464 research outputs found
Effects of Long-Range Interactions on Magnetic Excitations and Phase Transition on a Magnetically Frustrated Square Lattice
We investigate the effects of long-range interaction on the magnetic
excitations and the competition between magnetic phases on a frustrated square
lattice. Applying the spin wave theory and assisted with symmetry analysis, we
obtain analytical expression for spin wave spectrum of competing Neel and (pi,
0) stripe states of systems containing any-order long-range interactions. In
the specific case of long-range interactions with power-law decay, we found
surprisingly that staggered long-range interaction suppresses quantum
fluctuation and enlarges the ordered moment, especially in the Neel state, and
thus extends its phase boundary to the stripe state. Our findings only
illustrate the rich possibilities of the roles of long-range interactions, and
advocate future investigations in other magnetic systems with different
structures of interactions.Comment: 9 pages, 9 figure
The Energy Crisis in CPT II Variant Fibroblasts
Carnitine palmitoyltransferase II (CPT II) deficiency is one of the most common causes of fatty acid oxidation metabolism disorders. However, the molecular mechanism between CPT2 gene polymorphisms and metabolic stress has not been fully clarified. We previously reported that a number of patients show a thermal instable phenotype of compound hetero/homozygous variants of CPT II. To understand the mechanism of the metabolic disorder resulting from CPT II deficiency, the present study investigated CPT II variants in patient fibroblasts, [c.1102 G>A (p.V368I)] (heterozygous), [c.1102 G>A (p.V368I)] (homozygous), and [c.1055 T>G (p.F352C)] (heterozygous) + [c.1102 G>A (p.V368I)] (homozygous) compared with fibroblasts from healthy controls. CPT II variants exerted an effect of dominant negative on the homotetrameric proteins that showed thermal instability, reduced residual enzyme activities and a short half-life. Moreover, CPT II variant fibroblasts showed a significant decrease in fatty acid β-oxidation and adenosine triphosphate generation, combined with a reduced mitochondrial membrane potential, resulting in cellular apoptosis. Collectively, our data indicate that the CPT II deficiency induces an energy crisis of the fatty acid metabolic pathway. These findings may contribute to the elucidation of the genetic factors involved in metabolic disorder encephalopathy caused by the CPT II deficiency
Edge effect removal in Fourier ptychographic microscopy via perfect Fourier transformation (PFT)
Edge effect may degrade the imaging precision and is caused by the aperiodic
image extension of fast Fourier transform (FFT). In this letter, a perfect
Fourier transform algorithm termed PFT was reported to remove the artifacts
with comparable efficiency to FFT. Although we demonstrated the performance of
PFT in Fourier ptychographic microscopy (FPM) only, it can be expanded in any
occasion where the conventional FFT is used.Comment: 4 pages, 6 figure
Human Ecology, Process Philosophy and the Global Ecological Crisis
This paper argues that human ecology, based on process philosophy and challenging scientific materialism, is required to effectively confront the global ecological crisis now facing us
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Assessing agricultural drought in summer over Oklahoma Mesonet sites using the water-related vegetation index from MODIS.
Agricultural drought, a common phenomenon in most parts of the world, is one of the most challenging natural hazards to monitor effectively. Land surface water index (LSWI), calculated as a normalized ratio between near infrared (NIR) and short-wave infrared (SWIR), is sensitive to vegetation and soil water content. This study examined the potential of a LSWI-based, drought-monitoring algorithm to assess summer drought over 113 Oklahoma Mesonet stations comprising various land cover and soil types in Oklahoma. Drought duration in a year was determined by the number of days with LSWI <0 (DNLSWI) during summer months (June-August). Summer rainfall anomalies and LSWI anomalies followed a similar seasonal dynamics and showed strong correlations (r 2 = 0.62-0.73) during drought years (2001, 2006, 2011, and 2012). The DNLSWI tracked the east-west gradient of summer rainfall in Oklahoma. Drought intensity increased with increasing duration of DNLSWI, and the intensity increased rapidly when DNLSWI was more than 48 days. The comparison between LSWI and the US Drought Monitor (USDM) showed a strong linear negative relationship; i.e., higher drought intensity tends to have lower LSWI values and vice versa. However, the agreement between LSWI-based algorithm and USDM indicators varied substantially from 32 % (D 2 class, moderate drought) to 77 % (0 and D 0 class, no drought) for different drought intensity classes and varied from ∼30 % (western Oklahoma) to >80 % (eastern Oklahoma) across regions. Our results illustrated that drought intensity thresholds can be established by counting DNLSWI (in days) and used as a simple complementary tool in several drought applications for semi-arid and semi-humid regions of Oklahoma. However, larger discrepancies between USDM and the LSWI-based algorithm in arid regions of western Oklahoma suggest the requirement of further adjustment in the algorithm for its application in arid regions
Solid Electrolyte Interphase Formation in Tellurium Iodide Perovskites during Electrochemistry and Photoelectrochemistry
Halide perovskites are promising photoelectrocatalytic materials. Their further development requires understanding of surface processes during electrochemistry. Thin films of tellurium-based vacancy-ordered perovskites with formula A2TeI6, A = Cs, methylammonium (MA), were deposited onto transparent conducting substrates using aerosol-assisted chemical vapor deposition. Thin film stability as electrodes and photoelectrodes was tested in dichloromethane containing tetrabutylammonium PF6 (TBAPF6). Using photoemission spectroscopy, we show that the formation of a solid electrolyte interphase on the surface of the Cs2TeI6, consisting of CsPF6, enhances the stability of the electrode and allows extended chopped-light chronoamperometry measurements at up to 1.1 V with a photocurrent density of 16 μA/cm2. In contrast, (CH3NH3)2TeI6 does not form a passivating layer and rapidly degrades upon identical electrochemical treatment. This demonstrates the importance of surface chemistry in halide perovskite electrochemistry and photoelectrocatalysis
Fear of eyes: triadic relation among social anxiety, trypophobia, and discomfort for eye cluster
How Does Adult Attachment Affect Human Recognition of Love-related and Sex-related Stimuli: An ERP Study
Journal articleThis paper reports the descriptive analysis of a large sample of safety climate survey data (n = 110,014) collected over 10 years from U.S. Naval aircrew using the Command Safety Assessment Survey (CSAS)
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