Now, findings from researchers at Texas A&M University provide new, evidence-based insight into minimizing the risk of these diseases at canine facilities.

“In adult, healthy humans and animals, these diseases usually cause diarrhea and occasionally other minor ailments, but for infants, puppies and the immunocompromised, infection could be deadly,” said Loni Taylor, PhD, DVM, an epidemiologist with the Texas A&M University School of Public Health, who led the study. “We wanted to identify the factors associated with kennel-housed dogs in Texas that test positive for both diseases.”

For their study, published in Comparative Medicine, Taylor and five colleagues with Texas A&M’s College of Veterinary Medicine & Biomedical Sciences sought to find out if a dog’s score on the Purina Fecal Scoring chart, breed, sex or age was associated with testing positive on a fecal screening test for either Giardia, Cryptosporidium or both organisms together.

To accomplish this, they tested fecal samples collected from a census sample of 153 clinically normal dogs housed at Texas kennels between March and October 2021. Breeds included golden retrievers, Labrador retrievers, beagles and a variety of large hounds and hound mixes.

The sex, age, breed and location were noted for the 153 dogs studied. In addition, fecal scores were determined by a single researcher using visual assessment of the samples, based on the Purina Institute metric (where 1 is hard and 7 is watery).

A secondary data analysis and statistical analysis found that dogs were significantly more likely to test positive for Giardia (45%) than Cryptosporidium (7%) (P < 0.01), although no clear link was found between sex or breed and these infections.

In addition, kennel-housed dogs 18 months of age or younger had 3.4 times the odds of Giardia infection compared with older dogs, and hard stool was associated with negative test status for Giardia in the stool.

No statistically significant relationship was found for age or fecal score and Cryptosporidium-positive test status, and Taylor noted that additional studies with larger sample sizes could help identify such a relationship.

“The primary takeaway is that age and fecal score are important factors for choosing which dogs to screen for subclinical Giardia,” Taylor said. “And given the increased odds of Giardia infection, screening should be as robust as the recommended combination of testing methods.”

Now, researchers in the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) are doubling down, literally, on metasurface technology by creating a bilayer metasurface, made of not one, but two stacked layers of titanium dioxide nanostructures. Under a microscope, the new device looks like a dense array of stepped skyscrapers.

The research is published in Nature Communications.

“This is a feat of nanotechnology at the highest level,” said senior author Federico Capasso, the Robert L. Wallace Professor of Applied Physics and Vinton Hayes Senior Research Fellow in Electrical Engineering at SEAS. “It opens up a new way to structure light, in which we can engineer all its aspects such as wavelength, phase and polarization in an unprecedented manner…It signifies a new avenue for metasurfaces that so far has been just scratching the surface.”

For centuries, optical systems have relied on bulky, curved lenses made of glass or plastic to bend and focus light. The SEAS-led metasurface revolution of the last decade has produced flat, ultra-thin structures patterned with millions of tiny elements that can manipulate light with nanometer precision. A striking example technology is the metalens: Unlike conventional lenses, metalenses can be fabricated with existing semiconductor manufacturing, making possible compact, integrated optical systems in devices like smartphones, cameras, and augmented reality displays.

After Capasso’s team reported their first working metalens that can bend visible light, they worked with Harvard’s Office of Technology Development to license the technology and start a company, Metalenz. They’ve since demonstrated a host of potential applications, including an endoscope, an artificial eye, and a telescope lens.

But the single-layer nanostructure design Capasso’s team invented has been in some ways limiting. For example, previous metasurfaces put specific requirements on the manipulation of light’s polarization — that is, the orientation of the light waves — in order to control the light’s behavior.

“Many people had investigated the theoretical possibility of a bilayer metasurface, but the real bottleneck was the fabrication,” said Alfonso Palmieri, graduate student and co-lead author of the study. With this breakthrough, Palmieri explained, one could imagine new kinds of multifunctional optical devices — for example, a system that projects one image from one side and a completely different image from the other.

Using the facilities of the Center for Nanoscale Systems at Harvard, the team that included former postdoctoral researchers Ahmed Dorrah and Joon-Suh Park came up with a fabrication process for freestanding, sturdy structures of two metasurfaces that hold strongly together but do not affect each other chemically. While such multi-level patterning has been common in the silicon semiconductor world, it had not been as well explored in optics and metaoptics.

To demonstrate the power of their device, the team devised an experiment in which they used their bilayer metalens to act on polarized light in the same way that a complicated system of waveplates and mirrors does.

In future experiments, the team could expand into even more layers to exert control over other aspects of light, such as extreme broadband operation with high efficiency across the entire visible and near infrared spectrum, opening the door to even more sophisticated light-based functionalities.

The research was supported by several federal funding sources, including the Office of Naval Research under grant No. N00014-20-1-2450, and from the Air Force Office of Scientific Research under grant No.s FA9550-21-1-0312 and FA9550-22-1-0243. The devices were made at the Harvard University Center for Nanoscale Systems, part of the National Nanotechnology Coordinated Infrastructure Network, which is supported by the National Science Foundation under NSF award No. ECCS-2025158.

Staff acknowledgments: Stephan Kraemer supported the focused ion beam process, and Mac Hathaway supported the atomic layer deposition process.

Think of it as the “butterfly effect” — the idea that something as small as the flapping of a butterfly’s wings can eventually lead to a major event such as a hurricane — in reverse.

The new study, published in the journal Nature Ecology and Evolution, also suggests that a lack of comprehensive global data about insects may leave conservationists and policymakers ill-prepared to mitigate biodiversity loss from climate change for a wide range of insect species.

For the study, a team co-led by Yale ecologist Walter Jetz analyzed phylogenetic and geographic range data for more than 12,000 butterfly species worldwide. The team was also co-led by Stefan Pinkert, an entomologist at the University of Marburg, in Germany, and former postdoctoral associate at Yale.

They found that butterfly diversity is highly clustered in tropical and subtropical mountain systems: two-thirds of butterfly species live primarily in the mountains, which contain 3 1/2 times more butterfly hotspots than lowlands.

Yet those mountain ecosystems — and surrounding areas — are quickly changing as a result of climate change. According to the study, 64% of the temperature niche space of butterflies in tropical areas will erode by 2070, with the geographically restricted temperature conditions of mountains constantly shrinking.

“The diversity, elegance, and sheer beauty of butterflies impassion people worldwide,” said Jetz, professor of ecology and evolutionary biology in Yale’s Faculty of Arts and Sciences and director of the Yale Center for Biodiversity and Global Change (BGC Center).

“Co-evolved with host plants, butterflies form an integral part of an ecologically functioning web of life,” he added. “Unfortunately, our first global assessment of butterfly diversity and threats finds that butterflies’ fascinating diversification into higher-elevation environments might now spell their demise, with potentially thousands of species committed to extinction from global warming this century.”

Pinkert, a former postdoctoral researcher at the BGC Center, added: “As an entomologist, I am committed to informing the public about the distribution of insect diversity and targeted ways to protect it. Our results are insightful from an ecological point of view but unfortunately also very alarming.”

Current priorities in biodiversity preservation, the researchers note, are geared to animals and plants, rather than insects. Until now, a global assessment of the geographic coincidence of diversity, rarity, and climate change threats for an insect system did not exist.

The new assessment reveals that patterns in butterfly diversity differ strongly from those of much better studied groups such as birds, mammals, and amphibians — challenging the relevance of existing conservation priorities, the researchers said.

“This research was made possible by many years of mobilizing various global data and newly developed integrative approaches, all aimed at filling this critical information gap for at least one insect taxon,” Pinkert said.

Jetz said he hoped the new study — and future research enabled by the Map of Life, a global database, directed by Jetz, that tracks the distribution of known species worldwide — will support conservation managers to include insects in their plans for biodiversity preservation.

“A reduction of carbon emissions, combined with proactive identification and preservation of key butterfly habitats and migratory corridors, will be key to ensuring that much of butterfly diversity survives to benefit future generations,” Jetz said.

Co-authors of the study are Nina Farwig of the University of Marburg and Akito Kawahara of the University of Florida.

The research was supported, in part, by the Alexander von Humboldt Foundation, the Gordon and Betty Moore Foundation, the National Science Foundation, and the E.O. Wilson Biodiversity Foundation.

This research, led by Dr. Robert D. Meade, former Senior Postdoctoral Fellow and Dr. Glen Kenny, Director of HEPRU and professor of physiology at uOttawa’s Faculty of Health Sciences, highlights the urgent need to address the impacts of climate change on human health.

The study found that many regions may soon experience heat and humidity levels that exceed the safe limits for human survival. “Our research provided important data supporting recent suggestions that the conditions under which humans can effectively regulate their body temperature are actually much lower than earlier models suggested,” states Kenny. “This is critical information as we face increasing global temperatures.”

Utilizing a widely used technique known as thermal-step protocols, Meade and his team exposed 12 volunteers to various heat and humidity conditions to identify the point at which thermoregulation becomes impossible. What made this study different, was that participants returned to the laboratory for a daylong exposure to conditions just above their estimated limit for thermoregulation. Participants were subjected to extreme conditions, 42°C with 57% humidity, representing a humidex of approximately 62°C. “The results were clear. The participants’ core temperature streamed upwards unabated, and many participants were unable to finish the 9-hour exposure. These data provide the first direct validation of thermal step protocols, which have been used to estimate upper limits for thermoregulation for nearly 50 years,” says Meade.

“Our findings especially timely, given estimated limits for thermoregulation are being increasingly incorporated into large scale climate modelling” explains Meade. “They also underscore the physiological strain experienced during prolonged exposure to extreme heat, which is becoming more common due to climate change.”

The implications of this research extend beyond academia. As cities prepare for hotter summers, understanding these limits can help guide health policies and public safety measures. “By integrating physiological data with climate models, we hope to better predict and prepare for heat-related health issues,” adds Kenny.

As the world grapples with the realities of climate change, this research aims to spark important conversations about our safety and adaptability in increasingly extreme environments.