704 resultados para Conical mirrors


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Background: Copeptin (CP), a derivate from the antidiuretic hormone (ADH) precursor pre-pro-vasopressin, stochiometrically mirrors ADH secretion. CP is increasingly evaluated as a diagnostic and prognostic biomarker in different diseases. It is therefore important to recognize possible confounding factors when interpreting CP levels. In healthy regularly menstruating women, there is a small but measurable physiological variability of hormones involved in fluid regulation. ADH plasma levels have been found to be lowest at menstruation, increasing during the follicular phase with a peak at ovulation and a drop in the luteal phase. We investigated the variability of CP during the menstrual cycle (MC) and its correlation to MC hormones. Methods: In total, 15 healthy women with regular MC (from 26 to 33 days) were included in this study. Ovulation was confirmed by progesterone (prog) levels on day 21 of the MC before entering the study and during the study. Blood collection was performed on days 3, 5, 8-16, 18, 21, 24 and 27 of their MC. Serums were assayed for prog, estradiol (E2), LH, and CP. Mixed linear regression analysis for repeated measures was performed to study the changes of CP, prog, E2 and LH during the MC, and to test the correlation of CP with sex hormones during the MC. Results: Mean MC length in all subjects was 28.5±2.2 d. E2, prog, and LH exhibited characteristic changes during the MC (all P< 0.05). All cycles were ovulatory (peak prog 54±15 nmol/l). CP levels did not change significantly throughout the MC, and were not associated with changes in prog, E2 or LH-levels (all P=ns). Conclusion: CP levels remain stable during the MC and are not influenced by changes in sex hormones. This implicates that it is not necessary to consider MC phases when using CP as a biomarker in premenopausal women.

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Despite the considerable evidence showing that dispersal between habitat patches is often asymmetric, most of the metapopulation models assume symmetric dispersal. In this paper, we develop a Monte Carlo simulation model to quantify the effect of asymmetric dispersal on metapopulation persistence. Our results suggest that metapopulation extinctions are more likely when dispersal is asymmetric. Metapopulation viability in systems with symmetric dispersal mirrors results from a mean field approximation, where the system persists if the expected per patch colonization probability exceeds the expected per patch local extinction rate. For asymmetric cases, the mean field approximation underestimates the number of patches necessary for maintaining population persistence. If we use a model assuming symmetric dispersal when dispersal is actually asymmetric, the estimation of metapopulation persistence is wrong in more than 50% of the cases. Metapopulation viability depends on patch connectivity in symmetric systems, whereas in the asymmetric case the number of patches is more important. These results have important implications for managing spatially structured populations, when asymmetric dispersal may occur. Future metapopulation models should account for asymmetric dispersal, while empirical work is needed to quantify the patterns and the consequences of asymmetric dispersal in natural metapopulations.

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This paper surveys the literature on the implications of trade liberalisation for intra-national economic geographies. Three results stand out. First, neither urban systems models nor new economic geography models imply a robust prediction for the impact of trade openness on spatial concentration. Whether trade promotes concentration or dispersion depends on subtle modelling choices among which it is impossible to adjudicate a priori. Second, empirical evidence mirrors the theoretical indeterminacy: a majority of cross-country studies find no significant effect of openness on urban concentration or regional inequality. Third, the available models predict that, other things equal, regions with inherently less costly access to foreign markets, such as border or port regions, stand to reap the largest gains from trade liberalisation. This prediction is confirmed by the available evidence. Whether trade liberalisation raises or lowers regional inequality therefore depends on each country's specific geography.

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Between 1995 and 2005, the number of aortic aneurysms treated annually using endovascular techniques (EVAR) increased from 0 to 50, including all aortic stages. Our organization includes a large team of surgeons, a stock of three complete families of endoprostheses (straight, conical and bifurcated), a mobile trolley with accessories (arterial introducer/introducer sheath, guide wire, catheters, balloons, etc.) and an appliance on wheels for intravascular ultrasound examination (IVUS). This appliance, together with a mobile fluoroscopy device (c-arm), allows endovascular aneurysms analysis of every operating room in our institution, usually without angiography or the use of contrast medium. In general, we are therefore not depending on substantial preoperative imaging in order to identify candidates for endovascular aneurysms repair and can treat abdominal and thoracic aortic ruptures without delay. For endovascular aortic aneurysms repair we distinguish between process steps on the one hand (determining indications, imaging of the access vessels, measurement using IVUS and road mapping via fluoroscopy, selection of implant, implant insertion, positioning, setting the implant, determining success, reconstruction of the access vessel and follow-up) and the level of competence on the other (assistant, senior and directing physicians). Our ultrasound supported technique for endovascular aneurysms repair has been successfully brought to other hospitals using an IVUS transporter and telementoring.

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Siiloja käytetään jauhemaisten ja rakeisten aineiden varastointiin ja annosteluun maataloudessa sekä mm. lasi-, laasti- ja tasoiteteollisuudessa. Tällaiset laitokset toimitetaan usein kokonaistoimituksina, joissa tavanomaisten teräsrakenteiden kustannusvaikutus voi olla jopa 30 % koko toimituksen arvosta. Niinpä osaltaan siilojen tehokkaalla mitoituksella ja erilaisiarakenneratkaisuja vertailemalla voidaan alentaa toimitusten kokonaiskustannuksia. Tässä diplomityössä perehdyttiin siilojen rakenteisiin ja niiden lujuustekniseen mitoitukseen etenkin tuentaratkaisujen osalta. Mitoituksen osalta työssä perehdyttiin pääasiassa uusiin Eurooppalaisiin standardeihin SFS-EN 1991-4 ja SFS-EN 1993-4-1. Niiden mukaan määritetään mitoituskuormat sekä tehdään lujuustekninen mitoitus. Työn tuloksena laadittiin Microsoft Excel -pohjainen mitoitusohjelma, jolla voidaan nopeasti mitoittaa siilojen olennaisimmat teräsrakenteet. Ohjelmalla voidaan määrittää mitoitus koskien siilon lieriön ja kartion seinämiä sekä tuentaratkaisuja. Ohjelma nopeuttaa erityisesti tarjousvaiheen suunnittelua ja antaa pohjan varsinaiselle siilojen yksityiskohtaiselle mitoittamiselle ja suunnittelulle.

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Climate impact studies have indicated ecological fingerprints of recent global warming across a wide range of habitats. Whereas these studies have shown responses from various local case studies, a coherent large-scale account on temperature-driven changes of biotic communities has been lacking. Here we use 867 vegetation samples above the treeline from 60 summit sites in all major European mountain systems to show that ongoing climate change gradually transforms mountain plant communities. We provide evidence that the more cold-adapted species decline and the more warm-adapted species increase, a process described here as thermophilisation. At the scale of individual mountains this general trend may not be apparent, but at the¦larger, continental scale we observed a significantly higher abundance of thermophilic species in 2008, compared with 2001. Thermophilisation of mountain plant communities mirrors the degree of recent warming and is more pronounced in areas where the temperature increase has been higher. In view of the projected climate change the observed transformation suggests a progressive decline of cold mountain habitats and their biota.

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El presente trabajo tiene por objetivo principal analizar tres funciones de perfil del fuste sobre tres clones de Populus x euramericana (Canadá Blanco, I-214 y MC) en la Comunidad Foral de Navarra para elaborar una tarifa de cubicación con clasificación de volumen. Para minimizar el efecto de la autocorrelación entre los residuos se emplea una estructura de error continua autorregresiva de orden 2 o de orden 3 en función del clon analizado. Por otra parte, se compara el coeficiente local de forma de cada uno de los clones estudiados mediante dos metodologías: el análisis de la varianza de la estimación individual de dicho coeficiente y el contraste del estadístico de máxima verosimilitud entre ajustes, resultando ser el clon Canadá el más cónico de los tres. Los datos utilizados provienen de 143 chopos de plantaciones coetáneas y con mismo marco de plantación (marco real de 4,5 × 4,5 m).

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L'objectiu d'aquest article és discutir una antiga matriu comunicativa parcialment assenyalada per A. Comte, Ch. S. Peirce i U. Eco. Aquests autors reconegueren la relació entre marques, fletxes, ensenyes i espills com a diferents metàfores bàsiques de diverses operacions cognitives, encara que no en van presentar una visió de conjunt. Tots tres van treballar la distinció entre metàfora i metonímia, que va resultar tan fructífera en diferents dominis de recerca, com Jakobson (entre altres) ens va ensenyar. La meua hipòtesi és que aquestes quatre metàfores bàsiques (marques, fletxes, ensenyes i espills) es poden deduir correctament d'una matriu que relacioni l'eix metàfora-metonímia amb menes de codi ficació. E. Verón llançà una interessant reflexió sobre els modes analògic i digital, tot partint d'un problema semblant. Marques, etxes, ensenyes i miralls poden recordar bé operacions com senyalar i assenyalar, representar i reflectir, respectivament: estipular de manera aproximada com aquests objectes i aquestes operacions estan connectats podria ser una petita contribució a l'antic programa de Peirce i els altres.

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Tässä työssä selostetaan kuumalanka-anemometrin käyttö virtausmittauksissa. Kuumalanka-anemometrilla saadaan mitattua virtausnopeuden ja -suunnan lisäksi nopeusheilahteluja. Mittaustaajuus on tyypillisesti useita kymmeniä tuhansia mittauksia sekunnissa ja signaali on jatkuva. Nykytekniikalla pystytään helposti tallentamaan mittauslaitteistolta saatu viesti tietokoneelle ja muuntamaan se nopeudeksi. Hetkellisten nopeuksien avulla voidaan laskea turbulenttisen virtauksen ominaisuuksia, kuten turbulenssin intensiteetti ja spektri. Kuumalanka-anemometrissa lämmitetään sähköisesti ohutta lankaa, joka on mitattavassa virtauksessa. Langan sähköteho on suunnilleen yhtäsuuri kuin langasta konvektiolla siirtyvä lämpöteho. Tällöin on teoreettisesti mahdollista laskea virtausnopeus lämpötehosta lämmönsiirtokorrelaatioilla. Käytännössä laitteisto joudutaan kuitenkin erikseen kalibroimaan, mutta sähkötehon teoreettista riippuvuutta konvektiosta käytetään hyväksi. Kuumalangan lämmitettävä osuus on tyypillisesti halkaisijaltaan 5 µm ja pituudeltaan noin 1 mm. Sitä käytetään pääasiassa kaasuvirtausten mittaamiseen ja valtaosassa mittauksissa virtausaineena on ilma. Kuumalanka voi olla toteutettu kuumakalvotekniikalla, jossa halkaisijaltaan noin 50 - 70 µm paksuinen kuitu on päällystetty ohuella sähköä johtavalla kalvolla. Kuumakalvoanturin ei tarvitse olla muodoltaan sylinterimäinen, se voi olla mm. kartiomainen tai kiilamainen. Erikoispäällystetyllä kuumakalvoanturilla on mahdollista mitata myös nestevirtauksia. Mitattaessa kaasuvirtauksia kuumakalvon etuna on selvästi parempi kestävyys verrattuna kuumalankaan. Nimitystä kuumalanka-anemometri käytetään yleisesti molemmista anturityypeistä Tämän työn alussa käsitellään sylinterin yli tapahtuvaan virtaukseen liittyvää virtausmekaniikkaa ja lämmönsiirtoa. Anemometrin sähköinen osa, laitteisto ja sen kalibrointi käydään läpi. Langan suuntariippuvuuden laskentaan esitetään tarvittavat yhtälöt. Työssä esitellään kolme laitteistolla tehtyä perusmittausta: anturin kohtauskulman muuttaminen, pyörähdyssymmerisen suihkun nopeuskenttä ja tuulitunnelin rajakerros. Lisäksi esitellään yksi käytännöllinen ja vaativampi mittaus, jossa on mitattu nopeusprofiili radiaalikompressorin diffuusorin loppuosassa.

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The aim of this study is to gain a better understanding of the structure and the deformation history of a NW-SE trending regional, crustal-scale shear structure in the Åland archipelago, SW Finland, called the Sottunga-Jurmo shear zone (SJSZ). Approaches involving e.g. structural geology, geochronology, geochemistry and metamorphic petrology were utilised in order to reconstruct the overall deformation history of the study area. The study therefore describes several features of the shear zone including structures, kinematics and lithologies within the study area, the ages of the different deformation phases (ductile to brittle) within the shear zone, as well as some geothermobarometric results. The results indicate that the SJSZ outlines a major crustal discontinuity between the extensively migmatized rocks NE of the shear zone and the unmigmatised, amphibolite facies rocks SW of the zone. The main SJSZ shows overall dextral lateral kinematics with a SW-side up vertical component and deformation partitioning into pure shear and simple shear dominated deformation styles that was intensified toward later stages of the deformation history. The deformation partitioning resulted in complex folding and refolding against the SW margin of the SJSZ, including conical and sheath folds, and in a formation of several minor strike-slip shear zones both parallel and conjugate to the main SJSZ in order to accommodate the regional transpressive stresses. Different deformation phases within the study area were dated by SIMS (zircon U-Pb), ID-TIMS (titanite U-Pb) and 40Ar/39Ar (pseudotachylyte wholerock) methods. The first deformation phase within the ca. 1.88 Ga rocks of the study area is dated at ca. 1.85 Ga, and the shear zone was reactivated twice within the ductile regime (at ca. 1.83 Ga and 1.79 Ga), during which the strain was successively increasingly partitioned into the main SJSZ and the minor shear zones. The age determinations suggest that the orogenic processes within the study area did not occur in a temporal continuum; instead, the metamorphic zircon rims and titanites show distinct, 10-20 Ma long breaks in deformation between phases of active deformation. The results of this study further imply slow cooling of the rocks through 600-700ºC so that at 1.79 Ga, 2 the temperature was still at least 600ºC. The highest recorded metamorphic pressures are 6.4-7.1 kbar. At the late stages or soon after the last ductile phase (ca. 1.79 Ga), relatively high-T mylonites and ultramylonites were formed, witnessing extreme deformation partitioning and high strain rates. After the rocks reached lower amphibolite facies to amphibolite-greenschist facies transitional conditions (ca. 500-550ºC), they cooled rapidly, probably due to crustal uplift and exhumation. The shear zone was reactivated at least once within the semi-brittle to brittle regime between ca. 1.79 Ga and 1.58 Ga, as evidenced by cataclasites and pseudotachylytes. In summary, the results of this study suggest that the Sottunga-Jurmo shear zone (and the South Finland shear zone) defines a major crustal discontinuity, and played a central role in accommodating the regional stresses during and after the Svecofennian orogeny.

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Objective: The goal of the present retrospective study is to describe the distribution of the supernumerary teeth in a population of patients that have been attended at the Public Clinic of the Department of Oral Surgery. Background: Supernumerary teeth and multiple hyperdontia are usually associated with different syndromes, such as Gardner syndrome, or with facial fissures; however, they can appear in patients without any pathology. Their prevalence oscillates to 0.5-3.8% in patients with permanent teeth and to 0.35-0.6% in patients with primary teeth. Patients and Methods: A total of 36,057 clinical histories of patients that were admitted at the clinic between September of 1991 and March of 2003 were revised. The following data were extrapolated: age, sex, number of extracted supernumerary teeth, localization, morphology and type of supernumerary teeth. Consequently, 102 patients were included into the present study. Results: Of the 147 supernumerary teeth identified in the oral cavities of patients 145 were extracted. The most frequent supernumerary teeth identified were mesiodens (46.9%), followed by premolars (24.1%) and fourth molars or distal molars (18%). As for location, 74.5% of the supernumerary teeth were found in the superior maxillary bone and 46.9% of the supernumerary teeth were present in the palatine/lingual area. Heteromorphology was found in two thirds of the supernumerary teeth, with conical shape being the most frequent. Finally, 29.7% of the supernumerary teeth had occlusion with permanent teeth, and mesiodens were the predominating type of supernumerary teeth that showed this feature. Conclusions: Mesiodens very frequently cause retention of permanent incisors, which erupt spontaneously after the extraction of supernumerary teeth, if there is sufficient space in the dental arch and if they conserve the eruptive force. Generally, supernumerary premolars are eumorphic and are casually discovered during radiological exam, if not producing any symptomology.

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Catalunya és un dels territoris on hi ha hagut més auge del sector de la cervesa artesana, i són molt nombroses les microcerveseries i les botigues especialitzades on es poden trobar els recursos materials necessaris, a més de ser centres difusió de coneixements relacionats. Així, doncs, aquest projecte està emmarcat en un context que permet el desenvolupament de tècniques d’elaboració de cervesa artesana. Aquest projecte es basa en la construcció d’un equip amb materials reutilitzats i amb un pressupost limitat que permet reproduir a petita escala els processos d’elaboració que es duen a terme en les microcerveseries artesanes actuals. El projecte s’ha assentat sobre la comprensió dels fonaments teòrics i pràctics del procés d’elaboració de cervesa, i amb l’experiència inicial d’elaboració de cervesa amb un equip bàsic de tipus homebrewer. Per minimintzar costos els tancs s’han construït a partir de barrils de cervesa i les parts sobrants s’han aprofitat per a altres elements. S’han emprat elements quotidians com una olla a pressió i s’ha construït un sistema regulador de pressió (per al tanc de fermentació cilindrocònic isobàric construït) en lloc d’adquirir-lo. S’ha posat l’èmfasi en minimitzar la necessitat de manipulació manual durant l’elaboració. Per tant, s’han instal·lat els components de l’equip formant un circuit tancat amb sistema de bombeig, i s’ha incorporat un sistema que permet el control i la lectura de les temperatures de cada procés. Altres elements són el sistema de filtres amb mecanisme de tub en forma d’ela (que permet l’extracció del most dels tanc de maceració i de cocció d’una manera efectiva i sense necessitat de manipulació) i el sistema de dutxa (que permet automatitzar el procés de rentat i filtrat). Un element que distingeix aquest equip d’altres equips emprats en algunes microcerveseries artesanes és el tanc de fermentació cilindrocònic isobàric amb vàlvula controladora de pressió, que permet prescindir de la doble fermentació en ampolla, ja que permet aprofitar el gas carbònic produït durant la fermentació per la carbonatació de la cervesa. Es pot concloure que gràcies a les seves característiques, l’equip permet realitzar successives elaboracions obtenint el mateix producte amb les mateixes característiques organolèptiques, principalement gràcies a la cambra de fermentació, que permet realitzar les etapes de fermentació, maduració i clarificació controlant la temperatura desitjada; al tanc de maceració amb aïllament, que permet realitzar el procés a temperatura constant sense pèrdues tèrmiques i al sistema de control de temperatura de totes les etapes. L’únic inconvenient és que, degut a la manca pressupostària, ha estat impossible l’adquisició d’un sistema d’embotellament isobàric que permeti realitzar l’embotellament sense pèrdues del gas carbònic. Per tant, el producte final pot embotellar-se amb una lleugera pèrdua de gas o es pot emmagatzemar en el mateix fermentador cilindrocònic per al seu consum directe, a l’estil d’alguns brewpubs.

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In this paper we describe how to make a very simple stereoscope for observation of molecular models produced by several recent computer programmes. With this instrument, constructed essentially with four mirrors, the chemist can visualize molecular models in three dimensions directly from the personal computer monitor screen.

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A method for the determination of trace amounts of palladium was developed using homogeneous liquid-liquid microextraction via flotation assistance (HLLME-FA) followed by graphite furnace atomic absorption spectrometry (GFAAS). Ammonium pyrrolidine dithiocarbamate (APDC) was used as a complexing agent. This was applied to determine palladium in three types of water samples. In this study, a special extraction cell was designed to facilitate collection of the low-density solvent extraction. No centrifugation was required in this procedure. The water sample solution was added to the extraction cell which contained an appropriate mixture of extraction and homogeneous solvents. By using air flotation, the organic solvent was collected at the conical part of the designed cell. Parameters affecting extraction efficiency were investigated and optimized. Under the optimum conditions, the calibration graph was linear in the range of 1.0-200 µg L-1 with a limit of detection of 0.3 µg L-1. The performance of the method was evaluated for the extraction and determination of palladium in water samples and satisfactory results were obtained. In order to verify the accuracy of the approach, the standard addition method was applied for the determination of palladium in spiked synthetic samples and satisfactory results were obtained.

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Continuing the inventory of the Coelenterate Fauna of the Brazilian coast, 23 species of Hydrozoa and a Scyphomedusa are recorded from different points of the coast aproximately between 22º and 24º lat. S. Of these, 14 species were already known from other points of the coast and the remaining 10 were unknown from this latitude. Two species are here listed as new, they are: Halocordyle fragHis and Calicella gabriellae. 1. - Halocordyle fragilis, Stechow's (1923) correction of the generic name Pennaria has been followed, shows remarkable distinctive specific characters such as: alternate distribution of the cladii which do not lie all in the same plane, they are inserted at random on the hydrocaulus with a tendency towards a spiral dexiotropic distribution, sparse distribution of the pedicels which are alternate and not all located on the same side of the hydrocladium, and, finally, the long, wiry aspect of the colony which is as brittle as light glass. This characteristics are not sufficient, to my belief, to establish a new genus, since the polyps and the gonophores are entirely of the Halocordyle type, but they confer upon the species a very peculiar habitus. 2. - Calicella gabriellae forms erect hydrocauli which are extremely soft and flexuose, with hydrothecate and intermediate internodes. The thecae are deep, cylindrical, with a conical base, there are 10-12 long and narrow opercular valves. The gonangia are small, conical, with a short distal digitiform process. The included sporosac exhibits maturing ova. Dynamena heteroclonta described by Jarvis (1922) as a new species, is here considered as a new form of the very variable species Dynamena quadridentata. Schizotricha billardi nom. nov., is specifically separated from Sch. diaphana (Heller) to which it had been identified up to know. The Brazilian colonies agree with the French Somaliland specimens described by Billard (1904) and they are reunited in a new species named after the French worker. The main difference, between the two mentioned species are: shape and size of the gonothecae, of the thecae and of the nematophores. A description is given of all the species not previously recorded from the Brazilian coast as well as biological observations on Olindias sambaquiensis whose shoals during winter months are very large and may entangle partially the fishermen's nets. Its feeding and swimming habits are described and the species proves to be an excellent laboratory animal both for class and research purposes, for it easily endures long transportation (even up to 12 hours during summer months) as well as unoxygenized acquaria and nevertheless greadily feeds on any animal food.