Fast Protein Fine-Tunes the Ear

first_imgRemember prestin?  It’s a motor protein in the inner ear, discovered in 2001 (03/27/2001), that acts so fast – within millionths of a second – its discoverers named it after the word “presto!” (02/21/2002).  Scientists have been studying its role as a volume adjuster (07/31/2007) that allows it to amplify sound 10,000-fold (09/19/2002) .  New evidence suggests that prestin also fine-tunes the pitch across the audible range.  A paper on this appeared this week in Current Biology.1    The human ear responds to volume differences over 12 orders of magnitude – a phenomenal dynamic range, allowing us to hear the faintest whisper of a breeze to the roar of a jet engine.  If the cochlea had the same sensitivity throughout the dynamic range, the result would be literally deafening.  The cochlea has, therefore, both fast-adaptation and slow-adaptation mechanisms to quench overpowering sounds.  An analogy might be to a sound system that instantly cuts off ear-piercing feedback then adjusts the volume level by a slider.  Prestin has been implicated in fast-adaptation.  It stiffens the outer hair cells to prevent loud sounds from blowing them over, but loosens them to respond to gentle vibrations.    The authors began their abstract, “The remarkable power amplifier of the cochlea boosts low-level and compresses high-level vibrations of the basilar membrane.”  This means your ears have a high-tech device, familiar to audio technicians, called a compressor-limiter.  You’re not hearing what is really “out there” in its raw form.  Your ear is protecting your brain by delivering processed sound.  It automatically turns up the volume on the soft sounds, and turns it down on the loud sounds.    The authors of this paper agreed that prestin is the prime contender for the power amplifier, but then found something even more amazing: prestin tunes the pitch, too.  They found to their surprise that mice with prestin knocked out were just as sensitive in the high-frequency range – but heard sounds a half-octave too low.  There appears to be a trade-off between volume sensitivity and pitch accuracy that prestin, somehow, solves.  To do this, the motor protein must be able to parse the frequency spectrum of the sound wave.  Here it is in their technical jargon:We propose that the absence of prestin from OHCs [outer hair cells in the cochlea], and consequent reduction in stiffness of the cochlea partition, changes the passive impedance of the BM [basilar membrane] at high frequencies, including the CF [characteristic frequency].  We conclude that prestin influences the cochlear partition’s dynamic properties that permit transmission of its vibrations into neural excitation.  Prestin is crucial for defining sharp and sensitive cochlear frequency tuning by reducing the sensitivity of the low-frequency tail of the tuning curve, although this necessitates a cochlear amplifier to determine the narrowly tuned tip.1.  Lagarde, Drexl, Lukashkin, Zuo and Russell, “Prestin’s Role in Cochlear Frequency Tuning and Transmission of Mechanical Responses to Neural Excitation,”Whatever is going on inside your head, when it works, it works extremely well.  The mechanisms at work to provide such exquisite sensitivity to the tiniest of air vibrations are still being figured out.  This paper shows that the initial models of how prestin works are too simple.  Their experiments on mice with and without prestin “provides further indication that neural tuning is not a direct consequence of BM [basilar membrane] tuning but depends on complex interaction between the various elements of the cochlear partition,” including prestin and the arrangement of the hair cell bundles.    Everything works as a functional unit.  Did you hear anything about evolution?  We hope not, because they never used the E-word once in their entire paper.  Their language was the lingo of auditory engineering: microphones, characteristic frequencies, amplifiers, compressor-limiters, thresholds, dynamic range and frequency response.  Ask a sound technician if he operates by random mutation and natural selection.  You are likely to get an earful.(Visited 11 times, 1 visits today)FacebookTwitterPinterestSave分享0last_img read more

How to prepare yourself for an investor: a guide

first_imgA recent survey found that many South African entrepreneurs needed help with things such as business planning. Find out more about how to prepare yourself for an investor, here.The Real State of Entrepreneurship in South Africa 2017 survey finds that some entrepreneurs do not know where to go for funding. There are various sources of funding, such as angel investors and crowdfunding. (Image: Brand South Africa)Brand South Africa reporterFunding is one of the challenges faced by many entrepreneurs in South Africa. In the Real State of Entrepreneurship in South Africa 2017 survey, many entrepreneurs indicated that they required education specific to the practicalities of running a business such as marketing support and business planning.According to the Seed Academy, which conducted the survey, there were more than 1,200 respondents this year. In addition, to deepen its insight into the true state of entrepreneurship in South Africa, the survey expanded its scope from start-ups to all entrepreneurs at any stage of business development.It was found that 18% of respondents had attempted to get funding from banks or development funding institutions such as the Industrial Development Corporation or the Department of Trade and Industry.“Some entrepreneurs indicated that they simply didn’t know where to go for funding, especially in light of the fact that most early-stage business funding requirements are below the R100,000 threshold,” said Donna Rachelson, CEO of Seed Engine, which incorporates the Seed Academy and the WDB Seed Fund. This is the third annual survey the Academy has conducted.Here are some learnings to prepare yourself before you approach an investor for funding:The different types of fundingOnline publication Entrepreneur Magazine lists the different forms of funding as angel investment, funding from a bank, crowdfunding, funding for previously disadvantaged individuals, and bootstrapping.Angel investment is when a wealthy professional provides you with start-up capital in exchange for equity in the business or a fixed percentage interest on the loan. Angel investors can be individuals or can be part of an angel network, to distribute risk.Bank funding depends on the different types of loans available and which kind is best suited to your needs. You need to provide a full set of financials and a comprehensive business plan for the bank officials to examine.Crowdfunding is similar to angel investment, but many individuals may pledge different amounts to the business in exchange for equity, interest or other more creative returns. There are South Africans platforms for crowdfunding:, and You can also try international crowdfunding platforms such as, and for previously disadvantaged individuals can be in the form of a grant, loan or tender, which is given to previously disadvantaged people who have small businesses.Bootstrapping means starting and growing your business without any external help.Essential elements an investor wantsMarketability, sustainability and the business owner’s passion for the project were the essential elements that would interest an investor, said Gerrie van Biljon, executive director of Business Partners. He told the online business network SME Toolkit South Africa that entrepreneurs should prepare a concise story around their business idea.Van Biljon also advised that the entrepreneur know every detail of their idea and business plan. “Your value proposition should come through succinctly – what are you offering to whom, and why will they be prepared to buy it.”Useful documents for preparing your business planDownload the Industrial Development Corporation’s guidelines on how to prepare a business plan; or download the Seed Academy’s Essential Guide to Funding, or download the Yali Network’s business plan checklist.Experts on what investors wantTafadzwa Madavo, business development manager at Riversands Incubation Hub, told SME South Africa that if entrepreneurs were looking for funding, they should test their ideas first. “They call it a minimal viable product. Don’t look at getting a R1-million for a concept you haven’t even tested.”Robynne Erwin, operations manager of FinFind, agreed with this sentiment. “If you are still at the ideas stage, you need to be aware of the fact that ideas are considered to be cheap. [It] only gets a value when you have taken a step to make it real.”Andrew Louw, CEO of +Louw, advised that the entrepreneur must be able to explain their idea simply and easily in 30 seconds or less. “Focus on the things you can do easily without raising funding. Also, bootstrap as far as you can without needing to raise extra capital.”Watch the three experts give more advice, here:Speaking to the University of Pretoria’s Gordon Institute of Business Science, social entrepreneurs unpacked lessons they had learned when approaching investors.Pat Pillai, founder of Lifeco UnLtd, said the fundraising secret was to always trade for change. “Whether it is an investor, or it is someone who pays you a fee to make sure you grow young entrepreneurs in the most deserving and unprivileged part of our country, there’s always a report back on a return.”Sharanjeet Shan, founder of the Maths Centre, said that clarity and conviction about who you were and what you wanted to do was important. “If you’re not talking from the gut, it’s not going to work.”She added: “Why should I invest money in these people? I’m investing money because somebody’s life is going to change. If one person’s life changes, the lives of their community and the people around them change.”Stacey Brewer, co-founder of the Spark School, said she had learned that you should not change your mission nor your vision based on funding. “Believe in what you are and keep going, keep going.”Gregory Maqoma, founder of the Vuyani Dance Theatre, explained the conversation he had with his funders: “I allow them to understand the vision.“I also allow them to understand where we’re going — we talk about a five-year strategy. So, it’s a long term commitment rather than just focusing on a project. We align ourselves with what is desirable in terms of the space that we are serving.”His company was contributing to a bigger picture. “We can also be in a position where we can say it’s not only serving the community directly affected by the Vuyani Dance Theatre but it’s also about influencing policy; it’s about influencing change on a bigger platform, on a bigger scale.”Watch the video here:Know the term ‘due diligence’?You should educate yourself about due diligence if you are on the hunt for funding for your business, or if you are hoping to work with the government or with bigger companies as a supplier.SME South Africa explained that small and medium enterprises underwent due diligence when an investor evaluated the business as a potential investment opportunity, or a buyer was looking to acquire the enterprise.“Due diligence is a process where a business owner investigates the organisation based on their needs or requirements. The investigation can be legal, financial or anything that the business owner wants to evaluate before they contract themselves,” it reported.Learn more about how “due diligence” works, here.Sources: SME Toolkit South Africa, Entrepreneur Magazine, SME South Africa, Industrial Development Corporation, the YALI Network, and Seed Engine.Would you like to use this article in your publication or on your website? See Using Brand South Africa material.last_img read more

Zite Gets New CEO, Updates to Cooperate With Publishers

first_imgTags:#mobile#news#Social Bookmarking#web Social aggregation magazine Zite (our review) released an update to its application this morning that is a direct response to the Cease & Desist letters it received from news publishers after launching the application in late March.The company also announced that it has a new CEO as Mark Johnson replaced founder Ali Davar as chief executive. Davar will step into the role of president “where he’ll lead the publisher relations team to explore innovations in publisher monetization,” according to a post on Zite’s blog.Publishers had been unhappy with Zite after its debut because it stripped ads out of its aggregated content. The update to the application now shows articles from certain publications in “Web” format as opposed to its stripped down “reading format” hence preserving the ads.See Also:UX Evolutions: News On iPadIn a post on his personal blog, new CEO Johnson says that his goals are to improve the quality of Zite’s recommendations, improve the sleek user interface and work with publishers on monetization strategies.“I liken where Zite is to the early days of search: everyone loved search engines because they allowed us to sift through the rapidly growing web, even though most searches ended up in failure,” Johnson wrote. “Similarly, Zite’s personalization isn’t perfect, but we’ve made a breakthrough advance.”Johnson has been an advisor to Zite (before it pivoted from “discovery engine” Worio) for two years before becoming the CEO today. He has worked with Microsoft on Bing and other search related startups such as Kosmix, SideStep and Powerset. From a technology perspective, Johnson is a good fit to be the CEO of Zite because the app uses its Worio search background as the basis for the iPad Magazine. Zite crawls content sources much the same way that a search engine would and returns results to the application interface. Zite also uses social media feeds to bring in content and has a recommendation engine similar to “music genome project” created by streaming music service Pandora. Related Posts A Comprehensive Guide to a Content Audit The Dos and Don’ts of Brand Awareness Videoscenter_img Facebook is Becoming Less Personal and More Pro… dan rowinski Guide to Performing Bulk Email Verificationlast_img read more

Greater Than Experience

first_imgIn most cases:Attitude: I would hire for attitude over experience. Someone with the right attitude can quickly gain experience. The person with a good attitude is a better hire than an experienced person with a poor attitude.Skills: I would also hire for skills before experience, too. Especially people skills. Someone who knows how to work with people is a better hire than someone who has experience but extremely poor people skills. Most of us produce results through and with other people.Character: A person with high character is always a better hire than someone with bad character, regardless of their experience. Severe character flaws eventually cause serious problems. Character flaws always eliminate any value in the person’s experience.Work Ethic: A person with a great work ethic is always a better hire than someone who is lazy. A hustler with little skills will outproduce an experienced person who refuses to do the work. Lazy people are never a good hire, no matter how much they know.Coachable: Coachable people are better hires than people who believe they know enough and have no real need to learn anything new. The coachable person can grow, but the non-coachable person will stagnate, becoming less effective over time.Willingness: The better hire is one who is willing to do whatever it takes over someone who is unwilling to do what is necessary. This is true even when the unwilling person has great experience. The experienced person may know what needs to be done, but not doing what needs to be done is the same as not knowing.When Experience MattersIn 1992, I had a brain surgery. In this case, I wanted the best person in the world for the operation I needed. I cared deeply about their experience with this particular type of surgery. I chose someone with extensive experience and a history of massive successes. I didn’t care about his attitude or his coachability.There are some cases where experience matters a great deal and some where experience outweighs almost any other factor. But most of the time, experience shouldn’t be weighted as heavily as it is in hiring decisions.last_img read more

Before You Start Your Side Hustle

first_img Essential Reading! Get my 2nd book: The Lost Art of Closing “In The Lost Art of Closing, Anthony proves that the final commitment can actually be one of the easiest parts of the sales process—if you’ve set it up properly with other commitments that have to happen long before the close. The key is to lead customers through a series of necessary steps designed to prevent a purchase stall.” Buy Now If you want to acquire greater business acumen faster, one way to do that is to start and manage your own business, in the popular vernacular what is called a “side hustle.” However, entrepreneurship isn’t for everyone, even though many glamorize it in this new economy.If you are going to start your side hustle, there are some things to make sure you have in place for you begin.Customer or client acquisition strategy: How are you going to find and attract customers or clients you need to run a successful business? If there is one primary reason new companies fail, it would be the most fundamental of all failures, it is that they do not acquire enough customers. A website by itself is not a customer acquisition strategy.The ability to manage a sales process: It is your responsibility to help any prospective client or customer through a process that helps them decide to buy from you and become a customer (or client). Without knowing how to manage the sales process, you make customer acquisition difficult at best, impossible at worst.The time and energy to execute: Here’s the thing about a side hustle. It’s a side hustle. That means you have a main hustle providing your present income. It may also be what’s funding your side hustle. For most people, “side hustle” means working nights and weekends. That means giving up hours in front of the television watching sports, bingeing on Netflix, and potentially spending time with the most important people in your life.External resources: If there is one thing that enables the side hustle more than anything else in this new economy, it is the proliferation of people who can provide services necessary. Whether it’s editing content, bookkeeping, marketing support, or human resources, you will need other people to do some of the work of running a business so you can focus on client acquisition, sales, and execution.A business model: This might have come first on this list, because of its critical nature. It’s last on this list because you have to have a model that allows you to be profitable. Which means the money you spend on acquiring clients, providing services, and paying for the external resources you need cannot exceed your revenue.If you want to know why businesses fail, you will likely find on this list. If you want to know why most startups never make it out of the starting gate, is because they’re missing one or more of the things in the paragraphs above.last_img read more

24 girls rescued from U.P. home


Tyson to announce his fitness center academy in Dubai

first_imgDubai, Apr 19 (PTI) Former world heavyweight boxing champion Mike Tyson has chosen the Middle Easts top city to launch his new business venture, a franchise of fitness centres called the Mike Tyson Academy (MTA). MTA has already garnered international interest with academies looking to open in the Middle East, Australia, France, West Africa and China. Tyson held the record of being the youngest boxer to win the WBA, WBC and IBF heavyweight titles at the age of 20. The 50-year-old Tyson will be revealing more about the venture on May 4 to be followed by the launch on May 6. Asked why he chose Dubai to make this announcement, Tyson said the city has established itself on the world map by hosting many leading sporting events and icons, besides attributing it to the residents obsession with fitness. “I strive to maintain consistency across all my centres with trainers that have been certified by me as well as exceptional training staff who will be on site to ensure a certain benchmark is maintained,” Tyson said. The American boxing icon added, “I am positive that this is going to be only the beginning of a long-running successful association between myself and the region.” PTI AH AHlast_img read more

Mourinho explains Fred absence for Man United

first_imgManchester United boss Jose Mourinho has no plans to use Fred until his side are defensively strongerThe Brazilian midfielder arrived at Old Trafford in the summer from Shakhtar Donetsk in a £52m deal.But life at United hasn’t gone to plan for Fred with just 10 appearances in all competitions this season and he hasn’t featured in the club’s last four Premier League matches.“Step by step,” said Mourinho on the club website, about Fred’s adaption.harry maguire, manchester UnitedMaguire says United need to build on today’s win George Patchias – September 14, 2019 Harry Maguire wants his United teammates to build on the victory over Leicester City.During the summer, Harry Maguire was referred to as the ultimate…“You also have other players at other clubs that needed their time and you have some of them that play even less than what Fred is playing.“I think Fred [will play more], when the team is defensively stronger and doesn’t need in midfield people that are more worried about giving some balance to the team than being involved in the creation and attacking dynamics.“The day we are stronger defensively, I think the horizons for Fred change completely.”United will host Fulham at Old Trafford this Saturday in the Premier League.last_img read more

Felix Dennis in Deal Talks With American Magazine


Union Budget 2013 Live Blog FM Proposes Exclusive Bank for Women ₹1000