No description available.

Semiconductor quantum dots (QDs) are prime candidates for single and entangled photon sources in quantum information technologies due to their unique optical properties. This thesis investigates the development of QD sources operating at the telecom C-band ---around 1550 nm---, a critical aspect for long-distance applications in optical fibers. The research focuses on the design and optimization of InAs/GaAs QDs for efficient single photon emission within the telecom C-band. This thesis delves into the optimization of the quantum dot environment, by etching its matrix as a microlens (ML). The design process utilizes both simulations and lab fabrication techniques to achieve a source with high single photon throughput, a key requirement for quantum key distribution (QKD). To achieve this, the design optimizes factors such as material growth techniques, device structures, and microlens array configuration to enhance light collection efficiency by a microscope objective and Purcell effect for higher single-photon emission rate. The optimized microlens geometries, particularly the Gaussian and hemispherical shapes, significantly enhanced light extraction efficiency by the objective, achieving up to 40\% and 35\% respectively. The combined fabrication techniques of FIB milling, photolithography, and dry etching resulted in upgraded optical properties and minimal scattering in the microlenses. Furthermore, this work builds upon previous research conducted at the Royal Institute of Technology (KTH). The Quantum Nano Photonics (QNP) group successfully employed QDs to generate entangled photon states. This thesis extends this research by focusing on the design and optimization of a telecom C-band QD source suitable for long-distance transmission through existing fiber optic infrastructure over the Greater Stockholm Metropolitan Area, i.e. between the QNP-group lab at KTH AlbaNova campus and Ericsson HQ, in Kista, Stockholm. The feasibility of such transmission is explored by demonstrating the transmission of single photons from a QD source in the QNP lab at KTH to Ericsson's lab. This thesis contributes to the advancement of QD-based telecom C-band photon sources for future quantum communication networks, with a specific focus on microlens design and fabrication for enhanced single-photon emission efficiency. / Halvledarkvantprickar (QD) är utmärkta kandidater för enstaka och sammanflätade fotonkällor i kvantinformationsteknik på grund av deras unika optiska egenskaper. Denna avhandling undersöker utvecklingen av QD-källor som strålar på telekom C-band ---cirka 1550 nm---, en kritisk aspekt för långdistansapplikationer i optiska fiber. Forskningen fokuserar på design och optimering av InAs/GaAs QDs för effektiv emission av enstaka fotoner inom telekom C-bandet. Denna avhandling fördjupar sig i utformningen av kvantprickarkällan, med hjälp av en mikrolins (ML) array. Designprocessen använder både simuleringar och tillverkningstekniker för att uppnå en källa med hög enfotonrenhet, ett viktigt krav för kvantnyckeldistribution (QKD). För att uppnå detta optimerar designen faktorer som materialtillväxttekniker, enhetsstrukturer och mikrolinskonfiguration för att förbättra ljusinsamlingseffektiviteten och Purcell-effekten för ljusare och snabbare emission av enstaka fotoner. De optimerade mikrolinsgeometrierna, särskilt de gaussiska och halvsfäriska formerna, förbättrade avsevärt ljusextraktionseffektiviteten och nådde upp till 40\% respektive 35\%. De kombinerade tillverkningsteknikerna FIB-fräsning, fotolitografi och torretsning resulterade i uppgraderade optiska egenskaper och minimal spridning i de mikrolinserna. Vidare bygger detta arbete på tidigare forskning som bedrivits vid Kungliga Tekniska Högskolan (KTH). Quantum Nano Photonics-gruppen (QNP) använde framgångsrikt QD för att generera sammanflätade fotontillstånd. Denna avhandling utvidgar denna forskning genom att fokusera på design och optimering av en telekom C-band QD-källa lämplig för långdistansöverföring genom befintlig fiberoptisk infrastruktur över Storstockholmsområdet, dvs. mellan QNP-gruppens labb på KTH AlbaNova campus och Ericssons huvudkontor i Kista, Stockholm. Genomförbarheten av sådan överföring undersöks genom att demonstrera överföringen av enstaka fotoner från en QD-källa i QNP-labbet på KTH till Ericssons labb. Denna avhandling bidrar till utvecklingen av QD-baserade C-bandsfotonkällor för framtida kvantkommunikationsnätverk, med ett specifikt fokus på mikrolinsarraydesign för förbättrad renhet och emissionseffektivitet för enskilda fotoner. Arbetet bygger på tidigare forskning om generering av kvantsammanflätning och banar väg för säkra kvantkommunikationsnätverk över långa avstånd.

<p>Unsafe food is responsible for causing more than 600 million cases of foodborne illnesses and 420,000 deaths each year. These foodborne illnesses have direct impact on growth and development in children, food and nutrition security, national economies, and sustainable development. Food manufactures, research institutions, governments, and consumers, together, play a pivotal role in establishing and implementing effective food safety systems. <em>Salmonella</em> spp. and <em>Listeria monocytogenes</em> are recognized as major threats to global food safety and security among other 31 known and unknown pathogens associated with foodborne illnesses and deaths. Since these pathogens can be transmitted through contaminated food and water, contaminated environmental surfaces, and subsequently from environment to food via cross-contamination, there is an urgent need for data-driven approaches to identify key points of contamination along the food systems to suggest interventions. While it is important to enhance food safety research in developed economies, developing capacity to enable conditions for food safety research translation and practice in developing economies is crucial for global food safety. In this dissertation, we presented three different research projects as summarized below-</p> <p>In Chapter 2 “Evaluating the efficacy of celery powder in ready-to-eat deli style turkey breast against <em>L. monocytogenes</em> under ideal and temperature abuse conditions”. In this study, we artificially inoculated “clean label” deli style turkey breast formulated with celery powder to evaluate the efficacy of this natural antimicrobial in inhibiting the growth of this pathogen. We stored the inoculated samples at ideal (4 °C) and abuse temperature conditions (7 °C, 10 °C, and 15 °C) for 21 d mimicking the possible temperature abuse along the cold chain, transportation, and at consumer refrigerator. Our findings indicated that although deli meat samples stored at 4 °C and 7 °C did not achieve significant growth of <em>L. monocytogenes;</em> increasing temperatures to 10 °C and 15 °C led to significant increase in the growth rate of this pathogen. This study evaluates the use and effectiveness of celery powder as an antimicrobial used by deli meat processors against <em>L. monocytogenes</em> in deli products. These data underscore the importance of maintaining refrigeration temperatures to complement the efficacy of antimicrobials. </p> <p>Chapter 3 “Investigating sanitary solutions to <em>L. monocytogenes, Salmonella enterica</em> ser. Typhimurium, and <em>Pseudomonas aeruginosa</em> dry surface biofilms”. In this study, we developed <em>in vitro</em> mono- and mix-culture dry surface biofilm (DSB) models of <em>L. monocytogenes, Salmonella enterica</em> ser. Typhimurium, and <em>Pseudomonas aeruginosa</em> leveraging the EPA MLB SOP MB-19 standard protocol using the CDC Biofilm Reactor and evaluated sanitation control strategies currently adopted by low-moisture food (LMF) food processors to determine their ability to inactive DSB, a decidedly difficult reservoir to eliminate. This study targets multiple biological hazards in a research area with very limited publicly available data and is the first of its kind to refine mono- and multi-species <em>in vitro</em> DSB models that mimic LMF facility conditions and combinations of relevant microorganisms for use cases (e.g., EPA adoption). The findings from this study indicated that these foodborne pathogens could form DSBs and serve as a source of pathogen reservoir and cross-contamination. Results from the efficacy testing of sanitizer and microfiber swabbing suggested that current sanitation practices may not be sufficient to remove or inactivate DSBs. This study will define future needs and new strategies to improve confidence in sanitation efficacy with private sector practitioners.</p> <p>Chapter 4 “Enhancing research for development opportunities for Minority Serving Institutions: a case study in food safety”. Most developing economies have limited viable food safety systems due to underdeveloped research capabilities, competing resource demands, and insufficient enabling conditions, which undermines food security. United States Minority Serving Institution (MSIs) researchers and outreach specialists are familiar with and arguably best positioned to address global food safety and security challenges and needs, but MSIs implement limited research for development programs (e.g., U.S. university-led Feed the Future (FTF) Innovation Labs (ILs) funded by the United States Agency for International Development (USAID)) aimed to solve these challenges. Recognizing this opportunity, the Feed the Future Innovation Lab for Food Safety (FSIL) led by Purdue University in partnership with Cornell University, created and implemented an MSI-led research partnerships for global food safety research programs. In this chapter, we put together the process of a three-stage Request for Applications (RFA) process, which included non-competitive and competitive stages to encourage partnership and to refine ideas.  At the end of this process, seven individuals were invited to submit full proposals; two were funded. Intentional research opportunities and partnerships are essential to strengthen MSI competitiveness for research for development programs that develop and scale technologies to address urgent global agriculture, food security, and safety challenges.</p>

Neste estudo analisamos a diversidade e endemismos da flora lenhosa das florestas estacionais decíduas (FEDs) do norte e centro do Perú. Caracterizamos a diversidade das plantas lenhosas ao longo dos vales, para definir os valores de conservação da área a nível nacional. Os resultados indicam que as FEDs do vale do Marañón apresentam valores significativamente altos em endemias em relação às outras FEDs do Perú e FEDs vizinhas e o padrão de endemismos e estrutura populacional das espécies variam no gradiente geográfico e altitudinal. Em constraste, as FEDs do vale do rio Tambo, centro do Perú, são moderadamente ricas em espécies do que a média das FEDs neotropicais e apresentam escassos endemismos. Esta região necessita de mais esforços de pesquisas para conhecer mais profundamente os elementos da biodiversidade. Neste estudo, também realizamos a caracterização dendro-anatômica do lenho das árvores de 87 espécies, sendo o primeiro registro da anatomia da madeira das árvores dos dois vales. Das análises do lenho das 183 espécies registradas nas florestas do norte e centro do Perú, só 157 apresentam anéis de crescimento e precisam ser analisadas em detalhe com outras pesquisas de desenvolvimento cambial e técnicas tradicionais de análises dendrocronológicas. A derivação desta informação pode alcançar alto impacto em estudos de variabilidade climática e aplicações na conservação. Assim mesmo, a análise preliminar dendrocronológica das taxas de crescimento do tronco revelam que as árvores de Cedrela kuelapensis apresentam as taxas de crescimento mais altas e ressaltam como um excelente recurso para programas de reflorestamento nos vales interandinos, além, das populações endêmicas de Cordia iguaguana e Esenbeckia cornuta são principalmente de exemplares jovens. Esperamos que as informações dos cinco capítulos constituam-se uma eficiente e importante ferramenta para melhorar a gestão dos recursos florestais dos vales estudados. / In this study we analyzed the diversity and endemism of the woody flora of Seazonally dry tropical forests (SDTF) in northern and central Peru. We characterized the diversity of woody plants along the valleys to define the conservation values of the area at the national and international levels. The results indicate that the SDTF s of the Marañón Valley show surprisingly high values in endemics in relation to other SDTF s in Peru and neighboring SDTFs, and the pattern of endemism and population structure of the species varies in geographic and altitudinal grades. In contrast, the SDTFs of the Tambo River Valley, central Peru, are moderately rich in species that average the neotropical SDTFs and have scarce endemism. This region needs more efforts to get to know the elements of biodiversity more deeply. In this study, we also performed the dendroanatomic characterization of 87 species and is the first report of the anatomy of the wood for the two valleys. From the analysis of the wood of the 183 species recorded in the forests of northern and central Peru, only 157 have growth rings and need to be analyzed in detail with other studies of exchange rate development and traditional techniques of dendrochronological analysis. The derivation of this information can reach high impact in studies of climatic variability and conservation applications. Likewise, the preliminary dendrochronological analysis of growth rates reveals that Cedrela kuelapensis showed the highest growth rates and stands out as an excellent resource for reforestation programs in the inter-Andean valleys, in addition, Cordia iguaguana and Esenbeckia cornuta endemic populations are mainly from young individuals. We hope that the information in the five chapters constitutes in efficient and important tool to improve the management of forest resources in the valleys studied.

Dry powder inhalers (DPIs) are advantageous for delivering medication to the lungs for the treatment of respiratory diseases because of the stability of the powders, relative low cost, synchronization of inhalation and dose delivery, and many design options that can be used for optimization. However, currently marketed DPIs are very inefficient in delivering medications to the lungs. This study has developed multiple new high efficiency DPIs for use with spray dried excipient enhanced growth (EEG) powder formulations based on the following platforms: capsule-based for oral inhalation, high-dose for oral inhalation, inline with 3D rod array dispersion, and inline with capillary jet dispersion. The capsule-based DPIs for oral inhalation implemented a 3D rod array for aerosol dispersion with optimal designs producing mass median aerodynamic diameters (MMADs) in the range of 1.3-1.5 µm and emitted doses in the range of 79-81%. Keys to inhaler success were the orientation of the capsule and inclusion of the 3D rod array. For the high-dose oral inhaler, performance was similar to the optimized capsule-based devices, while aerosolizing a much larger mass of powder. Surprisingly, removal of the fluidized bed of spheres improved performance producing a simple high dose device containing only a single dose sphere. The inline device using the 3D rod array was effective in producing particles of approximately 1.5 µm, at flow rates consistent with high flow therapy using a 1 L ventilation bag as the delivery mechanism. Using a capillary jet as the dispersion mechanism, further advances were made to allow for both delivery using a low volume (LV) of air and delivery in low flow therapy. This easily adaptable platform was able to produce a high quality aerosol out of a nasal cannula with an ED greater than 60% and a size (~2 µm) that should produce minimal extrathoracic losses. In conclusion, this study demonstrates (i) the design and optimization of DPIs capable of delivering EEG aerosols to the lungs using oral inhalation, (ii) the ability to deliver EEG aerosols using N2L aerosol administration, and (iii) the design of a new flexible LV-DPI device that is easily adaptable to multiple patients and delivery platforms, which are greatly needed in clinical environments.

Il sorgo zuccherino utilizzato per produrre cibo, mangimi e carburante con limitato impiego di risorse, risponde ai criteri dell’agricoltura moderna ed è impiegato nella produzione di bioenergia. È una pianta C4 adattata agli ambienti semi-aridi, caratteristica che dovrebbe essere mantenuta e migliorata nel processo di ottenimento di nuovi genotipi. Per comprendere le basi genetiche e fisiologiche della tolleranza alla siccità, genotipi di sorgo (IS 19453, Mpwekwa, SDS19483, IS33350, BR505, BR501) sono stati valutati in camera di crescita e in serra. Lo stress idrico è iniziato quando le piante avevano consumato l'80% di acqua disponibile. L’RNA totale è stato estratto da piante irrigate e non a diversi livelli di stress idrico. L'analisi di espressione genica è stata eseguita attraverso l’uso delle tecniche microarray e q-RT PCR. Il numero dei geni differenzialmente espressi aumentava all’aumentare del livello di stress. Gran parte dei geni sovra espressi erano coinvolti nei meccanismi di difesa, di trasporto, di regolazione genica, e nel metabolismo lipidico, proteico e degli zuccheri. Nelle piante non irrigate, al più alto livello di stress, i geni sovra-regolati presentavano livelli di espressione di 2-5 volte superiori rispetto ai campioni di controllo. Questi risultati serviranno all’identificazione di ”single nucleotide polymorphisms” nelle sequenze dei geni candidati e al loro impiego come marcatori nel processo di miglioramento genetico assistito. / Sweet sorghum providing food, feed and fuel with a limited use of resources, responds to the criteria of sustainable bioenergy production. Sorghum is a C4 plant adapted to semi-arid environments, characteristic that should be maintained and further improved in the process of breding new genotypes for bioenergy production. To understand the genetic and physiological basis of drought tolerance, sorghum genotypes (IS 19453, Mpwekwa, SDS19483, IS33350, BR505, BR501) were evaluated in growth chamber and greenhouse experiments. Drought stress started when plants had consumed 80% of transpirable soil water. Total RNA was extracted from irrigated and not irrigated plants at different levels of water stress, and gene expression analysis was carried out using microarray and q-RT PCR techniques. The number of differentially expressed genes increased with the stress level. Most of the up regulated genes were involved in cell rescue, transport, nucleic acid binding, and in lipid, protein and sugar metabolism. In non-irrigated plants, at the higher stress level, up-regulated genes presented levels of expression 2-5 fold higher compared to control samples. These preliminary results will be useful for the identification of single nucleotide polymorphisms in candidate genes sequences in order to use them as markers for assisted breeding.

No description available.

Dry forest is one of the most threatened tropical forests in the world. Human impact has caused its massive transformation but conservation of dry forest has often been neglected across Latin America. In Colombia, less than 10% of the original extension of dry forest remains. This thesis studies the phytogeography of neotropical dry forest and its relevance for conservation using data from 1602 tree species inventories made in dry forests across Latin America and the Caribbean synthesised by The Latin American Seasonally Dry Tropical Forest Floristic Network (DRYFLOR). Clustering and ordination analyses were used to explore the floristic relationships of dry forest across the entire Neotropics, revealing distinctive regional clusters defined by their tree species composition. Colombian dry forests are shown to be part of two wider clusters, one including neighbouring forests in Venezuela and southern Central America, and the second including the inter-Andean dry forests. The high turnover of floristic diversity and endemism within and amongst the main floristic groups demonstrates that to conserve the full species diversity in dry forests across Latin America and the Caribbean will require protecting it simultaneously across multiple regions. A regionally focused study of floristic relationships in the Central American and northern South American dry tropical forest group, using quantitative approaches to conservation prioritization, including a new Conservation Priority Index (CPI), suggests that conservation priority should be placed on the South American Caribbean Coast in the cross-border area of Colombia and Venezuela. This emphasises the need for a biogeographical approach to conservation that cannot be restricted by political borders. Within Colombia, new quantitative floristic data were used to investigate controls of floristic composition in dry forests. Multivariate analyses showed that space related variables explain a larger fraction of the variance of the floristic composition than climatic or edaphic variables. The importance of spatial variables implies that biogeography is a key element in understanding the structure of communities, and that the Andean cordilleras might be acting as geographical barriers isolating these seasonally dry formations. The value of floristic inventory data for assessing the conservation status of tree species using IUCN criteria was assessed in a case of study of the Andean Piedmont dry forest. By combining inventory data from the DRYFLOR database and herbarium records, the number of species for which we have sufficient information to make conservation assessments increases by 16% and the accuracy of predictive species distribution improves for 84% of the species. Together, these results reveal the importance of ecological inventory data as a complementary data source in conservation assessment for dry forest trees in the Neotropics. Finally, the conclusions chapter places these results in the context of conservation planning for Colombian dry forests, including some suggestions for research, policies and actions. These actions include restoration programmes focusing on sustainable harvesting of native dry forest tree species, for example for firewood and other forest resources such as fruits, fibres and medicines. A land use mosaic, including forest fallows and strict conservation areas, may help to guarantee the long-term maintenance dry forest species in Colombia.

The aim of this thesis was to determine the effect of row spacing on sorghum yields and dry matter. The trial was established on 29 May 2015 on land belonging to the Agricultural Cooperative Milevsko, which is situated in the corn-growing area. The trial compared four varieties of sorghum, namely Aristos, Goliath, KWS Freya and KWS Sole. The varieties were sown in different row spacings, namely 75 cm, 60 cm, 45 cm a 30 cm. The samples taken on three dates were analysed for dry matter content. Each variety showed a gradual increase in the dry matter content. During the harvest on 5 October 2015 the varieties KWS Freya and KWS Sole reached an optimal value of the dry matter when planted in all spacings. All varieties produced the highest average yield of green matter when planted in rows spaced 60 cm apart. The variety Aristos produced the highest average yield of green matter. The KWS Sole variety reached the lowest average yield of green matter when planted in rows 76 cm apart. All varieties with 60 cm row spacings, except for KWS Sole, produced the highest average yield of dry matter. The highest average yield of dry matter was reached by Aristos and the lowest by KWS Sole. The results of the one-year trial did not prove a direct connection of the effect of row spacing on dry matter. The effect of row spacing on green and dry matter yield was proved. The optimum row spacing seems to be 60 cm.

Neste estudo analisamos a diversidade e endemismos da flora lenhosa das florestas estacionais decíduas (FEDs) do norte e centro do Perú. Caracterizamos a diversidade das plantas lenhosas ao longo dos vales, para definir os valores de conservação da área a nível nacional. Os resultados indicam que as FEDs do vale do Marañón apresentam valores significativamente altos em endemias em relação às outras FEDs do Perú e FEDs vizinhas e o padrão de endemismos e estrutura populacional das espécies variam no gradiente geográfico e altitudinal. Em constraste, as FEDs do vale do rio Tambo, centro do Perú, são moderadamente ricas em espécies do que a média das FEDs neotropicais e apresentam escassos endemismos. Esta região necessita de mais esforços de pesquisas para conhecer mais profundamente os elementos da biodiversidade. Neste estudo, também realizamos a caracterização dendro-anatômica do lenho das árvores de 87 espécies, sendo o primeiro registro da anatomia da madeira das árvores dos dois vales. Das análises do lenho das 183 espécies registradas nas florestas do norte e centro do Perú, só 157 apresentam anéis de crescimento e precisam ser analisadas em detalhe com outras pesquisas de desenvolvimento cambial e técnicas tradicionais de análises dendrocronológicas. A derivação desta informação pode alcançar alto impacto em estudos de variabilidade climática e aplicações na conservação. Assim mesmo, a análise preliminar dendrocronológica das taxas de crescimento do tronco revelam que as árvores de Cedrela kuelapensis apresentam as taxas de crescimento mais altas e ressaltam como um excelente recurso para programas de reflorestamento nos vales interandinos, além, das populações endêmicas de Cordia iguaguana e Esenbeckia cornuta são principalmente de exemplares jovens. Esperamos que as informações dos cinco capítulos constituam-se uma eficiente e importante ferramenta para melhorar a gestão dos recursos florestais dos vales estudados. / In this study we analyzed the diversity and endemism of the woody flora of Seazonally dry tropical forests (SDTF) in northern and central Peru. We characterized the diversity of woody plants along the valleys to define the conservation values of the area at the national and international levels. The results indicate that the SDTF s of the Marañón Valley show surprisingly high values in endemics in relation to other SDTF s in Peru and neighboring SDTFs, and the pattern of endemism and population structure of the species varies in geographic and altitudinal grades. In contrast, the SDTFs of the Tambo River Valley, central Peru, are moderately rich in species that average the neotropical SDTFs and have scarce endemism. This region needs more efforts to get to know the elements of biodiversity more deeply. In this study, we also performed the dendroanatomic characterization of 87 species and is the first report of the anatomy of the wood for the two valleys. From the analysis of the wood of the 183 species recorded in the forests of northern and central Peru, only 157 have growth rings and need to be analyzed in detail with other studies of exchange rate development and traditional techniques of dendrochronological analysis. The derivation of this information can reach high impact in studies of climatic variability and conservation applications. Likewise, the preliminary dendrochronological analysis of growth rates reveals that Cedrela kuelapensis showed the highest growth rates and stands out as an excellent resource for reforestation programs in the inter-Andean valleys, in addition, Cordia iguaguana and Esenbeckia cornuta endemic populations are mainly from young individuals. We hope that the information in the five chapters constitutes in efficient and important tool to improve the management of forest resources in the valleys studied.