Comics, Dolls and The Disavowal of Racism: Learning from Mexican Mestizaje

‘Mestizaje’ and ‘creolization’ are parallel and competing terms. Both refer to processes and discourses of mixture, racial and cultural, emanating from colonial encounters in the Americas. Moreover, mestizaje also refers to nineteenth- and twentieth-century political projects with varying degrees of institutionalization. Mestizaje is an ambitious idea that aims to represent the inauguration of modernity to which the contact between Europe, America, Asia and Africa gave precedent. It is, simultaneously, a living and shifting process of racial miscegenation, cultural transformation and nation-building. Mestizaje has moved beyond the realm of linguistics, culture and identity of creolization, to include a top-down official political dimension that has rewritten national histories in order to cohere nation states in Latin America

Dorsal hindbrain ablation results in rerouting of neural crest migration and changes in gene expression, but normal hyoid development

Our previous studies have shown that hindbrain neural tube cells can regulate to form neural crest cells for a limited time after neural fold removal (Scherson, T., Serbedzija, G., Fraser, S. E. and Bronner-Fraser, M. (1993). Development 188, 1049-1061; Sechrist, J., Nieto, M. A., Zamanian, R. T. and Bronner-Fraser, M. (1995). Development 121, 4103-4115). In the present study, we ablated the dorsal hindbrain at later stages to examine possible alterations in migratory behavior and/or gene expression in neural crest populations rostral and caudal to the operated region. The results were compared with those obtained by misdirecting neural crest cells via rhombomere rotation. Following surgical ablation of dorsal r5 and r6 prior to the 10 somite stage, r4 neural crest cells migrate along normal pathways toward the second branchial arch. Similarly, r7 neural crest cells migrate primarily to the fourth branchial arch. When analogous ablations are performed at the 10- 12 somite stage, however, a marked increase in the numbers of DiI/Hoxa-3-positive cells from r7 are observed within the third branchial arch. In addition, some DiI-labeled r4 cells migrate into the depleted hindbrain region and the third branchial arch. During their migration, a subset of these r4 cells up-regulate Hoxa-3, a transcript they do not normally express. Krox20 transcript levels were augmented after ablation in a population of neural crest cells migrating from r4, caudal r3 and rostral r3. Long-term survivors of bilateral ablations possess normal neural crest-derived cartilage of the hyoid complex, suggesting that misrouted r4 and r7 cells contribute to cranial derivatives appropriate for their new location. In contrast, misdirecting of the neural crest by rostrocaudal rotation of r4 through r6 results in a reduction of Hoxa-3 expression in the third branchial arch and corresponding deficits in third arch-derived structures of the hyoid apparatus. These results demonstrate that neural crest/tube progenitors in the hindbrain can compensate by altering migratory trajectories and patterns of gene expression when the adjacent neural crest is removed, but fail to compensate appropriately when the existing neural crest is misrouted by neural tube rotation

Rhombomere of origin determines autonomous versus environmentally regulated expression of Hoxa3 in the avian embryo

We have investigated the pattern and regulation of Hoxa3 expression in the hindbrain and associated neural crest cells in the chick embryo, using whole mount in situ hybridization in conjunction with DiI labeling of neural crest cells and microsurgical manipulations. Hoxa3 is expressed in the neural plate and later in the neural tube with a rostral border of expression corresponding to the boundary between rhombomeres (r) 4 and 5. Initial expression is diffuse and becomes sharp after boundary formation. Hoxa3 exhibits uniform expression within r5 after formation of rhombomeric borders. Cell marking experiments reveal that neural crest cells migrating caudally, but not rostrally, from r5 and caudally from r6 express Hoxa3 in normal embryo. Results from transposition experiments demonstrate that expression of Hoxa3 in r5 neural crest cells is not strictly cell-autonomous. When r5 is transposed with r4 by rostrocaudal rotation of the rhomobomeres, Hoxa3 is expressed in cells migrating lateral to transposed r5 and for a short time, in condensing ganglia, but not by neural crest within the second branchial arch. Since DiI-labeled cells from transposed r5 are present in the second arch, Hoxa3-expressing neural crest cells from r5 appear to down-regulate their Hoxa3 expression in their new environment. In contrast, when r6 is transposed to the position of r4 after boundary formation, Hoxa3 is maintained in both migrating neural crest cells and those positioned within the second branchial arch and associated ganglia. These results suggest that Hoxa3 expression is cell-autonomous in r6 and its associated neural crest. Our results suggest that neural crest cells expressing the same Hox gene are not eqivalent; they respond differently to environmental signals and exhibit distinct degrees of cell autonomy depending upon their rhombomere of origin

How Varroa Parasitism affects the immunological and nutritional status of the honey bee, Apis mellifera

We investigated the effect of the parasitic mite Varroa destructor on the immunological and nutritional condition of honey bees, Apis mellifera, from the perspective of the individual bee and the colony. Pupae, newly-emerged adults and foraging adults were sampled from honey bee colonies at one site in S. Texas, USA. Varroa infested bees displayed elevated titer of Deformed Wing Virus (DWV), suggestive of depressed capacity to limit viral replication. Expression of genes coding three anti-microbial peptides (defensin1, abaecin, hymenoptaecin) was either not significantly different between Varroa-infested and uninfested bees or was significantly elevated in Varroa-infested bees, varying with sampling date and bee developmental age. The effect of Varroa on nutritional indices of the bees was complex, with protein, triglyceride, glycogen and sugar levels strongly influenced by life-stage of the bee and individual colony. Protein content was depressed and free amino acid content elevated in Varroa-infested pupae, suggesting that protein synthesis, and consequently growth, may be limited in these insects. No simple relationship between the values of nutritional and immune-related indices was observed, and colony-scale effects were indicated by the reduced weight of pupae in colonies with high Varroa abundance, irrespective of whether the individual pupa bore Varroa

Efeito de substâncias desinfetantes na adesão à dentina de um adesivo de quarta geração

The purpose of the present study was to evaluate the influence of different disinfectant solutions on the tensile bond strength of a fourth generation dentin bonding agent. Forty non carious human molars were selected. Teeth were embedded in acrylic resin and ground until the exposure of a flat superficial dentin surface. Teeth were randomly divided in 4 groups and treated as follows: Group 1 - 2.5% NaOCl for 40 seconds; Group 2 - 2% chlorhexidine for 40 seconds; Group 3 - 1.23% acidulated fluoride for 4 minutes; and Group 4 - control (without disinfectant solution). Following treatments, Scotchbond Multipurpose Plus® (3M) was used according to the manufacturer’s instructions. After that, the test specimens were built with composite resin (Z100®-3M), using a standard Teflon matrix. The specimens were stored in distilled water for 24 hours at a temperature of 37ºC. The tensile strength test was performed using a Mini Instrom testing machine. The mean values obtained for each group, in MPa, were: Group 1 - 7.37 (± 2.51); Group 2 - 11.25 (± 4.65); Group 3 - 9.80 (± 3.11); and Group 4 - 10.96 (± 3.37). The results were submitted to statistical analysis using the ANOVA test, and no statistical significant differences among the groups were found. It can be concluded that the different disinfectant substances used in this research do not adversely affect dentin adhesion.O objetivo do presente trabalho foi avaliar a influência de diferentes substâncias de desinfecção cavitária na resistência à tração de um sistema adesivo de quarta geração. Foram selecionados 40 molares humanos livres de cáries. Os dentes foram incluídos em resina acrílica e desgastados até expor dentina superficial. Os dentes foram divididos aleatoriamente em 4 grupos e assim tratados: Grupo 1 - NaOCl a 2,5% por 40 segundos; Grupo 2 - clorexidina a 2% por 40 segundos; Grupo 3 - flúor-fosfato acidulado a 1,23% por 4 minutos; e Grupo 4 - controle. Após os diferentes tratamentos superficiais o sistema adesivo Scotchbond Multipurpose Plus® (3M) foi aplicado na dentina, de acordo com as instruções do fabricante. Os corpos-de-prova foram confeccionados com resina composta Z100® (3M) utilizando uma matriz padronizada. Após armazenagem em água destilada por 24 horas, os espécimes foram submetidos ao teste de tração em uma máquina universal Mini Instrom. Os resultados em MPa para os diferentes grupos foram: Grupo 1 - 7,37 (± 2,51); Grupo 2 - 11,25 (± 4,65); Grupo 3 - 9,80 (± 3,11); e Grupo 4 - 10,96 (± 3,37). Os dados foram submetido à análise estatística de variância, a qual não permitiu detectar diferenças estatisticamente significantes entre os grupos. Foi possível concluir que as substâncias desinfetantes não ocasionaram alteração na capacidade adesiva do sistema adesivo de quarta geração empregado

“Colmillos de sangre”: etnografías oníricas sobre las experiencias de ensoñación en jóvenes latinoamericanos residentes en la región de Los Lagos, Chile (2020-2023)

El articulo muestra reflexiones fenomenológicas a partir de una etnografía-narrativa sobre las experiencias de ensoñación que manifiestan jóvenes latinoamericanos residentes entre los años 2020-2023 en áreas urbanas de la región de Los Lagos, ciudades localizadas en la norpatagonia de Chile, a objeto de comprender las dimensiones culturales de la vida migrante y sus representaciones simbólicas asociadas con el mundo de los sueños. La metodología propuesta es, en un primer momento, pensada desde una etnografía especular que dialogaba con la interdisciplina, sobre todo en la elaboración de talleres participativos, los cuales permitieron la exploración del objeto de estudio desde las subjetividades como prácticas culturales que fueron narradas a través de la descripción densa. Los resultados muestran cómo las prácticas oníricas y las experiencias de ensoñación donde los sujetos interpretan sus experiencias vividas, se asociaban con la proyección de los significados migratorios en torno a sus estadías, deseos y demandas en Chile. Los aportes que hace este trabajo a los estudios migratorios son, precisamente, un tipo de conocimiento nuevo sobre las formas en las que los sujetos se relacionan e interaccionan en espacios de anclaje donde proyectan parte de sus experiencias basadas en el afrontamiento a los nuevos lugares de residencia, representaciones que bien pueden comprenderse como significados de la nostalgia, estados nerviosos y temores asociados con lo desconocido

Correlation between obesity and severity of distal radius fractures

Introduction: The incidence of obesity has increased significantly worldwide. Our hypothesis was that patients with obesity have a more severe distal radius fracture and we realized a study to evaluate this correlation between obesity and severity of distal radius fractures caused by low-energy injuries. Materials and methods: A total of 114 patients with distal radius fracture were examined in

Towards an eco-friendly coffee rust control : compilation of natural alternatives from a nutritional and antifungal perspective

Hemileia vastatrix (HV) is the pathogen responsible for the coffee leaf rust (CLR) disease that has spread globally. CLR causes losses of up to a billion dollars annually and affects all types of crops regardless of their production regime (organic or inorganic). Additionally, smallholders produce approximately 80% of coffee in developing countries. The condition causes losses of up to a billion dollars annually. It affects all types of crops regardless of their production regime (organic or inorganic). Approximately 80% of coffee is produced by smallholders in developing countries. Until the 90s, shaded-production systems and native varieties were encouraged; however, the rapid spread of CLR has forced farmers to migrate towards inorganic schemes, mainly due to a lack of knowledge about natural alternatives to pesticides that can be implemented to control HV. Therefore, the purpose of this article is to compile the currently existing options, emphasizing two key factors that guarantee efficient rust control: selective fungicidal activity against HV and the nutrition of coffee crops. Thus, by comprehending how these natural compounds (such as plant, bacteria, fungi, animals, or algae metabolites) impact coffee rust proliferation. Furthermore, since a various range of biochar effects contributes to the control of foliar fungal pathogens through modification of root exudates, soil properties, and nutrient availability, which influence the growth of antagonist microorganisms, we present a review of the pathogen-suppressive effects of biochar, and new control strategies suitable for organic schemes can be developed.Publisher PDFPeer reviewe