880 research outputs found
Electric field control of multiferroic domains in NiVO imaged by X-ray polarization enhanced topography
The magnetic structure of multiferroic NiVO has been investigated
using non-resonant X-ray magnetic scattering. Incident circularly polarized
X-rays combined with full polarization analysis of the scattered beam is shown
to yield high sensitivity to the components of the cycloidal magnetic order,
including their relative phases. New information on the magnetic structure in
the ferroelectric phase is obtained, where it is found that the magnetic
moments on the "cross-tie" sites are quenched relative to those on the "spine"
sites. This implies that the onset of ferroelectricity is associated mainly
with spine site magnetic order. We also demonstrate that our technique enables
the imaging of multiferroic domains through polarization enhanced topography.
This approach is used to image the domains as the sample is cycled by an
electric field through its hysteresis loop, revealing the gradual switching of
domains without nucleation.Comment: 9 pages, 6 figure
The Importance of Physical Activity to Augment Mood during COVID-19 Lockdown
The purpose of this study was to assess the effect of COVID-19 lockdown on mood and
objective physical activity. A sample of 78 college students in Spain completed an assessment of
mood using the valid Profile of Mood State (POMS) questionnaire and had their physical activity
tracked objectively using a validated wrist-worn accelerometer (Xiaomi Mi Band 2) for one week
before being under COVID-19 lockdown (T1) and for one week during COVID-19 lockdown (T2).
Paired samples t-tests revealed significantly greater (p = 0.027) POMS Total Mood Disturbance
(TMD) Score T2 (mean ± SD) (22.6 ± 28.0) compared to T1 (17.7 ± 22.6) (lower score represents
better mood) and significantly lower (p ≤ 0.001) POMS Vigor Score T2 (14.1 ± 5.0) compared to T1
(18.2 ± 4.5) (lower vigor score represents lower mental and physical energy levels). Additionally,
Total Objective Steps was significantly less (p ≤ 0.001) lT2 (15,841.9 ± 17,253.2 steps) compared to
T1 (64,607.0 ± 50,525.2 steps). Regression analyses demonstrated significant negative relationships
of Total Objective Steps and POMS Depression (p = 0.014, Beta = −0.277, t = −2.511), POMS Anger
(p = 0.040, Beta = −0.233, t = −2.091), and POMS TMD (p = 0.007, Beta = −0.302, t = −2.754) T2.
The regressions also revealed a significant positive relationship (p = 0.012, Beta = 0.283, t = 2.57) of
Total Objective Steps and POMS Vigor T2. These data suggest that being in a lockdown due to a
pandemic may have negative physical and mental health-related consequences and that engaging in
physical activity may reduce these deleterious mental health-related consequences during lockdowns
and quarantines
A detailed study of the diastereoselective catalytic hydrogenation of 6-hydroxytetrahydroisoquinoline-(3R)-carboxylic ester intermediates
A key step towards a highly-selective antagonist of ionotropic glutamate receptors entails the diastereoselective arene hydrogenation of an enantiopure tetrahydroisoquinoline. An extensive screen using parallel reactors was conducted and led to the discovery of several Pd/C catalysts giving high yield and improved diastereoselectivity from 75 : 25 to 95 : 5. A detailed kinetic study of the best system was performed and supports the reduction occuring in two-steps.
Associations of Objectively-Assessed Smartphone Use with Physical Activity, Sedentary Behavior, Mood, and Sleep Quality in Young Adults: A Cross-Sectional Study
This study assesses the associations of objectively-measured smartphone time with physical activity, sedentary behavior, mood, and sleep patterns among young adults by collecting real-time data of the smartphone screen-state. The sample consisted of 306 college-aged students (mean age ± SD: 20.7 ± 1.4 years; 60% males). Over seven days of time, the following variables were measured in the participants: objectively-measured smartphone use (Your Hour and Screen Time applications), objective and subjective physical activity (GoogleFit and Apple Health applications, and the International Physical Activity Questionnaire (IPAQ), respectively), the number of hours sitting (IPAQ), mood (The Profile of Mood State (POMS)), and sleep (The Pittsburgh Sleep Quality Index (PSQI)). Multiple regressions analyses showed that the number of hours sitting per day, physical activity, and the POMS Global Score significantly predicted smartphone use (adj.R2 = 0.15). Further, participants with low levels of physical activity were more likely to increase the use of smartphones (OR = 2.981). Moreover, mood state (β = 0.185; 95% CI = 0.05, 0.32) and sleep quality (β = 0.076; 95% CI = −0.06, 0.21) predicted smartphone use, with those reporting poor quality of sleep (PSQI index >5) being more likely to use the smartphone (OR = 2.679). In conclusion, there is an association between objectively-measured smartphone use and physical activity, sedentary behavior, mood, and sleep patterns. Those participants with low levels of physical activity, high levels of sedentary behavior, poor mood state, and poor sleep quality were more likely to spend more time using their smartphones
SUSTAINABILITY INITIATIVES OF FLY-FISHING LODGES: A GLOBAL APPROACH
Usprkos sve većoj popularnosti mušičarenja, malo je studija utjecaja koje ono ima na okoliš i na društvo. Ovaj rad predstavlja prvo opsežno istraživanje o ribičkim kućicama kao gospodarskoj aktivnosti i njihovim praksama koje se odnose na održivo poslovanje. Okvirom izbora uzorka bile su obuhvaćene ribičke kućice iz raznih dijelova svijeta koje navodi nekoliko glavnih trgovaca opremom za mušičarenje, putničkih poduzeća koja se bave mušičarenjem i publikacija. Odabran je uzorak od 196 kućica i na njihovim internetskim stranicama provedena je analiza njihove komunikacije o održivim praksama. Analiza je pokazala da je razina izvještavanja o njihovim inicijativama vezanima uz održivost niska, premda je prisustvo ribičkih kućica na internetu veliko (samo 16,3% uzorka nema internetsku stranicu). Među najpopularnijim inicijativama su praksa “uhvati i pusti”, korištenje obnovljive energije, obnova staništa, podrška lokalnoj zajednici te uzgoj organske hrane. Iako mnoge ribičke kućice otvoreno promoviraju odlazak na manje pristupačna područja, rijetko se bave njihovim utjecajem na okoliš i djelotvornošću praksi vezanih uz održivost.Despite fly-fishing’s growing popularity, there are few studies on its environmental and social impacts. The present study is the first large-scale investigation of the fly-fishing lodge sector and its sustainability practices. A sampling frame of global fly-fishing lodges was created by including lodges featured by several major fly-fishing outfitters, fly-fishing travel companies, and publications. A sample of 196 lodges was drawn and their websites analyzed with respect to sustainability communications. The analysis indicated that although the web presence of fly-fishing lodges is high (only 16.3% of the sample did not have a website), reporting on sustainability initiatives is low. The most popular initiatives included catch and release practices, renewable energy use, restoration of habitats, support for local community, and growing organic food. While many lodges explicitly promoted access to remote areas, they rarely addressed their own impacts and sustainability performance
Analysis of plasmaspheric hiss wave amplitudes inferred from low-altitude POES electron data: Technique sensitivity analysis
A novel technique capable of inferring wave amplitudes from low-altitude electron measurements from the Polar Operational Environmental Satellites (POES) spacecraft has been previously proposed to construct a global dynamic model of chorus and plasmaspheric hiss waves. In this paper we focus on plasmaspheric hiss, which is an incoherent broadband emission that plays a dominant role in the loss of energetic electrons from the inner magnetosphere. We analyze the sensitivity of the POES technique to different inputs used to infer the hiss wave amplitudes during three conjunction events with the Van Allen Probes. These amplitudes are calculated with different input models of the plasma density, wave frequency spectrum, and electron energy spectrum, and the results are compared to the wave observations from the twin Van Allen Probes. Only one parameter is varied at a time in order to isolate its effect on the output, while the two other inputs are set to the values observed by the Van Allen Probes. The results show that the predicted hiss amplitudes are most sensitive to the adopted frequency spectrum, followed by the plasma density, but they are not very sensitive to the electron energy spectrum. Moreover, the standard Gaussian representation of the wave frequency spectrum (centered at 550 Hz) peaks at frequencies that are much higher than those observed in individual cases as well as in statistical wave distributions, which produces large overestimates of the hiss wave amplitude. For this reason, a realistic statistical model of the wave frequency spectrum should be used in the POES technique to infer the plasmaspheric hiss wave intensity rather than a standard Gaussian distribution, since the former better reproduces the observed plasmaspheric hiss wave amplitudes
Constructing Dirac linear fermions in terms of non-linear Heisenberg spinors
We show that the massive (or massless) neutrinos can be described as special
states of Heisenberg nonlinear spinors. As a by-product of this decomposition a
particularly attractive consequence appears: the possibility of relating the
existence of only three species of mass-less neutrinos to such internal
non-linear structure. At the same time it allows the possibility that neutrino
oscillation can occurs even for massless neutrinos
Toxoplasma and Plasmodium protein kinases: roles in invasion and host cell remodelling
Some apicomplexan parasites have evolved distinct protein kinase families to modulate host cell structure and function. Toxoplasma gondii rhoptry protein kinases and pseudokinases are involved in virulence and modulation of host cell signalling. The proteome of Plasmodium falciparum contains a family of putative kinases called FIKKs, some of which are exported to the host red blood cell and might play a role in erythrocyte remodelling. In this review we will discuss kinases known to be critical for host cell invasion, intracellular growth and egress, focusing on (i) calcium-dependent protein kinases and (ii) the secreted kinases that are unique to Toxoplasma (rhoptry protein kinases and pseudokinases) and Plasmodium (FIKKs)
The levels and predictors of physical activity engagement within the treatment seeking transgender population: a matched control study
Background: Physical activity has been found to alleviate mental health problems and could be beneficial for at-risk populations, such as transgender people. This study had three aims. First, to explore the amount of physical activity that treatment seeking transgender people engage in, and to compare this to matched cisgender people. Second, to determine whether there was a difference in physical activity depending on cross-sex hormone use. Third, to determine factors which predict physical activity among treatment seeking transgender people.
Method: Transgender (n=360) and cisgender people (n=314) were recruited from the UK. Participants were asked to complete questionnaires about physical activity, symptoms of anxiety and depression, self-esteem, body satisfaction and transphobia.
Results: Transgender people engaged in less physical activity than cisgender people. Transgender people who were on cross-sex hormones engaged in more physical activity than transgender people who were not. In transgender people on cross-sex hormones, high body satisfaction was the best statistical predictor of physical activity while high self-esteem was the best statistical predictor in people who were not.
Conclusion: Transgender people are less active than cisgender people. Cross-sex hormone treatment appears to be able to indirectly increase physical activity within this population, which may be beneficial for mental well-being
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