Effect of training systems and pruning methods on fruit quality in apple

The introduction of dwarfed rootstocks in apple crop has led to a new concept of intensive planting systems with the aim of producing early high yield and with returns of the initial high investment. Although yield is an important aspect to the grower, the consumer has become demanding regards fruit quality and is generally attracted by appearance. To fulfil the consumer’s expectations the grower may need to choose a proper training system along with an ideal pruning technique, which ensure a good light distribution in different parts of the canopy and a marketable fruit quality in terms of size and skin colour. Although these aspects are important, these fruits might not reach the proper ripening stage within the canopy because they are often heterogeneous. To describe the variability present in a tree, a software (PlantToon®), was used to recreate the tree architecture in 3D in the two training systems. The ripening stage of each of the fruits was determined using a non-destructive device (DA-Meter), thus allowing to estimate the fruit ripening variability. This study deals with some of the main parameters that can influence fruit quality and ripening stage within the canopy and orchard management techniques that can ameliorate a ripening fruit homogeneity. Significant differences in fruit quality were found within the canopies due to their position, flowering time and bud wood age. Bi-axis appeared to be suitable for high density planting, even though the fruit quality traits resulted often similar to those obtained with a Slender Spindle, suggesting similar fruit light availability within the canopies. Crop load confirmed to be an important factor that influenced fruit quality as much as the interesting innovative pruning method “Click”, in intensive planting systems.

Theoretical study of correlated systems using hybrid functionals

Diese Arbeit unterstreicht das Potential von Hybridfunktionalen (B3LYP) für die Untersuchung einer großen Bandbreite von Systemen. Durch die Einbeziehung der exakten Hartree-Fock Austauschenergie kann B3LYP für molekulare und kristalline Systeme eingesetzt werden. Zum Beispiel können stark korrelierte Systeme mit B3LYP erfolgreich erforscht werden. Die elektronische Struktur von PAHs wurde mit B3LYP Hybriddichtefunktionalen untersucht. Mit der ∆SCF-Methode wurden Elektronenbindungsenergien bestimmt, welche die mit UPS gewonnenen experimentellen Resultate bestätigen und ergänzen. Symmetrieeigenschaften der molekularen Orbitale wurden analysiert, um eine Zuordnung und Einschätzung der zugehörigen Signalstärke zu ermöglichen. Während σ-artige Orbitale nur schwer durch UPS-Messungen an dünnen Filmen detektiert werden können, bieten Rechnungen eine detaillierte Einsicht in die verborgenen Teile der Spektren.rnWeiterhin wurden π−π-Komplexe untersucht, welche von verschiedenen Donor- und Akzeptor-Molekülen gebildet werden. Die Moleküle basieren auf polyzyklischen, aromatischen Kohlenwasserstoffen. Für Ladungstransferkomplexe finden DFT Rechnungen ein Minimum in der Oberfläche der potentiellen Energie. Diese attraktive Wechselwirkung wird durch Coulombanziehung verursacht. Allerdings ist die Coulombanziehung nicht die stärkste Wechselwirkung in Ladungstransferkomplexen. Die Einbeziehung von van der Waals-Korrekturen verbessert den intermolekularen Abstand und die Bindungsenergie.rnEine Verkleinerung der intermolekularen Abstände führt zu einer großen Verschiebung der HOMO- und LUMO-Energie.rnAus der Klasse der kristallinen korrelierten Systeme wurden Rb4O6 und FeSe untersucht. Im Falle von Rb4O6 führen Ladungsordnung und Korrelationen zu einem isolierenden Grundzustand. Das hypothetische druckabhängige Phasendiagramm wurde untersucht. Eine Erhöhung des Drucks führt zu einer vergrößerten Bandlücke. Bei etwa 75 GPa wird die Bandbreite W größer als der Bandabstand U und das System nimmt einen homogen gemischt valenten Zustand mit teilweise besetzten π−π-Orbitalen an. Für Drücke ab 160 GPa wird W sehr viel größer als U und das System wird metallisch.rnIm Fall von FeSe finden wir eine korrelierte und isolierende Phase bei hohen Drücken, während das System bei niedrigen Drücken supraleitendes Verhalten zeigt. Die Berechnungen der Elektronenstruktur mit dem Hybridfunktional B3LYP führt zum korrekten halbleitenden Grundzustand in der NiAs- und MnP-Struktur von FeSe. Die Rolle der Korrelationen, der Stöchiometrie und der Nähe zum Magnetismus wird besprochen. Im Speziellen wird gezeigt, dass die Phase mit NiAs-Struktur starke lokale Korrelationen aufweist, was zu einem halbleitenden Zustand in einem weiten Druckbereich führt.

Numerical studies of colloidal systems

The interplay of hydrodynamic and electrostatic forces is of great importance for the understanding of colloidal dispersions. Theoretical descriptions are often based on the so called standard electrokinetic model. This Mean Field approach combines the Stokes equation for the hydrodynamic flow field, the Poisson equation for electrostatics and a continuity equation describing the evolution of the ion concentration fields. In the first part of this thesis a new lattice method is presented in order to efficiently solve the set of non-linear equations for a charge-stabilized colloidal dispersion in the presence of an external electric field. Within this framework, the research is mainly focused on the calculation of the electrophoretic mobility. Since this transport coefficient is independent of the electric field only for small driving, the algorithm is based upon a linearization of the governing equations. The zeroth order is the well known Poisson-Boltzmann theory and the first order is a coupled set of linear equations. Furthermore, this set of equations is divided into several subproblems. A specialized solver for each subproblem is developed, and various tests and applications are discussed for every particular method. Finally, all solvers are combined in an iterative procedure and applied to several interesting questions, for example, the effect of the screening mechanism on the electrophoretic mobility or the charge dependence of the field-induced dipole moment and ion clouds surrounding a weakly charged sphere. In the second part a quantitative data analysis method is developed for a new experimental approach, known as "Total Internal Reflection Fluorescence Cross-Correlation Spectroscopy" (TIR-FCCS). The TIR-FCCS setup is an optical method using fluorescent colloidal particles to analyze the flow field close to a solid-fluid interface. The interpretation of the experimental results requires a theoretical model, which is usually the solution of a convection-diffusion equation. Since an analytic solution is not available due to the form of the flow field and the boundary conditions, an alternative numerical approach is presented. It is based on stochastic methods, i. e. a combination of a Brownian Dynamics algorithm and Monte Carlo techniques. Finally, experimental measurements for a hydrophilic surface are analyzed using this new numerical approach.

Multiple pathogen detection using nanoplasmonic sensing

Opportunistic diseases caused by Human Immunodeficiency Virus (HIV) and Hepatitis B Virus (HBV) is an omnipresent global challenge. In order to manage these epidemics, we need to have low cost and easily deployable platforms at the point-of-care in high congestions regions like airports and public transit systems. In this dissertation we present our findings in using Localized Surface Plasmon Resonance (LSPR)-based detection of pathogens and other clinically relevant applications using microfluidic platforms at the point-of-care setting in resource constrained environment. The work presented here adopts the novel technique of LSPR to multiplex a lab-on-a-chip device capable of quantitatively detecting various types of intact viruses and its various subtypes, based on the principle of a change in wavelength occurring when metal nano-particle surface is modified with a specific surface chemistry allowing the binding of a desired pathogen to a specific antibody. We demonstrate the ability to detect and quantify subtype A, B, C, D, E, G and panel HIV with a specificity of down to 100 copies/mL using both whole blood sample and HIV-patient blood sample discarded from clinics. These results were compared against the gold standard Reverse Transcriptase Polymerase Chain Reaction (RT-qPCR). This microfluidic device has a total evaluation time for the assays of about 70 minutes, where 60 minutes is needed for the capture and 10 minutes for data acquisition and processing. This LOC platform eliminates the need for any sample preparation before processing. This platform is highly multiplexable as the same surface chemistry can be adapted to capture and detect several other pathogens like dengue virus, E. coli, M. Tuberculosis, etc.

Mechanical properties and structure of gel systems

Understanding the origins of the mechanical properties and its correlation withrnthe microstructure of gel systems is of great scientific and industrial interest. Inrngeneral, colloidal gels can be classified into chemical and physical gels, accordingrnto the life time of the network bonds. The characteristic di↵erences in gelationrndynamics can be observed with rheological measurements.rnAs a model system, a mixture of sodium silicate and low concentration sulfuric acidrnwas used. Nano-sized silica particles grow and aggregate to a system-spanning gelrnnetwork. The influence of the finite solubility of silica at high pH on the gelationrnwas studied with classical and piezo rheometer. The storage modulus of therngel grew logarithmically with time with two distinct growth laws. A relaxationrnat low frequency was observed in the frequency dependent measurements. I attributernthese two behaviors as a sign of structural rearrangements due to the finiternsolubility of silica at high pH. The reaction equilibrium between formation andrndissolution of bonds leads to a finite life time of the bonds and behavior similar tornphysical gel. The frequency dependence was more pronounced for lower water concentrations,rnhigher temperatures and shorter reaction times. With two relaxationrnmodels, I deduced characteristic relaxation times from the experimental data. Besidesrnrheology, the evolution of silica gels at high pH on di↵erent length scales wasrnstudied by NMR and dynamic light scattering. The results revealed that the primaryrnparticles existed already in sodium silicate and aggregated after the mixingrnof reactants due to a chemical reaction. Throughout the aggregation process thernsystem was in its chemical reaction equilibrium. Applying large oscillatory shearrnstrain to the gel allowed for modifying the gel modulus. The e↵ect of shear andrnshear history on the rheological properties of the gel were investigated. The storagernmodulus of the final gel increased with increasing strain. This behavior can be explained with (i) shear-induced aggregate compaction and (ii) combination ofrnbreakage and new formation of bonds.rnIn comparison with the physical gel-like behavior of the silica gel at high pH, typicalrnchemical gel features were exhibited by other gels formed from various chemicalrnreactions. Influences of the chemical structure modification on the gelation wererninvestigated with the piezo-rheometer. The external stimuli can be applied to tunernthe mechanical properties of the gel systems.

Il modello green office come nicchia strategica per la transizione sostenibile del sistema universita the green office model as strategic niche for sustainability transition of hei systems

Nella prima parte di questo progetto di tesi, ho analizzato tutte le nozioni teoriche rilevanti in merito alla teoria della transizione. Il primo concetto condiviso in questa trattazione è quello di transizione. Nella parte finale del capitolo, il focus si sposta sul ruolo, in una generica transizione, delle nicchie. Lo strumento centrale in questa struttura sono gli esperimenti di transizione, i quali forniscono un approccio alternativo ai progetti di innovazione classica che sono incentrati nell'ottenimento di soluzioni a breve termine. Vi è dunque una forte relazione tra nicchia e sperimentazione. Infine la trattazione si concentra sul tema dello Strategic Niche Management. Nel secondo capitolo, analizzo il tema della sostenibilità inserita in un contesto universitario. Questa sezione si focalizza sulle strategie di alto livello richieste per dare avvio alla transizione universitaria verso la sostenibilità, identificando gli ostacoli e gli elementi portanti, e definendo una vision al fine di concretizzarla. Il capitolo guida, passo per passo, le università che tentano di mettere in pratica il proprio obiettivo e la vision di sviluppo sostenibile. Una delle problematiche principali per stimare gli sforzi verso la sostenibilità nelle università è costituita in modo particolare dagli strumenti di valutazione. Per questo motivo, è stata sviluppata la valutazione grafica della sostenibilità nell'università (GASU). Al fine di riassumere quanto detto fin qui ed avere un quadro generale più chiaro dell'organizzazione di un campus universitario che mira a diventare sostenibile, ho utilizzato lo strumento gestionale della SWOT Analysis. Negli ultimi due capitoli, infine, analizzo nel dettaglio il modello Green Office. La teorizzazione di questo modello e l'elaborazione dei 6 principi del Green Office sono state effettuate da rootAbility. Le seguenti pagine presentano 3 casi studio di come i 6 principi dei Green Office sono stati adattati alle 3 unità di sostenibilità guidate da studenti e supportate da staff qualificato. L'oggetto della trattazione sono i principali GO affermatisi nei Paesi Bassi. A seguito dell'introduzione del modello relativo al Green Office e dell'illustrazione degli esempi presi in esame, è stato sfruttato lo strumento della feasibility analysis al fine di giudicare se l'idea di business sia praticabile. Il mezzo con cui ho condotto l'analisi sotto riportata è un questionario relativo al modello di Green Office implementato, nel quale viene chiesto di valutare gli aspetti relativi alla organizational feasibility e alla financial feasibility. Infine nella sezione finale ho considerato i Green Office come fossero un unico movimento. L'analisi mira a considerare l'impatto globale del Green Office Movement nei sistemi universitari e come, a seguito del loro consolidarsi nella struttura accademica, possano divenire prassi comune. La struttura proposta contiene elementi sia da il SNM (Strategic Niche Management) che dal TE (Transition Experiment).

Supergeometry: a categorical point of view

In questa tesi viene studiato l'approccio funtoriale alla supergeometria. In particolare si usano le topologie di Grothendieck per studiare il concetto di rappresentabilità in questo contesto, in analogia a quanto fatto in geometria algebrica classica. Vengono poi introdotti i funtori di Weil-Berezin e lo Schwarz embedding, motivando i legami tra questi concetti e la rappresentabilità nel caso classico.

Longitudinal patterns in survival, comorbidity, healthcare utilization and quality of care among older women following breast cancer diagnosis

OBJECTIVES To compare longitudinal patterns of health care utilization and quality of care for other health conditions between breast cancer-surviving older women and a matched cohort without breast cancer. DESIGN Prospective five-year longitudinal comparison of cases and matched controls. SUBJECTS Newly identified breast cancer patients recruited during 1997–1999 from four geographic regions (Los Angeles, CA; Minnesota; North Carolina; and Rhode Island; N = 422) were matched by age, race, baseline comorbidity and zip code location with up to four non-breast-cancer controls (N = 1,656). OUTCOMES Survival; numbers of hospitalized days and physician visits; total inpatient and outpatient Medicare payments; guideline monitoring for patients with cardiovascular disease and diabetes, and bone density testing and colorectal cancer screening. RESULTS Five-year survival was similar for cases and controls (80% and 82%, respectively; p = 0.18). In the first follow-up year, comorbidity burden and health care utilization were higher for cases (p < 0.01), with most differences diminishing over time. However, the number of physician visits was higher for cases (p < 0.01) in every year, driven partly by more cancer and surgical specialist visits. Cases and controls adhered similarly to recommended bone density testing, and monitoring of cardiovascular disease and diabetes; adherence to recommended colorectal cancer screening was better among cases. CONCLUSION Breast cancer survivors’ health care utilization and disease burden return to pre-diagnosis levels after one year, yet their greater use of outpatient care persists at least five years. Quality of care for other chronic health problems is similar for cases and controls.

Gender inequity in the provision of care for hip disease: population-based cross-sectional study

Objectives To examine gender differences along the care pathway to total hip replacement. Methods We conducted a population-based cross-sectional study of 26,046 individuals aged 35 years and over in Avon and Somerset. Participants completed a questionnaire asking about care provision at five milestones on the pathway to total hip replacement. Those reporting hip disease were invited to a clinical examination. We estimated odds ratios (ORs) [95% confidence intervals (CI)] for provision of care to women compared with men. Results 3169 people reported hip pain, 2018 were invited for clinical examination, and 1405 attended (69.6%). After adjustment for age and disease severity, women were less likely than men to have consulted their general practitioner (OR 0.78, 95%-CI 0.61–1.00), as likely as men to have received drug therapy for hip pain in the previous year (OR 0.96, 95%-CI 0.74–1.24), but less likely to have been referred to specialist care (OR 0.53, 95%-CI 0.40–0.70), to have consulted an orthopaedic surgeon (OR 0.50, 95%-CI 0.32–0.78), or to be on a waiting list for total hip replacement (OR 0.41, 95%-CI 0.20–0.87). Differences remained in the 746 people who had sought care from their general practitioner, and after adjustment for willingness and fitness for surgery. Conclusions There are gender inequalities in provision of care for hip disease in England, which are not fully accounted for by gender differences in care seeking and treatment preferences. Differences in referral to specialist care by general practitioners might unwittingly contribute to this inequity. Accurate information about availability, benefits and risks of hip replacement for providers and patients, and continuing education to ensure that clinicians interpret and correct patients' assumptions could help reduce inequalities.

Comparing expectations and experiences of care for sexually transmitted infections in general practice: a qualitative study

Background A key aim of England's National Strategy for Sexual Health is to extend high-quality sexual health services in primary care. Objectives To explore the expectations and experiences of men and women who initially presented at their general practice with a suspected sexually transmitted infection in order to identify areas where change could improve service delivery. Methods Semi-structured interviews were carried out in six general practices and two genitourinary medicine (GUM) clinics in Brent primary care trust (London) and Bristol (southwest England). Patients within general practice, and GUM patients who had initially attended general practice were eligible to participate. Interview transcripts were analysed using thematic analysis. Results 49 patients (29 women, 20 men) were interviewed. Patients approaching their GP practice typically expected written referral or in-house care, but this expectation was often not met. Absence of formal referral, lack of information and perceived avoidance of sexual health matters by practitioners were commonly cited as reasons for disappointment. However, a dedicated service within general practice met expectations well. Conclusion Purchasers and providers of all general practice services should ensure that any patient consulting in primary care with a suspected sexually transmitted infection can either receive appropriate care there, or a formal and supported referral to a specialised GUM clinic or primary care service.