179 research outputs found
Analisis proteomico de la subunidad LsL1 de la lectina del Camaron Blanco del Golfo de México Litopenaeus setiferus
Se purificó por filtración en Sephacryl S-300 una subunidad de 84 kDa de la lectina de L. setiferus (LsL1), específica para azucares N-acetilados. Por dicroísmo circular se encontró que LsL1 contiene en su estructura secundaria 49% de hojas plegadas beta y 6.9% de alfa hélices. La secuencia de aminoácidos de la subunidad LsL1 se determinó por MALDI-TOF a partir de péptidos trípticos. Comparando los valores con la base de datos NCBInr (Swiss-Prot 2003/08/06), esta subunidad mostró 23% de similitud con el precursor hemocianina, proteína responsable de la respiración en crustáceos, que a su vez ha sido relacionada con la generación de péptidos de defensa; al alinear el péptido con otras proteínas involucradas con la defensa en crustáceos muestran una similitud del 80% con hemocianina, y profenoloxidasa, por lo que podemos asumir que las lectinas de esta especie participan en procesos de defensa
Characterization of LR-115 Type 2 Detectors for Monitoring Indoor Radon 222: Determination of the Calibration Factor
The city of Lima, capital of Peru, has about 11 million inhabitants. Lima has no records about the indoor Radon 222 concentration levels in dwellings. Hereby, we are planning to register the indoor radon concentrations in Lima and in other cities of Peru in the next three years. First, we will determine the calibration factor for the detectors which will be used in our measurements. For this purpose, Solid State Nuclear Tracks Detectors of nitrocellulose nitrate (LR-115 type 2) were used.The calibration process using a Radium 226 source was described to obtain the calibration factor. Linear response in tracks number was found in relation with irradiation time and its stability after time at the calibration chamber
Effects of incidental physical activity on morphosyntactic processing in aging
Older adults have difficulties in sentence comprehension when working memory (WM) load increases (e.g., multiple embedded clauses). Structured physical activity has been related to improvements in cognition; however, incidental physical activity (PA, i.e., unstructured daily physical activities), particularly incidental vigorous activity has been poorly studied in relation to its effects on behavior. Furthermore, no positive effect on language has been reported in either form of physical activity. The aim of this study was to evaluate how two levels of PA (high or low) affect WM processing and how this, in turn, may affect morphosyntactic processing in older adults. Individuals with high PA (n = 18) had a higher WM load effect than those with low PA (n = 18), both behaviorally (greater differences between high and low WM loads in correct responses) and in terms of event-related potentials (only subjects with high PA showed LAN and P600b amplitude differences between high and low WM loads). These findings suggest that PA promotes cognitive strategies to face WM loads and morphosyntactic processing
"Optimización de secado del yawuarchunka (Pleysalis Peruviana Linnaeus), empleando la técnica de un proceso combinado aire calientemicroondas"
En este trabajo se determinan las condiciones óptimas de temperatura para un proceso de secado del yawuarchunka (Physalis Peruviana L.), empleando la técnica de un proceso combinado-microondas .Se realiza un seguimiento de la degradación del ácido ascórbico con el tiempo y la temperatura. La investigación realizada fue del tipo experimental y partió de la preparación de la muestra experimental, la cual fue sometida a ensayos en un equipo diseñado y construido, que permitió hacer variaciones de temperatura de aire caliente y pulsaciones de microondas, con el posterior análisis de ácido ascórbico en cada muestra que pasó a través del proceso de secado a fin de lograr la optimización.
Los resultados óptimos para lograr la máxima retención del ácido ascórbico contenido en yawuarchunka (Physalis Peruviana L.), se obtuvieron a la temperatura de 51°C con un intervalo de 5 segundos de pulsaciones, empleando la técnica del proceso combinado aire caliente - microondas. Este resultado servirá de referencia en la aplicación en otras materias primas.Tesi
Two Different Populations within the Healthy Elderly: Lack of Conflict Detection in Those at Risk of Cognitive Decline
During healthy aging, inhibitory processing is affected at the sensorial, perceptual, and cognitive levels. The assessment of event-related potentials (ERPs) during the Stroop task has been used to study age-related decline in the efficiency of inhibitory processes. Studies using ERPs have found that the P300 amplitude increases and the N500 amplitude is attenuated in healthy elderly adults compared to those in young adults. On the other hand, it has been reported that theta excess in resting EEG with eyes closed is a good predictor of cognitive decline during aging 7 years later, while a normal EEG increases the probability of not developing cognitive decline. The behavioral and ERP responses during a Counting-Stroop task were compared between 22 healthy elderly subjects with normal EEG (Normal-EEG group) and 22 healthy elderly subjects with an excess of EEG theta activity (Theta-EEG group). Behaviorally, the Normal-EEG group showed a higher behavioral interference effect than the Theta-EEG group. ERP patterns were different between the groups, and two facts are highlighted: (a) the P300 amplitude was higher in the Theta-EEG group, with both groups showing a P300 effect in almost all electrodes, and (b) the Theta-EEG group did not show an N500 effect. These results suggest that the diminishment in inhibitory control observed in the Theta-EEG group may be compensated by different processes in earlier stages, which would allow them to perform the task with similar efficiency to that of participants with a normal EEG. This study is the first to show that healthy elderly subjects with an excess of theta EEG activity not only are at risk of developing cognitive decline but already have a cognitive impairment
Protocol of sterile personal protective equipment for surgical personnel against SARS-CoV-2 during the COVID-19 pandemic
Background: COVID-19 represents the major pandemic seen the last years generating morbidity and mortality around the world. It is well known the propagation of the virus occurs by air mostly, so it is needed a barrier when the medic personal is treating suspect or confirm patients. Personal protective equipment represents a barrier between the health personnel and the patient during the COVID-19 pandemic. The surgical team during a COVID-19 confirmed o suspicious case procedure requires using PPE to be protected and keep the sterility for the patient safety.Methods: A team of surgeons from a 100% COVID-19 hospital of the Mexican institute of social security developed an inner protocol of safe use PPE maintaining sterility for the surgery.Conclusions: The protocol described provides safety to surgical team and the patient minimizing risk of surgical infections
Selecting Quasars by their Intrinsic Variability
We present a new and simple technique for selecting extensive, complete and
pure quasar samples, based on their intrinsic variability. We parametrize the
single-band variability by a power-law model for the light-curve structure
function, with amplitude A and power-law index gamma. We show that quasars can
be efficiently separated from other non-variable and variable sources by the
location of the individual sources in the A-gamma plane. We use ~60 epochs of
imaging data, taken over ~5 years, from the SDSS stripe 82 (S82) survey, where
extensive spectroscopy provides a reference sample of quasars, to demonstrate
the power of variability as a quasar classifier in multi-epoch surveys. For
UV-excess selected objects, variability performs just as well as the standard
SDSS color selection, identifying quasars with a completeness of 90% and a
purity of 95%. In the redshift range 2.5<z<3, where color selection is known to
be problematic, variability can select quasars with a completeness of 90% and a
purity of 96%. This is a factor of 5-10 times more pure than existing
color-selection of quasars in this redshift range. Selecting objects from a
broad griz color box without u-band information, variability selection in S82
can afford completeness and purity of 92%, despite a factor of 30 more
contaminants than quasars in the color-selected feeder sample. This confirms
that the fraction of quasars hidden in the 'stellar locus' of color-space is
small. To test variability selection in the context of Pan-STARRS 1 (PS1) we
created mock PS1 data by down-sampling the S82 data to just 6 epochs over 3
years. Even with this much sparser time sampling, variability is an
encouragingly efficient classifier. For instance, a 92% pure and 44% complete
quasar candidate sample is attainable from the above -selected catalog.Comment: 16 pages, 9 color figures and 5 tables - v3: Equations corrected and
text updated (see Erratum for details of corrections). Erratum:
http://adsabs.harvard.edu/abs/2010ApJ...721.1941S Original Paper:
http://adsabs.harvard.edu/abs/2010ApJ...714.1194
Taking the steps toward sustainable livestock: our multidisciplinary global farm platform journey
The sympathetic nervous system regulates skeletal muscle motor innervation and acetylcholine receptor stability
Aim: Symptoms of autonomic failure are frequently the presentation of advanced age and neurodegenerative diseases that impair adaptation to common physiologic stressors. The aim of this work was to examine the interaction between the sympathetic and motor nervous system, the involvement of the sympathetic nervous system (SNS) in neuromuscular junction (NMJ) presynaptic motor function, the stability of postsynaptic molecular organization, and the skeletal muscle composition and function. Methods: Since muscle weakness is a symptom of diseases characterized by autonomic dysfunction, we studied the impact of regional sympathetic ablation on muscle motor innervation by using transcriptome analysis, retrograde tracing of the sympathetic outflow to the skeletal muscle, confocal and electron microscopy, NMJ transmission by electrophysiological methods, protein analysis, and state of the art microsurgical techniques, in C57BL6, MuRF1KO and Thy-1 mice. Results: We found that the SNS regulates motor nerve synaptic vesicle release, skeletal muscle transcriptome, muscle force generated by motor nerve activity, axonal neurofilament phosphorylation, myelin thickness, and myofibre subtype composition and CSA. The SNS also modulates the levels of postsynaptic membrane acetylcholine receptor by regulating the Gα i2 -Hdac4-Myogenin-MuRF1pathway, which is prevented by the overexpression of the guanine nucleotide-binding protein Gα i2 (Q205L), a constitutively active mutant G protein subunit. Conclusion: The SNS regulates NMJ transmission, maintains optimal Gα i2 expression, and prevents any increase in Hdac4, myogenin, MuRF1, and miR-206. SNS ablation leads to upregulation of MuRF1, muscle atrophy, and downregulation of postsynaptic AChR. Our findings are relevant to clinical conditions characterized by progressive decline of sympathetic innervation, such as neurodegenerative diseases and aging.Fil: Rodrigues, Anna C. Zaia. Wake Forest School of Medicine; Estados UnidosFil: Messi, Maria Laura. Wake Forest School of Medicine; Estados UnidosFil: Wang, Zhong Min. Wake Forest School of Medicine; Estados UnidosFil: Abba, Martín Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Investigaciones Inmunológicas Básicas y Aplicadas; ArgentinaFil: Pereyra, Andrea Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Wake Forest School of Medicine; Estados UnidosFil: Birbrair, Alexander. Wake Forest School of Medicine; Estados UnidosFil: Zhang, Tan. Wake Forest School of Medicine; Estados UnidosFil: O´Meara, Meaghan. Wake Forest School of Medicine; Estados UnidosFil: Kwan, Ping. Wake Forest School of Medicine; Estados UnidosFil: Lopez, Elsa I. S.. Wake Forest School of Medicine; Estados UnidosFil: Willis, Monte S.. University of North Carolina; Estados UnidosFil: Mintz, Akiva. Wake Forest School of Medicine; Estados UnidosFil: Files, D. Clark. University of North Carolina; Estados UnidosFil: Furdui, Cristina. Wake Forest School of Medicine; Estados UnidosFil: Oppenheim, Ronald W.. Wake Forest School of Medicine; Estados UnidosFil: Delbono, Osvaldo. Wake Forest School of Medicine; Estados Unido
Deciphering the unusual stellar progenitor of GRB 210704A
GRB~210704A is a burst of intermediate duration (~s)
followed by a fading afterglow and an optical excess that peaked about 7 days
after the explosion. Its properties, and in particular those of the excess, do
not easily fit into the well established classification scheme of GRBs as being
long or short, leaving the nature of its progenitor uncertain. We present
multi-wavelength observations of the GRB and its counterpart, observed up to
160 days after the burst. In order to decipher the nature of the progenitor
system, we present a detailed analysis of the GRB high-energy properties
(duration, spectral lag, and Amati correlation), its environment, and late-time
optical excess. We discuss three possible scenarios: a neutron star merger, a
collapsing massive star, and an atypical explosion possibly hosted in a cluster
of galaxies. We find that traditional kilonova and supernova models do not
match well the properties of the optical excess, leaving us with the intriguing
suggestion that this event was an exotic high-energy merger.Comment: Revised version submitted to MNRAS after minor comments, 14 pages, 9
figure
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