444 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
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
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
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
Nanostructuring of Teflon-likes in Single Step Processes
It is a general trend nowadays, and is also an useful approach for many important industrial applications, to tailor polymers to the desired chemistry or nano-morphology. The combination of both, chemistry and morphology, is a surplus value. Particularly if it is possible to tune each feature independently of the other.Nagasaki Symposium on Nano-Dynamics 2008 (NSND2008) 平成20年1月29日(火)於長崎大学 Invited Lectur
Biochemical and structural characterization of a novel arginine kinase from the spider <i>Polybetes pythagoricus</i>
Energy buffering systems are key for homeostasis during variations in energy supply. Spiders are the most important predators for insects and therefore key in terrestrial ecosystems. From biomedical interest, spiders are important for their venoms and as a source of potent allergens, such as arginine kinase (AK, EC 2.7.3.3). AK is an enzyme crucial for energy metabolism, keeping the pool of phosphagens in invertebrates, and also an allergen for humans. In this work, we studied AK from the Argentininan spider Polybetes pythagoricus (PpAK), from its complementary DNA to the crystal structure. The PpAK cDNA from muscle was cloned, and it is comprised of 1068 nucleotides that encode a 384-amino acids protein, similar to other invertebrate AKs. The apparent Michaelis-Menten kinetic constant (Km) was 1.7 mM with a kcat of 75 s-1. Two crystal structures are presented, the apoPvAK and PpAK bound to arginine, both in the open conformation with the active site lid (residues 310-320) completely disordered. The guanidino group binding site in the apo structure appears to be organized to accept the arginine substrate. Finally, these results contribute to knowledge of mechanistic details of the function of arginine kinase.Instituto de Investigaciones Bioquímicas de La Plat
Biochemical and structural characterization of a novel arginine kinase from the spider <i>Polybetes pythagoricus</i>
Energy buffering systems are key for homeostasis during variations in energy supply. Spiders are the most important predators for insects and therefore key in terrestrial ecosystems. From biomedical interest, spiders are important for their venoms and as a source of potent allergens, such as arginine kinase (AK, EC 2.7.3.3). AK is an enzyme crucial for energy metabolism, keeping the pool of phosphagens in invertebrates, and also an allergen for humans. In this work, we studied AK from the Argentininan spider Polybetes pythagoricus (PpAK), from its complementary DNA to the crystal structure. The PpAK cDNA from muscle was cloned, and it is comprised of 1068 nucleotides that encode a 384-amino acids protein, similar to other invertebrate AKs. The apparent Michaelis-Menten kinetic constant (Km) was 1.7 mM with a kcat of 75 s-1. Two crystal structures are presented, the apoPvAK and PpAK bound to arginine, both in the open conformation with the active site lid (residues 310-320) completely disordered. The guanidino group binding site in the apo structure appears to be organized to accept the arginine substrate. Finally, these results contribute to knowledge of mechanistic details of the function of arginine kinase.Instituto de Investigaciones Bioquímicas de La Plat
Prevalence and Predictors of Herbal Medicine Use Among Adults in the United States
Objective: To describe the prevalence of herbal medicine use among US adults and to assess factors associated with and predictors of herbal use. Design: The data for herbal products use were collected from the 2015 National Consumer Survey on the Medication Experience and Pharmacists’ Roles. Chi-square test was used to analyz factors associated with herbal use, and predictors of herbal use were assessed with logistic regression analysis. Results: Factors associated with herbal supplement use include age older than 70, having a higher than high school education, using prescription medications or over-thecounter (OTC) medications, and using a mail-order pharmacy.” All Disease state associated significantly with herbal use. Approximately thirty-eight percent of those who used herbals used prescription medications and 42% of those who used herbals also used an OTC medication. The most frequent conditions associated with herbal supplement use were a stroke (48.7%), cancer (43.1%), and arthritis (43.0%). Among herbal product users, factors that predicted use included having higher than school education, using OTC medications, using mail-order pharmacy, stroke, obesity, arthritis, and breathing problems. Conclusions: More than one-third of respondents reported using herbal supplements. Older age and higher education were associated with a higher use of herbal supplements. People with chronic diseases are more likely to use herbal medicines than others. OTC drug users and patients with stroke are more likely to use herbal medicines than others
Quetiapine augmentation of SRIs in treatment refractory obsessive-compulsive disorder: a double-blind, randomised, placebo-controlled study [ISRCTN83050762]
BACKGROUND: Although serotonin reuptake inhibitors are effective in the treatment of OCD, many patients fail to respond to these agents. Growing evidence from open-label and placebo-controlled trials suggests a role for augmentation of SRIs with atypical antipsychotics in OCD. Quetiapine is generally well tolerated and previous open-label data has produced mixed results in OCD and additional controlled data is needed. METHODS: We undertook a double-blind, randomised, parallel-group, flexible-dose, placebo-controlled study of quetiapine augmentation in subjects who had responded inadequately to open-label treatment with an SRI for 12 weeks. Following informed consent and screening, forty-two subjects were randomised to either placebo or quetiapine for six weeks. RESULTS: There was significant improvement from baseline to endpoint on the Yale-Brown Obsessive-Compulsive Scale in both the quetiapine and placebo groups (quetiapine, n = 20, p < 0.0001; placebo, n = 21, p = 0.001) with 40% (n = 8) of quetiapine and 47.6% (n = 10) of placebo treated subjects being classified as responders. Quetiapine did not demonstrate a significant benefit over placebo at the end of the six-week treatment period (p = .636). Similarly quetiapine failed to separate from placebo in the subgroup of subjects (n = 10) with co-morbid tics. Quetiapine was generally well tolerated. CONCLUSIONS: In this study, quetiapine augmentation was no more effective than placebo augmentation of SRIs. A number of limitations in study design make comparisons with previous studies in this area difficult and probably contributed to our negative findings. Future work in this important clinical area should address these limitations
Reversal of economic fortunes: institutions and the changing ascendancy of Barcelona and Madrid as economic hubs
This paper looks at the divergent economic trajectories of Barcelona and Madrid since Spain's transition to democracy. It highlights how Barcelona, the city that was better positioned four decades ago to emerge as the main Spanish economic hub, has lost out to Madrid. We argue that the contrasting trajectories of the two cities have less to do with the pull of Madrid as the capital of Spain, with the development of new infrastructure in the country, or with agglomeration economies, and more with institutional factors. A growing societal divide in Barcelona along economic, social, and identity lines has led to a greater breakdown of trust and to the development of strong groups with limited capacity to bridge with one another than in Madrid. This has entailed the emergence of negative externalities that have limited the economic potential for growth in Barcelona and facilitated the rise of Madrid as the main economic hub within Spain
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