The Zeeman effect in the G band

We investigate the possibility of measuring magnetic field strength in G-band bright points through the analysis of Zeeman polarization in molecular CH lines. To this end we solve the equations of polarized radiative transfer in the G band through a standard plane-parallel model of the solar atmosphere with an imposed magnetic field, and through a more realistic snapshot from a simulation of solar magneto-convection. This region of the spectrum is crowded with many atomic and molecular lines. Nevertheless, we find several instances of isolated groups of CH lines that are predicted to produce a measurable Stokes V signal in the presence of magnetic fields. In part this is possible because the effective Land\'{e} factors of lines in the stronger main branch of the CH A$^{2}\Delta$--X$^{2}\Pi$ transition tend to zero rather quickly for increasing total angular momentum $J$, resulting in a Stokes $V$ spectrum of the G band that is less crowded than the corresponding Stokes $I$ spectrum. We indicate that, by contrast, the effective Land\'{e} factors of the $R$ and $P$ satellite sub-branches of this transition tend to $\pm 1$ for increasing $J$. However, these lines are in general considerably weaker, and do not contribute significantly to the polarization signal. In one wavelength location near 430.4 nm the overlap of several magnetically sensitive and non-sensitive CH lines is predicted to result in a single-lobed Stokes $V$ profile, raising the possibility of high spatial-resolution narrow-band polarimetric imaging. In the magneto-convection snapshot we find circular polarization signals of the order of 1% prompting us to conclude that measuring magnetic field strength in small-scale elements through the Zeeman effect in CH lines is a realistic prospect.Comment: 22 pages, 6 figures. To be published in the Astrophysical Journa

Hospital revascularisation capability and quality of care after an acute coronary syndrome in Switzerland.

BACKGROUND: Patients with acute coronary syndrome (ACS) transferred to regional nonacademic hospitals after percutaneous coronary intervention (PCI) may receive fewer preventive interventions than patients who remain in university hospitals. We aimed at comparing hospitals with and without PCI facilities regarding guidelines-recommended secondary prevention interventions after an ACS. METHODS: We studied patients with ACS admitted to a university hospital with PCI facilities in Switzerland, and either transferred within 48 hours to regional nonacademic hospitals without PCI facilities or directly discharged from the university hospital. We measured prescription rates of evidence-based recommended therapies after ACS including reasons for nonprescription of aspirin, statins, β-blockers, angiotensin converting-enzyme inhibitors (ACEI) / angiotensin II receptor blockers (ARB), along with cardiac rehabilitation attendance and delivery of a smoking cessation intervention. RESULTS: Overall, 720 patients with ACS were enrolled; 541 (75.1%) were discharged from the hospital with PCI facilities, 179 (24.9%) were transferred to hospitals without PCI facilities. Concomitant prescription of aspirin, β-blockers, ACEI/ARB and statins at discharge was similar in hospitals with and without PCI facilities, reaching 83.9% and 85.5%, respectively (p = 0.62). Attendance at cardiac rehabilitation reached 55.5% for the hospital with PCI facilities and 65.7% for hospitals without PCI facilities (p = 0.02). In-hospital smoking cessation interventions were delivered to 70.8% patients exclusively at the hospital with PCI facilities. CONCLUSION: Quality of care for patients with ACS discharged from hospitals without PCI facilities was similar to that of patients directly discharged from the hospital with PCI facilities, except for in-hospital smoking cessation counselling and cardiac rehabilitation attendance

Separate Origins of Group I Introns in Two Mitochondrial Genes of the Katablepharid Leucocryptos marina

Mitochondria are descendants of the endosymbiotic α-proteobacterium most likely engulfed by the ancestral eukaryotic cells, and the proto-mitochondrial genome should have been severely streamlined in terms of both genome size and gene repertoire. In addition, mitochondrial (mt) sequence data indicated that frequent intron gain/loss events contributed to shaping the modern mt genome organizations, resulting in the homologous introns being shared between two distantly related mt genomes. Unfortunately, the bulk of mt sequence data currently available are of phylogenetically restricted lineages, i.e., metazoans, fungi, and land plants, and are insufficient to elucidate the entire picture of intron evolution in mt genomes. In this work, we sequenced a 12 kbp-fragment of the mt genome of the katablepharid Leucocryptos marina. Among nine protein-coding genes included in the mt genome fragment, the genes encoding cytochrome b and cytochrome c oxidase subunit I (cob and cox1) were interrupted by group I introns. We further identified that the cob and cox1 introns host open reading frames for homing endonucleases (HEs) belonging to distantly related superfamilies. Phylogenetic analyses recovered an affinity between the HE in the Leucocryptos cob intron and two green algal HEs, and that between the HE in the Leucocryptos cox1 intron and a fungal HE, suggesting that the Leucocryptos cob and cox1 introns possess distinct evolutionary origins. Although the current intron (and intronic HE) data are insufficient to infer how the homologous introns were distributed to distantly related mt genomes, the results presented here successfully expanded the evolutionary dynamism of group I introns in mt genomes

Integrative mapping analysis of chicken microchromosome 16 organization

<p>Abstract</p> <p>Background</p> <p>The chicken karyotype is composed of 39 chromosome pairs, of which 9 still remain totally absent from the current genome sequence assembly, despite international efforts towards complete coverage. Some others are only very partially sequenced, amongst which microchromosome 16 (GGA16), particularly under-represented, with only 433 kb assembled for a full estimated size of 9 to 11 Mb. Besides the obvious need of full genome coverage with genetic markers for QTL (Quantitative Trait Loci) mapping and major genes identification studies, there is a major interest in the detailed study of this chromosome because it carries the two genetically independent <it>MHC </it>complexes <it>B </it>and <it>Y</it>. In addition, GGA16 carries the ribosomal RNA (<it>rRNA</it>) genes cluster, also known as the <it>NOR </it>(nucleolus organizer region). The purpose of the present study is to construct and present high resolution integrated maps of GGA16 to refine its organization and improve its coverage with genetic markers.</p> <p>Results</p> <p>We developed 79 STS (Sequence Tagged Site) markers to build a physical RH (radiation hybrid) map and 34 genetic markers to extend the genetic map of GGA16. We screened a BAC (Bacterial Artificial Chromosome) library with markers for the <it>MHC-B</it>, <it>MHC-Y </it>and <it>rRNA </it>complexes. Selected clones were used to perform high resolution FISH (Fluorescent <it>In Situ </it>Hybridization) mapping on giant meiotic lampbrush chromosomes, allowing meiotic mapping in addition to the confirmation of the order of the three clusters along the chromosome. A region with high recombination rates and containing PO41 repeated elements separates the two <it>MHC </it>complexes.</p> <p>Conclusions</p> <p>The three complementary mapping strategies used refine greatly our knowledge of chicken microchromosome 16 organisation. The characterisation of the recombination hotspots separating the two <it>MHC </it>complexes demonstrates the presence of PO41 repetitive sequences both in tandem and inverted orientation. However, this region still needs to be studied in more detail.</p

Discovery of rare variants associated with blood pressure regulation through meta-analysis of 1.3 million individuals

Correction: Volume53, Issue5 Page 762-762 DOI: 10.1038/s41588-021-00832-z Published MAY 2021Genetic studies of blood pressure (BP) to date have mainly analyzed common variants (minor allele frequency > 0.05). In a meta-analysis of up to similar to 1.3 million participants, we discovered 106 new BP-associated genomic regions and 87 rare (minor allele frequencyPeer reviewe

Cross Adaptation - Heat and Cold Adaptation to Improve Physiological and Cellular Responses to Hypoxia

To prepare for extremes of heat, cold or low partial pressures of O2, humans can undertake a period of acclimation or acclimatization to induce environment specific adaptations e.g. heat acclimation (HA), cold acclimation (CA), or altitude training. Whilst these strategies are effective, they are not always feasible, due to logistical impracticalities. Cross adaptation is a term used to describe the phenomenon whereby alternative environmental interventions e.g. HA, or CA, may be a beneficial alternative to altitude interventions, providing physiological stress and inducing adaptations observable at altitude. HA can attenuate physiological strain at rest and during moderate intensity exercise at altitude via adaptations allied to improved oxygen delivery to metabolically active tissue, likely following increases in plasma volume and reductions in body temperature. CA appears to improve physiological responses to altitude by attenuating the autonomic response to altitude. While no cross acclimation-derived exercise performance/capacity data have been measured following CA, post-HA improvements in performance underpinned by aerobic metabolism, and therefore dependent on oxygen delivery at altitude, are likely. At a cellular level, heat shock protein responses to altitude are attenuated by prior HA suggesting that an attenuation of the cellular stress response and therefore a reduced disruption to homeostasis at altitude has occurred. This process is known as cross tolerance. The effects of CA on markers of cross tolerance is an area requiring further investigation. Because much of the evidence relating to cross adaptation to altitude has examined the benefits at moderate to high altitudes, future research examining responses at lower altitudes should be conducted given that these environments are more frequently visited by athletes and workers. Mechanistic work to identify the specific physiological and cellular pathways responsible for cross adaptation between heat and altitude, and between cold and altitude, is warranted, as is exploration of benefits across different populations and physical activity profiles

Clinical impact of a structured secondary cardiovascular prevention program following acute coronary syndromes: A prospective multicenter healthcare intervention.

Structured secondary cardiovascular prevention programs (SSCP) following acute coronary syndromes (ACS) may reduce major adverse cardiovascular events (MACE) through better adherence to post-ACS recommendations. Through a prospective multicenter cohort study, we compared the outcomes of two sequential post-ACS patient cohorts, the initial one receiving standard care (SC) followed by one receiving additional interventions (SSCP) aimed at improving patient education as well as healthcare provider and hospital systems. The primary endpoint was MACE at one year. Secondary endpoints included adherence to recommended therapies, attendance to cardiac rehabilitation (CR) and successful achievement of cardiovascular risk factor (CVRF) targets. In total, 2498 post-ACS patients from 4 Swiss university hospitals were included: 1210 vs 1288 in the SC and SSCP groups, respectively. The SSCP group demonstrated a significant increase in attendance to CR programs (RR 1.08, 95%CI 1.02-1.14, P = 0.006), despite not achieving the primary MACE endpoint (HR 0.97, 95%CI 0.77-1.22, P = 0.79). After age-stratification, significant reductions in cardiac death, MI and stroke events (HR 0.53, 95%CI 0.30-0.93, P for interaction = 0.016) were observed for SSCP patients ≤ 65 years old. The SSCP group also scored significantly better for the LDL cholesterol target (RR 1.07, 95%CI 1.02-1.13, P = 0.012), systolic blood pressure target (RR 1.06, 95%CI 1.01-1.13, P = 0.029) and physical activity (RR 1.10, 95%CI 1.01-1.20, P = 0.021). The implementation of an SSCP post ACS was associated with an improvement in the control of CVRF and attendance to CR programs, and was also associated with significant reductions in cardiac death, MI and stroke at one year for patients ≤65years old

Prognosis of Patients With Familial Hypercholesterolemia After Acute Coronary Syndromes.

BACKGROUND: Patients with heterozygous familial hypercholesterolemia (FH) and coronary heart disease have high mortality rates. However, in an era of high-dose statin prescription after acute coronary syndrome (ACS), the risk of recurrent coronary and cardiovascular events associated with FH might be mitigated. We compared coronary event rates between patients with and without FH after ACS. METHODS: We studied 4534 patients with ACS enrolled in a multicenter, prospective cohort study in Switzerland between 2009 and 2013 who were individually screened for FH on the basis of clinical criteria according to 3 definitions: the American Heart Association definition, the Simon Broome definition, and the Dutch Lipid Clinic definition. We used Cox proportional models to assess the 1-year risk of first recurrent coronary events defined as coronary death or myocardial infarction and adjusted for age, sex, body mass index, smoking, hypertension, diabetes mellitus, existing cardiovascular disease, high-dose statin at discharge, attendance at cardiac rehabilitation, and the GRACE (Global Registry of Acute Coronary Events) risk score for severity of ACS. RESULTS: At the 1-year follow-up, 153 patients (3.4%) had died, including 104 (2.3%) of fatal myocardial infarction. A further 113 patients (2.5%) experienced nonfatal myocardial infarction. The prevalence of FH was 2.5% with the American Heart Association definition, 5.5% with the Simon Broome definition, and 1.6% with the Dutch Lipid Clinic definition. Compared with patients without FH, the risk of coronary event recurrence after ACS was similar in patients with FH in unadjusted analyses, although patients with FH were &gt;10 years younger. However, after multivariable adjustment including age, the risk was greater in patients with FH than without, with an adjusted hazard ratio of 2.46 (95% confidence interval, 1.07-5.65; P=0.034) for the American Heart Association definition, 2.73 (95% confidence interval, 1.46-5.11; P=0.002) for the Simon Broome definition, and 3.53 (95% confidence interval, 1.26-9.94; P=0.017) for the Dutch Lipid Clinic definition. Depending on which clinical definition of FH was used, between 94.5% and 99.1% of patients with FH were discharged on statins and between 74.0% and 82.3% on high-dose statins. CONCLUSIONS: Patients with FH and ACS have a &gt;2-fold adjusted risk of coronary event recurrence within the first year after discharge than patients without FH despite the widespread use of high-intensity statins