Comparative Study of Vibration Response in Steel and Braided-Carbon-Fiber Bicycle Handlebars: A Numerical-Experimental Approach with Various Sensors

\ua9 2024 by the authors. The comfort and safety of a cyclist are directly influenced by the vibrational behavior of the handlebar. Hence, the objective of this article is to comparatively assess the vibrational characteristics of two bicycle handlebars: one made of steel and the other made of braided composite material. The transmissibility function represents the relationship between the excitation applied to both handlebars through their stems and the corresponding response in the handle area, which was experimentally obtained by applying a random vibrating signal (constant amplitude of 0.01 g2/Hz) using a shaker. This signal was applied in a frequency range between 100 Hz and 1200 Hz, and the response was measured at one of the two cantilevered ends of the handlebar. Different sensors, including a laser vibrometer and a control accelerometer in the shaker, were utilized. The transmissibility, natural frequencies and damping functions were obtained. Subsequently, another experimental analysis was carried out with the instrumented handlebars mounted on a bicycle, placing three accelerometers and a GPS meter and traveling through a real test circuit, with a rough surface, speed bumps and areas with shaped warning bands. Power Spectral Density (PSD) curves were obtained for the steel and carbon-fiber-composite handlebars in order to quantify the signal intensity. Finally, a fatigue analysis was carried out in order to evaluate the expected life of both handlebars under the experimentally applied load, which is considered the reference cycle. This study offers a comparative analysis of the vibration behavior exhibited by steel and carbon-fiber-composite bicycle handlebars under experimentally applied load. In conclusion, data on natural frequencies, damping functions and fatigue life expectancy for both handlebar materials were obtained. Our study provides valuable insights into the vibrational behavior and performance characteristics of steel and carbon-fiber-composite bicycle handlebars, contributing to the understanding of their comfort and safety implications for cyclists

Exploring reported genes of microglia RNA-sequencing data:Uses and considerations

The advent of RNA-sequencing techniques has made it possible to generate large, unbiased gene expression datasets of tissues and cell types. Several studies describing gene expression data of microglia from Alzheimer's disease or multiple sclerosis have been published, aiming to generate more insight into the role of microglia in these neurological diseases. Though the raw sequencing data are often deposited in open access databases, the most accessible source of data for scientists is what is reported in published manuscripts. We observed a relatively limited overlap in reported differentially expressed genes between various microglia RNA-sequencing studies from multiple sclerosis or Alzheimer's diseases. It was clear that differences in experimental set up influenced the number of overlapping reported genes. However, even when the experimental set up was very similar, we observed that overlap in reported genes could be low. We identified that papers reporting large numbers of differentially expressed microglial genes generally showed higher overlap with other papers. In addition, though the pathology present within the tissue used for sequencing can greatly influence microglia gene expression, often the pathology present in samples used for sequencing was underreported, leaving it difficult to assess the data. Whereas reanalyzing every raw dataset could reduce the variation that contributes to the observed limited overlap in reported genes, this is not feasible for labs without (access to) bioinformatic expertise. In this study, we thus provide an overview of data present in manuscripts and their supplementary files and how these data can be interpreted

Mind the chasm: A UK fisheye lens view of sustainable software engineering

Requirements that express the needs of all stakeholders and cover the key aspects of a software system (such as those addressing sustainability) are critical to the system’s successful development and adoption. For practitioners who want to develop sustainable software-intensive systems, it is also argued that software requirements are the key leverage point. But what do software developers know about broader sustainability and sustainability requirements in particular? As part of the University of Huddersfield’s ’Student as a Researcher’ initiative, this paper provides a FishEye Lens View on how novice software developers who design and develop software systems at software companies relate to the notions of sustainability and sustainability requirements. The study has found that although sustainability is valued highly by the novice software developers, the concept of sustainability and sustainability requirements are not fully understood. This lack of knowledge in the software industry and organizations must be addressed to enable delivery of truly sustainability enabling software systems

Maximising embryo production in endangered sheep breeds: in vitro procedures that complement in vivo techniques

This study investigated the use of previously superovulated ovaries as a source of oocytes, assessing the competence of them for in vitro embryo production. Two superovulatory treatments were performed: equine Chorionic Gonadotrophin (eCG) plus porcine Follicle-Stimulating Hormone (pFSH) in a single dose or the conventional protocol of six decreasing doses of pFSH. Thirty donor ewes of the endangered Ojalada breed were given either the simplified (group S; n=15) or the decreasing-dose (group D; n=15) treatments three times at intervals of ≥50 days. Ovaries were recovered on day 7 after the oestrus following the third treatment, just after embryo flushing, and the oocytes were collected to assess in vitro maturation, fertilisation and development to the blastocyst stage. The two superovulatory treatments did not differ in the mean number of oocytes selected for maturation (7.1±1.2 and 8.5±1.5 per ewe in the D and S groups, respectively). The oocytes recovered from ewes in Group D (87.5%) had a significantly (p<0.05) higher maturation rate than did those recovered from ewes in group S (75%), but no differences were found in fertilisation rate (94% and 94.6% in the D and S groups, respectively); both groups did not differ in their blastocyst rates and the total number of cells in in vitro-produced blastocysts. In the two experimental groups, 1.7 (D) and 1.8 (S) in vitro-produced blastocysts were generated per ewe, which indicate that it is feasible to combine in vivo and in vitro techniques to maximise embryo production in endangered sheep breeds.EEA ChubutFil: Forcada, Fernando. Universidad de Zaragoza. Instituto de Investigación de Ciencias Ambientales de Aragón. Grupo de Biología y Fisiología de la Reproducción; EspañaFil: Buffoni, Andres. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Chubut; ArgentinaFil: Abecia, José Alfonso. Universidad de Zaragoza. Instituto de Investigación de Ciencias Ambientales de Aragón. Grupo de Biología y Fisiología de la Reproducción; EspañaFil: Asenjo, B. Universidad de Valladolid. Escuela Universitaria de Ingenierías Agrarias de Soria; EspañaFil: Palacin, José Ignacio. Universidad de Zaragoza. Instituto de Investigación de Ciencias Ambientales de Aragón. Grupo de Biología y Fisiología de la Reproducción; EspañaFil: Vázquez, M.I. Universidad de Zaragoza. Instituto de Investigación de Ciencias Ambientales de Aragón. Grupo de Biología y Fisiología de la Reproducción; EspañaFil: Rodriguez Castillo, José del Carmen. Benemérita Universidad Autónoma de Puebla. Facultad de Medicina Veterinaria y Zootecnia; MéxicoFil: Sanchez Prieto, L. Universidad de Zaragoza. Instituto de Investigación de Ciencias Ambientales de Aragón. Grupo de Biología y Fisiología de la Reproducción; EspañaFil: Casao, A. Universidad de Zaragoza. Instituto de Investigación de Ciencias Ambientales de Aragón. Grupo de Biología y Fisiología de la Reproducción; Españ

TWO-SCALE MODELLING OF THE CONCENTRATION POLARIZATION IN A REVERSE OSMOSIS MEMBRANE

Abstract In the design and control of reverse osmosis desalination plants, the clean water flux, which passes through the membranes, is the most important variable. Flux depends on several parameters, such as the membrane permeability or the temperature, but mainly on the salt concentration on the membrane surface. The salt concentration is easily measured in the bulk of the feed, but not on the membrane surface, where it should be estimated. The concentration polarization creates an unwanted increase of the salt concentration between the bulk side and the membrane surface. The polarization effect is due to the convective transport of salt molecules by the water flow to the boundary layer of the membrane, and their subsequent blockage by the membrane itself. A correct estimation of the concentration polarization is fundamental to predict the clean water flux, and finally, to be able to carry out a good design and control of the desalination plant. Several models have been proposed in the literature to calculate the concentration polarization (or the salt concentration on the membrane surface). This paper presents a new model, which aims to solve some of the disadvantages of the previous models

A dual role for A-type lamins in DNA double-strand break repair

A-type lamins are emerging as regulators of nuclear organization and function. Changes in their expression are associated with cancer and mutations are linked to degenerative diseases—laminopathies. Although a correlation exists between alterations in lamins and genomic instability, the molecular mechanisms remain largely unknown. We previously found that loss of A-type lamins leads to degradation of 53BP1 protein and defective long-range non-homologous end-joining (NHEJ) of dysfunctional telomeres. Here, we determined how loss of A-type lamins affects the repair of short-range DNA double-strand breaks (DSBs) induced by ionizing radiation (IR). We find that lamins deficiency allows activation of the DNA damage response, but compromises the accumulation of 53BP1 at IR-induced foci (IRIF), hindering the fast phase of repair corresponding to classical-NHEJ. Importantly, reconstitution of 53BP1 is sufficient to rescue long-range and short-range NHEJ. Moreover, we demonstrate an unprecedented role for A-type lamins in the maintenance of homologous recombination (HR). Depletion of lamins compromises HR by a mechanism involving transcriptional downregulation of BRCA1 and RAD51 by the repressor complex formed by the Rb family member p130 and E2F4. In line with the DNA repair defects, lamins-deficient cells exhibit increased radiosensitivity. This study demonstrates that A-type lamins promote genomic stability by maintaining the levels of proteins with key roles in DNA DSBs repair by NHEJ and HR. Our results suggest that silencing of A-type lamins by DNA methylation in some cancers could contribute to the genomic instability that drives malignancy. In addition, lamins-deficient tumor cells could represent a good target for radiation therapy

Primera aproximación a las moscas blancas (Hemiptera: Aleyrodidae) sus plantas hospedantes y parasitoides asociados en Huánuco, Perú

Whiteflies are considered insects of great economic importance, because they cause direct and indirect damage that reduce the yields of various crops in some cases by 100%. Collections were made in the Huánuco valley (2013-2016), taking the leaves of various plants containing immature stages of the IV instar of whitefly, which were processed using the technique of Martin (1987) modified by Caballero (1996). For identification, the keys of Hodges and Evans (2005), Valencia (2000), Dooley (2006) and Nakahara (2002) were used; and for the identification of parasitoids, codes from Evans (2008) and Valencia (2000) were used. 10 species of whitefly distributed in the Huánuco valley were identified. The recovered parasitoids were Amitus sp., Encarsia sp., E. formosa and Cales sp. 30 host plants were recorded in 21 botanical families. Whitefly species, host plants, and associated parasitoids are recorded for the first time for Huánuco. Keywords: Aleyrodidae, whitefly, host plants, parasitoids, HuánucoLas moscas blancas son consideradas insectos de gran importancia económica, debido a que causan daños directos e indirectos que reducen los rendimientos de los diversos cultivos en algunos casos en un 100%. Se realizaron colectas en el valle de Huánuco (2013-2016), tomando las hojas de diversas plantas conteniendo estados inmaduros del IV instar de mosca blanca, los cuales fueron procesados mediante la técnica de Martin (1987) modificado por Caballero (1996). Para la identificación se emplearon las claves de Hodges y Evans (2005), Valencia (2000), Dooley (2006) y Nakahara (2002); y para la identificación de parasitoides se emplearon claves de Evans (2008) y Valencia (2000). Se identificaron 10 especies de mosca blanca distribuidos en el valle de Huánuco. Los parasitoides recuperados fueron Amitus sp., Encarsia sp., E. formosa y Cales sp. Se registraron 30 plantas hospedantes en 21 familias botánicas. Las especies de mosca blanca, las plantas hospedantes y los parasitoides asociados se registran por primera vez para Huánuco