Caffeine and Athletic Performance

You’re watching the summer X Games and you see Danny Way chug a Monster energy drink before dropping in, or maybe during the commercial break you see New York Jets wide receiver Braylon Edwards throw back a 5 hour energy shot. The message the public receives is put caffeine in your body, and your athletic performance will increase. However, how much of this is actually true and can be proven with science? Does caffeine actually improve our 40-yard dash times or allow us to pull 900-degree spins? In J.K. Davis and J. Matt Green’s study entitled “Caffeine and Anaerobic Performance” these questions are answered to an extent.

Caffeine has been used as a stimulant for hundreds of years, but in the past decade or so has experienced tremendous growth, especially in the variety of forms it comes in. Coffee and caffeinated soft drinks have been popular for years, however now we can receive an energy boost from pills, gels, energy drinks, etc. Athletes these days often use these items to gain a competitive advantage, which has lead organizations such as the NCAA to “implement urinary caffeine restrictions,” for ethical reasons. For these reasons, several studies have been completed regarding the aerobic performance of subjects on caffeine; however, few studies have examined the effects of caffeine on anaerobic performance. In this review, the researches study caffeine’s effects on anaerobic performance exclusively, especially for 4-180 second durations. Aerobic performance refers to muscle use in which oxygen is the main fuel for our metabolism, allowing us to perform without fatigue. Anaerobic performance concerns muscle use without the presence of oxygen, making our muscles rely on other, wasteful reactions to power movement, which causes fatigue.

J.K. Davis works in the Department of Health and Human Performance at Texas A&M and J. Matt Green works in the Department of Health / Physical Education and Recreation at the University of North Alabama. Their article looks at several different professional studies that test the effects of caffeine on various aspects of anaerobic performance. These tests all posses some similarities, such as a placebo group and whether or not caffeine has an ergogenic effect, or enhances performance. The first study looked at by Davis and Green concerned caffeine influenced performance in the Wingate test. The Wingate test was developed at the Wingate Institute, in Israel, during the 1970’s. It is possibly the most widely used assessment of anaerobic power, anaerobic fatigue and total anaerobic capacity. The Wingate test involves a participant who must pedal a stationary bike, “all out”, for a total of 30 seconds. The participant begins pedaling with no resistance; however, after three seconds of no resistance, a fixed amount of resistance is applied. While the participant pedals, a counter measures wheel revolutions in five-second intervals.

Most studies of athletic performance supplemented by caffeine using the Wingate test have shown no actual improvement in anaerobic performance while being treated with caffeine. In fact, in one study done in 1998 by Greer showed a decline in anaerobic performance on the fourth Wingate test when compared to the placebo. Kang did the only study known to show an ergogenic effect from caffeine. In Kang’s study, there were both trained cyclists and untrained participants. Both groups in Kang’s study actually showed an improvement in mean, total and peak power while treated with caffeine compared to the placebo. It is important to remember though; that this is the only study that’s shows any egogenic effect of caffeine during sustained, high-intensity activity and that is unclear why performance increased.

While the Wingate test may be a good measure of anaerobic performance in general, it does not necessarily simulate the nature of most sports. The majority of sports are characterized by short bursts of high-intensity activity, like a break away in hockey or a point guard driving to the hole in basketball. These activities generally last between two and 5 seconds and happen intermittently through out games in intervals with periods of rest. The Wingate test, which as mentioned earlier measures performance in 30-second intervals, does not reflect these activities and therefore may not be the most effective method of measuring anaerobic performance. Because of this, another research named Schneiker created an experiment to more closely mimic common athletic competition for testing the effects of caffeine on anaerobic performance. In his test, subjects participated in two, 36-minute halves, each made up of 18 four-second bursts of “maximum exertion” cycling with two minute recovery periods between sprints. The subjects using caffeine experienced significant performance improvement in both halves for total work and peak power. These results showed that when the experiment more closely resembled actual athletic competition, caffeine actual does provide an athletic advantage.

In this study, Green and Davis both prove and disprove that caffeine is an ergogenic aid when it comes to athletic performance. Traditional tests such as the Wingate test, which measure sustained, high-intensity activity, do not show any athletic enhancement from caffeine, and in fact have the potential for detrimental effects on anaerobic perfomance. However, when the scientists replicated more common athletic events in their tests, they did observe enhanced performance in all categories from subjects treated with caffeine. So should all athletes use caffeine? According to the research it has the potential to improve Usain Bolt’s 100 m dash time, or allow B.J. Upton to steal home in the bottom of the 9th when they might not be able to under normal circumstances.

http://ehis.ebscohost.com/ehost/pdfviewer/pdfviewer?vid=4&hid=4&sid=342e141e-c766-49aa-83ff-71f84c628795%40sessionmgr111

http://www.myfooddiary.com/resources/ask_the_expert/aerobic_vs_anaerobic.asp

Families’ Effects of Alcohol Use Disorders on College Students

Ashleigh Dorman

College students choose to partake in numerous activities, including attending class, choosing what food to eat, and deciding what to do with their spare time. Some students choose to spend their Friday nights watching a movie with friends while others choose to go out and party. The partygoers that decide to drink might do so because they want others to like them, because they just want to, or because alcoholism is a part of their family history. Doctors speculate that the college students that have family members who have a history with alcohol are more likely to drink alcohol. This hypothesis would make sense if it were true because the students probably grew up seeing alcohol in the house and now see it as a part of their lives.

Along with students’ families having alcohol use disorders, AUD, doctors also believe other prominent people in their lives that drink increase the chances of the students obtaining these disorders. “Specific genes that influence the development of alcohol-related problems have been identified…” (Pulido, 66) Some scientists have found evidence showing that biology does have an effect on the increase of AUD among college students whose families have AUD history. The younger generation tends to mimic their elders’ actions, choices, and behaviors. It all comes down to the environment the child is raised in. If the child is brought up with the idea that drinking alcohol is not only okay, but it is also okay to drink it in excessive amounts, then that child is going to be more prone to following in their parents’ footsteps because they think it’s what everyone is supposed to do.

Another contributing factor to the increase of college students having AUD is the visual images pertaining to alcohol students see on a daily basis, whether that be through their parents or through television or advertisements. Upon seeing these pictures doctors say, “…alcohol advertisements may be an important factor in the maintenance and progression of alcohol use for youth.” (Pulido, 66) The experiment explained in the article, Heavy drinking relates to positive valence ratings of alcohol cues, basically consisted of 227 participants who reviewed an array of pictures and then answered questions about valence picture ratings. “Of the 227 participants, 14% indicated a FH, 62% reported exposure to problem drinking models and 14% scored in the elevated range for depressed mood.” (Pulido 69)

In the end, the experiment did not support the initial hypothesis; the least amount of participants in the survey were influenced by having family history of alcohol use disorders. It was interesting to see that the students whose families had backgrounds of AUD did not really have a strong effect on them choosing to drink. I would have thought the students would have chosen to be around alcohol so I would have had the same hypothesis as the doctors because it would make sense to keep that familiar presence in their life. However, from this particular experiment, the main reason students choose to drink is because of other people in their life putting the image of alcohol into their minds.

Pulido, Carmen, Alex Mok, Sandra A. Brown, and Susan F. Tapert. "Heavy Drinking Relates to Positive Valence Ratings of Alcohol Cues." Addiction Biology 14.1 (2009): 65-72.

Video game technology benefiting or hurting young children?

Kelsey Kolojejchick

Video games and technology are a fact of life for many American children, but is this lifestyle helpful for their learning abilities or a setback? The author of “Serious fun with computer games” claims that sophisticated computer-based play can engage more students and support learning in schools. He believes that with the correct technology and useful purpose of these games, children will have a better understanding of concepts than those who did not use video games. The author of “TV viewing, Video game play contributes to kids’ attention problems” claims that TV, video games and technology are associated with increased attention problems in children. They believe that video games can create bad habits for children as well as expose them to a higher chance of obtaining attention problems. Each author has a different viewpoint where one believes computer-based play is educational for students while the other author believes it leads to attention problems and poor habits for young children.

The author or “Serious fun with computer games” focuses mainly on the good mechanics of a video game that can help support learning in schools. He focuses on the message a video game is trying to convey to determine how effective they are towards young students. If the message is not entertaining, it can lose the interests of young students. If the message is entertaining but not educational it will lose its purpose to benefit students in school. The UK government's education department and a software publishers' association, found that students whose lessons included interactive games were more engaged in curriculum content and demonstrated deeper understanding of concepts (Krotoski). Broadening the appeal of these video games is crucial to determine its success rate because it needs to be believable for the student and not over dazzle the student because they will not retain any knowledge. The education video game if planned and produced correctly will help the development of young students for our future.

The author of “TV viewing, Video game play contributes to kids’ attention problems” shows research explaining that young kids that play video games are more likely to have attention problems growing up. The habits young children get by watching TV or playing video games transfers to attention problems at home with parents and attention problems in school as well. "Brain science demonstrates that the brain becomes what the brain does," Gentile said. "If we train the brain to require constant stimulation and constant flickering lights, changes in sound and camera angle, or immediate feedback, such as video games can provide, then when the child lands in the classroom where the teacher doesn't have a million-dollar-per-episode budget, it may be hard to get children to sustain their attention” (Gentile). The brain adapts and changes to the repetitive video game exposure which can be a reason why children can have attention problems. Researchers believe video games have an impact on children’s attention spans which can have a negative impact in their learning abilities in school.

I think the idea of having a educational video game for young students is appropriate because it could be a fun way for them to learn. If they like to have fun and play a game but also gain knowledge from a certain topic can be successful in the long run for our children in the future. The issue is finding that appropriate video game without losing the attention of these children. If it is not educational enough it will not be suitable for schools and could also lead to attention problems for these young students. The proper video game that keeps the attention of these students and is educational as well can definitely become a successful program.

Articles:
http://www.nature.com.libproxy.lib.unc.edu/nature/journal/v466/n7307/full/466695a.html
http://www.sciencedaily.com/releases/2010/07/100706161759.htm

Embryonic Stem Cell Research: To Be or Not To Be

By: Ashley Contreras

“All life is an experiment. The more experiments you make the better.” This metaphor by Ralph Emerson sets the fundamental grounds for research itself. But the attempt to gaining knowledge through research can sometimes go beyond the boundaries of ethics, this is the case with Embryonic stem cell research.  Using a a baby that is not even fully developed as research   raises the morality and legality of using embryonic stem cells for research. Embryonic stem cell research is considered promising in curing a number of diseases and disabilities. Embryonic stem cell research requires deriving cells from embryos that develop from eggs that have been fertilized in vitro—in an in vitro fertilization clinic—and then donated for research purposes with informed consent of the donors. They are not derived from eggs fertilized in a woman's body (stemcells.nih.gov). Although, the results seem promising the controversy of the research destroying a potential life still exist. Just last week federal judge Royce Lamberth issued an injunction putting a halt in the funding of the research. According to A Law in Time, an editorial found in Nature magazine, “Scientists, patients and others who care about the survival of a highly promising area of biomedical research should not expect the courts to act in their favour.”  

Many scientists have no choice but to wait on this decision, “Unless the injunction is quickly reversed, and unless the government then prevails when the case is heard on its merits, hundreds of experiments funded by the National Institutes of Health (NIH) will be crippled, and many will have to be abandoned” (Nature). On the other hand, there are scientists that are in favor of the injunction, and hope to see the research put to a complete halt. According to scientists interviewed for the Wall Street Journal article, Stem-Cell Plaintiffs Ethical Motivation, “work using material derived from embryos is morally objectionable, unlikely to yield cures.” James Sherley of Boston and Theresa Deisher of Seattle are both scientists that have been recruited for to challenge the federal policy. Having a strong religious background, they believe that they have a responsibility of conducting ethical research and that the stem cell research is nothing short of immoral (Wall Street Journal).  

The case is related directly to abortion and the US Court of Appeals is dominated by conservatives, which are more than likely favoring the injunction. But according to Nature polls, 50-60% of Americans, many of which oppose abortion, sympathize the funding for embryonic stem cell research. Dr. Deisher furthers her claim as a “radical Feminist” stating that embryonic stem-cell research is morally objectionable and unlikely to produce promised treatments or cures. Both scientists said research using adult stem cells, the field each of them works in, has more potential to help patients. They fully support the Dickey-Wicker bill that is present, stating that This prohibition encompasses all 'research in which' an embryo is destroyed, not just the 'piece of research' in which the embryo is destroyed, while Diana DeGette is working on new bill “notwithstanding any other provision of law” (read: Dickey–Wicker), the government shall conduct and support research using human embryonic stem cells. As is the case under Obama's current policy, the cells must be derived from leftover embryos at fertility clinics that would otherwise be discarded, and the donors must have given informed consent. (Nature)

Both articles depict both sides of the argument; on one side you have the Wall Street Journal article that has scientists, who like many other conservatives are not in favor of using embryos for research for cures that are unlikely to be successful, then you have the Nature article that emphasizes the potential harm to important research in progress by the injunction. This is a debate of morality based on opinion similarly to the abortion controversy, but unlike abortion these embryos are not destroyed to prevent a life but used to help save one.

http://www.nature.com.libproxy.lib.unc.edu/nature/journal/v467/n7311/full/467007a.html
http://online.wsj.com/article/SB10001424052748704791004575466081896678078.html

Republicans oppose stimulus-funded science projects

Ashleigh Dorman

A major controversy between the Republicans and the Democrats right now is the issue of implementing stimulus-funded science projects. In “Cheap Shots,” the criticism from the Republicans is somewhat overcritical because they are disapproving of the stimulus-funded projects without showing valid evidence that they have done their research. In the second article, “Stimulus and Jobs: What the Fight’s All About,” more focus is put on the question of the number of jobs generated from the stimulus-funded science projects. The second article is more convincing than the first because it explains how the projects are benefiting the unemployment rate by increasing the number of available jobs while the first article doesn’t give any valid reasons as to why the projects should be opposed.

The stimulus-funded projects are questionable to Republicans because they seem to have not done their research on the benefits from the projects, according to “Cheap Shots.” “But a look at McCain and Cobum’s discussion of the science projects on their list suggests that their analyses are at best superficial, and at worst just a series of cheap shots.” (Nature) The two Republican senators released Summertime Blues: 100 Stimulus Projects that Give Taxpayers the Blues, where they shoot down every stimulus project and the reasons associated with performing the study. John McCain and Tom Cobum talk down every project instead of giving their listeners the benefits the scientific community reaps from performing the experiments, like in the “Monkeys Get High for Science” study at Wake Forest University. “The ultimate goal is more effective treatment for addicts. However, McCain and Cobum mention none of this, instead asking “how studying drug-crazed primates would improve the national economy.” (Nature)

With the approval of stimulus-funded science projects comes the opportunity of new jobs, which is a positive gain for the economy with how high unemployment rates are. “Stimulus and Jobs: What the Fight’s All About” says that more jobs should become available with all the stimulus money. The Republicans, including McCain and Cobum, disapprove of this idea. This party says that it has not furthered the economy in any way and is certainly not helping lower the unemployment rates. “The White House also says the Recovery Act has created 2 million jobs…The administration says the unemployment would be much worse if the stimulus program didn't exist. A year ago, the economy was losing 691,000 per month, on average, in the first quarter. In December, the number was down to 85,000 jobs lost.” (CNNMoney) This type of data is more helpful to show the effects of the stimulus-funded projects and how they can help improve the economy.

The thesis statement for “Cheap Shots” is “Republican criticism of stimulus-funded science projects is ill-informed and wide of the mark.” (Nature) John McCain and Tom Cobum are obviously against the issue but do not give valid information to convince others to be against the stimulus-funded science projects in their report, Summertime Blues: 100 Stimulus Projects that Give Taxpayers the Blues. “The Obama administration credits the American Recovery and Reinvestment Act with turning around the economy and bringing America out of the worst downturn since the Great Depression. Without it, things would have been a lot worse.” (CNNMoney) The second article is more convincing than the first because it provides substantial statistics of unemployment rates and the number of created jobs from the stimulus-funds, unlike the first article that mainly disapproves of the way the Republicans criticize the issue with no support or evidence.

http://www.nature.com/nature/journal/v466/n7308/full/466797b.html

http://money.cnn.com/2010/01/26/news/economy/stimulus_jobs_questions/index.htm

9 Billion mouths to feed

Davis Rainey

Have you ever considered the world’s rapidly growing population, and the world’s decreasing food supply? Do you think we will ever run out of food? The author of “How to feed a hungry world” says that the current population of 6.8 billion is expected to grow to 9.1 billion in 2050. This raises a concerning question: how will all these extra mouths be fed? The author of “How to feed a hungry world” claimed that when the world’s population went from 3 billion to more than 6 billion from 1961 to 2007, the agricultural output managed to keep pace. Current projections show that it should continue to do so (“How to feed a hungry world”). Though enough food can be provided, there are many discoveries and technologies will still need for better food productivity. These steps must be taken for our world to prosper.

Beth Adler, author of “How to Feed the World in 2050”, reported on the FAO’s (UN Food Security and Agriculture Organization) forum held in October. Adler claimed it stated the groundwork for conversation at the World Food Summit to be held in mid-November. Like the author of “How to feed a hungry world”, Adler reports that there was a general consensus from the meeting that we should be able to provide enough food to feed to growing population. In fact, the official at the FAO of the United Nations said that the task of feeding the world’s population in 2050 in itself seems “easily possible” (“How to feed a hungry world”).

These two authors agree, with the rest of the world, that enough food can be provided, but different factors will come in to play. The author of “How to feed a hungry world” says that what is really needed to become agriculturally wealthy is a second green revolution, what Britain’s Royal Society describes as the “sustainable intensification of global agriculture” (“How to feed a hungry world”). The uncertainty of external shocks, such as climate change, brings difficulty to the projections of agricultural output (“How to feed a hungry world”). These uncertainties show that there is a need for new crop varieties. As the author of “How to feed a hungry world” relies on help from mother nature, Adler says that in order to achieve this growth, investments in research, technology; infrastructure, and sustainable resource management are essential.
Adler states that achieving food security will not only depend on whether the world can produce enough food (“How to Feed the World in 2050”). She says that policies are needed to enhance the access and usage of food so that people can sustain well nourished lives. “How to Feed the World in 2050” also states that well functioned markets, and easier opportunities for market access are critical components for good food security.

As Adler states the priorities of the people, the author of “How to feed a hungry world” brings up an important point in world hunger. Today, the world currently has enough food, but some 1 billion people go hungry because they cannot afford it (“How to feed a hungry world”). The author believes poverty is the root of world hunger, not lack of food production. The food crisis in 2008, which put around 100 million people into hunger, was caused more so from the unpredictability of the market than from the food shortage. Prices soared through the roof and many people became unable to meet the inflation.

Whether more personnel in scientific research is the key to bringing us new technologies, or the root of the crisis is people itself, the population is growing rapidly. While the authors may disagree on how to provide for a hungry world, both can agree that changes must be made in productivity and efficiency for the world to prosper. The FAO claims that the task of feeding so many mouths will be easy, but there will be challenges. So next time you bite into a juicy Big-Mac, pray that it isn’t your last.


“How to feed a hungry world.” Nature (2010). Article: Nature. 28 July 2010. Web

Adler, Beth. "How to Feed the World in 2050." (2009): n. pag. Web. 7 Sep 2010.

Climate Change Gossip
Joe Weitz

Like religion, politics, and baseball, climate change is one of those topics that divides people and causes some of the most passionate debates. Each side of the issues facing climate change has their own valid opinions and facts, but among the scientific community, it is widely accepted that climate change is a reality. So why is there still so much controversy and political resistance surrounding climate change if the leading scientists in the world and the general public acknowledge the reality we face? According to an editorial in Nature, a weekly science journal, entitled “A Question of Trust”, the scientific community itself maybe partly responsible for the remaining percentage of public mistrust and the lack of real political action.

Multiple scandals involving falsified data and leaked emails have made a significant minority of the public weary of scientist’s efforts, despite the over whelming concrete evidence that is available. The editorial states that it isn’t that general public that scientists are now trying to inform, in fact the majority of people accept climate change as a reality, but instead our governments that need convincing. Scientific mistakes aside, the evidence for climate change is overwhelming. So the question remains, with this general public acceptance of climate change, why have our governments not readily adopted policies to combat a warming climate? According to the author of “A Question of Trust”, politicians, like people, have many vested interests that are contrary to some potential environmental policies. Upcoming reelections, public opinion, and monetary incentives, among other factors, are all being put ahead of this potential crisis by many politicians.

The author of “A Question of Trust” states that in order for any real action to take place, scientists must be more careful about falsified data and be more open with the public when it comes to the uncertainties of climate change. Instead of playing them down, scientists should inform the community on the known facts, but also be open about what the honestly don’t know. Many skeptics view scientists as a different species in a way, a highbrow class with their own agendas. This alienates a very significant percentage of people, especially Americans. By stating the known facts and expressing their own uncertainties scientists will come across as more human, allowing more of the public, and eventually politicians, to identify with them.

In Zeeya Merali’s editorial, “UK Climate Data were not Tampered With,” it is stated that the scientists who were blamed for falsifying statistical evidence, actual did not. Thousands of emails were hacked from the Climatic Research Unit (CRU) at the University of East Anglia in Norwich, UK, and because they were never encrypted and never made public it was assumed that they possessed falsified data. A team led by Muir Russell, the former vice-chancellor of the University of Glasgow, UK, was given the task of investigating the scientist’s actions. A 160-page report stated that the team found “no evidence of malicious intent, but rather a ‘consistent pattern of failing to display the proper degree of openness’ both among researchers and in the university's leadership in handling the affair.”

Falsified data or not, the reality is not enough is being done about climate change and all of the surrounding controversy, most of which can be avoided simply through more easily accessible data and research, is only slowing down any real progress. Being honest with the public and gaining their trust is the only way to convince our governments that we need to prepare for climate change.

http://www.nature.com/nature/journal/v466/n7302/full/466007a.html

http://www.nature.com/news/2010/100707/full/news.2010.335.html

About Us

Our blog is meant for university students who have not decided what they want to major in. Our focuses are Sciences, Social Sciences, and Humanities. Our goal is to provide students with knowledge about these subjects to give them a gist to aid their decision. It’s a blog for students by tudents. The eclectic and generally undecided nature of our group should provide a a cultivating environment for this goal.

Our group thinks that citing our sources is very important to not only uphold the integrity of what we’re writing but also the development of our arguments. By having citations we can give credit to where we pulled our research from. Citing our sources are a way for our readers to further research our topic and appreciate the works of others that have influenced us in writing our particular subject.

For our blog, we have decided to cite our sources at the end of each article. Also we will use hyperlinks within the article if we feel it’s necessary for quicker access to our sources.

Here’s an introduction

Here's an introduction to the members of our group:

Open fields, crickets chirping, and mama’s home cooking; I connect these memories with my hometown, Dunn, North Carolina. I love UNC and all of its diversity but I still get that secret smile when I hear the slip of a southern accent. My name is Ashleigh Dorman and I am a 5’9” fiery red head who enjoys playing tennis and has a knack for business. I am majoring in Economics and hope to get a masters degree in Accounting and later become a CPA. I am also minoring in Entrepreneurship so that I can gain the knowledge needed to open my very own drive-in movie theatre. This has always been a dream of mine so that teens and adults alike can watch new movies in a classic, old-fashioned way.
My name is Ashley Contreras and I am a sophomore at UNC-CH majoring in Nursing with hopes of specializing in Neonatal. Children and their development have always been an interest to me and that is partially one of the reasons I want to get in to the neonatal field. I love being around children and watching them reach their milestones in life.I plan to go to graduate school and become a neonatal nurse practitioner. I have lived in North Carolina all my life in a small town called Wendell. Although I love North Carolina, I hope to on day travel to under developed countries and provide health care to women and their children.
Hi my name is Kelsey Kolojejchick and I am a sophomore from Larksville, PA. I am currently on the field hockey team at UNC and I am undecided but plan on majoring in Communications.

My name is Joe Weitz and I’m a freshman at the University of North Carolina – Chapel Hill. I plan double majoring in Art and Environmental Studies and intend to use this interdisciplinary approach to attend graduate school at the University of British Columbia - Vancouver to study architecture. I’m from Durham, North Carolina, where I attended Riverside High School and played soccer and lacrosse. I’ve lived in North Carolina all my life and love it here, however, I’d rather be backpacking in Alaska or skiing In British Columbia. I enjoy anything that challenges me and puts me out of my comfort zone. I’ve found that these experiences have taught me the most about life and myself. As with the rest of the group, this is my first blogging experience and I’m not exactly sure how to approach it, but I’m looking forward to the challenge even though it’s on a computer and not a mountain.

Hey, my name is Davis Rainey. I am a freshmen at the University of North Carolina at Chapel Hill where I plan on majoring in business. I am from Winston-Salem, North Carolina, where I attended RJ Reynolds High School. There I played soccer, basketball, and lacrosse. I have never blogged before but am eager and excited to try it over the course of this semester.