Categorizing models using Self-Organizing Maps: an application to modified gravity theories probed by cosmic shear

We propose to use Self-Organizing Maps (SOM) to map the impact of physical models onto observables. Using this approach, we are able to determine how theories relate to each other given their signatures. In cosmology this will be particularly useful to determine cosmological models (such as dark energy, modified gravity or inflationary models) that should be tested by the new generation of experiments. As a first example, we apply this approach to the representation of a subset of the space of modified gravity theories probed by cosmic shear. We therefore train a SOM on shear correlation functions in the f(R), dilaton and symmetron models. The results indicate these three theories have similar signatures on shear for small values of their parameters but the dilaton has different signature for higher values. We also show that modified gravity (especially the dilaton model) has a different impact on cosmic shear compared to a dynamical dark energy so both need to be tested by galaxy surveys.Comment: 6 pages, 4 figure

Noise Can Reduce Disorder in Chaotic Dynamics

We evoke the idea of representation of the chaotic attractor by the set of unstable periodic orbits and disclose a novel noise-induced ordering phenomenon. For long unstable periodic orbits forming the strange attractor the weights (or natural measure) is generally highly inhomogeneous over the set, either diminishing or enhancing the contribution of these orbits into system dynamics. We show analytically and numerically a weak noise to reduce this inhomogeneity and, additionally to obvious perturbing impact, make a regularizing influence on the chaotic dynamics. This universal effect is rooted into the nature of deterministic chaos.Comment: 11 pages, 5 figure

The LKB1-salt-inducible kinase pathway functions as a key gluconeogenic suppressor in the liver

LKB1 is a master kinase that regulates metabolism and growth through adenosine monophosphate-activated protein kinase (AMPK) and 12 other closely related kinases. Liver-specific ablation of LKB1 causes increased glucose production in hepatocytes in vitro and hyperglycaemia in fasting mice in vivo. Here we report that the salt-inducible kinases (SIK1, 2 and 3), members of the AMPK-related kinase family, play a key role as gluconeogenic suppressors downstream of LKB1 in the liver. The selective SIK inhibitor HG-9-91-01 promotes dephosphorylation of transcriptional co-activators CRTC2/3 resulting in enhanced gluconeogenic gene expression and glucose production in hepatocytes, an effect that is abolished when an HG-9-91-01-insensitive mutant SIK is introduced or LKB1 is ablated. Although SIK2 was proposed as a key regulator of insulin-mediated suppression of gluconeogenesis, we provide genetic evidence that liver-specific ablation of SIK2 alone has no effect on gluconeogenesis and insulin does not modulate SIK2 phosphorylation or activity. Collectively, we demonstrate that the LKB1-SIK pathway functions as a key gluconeogenic gatekeeper in the liver

Opioid Doses and Acute Care Utilization Outcomes for Adults with Sickle Cell Disease: Emergency Department versus Acute Care Unit

Background Acute care units (ACUs) with focused sickle cell disease (SCD) care have been shown to effectively address pain and limit hospitalizations compared to emergency departments (ED), the reason for differences in admission rates is understudied. Our aim was compare effects of usual care for adult SCD pain in ACU and ED on opioid doses and discharge pain ratings, hospital admission rates and lengths of stay. Methods In a retrospective, comparative cohort, single academic tertiary center study, 148 adults with sickle cell pain received care in the ED, ACU or both. From the medical records we documented opioid doses, unit discharge pain ratings, hospital admission rates, and lengths of stay. Findings Pain on admission to the ED averaged 8.7 ± 1.5 and to the ACU averaged 8.0 ± 1.6. The average pain on discharge from the ED was 6.4 ± 3.0 and for the ACU was 4.5 ± 2.5. 70% of the 144 ED visits resulted in hospital admissions as compared to 37% of the 73 ACU visits. Admissions from the ED or ACU had similar inpatient lengths of stay. Significant differences between ED and ACU in first opioid dose and hourly opioid dose were noted. Conclusions Applying guidelines for higher dosing of opioids for acute painful episodes in adults with SCD in ACU was associated with improved pain outcomes and decreased hospitalizations, compared to ED. Adoption of this approach for SCD pain in ED may result in improved outcomes, including a decrease in hospital admissions

The CREB coactivator TORC2 functions as a calcium- and cAMP-sensitive coincidence detector

Elevations in circulating glucose and gut hormones during feeding promote pancreatic islet cell viability in part via the calcium- and cAMP-dependent activation of the transcription factor CREB. Here, we describe a signaling module that mediates the synergistic effects of these pathways on cellular gene expression by stimulating the dephosphorylation and nuclear entry of TORC2, a CREB coactivator. This module consists of the calcium-regulated phosphatase calcineurin and the Ser/Thr kinase SIK2, both of which associate with TORC2. Under resting conditions, TORC2 is sequestered in the cytoplasm via a phosphorylation-dependent interaction with 14-3-3 proteins. Triggering of the calcium and cAMP second messenger pathways by glucose and gut hormones disrupts TORC2:14-3-3 complexes via complementary effects on TORC2 dephosphorylation; calcium influx increases calcineurin activity, whereas cAMP inhibits SIK2 kinase activity. Our results illustrate how a phosphatase/kinase module connects two signaling pathways in response to nutrient and hormonal cues

F.A.R.O.G. FORUM, Vol. 2 No. 6

https://digitalcommons.library.umaine.edu/francoamericain_forum/1006/thumbnail.jp

Age influence on effectiveness of a novel 3-phytase in barley-wheat based diets for pigs from 12 to 108 kg under commercial conditions

[EN] The main objective of this study was to evaluate the influence of pig's age on the effectiveness of a new microbial 3-phytase, produced by Komagataella phaffii, under commercial conditions in barley-wheat based diets. Two experiments were conducted in weaned, growing and finishing pigs; firstly, to determine phytase efficacy on dry matter, organic matter, energy, protein and mineral (phosphorus, P and calcium, Ca) digestibility (n = 48; Experiment 1), and secondly, to evaluate the effect of phytase on growth performance and bone mineralization (n = 312; Experiment 2). In each experiment, three barley-wheat based diets were formulated following the recommendations for each animal age, of which two versions were manufactured, including 0 and 1000 phytase units (FTU)/kg of feed of the new 3-phytase to be tested. Results showed the new phytase had the potential to increase the digestibility of Ca and P (on av. + 0.05 and +0.06, respectively; P < 0.01), especially P digestibility in growing pigs (+0.10; P < 0.001), consequently decreasing P and Ca excretion. Digestible energy (DE) of the diet increased with the addition of phytase in weaned pigs (+0.69 MJ/kg of dry matter (DM); P < 0.001). Dietary inclusion of new 3-phytase enhanced average daily gain from 46 to 94 days of age (+0.07 kg/d; P < 0.05) and decreased feed conversion ratio from 46 to 154 days of age (on av. -0.13; P < 0.05), although no significant effect was observed from 154 to 185 days of age. Addition of the new 3-phytase also promoted bone mineralization, increasing the weight of the bones (+3.99 and +3.64 g of tibia at 95 days and metacarpus at 100 days of age, respectively; P < 0.05) and the ash, Ca and P content in these bones (e.g. + 0.46 and +0.33 g of P in tibia at 95 days and metacarpus at 100 days of age, respectively; P < 0.001). In conclusion, pig age affected the efficacy of a new 3-phytase on P and Ca digestibility both in weaned and growing diets and DE content of the weaned diets, which also resulted in improvements in growth, feed conversion and bone development until 154 days of age. These effects seem to be reduced during the finishing period, although the advantages of the new 3-phytase on bone mineralization were maintained until 185 days of age.We thank the technical staff at the experimental farms of the Research and Technology Animal Centre (CITA-IVIA), the Institute of Animal Science and Technology (Universitat Politècnica de Valencia) and Javier Gómez (Crianzas Campovivo) for expert technical assistance and experimental support.Cambra López, M.; Cerisuelo, A.; Ferrer, P.; Ródenas Martínez, L.; Aligué, R.; Moset, V.; Pascual Amorós, JJ. (2020). Age influence on effectiveness of a novel 3-phytase in barley-wheat based diets for pigs from 12 to 108 kg under commercial conditions. Animal Feed Science and Technology. 267:1-13. https://doi.org/10.1016/j.anifeedsci.2020.114549S113267Adeola, O., & Cowieson, A. J. (2011). BOARD-INVITED REVIEW: Opportunities and challenges in using exogenous enzymes to improve nonruminant animal production. 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Activation of Pregnane X Receptor by Pregnenolone 16 α-carbonitrile Prevents High-Fat Diet-Induced Obesity in AKR/J Mice

Pregnane X receptor (PXR) is known to function as a xenobiotic sensor to regulate xenobiotic metabolism through selective transcription of genes responsible for maintaining physiological homeostasis. Here we report that the activation of PXR by pregnenolone 16α-carbonitrile (PCN) in AKR/J mice can prevent the development of high-fat diet-induced obesity and insulin resistance. The beneficial effects of PCN treatment are seen with reduced lipogenesis and gluconeogenesis in the liver, and lack of hepatic accumulation of lipid and lipid storage in the adipose tissues. RT-PCR analysis of genes involved in gluconeogenesis, lipid metabolism and energy homeostasis reveal that PCN treatment on high-fat diet-fed mice reduces expression in the liver of G6Pase, Pepck, Cyp7a1, Cd36, L-Fabp, Srebp, and Fas genes and slightly enhances expression of Cyp27a1 and Abca1 genes. RT-PCR analysis of genes involved in adipocyte differentiation and lipid metabolism in white adipose tissue show that PCN treatment reduces expression of Pparγ2, Acc1, Cd36, but increases expression of Cpt1b and Pparα genes in mice fed with high-fat diet. Similarly, PCN treatment of animals on high-fat diet increases expression in brown adipose tissue of Pparα, Hsl, Cpt1b, and Cd36 genes, but reduces expression of Acc1 and Scd-1 genes. PXR activation by PCN in high-fat diet fed mice also increases expression of genes involved in thermogenesis in brown adipose tissue including Dio2, Pgc-1α, Pgc-1β, Cidea, and Ucp-3. These results verify the important function of PXR in lipid and energy metabolism and suggest that PXR represents a novel therapeutic target for prevention and treatment of obesity and insulin resistance

Naturally Occurring Lipid A Mutants in Neisseria meningitidis from Patients with Invasive Meningococcal Disease Are Associated with Reduced Coagulopathy

Neisseria meningitidis is a major cause of bacterial meningitis and sepsis worldwide. Lipopolysaccharide (LPS), a major component of the Gram-negative bacterial outer membrane, is sensed by mammalian cells through Toll-like receptor 4 (TLR4), resulting in activation of proinflammatory cytokine pathways. TLR4 recognizes the lipid A moiety of the LPS molecule, and the chemical composition of the lipid A determines how well it is recognized by TLR4. N. meningitidis has been reported to produce lipid A with six acyl chains, the optimal number for TLR4 recognition. Indeed, meningococcal sepsis is generally seen as the prototypical endotoxin-mediated disease. In the present study, we screened meningococcal disease isolates from 464 patients for their ability to induce cytokine production in vitro. We found that around 9% of them were dramatically less potent than wild-type strains. Analysis of the lipid A of several of the low-activity strains by mass spectrometry revealed they were penta-acylated, suggesting a mutation in the lpxL1 or lpxL2 genes required for addition of secondary acyl chains. Sequencing of these genes showed that all the low activity strains had mutations that inactivated the lpxL1 gene. In order to see whether lpxL1 mutants might give a different clinical picture, we investigated the clinical correlate of these mutations in a prospective nationwide observational cohort study of adults with meningococcal meningitis. Patients infected with an lpxL1 mutant presented significantly less frequently with rash and had higher thrombocyte counts, consistent with reduced cytokine induction and less activation of tissue-factor mediated coagulopathy. In conclusion, here we report for the first time that a surprisingly large fraction of meningococcal clinical isolates have LPS with underacylated lipid A due to mutations in the lpxL1 gene. The resulting low-activity LPS may have an important role in virulence by aiding the bacteria to evade the innate immune system. Our results provide the first example of a specific mutation in N. meningitidis that can be correlated with the clinical course of meningococcal disease