683 research outputs found
Gold-Catalyzed Aerobic Oxidation of Benzyl Alcohol: Effect of Gold Particle Size on Activity and Selectivity in Different Solvents
The effect of the size of gold particles deposited on CeO2 and TiO2 supports on their catalytic behavior in the aerobic oxidation of benzyl alcohol in different solvents (mesitylene, toluene, and supercritical carbon dioxide) has been investigated. The size of supported gold particles deposited via a colloidal route was in the range 1.3-11.3nm, as determined by means of EXAFS and HAADF-STEM measurements. The catalytic performance of the supported gold catalysts in the different solvents revealed a significant effect of the gold particle size. Optimal activity was observed for catalysts with medium particle size (ca. 6.9nm) whereas smaller and bigger particles showed inferior activity. Identical trends for the activity-particle size relationship were found using Au/CeO2 and Au/TiO2 for the reaction at atmospheric pressure in conventional solvents (mesitylene, toluene) as well as under supercritical conditions (scCO2). Selectivity to benzaldehyde was only weakly affected by the gold particle size and mainly depended on reaction conditions. In supercritical CO2 (scCO2) selectivity was higher than in the conventional solvents under atmospheric pressure. All catalysts tested with particle sizes ranging from 1.3 to 11.3nm showed excellent selectivity of 99% or higher under supercritical condition
Environmental Management / Farmers\u2019 Preferences for Future Agricultural Land Use Under the Consideration of Climate Change
Abstract in deutscher Sprache nicht verf\ufcgbarCultural landscapes in Austria are multifunctional through their simultaneous support of productive, habitat, regulatory, social, and economic functions. This study investigates, if changing climatic conditions in Austria will lead to landscape change. Based on the assumption that farmers are the crucial decision makers when it comes to the implementation of agricultural climate change policies, this study analyzes farmers\u2019 decision-making under the consideration of potential future climate change scenarios and risk, varying economic conditions, and different policy regimes through a discrete choice experiment. Results show that if a warming climate will offer new opportunities to increase income, either through expansion of cash crop cultivation or new land use options such as short-term rotation forestry, these opportunities will almost always be seized. Even if high environmental premiums were offered to maintain current cultural landscapes, only 43 % of farmers would prefer the existing grassland cultivation. Therefore, the continuity of characteristic Austrian landscape patterns seems unlikely. In conclusion, despite governmental regulations of and incentives for agriculture, climate change will have significant effects on traditional landscapes. Any opportunities for crop intensification will be embraced, which will ultimately impact ecosystem services, tourism opportunities, and biodiversity
Segmentation by motivation for rural tourism activities in The Gambia
h i g h l i g h t s We conduct a survey of 430 tourists in The Gambia to find out about market potential for rural tourism. We employ a combined factor-clustering method to extract distinct market segments for tourism activities in The Gambia. We find four distinct market segments. There is high (latent) market potential for rural tourism businesses in The Gambia. We sketch out a 'development path' on how an event-based rural tourism can actually be implemented
Translational molecular imaging and drug development in Parkinson's disease
Parkinson's disease (PD) is a progressive neurodegenerative disorder that primarily affects elderly people and constitutes a major source of disability worldwide. Notably, the neuropathological hallmarks of PD include nigrostriatal loss and the formation of intracellular inclusion bodies containing misfolded α-synuclein protein aggregates. Cardinal motor symptoms, which include tremor, rigidity and bradykinesia, can effectively be managed with dopaminergic therapy for years following symptom onset. Nonetheless, patients ultimately develop symptoms that no longer fully respond to dopaminergic treatment. Attempts to discover disease-modifying agents have increasingly been supported by translational molecular imaging concepts, targeting the most prominent pathological hallmark of PD, α-synuclein accumulation, as well as other molecular pathways that contribute to the pathophysiology of PD. Indeed, molecular imaging modalities such as positron emission tomography (PET) and single-photon emission computed tomography (SPECT) can be leveraged to study parkinsonism not only in animal models but also in living patients. For instance, mitochondrial dysfunction can be assessed with probes that target the mitochondrial complex I (MC-I), while nigrostriatal degeneration is typically evaluated with probes designed to non-invasively quantify dopaminergic nerve loss. In addition to dopaminergic imaging, serotonin transporter and N-methyl-D-aspartate (NMDA) receptor probes are increasingly used as research tools to better understand the complexity of neurotransmitter dysregulation in PD. Non-invasive quantification of neuroinflammatory processes is mainly conducted by targeting the translocator protein 18 kDa (TSPO) on activated microglia using established imaging agents. Despite the overwhelming involvement of the brain and brainstem, the pathophysiology of PD is not restricted to the central nervous system (CNS). In fact, PD also affects various peripheral organs such as the heart and gastrointestinal tract - primarily via autonomic dysfunction. As such, research into peripheral biomarkers has taken advantage of cardiac autonomic denervation in PD, allowing the differential diagnosis between PD and multiple system atrophy with probes that visualize sympathetic nerve terminals in the myocardium. Further, α-synuclein has recently gained attention as a potential peripheral biomarker in PD. This review discusses breakthrough discoveries that have led to the contemporary molecular concepts of PD pathophysiology and how they can be harnessed to develop effective imaging probes and therapeutic agents. Further, we will shed light on potential future trends, thereby focusing on potential novel diagnostic tracers and disease-modifying therapeutic interventions
Introduction: Relationships Between Protected Areas and Sustainable Forest Management: Where are We Heading?
The relationship between protected areas and forest management has been one that has often been fraught with
conflict. New practices in the forest sector and new ecological insights have led more recently to better co-operation in some regions, although it is debatable to what extent cooperative approaches are desirable. In this introduction to the special section on the relationships between protected areas and sustainable forest management, we outline the history of the forestry and protected areas sectors in Canada, and the evolution of the relationships between them. We define key terms for the debate and offer a novel framework for understanding the relationship between the two sectors as management regimes that occur along parallel continua of sustainability. This framework is contrasted against real-world findings from across Canada, and with examples from elsewhere in the world
Is Vesicostomy Still a Contemporary Method of Managing Posterior Urethral Valves?
In boys with posterior urethral valves (PUVs) the main treatment aim is to preserve long-term bladder and renal function. To determine the effectiveness of secondary vesicostomy in boys with PUVs, the medical records of 21 patients with PUV (2010–2019), divided into two groups (group I: valve ablation; group II: secondary vesicostomy), were reviewed regarding the course of serum creatinine, renal ultrasound, voiding cystourethrogram, urodynamics, postoperative complications, need of further surgery, and long-term solution. The median age of all patients at first follow-up was 11 (9–13) months and at last follow-up 64.5 (39.5–102.5) months. Despite a significant difference of the SWDR score (shape, wall, reflux, and diverticula) (p = 0.014), both groups showed no significant differences preoperatively. Postoperatively, serum creatinine (p = 0.024), grade of vesicoureteral reflux (p = 0.003), side of upper tract dilatation (p = 0.006), side of megaureter (p = 0.004), and SWDR score (p = 0.002) were significantly decreased in group II. Postoperative urodynamic measurements showed comparable results in both groups. Stoma complications were found in three (20%) patients (group II). Eight (53.3%) patients already received a closure of the vesicostomy. Seven out of eight (87.5%) patients were able to micturate spontaneously. Vesicostomy remains a reliable treatment option for boys with PUV to improve bladder function and avoid further damage to the urinary tract
LED's Buy Greener: Shedding Light on Sustainable Procurement
In last decade, the lighting industry significantly changed with the development of light emitting diodes (LEDs) and their corresponding penetration of the market. The new technology increases energy efficiency and longevity compared to other types of lamps. As a result, LEDs can improve the sustainability performance of cities and towns, contributing to the mitigation of climate change and cutting costs over the long term. This report reviews LED procurement from multiple perspectives, formulated as a guide to help public and private stakeholders make more effective and sustainable decisions when buying lighting products. This publication is the collective work of students involved in the Masters of Environmental Science, Policy and Management (MESPOM) programme, currently enrolled at International Institute for Industrial Environmental Economics (IIIEE). The research has been performed for the European Union Inter-reg Lighting Metropolis Project, which involves institutions, designers and producers, and municipalities in the Ă–resund (or Greater Copenhagen) Region of Denmark and Sweden. The first two chapters of the report dive into the initial and final stages of the life cycle of LEDs. These chapters connect the impacts and risks of raw material extraction and supply chains to lighting procurement, and provide recommendations for the integration of end-of-life considerations into the procurement process. Chapter three analyses various national policies that contribute to promoting LEDs in public procurement. Chapter four examines the drivers and barriers for implementing innovative business models through the mapping various actors and their relationships. Finally, chapter five explores the decision-making process and the drivers and barriers of municipalities when procuring lighting solutions. Together, these five chapters provide a comprehensive set of recommendations to improve decision making for sustainable lighting solutions
A gate-tunable, field-compatible fluxonium
Circuit quantum electrodynamics, where photons are coherently coupled to
artificial atoms built with superconducting circuits, has enabled the
investigation and control of macroscopic quantum-mechanical phenomena in
superconductors. Recently, hybrid circuits incorporating semiconducting
nanowires and other electrostatically-gateable elements have provided new
insights into mesoscopic superconductivity. Extending the capabilities of
hybrid flux-based circuits to work in magnetic fields would be especially
useful both as a probe of spin-polarized Andreev bound states and as a possible
platform for topological qubits. The fluxonium is particularly suitable as a
readout circuit for topological qubits due to its unique persistent-current
based eigenstates. In this Letter, we present a magnetic-field compatible
hybrid fluxonium with an electrostatically-tuned semiconducting nanowire as its
non-linear element. We operate the fluxonium in magnetic fields up to 1T and
use it to observe the -Josephson effect. This combination of
gate-tunability and field-compatibility opens avenues for the exploration and
control of spin-polarized phenomena using superconducting circuits and enables
the use of the fluxonium as a readout device for topological qubits
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Valuing seafood attributes: stated choice model
This study applied brand choice model and stated preference data collected in French context by means of choice experiment to investigate value of intrinsic and extrinsic attributes of various fresh seafood species. The estimated models show that the extrinsic attributes (i.e. product forms, production method, and product origin) and intrinsic attributes (i.e. seafood species: salmon, cod, mussels, ect.) were significant determinants of consumer choice of seafood for their household consumption. Consumers assigned a significantly higher value for domestic and wild catch product. However, a deeper look into the market structure we revealed that only 39.5% of the sample is willing to pay a premium price for domestic and wild catch items in general. Salmon, cod, and saithe were evaluated relatively highest valued products while oyster, pangasius, and crab are lowest valued items. Market shares of the species in segments and entire market were predicted and appeared closely to actual market shares. The segment membership probability was estimated by the model and then regressed on demographic to give good suggestions for managers
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Market structure and segments for seafood: A stated preference approach
Demand structure and market segmentation for seafood have been investigated intensively. However, most the researches so far applied traditional demand analysis and descriptive segmentation approach by separated models. The traditional demand analysis assuming consumer homogeneity, behavior consistence, and using aggregate data may result biased estimation, while the segmentation based on descriptive approach has results less accessible and actionable. We the first used discrete choice model and stated preference data to simultaneously estimate the demand structure and segments for twelve seafood species in French context. The four-latent segments model have the best fit to the data and demand elasticities estimated are comparable to those in the traditional studies but provide more efficient and actionable guidance for practitioners. Consistence with previous seafood demand study we found that elasticities of high valued fish such as salmon, tuna, cod, sole, and shrimp are price elastic while low valued species like mussels, oyster, and pangasius are inelastic. Moreover, latent class model revealed that 39.5% of the sample are not price sensitive, 29.6% moderate sensitive, 20.3% sensitive, and 10.6% are very sensitive. Similarly, we investigated deeper for particular species and uncovered demand structure of each species. For instance, only 30.9% of consumers are price elastic for salmon, while 39.5% and 29.6% of the sample are inelastic and moderate elastic for this species, respectively. We also regressed the segment membership probabilities on the consumer characteristics to give better segment description and provide efficient guidance for seafood producers and marketers
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