A New Species of Hypostomus (Siluriformes: Loricariidae) from the Upper Rio Paraguay Basin, Brazil

A new small Loricariidae, Hypostomus careopinnatus, is described from the Rio Taquari drainage, upper Rio Paraguay basin, Mato Grosso, Brazil. The new species can be easily distinguished from all congeners, except Hypostomus kids, by the absence of adipose fin. Hypostomus careopinnatus is distinguished from H. levis mainly by the presence of slender bifid teeth, with mesial cusp large and rounded, and lateral cusp small and pointed (vs. spoon-shaped teeth). The new species described herein completely lacks the adipose fin and also lacks the median pre-adipose plates in almost all specimens examined. The absence of adipose fin is probably an independent acquisition for Hypostomus careopinnatus and Hypostomus levis.

Review of the Genus Cathorops (Siluriformes: Ariidae) from the Caribbean and Atlantic South America, with Description of a New Species

The New World genus Cathorops in the family Ariidae (Sea Catfishes) includes species that inhabit estuarine and coastal waters as well as freshwaters, playing an important role in Neotropical coastal and estuarine fisheries. The relatively conserved external morphology coupled with the marked sexual dimorphism and ontogenetic variation makes it difficult to recognize and diagnose the species. One of the major problems concerns the nomenclatural and geographical limits, of C. spixii, described from tropical Brazil and often treated as the only coastal marine species in the genus from the Western Atlantic. Examination of types of nominal species as well as comprehensive collections of non-types from Caribbean and Atlantic South America, lead us to conclude that C. spixii is restricted to Brazil and that C. nuchalis is a valid species, ranging from Venezuela to Guyana. The nominal species Arius laticeps, Arius nigricans, and Arius variolosus are synonyms of C. nuchalis, C. spixii, and C. arenatus, respectively. We also describe a new species in the Cathorops mapale species group from Colombia and Venezuela.

Fatty acids as a tool to compare cachara (Pseudoplatystoma reticulatum) (Siluriformes: Pimelodidae) and hybrid (Pseudoplatystoma corruscans x Pseudoplatystoma reticulatum) larvae during early development

In this study, we investigated the physiological alterations during ontogeny for cachara (Pseudoplatystoma reticulatum) and their hybrid larvae (Pseudoplatystoma corruscans x P. reticulatum) using lipids and fatty acids as physiological tools to elucidate the basis for differences in these groups' productivity in an industrial setting. Eggs and larvae samples were collected during January and February of 2008 in the city of Bandeirantes, MS, and were divided into three primary phases: phase I (0-16 h after fertilization); phase II (24 h after fertilization to 6 days after fertilization); and phase III (7-25 days after fertilization). The larvae of both groups showed a high degree of similarity, suggesting that the hybrid larvae showed a high level of heritability from the cachara broodstock. Analysis of the total lipid content provided evidence that there is no alteration in lipid concentration during ontogeny for both groups (i.e., the cachara and hybrids). However, the fatty acid profile showed that during the endogenous feeding period (phase II), when the larvae must use the energy reserves from the mother, the cachara larvae used mainly monounsaturated fatty acids for development. This is typical for most fish species, though notably, the hybrids preferentially used saturated fatty acids. Furthermore, certain specific changes demonstrate unique patterns of energy utilization and structural substrates, which may aid in elucidating the empirical differences reported by fish farmers (i.e., that the hybrids perform better than cacharas in captivity).

Cytogenetic and molecular analyses in troglobitic and epigean species of Pimelodella (Siluriformes: Heptapteridae) from Brazil

Samples from seven different locations of the genus Pimelodella were genetically examined, two caves (exclusively subterranean, upper Tocantins River and Sao Francisco River) and five epigean (from upper Parana River basin). Cytogenetic analyses revealed the same diploid number (2n=46) for all species besides similarities in both number and location of nucleolar organizer regions and C bands. FISH with 5S rDNA probes and CMA(3) staining indicated significant differences among the studied species. Application of PCR-RFLP in ATPase 6 and 8 mitochondrial genes allowed building a minimum evolution phenogram identifying the close evolutionary relationship among groups. Both chromosomal and molecular data were useful to infer the relationships among studied Pimelodella species.

Iheringichthys syi (Siluriformes: Pimelodidae), a new pimelodid species from upper Paraná basin, Brazil

We describe a new species of pimelodid catfish of the genus Iheringichthys from the upper Paraná basin, Brazil. Iheringichthys syi n. sp. is distinguished by the comparatively fine serration along the anterior margin of the pectoral-fin spine, an adpressed dorsal-fin remote from the adipose-fin origin, a large eye (23.2-31.2% of head length), narrow interorbital (16.2-23.0% of head length), long snout (42.0-51.0% of head length), long postorbital length (30.6-34.0% of head length), low adipose fin (4.8-7.8% of standard length), eye diameter 97.0-140.0% of interorbital length, and body with numerous, small dots irregularly scattered on flanks, especially marked on anterior half of flank.

The cascudos of the genus Hypostomus Lacépède (Ostariophysi: Loricariidae) from the rio Iguaçu basin

We reviewed several large collections of the genus Hypostomus from the rio Iguaçu basin summing up to 793 specimens mainly from the Laboratório de Ictiologia do Departamento de Ecologia e Biologia Evolutiva from Universidade Federal de São Carlos, from fish collection of Núcleo de Pesquisas em Limnologia, Ictiologia e Aquicultura da Universidade Estadual de Maringá, and from the Museu de História Natural do Capão da Imbuia. Hypostomus albopunctatus, H. commersoni, H. derbyi, and H. myersi are redescribed and Hypostomus nigropunctatus is described as a new species. A practical key for identification of Hypostomus species from the rio Iguaçu is also provided.

Embryonic development and larval stages of Steindachneridion parahybae (Siluriformes: Pimelodidae): implications for the conservation and rearing of this endangered Neotropical species

Steindachneridion parahybae is a freshwater catfish endemic to the Paraíba do Sul River and is classified as an endangered Neotropical species. An increasing number of conservation biologists are incorporating morphological and physiological research data to help conservation managers in rescue these endangered species. This study investigated the embryonic and larval development of S. parahybae in captivity, with emphasis in major events during the ontogeny of S. parahybae. Broodstocks were artificially induced to reproduce, and the extrusion occurred 200-255 degree-hours after hormonal induction at 24°C. Larval ontogeny was evaluated every 10 minutes under microscopic/stereomicroscopic using fresh eggs samples. The main embryogenic development stages were identified: zygote, cleavage, including the morula, blastula, gastrula phase, organogenesis, and hatching. The extruded oocytes showed an average diameter of 1.10 ± 0.10 mm, and after fertilization and hydration of eggs, the average diameter of eggs increased to about 1.90 ± 0.60 mm, characterized by a large perivitelline space that persisted up to embryo development, the double chorion, and the poles (animal and vegetative). Cell division started about 2 minutes after fertilization (AF), resulting in 2, 4, 8 (4 x 2 arrangement of cells), 16 (4 x 4), 32 (4 x 8) and 64 (2 x 4 x 8) cells. Furthermore, the blastula and gastrula stages followed after these cells divisions. The closed blastopore occurred at 11 h 20 min AF; following the development, the organogenetic stages were identified and subdivided respectively in: early segmentation phase and late segmentation phase. In the early segmentation phase, there was the establishment of the embryonic axis, and it was possible to distinguish between the cephalic and caudal regions; somites, and the optic vesicles developed about 20 h AF. Total hatching occurred at 54 h AF, and the larvae average length was 4.30 ± 0.70 mm. Gradual yolk sac reduction was observed during the first two days of larval development. The first feeding occurred at the end of the second day. During the larval phase, cannibalism, heterogeneous larval growth and photophobia were also observed. This information will be important in improving the artificial reproduction protocols of S. parahybae in controlled breeding programs.

Three new species of Lebiasina (Characiformes: Lebiasinidae) from the Brazilian shield border at Serra do Cachimbo, Pará, Brazil

Lebiasina marilynae n. sp., L. melanoguttata n. sp., and L. minuta n. sp. are described from the headwaters of the rio Curuá, in Serra do Cachimbo, Pará, Brazil, and represent the only members of the Lebiasininae in the Brazilian Shied, so far. A close relationship among these species is proposed based on: 1) the presence of a pair of foramina through which the ramus palatinus of the facial nerve passes, a modification unique in Lebiasinidae and apparently in the Characiformes, 2) the enlargement of the extrascapular bone, 3) the absence of the secondary stripe, and 4) the nearly equal length of caudal-fin lobes. Lebiasina marilynae additionally differs from all congeners in having the primary stripe extending from the tip of the snout to the distal border of the caudal-fin peduncle, the possession of two series of dark blotches parallel to the primary stripe, and a rounded dorsal surface of the mesethmoid. Lebiasina melanoguttata and Lebiasina minuta additionally differ from all congeners in the absence of the primary stripe and the caudal blotch, and the presence of three longitudinal series of dark blotches at the base of the scales of series 3-5. Lebiasina melanoguttata differs from Lebiasina minuta in the absence of a dark blotch at the base of the median rays of the dorsal fin, second infrapharyngobranchial bearing conical teeth, the reddish overall coloration of the eye and fins, and the dark blotches never coalescing (vs. dark dorsal-fin blotch present; the second infrapharyngobranchial being edentulous; dark, olive green eyes, and the yellowish overall color of body and fins; and the dark blotches of longitudinal series 3 and 4 coalescing where scales of adjacent longitudinal series overlap). The occurrence of species of the Lebiasininae on the Brazilian Shield is discussed, and the distribution pattern of the species described herein is compared to that of other endemic species of the Serra do Cachimbo, a highly biodiverse area isolated from the rest of the Amazon basin.

Kinematics of fibrous aggregates

This thesis reports on a research into the progressive development of fibrous aggregates, e.g. calcite, quartz and mica crystals in veins and strain fringes. The study is based on microstructural analysis of natural examples and on computer experiments. Investigation of fibrous looking elongate crystals in striped bedding-veins from the Orobic Alps, Italy indicate that these crystals do not track the opening trajectory of the veins but are oriented at an angle of up to 80° to the opening direction. Microstructural analysis of quartz, calcite and chlorite fibres in antitaxial strain fringes indicate that most strain fringes contain complex intergrowth of tracking (displacement-controlled) and non-tracking (face-controlled) fibres. To explain these growth features the computer program

Entwicklung der zeitaufgelösten Photoemissions-Elektronenmikroskopie für die Untersuchung der Magnetisierungsdynamik von mikrostrukturierten magnetischen Schichten

Im Rahmen dieser Arbeit wurde die zeitaufgelöste Photoemissions Elektronenmikroskopie (TR-PEEM) für die in-situ Untersuchung ultraschneller dynamischer Prozesse in dünnen mikrostrukturierten magnetischen Schichten während eines rasch verändernden externen Magnetfelds entwickelt. Das Experiment basiert auf der Nutzung des XMCD-Kontrasts (X-ray magnetic circular dichroism) mit Hilfe des zirkularpolarisierten Lichts von Synchrotronstrahlungsquellen (Elektronenspeicherringen BESSY II (Berlin) und ESRF (Grenoble)) für die dynamische Darstellung der magnetischen Domänen während ultraschneller Magnetisierungsvorgänge. Die hier entwickelte Methode wurde als erfolgreiche Kombination aus einer hohen Orts- und Zeitauflösung (weniger als 55 nm bzw. 15 ps) realisiert. Mit der hier beschriebenen Methode konnte nachgewiesen werden, dass die Magnetisierungsdynamik in großen Permalloy-Mikrostrukturen (40 µm x 80 µm und 20 µm x 80 µm, 40 nm dick) durch inkohärente Drehung der Magnetisierung und mit der Bildung von zeitlich abhängigen Übergangsdomänen einher geht, die den Ummagnetisierungsvorgang blockieren. Es wurden neue markante Differenzen zwischen der magnetischen Response einer vorgegebenen Dünnfilm-Mikrostruktur auf ein gepulstes externes Magnetfeld im Vergleich zu dem quasi-statischen Fall gefunden. Dies betrifft die Erscheinung von transienten raumzeitlichen Domänenmustern und besonderen Detailstrukturen in diesen Mustern, welche im quasi-statischen Fall nicht auftreten. Es wurden Beispiele solcher Domänenmuster in Permalloy-Mikrostrukturen verschiedener Formen und Größen untersucht und diskutiert. Insbesondere wurde die schnelle Verbreiterung von Domänenwänden infolge des präzessionalen Magnetisierungsvorgangs, die Ausbildung von transienten Domänenwänden und transienten Vortizes sowie die Erscheinung einer gestreiften Domänenphase aufgrund der inkohärenten Drehung der Magnetisierung diskutiert. Ferner wurde die Methode für die Untersuchung von stehenden Spinwellen auf ultradünnen (16 µm x 32 µm groß und 10 nm dick) Permalloy-Mikrostrukturen herangezogen. In einer zum periodischen Anregungsfeld senkrecht orientierten rechteckigen Mikrostruktur wurde ein induziertes magnetisches Moment gefunden. Dieses Phänomen wurde als „selbstfangende“ Spinwellenmode interpretiert. Es wurde gezeigt, dass sich eine erzwungene Normalmode durch Verschiebung einer 180°-Néelwand stabilisiert. Wird das System knapp unterhalb seiner Resonanzfrequenz angeregt, passt sich die Magnetisierungsverteilung derart an, dass ein möglichst großer Teil der durch das Anregungsfeld eingebrachten Energie im System verbleibt. Über einem bestimmten Grenzwert verursacht die Spinwellenmode nahe der Resonanzfrequenz eine effektive Kraft senkrecht zur 180°-Néel-Wand. Diese entsteht im Zentrum der Mikrostruktur und wird durch die streufeldinduzierte Kraft kompensiert. Als zusätzliche Möglichkeit wurden die Streufelder von magnetischen Mikrostrukturen während der dynamischen Prozesse quantitativ bestimmt und das genaue zeitliche Profil des Streufelds untersucht. Es wurde gezeigt, dass das zeitaufgelöste Photoemissions Elektronenmikroskop als ultraschnelles oberflächensensitives Magnetometer eingesetzt werden kann.

Improved column-based radiochemical processing of the generator produced 68Ga

An improved chemical strategy for processing of the generator produced 68Ga was developed based on processing of the original 68Ge/68Ga generator eluate on a micro-column. Direct pre-concentration and purification of the eluted 68Ga is performed on a cation-exchange resin in hydrochloric acid/acetone media. A supplementary step based on a second micro-column filled with a second resin allows direct re-adsorption of 68Ga eluted from the cation exchanger. 68Ga is finally striped from the second resin with a small volume of pure water. For this purpose a strong anion exchanger and a novel extraction chromatographic resin based on tetraalkyldiglycolamides are characterized. The strategy allows online pre-concentration and purification of 68Ga from the original generator eluate. The supplementary column allows transferring 68Ga with high radionuclide and chemical quality in the aqueous solution with small volume and low acidity useful for direct radiolabeling reactions.

Panel 9: Aftereffects and Memory of the Holocaust

Panel 9: Aftereffects and Memory of the Holocaust Stefanie Rauch, University of Leicester, United Kingdom: “British Responses to the Film ‘The Boy in the Striped Pajamas’” Download paper (login required) Emily Stiles, University of Winchester, United Kingdom: "The Evil They Helped to Defeat: Exhibiting the Holocaust in Britain's National Museum of Modern Conflict" Download paper (login required) Kara Critchell, University of Winchester, United Kingdom: “The Heart of Holocaust Education: Holocaust Survivors and the Construction of Holocaust Consciousness in Britain" Download paper (login required) Noemi Staszewski, University of Frankfurt, Germany: "The Drama of Getting Dependent on Assistance in the Shadow of the Shoah: Working Experiences with Old Age Survivors in Germany " Download paper (login required) Chair: Emily Dabney and James Burnham Sedgwick, Clark UniversityComment: Marianne Hirsch, Columbia University

Reproductive parasitism: male and female responses to conspecific and heterospecific intrusions at spawning in a mouth-brooding cichlid Ophthalmotilapia ventralis

A rare form of alternative reproductive behaviour without simultaneous parasitic spawning was observed in Ophthalmotilapia ventralis, a lekking mouth-brooding cichlid from Lake Tanganyika. Floater males attempted to sneak opportunistically into the territory to actively court the female, while the owner (bourgeois male) defended the territory against other potential intruders. Floater males had more body fat than territory owners and generally higher condition factors. In field experiments, the response of bourgeois males and courted females was tested towards floaters and egg predators (a catfish Synodontis multipunctatus) present in the territories. Territory owners responded aggressively particularly to floaters, and female responsiveness to bourgeois male courtship tended to decline when floaters were present. The potential influence of reproductive parasitism on sexual selection in mouth-brooding cichlids is discussed.

Two-dimensional assembly and local redox-activity of molecular hybrid structures in an electrochemical environment

The self-assembly and redox-properties of two viologen derivatives, N-hexyl-N-(6-thiohexyl)-4,4-bipyridinium bromide (HS-6V6-H) and N,N-bis(6-thiohexyl)-4,4-bipyridinium bromide (HS-6V6-SH), immobilized on Au(111)-(1x1) macro-electrodes were investigated by cyclic voltammetry, surface enhanced infrared spectroscopy (SEIRAS) and in situ scanning tunneling microscopy (STM). Depending on the assembly conditions one could distinguish three different types of adlayers for both viologens: a low coverage disordered and an ordered striped phase of flat oriented molecules as well as a high coverage monolayer composed of tilted viologen moieties. Both molecules, HS-6V6-H and HS-6V6-SH, were successfully immobilized on Au(poly) nano-electrodes, which gave a well-defined redox-response in the lower pA–current range. An in situ STM configuration was employed to explore electron transport properties of single molecule junctions Au(T)|HS-6V6-SH(HS-6V6-H)|Au(S). The observed sigmoidal potential dependence, measured at variable substrate potential ES and at constant bias voltage (ET–ES), was attributed to electronic structure changes of the viologen moiety during the one-electron reduction/re-oxidation process V2+ V+. Tunneling experiments in asymmetric, STM-based junctions Au(T)-S-6V6-H|Au(S) revealed current (iT)–voltage (ET) curves with a maximum located at the equilibrium potential of the redox-process V2+ V+. The experimental iT–ET characteristics of the HS-6V6-H–modified tunneling junction were tentatively attributed to a sequential two-step electron transfer mechanism.

Contrasting Effects of Ethylene Biosynthesis on Induced Plant Resistance against a Chewing and a Piercing-Sucking Herbivore in Rice

Ethylene is a stress hormone with contrasting effects on herbivore resistance. However, it remains unknown whether these differences are plant- or herbivore-specific. We cloned a rice 1-aminocyclopropane-1-carboxylic acid (ACC) synthase gene, OsACS2, whose transcripts were rapidly up-regulated in response to mechanical wounding and infestation by two important pests: the striped stem borer (SSB) Chilo suppressalis and the brown planthopper (BPH) Nilaparvata lugens. Antisense expression of OsACS2 (as-acs) reduced elicited ethylene emission, SSB-elicited trypsin protease inhibitor (TrypPI) activity, SSB-induced volatile release, and SSB resistance. Exogenous application of ACC restored TrypPI activity and SSB resistance. In contrast to SSB, BPH infestation increased volatile emission in as-acs lines. Accordingly, BPH preferred to feed and oviposit on wild-type (WT) plants—an effect that could be attributed to two repellent volatiles, 2-heptanone and 2-heptanol, that were emitted in higher amounts by as-acs plants. BPH honeydew excretion was reduced and natural enemy attraction was enhanced in as-acs lines, resulting in higher overall resistance to BPH. These results demonstrate that ethylene signaling has contrasting, herbivore-specific effects on rice defense responses and resistance against a chewing and a piercing-sucking insect, and may mediate resistance trade-offs between herbivores of different feeding guilds in rice.