Structural changes in soybean seed coat due to harvest time and storage

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Neural coding tools, based on Information Theory, applied to discrete time series: from electrophysiology to neuroethology

This work is supported by Brazilian agencies Fapesp, CAPES and CNPq

Day-to-night time differences in the relationship between cardiorespiratory coordination and heart rate variability

Heart rate variability (HRV) and cardiorespiratory coordination, i.e. the temporal interplay between oscillations of heartbeat and respiration, reflect information related to the cardiovascular and autonomic nervous system. The purpose of this study was to investigate the relationship between spectral measures of HRV and measures of cardiorespiratory coordination. In 127 subjects from a normal population a 24 h Holter ECG was recorded. Average heart rate (HR) and the following HRV parameters were calculated: very low (VLF), low (LF) and high frequency (HF) oscillations and LF/HF. Cardiorespiratory coordination was quantified using average respiratory rate (RespR), the ratio of heart rate and respiratory rate (HRR), the phase coordination ratio (PCR) and the extent of cardiorespiratory coordination (PP). Pearson's correlation coefficient r was used to quantify the relationship between each pair of the variables across all subjects. HR and HRR correlated strongest during daytime (r = 0.89). LF/HF and PP showed a negative correlation to a reasonable degree (r = -0.69). During nighttime sleep these correlations decreased whereas the correlation between HRR and RespR (r = -0.47) as well as between HRR and PCR (r = 0.73) increased substantially. In conclusion, HRR and PCR deliver considerably different information compared to HRV measures whereas PP is partially linked reciprocally to LF/HF.

Relationship between onset-to-door time and door-to-thrombolysis time: a pooled analysis of 10 dedicated stroke centers

BACKGROUND AND PURPOSE Inverse relationship between onset-to-door time (ODT) and door-to-needle time (DNT) in stroke thrombolysis was reported from various registries. We analyzed this relationship and other determinants of DNT in dedicated stroke centers. METHODS Prospectively collected data of consecutive ischemic stroke patients from 10 centers who received IV thrombolysis within 4.5 hours from symptom onset were merged (n=7106). DNT was analyzed as a function of demographic and prehospital variables using regression analyses, and change over time was considered. RESULTS In 6348 eligible patients with known treatment delays, median DNT was 42 minutes and kept decreasing steeply every year (P<0.001). Median DNT of 55 minutes was observed in patients with ODT ≤30 minutes, whereas it declined for patients presenting within the last 30 minutes of the 3-hour time window (median, 33 minutes) and of the 4.5-hour time window (20 minutes). For ODT within the first 30 minutes of the extended time window (181-210 minutes), DNT increased to 42 minutes. DNT was stable for ODT for 30 to 150 minutes (40-45 minutes). We found a weak inverse overall correlation between ODT and DNT (R(2)=-0.12; P<0.001), but it was strong in patients treated between 3 and 4.5 hours (R(2)=-0.75; P<0.001). ODT was independently inversely associated with DNT (P<0.001) in regression analysis. Octogenarians and women tended to have longer DNT. CONCLUSIONS DNT was decreasing steeply over the last years in dedicated stroke centers; however, significant oscillations of in-hospital treatment delays occurred at both ends of the time window. This suggests that further improvements can be achieved, particularly in the elderly.

Chronological Order of Appearance of Extraintestinal Manifestations Relative to the Time of IBD Diagnosis in the Swiss Inflammatory Bowel Disease Cohort.

BACKGROUND Data evaluating the chronological order of appearance of extraintestinal manifestations (EIMs) relative to the time of inflammatory bowel disease (IBD) diagnosis is currently lacking. We aimed to assess the type, frequency, and chronological order of appearance of EIMs in patients with IBD. METHODS Data from the Swiss Inflammatory Bowel Disease Cohort Study were analyzed. RESULTS The data on 1249 patients were analyzed (49.8% female, median age: 40 [interquartile range, 30-51 yr], 735 [58.8%] with Crohn's disease, 483 [38.7%] with ulcerative colitis, and 31 [2.5%] with indeterminate colitis). A total of 366 patients presented with EIMs (29.3%). Of those, 63.4% presented with 1, 26.5% with 2, 4.9% with 3, 2.5% with 4, and 2.7% with 5 EIMs during their lifetime. Patients presented with the following diseases as first EIMs: peripheral arthritis 70.0%, aphthous stomatitis 21.6%, axial arthropathy/ankylosing spondylitis 16.4%, uveitis 13.7%, erythema nodosum 12.6%, primary sclerosing cholangitis 6.6%, pyoderma gangrenosum 4.9%, and psoriasis 2.7%. In 25.8% of cases, patients presented with their first EIM before IBD was diagnosed (median time 5 mo before IBD diagnosis: range, 0-25 mo), and in 74.2% of cases, the first EIM manifested itself after IBD diagnosis (median: 92 mo; range, 29-183 mo). CONCLUSIONS In one quarter of patients with IBD, EIMs appeared before the time of IBD diagnosis. Occurrence of EIMs should prompt physicians to look for potential underlying IBD.

Is sensitization to stimulants time dependent and mediated via NMDA receptors?

Chronic administration of psychomotor stimulants has been reported to produce behavioral sensitization to its effects on motor activity. This adaptation may be related to the pathophysiology of recurrent psychiatric disorders. Since disturbances in circadian rhythms are also found in many of these disorders, the relationship between sensitization and chronobiological factors became of interest. Therefore, a computerized monitoring system investigated the following: whether repeated exposure to methylphenidate (MPD) and amphetamine (AMP) could produce sensitization to its locomotor effects in the rat; whether sensitization to MPD and AMP was dependent on the circadian time of drug administration; whether the baseline levels of locomotor activity would be effected by repeated exposure to MPD and AMP; whether the expression of a sensitized response could be affected by the photoperiod; and whether MK-801, a non-competitive NMDA antagonist, could disrupt the development of sensitization to MPD. Dawley rats were housed in test cages and motor activity was recorded continuously for 16 days. The first 2 days served as baseline for each rat, and on day 3 each rat received a saline injection. The locomotor response to 0.6, 2.5, or 10 mg/kg of MPD was tested on day 4, followed by five days of single injections of 2.5 mg/kg MPD (days 5–9). After five days without injection (days 10–14) rats were re-challenged (day 15) with the same doses they received on day 4. There were three separate dose groups ran at four different times of administration, 08:00, 14:00, 20:00, or 02:00 (i.e. 12 groups). The same protocol was conducted with AMP with the doses of 0.3, 0.6, and 1.2 mg/kg given on day 4 and 15, and 0.6 mg/kg AMP as the repeated dose on days 5 to 9. In the second set of experiments only sensitization to MPD was investigated. The expression of the sensitized response was dose-dependent and mainly observed with challenge of the lower dose groups. The development of sensitization to MPD and ANT was differentially time-dependent. For MPD, the most robust sensitization occurred during the light phase, with no sensitization during the middle of the dark phase. (Abstract shortened by UMI.) ^

"Power to the people" : De la Hegemonía al Policentrismo: Una mirada desde las Antípodas sobre el devenir del inglés en el contexto postcolonial de Asia del Sur

Esta tesis buscará diferencias y similitudes sobre el fenómeno "Imperialismo Lingüístico" en contextos poscoloniales desde la mirada de lingüistas angloparlantes, por un lado occidentales, para quienes el inglés es su lengua materna, como así también orientales, para quienes es una segunda lengua. Creemos que los fuertes procesos de apropiación, naturalización, indigenización y re-significación de la lengua inglesa por parte de la población de Asia del Sur han hecho del inglés una lengua de carácter policéntrico, lengua de cultura (Guitarte, 1991) más que una lengua de carácter hegemónico, lengua de culto (Guitarte, 1991). Esta lengua poli/pluricéntrica, lejos de ser una lengua que perpetúe la inequidad social, como proponen los teóricos occidentales, es una lengua que empodera a sus hablantes, inclusive a aquellos más excluidos del sistema social como los dalits. Los textos para el análisis corresponden a las variedades postcoloniales del inglés indio (Indian English) y sri lankeano (Sri Lankean English) que se ubican dentro de los denominados inglés[es] Sud asiático[s] (South Asian English[es]). La evaluación en India y Sri Lanka (colonizados) respecto de la imposición de la Lengua Inglesa es altamente positiva, no sólo en los estratos sociales elevados sino también en los estratos sociales de menores recursos (los dalits). Esto se opone a la evaluación del mismo fenómeno visto desde occidente (colonizadores), quienes consideran haber cometido, a través de la imposición, una especie de genocidio lingüístico de las lenguas locales. Si bien, ambas posturas coinciden en ver al inglés como a un medio capaz de crear un nuevo estrato social: ?la casta de los hablantes bilingües del inglés?, creemos que la diferencia principal radica en que esta capacidad es vista como exclusiva por parte de los occidentales, y es vista como inclusiva por los orientales. Mientras que los primeros se preguntan quiénes quedan afuera del uso predominante del inglés para la comunicación y el acceso a la tecnología, la ciencia, la educación y la cultura; los orientales se preguntan quiénes quedan adentro del uso del inglés para las distintas funciones intra e internacionales. Los autores del este dan un paso más allá de la mera descripción del estado de cosas y proponen políticas lingüísticas que contemplan sus variedades estandarizadas. Queremos también mostrar que la capacidad de transformar algo negativo en positivo; algo que ha sido impuesto, en algo propio es característica de la cultura india. Esto se refleja también en otros ámbitos, como el audiovisual, el gastronómico o el religioso

"Power to the people" : De la Hegemonía al Policentrismo: Una mirada desde las Antípodas sobre el devenir del inglés en el contexto postcolonial de Asia del Sur

Esta tesis buscará diferencias y similitudes sobre el fenómeno "Imperialismo Lingüístico" en contextos poscoloniales desde la mirada de lingüistas angloparlantes, por un lado occidentales, para quienes el inglés es su lengua materna, como así también orientales, para quienes es una segunda lengua. Creemos que los fuertes procesos de apropiación, naturalización, indigenización y re-significación de la lengua inglesa por parte de la población de Asia del Sur han hecho del inglés una lengua de carácter policéntrico, lengua de cultura (Guitarte, 1991) más que una lengua de carácter hegemónico, lengua de culto (Guitarte, 1991). Esta lengua poli/pluricéntrica, lejos de ser una lengua que perpetúe la inequidad social, como proponen los teóricos occidentales, es una lengua que empodera a sus hablantes, inclusive a aquellos más excluidos del sistema social como los dalits. Los textos para el análisis corresponden a las variedades postcoloniales del inglés indio (Indian English) y sri lankeano (Sri Lankean English) que se ubican dentro de los denominados inglés[es] Sud asiático[s] (South Asian English[es]). La evaluación en India y Sri Lanka (colonizados) respecto de la imposición de la Lengua Inglesa es altamente positiva, no sólo en los estratos sociales elevados sino también en los estratos sociales de menores recursos (los dalits). Esto se opone a la evaluación del mismo fenómeno visto desde occidente (colonizadores), quienes consideran haber cometido, a través de la imposición, una especie de genocidio lingüístico de las lenguas locales. Si bien, ambas posturas coinciden en ver al inglés como a un medio capaz de crear un nuevo estrato social: ?la casta de los hablantes bilingües del inglés?, creemos que la diferencia principal radica en que esta capacidad es vista como exclusiva por parte de los occidentales, y es vista como inclusiva por los orientales. Mientras que los primeros se preguntan quiénes quedan afuera del uso predominante del inglés para la comunicación y el acceso a la tecnología, la ciencia, la educación y la cultura; los orientales se preguntan quiénes quedan adentro del uso del inglés para las distintas funciones intra e internacionales. Los autores del este dan un paso más allá de la mera descripción del estado de cosas y proponen políticas lingüísticas que contemplan sus variedades estandarizadas. Queremos también mostrar que la capacidad de transformar algo negativo en positivo; algo que ha sido impuesto, en algo propio es característica de la cultura india. Esto se refleja también en otros ámbitos, como el audiovisual, el gastronómico o el religioso

Brownian dynamics simulations of protein folding: Access to milliseconds time scale and beyond

Protein folding occurs on a time scale ranging from milliseconds to minutes for a majority of proteins. Computer simulation of protein folding, from a random configuration to the native structure, is nontrivial owing to the large disparity between the simulation and folding time scales. As an effort to overcome this limitation, simple models with idealized protein subdomains, e.g., the diffusion–collision model of Karplus and Weaver, have gained some popularity. We present here new results for the folding of a four-helix bundle within the framework of the diffusion–collision model. Even with such simplifying assumptions, a direct application of standard Brownian dynamics methods would consume 10,000 processor-years on current supercomputers. We circumvent this difficulty by invoking a special Brownian dynamics simulation. The method features the calculation of the mean passage time of an event from the flux overpopulation method and the sampling of events that lead to productive collisions even if their probability is extremely small (because of large free-energy barriers that separate them from the higher probability events). Using these developments, we demonstrate that a coarse-grained model of the four-helix bundle can be simulated in several days on current supercomputers. Furthermore, such simulations yield folding times that are in the range of time scales observed in experiments.

Antigenic peptides containing large PEG loops designed to extend out of the HLA-A2 binding site form stable complexes with class I major histocompatibility complex molecules.

Recognition of peptides bound to class I major histocompatibility complex (MHC) molecules by specific receptors on T cells regulates the development and activity of the cellular immune system. We have designed and synthesized de novo cyclic peptides that incorporate PEG in the ring structure for binding to class I MHC molecules. The large PEG loops are positioned to extend out of the peptide binding site, thus creating steric effects aimed at preventing the recognition of class I MHC complexes by T-cell receptors. Peptides were synthesized and cyclized on polymer support using high molecular weight symmetrical PEG dicarboxylic acids to link the side chains of lysine residues substituted at positions 4 and 8 in the sequence of the HLA-A2-restricted human T-lymphotrophic virus type I Tax peptide. Cyclic peptides promoted the in vitro folding and assembly of HLA-A2 complexes. Thermal denaturation studies using circular dichroism spectroscopy showed that these complexes are as stable as complexes formed with antigenic peptides.