Arte público colaborativo- participativo. La función pedagógica y transformadora del arte colaborativo. POCS association- 24 horas una línea en la ciudad- Ciudades en red (2003-2008)

This text exposes the development from 2003 of POCS, association independent artists’ that investigate and develop projects in the public space and that it establishes relations with different groups.En este texto se expone el desarrollo desde 2003 de POCS, asociación independiente de artistas que investigan y desarrollan proyectos en el espacio público y que establece relaciones con diferentes colectivos

Mini-chromosome maintenance complexes form a filament to remodel DNA structure and topology.

Deregulation of mini-chromosome maintenance (MCM) proteins is associated with genomic instability and cancer. MCM complexes are recruited to replication origins for genome duplication. Paradoxically, MCM proteins are in excess than the number of origins and are associated with chromatin regions away from the origins during G1 and S phases. Here, we report an unusually wide left-handed filament structure for an archaeal MCM, as determined by X-ray and electron microscopy. The crystal structure reveals that an α-helix bundle formed between two neighboring subunits plays a critical role in filament formation. The filament has a remarkably strong electro-positive surface spiraling along the inner filament channel for DNA binding. We show that this MCM filament binding to DNA causes dramatic DNA topology change. This newly identified function of MCM to change DNA topology may imply a wider functional role for MCM in DNA metabolisms beyond helicase function. Finally, using yeast genetics, we show that the inter-subunit interactions, important for MCM filament formation, play a role for cell growth and survival

Functional role of PGAM5 multimeric assemblies and their polymerization into filaments.

PGAM5 is a mitochondrial protein phosphatase whose genetic ablation in mice results in mitochondria-related disorders, including neurodegeneration. Functions of PGAM5 include regulation of mitophagy, cell death, metabolism and aging. However, mechanisms regulating PGAM5 activation and signaling are poorly understood. Using electron cryo-microscopy, we show that PGAM5 forms dodecamers in solution. We also present a crystal structure of PGAM5 that reveals the determinants of dodecamer formation. Furthermore, we observe PGAM5 dodecamer assembly into filaments both in vitro and in cells. We find that PGAM5 oligomerization into a dodecamer is not only essential for catalytic activation, but this form also plays a structural role on mitochondrial membranes, which is independent of phosphatase activity. Together, these findings suggest that modulation of the oligomerization of PGAM5 may be a regulatory switch of potential therapeutic interest

24-hour changes in circulating prolactin, follicle-stimulating hormone, luteinizing hormone and testosterone in male rats subjected to social isolation

BACKGROUND: This work analyzes the effect of social isolation (a mild stressor) on the 24-h variation of pituitary-testicular function in young Wistar rats, assessed by measuring circulating levels of prolactin, FSH, LH and testosterone. METHODS: Animals were either individually caged or kept in groups (4–5 animals per cage) under a 12:12 h light-dark cycle (lights on at 0800 h) for 30 days starting on day 35 of life. Rats were killed at 4-h intervals during a 24-h cycle, beginning at 0900 h. RESULTS: Isolation brought about a decrease in prolactin, LH and testosterone secretion and an increase of FSH secretion. In isolated rats the 24-h secretory pattern of prolactin and testosterone became modified, i.e., the maximum in prolactin seen in control animals at the beginning of the activity span was no longer detected, whereas the maximum in circulating testosterone taking place at 1700 h in controls was phase-delayed to 2100 h in isolated rats. CONCLUSION: Social isolation affects the 24-h variation of pituitary-testicular function in young rats. Secretion of prolactin, LH and testosterone decreases, and secretion of FSH increases, in isolated rats. The maximum in prolactin seen in group-caged rats at the beginning of the activity span is not observed in isolated rats. The maximum in circulating testosterone taking place at the second part of the rest span in controls is phase-delayed to the light-dark transition in isolated rats

Control de los niveles de garantía de extracto etéreo, proteína bruta y fósforo declarados en alimentos comerciales para perros y gatos / Control of the warranty level of ether extract, gross protein and phosphorous expressed in the label of dog and cat

The warranty level of ether extract, gross protein and phosphorusof five dogs and three cats’ commercial food labels wereanalysed. Ether extract, gross protein and phosphorous were determinedby direct intermittent extract means of soxhlet, Kjeldahland colourimetric by reduction of sulphur-molybdate respectively.Each determination was repeated three times and the meanvalue obtained was expressed as a percentage of dry matter, thereafter,the obtained values were compared with those informedby the manufacturer. The ether extract values determined of fivedogs and two cat food was lower than those expressed in the label.The phosphorous value was lower in two dog food, and thelevel of gross protein was lower in four dogs and one cat food inrelation to the label data. Just one dog food showed values of etherextract higher than those expressed in the label. The content ofmoisture was determined by the indirect gravimetric method,desiccating the sample at 65 °C for 48 hours, and observing valuesof 46.6%, lower than those informed by the label. It concludedthat all dog food had incoherency in at least one of the parameterstudied with respect to the information presented in the manufacturerlabel. In relation to the cat food just one fulfils the valuesinformed in the manufacturer label. Finally, it was stunned thelow level of moisture found in all pet food analysed.Se analizaron los niveles de garantía de Extracto Etéreo, Proteína Bruta y Fósforo declarados en la etiqueta de alimentos balanceados para perros y gatos. Se evaluaron muestras obtenidas de 8 alimentos balanceados comerciales para perros y 3 paragatos. Para la determinación de Extracto Etéreo, Proteína Bruta y Fósforo se emplearon los métodos directo de extracción intermitente por Soxhlet, Kjeldahl y colorimétrico por reducción del sulfomolibdato respectivamente. Se realizaron tres repeticionesde cada análisis, el valor promedio calculado fue corregido respecto al porcentaje de materia seca. Los porcentajes corregidos, expresados en base a Materia Seca fueron comparados con los niveles de garantía informados por los fabricantes en las etiquetascon respecto al Extracto Etéreo el porcentaje expresado en la etiqueta fue menor en cinco alimentos para perros y dos para gatos. Respecto al porcentaje de Fósforo en dos alimentos para perros y de Proteína Bruta en cuatro alimentos para perros y uno para gatos fueron menores a los informados en las etiquetas. Se encontró mayor porcentaje de Extracto Etéreo en un alimento para cachorros. Los porcentajes de humedad, determinadospor el método gravimétrico indirecto por desecación a 65°C por 48 h, dieron porcentajes promedio de 46,6% inferior a los informados. Se concluye que todos los alimentos para perros tienen alguna incoherencia en alguno de los niveles de garantía informados en las etiquetas con respecto a Extracto Etéreo, Fosforo o Proteína Bruta. De los alimentos destinados a gatos, sólo uno cumplió con los niveles informados. Es llamativo el bajo porcentaje de humedad encontrado en todos los alimentos analizados.

Brucelosis canina

Canine brucellosis caused by Brucella canis is a contageous and infectious disease that affects dogs. It has been diagnosed in EEUU and several other coutries, including Russia, Japan, Nigeria, India, China and Argentina. Natural infection can occurs by vertical or horizontal route, by means of seminal or vaginal secretions and by oronasal and conjunctival mucous. The most significating sign of the disease is abortion and reproductive failure in females and orchitis and epididimitis followed by infertility in males. The diagnosis is based on isolation of the bacteria from hemoculture and serologic tests with specific antigens of Brucella canis. The treatment is expensive, extended and not 100% effective, and the infection often reccurs after it. The transmission of Brucella canis to man commonly occurs through contact with infected dogs or their secretions or through direct laboratory exposure, but is not frequent and is easily treated.La brucelosis canina causada por Brucella canis es una enfermedad infecciosa y contagiosa que afecta a los perros. Ha sido diagnosticada en EEUU y otros países, incluyendo Rusia, Japón, Nigeria, China y Argentina. La infección natural puede ocurrir por vía vertical u horizontal, a través de secreciones seminales o vaginales, y a través de mucosa oronasal y conjuntival. Los signos más significativos de la enfermedad en la hembra son el aborto y la falla reproductiva, en los machos la orquitis y la epididimitis seguidas de infertilidad. El diagnóstico se basa en el aislamiento de la bacteria a partir de he mocultivos y pruebas serológicas con antígeno específico de Brucella canis. El tratamiento es caro, prolongado, no es 100% efectivo y la infección usualmente recurre despué s del mismo. La transmisión de Brucella canis al hombre comúnmente ocurre por contacto directo con perros infectados, sus secreciones o a través de exposisción directa en laboratorio. El contagio no es frecuente, pero cuando ocurre es fácilmente tratada

Análise estrutural de flexo-torção: um comparativo analítico, experimental e numérico

Na solução dos problemas de engenharia, existem basicamente três abordagens: enfoque teórico (analítico), numérico ou experimental. Alguns problemas em específico requerem a utilização, de forma complementar, de métodos combinados. A extensometria é uma técnica utilizada para a análise experimental de tensões e deformações em estruturas mecânicas, máquinas e equipamentos, na qual utilizam-se extensômetros (strain-gauges), que são baseados na mudança de resistência elétrica do material ao ser submetido a tensões. Estes dispositivos também podem ser associados a transdutores para medir pressão, tensão, força, aceleração entre outros. Neste trabalho é realizado um comparativo dos valores de tensões e deformações presentes na estrutura de um dispositivo mecânico de flexo-torção, sendo o objetivo analisar e comparar os dados experimentais com os resultados analíticos e de simulações em software. Quanto aos resultados obtidos, foram utilizadas três massas diferentes nos experimentos, verificando que a tensão de Von Mises atingiu valores de 23, 24 e 27% distantes dos valores teóricos e 14, 15 e 19% distantes dos resultados simulados computacionalmente