Relation of the disaccharidases in the small intestine of the rat to the degree of experimentally induced iron-deficiency anemia

Hypolactasia associated with severe iron-deficiency anemia has been reported in several studies. The objective of the present study was to determine whether hypolactasia is associated with the degree and duration of iron-deficiency anemia. Newly weaned male Wistar rats were divided into a control group receiving a diet supplemented with iron (C) and an experimental group (E) receiving a diet not supplemented with iron (iron-deficiency diet). The animals were studied on the 3rd, 5th, 7th, 14th, 21st, 28th and 35th days of the experiment, when overall and iron nutritional status and disaccharidase activity in the small intestine were determined by the Dahlqvist method. A reduction in weight occurred in the anemic animals starting on the 5th day of the study. Anemia was present in the experimental animals, with a progressive worsening up to the 14th day (hemoglobin: C = 13.27 and E = 5.37) and stabilizing thereafter. Saccharase and maltase activities did not differ significantly between groups, whereas lactase showed a significant reduction in total (TA) and specific activity (SA) in the anemic animals starting on the 21st day of the study. Median lactase TA for the C and E groups was 2.27 and 1.25 U on the 21st day, 2.87 and 1.88 U on the 28th day, and 4.20 and 1.59 U on the 35th day, respectively. Median lactase SA was 0.31 and 0.20 U/g wet weight on the 21st day, 0.39 and 0.24 U/g wet weight on the 28th day, and 0.42 and 0.23 U/g wet weight on the 35th day, respectively. These findings suggest a relationship between the enzymatic alterations observed and both the degree and duration of the anemic process. Analysis of other studies on intestinal disaccharidases in anemia suggests that the mechanism of these changes may be functional, i.e., that the enterocytes may suffer a reduction in their ability to synthesize these enzymes.

Spontaneous Focusing on Numerosity in the Development of Early Mathematical Skills

The aim of the present set of longitudinal studies was to explore 3-7-year-old children.s Spontaneous FOcusing on Numerosity (SFON) and its relation to early mathematical development. The specific goals were to capture in method and theory the distinct process by which children focus on numerosity as a part of their activities involving exact number recognition, and individual differences in this process that may be informative in the development of more complex number skills. Over the course of conducting the five studies, fifteen novel tasks were progressively developed for the SFON assessments. In the tasks, confounding effects of insufficient number recognition, verbal comprehension, other procedural skills as well as working memory capacity were aimed to be controlled. Furthermore, how children.s individual differences in SFON are related to their development of number sequence, subitizing-based enumeration, object counting and basic arithmetic skills was explored. The effect of social interaction on SFON was tested. Study I captured the first phase of the 3-year longitudinal study with 39 children. It was investigated whether there were differences in 3-year-old children.s tendency to focus on numerosity, and whether these differences were related to the children.s development of cardinality recognition skills from the age of 3 to 4 years. It was found that the two groups of children formed on the basis of their amount of SFON tendency at the age of 3 years differed in their development of recognising and producing small numbers. The children whose SFON tendency was very predominant developed faster in cardinality related skills from the age of 3 to 4 years than the children whose SFON tendency was not as predominant. Thus, children.s development in cardinality recognition skills is related to their SFON tendency. Studies II and III were conducted to investigate, firstly, children.s individual differences in SFON, and, secondly, whether children.s SFON is related to their counting development. Altogether nine tasks were designed for the assessments of spontaneous and guided focusing on numerosity. The longitudinal data of 39 children in Study II from the age of 3.5 to 6 years showed individual differences in SFON at the ages of 4, 5 and 6 years, as well as stability in children.s SFON across tasks used at different ages. The counting skills were assessed at the ages of 3.5, 5 and 6 years. Path analyses indicated a reciprocal tendency in the relationship between SFON and counting development. In Study III, these results on the individual differences in SFON tendency, the stability of SFON across different tasks and the relationship of SFON and mathematical skills were confirmed by a larger-scale cross-sectional study of 183 on average 6.5-year-old children (range 6;0-7;0 years). The significant amount of unique variance that SFON accounted for number sequence elaboration, object counting and basic arithmetic skills stayed statistically significant (partial correlations varying from .27 to .37) when the effects of non-verbal IQ and verbal comprehension were controlled. In addition, to confirm that the SFON tasks assess SFON tendency independently from enumeration skills, guided focusing tasks were used for children who had failed in SFON tasks. It was explored whether these children were able to proceed in similar tasks to SFON tasks once they were guided to focus on number. The results showed that these children.s poor performance in the SFON tasks was not caused by their deficiency in executing the tasks but on lacking focusing on numerosity. The longitudinal Study IV of 39 children aimed at increasing the knowledge of associations between children.s long-term SFON tendency, subitizing-based enumeration and verbal counting skills. Children were tested twice at the age of 4-5 years on their SFON, and once at the age of 5 on their subitizing-based enumeration, number sequence production, as well as on their skills for counting of objects. Results showed considerable stability in SFON tendency measured at different ages, and that there is a positive direct association between SFON and number sequence production. The association between SFON and object counting skills was significantly mediated by subitizing-based enumeration. These results indicate that the associations between the child.s SFON and sub-skills of verbal counting may differ on the basis of how significant a role understanding the cardinal meanings of number words plays in learning these skills. The specific goal of Study V was to investigate whether it is possible to enhance 3-year old children.s SFON tendency, and thus start children.s deliberate practice in early mathematical skills. Participants were 3-year-old children in Finnish day care. The SFON scores and cardinality-related skills of the experimental group of 17 children were compared to the corresponding results of the 17 children in the control group. The results show an experimental effect on SFON tendency and subsequent development in cardinality-related skills during the 6-month period from pretest to delayed posttest in the children with some initial SFON tendency in the experimental group. Social interaction has an effect on children.s SFON tendency. The results of the five studies assert that within a child.s existing mathematical competence, it is possible to distinguish a separate process, which refers to the child.s tendency to spontaneously focus on numerosity. Moreover, there are significant individual differences in children.s SFON at the age of 3-7 years. Moderate stability was found in this tendency across different tasks assessed both at the same and at different ages. Furthermore, SFON tendency is related to the development of early mathematical skills. Educational implications of the findings emphasise, first, the importance of regarding focusing on numerosity as a separate, essential process in the assessments of young children.s mathematical skills. Second, the substantial individual differences in SFON tendency during the childhood years suggest that uncovering and modeling this kind of mathematically meaningful perceiving of the surroundings and tasks could be an efficient tool for promoting young children.s mathematical development, and thus prevent later failures in learning mathematical skills. It is proposed to consider focusing on numerosity as one potential sub-process of activities involving exact number recognition in future studies.

Cassava starch in the Brazilian food industry

Cassava starch is a valued raw material for producing many kinds of modified starches for food applications. Its physicochemical properties, as well as its availability, have made it an interesting and challenging ingredient for the food industry. In the present work, food grade modified cassava starches were purchased from producers and analyzed for selected physicochemical characteristics. Samples of sour cassava starch were included, as well as one sample of native cassava starch. Results showed that almost all modified starches were resistant to syneresis, produced pastes more stable to stirred cooking, and some of them were difficult to cook. The sour cassava starches presented high acidity and resulted in clear and unstable pastes during stirred cooking, susceptible to syneresis.

" Nonlinear Signal Processing of Electroencephalogram .' Application in the Study of Neurodynamics. "

Interfacings of various subjects generate new field ofstudy and research that help in advancing human knowledge. One of the latest of such fields is Neurotechnology, which is an effective amalgamation of neuroscience, physics, biomedical engineering and computational methods. Neurotechnology provides a platform to interact physicist; neurologist and engineers to break methodology and terminology related barriers. Advancements in Computational capability, wider scope of applications in nonlinear dynamics and chaos in complex systems enhanced study of neurodynamics. However there is a need for an effective dialogue among physicists, neurologists and engineers. Application of computer based technology in the field of medicine through signal and image processing, creation of clinical databases for helping clinicians etc are widely acknowledged. Such synergic effects between widely separated disciplines may help in enhancing the effectiveness of existing diagnostic methods. One of the recent methods in this direction is analysis of electroencephalogram with the help of methods in nonlinear dynamics. This thesis is an effort to understand the functional aspects of human brain by studying electroencephalogram. The algorithms and other related methods developed in the present work can be interfaced with a digital EEG machine to unfold the information hidden in the signal. Ultimately this can be used as a diagnostic tool.

Molecular characterization of a crustinlike antimicrobial peptide in the giant tiger shrimp, Penaeus monodon, and its expression profile in response to various immunostimulants and challenge with WSSV

A crustinlike antimicrobial peptide from the haemocytes of giant tiger shrimp, Penaeus monodon was partially characterized at the molecular level and phylogenetic analysis was performed. The partial coding sequence of 299 bp and 91 deduced amino acid residues possessed conserved cysteine residues characteristic of the shrimp crustins. Phylogenetic tree and sequence comparison clearly confirmed divergence of this crustinlike AMP from other shrimp crustins. The differential expression of the crustinlike AMP in P. monodon in response to the administration of various immunostimulants viz., two marine yeasts (Candida haemulonii S27 and Candida sake S165) and two bglucan isolates (extracted from C. haemulonii S27 and C. sake S165) were noted during the study. Responses to the application of two grampositive probiotic bacteria (Bacillus MCCB101 and Micrococcus MCCB104) were also observed. The immune profile was recorded preand postchallenge white spot syndrome virus (WSSV) by semiquantitative RTPCR. Expressions of seven WSSV genes were also observed for studying the intensity of viral infection in the experimental animals. The crustinlike AMP was found to be constitutively expressed in the animal and a significant downregulation could be noted postchallenge WSSV. Remarkable downregulation of the gene was observed in the immunostimulant fed animals prechallenge followed by a significant upregulation postchallenge WSSV. Tissuewise expression of crustinlike AMP on administration of C. haemulonii and Bacillus showed maximum transcripts in gill and intestine. The marine yeast, C. haemulonii and the probiotic bacteria, Bacillus were found to enhance the production of crustinlike AMP and confer significant protection to P. monodon against WSSV infection

Quantization of specific trace metals in bivalve, Villorita Cyprinoides Var Cochinensis in the Cochin estuary

Present study consists the quantization of specific metals-- Cr, Cd, Pb, Zn and Cu observed in the experimental bivalve, Villorita species. Bivalve specimens were collected seasonally from the identified three hot spots of Vembanad Lake. Soft tissue concentrations of metals are very sensitive in reflecting changes in the ambient environment and hence important in assessing the environmental quality. Concentrations of Zn in bivalves were fairly high compared to other metals. All the stations showed a maximum concentration during premonsoon and minimum during the other two seasons. Levels of Pb, Cu, Zn, Cd and Cr are between 0-6.17mg/kg, 0-17.224mg/kg, 1.916-255.163mg/kg, 0.325-4.133mg/kg, and 0-15.233mg/kg respectively

Influence of Interface Surface Geometries In The Tensile Characteristics Of Friction Welded Joints From Aluminium Alloys

Friction welding is a solid state joining process that produces coalescence in materials, using the heat developed between surfaces through a combination of mechanical induced rubbing motion and applied load. In rotary friction welding technique heat is generated by the conversion of mechanical energy into thermal energy at the interface of the work pieces during rotation under pressure. Traditionally friction welding is carried out on a dedicated machine because of its adaptability to mass production. In the present work, steps were made to modify a conventional lathe to rotary friction welding set up to obtain friction welding with different interface surface geometries at two different speeds and to carry out tensile characteristic studies. The surface geometries welded include flat-flat, flat-tapered, tapered-tapered, concave-convex and convex-convex. A comparison of maximum load, breaking load and percentage elongation of different welded geometries has been realized through this project. The maximum load and breaking load were found to be highest for weld formed between rotating flat and stationary tapered at 500RPM and the values were 19.219kN and 14.28 kN respectively. The percentage elongation was found to be highest for weld formed between rotating flat and stationary flat at 500RPM and the value was 21.4%. Hence from the studies it is cleared that process parameter like “interfacing surface geometries” of weld specimens have strong influence on tensile characteristics of friction welded joints

Functional and molecular characterization of Tachykinins and tachykinin receptors in the mouse uterus

The aim of this study was to analyze the function and expression of tachykinins, tachykinin receptors, and neprilysin (NEP) in the mouse uterus. A previous study showed that the uterotonic effects of substance P (SP), neurokinin A (NKA), and neurokinin B (NKB) in estrogen-treated mice were mainly mediated by the tachykinin NK, receptor. In the present work, further contractility studies were undertaken to determine the nature of the receptors mediating responses to tachykinins in uteri of late pregnant mice. Endpoint and real-time quantitative RTPCR were used to analyze the expression of the genes that encode the tachykinins SP/NKA, NKB, and hemokinin-1 (HK-1) (Tac1, Tac2, and Tac4); and the genes that encode tachykinin NK1 (Tacr1), NK2 (Tacr2), and NK3 (Tacr3) receptors in uteri from pregnant and nonpregnant mice. The data show that the mRNAs of tachykinins (particularly NKB and HK-1), tachykinin receptors, and NEP are locally expressed in the mouse uterus, and their expression changes during the estrous cycle and during pregnancy. The tachykinin INK, receptor is the predominant tachykinin receptor in the nonpregnant and early pregnant mouse and may mediate tachykinin-induced uterine contractions in the nonpregnant mouse. The tachykinin NK, receptor is predominant in the late pregnant mouse and is the main receptor mediating uterotonic responses to tachykinins at late pregnancy. The tachykinin NK, receptor is expressed in considerable amounts only in uteri from nonpregnant diestrous animals, and its physiological significance remains to be clarified.

Comparative Cytogenetics and Molecular Phylogeography in the Group Astyanax altiparanae - Astyanax aff. bimaculatus (Teleostei, Characidae)

The genus Astyanax comprises small characin fish of the neotropical region. The so-called `yellow-tailed characins` compose one of the most widely distributed Astyanax groups. A. altiparanae and A. aff. bimaculatus, are evolutionarily closely related and commonly found in several Brazilian hydrographic basins. In the present work, chromosomal data of specimens of A. altiparanae and A. aff. bimaculatus from 4 hydrographic basins in the states of Sao Paulo (Upper Tiete, Paranapanema, Ribeira de Iguape) and Rio de Janeiro (Guapimirim) are shown. All the populations showed 50 chromosomes, with different karyotypic formula. Although only a single Ag-NOR bearing chromosome pair was observed, all populations possess multiple cistrons of 18S rDNA. FISH with the 5S rDNA probe showed single signals at the interstitial position of one metacentric chromosome pair. C-bands are distributed in the terminal and interstitial regions of several chromosomes. However, the As-51 satDNA are frugally located in a few chromosomes of fishes from Upper Tiete, Paranapanema and Guapimirim Rivers, being absent in individuals of A. aff. bimaculatus from Ribeira de Iguape River basin. Beside these 4 populations, molecular phylogeography studies were also performed in individuals from Middle and Lower Tiete River basin and from 2 additional collection sites in the Paranapanema and Ribeira de Iguape River basins. The phylogeographic analysis using 2 mtDNA regions (totalizing 1.314 bp of ND2 and ATPase6/8 genes) of 8 populations of the group of `yellow-tailed characins` from 3 major hydrographic basins showed structuring of populations, suggesting a correlation between chromosomal (nuclear) and molecular (mitochondrial) data. Copyright (C) 2011 S. Karger AG, Basel

Gene Mapping of 18S and 5S rDNA Genes in the Karyotype of the Three-Spot Gourami Trichogaster trichopterus (Perciformes, Osphronemidae)

Ornamental fish culture is important as an economic activity and for biodiversity conservation as well. The species of the genus Trichogaster (Perciformes, Osphronemidae), popularly known as three-spot gourami, are among the several commercial species raised around the world. In the present work, eight specimens of Thrichogaster trichopterus from aquarium trade facilities were analyzed. The karyotype was composed of 23 pairs of subtelo/acrocentric chromosomes. Fluorescent in situ hybridization allowed identifying the 18S ribosomal gene at telomeric region on long arms of the largest acrocentric pair. On the other hand, the 5S rRNA gene is located at a proximal region on a pair of medium-sized chromosomes. Such information is extremely useful in face of the risks of introduction and the development of ornamental fish trade, once many fish species can be identified only by genetic studies.

Differential effects of neuromuscular blockers on twitches and tetani in the isolated rat muscle: a multiple comparison study using simultaneous confidence intervals

In the present work a comparative quantitative evaluation of the differential effects of neuromuscular blockers on twitches and tetani was performed, encompassing: atracurium, cisatracurium, mivacurium, pancuronium, rocuronium and vecuronium. The sciatic nerve-extensor digitorum longus muscle of the rat was used, in vitro. Twitches were evoked at 0.1 Hz and tetani at 50 Hz. The differential effects of the studied compounds on twitches and tetani were statistically compared using simultaneous confidence intervals for the ratios between mean IC(50) for the block of twitches and mean IC(50) for the block of tetani. The results of ratios of mean IC(50) together with their corresponding 95% simultaneous confidence intervals were: vecuronium: 2.5 (1.8-3.5); mivacurium: 3.8 (3.0-4.9); pancuronium: 3.9 (2.0-7.6); rocuronium: 6.1 (3.8-9.9); atracurium: 9.0 (6.4-12.6); cisatracurium: 13.1 (6.0-28.4). Using the criteria that neuromuscular blockers displaying disjunct confidence intervals for the ratios of mean IC(50) differ statistically with regard to differential effects on twitches and tetani, significant differences in ratios of IC(50) were detected in the following cases: vecuronium vs. rocuronium, vs. atracurium and vs. cisatracurium and mivacurium vs: cisatracurium and vs. atracurium. The results show that the magnitude of the differential effects of neuromuscular blockers on twitches and tetani, as evaluated in the present work in the form of ratios of mean IC(50), does not depend on the chemical structure (comparing steroidal and isoquinolinic compounds), but seems to depend on differential pre- and post-synaptic effects of the compounds. It is also suggested that the greater the ability of a compound to block twitches and tetani in a differential manner, the safer is the compound from the clinical anesthesiology viewpoint.

Neurodegeneration and Increased Production of Nitrotyrosine, Nitric Oxide Synthase, IFN-gamma and S100 beta Protein in the Spinal Cord of IL-12p40-Deficient Mice Infected with Trypanosoma cruzi

Background/Aim: Chagas` disease is caused by Trypanosoma cruzi and occurs in most Latin American countries. The protozoan may colonize the central nervous system (CNS) of immune-compromised human hosts, thus causing neuronal disorders. Systemic control of the intracellular forms of the parasite greatly depends on the establishment of a TH1 response and subsequent nitric oxide (NO) release. At the CNS, it is known that low concentrations of NO promote neuronal survival and growth, while high concentrations exert toxic effects and neuron death. Accounting for NO production by astrocytes is the glia-derived factor S100 beta, which is overproduced in some neurodegenerative diseases. In the current work, we studied the expression of NO, interferon (IFN)-gamma and S100 beta in the spinal cord tissue of IL-12p40KO mice infected with T. cruzi, a model of neurodegenerative process. Methods: IL-12p40KO and wild-type (WT) female mice infected with T. cruzi Sylvio X10/4 (10(5) trypomastigotes, intraperitoneally) were euthanized when IL-12p40KO individuals presented limb paralysis. Spinal cord sections were submitted to immunohistochemical procedures for localization of neurofilament, laminin, nitrotyrosine, NO synthases (NOS), IFN-gamma and S100 beta. The total number of neurons was estimated by stereological analysis and the area and intensity of immunoreactivities were assessed by microdensitometric/morphometric image analysis. Results: No lesion was found in the spinal cord sections of WT mice, while morphological disarrangements, many inflammatory foci, enlarged vessels, amastigote nests and dying neurons were seen at various levels of IL-12p40KO spinal cord. Compared to WT mice, IL-12p40KO mice presented a decrement on total number of neurons (46.4%, p<0.05) and showed increased values of immunoreactive area for nitrotyrosine (239%, p<0.01) and NOS (544%, p<0.001). Moreover, the intensity of nitrotyrosine (16%, p<0.01), NOS (38%, p<0.05) and S100 beta (21%, p<0.001) immunoreactivities were also augmented. No IFN-gamma labeled cells were seen in WT spinal cord tissue, contrary to IL-12p40KO tissue that displayed inflammatory infiltrating cells and also some parenchymal cells positively labeled.Conclusion: We suggest that overproduction of NO may account for neuronal death at the spinal cord of T. cruzi-infected IL-12p40KO mice and that IFN-gamma and S100 beta may contribute to NOS activation in the absence of IL-12. Copyright (C) 2009 S. Karger AG, Basel

The Trypanosoma cruzi proteins TcCox10 and TcCox15 catalyze the formation of heme A in the yeast Saccharomyces cerevisiae

Trypanosoma cruzi, the etiologic agent for Chagas` disease, has requirements for several cofactors, one of which is heme. Because this organism is unable to synthesize heme, which serves as a prosthetic group for several heme proteins (including the respiratory chain complexes), it therefore must be acquired from the environment. Considering this deficiency, it is an open question as to how heme A, the essential cofactor for eukaryotic CcO enzymes, is acquired by this parasite. In the present work, we provide evidence for the presence and functionality of genes coding for heme O and heme A synthases, which catalyze the synthesis of heme O and its conversion into heme A, respectively. The functions of these T. cruzi proteins were evaluated using yeast complementation assays, and the mRNA levels of their respective genes were analyzed at the different T. cruzi life stages. It was observed that the amount of mRNA coding for these proteins changes during the parasite life cycle, suggesting that this variation could reflect different respiratory requirements in the different parasite life stages.

Coherent states of non-relativistic electron in the magnetic-solenoid field

In the present work we construct coherent states in the magnetic-solenoid field, which is a superposition of the Aharonov-Bohm field and a collinear uniform magnetic field. In the problem under consideration there are two kinds of coherent states, those which correspond to classical trajectories which embrace the solenoid and those which do not. The constructed coherent states reproduce exactly classical trajectories, maintain their form under the time evolution and form a complete set of functions, which can be useful in semiclassical calculations. In the absence of the solenoid field these states are reduced to the well known in the case of uniform magnetic field Malkin-Man`ko coherent states.

On a uniform turnpike of the third kind in the Robinson-Solow-Srinivasan model

On using McKenzie’s taxonomy of optimal accumulation in the longrun, we report a “uniform turnpike” theorem of the third kind in a model original to Robinson, Solow and Srinivasan (RSS), and further studied by Stiglitz. Our results are presented in the undiscounted, discrete-time setting emphasized in the recent work of Khan-Mitra, and they rely on the importance of strictly concave felicity functions, or alternatively, on the value of a “marginal rate of transformation”, ξσ, from one period to the next not being unity. Our results, despite their specificity, contribute to the methodology of intertemporal optimization theory, as developed in economics by Ramsey, von Neumann and their followers.