Evans M.E.K.,University of Arizona |
Merow C.,Yale University |
Record S.,Bryn Mawr College |
McMahon S.M.,Smithsonian Environmental Research Center |
And 3 more authors.
Trends in Ecology and Evolution | Year: 2016
Understanding and forecasting species’ geographic distributions in the face of global change is a central priority in biodiversity science. The existing view is that one must choose between correlative models for many species versus process-based models for few species. We suggest that opportunities exist to produce process-based range models for many species, by using hierarchical and inverse modeling to borrow strength across species, fill data gaps, fuse diverse data sets, and model across biological and spatial scales. We review the statistical ecology and population and range modeling literature, illustrating these modeling strategies in action. A variety of large, coordinated ecological datasets that can feed into these modeling solutions already exist, and we highlight organisms that seem ripe for the challenge. © 2016 Elsevier Ltd
Sujitha M.,Center for Environmental Studies |
Kanmani S.,Center for Environmental Studies
Journal of Industrial Pollution Control | Year: 2014
A highly photoactive Ti-containing Cr-modified MCM-48 photocatalyst was prepared by a facile one-step method at room temperature. A combination of various physicochemical techniques such as X-ray diffraction (XRD), diffuse reflectance UV-vis spectra (DRS) and scanning electron microscopy (SEM) were used to characterize the properties of the synthetic catalysts. The characterization and experimental results indicated that tetrahedral Ti oxide moieties as dominant Ti oxide were loaded into the mesoporous structure and there was a synergistic interaction between the Ti species anchored on the walls and the Cr ions presented in the MCM-48 framework, which was considered to be directly correlated to the photoactivity. The optimized for maximum hydrogen production of 333.41 mL was found to be 2 g catalyst dosage, 722 W/m2 light intensity and 60 min of irradiation. © EM International.
Ahmed Z.,University of Technology Malaysia |
Hwang S.-J.,Center for Environmental Studies |
Shin S.-K.,Sejong University |
Song J.,Sejong University
Journal of Hazardous Materials | Year: 2010
The yeast strain Candida tropicalis was used for the biodegradation of gaseous toluene. Toluene was effectively treated by a liquid culture of C. tropicalis in a bubble-column bioreactor, and the toluene removal efficiency increased with decreasing gas flow rate. However, toluene mass transfer from the gas-to-liquid phase was a major limitation for the uptake of toluene by C. tropicalis. The toluene removal efficiency was enhanced when granular activated carbon (GAC) was added as a fluidized material. The GAC fluidized bioreactor demonstrated toluene removal efficiencies ranging from 50 to 82% when the inlet toluene loading was varied between 13.1 and 26.9 g/m3/h. The yield value of C. tropicalis ranged from 0.11 to 0.21 g-biomass/g-toluene, which was substantially lower than yield values for bacteria reported in the literature. The maximum elimination capacity determined in the GAC fluidized bioreactor was 172 g/m3/h at a toluene loading of 291 g/m3/h. Transient loading experiments revealed that approximately 50% of the toluene introduced was initially adsorbed onto the GAC during an increased loading period, and then slowly desorbed and became available to the yeast culture. Hence, the fluidized GAC mediated in improving the gas-to-liquid mass transfer of toluene, resulting in a high toluene removal capacity. Consequently, the GAC bubble-column bioreactor using the culture of C. tropicalis can be successfully applied for the removal of gaseous toluene. © 2009 Elsevier B.V. All rights reserved.
Hashmi D.R.,Center for Environmental Studies |
Shareef A.,Center for Environmental Studies
Pakistan Journal of Scientific and Industrial Research Series A: Physical Sciences | Year: 2016
The present study examines the variation of ambient aerosol (PM10) concentrations in Karachi, city. Samples were collected from ten different locations, representative of urban background, residential, traffic and industrial areas from 2007 to 2011. At each location, PM10 was measured continuously from 08:00 am to 06:00 pm at local time. The maximum 10 h average particulate matter (PM10) mass concentrations were found at Tibet Centre (440.1μg/m3) and minimum at PCSIR Campus (21.7μg/m3) during 2008. A rising trend during 2008 may be due to the civil works for bridges and extension of roads at different locations in Karachi. The results also suggest that urban traffic and industrial areas appeared to have higher PM10 concentration than residential and background areas. © 2016, PCSIR-Scientific Information Centre. All rights reserved.
Chakrabarti S.,Center for Environmental Studies |
Patra P.K.,Center for Environmental Studies |
Mandal B.,Visva Bharati |
Mahato D.,Center for Environmental Studies
Fluoride | Year: 2012
The influence of 0, 10, 20, and 30 mg NaF/L in an aqueous nutrient solution on germination, seedling growth, and biochemistry of Bengal gram (Cicer arieninum) seeds and seedlings was studied under controlled conditions. At the end of 15 days, significant reductions were observed with increasing F concentration in the various parameters studied, including percentage of seed germination, root and shoot length, biomass, vigor index, chlorophyll, and ascorbic acid content. F uptake by the roots and shoots of the seedlings increased with increasing F concentration, and although F accumulation in the roots was higher than in the shoots of the seedlings, the root-to-shoot translocation factor was quite high (>0.80). © 2012 The International Society for Fluoride Research Inc.
Lee M.J.,Center for Environmental Studies |
Kim Y.S.,Center for Environmental Studies |
Yoo C.K.,Center for Environmental Studies |
Song J.H.,Sejong University |
Hwang S.J.,Center for Environmental Studies
Environmental Technology | Year: 2010
The main objective of this study was to suggest a feasible, effective process for the reduction of sewage sludge using ozone oxidation catalysed by metal ion. A series of lab-scale experiments was conducted to select a suitable catalyst and its proper dose to achieve optimum sludge reduction. Using a central composite design under response surface methodology (RSM), system optimization with respect to sludge reduction and cost-effectiveness was performed by varying the independent parameters: dosages of ozone and ions. Five metal ions, Mn2+, Fe2+, Zn2+, Cu2+, and Al3+, were tested, and the manganese ion showed the highest sludge reduction, as measured by a decrease in total suspended solids. The ozone/Mn combination achieved approximately twice as much sludge reduction as the ozonation alone. Furthermore, the Mn dose of 10 mg/g-TS (total solids) resulted in the highest sludge reduction efficiency among the different doses, which ranged from 0 to 20 mg-Mn/g-TS. The predicted efficiency of sewage sludge reduction using the RSM was found to agree well with the experimental results, and the statistical analyses predicted optimum ranges for the doses of ozone and Mn ions, taking into account the overall cost for sewage sludge treatment.
Chakrabarti S.,Center for Environmental Studies |
Patra P.K.,Center for Environmental Studies |
Mondal B.,Visva Bharati
Paddy and Water Environment | Year: 2013
The use of fluoride enriched groundwater for irrigating the paddy crops is prevalent in many parts of the world. The fluoride in the irrigated water not only affects the growth and productivity of the crops, but is also accumulated in the plant tissues. We studied the accumulation of fluoride in roots, leaves and seeds two paddy varieties (i. e. Oryza sativa L. var. IR-36 and Oryza sativa L. var. Swarno) when treated with different concentrations of fluoridated water. The translocation pattern of fluoride was also observed. The water soluble fluoride (FH2O) in the soil and plant parts increased substantially with increasing fluoride concentration in treated water. The Swarno variety showed a slight but consistent higher uptake of fluoride than the IR-36 variety. Fluoride uptake by the germinated seedlings was many folds higher than the uptake by mature plants. At 30 mg l-1 fluoride exposure, the mean FH2O accumulation (mg kg-1 dry weight) in root, leaves, and seeds of Swarno was 54. 1, 51. 4 and 42. 3, whereas the corresponding values in IR-36 were 50. 9, 48. 5 and 39. 2. For the same exposure, the fluoride accumulation in root and shoot of Swarno and IR-36 seedlings were 3,480, 3,463 and 3,386, 3,360 mg kg-1, respectively. Normally, the fluoride accumulation follows the order of soil > root > shoot > grain. However, at early stage of fluoride contamination (5 mg l-1 NaF) roots tended to hyper accumulate fluoride from the soil. © 2012 Springer-Verlag.
Maity S.,Center for Environmental Studies |
Roy S.,Siksha Bhavana |
Bhattacharya S.,Siksha Bhavana |
Chaudhury S.,Center for Environmental Studies
European Journal of Soil Biology | Year: 2011
Biomarkers allow the evaluation of possible biochemical effects under various metal contaminations in the terrestrial environment. In order to attain this objective adult, sexually mature Lampito mauritii were exposed to different concentrations of lead (Pb) and zinc (Zn) separately for 28 days and concentrations of metallothionein were assessed by radioassay method using 203Hg. A significant increase in tissue metallothionein level was recorded in L. mauritii exposed to Pb and Zn contaminated soil. Thus it may be surmised that metallothioneins are directly involved in metal ion detoxification and helps L. mauritii to survive in metal contaminated soil. Moreover the sensitivity of this biochemical parameter observed in L. mauritii exposed to Pb and Zn can be used as reliable biomarker in monitoring metal pollution. © 2010 Elsevier Masson SAS.
News Article | August 30, 2016
When the Moon abruptly cuts off sunlight from Earth at a total solar eclipse, our weather reacts to the sudden darkness. A new issue of the Philosophical Transactions of the Royal Society of London, the oldest surviving scientific journal, deals with the effects of the March 20, 2015 eclipse. Williams College professor Jay Pasachoff, former Fulbright visitor to Williams College Marcos Peñaloza-Murillo, recent alumna Allison Carter '16, and University of Michigan postdoc Michael Roman have an article in this theme issue of "Phil Trans A" discussing the effect measured. Pasachoff and Carter had been on Svalbard, an Arctic archipelago controlled by Norway, for the eclipse. They had carried sensors for temperature and pressure borrowed from Williams College's Jay Racela of the Center for Environmental Studies. The expedition to Svalbard was supported by a grant to Pasachoff from the Committee for Research and Exploration of the National Geographic Society. The bulk of the theme issue was about the effect of the partial eclipse that was also visible from the U.K. The dimming of sunlight over the hour or so during the partial eclipse making its effects measurable. On Svalbard, for the total eclipse, the temperature and pressure automatic sensors found only slight effects, though a thermometer hanging from one of the camera tripods recorded a dip in temperature from the 8°F to which the morning temperature had risen down to –7° a few minutes after the center of totality. Pasachoff and Peñaloza-Murillo, who is professor emeritus at the Universidad de los Andes in Mérida, Venezuela, have published a previous paper about the effect of a total eclipse on weather, and are planning further observations, again in collaboration with Roman, at the August 21, 2017, total solar eclipse that they will attempt to observe from Salem, Oregon. This time the expedition will again be supported in part by the Committee for Research and Exploration of the National Geographic Society, and Williams College, with Pasachoff as Principal Investigator, has also received a research grant from the Solar Terrestrial Program of the Atmospheric and Geospace Sciences Division of the U.S. National Science Foundation. Pasachoff has also borrowed temperature and pressure sensors, a datalogger system called HOBO made by Onset Computer Corporation, as part of his observations of the September 1 annular solar eclipse this week. Pasachoff, along with Naomi Pasachoff, Research Associate at Williams College, is observing the eclipse from Isle de la Réunion in the Indian Ocean east of Madagascar. They are joined there by Rob Lucas of the University of Sydney; Michael Kentrianakis, project manager for the Eclipse 2017 Task Force of the American Astronomical Society; Stephen Bedingfield of Canada; and Xavier Jubier of France, who has provided Google Maps of various eclipse paths, accessible through the website http://eclipses.info that Pasachoff maintains as Chair of the Working Group on Solar Eclipses of the International Astronomical Union. This event is Pasachoff's 64th solar eclipse and the 16th annular solar eclipse. The theme issue of Phil Trans A, titled "Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse," has been edited by Giles Harrison of the University of Reading and Edward Hanna of the University of Sheffield, both in the UK. The article by Pasachoff, Peñaloza-Murillo, Roman, and Carter is entitled "Terrestrial atmospheric responses on Svalbard to the 20 March 2015 Arctic total solar eclipse under extreme conditions." Pasachoff drafted the article as part of his spring-2016 sabbatical leave in the Planetary Sciences Department of the California Institute of Technology. Another article, "Symbolism and Discovery: Eclipses in Art," by Ian Blatchford, head of the group that runs the Science Museum, London, draws heavily on and acknowledges work on the overlap of art and astronomy by Pasachoff in collaboration with art-historian Roberta J. M. Olson of the New-York Historical Society. The theme issue will be officially published on September 28, as volume 374, issue 2077, of Philosophical Transactions A, though the papers are already available online. The Phil Trans was established in 1665, making it the longest running scientific journal in the world. "Philosophical" refers to natural philosophy, an old term for what we know call "science." More information: Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse. rsta.royalsocietypublishing.org/content/atmospheric-effects-solar-eclipses-stimulated-2015-uk-eclipse
News Article | February 15, 2017
Kristina Trotta was working for the Florida Department of Environmental Protection (DEP) in Miami in 2014 when she and her colleagues were called into a staff meeting. “We were told by the regional director that we were no longer supposed to say ‘global warming,’ ‘climate change’ or ‘sea level rise,’” says Trotta, who works on coral reef conservation. “We were finally told we are the governor’s agency and this is what the governor wants, and so this is what we’re going to do.” Florida’s hush order, along with a similar effort in North Carolina, offers a preview of what will happen if Pres. Donald Trump continues preliminary moves to muzzle climate communication from key federal agencies. The Florida gag effort was part of a broader move by Gov. Rick Scott, a Republican who questions the scientific consensus on climate change. Experts and local officials say it hampered community efforts to plan for worsening flooding and extreme weather. Now on the national level all references to climate change have been removed from the White House Web site (except those promising to eliminate Obama climate policies). Trump aides also reportedly ordered the deletion of the U.S. Environmental Protection Agency’s main page on the topic, although those plans were put on hold after word leaked out. Federal agencies have more responsibilities than state authorities, including gathering and analyzing authoritative data about effects on wide areas of the country. If they pull back, the negative effects could be much bigger. In an e-mail to Scientific American about climate change denial, Florida DEP spokeswoman Dee Ann Miller wrote the state agency “does not have, nor has it had, any such policy in place,” and pointed to efforts to study and address sea level rise. Scott, in fact, did not ban the study of climate impacts outright (and the list of proscribed terms varied, so sea level rise was sometimes okay, sometimes not). The governor, however, made his priorities clear. The Florida government disengaged from active statewide policymaking and planning on sea level rise and related issues, coastal scientists and environmental groups say, even as problems mounted and cities and towns began to organize on their own. Without statewide leadership and coordination, it is hard to systematically protect the coast, says Leonard Berry, a climate scientist and former director of the Center for Environmental Studies at Florida Atlantic University. If one city builds a seawall, for instance, it may displace the water across the border to the next town over, which may have a different approach. As plans and protections vary, some areas and people will end up facing more risk than others. Facing a tough reelection campaign in 2014, Scott moderated his environmental platform somewhat. Florida’s water management districts, which are state agencies, have begun grappling with the issue on a statewide level, Berry says. “There is a slow edging toward dealing with what we see here as reality,” he says. “But it has not resulted in any statewide strategy or policies. I wouldn’t rule that out—though it would not be something to deal with ‘climate change’ but rather strategies to deal with specific problems we’re having.” North Carolina, whose barrier islands are particularly vulnerable to sea level rise, was widely mocked in 2012 when the General Assembly passed a law barring communities from using a report containing 100-year projections of sea level rise—up to 39 inches—in their planning. Three years later a compromise was reached; legislators found a new report with a 30-year time horizon less alarming, and agreed that was permissible. In the interim, though, coastal planning lagged. Under then-Governor Pat McCrory (R), climate change information disappeared from the state’s Department of Environmental Quality Web site. The legislature altered the makeup of the Coastal Resources Commission, which overseas coastal planning, to remove some scientists and conservation group representatives and replaced them with more business-friendly members. The trouble in North Carolina is that real estate developers dominate the politics of many coastal resort communities, says Rob Young, director of Duke and Western Carolina universities’ joint Program for the Study of Developed Shorelines. Developer priorities are usually short-term fixes such as seawalls or drainage projects that reinforce an unsustainable status quo and may harm ecosystems. They avoid grappling with more ambitious, controversial fixes—for example, whether to restrict new construction in a vulnerable area. “I don’t think the reticence to do long-term planning for sea level rise is restricted to the North Carolina legislature. I don’t think it’s restricted to North Carolina either,” Young says. “It’s hard to point to anybody on east or Gulf coast[s] doing serious sea level rise planning that involves more than talking about it.” (Louisiana, he noted, is one exception because its rapidly sinking coastal marshes have left communities exposed to dangerous flooding faster than anywhere else in the U.S., forcing the issue.) The federal government could take steps to fill that void in North Carolina and elsewhere. State and local governments, scientists and nongovernmental organizations all depend on federal data and expertise on climate, the ocean and the coast to make decisions and coordinate their actions. For instance, Broward County in Florida has relied on a series of federal grants to map coastal vulnerabilities, says Jason Liechty, the county’s environmental projects coordinator. Now Liechty thinks that such programs might be in danger. “All it takes is a couple of ideologically-minded folks in the right place in the administration to cross out that line the budget, or direct resources away from it,” he says.