El esperado regreso de Perséfone, una nueva primavera ante el cambio climático

En i-3 se dedica un reportaje a la primavera. Se explica el mito de Perséfone, para introducir la entrevista realizada a la Directora del Departamento de Meteorología de TVE Mónica López. Formulándose una pregunta: ¿puede el cambio climático poner en peligro las estaciones y la vida tal como la conocemos

小学教育背景下与网络暴力目击者相关的危险因素

Cyberbullying is a harmful and intentional act of an aggressor/s to a victim, through technology, which causes an imbalance of power. The role of bystanders is key for early intervention in the phenomenon. The objective of the study is to detect risk factors associated with cyberbystanders in Primary Education based on individual variables related to the use of technologies (number of technologies, type of technology, frequency, purpose of use, time slot, and place of connection) and experiences as victims or aggressors of cyberbullying. A sample of 1169 families whose children were in 5th or 6th grade of Primary Education was selected and surveyed using a self-administered questionnaire that measures all the indicated variables (α = .84). The study of the risk factors was carried out using binary logistic regression (bivariate models and multivariate model) with the software R version 4.1.0. Bivariate analyses identified: a) using a mobile phone with the Internet, b) Internet connection to talk with friends, c) cybervictimization, and d) cyberperpetration as possible individual risk factors (p < .05). The multivariate model showed joint predictors of the risk of being cyberbystanders in Primary Education: cyberperpetration, cybervictimization, number of technologies used and using the Internet to talk with friends. The interrelation between the roles of cyberbullying and the risk derived from the very frequent use of various technological devices is evidenced. Implications for educational practice are studied.El ciberacoso es un acto dañino e intencional de un agresor/es a una víctima, mediante las tecnologías, que provoca un desequilibrio de poder. El papel de los testigos es clave a la hora de intervenir de manera temprana en el fenómeno. El objetivo del estudio es detectar factores de riesgo asociados con los cibertestigos en Educación Primaria a partir de las variables individuales relacionadas con el uso de las tecnologías (número de tecnologías, tipo de tecnología, frecuencia y finalidad de uso, franja horaria y lugar de conexión) y las experiencias como víctimas o agresores de ciberacoso.  Se seleccionó una muestra de 1169 familias cuyos hijos cursaban 5º o 6º de Educación Primaria, encuestada mediante un cuestionario autoadministrado que mide todas las variables indicadas (α = .84). El estudio de los factores de riesgo se llevó a cabo mediante la regresión logística binaria (modelos bivariantes y modelo multivariante). Los análisis bivariantes identificaron: a) uso del teléfono móvil con Internet, b) conexión a Internet para hablar con amigos, c) ser víctima de ciberacoso y d) ser ciberperpetrador como posibles factores de riesgo individuales (p < .05). El modelo multivariante mostró como predictores conjuntos del riesgo de ser cibertestigos en Educación Primaria: ser ciberagresor, ser víctima de ciberacoso, número de tecnologías empleadas y usar Internet para hablar con amigos. Se evidencia la interrelación de los roles de ciberacoso y el riesgo derivado del uso muy frecuente de varios dispositivos tecnológicos. Se estudian las implicaciones para la práctica educativa.O cyberbullying é um ato prejudicial e intencional de um agressor ou uma agressora a uma vítima, através das tecnologias, que provoca um desequilíbrio de poder. O papel das testemunhas é fundamental para uma intervenção precoce no fenómeno. O objetivo do estudo é detetar fatores de risco associados ao cyberbullying no Ensino Primário a partir das variáveis individuais relacionadas com a utilização das tecnologias (número de tecnologias, tipo de tecnologia, frequência e finalidade de utilização, intervalo horário e local de ligação) e as experiências como vítimas ou agressores de cyberbullying. Selecionou-se uma amostra de 1169 famílias cujos filhos estavam no 5.º ou 6.º ano do Ensino Básico, que foram inquiridas utilizando um questionário autoadministrado que mede todas as variáveis indicadas (α = .84). O estudo dos fatores de risco foi realizado mediante a regressão logística binária (modelos bivariantes e modelo multivariante). As análises bivariantes identificaram: a) uso do telemóvel com Internet, b) ligação à Internet para falar com amigos, c) ser vítima de cyberbullying e d) ser um ciberperpetrador como possíveis fatores de risco individuais (p < .05). O modelo multivariante mostrou como preditores conjuntos do risco de ser um testemunhas de cyberbullying no Ensino Primário: ser ciberagressor, ser vítima de cyberbullying, número de tecnologias utilizadas e utilizar a Internet para falar com amigos. A inter-relação dos papéis de cyberbullying e o risco derivado da utilização muito frequente de vários dispositivos tecnológicos é evidente. As implicações para a prática educativa são estudadas.O cyberbullying é um ato prejudicial e intencional de um agressor ou uma agressora a uma vítima, através das tecnologias, que provoca um desequilíbrio de poder. O papel das testemunhas é fundamental para uma intervenção precoce no fenómeno. O objetivo do estudo é detetar fatores de risco associados ao cyberbullying no Ensino Primário a partir das variáveis individuais relacionadas com a utilização das tecnologias (número de tecnologias, tipo de tecnologia, frequência e finalidade de utilização, intervalo horário e local de ligação) e as experiências como vítimas ou agressores de cyberbullying. Selecionou-se uma amostra de 1169 famílias cujos filhos estavam no 5.º ou 6.º ano do Ensino Básico, que foram inquiridas utilizando um questionário autoadministrado que mede todas as variáveis indicadas (α = .84). O estudo dos fatores de risco foi realizado mediante a regressão logística binária (modelos bivariantes e modelo multivariante). As análises bivariantes identificaram: a) uso do telemóvel com Internet, b) ligação à Internet para falar com amigos, c) ser vítima de cyberbullying e d) ser um ciberperpetrador como possíveis fatores de risco individuais (p < .05). O modelo multivariante mostrou como preditores conjuntos do risco de ser um testemunhas de cyberbullying no Ensino Primário: ser ciberagressor, ser vítima de cyberbullying, número de tecnologias utilizadas e utilizar a Internet para falar com amigos. A inter-relação dos papéis de cyberbullying e o risco derivado da utilização muito frequente de vários dispositivos tecnológicos é evidente. As implicações para a prática educativa são estudadas.网络暴力是施暴者通过科技手段，对受害者进行的有意图的危害行径，网络暴力直接导致了权利平衡的偏失。在对网络暴力的早期干预中目击者的角色至关重要。目标：该研究的目的是通过与科技使用相关的独立变量（科技数量、科技种类、使用频率和目的、连接时间段和地址）来发现小学背景下与网络暴力目击者相关的危险因素，同时发现作为网络暴力施暴者或受害者的相关经历。我们选择了由1169个家庭组成的样本，这些家庭的共同特点是他们的孩子正处于小学的五、六年级。我们采用自编问卷对样本的上述变量进行测量（α = 0.84）。对危险因素的研究采用了二元逻辑回归（双变量模型和多变量模型）。通过双变量分析确定：（1）使用联网的手机；（2）联网与朋友沟通；（3）是网络暴力的受害者；（4）是网络暴力的施暴者，这四项可能的独立危险因素（p <0 .05）。多变量模型显示了在小学背景下作为网络暴力目击者所面临危险的共同预测因素：是网络暴力施暴者、是网络暴力的受害者、科技数量和使用网络跟朋友交流。一方面研究显示出了网络暴力不同角色的相互关系、多科技设备的频繁使用所带来的风险都是十分突出的问题，另一方面也探讨了该研究在教育实践中的应用

AB toxins as high-affinity ligands for cell targeting in cancer therapy

Conventional targeted therapies for the treatment of cancer have limitations, including the development of acquired resistance. However, novel alternatives have emerged in the form of targeted therapies based on AB toxins. These biotoxins are a diverse group of highly poisonous molecules that show a nanomolar affinity for their target cell receptors, making them an invaluable source of ligands for biomedical applications. Bacterial AB toxins, in particular, are modular proteins that can be genetically engineered to develop high-affinity therapeutic compounds. These toxins consist of two distinct domains: a catalytically active domain and an innocuous domain that acts as a ligand, directing the catalytic domain to the target cells. Interestingly, many tumor cells show receptors on the surface that are recognized by AB toxins, making these high-affinity proteins promising tools for developing new methods for targeting anticancer therapies. Here we describe the structure and mechanisms of action of Diphtheria (Dtx), Anthrax (Atx), Shiga (Stx), and Cholera (Ctx) toxins, and review the potential uses of AB toxins in cancer therapy. We also discuss the main advances in this field, some successful results, and, finally, the possible development of innovative and precise applications in oncology based on engineered recombinant AB toxins

De las TICs a las TACs : la importancia de crear contenidos educativos digitales

El progreso tecnológico y el desarrollo de sistemas informáticos de las últimas décadas, unido a su impacto en nuestra vida cotidiana, ha provocado un replanteamiento de las metodologías de enseñanza-aprendizaje en las aulas, permitiendo la incorporación en las aulas de las TICs y las TACs y así, favoreciendo el modelo TPACK, que implica el uso de contenidos educativos digitales en las aulas, por lo que se hace indispensable el desarrollo de la competencia digital de los docentes, que a su vez fomentará el desarrollo de la competencia digital de los alumnos, garantizando una educación y un proceso de enseñanza-aprendizaje adaptado a la sociedad del siglo XXI.Technological progress and the development of computer systems in recent decades, along with its impact on our daily lives has led to the emergence of the teaching-learning methodologies in the classroom, allowing the incorporation of ICT management and LTK in the classrooms, and thus favoring the TPACK model, which involves the use of digital educational content in the classrooms, so it is essential to the development of digital competence of teachers, which in turn promote the development of digital competence of students, thereby ensuring an education and teaching-learning process adapted to the XXI century

Extended linear-homothetic preferences and the Cournot-Bertrand profit differential

This paper introduces the ‘extended linear-homothetic’ preferences to model consumer choice. Specifically, we extend Datta and Dixon’s (2000) ‘standard linear-homothetic’ preferences by adding an additional term to the unit cost function. This term captures the relative importance of price interactions within sectors on the unit cost of utility. In an economy composed of a large number of sectors (K) with a sufficiently large number of firms (n) in each, the ‘extended linear-homothetic’ preferences yield (perceived) linear demands in own strategy and competitors’ strategies - where goods are characterized as substitutes. Thus, the linearity and homotheticity properties of the preferences open the possibility to develop a tractable model of oligopoly in general equilibrium. An additional novelty introduced by the ‘extended linear-homothetic’ preferences is the presence of a sectoral-specific price index in product demand. For n small, this implies that firms internalize the sectoral price effects of their individual pricing strategies. The latter, we argue, may provide us with a link between nonatomistic price and wage setters and the monetary authority

Macroeconomic Effects of Oligopolistic Competition with Wage Bargaining

Modelling oligopoly in general equilibrium is about understanding the aggregate effects of the strategic behavior that nonatomistic agents may exhibit in their markets. Real-world economies appear to be characterized by (monopoly) power-endowed agents behaving strategically - namely, firms and unions. By abstracting from this behavior, we risk missing some important features of the macroeconomy. We develop a general equilibrium model of unionized oligopoly aimed at addressing this point. We evaluate the macroeconomic effects of supply-side shocks under alternative product and labor market structures. In addition, the micro foundations of the model capture an alternative channel for the development of strategic interactions among firms, unions and the monetary authority. This channel creates a transmission mechanism for real effects of monetary policy-related shocks, which we investigate. Finally, in the light of the predictions of the model, we discuss macroecomic performance in Continental Europe over the 1990s

International Transmission of Medium-Term Technology Cycles: Evidence from Spain as a Recipient Country

This paper documents stylized facts of international medium-term business cycles by exploring the pattern of comovement between a catching-up economy, Spain, and each of the obvious candidate countries to technological leadership of the 1950-2007 period, the U.S., France, Germany, Italy and the U.K. A remarkable feature of the international medium-term business cycle is the strong, positive lead displayed by the U.S. technology and terms of trade cycles over Spain's macroeconomic aggregates. The corresponding evidence when the counterpart to Spain is a large European economy is weaker, particularly in the case of Europe's medium-term technology cycles. Non-parametric tests results suggest that, over the medium-term cycle, a shift towards more economic integration may not necessarily be associated with increased international comovement.Medium-term business cycles; Stylized facts; International comovement; Technology diffusion.

THE COURNOT-BERTRAND PROFIT DIFFERENTIAL : A REVERSAL RESULT IN A DIFFERENTIATED DUOPOLY WITH WAGE BARGAINING

This paper compares Cournot and Bertrand equilibria in a downstream differentiated duopoly in which the input price (wage) paid by each downstream firm is the outcome of a strategic bargain with its upstream supplier (labour union). We show that the standard result that Cournot equilibrium profits exceed those under Bertrand competition - when the differentiated duopoly game is played in imperfect substitutes - is reversible. Whether equilibrium profits are higher under Cournot or Bertrand competition is shown to depend upon the nature of the upstream agents’ preferences, on the distribution of bargaining power over the input price and on the degree of product market differentiation. We find that the standard result holds unless unions are both powerful and place considerable weight on the wage argument in their utility function. One implication of this is that if the upstream agents are profit-maximising firms, then the standard result will obtain.differentiated duopoly ; wage bargaining ; Cournot ; Bertrand.

Relevamiento de la contaminación con mercurio en el canal cacique Guaymallén y evaluación del riesgo potencial en alimentos

En el año 2010 en la provincia de Mendoza, una industria que elaboraba cloro-álcali utilizando el método de la celda de cátodo de mercurio, ocasionó un importante incidente produciendo la liberación de mercurio metálico y la consecuente contaminación del suelo y el agua de un cauce. En este proceso electrolítico se generaban “lodos" ricos en mercurio metálico que se depositaban en diferentes recintos de la planta, estos lodos se acumulaban de forma deliberada cuya disposición final se realizaba a través del sistema cloacal. Luego de un tiempo el sistema cloacal colapsó y se desbordó volcando todo el residuo acumulado hacia el Canal Cacique Guaymallén. Por este hecho se vieron afectadas las industrias que hacían uso de este recurso y las plantas potabilizadoras de agua Benegas y Alto Godoy que tuvieron que cesar su funcionamiento hasta que se culminaran las tareas de saneamiento y los análisis dieran como resultado que no existía riesgo alguno de contaminación. Para conocer la situación actual de contaminación que reviste el Canal Cacique Guaymallén y el riesgo potencial que esto significa para la población y el medio ambiente se extrajeron muestras de agua y suelo de siete puntos de muestreo a lo largo del predio de la fábrica en tres años diferentes. Las muestras se procesaron siguiendo las especificaciones de normas adecuadas para este tipo de muestras, luego se determinó mercurio a través de la técnica de absorción atómica de vapor frío o generador de hidruros. Para lo cual se utilizó un espectrofotómetro de absorción atómica marca SHIMADZU modelo AA 7000 con acoplamiento de generador de hidruros marca SHIMADZU modelo HVG-1. Se obtuvieron en algunas muestras de agua y suelo valores de mercurio que superaron los límites permitidos de varias legislaciones. A pesar del paso del tiempo sigue existiendo contaminación con mercurio en la zona debido a que este metal es capaz de movilizarse, de formar compuestos orgánicos, de bioacumularse y biomagnificarse en el ambiente.Fil: López, Marcela Mónica. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias

Dietética: a essência da nutrição clínica

La nutrición, como una disciplina del campo clínico, depende altamente del desarrollo tecnológico y de los avances científicos para que pueda ejercerse de acuerdo con la evidencia, considerando la evolución de la terapia y manteniéndose en vanguardia