Cultural Differences in Perceptual Reorganization in US and Pirahã Adults

Visual illusions and other perceptual phenomena can be used as tools to uncover the otherwise hidden constructive processes that give rise to perception. Although many perceptual processes are assumed to be universal, variable susceptibility to certain illusions and perceptual effects across populations suggests a role for factors that vary culturally. One striking phenomenon is seen with two-tone images—photos reduced to two tones: black and white. Deficient recognition is observed in young children under conditions that trigger automatic recognition in adults. Here we show a similar lack of cue-triggered perceptual reorganization in the Pirahã, a hunter-gatherer tribe with limited exposure to modern visual media, suggesting such recognition is experience- and culture-specific

A coupling matrix vision for mobile filtering devices with micro-acoustic wave technologies. A systematic approach

Con el espectro radioeléctrico cada vez más saturado, los filtros y duplexores son elementos claves de la tecnología en el mercado de dispositivos discretos para la telefonía móvil. El segmento de usuario de los sistemas de comunicaciones inalámbricas aprovecha las destacadas propiedades de los dispositivos filtrantes basados en resonadores acústicos. Generalmente, el diseño de dispositivos de onda acústica ha sido asumido por técnicas de optimización debido a las restrictivas limitaciones impuestas por la viabilidad tecnológica de los resonadores SAW y BAW, así como las exigentes especificaciones eléctricas. Una respuesta de transmisión muy restrictiva y factores tecnológicos muy limitantes conducen a hacer el diseño más y más complejo y una tarea muy desafiante. El objetivo del trabajo está enfocado en facilitar el diseño de filtros/duplexores y hacerlo más eficiente. En consecuencia, la formulación inicial del problema se ha centrado en la viabilidad tecnológica para implementar filtros de onda acústica. Proporcionar una metodología sistemática es útil para acelerar la curva de aprendizaje de nuevos diseñadores. Los filtros de microondas con elevada selectividad son posibles si sus funciones de transferencia incorporan ceros de transmisión finitos. La introducción de nodos no-resonantes (NRN) da la posibilidad de diseñar filtros con el máximo número de ceros de transmisión finitos sin tener que implementar acoplamientos directos entre la fuente y la carga. Además, las configuraciones en línea con NRN permiten la extracción de los elementos analíticamente. La típica configuración de filtro ladder presenta similitudes características de acuerdo con las redes de prototipo en línea con nodos resonantes y no-resonantes, que son las propiedades de modularidad, para controlar los ceros de transmisión con resonadores independientes, y respuestas completamente canonícas sin acoplamiento fuente-carga directo. Los elementos de la red pasobanda son dados por ecuaciones explícitas en términos de aquellos en los prototipos en línea con NRN que pueden ser sintetizados analíticamente. Como consecuencia, es posible definir una metodología de síntesis directa para obtener los parámetros pasobanda eléctricos de un filtro RF general que está basado en resonadores acústicos. Este trabajo presenta una metodología que proporciona un procedimiento de síntesis sistemático para diseñar filtros y duplexores ladder basados en resonadores de onda micro-acústica. La metodología de diseño utiliza un enfoque nodal basado en NRN y nodos resonantes. La representación de la red mediante una matriz de acoplamiento mixta de nodos resonantes y no resonantes es capaz de gestionar de forma eficiente las restricciones tecnológicas. El procedimiento es eficiente en tiempo, preciso en los resultados y proporciona un profundo entendimiento de las particulares interacciones que se producen entre las restricciones tecnológicas y el funcionamiento del dispositivo. Un completo paquete de software, con un simulador rápido, preciso y de fácil uso, ha sido desarrollado, permitiendo obtener diseños de primera etapa exitosos. Como resultado de la metodología sistemática, hemos desarrollado un método de diseño que combina y sistemáticamente gestiona redes filtrantes compuestas de bloques de polo extraído con bloques de resonadores acoplados, es decir, celdas ladder con secciones CRF. Además, la metodología has sido extendida exitosamente para tener en cuenta el diseño de divisores de potencia con respuesta filtrante por medio de dos topologías diferentes: la configuración ladder y las secciones CRF. La metodología propuesta ofrece una solución que combina el completo cumplimiento de las máscaras de espectro con topologías preparadas para acomodar las restricciones tecnológicas de la tecnología micro-acústica. La metodología ha sido desarrollada orientada nativamente a gestionar la tecnología, como es el ajuste de la limitación en el acoplo electromagnético, y basada en fundamentos de síntesis rigurosos.With a spectrum more and more overcrowded, filters and duplexers are drivers of the technology in the discrete device mobile market. The user segment of wireless communication systems takes profit of the outstanding performance of filtering devices based on acoustic resonators. Usually, the design of acoustic wave devices have been mainly entrusted to optimization techniques because the stringent constraints imposed by the technological feasibility of SAW and BAW resonators and the challenging electrical specifications. A stringent transmission response and very restrictive technological factors lead the design to a more and more complex and challenging task. The aim of the work is focused on easing the filters/duplexers designs and making it more efficient. Consequently, the initial formulation of the problem was focused on the technological feasibility of acoustic wave filters. Providing a systematic methodology is useful to accelerate the learning curve of new entrant designers. Microwave filters with high selectivity are possible if their transfer functions incorporates finite transmission zeros. The inclusion of non-resonant nodes gives the possibility of designing filters with the maximum number of finite transmission zeros without implementing direct couplings between source and load. Furthermore, inline configuration with NRN allows the extraction of the elements analytically. The common ladder filter configuration exhibits characteristic similarities regarding inline prototype networks with resonant and non-resonant nodes, which are the property of modularity, to control transmission zeros by independent resonators, and fully canonical response without a direct source-load coupling. The elements of the lowpass prototype are given by explicit equations in terms of those in in-line prototypes with non-resonating nodes that can be synthesized analytically. As a consequence it is possible to define a direct synthesis methodology to obtain the bandpass electric parameters of a general RF filter that is based on acoustic resonators. This work presents a methodology that provides a systematic synthesis procedure for designing ladder filters and duplexers based on acoustic wave resonators. The methodology uses a nodal approach based on resonating and non-resonating nodes. The coupling matrix representation with a mix of different nature nodes, resonant and non-resonant, is able to efficiently manage the technological restrictions. The procedure is time efficient, precise in the outcomes and provides a deep understanding of the particular interactions between technological constraints and device performance. A complete software package with fast, accurate and easy-to-use simulator has been developed, enabling starting point design success. As a result of the systematic methodology, we have developed a design method that combines and systematically manages a filtering network composed of extracted-pole blocks with coupling resonators blocks, so it is ladder cells with CRF sections. Moreover, the methodology has been successfully extended to take into consideration filtering power dividers by means of two different topologies: ladder configuration and CRF sections. The proposed methodology offers a solution that combines a complete spectrum fulfillment with topologies ready to accommodate technological constraints of micro-acoustics technologies. The methodology has been developed natively oriented to manage with the technology, such as accommodating electromechanical coupling constraints, leveraged in rigorous synthesis foundations

Capacity development in food composition database management and nutritional research and education in Central and Eastern European, Middle Eastern and North African countries

Background/Objectives: Capacity development (CD) in food and nutrition is much more than formal training and includes human resource development, and organisational, institutional and legal framework development with the aim of enhancing nutrition-relevant knowledge and skills to support infrastructural development. The goal of the European Food Information Resource (EuroFIR) Network of Excellence has been to develop and integrate food composition data throughout Europe. EuroFIR joined forces in CD with the United Nations (UN) University and UN System Standing Committee on Nutrition, the Network for Capacity Development in Nutrition in Central and Eastern Europe, the Central and Eastern European Countries Food Data Systems network and with the Middle East and North African Capacity Building Initiative. The aim of this paper is to discuss an inventory of the status of food composition databases (FCDBs) and the training needs of compilers in non-EuroFIR countries in Central and Eastern Europe (CEE) and in the Middle East and North Africa (MENA), and to present the CD achieved through EuroFIR and other network collaborations. Subjects/Methods: Two online questionnaires were created addressing the FCDB status and specific training needs in countries of the targeted regions. Data were collected during 2006-2008 and then analysed. Subsequently, CD activities were organised. Results: Contacts were established in 19 CEE and 7 MENA countries, of which several had national food composition tables, but no electronic versions. Education, training, workshops, networking and the sharing of experiences were uniformly requested. Subsequently, CD activities in EuroFIR were organised focussing on food composition courses, exchange visits, workshops and individual training for PhD students, junior scientists and other staff categories, as well as conferences linked to food composition research and food information. To facilitate CD activities, EuroFIR has signed a Memorandum of Understanding with the Czech Republic, Hungary, Slovenia, Croatia and Estonia. Conclusions: EuroFIR has created training activities that complement national activities. Collaboration with other networks has provided an overview of FCDB status and training needs, providing directions for CD activities in those countries. This provides a platform for new funding and further development and networking for CD, which would be conducive to European Commission objectives and public health strategies for CD. European Journal of Clinical Nutrition (2010) 64, S134-S138; doi:10.1038/ejcn.2010.22

Human Folate Bioavailability

The vitamin folate is recognized as beneficial health-wise in the prevention of neural tube defects, anemia, cardiovascular diseases, poor cognitive performance, and some forms of cancer. However, suboptimal dietary folate intake has been reported in a number of countries. Several national health authorities have therefore introduced mandatory food fortification with synthetic folic acid, which is considered a convenient fortificant, being cost-efficient in production, more stable than natural food folate, and superior in terms of bioavailability and bioefficacy. Other countries have decided against fortification due to the ambiguous role of synthetic folic acid regarding promotion of subclinical cancers and other adverse health effects. This paper reviews recent studies on folate bioavailability after intervention with folate from food. Our conclusions were that limited folate bioavailability data are available for vegetables, fruits, cereal products, and fortified foods, and that it is difficult to evaluate the bioavailability of food folate or whether intervention with food folate improves folate status. We recommend revising the classical approach of using folic acid as a reference dose for estimating the plasma kinetics and relative bioavailability of food folate

augustin

Green tea catechins (GTC) have been shown to inhibit the activities of enzymes involved in folate uptake. Hence, regular green tea drinkers may be at risk of impaired folate status. The present experiments aimed at studying the impact of dietary GTC on folate concentrations and metabolism. In a human pilot study (parallel design) healthy men consumed for 3 weeks 6 capsules (~670 mg GTC) per day (2 capsules with each principal meal) containing aqueous extracts of the leaves of Camellia sinensis (n=17) or placebo (n=16). No differences in plasma folate concentrations were observed between treatments. We further fed groups of 10 male rats diets fortified with 0, 0.05, 0.5, 1, or 5 g GTC/kg for 6 weeks. Only at the highest intake, GTC significantly decreased serum 5-methyl-tetrahydrofolate concentrations in rats, while mRNA concentrations of reduced folate carrier, proton-coupled folate transporter/heme carrier protein 1, and dihydrofolate reductase (DHFR) remained unchanged in intestinal mucosa. Using an in vitro enzyme activity assay, we observed a time-and dose-dependent inhibition of DHFR activity by epigallocatechin gallate and a green tea extract. Our data suggest that regular green tea consumption is unlikely to impair folate status in healthy males, despite the DHFR inhibitory activity of GTC. K e y w o r d s : folates, catechins, bioavailability, human, rat MATERIAL AND METHODS Dihydrofolate reductase activity The inhibition of human dihydrofolate reductase (DHFR) activity by (-) epigallocatechin gallate (EGCG) and a standardized green tea extract (Polyphenon 60 (P60); Sigma Chemical Co., St Louis, MO, USA) was measured using a commercial dihydrofolate reductase assay kit (Sigma-Aldrich) according to the manufacturer's protocol. Methotrexate, a well-known competitive DHFR inhibitor was used as a positive control. EGCG and P60 were dissolved in ultra pure-water (containing 1% ascorbic acid (w/v) (Merck KGaA, Darmstadt, Germany) to stabilize the catechins) on the day of the experiments. DHFR was used at a final activity of 1.5 x 10 -3 units per reaction. Final concentrations of EGCG and methotrexate were 1000, 100 and 10 nmol/L per reaction. P60 was used at final concentrations of 1428 .57, 142.86, and 14.29 µg/L and, thus, contained 1060 , 106, and 10.6 nmol/L EGCG and 1427.3 nmol/L of the gallated catechins (EGCG, ECG and gallocatechin gallate), respectively. Rat study Fifty male Wistar rats (Harlan Winkelmann GmbH, Borchen, Germany) with an initial body weight of 99.8 ± 2.0 g (mean ± SEM) were randomized into 5 groups of 10 animals each and housed pair-wise with sawdust bedding under controlled environmental conditions (23 ± 2°C and 65 ± 5% relative humidity, 12 h dark-light cycle). The rats were kept for 5 days on a folate-adjusted rat diet for growing animals containing 2 mg of folic acid/kg (C1027; Altromin GmbH, Lage, Germany) and thereafter received their respective experimental diets consisting of the standard diet supplemented with 0, 0.05, 0.5, 1, or 5 g green tea catechins per kg diet using P60 as the source of catechins (see The animal experiment was conducted in accordance with the German Guidelines and Regulations on Animal Care (Deutsches Tierschutzgesetz, 2006) and was approved by the University of Kiel Ethics Committee on Animal Care. Human pilot study Healthy males were recruited by advertisement at the University and local community of Reading (United Kingdom) and amongst volunteers who previously participated in nutritional trials at the Hugh Sinclair Human Nutrition Unit. Inclusion criteria were: male gender, 18-55 y of age, and a BMI in the range of 22-32 kg/m 2 . Subjects were excluded from the trial if they were diagnosed with any illness or on long-term medication, used dietary supplements, participated in >5 h of aerobic exercise activity per week, or were involved in a clinical trial within 3 months prior to the study. The study protocol was approved by the University of Reading ethics committee and all subjects gave written informed consent before participation. A standardized aqueous green tea extract prepared from the leaves of Camellia sinensis L. (a kind gift of Cognis Deutschland GmbH & Co KG, Monheim am Rhein, Germany) was used to make the green tea extract (GTE) capsules. The composition of the GTE is given in The trial was designed as a double-blind placebo-controlled parallel study. Thirty-one volunteers were randomly assigned to one of two treatment groups (GTE, n=16 or placebo, n=15) with similar BMI and age (data not shown). Subjects took 6 capsules per day, two with each principal meal, for 3 weeks and were instructed to limit their daily tea and coffee consumption to ≤ 3 cups, but to otherwise maintain their normal diet and exercise patterns. Compliance was determined by counting of the returned capsules at the end of the trial and was high (>98%). Blood samples (20 ml) were drawn into tubes containing 0.05 mL 15% K 3 EDTA (Vacutainer; Becton Dickinson UK Ltd., Oxford, UK) after an overnight fast on the first and last day of the intervention period. Plasma was immediately obtained by centrifugation (1,000 x g, 10 min) and 3 ml aliquots were stored at -80°C until analysis. Folate quantification by HPLC Procedures for extraction and purification of folates from human plasma and rat serum and liver samples by strong anion exchange solid-phase extraction were described previously by Witthoft et al. (18). Dialysed rat serum (500 µl/g) was used to ensure complete deconjugation of folate polyglutamates in liver samples; modified from Patring et al. (19). Analyses were performed using an HPLC system (Agilent 1100) consisting of a 104 10-formyltetrahydrofolate (10-HCO-H 4 folate), and 5,10-methenyltetrahydrofolate (5,10-CH + -H 4 folate) (a gift of Merck Eprova AG, Schaffhausen, Switzerland, except 10-HCO-H 4 folate, which was purchased from Schircks Laboratories, Jona, Switzerland). Quantification was based on a multilevel (n=7) external calibration curve with a linear range over 1.2-118.0 ng/mL for H 4 folate, 0.6-93.1 ng/mL for 5-CH 3 -H 4 folate, 0.9-184.1 ng/mL for 10-HCO-H 4 folate and 9.3-184.5 ng/mL for 5,10-CH + -H 4 folate. mRNA quantification RNA was isolated from rat duodenal mucosa using the RNeasy Lipid Tissue Kit (Qiagen GmbH, Hilden, Germany) according to the manufacturer's protocol. DNA digestion was performed with RNase-Free DNase Set (Qiagen). RNA integrity was checked by electrophoresis on a denaturing agarose gel and ethidium bromide staining. The concentration and purity of isolated RNA was determined by measuring the absorbance (AB) at 260 and 280 nm in a spectrophotometer (DU800, Beckmann Instruments; Munich, Germany). A ratio of >1.8 between AB 260nm and AB 280nm was considered as acceptable. RNA aliquots were stored at -80°C until analysis. Primer pairs of β-actin, reduced folate carrier (RFC) and proton-coupled folate transporter/heme carrier protein-1 (PCFT/HCP1) were designed to the corresponding sequences of Rattus norvegicus mRNA with Primer3 software (http://frodo.wi.mit.edu/cgi-bin/primer3/ primer3_www.cgi; 03.05.2007) and purchased from MWGBiotech AG (Ebersberg, Germany). The sequences of primers used in this study were as follows: Sense primer for β-actin, 5´-GGGGTGTTGAAGGTCTCAAA-3´, antisense primer for β-actin, 5´-TGTCACCAACTGGGACGATA-3´; sense primer for RFC, 5´-GGCTCGTGTTCTACCTCTGC-3´, antisense primer for RFC, 5´-GGTAGTCGGTGAGCAGGAAG-3´; sense primer for PCFT/HCP1, 5´-TGAGCTAAGCACACCCCTCT-3´, antisense primer for PCFT/HCP1, 5´-TCCGTACCCTGTGAACATGA-3´. The product size was 90 base pair (bp) for β-actin; 183 bp for RFC and 217 bp for PCFT/HCP1. QuantiTect ® Primer Assay (Qiagen) was used for DHFR mRNA amplification, with a product size of 88 bp. For one-step quantitative reverse transcriptase polymerase chain reaction (one-step qRT-PCR) two aliquots of RNA were amplified. External relative standard curves of total RNA were determined with each run. Data was normalized by dividing the concentrations of RFC, PCFT/HCP1 or DHFR by the concentrations of β-actin mRNA. Each PCR reaction (final volume 20 µl) contained 0.5 µmol/L of each primer, 10 µl of 2x QuantiTect ® SYBR ® Green RT-PCR Master Mix (Qiagen), 0.2 µl QuantiTect RT-Mix (Qiagen), 8 µl of RNA dilution and 1.4 µl water. Real-time cycler conditions were set according to the manufacturers protocol to 40 cycles with annealing temperatures of 56°C for β-actin, 59°C for RFC, 56°C for PCFT/HCP1 and 55°C for DHFR, respectively. Quantification and melting curves of the amplified products were analysed using the RotorGene 6.0 software (Corbett Lifescience; Sydney, Australia). Melting curve analyses and agarose gel electrophoresis with ethidium bromide staining were performed to exclude non-specific products. Statistical analyses Statistical calculations were performed with GraphPad Prism 4 software (GraphPad Software Inc., San Diego, CA, USA). Analyses of the data from the rat study and the in vitro assay were performed by means of a one-way ANOVA followed by Dunnetts test for multiple comparisons of group means between animals receiving GTC or control diet. Analyses of the data from the human pilot study were performed by means of a paired Student's t-test for comparison of baseline vs. treatment and by means of an unpaired Student's t-test for comparisons between subjects receiving GTE or placebo. Reported values are means ± SEM and effects were considered significant at P<0.05. RESULTS Dihydrofolate reductase activity in vitro Both pure EGCG and P60, at concentrations of 1000 for EGCG and 1060 nmol/L for EGCG from P60, respectively, time-dependently inhibited DHFR activity Serum and liver folate concentrations in rats Feed consumption and final body mass (318.7 ± 4.8 g) of the Wistar rats were similar in all groups. Intake of diets containing 0.5% GTC over a period of 42 days significantly decreased the serum concentration of 5-CH 3 -H 4 folate compared to control rats, whereas the concentrations of H 4 folate remained unchanged ( Relative mRNA levels of reduced folate carrier and dihydrofolate reductase in rat duodenal mucosa The housekeeping gene β-actin was expressed at similar levels in all animals and no significant differences in the relative mRNA levels of RFC, PCFT/HCP1 or DHFR in the duodenal mucosa were observed Plasma folate concentrations in humans Consumption of 670 mg of GTC per day or placebo did not affect plasma folate concentrations in healthy male volunteers. No significant differences in plasma concentrations of 5-CH 3 -H 4 folate were observed between the treatment groups at baseline (placebo, 16.3 ± 2.6 nmol/L; GTE, 19.1 ± 2.4 nmol/L) or after intervention (placebo, 15.5 ± 2.1 nmol/L; GTE, 17.6 ± 2.4 nmol/L). DISCUSSION Green tea is a widely consumed beverage in many countries and contains appreciable amounts of polyphenols. Catechins (flavanols) are the major subclass of bioactive compounds within the polyphenol fraction of green tea. Epidemiological studies associated a high dietary intake of catechins with a reduced risk to suffer from a variety of diseases (reviewed in 20), including certain forms of cancer (21). The underlying molecular and cellular mechanisms by which green tea catechins may mediate anticarcinogenic acitivty seem to be diverse: Cell culture experiments as well as studies in rodents indicate that green tea catechin may inhibit angiogenesis via a down-regulation of vascular endothelial growth factor (reviewed in 22). Furthermore it has been suggested that the anticancer activity of green tea catechins against different kind of cancers may find an explanation in direct targeting of lipid rafts (23). Recent in vitro studies have shown that epigallocatechin gallate (EGCG), the predominant catechin in green tea, competitively inhibits the enzyme dihydrofolate reductase (DHFR) (9, 13). DHFR inhibition is the mechanism by which so-called antifolates, such as the cytostatic drug methotrexate, inhibit cell division and reduce tumor growth (15, 24). Co-administration of folic acid and the DHFR inhibitors methotrexate and pyrimethamine, respectively, reduced plasma folate concentrations in rats The commercial green tea extract Polyphenon 60 (P60) used in the rat study and its principle bioactive ingredient EGCG inhibited DHRF activity time-and concentration-dependently in vitro In order to study whether or not the effects observed in vitro bear a meaning for the more complex physiological processes in vivo, Wistar rats were fed for 42 days with diets fortified with increasing concentrations of green tea catechins (GTC) using a standardized green tea extract (P60). The diets contained 2 mg folic acid per kg, which is equivalent to twice the dietary recommendations for laboratory rats as given by the National Research Council (28). It is noteworthy that folates synthesized by the microflora of the large intestine are absorbed and may significantly contribute to blood folate concentrations (reviewed in 29). The diet used in this study was therefore formulated to provide a minimum of substrate to the intestinal microflora to limit bacterial folate synthesis. Only in those animals fed the highest concentrations of the green tea extract (0.5% GTC), did we observe a significant decrease in serum 5-CH 3 -H 4 folate concentrations as compared to the control group ( At a given substrate affinity and substrate concentration, the capacity of enzymatic turnover of folates as well as the amount of their carrier-mediated transport across cellular membranes is mainly affected by the amount of enzymes/carriers present at the tissue level. Because catechins are known to alter the gene expression for a variety of proteins (35), we quantified relative mRNA concentrations of the RFC, PCFT/HCP1, and DHFR in the duodenal mucosa of rats fed GTC. No significant differences in mRNA concentrations of RFC, PCFT/HCP1, and of DHFR were found between the experimental groups The current findings suggested that GTC might decrease serum folate concentrations only if supplied at supra-nutritional doses. A 70 kg human would have to drink almost 100 cups of green tea infusion per day to match the highest dose fed to rats in the present study. Because such a human study would be unfeasible as well as unrealistic, we designed a pilot study with a standardized green tea extract to assess whether or not regular consumption of high doses of GTC might affect plasma folate concentrations in humans. The intake of 670 mg of GTC per day, which corresponds to about 20 cups of green tea, caused no significant differences in plasma concentrations of 5-CH 3 -H 4 folate between the treatment and placebo groups, both of which consuming a normal diet containing on average ~328 ± 26 µg folate/d. Insufficient dietary intake of folates for as short as 2-3 weeks has been reported to result in reduced blood concentrations of the vitamin (30). Our findings therefore suggest that green tea drinking is unlikely to affect plasma folate concentrations in healthy, free-living subjects and that a longer treatment period and/or even higher doses of dietary GTC may be necessary to induce changes in folate concentrations, if possible at all. Further human studies with GTC and a standardized supply of folic acid (in the absence of naturally occurring reduced folates) are warranted to investigate the influence of GTC on DHFR activity in vivo. In addition, the measurement of (oxidized) serum folic acid should be considered because folic acid has been found in serum of subjects consuming folic acid-fortified foods for 5 d (11). Based on the experiments presented here, it appears unlikely that daily green tea consumption, even at high levels, may affect folate concentrations in healthy humans. Acknowledgement

The emergence of synaesthesia in a Neuronal Network Model via changes in perceptual sensitivity and plasticity

Synaesthesia is an unusual perceptual experience in which an inducer stimulus triggers a percept in a different domain in addition to its own. To explore the conditions under which synaesthesia evolves, we studied a neuronal network model that represents two recurrently connected neural systems. The interactions in the network evolve according to learning rules that optimize sensory sensitivity. We demonstrate several scenarios, such as sensory deprivation or heightened plasticity, under which synaesthesia can evolve even though the inputs to the two systems are statistically independent and the initial cross-talk interactions are zero. Sensory deprivation is the known causal mechanism for acquired synaesthesia and increased plasticity is implicated in developmental synaesthesia. The model unifies different causes of synaesthesia within a single theoretical framework and repositions synaesthesia not as some quirk of aberrant connectivity, but rather as a functional brain state that can emerge as a consequence of optimising sensory information processing

Effects of mannoprotein E1 in liquid diet on inflammatory response and TLR5 expression in the gut of rats infected by Salmonella typhimurium

<p>Abstract</p> <p>Background</p> <p>Mannoproteins are yeast cell wall componend, and rich in mannose. The use of foods rich in mannose as carbohydrate, could have a bioprotective effect against entrobacteria intestinal infection. Nothing is known about mannoproteins' activity in inflammatory bowel processes induced by entrobacteria.</p> <p>This study investigates the effects of mannoprotein administration via a liquid diet on inflammatory response and TLR5 expression during intestinal tissue injury in a rat model of infection with <it>Salmonella typhimurium</it>.</p> <p>Methods</p> <p>Adult Wistar male rats were divided into three groups: control, and mannoprotein E₁at 10 or 15%. Animals were fed with a liquid diet supplemented or not with mannoprotein E₁. Groups were infected by intragastrical administration of <it>S. typhimurium</it>. 24 h post-inoculation samples of spleen, ileum and liver were collected for microbiological studies. Gut samples were processed to determine levels of proinflammatory cytokines (mRNA) and TLR5 (mRNA and protein) by quantitative PCR and Western-blot, and the number of proliferative and apoptotic cells determined by immunohistochemistry.</p> <p>Results</p> <p>Ininfected levels of proinflammatory cytokines and TLR5 were higher in untreated controls than in the animals receiving mannoprotein. Proliferation was similar in both groups, whereas apoptosis was higher in controls. Curiosly, the mannoprotein effect was dose dependent.</p> <p>Conclusions</p> <p>Mannoprotein administration in a liquid diet seems to protect intestinal tissue against <it>S. typhimurium </it>infection. This protection seems to expressed as a lower pro-inflammatory response and TLR5 downregulation in gut epithelium, as well as by an inhibition of apoptosis. Nevertheless, the molecular mechanism by which mannoprotein is able to regulate these responses remain unclear. These results could open up new avenues in the use of mannoproteins as prebiotics in the therapeutic strategy for treatment of inflammatory gut processes induced by microbia.</p

Illusions of Visual Motion Elicited by Electrical Stimulation of Human MT Complex

Human cortical area MT+ (hMT+) is known to respond to visual motion stimuli, but its causal role in the conscious experience of motion remains largely unexplored. Studies in non-human primates demonstrate that altering activity in area MT can influence motion perception judgments, but animal studies are inherently limited in assessing subjective conscious experience. In the current study, we use functional magnetic resonance imaging (fMRI), intracranial electrocorticography (ECoG), and electrical brain stimulation (EBS) in three patients implanted with intracranial electrodes to address the role of area hMT+ in conscious visual motion perception. We show that in conscious human subjects, reproducible illusory motion can be elicited by electrical stimulation of hMT+. These visual motion percepts only occurred when the site of stimulation overlapped directly with the region of the brain that had increased fMRI and electrophysiological activity during moving compared to static visual stimuli in the same individual subjects. Electrical stimulation in neighboring regions failed to produce illusory motion. Our study provides evidence for the sufficient causal link between the hMT+ network and the human conscious experience of visual motion. It also suggests a clear spatial relationship between fMRI signal and ECoG activity in the human brain

Pseudo-Synesthesia through Reading Books with Colored Letters

Background Synesthesia is a phenomenon where a stimulus produces consistent extraordinary subjective experiences. A relatively common type of synesthesia involves perception of color when viewing letters (e.g. the letter ‘a’ always appears as light blue). In this study, we examine whether traits typically regarded as markers of synesthesia can be acquired by simply reading in color. Methodology/Principal Findings Non-synesthetes were given specially prepared colored books to read. A modified Stroop task was administered before and after reading. A perceptual crowding task was administered after reading. Reading one book (>49,000 words) was sufficient to induce effects regarded as behavioral markers for synesthesia. The results of the Stroop tasks indicate that it is possible to learn letter-color associations through reading in color (F(1, 14) = 5.85, p = .030). Furthermore, Stroop effects correlated with subjective reports about experiencing letters in color (r(13) = 0.51, p = .05). The frequency of viewing letters is related to the level of association as seen by the difference in the Stroop effect size between upper- and lower-case letters (t(14) = 2.79, p = .014) and in a subgroup of participants whose Stroop effects increased as they continued to read in color. Readers did not show significant performance advantages on the crowding task compared to controls. Acknowledging the many differences between trainees and synesthetes, results suggest that it may be possible to acquire a subset of synesthetic behavioral traits in adulthood through training. Conclusion/Significance To our knowledge, this is the first evidence of acquiring letter-color associations through reading in color. Reading in color appears to be a promising avenue in which we may explore the differences and similarities between synesthetes and non-synesthetes. Additionally, reading in color is a plausible method for a long-term ‘synesthetic’ training program