Connect with us

Technology

Scientists find coral reefs emit dazzling colours as ‘sunscreen’ against warming waters

Published

on


Corals during a colourful bleaching event in the Philippines in 2010 (Credits: PA)

Some corals emit a ‘sunscreen’ in the form of a dazzling colourful display to protect them from rising sea temperatures, according to new research.

Scientists at the University of Southampton believe that the corals emit the bright neon colours in a fight for survival.

The team from the university’s coral reef laboratory explained in a report published in the journal Current Biology that many coral animals live in a fragile symbiosis with algae embedded in their cells.

A rise in water temperature of just 1C can cause this relationship to break down causing the algae to be lost leaving the coral’s limestone skeleton exposed through its transparent tissue leading to the fatal condition of coral bleaching.

But the study found that in mild or brief warming incidents, some coral produced a type of sunscreen which takes the form of the colourful display which encourages the algae to return in an ‘optical feedback loop’.

The University of Southampton's waterfront campus where researchers looked at how corals protect themselves against warming temperatures. (Credits: PA)

The University of Southampton’s waterfront campus where researchers looked at how corals protect themselves against warming temperatures. (Credits: PA)

Professor Jorg Wiedenmann explained: ‘Our research shows colourful bleaching involves a self-regulating mechanism, a so-called optical feedback loop, which involves both partners of the symbiosis.

‘In healthy corals, much of the sunlight is taken up by the photosynthetic pigments of the algal symbionts.

‘When corals lose their symbionts, the excess light travels back and forth inside the animal tissue, reflected by the white coral skeleton.

‘This increased internal light level is very stressful for the symbionts and may delay or even prevent their return after conditions return to normal.

‘However, if the coral cells can still carry out at least some of their normal functions, despite the environmental stress that caused bleaching, the increased internal light levels will boost the production of colourful, photoprotective pigments.

‘The resulting sunscreen layer will subsequently promote the return of the symbionts.’

Staghorn corals during a colourful bleaching event in New Caledonia in 2016. (Credits: PA)

Staghorn corals during a colourful bleaching event in New Caledonia in 2016. (Credits: PA)

‘As the recovering algal population starts taking up the light for their photosynthesis again, the light levels inside the coral will drop and the coral cells will lower the production of the colourful pigments to their normal level.’

Dr Cecilia D’Angelo, lecturer of molecular coral biology at Southampton, added: ‘Bleaching is not always a death sentence for corals, the coral animal can still be alive.’

Staghorn corals during a colourful bleaching event off Lizard Island in 2010.  (Credits: PA)

Staghorn corals during a colourful bleaching event off Lizard Island in 2010. (Credits: PA)

‘If the stress event is mild enough, corals can re-establish the symbiosis with their algal partner.

‘Unfortunately, recent episodes of global bleaching caused by unusually warm water have resulted in high coral mortality, leaving the world’s coral reefs struggling for survival.’



Source link

قالب وردپرس

Continue Reading
Click to comment

Leave a Reply

Your email address will not be published. Required fields are marked *

Technology

How to Use Dictation on a Mac for Voice-to-Text Typing

Published

on


Typing isn’t for everyone. If you have clumsy fingers or difficulty spelling, typing might be your least favorite part of using a computer. Fortunately, you can use the built-in dictation software on your Mac to speak what you want to type instead.

Unlike Voice Control—which is Apple’s fully-featured accessibility tool—dictation is easy to use. It’s also so accurate at translating your voice that some of the best dictation software developers, like Dragon Dictate, stopped making their own dictation apps for Mac to compete with it.

How to Use Dictation on a Mac

Popup window for enabling Dictation on a Mac

Double-press the Fn button to start dictating on your Mac. You should see a microphone icon appear or hear a macOS confirmation tone. If this is your first time using Dictation, click OK in the popup window to confirm you want to use it.

After activating Dictation, start saying what you want to type to see it appear on screen. Dictation ignores pauses in your speech, allowing you to take a moment to compose your thoughts. However, this does mean you need to dictate your own punctuation, which we explain below.

Dictation microphone icon on Mac

Apple suggests you dictate in short bursts of 40 seconds or less. This keeps your Mac from falling behind, since you can speak much faster than it can process what you say.

You can dictate text anywhere you’d usually type on your Mac. That includes writing documents, using Spotlight or search bars, entering web addresses, and composing emails. If that sounds useful, you might want to take a look at these dictation apps for your Android phone as well.

Use any of the following methods to stop dictating:

  • Press Fn again
  • Hit Return
  • Click Done beneath the microphone

Your dictated words appear underlined while your Mac is processing them. After you stop dictating, they’ll reformat themselves, and any words your Mac was unsure of appear underlined in blue. Click these words to pick an alternative option or type it out manually if it was wrong.

The more you use Dictation, the better your Mac gets at understanding your voice. This means you’ll see fewer mistakes and words underlined in blue less often.

How to Add Punctuation and Format Your Dictation

Chances are that you need to add punctuation to your dictation to make sure it’s formatted correctly. This is easy to do while dictating your text by saying the particular punctuation marks you want to add.

For example, to dictate the following text:

Hello, my name is Dan. How are you?

You need to say:

Hello comma my name is Dan period how are you question mark

Dictation on a Mac with punctuation

Apple includes a long list of over 50 punctuation marks, typography symbols, currency signs, mathematical signs, and voice commands you can use with Dictation in the macOS user guide. Visit Apple’s voice dictation commands page to take a look at the list yourself.

Along with adding punctuation, you can also use a small set of voice commands to change the formatting of dictated text on your Mac. These commands include capitalization, line breaks, and even typing without spaces.

Say the following voice commands to format text with Dictation:

  • New Line: Equivalent to pressing the Return key once
  • New Paragraph: Equivalent to pressing the Return key twice
  • Caps On/Off: Types the following words in “Title Case”
  • All Caps On/Off: Types the following words in “ALL CAPS”
  • No Space On/Off: Types the following words “withoutspaces” (useful for website URLs)

Troubleshoot Dictation Problems on Your Mac

Dictation is a fairly simple tool, but it doesn’t work all the time. There are a few different problems that might stop you from being able to use Dictation on your Mac. Here’s what they are and how to fix them.

Change the Dictation Shortcut

If nothing happens when you double-press the Fn button, you might have changed the Dictation shortcut on your Mac. You can change this shortcut to whatever you like, or check what the new shortcut is and use that instead.

To do so, open System Preferences and go to Keyboard > Dictation. Open the Shortcut dropdown menu and choose the dictation shortcut you want to use. To create your own, click Customize, then press the keyboard shortcut you’d like.

Dictation shortcut dropdown menu in System Preferences

Test Your Internet Connection

Your Mac requires an active internet connection to use Dictation. This is because Apple processes your voice on its servers—using the latest language data—rather than locally on your Mac.

Without an internet connection, the microphone icon appears with three dots in it, but vanishes before you can start dictating.

To make sure your internet connection is working, try streaming a video on YouTube. To fix problems with your connection, restart your Wi-Fi router and follow our steps to get your Mac connected to Wi-Fi again. Contact your internet service provider for more help.

Choose a Different Microphone to Use

As you dictate, you should see a white bar in the microphone icon that fluctuates with the loudness of your voice. This shows the microphone input on your Mac. If nothing appears in the microphone, your Mac can’t hear you. You need to use a different microphone to fix it.

Go to System Preferences > Keyboard > Dictation. Open the dropdown menu beneath the microphone at the left of the window to choose a different microphone. If you can’t see your microphone, make sure it’s connected with the latest drivers installed.

Microphone selection from Dictation System Preferences

Change the Dictation Language

To dictate in a different language, you need to add that language in System Preferences and select it from the Dictation icon. Using the wrong language results in a lot of mistakes, as Dictation will use regional spellings or replace what you said with similar-sounding words from another language.

In System Preferences, go to Keyboard > Dictation and open the Language dropdown menu. Click Add Language and check the box next to whichever languages you want to use. Make sure you choose the appropriate region if your language is used in multiple countries.

The next time you activate Dictation, you should see the current language displayed beneath the microphone icon. Click it to change to another dictation language instead.

Dictation microphone with language options

How to Make Dictation as Private as Possible

Dictation communicates with Apple’s servers to convert your speech to text. This means it’s never completely private, as explained by the popup message that appears when you enable Dictation for the first time. That said, there are still steps you can take to reclaim as much Dictation privacy as possible.

To change the data Dictation uses, open System Preferences and click on Security & Privacy. Go to the Privacy tab and scroll down to select Analytics & Improvements in the sidebar. Disable the option to Improve Siri & Dictation to stop Apple from storing or reviewing your future Dictation recordings.

Improve Siri & Dictation option in Privacy System Preferences

Apple usually does this to help improve Dictation. Even with this option disabled, you still need to delete existing recordings from Apple’s servers. Go to System Preferences > Siri and click Delete Siri & Dictation History to do so.

Do More With Your Voice Using Voice Control

Although many people confuse the two, Dictation and Voice Control are two separate features on your Mac. As we’ve explained, Dictation allows you to convert your speech to text, adding punctuation and line breaks where necessary. But Voice Control unlocks an entire world of voice commands that control your Mac.

If you want to save documents, switch applications, open menus, and do much more with your voice, you need to use Voice Control. This is primarily an accessibility tool; it lets anyone control a Mac using nothing but their voice. Take a look at our Mac Voice Control guide to learn how it works.

Read the full article: How to Use Dictation on a Mac for Voice-to-Text Typing



Source link

قالب وردپرس

Continue Reading

Technology

Of course technology perpetuates racism. It was designed that way.

Published

on


Today the United States crumbles under the weight of two pandemics: coronavirus and police brutality. 

Both wreak physical and psychological violence. Both disproportionately kill and debilitate black and brown people. And both are animated by technology that we design, repurpose, and deploy—whether it’s contact tracing, facial recognition, or social media.

We often call on technology to help solve problems. But when society defines, frames, and represents people of color as “the problem,” those solutions often do more harm than good. We’ve designed facial recognition technologies that target criminal suspects on the basis of skin color. We’ve trained automated risk profiling systems that disproportionately identify Latinx people as illegal immigrants. We’ve devised credit scoring algorithms that disproportionately identify black people as risks and prevent them from buying homes, getting loans, or finding jobs.

So the question we have to confront is whether we will continue to design and deploy tools that serve the interests of racism and white supremacy, 

Of course, it’s not a new question at all.

Uncivil rights

In 1960, Democratic Party leaders confronted their own problem: How could their presidential candidate, John F. Kennedy, shore up waning support from black people and other racial minorities?

An enterprising political scientist at MIT, Ithiel de Sola Pool, approached them with a solution. He would gather voter data from earlier presidential elections, feed it into a new digital processing machine, develop an algorithm to model voting behavior, predict what policy positions would lead to the most favorable results, anf then advise the Kennedy campaign to act accordingly. Pool started a new company, the Simulmatics Corporation, and executed his plan. He succeeded, Kennedy was elected, and the results showcased the power of this new method of predictive modeling.

Racial tension escalated throughout the 1960s. Then came the long, hot summer of 1967. Cities across the nation burned, from Birmingham, Alabama, to Rochester, New York, to Minneapolis Minnesota, and many more in between. Black Americans protested the oppression and discrimination they faced at the hands of America’s criminal justice system. But President Johnson called it “civil disorder,” and formed the Kerner Commission to understand the causes of “ghetto riots.” The commission called on Simulmatics. 

As part of a DARPA project aimed at turning the tide of the Vietnam War, Pool’s company had been hard at work preparing a massive propaganda and psychological campaign against the Vietcong. President Johnson was eager to deploy Simulmatics’s behavioral influence technology to quell the nation’s domestic threat, not just its foreign enemies. Under the guise of what they called a “media study,” Simulmatics built a team for what amounted to a large-scale surveillance campaign in the “riot-affected areas” that captured the nation’s attention that summer of 1967.

Three-member teams went into areas where riots had taken place that summer. They identified and interviewed strategically important black people. They followed up to identify and interview other black residents, in every venue from barbershops to churches. They asked residents what they thought about the news media’s coverage of the “riots.” But they collected data on so much more, too: how people moved in and around the city during the unrest, who they talked to before and during, and how they prepared for the aftermath. They collected data on toll booth usage, gas station sales, and bus routes. They gained entry to these communities under the pretense of trying to understand how news media supposedly inflamed “riots.” But Johnson and the nation’s political leaders were trying to solve a problem. They aimed to use the information that Simulmatics collected to trace information flow during protests to identify influencers and decapitate the protests’ leadership.

They didn’t accomplish this directly. They did not murder people, put people in jail, or secretly “disappear” them.

But by the end of the 1960s, this kind of information had helped create what came to be known as “criminal justice information systems.” They proliferated through the decades, laying the foundation for racial profiling, predictive policing, and racially targeted surveillance. They left behind a legacy that includes millions of black and brown women and men incarcerated.

Reframing the problem

Blackness and black people. Both persist as our nation’s—dare I say even our world’s—problem. When contact tracing first cropped up at the beginning of the pandemic, it was easy to see it as a necessary but benign health surveillance tool. The coronavirus was our problem, and we began to design new surveillance technologies in the form of contact tracing, temperature monitoring, and threat mapping applications to help address it. 

But something both curious and tragic happened. We discovered that black people, Latinx people, and indigenous populations were disproportionately infected and affected. Suddenly, we also became a national problem; we disproportionately threatened to spread the virus. That was compounded when the tragic murder of George Floyd by a white police officer sent thousands of protesters into the streets. When the looting and rioting started, we—black people—were again seen as a threat to law and order, a threat to a system that perpetuates white racial power. It makes you wonder how long it will take for law enforcement to deploy those technologies we first designed to fight covid-19 to quell the threat that black people supposedly pose to the nation’s safety.

If we don’t want our technology to be used to perpetuate racism, then we must make sure that we don’t conflate social problems like crime or violence or disease with black and brown people. When we do that, we risk turning those people into the problems that we deploy our technology to solve, the threat we design it to eradicate.

—Charlton McIlwain is a professor of media, culture, and communication at New York University and author of Black Software: The Internet & Racial Justice, From the AfroNet to Black Lives Matter



Source link

قالب وردپرس

Continue Reading

Technology

Surviving The Pandemic As A Hacker: Peering Behind The Mask

Published

on


We’re now several months into the global response to the COVID-19 pandemic, with most parts of the world falling somewhere on the lockdown/social distancing/opening up path.

It’s fair to say now that while the medical emergency has not passed, the level of knowledge about it has changed significantly. When communities were fighting to slow the initial spead, the focus was on solving the problem of medical protection gear and other equipment shortages at all costs with some interesting yet possibly hazardous solutions. Now the focus has moved towards protecting the general public when they do need to venture out, and as society learns to get life moving again with safety measures in place.

So, we all need masks of some sort. What type to do you need? Is one type better than another? And how do we all get them when everyone suddenly needs what was once a somewhat niche item?

Masks Offer Basic Protection for Everyone in Public Areas

It’s rather sickening to look at the quantity of droplets expelled by a sneeze. James Gathany / Public domain

Some parts of the world are coming to terms with the effects of long term lockdown, while others are beginning to contemplate how they might start moving back towards some kind of normality. The issue of mask wearing a practical one, because there are indications that it will slow the spread of the disease.

When considering face masks, it’s important to start by defining what a mask for the general public should be, and what it is trying to achieve. This is not the same breed as the masks worn by intensive care staff where the primary intention is to protect the wearer by filtering the virus from an atmosphere heavily contaminated with it, instead it is a mask intended to be worn in environments where only a few people may be spreading the virus (with the pesky detail of not knowing who those few people are).

The goal of masks is to reduce the chances of transmission by infected droplets. It’s an idea wittily illustrated in the “Urine Test” meme, that such a mask will not guarantee your escape from the virus but it should significantly reduce the odds of its transmission. We’re told that these odds tilt further against the virus the more people in an environment wear a mask, and since it’s a relatively easy step to take it’s one that everyone should be taking as a courtesy to your fellow humans.

We’re Makers, Yes… But You Can Learn a Lot From Commercial Masks

In our community the first thought turns invariably towards making our own and indeed that’s part of the official advice in many territories, but before we go there it’s worth considering the commercial alternatives. These normally use a composite design featuring multiple layers of fabric for comfort and filtration, with the main filter layer(s) being of a blown fabric rather than a woven one.

A variety of commercial masks, left to right: FFP3 industrial dust mask, T32610-2016 surgcal-style mask, very cheap unrated single layer dust mask.ic
A variety of commercial masks, left to right: FFP3 industrial dust mask, T32610-2016 surgical-style mask, very cheap unrated single layer dust mask.

If you have a supply of the top-spec medical masks then you’re all set, but since pandemic demand has caused a supply shortage that’s a luxury most of us can’t claim and shouldn’t be taking from the professionals who need them anyway. We will often have an array of other masks to hand as dust protection in the workshop, and among these can be found some surprisingly good protection for our application. The key is in the rating which should be printed on the box or the outside of the mask, but to decode what it means will sometimes require a bit of digging into the world of international standards.

Assuming that you didn’t buy from the cheapest seller on AliExpress and your mask isn’t counterfeit, you may encounter US standards (N95 etc), EU standards (EN149, FFP etc.), or Chinese standards (T3210-2016 etc.). These deal among other properties with the mask’s particulate filtration ability both in terms of particle size and percentage removal, and with the breathing force required to make air pass through them. Happily our requirement for a droplet-catcher does not require the most stringent of standards. As an aside, the official versions of all the above mentioned standards seem all to be behind very expensive paywalls. It’s not difficult to find them online through your search engine though.

Tearing Down Some Masks

Five layers in this FFP3 dust mask.
Five layers in this FFP3 dust mask.

So casting around the commercial masks we have to hand here brings out a pair of dust masks and a surgical style mask that admirably illustrate the range on offer. An FFP3 dust mask is a European-rated rough equivalent of those N95 surgical masks in industrial form, and it feels thick between finger and thumb. Despite having probably the best available filtration, our FFP3 is not suitable as virus protection because it manages exhalation through a non-return valve that would release droplets into the atmosphere.

Taking the used FFP3 mask from my overall pocket that has protected me from dust during several woodwork machining sessions at MK Makerspace and cutting it open, it is revealed as having five non-woven layers including a thick and fluffy one and a very dense one. When compressed with a micrometer screw gauge its thickness is a relatively substantial 0.94mm.

Three layers in this T32610-2016 surgical-style mask.
Three layers in this T32610-2016 surgical-style mask.

The next mask up for dissection is a Chinese-manufactured three-layer surgical mask with T3210-2016 spec, whose box clearly states that it isn’t a medical device. That warning sounds concerning but in this case it isn’t; masks to that particular standard are intended to be worn by the general public and not by medical staff. In fact this mask is purpose-made as everyday-life dust and droplet-catching PPE, so is just the job. Cutting it open reveals three layers with the middle filter layer being a dense non-woven fabric, and the micrometer reveals it to have a svelte 0.28mm compressed thickness.

The final mask is another dust mask, a Silverline single-layer mask from a pack I bought for showing people round a dusty church tower. It’s a single layer of 0.45mm thick stiff blown-polymer fabric moulded into a mask shape, and its packaging has the ominous warning that it does not offer rated protection to the wearer. It was very cheap indeed and just about adequate for the purpose I bought it for, but I have to admit I’d be happier with more than its very basic level of protection during the pandemic.

With steamed up glasses and an unruly lockdown hairstyle, illustrating the importance of a good seal round the nose.
With steamed up glasses and an unruly lockdown hairstyle, illustrating the importance of a good seal round the nose.

All three masks feature a piece of stiff wire or metal strip above the nose designed to fit the contours of the bridge of the nose and clamp shut any gaps through which breath can escape. It’s easy to tell whether they are effective if you wear glasses, because they will immediately steam up if damp air from your breath escapes. Of the three it was the disposable surgical-style mask that did the worst job of this, the FFP3 had a very sturdy plastic and wire tape that lets nothing through and the cheap unrated mask has a metal strip, but the surgical-style mask’s single piece of thin wire simply isn’t up to the job.

I’ve worn all three for extended periods of time to test them, and while driving into town for a prescription wearing this one I had to stop and take it off as the risk of not seeing where I was going became too great. This can be mitigated with folded-up kitchen towel to plug the gaps or even medical tape to secure it, but such things rapidly become very annoying.

As for the fogging, there is some advice out there for this as well. Using dish soap that does not have lotion in it, or say that it’s for sensitive skin will work. Apply to the inside of the lens, let sit a bit, then buff it until clear. The same is said to work with shaving cream although I’ve yet to try either method.

Freedom To Be Uninfected

What’s to be gained from this insight into masks and their construction? In the first instance, it pays to be educated and informed when finding a mask for yourself. Over the past few months I’ve been offered the chance to buy masks from everyone from my PCB supplier through the local tool shop to my stationery provider, alongside any number of unsolicited emails. It’s a confusing marketplace with traps for the unwary that with luck will have become a little clearer.

In the next part of this series I will look at home made mask design and demonstrate how I have made masks of my own. Dust off your sewing machine, that article will be out next week.



Source link

قالب وردپرس

Continue Reading

Trending