bluuebunny/crossref_metadata_2025 huggingface dataset:
Geochemistry of Mixed-Layer Illite-Smectites from an Extensional Basin, Antalya Unit, Southwestern Turkey
Authors: Bozkaya Ömer , Yalçin Hüseyin
Published: December 2010

The Antalya Unit, one of the allochthonous units of the Tauride belt, is of critical, regional tectonic importance because of the presence of rifting remnants related to the break-up of the northern margin of Gondwana during Triassic time. Paleozoic — Mesozoic sedimentary rocks of the Antalya Unit consist mainly of calcite, dolomite, quartz, feldspar, and phyllosilicate (illite-smectite, smectite, kaolinite, chlorite, illite, chlorite-smectite, and chlorite-vermiculite) minerals. Illite-smectite (I-S) was found in all of the sequences from Cambrian to Cretaceous, but smectite was only identified in Late Triassic-Cretaceous sediments. R0 I-S occurs exclusively in early-diagenetic Triassic—Cretaceous units of the Alakırçay Nappe (rift sediments), whereas R3 I-S is present in late-diagenetic to low-anchimetamorphic Cambrian—Early Triassic units of the Tahtalıdağ Nappe (pre-rift sediments). Kübler Index (KI) values and the illite content of I-S reflect increasing diagenetic grades along with increasing depth. Major-element, trace-element, rare-earth-element (REE), and stable-isotope (O and H) compositions were investigated in dioctahedral and trioctahedral smectites and I-S samples from the pre-rift and rift-related formations. Both total layer charge and interlayer K increase, whereas tetrahedral Si and interlayer Ca decrease from smectite to R3 I-S. Trace-element and REE concentrations of the I-S are greater in pre-rift sediments than in rift sediments, except for P, Eu, Ni, Cu, Zn, and Bi. On the basis of North American Shale Composite (NASC)-normalized values, the REE patterns of I-S in the pre-rift and rift sediments are clearly separate and distinct. Oxygen (δ18O) and hydrogen (δD) values relative to SMOW (Standard Mean Oceanic Water) of smectite and I-S reflect supergene conditions, with decreasing δ18O but increasing δD values with increasing diagenetic grade. Lower dD values for these I-S samples are characteristic of rift sediments, and pre-rift sediments have greater values. On the basis of isotopic data from these I-S samples, the diagenesis of the Antalya Unit possibly occurred under a high geothermal gradient (>35ºC/km), perhaps originating under typical extensional-basin conditions with high heat flow. The geochemical findings from I-S and smectites were controlled by diagenetic grade and can be used as an additional tool for understanding the basin maturity along with mineralogical data.
Effect of a Thermal Gradient on Iron-Clay Interactions
Authors: Jodin-Caumon Marie-Camille , Mosser-Ruck Regine , Rousset Davy , Randi Aurelien , Cathelineau Michel , Michau Nicolas
Published: December 2010

Disposal facilities in deep geological formations are considered to be a possible solution for long-term management of high-level nuclear waste (HLW). The design of the repository generally consists of a multiple-barrier system including Fe-based canisters and a clay backfill material. The Fe-clay system will undergo a thermal gradient in time and space, the heat source being the HLW inside the canisters. In the present paper, the effect of a thermal gradient in space on Fe-smectite interactions was investigated. For this purpose, a tube-in-tube experimental device was developed and an 80–300ºC thermal gradient was applied to a mixture of MX80 bentonite, metallic Fe (powder and plate), magnetite, and fluid over periods of 1 to 10 months. Transformed and newly formed clay minerals were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and Mössbauer spectroscopy. The main mineralogical transformations were similar to those described for batch experiments: smectite was destabilized into an Fe-enriched trioctahedral smectite and Fe-serpentine or chlorite as a function of the experimental conditions. Newly formed clay was observed all along the walls of the gold tube. Their crystal chemistry was clearly different from the clays observed in the hot and cold part of the tubes. The thermal diffusion of elements was also observed, especially that of Mg, which migrated toward the hottest parts of the tubes. In the end, the thermal gradient affected the redox equilibria; more reduced conditions were observed in the hotter parts of the tubes.
Reductive Activity of Adsorbed Fe(II) on Iron (Oxyhydr)Oxides for 2-Nitrophenol Transformation
Authors: Tao Liang , Li Fangbai , Wang Yongkui , Sun Kewen
Published: December 2010

Much attention has been paid to the adsorption of Fe(II) onto mineral surfaces as it is a crucial step in enhancing the reductive activity of Fe(II) species. The present study elucidates the role of Fe(II) adsorbed on Fe (oxyhydr)oxides (γ-FeOOH, α-FeOOH, and α-Fe2O3) for the reductive transformation of 2-nitrophenol (2-NP), using cyclic voltammetry (CV). Studies of Fe(II) adsorption and 2-NP reduction kinetics showed that an increase in pH gave rise to an elevated density of adsorbed Fe(II) on mineral surfaces, which further resulted in an enhanced reaction rate of 2-NP reduction. In addition, CV tests showed that the enhanced activity of Fe(II) species is attributed to the negative shift of peak oxidation potential (EP) of the Fe(III)/Fe(II) couple. The dependence of adsorbed Fe(II) reactivity on pH values was proven by the three linear correlations obtained (ln kvs. pH, EPvs. pH, and ln kvs. EP). The present study demonstrated that the reductive activity of adsorbed Fe(II) species can be indicated by the EP value of active Fe(II) species. Moreover, the electrochemical approach can be used as an effective tool to study the reductive activity of adsorbed Fe(II) species in subsurface environments.
Seasonal Variation in the Mineralogy of the Suspended Particulate Matter of the Lower Changjiang River at Nanjing, China
Authors: Mao Changping , Chen Jun , Yuan Xuyin , Yang Zhongfang , Balsam William , Ji Junfeng
Published: December 2010

The source and temporal changes of minerals transported by the world's large rivers are important. In particular, clay minerals are important in evaluating the maturity of suspended sediments, weathering intensity, and source area. To examine seasonal changes in mineralogical compositions of the Changjiang River (CR), suspended particulate matter (SPM) samples were collected monthly for two hydrological cycles in Nanjing city and then were studied using X-ray diffraction (XRD), diffuse reflectance spectrophotometry (DRS), X-ray fluorescence spectrometry (XRF), and chemical analyses. The results indicate that the concentration of CR SPM ranges from 11.3 to 152 mg/L and is highly correlated to the rate of water discharge, with a greater concentration in flood season and lower concentrations during the dry season. CaO, MgO, and Na2O increase with increasing discharge whereas Al2O3 decreases sharply with increasing discharge. Dolomite, calcite, and plagioclase show strikingly similar seasonal variations and increase with increasing discharge with maximum concentrations in the flood season. In contrast, the clay mineral content exhibits the opposite trend with the lowest concentrations in the flood season. Illite dominates the clay minerals of the CR SPM, followed by chlorite, kaolinite, and smectite. Illite and kaolinite show distinctly seasonal variations; SPM contains more illite and less kaolinite during the flood season than during the dry season. The illite chemistry index and crystallinity, as well as kaolinite/illite ratio, all indicate intense physical erosion in the CR basin during the rainy season. Total iron (FeT) and highly reactive iron (FeHR) concentrations display slight seasonal changes with the smallest values observed during the flood season. Goethite is the dominant Fe oxide mineral phase in the CR SPM and hematite is a minor component, as revealed by DRS analyses. The FeT flux and FeHR flux are 2.786×106 T/y and 1.196×106 T/y, respectively.
Quantification of Allophane from Ecuador
Authors: Kaufhold Stephan , Ufer Kristian , Kaufhold Annette , Stucki Joseph W. , Anastácio Alexandre S. , Jahn Reinhold , Dohrmann Reiner
Published: December 2010

Allophane is a very fine-grained clay mineral which is especially common in Andosols. Its importance in soils derives from its large reactive surface area. Owing to its short-range order, allophane cannot be quantified by powder X-ray diffraction (XRD) directly. It is commonly dissolved from the soil by applying extraction methods. In the present study the standard extraction method (oxalate) was judged to be unsuitable for the quantification of allophane in a soil/clay deposit from Ecuador, probably because of the large allophane content (>60 wt.%). This standard extraction method systematically underestimated the allophane content but the weakness was less pronounced in samples with small allophane contents. In the case of allophane-rich materials, the Rietveld XRD technique, using an internal standard to determine the sum of X-ray amorphous phases, is recommended if appropriate structural models are available for the other phases present in the sample. The allophane (+imogolite) content is measured by subtracting the amount of oxalate-soluble phases (e.g. ferrihydrite). No correction would be required if oxalate-soluble Fe were incorporated in the allophane structure. The present study, however, provides no evidence for this hypothesis. Mössbauer and scanning electron microscopy investigations indicate that goethite and poorly ordered hematite are the dominant Fe minerals and occur as very fine grains (or coatings) being dispersed in the cloud-like allophane aggregates.

Allophane is known to adsorb appreciable amounts of water, depending on ambient conditions. The mass fraction of the sample attributed to this mineral thus changes accordingly; the choice of a reference hydration state is, therefore, a fundamental factor in the quantification of allophane in a sample. Results from the present study revealed that (1) drying at 105ºC produced a suitable reference state, and (2) water adsorption has no effect on quantification by XRD analysis.
Comment on “The Role of H3O+ in the Crystal Structure of Illite” By F. Nieto, M. Melini, And I. Abad
Authors: Vidal Olivier , Dubacq Benoît , Lanari Pierre
Published: December 2010

The arguments of Nieto et al. (2010) in favor of the incorporation of H3O+ rather than H2O in interlayer positions of illite are disputable. Stoichiometric arguments suggest that the excess water in the Silver Hill illite is in the form of H2O. Moreover, recent thermodynamic models assuming the incorporation of interlayer H2O in illite provide reasonable estimates of temperature and water content using the AEM/TEM analyses of Nieto et al. (2010).
Reply to the Comment by Vidal, Dubacq, and Lanari on “The Role of H3O+ in the Crystal Structure of Illite”
Authors: Nieto Fernando , Mellini Marcello , Abad Isabel
Published: December 2010

The arguments of Vidal et al. (2010) against the incorporation of H3O+ rather than of H2O in the interlayer position of illite are disputable. Stoichiometric arguments do indeed suggest that the excess water in the Silver Hill illite is in the formof H3O+. No reason exists to assume less water content in the IMt-2 sample than in those determined by Hower and Mowatt (1966) and confirmed by the thermogravimetric analyses of Nieto et al. (2010). The comparison between element contents calculated from end-members and those from the structural formula in figure 1 of Vidal et al. (2010) is not an experimental result, but rather a trivial mathematical artifact. The fact that thermodynamic models, based on the incorporation of interlayer H2O in illite, may provide reasonable estimates neither proves nor disproves the presence of H3O+; this is because thermodynamics is a non-atomistic, macroscopic approach.
Erratum to: Porosity Evolution of Free and Confined Bentonites During Interlayer Hydration
Authors: Likos William J. , Wayllace Alexandra
Published: December 2010

In the paper ‘Porosity evolution of free and confined bentonites during interlayer hydration” from Clays and Clay Minerals, vol. 58, (2010), 399–414
Biomarkers in Fasting Serum to Estimate Glucose Tolerance, Insulin Sensitivity, and Insulin Secretion
Authors: Goldfine Allison B , Gerwien Robert W , Kolberg Janice A , O'Shea Sheila , Hamren Sarah , Hein Glenn P , Xu Xiaomei M , Patti Mary Elizabeth
Published: December 2010

BACKGROUND

Biomarkers for estimating reduced glucose tolerance, insulin sensitivity, or impaired insulin secretion would be clinically useful, since these physiologic measures are important in the pathogenesis of type 2 diabetes mellitus.

METHODS

We conducted a cross-sectional study in which 94 individuals, of whom 84 had 1 or more risk factors and 10 had no known risk factors for diabetes, underwent oral glucose tolerance testing. We measured 34 protein biomarkers associated with diabetes risk in 250-μL fasting serum samples. We applied multiple regression selection techniques to identify the most informative biomarkers and develop multivariate models to estimate glucose tolerance, insulin sensitivity, and insulin secretion. The ability of the glucose tolerance model to discriminate between diabetic individuals and those with impaired or normal glucose tolerance was evaluated by area under the ROC curve (AUC) analysis.

RESULTS

Of the at-risk participants, 25 (30%) were found to have impaired glucose tolerance, and 11 (13%) diabetes. Using molecular counting technology, we assessed multiple biomarkers with high accuracy in small volume samples. Multivariate biomarker models derived from fasting samples correlated strongly with 2-h postload glucose tolerance (R2 = 0.45, P < 0.0001), composite insulin sensitivity index (R2 = 0.91, P < 0.0001), and insulin secretion (R2 = 0.45, P < 0.0001). Additionally, the glucose tolerance model provided strong discrimination between diabetes vs impaired or normal glucose tolerance (AUC 0.89) and between diabetes and impaired glucose tolerance vs normal tolerance (AUC 0.78).

CONCLUSIONS

Biomarkers in fasting blood samples may be useful in estimating glucose tolerance, insulin sensitivity, and insulin secretion.
The Intersection of Multiple Minority Identities: Perspectives of White Lesbian Couples Adopting Racial/Ethnic Minority Children
Authors: Richardson Hannah B. , Goldberg Abbie E.
Published: December 2010

In order to analyse the salience of race/ethnicity, sexual orientation, and adoptive status for lesbian adoptive parents, this study examined the challenges and strengths described by 20 White lesbian couples (40 women) who were adopting racial/ethnic minority children from within the United States. Data from two time points (pre‐ and post‐adoptive placement) were analysed qualitatively. Results indicated that the majority of women voiced concerns about raising racial/ethnic minority children in a ‘White privileged’ society. Many women reported facing a lack of understanding from others and were aware of multiple layers of stigma. However, having faced discrimination themselves as sexual minorities, many also perceived themselves as possessing unique strengths (e.g., experience coping with stigma). Many women expressed feeling that by drawing on support from their communities as well as their own awareness of and experience with diversity issues, they could prepare their children for the challenges they might face.
Organising Work and Home in Same‐Sex Parented Families: Findings From the Work Love Play Study
Authors: Perlesz Amaryll , Power Jennifer , Brown Rhonda , McNair Ruth , Schofield Margot , Pitts Marian , Barrett Anna , Bickerdike Andrew
Published: December 2010

In this article we present findings from the Work, Love and Play (WLP) study: a survey completed by 445 same‐sex attracted parents across Australia and New Zealand. Comparisons of household division of labour are made between a sub‐sample of WLP participants, who were currently cohabiting with a same‐sex partner (n = 317), and 958 cohabiting opposite‐sex parents surveyed as part of a major Australian study, Negotiating the Life Course. This comparison showed that same‐sex couples divided household labour significantly more equally than heterosexual parents, and lesbian couples also shared parenting tasks more equally. Qualitative findings from the WLP study indicate that, for many same‐sex couples, major decisions around who gives up paid work and how many hours parents choose to work, as well as decisions around work/family balance, are negotiated on the basis of couple's preferences and circumstance rather than an assumption that one parent will be the primary child carer. It is speculated that this finding highlights an important point of difference between same‐sex couples and heterosexual couples where the division of household labour is often based on the assumption that the mother will almost always be the primary child carer and homemaker. The research is a collaborative partnership between La Trobe University, Deakin University, The University of Melbourne, and Relationships Australia Victoria.
Reviews
Authors: McDowall Anna , Crombie Pru
Published: December 2010

Raising Parents: Attachment, Parenting and Child Safety: Patricia McKinsey‐Crittenden

The Child's Voice in Family Therapy: A Systemic Perspective: Gammer, Carole, WW Norton & Company Inc.
Genetic Association in Multivariate Phenotypic Data: Power in Five Models
Authors: Minica Camelia C. , Boomsma Dorret I. , van der Sluis Sophie , Dolan Conor V.
Published: December 2010

This article concerns the power of various data analytic strategies to detect the effect of a single genetic variant (GV) in multivariate data. We simulated exactly fitting monozygotic and dizygotic phenotypic data according to single and two common factor models, and simplex models. We calculated the power to detect the GV in twin 1 data in an ANOVA of phenotypic sum scores, in a MANOVA, and in exploratory factor analysis (EFA), in which the common factors are regressed on the genetic variant. We also report power in the full twin model, and power of the single phenotype ANOVA. The results indicate that (1) if the GV affects all phenotypes, the sum score ANOVA and the EFA are most powerful, while the MANOVA is less powerful. Increasing phenotypic correlations further decreases the power of the MANOVA; and (2) if the GV affects only a subset of the phenotypes, the EFA or the MANOVA are most powerful, while sum score ANOVA is less powerful. In this case, an increase in phenotypic correlations may enhance the power of MANOVA and EFA. If the effect of the GV is modeled directly on the phenotypes in the EFA, the power of the EFA is approximately equal to the power of the MANOVA.
Depressive and Psychosomatic Symptoms in Twins With Special Reference to Co-Twin Dependence
Authors: Trias Tuulikki , Ebeling Hanna , Penninkilampi-Kerola Varpu , Moilanen Irma
Published: December 2010

We analyzed depressive and psychosomatic symptoms in relation to co-twin dependence in 419 twins at the age of 22 to 30 years. Depressive symptoms were assessed, as previously, with Children's Depression Inventory modified to be suitable for this age and reported as a total score and three subscales (low self-confidence, anhedonia and sadness) based on factor analysis as reported in a previous epidemiological study conducted in Finland. Items assessing nervous complaints and somatic symptoms were adapted from Finnish studies of juvenile health habits. Inter-twin dependence decreased with increasing age in both genders. Monozygotic twins, especially monozygotic females, reported most often to be dependent on their co-twin. When the symptom reporting was evaluated in relation to co-twin dependence, no relation was found between co-twin dependence and depressive symptom reporting. However, dependence-independence imbalance within twin pair was associated with elevated levels of depressive and psychosomatic symptoms, especially in twins who perceived themselves as dependent and the co-twin as independent. We conclude that there was no relation found between co-twin dependence and depressive symptom reporting in male and female twins except for the few imbalance cases, where most symptoms were reported by those dependent twins who felt their co-twin as independent.
A Twins Heritability Study on Alpha Hemoglobin Stabilizing Protein (AHSP) Expression Variability
Authors: Lai Mei I. , Garner Chad , Jiang Jie , Silver Nicholas , Best Steve , Menzel Stephan , Thein Swee L.
Published: December 2010

Cytotoxic precipitation of free α-globin monomers and its production of reactive oxygen species cause red cell membrane damage that leads to anemia and eventually ineffective erythropoiesis in β-thalassemia. Alpha hemoglobin stabilizing protein (AHSP) was found to bind only to free α-globin monomers creating a stable and inert complex which remains soluble in the cytoplasm thus preventing harmful precipitations. Alpha hemoglobin stabilizing protein was shown to bind nascent α-globin monomers with transient strength before transferring α-globin to β-globin to form hemoglobin tetramer. A classical twin study would be beneficial to investigate the role of genetics and environment in the variation of alpha hemoglobin stabilizing protein expression as this knowledge will enable us to determine further investigations with regards to therapeutic interventions if alpha hemoglobin stabilizing protein is to be a therapeutic agent for β-thalassemia. This study investigates the heritability influence of alpha hemoglobin stabilizing protein expression and factors that may contribute to this. Results indicated that a major proportion of alpha hemoglobin stabilizing protein expression was influenced by genetic heritability (46%) withcis-acting factors accounting for 19% andtrans-acting factors at 27%.
Monozygotic Twins With Neurofibromatosis Type 1 (NF1) Display Differences in Methylation ofNF1Gene Promoter Elements, 5' Untranslated region, Exon and Intron 1
Authors: Harder Anja , Titze Sabrina , Herbst Lena , Harder Thomas , Guse Katrin , Tinschert Sigrid , Kaufmann Dieter , Rosenbaum Thorsten , Mautner Victor Felix , Windt Elke , Wahlländer-Danek Ute , Wimmer Katharina , Mundlos Stefan , Peters Hartmut
Published: December 2010

Neurofibromatosis type 1 (NF1) is a common autosomal dominant disorder caused by heterozygotic inactivation of the NF1 tumor suppressor gene at 17q11.2. The associated phenotypes are highly variable, and modifying genes have been proposed to explain at least in part the intriguing expressivity. Given that haploinsufficiency of the NF1 gene product neurofibromin is responsible for some of the clinical manifestations, variations in expression of the wildtype NF1 allele might modify the phenotype. We therefore investigated epigenetic molecular modifications that could result in variable expression of the normal NF1 allele. To exclude confounding by DNA sequence variations, we analyzed monozygotic twin pairs with NF1 who presented with several discordant features. We fine-mapped the methylation pattern of a nearly 1 kb NF1 promoter region in lymphocytes of 8 twin pairs. All twin pairs showed significant intra-pair differences in methylation, especially of specific promoter subregions such as 5'UTR, exon 1 and intron 1 (+7 to +622), transcription factor binding sites and promoter elements like NF1HCS. Furthermore, we detected significant intra-pair differences in cytosine methylation for the region from -249 to -234 with regard to discordance for optic glioma with a higher grade of methylation in glioma cases. In conclusion, our findings of epigenetic differences of the NF1 promoter in leukocytes within mono zygotic twin pairs may serve as a proof of principle for other tissues. The results point towards a role of methylation patterns of the normal NF1 allele for expression differences and for modification of the NF1 phenotype.
Recorded Pregnancy Histories of the Mothers of Singletons and the Mothers of Twins: A Longitudinal Comparison
Authors: Croft Maxine L. , Morgan Vera , Read Anne W. , Jablensky Assen S.
Published: December 2010

A population-based record linkage case cohort of 239,995 births, to 119,214 women, born in Western Australia from 1980 to 2001 inclusive, was used to measure the recording of selected indicators of maternal health (current and prior) during pregnancy. We compared records of women with singleton pregnancies with that in twin pregnancies Mothers of first- and second-born singletons (n= 117,647) were compared with women with a first-born singleton followed by twins (n= 1,567). Binary indicators were used to calculate population prevalence of medical conditions, pregnancy complications and birth outcomes. Infant outcomes included stillbirth, low birthweight, preterm birth and birth defects. Women with twins were significantly older and taller, with similar rates of medical conditions and pregnancy complications during first singleton pregnancies compared with women with two consecutive singletons. However, during their second pregnancy, women with twins had significantly higher rates of essential hypertension, pre-eclampsia, threatened abortion, premature rupture of the membranes and ante partum hemorrhage with abruption than women with singletons. For both groups, maternal conditions in the first pregnancy were underreported in the second pregnancy, including diabetes, epilepsy, asthma, chronic renal dysfunction and essential hypertension. At the second birth, twins were 3 times more likely to be stillborn, 17 times more likely to be low birthweight and 4 times more likely to be delivered preterm compared with singletons. This research demonstrates the importance for epidemiologists and others, of having access to a complete maternal medical history for analyses of risks associated with maternal, infant and childhood morbidity.
CX3CR1 in Microglia Regulates Brain Amyloid Deposition through Selective Protofibrillar Amyloid-β Phagocytosis
Authors: Liu Zhiqiang , Condello Carlo , Schain Aaron , Harb Roa , Grutzendler Jaime
Published: December 2010

In Alzheimer's disease (AD), amyloid-β (Aβ) deposits are frequently surrounded by activated microglia but the precise role of these cells in disease progression remains unclear. The chemokine receptor CX3CR1 is selectively expressed in microglia and is thought to modulate their activity. To study the specific effects of microglia activation on amyloid pathologyin vivo, we crossbred mice lacking CX3CR1 with the Alzheimer's mouse model CRND8. Surprisingly, we found that CX3CR1-deficient mice had lower brain levels of Aβ40 and Aβ42 and reduced amyloid deposits. Quantification of Aβ within microglia and time-lapse two-photon microscopy in live mice revealed that these cells were highly effective at the uptake of protofibrillar amyloid but were incapable of phagocytosis of fibrillar congophilic Aβ. CX3CR1 deletion was associated with increased phagocytic ability, which led to greater amyloid content within microglial phagolysosomes. Furthermore, CX3CR1-deficient mice had an increased number of microglia around individual plaques because of higher proliferative rates, which likely contributed to an overall greater phagocytic capacity. CX3CR1 deletion did not affect the degree of neuronal or synaptic damage around plaques despite increased microglia density. Our results demonstrate that microglia can regulate brain Aβ levels and plaque deposition via selective protofibrillar Aβ phagocytosis. Modulation of microglia activity and proliferation by CX3CR1 signaling may represent a therapeutic strategy for AD.
Reimagining Alzheimer's Disease—An Age-Based Hypothesis
Authors: Herrup Karl
Published: December 2010

The historical roots of Alzheimer's disease provide a sound conceptual basis for linking the behavioral and neurological symptoms of the disease with the frequently associated pathology of amyloid plaques and neurofibrillary tangles. Out of these roots has grown the “amyloid cascade hypothesis”—a vision of the etiology of Alzheimer's that has spurred the discovery of many important insights into the neurobiology of the disease. Despite these successes, the wealth of new data now available to biomedical researchers urges a full review of the origins of Alzheimer's, and such a reconsideration is offered here. It begins with the most widely accepted risk factor for developing Alzheimer's disease: age. Then, for an individual to progress from normal age-appropriate cognitive function to a condition where the full palette of clinical symptoms is expressed, three key steps are envisioned: (1) an initiating injury, (2) a chronic neuroinflammatory response, and (3) a discontinuous cellular change of state involving most, if not all, of the cell types of the brain. The amyloid cascade is integrated into this sequence, but reconfigured as an amyloid deposition cycle. In this way, the pathology of amyloid plaques is envisioned as highly correlated with, but mechanistically distinct from, the three obligatory steps leading to Alzheimer's disease. The implications of this new model are discussed with respect to our current diagnostic criteria, and suggestions are put forward for expanding our future research efforts.
More Is Less: A Disinhibited Prefrontal Cortex Impairs Cognitive Flexibility
Authors: Gruber Aaron J. , Calhoon Gwendolyn G. , Shusterman Igor , Schoenbaum Geoffrey , Roesch Matthew R. , O'Donnell Patricio
Published: December 2010

The prefrontal cortex (PFC) is critical for decision making, and it becomes dysfunctional in many neuropsychiatric disorders. Studies in schizophrenia patients and relevant animal models suggest loss of PFC inhibitory interneuron function. For instance, rats with a neonatal ventral hippocampal lesion (NVHL) show a deficient modulation of PFC interneurons by dopamine (DA). Whether the PFC becomes disinhibited in this model and alters decision making remains to be determined. Here, we recorded neural activity in the medial PFC of NVHL rats during a reward-discounting choice task that activated DA systems. Rats were trained to sample odors that instructed them to select one of two feeders that delivered unequal amounts of liquid. Putative pyramidal neurons in the PFC were hyperactive whereas task-related field potential oscillations were significantly reduced in NVHL rats, consistent with impaired interneuron activation by DA during odor sampling leading to disorganized processing. Cognitive flexibility was tested by examining response bias and errors after reversing reward outcomes. NVHL rats demonstrated impaired flexibility as they were less able to track changes in reward outcome and made more response errors than controls did. Reducing cortical excitability with the metabotropic glutamate receptor 2/3 agonist LY379268 (1 mg/kg, i.p.) improved behavioral flexibility in NVHL rats but not controls. Furthermore, D2 dopamine receptors were involved, as the antagonist eticlopride (0.02 mg/kg, i.p.) reduced the ability to switch only in control animals. We conclude that NVHL rats present PFC disinhibition, which affects neural information processing and the selection of appropriate behavioral responses.
Figura
Authors: Aris Marc-Aeilko
Published: December 2010

The question of whether relics which were part of the historical body of Jesus could exist, arose in the first decades of the 12th century, as the monks of St. Medard des Soissons claimed to have a tooth of Jesus. Based on historical and theological reasoning it seemed to Guibert of Nogent impossible that this kind of relic could exist or that they could mediate the redemption which Christ attained on the Cross. According to him, the prize of salvation could only be mediated through the eucharist. Guibert perceived a twofold mediality of the eucharist which at the same time reprents the holy body of Christ and mediates salvation. This medial dimension of the eucharist is denoted with the term figura. Since the Second Eucharist Debate and as a result of the criticism of Berengar of Tours the term figura became precarious. The discussion between Berengar and his opponents such as Durandus of Troarn, Guitmund of Adversa, Alger of Liège about the term figura can be viewed as a debate concerning mediality.
Ostentation. Zum Verhältnis von Phänomenen und Semantiken des Zeigens bei Thomas von Aquin und in ,Der Saelden Hort‘
Authors: Prica Aleksandra
Published: December 2010

By analising the specific use made by Thomas Aquinas of the verb ‘ostendere’ in the context of systematic philosophical conclusions as well as his presentation of biblical events and by scrutinizing the narrative strategies relative to ‘ostentatio’ (in the sense of displaying, hinting at, demonstrating) in ‘Der Saelden Hort’, a late medieval text on salvation, this paper makes clear that ostentation is a central category of mediality in the Middle Ages.
Sorption of neptunium(V) on Opalinus Clay under aerobic/anaerobic conditions
Authors: Fröhlich D. R. , Amayri S. , Drebert J. , Reich T.
Published: December 2010

The interaction between neptunium(V) and a natural argillaceous rock (Opalinus Clay (OPA), Mont Terri, Switzerland) has been investigated in batch sorption experiments by varying pH (6–10), Np(V) concentration (10−12–10−4 M), solid-to-liquid ratio (2–20 g/L), and partial pressure of CO2 (10−3.5 and 10−2.3 atm) under aerobic/anaerobic conditions in saturated calcite solution. All batch experiments were carried out using well characterized aerobic and anaerobic dry powders of OPA. The results show a great influence of pH on Np(V) sorption. Under aerobic conditions sorption increases with increasing pH until maximum sorption is reached between pH 8–9. At pH>9 sorption decreases due to the formation of negatively charged Np(V)-carbonate complexes. By increasing p
CO2
from 10−3.5 to 10−2.3 atm, the sorption edge is shifted ≈0.5 units to lower pH values. Under anaerobic conditions stronger sorption of 8×10−6 M Np(V) was found, possibly due to partial reduction of Np(V) to Np(IV). The sorption of 8×10−6 M Np(V) under aerobic conditions at pH 8.2 in saturated calcite solution increases continuously with increasing solid-to-liquid ratio of OPA in the range of 2–20 g/L with a constant K
d value of 126±13 L/kg. The sorption isotherm was measured over seven orders of magnitude in Np(V) concentration using 239Np as tracer. The sorption isotherm could be divided in a part of linear sorption behaviour between 10−13–10−9 M Np(V) and non-linear behaviour in the range of 10−9–10−4 M Np(V).
Hélisenne de Crenne et l'infinie variété de la lettre invective
Authors: Charité Claude La
Published: December 2010

La lettre invective a joui d'une grande fortune à la Renaissance, comme en témoignent Les Epistres familieres et invectives (1539) d'Hélisenne de Crenne. Une relecture de ce recueil à la lumière de la théorie épistolaire permet de nuancer nos a priori défavorables à cette pratique épistolaire que l'on aurait tort de réduire à une «bordée d'injures» aussi gratuites que disgracieuses. Ces épîtres invectives donnent à voir que le recours à l'insulte n'est jamais une fin en soi, mais un moyen de persuasion au service de la déconstruction de l'ethos de l'adversaire et du renforcement de la crédibilité de l'épistolier.
Intercenter Differences in Bronchopulmonary Dysplasia or Death Among Very Low Birth Weight Infants
Authors: Ambalavanan Namasivayam , Walsh Michele , Bobashev Georgiy , Das Abhik , Levine Burton , Carlo Waldemar A. , Higgins Rosemary D. ,   for the NICHD Neonatal Research Network
Published: December 2010

OBJECTIVES:

To determine (1) the magnitude of clustering of bronchopulmonary dysplasia (36 weeks) or death (the outcome) across centers of the Eunice Kennedy Shriver National Institute of Child and Human Development National Research Network, (2) the infant-level variables associated with the outcome and estimate their clustering, and (3) the center-specific practices associated with the differences and build predictive models.

METHODS:

Data on neonates with a birth weight of <1250 g from the cluster-randomized benchmarking trial were used to determine the magnitude of clustering of the outcome according to alternating logistic regression by using pairwise odds ratio and predictive modeling. Clinical variables associated with the outcome were identified by using multivariate analysis. The magnitude of clustering was then evaluated after correction for infant-level variables. Predictive models were developed by using center-specific and infant-level variables for data from 2001 2004 and projected to 2006.

RESULTS:

In 2001–2004, clustering of bronchopulmonary dysplasia/death was significant (pairwise odds ratio: 1.3; P < .001) and increased in 2006 (pairwise odds ratio: 1.6; overall incidence: 52%; range across centers: 32%–74%); center rates were relatively stable over time. Variables that varied according to center and were associated with increased risk of outcome included lower body temperature at NICU admission, use of prophylactic indomethacin, specific drug therapy on day 1, and lack of endotracheal intubation. Center differences remained significant even after correction for clustered variables.

CONCLUSION:

Bronchopulmonary dysplasia/death rates demonstrated moderate clustering according to center. Clinical variables associated with the outcome were also clustered. Center differences after correction of clustered variables indicate presence of as-yet unmeasured center variables.
Hemiatrofia facial de romberg: relato de caso
Authors: Figueiredo Neto Nicandro De , Martins Johnny Wesley G. , Farage Filho Miguel , Henriques Fernando Guilhon
Published: December 2010

Os autores apresentam o caso de uma paciente de 45 anos de idade com história de 15 meses de evolução, de hemiatrofia progressiva da face e língua à esquerda. A investigação laboratorial e de imagens foi normal, incluindo exames de sangue de rotina, líquido cerebro-espinhal, provas de função hepática, renal e reumáticas; além de raio X, tomografia computadorizada e ressonância magnética de crânio. A eletroneuromiografia mostrou alterações neurogênicas periféricas dos nervos trigêmio motor e hipoglosso, predominantemente à esquerda. Esses achados são compatíveis com o diagnóstico de hemiatrofia facial de Romberg, motivando a discussão de diversos aspectos desta rara doença de acordo com o relato e com a literatura.
Condroblastoma benigno do osso occipital: Relato do caso
Authors: Araújo João Flávio Mattos , Castro Guilherme Contatore Bierrenbach De , Iafigliola Maria Gracia , Balbo Roque José
Published: December 2010

Condroblastoma benigno é tumor ósseo raro, tendo como origem células cartilagíneas. Classicamente este tumor acomete regiões epifisárias de ossos longos, sendo incomum o envolvimento de ossos do crânio, principalmente o osso occipital. Relatamos o caso de uma paciente com 16 anos de idade, com o diagnóstico de condroblastoma benigno do osso occipital e discutimos os principais aspectos deste tumor.
Fibroma condromixóide da coluna torácica: Relato de caso e revisão da literatura
Authors: Leal Filho Manoel Baldoino , Pereira Neto Aldo , Pereira Luís Cláudio Modesto , Franco Paulo Saide , Suzuki Kunio , De Mello Paulo Andrade , Burnett José Cláudio B. , Veloso Moema Gonçalves P.
Published: December 2010

Os autores relatam caso de compressão medular torácica por lesão da quinta articulação costovertebral à direita. O diagnóstico pré-operatório, com mielotomografia, foi de processo expansivo intrarraquidiano extradural ao nível de T5. Feita a abordagem cirúrgica por laminectomia, com ressecção apenas da lesão intrarraquidiana. O diagnóstico de fibroma condromixóide somente foi definido com o estudo histopatológico. A paciente teve importante melhora neurológica. Decidiu-se pelo acompanhamento clínico e radiológico. Após dois anos houve recidiva do processo para dentro do canal raquidiano. Desta vez, foi realizada abordagem posterolateral à direita, por costotransversectomia e retirada da lesão. O diagnóstico histopatológico foi o mesmo. A paciente evoluiu com melhora neurológica e está sendo feito o seguimento há dois anos. Chamamos a atenção para a raridade do caso e discutimos a conduta.
Hematoma subdural agudo traumático: estudo de 110 pacientes
Authors: Figueiredo Neto Nicandro de , Martins Johnny Wesley G. , Parage Filho Miguel , Motta Luiz Augusto Casulari Roxo da , Mello Paulo Andrade de , Pereira Ronaldo Sérgio Santana
Published: December 2010

Apresentamos uma série consecutiva de 110 pacientes com hematoma subdural agudo traumático (HSDA) admitidos no serviço de emergência do HBDF no período de 1°-janeiro a 1°-dezembro-1994. Todos os pacientes foram atendidos de acordo com o mesmo protocolo. Houve predominância do sexo masculino (79%), com idade variando entre 14 e 70 anos, sendo os atropelamentos (34%) e os acidentes automobilísticos (20%) as causas mais comuns. A maioria dos pacientes (85,7%) foi admitida muito grave, com 8 pontos ou menos na Escala de Coma Glasgow (ECG), o que influenciou diretamente na mortalidade. A tomografia computadorizada de crânio foi o exame diagnóstico de escolha que mostrou serem as contusões e o inchaço cerebral ("swelling") as lesões intracranianas associadas mais freqüentes. A cirurgia foi realizada em 45,1% dos pacientes, e, em sua maioria, através de craniotomia fronto-têmporo-parietal ampla, com drenagem do hematoma, seguida de plástica da dura-mater. Em 54,9% as condições clínicas não permitiram a realização da cirurgia; neste grupo, cerca de 69,6% estavam em coma profundo à admissão, com 3 pontos na ECG. A letalidade cirúrgica foi de 61,2% e esteve diretamente relacionada à condição clínica inicial e à idade do paciente. A letalidade, incluindo todos os pacientes cirúrgicos e não cirúrgicos com HSDA, mesmo aqueles admitidos já com sinais de falência de tronco cerebral, foi de 79,5%. Além destes pacientes que faleceram, cerca de 7% evoluíram sem seqüelas ou com seqüelas mínimas; outros 11,4% com seqüelas de moderadas a paves e 2,1 % permaneceram em estado vegetativo persistente. Nossos dados estão de acordo com os da literatura no que se refere a elevada taxa de morbidade e mortalidade dos pacientes com HSDA.
Pode um liberal apoiar a subvenção à arte?
Authors: Silveira Pablo da
Published: December 2010

Para alguns teóricos liberais contemporâneos, entre os quais John Rawls, um Estado liberal-democrático não pode orientar sua intervenção por concepções "perfeccionistas", isto é, por julgamentos sobre o valor intrínseco de pessoas, atividades ou concepções do bem. Examina-se se essa concepção de "neutralidade antiperfeccionista" é compatível com a intervenção estatal voltada para a promoção da excelência artística de uma sociedade.
Enraizamento de estacas de Sebastiania schottiana Müll. Arg.
Authors: Frassetto Eduardo Garcia , Franco Elci Terezinha Henz , Kielse Paula , Amaral Vanessa Fiad Martins do
Published: December 2010

O pouco domínio dos processos envolvidos no enraizamento de estacas de diversas espécies florestais tem sido um fator limitador para a produção de mudas via propagação vegetativa, impedindo possíveis ganhos econômicos e ecológicos nas atividades de reflorestamento e recuperação de áreas degradadas. O objetivo deste estudo foi verificar o potencial de enraizamento de estacas de Sebastiania schottiana, submetidas a diferentes doses e tempos de imersão em produto comercial Orgasol® FTS (composto de aminoácidos e micronutrientes). Estacas basais, medianas e apicais tiveram suas bases imersas em Orgasol® FTS nas doses de 0; 5; 10 e 15mL L-1, durante 1 minuto. O delineamento experimental foi realizado em blocos ao acaso, com três repetições de 20 estacas por parcela. Aos 75 dias, avaliou-se a porcentagem de estacas enraizadas, o comprimento e diâmetro da raiz mais longa. Em um segundo experimento, estacas basais e medianas foram tratadas em 15mL L-1 do produto, durante 0, 15, 30 e 45 minutos. O delineamento experimental foi realizado em blocos ao acaso, com três repetições e 20 estacas por parcela. Aos 150 dias, avaliou-se a porcentagem de estacas enraizadas, massa seca das raízes e o comprimento e diâmetro da raiz mais longa. No primeiro experimento, o aumento da dose do produto promoveu um maior potencial de enraizamento em todos os tipos de estacas, com maior porcentagem de estacas enraizadas no tratamento com 15mL L-1 do produto. No segundo experimento, os maiores potenciais de enraizamento foram observados em estacas basais e medianas tratadas com 15mL L-1 do produto, por 45 minutos. O uso do produto comercial Orgasol® FTS favoreceu a indução de raízes adventícias em estacas de Sebastiania schottiana.
Panorama dos estudos sobre nutrição e doenças negligenciadas no Brasil
Authors: Werneck Guilherme Loureiro , Hasselmann Maria Helena , Gouvêa Thaise Gasser
Published: December 2010

O objetivo deste artigo é revisar a literatura acerca da relação entre nutrição e doenças infecciosas negligenciadas em populações brasileiras, focalizando especificamente a doença de Chagas, a malária, a esquistossomose e a leishmaniose visceral. A revisão da literatura foi realizada em janeiro de 2010 a partir de um levantamento bibliográfico nas bases SciELO, LILACS e Medline. Foram captados 293 resumos; dentre estes, 66 foram selecionados para leitura de texto completo e 43 incluídos na revisão. A presente revisão salienta a relevância dos estudos nutricionais no campo da Saúde Coletiva para melhor compreensão dos aspectos envolvidos no risco e prognóstico de malária, esquistossomose, leishmaniose visceral e doença de Chagas. Evidencia-se também certo desbalanceamento na literatura sobre o tema, com muito mais estudos experimentais do que estudos em populações humanas. Ainda que os primeiros sejam essenciais para esclarecer os mecanismos fisiopatológicos subjacentes à relação entre déficits nutricionais e estas doenças, estudos bem delineados em populações humanas são fundamentais para que o conhecimento científico se traduza em ações efetivas para o controle de doenças negligenciadas.
A atuação da sociedade civil na construção do campo da Alimentação e Nutrição no Brasil: elementos para reflexão
Authors: Burlandy Luciene
Published: December 2010

A inserção dos temas da Alimentação e Nutrição (AN) na agenda pública ganhou progressiva relevância no Brasil, e a sociedade civil desempenhou um papel importante neste processo. Este artigo examina a influência das organizações sociais na construção do campo da AN, numa perspectiva histórica de sua atuação em espaços de interlocução com o governo federal. A análise foi norteada pelas seguintes questões: (1) os diferentes formatos políticos e institucionais desta participação; (2) os temas e demandas políticas pautados; (3) as possíveis repercussões deste processo na construção de institucionalidade pública. Os instrumentos de pesquisa conjugaram revisão bibliográfica e análise documental. Concluiu-se que a atuação das organizações sociais foi fundamental para a consolidação da Política Nacional de AN e de Segurança Alimentar e Nutricional. A engenharia institucional e o perfil das organizações sociais variaram desde movimentos sociais até redes de políticas. Os temas em pauta modificaram-se ao longo do período estudado, com o fortalecimento das temáticas étnicas, raciais e de gênero. Os ganhos deste processo dependem da capacidade do setor público de regular e apoiar o funcionamento desses espaços e envolver os segmentos governamentais que de fato têm poder decisório.
Políticas nacionais e o campo da Alimentação e Nutrição em Saúde Coletiva: cenário atual
Authors: Recine Elisabetta , Vasconcellos Ana Beatriz
Published: December 2010

É apresentado um balanço da implementação das diretrizes da Política Nacional de Alimentação e Nutrição (PNAN) contextualizando as ações no cenário do Sistema Único de Saúde (SUS). Aos dez anos de sua publicação, a PNAN se defronta com desafios tanto para expandir como para qualificar as ações de alimentação e nutrição na saúde, e também para se apresentar como interlocutora e representante legítima da área da saúde, no contexto político e institucional da segurança alimentar e nutricional. Questões relacionadas à articulação da PNAN e da futura Política Nacional de Segurança Alimentar e Nutricional são analisadas para demonstrar a confluência de agendas entre as prioridades para a garantia da SAN. São apontadas as potencialidades desse campo de ação, a partir do atual cenário institucional, e a necessidade de soluções abrangentes que atendam à complexidade da alimentação e nutrição em Saúde Coletiva.