Are Honeybees Losing Their Way?

A single honeybee visits hundreds, sometimes thousands, of flowers a day in search of nectar and pollen. Then it must find its way back to the hive, navigating distances up to five miles (eight kilometers), and perform a "waggle dance" to tell the other bees where the flowers are.

A new study shows that long-term exposure to a combination of certain pesticides might impair the bee's ability to carry out its pollen mission.

"Any impairment in their ability to do this could have a strong effect on their survival," said Geraldine Wright, a neuroscientist at Newcastle University in England and co-author of a new study posted online February 7, 2013, in the Journal of Experimental Biology.

Wright's study adds to the growing body of research that shows that the honeybee's ability to thrive is being threatened. Scientists are still researching how pesticides may be contributing to colony collapse disorder (CCD), a rapid die-off seen in millions of honeybees throughout the world since 2006.

"Pesticides are very likely to be involved in CCD and also in the loss of other types of pollinators," Wright said. (See the diversity of pollinating creatures in a photo gallery from National Geographic magazine.)

Bees depend on what's called "scent memory" to find flowers teeming with nectar and pollen. Their ability to rapidly learn, remember, and communicate with each other has made them highly efficient foragers, using the waggle dance to educate others about the site of the food source.

Watch as National Geographic explains the waggle dance.

Their pollination of plants is responsible for the existence of nearly a third of the food we eat and has a similar impact on wildlife food supplies.

Previous studies have shown certain types of pesticides affect a bee's learning and memory. Wright's team wanted to investigate if the combination of different pesticides had an even greater effect on the learning and memory of honeybees.

"Honeybees learn to associate floral colors and scents with the quality of food rewards," Wright explained. "The pesticides affect the neurons involved in these behaviors. These [affected] bees are likely to have difficulty communicating with other members of the colony."

The experiment used a classic procedure with a daunting name: olfactory conditioning of the proboscis extension reflex. In layman's terms, the bee sticks out its tongue in response to odor and food rewards.

For the experiment, bees were collected from the colony entrance, placed in glass vials, and then transferred into plastic sandwich boxes. For three days the bees were fed a sucrose solution laced with sublethal doses of pesticides. The team measured short-term and long-term memory at 10-minute and 24-hour intervals respectively. (Watch of a video of a similar type of bee experiment.)

This study is the first to show that when pesticides are combined, the impact on bees is far worse than exposure to just one pesticide. "This is particularly important because one of the pesticides we used, coumaphos, is a 'medicine' used to treat Varroa mites [pests that have been implicated in CCD] in honeybee colonies throughout the world," Wright said.

The pesticide, in addition to killing the mites, might also be making honeybees more vulnerable to poisoning and effects from other pesticides.

Stephen Buchmann of the Pollinator Partnership, who was not part of Wright's study, underscored how critical pollinators are for the world. "The main threat to pollinators is habitat destruction and alteration. We're rapidly losing pollinator habitats, natural areas, and food—producing agricultural lands that are essential for our survival and well being. Along with habitat destruction, insecticides weaken pollinators and other beneficial insects."

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Ship Stranded: Love Boat to Horror Honeymoon

A Texas couple's fantasy wedding quickly turned into a nightmare honeymoon when the fire-damaged Carnival Cruise ship carrying them became stranded in the Gulf of Mexico.

Rob Mowlam, 37, and Stephanie Stevenson, 27, of Nederland, Texas, got married on the Carnival Triumph on Saturday. The four-day cruise was meant to be back to shore on Monday, but was left disabled by an engine fire on Sunday.

The ship is being slowly towed to shore and is expected to dock in Mobile, Ala., on Thursday if weather permits. The vessel is without air conditioning, many working toilets and some restaurant service. Passengers, many who are sleeping in tents on deck, have told ABC News the smell on the ship is foul.

That is the honeymoon setting for Mowlam and Stevenson.

"[Rob Mowlam] had been with his girlfriend, or fiance, for a long period of time and they just took the next step," Mowlam's brother James Mowlam III told ABCNews.com. "The captain is the king of the world when they're on the boat and he hitched them up."

James Mowlam said he was shocked when he heard about the stranded boat and the increasingly dire conditions on the ship.

"It is an atrocious scene to be subjected to," he said.

Mowlam said he has not been able to communicate with his brother, but that his father has had sporadic communication with him.

"It would be my guess that this would probably not be on anyone's great list of memorable wedding experiences," Mowlam said with a laugh. "Although, my mom told him that she was hoping they had a memorable wedding and I think this would classify as a memorable wedding experience."

Lt. Cmdr. Paul McConnell/U.S. Coast Guard/AP Photo

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The bride's brother, Justin Davis, told ABCNews.com that his sister works for a doctor's office and the cruise was a gift from the doctor to the staff.

Davis has not been able to speak to Stevenson but said that her two young sons are being cared for by her mother. He said his sister is tough and he guesses she's probably not scared.

"She might be a little aggravated at the situation, but I'd say she's [probably] handling it really well," he said.

Others on the ship do not seem to be handling the situation so well.

Elderly and disabled passengers aboard the ship are struggling to cope with the worsening conditions, according to at least one passenger.

"Elderly and handicap are struggling, the smell is gross," passenger Ann Barlow text-messaged ABC News overnight. "Our room is leaking sewage."

The head of Carnival Cruise Lines said the British-U.S.-owned company was working hard to ensure the thousands of passengers stranded on the disabled ship were as comfortable as possible while the vessel was being towed to a port in Alabama.

"I need to apologize to our guests and to our families that have been affected by a very difficult situation," Carnival Cruise Lines president and CEO Gerry Cahill said at a news conference Tuesday evening.

It was the first time since a fire erupted in Triumph's engine room Sunday, knocking out its four engines, that a company representative had spoken publicly. The Triumph, with roughly 4,200 people on board, was left bobbing like a 100,000-ton cork for more than 24 hours. Giant sea-faring tugboats then hooked up to the ship and began towing the nearly 900-foot-long ship to land.

Carnival spokeswoman Joyce Oliva told The Associated Press Tuesday that a passenger with a pre-existing medical condition was taken off the ship as a precaution. Everyone else will likely have to weather conditions such as scarce running water, no air conditioning and long lines for food.

Back on land, passenger Barlow's 11-year-old twins told ABC News Tuesday they are worried as more passengers continue to talk about living with limited power and sanitation.

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Plants listen more closely to kin than strangers

It is not just humans that like a natter with their nearest and dearest – plants pay most attention to their closest relatives.

When an insect bites a leaf, many plants release volatile chemicals to prime their neighbours for attack. The defences this triggers vary – some plants respond by attracting predatory insects that eat the herbivores, others make themselves less tasty.

Now Richard Karban of the University of California, Davis, has shown that for the sagebrush, responses to these warning signals can vary with relatedness.

At the start of three growing seasons, Karban's team exposed different branches of the same plants to volatile chemicals. The substances came from relatives of the same species whose leaves had been clipped to trigger chemical release.

By the end of the seasons, herbivores had done less damage to the branches exposed to chemicals from close relatives than to those receiving signals from more distant relatives – the warning probably prompting the plants to release herbivore-deterring chemicals, says Karban.

He has previously shown that the blend of volatiles varies enormously between individuals – "so much so that big peaks in some individuals are undetectable in others", he says.

However, there is some similarity between family members. Karban thinks this variability is being exploited by the plants as a kind of family-specific signature, to prevent eavesdroppers from listening in and to give those that share the same genes a greater chance of survival.

Some plants are genetically more resistant to being eaten than others, so it makes sense that plants should care more about their kin's fate than that of the general population.

"It is very elegant work," says Susan Dudley from McMaster University in Ontario, Canada, who has shown that plants competing for space in a small pot are less aggressive if they are related to their neighbours.

She thinks this kind of kin-recognition is probably common among many plants.

Journal Reference: Proceedings of the Royal Society B, doi: 10.1098/rspb.2012.3062

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17 gunmen dead in Thai military base attack

 

BANGKOK, Thailand: Scores of heavily-armed gunmen stormed a military base in unrest-plagued southern Thailand, an army spokesman said on Wednesday, in a major assault that left at least 17 militants dead.

"Some 100 fully armed militants stormed the base, where there were 60 marines," Colonel Pramote Promin, southern army spokesman, told AFP.

He said the attack, one of the most ambitious in several years of violence in Thailand's three southernmost provinces, had left at least 17 assailants dead. No military casualties were reported.

- AFP/de

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Shatner: J.J. Abrams a 'pig' for taking on 'Star Wars'

William Shatner speaks to Movie Fanatic.

(Credit:
Video screenshot by Amanda Kooser/CNET)

J.J. Abrams is a busy man. The director who breathed new life into the "Star Trek" film franchise recently agreed to helm the new "Star Wars" movie. This may have fueled geeky fever dreams of crossover "Star Trek"/"Star Wars" projects, but it also led to some head-scratching. Does Abrams really have time to head up two major sci-fi film series?

"Star Trek" did have Abrams first. His sudden commitment to "Star Wars" may have left a few Trekkies feeling like they've gotten involved in an unexpected cinematic menage a trois. That's why I have some sympathy for William Shatner's recent comments to Movie Fanatic.

When asked to share his thoughts on Abrams adding "Star Wars" to his resume, Shatner said, "He's being a pig. He's collecting the two franchises and holding them close to his vest. And he's probably the most talented director of that ilk we have, but he's gone too far this time."

It sounds like we have a little bit of sci-fi smack talk going on here. Shatner goes on to say that he thinks of Abrams as a buddy and they've had sushi together. Then, things take a turn toward the heart of the matter. Shatner says he needs to have another talk with Abrams about his foolhardiness in not employing Shatner for either franchise.

We all know Shatner has a sense of humor, but his body language and tone come across as pretty serious in the video of the interview. It looks like he's not satisfied with just doing Priceline commercials anymore. I'm trying to imagine what role he would play in "Star Wars." Darth Tiberius, anyone?

(Via GeekTyrant)

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Where Will Pope Benedict XVI Retire?

Someone with a suspicious mind and deep knowledge of Vatican trivia might have guessed that something was going on months ago. Last November, a community of cloistered nuns vacated the  Mater Ecclesiae monastery, located inside Vatican Gardens, two years before they were expected to do so.

The monastery has since been closed for renovation.

On Monday, in the press conference that followed Pope Benedict XVI's announcement that he will resign at the end of the month, Father Federico Lombardi, director of the Holy See Press Office,  revealed that the monastery will be the retired pontiff's new home. (Photo Gallery: Inside the Vatican.)

"When renovation work on the monastery of cloistered nuns inside the Vatican is complete, the Holy Father will move there for a period of prayer and reflection," Lombardi said.

Until then, the pope will stay at the Apostolical Palace and the Pontifical Villas in Castel Gandolfo, a small lake town about 15 miles (24 kilometers) southeast of Rome, which serves as the traditional summer residence for popes.

The Mater Ecclesiae monastery was founded in 1992 by Benedict's predecessor, John Paul II, "to create a place to house an international convent for contemplative life within the walls of Vatican City," according to the Vatican City State website.

It has housed small communities of cloistered nuns whose main task has been to provide spiritual assistance to the pope and to the Roman Catholic Church as a whole by praying in Latin and singing Gregorian chants.

The nuns would also embroider papal garments and cultivate a small organic orchard and a rose garden next to their residence. In a 2009 interview with the Vatican newspaper L'Osservatore Romano, the monastery's then abbess said that Benedict particularly appreciated the special-recipe marmalade that the nuns would prepare out of the oranges and lemons they picked in the Vatican orchard.

It is not yet clear for how long the soon-to-be-former pope will stay at the monastery. Lombardi has said that Benedict will not participate in the March conclave that will elect his successor, stressing that there will be "no confusion or division arising from his resignation."

Lombardi also said that he wasn't sure of Benedict's future title-there are no canon law provisions or historical precedents regarding the statute, prerogatives, or titles for a retired pope.

Resignations of Popes Past

Only a handful of popes have willfully or forcefully resigned in the church's history, the last case going back to 1415, almost 600 years ago.

"It was Pope Gregory XII, who, in a very sacrificial gesture, offered to resign so that the Council of Constance could assume his power and appoint a new pope, and in so doing bring an end [to the] Great Western Schism," Donald Prudlo, associate professor of history at Jacksonville State University in Alabama, told Vatican Radio.

Italian and foreign commentators have been likening Benedict's choice to a famous case of papal abdication-that of Celestine V, who was elected in 1294 and left the Roman throne only five months later.

"At the end of the 13th century, a very holy hermit named Peter was elected as Pope Celestine V in order to break a deadlock in the conclave that had lasted nearly three years," Prudlo explained. "He was elected because of his personal holiness, sort of a unity candidate. And once he got there, being a hermit, not used to the ways of the Roman Curia, he found himself somewhat unsuited to the task."

So he resigned and lived as a hermit—or, some historians say, as a prisoner—in a castle belonging to his successor, Boniface VIII, before dying in 1296.

Celestine is widely recognized as the object of Dante Alighieri's scolding verses in his Divine Comedy. The former pope was proclaimed saint in 1313.

In 2009, Benedict XVI visited Celestine's tomb in L'Aquila (map) and left the pallium—a vestment that is the symbol of papal authority—on the grave. Now that gesture is being interpreted as a premonition of the choice he would eventually make.

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Officer Dies After Dorner Shootout; Cabin on Fire

Police are in a tense standoff with fugitive former-cop Christopher Dorner, who barricaded himself inside a remote mountain cabin near Big Bear, Calif., after a shootout with police in which he shot two cops, killing one, authorities said.

Smoke was seen coming from near or at the cabin shortly before 4:30 p.m. PT, and a fire has been reported to authorities.

Dorner, a former Navy marksman wanted for murdering a police officer and suspected in the deaths of two other people earlier this month, engaged in a gunfight with two San Bernardino County Sheriff's deputies who had pursued him.

The two were airlifted to a nearby hospital, where one died, police said.

Dozens of local, state and federal authorities are at the scene in the San Bernardino Mountains, and have the the cabin surrounded. Dorner has sworn to kill police and their family members in a manifesto discovered online last week.

The search for Dorner, one of the largest manhunts in recent memory, culminated in a call to police this afternoon that a suspect resembling Dorner had broken into a nearby home, taken hostages and stolen a car.

Police said the former cop, believed to be heavily armed and extremely dangerous, took two women hostage before stealing a car just after noon local time today, police said.

The two hostages, who were tied up by Dorner but later escaped, were evaluated by paramedics and were determined to be uninjured.

Officials say Dorner crashed the stolen vehicle and fled on foot to the cabin where he barricaded himself and exchanged fire with deputies from the San Bernardino Sheriff's Office and state Fish and Game officers.

Los Angeles Police Department/AP Photo

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Police have sealed all roads going into the area and imposed a no-fly zone above the cabin, nestled in a wooded area that has received several inches of snow in recent days.

Four Big Bear area schools were briefly placed on lockdown.

The San Bernardino County Sheriff's Department stopped all traffic leaving the area and thoroughly searched vehicles, as SWAT team and tactical units could be seen driving toward the cabin, their sirens blaring.

FULL COVERAGE: Christopher Dorner Manhunt

Authorities say they believe Dorner may be watching reports of the standoff and have asked media not to broadcast images of police surrounding the cabin.

"If he's watching this, the message ... is: Enough is enough. It's time to turn yourself in. It's time to stop the bloodshed. It's time to let this event and let this incident be over," said Los Angeles Police Department spokesman Andy Smith, told reporters at a press conference.

Dorner faces capital murder charges that involve the killing of Riverside police officer Michael Crain, who was gunned down in an ambush last Thursday.

Since then a massive manhunt has been under way, focused primarily in the San Bernardino Mountains, but extending to neighboring states and as far away as Mexico.

A capital murder charge could result in the death penalty if Dorner is captured alive and convicted. Crain was married with two children, aged 10 and 4.

The charges do not involve the slayings of Monica Quan and her fiance, who were found shot to death Feb. 3. Quan was the daughter of former LAPD Capt. Randal Quan, who was mentioned as a target of Dorner's fury in his so-called "manifesto," which he posted on his Facebook page.

PHOTOS: Former LAPD Officer Suspected in Shootings

In the 6,000 word "manifesto," Dorner outlined his anger at the Los Angeles Police Department for firing him, and made threats against individuals he believed were responsible for ending his career with the police force five years ago.

Dorner's grievance with police goes back five years, to when he was fired after filing what the LAPD determined to be a false report accusing other cops of brutality.

The LAPD has assigned 50 protection details to guard officers and their families who were deemed possible targets.

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Arctic sunshine cranks up threat from greenhouse gases

IT'S a solar double whammy. Not only does sunlight melt Arctic ice, but it also speeds up the conversion of frozen organic matter into carbon dioxide.

The amount of carbon in dead vegetation preserved in the far northern permafrost is estimated to be twice what the atmosphere holds as CO₂. Global warming could allow this plant matter to decompose, releasing either CO₂ or methane – both greenhouse gases. The extent of the risk remains uncertain because the release mechanisms are not clear.

Rose Cory at the University of North Carolina at Chapel Hill and her colleagues analysed water from ponds forming on melting permafrost at 27 sites across the Arctic. They found that the amount of CO₂ released was 40 per cent higher when the water was exposed to ultraviolet light than when kept dark. This is because UV light, a component of sunlight, raises the respiration rate of soil bacteria and fungi, amplifying the amount of organic matter they break down and the amount of CO₂ released.

The thawing Arctic is emerging as a potentially major source of positive feedback that could accelerate global warming beyond existing projections. "Our task now is to quantify how fast this previously frozen carbon may be converted to CO₂, so that models can include the process," Cory says.

Journal reference: PNAS, DOI: 10.1073/pnas.1214104110.

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Anti-whaling group takes battle to top US court

WASHINGTON: The Sea Shepherd conservation group asked the US Supreme Court on Monday to lift an order forcing it to steer clear of Japan's whalers, who are seeking legal reprisals over harassment at sea.

Since 2002, Sea Shepherd has annually disrupted Japan's contested hunt in the Southern Ocean but a US court issued an injunction on December 17 for the activists to stay at least 500 yards away from the whaling vessels.

Environmental lawyer Robert F. Kennedy Jr., the son and namesake of the slain political icon, urged the United States to show support for the Sea Shepherd Conservation Society and its fugitive founder Paul Watson.

"It's a mission that only they are capable of accomplishing and that is absolutely vital to the enforcement of international agreements on the high seas which otherwise go unenforced," Kennedy told reporters.

The International Whaling Commission has designated a whale sanctuary in the Southern Ocean. Japan kills whales in the area through a loophole in a 1986 moratorium on commercial whaling that allows lethal research.

Kennedy called Japan's government-supported Institute of Cetacean Research, which runs the whaling program and sued Sea Shepherd, "a pirate organisation masquerading as a scientific research group."

In a filing to the Supreme Court on Friday, Sea Shepherd and Watson said that the lower court "acted rashly" and voiced concern over the order's "extraordinarily long reach" to areas outside US jurisdiction.

The document said that the injunction marked "a potentially existential threat" to Sea Shepherd as more than 80 per cent of its funding comes from donations, which "may slow to a trickle" without the anti-whaling campaign.

The US Court of Appeals for the Ninth Circuit cited safety concerns when it issued the injunction, effective until a decision on the case.

The Institute of Cetacean Research hit back and was believed to have asked the judge to find Sea Shepherd in contempt of court -- which would potentially lead to punishment.

Sea Shepherd released a letter from a lawyer representing the institute, which complained that MV Brigitte Bardot, a former ocean racer named after the French actress and animal rights activist, violated the 500-yard injunction on January 29.

The letter warned of legal action unless Sea Shepherd ordered the Brigitte Bardot to comply with the injunction or returned it to port.

The Oregon-based group contended that it was observing the injunction, saying that the Brigitte Bardot sails under an Australian flag and is operated by Sea Shepherd's Australian sister organisation.

Japan's institute is "just like a bully who is finally challenged and runs to his mommy," said Scott West, the director of intelligence and investigation for US Sea Shepherd.

Sea Shepherd boasted that it has prevented Japan from killing whales this season. Japan, which makes no secret that meat from whaling ends up on dinner plates, accuses Western nations of disrespecting its cultural traditions.

Gavin Carter, a US-based spokesman for the Institute of Cetacean Research, called Sea Shepherd's Supreme Court filing an "unusual approach."

Watson, a dual US and Canadian citizen, has kept his whereabouts unknown since July, when he jumped bail in Germany, where he was arrested on charges from Costa Rica related to a confrontation over shark finning.

- AFP/jc

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How we test: Monitors

CNET's monitor testing encompasses both the taking scientific measurements as well as making subjective judgements on quality.

(Credit:
Eric Franklin/CNET)

To evaluate a display's performance, CNET uses a variety of DisplayMate test screens in conjunction with diagnostic equipment, and our most important tool, the human eye. Each test screen we use is specifically designed to emphasize a particular area of performance, such as text readability, color accuracy, or screen uniformity.

Test bed
CNET Labs' monitor test bed consists of a 3.2GHz Core i7 960 CPU, 4GB of DDR3 RAM running at 533MHz, an ATI Radeon HD 6850-based graphics card, centered around the 32-bit version of
Windows 7. We test all monitors with Windows' Display Properties set to 32-bit color and use the display's native pixel resolution as specified by the manufacturer.

We are currently evaluating the possibility of upgrading our testbed, including a move to
Windows 8.

Calibration
Variables such as the light source, the viewing angle, and the system's graphics card can have a dramatic effect on a display's performance. To maintain consistent and ideal viewing conditions, all testing is performed in a controlled lighting environment using CinemaQuest Ideal-Lume lights, which help to preserve accurate color perception. Additionally, each display is adjusted to perform optimally, based on contrast setting recommendations from DisplayMate.

Brightness tests
CNET Labs tests luminance levels using the Minolta CA-210 LCD color analyzer. Because displays typically vary in brightness across the entire screen, we take brightness readings from different sections of the display as laid out in the VESA Brightness Uniformity Test screen found in the DisplayMate test suite. The brightness number that CNET publishes represents an average of the luminance readings taken at nine specific points on the screen.

Contrast ratio
To test a monitor's contrast ratio, we use the display's factory default contrast and brightness settings, under its default preset. Using the Minolta CA-210 LCD color analyzer, we measure the brightness of both the light and dark squares found on the DisplayMate ANSI Checkerboard Contrast screen. We divide the average luminance of the white squares by the average luminance of the dark squares to yield the display's contrast ratio.

DisplayMate tests
With guidance from DisplayMate Technologies, we created our own scripted selection of test screens in DisplayMate. These screens are designed to isolate common phenomena such as digital noise, streaking and ghosting, ringing and overshoot, and color-tracking errors.

We evaluate each display in four categories: sharpness, grayscale range, color quality, and image uniformity. We compile the product's performance scores from each category and distill them into a single performance rating: the CNET Labs DisplayMate test score.

Most of the screens in this test suite can be configured in a number of different ways, such as altering the background and foreground colors. Depending on the characteristics of an individual display, we might use several variations of these screens as well as additional DisplayMate screens not found in our custom script to conduct further testing. Check below for details on the actual tests we run.

Real-world testing
In addition to our suite of DisplayMate test screens, we also use a number of tests designed to mirror real-world use, such as Blu-ray movie playback and games. For our Blu-ray test, we use Panasonic DMP-BDT220 Blu-ray player with an "Avatar" Blu-ray disc. We use this movie to evaluate a monitor's ability to display dark detail in dark scenes as well as color quality. For color quality we look at the display's ability to reproduce bright, vivid, accurate colors, including bright whites and solid, deep blacks.

We use several games for games testing, including, but not limited to Dragon Age II, Starcraft 2, and Crysis 2. With games we evaluate vibrancy and color quality. To test streaking, we use DisplayMate's motion graphics tests where we closely watch a number of colored blocks as they move around the screen at various speeds. Each block leaves an impression of its image behind as it moves around. The longer the impression, the worse the streaking.
Page of text
These screens illustrate a display's ability to render text under a variety of conditions. We cycle through various text and background colors, view split screens with inverse text and background colors, and adjust the type and the size of a font.
Intensity and grayscale
Monitors often have trouble reproducing all of the levels of the grayscale (the range of grays between true black and true white). This screen helps to identify a display's ability to deliver seamless gradation across the full spectrum of grays, both horizontally and vertically across the screen.

Low saturation colors
When producing a bright white image, many monitors oversaturate the grayscale: the lightest grays of the scale are lost in the white background. Oversaturation can also lead to loss of color range; this screen is used to evaluate color reproduction at the brightest end of the scale, closest to white.

Extreme grayscale bars
As the title suggests, this screen has the dual function of evaluating the darkest and brightest areas of the grayscale. These outermost edges are the most difficult part of the scale for monitors to produce. We use this screen primarily for the dark end of the scale to check a monitor's ability to deliver a true black and still produce the darkest grays of the grayscale.

64-256 intensity color ramp
Similar to the grayscale tests, the color ramp illustrates a monitor's capacity to render gradations of primary colors smoothly, uniformly, and consistently. This screen is also used to check that the colors don't shift hue as the color levels increase or decrease.

Color tracking
A color-tracking error occurs when the intensity of red, green, and blue (RGB) do not adjust identically with signal-level changes. This lack of balance among the RGB channels affects color as well as grayscale, but it is most easily identified as a shift in color within shades of gray. We use this screen to look for grays that appear to be tinted with color.

256 intensity color ramp
Similar to the grayscale tests, the color ramp illustrates a monitor's capacity to render gradations of primary colors smoothly, uniformly, and consistently. This screen is also used to check that the colors don't shift hue as the color levels increase or decrease. This is a good screen to test for evidence of color banding.

Dark screen
Because this test screen is designed to appear uniformly black, it is useful for evaluating a monitor's black-level capabilities. Additionally, a dark screen is the easiest way to spot glare and reflection problems, both of which can have distracting effects when you're viewing an LCD.

Color scales
Similar to the intensity color ramp, the color-scales screen helps us evaluate the smooth gradation of colors, expanding the palette to 10 principal colors.

Streaking and ghosting
This screen helps us detect streaking and ghosting -- light or dark shadows that trail an image in areas where large changes in contrast are present. This should not be confused with the streaking that is often found in moving images. This test deals only with problems that arise when a display renders large, chunky graphic elements, such as bar graphs or tiled arrangements of open windows.

Screen uniformity
Perfectly uniform backlighting across a monitor's entire display surface is difficult to achieve. It is not uncommon for a monitor to have bright or dim patches or subtler variations in color intensity, which give the appearance of shading across the screen, or variable color intensity on the display. We use this screen to check for irregularities caused by backlighting issues or other screen-uniformity factors, such as variations or reflections inside the glass panel.

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