584 research outputs found
A Study of the Type and Extent of Hearing Loss of Speech Defective Children in the Elementary Schools of Cache County and of the Logan City School Districts
Many articles and textbooks which have recently been written in the field of speech correction indicate that a high percent of all children who have speech defects also have a hearing deficiency. Some even say that a higher percent of these children have hearing deficiencies than do children who are normal in speech. Because of the great interest which has been aroused in the nature of the problems of the speech defectives, and because of the desire which exists for them to be helped in their handicaps, there is a necessity for their problems to be understood as thoroughly as possible. The present investigation has therefore been undertaken to establish the type and extent of hearing loss in the speech defective children in the first six grades of the elementary schools of Cache County and of the Logan City school districts
Fibulin-4 is essential for maintaining arterial wall integrity in conduit but not muscular arteries
Homozygous or compound heterozygous mutations in fibulin-4 (FBLN4) lead to autosomal recessive cutis laxa type 1B (ARCL1B), a multisystem disorder characterized by significant cardiovascular abnormalities, including abnormal elastin assembly, arterial tortuosity, and aortic aneurysms. We sought to determine the consequences of a human disease-causing mutation in FBLN4 (E57K) on the cardiovascular system and vascular elastic fibers in a mouse model of ARCL1B. Fbln4E57K/E57K mice were hypertensive and developed arterial elongation, tortuosity, and ascending aortic aneurysms. Smooth muscle cell organization within the arterial wall of large conducting vessels was abnormal, and elastic fibers were fragmented and had a moth-eaten appearance. In contrast, vessel wall structure and elastic fiber integrity were normal in resistance/muscular arteries (renal, mesenteric, and saphenous). Elastin cross-linking and total elastin content were unchanged in large or small arteries, whereas elastic fiber architecture was abnormal in large vessels. While the E57K mutation did not affect Fbln4 mRNA levels, FBLN4 protein was lower in the ascending aorta of mutant animals compared to wild-type arteries but equivalent in mesenteric arteries. We found a differential role of FBLN4 in elastic fiber assembly, where it functions mainly in large conduit arteries. These results suggest that elastin assembly has different requirements depending on vessel type. Normal levels of elastin cross-links in mutant tissue call into question FBLN4\u27s suggested role in mediating lysyl oxidase-elastin interactions. Future studies investigating tissuespecific elastic fiber assembly may lead to novel therapeutic interventions for ARCL1B and other disorders of elastic fiber assembly. 2017 © The Authors, some rights reserved
Navigating Pandemic Schooling for Novice Teachers
Teachers navigated a vast set of challenges during the 2019-20 school year when a pandemic shut down school and changed the face of classrooms. The challenges that emerged during this time were heaped upon the already full plates of the novice teachers featured in this study who were just gaining confidence in the classroom. This article highlights the six themes that emerged from interviews done in spring of 2020 as part of a larger longitudinal study following teacher education graduates. This snapshot of the data provides inside into the effect of the early stages of the pandemic on these teachers classrooms, perspectives, roles, and impact on their students
The Effects of Chanellization and Channel Restoration on Aquatic Habitat and Biota of the Pecos River, New Mexico
River channelization has been shown to negatively impact riverine ecosystems by degrading aquatic habitat conditions, decreasing diversity of both fish and aquatic invertebrate assemblages and impairing fish recruitment. As knowledge of the negative impacts of channelization has increased, so have channel restoration efforts. We evaluated a recent channel restoration project on the Pecos River, New Mexico by comparing abiotic and biotic conditions among five reaches of river, including the restored reach, an unchannelized reach and a channelized reach all prone to streamflow intermittence and an unchannelized reach and channelized reach more perennial in nature. Our first objective was to assess reach-scale differences in aquatic habitat conditions and fish assemblage structure and diversity, as well as to assess mesohabitat associations of fish species. We found that aquatic habitat availability was greatest in the more perennial unchannelized reach and that little difference in habitat availability existed among other reaches. In addition, we found minimal differences in habitat diversity among reaches. Diversity of fish assemblages showed no difference among reaches and differences in fish assemblage composition among reaches were minimal. We found that pelagic-broadcast spawning species were associated with high velocity habitats of greater depth and volume, while demersal adhesive spawning species and live bearers were associated with low velocity habitats of lesser depth and volume. vi Our second objective was to assess reach-scale differences in nursery habitat availability, fish recruitment and abundance of potential prey items (i.e. meiofauna). We found that slackwater availability was greatest in unchannelized reaches and that differences in recruitment were noticeable for two fish species, the plains killifish (Fundulus zebrinus) and western mosquitofish (Gambusia affinis). Plains killifish exhibited greater recruitment in unchannelized reaches, while western mosquitofish exhibited greater recruitment in channelized reaches. The abundance of total potential prey items was greatest in the more perennial channelized reach. Collectively, channel restoration showed no improvement to aquatic habitat conditions, fish assemblage diversity and composition, provision of slackwater nursery areas, recruitment of early-juvenile fishes and provision of potential prey items. We feel that periods of low discharge and streamflow intermittence likely impaired our ability to effectively assess the restoration effort. Thus, we suggest that future restoration efforts focus on a more holistic approach that includes both physical channel restoration and flow regime restoration
Identification of the growth factor-binding sequence in the extracellular matrix protein MAGP-1
Editorial
Análisis de casos
Reforma agraria y lucha por la tierra en América Latina
La Reforma Agraria en América Latina: una revolución frustrada
Plinio Arruda Sampaio
A Nova Questão Agrária e a Reinvenção do Campesinato: o caso do MST
Carlos Walter Porto-Gonçalves
El movimiento campesino en el Paraguay: conflictos, planteamientos y desafÃos
Tomás Palau Viladesau
Movimientos campesinos e indÃgenas en México: la lucha por la tierra
Luciano Concheiro Bórquez y Sergio Grajales Ventura
Las luchas campesinas en Colombia en los albores del siglo XXI: de la frustración a la esperanza
IsaÃas Tobasura Acuña
Documentos
O que precisa ser feito para mudar a vida do povo!
Comunicado del Frente Nacional Campesino
Ezequiel Zamora de Venezuela
CronologÃa del conflicto
La geografÃa polÃtica
del conflicto social en América Latina
José Seoane y Clara Algranati
Región Sur
Los sindicatos uruguayos ante el primer gobierno de izquierda
Luis Senatore y Jaime Yaffé
• Argentina
• Brasil
• Chile
• Paraguay
• Uruguay
Región Andina
Quito en abril: los forajidos derrotan al coronel
Mario Unda
• Bolivia
• Colombia
• Ecuador
• Perú
• Venezuela
Región Norte
La Guatemala de la resistencia y de la esperanza: las jornadas de lucha contra el CAFTA
Simona Violetta Yagenova
• Costa Rica
• El Salvador
• Guatemala
• Honduras
• México
• Nicaragua
• Panamá
• Puerto Rico
• República Dominicana
Debates
Territorio y movimientos sociales
O retorno do território Apresentação por Maria Adélia Aparecida de Souza
Milton Santos
Outros territórios, outros mapas
Ana Clara Torres Ribeiro
Movimentos socioterritoriais e movimentos socioespaciais
Bernardo Mançano Fernandes
Territorios en disputa: iniciativas productivas y acción polÃtica en Mosconi, Argentina
Norma Giarracca y Juan Wahren
Sarjam [Vocablo en lengua aymara que significa ándate]
Jorge A. Sainz Cardon
Controlling release from 3D printed medical devices using CLIP and drug-loaded liquid resins
Mass customization along with the ability to generate designs using medical imaging data makes 3D printing an attractive method for the fabrication of patient-tailored drug and medical devices. Herein we describe the application of Continuous Liquid Interface Production (CLIP) as a method to fabricate biocompatible and drug-loaded devices with controlled release properties, using liquid resins containing active pharmaceutical ingredients (API). In this work, we characterize how the release kinetics of a model small molecule, rhodamine B-base (RhB), are affected by device geometry, network crosslink density, and the polymer composition of polycaprolactone- and poly (ethylene glycol)-based networks. To demonstrate the applicability of using API-loaded liquid resins with CLIP, the UV stability was evaluated for a panel of clinically-relevant small molecule drugs. Finally, select formulations were tested for biocompatibility, degradation and encapsulation of docetaxel (DTXL) and dexamethasone-acetate (DexAc). Formulations were shown to be biocompatible over the course of 175-days of in vitro degradation and the clinically-relevant drugs could be encapsulated and released in a controlled fashion. This study reveals the potential of the CLIP manufacturing platform to serve as a method for the fabrication of patient-specific medical and drug-delivery devices for personalized medicine
Sterilization of lung matrices by supercritical carbon dioxide
Lung engineering is a potential alternative to transplantation for patients with end-stage pulmonary failure. Two challenges critical to the successful development of an engineered lung developed from a decellularized scaffold include (i) the suppression of resident infectious bioburden in the lung matrix, and (ii) the ability to sterilize decellularized tissues while preserving the essential biological and mechanical features intact. To date, the majority of lungs are sterilized using high concentrations of peracetic acid (PAA) resulting in extracellular matrix (ECM) depletion. These mechanically altered tissues have little to no storage potential. In this study, we report a sterilizing technique using supercritical carbon dioxide (ScCO(2)) that can achieve a sterility assurance level 10(−6) in decellularized lung matrix. The effects of ScCO(2) treatment on the histological, mechanical, and biochemical properties of the sterile decellularized lung were evaluated and compared with those of freshly decellularized lung matrix and with PAA-treated acellular lung. Exposure of the decellularized tissue to ScCO(2) did not significantly alter tissue architecture, ECM content or organization (glycosaminoglycans, elastin, collagen, and laminin), observations of cell engraftment, or mechanical integrity of the tissue. Furthermore, these attributes of lung matrix did not change after 6 months in sterile buffer following sterilization with ScCO(2), indicating that ScCO(2) produces a matrix that is stable during storage. The current study's results indicate that ScCO(2) can be used to sterilize acellular lung tissue while simultaneously preserving key biological components required for the function of the scaffold for regenerative medicine purposes
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