CRITICAL URBAN PEDAGOGY: Convites as Sites of Southern Urbanism, Solidarity Construction and Urban Learning

Learning from the pedagogical potentials of Southern city-making practices is imperative to foster emancipatory urban learning settings. However, the ways in which urban learning spaces beyond professional settings operate and how Southern urbanism practices constitute new critical pedagogies are poorly understood. We draw on research about urban learning on ‘slum upgrading’ in the city of Medellín (Colombia), a benchmark in dealing in tandem with informality and urban violence, to analyze the pedagogical potentials of convites. Convites are an essential sociospatial mechanism of self-build settlements rooted in solidarity networks that initiate collective action and celebration through public cooking. This practice of makeshift community kitchens led by women became the backbone of the response to the scarcities caused by the pandemic in self-built neighborhoods in Latin America. In this article we ask what Southern urbanism and critical pedagogy can learn from convites. We then analyze the ways in which convites combine community kitchens as learning environments, the use of collective storytelling as a learning device, and collective action through networked solidarities. We argue that critical urban pedagogy is a situated pedagogy derived from everyday relations of place, body and materiality infused by memory and articulated by storytelling

Effect on signal-to-noise ratio of splitting the continuous contacts of cuff electrodes into smaller recording areas.

BackgroundCuff electrodes have been widely used chronically in different clinical applications. This neural interface has been dominantly used for nerve stimulation while interfering noise is the major issue when employed for recording purposes. Advancements have been made in rejecting extra-neural interference by using continuous ring contacts in tripolar topologies. Ring contacts provide an average of the neural activity, and thus reduce the information retrieved. Splitting these contacts into smaller recording areas could potentially increase the information content. In this study, we investigate the impact of such discretization on the Signal-to-Noise Ratio (SNR). The effect of contacts positioning and an additional short circuited pair of electrodes were also addressed.MethodsDifferent recording configurations using ring, dot, and a mixed of both contacts were studied in vitro in a frog model. An interfering signal was induced in the medium to simulate myoelectric noise. The experimental setup was design in such a way that the only difference between recordings was the configuration used. The inter-session experimental differences were taken care of by a common configuration that allowed normalization between electrode designs.ResultsIt was found that splitting all contacts into small recording areas had negative effects on noise rejection. However, if this is only applied to the central contact creating a mixed tripole configuration, a considerable and statistically significant improvement was observed. Moreover, the signal to noise ratio was equal or larger than what can be achieved with the best known configuration, namely the short circuited tripole. This suggests that for recording purposes, any tripole topology would benefit from splitting the central contact into one or more discrete contacts.ConclusionsOur results showed that a mixed tripole configuration performs better than the configuration including only ring contacts. Therefore, splitting the central ring contact of a cuff electrode into a number of dot contacts not only provides additional information but also an improved SNR. In addition, the effect of an additional pair of short circuited electrodes and the "end effect" observed with the presented method are in line with previous findings by other authors

Pandemias, zoonosis y comercio de animales silvestres

La pandemia de COVID-19 tiene un origen zoonótico: fue transmitida de los animales a los humanos. Lo mismo ha sucedido con otras epidemias recientes (como las causadas por los virus SARS-CoV-1 y H7N9, entre otros). Estas epidemias surgieron en un contexto de explotación animal: el comercio de animales silvestres. Mucha gente ha pedido la prohibición total de la venta de animales silvestres en mercados. Sin embargo, la prohibición puede ser contraproducente y tener peores consecuencias tanto para los animales como para la salud pública. Este artículo argumenta en contra de una prohibición total y a favor de una regulación progresiva que tome en cuenta el bienestar de los animales, pero que tenga como finalidad última la desaparición del comercio de animales silvestres

Patterns of evolution of host proteins involved in retroviral pathogenesis

BACKGROUND: Evolutionary analysis may serve as a useful approach to identify and characterize host defense and viral proteins involved in genetic conflicts. We analyzed patterns of coding sequence evolution of genes with known (TRIM5α and APOBEC3G) or suspected (TRIM19/PML) roles in virus restriction, or in viral pathogenesis (PPIA, encoding Cyclophilin A), in the same set of human and non-human primate species. RESULTS AND CONCLUSION: This analysis revealed previously unidentified clusters of positively selected sites in APOBEC3G and TRIM5α that may delineate new virus-interaction domains. In contrast, our evolutionary analyses suggest that PPIA is not under diversifying selection in primates, consistent with the interaction of Cyclophilin A being limited to the HIV-1M/SIVcpz lineage. The strong sequence conservation of the TRIM19/PML sequences among primates suggests that this gene does not play a role in antiretroviral defense

Activity of ancestral restriction factors against ancient retroviruses

Analysis of TRIM5α and APOBEC3G genes suggests that these two restriction factors underwent strong positive selection throughout primate evolution. This pressure was possibly imposed by ancient exogenous retroviruses, of which endogenous retroviruses are remnants. Our study aims to assess in vitro the activity of these factors against ancient retroviruses by reconstructing their ancestral gag sequences, as well as the ancestral TRIM5α and APOBEC3G for primates. Based on evolutionary genomics approach, we reconstructed ancestors of the two largest families of human endogenous retroviruses (HERV), namely HERV-K and HERV-H, as well as primate ancestral TRIM5α and APOBEC3G variants. The oldest TRIM5α sequence was the catarhinne TRIM5α, common ancestor of Old World monkeys and hominoids, dated from 25 million years ago (mya). From the oldest, to the youngest, ancestral TRIM5α variants showed less restriction of HIV-1 in vitro [1]. Likewise three ancestral APOBEC3Gs sequences common to hominoids (18 mya), Old World monkeys, and catarhinnes (25 mya) were reconstructed. All ancestral APOBEC3G variants inhibited efficiently HIV-1Δvif in vitro, compared to modern APOBEC3Gs. The ability of Vif proteins (HIV-1, HIV-2, SIVmac and SIVagm) to counteract their activity tallied with the residue 128 on ancestral APOBEC3Gs. Moreover we are attempting to reconstruct older ancestral sequences of both restriction factors by using prosimian orthologue sequences. An infectious onemillion- years-old HERV-KCON previously reconstituted was shown to be resistant to modern TRIM5α and APOBEC3G [2]. Our ancestral TRIM5α and APOBEC3G variants were inactive against HERV-KCON. Besides we reconstructed chimeric HERV-K bearing ancestral capsids (up to 7 mya) that resulted in infectious viruses resistant to modern and ancestral TRIM5α. Likewise HERV-K viruses bearing ancestral nucleocapsids will be tested for ancestral and modern APOBEC3G restriction. In silico reconstruction and structural modeling of ancestral HERV-H capsids resulted in structures homologous to that of the gammaretrovirus MLV. Thus we are attempting to construct chimeric MLV virus bearing HERV-H ancestral capsids. These chimeric ancestral HERVs will be tested for infectivity and restriction by ancestral TRIM5α. Similarly chimeric MLV viruses bearing ancestral HERV-H nucleocapsids will be reconstructed and tested for APOBEC3G restriction

The Application of Beta-Tricalcium Phosphate in Implant Dentistry: A Systematic Evaluation of Clinical Studies

The demand for synthetic graft materials in implant dentistry is rising. This systematic review aims to evaluate the survival rate of dental implants placed simultaneously with bone regeneration procedures using the material β-tricalcium phosphate, one of the most promising synthetic graft materials. The electronic search was conducted in PubMed, Scielo, and the Cochrane Central Register of Controlled Trials. Five randomized clinical trials, one non-randomized controlled clinical trial and four observational studies without control group were include. Implant survival rate and other clinical, radiographic, and histological parameters did not differ from those of implants placed simultaneously with another type of graft material, or placed in blood clots or natural alveolar ridges. Based on the available literature, β-tricalcium phosphate seems to be a promising graft material in implant dentistry. Nevertheless, more randomized clinical trials, with long follow-up periods, preoperative and postoperative CBCT, and histological analysis, are necessary to assess its long-term behavior

Estudio del aprovechamiento de los desechos del camarón y otros crustáceos.

El presente estudio se realizó en Frigopesca, Cartagena y en la Universidad Tecnológica del Magdalena, Santa Marta (Magdalena), Colombia, con la finalidad de efectuar un estudio del Aprovechamiento de los Desechos del Camarón y otros Crustáceos, utilizándolos en la elaboración de productos alimenticios para consumo Humano y/o Animal. Las materias primas pesqueras- adquiridas en las plantas operadoras de Camarón de Cartagena y en la Planta Piloto Pesquera Taganga, fueron sometidas a un lavado con solución de hipoclorito de sodio 25 p.m. por un tiempo de 20 minutos, con el fin de disminuir la carga bacteriana. A continuación, se realizaron los procesos de cocción, secado solar, molienda (molino manual Corona) y empacado. También se elaboró Harina de Desechos de Crustáceos (H.D.C.) en la Fábrica Frigo pesca, Cartagena; mediante el método de reducción 50% (Dieta 3), respectivamente. Por otro lado, el agua-resultante de ja cocción de los Desechos de Crustáceos fue analizada física y bromatológicamente. Las tres harinas elaboradas con materias primas pesqueras fueron analizadas bromatológica y físicamente determinándose proteína, grasa, humedad y cenizas (g/100g) entre 47.39,15.50, 7.45 y 17.58 (H.D.C.); 44.04, 4.90, 12.49 y 24.21 (Harina de cáscara de camarón); 95.30, 2.48, 7.12 y 4.03 (Harina de pulpa y desechos de Tiburón). La densidad (g/cc) y grado de emparedamiento no enzimático (absorbancia a 420nm/g) fueron de:0.58 y 0.60 (H.D.C.); 0.44 y 0.56 ¿Harina de cáscara de camarón); 0?52 y.0.11 (Harina de pulpa y desechos de Tiburón). Según el análisis granulométrico las tres harinas poseen un grado de uniformidad de orden "Mediano". Los rendimientos obtenidos oscilaron entre 50 y 30% (H.D.C.); 5% (Harina, integral de tiburón) y 20% (Harina de Cáscara de Camarón). El análisis microbiológico en la H.D.C. procesada en la Planta Piloto Pesquera Taganga mostró presencia negativa de Salmonella-Shigella. E. coli, Termófilos y N.M.P. de Coliformes Totales y Fecales; mientras 'que el recuento de Anaerobios, Mesófilo y StaphylococCus aureus y Hongos y Levaduras presentaron una-carga menor a 103m.o/ge_ Cada una de las harinas elaboradas fue almacenada a temperatura ambiente (35-37gC), por cuatro meses, tiempo después del cual se mantuvieron estables la coloración, el olor y la apariencia general. Durante la fabricación de las pastas alimenticias con H.D.C. ' se adicionaron ingredientes y preservativos- (colorante, B.H.T. polifosfato de sodio, glutamato monosódico, ácido ascórbico y nitrito de sodio, los cuales se mantuvieron en-relación constante en cada una de las formulaciones. El mezclado y la homogenización se llevaron a cabo durante,10 minutos, en un mezclador de paletas eléctrico, agregando agua (37 m1/100g) a 40ºC. El secado subsiguiente al moldeado, se realizó a temperatura ambiente durante 24 horas. En las pastas alimenticias los análisis bromatológicos determinaron los siguientes valores de proteína, cenizas y humedad (g/100g): 18.57, 1.80 y 7.56 (Formulación con 10% de H.D.C.); 23.55, 3.20 y 10.08 (Formulación con el 20% de H.D.C.); 20.40 y 9.20 (Formulación con el 15% de H.D.C.). Los análisis microbiológicos determinaron recuentos negativos de Salmonella-Shigella, N.M.P. de Coliformes Totales y Fecales y E. coli. Anaerobias, Hongos y Levaduras, Staphylococcus auAoreus, Termófilos r Mesó-filos presentaron carga inferior a 103 m.o/g. Los cuales se encuentran dentro de los intervalos permisibles para este alimento de origen pesquero: Las pastas alimenticias fueron empacadas en bolsas de polietileno y almacenadas a temperatura ambiente (35-37QC), por cuatro meses. A través de los procesos tecnológicos realizados para la obtención de las pastas alimenticias, se determinó un rendimiento del 95%, presentándose pérdidas sólo durante el corte. Con base en una rentabilidad del 25% sobre el costo-de producción, se obtuvieron los siguientes precios de venta ($/Kg): 179.08 (Formulación con 10$94.00 Kg). Se estableció un precio de venta para cada dieta peletizada, con base en una rentabilidad: bruta del 25%, igual ($/Kg) a': 159.34 (Dieta 1); 12.5.33' (Dieta 2) y 91.101(Dieta 3). Además, se intentó la extracción química de quitina a partir de los caparazones de -e-ama-x.6n Con resultados no satisfactorios desde el punto de vista técnico. Así mismo, el agua resultante de- la cocción de los desechos de crustáceos fue analizada bromatológicamente, determinándose proteína igual a 6.48 g/100g grasa, 10.88 g/100g y cenizas, 12.05 g/100g, condición favorable que permita la utilización futura de ésta "agua de cola" para 'Preparación de alimento destinado a la nutrición animal

Nutrient removal from agricultural run-off in demonstrative full scale tubular photobioreactors for microalgae growth

The objective of this paper is to present the design, construction and operation (during one year) of 3 full scale semi-closed, horizontal tubular photobioreactors (PBR, 11.7 m3 of volume each) used to remove nutrients of a mixture of agricultural run-off (90%) and treated domestic wastewater (10%). PBRs were located outdoor and have 2 paddlewheels (engines of 0.25 kW) to ensure the movement of the mixed liquor. The microalgal biomass produced in the PBRs was harvested in a static lamella settling tank in which a polyaluminium chloride coagulant is applied. Each PBR treated in average 2.3 m3/d, being the actual mean hydraulic retention time 5 d. PBRs were submitted to strong seasonal changes regarding solar radiation and temperature, which had a direct impact in the activity of microalgae and the efficiency of the system. Higher mixed liquor pH values were registered in summer (daily average > 10). These high values were not observed in the effluents because the system was designed to discharge the mixed liquor (effluent) only at the end of night, when pH reached the lowest daily values (around 8.5). Most of the influent and effluent nitrogen content was inorganic (average of 9.0¿mg¿N/L and 3.17 mg N/L, respectively), and in the form of nitrate (62% and 50%, respectively). Average nitrogen removal efficiency was 65%, with values of around 90% in summer, 80% in autumn, 50% in winter and 60% in spring. Most of the influent and effluent phosphorus content was in the form of orthophosphate. Influent average was 0.62 mg P/L, but with great variations and in a considerable number of samples not detected. Removal efficiency (when influent values were detected) was very high during all the study, usually greater than 95%, and there were not clear seasonal trends for efficiency as observed for TIN. Volumetric biomass production greatly changed between seasons with much lower values in winter (7 g VSS (volatile suspended solids)/m3·d) than in summer (43 g VSS/m3·d). Biomass separation efficiency of the settler was very good in either terms of turbidity and total suspended solids, being most of the time lower than 5 UNT and 25 mg/L, respectively. Overall this study demonstrated the reliable and good effectiveness of microalgae based technologies such as the PBR to remove nutrients at a full scale size.Peer ReviewedPostprint (author's final draft

Nutrient removal from agricultural run-off in demonstrative full scale tubular photobioreactors for microalgae growth

The objective of this paper is to present the design, construction and operation (during one year) of 3 full scale semi-closed, horizontal tubular photobioreactors (PBR, 11.7 m3 of volume each) used to remove nutrients of a mixture of agricultural run-off (90%) and treated domestic wastewater (10%). PBRs were located outdoor and have 2 paddlewheels (engines of 0.25 kW) to ensure the movement of the mixed liquor. The microalgal biomass produced in the PBRs was harvested in a static lamella settling tank in which a polyaluminium chloride coagulant is applied. Each PBR treated in average 2.3 m3/d, being the actual mean hydraulic retention time 5 d. PBRs were submitted to strong seasonal changes regarding solar radiation and temperature, which had a direct impact in the activity of microalgae and the efficiency of the system. Higher mixed liquor pH values were registered in summer (daily average > 10). These high values were not observed in the effluents because the system was designed to discharge the mixed liquor (effluent) only at the end of night, when pH reached the lowest daily values (around 8.5). Most of the influent and effluent nitrogen content was inorganic (average of 9.0¿mg¿N/L and 3.17 mg N/L, respectively), and in the form of nitrate (62% and 50%, respectively). Average nitrogen removal efficiency was 65%, with values of around 90% in summer, 80% in autumn, 50% in winter and 60% in spring. Most of the influent and effluent phosphorus content was in the form of orthophosphate. Influent average was 0.62 mg P/L, but with great variations and in a considerable number of samples not detected. Removal efficiency (when influent values were detected) was very high during all the study, usually greater than 95%, and there were not clear seasonal trends for efficiency as observed for TIN. Volumetric biomass production greatly changed between seasons with much lower values in winter (7 g VSS (volatile suspended solids)/m3·d) than in summer (43 g VSS/m3·d). Biomass separation efficiency of the settler was very good in either terms of turbidity and total suspended solids, being most of the time lower than 5 UNT and 25 mg/L, respectively. Overall this study demonstrated the reliable and good effectiveness of microalgae based technologies such as the PBR to remove nutrients at a full scale size.Peer ReviewedPostprint (author's final draft