Thermal tests on the LISA pathfinder engineering model

Report for the scientific sojourn carried out at Albert Einstein Institut in Germany, from April to July 2006.

Diagnosis socioambiental y presupuesto para el Parque Nacional Los Quetzales (Costa Rica)

Se realiza una diagnosis socioambiental y un presupuesto para el Plan de Manejo del Parque Nacional Los Quetzales (PNLQ). El PNLQ ocupa una superficie de 4117 ha. Presenta un régimen hí­drico elevado favorecido por la topografí­a quebrada que permite la presencia de fajas de condensación. Estas condiciones favorecen la presencia del bosque nublado que como se ha observado es el hábitat de innumerables especies, algunas de las cuales presentan gran valor ecológico. El presupuesto para el Plan de Manejo refleja cómo los gastos superan en una proporción importante a los ingresos, por lo que se recomienda centrar los esfuerzos en la búsqueda de formas de financiación (pago por servicios ambientales, convenios, co-manejo y donaciones). También se hace precisa una aportación anual del Gobierno Central para la ejecución del Plan.

On the applicability of mathematics : philosophical and historical perspectives

The present thesis is a contribution to the debate on the applicability of mathematics; it examines the interplay between mathematics and the world, using historical case studies. The first part of the thesis consists of four small case studies. In chapter 1, I criticize "ante rem structuralism", proposed by Stewart Shapiro, by showing that his so-called "finite cardinal structures" are in conflict with mathematical practice. In chapter 2, I discuss Leonhard Euler's solution to the Königsberg bridges problem. I propose interpreting Euler's solution both as an explanation within mathematics and as a scientific explanation. I put the insights from the historical case to work against recent philosophical accounts of the Königsberg case. In chapter 3, I analyze the predator-prey model, proposed by Lotka and Volterra. I extract some interesting philosophical lessons from Volterra's original account of the model, such as: Volterra's remarks on mathematical methodology; the relation between mathematics and idealization in the construction of the model; some relevant details in the derivation of the Third Law, and; notions of intervention that are motivated by one of Volterra's main mathematical tools, phase spaces. In chapter 4, I discuss scientific and mathematical attempts to explain the structure of the bee's honeycomb. In the first part, I discuss a candidate explanation, based on the mathematical Honeycomb Conjecture, presented in Lyon and Colyvan (2008). I argue that this explanation is not scientifically adequate. In the second part, I discuss other mathematical, physical and biological studies that could contribute to an explanation of the bee's honeycomb. The upshot is that most of the relevant mathematics is not yet sufficiently understood, and there is also an ongoing debate as to the biological details of the construction of the bee's honeycomb. The second part of the thesis is a bigger case study from physics: the genesis of GR. Chapter 5 is a short introduction to the history, physics and mathematics that is relevant to the genesis of general relativity (GR). Chapter 6 discusses the historical question as to what Marcel Grossmann contributed to the genesis of GR. I will examine the so-called "Entwurf" paper, an important joint publication by Einstein and Grossmann, containing the first tensorial formulation of GR. By comparing Grossmann's part with the mathematical theories he used, we can gain a better understanding of what is involved in the first steps of assimilating a mathematical theory to a physical question. In chapter 7, I introduce, and discuss, a recent account of the applicability of mathematics to the world, the Inferential Conception (IC), proposed by Bueno and Colyvan (2011). I give a short exposition of the IC, offer some critical remarks on the account, discuss potential philosophical objections, and I propose some extensions of the IC. In chapter 8, I put the Inferential Conception (IC) to work in the historical case study: the genesis of GR. I analyze three historical episodes, using the conceptual apparatus provided by the IC. In episode one, I investigate how the starting point of the application process, the "assumed structure", is chosen. Then I analyze two small application cycles that led to revisions of the initial assumed structure. In episode two, I examine how the application of "new" mathematics - the application of the Absolute Differential Calculus (ADC) to gravitational theory - meshes with the IC. In episode three, I take a closer look at two of Einstein's failed attempts to find a suitable differential operator for the field equations, and apply the conceptual tools provided by the IC so as to better understand why he erroneously rejected both the Ricci tensor and the November tensor in the Zurich Notebook.

Ultrastructure of the ovary of Dermatobia hominis (Diptera: cuterebridae). I. Development during the 3rd larval instar

The ultrastructure and distribution of gonial and somatic cells in the ovary of Dermatobia hominis was studied during the 3rd larval instar. In larvae weighing between 400 and 500 mg, the ovary is partially divided into basal and apical regions by oblong somatic cells that penetrate from the periphery; these cells show ovoid nucleus and cytoplasm full of microtubules. In both regions, gonial cells with regular outlines, large nucleus and low electron-density cytoplasm are scattered among the interstitial somatic cells. These later cells have small nucleus and electrodense cytoplasm. Clear somatic cells with small nucleus and cytoplasm of very low electron-density are restrict to the apical region of the gonad. Degenerating interstitial somatic cells are seen in the basal portion close to the ovary peduncle. During all this larval period the morphological features of the ovary remain almost the same. At the end of the period there is a gradual deposition of glycogen in the cytoplasm of the somatic cells, increase in the number and density of their mitochondria plus nuclear modification as membrane wrinkling and chromatin condensation in masses.

Morphological features of collagen degradation in advanced hepatic schistosomiasis of man

Optical and electron microscopical evidences of focal matrix degradation were frequently seen in liver sections taken from patients with periportal ("pipe-stem") fibrosis caused by schistosomiasis mansoni. Besides present of focal areas of rarefaction, fragmentation and dispersion of collagen fibers, the enlargend portal spaces also showed hyperplasia of elastic tisue and disarray of smooth muscle fibers following the destrution of portal vein branches. Ultrastructural cahnges represented by focal lytic and/or electron dense alterations of colagen fibrils were similar to those first seen in experimental material and designated as "chronic collagen degradation". Elastin and related microfibrils were also affected by focal condensation, fragmentation, distorsion and dissolution. Schistosome eggs were scanty in the tissue sections examined. Matrix degradation represented involuting changes related to the progressive diminution of parasite aggression, which occurs spontaneously with age or after cure by chemotherapy. Changes of focal matrix degradation now being described represent the basic morphological counterpart of periportal fibrosis involution documented clinically, especially by ultrasonography, in patients with hepatosplenic schistosomiasis submitted to curative chemotherapy.

Positive Torsional Strain Causes the Formation of a Four-Way Junction at Replication Forks.

Research by L. Postow, C. Ullsperger, R.W. Keller, C. Bustamante, A.V. Vologodskii, and N.R. Cozzarelli, J. Biol. Chem. 2001, 276, 2790 Condensation and commentary by Alexander Bucka and Andrzej Stasiak, Universite ´ de Lausanne, Switzerland Purpose of the Study To demonstrate that positive torsional strain generated during DNA replication can lead to reversals of replication forks and, consequently can result in the formation of four-way DNA junctions

Dihydroaeruginoic acid synthetase and pyochelin synthetase, products of the pchEF genes, are induced by extracellular pyochelin in Pseudomonas aeruginosa.

The siderophore pyochelin of Pseudomonas aeruginosa is derived from one molecule of salicylate and two molecules of cysteine. Two cotranscribed genes, pchEF, encoding peptide synthetases have been identified and characterized. pchE was required for the conversion of salicylate to dihydroaeruginoate (Dha), the condensation product of salicylate and one cysteine residue and pchF was essential for the synthesis of pyochelin from Dha. The deduced PchE (156 kDa) and PchF (197 kDa) proteins had adenylation, thiolation and condensation/cyclization motifs arranged as modules which are typical of those peptide synthetases forming thiazoline rings. The pchEF genes were coregulated with the pchDCBA operon, which provides enzymes for the synthesis (PchBA) and activation (PchD) of salicylate as well as a putative thioesterase (PchC). Expression of a translational pchE'-'lacZ fusion was strictly dependent on the PchR regulator and was induced by extracellular pyochelin, the end product of the pathway. Iron replete conditions led to Fur (ferric uptake regulator)-dependent repression of the pchE'-'lacZ fusion. A translational pchD'-'lacZ fusion was also positively regulated by PchR and pyochelin and repressed by Fur and iron. Thus, autoinduction by pyochelin (or ferric pyochelin) and repression by iron ensure a sensitive control of the pyochelin pathway in P. aeruginosa.

Dalí et le dynamisme des formes. L'élaboration de l'activité « paranoïaque-critique » dans le contexte socioculturel des années 1920-1930

RESUME Dalí et le dynamisme des formes. L'élaboration de l'activité « paranoïaque-critique » dans le contexte socioculturel des années 1920-1930 Rendre à nouveau lisibles des textes dont on ne sait plus reconnaître les enjeux historiques et cognitifs, tel est le principal défi que cet ouvrage consacré aux écrits surréalistes de Dalí se propose de relever. La thèse fait ressortir l'image sans doute un peu déroutante d'un créateur stratège qui, assimilant de manière originale les savoirs les plus variés et dialoguant avec les intellectuels de son temps, propose au tournant des années 1930 une théorie du surréalisme novatrice, capable de redynamiser un groupe en pleine crise. L'étude, combinant des perspectives sociologiques et linguistiques, explore tout d'abord les écrits à caractère manifestaire et dessine les traits conceptuels et stylistiques qui font la singularité du projet de Dalí dans le cadre du mouvement surréaliste. S'inspirant des images-devinettes, de la production des fous, de l'interprétation des figures aux formes indéterminées, le Catalan conçoit une méthode créative et cognitive qui se fonde sur une pensée subconsciente active, schématisant et fertilisant automatiquement toute donnée perçue. Dans le domaine de la peinture, ce sont les formes des objets qui sont surdéterminées par les désirs subconscients du créateur et du spectateur et qui acquièrent ainsi des significations inattendues. Dans le domaine de l'écriture, ce sont les formes sonores et graphiques des mots ou encore l'ossature discursive qui, investies par les fantasmes de l'écrivain et du lecteur, génèrent une multitude d'images. A l'aune des modes de connaissance propres à l'époque, l'étude porte ensuite sur deux modèles de pensée - le paradigme photographique et l'imaginaire lié à la notion d'espace-temps développée par Einstein dans le cadre de la théorie de la relativité générale - qui sont en vogue pendant les années 1930 et que le peintre se réapproprie pour signifier la dimension « révélatrice » et « objective » de ses oeuvres. Premièrement, pour penser la méthode « paranoïaque-critique », le Catalan reprend et détourne les phases de production du cliché : loin de reproduire fidèlement le visible, le dispositif photographique dalinien permet de révéler les pensées subconscientes. Deuxièmement, dès 1933-1934, Dalí reformule le modèle de l'espace-temps de la relativité générale d'Einstein pour penser la façon dont une entité invisible (le fantasme) s'objective et se matérialise dans la réalité extérieure. L'étude du dynamisme psychique conféré par Dalí aux formes des objets, aux formes verbales et picturales permet finalement de mettre en lumière le foisonnement mais aussi l'extrême cohérence de l'univers surréaliste du Catalan, et de souligner la valeur de l'approche « paranoïaque-critique » de la réalité tant sur le plan de l'histoire culturelle que sur le plan de la connaissance.

Characterization of larval moulting cycles in Maja brachydactyla (Brachyura, Majidae) reared in the laboratory

The moulting cycles of all larval instars (zoea I, zoea II, and megalopa) of the spider crab Maja brachydactyla Balss 1922 were studied in laboratory rearing experiments. Morphological changes in the epidermis and cuticle were photographically documented in daily intervals and assigned to successive stages of the moulting cycle (based on Drach's classification system). Our moult-stage characterizations are based on microscopical examination of integumental modifications mainly in the telson, using epidermal condensation, the degree of epidermal retraction (apolysis), and morphogenesis (mainly setagenesis) as criteria. In the zoea II and megalopa, the formation of new setae was also observed in larval appendages including the antenna, maxillule, maxilla, second maxilliped, pleopods, and uropods. As principal stages within the zoea I moulting cycle, we describe postmoult (Drach's stages A–B combined), intermoult (C), and premoult (D), the latter with three substages (D0, D1, and D2). In the zoea II and megalopa, D0 and D1 had to be combined, because morphogenesis (the main characteristic of D1) was unclear in the telson and did not occur synchronically in different appendices. The knowledge of the course and time scale of successive moult-cycle events can be used as a tool for the evaluation of the developmental state within individual larval instars, providing a morphological reference system for physiological and biochemical studies related to crab aquaculture.

Extracellular serine-proteinases isolated from Streptomyces alboniger: Partial characterization and effect of aprotinin on cellular structure

Streptomyces alboniger ATCC 12461 grown in brain heart infusion (BHI) medium produced two extracellular serine-proteinases, denoted SP I and SP II, which were purified by ammonium sulfate precipitation and aprotinin-agarose affinity chromatography. SP I was purified 88,9-fold and SP II 66,7- fold, with 33.4% and 10.4% yield, respectively. The optimum pH for the proteinases activity, using a-N-p-tosyl-L-arginine-methyl ester (TAME) as substrate, was 9-10 and the optimum temperature was 37ºC. The proteolytic activity of SP I and SP II was inhibited by aprotinin and SP I was partially inhibited by leupeptin, both serine-proteinase inhibitors. S. alboniger growth in BHI-liquid medium decreased when 5 mg/ml, 10 mg/ml of aprotinin was used, being completely inhibited with 20 mg/ml and 40 mg/ml. At the ultrastructural level, aprotinin-treated S. alboniger cells showed swelling of the bacterial body and condensation of the genetic material, probably related to the inhibition of its growth.

Tackling Fuel Poverty can Improve Health, but needs Resources

Fuel poverty is a significant threat to public health with its links to heart disease, respiratory illness and mental health. People on low incomes are most likely to live in fuel poverty. The Fuel Poverty Strategy, which was launched 23 November, 2004, needed to be adequately resourced to help reduce the devastating effects of health inequalities in our society, according to the Institute of Public Health in Ireland. The Institute of Public Health recently completed research which showed that locally based projects are an effective way of improving the energy efficiency of homes. The findings from the research conducted by the Institute of Public Health showed that local fuel poverty interventions can reduce fuel poverty and improve health: - The energy efficiency of homes were significantly improved - There was a statistically significant increase in levels of benefit uptake - People reported spending less on fuel after intervention - There were significant reductions in the presence of condensation, mould and damp, which is where we have the strongest evidence of links to ill-health - There was a significant reduction in the number of illnesses (associated with fuel poverty) reported by those who received the heating conversion and insulation - People reported reductions in the use of health services after intervention

Forces de Casimir i les seves aplicacions

Report for the scientific sojourn carried out at the Darmouth College, from august 2007 until february 2008. It has been very successful, from different viewpoints: scientific, philosophical, human. We have definitely advanced, during the past six months, towards the comprehension of the behaviour of the fluctuations of the quantum vacuum in the presence of boundaries, moving and non-moving, and also in situations where the topology of space-time changes: the dynamical Casimir effect, regularization problems, particle creation statistics, according to different BC, etc. We have solved some longstanding problems and got in this subject quite remarkable results (as we will explain in more detail below). We also pursued a general approach towards a viable modified f(R) gravity in both the Jordan and the Einstein frames (which are known to be mathematically equivalent, but physically not so). A class of exponential, realistic modified gravities has been introduced by us and investigated with care. Special focus was made on step-class models, most promising from the phenomenological viewpoint and which provide a natural way to classify all viable modified gravities. One- and two-steps models were considered, but the analysis is extensible to N-step models. Both inflation in the early universe and the onset of recent accelerated expansion arise in these models in a natural, unified way, what makes them very promising. Moreover, it is monstrated in our work that models in this category easily pass all local tests, including stability of spherical body solution, non-violation of Newton's law, and generation of a very heavy positive mass for the additional scalar degree of freedom.

Aptian to Cenomanian deeper-water hiatal stromatolites from the northern Tethyan margin

A suite of deeper-water hiatal (DWH) stromatolites has been identified in the phosphatic and glauconitic sediments of Aptian to Cenomanian age in the alpine Helvetic thrust-and-fold belt, which represents the former northern Tethyan margin. The most important occurrences date from the latest Early to Late Aptian, the late Early to early middle Albian, and the Early Cenomanian. They are invariably associated with condensed phosphatic beds and occur preferentially on top of hardgrounds or on reworked pebbles and fossils. The zone of optimal stromatolite growth and preservation coincides with the zone of maximal sedimentary condensation, in the deeper parts of phosphogenic areas. The DWH stromatolites show variable morphologies, ranging from isolated laminae ("films") to internally laminated columns and crusts. They reach thicknesses of maximal 10 cm and are either preserved in phosphate or micrite. In the latter case, they may show peripheral impregnations of phosphate or iron oxyhydroxides. The quasi-complete lack of macroscopic sessile organisms suggests that the DWH stromatolites grew close to the upper boundary of an oxygen-minimum zone. Electron-scanning microscopic images show that the Early Cenomanian examples preserved in micrite consist of filamentous structures, which form spaghetti-like assemblages. They are. interpreted as the remains of poikiloaerobic, heterotrophic microbes. Coeval DWH stromatolites are known from the entire European segment of the northern Tethyan margin, and shallow-water counterparts are commonplace on Tethyan carbonate platforms. This indicates that, in general, paleoceanographic and paleoenvironmental conditions were appropriate for stromatolite growth and preservation. The here-described DWH stromatolites proliferated especially in time windows, which followed upon the oceanic anoxic periods OAE la (Early Aptian), lb (latest Aptian and earliest Albian), and Id (latest Albian). They may represent pioneer ecosystems, which thrived during the recovery phases following the "mid"-Cretaceous OAEs.

Location of ribosomal genes in the chromosomes of Anopheles darlingi and Anopheles nuneztovari (Diptera, Culicidae) from the Brazilian Amazon

Fluorescence in situ hybridization of Anopheles darlingi and A. nuneztovari demonstrated nucleolar organizer region activity at the end of the fourth larval instar, when the nucleolar organizer regions underwent gradual condensation. The heteromorphic sex chromosomes showed intraindividual size variation in the rDNA blocks located in the pericentromeric region and this coincided with the location of constitutive heterochromatin (C-banding).

The in vitro cytopathology of a porcine and the simian (SA-11) strains of rotavirus

Rotaviruses have been implicated as the major causal agents of acute diarrhoea in mammals and fowls. Experimental rotavirus infection have been associated to a series of sub-cellular pathologic alterations leading to cell lysis which may represent key functions in the pathogenesis of the diarrhoeic disease. The current work describes the cytopathic changes in cultured MA-104 cells infected by a simian (SA-11) and a porcine (1154) rotavirus strains. Trypan blue exclusion staining showed increased cell permeability after infection by both strains, as demonstrated by cell viability. This effect was confirmed by the leakage of infected cells evaluated by chromium release. Nuclear fragmentation was observed by acridine orange and Wright staining but specific DNA cleavage was not detected. Ultrastructural changes, such as chromatin condensation, cytoplasm vacuolisation, and loss of intercellular contact were shown in infected cells for both strains. In situ terminal deoxynucleotidyl transferase (Tunel) assay did not show positive result. In conclusion, we demonstrated that both strains of rotavirus induced necrosis as the major degenerative effect.