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A gas–liquid chromatographic micromethod for quantitation of cholesterol in 20 μl of plasma was developed using 5α-cholestane as an internal standard, saponification with tetramethylammonium hydroxide–isopropanol, and extraction with tetrachloroethylene–methyl butyrate. Cholesterol levels in plasma samples were calculated by comparing cholesterol–cholestane peak height ratios with those of preassayed reference plasma. Over a plasma cholesterol range of 44 to 468 mg/100 ml, the gas–liquid chromatographic micromethod and the automated ferric chloride colorimetric method gave nearly identical results (r = 0.99) in duplicate aliquots of 131 plasma samples.

Los estudios petrográficos, macroquímicos y por microsonda de una secuencia de rocas del Volcán El Chichón, Chiapas, México, indican que los materiales “juveniles” de las erupciones de 1982 y las anteriores presentan esencialmente la misma química y la misma mineralogía. Nuestros datos analíticos sugieren que los productos magmáticos han permanecido uniformes en composición química durante los aproximadamente 0.3 m.a. representados por las muestras. Modalmente, la plagioclasa es el fenocristo predominante, seguido por la anfibolita, clinopiroxeno y otras varias fases menores, incluyendo anhidrita. La ausencia de anhidrita de todas menos una de las muestras anteriores a 1982 refleja posiblemente el efecto de la lixiviación post-eruptiva de agua meteorica. Los fenocristos de plagioclasa están complejamente zoneados, con agudos picos en los contenidos de Ca en los limites entre las zonas claras y las zonas ricas en inclusiones de plagioclasa. Estas zonas ricas en anortitas en plagioclasa parecen producirse por fluctuaciones en la presión de los volátiles sobre el magma y podrían reflejar los cambios en la cámara magmática de El Chichón provocados por la actividad eruptiva explosiva, repetitiva. doi: https://doi.org/10.22201/igeof.00167169p.1987.26.1.1190

A simple and rapid method is described for determining the free acetate concentration in liver and serum. After extraction, the acetate is converted to its benzyl ester by thermal degradation of its benzyldimethylphenylammonium salt in the vaporizer of a gas chromatography. Good quantitation is achieved in the range of 0.033-2.5 mumoles of acetate per gram of liver or per milliliter of serum.

Alkylation reactions and their products are considered crucial in various contexts. Synthetically, the alkylation of a nucleophile is usually promoted using hazardous alkyl halides. Here, we aim to highlight the potential of pnictogen (ammonium or phosphonium) and chalcogen salts (sulfonium, selenonium, and telluronium) to function as alkylating agents. These compounds can be considered as non-volatile electrophilic alkyl reservoirs. We will center our discussion on the strategies developed in recent years to expand the synthetic utility of these salts in terms of transferable alkyl groups, substrate scope, and product selectivity., (© 2024 The Chemical Society of Japan and Wiley-VCH GmbH.)

The idea that individuals can create a new beginning, known as the fresh start mindset, is deeply embedded in American culture. This mindset represents an accessible, shared construct that may be particularly relevant for changing attitudes toward two highly stigmatized groups: ex-offenders and drug addicts. While previous advertising literature has suggested that ambiguous or symbolic approaches may help improve consumer response, we show (using four studies) that cultural identity mindset framing (CIMF) can generate more positive affect toward the sponsoring brand and more positive attitudes toward the stigmatized group. Study 1 shows that explicitly referencing a highly stigmatized group leads to a less positive affective response toward the brand. Study 2 reveals that CIMF improves that response. Study 3 uses a real brand to replicate the positive affect toward the sponsoring brand. Study 4 documents a positive attitude shift toward the stigmatized group. Our research opens a new research corridor for explicitly referencing a stigmatized group, expands the stigmatized group discourse to two underrepresented groups, provides empirical evidence for the fresh start message frame, and answers a call to understand whether corporate social responsibility advertising is better than not advertising it at all. [ABSTRACT FROM AUTHOR]

Food-energy-water (FEW) nexus research emphasizes the links among food, energy, and water resource systems and is introduced as an attempt to overcome independent single-sector approaches that dominate the governing of resources today. Focus on multiple sectors and links among them is a key concept to the systems approach and methodology for its implementation by identifying and quantifying the connections between food, energy, and water sectors; modeling the FEW nexus system; and simulation of future management scenarios for decision-making assistance. This paper investigates the FEW nexus methodology within the system context by comparing simulation results obtained by the fully integrated model of global change, named ANEMI, and its modification, ANEMI_FEW, obtained by isolating nexus sectors from the rest of the model. Developing ANEMI_FEW requires breaking multiple feedback relationships that define the dynamic behavior of the modeled systems. A comparison of the simulation results confirms that the nexus model structure generates misleading results due to the break of significant feedbacks between FEW nexus and other sectors of the global change model. Obtained results are strongly suggesting that the nexus approach should be replaced with a more comprehensive structure of the global change model. The global ANEMI model is used as an example to investigate the research question. The findings generated by simulations of ANEMI and ANEMI_FEW are applicable to modeling at any scale (global, regional, or local). [ABSTRACT FROM AUTHOR]

I study how credit and default affect optimal health insurance, constructing a life‐cycle model of health investment with a strategic default option on emergency room bills and financial debts. The model is calibrated to the U.S. economy and used to compare the optimal policy for Medicaid by the availability of the default option and credit. I find that strategic default induces the optimal policy to be more redistributive. With (Without) the option, the optimal income threshold for Medicaid eligibility is 44% (25%) of the average income. In these findings, the interaction between strategic default and preventative medical spending is important. [ABSTRACT FROM AUTHOR]

This article constructs an overlapping generations general equilibrium model to explore the extent to which heterogeneity in time investment shapes intergenerational mobility of lifetime income. The calibrated model successfully accounts for untargeted distributional aspects of income mobility. Counterfactual exercises show that removing heterogeneity in parental time investment reduces intergenerational persistence by around 7–8% for early childhood but only marginally in later childhood. Policy experiments find that an asset‐tested subsidy for parental monetary investments in early childhood can raise intergenerational mobility in a cost‐effective way, though it reduces mobility substantially if given to parents with older school‐aged children. [ABSTRACT FROM AUTHOR]

The problem of techno-economic approaches to evaluating energy transition pathways has been constantly reported in the literature, while existing research recognises the critical role played by social aspects in energy systems models. System dynamics (SD) has been pointed out among modelling techniques as a suitable tool to evaluate the interdisciplinary nature of energy transitions. This paper explores how energy system-related SD models have incorporated social aspects through a literature review. Models were assessed based on their geographical resolution, time horizon, methodological approach, and main themes: supply-demand, energy-economyenvironment (3E), energy-transport, water-energy-food (WEF) nexus, and consumer-centric and socio-political dynamics. Social aspects considered include behaviour and lifestyle changes, social acceptance, willingness to participate, socio-economic measures, among others. As expected, the representation of social aspects was not standard among the papers analysed. Socioeconomic aspects were most commonly included in supply-demand and 3E models. Energytransport and WEF models mainly incorporated changes in travel and consumption habits, respectively. The last theme had a more diverse approach to social aspects that deserves further attention, especially for energy access and justice issues. Other research lines include modelling approaches combination, enhanced participatory and transparent processes during model development, and use of SD models in policy-aiding and stakeholders' information processes. [ABSTRACT FROM AUTHOR]

Humidity is one of the most significant climate factors influencing destination decisions and the distribution pattern of vacationers during various seasons. This variable influences the benefit of day-to-day travel industry activities and keeps up the destination competitiveness. In this paper, the univariate Seasonal Autoregressive Integrated Moving Average (SARIMA) model has been applied to conjecture month-to-month humidity for Bangladesh mainstream tourist spots up to the year 2025. Later, the influence of humidity on tourist arrival that contributes to the national economy was also assessed usi ng the Seasonal Analysis of Covariance (SANCOVA) model. Our findings indicate that the Bangladesh tourism industry is more vulnerable to seasonal variation, and this seasonality has a 72% effect on tourist arrival and a 58% effect on overall humidi ty. The findings suggest that if per unit humidity in seasonality increases, then the tourism indus try income will increase by approximately 59.463 thousand Taka (Bangladesh currency) in every season. [ABSTRACT FROM AUTHOR]

Revolving credit is the prime determinant of short-run household liquidity and comoves positively with product variety and negatively with unemployment. I develop a theory of feedback between revolving credit and product development and examine its ability to explain labor market volatility. Extending the Mortensen–Pissarides model with an endogenous borrowing constraint and free entry of monopolistically competitive firms reproduces stylized facts in the data and amplifies both productivity and financial shocks through mutual causality. Higher debt limits encourage firm entry and raise product variety (the entry channel), and greater variety makes default more costly and thereby raises the equilibrium debt level (the consumption value channel). Though productivity shocks are sufficient to generate higher volatility, financial shocks are essential in approximating the time series patterns of unemployment, vacancies, and revolving credit in the data, and reproduce the rise in unemployment during the Great Recession. [ABSTRACT FROM AUTHOR]

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Empirically, earnings at the start or end of earnings spells are lower and more volatile than in the interior of earnings histories, reflecting mainly the effects of working less than the full year. Ignoring these properties leads to a mismeasurement of the permanent and transitory shock variances and induces the large and widely documented divergence in the estimates of those variances based on fitting the earnings moments in levels or growth rates. Accounting for these effects enables more accurate analysis using quantitative models with permanent and transitory earnings risk and improves empirical estimates of consumption insurance against permanent earnings shocks. [ABSTRACT FROM AUTHOR]

Fatty acids (FAs) are among the most informative parts of nonspecific soil organic matter). Their composition and content reflect the specific features of many soil processes and the structure of the soil microbiome. One of the simplest and fastest methods to analyze FAs is thermochemolysis. Thermochemolysis is widely used to assess the content and composition of soil FAs but has many insufficiently clarified methodological issues. The goal of our work is to study the influence of various conditions of thermochemolysis on the detected FA composition by the case study of typical chernozem. The yield of fatty acid methyl esters (FAMEs) depending on the concentration of the methylating agent tetramethylammonium hydroxide (TMAH) is estimated as well as the pyrolysis temperature and the time of soil exposure to TMAH. It is shown that an excessive amount of the derivatizing agent at high pyrolysis temperature decreases the yield of FAMEs and the relative abundance of monounsaturated FAMEs. The optimal conditions for assaying the FA content are the temperature range of 300–500°C and 15–40 mmol/g C TMAH. It is shown that the time of soil exposure to TMAH before analysis has no effect on the results of thermochemolysis. [ABSTRACT FROM AUTHOR]

The Yangtze River, the largest river in China, has been facing major challenges in massive flooding and eco-environmental health over the past decades. Sustainable socioeconomic development in the Yangtze River Basin depends on water and ecosystem security. This overview addresses eco-water security under the changing environment of the Yangtze River Basin. Looking forward to a healthy Yangtze River in the future, there are still uncertainties regarding how to assess and wisely manage the Yangtze River through a systematic, integrated approach applied to multiple dimensions, water, biodiversity, ecological services, and resilience, for the sustainable development of ecosystems and human beings. The Yangtze Simulator, an integrated river basin model powered by artificial intelligence and interdisciplinary science, is introduced and discussed, and it will serve as a robust tool for good governance of the Yangtze River Basin. [ABSTRACT FROM AUTHOR]

Legumes are rich in secondary metabolites, such as polyphenols, alkaloids, and saponins, which are important defense compounds to protect the plant against herbivores and pathogens, and act as signaling molecules between the plant and its biotic environment. Legume-sourced secondary metabolites are well known for their potential benefits to human health as pharmaceuticals and nutraceuticals. During domestication, the color, smell, and taste of crop plants have been the focus of artificial selection by breeders. Since these agronomic traits are regulated by secondary metabolites, the basis behind the genomic evolution was the selection of the secondary metabolite composition. In this review, we will discuss the classification, occurrence, and health benefits of secondary metabolites in legumes. The differences in their profiles between wild legumes and their cultivated counterparts will be investigated to trace the possible effects of domestication on secondary metabolite compositions, and the advantages and drawbacks of such modifications. The changes in secondary metabolite contents will also be discussed at the genetic level to examine the genes responsible for determining the secondary metabolite composition that might have been lost due to domestication. Understanding these genes would enable breeding programs and metabolic engineering to produce legume varieties with favorable secondary metabolite profiles for facilitating adaptations to a changing climate, promoting beneficial interactions with biotic factors, and enhancing health-beneficial secondary metabolite contents for human consumption. [ABSTRACT FROM AUTHOR]

We document that the credit spread on consumer unsecured debt exhibits a persistent, hump-shaped response to an increase in the charge-off rate. This stylized fact poses a significant challenge for a standard model of consumer default in which lenders have rational expectations and, therefore, the credit spread continuously adjusts to reflect the true default incentives of each borrower. In an effort to explain this feature of the data, we construct a model of consumer default with countercyclical income risk in which lenders learn about default risk over time by observing the history of repayment decisions, as is the case in practice. In addition to matching credit spread dynamics, allowing lenders to learn about default risk substantially improves the model's ability to generate realistic business cycle fluctuations in the consumer unsecured credit market and match the cross-sectional distribution of unsecured debt and dispersion of interest rates observed in the data. [ABSTRACT FROM AUTHOR]