367 research outputs found
Mirror anomaly and anomalous Hall effect in type-I Dirac semimetals
In addition to the well known chiral anomaly, Dirac semimetals have been
argued to exhibit mirror anomaly, close analogue to the parity anomaly of
()-dimensional massive Dirac fermions. The observable response of such
anomaly is manifested in a singular step-like anomalous Hall response across
the mirror-symmetric plane in the presence of a magnetic field. Although this
result seems to be valid in type-II Dirac semimetals (strictly speaking, in the
linearized theory), we find that type-I Dirac semimetals do not possess such an
anomaly in anomalous Hall response even at the level of the linearized theory.
In particular, we show that the anomalous Hall response continuously approaches
zero as one approaches the mirror symmetric angle in a type-I Dirac semimetal
as opposed to the singular Hall response in a type-II Dirac semimetal.
Moreover, we show that, under certain condition, the anomalous Hall response
may vanish in a linearized type-I Dirac semimetal, even in the presence of time
reversal symmetry breaking.Comment: 6 pages, 5 figure
Longitudinal EEG power in the first postnatal year differentiates autism outcomes
An aim of autism spectrum disorder (ASD) research is to identify early biomarkers that inform ASD pathophysiology and expedite detection. Brain oscillations captured in electroencephalography (EEG) are thought to be disrupted as core ASD pathophysiology. We leverage longitudinal EEG power measurements from 3 to 36 months of age in infants at low- and high-risk for ASD to test how and when power distinguishes ASD risk and diagnosis by age 3-years. Power trajectories across the first year, second year, or first three years postnatally were submitted to data-driven modeling to differentiate ASD outcomes. Power dynamics during the first postnatal year best differentiate ASD diagnoses. Delta and gamma frequency power trajectories consistently distinguish infants with ASD diagnoses from others. There is also a developmental shift across timescales towards including higher-frequency power to differentiate outcomes. These findings reveal the importance of developmental timing and trajectory in understanding pathophysiology and classifying ASD outcomes.R01 DC010290 - NIDCD NIH HHS; T32 MH112510 - NIMH NIH HHS; U54 HD090255 - NICHD NIH HHSPublished versio
Proper Motion of the Faint Star near KIC 8462852 (Boyajian's Star) - Not a Binary System
A faint star located 2 arcsec from KIC 8462852 was discovered in Keck 10 m
adaptive optics imaging in the near-infrared (NIR) in 2014 by Boyajian et
al. (2016). The closeness of the star to KIC 8462852 suggested the two could
constitute a binary, which might have implications for the cause of the
brightness dips seen by {\it Kepler} (Boyajian et al. (2016) and in
ground-based optical studies Boyajian et al. (2018). Here, NIR imaging in 2017
using the Mimir instrument resolved the pair and enabled measuring their
separation. The faint star had moved milliarcsec (mas) relative to
KIC 8462852 since 2014. The relative proper motion of the faint star is mas yr, for a tangential velocity of km s if
it is at the same 390 pc distance as KIC 8462852. Circular velocity at the 750
AU current projected separation is km s, hence the star pair
cannot be bound.Comment: 10 pages, 2 figure
Centering the Marginalized: The Impact of the Pandemic on Online Student Retention
During the pandemic, much of the focus of administrators and scholars has been on its impact on residential students and the sudden shift to online instruction. While justified, researchers have yet to focus on online students—who often represent marginalized communities in higher education—to ask whether they were impacted by factors related to the pandemic other than the modality shift. In this study, we examined how the first-year retention of online students was affected during the pandemic, and whether it differed from first-year residential students who transitioned online. We examined records of two student cohorts (Fall 2017 and Fall 2019) from a university to determine each cohort’s retention rate by modality. Holding other relevant factors constant, we found the COVID cohort of students were less likely to persist to the following Fall regardless of modality, although residential students were still much more likely to be retained overall. However, Black and Hispanic students were less likely to be retained across both modalities, and even Black residential students were more vulnerable to not returning than their White counterparts, suggesting that racial inequalities persist across learning modalities. We conclude by suggesting how one retention tool—financial aid—could be used to address the particular needs of online students to improve their retention
Non-Invasive Neuromodulation Therapies for Parkinson’s Disease
Noninvasive brain stimulation (NIBS) technologies have been applied to study brain physiology and, more recently, have been recognized for their therapeutic potential as an adjunctive treatment for various neurologic and psychiatric disorders. Transcranial magnetic stimulation (TMS) and transcranial electric stimulation (tES) are two of the most studied NIBS modalities in Parkinson’s disease. They are non-systemic and relatively safe. Most therapeutic trials have been conducted to ameliorate motor symptoms of Parkinson’s disease (PD) with overall positive results using various stimulation modalities and methods. Notwithstanding significant results, evidence has not yet been compelling mainly due to small-size studies, lack of standardization of methodologies and other study design limitations. NIBS hold promise for treatment of PD symptoms and PD related complications. Large, well designed clinical trials are needed to corroborate these positive findings and inform its durability and the overall clinical relevance for the treatment of PD
Annexin-like protein from Arabidopsis thaliana rescues delta oxyR mutant of Escherichia coli from H2O2 stress.
Effect of eclampsia on pregnancy outcome at the tertiary care center
Background: Eclampsia is a common medical and life-threatening emergency condition mainly seen in 5-10% of all pregnancies and that is a major cause of maternal and perinatal morbidity and mortality The aim of the study to find out the fetomaternal outcomes of eclampsia in tertiary care hospital and to analyse the trend of eclampsia and associated epidemiological variables.Methods: This retrospective analytical study was undertaken with 40 clinically diagnosed women with eclampsia in their third trimester of pregnancy in the Department of Obstetrics and Gynaecology, at tertiary care hospital from July 2020 to December 2021. Women who came to the hospital with eclampsia or developed eclampsia during hospital stay were included in our study.Results: In our study, the antepartum eclampsia was in 32 cases (80%), primigravida 27 cases (67.5%), maternal age (21-30 years) 26 cases (65%). Cesarean section was the mode of delivery in 26 cases (65%). NICU admission is required by 20 neonates (50%).Conclusions: Eclampsia is an important cause of maternal and perinatal morbidity and mortality. Providing quality antenatal health care services, increasing awareness of patients about warning symptoms, proper investigations, timely delivery, and proper monitoring in the intrapartum and postpartum period have the potential to improve maternal and perinatal outcomes.
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