Implementing sustainable urban travel policies in Mexico

This report describes the main challenges to urban travel in Mexico. We focus on some of the basic causes of urban transport problems, and we analyze some urban travel policies that could be considered good practices towards sustainable urban development. Mexico City is the emblematic case

La vida silvestre: patrimonio nacional : conferencia pronunciada en la Sociedad Científica Argentina. Sesión pública del 20 de Octubre de 1970

Fil: Navas, Jorge R.. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentin

El precio del durazno para la toma de decisiones de los productores mexicanos

Peach producers in Mexico form their production expectations based on the future price; they wait for the price to increase in order to continue with the agricultural activity, reason why they do not make the decision of seeking other uses and markets for the fruit, different from the fresh market. The objective of this study was to analyze the dynamics of the formation of the market price of peach in Mexico, its trend and volatility, in order to predict its trajectory through time. The hypothesis was that peach prices present high volatility and a negative trend that converges in a price with a constant. With the methodology of a dynamic model under a simple market, a differential second degree equation and a Brownian equation, it was found that the real price of peach presented severe fluctuation with negative trend; that the trajectory in time led the price of the fruit towards a constant equilibrium price, although it was low compared to the levels in previous periods. Thus, it was confirmed that the future price will not increase in the next 15 years and, as consequence, facing this scenario of uncertainty, the producers of this fruit could cease to continue investing in the activity.Los productores de durazno en México forman sus expectativas de producción basadas en el precio futuro; estos esperan que el precio aumente para seguir con la actividad agrícola, razón por la cual no toman la decisión de buscar otros usos y mercados para la fruta, diferentes al mercado en fresco. El objetivo fue analizar la dinámica de la formación del precio de mercado del durazno en México, su tendencia y volatilidad a fin de pronosticar la trayectoria de este en el tiempo. La hipótesis fue que los precios del durazno presentan alta volatilidad y tendencia negativa que convergen a un precio con constante. Con la metodología de un modelo dinámico bajo un mercado simple, una ecuación diferencial de segundo grado y una ecuación browniana se obtuvo que el precio real del durazno presentó severas oscilaciones con tendencia negativa; que la trayectoria del tiempo condujo al precio de la fruta hacia un precio constante de equilibrio, pero que este fue bajo con respecto a los niveles de los periodos anteriores, por lo que se comprobó que el precio del fruto no aumentará en los próximos 15 años y en consecuencia, ante este escenario de incertidumbre, los productores de dicho fruto podrían dejar de seguir invirtiendo en la actividad

Visualization and 3D Reconstruction of Flame Cells of Taenia solium (Cestoda)

BACKGROUND: Flame cells are the terminal cells of protonephridial systems, which are part of the excretory systems of invertebrates. Although the knowledge of their biological role is incomplete, there is a consensus that these cells perform excretion/secretion activities. It has been suggested that the flame cells participate in the maintenance of the osmotic environment that the cestodes require to live inside their hosts. In live Platyhelminthes, by light microscopy, the cells appear beating their flames rapidly and, at the ultrastructural, the cells have a large body enclosing a tuft of cilia. Few studies have been performed to define the localization of the cytoskeletal proteins of these cells, and it is unclear how these proteins are involved in cell function. METHODOLOGY/PRINCIPAL FINDINGS: Parasites of two different developmental stages of T. solium were used: cysticerci recovered from naturally infected pigs and intestinal adults obtained from immunosuppressed and experimentally infected golden hamsters. Hamsters were fed viable cysticerci to recover adult parasites after one month of infection. In the present studies focusing on flame cells of cysticerci tissues was performed. Using several methods such as video, confocal and electron microscopy, in addition to computational analysis for reconstruction and modeling, we have provided a 3D visual rendition of the cytoskeletal architecture of Taenia solium flame cells. CONCLUSIONS/SIGNIFICANCE: We consider that visual representations of cells open a new way for understanding the role of these cells in the excretory systems of Platyhelminths. After reconstruction, the observation of high resolution 3D images allowed for virtual observation of the interior composition of cells. A combination of microscopic images, computational reconstructions and 3D modeling of cells appears to be useful for inferring the cellular dynamics of the flame cell cytoskeleton

Multiple sclerosis in Mexico: A multicentre study [Esclerosis múltiple en México: Un estudio multicéntrico]

Introduction. Multiple sclerosis (MS) is considered to be a low prevalence disease in Mexico; its characteristics have been described in isolated studies in small populations concentrated in a single region of the country and using heterogeneous methodological tools. Aims. In this study, our aim was define the clinical profile and some socio-demographic aspects of MS in Mexico using validated homogeneous criteria and tools. Patients and methods. Eight hospitals representing the five most densely populated regions of the country, the north, centre and south of Mexico, took part in the study. Data were obtained through a survey created, validated and published in Spanish (κ-interobserver 0.73 and κ-intraobserver 0.76), which consisted of 142 questions arranged in 10 sections and which was applied by 12 neurologists. The procedure was verified with 50 randomly selected surveys. A total of 337 surveys were applied, which were analysed by descriptive statistics using the EPIINFO, version 6.04b, software application. All the patients presented MS that had been clinically defined with the help of paraclinical studies according to Schumaher and Poser's criteria. Results. A sample of 337 patients was studied; 99.1% were mestizos, with an average age of 37 ± 9years, 69.7% were females and 30.3% males. 95% had access to the Social Security system and 96% had been born in Mexico to Mexican parents. No cases were found among native Mexicans. The clinical profile of the disease did not differ to that reported in other countries; the pattern observed corresponded to that found in northern latitudes. Conclusion. This is the first multicentre study carried out in Mexico with a population that is highly representative of the whole country and with a homogeneous methodology

Multiple sclerosis in Mexico: A multicentre study [Esclerosis múltiple en México: Un estudio multicéntrico]

Introduction. Multiple sclerosis (MS) is considered to be a low prevalence disease in Mexico; its characteristics have been described in isolated studies in small populations concentrated in a single region of the country and using heterogeneous methodological tools. Aims. In this study, our aim was define the clinical profile and some socio-demographic aspects of MS in Mexico using validated homogeneous criteria and tools. Patients and methods. Eight hospitals representing the five most densely populated regions of the country, the north, centre and south of Mexico, took part in the study. Data were obtained through a survey created, validated and published in Spanish (?-interobserver 0.73 and ?-intraobserver 0.76), which consisted of 142 questions arranged in 10 sections and which was applied by 12 neurologists. The procedure was verified with 50 randomly selected surveys. A total of 337 surveys were applied, which were analysed by descriptive statistics using the EPIINFO, version 6.04b, software application. All the patients presented MS that had been clinically defined with the help of paraclinical studies according to Schumaher and Poser's criteria. Results. A sample of 337 patients was studied; 99.1% were mestizos, with an average age of 37 Zapotitlán 9years, 69.7% were females and 30.3% males. 95% had access to the Social Security system and 96% had been born in Mexico to Mexican parents. No cases were found among native Mexicans. The clinical profile of the disease did not differ to that reported in other countries; the pattern observed corresponded to that found in northern latitudes. Conclusion. This is the first multicentre study carried out in Mexico with a population that is highly representative of the whole country and with a homogeneous methodology

Implementing Sustainable Urban Travel Policies in Mexico

This report describes the main challenges to urban travel in Mexico. We focus on some of the basic causes of urban transport problems, and we analyze some urban travel policies that could be considered good practices towards sustainable urban development. Mexico City is the emblematic case.

Control of Dental Caries in Children and Adolescents Using Fluoride: An Overview of Community-Level Fluoridation Methods

The maintenance of oral health is a crucial aspect of general well-being; however, a significant proportion of the worldwide population experiences a range of oral diseases. Dental caries is a highly prevalent non-communicable disease globally, especially in children and adolescents. Fluoride is involved in the control of dental caries, primarily by decreasing the critical pH for dental hard tissue dissolution and decreasing enamel solubility. Due to the substantial data supporting the efficacy of fluoride in controlling dental caries, many community-level fluoridation initiatives have been devised and executed as global public health preventive interventions. These initiatives encompass the fluoridation of water, salt, and milk. Water fluoridation is considered safe and effective when fluoride levels are maintained within the recommended range (0.6 to 1.1 mg/L). Salt fluoridation has a cariostatic potential similar to that of water fluoridation, and a fluoride concentration of 250 micrograms per gram in salt is not associated with an increased risk of developing dental fluorosis. However, there is currently an effort to reduce the consumption of table salt in order to mitigate the harmful effects of excessive salt consumption. It has been hypothesized that fluoride food supplementation, such as fluoridated milk, is associated with a decrease in caries experience in permanent teeth; however, the effect is not clear in primary teeth. Public-level fluoride interventions are more cost-effective than the operative care of caries lesions and limit the burden of care. The administration of fluorides should be conducted using safe methods, limiting ingestion, and adhering to the guidelines set by international and national health agencies in each country. This is particularly important when considering children with developing dentitions. Fluoride is an important tool in the control of dental caries, but it is crucial to combine it with good oral hygiene, a healthy diet, and regular visits to a dental professional to maintain long-term oral health

Renal dysfunction as a consequence of acute liver damage by bile duct ligation in cirrhotic rats

Renal failure is a common complication in patients with alcohol-induced cirrhosis who undergo a superimposed severe alcoholic hepatitis. Aim: Our aim was to evaluate renal dysfunction established as a consequence of acute liver damage (ALD) induced by bile duct ligation (BDL) in cirrhotic rats. Hepatic and renal functional assays were performed. Results: Hiperbilirubinemia and increased alanine aminotransferase and aspartate aminotransferase (p < 0.05) in rats with BDL were observed since the first day of bile obstruction in cirrhotic rats. Urinary volume and urinary sodium concentration showed a significant reduction (p < 0.05) on days 3 and 5 after BDL. Plasma renin activity, plasma renin concentration, serum creatinine, and BUN values increased (p < 0.05) from day 1 to day 7 after BDL. Glomerular filtration rate was substantially decreased from day 1 to day 7. Histological changes became apparent since day 3 after BDL in which glomeruli with mesangial hipercellularity took place in the absence of tubular necrosis; with portal inflammation and proliferation of biliar conduits. Results of the present work demonstrate that ALD induced by BDL in cirrhotic rats produces changes in renal function. In conclusion, this experimental model demonstrates that an ALD of variable etiology, either surgical or induced by CCl4, can cause important damage that eventually results in renal function deterioration. This experimental model may be suitable, to study the physiopathology of this syndrome, as well as for the evaluation of different pharmacological therapies. � 2006 Elsevier GmbH. All rights reserved