Growth of semi-polar GaN on high index silicon (11h) substrates by metal organic vapor phase epitaxy

Magdeburg, Univ., Fak. für Naturwiss., Diss., 2014

Invoking a cartesian product structure on social states: new resolutions of Sen's and Gibbard's impossibility theorems

The purpose of this article is to introduce a Cartesian product structure into the social choice theoretical framework and to examine if new possibility results to Gibbard's and Sen's paradoxes can be developed thanks to it. We believe that a Cartesian product structure is a pertinent way to describe individual rights in the social choice theory since it discriminates the personal features comprised in each social state. First we define some conceptual and formal tools related to the Cartesian product structure. We then apply these notions to Gibbard's paradox and to Sen's impossibility of a Paretian liberal. Finally we compare the advantages of our approach to other solutions proposed in the literature for both impossibility theorems.

A rotation method which gives linear Lp-Estimates for powers of the Ahlfors-Beurling operator

"Vegeu el resum a l'inici del document del fitxer adjunt."

Large deviation for BSDE with subdifferential operator

In this paper we prove that the solution of a backward stochastic differential equation, which involves a subdifferential operator and associated to a family of reflecting diffusion processes, converges to the solution of a deterministic backward equation and satisfes a large deviation principle.

Neuroscience, quantum indeterminism and the Cartesian soul.

Quantum indeterminism is frequently invoked as a solution to the problem of how a disembodied soul might interact with the brain (as Descartes proposed), and is sometimes invoked in theories of libertarian free will even when they do not involve dualistic assumptions. Taking as example the Eccles-Beck model of interaction between self (or soul) and brain at the level of synaptic exocytosis, I here evaluate the plausibility of these approaches. I conclude that Heisenbergian uncertainty is too small to affect synaptic function, and that amplification by chaos or by other means does not provide a solution to this problem. Furthermore, even if Heisenbergian effects did modify brain functioning, the changes would be swamped by those due to thermal noise. Cells and neural circuits have powerful noise-resistance mechanisms, that are adequate protection against thermal noise and must therefore be more than sufficient to buffer against Heisenbergian effects. Other forms of quantum indeterminism must be considered, because these can be much greater than Heisenbergian uncertainty, but these have not so far been shown to play a role in the brain.

Eimeria species (Apicomplexa: Eimeriidae) of podocnemis expansa (Schweigger) and geochelone denticulata (LINN.) from Amazonian Brazil (Reptilia: Chelonia)

Eimeria lagunculata, Eimeria mammiformis and Eimeria podocnemis n. spp., are described from the faeces of the fresh-water turtle Podocnemis expansa, in Pará State, north Brasil. Oocysts of E. lagunculata are ellipsoidal, 19.2 x 12.8 (17.0-20.7 x 11.8-14.1) mum, shape-index (= length/ width) 1.5 (1.4-1.7). Oocyst wall about 0.5-0.7 mum thick, with a prominent stopper-like micropyle at one pole. No oocyst residuum and no polar body. Sporocysts elongate ellipsoidal, 11.0 x 5.4 (10.4-11.8 x 5.2-6.0) mum, shape-index 2.0 (1.8-2.1): no Stieda body. A compact, ellipsoidal sporocyst residuum lies between the two sporozoites, which possess a posterior and an anterior refractile body. Oocysts of E. mammiformis broadly ellipsoidal, 30.0 x 19.4 (23.0-37.0 x 16.3-21.5) mum, shape-index 1.5 (1.1-1.9). Oocyst wall about 0.7 mum thick, with a prominent micropyle: no oocyst residuum and rarely a single polar body. Sporocysts ellipsoidal, 15.3 x 7.9 (14.8-17.0 x 7.4-9.6) mum, shape-index 2.0 (1.8-2.2), with a tiny Stieda body. Sporocyst residuum bulky, ellipsoidal: sporozoites with two conspicuous refractile bodies. E. podocnemis has broadly ellipsoidal oocysts, 17.0 x 12.8 (14.8-19.2 x 11.8-14.1) mum, shape-index 1.3 (1.1-1.4). Oocyst wall about 0.5-0.7 mum thick, with no micropyle. No oocyst residuum, but always a single polar body. Sporocysts ellipsoidal, 9.7 x 5.2 (8.9-10.4 x 4.4-6.0) mum, shape-index 1.9 (1.6-2.0), with no Stieda body. Sporocyst residuum bulky, ellipsoidal: sporocysts with 2 refractile bodies. Eimeria carinii n. sp., is recorded from the tortoise Geochelone denticulata, also from Pará. Oocyst wall about 1.2 mum thicl. No micropyle. Oocyst residuum limited to a number (about 10-20) of scattered granules: no polar body. Sporocysts broadly ellipsoidal, and with no Stieda body: they measure 8,8 x 7.3 (8.0-9.0 x 7.0-7.5) mum, shape-index 1.2 (1.1-1.3). Sporocyst residuum bulky, spherical to ellipsoidal: sporozoites possess both posterior and anterior refractile bodies.

Energetics of RecA-mediated recombination reactions. Without ATP hydrolysis RecA can mediate polar strand exchange but is unable to recycle.

We demonstrate that the step of DNA strand exchange during RecA-mediated recombination reaction can occur equally efficiently in the presence or absence of ATP hydrolysis. The polarity of strand exchange is the same when instead of ATP its non-hydrolyzable analog adenosine-5'-O-(3-thiotriphosphate) is used. We show that the ATP dependence of recombination reaction is limited to the post-exchange stages of the reactions. The low DNA affinity state of RecA protomers, induced after ATP hydrolysis, is necessary for the dissociation of RecA-DNA complexes at the end of the reaction. This dissociation of RecA from DNA is necessary for the release of recombinant DNA molecules from the complexes formed with RecA and for the recycling of RecA protomers for another round of the recombination reaction.

Observations on some Avian Coccidia (Apicomplexa: Eimeriidae) in Amazonian Brazil

Oocysts of Eimeria porphyrulae n. sp. are described in faeces of Porphyrula martinica (Aves: Gruiformes: Rallidae). They are ellipsoidal to oval, 22.4 x 17.7 (20.0-23.7 x 16.2-18.7) µm, shape-index (length/width) 1.3. Oocyst wall about 1.25 µm thick, colourless, with two layers: inner one prominently striated. Micropyle and sub-micropylar granule present: no oocyst residuum. Sporocysts 17.5 x 9.0 (17.0-19.0 x 8.0-10.0) µm, shape-index 1.9, with inconspicuous Stieda/sub-Stieda bodies. Sporocyst residuum of scattered granules, sometimes a compact mass: sporozoites with two refractile bodies. Eimeria crypturelli n. sp. is described in faeces of Crypturellus soiu (Tinamiformes: Tinamidae). Oocysts ellipsoidal-oval, 20.75 x 14.5 (17.5-25.0 x 11.25-21.25) µm, shape-index 1.4. Oocysts wall about 1.25 µm thick and bi-layered: inner layer faintly striated. Micropyle present, with oocyst residuum immediately below: single polar body rarely present. Sporocysts 13.0 x 7.5 (12.5-13.75 x 7,5-8.1) µm, shape-index 1.7, with a Stieda body but seemingly no sub-Stieda. Sporocyst residuum compact: sporozoites with two refractile bodies. Isospora cacici n. sp. is recorded from faeces of Cacicus cela cela (Passeriformes: Icteridae). Oocysts subspherical-spherical, 26.5 x 23.7 (22.5-27.5 x 20.0-26.2) µm, shape-index 1.1. Wall a single, colourless layer about 1.5 µm thick. No micropyle or oocyst residuum: 1-2 polar bodies. Sporocysts ellipsoidal, 17.7 x 12.5 (17.5-18.75 x 11.25-13.75) µm, shape-index 1.4, with pronounced Stieda/sub-Stieda bodies: residuum compact and sporozoites with two refractile bodies. Isospora thraupis n. sp. is described from faeces of Thraupis palmarum melanoptera (Passeriformes: Thraupidae). Oocysts subspherial-spherical, 19.9 x 19.0 (18.7-21.2 x 18.75-20.0) µm, shape-index 1.0. Wall about 0.6 µm thick, smooth, colourless and a single layer: no micropyle, oocyst residuum or polar bodies. Sporocysts 14.2 x 9.2 (13.7-16.2 x 8.7-10.0) µm, shape-index 1.5: Stied/sub-Stieda bodies inconspicuous. Residuum compact: sporozoites with two refractile bodies.

Eimeria peltocephali n. sp., (Apicomplexa:Eimeriidae) from the Freshwater Turtle Peltocephalus dumerilianus (Chelonia:Pelomusidae) and Eimeria molossi n. sp., from the Bat, Molossus ater (Mammalia:Chiroptera)

The oocyst is described of Eimeria peltocephali n.sp. from faeces of the freshwater turtle Peltocephalus dumerilianus from Barcelos, State of Amazonas, Brazil. Sporulation is exogenous and fully developed oocysts are elongate, ellipsoidal or cylindrical, frequently curved to a banana-shape, 54.4 x19.1 (37.5 - 68.7 x 18.7-20.0 µm), shape-index 2.8 (1.8 -3.9). The oocyst wall is a single thin, colourless layer about 1 µm thick, with no micropyle. There is a bulky oocyst residuum, at first spherical to ellipsoidal, 19 x 16 (16. 2 -26.2 x 16 - 21.5µm) , but becoming dispersed on maturation. There are no polar bodies. The sporocysts, 19.1 x 6.8 ( 17.5 -21.2 x 6.2 -7.5 µm), shape- index 2.8 (2.3 -3.2), are usually disposed in pairs at each end of the oocyst, and bear an inconspicuous Stieda body in the form of a flat cap. The sporozoites are elongate and slightly curved around the residuum. No refractile bodies were seen. Eimeria molossi n.sp., is described from the molossid bat Molossus ater. Sporulation is exogenous and the mature oocysts are predominantly broadly ellipsoidal, 23.4 x 17.5 (18-30 x 15-22.5 µm), shape-index 1.3 (1-1.6). The oocyst wall is about 2 µm thick, and of three layers: an inner thin, colourless one and two outer layers which are thicker, yellowish-brown, prominently striated and in close apposition. There is no micropyle or oocyst residuum, but one and occasionally two polar bodies are usually present. Sporocysts are ellipsoidal, 10.2 x 7.5 (10-12.5 x 7.5 µm), shape-index 1.4 (1.3-1.7) with an inconspicuous Stieda body. Endogenous stages are described in the epithelial cells of the small intestine

Mendacastrum n. gen. and Domuzdagia n. gen., two Jurassic spherical Spumellaria (Radiolaria) with hagiastrid medullary shell

Two new spumellarian radiolarian genera, Mendacastrum and Domuzdagia, are described from the lower Tithonian and lower Pliensbachian respectively. Both have a spherical cortical shell of actinommid type and a spherical or subspherical double medullary shell with the inner medullary shell of hagiastrid s.l. type. The inner medullary shell of Mendacastrum is of dactyliosphaerid or higumastrid s. sit. type, whereas that of Domuzdagia is of angulobracchiid type. Since they cannot be assigned to any described Mesozoic pyloniacean families, they are considered as type genera of two new families: Mendacastridae and Domuzdagiidae respectively.