23 research outputs found
Three-dimensional Pentagon Carbon with a genesis of emergent fermions
Carbon, the basic building block of our universe, enjoys a vast number of
allotropic structures. Owing to its bonding characteristic, most carbon
allotropes possess the motif of hexagonal rings. Here, with first-principles
calculations, we discover a new metastable three-dimensional carbon allotrope
entirely composed of pentagon rings. The unique structure of this "Pentagon
Carbon" leads to extraordinary electronic properties, making it a cornucopia of
emergent topological fermions. Under lattice strain, Pentagon Carbon exhibits
topological phase transitions, generating a series of novel quasiparticles,
from isospin-1 triplet fermions, to triply-degenerate fermions, and further to
concatenated Weyl-loop fermions. Its Landau level spectrum also exhibits
distinct features, including a huge number of almost degenerate chiral Landau
bands, implying pronounced magneto-transport signals. Our work not only
discovers a remarkable carbon allotrope with highly rare structural motifs, it
also reveals a fascinating hierarchical particle genesis with novel topological
fermions beyond the Dirac and Weyl paradigm
Development and validation of a multidimensional short version Zarit Burden Interview (ZBI-9) for caregivers of persons with cognitive impairment
Background:
There is a lack of appreciation of the full dimensionality of the original 22-item Zarit Burden Interview (ZBI) in the development of short versions. Existing short versions are premised upon a 1-factor or 2-factor structure or statistical techniques for item selection. Thus, there is a need for ZBI short versions that considers the multidimensional constructs of role strain, personal strain, and worry about performance (WaP) during item selection to provide a more holistic and comprehensive evaluation.
Purpose:
To develop and validate a short version of ZBI through a combined quantitative and qualitative approach that incorporates the validated 4-factor structure of role strain demands; role strain-control; personal strain, and WaP.
Patients:
We studied 202 caregivers of patients with dementia (84.2%) or mild cognitive impairment (15.8%) attending a memory clinic in Singapore.
Methods:
Confirmatory factor analysis and qualitative considerations from expert consensus were used for item selection. Confirmatory factor analysis fit statistics support the 4-factor structure. The 9-item ZBI-9 showed good internal consistency (Cronbach’s α=0.87) and convergent validity with anxiety and depression (Pearson correlation: Hospital Anxiety and Depression sub-scales, r≥0.56, P<0.001; ZBI- 22, r=0.95, P<0.001). Using a cut-off score of ≥13, ZBI-9 displayed good discriminatory ability for depressive symptoms (area under curve=0.79, P<0.001; sensitivity=70%, specificity=75%). The ZBI-9 also displayed comparable performance to the 22-item full version and three 12-item short versions.
Conclusion:
The ZBI-9 is a multidimensional short-version assessment tool for caregivers of persons with dementia and mild cognitive impairment that is reliable, valid, and discriminates depressive symptoms.Published versionThe research was funded by the Ng Teng Fong Healthcare Innovative Program, Singapore (NTF_JUN2018_I_C1_C_02)
Non-Point Source Pollution Characteristics of Agriculture-Derived Nitrogen in Groundwater in Suburban Area of Shanghai Based on Models
Part 1: GIS, GPS, RS and Precision FarmingInternational audienceThis paper analyzes the characteristics of the NPS nitrogen pollution of the groundwater in Guoyuan Village, Pudong District, Shanghai. And the associated effects on the surface and groundwater around the study area are discussed in detail based on the successive observed data, DNDC and L-THIA model. The results show that both of the surface and groundwater are polluted so seriously that they are not suitable to drink. The average content of total nitrogen in surface water is 6.3 mg/L and 16.85 mg/L in the groundwater, and both of them attribute to Grade V surface water standard (≤2.0 mg/L) according to the national standard(GB 3838-2002). It is concluded that the nitrogen pollution comes mainly from the fertilizer of the peach orchard based on the further modeling analysis. Therefore, reasonable adjustment of fertilization measures and project may be an effective and practical approach to control the nitrogen pollution around the peach orchard
Genomic Analysis of Bacillus megaterium NCT-2 Reveals Its Genetic Basis for the Bioremediation of Secondary Salinization Soil
Bacillus megaterium NCT-2 is a nitrate-uptake bacterial, which shows high bioremediation capacity in secondary salinization soil, including nitrate-reducing capacity, phosphate solubilization, and salinity adaptation. To gain insights into the bioremediation capacity at the genetic level, the complete genome sequence was obtained by using a multiplatform strategy involving HiSeq and PacBio sequencing. The NCT-2 genome consists of a circular chromosome of 5.19 Mbp and ten indigenous plasmids, totaling 5.88 Mbp with an average GC content of 37.87%. The chromosome encodes 5,606 genes, 142 tRNAs, and 53 rRNAs. Genes involved in the features of the bioremediation in secondary salinization soil and plant growth promotion were identified in the genome, such as nitrogen metabolism, phosphate uptake, the synthesis of organic acids and phosphatase for phosphate-solubilizing ability, and Trp-dependent IAA synthetic system. Furthermore, strain NCT-2 has great ability of adaption to environments due to the genes involved in cation transporters, osmotic stress, and oxidative stress. This study sheds light on understanding the molecular basis of using B. megaterium NCT-2 in bioremediation of the secondary salinization soils
‘24/7’ Caregiving: A Qualitative Analysis of an Emerging Phenomenon of Interest in Caregiving
The COVID-19 pandemic has exacerbated the difficulties faced by caregivers who have to provide continuous ‘24/7’ care to persons with dementia with minimal formal and informal support. While caregivers have reported heightened levels of caregiving distress and burden during the pandemic, there remains a dearth of research pertaining to their lived experiences of providing continuous care with little respite and the corresponding physical, psychosocial and emotional impacts of caregiving ‘24/7’. The present study uses data obtained from interviews with dementia caregivers (N = seven) that were collected as part of a larger study on Carer Matters, a hospital-based holistic caregiver support program held during COVID-19, to conduct a secondary thematic analysis. The findings revealed three themes that defined the shared experiences of ‘24/7’ caregivers: (1) A World Overturned, which refers to the increase in caregiving intensity and burden due to the pandemic; (2) Burning on Both Ends, which refers to the impossible balance between caregiving and their personal lives; and (3) At Wits’ End, which refers to an overwhelming sense of hopelessness and helplessness over their caregiving situation. These findings highlight the challenges and unsustainability of ‘24/7’ caregiving and the detrimental impact that round-the-clock care wields on caregivers’ physical and mental well-being. Implications and recommendations are discussed in accordance with the cultural particularities of the study’s Asian context (Singapore), with calls for greater caregiver support to be better integrated into society and the community, especially at the neighborhood and grassroots level, to alleviate caregiving burden and safeguard their well-being
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Three-dimensional Pentagon Carbon with a genesis of emergent fermions.
Carbon, the basic building block of our universe, enjoys a vast number of allotropic structures. Owing to its bonding characteristic, most carbon allotropes possess the motif of hexagonal rings. Here, with first-principles calculations, we discover a new metastable three-dimensional carbon allotrope entirely composed of pentagon rings. The unique structure of this Pentagon Carbon leads to extraordinary electronic properties, making it a cornucopia of emergent topological fermions. Under lattice strain, Pentagon Carbon exhibits topological phase transitions, generating a series of novel quasiparticles, from isospin-1 triplet fermions to triply degenerate fermions and further to Hopf-link Weyl-loop fermions. Its Landau level spectrum also exhibits distinct features, including a huge number of almost degenerate chiral Landau bands, implying pronounced magneto-transport signals. Our work not only discovers a remarkable carbon allotrope with highly rare structural motifs, it also reveals a fascinating hierarchical particle genesis with novel topological fermions beyond the Dirac and Weyl paradigm