• Mathematical model predicts best way to build muscle
    Mathematic

    Mathematical model predicts best way to build muscle

    Mathematical model predicts best way to build muscle
    Figure 1. The “textbook” hierarchy in the anatomy of skeletal muscle. The overall muscle is characterized by its cross-sectional area (CSA), which contains a certain number (Nc) of muscle fibers (the muscle cells with multiple nuclei or multinucleate myocytes). A given muscle has a nearly fixed number of myocytes: between Nc ≈ 1000 for the tensor tympani and Nc > 1,000,000 for large muscles (gastrocnemius, temporalis, etc. Credit: DOI: 10.1016/j.bpj.2021.07.023

    Researchers have developed a mathematical model that can predict the optimum exercise regimen for building muscle.

    The researchers, from the University of Cambridge, used methods of theoretical biophysics to construct the model, which can tell how much a specific amount of exertion will cause a muscle to grow and how long it will take. The model could form the basis of a software product, where users could optimize their exercise regimens by entering a few details of their individual physiology.

    The model is based on earlier work by the same team, which found that a component of muscle called titin is responsible for generating the chemical signals which affect muscle growth.

    The results, reported in the Biophysical Journal, suggest that there is an optimal weight at which to do resistance training for each person and each muscle growth target. Muscles can only be near their maximal load for a very short time, and it is the load integrated over time which activates the cell signaling pathway that leads to synthesis of new muscle proteins. But below a certain value, the load is insufficient to cause much signaling, and exercise time would have to increase exponentially to compensate. The value of this critical load is likely to depend on the particular physiology of the individual.

    We all know that exercise builds muscle. Or do we? “Surprisingly, not very much is known about why or how exercise builds muscles: there’s a lot of anecdotal knowledge and acquired wisdom, but very little in the way of hard or proven data,” said Professor Eugene Terentjev from Cambridge’s Cavendish Laboratory, one of the paper’s authors.

    When exercising, the higher the load, the more repetitions or the greater the frequency, then the greater the increase in muscle size. However, even when looking at the whole muscle, why or how much this happens isn’t known. The answers to both questions get even trickier as the focus goes down to a single muscle or its individual fibers.

    Muscles are made up of individual filaments, which are only 2 micrometers long and less than a micrometer across, smaller than the size of the muscle cell. “Because of this, part of the explanation for muscle growth must be at the molecular scale,” said co-author Neil Ibata. “The interactions between the main structural molecules in muscle were only pieced together around 50 years ago. How the smaller, accessory proteins fit into the picture is still not fully clear.”

    This is because the data is very difficult to obtain: people differ greatly in their physiology and behavior, making it almost impossible to conduct a controlled experiment on muscle size changes in a real person. “You can extract muscle cells and look at those individually, but that then ignores other problems like oxygen and glucose levels during exercise,” said Terentjev. “It’s very hard to look at it all together.”

    Terentjev and his colleagues started looking at the mechanisms of mechanosensing—the ability of cells to sense mechanical cues in their environment—several years ago. The research was noticed by the English Institute of Sport, who were interested in whether it might relate to their observations in muscle rehabilitation. Together, they found that muscle hyper/atrophy was directly linked to the Cambridge work.

    In 2018, the Cambridge researchers started a project on how the proteins in muscle filaments change under force. They found that main muscle constituents, actin and myosin, lack binding sites for signaling molecules, so it had to be the third-most abundant muscle component—titin—that was responsible for signaling the changes in applied force.

    Whenever part of a molecule is under tension for a sufficiently long time, it toggles into a different state, exposing a previously hidden region. If this region can then bind to a small molecule involved in cell signaling, it activates that molecule, generating a chemical signal chain. Titin is a giant protein, a large part of which is extended when a muscle is stretched, but a small part of the molecule is also under tension during muscle contraction. This part of titin contains the so-called titin kinase domain, which is the one that generates the chemical signal that affects muscle growth.

    The molecule will be more likely to open if it is under more force, or when kept under the same force for longer. Both conditions will increase the number of activated signaling molecules. These molecules then induce the synthesis of more messenger RNA, leading to production of new muscle proteins, and the cross-section of the muscle cell increases.

    This realization led to the current work, started by Ibata, himself a keen athlete. “I was excited to gain a better understanding of both the why and how of muscle growth,” he said. “So much time and resources could be saved in avoiding low-productivity exercise regimens, and maximizing athletes’ potential with regular higher value sessions, given a specific volume that the athlete is capable of achieving.”

    Terentjev and Ibata set out to constrict a mathematical model that could give quantitative predictions on muscle growth. They started with a simple model that kept track of titin molecules opening under force and starting the signaling cascade. They used microscopy data to determine the force-dependent probability that a titin kinase unit would open or close under force and activate a signaling molecule.

    They then made the model more complex by including additional information, such as metabolic energy exchange, as well as repetition length and recovery. The model was validated using past long-term studies on muscle hypertrophy.

    “Our model offers a physiological basis for the idea that muscle growth mainly occurs at 70% of the maximum load, which is the idea behind resistance training,” said Terentjev. “Below that, the opening rate of titin kinase drops precipitously and precludes mechanosensitive signaling from taking place. Above that, rapid exhaustion prevents a good outcome, which our model has quantitatively predicted.”

    “One of the challenges in preparing elite athletes is the common requirement for maximizing adaptations while balancing associated trade-offs like energy costs,” said Fionn MacPartlin, Senior Strength & Conditioning Coach at the English Institute of Sport. “This work gives us more insight into the potential mechanisms of how muscles sense and respond to load, which can help us more specifically design interventions to meet these goals.”

    The model also addresses the problem of muscle atrophy, which occurs during long periods of bed rest or for astronauts in microgravity, showing both how long can a muscle afford to remain inactive before starting to deteriorate, and what the optimal recovery regimen could be.

    Eventually, the researchers hope to produce a user-friendly software-based application that could give individualized exercise regimens for specific goals. The researchers also hope to improve their model by extending their analysis with detailed data for both men and women, as many exercise studies are heavily biased towards male athletes.


    Body builders aren’t necessarily the strongest athletes


    More information:
    Neil Ibata et al, Why exercise builds muscles: titin mechanosensing controls skeletal muscle growth under load, Biophysical Journal (2021). DOI: 10.1016/j.bpj.2021.07.023

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    University of Cambridge


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    Mathematical model predicts best way to build muscle (2021, August 23)
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  • Mathematical model predicts best way to build muscle — ScienceDaily
    Mathematic

    Mathematical model predicts best way to build muscle — ScienceDaily

    Researchers have developed a mathematical model that can predict the optimum exercise regime for building muscle.

    The researchers, from the University of Cambridge, used methods of theoretical biophysics to construct the model, which can tell how much a specific amount of exertion will cause a muscle to grow and how long it will take. The model could form the basis of a software product, where users could optimise their exercise regimes by entering a few details of their individual physiology.

    The model is based on earlier work by the same team, which found that a component of muscle called titin is responsible for generating the chemical signals which affect muscle growth.

    The results, reported in the Biophysical Journal, suggest that there is an optimal weight at which to do resistance training for each person and each muscle growth target. Muscles can only be near their maximal load for a very short time, and it is the load integrated over time which activates the cell signalling pathway that leads to synthesis of new muscle proteins. But below a certain value, the load is insufficient to cause much signalling, and exercise time would have to increase exponentially to compensate. The value of this critical load is likely to depend on the particular physiology of the individual.

    We all know that exercise builds muscle. Or do we? “Surprisingly, not very much is known about why or how exercise builds muscles: there’s a lot of anecdotal knowledge and acquired wisdom, but very little in the way of hard or proven data,” said Professor Eugene Terentjev from Cambridge’s Cavendish Laboratory, one of the paper’s authors.

    When exercising, the higher the load, the more repetitions or the greater the frequency, then the greater the increase in muscle size. However, even when looking at the whole muscle, why or how much this happens isn’t known. The answers to both questions get even trickier as the focus goes down to a single muscle or its individual fibres.

    Muscles are made up of individual filaments, which are only 2 micrometres long and less than a micrometre across, smaller than the size of the muscle cell. “Because of this, part of the explanation for muscle growth must be at the molecular scale,” said co-author Neil Ibata. “The interactions between the main structural molecules in muscle were only pieced together around 50 years ago. How the smaller, accessory proteins fit into the picture is still not fully clear.”

    This is because the data is very difficult to obtain: people differ greatly in their physiology and behaviour, making it almost impossible to conduct a controlled experiment on muscle size changes in a real person. “You can extract muscle cells and look at those individually, but that then ignores other problems like oxygen and glucose levels during exercise,” said Terentjev. “It’s very hard to look at it all together.”

    Terentjev and his colleagues started looking at the mechanisms of mechanosensing — the ability of cells to sense mechanical cues in their environment — several years ago. The research was noticed by the English Institute of Sport, who were interested in whether it might relate to their observations in muscle rehabilitation. Together, they found that muscle hyper/atrophy was directly linked to the Cambridge work.

    In 2018, the Cambridge researchers started a project on how the proteins in muscle filaments change under force. They found that main muscle constituents, actin and myosin, lack binding sites for signalling molecules, so it had to be the third-most abundant muscle component — titin — that was responsible for signalling the changes in applied force.

    Whenever part of a molecule is under tension for a sufficiently long time, it toggles into a different state, exposing a previously hidden region. If this region can then bind to a small molecule involved in cell signalling, it activates that molecule, generating a chemical signal chain. Titin is a giant protein, a large part of which is extended when a muscle is stretched, but a small part of the molecule is also under tension during muscle contraction. This part of titin contains the so-called titin kinase domain, which is the one that generates the chemical signal that affects muscle growth.

    The molecule will be more likely to open if it is under more force, or when kept under the same force for longer. Both conditions will increase the number of activated signalling molecules. These molecules then induce the synthesis of more messenger RNA, leading to production of new muscle proteins, and the cross-section of the muscle cell increases.

    This realisation led to the current work, started by Ibata, himself a keen athlete. “I was excited to gain a better understanding of both the why and how of muscle growth,” he said. “So much time and resources could be saved in avoiding low-productivity exercise regimes, and maximising athletes’ potential with regular higher value sessions, given a specific volume that the athlete is capable of achieving.”

    Terentjev and Ibata set out to constrict a mathematical model that could give quantitative predictions on muscle growth. They started with a simple model that kept track of titin molecules opening under force and starting the signalling cascade. They used microscopy data to determine the force-dependent probability that a titin kinase unit would open or close under force and activate a signalling molecule.

    They then made the model more complex by including additional information, such as metabolic energy exchange, as well as repetition length and recovery. The model was validated using past long-term studies on muscle hypertrophy.

    “Our model offers a physiological basis for the idea that muscle growth mainly occurs at 70% of the maximum load, which is the idea behind resistance training,” said Terentjev. “Below that, the opening rate of titin kinase drops precipitously and precludes mechanosensitive signalling from taking place. Above that, rapid exhaustion prevents a good outcome, which our model has quantitatively predicted.”

    “One of the challenges in preparing elite athletes is the common requirement for maximising adaptations while balancing associated trade-offs like energy costs,” said Fionn MacPartlin, Senior Strength & Conditioning Coach at the English Institute of Sport. “This work gives us more insight into the potential mechanisms of how muscles sense and respond to load, which can help us more specifically design interventions to meet these goals.”

    The model also addresses the problem of muscle atrophy, which occurs during long periods of bed rest or for astronauts in microgravity, showing both how long can a muscle afford to remain inactive before starting to deteriorate, and what the optimal recovery regime could be.

    Eventually, the researchers hope to produce a user-friendly software-based application that could give individualised exercise regimes for specific goals. The researchers also hope to improve their model by extending their analysis with detailed data for both men and women, as many exercise studies are heavily biased towards male athletes.

  • Governor Hochul Announces  Million REDI Regional Dredging Initiative Continues to Build Resiliency in Communities Along Lake Ontario
    STEAM Initiative

    Governor Hochul Announces $15 Million REDI Regional Dredging Initiative Continues to Build Resiliency in Communities Along Lake Ontario

    Governor Kathy Hochul announced today dredging is underway at Oak Orchard Harbor, a navigation channel in Orleans County, used by boaters to access Lake Ontario. The accumulation of silt, sand, and other debris can cause areas like Oak Orchard Harbor to become obstructed overtime. The dredging project will remove built-up sediment from the bottom of the waterway to allow for continued safe passage of watercraft to support the tourism economy and preserve wildlife in the region. Dredging of the navigation channel is part of a $15 million Regional Dredging Initiative through the State’s Resiliency and Economic Development Initiative.

    “Communities along Lake Ontario have been forced to grapple with the impacts of extreme weather and flooding for the past several years and New York is doing everything within its power to bolster the shoreline and ensure we do not see a repeat of 2019,” Governor Hochul said. “By undertaking these types of dredging and resiliency efforts, we are not only keeping people safe and easing the minds of lakefront homeowners, but also protecting the wildlife in the coastal habitats and helping boost tourism by creating safe recreational access for boaters.”

    The Oak Orchard Harbor project will remove approximately 8,400 cubic yards of sediment using mechanical dredging. Mechanical dredging uses heavy equipment, such as an excavator, to dig out the bed of the body of water and then remove the excess built up sediment. The dredging fleet for the Oak Orchard project includes a barge, excavator and two dump scows, as well one tugboat and one work boat to support the overall operation. Removed sediment will be placed in a designated nearshore area to the east of the harbor.

    Office of General Services Commissioner RoAnn Destito said, “With Governor Hochul’ s continued strong support and leadership, we at OGS are moving full steam ahead with the significant work that is getting accomplished under the REDI Regional Dredging Initiative. Working together with State, federal, local, and private sector partners, our efforts are benefitting recreational boaters, supporting local economies, and improving the habitats of wildlife along the great Lake Ontario and St. Lawrence River.”

    New York State Department of Environmental Conservation Commissioner and REDI Co-Chair Basil Seggos said, “The start of dredging work in Oak Orchard Harbor today marks a critical milestone in New York State’s sustained investments and infrastructure improvements in Orleans County that are strengthening protections along Lake Ontario and St. Lawrence River shoreline communities and helping New York communities rebuild stronger, smarter, and more resilient. Governor Hochul’s REDI team of experts continue to advance dredging projects that enhance harbor navigation throughout the region.”  

    State Parks Commissioner Erik Kulleseid said, “These dredging projects will be a great navigational benefit to the regional boating community, which is a vital part of the Lake Ontario and St. Lawrence River tourism and recreational economy. One of these projects this season allowed for the reopening of the boat launch at Golden Hill State Park in Niagara County, which had been closed due to sediment accumulation. These investments will result in benefits that will continue for years to come.”

    Governor Hochul also announced that there are two additional dredging projects underway in Wayne County. The Pultneyville Harbor project will remove approximately 4,000 cubic yards of sediment from the federal navigation channel using mechanical dredging. The dredging fleet includes a barge, an excavator on the barge, two dump scows and a tugboat. The sediment will be placed within a federal open lake placement area two miles north east of Sodus Bay. The Bear Creek Harbor project will remove approximately 600 cubic yards of sediment from the waterway. Dredging at this location will be undertaken in tandem with and using the same equipment as the PultneyvilleHarbor site. Sediment dredged from the harbor will be placed in a defined area of the lake to the east of the harbor. 

    Senator Robert Ortt said, “I applaud New York State and the Lake Ontario REDI Commission for identifying and proactively addressing the issue of harbor dredging in the towns and ports along Lake Ontario’s southern shore. For many of these towns, their ports are the reason the town is able to survive from a tourism and economic perspective, and the ability to access these ports is vital to their existence.” 

    Senator Pamela Helming said, “New York State has made critical investments to strengthen the local infrastructure that is essential to the economic stability and growth of our shoreline communities. These projects represent an important partnership between our counties and towns, the state, and the REDI Commission. I thank everyone involved for their continued hard work and commitment.” 

    Assemblyman Steve Hawley said, “The Oak Orchard Harbor REDI dredging project getting underway is great news for the residents of Carlton and the Lake Ontario community in general. It will assure that the harbor will continue to allow vessels to pass safely through it, and keep our regional economy growing.”

    Orleans County Legislature Chairman Lynn Johnson said, “As we look for ways to support and promote recreational activities along the shorelines of Lake Ontario, the dredging of Oak Orchard Harbor is vital to providing access to the over 400 boat slips and 6 launch lanes within the harbor.  This project undertaken by the Lake Ontario Resiliency and Economic Development Initiative demonstrates the commitment by the Governor to maintaining access to the navigable waterways that contribute to the success of the local fishing, boating and tourism activities within the Town of Carlton and Orleans County.”

    Town of Ontario Supervisor Frank Robusto said, “The REDI Program continues to assist municipalities along the Lake Ontario Shoreline in preparedness for future flooding events. The dredging at Bear Creek will ensure that the harbor remains open and safe for both visitors and those who call the town of Ontario home. We are thankful for the continued partnership with the State.”

    To date, the State has completed nine REDI dredging projects, and removed approximately 41,750 cubic yards of sediment, to provide recreational boaters with safe access to Lake Ontario and the St. Lawrence River. The completed dredging projects include Port Bay, Blind Sodus Bay and East Bay in Wayne County, Sandy Pond Inlet and Salmon River/Port Ontario in Oswego County, Irondequoit Bay and Braddock Bay in Monroe County, Little Sodus Bay in Cayuga County, and Golden Hill State Park in Niagara County.

    Through Phase I and II, the dredging initiative is tackling the necessary dredging of up to 20 harbor navigation channels. Upon completion of the project, over 100,000 cubic yards of sediment is anticipated to be dredged. 

    Future regional dredging initiative sites include:

    • Niagara County: Olcott Harbor
    • Orleans County: Johnson Creek
    • Monroe County: Sandy Creek, Long Pond Outlet
    • Jefferson County: Clayton French Creek Marina, Henderson “The Cut”
    • St. Lawrence County: Ogdensburg “City Front Channel,” Morristown Navigation Channel

    During Phase III, the State will provide counties with the information they need to update, expand, and implement an existing Regional Dredging Management Plan to keep the channels operational over time.

    In response to the extended pattern of flooding along the shores of Lake Ontario and the St. Lawrence River, REDI was created to increase the resilience of shoreline communities and bolster economic development in the region. Five REDI Regional Planning Committees, comprised of representatives from eight counties, Niagara and Orleans, Monroe, Wayne, Cayuga and Oswego, and Jefferson and St. Lawrence, were established to identify local priorities, at-risk infrastructure and other assets, and public safety concerns. 

    The REDI Commission allocated $20 million for homeowner assistance, $30 million to improve the resiliency of businesses, and $15 million toward a regional dredging effort that will benefit each of the eight counties in the REDI regions. The remaining $235 million has been allocated towards local and regional projects that advance and exemplify the REDI mission.

    For additional information on the REDI Regional Dredging Plan, project profiles and REDI news, click here.

  • UTSA hires leader to build bilingual education partnership with San Antonio ISD | UTSA Today | UTSA
    Bilingual Education

    UTSA hires leader to build bilingual education partnership with San Antonio ISD | UTSA Today | UTSA

    UTSA’s Mission

    The University of Texas at San Antonio is dedicated to the advancement of knowledge through research and discovery, teaching and learning, community engagement and public service. As an institution of access and excellence, UTSA embraces multicultural traditions and serves as a center for intellectual and creative resources as well as a catalyst for socioeconomic development and the commercialization of intellectual property – for Texas, the nation and the world.

    UTSA’s Vision

    To be a premier public research university, providing access to educational excellence and preparing citizen leaders for the global environment.

    UTSA’s Core Values

    We encourage an environment of dialogue and discovery, where integrity, excellence, inclusiveness, respect, collaboration and innovation are fostered.

    UTSA’S Destinations

    UTSA is a proud Hispanic Serving Institution (HSI) as designated by the U.S. Department of Education.

    Our Commitment to Inclusivity

    The University of Texas at San Antonio, a Hispanic Serving Institution situated in a global city that has been a crossroads of peoples and cultures for centuries, values diversity and inclusion in all aspects of university life. As an institution expressly founded to advance the education of Mexican Americans and other underserved communities, our university is committed to ending generations of discrimination and inequity. UTSA, a premier public research university, fosters academic excellence through a community of dialogue, discovery and innovation that embraces the uniqueness of each voice.