Spelling suggestions: "subject:"spots"" "subject:"cpots""
101 |
Inheritance of reactions to gray leaf spot and maize dwarf mosaic virus in maize and their associations with physiological traitsDonahue, Patrick J. January 1989 (has links)
Gray leaf spot, caused by Cercospora zeae-maydis, can be a yield-limiting factor in maize where continuous minimum tillage practices are followed. Commercial corn hybrids were evaluated for response to gray leaf spot for seven years at two Virginia locations (Shenandoah and Wythe Counties) and one year at a third location in Virginia (Montgomery County). Yield losses, when comparing resistant to susceptible classes, were approximately 2,000 kg ha⁻¹ at Wythe County in 1982, 750 kg ha⁻¹ at Shenandoah County in 1984, and 2,150 kg ha⁻¹ at Montgomery County in 1988. The inheritance of reaction to gray leaf spot was studied using a 14 inbred diallel in Montgomery and Wythe Counties, Virginia in 1987 and 1988 planted in randomized complete block designs. Resistance was found to be highly heritable and controlled by additive gene action. Inbreds producing high yielding, resistant, and agronomically superior hybrids were identified (B68, NC250, Pa875, Va14, Va17, and Va85); and several hybrids between these lines had high levels of resistance, high yield, and good general agronomic characters (B68 x KB1250, KB1250 x Pa875, and NC250 x Pa875). Currently available inbreds could be used to produce hybrids with higher levels of resistance than hybrids currently available to growers, and these could serve as a basis for gray leaf spot breeding programs. Lesion size measurements were not correlated with disease scores. Late-season photosynthesis rates were associated positively with resistance. The hybrids of some inbreds were found to produce high levels of pigment (believed to be anthocyanins) around the gray leaf spot lesions. These did not limit the size of the individual lesion later in the season. Some pigment(s)-producing genotypes were found to be resistant when the pigment character was expressed. This type of resistance must prevent or inhibit infection of the leaf but not later colonization, once established. Maize dwarf mosaic virus (MDMV) also limits maize production in some areas where johnsongrass (Sorghum halepense L.) is a problem. Resistance to MDMV was found to be mainly additive and highly heritable. However, a strong specific combining ability component was found, indicating that the background of the material receiving resistance genes may have a strong effect on the expression of resistance. Inbreds capable of producing high-yielding, resistant, and agronomically acceptable hybrids are available (B68, NC250, A632, Pa875, Va17, and Va85); and several hybrids between these lines have high levels of resistance, high yield, and good general agronomic characters (B68 x KB1250, KB1250 x Pa875, and NC250 x Pa875). / Ph. D.
|
102 |
A numerical investigation of hot spotting origin of ventilated disc brakesTang, Jinghan, Bryant, David, Qi, Hong Sheng January 2015 (has links)
no / Hot spots are high thermal gradients on the disc surface during brake events which can cause the undesired phenomena of thermal judder and drone. The origin of hot spotting has been presented by various theories such as Thermo elastic instability (TEI) and progressive waviness distortions (PWD). However, majority of the numerical models based on these theories mainly concentrated on solid disc rather than ventilated disc which is the most commonly used nowadays. According to the experimental work done by the authors, disc geometry factors such as vents and pins also have correlations with hot spot distribution; these phenomena are difficult to be predicted analytically. Thus a convenient 2D asymmetric finite element simulation has been performed in order to obtain the correlations observed in experiments. Further parameter studies investigated factors such as uneven initial temperature, vents, pins and pad length. The results have been correlated with the experimental data and demonstrate the contribution of geometric factors in the generation of hot spots and hot judder.
|
103 |
Caractérisation des hot spots de réactivité biogéochimique dans les eaux souterraines / Characterization of biogeochemical reactivity hot spots in groundwaterBochet, Olivier 08 December 2017 (has links)
Les processus microbiens ont une importance déterminante dans la dynamique des processus réactifs dans les eaux souterraines. La compréhension de la variabilité spatiale et temporelle de ces phénomènes, et le développement de méthodes expérimentales de terrain, ouvrent de nouveaux champs de recherches et d'applications allant de la remédiation des aquifères contaminés à la compréhension des grands cycles biogéochimiques naturels. Dans le premier volet de cette thèse nous présentons des observations de terrain permettant de comprendre le rôle des fractures sur la formation d'un ''hotspot'' d'activité microbienne en profondeur. Du fait de leur forte réactivité, ces ''hotspots'' peuvent dominer la dynamique biogéochimique des milieux souterrains, malgré leur faible extension spatiale. Nous avons ainsi analyser les conditions de formation d'un tapis microbien par des bactéries ferro-oxydantes à 60 mètres de profondeur sur l'observatoire de Ploemeur (réseau H+) alors que ces phénomènes ont été observé jusqu'à présent en surface. Les résultats de cette étude montrent que des circulations hétérogènes, liées à la structure des milieux fracturés, créent des zones mélanges entre des eaux riches en fer et des eaux oxygénées, à l'origine de ce hotspot microbien. Le deuxième volet de ce travail de thèse a été consacré au développement d'une méthode innovante pour la mesure en continu de l'activité microbienne dans les eaux souterraines. La méthode est basée sur l'utilisation de la Fluoréscéine DiAcétate (FDA) dont le produit de réaction peut être mesuré en continu par un fluorimètre de terrain. Après avoir testé et validé les protocoles sur des solutions enzymatiques et des eaux naturelles en laboratoire, nous avons mis en œuvre cette technique sur le terrain au cours d'expériences de traçages réactifs. Un modèle cinétique nous a permis d'approcher les résultats obtenus en laboratoire, et de comparer nos résultats de terrain aux calibrations effectuées in vitro. Cette méthode ouvre ainsi de nouvelles perspectives pour la caractérisation des processus biogéochimiques sur le terrain. / Microbial processes play a key role in controlling biogeochemical reactivity in groundwater. The understanding of the spatial and temporal variability of these phenomena and the development of novel experimental field methods, has opened new fields of research and applications, ranging from groundwater remediation to understanding of global biochemical cycles. In the first part of this thesis, we present field observations providing new insights on the role of fractures in the formation of a hotspot of microbial activity. Because of their large reactivity, these hotspots can dominate the biogeochemical dynamics of subsurface systems, despite their small spatial extent. We have thus analyzed the conditions for the formation of a microbial mat composed of iron-oxidizing bacteria at 60 meters depth in the Ploemeur fractured rock observatory (H+ network) while these phenomena are usually observed at the surface. These results show that heterogeneous flowpaths, linked to the structure of fractured media, create mixing zones between iron rich water and oxygen rich water, at the origin of the microbial hotspot. The second part of this work was devoted to the development of a novel method for a continuous measurement of microbial activity in groundwater. The method is based on the use of Fluorescein DiAcetate (FDA) whose product of reaction can be measured continuously by a field fluorimeter. After testing and validating protocols in the lab on enzymatic solutions and natural water, we have implemented this technic in the field in reactive tracer test experiments. A kinetic model allowed us to interpret the lab results, and to compare them to the field kinetics. This method thus opens new perspectives for the characterization of biogeochemical processes in the field.
|
104 |
En kartläggning av ekosystemtjänster kring Södra Munksjön och appliceringen av grönytefaktor i Jönköping / A mapping of ecosystem services in Södra Munksjön and the application of green area ratio in JönköpingGarneij, Cecilia, Johansson, Patricia January 2017 (has links)
Syfte: Städer behöver grönska, ekosystem och ekosystemtjänster. Grönytefaktor (GYF) är ett verktyg som säkerställer grönska i urbana miljöer. Jönköpings kommun ska som del i sin stadsutveckling av Södra Munksjön inkludera GYF i sin grönstrukturplan. För att utforma en GYF-modell måste man veta platsens förutsättningar och målbilden för staden. Denna studie syftar till att kartlägga de ES som finns i området idag samt vilka som bör skapas, skyddas, stärkas eller rent av skippas i den nya stadsdelen. Vidare studeras även hur den lokala GYF-modellen kan användas i andra områden i Jönköpings kommun. Metod: En kvalitativ studie har genomförts med hjälp av metoderna litteraturstudie, dokumentanalys, observation och intervjuer. Med utgångspunkt i Ekosystemtjänster i stadsplanering - en vägledning framtagen av ℅ city har ekosystemtjänster identifierats. Intervjuer har genomförts med landskapsarkitekter som arbetat med GYF i sammanhang som liknar det Södra Munksjön och Jönköpings kommun står inför. Resultat: Kartläggningen av ekosystemtjänster i Södra Munksjön visar att de flesta tjänsterna på ℅ citys lista kan identifieras och att de kulturella tjänsterna bör premieras i den GYF-modell som ska utformas för området. För att den lokala GYF-modellen ska kunna appliceras på andra områden underlättar det om modellens formuleringar är generella och kompletteras med separat platsspecifik information. För att GYF ska ge bra resultat är dock uttalade och formulerade mål att styra mot den viktigaste faktorn. Konsekvenser: Genom god planering kan en och samma lösning gynna flera ekosystemtjänster samtidigt, vilket rekommenderas i stadsmiljö. Slutsatsen är därför att fokus bör ligga på kulturella ekosystemtjänster och mångfunktionalitet som resulterar i att alla tjänster gynnas. Då GYF är ett nytt verktyg för Jönköping är det av stor vikt att inkludera berörda aktörer och byggherrar i ett tidigt skede. Begränsningar: Den kartläggning av ekosystemtjänster som gjorts i Södra Munksjön har utgått från en geografisk plats och dokument knutna till denna vilket gör att resultatet är begränsat till Södra Munksjön. Av den analys och diskussion som förs gällande hur en GYF-modell kan tas från ett aktuellt område till att appliceras på andra platser kan dock tas vidare av städer som planerar att använda GYF eller vill utveckla en befintlig GYF-modell. / Purpose: Cities need greenery, ecosystems and ecosystem services. Green area ratio (GAR) is a tool that ensures greenery in urban environments. As a part of its urban development of the new city area Södra Munksjön the municipality of Jönköping will include GAR in the local plan for green structure. In order to design a GAR model, one must know the conditions of the site and vision of the city. This study aims to map the ecosystem services located in the area today as well as the ecosystem services that can be created, protected, strengthened or skipped in the new city area. Furthermore, it is also investigated how the local GAR model can be used in other areas in Jönköping municipality. Method: A qualitative study has been conducted with the help of literature studies, document analysis, observation and interviews. With starting point in the model of guidance on ecosystem services in city planning from ℅ city ecosystem services has been identified. Interviews have been conducted with landscape architects with experience from working with GAR in a context similar to the one in Jönköping. Findings: The mapping of ecosystem services in the area of Södra Munksjön shows that most services from ℅ city can be identified and that the cultural ecosystem services should be premiered in the GAR model designed for the city area. In order for the local GAR model to be applied in other areas, it's easier if the formulations in the model are general and supplemented with separate site-specific information. However, in order for GAR to produce good results the most important factor is to have stated and well formulated goals to aim for. Implications: Through good planning, one solution can benefit several ecosystem services at the same time, which is recommended in urban environments. Thus the conclusion is that focus should lay on cultural ecosystem services and multi-functionality that result with all services benefiting. Since GAR is a new tool for Jönköping, it is of great importance to include stakeholders and building contractors at an early stage. Limitations: The mapping of ecosystem services made in Södra Munksjön has been based on a geographical location and documents linked to this place, which means that the results are limited to Södra Munksjön. However, the analysis and discussion of how a GAR model can be taken from a current area to be applied elsewhere could be taken on by cities that are planning to use GAR or want to develop an existing GAR model.
|
105 |
La música como recurso publicitario para cambiar las actitudes negativas en el público millennial. Caso ‘’Soy Yo’’ de Movistar / Music as an advertising resource to change negative attitudes in millennial audiences. Case ''Soy yo'' of MovistarCanales Guerra, Gianella Rous 13 September 2020 (has links)
La publicidad es un medio requerido, pero no siempre aceptado siendo esta la principal razón por la que se usa diversas corrientes creativas para priorizar la interacción emocional. En adición a esta premisa, la música, como elemento independiente, es bien acogida por las personas, despertando emociones diversas que generan remembranza e identificación. De tal forma, la publicidad y la música trabajan juntas para mejorar la comunicación e imagen de las marcas.
El presente trabajo profundiza en el valor de la música original y preexistente como recurso publicitario para el cambio de actitud hacia la marca Movistar mediante el uso de la canción ‘’Soy yo’’ en los spots de la campaña ¡Llegó Preplan! En relación a ello, se expone cómo la música es un medio de entretenimiento y targeting en las creaciones audiovisuales poniendo a prueba el carácter psicológico en los consumidores millennials a la hora de establecer un juicio sobre una marca. Analizando dichos conceptos se parte de la importancia que implica que una marca con tanta presencia en el Perú tenga un impacto negativo.
La relevancia y utilidad de este estudio recae en la investigación del valor que el consumidor le otorga a la música en la publicidad audiovisual. A nivel metodológico, se podrá obtener conocimiento de cómo una marca con problemas de aceptación podrá emplear acciones semejantes para cambiar actitudes y mejorar su desempeño en el mercado. / Advertising is a required but not always accepted, this being the main reason why various creative currents are used to prioritize emotional interaction. In addition to this premise, music, as an independent element, is well received by people, making them feel various emotions that generate remembrance and identification. In this way, advertising and music work together to improve their communication and image of brands.
This document studies in depth the value of the original and pre-existing music as an advertising resource for the change of attitude towards Movistar by using the song ''Soy Yo'' in the spots of the campaign ¡Llegó Preplan! In relation to this, it explains how music is an entertainment and targeting way in the audio-visual creations by testing the psychological aspect in millennial consumers when establishing their judgment over a brand.
The relevance and usefulness of this study is the research of the value that the consumer gives to music in audiovisual advertising. Methodologically, it will be possible to gain knowledge of how a brand with acceptance problems will be able to employ similar actions to change attitudes and improve its performance in the market. / Trabajo de investigación
|
106 |
The characterization and control of Phomopsis cane and leaf spot on vineMostert, Lizel 12 1900 (has links)
Thesis (MScAgric.)--Stellenbosch University, 2000. / ENGLISH ABSTRACT: Phomopsis cane and leaf spot disease of grapevine is an economically important disease
in many of the vine-growing areas of the world. Four different Phomopsis spp. have
previously been associated with this disease. The present study investigates the
taxonomic significance of the different taxa found on grapevines in South Africa, as well
as the endophytic growth and fungicide sensitivity of Phomopsis viticola isolates. The
thesis is compiled of several different parts, which deal with specific, but related topics,
and hence some duplication has been unavoidable.
Understanding the epidemiology of a disease is important for the correct timing of
disease control. To investigate the endophytic growth of P. viticola, asymptomatic
shoots were collected at eight different growth stages. Nodes, internodes, leaf petioles,
leaves, tendrils and bunch peduncles were investigated. Two Phomopsis spp., taxon 1 and
2 were identified in this study. The Phomopsis viticola-complex had a relative
importance of 9% and accounted for 3% of the isolations. P. viticola (taxon 2) is mainly
isolated from the nodes and internodes. Inoculations of healthy, young vine tissue
confirmed taxon 2 to be a virulent pathogen, suggesting that it is a latent pathogen rather
than an endophyte. In contrast, taxon 1 appeared to be a true endophyte, and did not
seem to be an important pathogen on vines.
The true identity of the causal organism of Phomopsis cane and leaf spot disease
was investigated by collecting samples from 58 different vineyards in the grapevine
growing areas of the Western Cape. P. viiicola occurred in grapevine material collected
from Lutzville to Swellendam, but was not found in the Oudtshoorn and Orange River
grapevine areas. Diaporthe perjuncta (taxon 1), P. vutcola (taxon 2), taxon 3 and a
Phomopsis species commonly associated with shoot blight of peaches in the U.S.A., P.
amygdali, were identified among the South African grapevine isolates. Examination of
the Australian culture designated as taxon 4 found it to be a species of Libertella, thus
excluding it from the P. viticola-complex. An Italian isolate was found to represent a
species of Phomopsis not previously known from grapevines, and this was subsequently
described as taxon 5. Species delimitation was based on morphological and cultural
characteristics, stem inoculations and the formation of the teleomorph in vitro. The
identity of each morphological taxon was confirmed by means of phylogenetic analyses
of the nuclear ribosomal DNA internal transcribed spacers (ITS 1 and ITS2) and the 5'
end partial sequence of the mitochondrial small subunit (mtSSU). P. amygdali,
associated with peach shoot blight in the U.S.A., was isolated once only and appeared to
be of lesser importance in this disease complex. Furthermore, taxa 1 (Diaporthe
perjuncta) and 3 were also rarely encountered and proved to be non-pathogenic,
indicating their non-functional role in Phomopsis cane and leaf spot disease. Taxon 2
(Phomopsis viticolas was common and widely distributed in diseased vineyards. This
taxon was associated with the typical disease symptoms and proved to be pathogenic.
Morphologically taxon 2 corresponded best with P. viticola, which was also neotypified
in this study. Taxon 2 was mostly isolated from buds and nodes, indicating that these are
important sites in which the fungus survives during winter. Molecular data indicated that
taxon 3 and P. amygdali were not host specific to grapevine.
The currently used foliar fungicides were compared to the new strobilurin
fungicides. The effects of nine fungicides (azoxystrobin, flusilazole, folpet, fosetyl-
Al+mancozeb, kresoxim-methyl, mancozeb, penconazole, spiroxamine and
trifloxystrobin) were tested in vitro on inhibition of mycelial growth. The following EC50
(ug/ml) values were obtained: azoxystrobin (0.350), flusilazole (0.007), folpet (4.489),
fosetyl-Al+mancozeb (3.925), kresoxim-methyl (1.665), mancozeb (2.891), penconazole
(0.023), spiroxamine (0.321) and trifloxystrobin (0.051). Additionally, azoxystrobin,
folpet, kresoxim-methyl, mancozeb, propineb and trifloxystrobin were tested for their
ability to inhibit spore germination in vitro. The subsequent EC50 (ug/ml) values were
obtained: azoxystrobin 0.123), folpet (0.510), kresoxim-methyl (0.0037), mancozeb
(0.250), propineb (0.156) and trifloxystrobin (0.003). The results reported in part 4
showed that the strobilurin fungicides inhibited the mycelial growth and spore
germination of P. viticola. However, further trials need to be conducted to verify these
findings under field conditions. In the present study taxa 1, 3 and P. amygdali were
infrequently isolated, suggesting that they played a less prominent role in the P. viticolacomplex. / AFRIKAANSE OPSOMMING: Streepvleksiekte van wingerd is 'n ekonomies belangrike siekte wat in die meeste
wingerdproduserende gebiede van die wêreld voorkom. Vier Phomopsis spesies is in die
verlede met dié siekte geassosieer. Hierdie studie ondersoek die taksonomiese
belangrikheid van die verskillende taksa wat op wingerd in Suid Afrika gevind word,
asook die endofietiese groei en fungisiedsensitiwiteit van die Phomopsis vitico/a isolate.
Hierdie tesis bestaan uit verskeie dele met spesifieke, maar verwante onderwerpe wat tot
onafwendbare duplisering lei.
Dit is belangrik om die epidemiologie van 'n siekte te verstaan sodat korrekte en
tydsberekende siektebeheer toegepas kan word. Die endofietiese groei van P. vitico/a is
ondersoek deur simptoomlose lote by agt verskillende groei stadiums te versamel.
Nodusse, internodusse, blaarstele, blare, rankies en trosstele is ondersoek. Twee
Phomopsis spp., takson 1 en 2 is geïdentifiseer. Die Phomopsis vitico/a-kompleks het
3% van die isolasies uitgemaak en 'n relatiewe belangrikheid van 9% getoon. P. vitico/a
(takson 2) is meestal uit die nodus en internodus geïsoleer. lnokulasies van gesonde, jong
wingerdweefsel het bevestig dat takson 2 'n virulente patogeen is en dat die takson eerder
'n latente patogeen as 'n endofiet is. In teenstelling hiermee is takson 1 'n ware endofiet
en 'n onbelangrike patogeen op wingerd.
Die ware identiteit van die veroorsakende organisme van streepvlek is ondersoek
deur plantmateriaal vanaf 58 verskillende wingerde in die wingerproduserende gebiede
van die Wes-Kaap te versamel. P. vitico/a is in wingerdmateriaal vanaf Lutzville tot
Swellendam aangetref, maar nie in die Oudtshoorn en Oranjerivier wingerd produserende
gebiede nie. Diaporthe perjuncta (takson 1), P. vitico/a (takson 2), takson 3 en P.
amygdali is in die Suid Afrikaanse wingerdisolate geïdentifiseer. P. amygdali word met
lootverskroeiing van perske bome in die V.S.A. geassosieer. Die Australiese isolaat wat
benoem is as takson 4, is met die huidige ondersoek gevind om 'n spesie van Libertella
te wees. Takson 4 is daarvolgens uit die P. vitico/a-kompleks gelaat. 'n Italiaanse isolaat
het 'n nuwe spesie van Phomopsis op wingerd verteenwoordig en is vervolgens as takson
5 beskryf. Spesie-onderskeiding is op morfologiese en kulturele eienskappe,
staminokulasies en die vorming van die teleomorf in vitro gebaseer. Die identiteit vanelke morfologiese takson is met behulp van filogenetiese analises van die nukleêre
ribosomale DNS intern transkriberende spasieerders (ITS 1 en ITS2) en die 5' punt
gedeeltelike nukleotied volgorde van die mitochondriale klein subeenheid (mtSSU)
bevestig. P. amygdali is slegs een keer geïsoleer en blyk van minder belang in die
siektekompleks te wees. Takson 1 (Diaporthe perjuneta) en takson 3 het ook min
voorgekom en is nie-patogenies, wat hul nie-funksionele rol in streepvleksiekte aandui.
Takson 2 (P. viticola) is algemeen geïsoleer en kom wyd verspreid voor. Hierdie takson
is geassosieer met die tipiese siektesimptome en is ook patogenies. Morfologies stem
takson 2 met P. viiicola ooreen en is ook geneotipifiseer in hierdie studie. Takson 2 is
meestal vanaf die ogies en nodusse geïsoleer, wat daarop dui dat hierdie belangrike setels
is waar die swam tydens die winter oorleef. Die molekulêre data toon aan dat takson 3 en
P. amygdali nie gasheerspesifiek tot wingerd is nie.
Die swamdoders wat tans teen streepvlek gebruik word, is met die nuwe
strobilurin swamdoders vergelyk. Die effek van nege swamdoders (azoksistrobin,
flusilasool, folpet, fosetyl-Al + mancozeb, kresoxirn-metiel, mankozeb, penconasool,
spiroksamien en trifloksistrobin) is in vitro op die inhibisie van miseliumgroei getoets.
Die volgende EKso-waardes (g/ml) is verkry: azoxystrobin (0.350), flusilasool (0.007),
folpet (4.489), fosetiel-Al + mankozeb (3.925), kresoxirn-metiel (l.665), mankozeb
(2.891), penkonasool (0.023), spiroksamien (0.321) en trifloxystrobin (0.051).
Azoxystrobin, folpet, kresoxim-rnetiel, mankozeb, propineb en trifloksistrobin is ook in
vitro getoets vir hul inhibisie op spoorontkieming. Die volgende EKso-waardes is verkry:
azoxystrobin (0.123), folpet (0.510), kresoxim-metiel (0.0037), mankozeb (0.250),
propineb (0.156) en trifloxystrobin (0.003). Die resultate vervat in deel 4 toon dat die
strobilurin swamdoders die miseliumgroei en spoorontkieming van P. viticola inhibeer.
Toetsing in die veld word egter benodig om die effektiwiteit van die middels te bevestig.
In hierdie studie is taksa I, 3 en P. amygdali selde geïsoleer, wat aangedui het dat hierdie
taksa 'n minder belangrike rol in die P. viticola-kompleks speel.
|
107 |
The variability of M dwarfsGoulding, Niall Thomas January 2013 (has links)
M dwarfs have been the subject of renewed interest as potential habitable planet hosts and have increasingly become the targets of planet detection surveys. Currently, however, the number of detections of transiting M dwarf planets remain low. The characterisation of M dwarf activity is an important consideration for such surveys, and provides constraints on the modelling of magnetically active low mass stars. Currently the spottedness of M dwarfs is not well understood owing to their intrinsic faintness and the lack of diagnostics for assessing starspot morphologies and distributions. The WFCAM Transit Survey (WTS) contains long term observations of M dwarfs in the near infra-red and presents an opportunity to study the long term variability of M dwarfs. The M dwarfs in the WTS are identified by use of colour-spectral type relations, and the periodically variable M dwarfs in the sample are detected using a Lomb-Scargle periodogram analysis. A total of 72 periodically variable M dwarfs are found with periods ranging from 0.16 to 90.33 days. The relations between the spectral subtypes, amplitudes and periods are studied and comparisons to earlier works studying M dwarf rotation are made. A number of examples of significant spot evolution are found, which exhibit complex light curve morphologies that vary in form and amplitude over periods of months to years. This provides an indication as to the nature of the spottedness of these stars. Simulations are performed to probe the connection between spot coverage, temperature and light curve amplitude. Using the results from these simulations, the spot coverage fractions of the WTS M dwarfs are estimated and they are found to be heavily spotted. Dynamic models with spots evolving at various average rates are used to explore how spot evolution can drive increased dispersion in the light curves, and to what extent this affects the detectability of periodicity by the method used. It is found that spot evolution can invoke significant noise in an M dwarf light curve, and in combination with photon noise, can in some instances inhibit the detection of a period. In reflection of the results, the relation between the light curve dispersion and spot coverage of the WTS M dwarfs is considered and it is found that more heavily spotted M dwarfs have intrinsically noisier light curves. The morphologies of the light curves produced by the simulations, and the manner in which they evolve, are qualitatively similar to the real M dwarfs in the WTS sample and indicate how models extrapolated from sunspot distributions can explain behaviour seen in active M dwarf light curves.
|
108 |
A NEW APPROACH TO DRIED BLOOD SPOT ANALYSIS FOR NEWBORN SCREENING USING HIGH RESOLUTION LIQUID CHROMATOGRAPHY TANDEM MASS SPECTROMETRYMiller, John H., IV 21 November 2012 (has links)
The primary purpose of newborn screening is to quickly identify children that are at risk of having a specific disorder in order to start treatment, prevent early death and reduce the chances of permanent physical or mental damage. The current and widely accepted approach used for identification of metabolism disorders involves a flow injection analysis with mass spectrometry detection of acylcarnitines and amino acids. Although this approach is widely accepted and has shown to be sufficient for identification of multiple metabolism disorders the method is not fully quantitative and results often have to be confirmed by second-tier tests. The primary focus of this research was to improve the accuracy and selectivity of this screening method by employing a high resolution chromatographic separation for the combined analysis of twelve acylcarnitines and seven amino acids. This method is an improvement over the current methodology allowing for separation of key isomers that are diagnostic for different metabolism disorders, reducing the need for multiple second-tier tests to confirm results and shortening the time to diagnosis. In order to further improve the efficiency of newborn screening we developed an in-line desorption device, which allows for direct analysis of DBS eliminating the need for punching disks from the filter paper cards. Our device was the first published paper that demonstrated the ability to directly analyze dried blood spots, without the need for any offline sample processing. Using this device, we validated a method to quantify biomarkers related to Maple Syrup Urine Disease, a disorder that requires a second-tier test for confirmation. To further improve the accuracy of dried blood spot analysis we evaluated a technique to correct the sample volume in low and high hematocrit samples. The level of hematocrit in blood spotted on filter paper cards affects the volume of sample analyzed, leading to errors in accuracy. Diffuse reflectance was used to relate differences in sample hematocrit on dried blood spots. We validated our technique with eighteen donor samples at various levels of hematocrit. Correcting sample volume for hematocrit showed improved precision and accuracy over the standard approach, ultimately reducing the potential to misidentify samples.
|
109 |
Nanoestruturas metálicas e de silício para intensificação de campo próximo. / Metal and silicon nanostructures to near-field intensification.Raimundo, Daniel Scodeler 08 October 2009 (has links)
Durante os últimos cinco anos, a nanotecnologia tem atingido avanços significativos em diversas áreas da ciência e tecnologia. Um dos assuntos que está sendo intensamente estudado pela comunidade científica é a intensificação de campo próximo (hot spot) que pode ser aplicada em dispositivos sensores com capacidade de detecção de apenas uma molécula e em nano-antenas ópticas aplicadas na fabricação de dispositivos plasmônicos. Neste sentido, as principais contribuições da presente tese são processos de fabricação de nanoestruturas metálicas e de silício e o estudo da intensificação de campo próximo denominada de pontos quentes (hot spots) nestas estruturas. As nanoestruturas metálicas de Au (ouro) foram obtidas a partir do processo de auto-organização de esferas de poliestireno. As esferas de poliestireno serviram como camada sacrificial (molde) para a obtenção de nanoestruturas metálicas organizadas. Sobre as estruturas de Au organizadas foram depositadas moléculas de cristal violeta para serem utilizadas como moléculas de prova (sondas) no monitoramento da existência dos pontos quentes com o auxílio do espalhamento Raman das moléculas. As nanoestruturas de Au possibilitaram uma intensificação do espalhamento Raman devido à intensificação do campo próximo na superfície metálica periódica de Au. As nanoestruturas e microestruturas de silício foram obtidas a partir da tecnologia de silício poroso. As propriedades do silício poroso foram moduladas através da implantação de íons de hidrogênio (H +) que possibilitou a formação de silício microporoso com forte emissão fotoluminescente (PL) e intensificação do espalhamento Raman superficial devido ao fenômeno de Raman ressonante. Sobre as estruturas macroporosas de silício foram adsorvidas moléculas de azul de metileno para serem utilizadas como moléculas de prova para monitoramento da intensificação do campo próximo e do efeito SERS no silício. A obtenção da intensificação de campo próximo em silício é uma contribuição completamente inédita, pois este fenômeno devia-se, até o momento, somente a materiais metálicos (nanoestruturas metálicas), mostrando sua existência também no silício. / During the last five years, nanotechnology has achieved significant progress in several areas of science and technology. One of the issues that are being intensively studied by the scientific community is the intensification of near-field (hot spot) that can be applied to devices with sensors capable of detecting a single molecule and nano-optical antennas used in the fabrication of plasmonic devices. In this sense, the main contributions of this thesis are processes for manufacture of metal and silicon nanostructures and the study of near-field intensification called hot spots in these structures. The metal nanostructures of Au (gold) were obtained from the process of self-assembling of polystyrene beads. The polystyrene beads were used as sacrificial layer (mold) for obtaining organized metallic nanostructures. On the structures of organized Au were deposited molecules of violet crystal to be used as proof of molecules (probes) to monitor the existence of hot spots with the help of Raman scattering of molecules. The Au nanostructures allowed an intensification of the Raman scattering due to the intensification of the near-field in the periodic Au surface. The microstructures and nanostructures of silicon were obtained using the porous silicon technology. The properties of porous silicon were modulated by the implantation of hydrogen ions (H +) that allowed the formation of microporous silicon which showed high photoluminescence emission (PL) and Raman scattering intensification of the surface due to the phenomenon of resonant Raman. Methylene blue molecules were adsorbed on the macroporous silicon structures to be used as probe molecule for the monitoring of near-field intensification and the SERS effect in silicon. The obtaining of near-field intensification in silicon is an entirely unprecedented contribution, because this phenomenon had been observed, so far, only on the metallic materials (metal nanostructures), showing its existence in the silicon too.
|
110 |
Les discours politiques dans l'Espagne démocratique (1982-2006) / Political speeches in democratic Spain (1982-2008)Decobert, Claire 19 November 2011 (has links)
Dans cette thèse, j’ai souhaité explorer la communication politique espagnole réactivée après plus de quarante ans de dictature et porter une attention particulière au nouveau schéma communicationnel que l’Espagne a dû se réinventer, en s’inspirant des pratiques marketing déjà ancrées chez ses homologues européens et américains. Encouragé par l’augmentation du nombre de convocations électorales, la prolifération des discours parlementaires et l’essor des moyens de communication de masse, un nouveau jeu de langage politique est né entre les acteurs de cette communication politique que sont les hommes politiques, les médias et l’opinion publique. Aussi, insérés dans un contexte socio-historique extrêmement riche, les discours politiques prononcés dans l’Espagne démocratique (1982-2008) par le PP et le PSOE en campagne ou hors campagne sont non seulement révélateurs de l’évolution d’une société démocratique en quête de construction et de reconnaissance sur la scène internationale ; ils marquent également la fin des clivages idéologiques. La diversité de mon corpus a cherché à lever le voile sur la nouvelle parole politique, tiraillée entre la transmission des idéologies et la politique spectacle. La première partie de ce travail de recherche jette les bases théoriques de la communication politique et du discours politique généralisables à toutes les démocraties occidentales, en centrant son attention sur le cas espagnol, qui a su adapter sa manière de communiquer et de produire des discours dans la sphère politique aux exigences contemporaines sous l’égide du marketing politique. La seconde partie interroge les spots électoraux émis par les deux partis majoritaires au cours des élections législatives de 1982 à 2008 du point de vue des stratégies discursives en portant une attention particulière à l’image. La troisième partie livre une analyse lexicale des discours d’investiture prononcés depuis 1982 par les chefs de gouvernement espagnols, étude complétée par une analyse du contenu qui met en exergue les caractéristiques de chacun d’entre eux et confronte chaque allocution au débat qui a opposé le candidat aspirant à la Moncloa au porte-parole de l’opposition. / In this thesis, I intend to investigate the Spanish means of political communication that have been reactivated after more than forty years of dictatorship, and to pay particular attention to the new communication strategy that Spain has had to reinvent, by drawing inspiration from marketing practices already well established in her European and American counterparts. Encouraged by the increase in the number of elections, the proliferation of parliamentary speeches and the development of mass media, a new kind of political language has come about between the political communicators who are the politicians, the media, and the public. Furthermore, set in an extremely rich socio-historic context, the political speeches delivered in democratic Spain (1982-2008) by the PP and the PSOE during or outside their campaigns not only deal with a society in transition to democracy and which is internationally recognised on the but they also mark the end of ideological splits. The variety of documents in my corpus aims at unveiling the new political vocabulary, pulled between conveying ideologies and « showbiz politics ». The first part of this research lays the foundations of political communication and political language that can be applied to all western democracies, focusing on the Spanish case which was able to adapt its way of communicating and producing speeches in the political sphere to the contemporary requirements under the aegis of political marketing. The second part questions t both major parties’ party political broadcast during the general elections from 1982 to 2008 from the strategic point of view of the speeches, by paying particular attention to images. Third part is a lexical analysis of nomination speeches since 1982 by successive Spanish heads of government. This study is completed by an analysis of the content of the speeches and compares every political commentary with the debate that set the candidate aspiring to the Moncloa against the opposition’s spokesman.
|
Page generated in 0.0268 seconds