Estudo do potencial refratário de argilas sílico-aluminosas do Rio Grande do Norte

The segment of the structural ceramics industry is one of the most important to the economy of Rio Grande do Norte. The supply chain makes a total of 206 companies that are distributed in 39 counties, concentrated in three regional centers: Seridó Apodi / Assu and great Natal. The ceramic industry in the state is around 80 million pieces per month, with 50,186 million of these tiles, which makes the Rio Grande do Norte one of the largest manufacturers of product in the Country. Different ceramic products can be manufactured by mixing two or more clays and accessory minerals. Mixtures acquire characteristics and form what is called the ceramic body. Refractory masses have a high melting point and thermal shock support. Its composition contains refractory clays with a little iron oxide and material fluxes. A line of semi-refractory ceramic products that stands out for its high added value are the bricks in ivory or red, used in building barbecues, fireplaces, wood stoves and braziers. The aim of this study was to use alumina-clay or silica- alumina-clay to the industrial RN, for the production of refractory bricks semi-refractory burning light. Clay and Kaolin were characterized for their chemical and mineralogical composition, immediately after ceramic bodies were made with different concentrations of the components, they were raised, pressed and sintered. After sintering the resulting products were characterized in terms of mechanical, thermal and dimensional than the characterization by X-ray diffraction and scanning electron microscopy. After obtaining the results, we concluded that the studied clay can be used for the production of semi-refractory bricks

Evaluation of semen characteristics of the species Mazama americana in captivity

In recent years the concept of genomic resource banks has grown as a way of maintaining the genetic variability of populations, while the quality of cryopreservation of the gametes determines the effectiveness of such banks. However, the absence of basic knowledge regarding the physiology of species and their semen characteristics hampers the establishment of reproductive biotechnologies. Thus, this paper aimed to determine certain physicochemical (volume, colour, appearance, pH and osmolarity) and microscopic characteristics (mass movement, motility, vigour, concentration, and sperm morphology and morphometry) of semen of the species Mazama americana. To achieve this, five males of the species were used, and three semen samples per buck (electroejaculation) were collected at intervals of 2 weeks. The volume, pH and osmolarity of the ejaculate were 0.39 ± 0.14 mL, 6.90 ± 0.74 and 297.74 ± 19.10 mOsm/kg, respectively, while the values obtained for mass movement, motility, vigour and concentration were 3.33 ± 0.82; 69.6 ± 8.92%; 3.53 ± 0.50, and 244.07 ± 98.65 × 107/mL, respectively. Regarding the colour of the ejaculate, five samples were classified as ivory, two as yellowish, two as whitish and six as white. Regarding appearance, seven samples were considered creamy and eight, milky. Morphology was analysed in a humid chamber under phase contrast microscopy and 73.50 ± 5.57% of cells presented normal morphology, 8.37 ± 3.15% presented major defects and 18.13 ± 6.46% presented minor defects. To determine sperm morphometry, an optical microscope (Leica DM 5000B) and the Leica Qwin image analyser program were used, resulting in 8.09 ± 0.40, 4.65 ± 0.30, 2.81 ± 0.44 and 30.25 ± 3.02 m for length, largest width, smallest width and area, respectively. Copyright © CSIRO 2013.

Literatura e cinema: representações do feminino em Washington Square, Daisy Miller e The Europeans

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Aspectos fundamentais das medidas e interpretação de registros paleomagnéticos em rochas sedimentares da Formação Longá-Bacia do Parnaíba

Considerando que o número de dados paleomagnéticos para o Paleozóico Superior, principalmente Devoniano da América do Sul, é ainda insuficiente não permitindo que uma Curva de Deriva Polar confiável possa ser construída, foram amostrados 43 níveis estratigráficos da Formação Longá, os quais foram estudados paleomagneticamente com o propósito de contribuir para que uma Curva mais confiável possa ser construída. A amostragem foi feita segundo o método dos blocos ao longo dos perfis Teresina, Barras, Batalha, na rodovia PI-13 e Floriano, Nazaré do Piauí, Oeiras nas rodovias PI-24 e BR-230, no estado do Piauí. Os tratamentos foram iniciados no laboratório de Paleomagnetismo do IAG-USP e complementados no do NCGG-UFPa. Utilizou-se as técnicas de desmagnetização progressiva por campos alternados até 700 e/ou temperaturas até 670-700ºC. A interpretação dos resultados foi feita por meio dos diagramas vetoriais de Zijderveld, pelas curvas J-T/C de variação da intensidade magnética com os campos ou temperaturas, e pelos gráficos de variação na direção do vetor magnetização. Os cálculos de direção média e polos foram feitos segundo a Estatística de Fisher (1953). Foram identificadas 4 direções de magnetização remanente: 1. Uma secundária de origem química (CRM) e polaridade reversa, cujo mineral responsável é a hematita produzida provavelmente por alteração deutérica a partir da magnetita. Esta magnetização (identificada pela letra B) quando datada paleomagneticamente (coordenadas do polo 80ºS, 3°E, A₉₅ = 13.6°) indicou idade correspondente ao intervalo Carbonífero-Permiano. 2. Uma componente isotérmica (IRM) dura de espectro totalmente superposto à magnetização inicial que não foi afetada por nenhum dos tratamentos. Esta magnetização foi denominada D e apresentou direção muito estável em torno do ponto de declinação = 234.23º e inclinação = 41.94º. 3. Um grupo de direções de magnetização de origem viscosa (VRM) moles, identificados pela letra C, cuja direção média é dada por: declinação = 15º e inclinação = -20º. Foram removidas a temperatura entre 300 – 600ºC. 4. Finalmente uma magnetização principal, de polaridade normal, denominada A, provavelmente de origem detrítica (DRM) cujo correspondente polo paleomagnético (de coordenadas: 48ºS, 331.7ºE; A₉₅ = 9.9º) mostrou-se compatível com a idade da Formação (Devoniano Superior). Esta magnetização foi considerada inicial. Os polos paleomagnéticos correspondentes às magnetizações A e B, juntamente com outros da América do Sul, foram rotacionados para a África segundo a configuração pré-deriva de Smith e Hallam (1970) e comparados a polos Africanos e Australianos de mesma idade, mostrando-se coerentes. Suas polaridades também estão em acordo com as escalas magnetoestratigráficas publicadas por Irving e Pullaiah (1976) e Khramov e Rodionov (1981).

Jarina: o marfim das biojóias da Amazônia

A palmeira jarina (Phytelephas macrocarpa) é endêmica da Amazônia, onde se desenvolve sobre antigas planícies de inundação, cujos sedimentos são constituídos por quartzo, minerais de argila 2:1 e feldspatos, constituindo solos férteis e pouco ácidos a neutros. As sementes dessa palmeira são incluídas entre as gemas orgânicas raras. Devido a sua cor e brilho, as sementes são comparadas ao marfim animal, apesar da baixa dureza e baixa densidade, sendo empregadas na manufatura de biojóias e artefatos. Esses produtos são bem aceitos comercialmente devido às sementes serem susceptíveis a mudança de coloração e outros melhoramentos. Infelizmente, as jóias não apresentam vida longa, pois as sementes podem sofrer ataque de microorganismos entre 5 e 10 anos. Se houver uma política adequada para cadeia produtiva das sementes de jarina, a mesma poderá se tornar de grande importância para o desenvolvimento da região Amazônica, ao criar novas oportunidades de trabalho e agregação de valor aos produtos. No entanto faz-se necessário um especial cuidado para evitar exploração inadequada das sementes para assegurar a preservação da espécie.

Preparação e caracterização de derivados celulósicos obtidos a partir da celulose bacteriana e obtenção de filmes para aplicações óticas

Pós-graduação em Química - IQ

A fabulosa viagem do professor Hermenegildo rumo à educação matemática: relatos de experiências profissionais. -

Pós-graduação em Educação Matemática - IGCE

Consequences of Early Late-Pleistocene Megadroughts in Tropical Africa

Extremely arid conditions in tropical Africa occurred in several discrete episodes between 135 and 90 ka, as demonstrated by lake core and seismic records from multiple basins [Scholz CA, Johnson TC, Cohen AS, King JW, Peck J, Overpeck JT, Talbot MR, Brown ET, Kalindekafe L,Amoako PYO, et al. (2007) Proc Natl Acad SciUSA104:16416–16421]. This resulted in extraordinarily low lake levels, even in Africa’s deepest lakes.On the basis of well dated paleoecological records from Lake Malawi, which reflect both local and regional conditions, we show that this aridity had severe consequences for terrestrial and aquatic ecosystems. During the most arid phase, there was extremely low pollen production and limited charred-particle deposition, indicating insufficient vegetation to maintain substantial fires, and the Lake Malawi watershed experienced cool, semidesert conditions (<400 mm>/yr precipitation). Fossil and sedimentological data show that Lake Malawi itself, currently 706mdeep, was reduced to an ~125 m deep saline, alkaline, well mixed lake. This episode of aridity was far more extreme than any experienced in the Afrotropics during the Last Glacial Maximum (~35–15 ka). Aridity diminished after 95 ka, lake levels rose erratically, and salinity/alkalinity declined, reaching near-modern conditions after 60 ka. This record of lake levels and changing limnological conditions provides a framework for interpreting the evolution of the Lake Malawi fish and invertebrate species flocks. Moreover, this record, coupled with other regional records of early Late Pleistocene aridity, places new constraints on models of Afrotropical biogeographic refugia and early modern human population expansion into and out of tropical Africa.

Das Paläolithikum der Magdalenahöhle bei Gerolstein

Die vorliegende Arbeit hat das von 1969 – 1972 ergrabene Inventar der Magdalenahöhle bei Gerolstein unter kritischer Berücksichtigung der Originaldokumentation sowie der stratigraphischen und sedimentologischen Beschreibungen erneut untersucht und v.a. hinsichtlich zweier Arbeitshypothesen überprüft. Daneben fanden jedoch auch die Schmuckobjekte und in kursorischer Weise die Tierknochen Betrachtung. Die Elfenbeinobjekte setzen sich aus elf Fragmenten zusammen, die bereits in zerbrochenem Zustand in die Höhle gelangt sein müssen. Sie sind mit mehreren Linienbündeln verziert, die teilweise aus v- oder zickzack-förmigen Motiven bestehen. Auch gestanzte Punktreihen treten auf. In ihrer Größe und Form sind die Elfenbeinobjekte einzigartig. Lediglich aus der Csákvár-Höhle in Ungarn gibt es vergleichbare Stücke, deren genaue Altersstellung jedoch unklar ist. Daneben kommen in der Magdalenahöhle zwei vollständige durchlochte Hirschgrandeln sowie die Fragmente einer durchlochten Grandel sowie eines durchlochten Wolfzahns vor. Diese tragen teilweise Spuren einer Aufhängung bzw. Befestigung. Der Grund für ihre Niederlegung vor Ort ist indes nicht endgültig zu klären. Die überlieferten Tierknochen besitzen verschiedene Grade von Verfärbung und Erhaltung, lassen sich dadurch jedoch nicht verschiedenen Schichten zuordnen. Neben Modifikationen von Carnivoren, darunter v.a. durch Verdauungsprozesse, sind auch an einigen Exemplaren Schnittspuren festgestellt worden. Eine Bärenphalange aus der Fundschicht b1 eröffnet so die Perspektive, die menschliche Belegung erneut mit der Radiokohlenstoffmethode direkt zu datieren. Der Untere paläolithische Fundhorizont besteht aus relativ unspezifischen Quarzartefakten, die von einer opportunistischen Abschlags- und Werkzeugsgewinnung aus lokalen Schottern zeugen. Für den Oberen paläolithischen Fundhorizont zeigt die Steinartefaktanalyse, dass die Abschläge als Herstellungsreste dünner bifazieller Geräte angesprochen werden können. Während dieser Befund alleine auch im Zusammenhang mit den spätmittelpaläolithischen Blattspitzengruppen gesehen werden kann, sprechen die bereits erwähnten vergesellschafteten Schmuckobjekte, der Nachweis eines Klingenabbaus sowie die fast ausschließliche Verwendung exogenen Rohmaterials für einen jungpaläolithischen Kontext, d.h. für eine Affinität zum Solutréen. Die Steinartefakte der Magdalenahöhle zeugen gleichzeitig von einer sehr mobilen Lebensweise, da lediglich eine Phase des Herstellungsprozesses des bifaziellen Geräts vor Ort stattgefunden hat. Gleichzeitig wurden früher an anderem Ort gewonnene Abschläge mitgebracht und als Werkzeug verwendet. Ebenso wie der Kern selbst wurden Abschläge auch wieder abtransportiert. Insgesamt kann daher eine Rohmaterial konservierende Strategie rekonstruiert werden, in der neben dem Kern als Gerät selbst auch die Abschläge Verwendung finden. Da die Magdalenahöhle als östlicher Niederschlag des Solutréen und als Beleg für das maximale Verbreitungsgebiet dieses Technokomplexes gewertet werden muss, reiht sie sich in eine Reihe von Fundstellen und Argumenten ein, wonach das zentrale Mitteleuropa während des LGM s.l. nicht menschenleer war, sondern in sporadischen Exkursionen begangen wurde. Obwohl sich daran noch keine dauerhafte Wiederbesiedlung anschloss, muss vom Bild einer absoluten Siedlungsleere Abstand genommen werden. Weitere Fundstellen und absolutchronologische Datierungen, u.a. der Magdalenahöhle, könnten in Zukunft zu einem noch besseren Verständnis der menschlichen Anpassungsstragien an kaltzeitliche Umwelten beitragen.

Die Problematik des sogenannten Bettpaneels von Ugarit

Gegenstand meiner Arbeit ist das Bettpaneel von Ugarit und seine komplexe Ikonographie, die Motive unterschiedlicher künstlerischer Traditionen des Alten Orients vereint. Das Bettpaneel bietet die einmalige Gelegenheit, das gesamte Bildprogramm eines Möbels zu untersuchen und die Entwicklung des levantinischen Kunsthandwerks der Späten Bronzezeit (2. Hälfte des 2. Jt.s v. Chr.) besser zu verstehen, besonders in Bezug auf Prestigegüter. Bereits 1952 ist das Bettpaneel im Königspalast von Ugarit entdeckt, jedoch bisher noch nicht monographisch abhandelt worden.rnEs wird gezeigt, dass das Bettpaneel von Ugarit ein hervorragendes Erzeugnis des lokalen Kunsthandwerks ist, gleichzeitig aber die kontinuierliche Übernahme fremder Motive bezeugt.rnWelche Vorbilder haben diese Rezeption begünstigt? Handelte es sich dabei um bewusste Anpassung an heimische Vorstellungen oder vielmehr um getreue Wiedergabe? Warum ließen sich die ugaritischen Handwerker von fremden Kunsttraditionen inspirieren? rnDank der detaillierten Untersuchung des Bettpaneels von Ugarit lassen sich diese wesentlichen Fragen über die Mechanismen der sozialen und kulturellen Interaktionen zwischen den Zivilisationen des Ostmittelmeergebiets im 2 Jt.s v. Chr. endgültig antworten.

Prioritising prevention strategies for patients in antiretroviral treatment programmes in resource-limited settings

Expanded access to antiretroviral therapy (ART) offers opportunities to strengthen HIV prevention in resource-limited settings. We invited 27 ART programmes from urban settings in Africa, Asia and South America to participate in a survey, with the aim to examine what preventive services had been integrated in ART programmes. Twenty-two programmes participated; eight (36%) from South Africa, two from Brazil, two from Zambia and one each from Argentina, India, Thailand, Botswana, Ivory Coast, Malawi, Morocco, Uganda and Zimbabwe and one occupational programme of a brewery company included five countries (Nigeria, Republic of Congo, Democratic Republic of Congo, Rwanda and Burundi). Twenty-one sites (96%) provided health education and social support, and 18 (82%) provided HIV testing and counselling. All sites encouraged disclosure of HIV infection to spouses and partners, but only 11 (50%) had a protocol for partner notification. Twenty-one sites (96%) supplied male condoms, seven (32%) female condoms and 20 (91%) provided prophylactic ART for the prevention of mother-to child transmission. Seven sites (33%) regularly screened for sexually transmitted infections (STI). Twelve sites (55%) were involved in activities aimed at women or adolescents, and 10 sites (46%) in activities aimed at serodiscordant couples. Stigma and discrimination, gender roles and funding constraints were perceived as the main obstacles to effective prevention in ART programmes. We conclude that preventive services in ART programmes in lower income countries focus on health education and the provision of social support and male condoms. Strategies that might be equally or more important in this setting, including partner notification, prompt diagnosis and treatment of STI and reduction of stigma in the community, have not been implemented widely.

Infliximab inhibits bone resorption by circulating osteoclast precursor cells in patients with Rheumatoid Arthritis and Ankylosing Spondylitis

OBJECTIVE: To examine the effects of infliximab on bone resorption by osteoclast precursor cells (OCPs) in patients with rheumatoid arthritis (RA) and ankylosing spondylitis (AS) and to compare the results with changes in disease activity. METHODS: Before and during 24 weeks of infliximab treatment peripheral blood mononuclear cells of 9 RA and 10 AS patients were seeded onto ivory wafers and adherent cells, including OCPs, were grown in medium promoting osteoclast differentiation. Bone resorption was evaluated morphometrically and correlated to disease activity. 19 healthy individuals were studied in parallel. In addition, biochemical bone markers were assessed in all patients at baseline and after 24 weeks. RESULTS: OCPs from RA patients showed a higher bone resorption at baseline when compared to AS patients. Blocking of TNFalpha with infliximab resulted in a strong reduction of bone resorption by OCPs in both cohorts and did occur faster in RA compared to AS patients. This inhibition coincided with reduction of clinical disease activity in both patient cohorts and with an increase of serum osteocalcin levels and a relative decrease of collagen crosslinks in RA compared to AS patients. CONCLUSION: These results provide an explanation on the cellular level for the anticatabolic effect of TNF neutralization on bone. The variation in the kinetics of bone resorption by the OCPs in patients with RA and AS suggests disease-specific differences in the type or in the preactivation of OCPs.

A gamma-glutamyl peptide isolated from onion (Allium cepa L.) by bioassay-guided fractionation inhibits resorption activity of osteoclasts

One gram of onion added to the food of rats inhibits significantly (p < 0.05) bone resorption as assessed by the urinary excretion of tritium released from bone of 9-week-old rats prelabeled with tritiated tetracycline from weeks 1 to 6. To isolate and identify the bone resorption inhibiting compound from onion, onion powder was extracted and the extract fractionated by column chromatography and medium-pressure liquid chromatography. A single active peak was finally obtained by semipreparative high-performance liquid chromatography. The biological activity of the various fractions was tested in vitro on the activity of osteoclasts to form resorption pits on a mineralized substrate. Medium, containing the various fractions or the pure compound, was added to osteoclasts of new-born rats settled on ivory slices. After 24 h of incubation, the tartrate-resistant acid phosphatase positive multinucleated cells, that is, osteoclasts, were counted. Subsequently, the number of resorption pits was determined. Activity was calculated as the ratio of resorption pits/osteoclasts and was compared to a negative control, that is, medium containing 10% fetal bovine serum only and to calcitonin (10(-12) M) as a positive control. Finally, a single peak inhibited osteoclast activity significantly (p < 0.05). The structure of this compound was elucidated with high-performance liquid chromatography-electrospray ionization-mass spectrometry, time-of-flight electrospray ionization mass spectrometry, and nuclear magnetic resonance spectroscopy. The single peak was identified as gamma-L-glutamyl-trans-S-1-propenyl-L-cysteine sulfoxide (GPCS). It has a molecular mass of 306 Da and inhibits dose-dependently the resorption activity of osteoclasts, the minimal effective dose being approximately 2 mM. As no other peak displayed inhibitory activity, it likely is responsible for the effect of onion on bone resorption.

Pliocene-Plistocene deposition of carbonate and organic carbon in ODP Hole 159-959C

During Ocean Drilling Program (ODP) Leg 159, four sites (Sites 959-962) were drilled along a depth transect on the Côte d'Ivoire/Ghana Transform Margin. In this study, the Pliocene-Pleistocene history of carbonate and organic carbon accumulation at Hole 959C is reconstructed for the eastern equatorial Atlantic off the Ivory Coast/Ghana based on bulk carbonate, sand fraction, organic carbon, and other organic geochemical records (d13Corg, marine organic matter percentages derived from organic petrology, hydrogen index, C/N). Pliocene-Pleistocene sedimentation off the Ivory Coast/Ghana was strongly affected by low mean sedimentation rates, which are attributed to persistently enhanced bottom-water velocities related to the steep topography of the transform margin. Sand fraction and bulk carbonate records reveal typical glacial/interglacial cycles, preserved, however, with low time resolution. Intermediate carbonate accumulation rates observed throughout the Pliocene-Pleistocene suggest intense winnowing and sediment redistribution superimposed by terrigenous dilution. 'Atlantic-type' sand and carbonate cycles, consistent with records from pelagic areas of the eastern equatorial Atlantic, are encountered at Hole 959C prior to about 0.9 Ma. Total organic carbon (TOC) records are frequently inversely correlated to carbonate contents, indicating mainly productivity-driven carbonate dissolution related to changes in paleoproductivity. During Stages 22-24, 20, 16, 12, 8, and 4, sand and carbonate records reveal a 'Pacific-type' pattern, showing elevated contents during glacials commonly in conjunction with enhanced TOC records. Formation of 'Pacific-type' patterns off the Ivory Coast/Ghana is attributed to drastically increased bottom-water intensities along the transform margin in accordance with results reported from the Walvis Ridge area. Short-term glacial/interglacial changes in paleoproductivity off the Ivory Coast/Ghana are to some extend recognizable during glacials prior to 1.7 Ma and interglacial Stages 21, 19, 13, 9, and 1. Enhanced coastal upwelling during interglacials is attributed to local paleoclimatic and oceanographic conditions off the Ivory Coast/Ghana. Quantitative estimates of marine organic carbon based on organic petrologic and d13Corg records reveal an offset in concentration ranging from 15% to 60%. Highest variabilities of both records are recorded since ~0.9 Ma. Discrepancies between the isotopic and microscopic records are attributed to an admixture of C4 plant debris approaching the eastern equatorial Atlantic via atmospheric dust. Terrestrial organic material likely originated from the grass-savannah-covered Sahel zone in central Africa. Estimated C4 plant concentrations and accumulation rates range from 10% to 37% and from almost zero to 0.006 g/cm**2/k.y., respectively. The strongest eolian supply to the northern Gulf of Guinea is indicated between 1.9 and 1.68 Ma and during glacial isotopic Stages 22-24, 20, 14, and 12. The presence of grass-type plant debris is further supported by organic petrologic studies, which reveal well-preserved cell tissues of vascular plants or tube-shaped, elongated terrestrial macerals showing different levels of oxidation.