597 research outputs found
Decomposing changes in first birth trends : quantum, timing, or variance
In high-income countries, women and men born since the 1940s have delayed the birth of their first child, more of them have remained childless, and the timing of the first birth has become more diverse in these cohorts. The interaction between these three trends makes the research on first birth patterns more complex. This study has two main aims: (1) we introduce an alternative index, Expected Years Without Children (EYWC), to quantify changes in first birth behaviour; and (2) we decompose the changes in EYWC over time into three effects: remaining permanently childless, postponing the first birth, and the expansion of the standard deviation of the mean age at first birth. Using data from the Human Fertility Database, EYWC is calculated to illustrate time trends among women born in the 1910s-1960s in eight countries with longer series of data on cohort first birth trends: Canada, the Czech Republic, Japan, the Netherlands, Norway, Portugal, Sweden, and the United States. Our decomposition shows that the changes in EYWC are mainly attributable to postponement in North America and northern Europe, whereas these changes are largely due to increasing shares of women remaining childless in Japan and Portugal
The Reactome pathway knowledgebase
Reactome (http://www.reactome.org) is a manually curated open-source open-data resource of human pathways and reactions. The current version 46 describes 7088 human proteins (34% of the predicted human proteome), participating in 6744 reactions based on data extracted from 15 107 research publications with PubMed links. The Reactome Web site and analysis tool set have been completely redesigned to increase speed, flexibility and user friendliness. The data model has been extended to support annotation of disease processes due to infectious agents and to mutation
Sistema computarizado para la gestión del agua en sistemas de riego por gravedad en México
[ES] En México los distritos de riego enfrentan diversos problemas, tanto técnicos como de gestión administrativa. En la parte administrativa es preciso automatizar grandes volúmenes de información, de tal manera que ésta sea expedida. En la parte técnica es necesario, entre otros importantes y diversos problemas, mejorar la eficiencia de los distritos, maximizando la producción por unidad de agua utilizada. Una alternativa para apoyarlos en la solución de esta problemática es la incorporación y uso de diversas herramientas tecnológicas, software y hardware, que integradas permitan facilitar la gestión técnica y administrativa de dichos sistemas de riego. Con estos objetivos se creó el SICODE. El SICODE es un sistema de cómputo que integra de manera modular los siguientes programas: base de datos, sistema de información geográfica, simulación de balance de agua en el suelo (pronóstico del riego, apoyado en estaciones meteorológicas automatizadas), simulador biológico y sistema experto. El objetivo de este trabajo es presentar las principales características del SICODE, que actualmente está implementado en el distrito de riego: 010 Culiacán en el estado de Sinaloa, México.Mundo Molina, MD.; Martínez Austria, P. (2002). Sistema computarizado para la gestión del agua en sistemas de riego por gravedad en México. Ingeniería del Agua. 9(2):171-181. https://doi.org/10.4995/ia.2002.2614SWORD17118192ALLEN, R.G., PEREIRA, L.S., RAES, D., and SMITH, M. (1998). Crop evapotranspiration: Guidelines for computing crop requirements. Irrigation and Drainage Paper No. 56, FAO, Rome, Italy 300 p.DASTANE, N.G. (1974). Effective rainfall in irrigated agriculture. FAO. Irrigation and Drainage. 25. Rome.DICARTU. (1995). Sistema de información geográfica, AU2WIN V.3.0. Manual de usuario, Guadalajara, México.IBI. (1990). Information Builders, Inc. Level 5 Objects-Oriented Expert System. U.S.A.IBSNAT (1998). International Benchmark Sites Network for Agrotechnology Transfer. Decision Support System for Agrotechnology Transfer (DSSAT). University of Hawaii. U.S.A.MUNDO MOLINA M. D., HERNÁNDEZ LEONARDO, BOCANEGRA ANTONIO, MARTÍNEZ A. POLIOPTRO. (1995). Capacitación en el uso del sistema computacional para la distribución eficiente del agua en módulos de riego (SICODE), en: Informe interno anual del Instituto Mexicano de Tecnología del Agua (IMTA), pp. 2.MUNDO MOLINA M. D., HERNÁNDEZ LEONARDO, BOCANEGRA ANTONIO, MARTÍNEZ A. POLIOPTRO. (1997 a). Transferencia del SICODE a tres módulos de tres distritos de riego del país, Delicias, Chihuahua, Culiacán, Sinaloa y Navojoa, Sonora. Informe final. IMTA. México.MUNDO MOLINA M. D., MIRELES V. VICTOR., MARTÍNEZ A. POLIOPTRO. (1977 b). Sistema Computacional para la Distribución Eficiente del Agua en distritos de riego, SICODE, v.2.1. Revista de Ingeniería Hidráulica en México, Vol. XII, Núm. 2, II época, mayo-agosto, IMTA, México.MUNDO MOLINA M. D., HERNÁNDEZ LEONARDO, BOCANEGRA A., MARTÍNEZ A. POLIOPTRO. (1998). Transferencia del SICODE a tres distritos de riego del país: 05 Delicias, Chihuahua, 038 Culiacán, Sinaloa y 010 Navojoa, Sonora. Informe final. HC-9813. IMTA. Méxic
Right drug, right patient, right time: aspiration or future promise for biologics in rheumatoid arthritis?
Individualising biologic disease-modifying anti-rheumatic drugs (bDMARDs) to maximise outcomes and deliver safe and cost-effective care is a key goal in the management of rheumatoid arthritis (RA). Investigation to identify predictive tools of bDMARD response is a highly active and prolific area of research. In addition to clinical phenotyping, cellular and molecular characterisation of synovial tissue and blood in patients with RA, using different technologies, can facilitate predictive testing. This narrative review will summarise the literature for the available bDMARD classes and focus on where progress has been made. We will also look ahead and consider the increasing use of ‘omics’ technologies, the potential they hold as well as the challenges, and what is needed in the future to fully realise our ambition of personalised bDMARD treatment
The absence of P2X7 receptors (P2rx7) on non-haematopoietic cells leads to selective alteration in mood-related behaviour with dysregulated gene expression and stress reactivity in mice
The purpose of this study was to explore how genetic deletion
and pharmacological antagonism of the P2X7 receptor (P2rx7)
alter mood-related behaviour, gene expression and stress
reactivity in the brain. The forced swim test (FST), tail
suspension test (TST) and amphetamine-induced hyperlocomotion
(AH) tests were used in wild-type (P2rx7+/+) and P2rx7-deficient
(P2rx7-/-) mice. Biogenic amine levels were analysed in the
amygdala and striatum, adrenocorticotropic hormone (ACTH) and
corticosterone levels were measured in the plasma and pituitary
after restraint stress. Chimeric mice were generated by bone
marrow transplantation. A whole genome microarray analysis with
real-time polymerase chain reaction validation was performed on
the amygdala. In the absence of P2rx7s decreased behavioural
despair in the FST, reduced immobility in the TST and attenuated
amphetamine-induced hyperactivity were detected. Basal
norepinephrine levels were elevated in the amygdala, whereas
stress-induced ACTH and corticosterone responses were alleviated
in P2rx7-/- mice. Sub-acute treatment with the selective P2rx7
antagonist, Brilliant Blue G, reproduced the effect of genetic
deletion in the TST and AH test in P2rx7+/+ but not P2rx7-/-
mice. No change in behavioural phenotype was observed in
chimeras lacking the P2rx7 in their haematopoietic compartment.
Whole genome microarray analysis indicated a widespread up- and
down-regulation of genes crucial for synaptic function and
neuroplasticity by genetic deletion. Here, we present evidence
that the absence of P2rx7s on non-haematopoietic cells leads to
a mood-stabilizing phenotype in several behavioural models and
suggest a therapeutic potential of P2rx7 antagonists for the
treatment of mood disorders
Advances in quantum metrology
The statistical error in any estimation can be reduced by repeating the measurement and averaging the results. The central limit theorem implies that the reduction is proportional to the square root of the number of repetitions. Quantum metrology is the use of quantum techniques such as entanglement to yield higher statistical precision than purely classical approaches. In this Review, we analyse some of the most promising recent developments of this research field and point out some of the new experiments. We then look at one of the major new trends of the field: analyses of the effects of noise and experimental imperfections
Assessment of Copper Total Bioaccumulation and Genotoxicity in Boac River, Marinduque Island, Philippines Two Decades Post-Mining Disaster: Pseudodon sp. as Aquatic Fauna Indicator
In 1996, a mining drainage tunnel burst and released copper wastes into the Boac River—rendering it dead. Two decades after the disaster, the river is now used for aquaculture farming. This study assessed the total bioaccumulation of copper and its genotoxicity in the mussel Pseudodon sp. farmed in the river. A total of 30 Pseudodon sp. were collected randomly from the downstream tributaries of the river in September 2015. Total bioaccumulation in terms of total copper concentrations was determined by atomic absorption spectrometry and the genotoxicity by micronucleus cytome assay. The total copper concentrations were present in the soft tissues (Mean + Standard Error of the Mean [SEM] of 0.0550 + 0.0003 ppm). Genotoxic indicators of nuclear alterations showed the formation of micronuclei yielding the highest frequency (Mean + SEM of 10.257 + 0.793 per 1000 cells). Binucleated, nuclear buds, agranular, apoptotic, and necrotic nuclear anomalies were likewise evident. Total copper concentrations and the frequency of the hemocyte micronuclei occurrences showed a significant relationship (r=0.366; p = 0.047) while the other nuclear abnormalities were not significantly related to the total copper concentrations. Continuous biomonitoring of mining-affected areas is necessary to safeguard people’s health from the effects of mining wastes.
Keywords: bioaccumulation · copper · energy use · genotoxicity · heavy metal · mining · nuclear abnormalitie
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Dynamic Structural Change of Plant Epidermal Cell Walls under Strain
The molecular foundations of epidermal cell wall mechanics are critical for understanding structure-function relationships of primary cell walls in plants and facilitating the design of bioinspired materials. To uncover the molecular mechanisms regulating the high extensibility and strength of the cell wall, the onion epidermal wall is stretched uniaxially to various strains and cell wall structures from mesoscale to atomic scale are characterized. Upon longitudinal stretching to high strain, epidermal walls contract in the transverse direction, resulting in a reduced area. Atomic force microscopy shows that cellulose microfibrils exhibit orientation-dependent rearrangements at high strains: longitudinal microfibrils are straightened out and become highly ordered, while transverse microfibrils curve and kink. Small-angle X-ray scattering detects a 7.4 nm spacing aligned along the stretch direction at high strain, which is attributed to distances between individual cellulose microfibrils. Furthermore, wide-angle X-ray scattering reveals a widening of (004) lattice spacing and contraction of (200) lattice spacing in longitudinally aligned cellulose microfibrils at high strain, which implies longitudinal stretching of the cellulose crystal. These findings provide molecular insights into the ability of the wall to bear additional load after yielding: the aggregation of longitudinal microfibrils impedes sliding and enables further stretching of the cellulose to bear increased loads
Design of understeer characteristics through torque vectoring on a lumped-parameter full vehicle model
Active safety systems play a fundamental role in improving stability and safety performance of modern passenger cars. Within this context, Torque vectoring (TV) represents one of the most promising technologies for the improvement of vehicle dynamics performance. This paper proposes a TV-based Direct Yaw Moment Control (DYC) strategy aimed at designing the vehicle understeering behaviour through a software simulation environment based on an efficient Lumped-Parameter Full Vehicle Model (LPFVM). Simulation results show that the vehicle is able to successfully follow a predetermined understeer characteristic
Concept Modelling of Vehicle Joints and Beam-Like Structures through Dynamic FE-Based Methods
This paper presents dynamic methodologies able to obtain concept models of automotive beams and joints, which compare favourably with the existing literature methods, in terms of accuracy, easiness of implementation, and computational loads. For the concept beams, the proposed method is based on a dynamic finite element (FE) approach, which estimates the stiffness characteristics of equivalent 1D beam elements using the natural frequencies, computed by a modal analysis of the detailed 3D FE model of the structure. Concept beams are then connected to each other by a concept joint, which is obtained through a dynamic reduction technique that makes use of its vibration normal modes. The joint reduction is improved through the application of a new interface beam-to-joint element, able to interpolate accurately the nodal displacements of the outer contour of the section, to obtain displacements and rotations of the central connection node. The proposed approach is validated through an application case that is typical in vehicle body engineering: the analysis of a structure formed by three spot-welded thin-walled beams, connected by a joint
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