326 research outputs found
Comparación de las propiedades fÃsicas y mecánicas del ladrillo King Kong 18 huecos industrial y artesanal, Carabayllo – 2021
El objetivo general de la presente investigación es comparar las propiedades del
ladrillo artesanal Roy y ladrillo industrial Pirámide elaborado en Carabayllo, llevando
estas unidades al Laboratorio JJ GEOTECNIA S.A.C para poder determinar sus
propiedades, se realizó esta comparación mediante ensayos en sus propiedades
fÃsicas y mecánicas. La variable independiente evaluada fueron los ladrillos
industriales y artesanales King Kong 18 huecos teniendo como diseño de
investigación no experimental y el tipo de investigación aplicada. La población de
la presente investigación fueron las unidades de ladrillo artesanal Roy y ladrillo
industrial Pirámide, contando con una muestra de 50 ladrillos Pirámide y 50 ladrillos
Roy. Utilizando, asà como instrumentos los parámetros establecidos según el
laboratorio, mediante el cual se pudo realizar cada uno de los ensayos.
Concluyendo asà que en los ensayos realizados a las unidades de ladrillo Roy
Pirámide. En los ensayos de las propiedades fÃsicas clasificaron como tipo V según
la Norma E.070 y tipo 21 según la NTP 331.017, pero en los ensayos de resistencia
a la compresión por unidad es igual a 92 kg/cm2 clasificando como Tipo II según la
Norma E.070 y tipo 10 según la NTP 331.017
KINEMATIC ANALYSIS OF A ROUNDHOUSE KICK ACCORDING TO THE STANCE POSITION
The stance position has been pointed out as an important factor that can potentially affect the kick performance, so the stance position can be seen as a constraint for the execution. The aim of this study was to compare kinematic variables in some main instants during the roundhouse kick in taekwondo according to three stance positions (0º, 45º, 90º). Nine experienced athletes participated in the study. Kinematic analysis was measured by two 3D force plates and an eight-camera motion capture system. Data analyses were processed using Visual 3D software. Signifficant differences in kinematic data were found at the beggining of the kick; these differences disappear at the end of the kick. Athletes are able to adapt their technique even if the stance position is different
Can we have it all? The role of grassland conservation in supporting forage production and plant diversity
Context
A key global challenge is to meet both the growing demand for food and feed while maintaining biodiversity’s supporting functions. Protected grasslands, such as Natura 2000 sites in Europe, may play an important role in harmonising productivity and biodiversity goals. This work contributes to an understanding of the relationship between forage production and plant diversity in protected and non-protected grasslands.
Objectives
We aimed to identify differences in plant diversity and forage production between protected and non-protected grasslands by assessing the effects of land-use intensity (i.e. mowing, grazing, fertilising) on these variables.
Methods
Data were available for 95 managed grassland plots (50 × 50 m) in real-managed landscapes. After controlling for site conditions in the analysis, we tested for significant differences between protected and non-protected grasslands and used a multi-group structural equation modelling (SEM) framework to investigate the linkages between land-use intensity, biomass and plant diversity.
Results
In protected grasslands, plant diversity was significantly higher while forage production was significantly lower. In non-protected grasslands we found significantly higher land-use intensity, particularly in relation to mowing and fertilisation. Grazing intensity did not significantly differ between protected and non-protected grasslands. In non-protected grasslands we found a significant negative association between forage production and plant diversity. However, this effect was not significant in protected grasslands. We also found a negative association between land-use and plant diversity in both grassland types that was related to mowing and fertilising intensity. These two management aspects also influenced the positive association between land-use intensity and forage production. Furthermore, environmental conditions had a positive effect on forage production and a negative effect on plant diversity in protected grasslands.
Conclusions
Our results confirm that the protection of grassland sites is successful in achieving higher plant diversity compared to non-protected grasslands and that protected grasslands do not necessarily trade-off with forage production. This is possible under moderate grazing intensities as higher land-use intensity has a negative effect on plant diversity, particularly on rare species. However, forage production is lower in protected sites as it is driven by mowing and fertilisation intensity. Future research needs to further investigate if the nature of these relationships depends on the livestock type or other management practices
A Direct Comparison between the use of Double Gray and Multiwavelength Radiative Transfer in a General Circulation Model with and without Radiatively Active Clouds
Inhomogeneous cloud formation and wavelength-dependent phenomena are expected
to shape hot Jupiter atmospheres. We present a General Circulation Model (GCM)
with multiwavelength "picket fence" radiative transfer and radiatively active,
temperature dependent clouds, and compare the results to a double gray routine.
The double gray method inherently fails to model polychromatic effects in hot
Jupiter atmospheres, while picket fence captures these non-gray aspects and
performs well compared to fully wavelength-dependent methods. We compare both
methods with radiatively active clouds and cloud-free models, assessing the
limitations of the double gray method. Although there are broad similarities,
the picket fence models have larger day-night side temperature differences,
non-isothermal upper atmospheres, and multiwavelength effects in the presence
of radiatively active clouds. We model the well-known hot Jupiters HD 189733 b
and HD 209458 b. For the hotter HD 209458 b, the picket fence method prevents
clouds from thermostating dayside temperatures, resulting in hotter upper
atmospheres and the dissipation of dayside clouds. Differences in the
temperature structures are then associated with nuanced differences in the
circulation patterns and clouds. Models of the cooler HD 189733 b have global
cloud coverage, regardless of radiative transfer scheme, whereas there are
larger differences in the models of HD 209458 b, particularly in the extent of
the partial cloud coverage on its dayside. This results in minor changes to the
thermal and reflected light phase curves of HD 189733 b, but more significant
differences for the picket fence and double gray versions of HD 209458 b.Comment: Submitted to ApJ, 31 page
A Lack of Variability Between Repeated Spitzer Phase Curves of WASP-43b
Though the global atmospheres of hot Jupiters have been extensively studied
using phase curve observations, the level of time variability in these data is
not well constrained. To investigate possible time variability in a planetary
phase curve, we observed two full-orbit phase curves of the hot Jupiter
WASP-43b at 4.5 microns using the Spitzer Space Telescope, and reanalyzed a
previous 4.5 micron phase curve from Stevenson et al. (2017). We find no
significant time variability between these three phase curves, which span
timescales of weeks to years. The three observations are best fit by a single
phase curve with an eclipse depth of 3907 +- 85 ppm, a dayside-integrated
brightness temperature of 1479 +- 13 K, a nightside-integrated brightness
temperature of 755 +- 46 K, and an eastward-shifted peak of 10.4 +- 1.8
degrees. To model our observations, we performed 3D general circulation model
simulations of WASP-43b with simple cloud models of various vertical extents.
In comparing these simulations to our observations, we find that WASP-43b
likely has a cloudy nightside that transitions to a relatively cloud-free
dayside. We estimate that any change in WASP-43bs vertical cloud thickness of
more than three pressure scale heights is inconsistent with our observed upper
limit on variation. These observations, therefore, indicate that WASP-43bs
clouds are stable in their vertical and spatial extent over timescales up to
several years. These results strongly suggest that atmospheric properties
derived from previous, single Spitzer phase curve observations of hot Jupiters
likely show us the equilibrium properties of these atmospheres.Comment: 24 pages, 9 figures, Published in the Astronomical Journal (AJ
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TYK2 Protein-Coding Variants Protect against Rheumatoid Arthritis and Autoimmunity, with No Evidence of Major Pleiotropic Effects on Non-Autoimmune Complex Traits
Despite the success of genome-wide association studies (GWAS) in detecting a large number of loci for complex phenotypes such as rheumatoid arthritis (RA) susceptibility, the lack of information on the causal genes leaves important challenges to interpret GWAS results in the context of the disease biology. Here, we genetically fine-map the RA risk locus at 19p13 to define causal variants, and explore the pleiotropic effects of these same variants in other complex traits. First, we combined Immunochip dense genotyping (n = 23,092 case/control samples), Exomechip genotyping (n = 18,409 case/control samples) and targeted exon-sequencing (n = 2,236 case/controls samples) to demonstrate that three protein-coding variants in TYK2 (tyrosine kinase 2) independently protect against RA: P1104A (rs34536443, OR = 0.66, P = 2.3x10-21), A928V (rs35018800, OR = 0.53, P = 1.2x10-9), and I684S (rs12720356, OR = 0.86, P = 4.6x10-7). Second, we show that the same three TYK2 variants protect against systemic lupus erythematosus (SLE, Pomnibus = 6x10-18), and provide suggestive evidence that two of the TYK2 variants (P1104A and A928V) may also protect against inflammatory bowel disease (IBD; Pomnibus = 0.005). Finally, in a phenomewide association study (PheWAS) assessing >500 phenotypes using electronic medical records (EMR) in >29,000 subjects, we found no convincing evidence for association of P1104A and A928V with complex phenotypes other than autoimmune diseases such as RA, SLE and IBD. Together, our results demonstrate the role of TYK2 in the pathogenesis of RA, SLE and IBD, and provide supporting evidence for TYK2 as a promising drug target for the treatment of autoimmune diseases
Proline-specific aminopeptidase P prevents replication-associated genome instability
Genotoxic stress during DNA replication constitutes a serious threat to genome integrity and causes human diseases. Defects at different steps of DNA metabolism are known to induce replication stress, but the contribution of other aspects of cellular metabolism is less understood. We show that aminopeptidase P (APP1), a metalloprotease involved in the catabolism of peptides containing proline residues near their N-terminus, prevents replication-associated genome instability. Functional analysis of C. elegans mutants lacking APP-1 demonstrates that germ cells display replication defects including reduced proliferation, cell cycle arrest, and accumulation of mitotic DSBs. Despite these defects, app-1 mutants are competent in repairing DSBs induced by gamma irradiation, as well as SPO-11-dependent DSBs that initiate meiotic recombination. Moreover, in the absence of SPO-11, spontaneous DSBs arising in app-1 mutants are repaired as inter-homologue crossover events during meiosis, confirming that APP-1 is not required for homologous recombination. Thus, APP-1 prevents replication stress without having an apparent role in DSB repair. Depletion of APP1 (XPNPEP1) also causes DSB accumulation in mitotically-proliferating human cells, suggesting that APP1’s role in genome stability is evolutionarily conserved. Our findings uncover an unexpected role for APP1 in genome stability, suggesting functional connections between aminopeptidase-mediated protein catabolism and DNA replication
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Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72613/1/j.1467-6435.1957.tb00243.x.pd
CAMEMBERT: A Mini-Neptunes GCM Intercomparison, Protocol Version 1.0. A CUISINES Model Intercomparison Project
With an increased focus on the observing and modelling of mini-Neptunes,
there comes a need to better understand the tools we use to model their
atmospheres. In this paper, we present the protocol for the CAMEMBERT
(Comparing Atmospheric Models of Extrasolar Mini-neptunes Building and
Envisioning Retrievals and Transits) project, an intercomparison of general
circulation models (GCMs) used by the exoplanetary science community to
simulate the atmospheres of mini-Neptunes. We focus on two targets well studied
both observationally and theoretically with planned JWST Cycle 1 observations:
the warm GJ~1214b and the cooler K2-18b. For each target, we consider a
temperature-forced case, a clear sky dual-grey radiative transfer case, and a
clear sky multi band radiative transfer case, covering a range of complexities
and configurations where we know differences exist between GCMs in the
literature. This paper presents all the details necessary to participate in the
intercomparison, with the intention of presenting the results in future papers.
Currently, there are eight GCMs participating (ExoCAM, Exo-FMS, FMS PCM,
Generic PCM, MITgcm, RM-GCM, THOR, and the UM), and membership in the project
remains open. Those interested in participating are invited to contact the
authors.Comment: Accepted to PS
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