Comparison of methods for determining the fatty acid composition of photosynthetic tissues

The fatty acid (FA) composition of photosynthetic tissue differs from that in other plant or animal tissues. In leaves, the lipid fraction constitutes less than 10% of the dry weight and is mostly located in the chloroplasts. An extraction solvent should dissolve polar lipids readily, but should also overcome interactions between the lipids and the tissue matrix. A mixture of chloroform/methanol (C/M) is commonly used. However, less toxic alternative methods such as hexane/isopropanol (H/I) and ethanol (E) have been suggested. In this preliminary study we compared the effectiveness of these three methods which are used as standard extraction protocols for FA analysis of plant material at three different European Universities. C/M extraction gave the highest total FA content and H/I the lowest, suggesting that C/M is indeed the best general-purpose lipid extraction solvent. Significant differences were also observed for FA composition including the ratio of saturated to unsaturated FA indicating selectivity of the various solvents in extracting different individual FA. Further and more detailed investigations are required to confirm this hypothesi

Serotoninergic, peptidergic and GABAergic innervation of the ventrolateral and dorsolateral motor nuclei in the cat S1/S2 segments: An immunofluorescence study

Indirect single- and double-staining immunofluorescence techniques were used to study the serotoninergic, peptidergic and GABAergic innervation of the ventrolateral (Onuf's nucleus) and dorsolateral (innervating intrinsic foot sole muscles) nuclei, located in the S1/S2 segments of the cat spinal cord. The relative density of 5-hydroxytryptamine-, thyrotropin-releasing hormone-, substance P- and γ-aminobuytric acid-immunoreactive axonal varicosities was similar in both nuclei. The highest relative density was recorded for varicosities immunoreactive to γ-aminobutyric acid, while those immunoreactive to 5-hydroxytryptamine or thyrotropin-releasing hormone yielded the lowest values. The density of enkephalin-immunoreactive varicosities was higher in the ventrolateral than in the dorsolateral nucleus. Calcitonin gene-related peptide-like immunoreactivity could be seen in neurons of the ventrolateral and dorsolateral nuclei. Occasionally, calcitonin gene-related peptide-immunoreactive axonal fibers were also encountered in these nuclei. Virtually all thyrotropin-releasing hormone-immunoreactive varicosities in the ventrolateral and dorsolateral nuclei also contained 5-hydroxytryptamine-like immunoreactivity, while a somewhat smaller number of them were co-localized with substance P. About 5–10% of the 5-hydroxytryptamine-immunoreactive varicosities were devoid of peptide-like immunoreactivity, and the number of 5-hydroxytryptamine-immunoreactive varicosities lacking thyrotropin-releasing hormone-like immunoreactivity was higher in the dorsolateral than in the ventrolateral nucleus. Finally, the free fraction of substance P-immunoreactive varicosities, i.e., those lacking both 5-hydroxytryptamine and thyrotropin-releasing hormone, was about 39% in the ventrolateral and 26% in the dorsolateral nucleus. Spinal cord transection at the lower thoracic level induced a depletion of 5-hydroxytryptamine and thyrotropin-releasing hormone-immunoreactive fibers from the ventrolateral and dorsolateral nuclei, indicating an exclusive supraspinal origin for these fibers. A reduction in substance P-like immunoreactivity following spinal cord transection alone or spinal cord transection combined with unilateral dorsal rhizotomy was also detected in both nuclei, suggesting a dual origin for substance P-immunoreactive fibers, i.e., both supra- and intraspinal. The decrease in number of substance P-immunoreactive fibers was however smaller than expected from the analysis of the fraction of substance P-immunoreactive fibers co-localized with 5-hydroxytryptamine, indicating thus that the experimental lesions may have triggered a sprouting of substance P-immunoreactive axons originating from spinal cord sources. The distribution of γ-aminobutyric acid in the ventrolateral and dorsolateral nuclei was not affected by the different lesion paradigms. It is therefore assumed that these inputs are intrinsic to the spinal cord. Finally, both in the ventrolateral and the dorsolateral nucleus a small but statistically significant increase of axonal fibers immunoreactive to enkephalin was seen in response to the experimental lesions

Genuine Counterfactual Communication with a Nanophotonic Processor

In standard communication information is carried by particles or waves. Counterintuitively, in counterfactual communication particles and information can travel in opposite directions. The quantum Zeno effect allows Bob to transmit a message to Alice by encoding information in particles he never interacts with. The first suggested protocol not only required thousands of ideal optical components, but also resulted in a so-called "weak trace" of the particles having travelled from Bob to Alice, calling the scalability and counterfactuality of previous proposals and experiments into question. Here we overcome these challenges, implementing a new protocol in a programmable nanophotonic processor, based on reconfigurable silicon-on-insulator waveguides that operate at telecom wavelengths. This, together with our telecom single-photon source and highly-efficient superconducting nanowire single-photon detectors, provides a versatile and stable platform for a high-fidelity implementation of genuinely trace-free counterfactual communication, allowing us to actively tune the number of steps in the Zeno measurement, and achieve a bit error probability below 1%, with neither post-selection nor a weak trace. Our demonstration shows how our programmable nanophotonic processor could be applied to more complex counterfactual tasks and quantum information protocols.Comment: 6 pages, 4 figure

A Review of Direct Neck Measurement in Occupational Settings

No guidelines are available to orient researchers on the availability and applications of equipment and sensors for recording precise neck movements in occupational settings. In this study reports on direct measurements of neck movements in the workplace were reviewed. Using relevant keywords two independent reviewers searched for eligible studies in the following databases: Cinahal, Cochrane, Embase, Lilacs, PubMed, MEDLINE, PEDro, Scopus and Web of Science. After applying the inclusion criteria, 13 articles on direct neck measurements in occupational settings were retrieved from among 33,666 initial titles. These studies were then methodologically evaluated according to their design characteristics, exposure and outcome assessment, and statistical analysis. The results showed that in most of the studies the three axes of neck movement (flexion-extension, lateral flexion and rotation) were not simultaneously recorded. Deficiencies in available equipment explain this flaw, demonstrating that sensors and systems need to be improved so that a true understanding of real occupational exposure can be achieved. Further studies are also needed to assess neck movement in those who perform heavy-duty work, such as nurses and electricians, since no report about such jobs was identified

A Study of the Feasibility and Potential Implementation of Metro-Based Freight Transportation in Newcastle upon Tyne

The concept of using a metropolitan railway network to transport freight directly to a city centre from the surrounding businesses has been the subject of much research. This paper looks in depth at the Tyne and Wear Metro system, situated in Newcastle upon Tyne, to determine if such a scheme would be feasible. Through research into the modes of transport available, along with a review of literature and case studies, it was found that the current method of transporting the majority of freight by road is unsustainable and damaging to both the environment and local communities. Other options for the transportation of freight have been reviewed, and results showed that a modal shift will be necessary in the near future. The system was then modelled using software provided by the Department for Transport, which demonstrated that the implementation of such a scheme would provide vast accident savings, a reduction in the number of casualties on the road, and a monetary saving as a result of the lower casualty rate. The conclusion was reached that the scheme is viable, however further research and study is necessary before implementation

Qubit-excitation-based adaptive variational quantum eigensolver

Abstract: Molecular simulations with the variational quantum eigensolver (VQE) are a promising application for emerging noisy intermediate-scale quantum computers. Constructing accurate molecular ansätze that are easy to optimize and implemented by shallow quantum circuits is crucial for the successful implementation of such simulations. Ansätze are, generally, constructed as series of fermionic-excitation evolutions. Instead, we demonstrate the usefulness of constructing ansätze with "qubit-excitation evolutions”, which, contrary to fermionic excitation evolutions, obey "qubit commutation relations”. We show that qubit excitation evolutions, despite the lack of some of the physical features of fermionic excitation evolutions, accurately construct ansätze, while requiring asymptotically fewer gates. Utilizing qubit excitation evolutions, we introduce the qubit-excitation-based adaptive (QEB-ADAPT)-VQE protocol. The QEB-ADAPT-VQE is a modification of the ADAPT-VQE that performs molecular simulations using a problem-tailored ansatz, grown iteratively by appending evolutions of qubit excitation operators. By performing classical numerical simulations for small molecules, we benchmark the QEB-ADAPT-VQE, and compare it against the original fermionic-ADAPT-VQE and the qubit-ADAPT-VQE. In terms of circuit efficiency and convergence speed, we demonstrate that the QEB-ADAPT-VQE outperforms the qubit-ADAPT-VQE, which to our knowledge was the previous most circuit-efficient scalable VQE protocol for molecular simulations

Associations of Sleep Duration and Screen Time with Incidence of Overweight in European Children: The IDEFICS/I.Family Cohort

Introduction: Over the past decades, children have been increasingly using screen devices, while at the same time their sleep duration has decreased. Both behaviors have been associated with excess weight, and it is possible they act as mutually reinforcing behaviors for weight gain. The aim of the study was to explore independent, prospective associations of screen time and sleep duration with incident overweight in a sample of European children. Methods: Data from 4, 285 children of the IDEFICS/I.Family cohort who were followed up from 2009/2010 to 2013/2014 were analyzed. Hours per day of screen time and of sleep duration were reported by parents at baseline. Logistic regression analyses were carried out in separate and mutually adjusted models controlled for sex, age, European country region, parental level of education, and baseline BMI z-scores. Results: Among normal weight children at baseline (N = 3, 734), separate models suggest that every hour increase in screen time and every hour decrease in sleep duration were associated with higher odds of the child becoming overweight or obese at follow-up (OR = 1.16, 95% CI: 1.02-1.32 and OR = 1.23, 95% CI: 1.05-1.43, respectively). In the mutually adjusted model, both associations were attenuated slightly (screen time OR = 1.13, 95% CI: 0.99-1.28; sleep duration OR = 1.20, 95% CI: 1.03-1.40), being consistently somewhat stronger for sleep duration. Discussion/Conclusion: Both screen time and sleep duration increased the incidence of overweight or obesity by 13-20%. Interventions that include an emphasis on adequate sleep and minimal screen time are needed to establish their causal role in the prevention of overweight and obesity among European children. © 2021 The Author(s). Published by S. Karger AG, Basel

The economics of free: freemium games, branding and the impatience economy

The gaming industry has seen dramatic change and expansion with the emergence of ‘casual’ games that promote shorter periods of game play. Free to download, but structured around micro-payments, these games raise the complex relationship between game design and commercial strategies. Although offering a free gameplay experience in line with open access philosophies, these games also create systems that offer control over the temporal dynamics of that experience to monetise player attention and inattention. This article will examine three ‘freemium’ games, Snoopy Street Fair, The Simpsons’ Tapped Out and Dragonvale, to explore how they combine established branding strategies with gameplay methods that monetise player impatience. In examining these games, this article will ultimately indicate the need for game studies to interrogate the intersection between commercial motivations and game design 2 and a broader need for media and cultural studies to consider the social, cultural, economic and political implications of impatience