Papers by Guillermo Castro
En su momento, el educador ambiental panameño Kleber De Lora lo expresó con la mayor de las clari... more En su momento, el educador ambiental panameño Kleber De Lora lo expresó con la mayor de las claridades: la educación ambiental, dijo, es la educación. Y al escucharlo, se oía en el fondo el ruido, pequeño pero constante, de los guijarros que iban cayendo del muro de la modernidad. De eso se trata, a fin de cuentas: de que no vivimos en una época de cambios, en la que se puede añadir lo ambiental como una materia más a la educación existente, sino en un cambio de épocas, donde la incorporación de lo ambiental como problema fundamental para el desarrollo de nuestra especie pone en cuestión a toda la educación que ha contribuido-y contribuye-a la creación de ese problema. De la cristiandad acá-o de la Conquista acá, que es lo mismo si el asunto lo vemos desde nuestra América-hemos vivido otros cambios de época, y de la educación que había ayudado a crear las. En la Edad Media, por ejemplo, toda la cultura y buena parte de la vida se organizaban en torno a los problemas de la salvación del alma, en sociedades que tenían más fe en la llegada del Juicio Final de la que algunos tienen hoy en la existencia del cambio climático. En esas sociedades, por lo mismo, toda la educación se organizaba en torno a la disciplina que se ocupa del problema de la salvación, que es la teología. Aquella educación, como se recuerda, se estructuró en dos componentes fundamentales: el trívium-integrado por las ciencias de la razón: gramática, dialéctica y retórica-, y el quatrivium, que reunía a las ciencias que hacía uso de la razón así educada: aritmética, geometría, astronomía y música. Entre 1450 y 1650-el siglo XVI "largo" de que hablara Fernand Braudel-, se produjo un cambio de época,
Ciencia, cultura y cultura de la ciencia
Tareas, 2002
Mundo nuevo, 2025
Se vino abajo el mundo viejo, y es natural que se acumulen ahora, piedra a piedra, los materiales... more Se vino abajo el mundo viejo, y es natural que se acumulen ahora, piedra a piedra, los materiales del que ha de reemplazarlo. Los hombres se dan en esto una prisa gloriosa; pero cegados con el polvo de la fábrica, encorvados bajo el peso de los materiales que allegan con sus manos y acarrean en sus hombros, no bien seguros todavía de lo que darán de sí cuando se empalmen y en acomodación juiciosa enseñen la nueva fábrica del mundo, sucede que no alcanzan los hombres aún más que a presentar y bosquejar confusamente, en consecuencia de lo que tienen conocido, el resplandeciente mundo nuevo." José Martí, "Fragmentos" [
El anochecer del protectorado
La colonia continuó viviendo en la república; y nuestra América se está salvando de sus grandes y... more La colonia continuó viviendo en la república; y nuestra América se está salvando de sus grandes yerros-de la soberbia de las ciudades capitales, del triunfo ciego de los campesinos desdeñados, de la importación excesiva de las ideas y fórmulas ajenas, del desdén inicuo e impolítica de la raza aborigenpor la virtud superior, abonada con sangre necesaria,
José Martí. Textos sobre educación, 2024
Una breve antología de textos de José Martí sobre la educación en sociedades en transición.
El camino a la noosfera, 2024
"¿Nació de sí mismo el mundo en que vivimos? ¿Y se moverá como se mueve hoy perpetuamente, o se e... more "¿Nació de sí mismo el mundo en que vivimos? ¿Y se moverá como se mueve hoy perpetuamente, o se evaporará, y mecidos por sus vapores, iremos a confundirnos, en compenetración augusta y deleitosa, con un ser de quien la naturaleza es mera aparición?" José Martí, 18821
De nuestra historia ambiental, 2024
Dóblese sobre el hombre el que quiera revelar las leyes del hombre. Y no constituyan con la sotan... more Dóblese sobre el hombre el que quiera revelar las leyes del hombre. Y no constituyan con la sotana científica la sotana religiosa. […] Se han de estudiar a la vez, si se quiere saber de sociedades humanas, las influencias extrahumanas, los motivos generales de agencia humana, y las causas precipitantes o dilatorias que han obrado para alterar el ajuste natural entre estas dos fuerzas paralelas." José Martí1
Pharmaceutics
Liver inflammation represents a major clinical problem in a wide range of pathologies. Among the ... more Liver inflammation represents a major clinical problem in a wide range of pathologies. Among the strategies to prevent liver failure, dexamethasone (DXM) has been widely used to suppress inflammatory responses. The use of nanocarriers for encapsulation and sustained release of glucocorticoids to liver cells could provide a solution to prevent severe side effects associated with systemic delivery as the conventional treatment regime. Here we describe a nanostructured lipid carrier developed to efficiently encapsulate and release DXM. This nano-formulation proved to be stable over time, did not interact in vitro with plasma opsonins, and was well tolerated by primary non-parenchymal liver cells (NPCs). Released DXM preserved its pharmacological activity, as evidenced by inducing robust anti-inflammatory responses in NPCs. Taken together, nanostructured lipid carriers may constitute a reliable platform for the delivery of DXM to treat pathologies associated with chronic liver inflammat...
Comptes Rendus. Chimie, 2022
Sustainable Biomass Resources for Environmental, Agronomic, Biomaterials and Energy Applications ... more Sustainable Biomass Resources for Environmental, Agronomic, Biomaterials and Energy Applications 3 / Ressources de biomasse durables pour des applications environnementales, agronomiques, de biomatériaux et énergétiques 3 Pharmaceutical pollutants adsorption onto activated carbon: isotherm, kinetic investigations and DFT modeling approaches
ABSTRACT. This article describes the zygomatic implants placement procedure on patients with seve... more ABSTRACT. This article describes the zygomatic implants placement procedure on patients with severely resorbed maxillae. The advantages, indications, related anatomic and clinic (surgical and prosthetic) concepts will be discussed.
Los caracteres musicales del género musical del fandango son una de las bases del flamenco. Nueva... more Los caracteres musicales del género musical del fandango son una de las bases del flamenco. Nuevas e importantes fuentes documentales no estudiadas en anteriores investigaciones obligan a un relectura del mismo. A su vez, uno de los aspectos descuidados en el flamenco ha sido el estudio de su plantilla rítmica, la cual ha tenido un gran desarrollo desde principios del XVIII hasta la actualidad, característica ésta que estudiamos aquí en profundidad.
Revista TOMO, 2015
A peregrinação é um ritual religioso que consiste em fazer um percurso a pé ou mediante outros me... more A peregrinação é um ritual religioso que consiste em fazer um percurso a pé ou mediante outros meios de transporte, individual ou em grupo,que tem como meta chegar a uma cidade ou santuário comum a conotação sagrada e com uma finalidade espiritual. Na Península Ibérica, o Caminho de Santiago de Compostela constitui a máxima expressão deste ritual, tendo se transformado hoje num referencial do turismo cultural. Este texto analisa outro tipo de peregrinação, cuja finalidade não é religiosa se não política: a Marcha Popular Indignada, que em julho de 2011 movimentou centenas de caminhantesdesde a periferia até a Praça do Sol, no centro da capital espanhola, Madrid. Este “Caminho de Sol” é analisado com metáfora do 15M ,o movimento dos Indignados, surgido na Espanha em maio de 2011, a partir de acampamentos de protesto na maior parte das cidades, que teve sua culminância com a chegada da Marcha no local onde se iniciaram os acampamentos: na Praça do Sol. Através do relato de Guillermo, ...
Freshwater Science, 2017
Evaluating how environmental stressor interactions influence ecosystem structure and functioning ... more Evaluating how environmental stressor interactions influence ecosystem structure and functioning is critical to understanding the response of ecosystems to global change. We exposed a species-poor planktonic community to P pulses in the absence and presence of solar ultraviolet radiation (UVR). We used a field-mesocosm study in an oligotrophic mid-altitude lake to test the hypothesis that interaction between these factors affects the community's diversity and composition, but not its biomass-size spectrum, making this community resilient in terms of its C-transfer function. Our findings show that P pulses and UVR affected the relative abundance of different planktonic populations. The abundance of phytoplankton was enhanced strongly by P pulses and secondarily by UVR. The UVR Â P interaction affected only the smallest autotrophic species. Chlorococcal abundance increased, whereas chroococcal cyanobacteria decreased. However, UVR had a much more pronounced effect than P on the composition of microcrustaceans, and both factors interactively affected their biomass. Hence, the biomass-size spectrum was not resilient to the UVR Â P pulse interaction. The steepness of the slope increased under P-pulse conditions because zooplankton were not able to grow concomitantly with phytoplankton, as confirmed by the low zooplankton to phytoplankton biomass ratio (Z∶P). The observed planktonic changes under new foreseeable conditions that include an increase in UVR fluxes and P inputs might decouple the C cycle in inland oligotrophic lakes in the Mediterranean region.
Revista De Investigacion Sobre Flamenco La Madruga, 2009
American Journal of Clinical Pathology, 1988
S-100 protein has been used as a marker of various lesions, including peripheral nerve sheath, ca... more S-100 protein has been used as a marker of various lesions, including peripheral nerve sheath, cartilaginous and salivary gland tumors, chordomas, histiocytosis X, and melanomas, among others. The list of neoplasms that can express S-100 protein continues to expand. It has been suggested that staining for S-100 protein may be of aid in the differential diagnosis of amelanotic melanoma versus poorly differentiated tumors. Three hundred fifty primary and metastatic adenocarcinomas from various sites were immunostained for S-100 protein with the use of a commercially available polyclonal antibody. Forty-two percent of the adenocarcinomas tested expressed S-100 protein to varying degrees. The relative incidence of S-100-positive tumors varied with the primary sites, some expressing S-100 protein more often than others. A primary neoplasm able to express S-100 protein was usually associated with metastatic foci also expressing this marker. However, occasionally, a primary S-100-positive tumor was associated with metastasis that lacked expression of S-100. This study emphasizes the importance of testing for a panel of tumor markers in the evaluation of poorly differentiated tumors and cautions on possible difficulties that may arise in the interpretation of immunocytochemistry results.
PLOS ONE, 2015
Some of the most important effects of global change on coastal marine systems include increasing ... more Some of the most important effects of global change on coastal marine systems include increasing nutrient inputs and higher levels of ultraviolet radiation (UVR, 280-400 nm), which could affect primary producers, a key trophic link to the functioning of marine food webs. However, interactive effects of both factors on the phytoplankton community have not been assessed for the Mediterranean Sea. An in situ factorial experiment, with two levels of ultraviolet solar radiation (UVR+PAR vs. PAR) and nutrients (control vs. P-enriched), was performed to evaluate single and UVR×P effects on metabolic, enzymatic, stoichiometric and structural phytoplanktonic variables. While most phytoplankton variables were not affected by UVR, dissolved phosphatase (APA EX) and algal P content increased in the presence of UVR, which was interpreted as an acclimation mechanism of algae to oligotrophic marine waters. Synergistic UVR×P interactive effects were positive on photosynthetic variables (i.e., maximal electron transport rate, ETR max), but negative on primary production and phytoplankton biomass because the pulse of P unmasked the inhibitory effect of UVR. This unmasking effect might be related to greater photodamage caused by an excess of electron flux after a P pulse (higher ETR max) without an efficient release of carbon as the mechanism to dissipate the reducing power of photosynthetic electron transport.
Archives of pathology & laboratory medicine, 2010
Most renal diseases with organized deposits are relatively uncommon conditions, and proper pathol... more Most renal diseases with organized deposits are relatively uncommon conditions, and proper pathologic characterization determines the specific diagnosis. Different entities with specific clinical correlates have been recognized, and their correct diagnosis has an impact on patient management, treatment options, and determination of prognosis. The diagnosis of these conditions depends on careful evaluation of the findings by light microscopy together with immunofluorescence and electron microscopy. The objective of this manuscript is to delineate an algorithmic approach helpful in the pathologic assessment of these conditions at the light microscopic level. In some diseases, the immunomorphologic parameters short of electron microscopy provide solid information to suggest or make a definitive diagnosis. Nevertheless, electron microscopy plays a crucial role, because the criteria to separate these entities often are heavily influenced by the electron microscopic findings. Accepted dia...
Human papillomavirus typing of rare cervical carcinomas
Archives of pathology & laboratory medicine, 2004
Most cervical tumors are classified as squamous cell carcinoma or adenocarcinoma, both of which a... more Most cervical tumors are classified as squamous cell carcinoma or adenocarcinoma, both of which are associated with persistent human papillomavirus (HPV) infection. Although other (rare) types represent less than 5% of all cervical carcinomas, it is necessary that these more unusual tumors be studied in the current era of papillomavirus vaccine development, especially in regions with high incidence of cervical cancer. To compare papillomavirus types found in histologically rare cervical carcinomas (n = 29) with those types found in common cervical carcinomas (n = 14) archived at the Institute of Cancer in Mexico City, Mexico. Paraffin-embedded tissues were received and sectioned at the Louisiana State University Health Sciences Center at Shreveport. One section for each block was stained and examined by 2 pathologists. Specific histologies were categorized into 2 broad groups: common (squamous cell carcinoma or adenocarcinoma) or rare (adenosquamous, papillary, villoglandular, anapl...
International Journal of Nephrology and Renovascular Disease, 2010
Endothelium-derived nitric oxide (NO) is essential for maintenance and regulation of blood pressu... more Endothelium-derived nitric oxide (NO) is essential for maintenance and regulation of blood pressure. In animal models, altered endothelium-derived nitric oxide synthase (eNOS) expression and impaired NO generation are important factors for renal injury. However, the pattern of eNOS expression in the kidneys from hypertensive patients has not been well established. We have studied the eNOS immuno-expression in kidney biopsies from hypertensive patients. Compared to kidneys from normotensive individuals, there were no significant alterations of eNOS immuno-expression in the vasculature of patients with chronic essential hypertension. In contrast, the expression of eNOS was significantly decreased in the glomeruli and arterioles/small arteries of patients with malignant hypertension, particularly in those with significant intimal edema and myxoid degeneration or thrombi. Endothelial dysfunction is an important pathogenetic factor for chronic primary hypertension and eNOS plays a major role in the regulation of vascular tone and function. Unchanged eNOS in the kidney vasculature in chronic primary hypertension indicates that these patients have an ability to compensate. In patients with malignant hypertension, the expression of eNOS protein was diminished in the injured vasculature. Loss of the compensatory mechanism via continued release of NO to prevent vascular injury may be responsible for morphological changes typically seen in the renal vasculature in patients with accelerated hypertension.
Latin American Journal of Aquatic Research, 2014
Neuromast morphology and distribution are characterized during early ontogeny of anchoveta (Engra... more Neuromast morphology and distribution are characterized during early ontogeny of anchoveta (Engraulis ringens) and common sardine (Strangomera bentincki). Although both species share morphological features, they show several differences during their early ontogeny, such as size at hatching and yolk absorption. Larvae were obtained from incubation of planktonic eggs (at 12°C), collected during the spawning season 2001 (August-September) at Coliumo Bay. The neuromasts were observed from hatching to 25 days, and the pattern of neuromast appearance, in newly hatched larva, until yolk absorption, was determined using Janus Green staining and scanning electronic microscope. Results showed a similar pattern of neuromast development in both species. At hatching, two pairs of neuromasts were observed in the cephalic area and 8-9 in the rest of the body, which increased to 19 pairs and to 30-39 pairs at a larval size of 11 mm, respectively. On the average, 12 hair cells per neuromast were counted, with little variation among neuromasts. The polarity of these hair cells was closest to multiple polarity. Neuromast positioning for both species, anchoveta and common sardine larvae, are similar to those of Engraulis mordax and Clupea harengus, respectively. The similar development pattern of these species seems to be related to similar functional constraints and close taxonomic affinity.
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Papers by Guillermo Castro