Product quality judgments in a two-sequence cue environment

Previous research demonstrated that the sequence of informational cues and the level of distraction have an impact on the judgment of a product’s quality. This study investigates the influence of the force behind the processing of these cues, working memory (WM). The results indicate that without distraction, consumers with low and high WM capacity (WMC) equally base their product evaluation on the first sequential cue. In the presence of a distractor, however, low WM individuals are no longer able to recall the initial cue, and thus derive their product judgment from the final cue. Moreover, evidence of intercultural differences in the perception of product related cues, and their aptitude for signaling a favorable product quality is provided.

Single line for assembly just-in-sequence multiple models

Programa Doutoral em Líderes para as Indústrias Tecnológicas

A spectrophotometry based blood typing device

Blood typing is a crucial step before any blood transfusion. However, sometimes in emergency situations there is no time to determine the blood of the patient beforehand. In this cases, O negative blood type is administered, which has a lesser incompatibility risk to the patient. Nowadays, the “gold standard” blood typing devices cannot be used in emergency situations due to their high response time (about 30 minutes). This paper reports a blood typing device that determines the ABO and Rh human phenotypes. This device is fast (response time – 5 min), low-cost, and portable. Characteristics that make it suitable to be used in emergency situations, contributing to a higher efficiency and quality in healthcare.

Dinámica poblacional de Streptococcus mutans en niños de edad escolar de la provincia de Córdoba. Population dynamics of Streptococcus mutans in school age children in the province of Córdoba

La caries dental es una enfermedad infecciosa, crónica y trasmisible, que se caracteriza por la desmineralización de los tejidos duros del diente, producida por la acción de los ácidos resultantes de la actividad metabólica del biofilm desarrollado sobre los dientes. Si bien, la etiología de la caries sería polimicrobiana, los estreptococos del grupo mutans son señalados como los principales protagonistas en el inicio de la lesión cariosa. En la pared celular se destacan proteínas que participan en procesos de adhesión, agregación y co-agregación, además de polisacáridos que muestran distintas especificidades antigénicas, lo que permite distinguir cuatro serotipos: c, e, f y k. Es escasa la información de las características antigénicas de las cepas circulantes de estreptococos del grupo mutans y se desconoce la relación de las mismas con la actividad de caries. En este estudio nuestros objetivos son identificar y caracterizar fenotípica y genotípicamente las cepas de estreptococos del grupo mutans circulantes en la provincia de Córdoba. La población de estudio estará constituida por escolares, urbano–marginales de la capital y del interior de la provincia. Se determinarán los serotipos de las mismas a través de de amplificaciones por PCR de tipo multiplex y luego se secuenciarán 8 genes a través de la técnica de tipado multilocus, con el fin de realizar estudios de sistemática molecular, y de estimar la estructura genética de S. mutans. Una vez que se hayan caracterizado los patrones de diversidad y distribución geográfica de S. mutans del centro de Argentina, se intentará dilucidar cómo se relacionan la diversidad genética con la experiencia de caries de los niños del estudio. Se analizarán de forma conjunta nuestros resultados con los publicados por otros autores. De esta forma se logrará una mejor comprensión de los factores históricos y ecológicos que han moldeado su distribución y aportar conocimientos a la sistemática del grupo “mutans” en relación a otras bacterias del género Streptococcus. Dental caries is an infectious, chronic and transmissible disease, characterized by demineralization of the hard tissues of the teeth, produced by the action of acids resulting from the metabolic activity of biofilm developed on the teeth. Although the etiology of caries would be polymicrobial, the streptococci of the mutans group are identified as the major responsible in the initiation of the carious lesion. In the cell wall there are proteins involved in adhesion, aggregation and co-aggregation processes, as well as polysaccharides that present different antigenic specificities, which allow the distinction of four serotypes c, e, f and k. There is little information about the antigenic characteristics of the Streptococcus mutans strains and the relationship of those characteristics with the caries activity is unknown. In the present study our goals are to identify and characterize the phenotypic and genotypic strains of streptococci of the mutans group circulating in the province of Cordoba. The study population will consist of urban and rural scholar children from Cordoba city and from the interior of the province. In order to study the molecular systematic, and the genetic structure of S. mutans, different serotypes will be determined by multiplex PCR amplifications and eight genes will be sequenced by using the multilocus typing technique. Once the diversity and the geographical distribution patterns of S. mutans from the center of Argentina is characterized, we will attempt to clarify how the genetic diversity is related with the caries experience in the children of the study. Our results will be analyzed together with those published by other authors. This will achieve a better understanding of the historical and ecological factors that shaped the bacteria’s distribution and will contribute to the knowledge of the systematic of the mutans group in relation to other bacteria of the genus Streptococcus.

Implicit sequence learning in recurrent neural networks

Magdeburg, Univ., Fak. für Elektrotechnik, Diss., 2013

Results of a collaborative study of the EDNAP group regarding mitochondrial DNA heteroplasmy and segregation in hair shafts.

A collaborative exercise was carried out by the European DNA Profiling Group (EDNAP) in order to evaluate the distribution of mitochondrial DNA (mtDNA) heteroplasmy amongst the hairs of an individual who displays point heteroplasmy in blood and buccal cells. A second aim of the exercise was to study reproducibility of mtDNA sequencing of hairs between laboratories using differing chemistries, further to the first mtDNA reproducibility study carried out by the EDNAP group. Laboratories were asked to type 2 sections from each of 10 hairs, such that each hair was typed by at least two laboratories. Ten laboratories participated in the study, and a total of 55 hairs were typed. The results showed that the C/T point heteroplasmy observed in blood and buccal cells at position 16234 segregated differentially between hairs, such that some hairs showed only C, others only T and the remainder, C/T heteroplasmy at varying ratios. Additionally, differential segregation of heteroplasmic variants was confirmed in independent extracts at positions 16093 and the poly(C) tract at 302-309, whilst a complete A-G transition was confirmed at position 16129 in one hair. Heteroplasmy was observed at position 16195 on both strands of a single extract from one hair segment, but was not observed in the extracts from any other segment of the same hair. Similarly, heteroplasmy at position 16304 was observed on both strands of a single extract from one hair. Additional variants at positions 73, 249 and the HVII poly(C) region were reported by one laboratory; as these were not confirmed in independent extracts, the possibility of contamination cannot be excluded. Additionally, the electrophoresis and detection equipment used by this laboratory was different to those of the other laboratories, and the discrepancies at position 249 and the HVII poly(C) region appear to be due to reading errors that may be associated with this technology. The results, and their implications for forensic mtDNA typing, are discussed in the light of the biology of hair formation.

Are there two species of Pygmy Shrews (Sorex)? Revisiting the question using DNA sequence data

Pygmy Shrews in North America have variously been considered to be one species (Sorex hoyi) or two species (S. hoyi and S. thompsoni). Currently, only S. hoyi is recognized. In this study, we examine mitochondrial DNA sequence data for the cytochrome b gene to evaluate the level of differentiation and phylogeographic relationships among eleven samples of Pygmy Shrews from across Canada. Pygmy Shrews from eastern Canada (i.e., Ontario, Quebec, New Brunswick, Nova Scotia, and Prince Edward Island) are distinct from Pygmy Shrews from western Canada (Alberta, Yukon) and Alaska. The average level of sequence divergence between these clades (3.3%) falls within the range of values for other recognized pairs of sister species of shrews. A molecular clock based on third position transversion substitutions suggests that these two lineages diverged between 0.44 and 1.67 million years ago. These molecular phylogenetic data. combined with a reinterpretation of previously published morphological data, are suggestive of separate species status for S. hoyi and S. thompsoni as has been previously argued by others. Further analysis of specimens from geographically intermediate areas (e.g., Manitoba. northern Ontario) is required to determine if there is secondary contact and/or introgression between these two putative species.

Representation of motor habit in a sequence of repetitive reach and grasp movements performed by macaque monkeys: evidence for a contribution of the dorsolateral prefrontal cortex.

In the context of an autologous cell transplantation study, a unilateral biopsy of cortical tissue was surgically performed from the right dorsolateral prefrontal cortex (dlPFC) in two intact adult macaque monkeys (dlPFC lesioned group), together with the implantation of a chronic chamber providing access to the left motor cortex. Three other monkeys were subjected to the same chronic chamber implantation, but without dlPFC biopsy (control group). All monkeys were initially trained to perform sequential manual dexterity tasks, requiring precision grip. The motor performance and the prehension's sequence (temporal order to grasp pellets from different spatial locations) were analysed for each hand. Following the surgery, transient and moderate deficits of manual dexterity per se occurred in both groups, indicating that they were not due to the dlPFC lesion (most likely related to the recording chamber implantation and/or general anaesthesia/medication). In contrast, changes of motor habit were observed for the sequential order of grasping in the two monkeys with dlPFC lesion only. The changes were more prominent in the monkey subjected to the largest lesion, supporting the notion of a specific effect of the dlPFC lesion on the motor habit of the monkeys. These observations are reminiscent of previous studies using conditional tasks with delay that have proposed a specialization of the dlPFC for visuo-spatial working memory, except that this is in a different context of "free-will", non-conditional manual dexterity task, without a component of working memory.

Characterization of a Trypanosoma cruzi genomic fragment complementary to several species-specific mRNAs but different from the spliced leader sequence

We have isolated a clone of Trypanosoma cruzi genimic DNA, lambda 3b2-5, which contains sequences that are reiterated in the genome. Northtern blot analysis showed that clone 3b2-5 hybridizes to 1,200-5,000 bases different mRNA species. The number of mRNAs species hybridized to clone 3b2-5 exceeds its coding capacity showing that this clone carries sequences that are common to several mRNAs species and conserved in the poly A(+) RNA. These sequences are not homologous to the T. cruzi spliced leader sequence, since clone 3b2-5 hybridize to a synthetic 20 nucleotice complementary to the spliced leader sequence. Clone 3b2-5 does not hybridize to DNA and RNA from several genera of Trypanosomatidae and other Trypanosoma species indicating that it carries T. cruzi species-specific sequences.

Development of nuclear DNA probes for the typing of Trypanososma cruzi

We have developed and tested a new way of typing Trypanosoma cruzi, mamely the use of cloned nuclear DNA fragments as genetic markers. Restriction fragment length polymorphisms were verified on Soutern blots hybridized to random probes. Fragment patterns were analyzed and dendrograms constructed. Our results on well characterized laboratory strains correlate well to published isoenzyme studies. Some of the probes were also hybridized to chromosomes separated by pulse field gel electrophoresis a higher degree of heterogeneity was observed at this level.

A new repetitive DNA sequence from Trypanosoma cruzi

Tandemly repeated DNA sequences are found in the genome of higher eukaryotes, and have also been demonstrated in Trypanosoma cruzi. Repeated DNA sequences are potentially useful for the diagnostic detection of T. cruzi (A. Gonzales et al., 1984, Proc. Natl. Acad. Sci. USA, 81: 3356-3360). We have isoleted two clones from a genomic library of T. cruzi (Y strain) that contain, in one clone a family of at least seven copies of a repetitive sequence of approximately 600 base pairs, and in the other an independent copy of the same sequence. One copy of the repetition (HSP) and the independent clone (HCR) were sequenced by the Sanger procedure (Fig.). This sequence hybridized to four strains of T. cruzi tested and did not hybridize to eleven species of trypanosotids from five different Genera, being a good candidate for diagnostic assays. GenBank accession numbers: HSP#m31919, HCR#31920.

Versatile gene-specific sequence tags for Arabidopsis functional genomics: transcript profiling and reverse genetics applications.

Microarray transcript profiling and RNA interference are two new technologies crucial for large-scale gene function studies in multicellular eukaryotes. Both rely on sequence-specific hybridization between complementary nucleic acid strands, inciting us to create a collection of gene-specific sequence tags (GSTs) representing at least 21,500 Arabidopsis genes and which are compatible with both approaches. The GSTs were carefully selected to ensure that each of them shared no significant similarity with any other region in the Arabidopsis genome. They were synthesized by PCR amplification from genomic DNA. Spotted microarrays fabricated from the GSTs show good dynamic range, specificity, and sensitivity in transcript profiling experiments. The GSTs have also been transferred to bacterial plasmid vectors via recombinational cloning protocols. These cloned GSTs constitute the ideal starting point for a variety of functional approaches, including reverse genetics. We have subcloned GSTs on a large scale into vectors designed for gene silencing in plant cells. We show that in planta expression of GST hairpin RNA results in the expected phenotypes in silenced Arabidopsis lines. These versatile GST resources provide novel and powerful tools for functional genomics.

Induction in transgenic mice of HLA-A2.1-restricted cytotoxic T cells specific for a peptide sequence from a mutated p21ras protein.

Cytotoxic T cells (CTL) recognize short peptides that are derived from the proteolysis of endogenous cellular proteins and presented on the cell surface as a complex with MHC class I molecules. CTL can recognize single amino acid substitutions in proteins, including those involved in malignant transformation. The mutated sequence of an oncogene may be presented on the cell surface as a peptide, and thus represents a potential target antigen for tumour therapy. The p21ras gene is mutated in a wide variety of tumours and since the transforming mutations result in amino acid substitutions at positions 12, 13 and 61 of the protein, a limited number of ras peptides could potentially be used in the treatment of a wide variety of malignancies. A common substitution is Val for Gly at position 12 of p21ras. In this study, we show that the peptide sequence from position 5 to position 14 with Val at position 12-ras p5-14 (Val-12)-has a motif which allows it to bind to HLA-A2.1. HLA-A2.1-restricted ras p5-14 (Val-12)-specific CTL were induced in mice transgenic for both HLA-A2.1 and human beta2-microglobulin after in vivo priming with the peptide. The murine CTL could recognize the ras p5-14 (Val-12) peptide when they were presented on both murine and human target cells bearing HLA-A2.1. No cross-reactivity was observed with the native peptide ras p5-14 (Gly-12), and this peptide was not immunogenic in HLA-A2.1 transgenic mice. This represents an interesting model for the study of an HLA-restricted CD8 cytotoxic T cell response to a defined tumour antigen in vivo.