79 research outputs found
An orbital-free molecular dynamics study of melting in K_20, K_55, K_92, K_142, Rb_55 and Cs_55 clusters
The melting-like transition in potasium clusters K_N, with N=20, 55, 92 and
142, is studied by using an orbital-free density-functional constant-energy
molecular dynamics simulation method, and compared to previous theoretical
results on the melting-like transition in sodium clusters of the same sizes.
Melting in potasium and sodium clusters proceeds in a similar way: a surface
melting stage develops upon heating before the homogeneous melting temperature
is reached. Premelting effects are nevertheless more important and more easily
established in potasium clusters, and the transition regions spread over
temperature intervals which are wider than in the case of sodium. For all the
sizes considered, the percentage melting temperature reduction when passing
from Na to K clusters is substantially larger than in the bulk. Once those two
materials have been compared for a number of different cluster sizes, we study
the melting-like transition in Rb_55 and Cs_55 clusters and make a comparison
with the melting behavior of Na_55 and K_55. As the atomic number increases,
the height of the specific heat peaks decreases, their width increases, and the
melting temperature decreases as in bulk melting, but in a more pronounced way.Comment: LaTeX file. 6 pages with 17 pictures. Final version with minor
change
Decreased intelligence in children and exposure to fluoride and arsenic in drinking water
Antiferromagnetic metal phase in an electron-doped rare-earth nickelate
Long viewed as passive elements, antiferromagnetic materials have emerged as
promising candidates for spintronic devices due to their insensitivity to
external fields and potential for high-speed switching. Recent work exploiting
spin and orbital effects has identified ways to electrically control and probe
the spins in metallic antiferromagnets, especially in noncollinear or
noncentrosymmetric spin structures. The rare earth nickelate NdNiO3 is known to
be a noncollinear antiferromagnet where the onset of antiferromagnetic ordering
is concomitant with a transition to an insulating state. Here, we find that for
low electron doping, the magnetic order on the nickel site is preserved while
electronically a new metallic phase is induced. We show that this metallic
phase has a Fermi surface that is mostly gapped by an electronic reconstruction
driven by the bond disproportionation. Furthermore, we demonstrate the ability
to write to and read from the spin structure via a large zero-field planar Hall
effect. Our results expand the already rich phase diagram of the rare-earth
nickelates and may enable spintronics applications in this family of correlated
oxides.Comment: 25 pages, 4 figure
What should I do and who’s to blame?:A cross-national study on youth’s attitudes and beliefs in times of COVID-19
The COVID-19 crisis has had a major impact on youth. This study examined factors associated with youth's attitudes towards their government's response to the pandemic and their blaming of individuals from certain risk groups, ethnic backgrounds, and countries or regions. In a sample of 5,682 young adults (Mage = 22) from 14 countries, lower perceived burden due to COVID-19, more collectivistic and less individualistic values, and more empathy were associated with more positive attitudes towards the government and less blaming of individuals of certain groups. Youth's social identification with others in the pandemic mediated these associations in the same direction, apart from the COVID-19 burden on attitudes, which had a positive indirect effect. No evidence of country-level moderation was found
Emerging adults’ cultural values, prosocial behaviors, and mental health in 14 countries during the COVID-19 pandemic
Evidence suggests an impact of the COVID-19 pandemic on mental health, particularly among emerging adults. However, theories on altruism born of suffering or adversarial growth suggest that we might also see prosocial behavior as a function of the pandemic, which may protect against mental health challenges. Because cultural values are central in determining prosocial behavior, the current study explored how cultural values were differentially associated with adaptive prosocial behaviors that might protect against mental health challenges. Participants for the current study included 5,682 young people aged 18–25 years from 14 different countries around the world (68% female, 62% college students). Path analyses suggested that there were few differences in patterns as a function of culture, but revealed that horizontal individualism and horizontal and vertical collectivism were indirectly associated with lower levels of depression via prosocial behavior toward family members. Discussion focuses on the importance of coping by strengthening family relationships via prosocial behavior during the pandemic
What Should I do and Who’s to blame? A cross-national study on youth’s attitudes and beliefs in times of COVID-19
The COVID-19 crisis has had a major impact on youth. This study examined factors associated with youth’s attitudes towards their government’s response to the pandemic and their blaming of individuals from certain risk groups, ethnic backgrounds, and countries or regions. In a sample of 5,682 young adults (Mage = 22) from 14 countries, lower perceived burden due to COVID-19, more collectivistic and less individualistic values, and more empathy were associated with more positive attitudes towards the government and less blaming of individuals of certain groups. Youth’s social identification with others in the pandemic mediated these associations in the same direction, apart from the COVID-19 burden on attitudes, which had a positive indirect effect. No evidence of country-level moderation was found
Status and Trends of Physical Activity Surveillance, Policy, and Research in 164 Countries: Findings From the Global Observatory for Physical Activity—GoPA! 2015 and 2020 Surveys
Background: Physical activity (PA) surveillance, policy, and research efforts need to be periodically appraised to gain insight into national and global capacities for PA promotion. The aim of this paper was to assess the status and trends in PA surveillance, policy, and research in 164 countries. Methods: We used data from the Global Observatory for Physical Activity (GoPA!) 2015 and 2020 surveys. Comprehensive searches were performed for each country to determine the level of development of their PA surveillance, policy, and research, and the findings were verified by the GoPA! Country Contacts. Trends were analyzed based on the data available for both survey years. Results: The global 5-year progress in all 3 indicators was modest, with most countries either improving or staying at the same level. PA surveillance, policy, and research improved or remained at a high level in 48.1%, 40.6%, and 42.1% of the countries, respectively. PA surveillance, policy, and research scores decreased or remained at a low level in 8.3%, 15.8%, and 28.6% of the countries, respectively. The highest capacity for PA promotion was found in Europe, the lowest in Africa and low- and lower-middle-income countries. Although a large percentage of the world’s population benefit from at least some PA policy, surveillance, and research efforts in their countries, 49.6 million people are without PA surveillance, 629.4 million people are without PA policy, and 108.7 million live in countries without any PA research output. A total of 6.3 billion people or 88.2% of the world’s population live in countries where PA promotion capacity should be significantly improved. Conclusion: Despite PA is essential for health, there are large inequalities between countries and world regions in their capacity to promote PA. Coordinated efforts are needed to reduce the inequalities and improve the global capacity for PA promotion
CHARLESTON STRONG: Community Hope and Healing Through a Collaborative Mural Project
On June 17th, 2015 a horrific shooting at the iconic Emanuel Church in Charleston, SC shook our community, state, and nation. In the aftermath of the shooting issues of race relations, historic divides, anger, and healing permeated conversations at every level. Against this backdrop our college, already deeply immersed in service learning and community engagement, considered ways to be part of the healing, reflection, and positive action to grow out of this tragedy.
A collaboration among the college’s Fine Arts Department and Service Leaning and Civic Engagement program culminated in the interactive community of painting of a block-long mural the week of our annual campus-wide experiential learning event, Leadership Day. In the summer of 2015 Artist Gil Shuler created an inspirational palmetto tree and dove “CHARLESTON STRONG” artwork which he freely shared. For our Charleston Strong Mural project he consented to a large rendering of this art as a centerpiece of a block-long mural which community members augmented by adding their own dove to the Shuler’s nine doves signifying the Emanuel Nine.
For the preparation for the event, multiple approvals and funding sources had to be secured. The college paid to professionally repair and prep the wall with two coats of paint. Businesses and local artists generously contributed supplies, expertise, and person power to assist community members in adding colorful stenciled doves. College students from three fine arts classes (as well as “at large” student, VISTA, and staff volunteers) served across three open community “PaintStrong” full-day and half-day events. Throughout these events, students and faculty helped set up supplies for visitors that would help come paint on the wall.
Each person who came was invited to sign in to a guest book and to paint their own dove. Several school children had the opportunity to come and paint doves along with their families. The participating community members were diverse in every way – age, race, culture, neighborhood, occupation, religious and political affiliations, and connection to the Emanuel Nine. At the end of the project, a total of 1,678 doves were painted on the mural. The mural project’s purpose was to honor those who have lost their lives by bringing the community together. In the guestbook everyone was asked what they personally could do to make Charleston Strong. This poster will include a qualitative and quantitative analysis of the ideas generated by the diverse citizen population who came to share in the project as well as photos that capture both the process and final product
Brief report: How many dimensions in the prosocial behavior scale? Psychometric investigation in French-speaking adolescents
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