Cucurbit Pollination: Mechanisms and Management to Optimise Field Quality and Quantity

Negative impacts from intensifying agriculture have generated concerns that pollinator-dependent crop species, such as courgette Cucurbita pepo L., may be experiencing a pollination deficit. This thesis explores the extent to which pollination influences fruit set; how pollination could be improved; and how in doing so growers’ profits and agricultural resilience could increase, using UK field-grown courgettes as a model system. Inspired by evidence of parthenocarpy (fruit set in the absence of fertilisation) in courgette, a systematic review showed extensive use of parthenocarpy to circumvent the need for pollination in other ‘pollinator-dependent’ crop species across the globe. Nonetheless, pollination significantly increased yield and pollinators were abundant enough to fulfil the pollination requirements of courgette, which if extrapolated to the rest of the UK, equates to pollinators contributing approximately £2.7 million to annual UK courgette production. Furthermore, wild flowers within fields were shown to be effective at increasing the abundance of bumblebees and solitary bees. Further exploration of the mutualistic relationship between courgettes and pollinators showed that courgette can improve populations of Bombus terrestris (using the Bumble-BEEHAVE model), an important pollinator of courgette. This thesis concludes that pollination is a vital mechanism for ensuring optimal courgette yields and that whilst pollination levels were maximal at study sites, simple management, such as encouraging wild flowers within courgette fields could help to attract pollinators to courgette flowers and support bees’ nutritional requirements beyond the extensive, yet transient, resource provided by courgette. Understanding a crop’s requirement for pollinators can also aid growers in their decision making about what varieties and sites should be used which could increase their agricultural resilience and further their economic advantage. Further work is needed to understand how other environmental factors interact with pollination to influence fruit set so that growers can prioritise key regulating services in their management for optimal crop yields.Agriculture and Horticulture Development Boar

Analytical study of accelerated light ageing and cleaning effects on acrylic and PVAc dispersion paints used in Modern and Contemporary Art

En el trabajo con el título "Analytical study of accelerated light ageing and cleaning effects on acrylic and PVAc dispersion paints used in Modern and Contemporary Art" se han empleado diferentes técncias analíticas con el fin de optimizar protocolos experimentales para la caracterización de la estabilidad de acrílicos y acetatos de polivinilo (PVAc) frente a ensayos de envejecimeinto acelerado y tratamientos de limpieza. El estudio de los procesos de degradación causados por la exposición a la luz se ha desarrollado sobre una amplia seria de muestras acrílicas y vinílicas expuestas a dos tipos de envejecimiento acelerado con condiciones de envejecimiento artificail representativas de un envejecimiento natural. La información química y mecánica obtenida por ambos ensayos de envejecimiento acelerado permitió identificar procesos de degradación específicos tales como entrecruzamiento o escisión de cadenas. Las conclusiones obtenidas de forma general apuntan que los acrílicos son materiales más estables que los vinílicos y los estireno-acrílicos. Asimsismo, en este estudio se han aborado los efectos de los tratamientos de limpieza bien de base acuosa, bien con disolventes orgánicos, en las propiedades físico-qúimicas en muestras acrílicas y vinílicas. También se han evaluado otros métodos de limpieza tales como geles o emulsiones. Los resultados indican que los tratamientos acuosos extraen aditivos, afectan la morfología e inducen cambios en las propiedades mecánicas de las muestras. Estos efectos pueden ser reducidos con el uso de sistemas alternativos de limpieza.De Sousa Ramos Félix Silva, M. (2011). Analytical study of accelerated light ageing and cleaning effects on acrylic and PVAc dispersion paints used in Modern and Contemporary Art [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/13829Palanci

Life history tracking of social communication and navigation behaviors in honeybees (Apis mellifera L.)

The honeybee (Apis mellifera L.) is an ideal model for studying social behaviors and navigation. Social activities and navigational flights are two key aspects to regulate the function of social community. These complex processes usually involve dance communication, antennation, trophallaxis (social behaviors), and orientation and foraging flights (navigation). As group-living animals, honeybees are known to rely mainly on social information to help make decisions on whether, how and where to forage for food. However, honeybees may also constantly integrate their own experience with the information from other bees to make a final decision. Therefore, the degree to which bees follow the information from other individuals or apply their own knowledge would be age-dependent and experience-dependent on an individual basis. Meanwhile, honeybees, in particular living in a colony with small size, may be vulnerable to the external natural environment. There is no knowledge yet about how the development of the indoor and outdoor behaviors is and how the previously mentioned social and non-social factors influence bees’ behaviors indoors and outdoors, in particular how social behaviors influence the outdoor activities and vice versa. Therefore, the aim of the current study is to find the answers to these questions. This study combined the advantages of Raspberry Pi with video cameras by aid of infra-red illumination on one side, and harmonic radar on the other side to record the social behaviors inside of the colony without disruption and monitor flight trajectories outdoors in real-time. The social behaviors and flights were recorded over the bees’ lifetime within 15 days. In summary, each individual bee possesses their own rhythms with different levels of variation in responding to both social and non-social factors at both group and individual levels. The age dependence and experience dependence of the indoor and outdoor behaviors were found, however, of which the degrees of such dependence were various for different behaviors among different individuals and within an individual over the lifetime. Within the small community, my results showed that there was a small group of ‘elite’ bees that outperformed in both social interaction and flights, which in some sense reflect the collective characteristics and exquisite labor division in the eusocial community. Dance communication is known to convey vector information about the food sources that bees discover during foraging flights. Importantly, my studies firstly discovered that dance communication transmit both motivational and instructive role in the orientation and foraging flights, of which, the influence of information of direction and distance on the orientation and foraging flights in some degree was different. My result firstly discovered that dance communication plays important roles in both motivation and vector roles in bees’ orientation and foraging flights. Noise of information transfer is universal in dance communication. However, its influence on the orientation and foraging flights were not similar which depended on the different purposes of orientation and foraging flights. Honeybees could selectively determine to use flight information form dance communication. For the future, I suggest collecting more datasets about social behaviors to enrich the current conclusions. However, this is critically necessary to rely on an automatically tracking method with high accuracy and fast computing speed.Die Honigbiene (Apis mellifera L.) ist ein idealer Modellorganismus zur Untersuchung des Sozialverhaltens und der Navigation. Soziale Aktivitäten und Navigationsflüge sind zwei Schlüsselaspekte, die das Funktionieren der sozialen Gemeinschaft regeln. Zu diesen komplexen Prozessen gehören die Tanzkommunikation, Antennation und Trophallaxis (Sozialverhalten) sowie Orientierungs- und Sammelflüge (Navigation). Als in Gruppen lebende Tiere verlassen sich Honigbienen bekanntermaßen hauptsächlich auf soziale Informationen, um zu entscheiden, ob, wie und wo sie auf Nahrungssuche gehen. Allerdings können Honigbienen auch unentwegt ihre eigenen Erfahrungen mit den Informationen anderer Bienen kombinieren, um eine endgültige Entscheidung zu treffen. Inwieweit Bienen den Informationen anderer Individuen folgen oder ihr eigenes Wissen anwenden, ist daher individuell alters- und erfahrungsabhängig. In der Zwischenzeit sind Honigbienen, insbesondere wenn sie in einem kleinen Volk leben, anfällig für die äußere natürliche Umgebung sein. Es gibt noch keine Erkenntnisse darüber, wie sich das Verhalten in innerhalb und außerhalb des Volkes entwickelt und wie die zuvor genannten sozialen und nicht-sozialen Faktoren das Verhalten der Bienen innerhalb und außerhalb beeinflussen, insbesondere wie das soziale Verhalten die Aktivitäten im Freien beeinflusst und umgekehrt. Ziel der vorliegenden Studie ist es daher, Antworten auf diese Fragen zu finden. In dieser Studie wurden die Vorteile des Raspberry Pi mit Videokameras mit Hilfe von Infrarot-Beleuchtung auf der einen Seite und harmonischem Radar auf der anderen Seite kombiniert, um das Sozialverhalten innerhalb der Kolonie ohne Unterbrechung aufzuzeichnen und die Flugbahnen im Freien in Echtzeit zu überwachen. Das Sozialverhalten und die Flüge wurden über die gesamte Lebensdauer der Bienen innerhalb von 15 Tagen aufgezeichnet. Zusammenfassend hat jede einzelne Biene ihren eigenen Rhythmus, der sowohl auf Gruppen- als auch auf Individualebene unterschiedlich stark auf soziale und nicht- soziale Faktoren reagiert. Es wurde eine Alters- und Erfahrungsabhängigkeit des Innen- und Außenverhaltens festgestellt, wobei das Ausmaß dieser Abhängigkeit für verschiedene Verhaltensweisen bei verschiedenen Individuen und innerhalb eines Individuums im Laufe des Lebens unterschiedlich war. Innerhalb der kleinen Gemeinschaft des Versuchsstockes zeigten meine Ergebnisse, dass es eine kleine Gruppe von "Elite"-Bienen gab, die sowohl bei der sozialen Interaktion als auch bei den Flügen die Leistungen anderer übertrafen, was in gewisser Weise die kollektiven Merkmale und die exquisite Arbeitsteilung in der eusozialen Gemeinschaft widerspiegelt. Weiter ist bekannt, dass die Tanzkommunikation Vektorinformationen über die Nahrungsquellen vermittelt, die die Bienen während ihrer Flüge zur Futtersuche entdecken. Bedeutsam ist, dass meine Studien zunächst zeigen, dass die Tanzkommunikation sowohl eine motivierende als auch eine anweisende Rolle bei der Orientierung und den Futterflügen spielt, wobei der Einfluss von Richtungs- und Entfernungsinformationen auf die Orientierungs- und Sammelflüge zu einem gewissen Maße unterschiedlich war. Meine Ergebnisse zeigen weiterhin, dass die Tanzkommunikation sowohl eine motivierende als auch eine weisende Rolle bei den Orientierungs- und Sammelflügen der Bienen spielt. Ein Rauschen ist universell in der Informationsübertragung der Tanzkommunikation. Der Einfluss auf die Orientierungs- und Suchflüge war jedoch nicht gleich, was von den unterschiedlichen Zielen der Orientierungs- und Sammelflüge abhing. Honigbienen konnten selektiv entscheiden, ob sie Fluginformationen aus der Tanzkommunikation verwenden. Für zukünftige Studien schlage ich vor, weitere Datensätze über das Sozialverhalten zusammen um die aktuellen Schlussfolgerungen zu ergänzen. Dazu ist es jedoch unbedingt erforderlich, sich auf eine automatische Trackingmethode mit hoher Genauigkeit und schneller Rechengeschwindigkeit zu stützen

Estimating the effects of casino marketing activities on slot business volume: A model for leisure services businesses

This study researched the effect of marketing promotions on gaming volume (i.e., coin-in). Specifically, this study attempted (1) to gain an understanding of the relationship between specific marketing promotions (slot tournaments, special events, product prize drawings, and no marketing promotions) and gaming volume; and (2) to estimate the magnitude of incremental revenue for each type of promotion. A conceptual model was proposed to examine the effect of the different types of marketing promotions on gaming volume, including two other variables (holidays and day-of-the-week) previously found to influence gaming volume; Secondary data were collected from a Las Vegas Strip property for this exploratory study which employed a multiple regression model. The no marketing promotions variable had a significant negative effect on coin-in. Holidays and day-of-the-week continued to be significant variables for increasing gaming volumes. The results suggest that it may be a combination of the day of the week, holidays, and marketing promotions that significantly increase gaming volumes; Promotions should produce a strong spillover effect on slot machine coin-in, producing profits and not just increased revenue. Many casino promotions are not profitable and instead considered loss leaders. With the findings of the current work, casino operators could further evaluate whether their marketing promotions produce sufficient returns on investment. Additionally, this study adds valuable empirical results to the limited literature base associated with the impact of marketing promotions on gaming volume

Pheromones in social mole-rats and implications for the study of mammalian chemical communication

The work reported in this thesis represents an interdisciplinary approach on chemical (olfactory) communication in Zambian mole-rats of the genus Fukomys (family Bathyergidae, Rodentia). Although much attention has been given in this respect to rodents, the role of chemosensation (including acting signals) in these subterranean, eusocial mammals is still not well understood. Individual recognition and signals informing about the reproductive status, both providing the basis of incest avoidance and reproductive skew (Burda 1995), are of special interest particularly because their sensory mechanism remains obscure. The chapter Behavioural olfactory bioassays outlines the evidence for the importance of ano-genital odour in kinship- and individual recognition in mole-rats. Contrary, urine odours did not provide sufficient sensory information in this respect. Pilot endocrinological and colpocytological examinations in Fukomys reveal strong correlation between high mean estradiol- and progesterone values and sexual activity (chapter Steroids and reproductive status). Zambian Fukomys mole-rats are induced ovulators, primed exclusively through repeated and regular sexual activity and not solely through single copulation or separation from the queen as reported for the Damaraland mole-rats (cf., Molteno & Bennett 2000). The poorly understood molecular basis (outlined in the chapter Semiochemicals – HS-SPME-GC-MS-Analysis and in the chapter Lipocalines (MUP´s & Aphrodisin) – Proteomics) of chemosensation was studied, by means of a solvent-free HS-SPME-GS-MS, 2D-PAGE and MALDI-TOF/TOF-tandem MS developed within the framework of this research. Using this approach, it could be demonstrated, that 51 urinary compounds constituting individual volatile urinary pattern of the mole-rat were quite similar even between members of different families. A queen-specific component, 4-nonanone, and similarly 1-hexadecanol, typical for non-reproductive daughters, were identified by mass spectra. Reproductive males (kings) could, however, not be distinguished on the basis of their urinary volatile pattern from non-reproductive males. Males displayed higher amount of ß-caryophyllene in their volatile urinary pattern than females. Although altogether 41 different compounds were identified in urine of families, mole-rats cannot discriminate between different families on the base of odour. Carrot and potato diet influence the urinary composition. Generally, individual urine variations depend on sex (male or female) and reproductive status (queens or non-reproductive females) and not on individuality per se, supporting the outcomes of behavioural bioassays. Remarkably, a well-known lipocaline and sex pheromone of the golden hamster (Mesocricetus auratus) vaginal discharge, aphrodisin, was identified in the urine of Fukomys mole-rats, but without mass polymorphism and in atypically low concentration. In urine of two additionally examined genera of subterranean rodents (Spalax spp. and Spalacopus sp.), neither aphrodisin nor the lipocaline MUP (major urinary protein), generally present in the house mouse (Mus musculus musculus and Mus musculus domesticus1), was found. On these backgrounds, it is still questionable, if in Zambian Fukomys mole-rats aphrodisin takes on the role of a ligand carrier in the subterranean environment. Ligands such as the prospective 1-hexadecanol or 4-nonanone could be protected from degradation (once urine is deposited). Moreover, the slow release mechanism would prolong the olfactory signal which is proved with MUPs in the house mouse. Still it is not clear, if any or which meaning aphrodisin and/or the urinary volatiles have for the olfactory communication. Further research should concentrate on ano-genital odours (and body odours) because of the clear results of the behavioural assays

UNCERTAINTY CONTRIBUTIONS TO SPECIES SPECIFIC ISOTOPE DILUTION ANALYSIS

Mercury speciation in solid sample matrices has been investigated using high performance liquid chromatography (HPLC) coupled with multicollector sector field (MCSF) and quadrupole (Q) inductively coupled plasma mass spectrometry (ICP-MS) for species specific isotope dilution mass spectrometry (IDMS). 199Hg enriched methylmercurychloride has been synthesised and recovered in the solid form for use as a spike material. The stability of methylmercury during the IDMS procedure was investigated using 199Hg and 13C labelled methylmercury isotopomers and ¹H Nuclear Magnetic Resonance spectroscopy. IntermoIecuJar exchange of the methylmercury halide counter ion was observed, the halide counter ion order of preference was l>Br>Cl. No evidence was found for the decomposition, or formation, of methylmercury during equilibration with soil (NIST2710 SRM) or dogfish muscle (DORM-2 CRM), or during chromatographic separation. The extent of equilibration between the spike and the particulate bound mercury compounds was studied by temporal monitoring of the 200Hg:199Hg isotope amount ratio and determining the amount of Hg species in the liquid phase. For N1ST2710, complete equilibration was only achieved when concentrated HNO3 in combination with a microwave digestion was employed. For DORM-2, complete equilibration was achieved when using 1:1 H2O.CH3OH v\v and 0.01 % 2-mercaptoethanol as the solvent, even though only 47% of the analyte was extracted into the liquid phase. The mass fraction of methylmercurychloride has been determined in E)ORM-2 and BCR464 lobster hepatopancreas CRM by two different procedures, single IDMS and approximate matching double IDMS. Mercury cold vapour generation of the HPLC column eluent allowed isotope amount ratios measurements by MC-SF-ICP-MS. For each CRM the mass fraction of methylmercury determined by the two IDMS methods was not statistically different, within the limits of uncertainty, from the certified values. An uncertainty budget for both IDMS procedures has been formulated to allow the performance of each method to be compared For single IDMS the major uncertainty contribution was derived from the within replicate uncertainty, Uwithin The combined standard uncertainty of each replicate analysis was dominated by two components, the uncertainty associated with the natural isotonic abundance 200Hg: 199Hg isotope amount ratio and the uncertainty associated with the 199Hg enriched methylmercurychloride spike mass fraction. The between blend standard uncertainty, Ubetween, was the major contributor to the expanded uncertainty for approximate matching double IDMS. The combined standard uncertainty for each individual replicate was dominated by the contribution from the standard uncertainty associated with the measured 200Hg:199Hg isotope amount ratios in the spiked sample and the mass bias calibration blend.LG