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4 creative ways cities are transitioning to a clean energy future

Mayors from cities across the U.S. are stepping up and committing to broad and inspirational action to reduce greenhouse gas emissions and decarbonize local energy systems. This leadership is especially critical given lack of federal climate action, but translating a mayoral commitment to reality can be a challenge.





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India's largest coal-fired power producer appoints renewables head to speed transition

State-run NTPC Ltd., India’s largest coal-fired power producer, is appointing a new head of its renewables team to speed up its expansion into clean energy, according to a company official with knowledge of the plan.




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POWERGEN India 2020 to support energy transition in India

Clarion Energy & iTEN Media announce the launch of POWERGEN India 2020 co-located with Indian Utility Week & DISTRIBUTECH India




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The energy transition is underway: 10 charts tell the story

The renewable energy transition promises to reduce carbon emissions, but it’s happening at different speeds around the world. Read on for some key insights from BloombergNEF’s New Energy Outlook 2019, which provides a detailed road map to the future.




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Kickstarting the Energy Revolution: How Crowdfunding is Pushing the Renewable Energy Transition

When innovators come up with the idea for the next great technological breakthrough, the first roadblocks to seeing that idea to fruition are typically funding. Among renewable energy inventions, this need is typically filled through wealthy private investors, venture capital firms, or government grants. But today, in the age of the Internet, budding entrepreneurs have taken their funding needs online through crowdfunding sites like Kickstarter and Indiegogo.




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IRENA: Transition to Renewable Energy May Create an Entirely Different World

This week at the Assembly of the International Renewable Energy Agency (IRENA), political and business leaders from around the world outlined the far-reaching geopolitical implications of an energy transformation driven by the rapid growth of renewable energy.




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POWERGEN India 2020 to support energy transition in India

Clarion Energy & iTEN Media announce the launch of POWERGEN India 2020 co-located with Indian Utility Week & DISTRIBUTECH India




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India's largest coal-fired power producer appoints renewables head to speed transition

State-run NTPC Ltd., India’s largest coal-fired power producer, is appointing a new head of its renewables team to speed up its expansion into clean energy, according to a company official with knowledge of the plan.




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POWERGEN India 2020 to support energy transition in India

Clarion Energy & iTEN Media announce the launch of POWERGEN India 2020 co-located with Indian Utility Week & DISTRIBUTECH India




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The energy transition is underway: 10 charts tell the story

The renewable energy transition promises to reduce carbon emissions, but it’s happening at different speeds around the world. Read on for some key insights from BloombergNEF’s New Energy Outlook 2019, which provides a detailed road map to the future.




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Practical Aspects for Subtractive Etching of High Density Interconnects

Presentation by Don Ball of Chemcut Corporation




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Transitioning from Rigid to Flex/Rigid-Flex PCB Manufacturing

Presentation by Yash Sutariya of Saturn Electronics/Saturn Flex Systems, Inc.




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Protecting Workers and Communities During the Clean Energy Transition

When I worked at the New York Attorney General's Office, we sued coal-fired power plants because their air pollution was making people sick. But in some towns, I saw that the reliance on coal really had people in a bind. The coal plant was making them sick, but it was also a major tax generator for the town. If the plant closed, the town might have to lay off teachers and cops, in addition to losing the plant jobs.




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IRENA: Transition to Renewable Energy May Create an Entirely Different World

This week at the Assembly of the International Renewable Energy Agency (IRENA), political and business leaders from around the world outlined the far-reaching geopolitical implications of an energy transformation driven by the rapid growth of renewable energy.




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Pennsylvania joins electric vehicle race with new ‘roadmap’ for transition

Pennsylvania is promoting a new roadmap to electrify transportation by designing policies and setting targets to get more electric vehicles on the roads.





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India's largest coal-fired power producer appoints renewables head to speed transition

State-run NTPC Ltd., India’s largest coal-fired power producer, is appointing a new head of its renewables team to speed up its expansion into clean energy, according to a company official with knowledge of the plan.




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POWERGEN India 2020 to support energy transition in India

Clarion Energy & iTEN Media announce the launch of POWERGEN India 2020 co-located with Indian Utility Week & DISTRIBUTECH India




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The energy transition is underway: 10 charts tell the story

The renewable energy transition promises to reduce carbon emissions, but it’s happening at different speeds around the world. Read on for some key insights from BloombergNEF’s New Energy Outlook 2019, which provides a detailed road map to the future.




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East-West Center President to Speak on “U.S. – Asia Policy in Transition”

East-West Center President to Speak on “U.S. – Asia Policy in Transition”
HONOLULU (Sept. 29) – East-West Center President Dr. Charles E. Morrison will speak on “U.S.-Asia Policy in Transition” at a luncheon meeting of the Friends of the East-West Center on Thursday, Oct. 2, at the Halekulani Hotel’s Hau Terrace, 2199 Kalia Road.

Dr. Morrison will review critical issues, challenges and opportunities in U.S. relations with the Asia-Pacific region as we face an election and new U.S. leadership. Members of the public are welcome to attend.

Cost for the luncheon is $36, inclusive of service charge, tax and parking. Registration begins at 11:30 a.m., with the luncheon program commencing at noon. To make a reservation, contact (808) 944-7111/ 944-7691, or Friends@eastwestcenter.org .




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EWC Board Member Appointed to Lead Korean Presidential Transition Competitiveness Council

EWC Board Member Appointed to Lead Korean Presidential Transition Competitiveness Council
FOR IMMEDIATE RELEASE
 

Media Contact:
Derek Ferrar
Media Relations Specialist
East-West Center
Phone: (808) 944-7204
Email: ferrard@EastWestCenter.org




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Handling complex, reputationally sensitive and high value disputes in the world of Covid-19

In this session we look at high value/reputationally sensitive disputes in the education sector. Running a university or Higher Education Institution is always a complicated business – and never more so than now. The sector is facing a time of unp...




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Overnight sensation: ISDA publishes new definitions to facilitate transition from EONIA

On Friday 14 February 2020, the International Swaps and Derivatives Association, Inc. (“ISDA”) published the ISDA Collateral Agreement Interest Rate Definitions (the “Collateral Rate Definitions”). The Collateral Rate Definit...




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Rate expectations: Dear CEO letter encourages action from asset managers on LIBOR transition

The Financial Conduct Authority (the “FCA”) sent a letter to all UK regulated asset managers on 27 February 2020 (the “Dear CEO Letter”), to encourage the sector to prepare for the cessation of the sterling London interbank o...




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Sterling LIBOR Transition: Focus on Term SONIA

New LIBOR transition publications On 16 January 2020, the Bank of England, Financial Conduct Authority and Working Group on Sterling Risk-Free Reference Rates published a set of documents outlining priorities and milestones for sterling LIBOR transi...




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Energy Transition Club

Eversheds Sutherland Clean Energy and Sustainability Group is delighted to tell you that we have created the Energy Transition Club (ETC), which will operate globally and will bring together key participants focused on delivering the transition to ...




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The Crises of 2020 Will Delay the Transition to Clean Energy

The oil slump, global recession and uncertainty about the magnitude of the COVID-19 pandemic will fuel the appetite for cheaper fossil fuel energy and delay investments in renewables, affecting the targets of the Paris Agreement on climate change and the Sustainable Development Goals (SDGs). The countries of the developing South, and in particular oil exporters, […]

The post The Crises of 2020 Will Delay the Transition to Clean Energy appeared first on Inter Press Service.




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Bioenergy, the Ugly Duckling of Mexico’s Energy Transition

Rosa Manzano carefully arranges pieces of wood in a big mud igloo that, seven days after it is full, will produce charcoal of high caloric content. “Our forest also produces oak, which in the past was only sold as firewood and had little value. But with forest management and the work of women who have […]

The post Bioenergy, the Ugly Duckling of Mexico’s Energy Transition appeared first on Inter Press Service.




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The Effects of Privatization and Corporate Governance of SOEs in Transition Economy: The Case of Kazakhstan

Privatization has different effects depending on the types of owners to whom it gives control in corporate governance.




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The Effects of Privatization and Corporate Governance of SOEs in Transition Economy: The Case of Kazakhstan

Privatization has different effects depending on the types of owners to whom it gives control in corporate governance.




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Health Tip: Sensitive Teeth

Title: Health Tip: Sensitive Teeth
Category: Health News
Created: 5/2/2019 12:00:00 AM
Last Editorial Review: 5/2/2019 12:00:00 AM




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Crafting With Dry Pasta, Play-Doh Safe for Kids With Gluten Sensitivity: Study

Title: Crafting With Dry Pasta, Play-Doh Safe for Kids With Gluten Sensitivity: Study
Category: Health News
Created: 2/4/2020 12:00:00 AM
Last Editorial Review: 2/5/2020 12:00:00 AM




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Health Tip: Understanding the Menopausal Transition

Title: Health Tip: Understanding the Menopausal Transition
Category: Health News
Created: 12/2/2019 12:00:00 AM
Last Editorial Review: 12/2/2019 12:00:00 AM




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Back in Touch: Technology Restores Hand Sensitivity to Young Quadraplegic

Title: Back in Touch: Technology Restores Hand Sensitivity to Young Quadraplegic
Category: Health News
Created: 4/23/2020 12:00:00 AM
Last Editorial Review: 4/24/2020 12:00:00 AM




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Robustness in an Ultrasensitive Motor

ABSTRACT

In Escherichia coli, the chemotaxis response regulator CheY-P binds to FliM, a component of the switch complex at the base of the bacterial flagellar motor, to modulate the direction of motor rotation. The bacterial flagellar motor is ultrasensitive to the concentration of unbound CheY-P in the cytoplasm. CheY-P binds to FliM molecules both in the cytoplasm and on the motor. As the concentration of FliM unavoidably varies from cell to cell, leading to a variation of unbound CheY-P concentration in the cytoplasm, this raises the question whether the flagellar motor is robust against this variation, that is, whether the rotational bias of the motor is more or less constant as the concentration of FliM varies. Here, we showed that the motor is robust against variations of the concentration of FliM. We identified adaptive remodeling of the motor as the mechanism for this robustness. As the level of FliM molecules changes, resulting in different amounts of the unbound CheY-P molecules, the motor adaptively changes the composition of its switch complex to compensate for this effect.

IMPORTANCE The bacterial flagellar motor is an ultrasensitive motor. Its output, the probability of the motor turning clockwise, depends sensitively on the occupancy of the protein FliM (a component on the switch complex of the motor) by the input CheY-P molecules. With a limited cellular pool of CheY-P molecules, cell-to-cell variation of the FliM level would lead to large unwanted variation of the motor output if not compensated. Here, we showed that the motor output is robust against the variation of FliM level and identified the adaptive remodeling of the motor switch complex as the mechanism for this robustness.




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A Sensitive Yellow Fever Virus Entry Reporter Identifies Valosin-Containing Protein (VCP/p97) as an Essential Host Factor for Flavivirus Uncoating

ABSTRACT

While the basic mechanisms of flavivirus entry and fusion are understood, little is known about the postfusion events that precede RNA replication, such as nucleocapsid disassembly. We describe here a sensitive, conditionally replication-defective yellow fever virus (YFV) entry reporter, YFVSK/Nluc, to quantitively monitor the translation of incoming, virus particle-delivered genomes. We validated that YFVSK/Nluc gene expression can be neutralized by YFV-specific antisera and requires known flavivirus entry pathways and cellular factors, including clathrin- and dynamin-mediated endocytosis, endosomal acidification, YFV E glycoprotein-mediated fusion, and cellular LY6E and RPLP1 expression. The initial round of YFV translation was shown to require cellular ubiquitylation, consistent with recent findings that dengue virus capsid protein must be ubiquitylated in order for nucleocapsid uncoating to occur. Importantly, translation of incoming YFV genomes also required valosin-containing protein (VCP)/p97, a cellular ATPase that unfolds and extracts ubiquitylated client proteins from large complexes. RNA transfection and washout experiments showed that VCP/p97 functions at a postfusion, pretranslation step in YFV entry. Finally, VCP/p97 activity was required by other flaviviruses in mammalian cells and by YFV in mosquito cells. Together, these data support a critical role for VCP/p97 in the disassembly of incoming flavivirus nucleocapsids during a postfusion step in virus entry.

IMPORTANCE Flaviviruses are an important group of RNA viruses that cause significant human disease. The mechanisms by which flavivirus nucleocapsids are disassembled during virus entry remain unclear. Here, we used a yellow fever virus entry reporter, which expresses a sensitive reporter enzyme but does not replicate, to show that nucleocapsid disassembly requires the cellular protein-disaggregating enzyme valosin-containing protein, also known as p97.




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Conductance Mechanisms of Rapidly Desensitizing Cation Channelrhodopsins from Cryptophyte Algae

ABSTRACT

Channelrhodopsins guide algal phototaxis and are widely used as optogenetic probes for control of membrane potential with light. "Bacteriorhodopsin-like" cation channelrhodopsins (BCCRs) from cryptophytes differ in primary structure from other CCRs, lacking usual residues important for their cation conductance. Instead, the sequences of BCCR match more closely those of rhodopsin proton pumps, containing residues responsible for critical proton transfer reactions. We report 19 new BCCRs which, together with the earlier 6 known members of this family, form three branches (subfamilies) of a phylogenetic tree. Here, we show that the conductance mechanisms in two subfamilies differ with respect to involvement of the homolog of the proton donor in rhodopsin pumps. Two BCCRs from the genus Rhodomonas generate photocurrents that rapidly desensitize under continuous illumination. Using a combination of patch clamp electrophysiology, absorption, Raman spectroscopy, and flash photolysis, we found that the desensitization is due to rapid accumulation of a long-lived nonconducting intermediate of the photocycle with unusually blue-shifted absorption with a maximum at 330 nm. These observations reveal diversity within the BCCR family and contribute to deeper understanding of their independently evolved cation channel function.

IMPORTANCE Cation channelrhodopsins, light-gated channels from flagellate green algae, are extensively used as optogenetic photoactivators of neurons in research and recently have progressed to clinical trials for vision restoration. However, the molecular mechanisms of their photoactivation remain poorly understood. We recently identified cryptophyte cation channelrhodopsins, structurally different from those of green algae, which have separately evolved to converge on light-gated cation conductance. This study reveals diversity within this new protein family and describes a subclade with unusually rapid desensitization that results in short transient photocurrents in continuous light. Such transient currents have not been observed in the green algae channelrhodopsins and are potentially useful in optogenetic protocols. Kinetic UV-visible (UV-vis) spectroscopy and photoelectrophysiology reveal that the desensitization is caused by rapid accumulation of a nonconductive photointermediate in the photochemical reaction cycle. The absorption maximum of the intermediate is 330 nm, the shortest wavelength reported in any rhodopsin, indicating a novel chromophore structure.




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Neuraxial dysraphism in EPAS1-associated syndrome due to improper mesenchymal transition

Objective

To investigate the effect of somatic, postzygotic, gain-of-function mutation of Endothelial Per-Arnt-Sim (PAS) domain protein 1 (EPAS1) encoding hypoxia-inducible factor-2α (HIF-2α) on posterior fossa development and spinal dysraphism in EPAS1 gain-of-function syndrome, which consists of multiple paragangliomas, somatostatinoma, and polycythemia.

Methods

Patients referred to our institution for evaluation of new, recurrent, and/or metastatic paragangliomas/pheochromocytoma were confirmed for EPAS1 gain-of-function syndrome by identification of the EPAS1 gain-of-function mutation in resected tumors and/or circulating leukocytes. The posterior fossa, its contents, and the spine were evaluated retrospectively on available MRI and CT images of the head and neck performed for tumor staging and restaging. The transgenic mouse model underwent Microfil vascular perfusion and subsequent intact ex vivo 14T MRI and micro-CT as well as gross dissection, histology, and immunohistochemistry to assess the role of EPAS1 in identified malformations.

Results

All 8 patients with EPAS1 gain-of-function syndrome demonstrated incidental posterior fossa malformations—one Dandy-Walker variant and 7 Chiari malformations without syringomyelia. These findings were not associated with a small posterior fossa; rather, the posterior fossa volume exceeded that of its neural contents. Seven of 8 patients demonstrated spinal dysraphism; 4 of 8 demonstrated abnormal vertebral segmentation. The mouse model similarly demonstrated features of neuraxial dysraphism, including cervical myelomeningocele and spinal dysraphism, and cerebellar tonsil displacement through the foramen magnum. Histology and immunohistochemistry demonstrated incomplete mesenchymal transition in the mutant but not the control mouse.

Conclusions

This study characterized posterior fossa and spinal malformations seen in EPAS1 gain-of-function syndrome and suggests that gain-of-function mutation in HIF-2α results in improper mesenchymal transition.




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The South Kintyre Basin: its role in the stratigraphical and structural evolution of the Firth of Clyde region during the Devonian-Carboniferous transition

Late Devonian–Early Carboniferous rocks at the southern end of the Kintyre Peninsula closely resemble those of the Kinnesswood and Clyde Sandstone formations in more easterly portions of the Firth of Clyde. For example, a previously unrecognized thick marlstone with pedogenic calcretes is present in the Kinnesswood Formation at the south tip of the peninsula and, on the west coast, south of Machrihanish, a striking cliffed exposure includes massive phreatic calcretes developed from cross-bedded sandstones and red mudstones closely resembling those of the Clyde Sandstone on Great Cumbrae. A similar phreatic calcrete unit is present in the lower part of the Ballagan Formation in south Bute. The presence of vadose and phreatic calcrete provides valuable information concerning palaeoclimatic conditions in southwestern Scotland during the Devonian–Carboniferous transition. Overlying thick volcanic rocks are correlative with the Clyde Plateau Volcanic Formation. The sediments accumulated in the South Kintyre Basin on the west side of the Highland Boundary Fault (HBF). Formation of this basin, and the North East Arran and Cumbraes basins in the northeastern part of the Firth of Clyde, is interpreted as a response to development of a ‘locked zone’ in the HBF during an episode of sinistral faulting.




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Immediate reactions with glatiramer acetate: Diagnosis of allergy and desensitization protocols

Purpose of review

Diverse adverse events have been associated with administration of glatiramer acetate (GA), mainly local reactions at the injection site. Other, less frequent generalized reactions include isolated postinjection reactions and anaphylaxis, which may lead to discontinuation of GA.

Recent findings

Close collaboration between the allergy and neurology departments is needed to study adverse reactions to GA. The allergy study should include a detailed history and skin prick and intradermal tests with GA and, if possible, determination of specific IgE levels. Furthermore, the implication of other drugs should be ruled out.

Summary

An accurate diagnosis of reactions to GA is essential if we are to confirm or rule out allergy to GA. When an allergy diagnosis is confirmed or firmly suspected based on clinical evidence, desensitization protocols are increasingly seen as safe methods for reintroduction of GA.




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Enhancing CPR During Transition From Prehospital to Emergency Department: A QI Initiative

BACKGROUND AND OBJECTIVES:

High-quality cardiopulmonary resuscitation (CPR) increases the likelihood of survival of pediatric out-of-hospital cardiac arrest (OHCA). Maintenance of high-quality CPR during transition of care between prehospital and pediatric emergency department (PED) providers is challenging. Our objective for this initiative was to minimize pauses in compressions, in alignment with American Heart Association recommendations, for patients with OHCA during the handoffs from prehospital to PED providers. We aimed to decrease interruptions in compressions during the first 2 minutes of PED care from 17 seconds (baseline data) to 10 seconds over 12 months. Our secondary aims were to decrease the length of the longest pause in compressions to <10 seconds and eliminate encounters in which time to defibrillator pad placement was >120 seconds.

METHODS:

Our multidisciplinary team outlined our theory for improvement and designed interventions aimed at key drivers. Interventions included specific roles and responsibilities, CPR handoff choreography, and empowerment of frontline providers. Data were abstracted from video recordings of patients with OHCA receiving manual CPR on arrival.

RESULTS:

We analyzed 33 encounters between March 2018 and July 2019. We decreased total interruptions from 17 to 12 seconds during the first 2 minutes and decreased the time of the longest single pause from 14 to 7 seconds. We saw a decrease in variability of time to defibrillator pad placement.

CONCLUSIONS:

Implementation of a quality improvement initiative involving CPR transition choreography resulted in decreased interruptions in compressions and decreased variability of time to defibrillator pad placement.




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Complexes between C-Reactive Protein and Very Low Density Lipoprotein Delay Bacterial Clearance in Sepsis [INFECTIOUS DISEASE AND HOST RESPONSE]

Key Points

  • Kupffer cells phagocytose both bacteria and CRP–VLDL complexes.

  • High levels of CRP–VLDL complexes delay bacterial clearance.

  • Pch disrupts CRP–VLDL complexes to improve bacterial clearance.




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    A Point Mutation in carR Is Involved in the Emergence of Polymyxin B-Sensitive Vibrio cholerae O1 El Tor Biotype by Influencing Gene Transcription [Bacterial Infections]

    Antimicrobial peptides play an important role in host defense against Vibrio cholerae. Generally, the V. cholerae O1 classical biotype is polymyxin B (PB) sensitive and El Tor is relatively resistant. Detection of classical biotype traits like the production of classical cholera toxin and PB sensitivity in El Tor strains has been reported in recent years, including in the devastating Yemen cholera outbreak during 2016-2018. To investigate the factor(s) responsible for the shift in the trend of sensitivity to PB, we studied the two-component system encoded by carRS, regulating the lipid A modification of El Tor vibrios, and found that only carR contains a single nucleotide polymorphism (SNP) in recently emerged PB-sensitive strains. We designated the two alleles present in PB-resistant and -sensitive strains carRr and carRs alleles, respectively, and replaced the carRs allele of a sensitive strain with the carRr allele, using an allelic-exchange approach. The sensitive strain then became resistant. The PB-resistant strain N16961 was made susceptible to PB in a similar fashion. Our in silico CarR protein models suggested that the D89N substitution in the more stable CarRs protein brings the two structural domains of CarR closer, constricting the DNA binding cleft. This probably reduces the expression of the carR-regulated almEFG operon, inducing PB susceptibility. Expression of almEFG in PB-sensitive strains was found to be downregulated under natural culturing conditions. In addition, the expression of carR and almEG decreased in all strains with increased concentrations of extracellular Ca2+ but increased with a rise in pH. The downregulation of almEFG in CarRs strains confirmed that the G265A mutation is responsible for the emergence of PB-sensitive El Tor strains.




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    Reversal of hyperactive subthalamic circuits differentially mitigates pain hypersensitivity phenotypes in parkinsonian mice [Neuroscience]

    Although pain is a prevalent nonmotor symptom in Parkinson’s disease (PD), it is undertreated, in part because of our limited understanding of the underlying mechanisms. Considering that the basal ganglia are implicated in pain sensation, and that their synaptic outputs are controlled by the subthalamic nucleus (STN), we hypothesized that...




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    Emergent properties of branching morphologies modulate the sensitivity of coral calcification to high PCO2 [RESEARCH ARTICLE]

    Peter J. Edmunds and Scott C. Burgess

    Experiments with coral fragments (i.e. nubbins) have shown that net calcification is depressed by elevated PCO2. Evaluating the implications of this finding requires scaling of results from nubbins to colonies, yet the experiments to codify this process have not been carried out. Building from our previous research demonstrating that net calcification of Pocillopora verrucosa (2–13 cm diameter) was unaffected by PCO2 (400 and 1000 µatm) and temperature (26.5 and 29.7°C), we sought generality to this outcome by testing how colony size modulates PCO2 and temperature sensitivity in a branching acroporid. Together, these taxa represent two of the dominant lineages of branching corals on Indo-Pacific coral reefs. Two trials conducted over 2 years tested the hypothesis that the seasonal range in seawater temperature (26.5 and 29.2°C) and a future PCO2 (1062 µatm versus an ambient level of 461 µatm) affect net calcification of an ecologically relevant size range (5–20 cm diameter) of colonies of Acropora hyacinthus. As for P. verrucosa, the effects of temperature and PCO2 on net calcification (mg day–1) of A. verrucosa were not statistically detectable. These results support the generality of a null outcome on net calcification of exposing intact colonies of branching corals to environmental conditions contrasting seasonal variation in temperature and predicted future variation in PCO2. While there is a need to expand beyond an experimental culture relying on coral nubbins as tractable replicates, rigorously responding to this need poses substantial ethical and logistical challenges.




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    Seeing the rainbow: mechanisms underlying spectral sensitivity in teleost fishes [REVIEW]

    Karen L. Carleton, Daniel Escobar-Camacho, Sara M. Stieb, Fabio Cortesi, and N. Justin Marshall

    Among vertebrates, teleost eye diversity exceeds that found in all other groups. Their spectral sensitivities range from ultraviolet to red, and the number of visual pigments varies from 1 to over 40. This variation is correlated with the different ecologies and life histories of fish species, including their variable aquatic habitats: murky lakes, clear oceans, deep seas and turbulent rivers. These ecotopes often change with the season, but fish may also migrate between ecotopes diurnally, seasonally or ontogenetically. To survive in these variable light habitats, fish visual systems have evolved a suite of mechanisms that modulate spectral sensitivities on a range of timescales. These mechanisms include: (1) optical media that filter light, (2) variations in photoreceptor type and size to vary absorbance and sensitivity, and (3) changes in photoreceptor visual pigments to optimize peak sensitivity. The visual pigment changes can result from changes in chromophore or changes to the opsin. Opsin variation results from changes in opsin sequence, opsin expression or co-expression, and opsin gene duplications and losses. Here, we review visual diversity in a number of teleost groups where the structural and molecular mechanisms underlying their spectral sensitivities have been relatively well determined. Although we document considerable variability, this alone does not imply functional difference per se. We therefore highlight the need for more studies that examine species with known sensitivity differences, emphasizing behavioral experiments to test whether such differences actually matter in the execution of visual tasks that are relevant to the fish.




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    The spectral sensitivity of cone vision in the diurnal murid, Rhabdomys pumilio [RESEARCH ARTICLE]

    Annette E. Allen, Joshua W. Mouland, Jessica Rodgers, Beatriz Bano-Otalora, Ronald H. Douglas, Glen Jeffery, Anthony A. Vugler, Timothy M. Brown, and Robert J. Lucas

    An animal's temporal niche – the time of day at which it is active – is known to drive a variety of adaptations in the visual system. This includes variations in the topography, spectral sensitivity and density of retinal photoreceptors, and changes in the eye's gross anatomy and spectral transmission characteristics. We have characterised visual spectral sensitivity in the murid rodent Rhabdomys pumilio (‘the four-striped grass mouse’), which is the same family as (nocturnal) mice and rats, but exhibits a strong diurnal niche. As is common in diurnal species, the Rhabdomys lens acts as a long-pass spectral filter, providing limited transmission of light <400nm. Conversely, we found strong sequence homologies with the Rhabdomys SWS and MWS opsins and those of related nocturnal species (mice and rats) whose SWS opsins are maximally sensitive in the near UV. We continued to assess in vivo spectral sensitivity of cone vision using electroretinography and multi-channel recordings from the visual thalamus. These revealed that responses across the human visible range could be adequately described by those of a single pigment (assumed to be MWS opsin) maximally sensitive ~500nm, but that sensitivity in the near UV required inclusion of a second pigment whose peak sensitivity lay well into the UV range (max <400nm, likely ~360nm). We therefore conclude that, despite the UV-filtering effects of the lens, the Rhabdomys retains an SWS pigment with a UV-A max. In effect, this somewhat paradoxical combination of long-pass lens and UV-A max results in narrow-band sensitivity for SWS cone pathways in the UV-A range.




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    Transitions between the steps of forward and reverse splicing of group IIC introns [ARTICLE]

    Group II introns are mobile genetic elements that perform both self-splicing and intron mobility reactions. These ribozymes are comprised of a catalytic RNA core that binds to an intron-encoded protein (IEP) to form a ribonucleoprotein (RNP) complex. Splicing proceeds through two competing reactions: hydrolysis or branching. Group IIC intron ribozymes have a minimal RNA architecture, and splice almost exclusively through hydrolysis in ribozyme reactions. Addition of the IEP allows the splicing reaction to form branched lariat RNPs capable of intron mobility. Here we examine ribozyme splicing, IEP-dependent splicing, and mobility reactions of a group IIC intron from the thermophilic bacterium Thermoanerobacter italicus (Ta.it.I1). We show that Ta.it.I1 is highly active for ribozyme activity, forming linear hydrolytic intron products. Addition of purified IEP switches activity to the canonical lariat forming splicing reaction. We demonstrate that the Ta.it.I1 group IIC intron coordinates the progression of the forward splicing reaction through a –' interaction between intron domains II and VI. We further show that branched splicing is supported in the absence of the IEP when the –' interaction is mutated. We also investigated the regulation of the two steps of reverse splicing during intron mobility into DNA substrates. Using a fluorescent mobility assay that simultaneously visualizes all steps of intron integration into DNA, we show that completion of reverse splicing is tightly coupled to cDNA synthesis regardless of mutation of the –' interaction.




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    Correction: Histone demethylase KDM6B promotes epithelial-mesenchymal transition. [Additions and Corrections]

    VOLUME 287 (2012) PAGES 44508–44517In Fig. 1A, the wrong image for the control group was presented. The authors inadvertently cropped the control images in Fig. 1, A and E, from the same raw image. Fig. 1A has now been corrected and does not affect the results or conclusions of the work. The authors sincerely apologize for their mistake during figure preparation and for any inconvenience this may have caused readers.jbc;295/19/6781/F1F1F1Figure 1A.