The object of this study was to identify microscopic differences among six selected cultivars of harakeke traditionally used by Maori in weaving. The cultivars were Arawa, Makaweroa, Paretaniwha, Takaiapu, Takirikau, and Tapamangu. The effectiveness of different microscopy techniques for taking measurements of the dimensions of ultimate fibres using a factorial experimental design was investigated in part A. Constant variables were geographical location, location of specimens along the leaf, season (winter), individual plant, fan, north-facing fan, and age of plant (approximately seven years), and cultivars (Paretaniwha and Tapamangu). Experimental variables were the microscopy techniques used and measurement axis. Techniques selected use on further cultivars in part B were transverse sections of leaf specimens 4 m thick, embedded in Paraplast� and observed using LM, and non-fixed ultimate fibres observed using SEM. In part B the dimensions of ultimate fibres from the six selected cultivars of harakeke were measured, and analysed (ANOVA and Tukey's HSD), and the transverse section shapes of fibre aggregates were observed. Transverse widths of ultimate fibres ranged from 10.15 m (Takaipu) -12.80 m (Paretaniwha). Ultimate fibre lengths ranged from 3735 m (Takirikau) - 4751 m (Makaweroa). The cultivars prizes for muka, Arawa and Makaweroa, had the longest and finest ultimate fibre bundles more uniform in transverse-sectional shape than the other cultivars studied and perhaps this explains their selection for extraction of muka. Takirikau had a high yield of ultimate fibre bundles, and perhaps this makes extraction of muka worthwhile. Paretaniwha differed from the other five cultivars studied having an average number of ultimate fibre bundles per unit width that were narrow and non-uniform in shape, and composed of short, thick, ultimate fibre cells. The microscopic structure of muka from six selected cultivars of harakeke used traditionally for weaving varied and may explain differences perceived by weavers, and that different end uses are preferred for various cultivars.

The object of this study was to identify microscopic differences among six selected cultivars of harakeke traditionally used by Maori in weaving. The cultivars were Arawa, Makaweroa, Paretaniwha, Takaiapu, Takirikau, and Tapamangu. The effectiveness of different microscopy techniques for taking measurements of the dimensions of ultimate fibres using a factorial experimental design was investigated in part A. Constant variables were geographical location, location of specimens along the leaf, season (winter), individual plant, fan, north-facing fan, and age of plant (approximately seven years), and cultivars (Paretaniwha and Tapamangu). Experimental variables were the microscopy techniques used and measurement axis. Techniques selected use on further cultivars in part B were transverse sections of leaf specimens 4 m thick, embedded in Paraplast� and observed using LM, and non-fixed ultimate fibres observed using SEM. In part B the dimensions of ultimate fibres from the six selected cultivars of harakeke were measured, and analysed (ANOVA and Tukey's HSD), and the transverse section shapes of fibre aggregates were observed. Transverse widths of ultimate fibres ranged from 10.15 m (Takaipu) -12.80 m (Paretaniwha). Ultimate fibre lengths ranged from 3735 m (Takirikau) - 4751 m (Makaweroa). The cultivars prizes for muka, Arawa and Makaweroa, had the longest and finest ultimate fibre bundles more uniform in transverse-sectional shape than the other cultivars studied and perhaps this explains their selection for extraction of muka. Takirikau had a high yield of ultimate fibre bundles, and perhaps this makes extraction of muka worthwhile. Paretaniwha differed from the other five cultivars studied having an average number of ultimate fibre bundles per unit width that were narrow and non-uniform in shape, and composed of short, thick, ultimate fibre cells. The microscopic structure of muka from six selected cultivars of harakeke used traditionally for weaving varied and may explain differences perceived by weavers, and that different end uses are preferred for various cultivars.

Los sírfidos eristalinos (Syrphidae, Eristalinae: Eristalini) son importantes polinizadores en su estado adulto, tanto en ecosistemas naturales como antropizados, pudiendo actuar de manera conjunta o complementaria a la de los himenópteros. Además de este importante servicio ecosistémico, los hábitos saprófagos de su fase larvaria en medios líquidos o semisólidos hace que jueguen un papel relevante como biodescomponedores de la materia orgánica, así como útiles bioindicadores ambientales. Sin embargo, su utilización a gran escala está actualmente limitada por la escasez de métodos de cría en cautividad capaces de satisfacer su demanda a nivel industrial. Es por ello, que el objetivo fundamental de la presente tesis doctoral es profundizar en el conocimiento de aspectos básicos del ciclo biológico y morfología funcional larvaria de los sírfidos eristalinos, así como el análisis estandarizado de su cría artificial. Para ello, se han seleccionado las especies Eristalinus aeneus (Scopoli, 1763) y Eristalis tenax (Linnaeus, 1758) como representantes de los dos géneros de eristalinos con mayor potencial como agentes polinizadores a nivel comercial. De este modo, la tesis queda organizada en cuatro secciones y ocho capítulos, descritos a continuación. En la Sección I se describe por vez primera la morfología de las fases preimaginales de dos especies de los géneros Eristalinus y Eristalis con potencial para su cría artificial de manera complementaria a las especies objetivo de esta tesis. Mediante el uso de microscopía electrónica (SEM y cryo-SEM), se incluyen claves de identificación taxonómica de todas las especies de ambos géneros cuya morfología preimaginal es actualmente conocida. Por un lado, en el Capítulo 1 se describen las fases preimaginales (huevo y tercer estadio larvario) de Eristalis fratercula (Zetterstedt, 1838), una especie con distribución Holártica característica de climas predominantemente fríos del norte de Europa y América. Entre otros caracteres, destaca la presencia de espículas ramificadas en los labios laterales de la región antero-ventral del tórax como carácter diagnóstico de esta especie. Por otro lado, el Capítulo 2 recoge las descripciones del huevo, estadios larvarios, pupario y el esqueleto cefálico de Eristalinus punctulatus (Macquart, 1847) como potencial agente polinizador endémico de Australia. La larva posee proyecciones carnosas (lappets) en el segmento anal como característica distintiva, mientras que el pupario presenta un patrón específico en los espiráculos que lo diferencia de otras especies del género. Los objetivos de la Sección II están enfocados en conocer tanto la dinámica poblacional y características biológicas del ciclo de vida de las dos especies objetivo de esta tesis, como en la búsqueda de dietas larvarias alternativas a las actualmente conocidas. Para ello, se emplean herramientas que monitoreen cada uno de los individuos que conforman una población o cohorte mediante la metodología de tablas de vida: “age-stage, two-sex life table”. En el Capítulo 3 se comparan los ciclos de vida de E. aeneus y E. tenax usando avena fermentada como medio de desarrollo larvario. En general, los ciclos de vida de E. aeneus y de E. tenax se extendieron una media de 65,12 y 46,06 días respetivamente. Los resultados indican que, de manera general, con E. aeneus se obtienen mejores resultados de longevidad, tiempo de maduración y tasa de crecimiento poblacional en las condiciones de cría utilizadas. Adicionalmente, se identifican como los principales cuellos de botella de la cría artificial de ambas especies: la elevada mortalidad en los primeros días de desarrollo larvario, y el extenso tiempo que requieren las hembras para madurar sexualmente (especialmente E. tenax). En el Capítulo 4 se comparan varios medios alternativos a los granos de avena fermentados para optimizar la producción de E. aeneus. Entre los resultados obtenidos, destaca el efecto positivo del medio basado en yogur con probióticos sobre la fecundidad y longevidad de las hembras, proponiendo su aplicación como aditivo en futuros medios de desarrollo. La utilización del bagazo de cerveza artesanal arrojó resultados cercanos al medio basado en avena fermentada en cuanto a supervivencia y tiempo de desarrollo. Sin embargo, su utilización presenta mayores perspectivas de mejora, así como diversas ventajas asociadas, dado que se trata de un subproducto derivado de la producción de cerveza, permitiendo que sea un medio más rentable de obtener al formar parte una economía circular, lo cual conlleva además beneficios medioambientales. Con el fin de profundizar en el conocimiento de las estructuras relacionadas con la alimentación larvaria se plantearon diversos objetivos en la Sección III. Para ello, se llevó a cabo un estudio funcional para conocer el rango de partículas que eran capaces de ingerir las larvas a lo largo de su crecimiento. Además, se obtuvieron imágenes mediante el uso de SEM, cryo-SEM y Microscopía Confocal Láser de Barrido (CLSM). Esta sección se divide en dos capítulos enfocados en cada una de las especies objetivo: E. aeneus (Capítulo 5) y E. tenax (Capítulo 6). En cada capítulo se describe la morfología de la superficie preoral y del esqueleto cefálico de los tres estadios larvarios. La comparación entre ambas especies apunta a que las mayores diferencias se encuentran en el grado de esclerotización y número de crestas y cerdas de los lóbulos mandibulares; longitud de los cuernos dorsales del esclerito basal, y número y longitud de los filamentos del cibario. Estas diferencias indican que el esqueleto cefálico de E. aeneus es relativamente menos restrictivo, permitiendo la entrada de un mayor volumen de alimento, así como de partículas de mayor tamaño (80–100 μm) que el de E. tenax (70–80 μm). Este hecho podría explicar los mejores resultados de cría de esta especie frente a E. tenax. Por otro lado, se analizan las principales diferencias intraespecíficas entre los diferentes estadios de desarrollo larvario de ambas especies. En el primer estadio se observa un menor número de crestas en el cibario (2 frente a 9 en el tercer estadio), la ausencia de cerdas en las crestas del lóbulo mandibular; el labio y labro poco esclerotizados y no completamente fusionados al esclerito basal, siendo este último la estructura encargada de romper el corion del huevo durante la eclosión. A lo largo de la Sección IV se aborda el estudio del desarrollo intrapuparial de E. aeneus y E. tenax con objeto de desarrollar técnicas que permitan ejercer un mayor control sobre el momento de emergencia de los adultos. En concreto, se analiza el almacenamiento de las pupas a baja temperatura en diferentes momentos de su desarrollo, alargando el tiempo de emergencia del adulto y permitiendo su sincronización conforme a su demanda como polinizadores. De esta manera, en el Capítulo 7, se describe el desarrollo intrapuparial con el fin de detectar y caracterizar los principales cambios morfológicos que tienen lugar desde la formación del pupario hasta la emergencia del adulto. Se observa que ambas especies pasan por cuatro fases de desarrollo a lo largo de 189 ± 4 horas en E. aeneus y 192 ± 3 horas en E. tenax: prepupa, pupa criptocefálica, pupa fanerocefálica y adulto farado. Esta última fase constituye el 81% del total del desarrollo intrapuparial. En el presente estudio se describe, por vez primera en la familia Syrphidae, la esclerotización de la cutícula de la pupa sobre la región cefálica (“mascara pupal”) de ambas especies durante la fase de adulto farado. Posteriormente, en el Capítulo 8 se expusieron pupas de ambas especies a 5 ºC durante diferentes periodos de tiempo (5, 10, 15, 20 y 30 días) y en dos momentos distintos de su desarrollo (al comienzo y al final). Los resultados apuntan a que una exposición al comienzo de la fase de pupa (48 horas) resulta menos perjudicial que al final de esta fase. Además, E. tenax resultó ser algo más sensible al frío, mostrando porcentajes relativamente menores de supervivencia, así como un tiempo máximo de exposición más reducido que E. aeneus. Los resultados apuntan a que el momento de emergencia de los adultos podría alargarse en torno a 18 días en el caso de E. tenax y 23 en el caso de E. aeneus. Superado esos periodos, el número de malformaciones se incrementa y la tasa de supervivencia desciende, siendo próxima al 0% tras la exposición continuada al frío durante 30 días.

Sediments can act as both reservoir and source of legacy organic contaminants such as polychlorinated biphenyls (PCBs). Due to their chemical stability and ubiquity, these contaminants remain as model class of compounds in the field of sediment contamination. Whole sediment and organism concentrations have been often used as exposure metrics for ecological risk assessments. However, whole sediment concentrations often overestimate the potential for exposure to contaminants; while organism concentrations based on bioassay provide a better estimate of exposure, bioassays can also be labor intense, time consuming and expensive. Alternatively, accessiblity-based techniques such as Tenax extractions have been gaining ground, in the last few decades, as a rapid, reliable, and cost-effective approach to estimate exposure to organic contaminants from sediments. Tenax extractions measure the bioaccessible fraction of the contaminant that desorbes from sediment. Despite the simplicity, accuracy and robustness of the Tenax technique to estimate bioaccessibility of organic contaminants, there are still some remaining questions regarding the methodological standardization, and the applicability of the technique in sediments containing diverse carbonaceous sorbents associated adsorption/desorption of the contaminant. Therefore, the chapters of this dissertation were designed to address these questions. To this end, PCBs were chosen as a model compound class to represent a wide range of physicochemical properties of persistent organic contaminants, and because these compounds remain a worldwide legacy contamination problem. The dissertation goals were to: determine the best operational conditions for Tenax technique (Chapter 2); monitor the changes in bioaccessibility of field-collected sediments with different holding time conditions (Chapter 3); examine the effects of the type and quantity of organic carbon on bioaccessibility (Chapter 4); and evaluate the applicability of the Tenax technique to assess remediation success in contaminated marine sediments (Chapter 5). To address the methodological standardization of the Tenax technique, the operational parameters of solvent extract volume, Tenax sorption rate from water, and Tenax:OC (Tenax:Organic Carbon) ratios were investigated in Chapter 2. The highest efficiency of extraction of sorbed PCBs from Tenax resulted from using a 10 mL per each solvent wash during Tenax extraction procedure. For the Tenax sorption, it was found that 0.01 g of Tenax cleared PCB in 40 mL of water in 30 min, thus it would clear the water 48 times in 24 h. When this is extrapolated to the 0.5 of Tenax, typical amount used, it was found that the amount should clear the typical volume of water used on Tenax extraction about 2400 times. This represents unequivocal evidence that the Tenax resin would remove PCBs dissolved in the liquid phase (e.g., overlying or interstitial water) present in the sediment sample and be limited only by compound desorption and not by the Tenax sorption capacity. The results examining the impact of the relationship between the amount of Tenax required and the amount of organic carbon in the sediment extraction indicated that a minimum of 5:1 Tenax:OC ratio be used to conduct Tenax extractions. This will reduce (eliminate) the possibility of re-adsorption by the native OC in the sediment in competition with the Tenax. After ascertaining the best operational conditions for Tenax extractions, two additional methodological uncertainties, the effect of storage time after collection and the preservation method associated with the handling of collected sediment samples were investigated in Chapter 3. The effect of holding time and the preservation method on PCB concentrations from field-collected sediments was examined for a period of 196 d. All samples were held at 4 ºC in the dark and several holding times were chosen. The parameters to track the changes in PCB concentration in two sediments used three exposure metrics: exhaustive solvent extraction, tissue concentrations and Tenax extractions (Chapter 3). The results showed that the total exhaustive concentrations representing the whole sediment concentrations did not significantly change (ANOVA, p> 0.05) in either sediment over the course of 196 d. Similar results were also found for the total Tenax concentrations that represented the bioaccessible sediment concentrations, and for the total organism tissue concentrations representing exposure. The likely equilibrium of PCB in the sediment, their chemical stability of PCB and slow degradation can be underlined as the main factors leading to these results. The long time that legacy contaminants such as PCBs have been in contact with contaminated sites (e.g., Superfund sites) might have contributed to an equilibrium to be reached between the sediment particles and PCB molecules. The significance of this chapter is that sediments collected from PCB-contaminated sites can be stored longer than the 14 d as recommended by current standard protocols without disturbing the measures of bioavailability. The role of organic carbon composition within sediment on contaminant sorption was also investigated to ascertain the effects of type and quantity of OC from different origins on the bioaccessibility of PCBs in contaminated sediments (Chapter 4). Changes in PCB bioaccessibility in sediments amended at either 3 or 6% by dry weight with black carbon (BC), humic acid (HA) or sawdust (SD), showed that the lowest and highest PCB bioaccessibilities were observed in the BC and SD amendments, respectively. Specifically, the total amount of PCBs desorbed ranges from 3 to 27% for BC amendments, 12 to 55% for HA amendments and 16 to 80% for SD amendments. The results showed the influence of OC quantity on bioaccessibility having a much slower desorption of PCBs in 6% amendments compared to 3% amendments, and this finding was most evident in HA and BC amendments. The results also showed that the Tenax technique can be applied to tract the variation in type of carbon and quantity of OC in contaminated sediment to estimate exposure. Finally, the applicability of the Tenax technique as tool to assess the remediation success of PCB-contaminated marine sediments upon AC amendment at either 4.3 or 0.026% AC by dw was examined in Chapter 5. The results showed that bioaccessibility of PCBs was greatly reduced in sediment amended at the higher AC dose (4.3%); while, reduction was also observed even in the sediment amended at 0.026% AC. Furthermore, the results revealed that Tenax concentrations reflected the PCB reduction among AC amended sediments in the same direction as the PCB reduction in the organism bioaccumulation. Overall, this dissertation provides further evidence that the Tenax technique is a rapid, reliable, and cost-effective tool for estimating exposure to recalcitrant organic contaminants such as PCBs from contaminated sites. The applicability of the technique to estimate bioaccessible compound from both freshwater and marine aquatic sediments underline the robustness of the technique to widen its use among risk ecological assessor and researchers.

En nyligen genomförd studie visade att reaktioner mellan vissa radikaler och omättade alkener är snabbare vid rumstemperatur än vad man tidigare har trott. Dessa reaktioner är viktiga för atmosfäriska oxidationscykler och följaktligen var syftet med detta masterprojekt att beräkna hastighetskonstanterna för dessa reaktioner mellan metyljodid och 1-jodidpentan med tetrametyletylen, isopren och limonen vid rumstemperatur genom att kvantifiera respektive epoxid; tetrametyloxiran, isoprenmonoxid och limonen 1,2 epoxid, som producerades. För att uppfylla syftet utfördes experiment på referensföreningarna tetrametyletylen, isoprenmonoxid, limonen och limonen 1,2 epoxid och på prover tagna från en kolonnflödesreaktor. Dessa experiment genomfördes för att kunna utveckla en lämplig provtagningsmetod och analysmetod med termisk desorptionsenhet samt gaskromatografi och masspektrometri (TD-GCMS). Slutsatsen som drogs var att Tenax® TA adsorbentrör är kompatibla med dessa ämnen och att den föreslagna TD-GCMS metoden är effektiv. Dessutom drogs slutsatsen att tetrametyloxiran inte hittades i reaktorproverna (varken i alkenproverna eller reaktorproverna), vilket resulterade i att hastighetskonstanten inte kunde beräknas. Dessutom var kvantifiering av reaktorproverna inte möjlig. / A recent study has shown that the reaction between some radicals and unsaturated alkenes is faster at room temperature than previously believed. These reactions are important for atmospheric oxidation cycles and therefore the purpose of this master project was to measure the rate coefficients for the reactions between methyl iodine and 1-iodopentane with tetramethylethylene, isoprene and limonene at room temperature by quantifying the respective epoxide; tetramethyloxirane, isoprene monoxide and limonene 1,2 epoxide, produced. In order to fulfill the purpose, experiments were conducted using the reference compounds of tetramethylethylene, isoprene monoxide, limonene and limonene 1,2 epoxide and on column flow reactor samples produced in the above mentioned reactions. These were performed in order to be able to develop an appropriate sampling method, and analysis method using thermal desorption unit gas chromatography and mass spectrometry (TD-GCMS). It was concluded that Tenax® TA adsorbent tubes are compatible with these substances and that the TD-GCMS method suggested is appropriate. It was also concluded that no tetramethyloxirane was found in the reactor samples (neither in alkene samples nor after the reactions), resulting in that it was not possible to calculate the rate coefficient. Moreover, the quantification of the reactor samples was not possible.

No description available.

Microelectromechanical systems (MEMS) technology allows the realization of mechanical parts, sensors, actuators and electronics on silicon substrate. An attractive utilization of MEMS is to develop micro instruments for chemical analysis. An example is gas chromatography (GC) which is widely used in food, environmental, pharmaceutical, petroleum/refining, forensic/security, and flavors and fragrances industries. A MEMS-based micro GC (µGC) provides capabilities for quantitative analysis of complex chemical mixtures in the field with very short analysis time and small amounts of consumables. The aim of this research effort is to enhance the sensitivity and selectivity of µGC instruments by implementing chemical amplification method known as preconcentration. A micro preconcentrator (µPC) extracts the target analytes from the sample matrix, concentrates them, and injects them into the separation column for analysis. This work resulted in the development of silicon-glass bonded chips consisting of 7 mm x 7 mm x 0.38 mm multiport cavity with thousands of embedded 3D microstructures (to achieve high surface-to-volume ratio) coated with polymeric thin film adsorbents. Deep reactive ion etching (DRIE) was the enabling technology for the realization of µPCs. Several coating methods, such as inkjet printing of polymers and polymer precipitation from solution have been utilized to coat complex geometrical structures. One major outcome was the development of cobweb adsorbent structure. Moreover, the porous polymeric adsorbent Tenax TA in the film form was characterized, for the first time, for μPC application and shown to have similar properties to that of the granular form. Several μPC designs were experimentally evaluated for their performance in concentrating volatile organic compounds, including cancer biomarkers, Propofol (anesthetic agent), environmental pollutants, and chemical warfare simulants. The possibility of utilizing the μPCs in practical applications such breath analysis was also demonstrated. / Ph. D.

L’expérience SAM de la mission Mars Science Laboratory (MSL) a pour objectif de rechercher de la MO via l’utilisation des techniques EGA/CPG-SM. Pour améliorer la détection de MO, l’instrument SAM incorpore un laboratoire de chimie humide, une expérience de pyrolyse et des pièges adsorbants. L’utilisation de ces outils analytiques a soulevé de nouvelles problématiques concernant la compréhension de l’instrument analytique et sur l’interprétation des résultats obtenus. C’est dans ce cadre qu’intervient cette thèse. Dans un premier temps, nous avons défini l’impact lors des analyses des adsorbants de polymère de Tenax® contenus dans les pièges adsorbants de SAM. Nous avons également déterminé l’incidence de la durée conditionnement, des réactifs de dérivatisation et des perchlorates sur le Tenax®. Nous avons listé les sous-produits de la décomposition du Tenax® pur et mélangé aux réactifs de dérivatisation ou aux perchlorates. Nous montrons que l’agent de dérivatisation, le MTBSTFA, intensifie l’altération du Tenax®, que l’ajout du DMF au MTBSTFA réduit l’impact du MTBSTFA et que les sous-produits de décomposition des perchlorates accentuent la propagation de la dégradation du Tenax®. Dans un second temps, nous nous sommes intéressés à l’influence de la nontronite et des perchlorates sur la pyrolyse des composés organiques de familles chimiques variés susceptibles d’être présents sur Mars à savoir l’alanine, le phénanthrène et l’acide phtalique. Nous constatons que la nontronite de par sa nature acide (acide de Lewis et acide de Brönsted) catalyse certaines réactions impliquant la matière organique : la MO adsorbée sur la nontronite est majoritairement convertie en CO2 lors de la pyrolyse et la décarboxylation et la chloration de la matière organique sont favorisées. / The purpose of SAM experiment on board Mars Science Laboratory (MSL) rover is to detect OM through the usage of EGA/GC-MS techniques. To improve the detection of OM, SAM experiment incorporates a wet chemistry laboratory, a pyrolysis experiment and adsorbent traps. The utilization of these analytical tools raises new issues about the understanding of analytical instrument and the interpretation of the results obtained. It is within this framework that this thesis comes in. Initially, we have defined the impact of polymer adsorbents i.e. Tenax® contain on SAM trap during analysis. We also have determined the effect of conditioning duration, of derivatization reagents and of perchlorates on Tenax®. We have shown that the derivatization agent MTBSTFA intensify Tenax® degradation, that adding DMF to MTBSTFA reduce the impact of MTBSTFA on Tenax® and that perchlorates by-products accentuate the propagation of Tenax® degradation. Then, we get interested about the influence of nontronite and perchlorates in the pyrolysis of organic compounds from various chemical classes that may be present on Mars like alanine, phthalic acid and phenanthrene. We have noticed that the nontronite by its acidity (Lewis et Brönsted acid sites) catalyse some reactions involving OM: the organic matter adsorbed on the nontronite is mostly converted into CO2 during pyrolysis and the decarboxylation and the chlorination of OM is catalysed by the clay.

<p>Sagledavanje ukupnog genetičkog i fenotipskog diverziteta i evolucionog potencijala vrste E. tenax izvr&scaron;eno je analizom jedinki poreklom sa 42 područja Evrope, Australije, Severne i Južne Amerike i laboratorijske kolonije iz &Scaron;panije. Analiza intraspecijske varijabilnosti vrste E. tenax izvr&scaron;ena je kvantifikovanjem varijacija u veličini i obliku krila 1653 jedinke i obojenosti abdomena 936 jedinki. Analiza genetičkog diverziteta na nivou polimorfizma nukleotidnih sekvenci mtDNK je izvr&scaron;ena kod 58 jedinki, dok je analiza alozimske varijabilnosti obuhvatila 821 jedinku prirodnih populacija i laboratorijske kolonije vrste E. tenax. Rezultati su ukazali da inbriding i stohastički procesi utiču na redukciju genetičkog diverziteta i da &ldquo;oslobađaju&rdquo; skrivenu genetičku varijabilnost koja je povezana sa fenotipskom diferencijacijom. Vremenska distribucija fenotipskog diverziteta vrste E. tenax je kvantifikovana analizom jedinki četiri alohrona uzorka poreklom sa lokaliteta Venac, Fru&scaron;ka gora. Mali stepen genetičke i fenotipske diferencijacije između durmitorskih uzoraka vrste E. tenax ukazuje na odsustvo prostorne substruktuiranosti i njihovu međusobnu povezanost intenzivnim protokom gena. Analiza konspecifičkih populacija vrsta E. tenax ukazala je na odsustvo jasne međupopulacione diferencijacije na osnovu parametrara krila i molekularnih markera (alozimski lokusi i COI mtDNK), te se može zaključiti da postoji intenzivan protok gena koji elimini&scaron;e razlike između populacija. Registrovan je polni dimorfizam u veličini i obliku krila i obojenosti abdomena. Uočeno je da mužjaci u proseku imaju manja i uža krila i svetlije obojene abdomene od ženki. Analizom fenotipske diferencijacije u karakterima abdomena na uzorcima vrste E. tenax sakupljenim duž geografskog gradijenta Evrope je utvrđeno odsustvo promena po tipu kline. Dobijeni rezultati omogućavaju preciznije sagledavanje intra- i interpopulacione varijabilnosti ovog takona i ukazuju da vrsta E. tenax ima visok evolucioni potencijal za adaptacije na sredinske promene</p> / <p>This paper examines molecular and phenotypic variability in the widely spread hoverfly species Eristalis tenax. We compared 42 samples from Europe, Australia North and South America, with the aim of obtaining insights into the temporal and spatial variations and sexual dimorphism in the species. Additionally, wild specimens from Spain were compared with a laboratory colony reared on artificial media. The integrative approach was based on allozyme loci, cytochrome c oxidase I mitochondrial DNA, morphometric wing parameters (shape and size) and abdominal colour patterns. Our results indicate that the fourth and eighth generations of the laboratory colony show a severe lack of genetic diversity compared to the figures observed in natural populations. Reduced genetic diversity in subsequent generations of the laboratory colony was found to be linked with phenotypic divergence. The distribution of genetic diversity at polymorphic loci indicated genetic divergence among collection dates from Fru&scaron;ka Gora Mt, and landmark-based geometric morphometrics revealed significant wing shape variation throughout the year. Phenotypic differentiation in abdominal pattern of the E. tenax populations along latitudinal gradient Europe has not been established. Consistent sexual dimorphism was observed, indicating that male specimens had lighter abdomens and smaller and narrower wings than females. It is reasonable to assume high mobility of the dronefly and high rate of gene flow reflected the similarity of genetic and phenotypic diversity of otherwise geographically distinct populations. Hence, the present study expands our knowledge of the genetic diversity and phenotypic variability of E. tenax. The quantification of such variability represents a step towards the evaluation of the adaptive potential of this species of medical and epidemiological importance.</p>

A wide range of organic compounds are released from building and furnishing products and these have the potential to adversely affect indoor air quality. There are growing international requirements for testing and controlling these emissions for the protection of public health. The test methods require specialist analytical chemistry facilities based on thermal desorption/gas chromatography/mass spectrometry (TD/GC/MS). This project has addressed the need for better performance and greater automation of the analysis, as well as development of simpler screening tests. A variety of products were tested using screening techniques, with an emission cell method being used as a reference test. Short duration tests, using a micro-scale chamber at slightly elevated temperature, were shown to have the potential to predict emissions occurring during longer term reference tests. Multi-sorbent air sampling tubes, that have the potential to extend the volatility range of compounds determined by a single TD/GC/MS analysis, were compared with Tenax TA tubes specified by current standard methods. This showed no difference in performance for the range of compounds for which Tenax is optimal, with improved performance for a number of more volatile compounds. The determination of formaldehyde was investigated using 2-hydroxymethylpiperidine as a derivatising agent, followed by TD/GC/MS. The results showed the possibility of this method being developed as an alternative to the current standard method that involves solvent elution and liquid chromatography. The performance of a newly developed time-of-flight mass spectrometer was compared with a standard quadrupole instrument. This showed its potential, with the use of re-collection, to extend the concentration range of compounds quantified from a single air sample, of particular benefit for the determination of carcinogens. New compound identification software was applied to increase automation of analysis of the TD/GC/MS data. Good correlation with manual processing was achieved, demonstrating the possibility of routine application to material emissions testing.