Light-Heavy Symmetry: Geometric Mass Hierarchy for Three Families

The Universal Seesaw pattern coupled with a Light$\leftrightarrow$Heavy symmetry principle leads to the Diophantine equation $\displaystyle N = \sum_{i=1}^Nn_i$, where $n_i\geq 0$ and distinct. Its unique non-trivial solution $(3=0+1+2)$ gives rise to the geometric mass hierarchy $m_W$, $m_W\epsilon$, $m_W\epsilon^2$ for $N=3$ fermion families. This is realized in a model where the hybrid (yet Up$\leftrightarrow$Down symmetric) quark mass relations $m_d m_t \approx m_c^2\leftrightarrow m_u m_b \approx m_s^2$ play a crucial role in expressing the CKM mixings in terms of simple mass ratios, notably $\sin\theta_C \approx {m_c\over m_b}$.Comment: 12 pages, no figures, Revtex fil

QT interval dynamics in patients with ST-elevation MI

BackgroundAn association between excessively prolonged QT and ventricular arrhythmia in patients with ST-elevation myocardial infarction has been described; however, the QT dynamics, characterization, and long-term predictive value are not well known.ObjectiveTo characterize QT interval dynamics in patients undergoing ST elevation myocardial infarction (STEMI) and determine its association with mortality.MethodsA retrospective analysis of 4,936 consecutive patients, hospitalized for STEMI between 01/2013–12/2021. Patients with less than three electrocardiograms (ECGs) during index hospitalization were excluded. Baseline demographics, cardiovascular history, clinical risk factors, treatment measures, laboratory results, and mortality data were retrieved from the hospital’s electronic medical records.ResultsWe included 1,054 patients and 5,021 ECGs in our cohort with a median follow-up of 6 years [interquartile range (IQR) 4.3–7.4 years]. The QT was longer in women in comparison to men (428.6 ms ± 33.4 versus 419.8 ms ± 32.52, P-value = 0.001). QT prolongation was greater in females, elderly patients, and patients with STEMI caused by occlusion of the left anterior descending (LAD) coronary artery. We determined QT cutoff to be 445 ms. This value of QT divided our cohort upon arrival into a long QT group (217 patients, 26% of the cohort) and a “normal” QT group (835 patients, 74% of the cohort). The long QT group experienced an increase in combined short and long terms all-cause mortality. The QT upon arrival, on day 2 of hospitalization, and before discharge from the hospital, correlated with long-term mortality.ConclusionQT duration is often prolonged during STEMI; this prolongation is associated with increased mortality and adverse events. Gender is an important mediator of QT dynamics

Linking Geometric Mass Hierarchy with Threefold Family Replication

A link is established between the observed (approximate) geometric mass hierarchy of quarks and leptons and the triangular structure of their tenable flavor representations. This singles out SU(3) as the horizontal flavor group, thereby linking the Fermi mass hierarchy with the threefold family replication. These linkages are exploited within a flavor-chiral SU(3) model, with fermions and Higgs bosons in the 3+6* representation. The model is Left-Right symmetric and utilizes the universal see-saw mechanism with a geometric mass suppression pattern. Given certain assumptions, the model produces successful mass-ratio (rather than square-mass-ratio) mixing angle relations and fixes the light quark mass ratio.Comment: Revtex, 11 twocolumn pages, No figure

The use of virtual reality simulation to determine potential for endoscopic surgery skill acquisition

Background: Efficient acquisition of endoscopic technique is essential for high-level care in surgical practice. In contrast to similar substantial risk industries, there is no standard instrument capable of detecting the potential of surgical residency candidates to develop such skills. Material and methods: We used the Simbionix "Lapmentor" Virtual reality simulator basic skills tasks 1, 5 and 6 to establish baseline performance of 17 subjects lacking surgical experience, then divided them into two groups. One group trained on the Lapmentor, a validated trainer. The second group trained on a video box trainer using 3 FLS tasks, which correlate with real OR performance. After completing the training program, each group was tested on its training modality and correlations were sought between performance in the screening tasks and final scores in both groups. Results: Time in Lapmentor task 1 showed significant correlations with total FLS scores (R 0.807 P 0.015), in addition to other benchmark parameters. With the Lapmentor group, time on task 5 demonstrated correlation with itself on the final scores (R 0.794 P 0.011). Conclusions: Time in the Lapmentor task 1 demonstrates correlations with FLS scores, which translate to better OR performance. The Lapmentor thus shows potential to be used as a screening test for surgical talent

Increased A-to-I RNA editing in atherosclerosis and cardiomyopathies.

Adenosine-to-inosine RNA editing is essential to prevent undesired immune activation. This diverse process alters the genetic content of the RNA and may recode proteins, change splice sites and miRNA targets, and mimic genomic mutations. Recent studies have associated or implicated aberrant editing with pathological conditions, including cancer, autoimmune diseases, and neurological and psychiatric conditions. RNA editing patterns in cardiovascular tissues have not been investigated systematically so far, and little is known about its potential role in cardiac diseases. Some hints suggest robust editing in this system, including the fact that ADARB1 (ADAR2), the main coding-sequence editor, is most highly expressed in these tissues. Here we characterized RNA editing in the heart and arteries and examined a contributory role to the development of atherosclerosis and two structural heart diseases -Ischemic and Dilated Cardiomyopathies. Analyzing hundreds of RNA-seq samples taken from the heart and arteries of cardiac patients and controls, we find that global editing, alongside inflammatory gene expression, is increased in patients with atherosclerosis, cardiomyopathies, and heart failure. We describe a single recoding editing site and suggest it as a target for focused research. This recoding editing site in the IGFBP7 gene is one of the only evolutionary conserved sites between mammals, and we found it exhibits consistently increased levels of editing in these patients. Our findings reveal that RNA editing is abundant in arteries and is elevated in several key cardiovascular conditions. They thus provide a roadmap for basic and translational research of RNA as a mediator of atherosclerosis and non-genetic cardiomyopathies

Evaluation of Nitrate Nitrogen Fluxes from a Tile-Drained Watershed in Central Iowa

Nitrate Nfluxes fromtile-drained watersheds have been implicated in water quality studies of the Mississippi River basin, but actual NO3–N loads from small watersheds during long periods are poorly documented. We evaluated discharge and NO3–N fluxes passing the outlet of an Iowa watershed (5134 ha) and two of its tile-drained subbasins (493 and 863 ha) from mid-1992 through 2000. The cumulative NO3–N load from the catchment was 168 kg ha-1, and 176 and 229 kg ha-1 from the subbasins. The outlet had greater total discharge (1831 mm) and smaller flow-weighted mean NO3–N concentration (9.2 mg L-1) than the subbasins, while the larger subbasin had greater discharge (1712 vs. 1559 mm) and mean NO3–N concentration (13.4 vs. 11.3 mg L-1) than the smaller subbasin. Concentrations exceeding 10 mg L-1 were common, but least frequent at the outlet. Nitrate N was generally not diluted by large flows, except during 1993 flooding. The outlet showed smaller NO3–N concentrations at low flows. Relationships between discharge and NO3–N flux showed log–log slopes near 1.0 for the subbasins, and 1.2 for the outlet, considering autocorrelation and measurement-error effects. We estimated denitrification of subbasin NO3–N fluxes in a hypothetical wetland using published data. Assuming that temperature and NO3–N supply could limit denitrification, then about 20%of the NO3–N would have been denitrified by a wetland constructed to meet USDA-approved criteria. The low efficiency results from the seasonal timing and NO3–N content of large flows. Therefore, agricultural and wetland best management practices (BMPs) are needed to achieve water quality goals in tile-drained watersheds

Targeting Kruppel-like Factor 9 in Excitatory Neurons Protects against Chronic Stress-Induced Impairments in Dendritic Spines and Fear Responses

Summary: Stress exposure is associated with the pathogenesis of psychiatric disorders, including post-traumatic stress disorder (PTSD) and major depressive disorder (MDD). Here, we show in rodents that chronic stress exposure rapidly and transiently elevates hippocampal expression of Kruppel-like factor 9 (Klf9). Inducible genetic silencing of Klf9 expression in excitatory forebrain neurons in adulthood prior to, but not after, onset of stressor prevented chronic restraint stress (CRS)-induced potentiation of contextual fear acquisition in female mice and chronic corticosterone (CORT) exposure-induced fear generalization in male mice. Klf9 silencing prevented chronic CORT and CRS induced enlargement of dendritic spines in the ventral hippocampus of male and female mice, respectively. KLF9 mRNA density was increased in the anterior dentate gyrus of women, but not men, with more severe recent stressful life events and increased mortality. Thus, Klf9 functions as a stress-responsive transcription factor that mediates circuit and behavioral resilience in a sex-specific manner. : Besnard et al. show that chronic stress induces a transient elevation in hippocampal Klf9 expression in mice and that KLF9 expression is upregulated in hippocampus of women with MDD. Genetic silencing of Klf9 expression prevents chronic stress-induced enlargements of dendritic spines and maladaptive fear responses in male and female mice. Keywords: stress, dendritic spines, fear generalization, hippocampus, Klf9, dentate gyrus, CA1, PTSD, MDD, corticosteron