SN 2022crv: IIb, Or Not IIb: That is the Question

We present optical and near-infrared observations of SN~2022crv, a stripped envelope supernova in NGC~3054, discovered within 12 hrs of explosion by the Distance Less Than 40 Mpc Survey. We suggest SN~2022crv is a transitional object on the continuum between SNe Ib and SNe IIb. A high-velocity hydrogen feature ($\sim$$-$20,000 -- $-$16,000 $\rm km\,s^{-1}$) was conspicuous in SN~2022crv at early phases, and then quickly disappeared around maximum light. By comparing with hydrodynamic modeling, we find that a hydrogen envelope of $\sim 10^{-3}$ \msun{} can reproduce the behaviour of the hydrogen feature observed in SN~2022crv. The early light curve of SN~2022crv did not show envelope cooling emission, implying that SN~2022crv had a compact progenitor with extremely low amount of hydrogen. The analysis of the nebular spectra shows that SN~2022crv is consistent with the explosion of a He star with a final mass of $\sim$4.5 -- 5.6 \msun{} that has evolved from a $\sim$16 -- 22 \msun{} zero-age main sequence star in a binary system with about 1.0 -- 1.7 \msun{} of oxygen finally synthesized in the core. The high metallicity at the supernova site indicates that the progenitor experienced a strong stellar wind mass loss. In order to retain a small amount of residual hydrogen at such a high metallicity, the initial orbital separation of the binary system is likely larger than $\sim$1000~$\rm R_{\odot}$. The near-infrared spectra of SN~2022crv show a unique absorption feature on the blue side of He I line at $\sim$1.005~$\mu$m. This is the first time that such a feature has been observed in a Type Ib/IIb, and could be due to \ion{Sr}{2}. Further detailed modelling on SN~2022crv can shed light on the progenitor and the origin of the mysterious absorption feature in the near infrared.Comment: 33 pages, 23 figures, submitted to Ap

Why Does Exercise “Triggerâ€? Adaptive Protective Responses in the Heart?

Numerous epidemiological studies suggest that individuals who exercise have decreased cardiac morbidity and mortality. Pre-clinical studies in animal models also find clear cardioprotective phenotypes in animals that exercise, specifically characterized by lower myocardial infarction and arrhythmia. Despite the clear benefits, the underlying cellular and molecular mechanisms that are responsible for exercise preconditioning are not fully understood. In particular, the adaptive signaling events that occur during exercise to “trigger� cardioprotection represent emerging paradigms. In this review, we discuss recent studies that have identified several different factors that appear to initiate exercise preconditioning. We summarize the evidence for and against specific cellular factors in triggering exercise adaptations and identify areas for future study

Ground-based and JWST observations of SN 2022pul. I. Unusual signatures of carbon, oxygen, and circumstellar interaction in a peculiar type Ia supernova

Nebular-phase observations of peculiar Type Ia supernovae (SNe Ia) provide important constraints on progenitor scenarios and explosion dynamics for both these rare SNe and the more common, cosmologically useful SNe Ia. We present observations from an extensive ground- and space-based follow-up campaign to characterize SN 2022pul, a super-Chandrasekhar mass SN Ia (alternatively "03fg-like" SN), from before peak brightness to well into the nebular phase across optical to mid-infrared (MIR) wavelengths. The early rise of the light curve is atypical, exhibiting two distinct components, consistent with SN Ia ejecta interacting with dense carbon–oxygen (C/O)-rich circumstellar material (CSM). In the optical, SN 2022pul is most similar to SN 2012dn, having a low estimated peak luminosity (MB = −18.9 mag) and high photospheric velocity relative to other 03fg-like SNe. In the nebular phase, SN 2022pul adds to the increasing diversity of the 03fg-like subclass. From 168 to 336 days after peak B-band brightness, SN 2022pul exhibits asymmetric and narrow emission from [O i] λλ6300, 6364 (FWHM ≈ 2000 km s−1), strong, broad emission from [Ca ii] λλ7291, 7323 (FWHM ≈ 7300 km s−1), and a rapid Fe iii to Fe ii ionization change. Finally, we present the first ever optical-to-MIR nebular spectrum of an 03fg-like SN Ia using data from JWST. In the MIR, strong lines of neon and argon, weak emission from stable nickel, and strong thermal dust emission (with T ≈ 500 K), combined with prominent [O i] in the optical, suggest that SN 2022pul was produced by a white dwarf merger within C/O-rich CSM

Ground-based and JWST Observations of SN 2022pul. II. Evidence from nebular spectroscopy for a violent merger in a peculiar type Ia supernova

We present an analysis of ground-based and JWST observations of SN 2022pul, a peculiar "03fg-like" (or "super-Chandrasekhar") Type Ia supernova (SN Ia), in the nebular phase at 338 days postexplosion. Our combined spectrum continuously covers 0.4–14 μm and includes the first mid-infrared spectrum of a 03fg-like SN Ia. Compared to normal SN Ia 2021aefx, SN 2022pul exhibits a lower mean ionization state, asymmetric emission-line profiles, stronger emission from the intermediate-mass elements (IMEs) argon and calcium, weaker emission from iron-group elements (IGEs), and the first unambiguous detection of neon in a SN Ia. A strong, broad, centrally peaked [Ne ii] line at 12.81 μm was previously predicted as a hallmark of "violent merger" SN Ia models, where dynamical interaction between two sub-MCh white dwarfs (WDs) causes disruption of the lower-mass WD and detonation of the other. The violent merger scenario was already a leading hypothesis for 03fg-like SNe Ia; in SN 2022pul it can explain the large-scale ejecta asymmetries seen between the IMEs and IGEs and the central location of narrow oxygen and broad neon. We modify extant models to add clumping of the ejecta to reproduce the optical iron emission better, and add mass in the innermost region (<2000 km s−1) to account for the observed narrow [O i] λλ6300, 6364 emission. A violent WD–WD merger explains many of the observations of SN 2022pul, and our results favor this model interpretation for the subclass of 03fg-like SNe Ia

Factitious Illness – Red Flags for the Pediatric Emergency Medicine Physician

Factitious illness occurs when a caregiver exaggerates, falsifies, and/or induces symptoms of illness in a child. Emergency care providers are often in a unique position to evaluate these children and may be the first to recognize that factitious illness is present. The varied and unusual presentations of this entity present diagnostic challenges for the medical provider. Using a case-based approach, this article identifies important red flags that should alert the emergency care clinician to consider the possibility that a child is the victim of factitious illness

Factitious Illness – Red Flags for the Pediatric Emergency Medicine Physician

Factitious illness occurs when a caregiver exaggerates, falsifies, and/or induces symptoms of illness in a child. Emergency care providers are often in a unique position to evaluate these children and may be the first to recognize that factitious illness is present. The varied and unusual presentations of this entity present diagnostic challenges for the medical provider. Using a case-based approach, this article identifies important red flags that should alert the emergency care clinician to consider the possibility that a child is the victim of factitious illness

Neurological Manifestations of Medical Child Abuse

Background Medical child abuse occurs when a child receives unnecessary and harmful, or potentially harmful, medical care at the instigation of a caretaker through exaggeration, falsification, or induction of symptoms of illness in a child. Neurological manifestations are common with this type of maltreatment. Objectives We sought to review common reported neurological manifestations that may alert the clinician to consider medical child abuse. In addition, the possible sequelae of this form of child maltreatment is discussed, as well as practice recommendations for establishing the diagnosis and stopping the abuse once it is identified. Methods A review of the medical literature was conducted regarding the reported neurological presentations of this entity. Results Neurological manifestations of medical child abuse include false reports of apparent life-threatening events and seizures and reports of induction of symptoms from poisoning. Failure to correlate objective findings with subjective complaints may lead to unnecessary and potentially harmful testing or treatment. This form of child maltreatment puts a child at significant risk of long-term morbidity and mortality. Conclusions A wide variety of neurological manifestations have been reported in cases of medical child abuse. It is important for the practicing neurologist to include medical child abuse on the differential diagnosis

Traumatic pediatric firearm injuries during the COVID-19 pandemic

Statement of Purpose: The purpose of this study is to epidemiologically describe firearms injuries treated at a Level 1 pediatric trauma center occurring during the COVID-19 pandemic and compare them to injuries seen in the year prior. Methods: This is a retrospective chart review of patients seen by pediatric trauma surgery for a firearm injury between February 1, 2019 and March 30, 2021; the pre-pandemic time period included February 1, 2019 – March 9, 2020 and the pandemic period included March 10, 2020 – March 31, 2021. We excluded patients with firearms injuries that were not assessed by trauma surgery and patients with injuries from non-powder guns. Results: Twenty-eight patients were seen for firearm injuries in the pre-pandemic period; 22 (78.5%) were male, and the mean age was 13.3 years, with 17.8% of patients \u3c 10 years old. Sixteen (57.1%) were black, 8 (28.6%) white, and 4 (14.3%) multiracial. The pandemic period included 80 patients with firearm injuries, with 59 (74%) male, and a mean age of 12.5 years. Seventeen (21.5%) were \u3c 10 years old. Fifty-six (70%) of patients during the pandemic period were black, 15 (20%) white, 6 (7.5%) multiracial, and 2 (2.5%) Hispanic. There was no statistically significant difference between the two groups demographically. No patients were identified as having an intentional self-inflicted firearm injury. Conclusion: While there was a nearly threefold increase in pediatric firearm injuries seen during the pandemic, the demographics of the victims have not changed compared to pre-pandemic patterns. This reflects a need for ongoing and targeted preventive measures to reduce these extremely high-risk injuries