Farmers’ Attitudes Toward Recycled Water Use in Irrigated Agriculture

This study aims to investigate whether farmers are willing to use recycled water for irrigation purposes. It attempts to analyze the attitudinal, socio-demographics and environmental factors that affect a potential user’s acceptance for wastewater reuse. A primary research designed in order to elicit farmers’ preferences and a statistical analysis applied to analyze the relationships among the variables influence their attitudes. The results were obtained from data collected through 302 questionnaires that were answered by the farmers in Nestos catchment, Greece. The research findings might usefully assist policy-makers and planners in the implementation of strategy in water management sector. Farmers’ awareness about the recycling water and their level of acceptance to use it might constitute incoming parameters, on which the decisions in agriculture water planning could be based. Moreover, the identification of factors influencing stakeholders’ acceptance provide the underpinnings for success in any recycling project.     Keywords: public perceptions, behavior analysis, water recycling, integrated water resources management, agriculture water managemen

3D mid-air audio-haptic navigation for digital signage

In this workshop we discuss the application of using mid-air haptics to provide directions for navigation to users in large indoor spaces. We propose a feed-forward approach from objects and locations that enable a physical way of thinking, communication and general accessibility

Synthesis and Characterisation of Nanocomposite Coatings for Antibacterial/Antifouling Applications

Biofouling can occur everywhere water is present and is a major problem for a wide variety of materials and devices such as biomedical devices and implants, as well as industrial and marine equipment. After the ban of the efficient but environmentally harmful antifouling paints based on tributyltin, the creation of new, effective and low-toxic antifouling paints is a major challenge. The aim of this thesis is to develop novel modified nanoparticles (NPs) as functional fillers for low toxic and environmentally friendly antibacterial/antifouling coatings for mobile and stationary applications in maritime, hospitals, industries, etc. Application of mesoporous silica nanoparticles (MSNs) as antifouling/antibacterial carriers attracted a few attention so far, specifically with a dual synergetic effect. In the present work, MSNs modified with quaternary ammonium salts (QASs) and loaded with the active agent DCOIT were synthesized as functional fillers for antifouling/antibacterial coatings. From the family of the MSNs, MCM-48 was selected as a carrier because of its cubic pore structure, high surface area, and high specific pore volume. Chapter 3 details the synthesis and characterisation of spherical MCM-48 MSNs with two different average sizes; 400 nm and 120 nm. As revealed from the X-ray diffraction and nitrogen isotherms, both types of MSNs showed highly ordered cubic mesostructure, high BET surface area, high pore volume and narrow pore size distribution. From the morphological studies using scanning electron microscopy and transmission electron microscopy, the MCM-48 with average size of 400 nm exhibited spherical morphology and some aggregates or fused together particles were present, while the MCM-48 with average size of 120 nm showed spherical morphology and all the NPs were monodispersed. Chapter 4 documents the surface modification of MCM-48 NPs with two different types of QASs; dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride and dimethyltetradecyl[3-(triethoxysilyl)propyl]ammonium chloride. The QAS modified MCM-48 revealed strong covalent bonds between the QAS and the surface of the NPs. The surface functionalization was confirmed by diffuse reflectance infrared Fourier transform spectroscopy, thermogravimetric analysis, elemental analysis, and ζ-potential measurements. Additional loading of the QAS modified MCM-48 with a commercially available biocide (Parmetol S15) resulted in a synergetic dual antibacterial/antifouling effect. Either loaded or unloaded QAS-modified MSNs exhibited high antibacterial performance confirming their dual activity. In the case of the modified NPs with average size of 400 nm, the loaded QAS-modified MCM-48 (dual functionalised) killed all exposed bacteria after 3 h of incubation and presented 100% reduction at the antibacterial tests against Gram-negative and Gram-positive bacteria. Furthermore, the QAS-modified MCM-48 (single functionalised) presented 77−89% reduction against the exposed Gram-negative bacteria and 78−94% reduction against the exposed Gram-positive bacteria. Furthermore, spherical MCM-48 NPs with smaller average size of 120 nm were surface modified with the two types of QASs and tested against Gram-negative and Gram-positive bacteria in order to investigate if there is size-dependency at the antibacterial properties of silica-QAS core-shell NPs. The smaller sized modified Marios Michailidis – April 2018 8 | P a g e NPs showed increased antibacterial properties (83-94% reduction against Gram-negative bacteria and 87-97% reduction against Gram-positive bacteria) compared to their counterparts with average size of 400 nm implying that smaller size of modified NPs could provide better antibacterial properties. In chapter 5, the modified NPs were homogeneously added in coating formulations. The nanocontainer-doped paints showed good distribution of the functionalised nanocontainers in the coating matrix, increased hydrophobicity and similar roughness values with the pristine coating formulation. In the antibacterial tests, the formulated paints revealed excellent antibacterial properties where all the bacteria were dead after 16 hours of exposure. Additionally, the nanocontainer-doped paints presented high anti-macrofouling properties against mussels. The paints containing the dual functionalised NPs presented 100% inhibition of mussels’ attachment after 72 hours exposure of mussels in culture plates coated with the nanocontainer-doped paints. Furthermore, all of the nanocontainer-treated paints illustrated low toxicity against the Red Sea mussels Brachidontes pharaonis and the brine shrimps Artemia salina. Finally, PVC panels were coated with the formulated paints (containing either 2 or 5 wt % modified nanoparticles) and immersed in Red Sea (Eilat, Israel) for field test. After six months of exposure, the paints containing the NPs with dual effect showed significantly lower biofouling coverage (below 10%) compared to the biofouling coverage of pristine paint (50%) indicating their high antifouling properties in real sea water conditions. The results of this work show that (i) the dual functionalised MCM-48 can be used as functional fillers for coating formulations providing excellent antibacterial/antifouling properties to the coatings, (ii) the dual functionalised MCM-48 can be used as environmental-friendly low-toxic alternatives for tin-based paints and (iii) the covalently attached QASs on the surface of the nanoparticles remain active even after complete release of the biocide, which considerably increases their functional lifetime in the coating formulations

Stabilizing two-dimensional quantum scars by deformation and synchronization

Relaxation to a thermal state is the inevitable fate of non-equilibrium interacting quantum systems without special conservation laws. While thermalization in one-dimensional (1D) systems can often be suppressed by integrability mechanisms, in two spatial dimensions thermalization is expected to be far more effective due to the increased phase space. In this work we propose a general framework for escaping or delaying the emergence of the thermal state in two-dimensional (2D) arrays of Rydberg atoms via the mechanism of quantum scars, i.e. initial states that fail to thermalize. The suppression of thermalization is achieved in two complementary ways: by adding local perturbations or by adjusting the driving Rabi frequency according to the local connectivity of the lattice. We demonstrate that these mechanisms allow to realize robust quantum scars in various two-dimensional lattices, including decorated lattices with non-constant connectivity. In particular, we show that a small decrease of the Rabi frequency at the corners of the lattice is crucial for mitigating the strong boundary effects in two-dimensional systems. Our results identify synchronization as an important tool for future experiments on two-dimensional quantum scars

Slow quantum thermalization and many-body revivals from mixed phase space

The relaxation of few-body quantum systems can strongly depend on the initial state when the system’s semiclassical phase space is mixed; i.e., regions of chaotic motion coexist with regular islands. In recent years, there has been much effort to understand the process of thermalization in strongly interacting quantum systems that often lack an obvious semiclassical limit. The time-dependent variational principle (TDVP) allows one to systematically derive an effective classical (nonlinear) dynamical system by projecting unitary many-body dynamics onto a manifold of weakly entangled variational states. We demonstrate that such dynamical systems generally possess mixed phase space. When TDVP errors are small, the mixed phase space leaves a footprint on the exact dynamics of the quantum model. For example, when the system is initialized in a state belonging to a stable periodic orbit or the surrounding regular region, it exhibits persistent many-body quantum revivals. As a proof of principle, we identify new types of “quantum many-body scars,” i.e., initial states that lead to long-time oscillations in a model of interacting Rydberg atoms in one and two dimensions. Intriguingly, the initial states that give rise to most robust revivals are typically entangled states. On the other hand, even when TDVP errors are large, as in the thermalizing tilted-field Ising model, initializing the system in a regular region of phase space leads to a surprising slowdown of thermalization. Our work establishes TDVP as a method for identifying interacting quantum systems with anomalous dynamics in arbitrary dimensions. Moreover, the mixed phase space classical variational equations allow one to find slowly thermalizing initial conditions in interacting models. Our results shed light on a link between classical and quantum chaos, pointing toward possible extensions of the classical Kolmogorov-Arnold-Moser theorem to quantum systems

Increased prevalence of prolonged QT interval in males with primary or secondary hypogonadism : a pilot study

P>Symptoms and signs of male hypogonadism span all organ systems, including the cardiovascular apparatus. The electrocardiographic QT interval reflects cardiac ventricular repolarization and, if prolonged, increases the risk of malignant arrhythmias. QT interval duration is similar in boys and girls during childhood, but shortens in males after puberty and experimental studies suggest that testosterone is a major contributor to shortening of QT interval in men. The aim of the present pilot study was to assess the duration of ventricular repolarization in adult males with primary or secondary hypogonadism. Standard ECG recordings were performed in 26 men (mean age 39.2 +/- 2.17 years) with pituitary or testicular hypogonadism and repeated in 15 patients during testosterone replacement. Twenty-six age-matched control men were also analysed. Measured QT intervals were corrected for heart rate according to Bazzett's formula (QTc = QT/root RR interval). The prevalence of prolonged QTc was considerably higher in hypogonadal patients (four of 26 men) than in control men (none, p < 0.05) and in the general, healthy population (< 2.5%). QTc interval normalized on hormone replacement therapy in the four patients presenting prolonged QTc in the hypogonadal state. Heart rate and left ventricular mass did not differ among the two groups and no known QT-prolonging factor was apparent in patients with abnormal QTc interval. In conclusion, a high number prolonged QT interval measurements was observed in hypogonadal men who may therefore be at increased risk for cardiac arrhythmias. This observation reveals an additional feature of male hypogonadism, which may benefit from testosterone replacement therapy

Novel inhibition mechanism and potent antiviral activity of translocation-deficient reverse transcriptase inhibitors [abstract]

Abstract only availableNucleoside RT inhibitors (NRTIs) are among the most potent anti-HIV agents and act as chain terminators because they lack a 3'OH. However, this feature can reduce affinity for RT compared to the analogous dNTP substrate, as well as reduced intracellular conversion to the active dNTP. To overcome this, it was shown that certain nucleosides that retain the 3'OH and have substitutions at the 4' ribose and 2 position of the base have exceptional antiviral properties. One of these compounds, 4'-ethynyl, 2-fluoro deoxy-adenosine (4'E-2FdA) is the most potent NRTI inhibitor against wild-type and multi-drug resistant HIV viruses described to date. We have recently reported that 4'E-2FdA acts as a chain terminator despite the presence of an accessible 3'OH. We show that after 4'E-2FdA-MP incorporation, RT does not bind the next incoming dNTP. We analyzed RT translocation on different sequences terminated with 4'E-2FdA-MP, and found that even at sequences when RT is naturally found post-translocated, the inhibitor prevents translocation. This decrease in translocation efficiency explains the reduced binding of the next incoming dNTP and the termination of elongation. While the inhibitor stabilizes the pre-translocated 4'E-2FdA-MP-terminated primer, the pyrophosphate-dependent excision rate of 4'E-2FdA-MP was not very high compared to ddAMP. In conclusion, this highly potent chain termination activity arises from difficulty of the primer 3'-terminus to translocate following incorporation of the compound, and not from simple steric hindrance due to the 4' substitution. Therefore, we propose that 4'E-2FdA is a Translocation-Deficient Reverse Transcriptase Inhibitor (TDRTI) that acts by a novel mechanism.NIH grant to S. Sarafiano

Visualization of positive and negative sense viral RNA for probing the mechanism of direct-acting antivirals against hepatitis C virus

RNA viruses are highly successful pathogens and are the causative agents for many important diseases. To fully understand the replication of these viruses it is necessary to address the roles of both positive-strand RNA ((+)RNA) and negative-strand RNA ((-)RNA), and their interplay with viral and host proteins. Here we used branched DNA (bDNA) fluorescence in situ hybridization (FISH) to stain both the abundant (+)RNA and the far less abundant (-)RNA in both hepatitis C virus (HCV)- and Zika virus-infected cells, and combined these analyses with visualization of viral proteins through confocal imaging. We were able to phenotypically examine HCV-infected cells in the presence of uninfected cells and revealed the effect of direct-acting antivirals on HCV (+)RNA, (-)RNA, and protein, within hours of commencing treatment. Herein, we demonstrate that bDNA FISH is a powerful tool for the study of RNA viruses that can provide insights into drug efficacy and mechanism of action

Analysis of Gene Sets Based on the Underlying Regulatory Network

Networks are often used to represent the interactions among genes and proteins. These interactions are known to play an important role in vital cell functions and should be included in the analysis of genes that are differentially expressed. Methods of gene set analysis take advantage of external biological information and analyze a priori defined sets of genes. These methods can potentially preserve the correlation among genes; however, they do not directly incorporate the information about the gene network. In this paper, we propose a latent variable model that directly incorporates the network information. We then use the theory of mixed linear models to present a general inference framework for the problem of testing the significance of subnetworks. Several possible test procedures are introduced and a network based method for testing the changes in expression levels of genes as well as the structure of the network is presented. The performance of the proposed method is compared with methods of gene set analysis using both simulation studies, as well as real data on genes related to the galactose utilization pathway in yeast.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78147/1/cmb.2008.0081.pd