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The history of model railroading the the Walthers 1970 O Scale Catalog

Tangled Bank posted a photo:




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‘My Ting Different’ - Tosh Alexander blends R&B and dancehall on new single

Dynamic singer Tosh Alexander has been lighting up the music scene with her latest track, ' My Ting Different', a thrilling collaboration with American rapper and songwriter Lady London. The song fuses R...




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Polydisperse molecular architecture of connexin 26/30 heteromeric hemichannels revealed by atomic force microscopy imaging [Protein Structure and Folding]

Connexin (Cx) protein forms hemichannels and gap junctional channels, which play diverse and profound roles in human physiology and diseases. Gap junctions are arrays of intercellular channels formed by the docking of two hemichannels from adjacent cells. Each hexameric hemichannel contains the same or different Cx isoform. Although homomeric Cxs forms have been largely described functionally and structurally, the stoichiometry and arrangement of heteromeric Cx channels remain unknown. The latter, however, are widely expressed in human tissues and variation might have important implications on channel function. Investigating properties of heteromeric Cx channels is challenging considering the high number of potential subunit arrangements and stoichiometries, even when only combining two Cx isoforms. To tackle this problem, we engineered an HA tag onto Cx26 or Cx30 subunits and imaged hemichannels that were liganded by Fab-epitope antibody fragments via atomic force microscopy. For Cx26-HA/Cx30 or Cx30-HA/Cx26 heteromeric channels, the Fab-HA binding distribution was binomial with a maximum of three Fab-HA bound. Furthermore, imaged Cx26/Cx30-HA triple liganded by Fab-HA showed multiple arrangements that can be derived from the law of total probabilities. Atomic force microscopy imaging of ringlike structures of Cx26/Cx30-HA hemichannels confirmed these findings and also detected a polydisperse distribution of stoichiometries. Our results indicate a dominant subunit stoichiometry of 3Cx26:3Cx30 with the most abundant subunit arrangement of Cx26-Cx26-Cx30-Cx26-Cx30-Cx30. To our knowledge, this is the first time that the molecular architecture of heteromeric Cx channels has been revealed, thus providing the basis to explore the functional effect of these channels in biology.




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Determinants of replication protein A subunit interactions revealed using a phosphomimetic peptide [Molecular Biophysics]

Replication protein A (RPA) is a eukaryotic ssDNA-binding protein and contains three subunits: RPA70, RPA32, and RPA14. Phosphorylation of the N-terminal region of the RPA32 subunit plays an essential role in DNA metabolism in processes such as replication and damage response. Phosphorylated RPA32 (pRPA32) binds to RPA70 and possibly regulates the transient RPA70-Bloom syndrome helicase (BLM) interaction to inhibit DNA resection. However, the structural details and determinants of the phosphorylated RPA32–RPA70 interaction are still unknown. In this study, we provide molecular details of the interaction between RPA70 and a mimic of phosphorylated RPA32 (pmRPA32) using fluorescence polarization and NMR analysis. We show that the N-terminal domain of RPA70 (RPA70N) specifically participates in pmRPA32 binding, whereas the unphosphorylated RPA32 does not bind to RPA70N. Our NMR data revealed that RPA70N binds pmRPA32 using a basic cleft region. We also show that at least 6 negatively charged residues of pmRPA32 are required for RPA70N binding. By introducing alanine mutations into hydrophobic positions of pmRPA32, we found potential points of contact between RPA70N and the N-terminal half of pmRPA32. We used this information to guide docking simulations that suggest the orientation of pmRPA32 in complex with RPA70N. Our study demonstrates detailed features of the domain-domain interaction between RPA70 and RPA32 upon phosphorylation. This result provides insight into how phosphorylation tunes transient bindings between RPA and its partners in DNA resection.




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MMP activation-associated aminopeptidase N reveals a bivalent 14-3-3 binding motif [Protein Structure and Folding]

Aminopeptidase N (APN, CD13) is a transmembrane ectopeptidase involved in many crucial cellular functions. Besides its role as a peptidase, APN also mediates signal transduction and is involved in the activation of matrix metalloproteinases (MMPs). MMPs function in tissue remodeling within the extracellular space and are therefore involved in many human diseases, such as fibrosis, rheumatoid arthritis, tumor angiogenesis, and metastasis, as well as viral infections. However, the exact mechanism that leads to APN-driven MMP activation is unclear. It was previously shown that extracellular 14-3-3 adapter proteins bind to APN and thereby induce the transcription of MMPs. As a first step, we sought to identify potential 14-3-3–binding sites in the APN sequence. We constructed a set of phosphorylated peptides derived from APN to probe for interactions. We identified and characterized a canonical 14-3-3–binding site (site 1) within the flexible, structurally unresolved N-terminal APN region using direct binding fluorescence polarization assays and thermodynamic analysis. In addition, we identified a secondary, noncanonical binding site (site 2), which enhances the binding affinity in combination with site 1 by many orders of magnitude. Finally, we solved crystal structures of 14-3-3σ bound to mono- and bis-phosphorylated APN-derived peptides, which revealed atomic details of the binding mode of mono- and bivalent 14-3-3 interactions. Therefore, our findings shed some light on the first steps of APN-mediated MMP activation and open the field for further investigation of this important signaling pathway.




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Addressing Climate Catastrophe Concerns in Asthma Medication Delivery: Rethinking Inhaler Use for Environmental and Clinical Efficacy




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Secretory galectin-3 induced by glucocorticoid stress triggers stemness exhaustion of hepatic progenitor cells [Signal Transduction]

Adult progenitor cell populations typically exist in a quiescent state within a controlled niche environment. However, various stresses or forms of damage can disrupt this state, which often leads to dysfunction and aging. We built a glucocorticoid (GC)-induced liver damage model of mice, found that GC stress induced liver damage, leading to consequences for progenitor cells expansion. However, the mechanisms by which niche factors cause progenitor cells proliferation are largely unknown. We demonstrate that, within the liver progenitor cells niche, Galectin-3 (Gal-3) is responsible for driving a subset of progenitor cells to break quiescence. We show that GC stress causes aging of the niche, which induces the up-regulation of Gal-3. The increased Gal-3 population increasingly interacts with the progenitor cell marker CD133, which triggers focal adhesion kinase (FAK)/AMP-activated kinase (AMPK) signaling. This results in the loss of quiescence and leads to the eventual stemness exhaustion of progenitor cells. Conversely, blocking Gal-3 with the inhibitor TD139 prevents the loss of stemness and improves liver function. These experiments identify a stress-dependent change in progenitor cell niche that directly influence liver progenitor cell quiescence and function.




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Myeloid deletion and therapeutic activation of AMPK do not alter atherosclerosis in male or female mice

Nicholas D. LeBlond
Dec 1, 2020; 61:1697-1706
Research Articles




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Myeloid deletion and therapeutic activation of AMPK do not alter atherosclerosis in male or female mice [Research Articles]

The dysregulation of myeloid-derived cell metabolism can drive atherosclerosis. AMP-activated protein kinase (AMPK) controls various aspects of macrophage dynamics and lipid homeostasis, which are important during atherogenesis. Using LysM-Cre to drive the deletion of both the α1 and α2 catalytic subunits (MacKO), we aimed to clarify the role of myeloid-specific AMPK signaling in male and female mice made acutely atherosclerotic by injection of AAV vector encoding a gain-of-function mutant PCSK9 (PCSK9-AAV) and WD feeding. After 6 weeks of WD feeding, mice received a daily injection of either the AMPK activator A-769662 or a vehicle control for an additional 6 weeks. Following this (12 weeks total), we assessed myeloid cell populations and differences between genotype or sex were not observed. Similarly, aortic sinus plaque size, lipid staining, and necrotic area did not differ in male and female MacKO mice compared with their littermate floxed controls. Moreover, therapeutic intervention with A-769662 showed no treatment effect. There were also no observable differences in the amount of circulating total cholesterol or triglyceride, and only minor differences in the levels of inflammatory cytokines between groups. Finally, CD68+ area and markers of autophagy showed no effect of either lacking AMPK signaling or AMPK activation. Our data suggest that while defined roles for each catalytic AMPK subunit have been identified, complete deletion of myeloid AMPK signaling does not significantly impact atherosclerosis. Additionally, these findings suggest that intervention with the first-generation AMPK activator A-769662 is not able to stem the progression of atherosclerosis.




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Radiosensitization by Kinase Inhibition Revealed by Phosphoproteomic Analysis of Pancreatic Cancer Cells [Research]

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive cancers and known for its extensive genetic heterogeneity, high therapeutic resistance, and strong variation in intrinsic radiosensitivity. To understand the molecular mechanisms underlying radioresistance, we screened the phenotypic response of 38 PDAC cell lines to ionizing radiation. Subsequent phosphoproteomic analysis of two representative sensitive and resistant lines led to the reproducible identification of 7,800 proteins and 13,000 phosphorylation sites (p-sites). Approximately 700 p-sites on 400 proteins showed abundance changes after radiation in all cell lines regardless of their phenotypic sensitivity. Apart from recapitulating known radiation response phosphorylation markers such as on proteins involved in DNA damage repair, the analysis uncovered many novel members of a radiation-responsive signaling network that was apparent only at the level of protein phosphorylation. These regulated p-sites were enriched in potential ATM substrates and in vitro kinase assays corroborated 10 of these. Comparing the proteomes and phosphoproteomes of radiosensitive and -resistant cells pointed to additional tractable radioresistance mechanisms involving apoptotic proteins. For instance, elevated NADPH quinine oxidoreductase 1 (NQO1) expression in radioresistant cells may aid in clearing harmful reactive oxygen species. Resistant cells also showed elevated phosphorylation levels of proteins involved in cytoskeleton organization including actin dynamics and focal adhesion kinase (FAK) activity and one resistant cell line showed a strong migration phenotype. Pharmacological inhibition of the kinases FAK by Defactinib and of CHEK1 by Rabusertib showed a statistically significant sensitization to radiation in radioresistant PDAC cells. Together, the presented data map a comprehensive molecular network of radiation-induced signaling, improves the understanding of radioresistance and provides avenues for developing radiotherapeutic strategies.




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Quelles sont les principales pathologies en gastroentérologie ?

Les troubles gastro-intestinaux peuvent avoir un impact significatif sur la qualité de vie des patients. Ils engendrent en effet des symptômes variés et inconfortables allant de douleurs abdominales et nausées à des troubles plus graves comme les maladies inflammatoires chroniques de l’intestin. Quelles sont les principales pathologies rencontrées dans cette spécialité de la médecine ? À quel […]

L’article Quelles sont les principales pathologies en gastroentérologie ? est apparu en premier sur Ortho Doc France.




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Integrated glycoproteomics identifies a role of N-glycosylation and galectin-1 on myogenesis and muscle development [Research]

Many cell surface and secreted proteins are modified by the covalent addition of glycans that play an important role in the development of multicellular organisms. These glycan modifications enable communication between cells and the extracellular matrix via interactions with specific glycan-binding lectins and the regulation of receptor-mediated signaling. Aberrant protein glycosylation has been associated with the development of several muscular diseases suggesting essential glycan- and lectin-mediated functions in myogenesis and muscle development but our molecular understanding of the precise glycans, catalytic enzymes and lectins involved remain only partially understood. Here, we quantified dynamic remodeling of the membrane-associated proteome during a time-course of myogenesis in cell culture. We observed wide-spread changes in the abundance of several important lectins and enzymes facilitating glycan biosynthesis. Glycomics-based quantification of released N-linked glycans confirmed remodeling of the glycome consistent with the regulation of glycosyltransferases and glycosidases responsible for their formation including a previously unknown di-galactose-to-sialic acid switch supporting a functional role of these glycoepitopes in myogenesis. Furthermore, dynamic quantitative glycoproteomic analysis with multiplexed stable isotope labelling and analysis of enriched glycopeptides with multiple fragmentation approaches identified glycoproteins modified by these regulated glycans including several integrins and growth factor receptors. Myogenesis was also associated with the regulation of several lectins most notably the up-regulation of galectin-1 (LGALS1). CRISPR/Cas9-mediated deletion of Lgals1 inhibited differentiation and myotube formation suggesting an early functional role of galectin-1 in the myogenic program. Importantly, similar changes in N-glycosylation and the up-regulation of galectin-1 during postnatal skeletal muscle development were observed in mice. Treatment of new-born mice with recombinant adeno-associated viruses to overexpress galectin-1 in the musculature resulted in enhanced muscle mass. Our data form a valuable resource to further understand the glycobiology of myogenesis and will aid the development of intervention strategies to promote healthy muscle development or regeneration.




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Healthcare comes to standstill in east Aleppo as last hospitals are destroyed




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Angola Forum 2018: 30th Anniversary of the Battle of Cuito Cuanavale

Angola Forum 2018: 30th Anniversary of the Battle of Cuito Cuanavale 23 March 2018 — 10:00AM TO 2:30PM Anonymous (not verified) 8 March 2018 Chatham House, London

Reflections on Southern Africa’s Turning Point

23 March 2018 marks the 30th anniversary of the final assault of what became known as the Battle of Cuito Cuanavale.

The confrontation between the Angolan army, supported by Cuba and the Soviet Union, and the armed opposition UNITA, supported by the South African Defence Force, is the largest land battle to have taken place in Africa since World War Two.

The battle was a watershed in Angolan and southern African history, but its significance continues to be contested. Today, although the battlefield has a monument and museum, it remains one of the most landmine-contaminated parts of Angola and this hinders development plans for international tourism.

This event brings together veterans and experts to contribute towards developing a deeper understanding of the battle. Discussions will further focus on the significance of the wider events around the battle, its regional implications, as well as the legacy of the battlefield.




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GP leaders in Wales reject contract offer

General practice leaders in Wales have voted unanimously to reject the Welsh government’s GP contract offer for 2024-25.The BMA’s ​General Practitioners Committee Wales said the government’s general medical services contract offer for the current financial year “fails to provide a credible and sustainable future” for general practice.GPs in Wales will now vote on whether to accept or reject the contract in a referendum that will open later this month.Gareth Oelmann, chair of the committee, said, “The decision to disregard the serious concerns and valuable contribution of general practice in Wales is beyond insulting, it is dangerous, leaving more surgeries and their patients in peril. We are concerned that this offer will leave more practices with no option but to close. GPs are being denied the resources they need to deliver vital services to the population.”The BMA said it was not yet able to disclose any details on the offer, and...




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Theranostic GPA33-Pretargeted Radioimmunotherapy of Human Colorectal Carcinoma with a Bivalent 177Lu-Labeled Radiohapten

Radiolabeled small-molecule DOTA-haptens can be combined with antitumor/anti-DOTA bispecific antibodies (BsAbs) for pretargeted radioimmunotherapy (PRIT). For optimized delivery of the theranostic - and β-emitting isotope 177Lu with DOTA-based PRIT (DOTA-PRIT), bivalent Gemini (DOTA-Bn-thiourea-PEG4-thiourea-Bn-DOTA, aka (3,6,9,12-tetraoxatetradecane-1,14-diyl)bis(DOTA-benzyl thiourea)) was developed. Methods: Gemini was synthesized by linking 2 S-2-(4-isothiocyanatobenzyl)-DOTA molecules together via a 1,14-diamino-PEG4 linker. [177Lu]Lu-Gemini was prepared with no-carrier-added 177LuCl3 to a molar-specific activity of 123 GBq/μmol and radiochemical purity of more than 99%. The specificity of BsAb-177Lu-Gemini was verified in vitro. Subsequently, we evaluated biodistribution and whole-body clearance for [177Lu]Lu-Gemini and, for comparison, our gold-standard monovalent [177Lu]Lu-S-2-(4-aminobenzyl)-DOTA ([177Lu]Lu-DOTA-Bn) in naïve (tumor-free) athymic nude mice. For our proof-of-concept system, a 3-step pretargeting approach was performed with an established DOTA-PRIT regimen (anti-GPA33/anti-DOTA IgG-scFv BsAb, a clearing agent, and [177Lu]Lu-Gemini) in mouse models. Results: Initial in vivo studies showed that [177Lu]Lu-Gemini behaved similarly to [177Lu]Lu-DOTA-Bn, with almost identical blood and whole-body clearance kinetics, as well as biodistribution and mouse kidney dosimetry. Pretargeting [177Lu]Lu-Gemini to GPA33-expressing SW1222 human colorectal xenografts was highly effective, leading to absorbed doses of [177Lu]Lu-Gemini for blood, tumor, liver, spleen, and kidneys of 3.99, 455, 6.93, 5.36, and 14.0 cGy/MBq, respectively. Tumor–to–normal tissue absorbed-dose ratios (i.e., therapeutic indices [TIs]) for the blood and kidneys were 114 and 33, respectively. In addition, we demonstrate that the use of bivalent [177Lu]Lu-Gemini in DOTA-PRIT leads to improved TIs and augmented [177Lu]Lu-Gemini tumor uptake and retention in comparison to monovalent [177Lu]Lu-DOTA-Bn. Finally, we established efficacy in SW1222 tumor-bearing mice, demonstrating that a single injection of anti-GPA33 DOTA-PRIT with 44 MBq (1.2 mCi) of [177Lu]Lu-Gemini (estimated tumor-absorbed dose, 200 Gy) induced complete responses in 5 of 5 animals and a histologic cure in 2 of 5 (40%) animals. Moreover, a significant increase in survival compared with nontreated controls was noted (maximum tolerated dose not reached). Conclusion: We have developed a bivalent DOTA-radiohapten, [177Lu]Lu-Gemini, that showed improved radiopharmacology for DOTA-PRIT application. The use of bivalent [177Lu]Lu-Gemini in DOTA-PRIT, as opposed to monovalent [177Lu]Lu-DOTA-Bn, allows curative treatments with considerably less administered 177Lu activity while still achieving high TIs for both the blood (>100) and the kidneys (>30).




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Preclinical Evaluation of 177Lu-OncoFAP-23, a Multivalent FAP-Targeted Radiopharmaceutical Therapeutic for Solid Tumors

Fibroblast activation protein (FAP) is abundantly expressed in the stroma of most human solid tumors. Clinical-stage radiolabeled FAP ligands are increasingly used as tools for the detection of various cancer lesions. To unleash the full therapeutic potential of FAP-targeting agents, ligands need to remain at the tumor site for several days after administration. We recently described the discovery of OncoFAP, a high-affinity small organic ligand of FAP with a rapid accumulation in tumors and low uptake in healthy tissues in cancer patients. Trimerization of OncoFAP provided a derivative (named TriOncoFAP, or OncoFAP-23) with improved FAP affinity. In this work, we evaluated the tissue biodistribution profile and the therapeutic performance of OncoFAP-23 in tumor-bearing mice. Methods: OncoFAP-23 was radiolabeled with the theranostic radionuclide 177Lu. Preclinical experiments were conducted on mice bearing SK-RC-52.hFAP (BALB/c nude mice) or CT-26.hFAP (BALB/c mice) tumors. 177Lu-OncoFAP and 177Lu-FAP-2286 were included in the biodistribution study as controls. Toxicologic evaluation was performed on Wistar rats and CD1 mice by injecting high doses of OncoFAP-23 or its cold-labeled counterpart, respectively. Results: 177Lu-OncoFAP-23 emerged for its best-in-class biodistribution profile, high and prolonged tumor uptake (i.e., ~16 percentage injected dose/g at 96 h), and low accumulation in healthy organs, which correlates well with its potent single-agent anticancer activity at low levels of administered radioactivity. Combination treatment with the tumor-targeted interleukin 2 (L19-IL2, a clinical-stage immunocytokine) further expands the therapeutic window of 177Lu-OncoFAP-23 by potentiating its in vivo antitumor activity. Proteomics studies revealed a potent tumor-directed immune response on treatment with the combination. OncoFAP-23 and natLu-OncoFAP-23 exhibited a favorable toxicologic profile, without showing any side effects or signs of toxicity. Conclusion: OncoFAP-23 presents enhanced tumor uptake and tumor retention and low accumulation in healthy organs, findings that correspond to a strongly improved in vivo antitumor efficacy. The data presented in this work support the clinical development of 177Lu-OncoFAP-23 for the treatment of FAP-positive solid tumors.




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Capitals' Alex Ovechkin nets game winner vs. Predators, extends goal streak

Alex Ovechkin calmly slid into the right circle and sniped a snapshot past a blinded Juuse Saros to lead the Washington Capitals to a 3-2 triumph over the Nashville Predators.




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Chicago Bears fire offensive coordinator Shane Waldron, commit to QB Caleb Williams

Chicago Bears coach Matt Eberflus has fired offensive coordinator Shane Waldron, the team said Tuesday. The dismissal came less than a day after Eberflus committed to quarterback Caleb Williams, but promised "changes."




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Leveraging Exascale Era Technology for Advanced Computer-Aided Engineering

How can manufacturers apply lessons learned from the dawn of the “Exascale Era” to Computer-Aided Engineering to achieve results like never before? Join Addison Snell, CEO, Intersect360 Research, Bill Mannel, VP, High Performance […]

The post Leveraging Exascale Era Technology for Advanced Computer-Aided Engineering appeared first on HPCwire.




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Valentine's Day Got You Blue? There's an Upside

Unpleasant emotions like sadness and anger can feel overwhelming, but recent research suggests they can trigger behaviors that lead to something better





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Dwayne Johnson sings female empowerment song in 'Moana 2'

Dwayne Johnson sings a female empowerment song, titled "Can I Get a Chee Hoo?" in the upcoming "Moana" sequel.




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The Best Exercise For Brain Health Revealed By 98 Studies

Which types of exercise can help keep the brain healthy?



  • Boost Brain Power

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A bold plan to rewild the Earth — at massive scale | Kristine McDivitt Tompkins

The first step to saving nature is the rewilding of our own minds, says conservationist and former Patagonia CEO Kristine McDivitt Tompkins. With an unwavering commitment to protecting ecosystems, she and her late husband Douglas Tompkins created vast conservation parks across South America that allowed ancient flora and fauna to flourish once again. Now, she's carrying that legacy and mission forward with a bold plan to connect parks across geographic boundaries, creating a system of continental-scale wildlife corridors — before it's too late.




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What’s the future of food? A chef and a cardiologist answer | Jon Kung and Uma Valeti

What does food mean to you, your community and our planet? With ​​personal accounts from the kitchen to the operating room, chef and content creator Jon Kung and cardiologist Uma Valeti unpack how food cultivates creativity and offers opportunities to connect with and blend cultures. Exploring Valeti’s experiences developing a healthier meat alternative, they discuss what it takes to overcome the impossible — whether that’s saving a patient’s life or transforming ideas around traditional foods — and how we can all make steps towards more sustainable cooking.




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Can AI preserve your most precious memories? | Pau Aleikum Garcia

"Memories are the architects of our identity," says technologist Pau Aleikum Garcia, but they're not permanent. Photos can be lost amid political unrest or natural disaster, while illnesses like Alzhemier's can rob people of their past. He puts forward a novel solution — "synthetic memories," or dreamlike visualizations of long-gone moments created through generative AI — and explores how it could reconnect families or even enhance cognitive abilities.




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Budget Cuts Lead Wyoming to Scale Back Relationship With Accrediting Agency

AdvancED, the national accreditation company, has for the last two years operated Wyoming's entire accreditation process but the state will now do the work on its own.




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After Okla. Historic Pay Raise, Morale Is Up—But Teacher Shortage Persists

Despite a $6,100 teacher pay raise this spring, school districts report that they're starting the new academic year with nearly 500 teaching vacancies.




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Alexander preaches consensus in farewell to fractious Senate




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U.S. Backs Idaho Law Limiting Sports Participation by Transgender Females

In a case involving a transgender track athlete, the Trump administration says female transgender athletes are seeking "special treatment" to compete in girls' or women's sports.




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Judge Blocks Idaho Law Limiting Sports Participation by Transgender Females

The judge said the law likely discriminates on the basis of transgender status in violation of the equal-protection clause of the U.S. Constitution.




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Why CFP committee moved Indiana, BYU ahead of Tennessee. It wasn't Nico Iamaleava injury

Tennessee won easily over Mississippi State. Indiana and BYU won nail-biters. So why did they jump over the Vols? We asked the CFP committee chair.




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Alexis Markowski named to Wooden Award Watch List

Nebraska women’s basketball star Alexis Markowski was named to the Preseason Women’s Top 50 Watch List for the John R. Wooden Award. This news was confirmed on Thursday per a release from the athletic department. The award is given annually to that season's mos




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Openbook’s autumn edition showcases diverse talents of Australia’s creative community

Wednesday 6 March 2024
Showcasing diverse talents of Australia’s creative community.




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Multiscale Computer Model of the Spinal Dorsal Horn Reveals Changes in Network Processing Associated with Chronic Pain

Laura Medlock
Apr 13, 2022; 42:3133-3149
Systems/Circuits




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Diurnal Fluctuations in Steroid Hormones Tied to Variation in Intrinsic Functional Connectivity in a Densely Sampled Male

Hannah Grotzinger
May 29, 2024; 44:e1856232024-e1856232024
BehavioralSystemsCognitive




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Circadian Rhythms Tied to Changes in Brain Morphology in a Densely Sampled Male

Elle M. Murata
Sep 18, 2024; 44:e0573242024-e0573242024
BehavioralSystemsCognitive




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Mapping Human Cortical Areas In Vivo Based on Myelin Content as Revealed by T1- and T2-Weighted MRI

Matthew F. Glasser
Aug 10, 2011; 31:11597-11616
BehavioralSystemsCognitive




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Multiple Intrinsic Timescales Govern Distinct Brain States in Human Sleep

Human sleep exhibits multiple, recurrent temporal regularities, ranging from circadian rhythms to sleep stage cycles and neuronal oscillations during nonrapid eye movement sleep. Moreover, recent evidence revealed a functional role of aperiodic activity, which reliably discriminates different sleep stages. Aperiodic activity is commonly defined as the spectral slope of the 1/frequency (1/f) decay function of the electrophysiological power spectrum. However, several lines of inquiry now indicate that the aperiodic component of the power spectrum might be better characterized by a superposition of several decay processes with associated timescales. Here, we determined multiple timescales, which jointly shape aperiodic activity using human intracranial electroencephalography. Across three independent studies (47 participants, 23 female), our results reveal that aperiodic activity reliably dissociated sleep stage-dependent dynamics in a regionally specific manner. A principled approach to parametrize aperiodic activity delineated several, spatially and state-specific timescales. Lastly, we employed pharmacological modulation by means of propofol anesthesia to disentangle state-invariant timescales that may reflect physical properties of the underlying neural population from state-specific timescales that likely constitute functional interactions. Collectively, these results establish the presence of multiple intrinsic timescales that define the electrophysiological power spectrum during distinct brain states.




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Erratum: Rosenberg et al., "{beta}-Adrenergic Signaling Promotes Morphological Maturation of Astrocytes in Female Mice"




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Dynamic Organization of Neuronal Extracellular Matrix Revealed by HaloTag-HAPLN1

The brain's extracellular matrix (ECM) regulates neuronal plasticity and animal behavior. ECM staining shows a net-like structure around a subset of neurons, a ring-like structure at the nodes of Ranvier, and diffuse staining in the interstitial matrix. However, understanding the structural features of ECM deposition across various neuronal types and subcellular compartments remains limited. To visualize the organization pattern and assembly process of the hyaluronan-scaffolded ECM in the brain, we fused a HaloTag to hyaluronan proteoglycan link protein 1, which links hyaluronan and proteoglycans. Expression or application of the probe in primary rat neuronal cultures enables us to identify spatial and temporal regulation of ECM deposition and heterogeneity in ECM aggregation among neuronal populations. Dual-color birthdating shows the ECM assembly process in culture and in vivo. Sparse expression in mouse brains of either sex reveals detailed ECM architectures around excitatory neurons and developmentally regulated dendritic ECM. Our study uncovers extensive structural features of the brain's ECM, suggesting diverse roles in regulating neuronal plasticity.




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Differential Encoding of Two-Tone Harmonics in the Male and Female Mouse Auditory Cortex

Harmonics are an integral part of music, speech, and vocalizations of animals. Since the rest of the auditory environment is primarily made up of nonharmonic sounds, the auditory system needs to perceptually separate the above two kinds of sounds. In mice, harmonics, generally with two-tone components (two-tone harmonic complexes, TTHCs), form an important component of vocal communication. Communication by pups during isolation from the mother and by adult males during courtship elicits typical behaviors in female mice—dams and adult courting females, respectively. Our study shows that the processing of TTHC is specialized in mice providing neural basis for perceptual differences between tones and TTHCs and also nonharmonic sounds. Investigation of responses in the primary auditory cortex (Au1) from in vivo extracellular recordings and two-photon Ca2+ imaging of excitatory and inhibitory neurons to TTHCs exhibit enhancement, suppression, or no-effect with respect to tones. Irrespective of neuron type, harmonic enhancement is maximized, and suppression is minimized when the fundamental frequencies (F0) match the neuron's best fundamental frequency (BF0). Sex-specific processing of TTHC is evident from differences in the distributions of neurons’ best frequency (BF) and best fundamental frequency (BF0) in single units, differences in harmonic suppressed cases re-BF0, independent of neuron types, and from pairwise noise correlations among excitatory and parvalbumin inhibitory interneurons. Furthermore, TTHCs elicit a higher response compared with two-tone nonharmonics in females, but not in males. Thus, our study shows specialized neural processing of TTHCs over tones and nonharmonics, highlighting local network specialization among different neuronal types.




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Neurons Underlying Aggression-Like Actions That Are Shared by Both Males and Females in Drosophila

Aggression involves both sexually monomorphic and dimorphic actions. How the brain implements these two types of actions is poorly understood. We found that in Drosophila melanogaster, a set of neurons, which we call CL062, previously shown to mediate male aggression also mediate female aggression. These neurons elicit aggression acutely and without the presence of a target. Although the same set of actions is elicited in males and females, the overall behavior is sexually dimorphic. The CL062 neurons do not express fruitless, a gene required for sexual dimorphism in flies, and expressed by most other neurons important for controlling fly aggression. Connectomic analysis in a female electron microscopy dataset suggests that these neurons have limited connections with fruitless expressing neurons that have been shown to be important for aggression and signal to different descending neurons. Thus, CL062 is part of a monomorphic circuit for aggression that functions parallel to the known dimorphic circuits.




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Erratum: McCosh et al., "Norepinephrine Neurons in the Nucleus of the Solitary Tract Suppress Luteinizing Hormone Secretion in Female Mice"




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From Candy to Lightbulbs, Felix Gonzalez-Torres Showed Life and Loss Through Everyday Objects

A new exhibition co-presented by the National Portrait Gallery and the Archives of American Art explores the seminal artist’s work




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Countries recognize vital role of small-scale fishers

Countries today endorsed a set of wide-reaching guidelines that will boost the already vital [...]




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Ukraine: FAO scales up to support rural families, safeguard food security

Team on ground regrouped; strengthened with surge personnel; Declaration of corporate scale-up response




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A Right Whale Skeleton Arrives at the Smithsonian

See the process involved when a massive specimen arrives at the Smithsonian




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Memphis’ Beale Street and Beyond

The city famous for blues and barbecue is a little “ragged around the edges” according to tour guide Tad Pierson, who drives tourists around in his pink 1955 Cadillac by Lucian Perkins