Globally smooth expressions for shock pressure decay in impacts

Hypervelocity meteorite impacts on planets subject the target to very high shock pressures. The isobars in the affected region are approximately spherical and centered on a point at a certain depth below the point of impact. The decay of the shock pressure with increasing distance from that center is usually represented in the form lg p=a+n lg(r/R), where p is the shock pressure, r is the distance from the center of the sphere, R is the radius of the impactor, and a and n are fitting constants; a similar relation is also used for the particle velocity. Although its simplicity seems to speak in its favor, this form has some problems: it is not bounded from above, thus necessitating an imposed maximum value that depends on additional assumptions; the slope of the decay is not accurately described by a single n for all r; the transition between domains with different decay parameters introduces kinks into p(r) at poorly defined points. It is therefore proposed to replace the decay law with other functional forms that are bounded and smooth and can be fully derived from data from numerical experiments. The proposed functions are applied to data of dunite-on-dunite impacts from the literature

Regulación de la respuesta inmune en cepas de distinta virulencia del PRRSV-1

Forty years after its appearance, Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) continues being a major hazard for the economy of the porcine sector, due to the lack of fully effective tools for its diagnosis and control. This scenario, together with the re-emergence of virulent strains, has increased the interest of the scientific community in the study of the immunopathogenesis of the plethora of PRRSV strains. Virulent PRRSV strains cause more severe signs and more striking lesions, together with high viraemia and viral loads in different organs as well as an aberrant and erratic immune response. Recently, in 2018, the established genetic and antigenic differences between the former European genotype or PRRSV-1 and the American genotype or PRRSV-2 have led to classify them into two different viral species Betaarterivirus suid 1 (for PRRSV-1) and Betaarterivirus suid 2 (for PRRSV-2). One of the main characteristics of PRRSV, regardless of its virulence, is its ability to modulate the host immune response, facilitating viral distribution, replication and latency in the body. The following doctoral thesis entitled “Regulation of the host immune response by PRRSV-1 strains of different virulence” delves into until know underexplored processes modulated during the early stage of infection with PRRSV in target organs of infected piglets, carrying out a comparative study between two PRRSV-1 strains of different virulence, the low virulent 3249 strain and the virulent Lena strain. The thymus, as the source of development and maturation of T lymphocytes, has a key role in the proper establishment of the immune response. Of note, thymic atrophy is one of the characteristic lesions of PRRSV, especially described in animals infected by virulent strains of the virus. In this sense, the induction of cell death phenomena such as apoptosis has been one of the postulated mechanisms able to induce this thymic atrophy during PRRSV infection, modulating the host immune response. Thus, the objective of the first work of this doctoral thesis was the assessment of the lesional picture and the evaluation of the cell death phenomena in the thymus of infected piglets with the two strains of the virus above mentioned. Animals infected with the virulent Lena strain showed evident thymus atrophy in comparison with thymi from animals of either control or 3249-infected groups. This increase in the degree of injury in the animals infected with the virulent strain was related to a rise in the viral load and the expression of nucleocapsid protein (N protein) of the virus in this organ. Thymi from animals infected with 3249 strain, on the contrary, exhibited a mild to moderate degree of injury with lower levels of N protein and PRRSV viral load in the thymus. Additionally, in the thymus from animals infected with Lena strain, an increase in the expression of the generic marker of cell death TUNEL (terminal deoxynucleotidyl transferase dUTP nick-end labeling) and the protein cleaved caspase-3 (cCasp3), an executioner caspase in which converge extrinsic and intrinsic pathways of apoptosis, were observed by immunohistochemical labelling, coinciding with the enhancement in the severity of the lesion. In the thymus from both infected groups, a greater induction of the extrinsic pathway of apoptosis was observed, evidenced by an increase in the cleaved caspase-8 (cCasp8) and fas cell death receptor (Fas) proteins. This increase in cell death phenomena, especially in Lena strain-infected animals, may cause a lower number of viable and mature T lymphocytes and, consequently, an impairment in the host immune response. This finding helps to explain, at least in part, the increase in fever and the greater clinical signs, such as apathy, lethargy, anorexia, and respiratory signs, as well as the greater intensity of the lesions, for instance, suppurative bronchopneumonia, observed in these animals. In addition to induction of apoptosis in the thymus, improper T lymphocytes activation also constitutes a mechanism for modulating the immune response during infection with PRRSV. During antigen presentation by antigen-presenting cells (APCs) to T lymphocytes, the interplay of certain stimulatory and inhibitory signals, among others, is required. Under physiological conditions, inhibitory signals act as a brake for the immune system, modulating the inflammatory response and inducing immunotolerance. However, in pathological situations, such as cancer or chronic infections, these molecules, known as immune checkpoints, act as an escape mechanism, causing inadequate T-cell activation. In addition, some of these molecules may also affect T-cell development in the thymus as well as the activation and proliferation of T-cells in target organs and secondary lymphoid organs. Under this context, the second and third studies of this doctoral thesis aimed to evaluate the expression as well as the role of immune checkpoints in target organs (thymus, lung and tracheobronchial lymph node) of pigs infected with the two PRRSV-1 strains of different virulence. In the second study, focused on the thymus, several coinhibitory immune checkpoints [programmed cell death/programmed death-ligand 1 (PD1/PDL1), cytotoxic T-Lymphocyte antigen-4 (CTLA4), T-cell immunoglobulin domain and mucin domain 3 (TIM3), lymphocyte activating 3 (LAG3), CD200 receptor 1 (CD200R1) and indoleamine 2,3-dioxygenase 1 (IDO1)], related to the development and maturation of T lymphocytes, were evaluated using real-time quantitative PCR (qRT-PCR) and immunohistochemistry. The results showed an overexpression of the immune checkpoints PDL1, CTLA4, TIM3, LAG3 and IDO1, especially in the thymus of Lena-infected piglets, from the first week post-infection. The co-expression of these molecules may affect T lymphocytes development, maturation, and selection in the thymus and, in addition, in our study was associated with disease progression and apoptosis phenomena in infected pigs. The third study, focused on the lung and the tracheobronchial lymph node, comprised both coinhibitory [CTLA4, T-cell immunoreceptor with Ig and ITIM domains (TIGIT), PD1/PDL1, TIM3, LAG3 and IDO1] and costimulatory [CD28, CD226, tumour necrosis receptor superfamily member 9 (TNFRSF9), L-selectin (SELL or CD62L), inducible T-cell costimulator (ICOS) and CD40] immune checkpoints. Our results highlighted a mild increase of costimulatory molecules together with an earlier and stronger upregulation of coinhibitory molecules in target organs from PRRSV-1 infected animals, especially in the lung from virulent Lena strain. Simultaneous expression of coinhibitory immune checkpoints suggests a synergistic effect of these molecules most probably oriented to control the exacerbated inflammatory response during the early stage of PRRSV infection. In addition, the sustained expression of some immune checkpoints, particularly during late stages of PRRSV infection, might also impact the activation and proliferation of T cells impairing the onset of an efficient host immune response. During the process of antigen presentation and polarisation of T lymphocytes, they undergo a series of divisions and differentiations that will give rise to effector T lymphocytes, capable of producing specific cytokines and inducing cytolytic activity by proteins such as Fas/FasL. This event is determined by the action of different transcription factors (TFs), proteins that regulate cellular gene expression. Thus, the expression of the TF T-box transcription factor 21 (T-bet) will result in a polarisation towards a Th1 type response, forkhead box P3 (FOXP3) in a differentiation towards a regulatory response by regulatory T lymphocytes (Tregs), GATA binding protein 3 (GATA3) will be related to Th2 response and the TF eomesodermin (EOMES) will lead towards a cytotoxic response in charge of CD4 cytotoxic T lymphocytes (CTLs). Despite the importance of TFs in the onset of the adaptive immune response, their study in the context of PRRSV infection is scarce. Therefore, the third objective of this doctoral thesis was to evaluate the expression by qRT-PCR of different TFs (T-bet, GATA3, FOXP3 and EOMES) as well as the expression of the different effector cytokines [interferon gamma (IFNG), tumour necrosis factor alpha (TNFA) and interleukin (IL)-10 (IL10)] and FASL in target organs (lung, tracheobronchial lymph node and thymus) of pigs infected with two PRRSV-1 strains of different virulence. Organs from animals belonging to both infected groups, but especially those infected with Lena strain, showed an overexpression of the TFs T-bet, EOMES and FOXP3 together with an increase in the cytokine IFNG at the end of the study. These results show a polarisation of T cells towards a response of Th1 type, Tregs and CD4 CTLs, particularly after infection with the virulent Lena strain. Altogether, this doctoral thesis analyses different mechanisms which underlie PRRSV immunopathogenesis and serves as a basis for future functional studies addressed to better understand the disease.Cuarenta años después de su aparición, el Virus del Síndrome Reproductivo y Respiratorio Porcino (PRRSV, del inglés Porcine Reproductive and Respiratory Syndrome Virus) sigue siendo uno de los agentes patógenes con mayor repercusión económica en el sector porcino, debido a la falta de herramientas totalmente eficaces para su diagnóstico y control. Esto unido a la reemergencia de cepas virulentas ha aumentado el interés por parte de la comunidad científica en el estudio de la inmunopatogenia de las diferentes cepas del virus. Las cepas virulentas del PRRSV producen una sintomatología y lesiones más graves que las cepas clásicas o de baja virulencia, y se asocian con una elevada carga viral tanto en suero como en tejidos. Además, la respuesta inmune frente a la enfermedad es aberrante y errática. Debido a sus diferencias biológicas y a su aislamiento en los dos continentes, a principios de los 90 se designaron dos genotipos distintos del virus, genotipo europeo o PRRSV-1 y genotipo americano o PRRSV-2. Recientemente, en 2018, las diferencias genéticas y antigénicas estudiadas han permitido clasificarlo en dos especies víricas distintas Betaarterivirus suid 1 (o PRRSV-1) y Betaarterivirus suid 2 (o PRRSV-2). Una de las principales características de este virus, independientemente de su virulencia, es su capacidad para modular la respuesta inmune del hospedador. Así pues, el PRRSV, es capaz de regular diversos procesos biológicos del sistema inmune para favorecer su distribución, replicación y latencia en el organismo. En la siguiente tesis doctoral titulada “Regulación de la respuesta inmune en cepas de distinta virulencia del PRRSV-1” se profundiza en procesos pobremente estudiados que pueden ser modulados durante la etapa temprana de la infección con PRRSV en órganos diana de lechones infectados, realizándose un estudio comparativo entre dos cepas de distinta virulencia del PRRSV-1, una de baja virulencia, cepa 3249, y otra de elevada virulencia, cepa Lena. El timo es un órgano linfoide primario de importancia crucial en el correcto desarrollo de la respuesta inmune ya que es el órgano donde se produce el desarrollo y maduración de los linfocitos T. La atrofia tímica es una de las lesiones características del PRRSV, especialmente descrita en los animales infectados por cepas virulentas del virus. En este sentido, la inducción de los fenómenos de muerte celular como la apoptosis ha sido uno de los mecanismos postulados como causante de la atrofia tímica durante la infección por este virus, con una repercusión especial en la modulación de la respuesta inmune del hospedador. El objetivo del primer trabajo de esta tesis doctoral fue la valoración del cuadro lesional del timo de lechones infectados con las dos cepas anteriormente mencionadas del PRRSV-1, así como la evaluación de los fenómenos de muerte celular en los mismos. Los animales infectados con la cepa virulenta Lena mostraron una evidente atrofia del timo en comparación con los timos de los animales del grupo control y del grupo infectado con la cepa 3249 de baja virulencia. Este aumento en el grado de lesión de los animales infectados con la cepa virulenta se relacionaba con un aumento de la carga viral y de la expresión de la proteína N (proteína de la nucleocápside) del virus. El timo de los animales infectados con la cepa 3249, por el contrario, presentaron un grado de lesión leve a moderado con niveles más bajos de proteína N y carga viral de PRRSV en el timo. En el timo de los animales infectados con la cepa Lena se observó mediante inmunomarcaje un aumento del marcador genérico de muerte celular TUNEL (del inglés terminal deoxynucleotidyl transferase dUTP Nick-end labeling), así como un aumento de la proteína caspasa-3 activa (cCasp3, del inglés cleaved caspase-3), caspasa ejecutora en la que convergen las vías extrínseca e intrínseca de la apoptosis, que coincidía con el aumento del grado de lesión. En el timo de ambos grupos infectados se observó una mayor inducción de la vía extrínseca de la apoptosis, dado el aumento de la proteína caspasa-8 activa (cCasp8, del inglés cleaved caspase-8) y el receptor de muerte celular Fas (del inglés fas cell death receptor). Este incremento de los fenómenos de muerte celular, especialmente en los animales infectados con la cepa Lena, provocaría un menor número de linfocitos T viables y maduros y como consecuencia un deterioro en la respuesta inmune del hospedador. Este hallazgo ayuda a explicar el aumento de la fiebre y de signos clínicos más marcados (apatía, letargia, anorexia y signos respiratorios, entre otros), así como la mayor intensidad de las lesiones (por ejemplo, bronconeumonía supurativa) observadas en los animales infectados con la cepa virulenta Lena. Además de una inducción de la apoptosis en el timo, una incorrecta activación de los linfocitos T constituye también un mecanismo de modulación de la respuesta inmune durante la infección con PRRSV. Durante la presentación antigénica por parte de las células presentadoras de antígeno (APCs, del inglés antigen presenting cells) a los linfocitos T se requiere, entre otros, la interacción de ciertas señales estimuladoras e inhibidoras. En condiciones fisiológicas estas señales actúan como freno para el sistema inmune, modulando la respuesta inflamatoria e induciendo inmunotolerancia. Sin embargo, en situaciones patológicas como el cáncer o infecciones crónicas, estas moléculas conocidas como “puntos de control inmunitario” (o immune checkpoints en inglés) actúan como mecanismo de escape, provocando una incorrecta activación de los linfocitos T. Además, algunas de estas moléculas también interfieren durante el desarrollo de esta población en el timo. Bajo este contexto, el segundo y tercer trabajo de esta tesis doctoral tienen el objetivo de evaluar la expresión, así como el papel que podrían estar jugando los immune checkpoints en órganos diana (timo, pulmón y nódulo linfático traqueobronquial) de cerdos infectados con dos cepas de PRRSV-1 de diferente virulencia. En el segundo trabajo, centrado en el timo, se evaluaron varios immune checkpoints inhibitorios [PD1/PDL1 (del inglés programmed cell death/ programmed death-ligand 1), CTLA4 (del inglés cytotoxic T-lymphocyte Antigen-4), TIM3 (del inglés T-cell immunoglobulin domain and mucin domain 3), LAG3 (del inglés lymphocyte activating 3), CD200R1 (del inglés CD200 receptor 1) e IDO1 (del inglés indoleamine 2,3-dioxygenase 1)] mediante RT-PCR cuantitativa (RT-qPCR, del inglés qRT-PCR, real-time quantitative PCR) e inmunohistoquímica, que podrían estar afectando al desarrollo y maduración de los linfocitos T. Los resultados mostraron una sobreexpresión de los immune checkpoints PDL1, CTLA4, TIM3, LAG3 e IDO1 sobre todo en el timo de los lechones infectados con la cepa virulenta Lena desde la primera semana post-infección. La co-expresión de estas moléculas afecta al desarrollo, maduración y selección de los linfocitos T en el timo, lo que se asoció con una progresión de la enfermedad en los cerdos infectados y con los fenómenos de apoptosis en el órgano. El tercer estudio, se centró en el pulmón y en el nódulo linfático traqueobronquial y se evaluaron tanto immune checkpoints coestimulatorios [CD28, CD226, TNFRSF9 (del inglés tumour necrosis receptor superfamily member 9), SELL (del inglés l-sectin o CD62L), ICOS (del inglés inducible T-cell costimulator) y CD40] como coinhibitorios [(CTLA4, TIGIT (del inglés T cell immunoreceptor with Ig and IMIT domains), PD1/PDL1, TIM3, LAG3 e IDO1)]. Nuestros resultados mostraron un leve aumento de moléculas coestimuladoras junto con una temprana e intensa sobreexpresión de moléculas coinhibitorias en órganos diana de animales infectados con ambas cepas del PRRSV-1, especialmente en el pulmón de los animales infectados con la cepa virulenta Lena. La co-expresión de distintos immune checkpoints coinhibitorios sugiere un efecto sinérgico de estas moléculas orientadas probablemente a controlar la respuesta inflamatoria exacerbada durante la etapa temprana de la infección con PRRSV. Además, la expresión mantenida de algunos immune checkpoints, en particular durante etapas más tardías de la infección por PRRSV, también podría afectar a la activación y proliferación de linfocitos T, lo cual afecta al inicio de una respuesta inmune eficaz por parte del hospedador. Durante la presentación antigénica, los linfocitos T sufren una serie de divisiones y diferenciaciones que darán lugar a linfocitos T efectores, capaces de producir citoquinas específicas y de inducir actividad citolítica a cargo de proteínas como Fas/ FasL. Este acontecimiento viene determinado por la acción de diferentes factores de transcripción (FTs), proteínas que regulan la expresión de genes en las células. Así la expresión del FT T-bet (del inglés t-box transcription factor 21) resultará en una diferenciación hacia una respuesta de tipo Th1, la expresión del FT FOXP3 (del inglés forkhead box P3 gene) en una diferenciación hacia respuesta reguladora a cargo de las células T reguladoras (Tregs, del inglés regulatory T cells), el FT GATA3 (del inglés GATA binding protein 3) en una polarización de tipo Th2 y el FT EOMES (del inglés eomesodermin) hacia una respuesta citotóxica a cargo de linfocitos T citotóxicos CD4 (CTLs, del inglés cytotoxic T lymphocytes). A pesar de la importancia de los FTs en el inicio de la respuesta inmune adaptativa, su estudio en el contexto de la infección por PRRSV es escaso. Por tanto, el tercer objetivo de la presente tesis doctoral fue evaluar la expresión mediante RT-qPCR de diferentes FTs (T-bet, GATA3, FOXP3 y EOMES) así como la expresión de las diferentes citoquinas efectoras [IFNG (del inglés interferon gamma), TNFA (del inglés tumour necrosis factor alpha) e IL10 (del inglés interleukin 10)] y FASL en órganos diana (pulmón, nódulo linfático traqueobronquial y timo) de cerdos infectados con dos cepas de PRRSV-1 de distinta virulencia. Los órganos de los animales pertenecientes a los dos grupos infectados, pero especialmente de aquellos infectados con la cepa virulenta Lena, mostraron una sobreexpresión de los FTs T-bet, EOMES y FOXP3 junto con un incremento de la citoquina IFNG al final de estudio. Estos resultados muestran una polarización de las células T hacia una respuesta de las células de tipo Th1, Tregs y CD4 CTLs particularmente en respuesta de la cepa virulenta Lena. En resumen, esta tesis doctoral analiza diferentes mecanismos que hay detrás de la inmunopatogenia del PRRSV y sirve de base para futuros estudios funcionales dirigidos a aumentar el conocimiento de la enfermedad

History, Ethnography, and Politics in Amazonia: Implications of Diachronic and Synchronic Variability in Marubo Politics

The idea that indigenous Amazonian societies have been and are essentially egalitarian has been criticized in recent years. This essay critiques frameworks for the study of power in lowland South America by examining diachronic and synchronic variation in Marubo political organization. First, I analyze change over time in Marubo politics and how it relates to population fluctuations linked to contact situations. Based on this analysis, I argue that the small, atomized villages that twentieth-century anthropologists perceived as typifying indigenous Amazonia were products of the historical processes of political organization. Next, I show that leaders of different Marubo villages range from powerless to powerful, and that all positions in this range are acceptable to most Marubo. Thus, it is misleading to label the Marubo as either “egalitarian” or “hierarchical.” Based on this analysis, I argue that labeling indigenous Amazonian societies as egalitarian or hierarchical is a highly problematic endeavor, and that labeling all of Amazonia as egalitarian is clearly inaccurate. The debate on power in Amazonia should be redirected, away from efforts to classify the entirety of Amazonia, towards efforts to understand Amazonian groups on their own terms. A idea que as sociedades indígenas da Amazônia tem sido, e são, essencialmente igualitárias tem sido criticada nos últimos anos. Neste ensaio, critico estruturas conceituais no estudo do poder em Amazônia através de uma investigação das variações diacrônicas e sincrônicas na organização política dos Marubo. Primeiro, eu analiso mudanças hostóricas na politica Marubo, e como se relacionam com mudanças demográficas ligadas situações de contato. Baseiado neste análise eu sustento que as pequenas e isoladas aldeias que os antropólogos do século vinte perceberam como típicos da Amazônia indígena foram produtos dos processos históricos de contato interetnico e não podem serem considerados representativos de uma organização política indígena “normal.” Segundo, eu mostro variações em níveis de poder entre chefes de diferentes aldeias Marubo, desde chefes com pouco poder até chefes com poder significante, e também que todas as posições nesta série de possibilidades políticas são aceitáveis à maioria dos Marubo. Assim, é impossível classificar os Marubo como “igualitários” ou “hierárquicos.” Baseiado neste análise eu sustento que a classificação de sociedades indígenas Amazônicas como iguálitarias ou hierárquicas e altamente problemática, e a classificação do conjunto da Amazônia como igualitário é claramente inexato. O debate sobre o poder na Amazônia deveria mudar de enfoque, trocando esforços de classificação do conjunto da Amazônia por esforços de comprender a cada grupo indígena de acordo com a sua própria lógica político-cultural

Gender and Sociality in Amazonia: How Real People Are Made

Book review of Gender and Sociality in Amazonia: How Real People Are Made. Cecilia McCallum. Oxford: Berg Publishers, 2001. xii + 208 pp., figures, table, references, glossary, index. ISBN 1-85973-449-9

Editor\u27s Choice: Aldo Leopold Conservation Award

Every year since 2003, the American Society of Mammalogists confers during its annual meeting the Aldo Leopold Conservation Award on a highly deserving individual. A consequence of the award for the awardee is the responsibility to write a feature article in the pages of this journal. Aldo Leopold, the namesake of the award, is considered by an overwhelming majority of biologists to be the father of contemporary conservation biology. Born in Burlington, Iowa, Leopold graduated with a Master’s degree from the Yale Forest School, which had been endowed in 1902 by the Pinchot family and was one of the first institutions to grant graduate degrees in forestry in the United States. At Yale, Leopold was educated in the tradition of Gifford Pinchot’s Resource Conservation Ethic, which, while advocating for “the greatest good of the greatest number for the longest time” (Pinchot 1947) nevertheless reduced the environment to “just two things on this material earth—people and natural resources” (Pinchot 1947), with natural resources to be used by and for people

Indigenous Ritual Action Versus the World System: Marubo Rites of Healing, Solidarity, and Resistance

Este ensayo examina el papel de los rituales y discursos ceremoniales marubo en los enfrentamientos con el sistema global en sus aspectos político-económicos. Durante y después de la fiebre del caucho (aprox. 1890-1920), los antepasados de los marubo migraron desde sus ubicaciones previas hasta un nuevo lugar en las cabeceras de los riachuelos de la cuenca del Yavarí, aislándose de la participación en las actividades económicas del comercio del caucho. Ahí, construyeron una alianza entre miembros de diferentes etnias pano. La alianza fue mediada por el desarrollo de un nuevo sistema ceremonial centrado en los ritos de curación y las fiestas, ambas categorías justificadas por una filosofía de antiviolencia, intercambio y cuidado mutuo, explícitamente pensada para sobrevivir a la fiebre del caucho. Con el tiempo, la alianza se convirtió en fusión étnica, dando lugar a una nueva identidad étnica. A finales del siglo XX, los marubo se enfrentaron a una reintegración al sistema global, a través de la incorporación a la organización burocrática del estado brasileño. Otra vez crearon una alianza interétnica, la organización indígena CIVAJA. Esta alianza fue mediada por las reuniones del movimiento indígena y sus discursos sobre autonomía y poder indígena. El ensayo concluye mostrando un ejemplo concreto del uso del sistema ceremonial marubo para invertir las relaciones de poder entre indígenas y burocracia.This paper examines the role of Marubo ritual and ceremonial discourse in confrontations with the world system in its politico-economic aspects. During and after the rubber boom (c. 1890-1920), the ancestral Marubo migrated from their previous locations to a new home in the headwaters of the small rivers of the Javari River, isolating themselves from participation in the rubber economy. There, they built an alliance between distinct Panoan ethnic groups. The alliance was mediated by the development of a new ceremonial system centered on healing rituals and feasts, both categories justified by an ethic of anti-violence, exchange, and mutual care, explicitly thought out as a strategy for surviving the rubber boom. Over time, the alliance became an ethnic fusion, giving rise to a new ethnic identity. At the end of the twentieth century, the Marubo faced reintegration to the world system through incorporation into the Brazilian bureaucracy. Once again they created an interethnic alliance, the indigenous organization CIVAJA. This alliance was mediated by the indigenous movement’s political meetings and its discourses on indigenous autonomy and power. The essay concludes by showing a concrete example of the use of the Marubo ceremonial system to invert power relations between indigenous peoples and national bureaucracy

Dynamical effects of multiple impacts: Large impacts on a Mars-like planet

The earliest stage of the evolution of a fully assembled planet is profoundly affected by a number of basin-forming impacts large enough to change the dynamics of its deeper interior. These impacts are in some cases quite closely spaced and follow one another in short time intervals, so that their effects interact and result in behavior that may differ from a simple sum of the effects of two individual and isolated impacts. We use two-dimensional models of mantle convection in a Mars-like planet and a simple parameterized representation of the principal effects of impacts to study some of the dynamical effects and interactions of multiple large impacts. In models of only two impacts, we confirm that the dynamical effects of the impacts reinforce each other the closer they are in space and time but that the effects do not always correspond to straightforward superpositions of those of single, isolated impacts. In models with multiple (4-8) impacts with variable sizes, distances, and frequencies, the global response of the mantle is as variable as the impact sequences in the short term, but in the long term the different evolutionary paths converge for several indicator variables such as the mean flow velocity, temperature, or heat flow. Nonetheless, beyond a certain impact frequency and energy, lithospheric instabilities triggered by large impacts occur on a global scale, reinvigorate mantle dynamics for long time spans, and entail a late stage of melt production in addition to the initial melting stage that is not observed in one- or two-impact models. After one or several very large impacts, some lithospheric material may founder and sink to the core-mantle boundary, and if enough of it accumulates there, it enhances the heat flux out of the core for several hundred millions of years, with possible effects on dynamo activity.Comment: 24 pages, 10 figure

Intracellular Zn2+ detection with quantum dot-based FLIM nanosensors

Fluorescence Lifetime Imaging Microscopy (FLIM) has been employed for the detection of intracellular Zn2+ levels, implicated in various signalling pathways, using a family of quantum dot (QD) nanosensors. The sensing mechanism was based on photoinduced electron transfer (PET) between an azacycle receptor group and the QD nanoparticles.This work was supported by Fundación Ramon Areces and grant CTQ2014-56370-R from Ministerio de Economia y Competitividad of Spain

COPING STRATEGIES ADOPTED BY IRAYA-MANGYAN HOUSEHOLDS DURING FOOD INSECURITY IN ABRA, OCCIDENTAL MINDORO, PHILIPPINES

The study was conducted to determine the food security status of the Iraya Mangyans’ and their coping mechanisms employed. The quantitative research design was employed in the study. The modified Radimer/Cornell Hunger and Food Insecurity instrument and Coping Strategy Index (CSI) were used to determine the food security status and their coping mechanism. Result shows the Irayas were middle aged, have medium household size, with low level of basic education, and with an average monthly income slightly “above” the poverty threshold in the province. The Irayas experienced “food insecure without hunger” in which household food supply is adequate but there is an adjustment to household food management, including reduced quality of food and increased unusual coping patterns. The high cost of food items and low agricultural production were the “highly serious problem” on food security. Dietary change, which includes relying on less preferred and less expensive foods and consuming less variety of foods, is the most employed coping mechanism. Household monthly income and years spent in formal school are significantly related to the coping mechanisms employed during food insecurity. However, household size and age have no significant relationship

"Isocrater" impacts: Conditions and mantle dynamical responses for different impactor types

Impactors of different types and sizes can produce a final crater of the same diameter on a planet under certain conditions. We derive the condition for such "isocrater impacts" from scaling laws, as well as relations that describe how the different impactors affect the interior of the target planet; these relations are also valid for impacts that are too small to affect the mantle. The analysis reveals that in a given isocrater impact, asteroidal impactors produce anomalies in the interior of smaller spatial extent than cometary or similar impactors. The differences in the interior could be useful for characterizing the projectile that formed a given crater on the basis of geophysical observations and potentially offer a possibility to help constrain the demographics of the ancient impactor population. A series of numerical models of basin-forming impacts on Mercury, Venus, the Moon, and Mars illustrates the dynamical effects of the different impactor types on different planets. It shows that the signature of large impacts may be preserved to the present in Mars, the Moon, and Mercury, where convection is less vigorous and much of the anomaly merges with the growing lid. On the other hand, their signature will long have been destroyed in Venus, whose vigorous convection and recurring lithospheric instabilities obliterate larger coherent anomalies.Comment: 32 pages, 12 figure