] plume monitoring under favorable conditions. Injection commenced at Sleipner in 1996 with [Formula: see text] separated from natural gas being injected into the Utsira Sand, a major saline aquifer of late Cenozoic age. [Formula: see text] injection is via a near-horizontal well at a depth of about 1012 m below sea level (bsl) some 200 m below the reservoir top, at a rate approaching 1 million tonnes (Mt) per year, with more than 11 Mt currently stored.
AVO modeling of pressure-saturation effects in Weyburn CO2 sequestration
Authors: Ma Jinfeng , Morozov Igor
Published: February 2010

The Weyburn Field in southeastern Saskatchewan, Canada (Figure 1) was discovered in 1954 and has been water-flooded since the 1960s. In October 2000, injection of [Formula: see text] for enhanced oil recovery was started by EnCana, concurrently with a multidisciplinary International Energy Agency Greenhouse Gas (IEA GHG) [Formula: see text] Monitoring and Storage Project (CO2MSP). In order to monitor [Formula: see text] injection, storage, and oil recovery, several vintages of 3D and 3D/3-C data were acquired, starting with a baseline survey in December 1999. These time-lapse data sets were used to evaluate the quality and safety of [Formula: see text] sequestration, and monitor the reservoir pressure front, water flooding, and bypassed oil (White et al., 2004).
Microseismic event location for monitoring CO2 injection using double-difference tomography
Authors: Zhou Rongmao , Huang Lianjie , Rutledge James
Published: February 2010

Increases in pore pressure and volume caused by [Formula: see text] injection will perturb the ambient stress field and possibly trigger brittle failure on small fractures or faults, resulting in microearthquakes. Monitoring this induced seismicity can help understand the migration of the [Formula: see text] front, and the stress and strain changes in the reservoir (Miyazawa et al., 2008). As part of research efforts of the Southwest Regional Partnership on Carbon Sequestration supported by the U.S. Department of Energy and managed by the National Energy Technology Laboratory, a large number of microseismic events have been recorded since early 2008 using a geophone string cemented into a well for monitoring [Formula: see text] injection at the Aneth oil field in Utah. We use double-difference tomography to obtain high-precision locations of microseismic events and improve the spatial resolution of the velocity structure simultaneously. The double-difference seismic tomography method was developed for improving earthquake source locations and tomography imaging (Waldhauser and Ellsworth, 2000; Zhang and Thurber, 2003; Okada et al., 2006). The double-difference method uses both the absolute and differential arrival times to invert for the velocity distribution and the source locations simultaneously. Because catalog and cross-correlation data are combined into one system of equations, interevent distances within multiplets are determined to the accuracy of the cross-correlation data, while the relative locations between multiplets and uncorrelated events are simultaneously determined to the accuracy of the absolute traveltime data. From the studies conducted by Waldhauser and Ellsworth, the uncertainties in double-difference locations are improved by more than an order of magnitude compared to catalog locations. Zhang and Thurber tested the double-difference tomography on a synthetic data set and found that it produced a more accurate velocity model and event locations than standard tomography.
1α,25-Dihydroxyvitamin D3 Inhibits Growth of VCaP Prostate Cancer Cells Despite Inducing the Growth-Promoting TMPRSS2:ERG Gene Fusion
Authors: Washington Michele N. , Weigel Nancy L.
Published: February 2010

Vitamin D receptor (VDR) agonists have been shown to reduce the growth of several prostate cancer cell lines. However, the effects of VDR activation have not been examined in the presence of the recently identified androgen-regulated TMPRSS2:ERG gene fusions, which occur in a high percentage of prostate cancers and play a role in growth and invasiveness. In a previous microarray study, we found that VDR activation induces TMPRSS2 expression in LNCaP prostate cancer cells. Here we show that the natural VDR agonist 1α,25-dihydroxyvitamin D3 and its synthetic analog EB1089 increase expression of TMPRSS2:ERG mRNA in VCaP prostate cancer cells; this results in increased ETS-related gene (ERG) protein expression and ERG activity as demonstrated by an increase in the ERG target gene CACNA1D. In VCaP cells, we were not able to prevent EB1089-mediated TMPRSS2:ERG induction with an androgen receptor antagonist, Casodex, although in LNCaP cells, as reported for some other common androgen receptor and VDR target genes, Casodex reduces EB1089-mediated induction of TMPRSS2. However, despite inducing the fusion gene, VDR agonists reduce VCaP cell growth and expression of the ERG target gene c-Myc, a critical factor in VDR-mediated growth inhibition. Thus, the beneficial effects of VDR agonist treatment override some of the negative effects of ERG induction, although others remain to be tested.
Disruption of the Dopamine D2 Receptor Impairs Insulin Secretion and Causes Glucose Intolerance
Authors: García-Tornadú Isabel , Ornstein Ana M. , Chamson-Reig Astrid , Wheeler Michael B. , Hill David J. , Arany Edith , Rubinstein Marcelo , Becu-Villalobos Damasia
Published: February 2010

The relationship between antidopaminergic drugs and glucose has not been extensively studied, even though chronic neuroleptic treatment causes hyperinsulinemia in normal subjects or is associated with diabetes in psychiatric patients. We sought to evaluate dopamine D2 receptor (D2R) participation in pancreatic function. Glucose homeostasis was studied in D2R knockout mice (Drd2−/−) mice and in isolated islets from wild-type and Drd2−/− mice, using different pharmacological tools. Pancreas immunohistochemistry was performed. Drd2−/− male mice exhibited an impairment of insulin response to glucose and high fasting glucose levels and were glucose intolerant. Glucose intolerance resulted from a blunted insulin secretory response, rather than insulin resistance, as shown by glucose-stimulated insulin secretion tests (GSIS) in vivo and in vitro and by a conserved insulin tolerance test in vivo. On the other hand, short-term treatment with cabergoline, a dopamine agonist, resulted in glucose intolerance and decreased insulin response to glucose in wild-type but not in Drd2−/− mice; this effect was partially prevented by haloperidol, a D2R antagonist. In vitro results indicated that GSIS was impaired in islets from Drd2−/− mice and that only in wild-type islets did dopamine inhibit GSIS, an effect that was blocked by a D2R but not a D1R antagonist. Finally, immunohistochemistry showed a diminished pancreatic β-cell mass in Drd2−/− mice and decreased β-cell replication in 2-month-old Drd2−/− mice. Pancreatic D2Rs inhibit glucose-stimulated insulin release. Lack of dopaminergic inhibition throughout development may exert a gradual deteriorating effect on insulin homeostasis, so that eventually glucose intolerance develops.
Nuclear Targeting of Cyclin-Dependent Kinase 2 Reveals Essential Roles of Cyclin-Dependent Kinase 2 Localization and Cyclin E in Vitamin D-Mediated Growth Inhibition
Authors: Flores Omar , Wang Zhengying , Knudsen Karen E. , Burnstein Kerry L.
Published: February 2010

1,25-Dihydroxyvitamin D3 (1,25-(OH)2D3), inhibits proliferation of a variety of cell types including adenocarcinoma of the prostate. We have previously shown that 1,25-(OH)2D3 increases the stability of the cyclin-dependent kinase inhibitor p27KIP1, decreases cyclin-dependent kinase 2 (CDK2) activity, and promotes G1 phase accumulation in human prostate cancer cells. These effects correlate with cytoplasmic relocalization of CDK2. In this study, we investigated the role of CDK2 cytoplasmic relocalization in the antiproliferative effects of 1,25-(OH)2D3. CDK2 was found to be necessary for prostate cancer cell proliferation. Although induced by 1,25-(OH)2D3, the cyclin-dependent kinase inhibitor p27KIP1 was dispensable for 1,25-(OH)2D3-mediated growth inhibition. Reduction in CDK2 activity by 1,25-(OH)2D3 was associated with decreased T160 phosphorylation, a residue whose phosphorylation in the nucleus is essential for CDK2 activity. Ectopic expression of cyclin E was sufficient to overcome 1,25-(OH)2D3-mediated cytoplasmic mislocalization of CDK2 and all antiproliferative effects of 1,25-(OH)2D3, yet endogenous levels of cyclin E or binding to CDK2 were not affected by 1,25-(OH)2D3. Similarly, knockdown of the CDK2 substrate retinoblastoma, which causes cyclin E up-regulation, resulted in resistance to 1,25-(OH)2D3-mediated growth inhibition. Human prostate cancer cells resistant to growth inhibition by 1,25-(OH)2D3 but retaining fully functional vitamin D receptors were developed. These cells did not exhibit 1,25-(OH)2D3-mediated cytoplasmic relocalization of CDK2. Targeting CDK2 to the nucleus of 1,25-(OH)2D3-sensitive cancer cells blocked G1 accumulation and growth inhibition by 1,25-(OH)2D3. These data establish central roles for CDK2 nuclear-cytoplasmic trafficking and cyclin E in the mechanism of 1,25-(OH)2D3-mediated growth inhibition in prostate cancer cells.
Plasma Adipokines, Bone Mass, and Hip Geometry in Rural Chinese Adolescents
Authors: Hong Xiumei , Arguelles Lester M. , Tsai Hui-Ju , Zhang Shanchun , Wang Guoying , Wang Binyan , Liu Xue , Li Zhiping , Tang Genfu , Xing Houxun , Xu Xiping , Wang Xiaobin
Published: February 2010

Context: Adipokines have been linked to bone phenotypes recently, but with conflicting results. Few such studies have been conducted in adolescents.

Objective: The aim of the study was to examine the associations of adiponectin and leptin with multiple bone phenotypes in Chinese adolescents and estimate the genetic contribution to these associations.

Design and Setting: This was a cross-sectional study conducted in rural China.

Participants: A total of 675 males and 575 females aged 13–21 yr were included.

Outcome Measures: Fat mass (FM), lean mass (LM), bone area (BA), bone mineral content (BMC), cross-sectional area (CSA), and section modulus (SM) were measured by dual-energy x-ray absorptiometry. Plasma adipokine concentration was determined using sandwich immunoassays.

Results: Adiponectin was inversely associated with all BMCs in males (P < 0.01), but not in females, after adjusting for LM, body weight, or BMI singly, or for LM and FM simultaneously. No such relationships were observed for CSA or SM in both genders. Leptin was inversely associated with all BAs, total-hip BMC, CSA, and SM in both genders, when adjusting for body weight or BMI. These associations, except for whole-body BA and lumbar spine BA in females, disappeared when simultaneously adjusting for LM and FM. By Cholesky decomposition models using twin design, significant genetic correlations were detected between adiponectin and total-hip BMC in males and between leptin and total-hip BMC in both genders.

Conclusions: We demonstrated that adiponectin and leptin were inversely associated with adolescent bone phenotypes but showed differential associations by gender, type of bone phenotypes, and adjustment of FM. This study also suggested that adipokines and bone phenotypes may share a common set of genes.
Patient satisfaction with primary care in Armenia: good rating of bad services?
Authors: Harutyunyan Tsovinar , Demirchyan Anahit , Thompson Michael E , Petrosyan Varduhi
Published: February 2010

The study assessed the level of patient satisfaction at selected primary health-care facilities in Lori and Shirak provinces of Armenia. Self-administered questionnaires were distributed to 684 recent clients at primary health-care facilities. The majority of patients were satisfied with their provider (mean satisfaction score of 1.75 out of maximum 2). Most patients (89.0%) would visit the same provider again, and would recommend the provider to friends (85.6%). Satisfaction with other aspects of care, including waiting time, accessibility of services, confidentiality and cleanliness of the facility, was also high (mean score of 1.70 out of 2). Seventy-eight percent of respondents considered the care they received to be ‘excellent’ or ‘good’. The less educated and those in rural areas were more likely to be satisfied with the provider's quality. Despite the fundamental problems now challenging the Armenian primary health-care sector, patient satisfaction remains high. Given the high level of reported satisfaction, more focused satisfaction research tools and alternative approaches to patient assessments of care are needed to inform quality improvement in the Armenian setting.
Major incident planning in primary care trusts in north-west England: a cross-sectional survey
Authors: Day Thomas , Challen Kirsty , Walter Darren
Published: February 2010

The Civil Contingencies Act (2004) requires UK primary care trusts (PCTs) to plan and respond to major health incidents. We carried out a cross-sectional survey of all PCTs in the north-west region of England using a telephone interview with a structured questionnaire. We assessed: (1) staff members responsible for emergency planning; (2) risk assessment; (3) training and exercises; and (4) the planned response to a major incident. Response rate was 61% (20/33). Twelve out of 20 employed an emergency planning officer. All responding PCTs had participated in a tabletop exercise in the previous year and nine of 20 in a live exercise in the previous three years. Nine provided major incident training to new staff. Fifteen had discussed major incident preparations with their local acute trust but none could quantify the support they would be able to provide in terms of accelerated discharges. We have revealed potentially serious deficiencies in the emergency preparedness of many PCTs. PCTs are expected to play a vital role in coordinating the National Health Service (NHS) response to a major incident and these results have important implications for the ability of the NHS as a whole to effective respond to such incidents.
The skills gap in hospital management: a comparative analysis of hospital managers in the public and private sectors in South Africa
Authors: Pillay Rubin
Published: February 2010

A lack of management capacity has been identified as the key stumbling block to attaining the goals of health for all in South Africa. As part of the overall management development process, this research aims to identify the skills that are important for health services management and to evaluate managers' self-assessed proficiency in each of these skills. We also examined the impact of past training on perceived competency levels. A cross-sectional survey using a self-administered questionnaire was conducted among 404 hospital managers in the South African public and private sectors. Respondents were asked to rate the level of importance that each proposed competency had in their job and to indicate their proficiency in each skill. Both public and private sector managers rated competencies related to ‘people management’, ‘self-management’ and ‘task-related skills’ highest followed by ‘strategic planning’ and ‘health delivery’, respectively. The largest differences between mean importance rating and mean skill rating for public sector managers were for people management skills, task-related skills and self-management skills. The largest deficits for private sector managers were for people management skills, self-management skills and health delivery skills. Informal management development programmes were found to be more valuable in improving management skills. These findings reflect the reality of the local health service environment and the need of health managers. It will be useful in the conceptualization, design and delivery of health management programmes aimed at enhancing current and future management and leadership capacity in the health sector in South Africa.
Reducing the rate of unregistered studies
Authors: Tattersall Chris L , Peters M , Tee A
Published: February 2010

The aim of this audit cycle is to measure the extent to which unregistered or wrongly classified studies (research, clinical audit, satisfaction surveys/service evaluations) are conducted within a National Health Service (NHS) Trust, and to ascertain whether promotion of the correct processes can improve the results. An anonymous questionnaire was sent to staff in a single NHS Trust via internal post and email concerning unregistered or wrongly classified studies being conducted. An information sheet was attached to the questionnaire, which gave a brief description and information relating to conducting different types of study. The audit was conducted before and after the introduction of a variety of promotional activities within the Research and Development (R&D) department. The percentage of unregistered research was shown to be 45.8% in audit 1, with audit 2 showing a reduction in unregistered studies to 5.2% ( P = 0.005). For clinical audits the results were similar between audits (with no additional promotion) (2.3–2.4%). Satisfaction surveys which were included in the promotion of the research department reduced its level of unregistered studies from 46% to 5% ( P = 0.0084). With the targeted and persistent promotion of the relevant departments a dramatic reduction in unregistered studies can be achieved ( P = 0.01).
Dietary soy may not confound acute experimental stroke infarct volume outcomes in ovariectomized female rats
Authors: Prongay Kamm D , Lewis Anne D , Hurn Patricia D , Murphy Stephanie J
Published: February 2010

Oestrogen administration can alter experimental stroke outcomes. Soy as a source of phytoestrogens may therefore modulate responses in ‘oestrogen-sensitive’ stroke models, thus potentially confounding results. We evaluated the effects of dietary soy on acute infarct volumes in a pilot study using a rat focal stroke model. We hypothesized that ovariectomized (OVX) rats fed a soy-rich diet would have smaller acute infarct volumes than rats fed a soy-free diet. OVX rats were randomly assigned to a soy-free ( n = 6) or a soy-rich ( n = 6) diet for four weeks and weighed weekly. Following the dietary trial, rats underwent 2 h of middle cerebral artery occlusion (MCAO). Mean arterial blood pressure, rectal and temporalis muscle temperatures, arterial blood gases and blood glucose were recorded peri-ischaemia. Rats were euthanized 22 h following 2 h of MCAO. Brains were stained with 2,3,5-triphenyl tetrazolium chloride for acute infarct volume analysis. Uterine weight and histology were also evaluated as additional internal oestrogen-sensitive controls. Rats on the soy-free diet had greater gains in body weight (259 ± 6% baseline body weight) than rats on the soy-rich diet (238 ± 4% baseline body weight). No differences were seen in uterine weight and histology, peri-ischaemic physiological parameters and infarct volumes between the treatment groups. The results of this pilot study suggest that the dietary soy level tested may not alter acute infarct volumes in ischaemic female rat brain. More studies addressing the potential confounding effects of dietary soy in ‘oestrogen-sensitive’ stroke models are needed if investigators are to make informed choices regarding diets used in experimental stroke research.
The effects of intra-cage aspen tube on cardiac morphology and gene expression
Authors: Voipio H-M , Kasanen I H E , Leskinen H , Mäkinen T , Nevalainen T
Published: February 2010

According to the European recommendations rodents should be provided with a nest box if there is insufficient nesting material to build a complete, covered nest. Rats are generally poor nest builders; hence an additional structure is needed. Optimally, housing refinement may be combined with better science; at least it should not detract from the scientific integrity. In order to evaluate these options, there is a need to assess the items used in individual research projects. Studies investigating molecular mechanisms of cardiac hypertrophy and heart failure are typically long-lasting studies; therefore, refinement of the housing of rats in these studies is important. The aim of this study was to evaluate in rats whether a wooden tube has any impact on cardiac morphology or on basal gene expression of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP); known markers of cardiac overload, hypertrophy and heart failure. The experimental protocol simulated cardiovascular studies, but without any surgical operations. A total of 42 male Hsd:SD rats were used in an eight-week experiment. After weaning, the experimental group was provided with a rectangular aspen tube and nesting material, and the control group with only nesting material. ANP and BNP gene expression were measured from the left ventricles with Northern blot analysis postmortem along with the absolute weights of the whole heart, left and right atria and left and right chambers. The weights of the whole heart and left chamber were also analysed in relation to body weight. No statistically significant differences were observed in any of these variables. The inter-individual variation was also unchanged by the cage item. In conclusion, the aspen tube does not disrupt research results or alter the number of animals needed and can therefore be recommended for enrichment purposes in cardiovascular studies.
Oral Syringes: A Crucial and Economical Risk-Reduction Strategy that has Not Been Fully Utilized; Caution regarding Once-Weekly Levothyroxine; When Drug Strengths Differ by 10-Fold; Lower Colchicine Dose Effective and Safer
Authors: Cohen Michael R. , Smetzer Judy L.
Published: February 2010

These medication errors have occurred in health care facilities at least once. They will happen again—perhaps where you work. Through education and alertness of personnel and procedural safeguards, they can be avoided. You should consider publishing accounts of errors in your newsletters and/or presenting them at your inservice training programs.

Your assistance is required to continue this feature. The reports described here were received through the Institute for Safe Medication Practices (ISMP) Medication Errors Reporting Program. Any reports published by ISMP will be anonymous. Comments are also invited; the writers' names will be published if desired. ISMP may be contacted at the address shown below.

Errors, close calls, or hazardous conditions may be reported directly to ISMP through the ISMP Web site ( www.ismp.org ), by calling 800-FAIL-SAFE, or via e-mail at ismpinfo@ismp.org . ISMP guarantees the confidentiality and security of the information received and respects reporters' wishes as to the level of detail included in publications.
Social Integration in Employment Settings: Application of Intergroup Contact Theory
Authors: Novak Jeanne A. , Rogan Patricia M.
Published: February 2010

This study used a survey of 106 employment specialists to test the ability of intergroup contact theory to explain social integration outcomes of employees with disabilities. Contact theory suggests that coworkers are more accepting of employees with disabilities if they have sufficient opportunities to interact with them, equal status and interdependent working relationships, and supervisors who support equality and acceptance. The contact model and an expanded model that includes workplace culture significantly predicted not only coworker attitudes toward employees with disabilities but also the employees' level of social participation and feelings of social support. In addition, outcome dependency moderated the relation between the vocational competence of employees with disabilities and coworker attitudes toward them. Study findings have practical implications for facilitating social relationships in the supported workplace.
Introduction to Quasielastic Neutron Scattering
Authors: Embs Jan Peter , Juranyi Fanni , Hempelmann Rolf
Published: February 2010

This tutorial introduction has been written for people who are not specialized in neutron scattering or in other scattering methods but who are interested and would like to get an impression and learn about the method of Quasielastic Neutron Scattering (QENS). The theoretical (scattering process) as well as the experimental basics (neutron sources, neutron scattering instruments, experimental periphery) are explained in a generally understandable way, with only the most essential formulas. QENS addresses the stochastic dynamics in condensed matter, and it is pointed out for which problems and for which systems in condensed matter research QENS is a powerful method. Thus sufficient information is provided to enable non-experts to think about their own QENS experiment and to understand related literature in this area of research.
Recent Backscattering Instrument Developments at the ILL and SNS
Authors: Frick Bernhard , Mamontov Eugene , Eijck Lambert van , Seydel Tilo
Published: February 2010

We present new developments in neutron backscattering spectroscopy from two major neutron scattering centers. The first example is the reactor backscattering project IN16B, which is under construction at the Institut Laue-Langevin (ILL), Grenoble, France, the second is the spallation source near-backscattering spectrometer BASIS at the spallation neutron source SNS, Oak Ridge National Laboratory, USA, in operation since 2007. After explaining the energy resolution contributions to neutron backscattering and presenting the current status, we describe the layout, performance and the complementarity of the two most advanced backscattering projects. A few examples should illustrate the status and new experimental possibilities.
The Dynamic Response Function χ
T(Q,t) of Confined Supercooled Water and its Relation to the Dynamic Crossover Phenomenon
Authors: Chen Sow-Hsin , Zhang Yang , Lagi Marco , Chu X. , Liu Li , Faraone Antonio , Fratini Emiliano , Baglioni Piero
Published: February 2010

We have made a series of Quasi-Elastic Neutron Scattering (QENS) studies of supercooled water confined in 3-D and 1-D geometries, specifically, interstitial water in aged cement paste (3-D) and water confined in MCM-41-S and Double Wall Nano Tube DWNT (1-D). In addition, we also include the cases of hydration water on protein surface and other biopolymer surfaces (pseudo 2-D). By analyzing the QENS spectra using Relaxing Cage Model (RCM), we are able to extract accurately the self-intermediate scattering function of hydrogen atoms FH(Q,t), at low-Q as a function of temperature T, showing an α-relaxation process at long time. We can then construct the Dynamic Response Function χT(Q,t) = -dFH(Q,t)/dT. χT(Q,t) as a function of t at constant Q shows a single peak at the characteristic α-relaxation time 〈τ〉, the amplitude of which grows as we approach the dynamic crossover temperature TL observed before in each of these geometries. However, the peak height of χT(Q,t) decreases after passing the crossover temperature TL. We make an argument to relate the occurrence of the extremum of the peak height in χT to the existence of the dynamic crossover temperature in each of these cases.
Dynamical Properties of Decorated Lamellar Microemulsions in the Brush Regime
Authors: Holderer O , Frielinghaus H. , Byelov D. , Monkenbusch M , Allgaier J: , Richter D.
Published: February 2010

The elastic constants of bicontinuous microemulsions, consisting of water, oil (decane) and a surfactant, can be modified by the addition of diblock-copolymers (boosting effect). A similar decoration of the surfactant membrane is possible in the lamellar phase. At high diblock copolymer densities, in the brush regime, a change in the dependence of the bending rigidity on the molecular size and concentration of the diblock copolymer is predicted theoretically. In particular a very strong dependence of the bending rigidity on the radius of gyration of the diblock copolymer (κ ∝ R
5) is predicted. We have studied the structure and dynamics of lamellar microemulsions by small angle neutron scattering (SANS) and neutron spin echo spectroscopy (NSE) in the brush regime, with high diblock copolymer density. Decyl polyglycol ether (C10E4) has been used as surfactant, the amphiphilic diblock-copolymers were polyethylenepropylene/polyethyleneoxide (PEP5–PEO5). The influence of the diblock copolymer concentration when entering the brush regime on the bending rigidity κ and the correlation length ξ will be discussed.
Hydrogen Dynamics in Lightweight Tetrahydroborates
Authors: Remhof Arndt , Gremaud Robin , Buchter Florian , Lodziana Zbigniew , Embs Jan Peter , Ramirez-Cuesta Timmy A. J. , Borgschulte Andreas , Züttel Andreas
Published: February 2010

The high hydrogen content in complex hydrides such as M[AlH4]
x
and M[BH4]
x
(M = Li, Na, K, Mg, Ca) stimulated many research activities to utilize them as hydrogen storage materials. An understanding of the dynamical properties on the molecular level is important to understand and to improve the sorption kinetics. Hydrogen dynamics in complex hydrides comprise long range translational diffusion as well as localized motions like vibrations, librations or rotations. All the different motions are characterized by their specific length- and timescales. Within this review we give an introduction to the physical properties of lightweight complex hydrides and illustrate the huge variety of dynamical phenomena on selected examples.
Determinação da permeabilidade ao ar em amostras indeformadas de solo pelo método da pressão decrescente
Authors: Silva Álvaro Pires da , Leão Tairone Paiva , Tormena Cássio Antonio , Gonçalves Antonio Carlos Andrade
Published: February 2010

A permeabilidade do solo ao ar (Ka) determina o fluxo convectivo de gases na matriz do solo e a troca de gases na interface do sistema solo-atmosfera, influenciando diretamente a qualidade do ambiente físico para o crescimento de plantas e a taxa de ocorrência de processos dependentes da concentração de gases no solo. A Ka pode ser estimada por um método simplificado baseado em uma modificação da lei de Darcy para fluxo de gases no solo em pressão decrescente. Os objetivos deste trabalho foram modificar e aprimorar um permeâmetro para quantificar, em laboratório, a permeabilidade de amostras indeformadas de solos ao ar utilizando o método da pressão decrescente. Foram utilizados dois sistemas de aquisição de dados: um sistema eletrônico automatizado composto por um transdutor de pressão conectado a um datalogger (E1), e alternativamente um sistema composto de um manômetro digital para registro do decréscimo de pressão e um cronômetro (E2). No sistema E1, foram avaliadas amostras da camada superficial de um Nitossolo Vermelho eutroférrico argiloso, coletadas na área experimental da Escola Superior de Agricultura "Luiz de Queiroz" - USP, Piracicaba, SP, e no E2 foram avaliadas amostras de um perfil de Nitossolo Vermelho distroférrico muito argiloso, coletadas em intervalos de profundidade em área experimental da Universidade Estadual de Maringá, PR. Os ensaios para a determinação de Ka foram realizados em amostras indeformadas de solo com variação na densidade do solo e no conteúdo de água. A Ka aumentou com a redução do conteúdo de água do solo em função do maior volume de poros ocupados com ar e com o decréscimo da densidade do solo devido ao aumento da porosidade total das amostras. Os resultados mostraram que o método é versátil, rápido, de fácil aplicação e baixo custo para a determinação da Ka, independente do sistema de aquisição de dados utilizados.
Influência da qualidade da água de irrigação na dispersão da argila de Latossolos
Authors: Almeida Neto Onofre Barroca de , Matos Antonio Teixeira de , Abrahão Walter Antônio Pereira , Costa Liovando Marciano da , Duarte Alfredo
Published: February 2010

O fenômeno de dispersão da argila do solo pode ser provocado pela qualidade da água de irrigação. Objetivou-se estudar o efeito da irrigação com água com diferentes condutividades elétricas (CE), combinadas com diferentes valores de Relação de Adsorção de Sódio (RAS), na dispersão da argila de solos, de diferentes mineralogias, do Estado de Minas Gerais. As amostras foram coletadas no horizonte B de solos das cidades de Viçosa, Belo Horizonte e Barroso, classificados como Latossolo Vermelho-Amarelo distrófico típico (LVA), Latossolo Vermelho perférrico típico (LV) e Latossolo Vermelho distroférrico típico (LVd) destacados, respectivamente, pela presença de argilominerais caulinita, hematita e gibbsita. Os tratamentos corresponderam à percolação, nos três solos, de soluções de NaCl e CaCl2 preparadas de forma a se obter seis diferentes valores de CE (20; 50; 100; 200; 400 e 800 mS m-1) e cinco de RAS (0, 5, 10, 20 e 40 mmol c L-1), em três repetições, dispostos em um delineamento em blocos casualizados. A aplicação das soluções foi feita em permeâmetros de coluna vertical e carga constante. A solução foi aplicada até o momento em que a CE do efluente se aproximou daquela da solução aplicada (C/C0 = 1,0). Para avaliar o efeito das soluções aplicadas na estrutura do solo, foram quantificados os teores de argila dispersa em água (ADA). Os valores de ADA nas amostras de solo submetido à percolação das diferentes soluções salino-sódicas (ADA-S) foram relacionados com a CE e a RAS da solução percolada, ajustando-se superfícies de resposta com este fim. O comportamento dos solos foi diferenciado, no que se refere à dispersividade da argila, o que estava associado à mineralogia, mas, também, ao grau de intemperismo do solo. O LVA apresentou comportamento não dispersivo em todos os tratamentos e, no geral, todas as soluções de percolação, notadamente as de maiores CE, independentemente dos valores de RAS, proporcionaram diminuição no teor de argila dispersa (ADA-S) nos solos LV e LVd.
Carbon content in Amazonian Oxisols after forest conversion to pasture
Authors: Silva Júnior Mário Lopes da , Desjardins Thierry , Sarrazin Max , Melo Vânia Silva de , Martins Paulo Fernando da Silva , Santos Elaine Rodrigues , Carvalho Claudio José Reis de
Published: February 2010

Soil plays an important role in the C cycle, and substitution of tropical forest by cultivated land affects C dynamic and stock. This study was developed in an area of expansion of human settlement in the Eastern Amazon, in Itupiranga, State of Pará, to evaluate the effects of native forest conversion to Brachiaria brizantha pasture on C contents of a dystrophic Oxisol. Soil samples were collected in areas of native forest (NF), of 8 to 10 year old secondary forest (SF), 1 to 2 year old SF (P1-2), 5 to 7 year old SF (P5-7), and of 10 to 12 year old SF (P10-12), and from under pastures, in the layers 0-2, 2-5 and 5-10 cm, to evaluate C levels and stocks and carry out separation of OM based on particle size. After deforestation, soil density increased to a depth of 5 cm, with greater increase in older pastures. Variation in C levels was greatest in the top soil layer; C contents increased with increasing pasture age. In the layers 2-5 and 5-10 cm, C content proved to be stable for the types of plant cover evaluated. Highest C concentrations were found in the silt fraction; however, C contents were highest in the clay fraction, independent of the plant cover. An increase in C associated with the sand fraction in the form of little decomposed organic residues was observed in pastures, confirming greater sensitivity of this fraction to change in soil use.
Ammonia volatilization of urea in the out-of-season corn
Authors: Pereira Hamilton Seron , Leão Anabelisa Ferreira , Verginassi Adriana , Carneiro Marco Aurélio Carbone
Published: February 2010

The aim of this study was to evaluate the N losses due to volatilization at different rates of common urea, polymer coated urea and urease inhibitor-treated urea in the out-of-season corn, using semi-open static collectors. The treatments consisted of N levels on side-dressing fertilization with urea in different treatments: (a) control (without N), (b) urea 40 kg ha-1 N, (c) urea 80 kg ha-1 N, (d) polymer coated urea 40 kg ha-1 N, (e) polymer coated urea 80 kg ha-1 N and (f) urea with the urease inhibitor (UI) N 80 kg ha-1 N. The results showed that the treatments with polymer coated urea and with urease inhibitor-treated urea reduced the volatilization of N around 50 % compared to common urea, either in the first and the second N side-dressing fertilizations. Thus, they demonstrate that the polymer coat and the urease inhibitors were effective in reducing the volatilization of urea N applied in coverage, which resulted in higher productivity. There was also increasing urease activity in the treatments with application of common urea.
Cobalt and molybdenum concentrated suspension for soybean seed treatment
Authors: Lana Regina Maria Quintão , Faria Marcos Vieira de , Bonotto Ivan , Lana Ângela Maria Quintão
Published: February 2010

The concentrated suspension (CS), the basis of Mo trioxide, allows high Mo concentrations and is therefore a technical advance for seed treatment, since it allows the recommendation of the Mo at lower dosage than with the liquid solution formulations (LS). The purpose of this research was to evaluate the efficiency and doses of fertilizer with Mo and Co in concentrated suspension in comparison with liquid solution as well as fertilizers associated with phytohormones, applied in seed treatments, and their effect on soybean yield. Two experiments were carried out in the growing seasons of 2004/2005 and 2005/2006 at the Universidade Federal de Uberlandia (UFU).The first was conducted in an experimental area on the Fazenda Capim Branco, with six treatments and four replications: (1) Mo and Co (CS) - 22 g ha-1 + 1.08 g ha-1; (2) Mo and Co (CS) - 22 g ha-1 + + 1.08 g ha-1 + phytohormone -200 mL ha-1; 3) Mo and Co (LS), 20.7 g ha-1 + 4.13 g ha-1; 4) Mo and Co (LS), 20.7 g ha-1 + 4.13 g ha-1 + phytohormone -200 mL ha-1; (5) + control phytohormone-200 mL ha-1; and (6) control (free of Mo and Co in the seed treatment). The phytohormone consisted of: auxin (11 mg L-1) and cytokynin (0.031 mg L-1). The soybean cultivar Monsoy 8004 was used and a fertilization of 400 kg ha-1 of 02-20-20 NPK fertilizer was applied at sowing. Based on the results of the first experiment, the second was conducted on the Fazenda Floresta do Lobo, in Uberlândia, MG, evaluated in a randomized block design with nine treatments and four replications. The treatments consisted of Mo and Co (g ha-1) doses applied to soybean seeds, as CS formulation (15, 25, 35, 45, 60 and 0.74; 1.23; 1.72; 2.21; 2.95) and LS- (15; 20; 25 and 3.18; 4.25; 5.31), respectively, and the control (free of Mo and Co in the seed treatment). The variety Monarch was used, fertilized with 300 kg ha-1 of NPK fertilizer (03-32-06) at sowing; and 78 kg ha-1 (K2O) in topdressing 30 days after soybean emergence. The Mo and Co doses in the seed treatment with LS and CS resulted in higher soybean yields than in the control, from 20 g ha-1 Mo and 4.25 g ha-1 Co in liquid solution and 35 g ha-1Mo and 1.72 g ha-1 Co in the concentrated suspension.
Teores de nitrogênio mineral do solo para predição do potencial produtivo de cevada
Authors: Grohs Daniel Santos , Poletto Naracelis , Mundstock Claudio Mario
Published: February 2010

O teor de N mineral do solo não é usado na recomendação de adubação nitrogenada para cultivos de grãos no Brasil, devido à sua elevada instabilidade por efeito dos fatores ambientais. Seu uso poderia melhorar a eficiência das adubações e reduzir os custos de produção. Foi feita uma análise dos teores de NH4+ e de NO3- do solo, até 15 cm de profundidade, no período da pré-semeadura e do rendimento de grãos em 61 ensaios de cevada, em 20 municípios, em três Regiões Fisiográficas do Rio Grande do Sul, de 2002 a 2005. Os rendimentos foram divididos em classes (muito baixo, baixo, médio, alto e muito alto), que foram relacionadas aos teores de N mineral, usando o modelo de regressão de Gompertz. O ajuste indicou dois marcos de N mineral delimitadores do rendimento relativo: 8 e 18 mg kg-1 de N no solo. Abaixo de 8 mg kg-1 de N houve predomínio de muito baixos rendimentos, evidenciando o efeito da baixa disponibilidade sobre a produtividade. Acima de 18 mg kg-1 de N, este nutriente não foi mais fator decisivo na formação do potencial produtivo, sendo indicativo de potencial produtivo muito alto. Esses valores poderão futuramente ser incorporados como base de um modelo de recomendação de adubação nitrogenada.
Characteristic of Dystrustepts in the Venezuelan Andes
Authors: Ochoa Guido , Oballos Jajaira , Velásquez Juan Carlos , López Isabel , Manrique Jorge
Published: February 2010

The majority (60 %) of the soils in the Venezuelan Andes are Inceptisols, a large percentage of which are classified as Dystrustepts by the US Soil Taxonomy, Second Edition of 1999. Some of these soils were classified as Humitropepts (high organic - C-OC-soils) and Dystropepts by the Soil Taxonomy prior to 1999, but no equivalent large group was created for high-OC soils in the new Ustepts suborder. Dystrusepts developed on different materials, relief and vegetation. Their properties are closely related with the parent material. Soils developed on transported deposits or sediments have darker and thicker A horizons, a slightly acid reaction, greater CEC and OC contents than upland slope soils. Based on the previous classification into large groups (Humitropepts and Dystropepts) we found that: Humitropepts have a slightly less acid and higher values of CEC than Dystropepts. These properties or characteristics seem to be related to the fact that Humitropepts have a higher clay and OC content than the Dystropepts. Canonical discrimination analysis showed that the variables that discriminate the two great soil groups from each other are OC and silt. Data for Humitropepts are grouped around the OC vector (defining axis 3, principal component analysis), while Dystropepts are associated with the clay and sand vectors, with significant correlation. Given the importance of OC for soil properties, we propose the creation of a new large group named Humustepts for the order Inceptisol, suborder Ustepts.
The combined use of reflectance, emissivity and elevation Aster/Terra data for tropical soil studies
Authors: Breunig Fábio Marcelo , Galvão Lênio Soares , Formaggio Antonio Roberto , Couto Eduardo Guimarães
Published: February 2010

Reflectance, emissivity and elevation data of the sensor ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer)/Terra were used to characterize soil composition variations according to the toposequence position. Normalized data of SWIR (shortwave infrared) reflectance and TIR (thermal infrared) emissivity, coupled to a soil-fraction image from a spectral mixture model, were evaluated to separate bare soils from nonphotosynthetic vegetation. Regression relationships of some soil properties with reflectance and emissivity data were then applied on the exposed soil pixels. The resulting estimated values were plotted on the ASTER-derived digital elevation model. Results showed that the SWIR bands 5 and 6 and the TIR bands 10 and 14 measured the clay mineral absorption band and the quartz emissivity feature, respectively. These bands improved also the discrimination between nonphotosynthetic vegetation and soils. Despite the differences in pixel size and field sampling size, some soil properties were correlated with reflectance (R² of 0.65 for Al2O3 in band 6; 0.61 for Fe2O3 in band 3) and emissivity (R² of 0.65 for total sand fraction in the 10/14 band ratio). The combined use of reflectance, emissivity and elevation data revealed variations in soil composition with topography in specific parts of the landscape. From higher to lower slope positions, a general decrease in Al2O3 and increase in total sand fraction was observed, due to the prevalence of Rhodic Acrustox at the top and its gradual transition to Typic Acrustox at the bottom.
Topolitossequências de solos do Alto Paranaíba: atributos físicos, químicos e mineralógicos
Authors: Rolim Neto Fernando Cartaxo , Schaefer Carlos Ernesto G.R , Fernandes Filho Elpidio Inácio , Corrêa Marcelo Metri , Costa Liovando Marciano da , Parahyba Roberto da Boa Viagem , Guerra Sergio Monthezuma Santoianni , Heck Richard
Published: February 2010

Pouco se conhece sobre a diferenciação pedogenética no Alto Paranaíba (MG), quando são comparados materiais de composição química tão variada, como tufitos, rochas ígneas alcalinas e ultramáficas e carbonatitos, todos de ocorrência na região. Dessa forma, este trabalho teve como objetivo caracterizar física, química e mineralogicamente os solos representativos de três topolitossequências do Alto Paranaíba. Para isso, foram descritos e coletados 11 perfis de solos, entre os municípios de Serra do Salitre, Patrocínio e Coromandel, representando as variações litológicas na faixa do contato geológico entre os grupos Bambuí, rochas vulcânicas ultramáficas e Araxá. Nas amostras de solos foram realizadas análises físicas e químicas de rotina, além de determinações de Fe, Al e Si após extração por ataque sulfúrico; Fe por DCB e oxalato; Fe, Ca, Mg, K, P, Ti e outros metais pesados após digestão total (ataque triácido); e determinação dos diferentes componentes da fração argila por difratometria de raios X. Os Latossolos do Alto Paranaíba são extremamente intemperizados e com índices Ki e Kr muito baixos, indicativos de solos ricos em óxidos de Fe e de Al, não possuindo uma filiação definida com os materiais de origem subjacente, indicando intensa pedoturbação e provável mistura com materiais alóctones. As assinaturas geoquímicas indicativas da natureza ultramáfica são os teores elevados de Cr, Ni, Mn, Fe e Mg. A mineralogia da fração argila dos Latossolos indica a coexistência de vermiculita com hidroxi-Al entrecamadas, caulinita, gibbsita e anatásio, evidenciando uma gênese policíclica dos minerais da fração mais fina e o elevado grau de intemperismo. Nos Cambissolos, a rápida dessilificação atual conduz à coexistência de gibbsita e óxidos de Fe com esmectitas e illitas, em virtude da rápida ação do intemperismo nos substratos de rochas máficas ou ultramáficas-alcalinas, pobres em sílica.