Keeping rain out of the drain

Keeping rain out of the drain

David Vann of the School of Arts and Sciences heads up the research efforts around Shoemaker Green’s stormwater management system. Using sensors placed around the site, he hopes to be able to closely monitor how much water drains out of the system, and how quickly. (Photo: Eric Sucar) 

By Katherine Unger Baillie

Shoemaker Green, three acres of green space on Penn’s campus, is more than just a nice place to have lunch. Formerly home to tennis courts, the space was revamped in 2012 and now includes garden beds with native plantings, benches, and shaded walkways.

But all that conceals what is perhaps the most unusual facet of the Green—an underground cistern capable of holding 20,000 gallons of water.

The site represents one example of how the University is increasingly incorporating design features into campus buildings and landscapes to manage stormwater. From green roofs and rain gardens to buried storage tanks and water-reuse systems, Penn is playing a leading role in the city’s efforts to keep runoff from overwhelming the sewer system. All significant new building projects at Penn are designed to meet the Philadelphia Water Department goal of managing the first inch and a half of rain that falls on impervious surfaces.

“That means that the first inch and a half of water that falls from the sky literally can’t go down the drain as runoff,” says Bob Lundgren, Penn’s landscape architect. “That regulation dictates how we do a lot of projects here. We do green roofs, we do cisterns, we do permeable paving, so the rain can soak into Mother Earth or sit somewhere and then drain slowly or be reused.”

The rationale behind all of this attention on stormwater management is tied intimately with Philadelphia’s older infrastructure. In many parts of the city, the pipes that carry stormwater are connected to those that carry sewage. When a rainstorm sends a deluge into the storm drains, the overflow from these pipes goes directly into waterways, such as the Schuylkill and Delaware rivers, instead of routing to wastewater-treatment plants. These so-called “combined-sewer overflow” (CSO) events degrade the environment, make the rivers unsafe for recreation, and increase the cost of treating the water.

Lundgren notes that managing runoff has been part of campus design strategy since long before the city required it. The late Penn landscape architect Ian McHarg, lauded as an innovator in ecological design, incorporated such elements into campus plans half a century ago.

“When he designed Woodland Walk in the 1950s,” Lundgren says, “he disconnected the drainage system from the sewer line, used permeable paving—cobbles over gravel—and put in native species. He was one of the first to be taking that approach.”

And though Penn has been a leader in environmental design since McHarg’s tenure, Philadelphia’s 2006 Stormwater Management Regulations and 2011 launch of “Green Cities, Clean Waters” prompted a closer look at management efforts.

The “Green Cities” plan in particular places emphasis on green infrastructure—increasing permeable surfaces—over traditional infrastructure like larger stormwater pipes and storage tanks. The 25-year initiative, which emerged under the leadership of Howard Neukrug, then-commissioner and CEO of Philadelphia Water and now a professor of practice and executive director of the Water Center at Penn, aims to reduce stormwater pollution entering city waterways by 85 percent. The plan includes provisions to encourage large property owners to take on the brunt of the responsibility in reducing CSOs.

“Residential and smaller commercial landowners can take steps to address stormwater on their properties and the government can manage runoff from roads, but we won’t solve our problems unless large property owners do their part,” says Neukrug. “When we are talking about a 50-acre or larger property in the middle of the city, economies of scale make the cost and impact of the project that much more important.”

The University has taken up the reins on this issue. A Stormwater Master Plan for Penn published in 2013 identifies areas where stormwater management is already succeeding, and pinpointed opportunities to extend this influence to new areas.

Penn Park represents perhaps the largest project that has conferred stormwater-management benefits to campus. Constructed in 2011, the site was overhauled from a series of paved parking lots and other impervious surfaces to a 24-acre multi-use complex with turf playing fields, tennis courts, grass playing fields, picnic areas, and an orchard. The site includes a cistern with a 300,000-gallon capacity so stored rainwater can later be used for irrigation, as well as several large natural areas, including six acres of native-grass meadows that serve to collect rainwater and allow it to soak slowly into the ground.

“One of Penn’s first projects, Penn Park, became the model for how private landowners can respond to stormwater issues and gain additional benefits at the same time,” Neukrug says. “The ecological, economic, and recreational co-benefits of green stormwater infrastructure to Penn and Philadelphia as a whole speak for themselves.”

Some green infrastructure helps on a small scale: Tree pits and trenches, for example, can intercept runoff from paths and sidewalks before it reaches a storm drain. But large-scale projects make even more of a difference. At Penn, every recent significant building project has some stormwater-management elements. The Singh Center for NanotechnologyNew College House, and Golkin and Fagin halls have green roofs that function not only to keep rain from entering the sewer system but in some cases, provide green spaces to eat lunch or take a study break.

“We have 1.4 acres of green roofs on campus,” says Lundgren. “By the time New College House West comes out, we’ll have close to two acres. That’s a pretty big deal.”

While green infrastructure confers a variety of benefits, it also comes with challenges. The spaces around porous pavers must be kept clear to allow rainwater to seep into the ground. Underground cisterns with pumps for irrigation require significant upkeep and technical skills to operate.

“It can be a learning curve,” says Lundgren.

That’s part of the reason why, when Shoemaker Green was installed, provisions were made to carefully monitor its systems as well as conduct research aimed at improving it and other future stormwater-management projects.

David Vann, a research coordinator in the Department of Earth and Environmental Science in the School of Arts and Sciences, has led efforts to study and monitor those systems for several years. Partly as a component of a course on bioremediation and partly as independent research projects, Vann has worked with students to measure how much water the system is taking in, how fast or slow it drains, and how the plants and trees planted on the Green itself contribute to water management through evapotranspiration, the process by which water is taken up by plants and then evaporates from their leaves.

“We have found the system is doing pretty faithfully what it was designed to do: Regulate the stored water and permit it to drain slowly in the two or three days after a rain event,” says Vann. “One thing we’re looking at is whether, as the trees and plants grow, the contribution of evapotranspiration will increase.”

When Shoemaker Green was redesigned, care was taken to preserve six mature London planetrees in front of the Palestra, each estimated to be roughly 80 years old. As the largest trees at the site, their contribution to evapotranspiration is significant. Vann and colleagues have found that, in summer, evapotranspiration causes roughly 2,000 gallons per day to leave the system. As the Green’s younger bald cypress, red maple, swamp white oak, and other trees continue to mature, that figure may grow, leaving room in the cistern to capture additional rainfall.

Recently, Vann has identified places to drop down equipment that can measure the flow of water more precisely than the system’s original sensors. “With these wells, we’ll be able to measure the quantity of water in each of the catchment areas, so we can more or less understand where the water is at all times,” Vann says.

Beyond the quantity of water, Vann is also monitoring the quality of the water entering the cisterns. Though an environmentally friendly salt substitute is used to keep walkways on campus ice-free in the winter, Vann is concerned that rock salt used on the adjacent road may be infiltrating and building up in the system.

In the future, Vann would like to incorporate studies of the ecology and sociology of the space. “It’s not my area but there is interest in understanding how the space is being used by insects, birds, and even people,” he says. “Is it being integrated into the campus as intended, being used as a place where people can rest, relax, play soccer?”

Armed with data from such experiments, Lundgren hopes the University will continue to push the boundaries of designing with ecology and sustainability in mind. “The ecological health of a place is pretty much the highest thing on my list,” he says, “and that feeds right into stormwater management.”

Bob Lundgren is University landscape architect in Facilities and Real Estate Services.

Howard Neukrug is executive director of the Water Center at Penn and a professor of practice in the School of Arts and Sciences’ Department of Earth and Environmental Science.

David Vann is a research coordinator in the School of Arts and Sciences’ Department of Earth and Environmental Science.

A unique perspective on renewable energy

A unique perspective on renewable energy

By Michele W. Berger

Rachel Kyte has a unique perspective on climate change and the environment. She’s both a special representative to the United Nations and CEO of an international organization called Sustainable Energy for All, technically one job for which she wears two hats. All the work is geared toward broadening access to sustainable energy worldwide, including for the billion or so people who still don’t have access to electricity.

When Kyte came to Penn at the invitation of the Kleinman Center for Energy Policy, she spoke to an overflowing room about the U.N.’s Sustainable Development Goals, how the world can more easily transition to renewables, and how, despite the progress to date, there’s still much farther to go.

Penn Today discussed with Kyte her vision for making sustainable energy available to all.

How did you get your start in the sustainable energy world?
I’ve worked in aspects of sustainable development for a long time. I started off in youth politics in Europe, and in the early days of understanding climate change it was acid rain [that people worried about], but it was also the colonial footprint that Europe had on the world. I was born of the generation that wanted to change that; we wanted Europe to be a force for good in the world.

I’ve also worked for NGOs and the International Finance Corporation and at The World Bank, focusing on private investment. Those were the early days of what is now a robust green bond movement and other new financial tools used to speed up sustainability. Then, in the run-up to the Paris Climate Agreement, I ended up as special envoy and vice president for climate change for the whole of the World Bank group.

Where does Sustainable Energy for All fit into all of this?
Sustainable Energy for All was set up with one foot in the U.N., one foot outside of the U.N., to allow the private sector to be a genuine partner. When you’re inside the U.N., it’s a construct of member states, but, being outside, we’re a true partnership, so we can work in a way that’s more flexible.

Within that capacity, as the secretary general’s special representative, my job is to make sure that he and his senior team understand what’s going on in the energy transition and what member states need to understand, as well as where the U.N. can nudge, encourage, propel people forward faster. I’m bringing his view out to the world and bringing the world to him, saying, “There are these new developments, this is how we can understand them, and this is what it might mean for progress.”

From your vantage point, how has the renewable energy sector changed in the past decade?
In the last 10 years, the technology has improved, and the cost of the technology has fallen by 80%, in particular for solar photovoltaics and wind energy. Now, in most parts of the world, solar and wind are price-competitive, certainly with coal but with most fossil fuels. That’s not to say that you have two M&Ms in front of you, one’s blue, one’s brown, which do you pick? You have a grid into which the energy has to be absorbed, so you’ve got issues around stabilization and making sure that the grid can work, but it’s not the case that we can’t afford renewable energy. The revolution is here, and we’ve now got to exploit it. We can go at scale, and we can go affordably at scale. That’s a success story.

Are there other, lesser-known success stories?
Countries like Kenya are embracing [renewable energy] and you see them going from 20% to 50% electrification in just 20 years. You see Bangladesh having built a really effective model of a rural electrification agency, and you see those numbers going up very fast as well. In India, where Prime Minister Modi said he wanted everybody to have a toilet and everybody to have electricity, you see an extraordinary closing of the access gap. Where there’s a political will, there is now—because of technology—a way.

What happens if the political will doesn’t align with a focus on renewable energy and the Sustainable Development Goals?
From the U.N.’s perspective, the Sustainable Development Goals are universal. This need to have affordable, reliable, clean energy is as relevant if you’re living on a low income in a small town in rural Texas or if you’re living on a reservation in the northwest United States or if you’re living in a project in Brooklyn. You have the same rights, and the international community has the same responsibility. This isn’t a developing project for developing countries; this is about everybody.

When I travel around the United States, blue states or red states, what I hear and see are communities wanting good local jobs, clean air, and affordable energy bills. The really great news is that most of them have realized that is going to come from renewable energy. It’s also going to come from energy efficiency. We’ve got so much to thank fossil fuels for because they’ve allowed us to develop to this point. But that era is over.

That doesn’t seem to be the sentiment at the top levels of the U.S. government, at least not in 2019.
The federal government’s focus on propping up part of the energy system of the past is at odds with where the science is saying we need to go but also where investment—including U.S. investment, public at the level of states, and private—is voting. Private investment is going into the clean economy, public and private. We have a situation where we have one narrative coming from the federal government and another reality in large parts of the rest of the country. It’s not a Democrat-Republican dichotomy. It is a federal-and-everybody-else dichotomy.

We should be having a different conversation in the U.S., one about how to decarbonize the economy by 2050. In Alberta, an economy built on tar sands, there is a dialogue between the union, communities, the federal government, and the provincial government about what they want Alberta to look like in the future. In other parts of the world, like in Poland and Germany, that’s the conversation that’s going on. Americans are being short-changed by not having that conversation now.

Where do we go from here?
We’re standing at this really important moment. Everything’s a little bit too little too late. We’re not on course for the energy transition we need. We’re not on course for the climate action we need. But what’s exciting is that we have the money, we have the technology, mostly. Now we need the political will to put the policies in place that will make it go quickly. Energy systems of the future are going to look nothing like the energy systems of the past. They’re going to be highly digital, highly decentralized, and, in fact, democratized, and that’s actually very exciting.


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Though the world has made significant headway in the push toward renewable energy, with serious technological advancements and lower costs for those technologies, there’s one area that Kyte says the world isn’t yet doing well enough: Clean fuels for cooking.

“It seems ridiculous to me that in 2019, in a world with so many sophisticated solutions to so many problems, we can’t find a way for almost 3 billion people to have access to a meal that’s cooked with clean fuels,” she says.

It’s a deadly problem, she adds. The World Health Organization estimates that each year, nearly 4 million people die from illnesses related to indoor air pollution caused by using kerosene and solid fuels like charcoal and dung in open fires. The people who do the cooking—mostly poor women in rural areas—and their children experience the greatest levels of exposure.

But that fact, that there’s a human-health cost is finally starting to turn the tide in a way that environmental and climate pressures never did, Kyte says. “It’s been a silent problem because it’s a got a female face,” she adds. “But the health statistics are now beginning to force this issue to the top of the to-do list.”

Predilections of a destructive pest

Predilections of a destructive pest

Benjamin Rohr, a graduate student in environmental studies, is studying the invasive spotted lanternfly at The Woodlands, a large cemetery a stone’s throw from Penn’s campus. The pest was first spotted there last year, in the wilder portions of the property’s periphery, where SEPTA and Amtrak trains pass regularly. (Photo: Eric Sucar)

By Katherine Unger Baillie

By the chain link fence lining the southern border of The Woodlands Cemetery property, Benjamin Rohr attempts to avoid brushing against poison ivy as he approaches a large black walnut tree. “Oh good, it’s still up!” he says, assessing a wide, sticky band encircling the trunk, now covered with the bodies of dozens of small insects. “No SLFs I don’t think,” he observes, using a shorthand for spotted lanternfly, an exotic bug that is poised to wreak havoc on farms, wineries, and forests in the mid-Atlantic states.

Rohr, a student in Penn’s Master of Environmental Studies program, is embarking on his capstone project to culminate his degree. The premise of his experiment is straightforward: to determine the types of trees the lanternfly prefers beyond its known affinity for ailanthus, commonly known as tree of heaven, dozens of which sprout enthusiastically in several groves at The Woodlands and elsewhere around the region.

“Maybe they prefer cherry over ash or maple instead of willow,” says Rohr. “If we find these finer-grain preferences, and land managers on Penn’s campus or with the Natural Lands Trust are replanting, maybe they wouldn’t choose as many of those species that are lanternfly attractors.”

The stories of the ailanthus and spotted lanternfly (Lycorma delicatula) run in parallel, albeit a few centuries apart. Ailanthus, a tree species native to China and Taiwan, was introduced to the United States in 1784 by William Hamilton, an avid plant collector who inherited a sprawling estate along the Schuylkill River: The Woodlands. The species spread rapidly, outcompeting native species. They’re now widely considered “trash trees,” often targeted for removal.

Meanwhile, the spotted lanternfly’s introduction into the U.S. appears to have been accidental. The bugs, which can fly but more often hop, up to 20 meters or more in a go, were first seen in 2014 in Berks County, Pennsylvania, and quickly extended their range. They’re known to feed on 70 species of tree and vine, 30 of which occur in Pennsylvania. Using their piercing mouthparts, they feed on tree sap, leaving plants weak and vulnerable to secondary infections. Currently, 13 counties in Pennsylvania are under quarantine for the lanternfly, and the U.S. Department of Agriculture’s Animal Plant Health Inspection Service (USDA APHIS), in partnership with Penn State Extension and the Pennsylvania Department of Agriculture, have kicked into high gear to keep the species under control.

For Rohr, who just finished his first year in the MES program, the lanternfly wasn’t on his radar until the spring semester, when he took a course in urban forestry taught by Sally Willig and Lara Roman. When an alternative capstone project didn’t pan out, Willig invited him to attend a meeting headed by Penn’s Facilities and Real Estate Servicesdepartment focused on urban forest management. The Woodlands’ Facilities and Landscape Manager Robin Rick was also attending, and mentioned that she was working with USDA APHIS to manage what appeared to be an emerging infestation in parts of the property.

“I knew about the threat of the spotted lanternfly from reading different publications from Penn State and hearing about it in different horticultural forums,” says Rick. “I started to keep an eye out. And around the same time, we were approached by the USDA as a property owner in the city to participate in their efforts to control and stop the spread of the lanternfly. So that really raised our awareness.”

Following the FRES meeting, Rohr reached out to Rick, who was enthusiastic about a project on The Woodlands property. Together they formulated the experiment. At four different areas where ailanthus grow at The Woodlands, Rohr is affixing wide, sticky bands—in essence, big pieces of sturdy tape placed stick-side out—on one ailanthus tree. Then, within the 20-meter hopping range of the lanternfly, Rohr and Rick identified another tree species that the insects are known to feed on, and will monitor those trees as well.

To avoid catching birds, Rohr overlays the sticky band with chicken wire. The Woodlands will also post signage to inform visitors about the project. Rohr will switch out the bands once a week until the species goes dormant, likely around December, and count the lanternflies he catches on each tree.

The USDA has visited The Woodlands to note the location of ailanthus trees on the property and set up a treatment plan. The survey, Rick says, identified 274 saplings under 1 inch in diameter, 36 trees between 1 and 6 inches in diameter, and 45 larger trees greater than 6 inches in diameter. A couple are in the heart of the cemetery, but most sit along the fence line, bordering the Amtrak and SEPTA rail lines or the VA hospital. Rick says the first signs of lanternfly came from near the train tracks.

In Rohr’s first time out checking the bands, he found only five lanternflies—unsurprising since late May is when the nymphs generally emerge.

Once the season revs up, Rohr expects to find many more, and he’ll be tracking what happens after USDA treatment later this summer—herbicide for the smaller trees and pesticide applications on the larger ones.

“There are a lot of really old mature trees at The Woodlands, some have been there for centuries,” says Rohr. “These massive maples or black walnuts could drop branches if they get sick. So just from a safety perspective, it will be interesting to get a sense of how much this pest could damage The Woodlands, and how Robin, the USDA, and others might mitigate this.”

Eventually, Rohr would like to pull together his findings into a user-friendly format to serve as a guide for other land managers. And Rick hopes to spread the word to the West Philadelphia community that lives near or recreates in The Woodlands.

“Learning more about this bug is going to rely on collaboration,” Rick says. “Large institutions like Penn and SEPTA will need to work together with smaller ones like us as well as community members to understand how [the lanternflies] are moving through the area and take efforts to slow and stop them.”

With unprecedented threats to nature at hand, how to turn the tide

With unprecedented threats to nature at hand, how to turn the tide

The United Nations report noted five main drivers of threats to biodiversity: changes in land and sea use, direct exploitation of organisms, climate change, pollution, and invasion of alien species. Marine pollution was identified as a particular area of concern.

By Katherine Unger Baillie and Michele W. Berger

The scale of the threats is massive: One million plant and animal species face imminent extinction due to human activity. That was the major finding of a report by the United Nations’ Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services, a summary of which was released earlier this month.

The assessment, which took three years, involved 145 expert authors as well as indigenous and local knowledge, and reviewed 15,000 scientific and government sources, reveals unprecedented and accelerating risks for biodiversity and human life.

To shed light on the report’s implications, Penn Today reached out to experts across the University in a range of subjects, from psychology to sustainability, sociology to biology, asking for their primary impressions of the study and for advice on how to take action.

If you had to pinpoint a major takeaway from the report, what would it be?

Dan Janzen, professor of biology and Thomas G. and Louise E. DiMaura Term Chair, Department of BiologySchool of Arts and SciencesThis report simply reiterates what has been obvious to us globally and in Costa Rica since 1985 (when we started paying attention). Today it is old news, so the real takeaway is, why are humans so bent on destroying their nest? The answer is that those who are doing it are largely doing it on the backs of those who suffer the consequences: The person who lives next to and works all day in the pineapple plantation rather than the person who buys the pineapple in a Philadelphia grocery store. It has been the history of humans since the Pleistocene village and before for some to enslave others. You all know the drill. Upper class, middle class, and working class. What is the probability that the upper class will destroy that structure?

Katie Barott, assistant professor, Department of BiologySchool of Arts and Sciences: The biggest takeaway is that the natural world is intricately linked to and necessary for our own physical and social wellbeing, and a new paradigm is needed that considers sustainability a central and necessary component of all societal decisions.

David Yaden, doctoral student, Department of PsychologySchool of Arts and SciencesUrgent action is required to help minimize the negative effects of climate change.

Dan Garofalo, director, Penn Sustainability: For me, the key takeaways are right at the top: ‘Human actions threaten more species with global extinction now than ever before’ and ‘Globally, local varieties and breeds of domesticated plants and animals are disappearing. This loss of diversity, including genetic diversity, poses a serious risk to global food security by undermining the resilience of many agricultural systems to threats such as pests, pathogens, and climate change.’

Daniel Aldana Cohen, assistant professor, Department of SociologySchool of Arts and Sciences: The report’s main takeaway is that, while carbon is the most urgent global environmental problem we face, it is just one part of an even more holistic threat to human wellbeing. Decarbonizing our energy system isn’t enough. We need to overhaul our entire economic system so that we no longer have a model of affluence that systematically destroys the basis for human life on Earth.

Julie Ellis, senior research investigator, Department of PathobiologySchool of Veterinary MedicineWhat struck me most is the tension between feeding the world’s human population and conserving biodiversity. According to the report, land-use change has had the largest relative negative impact on nature, and agricultural expansion is the most widespread form of land-use change, with more than one third of the terrestrial land surface being used for cropping or animal husbandry. We urgently need innovative land-use strategies to reconcile feeding humanity and conserving biodiversity. And these strategies need to include the world’s most vulnerable populations.

How can a member of the public take action to stem the threat of mass extinction and biodiversity loss?

Dan Janzen: The answer to this question depends totally on whether you live in Costa Rica, Pakistan, or Pennsylvania. The one I always give to Penn students is, ‘Get very good at what you do well and like doing well, get very rich at it in either money or capacity, and offer that to the conserved or conservable wildland that catches your fancy and is political/logistically most accessible to you.’ And if you cannot find one that can absorb your skills, our efforts in Costa Rican tropical conservation can always absorb such donations and put them to very good use.

David YadenActive support for policy changes and sustainable consumption seem most important, but some psychological factors may help to encourage these actions. My research has explored ‘the overview effect,’ a psychologically impactful experience that astronauts sometimes report after viewing Earth from orbit. A similar kind of mental shift, from a local to a global perspective, may help to motivate action on behalf of Earth as a whole.

Dan Garofalo: Reducing your carbon or ecological footprint will reduce pressure on the natural world and all the species that inhabit it. There’s no silver bullet, and there’s no secret lever that will protect ecosystems from our collective impact, but there are actions that we can take: Pay attention to where you live, how you commute, your purchasing/consumption habits, your travel footprint, and what you eat. Those five things tend to define your impact.

Joseph Kable, Baird Term Professor, Department of PsychologySchool of Arts and Sciences: One thing people can do is prioritize these issues in their politics. Adequate tackling the issues raised in the U.N. report is going to require collective action at a large scale. While most people will say they are concerned about the environment if you directly ask them, very few volunteer environmental issues as one of the top concerns that drives their vote.

Daniel Aldana Cohen: The only remedy for the threats we face at the scale at which they confront us is massive political economic change. By far the most meaningful thing an individual person can do is join a social, political, or cultural movement aimed at transforming our political economy. No individual’s consumer choices and no group’s consumer choices are significant in the absence structural change.

Julie Ellis: I have three actions to recommend:

  • Plant native species in your yard. Native plants are adapted to local environmental conditions, so they require fewer resources such as water. In addition, they provide habitat for birds, native pollinators, and many other species of wildlife. Many populations of native pollinators, including bumble bees and butterflies, are facing some degree of extinction risk. Planting native wildflowers can give these populations a boost.
  • Reduce your plastic use, especially single-use items such as bags, straws, and flatware. There are a growing number of reusable and sustainable options for commonly used household products including toilet paper and toothbrushes made from bamboo and laundry detergent in biodegradable pods and compostable packaging. Talk to your local restaurants and coffee shops. Explain the problem of plastic pollution, and ask them to consider switching to sustainable, reusable materials. Make your voice heard and use your consumer power to pressure businesses to be more responsible in their resource use.
  • Vote for representatives who support innovation in sustainable energy and renewable resources.