Missing in lockdown -- new report reveals the vulnerable are more at risk

UNIVERSITY OF PORTSMOUTH

Research News

 

The number of people who went missing during the first national lockdown in England fell by over a third, compared to data from the previous year. However, a new report out today shows that those who did go missing were deemed more vulnerable and at higher risk.

Researchers from the University of Portsmouth and University of Liverpool worked with six police forces from across the UK, to understand the impact of lockdown on missing people and recommend changes for the future.

Missing people are one of the most challenging issues for modern police forces, with the number of reported cases reaching 382,960 in 2018/2019 (NCA, 2020). The recent pandemic, and the resultant national as well as localised lockdowns, have placed unique demands on the emergency services (WHO, 2020).

The study aimed to compare the characteristics of missing people cases reported to participating forces during the period of the COVID-19 lockdown in England, with sample of cases taken from the same time period last year. The sample comprised of reports of adults and children who went missing between 23rd March 2020 until 20th May 2020, and the same time period in 2019.

As expected, the lockdown period led to a substantial reduction in the overall number of missing persons. There was a 35% decrease in missing children reports and 36% reduction in reports of missing adults.

However, the research also highlighted that those who went missing were more likely to be high risk of harming themselves or others. Adults who went missing during this period were more prone to mental health issues; domestic abuse; have relationship, drug or alcohol problems; or have a history of self-harm or suicidal thoughts.

Dr Karen Shalev Greene, Reader in Criminology, Director of the Centre for the Study of Missing Persons, University of Portsmouth explains: "The reduction in missing people is entirely expected, it is much harder to go missing, when the country is locked down. However, what is significant about these figures is it highlights how desperate some people must have been."

"The report emphasises the vulnerability of people that go missing during lockdown. Perhaps they live in situations that impact their mental health more making them determined for freedom. Whatever the reason, this is a reflection of society as a whole, including criminal organisations, exploitation, vulnerability and those that need support. To help prevent high risk missing adults from going missing the response needs to be multi agency. Efforts should also focus on after care and support once they return."

The report also highlighted that children were more likely to be classified as low risk during lockdown. The reason for this needs further investigation and understanding.

Dr Freya O'Brien, Senior Lecturer in Psychology, University of Liverpool, explains: "Particular attention should be given to understanding the reasons why children from care homes frequently went missing during lockdown and why children travelled long distances. One theory is that children in care were trying to get home to their families. It is important to bear regional differences in mind. Each force should study the patterns of missing in their force and consider local context."

National Police Chiefs' Council Lead for Missing People, Assistant Chief Constable Catherine Hankinson, said: "This research helps us to understand the changing trends in missing people and the different reasons they went missing during the first lockdown. The trend in more incidents being categorised as high risk suggests some of us really struggled with being isolated from our normal support networks. Police and our partners in health, social care and local authorities need to learn from that experience and consider how we can support people, particularly those with mental health issues, through ongoing restrictions.

"The research found that missing children were more likely to be categorised as low risk which is partly because some of them were reported missing for breaking the lockdown rules but then often returned safe and well after a short time. However, we will closely consider the research in the context of child exploitation, county lines and organised crime. Police are already aware of how these criminals are changing the way they operate but there is always more to do and we're committed to tackling those who are intent on causing harm to our communities and young people.

"Our work with partners in local authorities and social services will consider how we maintain contact with vulnerable children during any further restrictions, as it is vital we all do everything possible to protect them from abuse and exploitation at home."

 

First US nationwide estimates of sexual minority representation in STEM fields

Results suggest a diversity of experiences -- with work to be done to achieve parity

PLOS

Research News

One of the first nationwide estimates of sexual minority representation across Science, Technology, Engineering, and Mathematics (STEM) degrees and occupations in the US publishes November 18, 2020 in the open-access journal PLOS ONE by Dario Sansone from the University of Exeter, UK, and Christopher S. Carpenter from Vanderbilt University, USA.

A body of research has documented wide gaps in STEM degrees and occupations based on gender and race/ethnicity; however, relatively few studies have examined the impact of sexual orientation on STEM representation, due in part to a lack of data. This is the first study to use nationwide datasets two orders of magnitude larger than those used for prior research in this area to illustrate the current state of representation in STEM for sexual minorities.

The authors pulled data from two sources: the 2009-2018 American Community Surveys (ACS), which identifies over 142,000 individuals in same-sex cohabiting romantic relationships and gives information on their current occupation and undergraduate major(s), and the 2013-2018 National Health Interview Surveys (NHIS), which gives detailed information on occupation and sexual orientation for 4,763 self-identified sexual minority individuals. (For the purposes of this study, the authors use the term "sexual minority" to refer to individuals who describe themselves as lesbian, gay, bisexual, queer, or "something else".)

The data indicate that men in same-sex couples are 12 percentage points less likely to have completed a bachelor's degree in a STEM field compared to men in different-sex couples. There was no gap observed for women in same-sex couples versus women in different-sex couples in terms of STEM degree completion. (For context, the STEM degree gap between men in same-sex and different-sex couples is larger than the STEM degree gap between white and black men, but smaller than the gender gap in STEM degrees--meaning women are still overall less likely to obtain a STEM degree regardless of orientation.) In terms of STEM occupations, however, women in same-sex couples are almost two percentage points more likely to work in a STEM field than women in different-sex couples. The gap between men in same-sex couples and different-sex couples is smaller when focusing on STEM occupations, but still present, at a statistically-significant one percentage point (these results were borne out by both the ACS and NHIS surveys). The authors also found that gay male representation in STEM fields (measured using either degrees or occupations) is systematically and positively associated with female representation in those same STEM fields.

There are limitations to the data used--most notably, the ACS survey only focused on cohabiting relationships, meaning that individuals who might be in same-sex relationships (or currently single) but living separately would not have been recognized as part of the sexual minority. (However, the NHIS survey did permit observation of single individuals). Additionally, neither survey used provided specific data on transgender individuals.

However, taken together, the results appears to demonstrate that, like race/ethnicity and gender, sexual orientation is an element that must be considered in order to bring equity and efficiency to STEM fields at the degree and occupation level--and highlights the need for more large nationally representative data on both sexual and gender minorities in STEM to better understand their representation and specific challenges.

The authors add: "We show that sexual minority men are less likely to have completed a bachelor's degree in a STEM field or to work in a STEM occupation compared to heterosexual men. Furthermore, we document that gay male representation in STEM fields (measured using either degrees or occupations) is systematically and positively associated with female representation in those same STEM fields."

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Citation: Sansone D, Carpenter CS (2020) Turing's children: Representation of sexual minorities in STEM. PLoS ONE 15(11): e0241596. https://doi.org/10.1371/journal.pone.0241596

Funding: The authors received no specific funding for this work.

Competing Interests: The authors have declared that no competing interests exist.

In your coverage please use this URL to provide access to the freely available article in PLOS ONE: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0241596

 Machine learning uncovers missing info about ethnicity in population health data: Study

University of Alberta epidemiologist says these key social determinants of health are often not tracked adequately in Canada

UNIVERSITY OF ALBERTA FACULTY OF MEDICINE & DENTISTRY

Research News

 

IMAGE: KAI ON WONG FOUND THAT MACHINE LEARNING CAN BE USED TO PREDICT ETHNIC BACKGROUND FROM PUBLIC HEALTH DATA, WHICH WOULD HELP FILL AN INFORMATION GAP AND COULD EVENTUALLY INFORM POLICIES... view more 

CREDIT: UNIVERSITY OF ALBERTA

Machine learning can be used to fill a significant gap in Canadian public health data related to ethnicity and Aboriginal status, according to research published today in PLOS ONE by a University of Alberta research epidemiologist.

Kai On Wong, senior data scientist at the Real World Evidence unit of the Northern Alberta Clinical Trials and Research Centre (NACTRC), said ethnicity and Aboriginal status are recognized as key social determinants of health but are often not reported in large databases that track acute and chronic diseases such as asthma, influenza, cancer, cardiovascular diseases, diabetes, disability and mental illness.

"If a database currently lacks ethnicity information, we will not be able to tell whether certain ethnic groups have higher rates of disease or worse clinical outcomes," Wong said, "This is a way to unlock that missing dimension from existing data sources, which may help us understand, monitor and address issues such as social inequities and racism in Canada."

Wong created a machine learning framework to analyze the names and geographic locations of 4.8 million people surveyed in the 1901 census, examining features such as spelling and phonetics to predict whether they belonged to one of 13 ethnic groups.

"Different ethnic and linguistic groups have different manifestations of features such as how the name sounds, how many letters in the name, how many vowels and unique letter sequences, and so on," said Wong, who created the program and shared it as a public GitHub repository as part of his doctoral thesis at the U of A's School of Public Health.

"Machine learning is like having a team of agents who are given vast amounts of information. They are instructed to detect and retain useful patterns to solve practical problems such as predicting the ethnicity from the readily available information," he said.

Wong said the program performed best at identifying individuals of Chinese, French, Japanese and Russian heritage based on name only, while the accuracy was improved for the Aboriginal classification when locations were also included.

Both the World Health Organization and the Government of Canada recognize ethnicity and Indigeneity as determinants of health, along with other factors such as income, education and gender. Wong first became interested in inequities in health care that affect Indigenous groups when he served as acting territorial epidemiologist for the Government of the Northwest Territories.

Wong said while American health records tend to include questions about ethnicity, this information is not collected consistently in Canadian databases ranging from hospital discharge records to cancer registries.

By using machine learning to uncover this missing information, researchers and policy-makers will be able to learn more from existing records rather than having to carry out new population-level surveys, which are expensive and time-consuming.

"A future step forward will be to validate this research with real-world applications using health evidence augmented with ethnicity generated by the machine learning framework and comparing it with existing literature, particularly on health and social inequities," Wong said.

Wong recommends first updating the ethnicity prediction tool using more recent census information and testing its accuracy when applied to various health records.

"It is unrealistic to expect machine learning predictions to be 100 per cent accurate at all times," Wong said. "The goal is to make predictions that are accurate and generalizable enough to discern underlying patterns in a meaningful way for a particular problem or application."

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Wong's research was funded by the Canadian Institutes of Health Research Frederick Banting and Charles Best Doctoral Research Award, the University of Alberta President's Doctoral Prize of Distinction and Queen Elizabeth II Doctoral Scholarship, and the Alberta Machine Intelligence Institute (Amii).

 

New studies find financially exploited seniors show brain differences and are more frail

New light shed on older peoples' risk for scams and fraud in a pair of studies from the Keck School of Medicine of USC

KECK SCHOOL OF MEDICINE OF USC

Research News

 

IMAGE: S. DUKE HAN, PHD, KECK SCHOOL OF MEDICINE OF USC view more 

CREDIT: RICHARD CARRASCO

Scams and fraud exact a heavy toll on older adults, with estimates of yearly losses ranging from $3 billion to $36 billion in the U.S. alone.

Lasting damage can occur. Because many seniors live off of resources accumulated across their working lifetimes, such as retirement savings, victims may be unable to recoup what's taken from them. Considering the additional impact on family members and caretakers, financial exploitation in this growing demographic is a significant public health concern.

Two recent studies led by USC provide new insight into the little-studied question of which factors put older adults at risk for financial exploitation.

One, published in Frontiers in Aging Neuroscience, is only the second brain imaging study to center on financial exploitation in older adults. The scientists found that those who report being financially exploited show differences in the activity of brain regions tied to decision-making and social judgments compared to those without a history of financial exploitation.

The other, which appears in Gerontology and Geriatric Medicine, is the first study to focus specifically on the relationship between financial exploitation and frailty in older adults. The findings showed that those who reported being financially exploited are frailer physically -- with particular deficits in vision and hearing -- compared to their peers.

The papers come out of the Finance, Cognition, and Health in Elder Study at USC, which enrolls participants who are 50 years and older with no history of dementia. It is led by Duke Han, senior author on both publications and professor of family medicine, neurology, psychology and gerontology in the Keck School of Medicine of USC.

"Ultimately, we want older adults to experience all the best in life, to hold onto their wealth and to live life well into old age," said Han, who is also director of neuropsychology in the USC Department of Family Medicine. "It crushes us to see them financially exploited. However, not all older adults are at risk for financial exploitation, and we want to try to predict which people might be more at risk."

Brain differences correlate with falling victim to fraud

The Frontiers in Aging Neuroscience study used magnetic resonance imaging to examine neurological co-activity. Han and his colleagues compared 16 older adults who reported experiencing financial exploitation with 16 who did not, studying their brains while in a resting state. The scientists delved into functional connectivity -- in other words, which brain regions activate at the same time.

Functional connectivity can serve as a sort of canary in the coal mine, signaling changes that come with age-related diseases, including Alzheimer's, before alterations to structures in the brain are detectable.

The research team focused in on three areas of the brain tied to making decisions and evaluating social situations. The study demonstrated subtle but significant differences between connectivity in these regions among those who reported financial exploitation compared to the control group:

• The medial frontal cortex, which is a seat of executive functioning in the brain

• The hippocampus, which is tied to remembering specific events and envisioning future scenarios

• The insula, which is associated with evaluating the trustworthiness of people or situations

"It makes sense that the ability to project a future self through the hippocampus and the ability to assess trustworthiness through the insula might be implicated in financial exploitation risk," Han said.

However, he emphasizes that the current study indicates correlation rather than causation. To zero in on cause and effect, a larger study that follows participants over time is necessary. Han is currently seeking federal grant funding to pursue such a study.

Problems seeing and hearing may put seniors at risk

For the Gerontology and Geriatric Medicine research, Han and his team employed a widely used questionnaire for identifying frailty to compare 24 seniors who reported financial exploitation with 13 peers who hadn't experienced it. The assessment asked about physical issues including fatigue, difficulty walking and poor hearing or vision; psychological issues such as anxiety and problems remembering; and social issues such as isolation and loneliness.

The participants who had experienced financial exploitation reported being significantly frailer than the control group, with that difference showing up on the physical scale but not the measures of psychological or social frailty. Specifically, they reported significantly poorer hearing and marginally poorer sight.

Although this study dealt in correlations, Han notes that it's unlikely that financial exploitation leads to hearing or vision loss.

"The methods that scammers and fraudsters use put a stress on being able to see and hear things accurately," he said. "It stands to reason that this would actually be a mechanism for how certain older adults might be more vulnerable to financial exploitation."

The researchers hope to build on these findings to conduct a larger study that investigates whether measures such as the use of hearing aids and properly calibrated corrective lenses provide protection against financial exploitation.

"This research really does point to the importance of regular visits with a doctor and keeping up on your hearing and vision," Han said. "If we can confirm the clinical relevance and then get the word out that the more you address sensory functioning, the more it potentially protects you against financial exploitation, then all the better."

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About the studies

The first author of the Frontiers in Aging Neuroscience study is Gali Weissberger, a former postdoctoral scholar from Han's lab at the Keck School of Medicine. Other authors are Dr. Laura Mosqueda, Annie Nguyen, Jenna Axelrod and Caroline Nguyen, all of the Keck School; Patricia Boyle of Rush University Medical Center; and Nathan Spreng of McGill University in Canada.

Axelrod, a postdoctoral scholar from Han's research group, is the first author of the Gerontology and Geriatric Medicine paper. The Keck School's Dr. Mosqueda, Weissberger, Nguyen and Emanuil Parunakian were co-authors, along with Boyle from Rush University.

Both studies were supported by the Elder Justice Foundation, the Cathay Bank Foundation, the National Institute on Aging (T32-AG000037) and the USC Department of Family Medicine.

New technique seamlessly converts ammonia to green hydrogen

Researchers leverage renewable electricity for widespread, distributed hydrogen fuel production

NORTHWESTERN UNIVERSITY

Research News

 

Northwestern University researchers have developed a highly effective, environmentally friendly method for converting ammonia into hydrogen. Outlined in a recent publication in the journal Joule, the new technique is a major step forward for enabling a zero-pollution, hydrogen-fueled economy.

The idea of using ammonia as a carrier for hydrogen delivery has gained traction in recent years because ammonia is much easier to liquify than hydrogen and is therefore much easier to store and transport. Northwestern's technological breakthrough overcomes several existing barriers to the production of clean hydrogen from ammonia.

"The bane for hydrogen fuel cells has been the lack of delivery infrastructure," said Sossina Haile, lead author of the study. "It's difficult and expensive to transport hydrogen, but an extensive ammonia delivery system already exists. There are pipelines for it. We deliver lots of ammonia all over the world for fertilizer. If you give us ammonia, the electrochemical systems we developed can convert that ammonia to fuel-cell-ready, clean hydrogen on-site at any scale."

Haile is Walter P. Murphy Professor of materials science and engineering at Northwestern's McCormick School of Engineering with additional appointments in applied physics and chemistry. She also is co-director at the University-wide Institute for Sustainability and Energy at Northwestern.

In the study, Haile and her research team report they are able to conduct the ammonia-to-hydrogen conversion using renewable electricity instead of fossil-fueled thermal energy because the process functions at much lower temperatures than traditional methods (250 degrees Celsius as opposed to 500 to 600 degrees Celsius). Second, the new technique generates pure hydrogen that does not need to be separated from any unreacted ammonia or other products. Third, the process is efficient because all of the electrical current supplied to the device directly produces hydrogen, without any loss to parasitic reactions. As an added advantage, because the hydrogen produced is pure, it can be directly pressurized for high-density storage by simply ramping up the electrical power.

To accomplish the conversion, the researchers built a unique electrochemical cell with a proton-conducting membrane and integrated it with an ammonia-splitting catalyst.

"The ammonia first encounters the catalyst that splits it into nitrogen and hydrogen," Haile said. "That hydrogen gets immediately converted into protons, which are then electrically driven across the proton-conducting membrane in our electrochemical cell. By continually pulling off the hydrogen, we drive the reaction to go further than it would otherwise. This is known as Le Chatelier's principle. By removing one of the products of the ammonia-splitting reaction--namely the hydrogen--we push the reaction forward, beyond what the ammonia-splitting catalyst can do alone."

The hydrogen generated from the ammonia splitting then can be used in a fuel cell. Like batteries, fuel cells produce electric power by converting energy produced by chemical reactions. Unlike batteries, fuel cells can produce electricity as long as fuel is supplied, never losing their charge. Hydrogen is a clean fuel that, when consumed in a fuel cell, produces water as its only byproduct. This stands in contrast with fossil fuels, which produce climate-changing greenhouse gases such as carbon dioxide, methane and nitrous oxide.

Haile predicts that the new technology could be especially transformative in the transportation sector. In 2018, the movement of people and goods by cars, trucks, trains, ships, airplanes and other vehicles accounted for 28% of greenhouse gas emissions in the U.S.--more than any other economic sector according to the Environmental Protection Agency.

"Battery-powered vehicles are great, but there's certainly a question of range and material supply," Haile said. "Converting ammonia to hydrogen on-site and in a distributed way would allow you to drive into a fueling station and get pressurized hydrogen for your car. There's also a growing interest for hydrogen fuel cells for the aviation industry because batteries are so heavy."

Haile and her team have made major advances in the area of fuel cells over the years. As a next step in their work, they are exploring new methods to produce ammonia in an environmentally friendly way.

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The paper is titled "Solid Acid Electrochemical Cell for the Production of Hydrogen from Ammonia." It was published online in Joule on Nov. 3 and was released in print on Nov. 18. Other authors include researchers from SAFCell, an energy startup company based in California.

Pod e-cigar study finds e-cigarettes less harmful than regular cigarettes, new

 BROWN UNIVERSITY

Research News

 

PROVIDENCE, R.I. [Brown University] -- Cigarette smoking causes more than 480,000 deaths each year in the United States, according to federal government data -- and some smokers find it nearly impossible to quit. Many of these smokers use regular, or combustible, cigarettes.

Physicians and scientists have for many years explored the health benefits and drawbacks of nicotine-based alternatives to cigarettes, and new research offers significant evidence that "pod" e-cigarettes are less damaging to health than traditional cigarettes.

"Nicotine is one of the most addictive substances on earth, both in animal models as well as to humans," said Dr. Jasjit S. Ahluwalia, a professor of behavioral and social sciences and medicine at Brown University. "So how can we help these people who can't quit smoking combustible cigarettes? They need other options, and e-cigarettes may be one such option. Our research shows that in the short-term, e-cigarettes are considerably safer than combustible cigarettes."

Ahluwalia is senior author of a new JAMA Network Open study, published on Wednesday, Nov. 18, on the world's first randomized clinical trial of fourth-generation pod e-cigarettes.

The trial included 186 African American and Latinx smokers, as racial and ethnic minority groups tend to experience higher rates of tobacco-related morbidity and mortality even when they smoke at the same rates as other groups. Two-thirds of the participants were provided e-cigarettes for six weeks, while the remaining participants were instructed to continue smoking combustible cigarettes as usual.

By the end of the study, participants who switched to e-cigarettes exhibited significantly lower levels of the potent pulmonary carcinogen NNAL compared to those who continued to smoke combustible cigarettes exclusively. The e-cigarette users also had significantly reduced carbon monoxide (CO) levels and reported fewer respiratory symptoms. These benefits -- reduced NNAL, reduced CO and respiratory symptom improvements -- were especially pronounced among participants who switched completely to e-cigarettes.

The researchers also measured participants' levels of cotinine, a breakdown product of nicotine, and determined that there were no significant differences between groups, an indication that e-cigarettes provided adequate replacement of nicotine.

"Anyone under 21 should not take up cigarettes, e-cigarettes or any nicotine product -- hands down, the best thing to do is to never start -- but if people use tobacco products, they should quit," Ahluwalia cautioned. "But if they cannot quit smoking combustible cigarettes, they should consider using novel nicotine products to either quit smoking altogether or to reduce their harm by transitioning fully to these products."

Going forward, work needs to be done to better understand the non-cancer risks associated with e-cigarettes, such as respiratory and cardiovascular disease. The researchers also plan to carry out year-long studies to further explore the harm-reduction potential of e-cigarettes.

"Most smokers who switched exclusively from combustible cigarettes to e-cigarettes during the study maintained this behavior at six months, but we need longer-term follow-up," said Kim Pulvers, a professor of psychology at California State University San Marcos who was the principal investigator of the study. "We also need continued study of dual users to determine whether they maintain harm reduction over time."

Ahluwalia said that because many individuals who use both e-cigarettes and combustible cigarettes will switch back to exclusively combustible cigarettes over time, there is a critical need for interventions that support those who try to switch to e-cigarettes but fail. He also emphasized the importance of alternatives to quitting outright, given the challenge that quitting poses for so many cigarette smokers.

"It's possible that nicotine e-cigarettes and other harm-reduction products will be game-changers for our field," Ahluwalia added. "I hope this study stimulates more people to do this research and to have an open mind about this. I also hope it inspires them to let science inform policy rather than emotion."

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In addition to Ahluwalia and Pulvers, additional contributors include Christopher H. Schmid and Kexin Qu from Brown; Nicole L. Nollen from the University of Kansas School of Medicine; Dr. Neal Benowitz from the University of California, San Francisco; and Myra Rice from California State University San Marcos.

Schmid served as a consultant for legal firms representing Eli Lilly, Boehringer-Ingelheim and Gilead outside the study. Benowitz received personal fees from Pfizer and Achieve Life Sciences and served as a consultant to pharmaceutical companies that market smoking cessation medications and as an expert witness in litigation against tobacco companies outside the study. Dr. Ahluwalia received personal fees from Lucy Goods outside the study. These points were fully disclosed in the study.

The study was funded by the National Institutes of Health (5SC3GM122628) and was also supported by the NIH-funded Center of Biomedical Research Excellence (P20GM130414) and the National Institute of General Medical Sciences of the NIH (U54GM115677).

 3D-printed, lifelike heart models could help train tomorrow's surgeons (video)

AMERICAN CHEMICAL SOCIETY

Research News

 

IMAGE: RESEARCHERS HAVE DEVELOPED A WAY TO 3D PRINT A FULL-SIZE MODEL OF A PATIENT'S OWN HEART. view more 

CREDIT: AMERICAN CHEMICAL SOCIETY

Full-size, realistic models of human organs could help surgeons train and practice before they cut into a patient. However, it's been challenging to make inexpensive models of a size, complexity and material that simulates human organs. Now, researchers reporting in ACS Biomaterials Science & Engineering have developed a way to 3D print a full-size model of a patient's own heart. Watch a video of how they made the 3D organ here.

For complex heart surgeries, having a chance to plan and practice on a realistic model could help surgeons anticipate problems, leading to more successful outcomes. Current 3D printing techniques have been used to make full-size organ models, but the materials generally don't replicate the feel or mechanical properties of natural tissue. And soft, tissue-like materials, such as silicone rubbers, often collapse when 3D printed in air, making it difficult to reproduce large, complex structures. Eman Mirdamadi, Adam Feinberg and colleagues recently developed a technique, called freeform reversible embedding of suspended hydrogels (FRESH), which involves 3D printing soft biomaterials within a gelatin bath to support delicate structures that would otherwise collapse in air. However, the technique was previously limited to small objects, so the researchers wanted to adapt it to full-size organs.

The team's first step was to show that alginate, an inexpensive material made from seaweed, has similar material and mechanical properties as cardiac tissue. Next, the researchers placed sutures in a piece of alginate, which held even when stretched -- suggesting that surgeons could practice stitching up a heart model made from the material. In preparation for making the heart model, the team modified their FRESH 3D printer to make larger objects. They used this device and magnetic resonance imaging (known as MRI) scans from a patient to model and print a full-size adult human heart, as well as a section of coronary artery that they could fill with simulated blood. The heart model was structurally accurate, reproducible and could be handled outside of the gelatin bath. The method could also be applied to printing other realistic organ models, such as kidneys or liver, the researchers say.

The authors acknowledge funding from the Office of Naval Research, the U.S. Food & Drug Administration and the National Institutes of Health.

The abstract that accompanies this paper can be viewed here.

The American Chemical Society (ACS) is a nonprofit organization chartered by the U.S. Congress. ACS' mission is to advance the broader chemistry enterprise and its practitioners for the benefit of Earth and its people. The Society is a global leader in providing access to chemistry-related information and research through its multiple research solutions, peer-reviewed journals, scientific conferences, eBooks and weekly news periodical Chemical & Engineering News. ACS journals are among the most cited, most trusted and most read within the scientific literature; however, ACS itself does not conduct chemical research. As a specialist in scientific information solutions (including SciFinder® and STN®), its CAS division powers global research, discovery and innovation. ACS' main offices are in Washington, D.C., and Columbus, Ohio.   To automatically receive news releases from the American Chemical Society, contact newsroom@acs.org.   Follow us: Twitter | Facebook

3D bioprinted heart provides new tool for surgeons

COLLEGE OF ENGINEERING, CARNEGIE MELLON UNIVERSITY

Research News

 

IMAGE: A 3D BIOPRINTED HEART MODEL DEVELOPED BY ADAM FEINBERG AND HIS TEAM. view more 

CREDIT: CARNEGIE MELLON UNIVERSITY COLLEGE OF ENGINEERING

Professor of Biomedical Engineering Adam Feinberg and his team have created the first full-size 3D bioprinted human heart model using their Freeform Reversible Embedding of Suspended Hydrogels (FRESH) technique. Showcased in a recent video by American Chemical Society and created from MRI data using a specially built 3D printer, the model mimics the elasticity of cardiac tissue and sutures realistically. This milestone represents the culmination of two years of research, holding both immediate promise for surgeons and clinicians, as well as long term implications for the future of bioengineered organ research.

The FRESH technique of 3D bioprinting was invented in Feinberg's lab to fill an unfilled demand for 3D printed soft polymers, which lack the rigidity to stand unsupported as in a normal print. FRESH 3D printing uses a needle to inject bioink into a bath of soft hydrogel, which supports the object as it prints. Once finished, a simple application of heat causes the hydrogel to melt away, leaving only the 3D bioprinted object.

While Feinberg's lab has proven both the versatility and the fidelity of the FRESH technique, the major obstacle to achieving this milestone was printing a human heart at full scale. This necessitated the building of a new 3D printer custom made to hold a gel support bath large enough to print at the desired size, as well as minor software changes to maintain the speed and fidelity of the print.

Major hospitals often have facilities for 3D printing models of a patient's body to help surgeons educate patients and plan for the actual procedure, however these tissues and organs can only be modeled in hard plastic or rubber. Feinberg's team's heart is made from a soft natural polymer called alginate, giving it properties similar to real cardiac tissue. For surgeons, this enables the creation of models that can cut, suture, and be manipulated in ways similar to a real heart. Feinberg's immediate goal is to begin working with surgeons and clinicians to fine tune their technique and ensure it's ready for the hospital setting.

"We can now build a model that not only allows for visual planning, but allows for physical practice," says Feinberg. "The surgeon can manipulate it and have it actually respond like real tissue, so that when they get into the operating site they've got an additional layer of realistic practice in that setting."

This paper represents another important marker on the long path to bioengineering a functional human organ. Soft, biocompatible scaffolds like that created by Feinberg's group may one day provide the structure onto which cells adhere and form an organ system, placing biomedicine one step closer to the ability to repair or replace full human organs.

"While major hurdles still exist in bioprinting a full-sized functional human heart, we are proud to help establish its foundational groundwork using the FRESH platform while showing immediate applications for realistic surgical simulation," added Eman Mirdamadi, lead author on the publication.

Published in ACS Biomaterials Science and Engineering, the paper was co-authored by Feinberg's students Joshua W. Tashman, Daniel J. Shiwarski, Rachelle N. Palchesko, and former student Eman Mirdamadi.

CAPTION

Modeling incorporates imaging data into the final 3D printed object.

CAPTION

A needle prints the alginate into a hydrogel bath, which is later melted away to leave the finished model.

Study identifies reasons for soaring nuclear plant cost overruns in the US

Analysis points to ways engineering strategies could be reimagined to minimize delays and other unanticipated expenses

MASSACHUSETTS INSTITUTE OF TECHNOLOGY

Research News

 

A new analysis by MIT researchers details many of the underlying issues that have caused cost overruns on new nuclear power plants in the U.S., which have soared ever higher over the last five decades. The new findings may help the designers of new plants build in resilience to the factors that tend to cause these overruns, thus helping to bring down the costs of such plants.

Many analysts believe nuclear power will play an essential part in reducing global emissions of greenhouse gases, and finding ways to curb these rising costs could be an important step toward encouraging the construction of new plants, the researchers say. The findings are being published in the journal Joule, in a paper by MIT professors Jessika Trancik and Jacopo Buongiorno, along with former students Philip Eash-Gates SM '19, Magdalena Klemun PhD '20, Goksin Kavlak PhD '18, and Research Scientist James McNerney.

Among the surprising findings in the study, which covered 50 years of U.S. nuclear power plant construction data, was that, contrary to expectations, building subsequent plants based on an existing design actually costs more, not less, than building the initial plant.

The authors also found that while changes in safety regulations could account for some of the excess costs, that was only one of numerous factors contributing to the overages.

"It's a known fact that costs have been rising in the U.S. and in a number of other locations, but what was not known is why and what to do about it," says Trancik, who is an associate professor of energy studies in MIT's Institute for Data, Systems and Society. The main lesson to be learned, she says, is that "we need to be rethinking our approach to engineering design."

Part of that rethinking, she says, is to pay close attention to the details of what has caused past plant construction costs to spiral out of control, and to design plants in a way that minimizes the likelihood of such factors arising. This requires new methods and theories of technological innovation and change, which the team has been advancing over the past two decades.

For example, many of the excess costs were associated with delays caused by the need to make last-minute design changes based on particular conditions at the construction site or other local circumstances, so if more components of the plant, or even the entire plant, could be built offsite under controlled factory conditions, such extra costs could be substantially cut.

Specific design changes to the containment buildings surrounding the reactor could also help to reduce costs significantly, Trancik says. For example, substituting some new kinds of concrete in the massive structures could reduce the overall amount of the material needed, and thus slash the onsite construction time as well as the material costs.

Many of the reasons behind the cost increases, Trancik says, "suggest that there's a lack of resilience, in the process of constructing these plants, to variable construction conditions." Those variations can come from safety regulations that are changing over time, but there are other reasons as well. "All of this points to the fact that there is a path forward to increasing resilience that involves understanding the mechanisms behind why costs increased in the first place."

Say overall construction costs are very sensitive to upfront design costs, for example: "If you're having to go back and redo the design because of something about a particular site or a changing safety regulation, then if you build into your design that you have all of these different possibilities based on these things that could happen," that can protect against the need for such last-minute redesign work.

"These are soft costs contributions," Trancik says, which have not tended to be prioritized in the typical design process. "They're not hardware costs, they are changes to the environment in which the construction is happening. ... If you build that in to your engineering models and your engineering design process, then you may be able to avoid the cost increases in the future."

One approach, which would involve designing nuclear plants that could be built in factories and trucked to the site, has been advocated by many nuclear engineers for years. For example, rather than today's huge nuclear plants, modular and smaller reactors could be completely self-contained and delivered to their final site with the nuclear fuel already installed. Numerous such plants could be ganged together to provide output comparable to that of larger plants, or they could be distributed more widely to reduce the need for long-distance transmission of the power. Alternatively, a larger plant could be designed to be assembled on site from an array of smaller factory-built subassemblies.

"This relationship between the hardware design and the soft costs really needs to be brought into the engineering design process," she says, "but it's not going to happen without a concerted effort, and without being informed by modeling that accounts for these potential ballooning soft costs."

Trancik says that while some of the steps to control costs involve increased use of automated processes, these need to be considered in a societal context. "Many of these involve human jobs and it is important, especially in this time, where there's such a need to create high-quality sustained jobs for people, this should also factor into the engineering design process. So it's not that you need to look only at costs." But the kind of analysis the team used, she says, can still be useful. "You can also look at the benefit of a technology in terms of jobs, and this approach to mechanistic modeling can allow you to do that."

The methodology the team used to analyze the causes of cost overruns could potentially also be applied to other large, capital-intensive construction projects, Trancik says, where similar kinds of cost overruns often occur.

"One way to think about it as you're bringing more of the entire construction process into manufacturing plants, that can be much more standardized." That kind of increased standardization is part of what has led, for example, to a 95 percent cost reduction in solar panels and in lithium-ion batteries over the last few decades, she says. "We can think of it as making these larger projects more similar to those manufacturing processes."

Buongiorno adds that "only by reducing the cost of new plants can we expect nuclear energy to play a pivotal role in the upcoming energy transformation."

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The work was supported by the David and Lucille Packard Foundation and the MIT Energy Initiative.

Written by David L. Chandler, MIT News Office

Mattress flammability standard is a lifesaver, NIST report 

NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY (NIST)

Research News

IMAGE: THE TEST SETUP DESCRIBED IN 16 CFR PART 1633 ENTAILS APPLYING TO GAS BURNER HEADS TO THE SIDE AND TOP OF A MATTRESS FOR UP TO 30 MINUTES. view more 

CREDIT: NIST/B. HAYES

No matter how soft and cozy, beds that have gone up in flames are a source of some of the deadliest fires in the U.S. As large pieces of furniture loaded with combustible cushioning materials, beds are substantial fuel sources for home fires. Once ignited, mattress fires can grow quickly, creating life-threatening situations in bedrooms or entire houses within minutes.

A 2007 standard for mattress flammability from the Consumer Product Safety Commission (CPSC), known as 16 CFR Part 1633, sought to curb the danger of bed fires sparked by flames, which caused an estimated 95 deaths annually from 2002-2005. But because of how infrequently consumers replace mattresses, the researchers who helped to develop the standard spent years in the dark about whether the safety requirements were living up to expectations.

Now, enough data has accumulated for researchers at the National Institute of Standards and Technology (NIST) to estimate that the standard prevented 65 deaths from bed fires annually in 2015 and 2016. That number is expected to rise as more mattresses are replaced with the newer, standard-compliant models.

"What we've got here is a clear case of fire researchers, manufacturers and regulators all working together, getting the science right, getting commercially acceptable versions of the mattresses right and getting the regulation right," said NIST research scientist Richard Gann. "It all came together, and as a result we have a real success story for the country."

Long before 2007, other standards were in place to crack down on a leading cause of bed fires in cigarettes, but they left the grave threat of flaming ignition sources, like lighters, matches or pieces of burning furniture, largely unaddressed.

To close that gap, the International Sleep Products Association (ISPA) -- the trade association for the mattress industry -- approached NIST about laying the groundwork for a new mattress flammability standard that would eliminate, or at least greatly reduce, the casualties from bed fires.

Gann and his colleagues leapt at the opportunity and set out to devise a realistic and practical way for manufacturers to test mattress flammability.

Since bed fires typically start with the ignition of blankets, sheets and other bedclothing items, the researchers aimed to replicate the danger they posed to mattresses. Gann and his team assembled several sets of bedclothes, set them ablaze and gauged the heat release rate (HRR) -- an indicator of how intensely something burns, measured in watts -- of each.

They used the HRR data to create a special test apparatus composed of twin propane burners that could mimic fires generated by an off-the-shelf set of bedclothes. With the burners, manufacturers could test their mattresses against conditions similar to real-world bedroom fires.

While the researchers developed this new test method, manufacturers experimented with fire-resistant fabrics -- such as those used in firefighter uniforms -- and implemented them into prototypes to lower their HRR.

But how much lower would the HRR of a mattress need to be? The limit had to be low enough to ensure that burning mattresses would not spark a "flashover," wherein a fire makes a room so hot that all other combustible items in it -- chairs, clothes, etc. -- suddenly and simultaneously ignite, Gann said.

To find the limit, they measured how much heat it would take to ignite small pieces of material, each representing an item commonly found in bedrooms, such as wooden furniture or softer items like upholstery or curtains. The researchers then burned both prototype and commercially available mattresses, measuring the flow of heat to several spots around the room.

With the two data sets, the team discovered that mattresses with a peak HRR of about 600 kilowatts (kW) or more would produce enough heat to reliably ignite soft materials almost anywhere in an ordinary bedroom. While the commercial king- and twin-sized beds they tested had peak HRRs far above this value, one prototype fared much better.

"The manufacturers made some prototypes and they worked. When they sent them here, we tested them," Gann said. "Four megawatts. One megawatt. And then down to 400 kilowatts for a king-size bed. In the world of fire safety, that's a game changer."

When mattresses burn below 400 kW, the odds of flashover decrease substantially, the researchers found. To prevent mattresses from coming close to this threshold, the CPSC's standard requires that mattresses maintain an HRR under 200 kW after being ignited by the burning-bedclothes-simulating burners.

By the time the standard became effective on July 1, 2007, mattresses that met the new requirements were widely available. But did this change actually translate into lives saved? If so, how many lives was it saving? Gann was eager to know, but when he set out two years later to find the answers, he learned that there was a colossal roadblock in the way.

Mattresses remain with their original owners for 10 to 12 years on average. And after that, they are often passed on to children or get refurbished and find a new life back on the market, Gann said. This meant it would take years before enough standard-compliant mattresses found their way into homes. With so little data available at the time, Gann had to wait this one out.

Returning to the issue 10 years later, now with a wealth of information available about fire incidents (fires, injuries and deaths) from the National Fire Incident Reporting System and mattress sales from ISPA, Gann brought aboard NIST economists Stanley Gilbert and Dave Butry, who have developed statistical methods to finally put numbers to the standard's effects.

One of their approaches was to compare the total number of incidents caused by bed fires in 2005 and 2006 combined to the number in 2015 and 2016. They didn't just look at the raw values, though. If other fire-influencing factors -- like the number of homes with smoke alarms -- were not identical between the two time periods, the comparison could be unfair.

To isolate the effect of the standard from other factors, Gilbert and Butry compared the outcomes of bed fires to upholstered furniture fires, as the combustible materials in both types of fires are similar. Because the standard is exclusively about mattresses, any spike or dip that only appeared in the bed fire numbers, but not upholstered furniture fires, would probably have been driven by the standard.

The researchers crunched the numbers and were pleased to identify several strong indicators suggesting that the standard was doing its job and doing it well. They found that, relative to upholstered furniture fires, the number of bed fires from 2015 and 2016 combined was 12% lower than in 2005 and 2006. In those 10 years, injuries decreased by 34% and, much to the delight of the researchers, deaths plummeted by 82%.

Evidence mounted further in support of the standard as the researchers examined the mattress sales data alongside fire incidents.

The researchers used the sales data to create mathematical models that could estimate how many pre-standard mattresses were being replaced with new ones. The models point to the standard as the likely source of the benefits, as the mattress replacements and reductions in casualties closely mirrored each other throughout the years.

"We used several different approaches to look at the data, and they all pointed to the same conclusion; the standard saves lives," Gilbert said.

Ryan Trainer, president of ISPA, which was involved in developing and implementing 16 CFR Part 1633, also voiced appreciation that the standard has borne fruit.

"The mattress industry has collaborated with NIST and CPSC to develop a standard that is based on sound science, reflects real world risks, improves safety and is practical for manufacturers to adopt," Trainer said. "We are gratified that NIST's analysis of national fire statistics shows that since Part 1633 was implemented, the number of bed fires ignited by open-flame heat sources, and especially the deaths and injuries from those fires, have dropped so significantly."

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