It’s also a problem UC Santa Barbara researchers Charlie Xiao, Elliot Hawkes and Bolin Liao are hoping to make a dent in. In a paper in the journal Device, the trio present an adaptive tile, which when deployed in arrays on roofs, can lower heating bills in winter and cooling bills in summer, without the need for electronics.

“It switches between a heating state and a cooling state, depending on the temperature of the tile,” said Xiao, the lead author of the study. “The target temperature is about 65° F — about 18° C.”

At about four inches square, this passive thermoregulating device is a blend of Liao’s expertise in thermal science and Hawkes’ work in mechanism design — a movable surface that can change its thermal properties in response to a range of temperatures. The idea for this project came to them during long drives between Santa Barbara and northern California a few years ago.

“Both our spouses were in Stanford at the time, so we were taking trips and wondering what we could potentially do together,” said Liao, who, like Hawkes, is a professor in UCSB’s Department of Mechanical Engineering. They then received seed funding from the California NanoSystems Institute on campus to design mechanically tunable thermal devices.

It wasn’t until Xiao’s idea of using a wax motor that the idea of adaptive roof tiles took its final shape. Based on the change in the volume of wax in response to temperatures it is exposed to, a wax motor creates pressure that moves mechanical parts, translating thermal energy into mechanical energy. Wax motors are commonly found in various appliances such as dishwashers and washing machines, as well in more specialized applications, such as in the aerospace industry.

In the case of the tile, the wax motor, depending on its state, can push or retract pistons that close or open louvers on the tile’s surface. So, in cooler temperatures, while the wax is solid, the louvers are closed and lay flat, exposing a surface that absorbs sunlight and minimizes heat dissipation through radiation.

But as soon as the temperatures reach around 18° C, the wax begins to melt and expand, pushing the louvers open and exposing a surface that reflects sunlight and emits heat.

In addition, during the melting or freezing process, the wax also absorbs or releases a large amount of heat, further stabilizing the temperature of the tile and the building.

“So we have a very predictable switching behavior that works within a very tight band,” Xiao explained. According to the researchers’ paper, testing has demonstrated a reduction in energy consumption for cooling by 3.1x and heating by 2.6x compared with non-switching devices covered with conventional reflective or absorbing coatings. Because of the wax motor, no electronics, batteries or external power sources are required to operate the device, and unlike other similar technologies, it is responsive within a few degrees of its target range. Additionally, the simplicity of its design lend itself to customization — different thermal coatings and various types of wax can be used to allow the device to operate at desired temperature ranges, while also lending itself toward mass manufacture.

“The device is still a proof-of-concept, but we hope it will lead to new technologies that one day could have a positive impact on energy expenditure in buildings,” said Hawkes.

Cattle on lifelong grass diets are known as “pasture finished,” while those that switch from grass to grain before slaughter are “grain finished.” Prior research has suggested that pasture-finished beef operations have a higher carbon footprint than grain-finished operations. However, most studies have limited their focus to the amount of greenhouse gases emitted directly by beef production without considering other factors that may affect the overall carbon footprint.

To help deepen understanding, Blaustein-Rejto and colleagues calculated and compared the carbon footprint of 100 beef operations located in 16 countries. In addition to direct greenhouse gas emissions, their calculations incorporated soil carbon sequestration — the capture and long-term storage in pasture soils of atmospheric carbon, often in the form of dead plants and cattle waste. They also accounted for the carbon opportunity cost — the carbon that would have been sequestered if the land had native ecosystems instead of being used for beef production.

Extensive statistical analysis showed that the pasture-finished operations produce 20 percent more greenhouse gases than grain-finished operations — in line with prior studies. However, after incorporating soil carbon sequestration and carbon opportunity cost, the total carbon footprint of pasture-finished operations was 42 percent higher, likely due to its more intense usage of land.

Further analysis suggested that an increase in land use intensity is indeed strongly associated with a bigger overall carbon footprint for beef operations. The calculations also suggest that, averaging across all operations in the study, carbon opportunity costs may contribute even more to an operation’s overall carbon footprint than its direct greenhouse gas emissions.

The researchers say their findings emphasize the need for climate mitigation efforts to account for carbon opportunity costs of beef production. With pasture-finished beef often being seen as more premium, carbon footprint data may also provide important additional information to aid consumer choice.

The authors add: “Our research reveals that the carbon cost of land use accounts for the largest part of beef’s carbon footprint. Therefore, there is an even larger carbon cost than typically found to land-intensive beef operations, such as many grass-fed systems, even when taking into account potential carbon sequestration due to grazing.”

In 2005, excavations in Varnhem, Sweden uncovered the remains of a Christian church, nearby which was a cemetery containing thousands of Viking graves dating to the 10th-12th century AD. In this study, Bertilsson and colleagues performed clinical and radiographical examination of the dentition of individuals from this site. In total, the team analyzed over 2300 teeth from 171 individuals.

Over 60% of the examined adults had signs of dental caries (tooth decay), most often on the root surface, while none of the juvenile individuals had caries. Other pathologies were also observed, including tooth infection and indications of teeth having been lost before death. Several individuals had caries severe enough to have caused tooth pain, and the authors noted a few cases of tooth abrasion that were likely intentional modifications intended to lessen tooth pain. Some teeth also exhibited abrasions consistent with tooth picking, likely to remove bits of food.

The prevalence of dental caries in this population is similar to what has been noted in other European populations of a similar age, although the authors caution that nearly a quarter of these Varnhem individuals’ teeth appear to have been lost before or after death, and this likely skews these results. For example, the prevalence of caries in this population was observed to decrease with adults’ age, an unexpected result which likely reflects increased tooth loss in older individuals such that the most decayed teeth were not present. Overall, these data provide insights into the lives of Vikings who suffered from and occasionally attempted to treat dental issues, as well as providing details into the pathology of untreated dental issues.

The authors add: “In a Swedish Viking population, around half of the individuals suffered from dental caries. The Vikings performed both tooth filing, tooth picking, and other dental treatment, including attempts to treat dental infections.”

Glycans are a type of sugar molecule structures that is linked to the proteins in our cells. The structure of the glycan determines the function of the protein. It has been known for a while that changes in glycan structure can indicate inflammation or disease in the body. Now, researchers at the University of Gothenburg have developed a way to distinguish different types of structural changes, which may provide a precise answer to what will change for a specific disease.

“We have analysed data from about 220 patients with 11 differently diagnosed cancers and have identified differences in the substructure of the glycan depending on the type of cancer. By letting our newly developed method, enhanced by AI, work through large amounts of data, we were able to find these connections,” says Daniel Bojar, associate senior lecturer in bioinformatics at the University of Gothenburg and lead author of the study published in Cell Reports Methods.

AI enhanced method found the patterns

There are also other research groups that study the substructures of the glycan in search of so-called biomarkers that describe what is wrong. This often involves statistical tests using mass spectroscopy to find out whether the level of individual sugars is significantly higher or lower in cancer. These tests have too low sensitivity and are not reliable because different sugars are structurally related and therefore not independent of each other.

Daniel Bojar’s research team uses a new method that includes AI, which takes these problems into account and can find the patterns in the data sets where others fail.

“We can rely on our results; they are statistically significant. If we know what we are looking for, it is easier to find the correct result. Now we will take these biomarkers and develop test methods,” says Daniel Bojar.

New mass spectrometer

During the fall, his research group received SEK 4 million from the Lundberg Foundation to purchase a state-of-the-art mass spectrometer. This instrument will serve as an AI platform to support researchers in the study of glycans, for example in lung cancer samples. The aim is to detect the cancer earlier to improve the chances of recovery.

“We want to develop a reliable and rapid analytical method to detect cancer, and also the type of cancer, through a blood sample or saliva. I think we might be able to perform clinical tests on human samples in 4-5 years,” says Daniel Bojar.