2,429 research outputs found
Sensory Perception
Different types of sensory systems with their functional modalities will be presented. The biological bases for how these functions are generated and modified will then be described. As vision is the principal means of perception, we will focus in this course most on visual processing. Scientific data will be integrated into the lectures, such that students develop critical skills in analyzing data and proposing hypotheses
Parámetros de resistencia mecánica de muros de tapial con un % en volumen de adición de tallos de cebada, Yauli - Huancavelica, 2021.
El siguiente estudio investigativo que lleva por título: Parámetros de resistencia mecánica de
muros de tapial con un % en volumen de adición de tallos de cebada, Yauli-Huancavelica, 2021.
Tuvo como finalidad fundamtenal, la determinación del incremento de los parámetros de
resistencia mecánica del muro de tapial con un % en volumen de adición de tallos de cebada,
Yauli-Huancavelica, 2021, de la misma manera se determinó la resistencia de tapial a compresión,
tracción indirecta y flexión con una muestra patrón de 0% de adición de tallos de cebada y muestras
con adición de tallos de cebada en 10%,15% y 20%.
De acuerdo a este planteamiento, el presente proyecto investigativo es de tipo aplicado, de nivel
explicativo, con método científico y diseño experimental por lo que se manipuló los % en volumen
de adición de tallos de cebada para medir el parámetro de resistencia mecánica de los muros de
tapial, la técnica que se utilizó fue la observación directa y el instrumento la ficha de observación,
la población de esta investigación está constituida por 72 especímenes y la muestra está por 48.
Finalmente se concluyó que los parámetros de resistencia mecánica de muros de tapial al adicionar
un porcentaje de volumen de tallo de cebada incrementan de manera creciente y favorable,
obteniéndose un resultado óptimo con 15% en volumen de adición de tallo de cebada. Sin embargo,
para los valores como el 20% de adición de tallos de cebada la resistencia disminuye en relación
al tapial con 15% de adición
La disciplina financiera en el contexto de la actividad empresarial y el sistema económico
"El presente trabajo analiza detalladamente el concepto de finanzas, estudia su
desarrollo dentro de la sociedad, examinada en relación con la economía y la
contabilidad, cierta relación enfocada dentro de dos campos específicos, el ámbito
de la empresa y el sistema económico. Las finanzas nacionales se comparan con las internacionales, con la intención de encontrar diferencias o semejanzas. Por último se relaciona a las finanzas con dos campos de estudio distintos, la economía y la contabilidad, se enfatizan los conocimientos contables y económicos requeridos, encontrándolos necesarios
para un claro objeto de estudio.
The first record of the genus Plega Navás, 1928 (Neuroptera: Rhachiberothidae: Symphrasinae) as a parasitoid of the sawfly genus Monoctenus Dahlbom, 1835 (Hymenoptera: Symphyta: Diprionidae)
The genus Plega Navás, 1928, belongs to the subfamily Symphrasinae, a group recently transferred from Mantispidae to Rhachiberothidae. This genus is herein reported as parasitoid of the symphytan family Diprionidae for the first time, becoming the first record of association between this neuropteran subfamily and non-aculeate Hymenoptera. This new association was discovered in “Ixcateopan de Cuauhtémoc”, in the Mexican state of Guerrero, where Plega spinosa Ardila et al., 2019 was found associated with immatures of the sawfly Monoctenus cuauhtemoci De Lira, 2021, a pest in forests of Juniperus flaccida Schlechtendal (white cedar). The neuropteran was found to be the most abundant parasitoid of this symphytan, becoming a potential candidate for biological control of phytophagous sawflies in juniper forests, an economically important plant species for the wood industry in the region. Considering the behavior and morphological aspects of the primary larvae and the behavior of the adults of Plega, three possible scenarios in which the primary larvae of P. spinosa board the larvae of Monoctenus to complete its life cycle are outlined. This finding reinforces the hypothesis of a generalist ectoparasitoid lifeway of the larvae of the genus Plega on larvae and pupae of holometabolous insects
Desarrollo e implementación de una fresadora y grabadora láser CNC para incrementar la versatilidad en la fabricación de piezas artesanales en acrílico y MDF
En la presente investigación se desarrolla y se implementa una maquina fresadora y
grabadora laser CNC (cabezales intercambiables), teniendo como objetivo general
desarrollar e implementar una Fresadora y Grabadora láser CNC para incrementar la
versatilidad en la fabricación de piezas artesanales en acrílico y MDF. Basados en teorías
y algoritmos de fresadoras los que nos permitieron calcular los parámetros principales de
la maquina (fuerza de corte, potencia de corte, torque del tornillo de potencia, velocidad
del husillo, etc.) desarrollamos una investigación de tipo aplicada con un alcance
descriptivo con datos cuantitativos con diseño pre experimental, se toma como población
y muestra la Fresadora y Grabadora Laser, para lo cual se realiza una guía de entrevista
para la recolección de necesidades y requerimientos técnicos de los artesanos de Trujillo,
para evaluar si la maquina incrementa la versatilidad en la fabricación de piezas
artesanales en acrílico y MDF, se realizó una guía de observación la cual se desarrolló
con presencia de los artesanos seleccionados aleatoriamente. Obteniendo una maquina
fabricada de perfil estructural de aluminio, con un sistema sensorico y control electrónico
compuesto por un arduino MEGA 2560 R3, firmware marlín y sensores finales de carrera
mecánicos, teniendo componentes mecánicos y electrónicos tales como, motores nema
17, un dremel que es la herramienta de fresar, y un láser de 2500 mw de potencia, el cual
nos permite grabar. Se logró incrementar la versatilidad en la fabricación de piezas
artesanales el principal objetivo de esta investigación, la cual se evaluó mediante una guía
de observación
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A single H/ACA small nucleolar RNA mediates tumor suppression downstream of oncogenic RAS.
Small nucleolar RNAs (snoRNAs) are a diverse group of non-coding RNAs that direct chemical modifications at specific residues on other RNA molecules, primarily on ribosomal RNA (rRNA). SnoRNAs are altered in several cancers; however, their role in cell homeostasis as well as in cellular transformation remains poorly explored. Here, we show that specific subsets of snoRNAs are differentially regulated during the earliest cellular response to oncogenic RASG12V expression. We describe a novel function for one H/ACA snoRNA, SNORA24, which guides two pseudouridine modifications within the small ribosomal subunit, in RAS-induced senescence in vivo. We find that in mouse models, loss of Snora24 cooperates with RASG12V to promote the development of liver cancer that closely resembles human steatohepatitic hepatocellular carcinoma (HCC). From a clinical perspective, we further show that human HCCs with low SNORA24 expression display increased lipid content and are associated with poor patient survival. We next asked whether ribosomes lacking SNORA24-guided pseudouridine modifications on 18S rRNA have alterations in their biophysical properties. Single-molecule Fluorescence Resonance Energy Transfer (FRET) analyses revealed that these ribosomes exhibit perturbations in aminoacyl-transfer RNA (aa-tRNA) selection and altered pre-translocation ribosome complex dynamics. Furthermore, we find that HCC cells lacking SNORA24-guided pseudouridine modifications have increased translational miscoding and stop codon readthrough frequencies. These findings highlight a role for specific snoRNAs in safeguarding against oncogenic insult and demonstrate a functional link between H/ACA snoRNAs regulated by RAS and the biophysical properties of ribosomes in cancer
Taxonomy, phylogeny, and biodiversity of Lumbrineridae (Annelida, Polychaeta) from the Central Pacific Clarion-Clipperton Zone
The DNA taxonomy of six species of the annelid family Lumbrineridae collected from the Clarion-Clipperton Zone (CCZ) in the Central Pacific, an area of potential mining interest for polymetallic nodules, is presented. Lumbrinerids are an ecologically important and understudied annelid family within the deep sea, with many species still undescribed. This study aims to document the taxonomy and biodiversity of the CCZ using specimens collected from the UK-1, OMS, and NORI-D exploration contract areas and Areas of Particular Environmental Interest. Species were identified through a combination of morphological and molecular phylogenetic analysis. We present informal species descriptions associated with voucher specimens, accessible through the Natural History Museum (London) collections, to improve future taxonomic and biodiversity studies of this region. Five taxa in this study had no morphological or genetic matches within the literature and therefore are possibly new to science, but their suboptimal morphological preservation prevented the formalisation of new species. The most abundant taxon Lumbrinerides cf. laubieri (NHM_0020) was compared with the holotype of Lumbrinerides laubieri Miura, 1980 from the deep Northeast Atlantic. Currently no reliable morphological characters separating the Pacific and Atlantic specimens have been found and molecular data from the Atlantic specimens was not available.publishedVersio
Embedding Order Inducible Between Hyperspace
Given a set X and denote by C(X) hyperspace all non-empty subcontinuos. For two continuos X and Y and the function...
Magnetic fields in M dwarfs from the CARMENES survey
M dwarfs are known to generate the strongest magnetic fields among
main-sequence stars with convective envelopes, but the link between the
magnetic fields and underlying dynamo mechanisms, rotation, and activity still
lacks a consistent picture. In this work we measure magnetic fields from the
high-resolution near-infrared spectra taken with the CARMENES radial-velocity
planet survey in a sample of 29 active M dwarfs and compare our results against
stellar parameters. We use the state-of-the-art radiative transfer code to
measure total magnetic flux densities from the Zeeman broadening of spectral
lines and filling factors. We detect strong kG magnetic fields in all our
targets. In 16 stars the magnetic fields were measured for the first time. Our
measurements are consistent with the magnetic field saturation in stars with
rotation periods P<4d. The analysis of the magnetic filling factors reveal two
different patterns of either very smooth distribution or a more patchy one,
which can be connected to the dynamo state of the stars and/or stellar mass.
Our measurements extend the list of M dwarfs with strong surface magnetic
fields. They also allow us to better constrain the interplay between the
magnetic energy, stellar rotation, and underlying dynamo action. The high
spectral resolution and observations at near-infrared wavelengths are the
beneficial capabilities of the CARMENES instrument that allow us to address
important questions about the stellar magnetism.Comment: 13 pages of main text, 14 pages of online material, 2 table
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