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Optimized incorporation of an unnatural fluorescent amino acid affords measurement of conformational dynamics governing high-fidelity DNA replication [DNA and Chromosomes]

DNA polymerase from bacteriophage T7 undergoes large, substrate-induced conformational changes that are thought to account for high replication fidelity, but prior studies were adversely affected by mutations required to construct a Cys-lite variant needed for site-specific fluorescence labeling. Here we have optimized the direct incorporation of a fluorescent un-natural amino acid, (7-hydroxy-4-coumarin-yl)-ethylglycine, using orthogonal amber suppression machinery in Escherichia coli. MS methods verify that the unnatural amino acid is only incorporated at one position with minimal background. We show that the single fluorophore provides a signal to detect nucleotide-induced conformational changes through equilibrium and stopped-flow kinetic measurements of correct nucleotide binding and incorporation. Pre-steady-state chemical quench methods show that the kinetics and fidelity of DNA replication catalyzed by the labeled enzyme are largely unaffected by the unnatural amino acid. These advances enable rigorous analysis to establish the kinetic and mechanistic basis for high-fidelity DNA replication.




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Reasons for optimism for each MLB club

On this opening week of Spring Training, all 30 Major League teams have one thing in common: optimism. Here's an optimism cheat sheet for each of them.




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Angels enter '19 optimistic for present, future

Since debuting in 2011, center fielder Mike Trout has been far and away the best player in the Majors, but the Angels have reached the postseason just once in his eight-year career.




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Reasons for optimism for each MLB club

On this opening week of Spring Training, all 30 Major League teams have one thing in common: optimism. Here's an optimism cheat sheet for each of them.




pti

Tuberculosis: Disruption to health services from pandemic has allowed cases to reach record levels worldwide




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Correction: Transcriptional factors Smad1 and Smad9 act redundantly to mediate zebrafish ventral specification downstream of Smad5. [Additions and Corrections]

VOLUME 289 (2014) PAGES 6604–6618In Fig. 4G, in the foxi1 panel, the images in Fig. 4G, i and l, corresponding to “smad1 MO” and “smad5 MO + samd1/9 mRNA” samples, respectively, were inadvertently reused during figure preparation. This error has now been corrected using images pertaining to each treatment and sample. This correction does not affect the results or conclusions of the work.jbc;295/52/18650/F4F1F4Figure 4G.




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Economic Recovery and Anticorruption in South Africa: Assessing Progress on the Reform Agenda

Economic Recovery and Anticorruption in South Africa: Assessing Progress on the Reform Agenda 4 December 2019 — 3:00PM TO 4:00PM Anonymous (not verified) 25 November 2019 Chatham House | 10 St James's Square | London | SW1Y 4LE

South Africa has significant economic potential based on its resource endowment, quality human capital and well-developed infrastructure compared to the region. However, the country’s economic growth rate has not topped 2 per cent since 2013, and in 2018, was below 1 per cent. This has put a strain on citizens and communities in a country that still suffers from structural inequality, poverty and high unemployment. Economic recovery and anti-corruption were the central pillars of President Cyril Ramaphosa’s 2019 electoral campaign and he has set an investment target of $100 billion. However, voters and investors alike are demanding faster and more visible progress from the country’s enigmatic leader who has a reputation for caution and calculation.

At this event, Professor Nick Binedell will discuss the progress of and opposition to the president’s economic reform agenda and the opportunities for international investment to support long term inclusive and sustainable growth in South Africa.

Attendance at this event is by invitation only.




pti

Can Liberation Movements Really Rid Southern Africa of Corruption?

Can Liberation Movements Really Rid Southern Africa of Corruption? Expert comment sysadmin 16 December 2019

Southern Africa’s national liberation movements have survived ‘end of decade’ elections across the region. Combating corruption has been at the heart of many of the campaigns, but the question is can they succeed?

Supporters of the Namibian incumbent president and ruling party South West Africa People’s Organisation (SWAPO) presidential candidate Hage Geingob cheer and dance. Photo by GIANLUIGI GUERCIA/AFP via Getty Images.

Swapo’s victory in Namibia two weeks ago was the last in a series of recent ‘end of decade’ elections that have returned dominant parties to power across Southern Africa. However, the “enduring appeal of liberation” is wearing thin.

Experiences across the region show that if governments are to deliver on their electoral promises, they must empower institutions, actively promote a culture of accountability and transparency within their party ranks and pursue economic reforms that untangle the web of party-state-business alliances. Such actions are critical for the survival of national liberation movements as the dominant force in the politics of Southern Africa – but will be difficult to implement.

Avoid political factionalism

South Africa, Botswana, Angola and Zimbabwe all saw new presidents take over just before elections. All used the rhetoric of anti-corruption to distance themselves from the tainted image of their predecessors. But acting on this requires a shift in mind-set in parties that have always preferred to deal with their problems behind closed doors. High profile adversaries from past regimes make tempting targets but could also drive party divisions.

In Angola, the transition of power was safeguarded by an agreement that former president José Eduardo dos Santos would be immune from prosecution. But this week his son faced corruption charges before the country’s supreme court, a high-profile example of a wave of anti-corruption cases across Southern Africa, driven by dominant parties wary of their future.

The allegations against José Filemino De Sousa Dos Santos, nickname ‘Zenu’, include a $500-million fraud involving the country’s central bank. Pressure is also mounting on Zenu’s sister Isabel — once prominent in Angola, she is now absent from public life.

Other leaders have had to tread more carefully. Immunity was a luxury Cyril Ramaphosa was neither willing nor politically able to grant Jacob Zuma in South Africa. Reliant on a few close allies at the top of the party, Ramaphosa lacks foot soldiers at the grassroots level, and his campaign against corruption within the ANC has faced persistent opposition.

Rebuilding institutions and empowering authorities takes time, and with few high-profile cases to point to, people are getting restless. This is also the case in Zimbabwe, where a worsening economic situation has left policy reformers politically isolated.

Party, state, and business

Long term incumbency has blurred the distinction between the party and the state. Liberation movements have created vast party-linked business empires. Political allegiance grants access to economic resources through appointments to lucrative positions in state-owned enterprises, preferential bids for tenders and licenses, and direct access to decision makers.

In Angola, this was fuelled by oil revenues. In South Africa, state capture flourished in an environment where the ANC and its constituent elements had significant power on the panels that chose leaders for state-owned enterprises (SOEs). In Namibia, an Icelandic fishing company paid backhanders to officials for fishing rights in what has become known as the ‘Fishrot’ scandal. Zanu-PF officials’ access to preferential foreign exchange rates present them with lucrative opportunities in Zimbabwe.

Ending this bureaucratic rent seeking goes beyond appointing ‘clean’ officials, which has been central to the anti-corruption campaigns in Angola and South Africa. Governments must also allow scrutiny of the state and empower those institutions designed for that role, such as the National Prosecuting Authority and the Public Protector in South Africa. Zimbabwe’s auditor general has published an in-depth report of the state of corruption in the country’s SOEs.

Companies must also be held to account for their role in aiding, and at worst directly benefitting, from state graft. International businesses have actively sought to benefit from corruption. They are now starting to face the consequences. A former Credit Suisse banker has pleaded guilty in the US over handling alleged kickbacks in Mozambique’s $2-billion “tuna bond” scandal. Global banks and consultancies continue to feel the squeeze for their complicity in state capture in South Africa.

Competition and pluralism

National liberation movements may only have a limited window within which to act. Across the region civil society campaigns and investigative journalists have shed light on some of the worst abuses of power. Anti-corruption campaigns are starting to bite. The state will continue to play a central role in Southern African economies, an important arbiter of economic transformation able to balance the region’s highly unequal and resource-dependent economies.

But opposition, civil society and the media are also critical for the progression towards democratic competition and pluralism in Southern Africa. Parliaments remain vital for holding rulers to account. Long used to unchallenged dominance, liberation movements have significant adjustments to make to rise to the challenge of a new era.

This article was originally published in the Mail and Guardian.




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Angola Forum 2021: Policy options to support economic recovery in Angola

Angola Forum 2021: Policy options to support economic recovery in Angola 7 October 2021 — 2:00PM TO 5:00PM Anonymous (not verified) 22 September 2021 Online

Speakers discuss policy options to support economic recovery in Angola as the country transitions away from a state-led oil economy to a private-sector-led growth model.

The government of Angola has made some progress on a range of policies targeting macroeconomic stability and structural reform. However, the country has been suffering from a recurring economic recession for six consecutive years, with the last positive annual GDP growth rate posted in 2015 at 0.9 per cent.

The national budget remains dependent on oil revenue, leaving the country highly exposed to volatile oil prices particularly during the COVID-19 pandemic. While revenues collapsed, increased spending was needed to respond to the health crisis and estimates of Angola’s debt spike range from 130 to 150 per cent of its GDP by the close of 2020.

At this virtual Angola Forum, speakers discuss policy options to support economic recovery in Angola as the country transitions away from a state-led oil economy to a private-sector-led growth model.

The Forum launches the English translation of the Angola Economic Report 2019-20 by the Centro de Estudos de Investigação (CEIC) of the Catholic University of Angola in partnership with the Konrad-Adenauer-Stiftung (KAS), and the findings of Afrobarometer’s first ever survey in Angola, Ovilongwa – Estudos de Opinião Pública, which interviewed 2,400 adult Angolans and sampled individual perceptions on democracy and economic reform in Angola.

This event will be held in English and Portuguese with simultaneous interpretation.

The Forum will also be broadcast live on the Africa Programme Facebook page.




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Disruptive technologies by nation states and malign cyber actors – the US response

Disruptive technologies by nation states and malign cyber actors – the US response 16 February 2023 — 1:00PM TO 2:00PM Anonymous (not verified) 2 February 2023 Chatham House and Online

Lisa Monaco, the US deputy attorney general, discusses how autocratic governments and malign cyber actors use disruptive technologies to project power and engage in illicit activity.

Weaponizing data, ransomware attacks and other illicit cyber activity represent significant threats to national security. 

Governments and malicious cyber actors around the world exploit disruptive technology to engage in criminal activity, track citizens and coerce other countries thereby weakening the rules-based order and fundamental principles of democracy. 

Lisa Monaco discusses how the world is at an inflection point when it comes to meeting this challenge and describes how the US and partner nations are responding to protect their citizens and the broader international community.

Key questions to discuss include:

  • What steps does the US government need to take to properly address this threat?
  • How are countries coordinating policies to confront the problem?
  • To what extent does this challenge go beyond US-China competition?

As with all member events, questions from the audience drive the conversation.

Read the transcript.




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Optimizing the Therapeutic Index of sdAb-Based Radiopharmaceuticals Using Pretargeting

Single-domain antibodies (sdAbs) demonstrate favorable pharmacokinetic profiles for molecular imaging applications. However, their renal excretion and retention are obstacles for applications in targeted radionuclide therapy (TRT). Methods: Using a click-chemistry–based pretargeting approach, we aimed to reduce kidney retention of a fibroblast activation protein α (FAP)–targeted sdAb, 4AH29, for 177Lu-TRT. Key pretargeting parameters (sdAb-injected mass and lag time) were optimized in healthy mice and U87MG (FAP+) xenografts. A TRT study in a pancreatic ductal adenocarcinoma (PDAC) patient-derived xenograft (PDX) model was performed as a pilot study for sdAb-based pretargeting applications. Results: Modification of 4AH29 with trans-cyclooctene (TCO) moieties did not modify the sdAb pharmacokinetic profile. A 200-µg injected mass of 4AH29-TCO and an 8-h lag time for the injection of [177Lu]Lu-DOTA-PEG7-tetrazine resulted in the highest kidney therapeutic index (2.0 ± 0.4), which was 5-fold higher than that of [177Lu]Lu-DOTA-4AH29 (0.4 ± 0.1). FAP expression in the tumor microenvironment was validated in a PDAC PDX model with both immunohistochemistry and PET/CT imaging. Mice treated with the pretargeting high-activity approach (4AH29-TCO + [177Lu]Lu-DOTA-PEG7-tetrazine; 3 x 88 MBq, 1 injection per week for 3 wk) demonstrated prolonged survival compared with the vehicle control and conventionally treated ([177Lu]Lu-DOTA-4AH29; 3 x 37 MBq, 1 injection per week for 3 wk) mice. Mesangial expansion was reported in 7 of 10 mice in the conventional cohort, suggesting treatment-related kidney morphologic changes, but was not observed in the pretargeting cohort. Conclusion: This study validates pretargeting to mitigate sdAbs’ kidney retention with no observation of morphologic changes on therapy regimen at early time points. Clinical translation of click-chemistry–based pre-TRT is warranted on the basis of its ability to alleviate toxicities related to biovectors’ intrinsic pharmacokinetic profiles. The absence of representative animal models with extensive stroma and high FAP expression on cancer-associated fibroblasts led to a low mean tumor-absorbed dose even with high injected activity and consequently to modest survival benefit in this PDAC PDX.





pti

Detroit Lions overcome 5 Jared Goff interceptions in comeback win over Houston Texans

A struggling Detroit Lions offense awoke late, scoring 19-unanswered points to rally past the Houston Texans and improve to 8-1 this season. The Lions overcame a career-high five interceptions Jared Goff threw.





pti

NIST Issues Post Quantum Cryptography Standards and Calls for their Adoption

After much anticipation, the National Institute of Standards and Technology (NIST) issued its first Post Quantum Cryptography (PQC) standards today. They are intended to defeat efforts by quantum computers powerful […]

The post NIST Issues Post Quantum Cryptography Standards and Calls for their Adoption appeared first on HPCwire.




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QCT QoolRack: An Optimized Liquid Cooling Solution for HPC/AI Workloads

Data center infrastructure running AI and HPC workloads requires powerful microprocessor chips and the use of CPUs, GPUs, and acceleration chips to carry out compute intensive tasks. AI and HPC […]

The post QCT QoolRack: An Optimized Liquid Cooling Solution for HPC/AI Workloads appeared first on HPCwire.




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QCT POD- An Adaptive Converged Platform for HPC and AI

Building an integrated workload-driven system with optimized performance is a resource-intensive and time-consuming effort. The QCT Platform on Demand (QCT POD) offers an on-premises HPC/AI converged system, featuring best-practice hardware […]

The post QCT POD- An Adaptive Converged Platform for HPC and AI appeared first on HPCwire.




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Do IT Now and Codee Partner to Enhance Code Correctness, Modernization and Optimization

BARCELONA, Spain, Nov. 7, 2024 — Codee, a provider of software developer tools for automated code review and testing specializing in correctness, modernization and optimization of Fortran/C/C++ code, is pleased […]

The post Do IT Now and Codee Partner to Enhance Code Correctness, Modernization and Optimization appeared first on HPCwire.




pti

MinIO Optimizes Arm-Based Chipsets for High-Performance AI

REDWOOD CITY, Calif., Nov. 4, 2024 — MinIO has announced compelling new optimizations and benchmarks for Arm-based chipsets powering on its object store. These optimizations underscore the relevance of low-power, […]

The post MinIO Optimizes Arm-Based Chipsets for High-Performance AI appeared first on HPCwire.




pti

Trust Local School Leaders, a State Chief Says as Optional Reopening Date Nears

Montana Superintendent Elsie Arntzen offers practical advice to schools that could open as early as May 7, even as she says "how they open schools and how learning takes place is up to them."




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Adoption of New Science Standards May Start With Rhode Island

Rhode Island may become the first state to adopt the Next Generation Science Standards.




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How Statewide LMS Options Could Help Schools Strengthen Remote Learning

Several states already offer a state-sanctioned LMS option to their schools, with some encouraging results in their efforts to cut costs and improve technical capabilities.




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Baptist couple ask court to ban book from son's school




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Tennessee Governor: COVID-19 Vaccines To Be Optional in K-12 Schools

“Vaccines are a choice and people have the choice and will have the choice in this state as to whether or not they should take that vaccine,” the governor said.




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Tennessee Governor: COVID-19 Vaccines To Be Optional in K-12 Schools

“Vaccines are a choice and people have the choice and will have the choice in this state as to whether or not they should take that vaccine,” the governor said.




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W.Va. Bill Would Give Districts More Choice in Textbook Adoption

But some Democrats say that could make the selection process more political.




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Synaptic Modifications in Cultured Hippocampal Neurons: Dependence on Spike Timing, Synaptic Strength, and Postsynaptic Cell Type

Guo-qiang Bi
Dec 15, 1998; 18:10464-10472
Articles




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{gamma}1 GABAA Receptors in Spinal Nociceptive Circuits

Elena Neumann
Oct 9, 2024; 44:e0591242024-e0591242024
Systems/Circuits




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Gravin Orchestrates Protein Kinase A and {beta}2-Adrenergic Receptor Signaling Critical for Synaptic Plasticity and Memory

Robbert Havekes
Dec 12, 2012; 32:18137-18149
BehavioralSystemsCognitive




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Neuregulin1 Nuclear Signaling Influences Adult Neurogenesis and Regulates a Schizophrenia Susceptibility Gene Network within the Mouse Dentate Gyrus

Prithviraj Rajebhosale
Oct 23, 2024; 44:e0063242024-e0063242024
Cellular




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A Hierarchy of Temporal Receptive Windows in Human Cortex

Uri Hasson
Mar 5, 2008; 28:2539-2550
BehavioralSystemsCognitive




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Topographic Mapping of a Hierarchy of Temporal Receptive Windows Using a Narrated Story

Yulia Lerner
Feb 23, 2011; 31:2906-2915
BehavioralSystemsCognitive




pti

A Systematic Structure-Function Characterization of a Human Mutation in Neurexin-3{alpha} Reveals an Extracellular Modulatory Sequence That Stabilizes Neuroligin-1 Binding to Enhance the Postsynaptic Properties of Excitatory Synapses

α-Neurexins are essential and highly expressed presynaptic cell-adhesion molecules that are frequently linked to neuropsychiatric and neurodevelopmental disorders. Despite their importance, how the elaborate extracellular sequences of α-neurexins contribute to synapse function is poorly understood. We recently characterized the presynaptic gain-of-function phenotype caused by a missense mutation in an evolutionarily conserved extracellular sequence of neurexin-3α (A687T) that we identified in a patient diagnosed with profound intellectual disability and epilepsy. The striking A687T gain-of-function mutation on neurexin-3α prompted us to systematically test using mutants whether the presynaptic gain-of-function phenotype is a consequence of the addition of side-chain bulk (i.e., A687V) or polar/hydrophilic properties (i.e., A687S). We used multidisciplinary approaches in mixed-sex primary hippocampal cultures to assess the impact of the neurexin-3αA687 residue on synapse morphology, function and ligand binding. Unexpectedly, neither A687V nor A687S recapitulated the neurexin-3α A687T phenotype. Instead, distinct from A687T, molecular replacement with A687S significantly enhanced postsynaptic properties exclusively at excitatory synapses and selectively increased binding to neuroligin-1 and neuroligin-3 without changing binding to neuroligin-2 or LRRTM2. Importantly, we provide the first experimental evidence supporting the notion that the position A687 of neurexin-3α and the N-terminal sequences of neuroligins may contribute to the stability of α-neurexin–neuroligin-1 trans-synaptic interactions and that these interactions may specifically regulate the postsynaptic strength of excitatory synapses.




pti

{gamma}1 GABAA Receptors in Spinal Nociceptive Circuits

GABAergic neurons and GABAA receptors (GABAARs) are critical elements of almost all neuronal circuits. Most GABAARs of the CNS are heteropentameric ion channels composed of two α, two β, and one subunits. These receptors serve as important drug targets for benzodiazepine (BDZ) site agonists, which potentiate the action of GABA at GABAARs. Most GABAAR classifications rely on the heterogeneity of the α subunit (α1–α6) included in the receptor complex. Heterogeneity of the subunits (1–3), which mediate synaptic clustering of GABAARs and contribute, together with α subunits, to the benzodiazepine (BDZ) binding site, has gained less attention, mainly because 2 subunits greatly outnumber the other subunits in most brain regions. Here, we have investigated a potential role of non-2 GABAARs in neural circuits of the spinal dorsal horn, a key site of nociceptive processing. Female and male mice were studied. We demonstrate that besides 2 subunits, 1 subunits are significantly expressed in the spinal dorsal horn, especially in its superficial layers. Unlike global 2 subunit deletion, which is lethal, spinal cord-specific loss of 2 subunits was well tolerated. GABAAR clustering in the superficial dorsal horn remained largely unaffected and antihyperalgesic actions of HZ-166, a nonsedative BDZ site agonist, were partially retained. Our results thus suggest that the superficial dorsal horn harbors functionally relevant amounts of 1 subunits that support the synaptic clustering of GABAARs in this site. They further suggest that 1 containing GABAARs contribute to the spinal control of nociceptive information flow.




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PDE4B Missense Variant Increases Susceptibility to Post-traumatic Stress Disorder-Relevant Phenotypes in Mice

Large-scale genome-wide association studies (GWASs) have associated intronic variants in PDE4B, encoding cAMP-specific phosphodiesterase-4B (PDE4B), with increased risk for post-traumatic stress disorder (PTSD), as well as schizophrenia and substance use disorders that are often comorbid with it. However, the pathophysiological mechanisms of genetic risk involving PDE4B are poorly understood. To examine the effects of PDE4B variation on phenotypes with translational relevance to psychiatric disorders, we focused on PDE4B missense variant M220T, which is present in the human genome as rare coding variant rs775201287. When expressed in HEK-293 cells, PDE4B1-M220T exhibited an attenuated response to a forskolin-elicited increase in the intracellular cAMP concentration. In behavioral tests, homozygous Pde4bM220T male mice with a C57BL/6JJcl background exhibited increased reactivity to novel environments, startle hyperreactivity, prepulse inhibition deficits, altered cued fear conditioning, and enhanced spatial memory, accompanied by an increase in cAMP signaling pathway-regulated expression of BDNF in the hippocampus. In response to a traumatic event (10 tone–shock pairings), neuronal activity was decreased in the cortex but enhanced in the amygdala and hippocampus of Pde4bM220T mice. At 24 h post-trauma, Pde4bM220T mice exhibited increased startle hyperreactivity and decreased plasma corticosterone levels, similar to phenotypes exhibited by PTSD patients. Trauma-exposed Pde4bM220T mice also exhibited a slower decay in freezing at 15 and 30 d post-trauma, demonstrating enhanced persistence of traumatic memories, similar to that exhibited by PTSD patients. These findings provide substantive mouse model evidence linking PDE4B variation to PTSD-relevant phenotypes and thus highlight how genetic variation of PDE4B may contribute to PTSD risk.




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Neuregulin1 Nuclear Signaling Influences Adult Neurogenesis and Regulates a Schizophrenia Susceptibility Gene Network within the Mouse Dentate Gyrus

Neuregulin1 (Nrg1) signaling is critical for neuronal development and function from fate specification to synaptic plasticity. Type III Nrg1 is a synaptic protein which engages in bidirectional signaling with its receptor ErbB4. Forward signaling engages ErbB4 phosphorylation, whereas back signaling engages two known mechanisms: (1) local axonal PI3K-AKT signaling and (2) cleavage by -secretase resulting in cytosolic release of the intracellular domain (ICD), which can traffic to the nucleus (Bao et al., 2003; Hancock et al., 2008). To dissect the contribution of these alternate signaling strategies to neuronal development, we generated a transgenic mouse with a missense mutation (V321L) in the Nrg1 transmembrane domain that disrupts nuclear back signaling with minimal effects on forward signaling or local back signaling and was previously found to be associated with psychosis (Walss-Bass et al., 2006). We combined RNA sequencing, retroviral fate mapping of neural stem cells, behavioral analyses, and various network analyses of transcriptomic data to investigate the effect of disrupting Nrg1 nuclear back signaling in the dentate gyrus (DG) of male and female mice. The V321L mutation impairs nuclear translocation of the Nrg1 ICD and alters gene expression in the DG. V321L mice show reduced stem cell proliferation, altered cell cycle dynamics, fate specification defects, and dendritic dysmorphogenesis. Orthologs of known schizophrenia (SCZ)-susceptibility genes were dysregulated in the V321L DG. These genes coordinated a larger network with other dysregulated genes. Weighted gene correlation network analysis and protein interaction network analyses revealed striking similarity between DG transcriptomes of V321L mouse and humans with SCZ.




pti

Our Brains on Art: An Ancient Prescription for 21st Century Solutions




pti

Pre- and Postsynaptic MEF2C Promotes Experience-Dependent, Input-Specific Development of Cortical Layer 4 to Layer 2/3 Excitatory Synapses and Regulates Activity-Dependent Expression of Synaptic Cell Adhesion Molecules

Experience- and activity-dependent transcription is a candidate mechanism to mediate development and refinement of specific cortical circuits. Here, we demonstrate that the activity-dependent transcription factor myocyte enhancer factor 2C (MEF2C) is required in both presynaptic layer (L) 4 and postsynaptic L2/3 mouse (male and female) somatosensory (S1) cortical neurons for development of this specific synaptic connection. While postsynaptic deletion of Mef2c weakens L4 synaptic inputs, it has no effect on inputs from local L2/3, contralateral S1, or the ipsilateral frontal/motor cortex. Similarly, homozygous or heterozygous deletion of Mef2c in presynaptic L4 neurons weakens L4 to L2/3 excitatory synaptic inputs by decreasing presynaptic release probability. Postsynaptic MEF2C is specifically required during an early postnatal, experience-dependent, period for L4 to L2/3 synapse function, and expression of transcriptionally active MEF2C (MEF2C-VP16) rescues weak L4 to L2/3 synaptic strength in sensory-deprived mice. Together, these results suggest that experience- and/or activity-dependent transcriptional activation of MEF2C promotes development of L4 to L2/3 synapses. Additionally, MEF2C regulates the expression of many pre- and postsynaptic genes in postnatal cortical neurons. Interestingly, MEF2C was necessary for activity-dependent expression of many presynaptic genes, including those that function in transsynaptic adhesion and neurotransmitter release. This work provides mechanistic insight into the experience-dependent development of specific cortical circuits.




pti

This Captivating Guide Uncovers the History and Mystery of Dinosaurs in 50 Fossils

A paleontologist at the Natural History Museum in London chronicles the age of the famous and fascinating massive reptiles




pti

A Coffin Is Unearthed Using Ancient Egyptian Tech

Archaeologists in Saqqara make a dazzling discovery: a late period Egyptian coffin with a gilded mask. Now, to bring it to the surface, they use a pulley known as a "tambora," a technology that dates back to Ancient Egypt




pti

Women Proved to Be Exceptional Pilots During WWII

With millions of men serving in WWII, the nation needed pilots to ferry planes from the factory to the air bases. That’s when Jackie Cochran proposed a novel idea: why not let women fly?




pti

We Asked: Are You Optimistic About the Earth’s Future?




pti

Space Archaeologist Sarah Parcak Uses Satellites to Uncover Ancient Egyptian Ruins

Sarah Parcak | Smithsonian Magazine’s 2016 American Ingenuity Award Winner for History This tech-savvy researcher of our past uses satellites and other remote-sensing tools to discover and explore stunning new evidence of lost cultures—including, just this year, another possible Viking site in North America. In addition, she has located an astonishing number of ancient Egyptian remains—thousands of settlements, lost tombs and hidden pyramids. A Yale- and Cambridge-trained Egyptologist and archaeologist, Parcak is a professor of anthropology at the University of Alabama at Birmingham, where she serves as founding director of the Laboratory for Global Observation. Read more about Parcak’s work: http://smithmag.co/ZuwTGP | #IngenuityAwards And more about the American Ingenuity Awards: http://smithmag.co/77xPqy




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1,700-Year-Old Sock Spins Yarn About Ancient Egyptian Fashion

This stripy toe sock appears to have warmed the foot of a tot in the late antiquity period




pti

These Ancient Egyptian Barracks Paint a Vivid Picture of Military Life During the Reign of Ramses II

Archaeologists unearthed a series of mudbrick rooms filled with religious tributes, soldiers' personal effects, engraved weaponry and animal bones




pti

See an Ancient Egyptian Temple's Brilliant Colors, Newly Revealed Beneath Layers of Dust and Soot

Experts are carefully uncovering traces of the original paint and fragments of gold leaf that once adorned the 2,000-year-old Temple of Edfu




pti

Archaeologists Discover Intricately Decorated Coffins Belonging to the Only Daughter of an Ancient Egyptian Governor

The 4,000-year-old burial chamber featured hieroglyphs referring to the woman, known as Idi, as the "lady of the house"




pti

This Pup Is Going Viral for Climbing to the Top of an Egyptian Pyramid

Paramotorists spotted the dog while soaring above one of Giza's pyramids last week




pti

Archaeologists Discover Ancient Egyptian Family Tomb Full of Necklaces, Bracelets and Rings

The 3,800-year-old site near the city of Luxor holds the remains of 11 individuals, who may have been members of the same family. Researchers think the tomb was used for several generations




pti

After the Death of Cassius, the World's Largest Captive Crocodile, Scientists Are Trying to Solve the Mystery of His Age

The beloved reptile in Australia died last weekend and was thought to be up to 120 years old, though that age is only an estimate. Research on his bones might reveal a more exact number