What the cognitive neurosciences mean to me

Cognitive Neuroscience is an interdisciplinary area of research that combines measurement of brain activity (mostly by means of neuroimaging) with a simultaneous performance of cognitive tasks by human subjects. These investigations have been successful in the task of connecting the sciences of the brain (Neurosciences) and the sciences of the mind (Cognitive Sciences). Advances on this kind of research provide a map of localization of cognitive functions in the human brain. Do these results help us to understand how mind relates to the brain? In my view, the results obtained by the Cognitive Neurosciences lead to new investigations in the domain of Molecular Neurobiology, aimed at discovering biophysical mechanisms that generate the activity measured by neuroimaging instruments. In this context, I argue that the understanding of how ionic/molecular processes support cognition and consciousness cannot be made by means of the standard reductionist explanations. Knowledge of ionic/molecular meclianisms can contribute to our understanding of the human mind as long as we assume an alternative form of explanation, based on psycho-physical similarities, together with an ontological view of mentality and spirituality as embedded in physical nature (and not outside nature, as frequently assumed in western culture).

Description of electrophoretic and chromatographic hemoglobin profile of Rhinoclemmys punctularia

Studies of the hemoglobin pattern in Brazilian reptiles are important for determining ecological and phylogenetic relationships, but they are scarce. Peripheral blood samples were obtained from 7 males and 18 females of Rhinoclemmys punctularia. The hematological profile was based on the total hemoglobin and hematocrit values. The hemoglobin profile was obtained using electrophoretic procedures at different pH, isoelectric focusing, globin chain electrophoresis, and HPLC. The hematocrit (31 ± 2%) and total hemoglobin (7.5 ± 0.2 g/dL) values did not indicate gender variations. Alkaline pH electrophoresis of the total blood samples treated with 1% saponin demonstrated the presence of four well-defined hemoglobin fractions, one major component (fraction I), showing cathodic migration and three others faster than fraction I with anodic migration. When the samples were precipitated with chloroform, only two hemoglobin fractions were observed, similar to fractions I and III from the first procedure. Isoelectric focusing and HPLC showed the same pattern. With acid and neutral pH electrophoresis, two fractions with anodic migration were observed. The globin chain identification at alkaline pH showed two fractions, but four fractions were observed at acidic pH, suggesting that different polypeptide chains are involved in the hemoglobin molecule. The chromatographic separation of the total blood sample demonstrated that the major fraction comprised 81.9% and the minor 18.1%. The results obtained demonstrated a similarity between these hemoglobin components and those of some Chelidae reported in the literature for both land and aquatic animals, reflecting the adaptation to environmental conditions. ©FUNPEC-RP.

HPLC determination of hemoglobins to establish reference values with the aid of statistics and informatics

The purpose of the present study was to establish reference values for hemoglobins (Hb) using HPLC, in samples containing normal Hb (AA), sickle cell trait without alpha-thalassemia (AS), sickle cell trait with alpha-thalassemia (ASH), sickle cell anemia (SS), and Hb SC disease (SC). The blood samples were analyzed by electrophoresis, HPLC and molecular procedures. The Hb A2 mean was 4.30 ± 0.44% in AS, 4.18 ± 0.42% in ASH, 3.90 ± 1.14% in SS, and 4.39 ± 0.35% in SC. They were similar, but above the normal range. Between the AS and ASH groups, only the amount of Hb S was higher in the AS group. The Hb S mean in the AS group was 38.54 ± 3.01% and in the ASH it was 36.54 ± 3.76%. In the qualitative analysis, using FastMap, distinct groups were seen: AA and SS located at opposite extremes, AS and ASH with overlapping values and intermediate distribution, SC between heterozygotes and the SS group. Hb S was confirmed by allele-specific polymerase chain reaction. The Hb values established will be available for use as a reference for the Brazilian population, drawing attention to the increased levels of Hb A2, which should be considered with caution to prevent incorrect diagnoses. ©FUNPEC-RP.

Abnormal hemoglobin phenotypes in carriers of mild anemia in Latin America.

We looked for abnormal hemoglobins in blood samples sent for diagnosis of anemia. Identification of the hemoglobins was made using electrophoretic, chromatographic and molecular procedures. The 2020 blood samples were of patients from various regions of Brazil and from some other Latin American countries. Among the abnormal hemoglobins that we found, 3.5% are known to be rare, while 51% had an electrophoretic profile similar to that of Hb S at alkaline pH. Differentiation was possible only by combining electrophoretic and chromatographic methods. Hb Hasharon, an alpha globin chain mutant, was the most frequently found variant hemoglobin; it accounted for 14.3% of the abnormal DNA samples. The other abnormal hemoglobin phenotypes displayed distinct electrophoretic profiles; most of them migrated faster than Hb A. The frequencies of the different abnormal hemoglobin profiles that we found reflect the miscegenation of the Latin American population and indicate the importance of hemoglobin studies using various methods in combination for accurate diagnosis and appropriate counseling of carriers and their families.

Further characterization of the subunits of the giant extracellular hemoglobin of Glossoscolex paulistus (HbGp) by SDS-PAGE electrophoresis and MALDI-TOF-MS

Further characterization of hemoglobin of Glossoscolex paulistus (HbGp) subunits was performed based on SDS-PAGE, size exclusion chromatography (SEC) and MALDI-TOF-MS analysis. SDS-PAGE has shown a total of four linker chains, two quite intense and two of lower intensity. HbGp fractions (I-VI), obtained by size exclusion chromatography (SEC), from oligomeric dissociation at alkaline pH 9.6, were monitored. Fraction I is identical to the whole protein. The monomeric chains c, obtained from the trimer abc reduction, present four isoforms with MM 17,336 Da, 17,414 Da, 17,546 Da and 17,620 Da. Furthermore, the trimer subunit presents two isoforms, T 1 and T 2, with MM 51,200 ± 60 and 51,985 ± 50 Da, respectively. Based on SDS-PAGE, the linker chains seem to be distributed along the different fractions of the SEC chromatogram, appearing along the peaks corresponding to fractions I-V. The fraction IV contains, predominantly, trimers with some linkers contamination. The strong interaction of linker chains L with the trimers abc, makes it difficult to obtain these subunits in pure form. The monomer d in fraction VI appears to be quite pure, in agreement with previous studies. © 2011 Elsevier Ltd. All rights reserved.

Influence of δβ-thalassemia or regulatory elements in individuals with increased fetal Hb levels in the São Paulo northwest population

Fetal hemoglobin (Hb F), formed by two alpha globin chains (α) and two gamma chains (γ) (α2 γ2), has reduced expression in adults, ranging from 0 to 1% of total hemoglobin. Increased levels of Hb F are due to mutations in the β-globin family, which cause hereditary persistence of fetal hemoglobin (HPFH) and delta-beta thalassemia (δβ-thalassemia).The control of the production takes place by the regulatory region and regions outside the β-globin family, among them 2q16, 6q23, 8q, and Xp22.2.The aims of this study were to determine the presence and frequency of two mutations for δβ-thalassemia, the XmnI polymorphism and β-globin haplotypes in healthy individuals with increased Hb F in the State of São Paulo. We analyzed 60 samples of peripheral blood of healthy adults, without complaints of anemia. The samples were separated into two groups according to Hb F level: group I - 34 samples with Hb F ranging from 2 to 15% and group II - 26 samples with Hb F over 15%. In relation to the polymorphisms examined, we found three heterozygous individuals (5%) for Spanish δβ-thalassemia, belonging to group I, whose Hb F levels were within the normal range.The Sicilian δβ-thalassemia mutation was not found, indicating the need to study other polymorphisms related to the increase of Hb F in adult life.The frequency of XmnI polymorphism was 33.3% and the mean Hb F levels were 15.48 ± 11.69%.The frequency observed in our study for this polymorphic site is higher than that found in the literature for healthy subjects.This polymorphism was more prevalent in individuals with Hb F levels below 15%. For four samples positive for this polymorphism, the Hb F levels were explained by the presence of HPFH and Spanish δβ-thalassemia mutations, so that the presence of the XmnI polymorphic site was not a determinant in the overexpression of γ-globin genes. Regarding β-globin haplotypes, 18 alleles and 27 distinct genotypic patterns were found.The pattern Atp1/Atp2 was the mostfrequent genotype (13.72%).Of the 18 alleles, 13 showed atypical patterns.The results show that the haplotype V was the most frequent (27.45%), followed by atypical Atp2 (13.72%) and Atp1 (11.76%), and that there was a higher correlation with the presence of HPFH and XmnI polymorphism.The high frequency of haplotype V in our samples and high frequency of atypical haplotypes may reflect a high rate of miscegenation in this population, suggesting an ethnic characteristic for the Brazilian population, requiring the evaluation of population genetic markers to corroborate this hypothesis. © FUNPEC-RP.

Annual and monthly mean global, direct and diffuse solar irradiation in Botucatu/SP/Brazil

This paper presents a climatic and statistical analysis of global, direct horizontal and diffuse radiation from a database of solar radiation measured from 1996 to 2006 in the city of Botucatu, SP, Brazil. Variation intervals of hourly and daily irradiation, annual mean 〈H̄G〉, 〈H̄bh〉 and 〈H̄d〉 irradiation, monthly mean 〈H̄G〉, 〈H̄ bh〉 and 〈H̄d〉 irradiation and monthly mean 〈K̄t〉, 〈K̄bh〉 and 〈K̄d〉 fractions were determined. Results showed that values of hourly and daily annual mean irradiation were as follows: 〈H̄G〉=1.49MJ/m2 and 〈H̄ G〉=17.74MJ/m2; 〈H̄bh〉=0. 90MJ/m2 and 〈H̄bh〉=10.33MJ/m2 and 〈H̄d〉=0.57 MJ/m2 and 〈H̄d〉=7.09MJ/m2, respectively. Variation intervals of hourly monthly mean irradiation were as follows: 〈H̄G〉 ranged from 1.65MJ/m2 in March to 1.16MJ/m2 in June; 〈H̄bh〉 ranged from 1.06MJ/m2 in April to 0.79MJ/m2 in June, and 〈H̄d〉 ranged from 0.70MJ/m2 in January to 0.37MJ/m2 in June and July. Similarly, daily 〈H̄ G〉 irradiation ranged from 21.35MJ/m2 in November to 12.94MJ/m2 in June; 〈H̄bh〉 ranged from 11.83MJ/m2 in April to 8.49MJ/m2 in June, and 〈H̄d〉 ranged from 10.29MJ/m2 in December to 4.38MJ/m2 in June. Variation intervals of hourly monthly mean fractions were as follows: 〈K̄t〉 ranged from 43.5% in January to 54.2% in April; 〈K̄bh〉 ranged from 33.6% in January to 58.0% in April and 〈K̄d〉 ranged from 66.4% in January to 42.0% in April. In the same way, daily 〈K̄ t〉 fractions ranged from 45.5% in January to 59.8% in August; 〈K̄bh〉 ranged from 38.9% in January to 62.0% in August and 〈K̄d〉 ranged from 61.1% in January to 37.7% in July.

Urea-induced unfolding of Glossoscolex paulistus hemoglobin, in oxy- and cyanomet-forms: A dissociation model

The urea effect on the giant extracellular hemoglobin of Glossoscolex paulistus (HbGp) stability was studied by analytical ultracentrifugation (AUC) and small angle X-ray scattering (SAXS). AUC data show that the sedimentation coefficient distributions curves c (S), at 1.0mol/L of urea, display a single peak at 57 S, associated to the undissociated protein. The increase in urea concentration, up to 4.0mol/L, induces the appearance of smaller species, due to oligomeric dissociation. The sedimentation coefficients and molecular masses are 9.2S and 204kDa for the dodecamer (abcd)3, 5.5S and 69kDa for the tetramer (abcd), 4.1S and 52kDa for the trimer (abc) and 2.0 S and 17kDa for the monomer d, respectively. SAXS data show initially a decrease in the I(0) values due to the oligomeric dissociation, and then, above 4.0mol/L of denaturant, for oxy-HbGp, and above 6.0mol/L for cyanomet-HbGp, an increase in the maximum dimension and gyration radius is observed, due to the unfolding process. According to AUC and SAXS data the HbGp unfolding is described by two phases: the first one, at low urea concentration, below 4.0mol/L, characterizes the oligomeric dissociation, while the second one, at higher urea concentration, is associated to the unfolding of dissociated species. Our results are complementary to a recent report based on spectroscopic observations. © 2012 Elsevier B.V.

Labour market flexibility: what does it really mean?

Includes bibliography

Use of hemoglobin as alternative to peroxidases in cholesterol amperometric biosensors

Sophisticated molecular architectures can be produced with the layer-by-layer (LbL) method, which may combine distinct materials on the same film. In this study, we take advantage of this capability to produce cholesterol amperometric biosensors from LbL films containing hemoglobin (Hb) and cholesterol oxidase in addition to the polyelectrolytes poly(allylamine hydrochloride) (PAH) and poly(ethylene imine) (PEI). Following an optimization procedure, we found that an LbL film deposited onto ITO substrates, with the architecture ITO(PEI/Hb)5(PEI/COx)10, yielded a sensitivity of 93.4 μA μmol L-1 cm-2 for cholesterol incorporated into phospholipid liposomes, comparable to state-of-the-art biosensors. Hb acted as efficient electron mediator and did not suffer interference from phospholipids. Significantly, cholesterol could also be detected in real samples from chicken egg yolk, with no effects from potential interferents, including phospholipids. Taken together these results demonstrate the possible fabrication of low cost, easy-to-use cholesterol amperometric biosensors, whose sensitivity can be enhanced by further optimizing the molecular architectures of the LbL films. © 2012 Elsevier B.V.

Thermal denaturation and aggregation of hemoglobin of Glossoscolex paulistus in acid and neutral media

The thermal denaturation and aggregation of the HbGp, in the oxy- and cyanomet-forms, was investigated by DSC, AUC, DLS, optical absorption and CD, in the pH range from 5.0 to 7.0. Oxy-HbGp has a denaturation process partially reversible and dependent on the temperature. DSC melting curve is characterized by a single peak with Tc value of 333.4±0.2K for oxy-HbGp, while two peaks with Tc values of 332.2±0.1 and 338.4±0.2K are observed for cyanomet-HbGp, at pH 7.0. In acidic pH oxy- and cyanomet-HbGp are more stable showing higher Tc values and aggregation. AUC data show that, HbGp, at pH 7.0, upon denaturation, remains undissociated at 323K, presenting oligomeric dissociation at 333 (12±3% of tetramer and 88±5% of whole HbGp) and 343K (70±5% of monomer and 30±2% of trimer). DLS data show that the lag period before aggregation is dependent on the temperature and HbGp concentration. Optical absorption and CD results show that the increase of temperature leads to the oxy-HbGp oxidation and aggregation, above 331K, in acidic pH. CD data, for HbGp, present a greater thermal stability in acid medium than at neutral pH, with similar Tc values for both oxidation forms. Our data are consistent with previous studies and represents an advance in understanding the thermal stability of oligomeric HbGp structure. © 2012 Elsevier B.V.

Mean surface temperature prediction models for broiler chickens-a study of sensible heat flow

Body surface temperature can be used to evaluate thermal equilibrium in animals. The bodies of broiler chickens, like those of all birds, are partially covered by feathers. Thus, the heat flow at the boundary layer between broilers' bodies and the environment differs between feathered and featherless areas. The aim of this investigation was to use linear regression models incorporating environmental parameters and age to predict the surface temperatures of the feathered and featherless areas of broiler chickens. The trial was conducted in a climate chamber, and 576 broilers were distributed in two groups. In the first trial, 288 broilers were monitored after exposure to comfortable or stressful conditions during a 6-week rearing period. Another 288 broilers were measured under the same conditions to test the predictive power of the models. Sensible heat flow was calculated, and for the regions covered by feathers, sensible heat flow was predicted based on the estimated surface temperatures. The surface temperatures of the feathered and featherless areas can be predicted based on air, black globe or operative temperatures. According to the sensible heat flow model, the broilers' ability to maintain thermal equilibrium by convection and radiation decreased during the rearing period. Sensible heat flow estimated based on estimated surface temperatures can be used to predict animal responses to comfortable and stressful conditions. © 2013 ISB.

A single chart with supplementary runs rules for monitoring the mean vector and the covariance matrix of multivariate processes

The MRMAX chart is a single chart based on the standardized sample means and sample ranges for monitoring the mean vector and the covariance matrix of multivariate processes. User's familiarity with the computation of these statistics is a point in favor of the MRMAX chart. As a single chart, the recently proposed MRMAX chart is very appropriate for supplementary runs rules. In this article, we compare the supplemented MRMAX chart and the synthetic MRMAX chart with the standard MRMAX chart. The supplementary and the synthetic runs rules enhance the performance of the MRMAX chart. © 2013 Elsevier Ltd.

Suplementação alimentar com ácidos graxos essenciais para tilápias do Nilo: desempenho produtivo, hematológico e granuloma por corpo estranho

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Contenção química com dexmedetomidina associada à cetamina em quatis (Nasua nasua) e a reversão dos efeitos sedativos pela iombina e o atipamezol

Pós-graduação em Medicina Veterinária - FMVZ