2019上海最新夜上海论坛 Tag Archive


Viral infections may have met their match

first_imgA Massachusetts General Hospital-led research team has identified an immune cell protein that is critical to setting off the body’s initial response against viral infection.The report describes finding that a protein called GEF-H1 is essential to the ability of macrophages — major contributors to the innate immune system — to respond to viral infections such as influenza. The report will be published in an upcoming issue of Nature Immunology and is receiving early online release.“The detection of viral genetic material inside an infected cell is critical to initiating the responses that signal the immune system to fight an infection and prevent its spread throughout the body,” said Hans-Christian Reinecker of the Center for the Study of Inflammatory Bowel Disease in the MGH Gastrointestinal Unit, senior author of the report. “Our findings indicate that GEF-H1 may control immune responses against a wide variety of RNA and DNA viruses that pose a threat to human health.”The body’s first line of defense against infection, the innate immune system rapidly responds to invading pathogens by mobilizing white blood cells, chemical factors called cytokines, and antimicrobial peptides. When viruses invade cells, they often move toward the nucleus to replicate and sometimes to integrate their own genetic material into that of the host cell, traveling along structures called microtubules that cells use for internal protein transport. But how microtubule-based movement of viral components contributes to induction of the immune response has been unknown.GEF-H1 is known to bind to microtubules, and previous research indicated that it has a role in immune recognition of bacteria. A series of experiments by Reinecker’s team found that GEF-H1 is expressed in macrophages — key components of the innate immune system — and activated in response to viral RNA, and that it controls the expression of beta interferon and other cytokines.  Mice in which expression of GEF-H1 was knocked out were unable to mount an effective immune response to influenza A and to encephalomyocarditis, a virus that causes several types of infection in animals.“The sensing of intracellular viral nucleic acids for induction of interferons is so important that many viruses, including influenza A, have evolved specific strategies to interfere with activation of the interferon defense system,” said Reinecker, an associate professor of medicine at Harvard Medical School. “We are hopeful that this discovery will allow the development of new strategies to curtail viral mechanisms that impede the immune responses to infections that are often associated with high mortality rates.”The co-lead authors of the Nature Immunology report are Hao-Sen Chiang and Yun Zhao, MGH Gastrointestinal Unit. Additional co-authors are Joo-Hye Song, Song Liu, Megha Basavappa, and Kate Jeffrey, MGH Gastrointestinal Unit; Ninghai Wang and Cox Terhorst, Beth Israel Deaconess Medical Center; and Arlene Sharpe, Harvard Medical School.  The study was supported by National Institutes of Health.last_img read more

Read More


Women at war

first_imgTwo female journalists covering the presidential election in eastern Afghanistan for The Associated Press were savagely attacked in April. Pulitzer Prize-winning photojournalist Anja Niedringhaus and reporter Kathy Gannon were traveling in a protected convoy of election workers when an attacker shot into their vehicle, killing Niedringhaus instantly and gravely wounding Gannon.The assault stunned their friends and colleagues in the media who knew them as respected, hard-working war correspondents who had spent years in Afghanistan, knew the country well, and were not prone to take foolhardy chances.Doing a job fraught with routine risks and daily dangers, journalists in conflict zones around the world rarely want to become news themselves, as Niedringhaus, a 2007 Nieman Fellow, and Gannon did when the attack on them was featured on the front page of The New York Times on April 5. The story offered a rare glimpse into the harrowing, uncertain circumstances that women reporting from war-torn areas frequently face.“It’s a reminder that if you’re doing this job, you might end up giving your life to do it,” said Liz Sly, Beirut bureau chief for The Washington Post and a longtime war correspondent in the Mideast and the Levant.Times reporter Carlotta Gall has covered Afghanistan since the 9/11 attacks and led the paper’s reporting that won a Pulitzer Prize in 2009. She wrote movingly about a lunch she had with Niedringhaus and Gannon in Kabul just a few days before the attack, and suspects they were targeted simply because they were foreigners.“Al-Qaida and Taliban have been doing this for years. They think if they kill a foreigner or two, it scares others away, it disrupts things, it makes it more difficult for the government. And I think they were hoping to disrupt the elections,” said Gall, now the North Africa bureau chief for the Times and a 2012 Nieman Fellow.The attack was a reminder that the job requires constant vigilance, staying under the radar of those who oppose the media or the West, and acceptance that even with experience and precaution, uncertainty always hangs over this work.“It really pains me because of just the fact that they know so much and they’re so valuable and they’d be so helpful to younger journalists who don’t have that experience,” said Jill Dougherty, former Moscow bureau chief for CNN and a spring 2014 fellow at the Shorenstein Center on Media, Politics, and Public Policy at the Harvard Kennedy School.“When you go into a zone like that, you literally never know what is going to happen from minute to minute, and that’s why you really have to have your wits about you and be prepared and be thinking ahead about what would you do if …” said Dougherty, who spent 30 years reporting from Russia, Ukraine, Libya, Iraq, and Afghanistan. “I carry that into my daily life.”“It certainly makes you very careful,” said Gall about the need to travel in groups whose members have been vetted for loyalty and trustworthiness, to avoid cultural missteps or drawing attention to yourself. “But you can never be sure. And so, even though it makes you pause, none of us stopped reporting because of [the attack]. If anything, we want to carry on and do the story in the place of people like Anja and Kathy who risked their lives, so we’ll carry on and get the story for them.”Risks on the riseWhile war reporting has always been dicey work, assaults, kidnappings, suspicious disappearances or imprisonments, and murders of journalists have become more common in recent yearsIn Syria, widely viewed as the most dangerous place to cover right now, at least 65 reporters have been killed since civil war broke out there in 2011, according to The Independent. Reporters Without Borders, a watchdog group that tracks press freedom and violence against journalists around the world, reported that 166 journalists have been imprisoned and 18 have been killed thus far in 2014. Since 2009, 384 journalists have been killed.Dougherty said CNN spends a great deal of time and resources on security and logistics, sending reporters through training exercises with former military personnel who are armed and dressed as insurgents and try to kidnap them as explosions are set off, all to prepare them for dangerous field scenarios.“You have to have a flak jacket, you have to have body armor, and you have to have a first-aid kit,” she said. “Everywhere we go, we take those because you don’t know what’s going to happen. You don’t always know where you’re going to get food, so you sometimes carry food with you. I’ve lived for days on PowerBars.“You’re running on adrenaline. In these zones, you’re often getting four hours of sleep or less a night, easily. So I’ve always found I felt tired, but you don’t really feel the tiredness until you get out of there,” said Dougherty.Early on in her career, Gall said she found that she could handle the unique rigors of the job, which naturally led her editors to continue sending her on difficult assignments.“And then over the years, I think I kept doing it because I really believed this was the most important journalism to be doing and that people were dying and it should be reported and people should know the truth of what it was like and what was happening so that better decisions could be made back home,” said Gall, who recently wrote a book about her time as the longest-serving Western journalist in Afghanistan. “I just came to really believe in the importance of good information in times of conflict for all concerned.”When bullets flyWomen now constitute a significant portion of the reporters on the ground.“What does amaze me is sometimes when I look around a room at a press conference or a front line in a battle zone, there’s an incredible amount of women,” said Gall. “Sometimes in Kabul, all the major papers and news stations had women reporters there. So I think what you’re seeing is a growing number of editors … are realizing that women make very good journalists.”But it wasn’t long ago that women who wanted to work in conflict zones were often met with astonishment or outright resistance.“Yes, definitely, we’re much more accepted by men and male editors and the establishment than we were before,” said Sly, who has reported from Afghanistan, Libya, Lebanon, and Syria since the 1980s. “People don’t bat an eyelash now that there’s a woman doing this job, whereas in those days, there was always some kind of slight puzzlement about it.”Sly recalled once being told by a male editor, as she prepared to head overseas on assignment, that “‘One of the reasons we don’t have women correspondents is because if we send them overseas, they’ll go and get pregnant,’” she said. “And now I know lots of women correspondents who have children and husbands and are also covering this region.”While the job is dangerous, and sexual assaults against women journalists are a genuine threat, they say they face no greater risks than their male colleagues do.“When you’re dealing with a war and things go bang and bullets fly, they fly equally in the direction of women as men,” said Sly. The notion that women are more vulnerable feeds “into stereotypes … that women have some special challenges in the field that men don’t have. I’m very much against that perception that somehow it’s extra hard for us because that perpetuates the idea that somehow women can’t do this job, or it’s a special favor to let us to do this job.”Said Gall: “When it comes to war reporting, I don’t think gender comes into it. I think some people are good at it and some aren’t, and that’s just a personality thing. It’s nothing to do with if you’re male or female.”In fact, a woman’s presence can often deflate tensions, prompt better behavior among armed men, and in some cases open doors that are closed to male journalists.“You’re kind of this creature from outer space — you’re not either sex, and you’re not local. So in that sense, they’ll accept you even though under normal circumstances if they saw a woman coming in, they wouldn’t,” said Dougherty.“Sometimes I’ve found very strict Muslim mullahs or leaders won’t talk to a woman or won’t allow you in their mosques … but on the other hand … you get invited into the family compound, which a male reporter never would,” said Gall. “So you can go and meet the wives and the children, which is an amazing extra advantage on the cultural side.”“There are people now who will tell you: ‘I’ll take you into Syria, but I won’t take a Western man, because you can wear a hijab and you can pretend to be my sister, but I can’t hide a man,’” said Sly.Given the instability of the front lines, Gall said one critical and universal skill that all journalists need is to know when to press ahead and when to bail.“My main maxim is, no story is worth a life. If you are in danger, you should stop and drop the story and get out,” she said. “There’s always going to be another story.”last_img read more

Read More


WHO won’t change H5N1 strains picked for vaccines

first_imgJul 20, 2005 (CIDRAP News) – The World Health Organization (WHO) has decided to stick with the strains of H5N1 avian influenza it chose in April 2004 for use in developing human vaccines against the virus, which many fear will trigger a flu pandemic.The WHO said today that analyses of 2004 and 2005 human and animal strains of H5N1 viruses from affected countries “did not provide any convincing evidence to change” the strains previously recommended for vaccine prototypes.The announcement comes three weeks after an international team of experts who studied the virus in Vietnam reported that it had not recently improved its ability to spread from birds to humans or from humans to humans. Their studies, in turn, were prompted by a report in May that changing patterns of human cases in northern Vietnam, including an increase in case clusters, suggested that the virus might be becoming more infectious.The WHO said today it would “continue to monitor the antigenic and genetic changes in circulating A/H5N1 viruses, especially in humans.” It went on to say, “For research purposes, WHO Collaborating Centres will develop experimental prototype vaccine strains from recent human influenza A/H5N1 viruses.”The US government has contracted with two companies, Sanofi Pasteur and Chiron, to make prototype H5N1 vaccines. A government-sponsored clinical trial of the Sanofi vaccine was launched at three universities in March. Sanofi is under contract to make 2 million doses of vaccine as part of preparations for a possible pandemic.In other news, the Vietnam News Service (VNS) said Vietnam will buy 415 million doses of avian flu vaccine from China and the Netherlands for use in poultry. The Chinese vaccine is for the H5N1 virus, while the Dutch vaccine is for H5N2, a less virulent strain, the report said.Vietnam previously announced plans to start vaccinating poultry in two provinces in August and expand the effort to the rest of the country later.Chickens, ducks, and fighting cocks will be vaccinated, VNS reported. Chickens and ducks are to receive three doses over a period of several months. Poultry within 3 kilometers of flu outbreaks will receive emergency inoculations.See also:Jun 29, 2005, CIDRAP News story “H5N1 virus has not grown more dangerous, experts say”last_img read more

Read More


Governor Wolf Announces 80 New Jobs with Whitehall Specialties Facility in Lawrence County

first_imgGovernor Wolf Announces 80 New Jobs with Whitehall Specialties Facility in Lawrence County October 25, 2016 Jobs That Pay,  Press Release Harrisburg, PA – Governor Tom Wolf announced today that Whitehall Specialties, a world leader in the custom non-standardized and processed cheese category, will establish a new facility in Lawrence County, a move that will create 80 new full-time jobs.“The acquisition and reuse of the existing facility is a great opportunity for both Whitehall and the community,” Governor Wolf said. “In addition to serving as a strong location for the company, with access to many of the commonwealth’s resources – from customer base proximity to a highly qualified workforce, it will also create jobs for the region’s residents, and support Pennsylvania’s growing economy.”Whitehall has purchased the former Castle Cheese facility in Slippery Rock Township. The company has reopened the 81,400-square-foot facility, expanding its manufacturing capacity for non-standardized and processed cheese products. Whitehall will invest at least $3,196,000 in the project, and has committed to creating 80 new, full-time jobs within three years.Whitehall received a funding proposal from the Department of Community and Economic Development that includes a $200,000 Pennsylvania First grant, $80,000 in Job Creation Tax Credits to be distributed upon creation of the new jobs, and $36,000 in WEDnetPA funding for employee training. The company has also been encouraged to apply for a $1.2 million low-interest loan from the Pennsylvania Industrial Development Authority.“The expansive facilities and access to an ample, skilled workforce are ideally suited to support our future growth plans,” said Karl Kramer, president and CEO of Whitehall Specialties. “Additionally, its location will enable us to better service our customers in the eastern U.S. while allowing for increased flexibility and capacity throughout our four-plant network. Finally, the support we have received from the Governor’s Action Team has been instrumental in getting this project off on the right foot.”The project was coordinated by the Governor’s Action Team, an experienced group of economic development professionals who report directly to the governor and work with businesses that are considering locating or expanding in Pennsylvania.Established in 1994, Whitehall Specialties is a world leader in the custom non-standardized and processed cheese category, producing a broad line of substitute, imitation, blends, and cheese products sold across the United States and in more than 30 countries worldwide.For more information about Whitehall Specialties, visit whitehall-specialities.com.For more information about the Governor’s Action Team or DCED, visit dced.pa.gov.Like Governor Tom Wolf on Facebook: Facebook.com/GovernorWolfcenter_img SHARE Email Facebook Twitterlast_img read more

Read More


Terrible Mistake about Diamond Dates

first_imgGeologists fess up to wrong conclusion about the “world’s oldest diamonds.”It’s just grit from polishing paste.  Read about it on Live Science.  The “terrible mistake” came to light five years after the claim was made in the world’s leading science journal.In 2007, an international team first reported discovering the tiny gems, which hid in pockets inside zircon crystals from Western Australia’s Jack Hills, in the journal Nature. But it turns out that the gems weren’t actually diamonds, but polishing paste, smushed into hairs’-width cracks when the zircons were prepared for laboratory tests, according to a study published online in the Feb. 1, 2014, edition of the journal Earth and Planetary Science Letters.Some very important claims had been based on the mistake:The presence of diamonds meant the young Earth was cool enough to make relatively thick continental crust. Many modelers have suggested that Earth was covered by a roiling lava sea for its first 500 million years — an era called the Hadean, for its hellishly hot temperatures. But diamond means that the surface was cold enough to crystallize miles-thick chunks of rock, under which diamonds form. The findings also supported the idea that plate tectonics was in motion, with plates of crust skidding about and colliding, creating the pressures that form diamonds.Some found the story “extraordinarily difficult to buy.”  Even more embarrassing, though, was that Nature had rejected a paper that tried to offer alternative evidence for the origin of the diamonds.  “Nature declined to comment on the rejection,” the article said.  See also the press release from UC Riverside.  The paper is to be published in the Feb. 2014 issue of Earth and Planetary Science Letters.What other sloppy science is being used to prop up magnificent claims about what we know of the early earth or universe?  It might take years, or decades, to find the errors – especially when favored worldviews are riding on the claims.  See also 11/14/2013, “What Do Geologists Know About the Early Earth?” and 3/25/13, “The Trouble with Zircons.”Critics might say, “Scientists made the mistake, but scientists also found the mistake.  Science is a self-correcting process.”  That may be true in some cases, but how much damage can be done before a mistake is found?  This mistake was found within 7 years, but Darwinism is a mistake that has been going on for 154 years in spite of repeated reporting of its errors.Young’s Law states that all great discoveries are made by mistake.  A corollary is that the greater the funding, the longer it takes to make the mistake.  We might modify this insight to propose that the greater the worldview implications, the longer it takes to find the mistakes in so-called great discoveries that are, in fact, mistaken. (Visited 36 times, 1 visits today)FacebookTwitterPinterestSave分享0last_img read more

Read More


Hoffman, Stander claim Argus Cycle Tour wins

first_img10 March 2014 Nolan Hoffman claimed his first win in the Cape Argus Pick n Pay Cycle Tour and Cherise Stander her third victory in the women’s race in Cape Town on Sunday. The Cycle Tour, which starts and finishes in Cape Town and takes place around the picturesque Cape Peninsula, is the largest individually timed cycle race in the world.Bunch sprint Team Abantu’s Hoffman, who had previously finished on the podium on three different occasions, finally made it to the top step after winning in a bunch sprint in two hours, 39 minutes and 31 seconds. He was followed over the finishing line by Eritrea’s Meron Teshome Hagos, riding for the MTB Qhubeka Feeder Team, and HB Kruger of Team Bonitas. Hoffman used his track speed to claim the line honours after excellent work from his team put him in position to top the finishing sprint. Some disorganisation among the other teams also helped.‘Perfect for me’ “There was sort of chaos among the MTN boys and that fell into my hands because they had the numbers,” Hoffman said afterwards. “They pretty much controlled it, which was perfect for me. I can hold myself in a sprint and I can see which wheels to follow. “Knowing there weren’t any strong guys, I had the confidence to sprint against these guys, but it wasn’t easy.”Women’s race While the men’s race finished in a sprint, Stander, riding for team RECM, secured a much more convincing women’s victory after taking an early lead that she never relinquished. The closest her title challenge came to being undermined was right at the finishing line when two cyclists in the group she was riding in went down in a hard crash. “I am extremely happy,” she said in a post-race interview. “Today, personally for me, it was quite difficult. Last year [after the death of my husband Burry], everything was such a blur and I lost my gran last year as well, and…she was quite the anchor in my cycling career. She was with me [in it] since I was nine years old and she died on the 15th of August. “Just over Suikerbossie, I kept thinking about her and Burry and how much I wanted this win for both of them and I was extremely happy [to win]. They were the motivation that got me over the line.”Winning time Stander’s winning time was two hours and 51 minutes, with seven-time winner Anriette Schoeman claiming second place, 31 seconds behind her. Dee Joubert ended third, just over a-minute-and-a-half further back.RESULTS MEN Nolan Hoffman (RSA) 2:39:31Meron Teshome Hagos (Eri) same timeHB Kruger (RSA) stNicholas Dougall (RSA) stFran Rabon (Cze) stJayde Julius (RSA) stShaun-Nick Bester (RSA) stKarl Platt (Ger) stDarren Lill (RSA) stCosta Seibeb (NAM) st Womencenter_img Cherise Stander (RSA) 2:51:00Anriette Schoeman (RSA) 2:51:31Dee Joubert (RSA) 2:53:03last_img read more

Read More


Kruger steps up efforts to save rhinos

first_img3 June 2015In continuing efforts to save its rhino population from poachers, Kruger National Park (KNP) has installed three boom gates on access roads north of the Sabie River into an area designated as an intensive protection zone (IPZ).A combination of resources and technology has been intensified in the IPZ to provide a more secure environment for the rhino in the park. The boom gates are meant to control night movement of people to minimize risk factors associated with late travelling between sunset and sunrise.They will be manned by the park’s rangers and will be operational effectively from 5 June. The IPZ barriers are found on: H1-2 road north-east of the Sand River low water bridge, H12 road on the Sabie high level bridge and on H10 between Lower Sabie and Tshokwane.“We are continuously taking steps to increase security in the park in our quest to continue to provide security for our rhino, which [are] severely under attack by poachers. Restrictions at these areas will allow us to closely monitor the movements associated with nightfall,” said the Kruger’s general manager of communications and marketing, William Mabasa.Part of the long-term plan around the IPZ is to improve fencing on the western and eastern borders, which will include fixed obstacles. “These strategies are expected to improve on assessment in terms of surveillance, early warning and detection,” Mabasa concluded.Forensic trailersIn a second move to bolster the fight against rhino poaching, four 4X4 forensic trailers were handed to South African National Parks (Sanparks), the North West department of economic development, environment, conservation and tourism, the Limpopo department of environment and tourism, and the Mpumalanga Tourism and Parks Agency.The trailers, bought by the national Department of Environmental Affairs through funding provided by the Global Environment Facility and the UN Environment Programme (UNEP-GEF) Rhino Programme, will help in the investigation of rhino poaching and other wildlife crime.Improved investigative capacity and crime scene management in respect of rhino poaching cases are among the measures outlined in the government’s Integrated Strategic Management of Rhinoceros. The programme was launched by Environmental Affairs Minister Edna Molewa on 12 August 2014.When urgent forensic sample results are required for bail hearings involving suspected poachers, it is vital the samples are processed to ensure that the evidence in question is not only acceptable, but delivered within a specified time frame for court purposes. This would be one example of when the trailers would be used.Furthermore, correctly collected and handled samples meet chain of custody requirements critical for successful prosecution. This type of evidence can help in among others, placing suspects at poaching crime scenes, identifying weapons used, and linking horns seized with rhino poached.The trailers have been equipped with, among others: generators; mobile fridges to store genetic material; metal detectors; electronic calipers; and, scales and knife sharpeners.“This newly available equipment will further aid crime scene management in outlying areas where the correct equipment needed for on-scene forensic investigations is not readily available,” Molewa said.The overall goal of the UNEP-GEF Rhino Programme is to improve efforts to combat wildlife crime in South Africa’s Protected Area System, with a focus on rhinoceros. This is done through improved forensic technologies and capabilities, particularly DNA-based forensics, and data sharing and co-ordination systems between relevant groups, to better control the recent upsurge in poaching of rhinoceros in South Africa.The four forensic mobile units will be used by the four environmental management inspectorate institutions that have been prioritised given the large volume of biodiversity rhino crime scenes.The trailers were officially handed over by Molewa. Ezemvelo KZN Wildlife and Free State have already received similar trailers through a donation from the US Department of State.“The Department of Environmental Affairs has long acknowledged that the fight against rhino poaching cannot be won alone, and in this regard we are grateful for the support of our international partners,” Molewa said.Funding from the UNEP-GEF Rhino Programme was also used to provide advanced crime scene management training. Further courses are scheduled for later in the year. Funding from the programme will also be used to convene a Magistrate Awareness Symposium in August, as well as a Prosecutor Training Conference planned to take place in November.Source: South African National Parkslast_img read more

Read More


Ohio Ag Net Podcast | Episode 41 | Farm Starts, Beef Policy and Farmland Values

first_imgShare Facebook Twitter Google + LinkedIn Pinterest This week on the Ohio Ag Net Podcast, brought to you by Agrigold, Ty Higgins and Matt Reese are joined by Abby Motter. Abby will be joining the team as an intern for the first few months of 2018! This week, learn more about Farm Starts as Joel Penhorwood visits with Helene Bergren about the program helping young and beginning farmers. Matt talks beef policy with National Cattlemen’s Beef Association’s VP of Government Affairs Colin Woodall and Ty calls up Randy Dickhut from National Farmers Company to visit about farmland values in Ohio and the Midwest.last_img read more

Read More


Ohio FFA members rock National Convention with drum line routine

first_imgShare Facebook Twitter Google + LinkedIn Pinterest The Felicity Franklin FFA drumline started out with a mission to diversity the state competition. Today, they found themselves on the National FFA Talent stage. This National FFA Convention coverage brought to you by Wilmington College.last_img

Read More


Five Types of R-Value

first_imgThis is a code-built house in Atlanta, so they used R-13 insulation in the walls. They’re putting half inch drywall on the interior, half inch OSB on the exterior with brick and stone cladding. My estimates of the various R-values are:Insulation:  R-13Center-of-cavity:  R-15Clear-wall:  R-14Whole-wall:  R-10.5Overall:  R-7.3I got the center-of-cavity R-value by adding the R-values of the layers. I calculated a framing factor (ratio of framing to insulated cavity area) of about 13% using 9-foot ceilings to find the clear-wall R-value. I estimated a framing factor of about 30% to find the whole-wall R-value. (The difference between those two framing factors is that the clear wall framing factor includes only studs and plates whereas the whole wall framing factor includes studs, plates, corners, T-walls, and headers.)And I used a U-factor of 0.33 (R-3) for the windows and doors to find the overall R-value.A standard home has a framing factor of about 23%, but this home has a lot of corners, intersections, and openings. If I use the 23% framing factor, the whole-wall R-value is 11.8.The thing to remember here is that the R-value in your walls, floors, and ceilings isn’t the same as the R-value of the insulation you put in them. Oh, and one more thing: The R-value you calculate according to the definitions above isn’t a static number. It changes with temperature and other factors. Allison Bailes of Decatur, Georgia, is a speaker, writer, energy consultant, RESNET-certified trainer, and the author of the Energy Vanguard Blog. Check out his in-depth course, Mastering Building Science at Heatspring Learning Institute, and follow him on Twitter at @EnergyVanguard. Center-of-cavity R-value. R-value estimation at a point in the wall’s cross-sectional R-value containing the most insulation.Clear-wall R-value. R-value estimation for the exterior wall area containing only insulation and necessary framing materials for a clear section with no fenestration, corners, or connections between other envelope elements such as roofs, foundations, and other walls.Whole-wall R-value. R-value estimation for the whole opaque wall including the thermal performance of not only the “clear wall” area, with insulation and structural elements, but also typical envelope interface details, including wall/wall (corners), wall /roof, wall/floor, wall/door, and wall/window connections.The first one doesn’t include any thermal bridging effects, so it’s not a good one to use when comparing buildings. Clear-wall R-value is better, but it doesn’t include enough of the thermal bridging since it ignores corners, T-walls, and other important thermal bridges.But none of those definitions above include the effects of the windows and doors. If you add those to the mix, you get the overall R-value.Whole-wall R-value is really what you want to know most of the time. In new home construction, complex building enclosures rule the market. Look at all the corners, roof-wall intersections, and other complexities in the photo below. At least on the front of this house, there’s not a whole lot of clear wall there. RELATED ARTICLESUnderstanding R-ValueA Bold Attempt to Slay R-ValueWhat is Thermal Bridging?Thermal BridgingThe Thermal Bridge to NowhereIn Cold Climates, R-5 Foam Beats R-6center_img We talk about R-value all the time. “I’ve got an R-19 wall,” or “Code requires R-38 in my ceiling.” But what are those numbers? As it turns out, when we talk about R-value we usually give the R-value of the insulation material itself. That’s the case with both of those statements above. But what’s the real R-value of the wall or the ceiling? Insulation makes up only a part of each. There’s also wood and drywall and sheathing and cladding and…If we use R-value to describe only the insulating properties of the insulation we install, we neglect the insulation value of the other layers in a building assembly. In a wall, those layers include drywall, sheathing, cladding, and air films. They add to total R-value of a given pathway (series heat flow).Similarly, using only the insulation’s R-value ignores the effects of thermal bridging. Wood has a lower R-value than insulation, so including it reduces the overall R-value of a wall. And then, if you want to factor that thermal bridging in, how do you do it?As it turns out, building scientists at the Oak Ridge National Laboratory (ORNL) worked on this back in the 1990s. Jan Kosny and Jeffrey E. Christian wrote a paper in 1995 titled Whole Wall Thermal Performance and introduced three new types of R-value. Here are the names and definitions, straight from their paper:last_img read more

Read More