FMC Corporation Announces Second Quarter 2008 Results MarketWatch - Jul 29, 2008 This event will be available live and as a replay on the web at http://www.fmc.com. Prior to the conference call, the Company will also provide supplemental ...FMC
Dominion Announces Second-Quarter 2008 Earnings Earthtimes (press release), UK - Jul 31, 2008 4) Refer to schedules 2 and 3 for details related to items excluded from operating earnings, or find "GAAP Reconciliation" on Dominion's Web site at ...D
Qualcomm Announces Third Quarter Fiscal 2008 Results FOXBusiness - Jul 23, 2008 Prior period reconciliations are presented on Qualcomm's Investor Relations web page at www.qualcomm.com. "We are pleased to report another strong quarter ...QCOM
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Web caching and Zipf-like distributions: evidence and implications - L Breslau, P Cao, L Fan, G Phillips, S Shenker - INFOCOM'99. Eighteenth Annual Joint Conference of the IEEE …, 1999 - ieeexplore.ieee.org ... Questnet NLANR L0.04 -0.08 0.003 -0.04 -0.02 -0.09 DEC UPisa FuNet UCB Questnet
NLANR -0.19 -0.27 0.005 0.002 -0.03 -0.08 the total number of web documents, q ...
Contact Sex Signals on Web and Cuticle of Tegenaria atrica (Araneae, Agelenidae) - O Prouvost, M Trabalon, M Papke, S Schulz - Archives of Insect Biochemistry and Physiology, 1999 - doi.wiley.com ... Receptive females Unreceptive females Determination Web Cuticle Web Cuticle ... Esters
Methyl tetradecanoate (myristate) 0.19 (0.05) 0.55 (0.11)* ...
The detrital food web in a shortgrass prairie - HW Hunt, DC Coleman, ER Ingham, RE Ingham, ET … - Biology and Fertility of Soils, 1987 - Springer ... HW Hunt et al.: The detrital food web in a shortgrass prairie ... 0.8 0.8 0.00058 0.56 0.19 0.8 0.8 0.0020 0.56 0.10 0.8 1.0 0.0020 0.56 0.10 0.5 0.8 0.021 0.56 ...
[PDF]Removal policies in network caches for world-wide web documents - S Williams, M Abrams, CR Strandridge, G Abdulla, E … - Computer Communication Review, 1996 - cs.kent.edu ... in networks with workloads like ours could dramat- ically reduce the load on popular Web servers. ... Video 0.19 18.29 0.35 25.77 0.34 39.15 0.00 0.04 0.04 3.58 ... -
Regulation of Lake Primary Productivity by Food Web Structure - SR Carpenter, JF Kitchell, JR Hodgson, PA Cochran, … - Ecology, 1987 - JSTOR ... December 1987 LAKE PRODUCTIVITY AND FOOD WEB STRUCTURE 1869 0.6-- 0.4- 0.2- 0 6-
4- 1984 I ... SE -- 0.47, n = 13) in 1984 to 1.14 x 106/um3/mL (SE = 0.19, n = 13 ...
B12—an essential vitamin for land-dwelling animals, including humans—also turns out to be an essential ingredient for growing marine plants that are critical to the ocean food web and Earth’s climate, scientists have found.
The presence or absence of B12 in the ocean plays a vital and previously overlooked role in determining where, how much, and what kinds of microscopic algae (called phytoplankton) will bloom in the sea, according to a study published in the May issue of the journal Limnology and Oceanography.
These photosynthesizing plants, in turn, have a critical impact on Earth’s climate: They draw huge amounts of carbon dioxide, a greenhouse gas, from the air, incorporating carbon into their bodies. When they die or are eaten, carbon is transferred to the ocean depths, where it cannot re-enter the atmosphere.
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B12 contains the metal cobalt and can be synthesized only by certain singled-celled bacteria and archaea. Humans, animals, and many algae require B12 to manufacture essential proteins, but they cannot make it and must either acquire it from the environment or eat food that contains B12, said the study’s lead authors, Erin Bertrand and Mak Saito. The two biogeochemists at the Woods Hole Oceanographic Institution wondered whether the vitamin was also important in the ocean, where B12 and cobalt are both found in exceedingly low concentrations.
Bertrand, Saito, and colleagues collected water samples from three locales in the highly fertile Ross Sea off Antarctica during an expedition in 2005 aboard the icebreaker Nathaniel B. Palmer. To one set of samples, they added B12 and iron (another essential nutrient for plant growth); to a second set, they added just iron; and to a third, they added neither. Samples stimulated with both iron and B12 showed significantly higher concentrations of plant life in general and greater concentrations of a particular type of marine algae called diatoms.
“The possibility that a vitamin could substantially influence phytoplankton growth and community composition in the marine environment is a novel and exciting finding,” the study’s authors wrote.
The finding underscores the complexities of the marine food web and raises questions about the delicately balanced ecosystem’s vulnerabilities to changing climate. It also sheds light on the sources and cycling of vitamin B12 and cobalt in the ocean, especially in the Southern Ocean around Antarctica, where the only nearby continent—a standard source of metal particles blown into the sea—is largely ice-covered.
Nevertheless, polar regions harbor some of the most extensive phytoplankton blooms in the world and are believed to play a significant role in exporting carbon to the deep ocean. In the Ross Sea, spectacular spring blooms of marine algae called Phaeocystis antarctica dissipate by summer and are followed by blooms of diatoms.
The scientists’ experiments—showing more diatom growth with the addition of B12—indicate that Phaeocystis may have a competitive advantage over diatoms in the Ross Sea’s springtime. The sea contains bacteria and archaea that make B12, but their populations are low, particularly in the spring, and so B12 supplies are limited.
Phaeocystis effectively monopolize the B12 supply by forming colonies cemented by sticky mucous that attracts B12 -making bacteria, Bertrand and Saito theorize. In a symbiotic relationship, the algae get their required vitamin and the bacteria get a steady supply of carbon made by the plants. When Phaeocystis dies off and the bacteria are eaten or decomposed, B12 is released once again to the ocean and is available to be used by diatoms.
Any disruption in the timing or abundances of these microbial populations has ramifications on the ecosystem and the climate, the scientists said. For example, Phaeocystis antarctica in the Ross Sea takes up more carbon dioxide than diatoms, so if the marine community shifts to diatoms, the Ross Sea would likely remove less carbon dioxide from the atmosphere. Unlike diatoms, Phaeocystis also produce a compound called dimethylsulfioniopriopionate, or DMSP, which is released into the air and helps produce clouds that block solar radiation.
Polar oceans do not have large bacterial populations to produce B12, making the vitamin a critical factor influencing the food web, the cycling of carbon in the ocean, and the climate, Bertrand and Saito said. At the same time, climate changes could affect the availability of B12 by causing changes in ocean temperatures, bacterial populations, and other factors. The ozone hole produced in the austral spring above Antarctica could also induce a cascade of effects by allowing more penetration of ultraviolet radiation that is known to degrade B12, they said.
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The National Science Foundation Office of Polar Program provided funding for the 2005 Controls on Ross Sea Algal Community Structure (CORSACS) expedition. Erin Bertrand was a Carl and Pacha Peterson Summer Research Fellow at WHOI and is now a graduate student in the MIT/WHOI Joint Program.
Pollutants, food ingredients, solvents may all cause harm, researchers say.
By Alan Mozes HealthDay Reporter
MONDAY, May 14 (HealthDay News) -- A detailed analysis of hundreds of completed breast cancer studies has linked disease development with environmental exposure to more than 200 chemical compounds.
The finding is part of an effort to build a free, online breast cancer database for researchers and the public.
Described as "the most comprehensive of its kind," the database will highlight growing concern about environmental carcinogens such as pollutants, food contaminants, and organic solvents. The scope of the project will also extend to work that explores risk-related lifestyle factors such as diet, levels of physical activity, smoking/drinking habits and body mass.
"This compilation is a great effort, because it summarizes all the evidence and gives us hints of what to look for next," explained researcher Leslie Bernstein, a professor of preventive medicine with the Keck School of Medicine at the University of Southern California in Los Angeles.
The results are outlined in a supplement to the May 14th online issue of Cancer. The database is already accessible at either www.silentspring.org/sciencereview or www.komen.org/environment.
According to the American Cancer Society (ACS), carcinogens are defined as agents that instigate abnormal cell division or harmful changes in the structure of a cell's DNA. They include chemicals, radiation, or infectious agents, among other things.
The ACS also notes that with the exception of skin cancer, breast cancer is the most common cancer among American women. This year, almost 179,000 women in the United States will be diagnosed with the disease, and about 40,000 will die.
The International Agency of Research on Cancer has already classified 90 or so compounds as human carcinogens, according to the ACS. But Bernstein's team said that most of the chemicals to which people are routinely exposed have not undergone any testing for carcinogenic risk. An estimated 80,000 chemicals are registered in the United States for commercial use, according to the researchers.
For more than two years, Bernstein worked alongside colleagues from Harvard University, the Roswell Park Cancer Institute, and the Silent Spring Institute to amass and sort through approximately 900 national and international breast cancer studies focused on carcinogens.
The team honed in on 460 human breast cancer studies, of which more than 150 looked at specific environmental carcinogens among breast cancer patients. Most of those studies were conducted in the 1990s.
The remaining studies involved animal or laboratory research. The researchers pointed out that animal studies are valid references, because all known human carcinogens have also triggered tumors in animal subjects.
In the animal studies alone, evidence surfaced that linked 216 chemicals to the onset of breast tumors. These included 36 industrial chemicals, 6 chlorinated solvents, 18 products of combustion, 10 pesticides, 18 dyes, four type of radiation, 47 pharmaceuticals, and 17 hormones.
Of these compounds, the researchers isolated 73 that can be found in either human food or consumer products.
They noted, for example, the lingering hazards associated with polychlorinated biphenyls (or PCBs), which were typically used in the production of electrical equipment until federally banned in 1979. PCBs continue to pose a risk via contaminated rivers, fish, and pre-existing building construction, the researchers warned.
In addition, the authors categorized 35 compounds as carcinogenic air pollutants, including polycyclic aromatic hydrocarbons (or PAHs), which are byproducts of combustion.
The team also drew attention to another group of 25 organic compounds, including dioxins, which are produced by waste incineration and manufacturing. These carcinogenic chemicals are present in many American workplaces and place more than 5,000 women at an increased risk for breast cancer, the researchers said. These include women working in machine shops, dry cleaners, hairdressers, glass manufacturers, and aircraft maintenance facilities, all of which use harmful organic solvents.
Furthermore, among the identified carcinogens, 29 are produced in large amounts -- upwards of one million pounds or more per year.
The database project did not set strict guidelines as to how to limit exposure to carcinogens. But the authors said they encouraged research and government oversight into the problem. They advised that people do try and limit their exposure to PCB-contaminated fish, gasoline-generated air pollution, chlorinated tap water, non-stick coated cookware, and detergents containing fluorescent whiteners.
Just how carcinogenic, in terms of breast cancer risk, are these and other compounds on the list? The jury is still out on that question, Bernstein said.
"Women are terribly concerned about environmental causes of breast cancer," she said. "But it's really very difficult to study. Often the only way we've been able to look at some of these things is during occupational exposures or accidents -- what we usually call disasters."
"So, this work is a very useful tool for those of us who want to try to understand what we've missed in breast cancer. Now, it's up to us to do something with all this information," Bernstein said.
Janet Gray, a professor of psychology and the director of the program in science, technology and society at Vassar College in Poughkeepsie, N.Y., called the new database "an enormous contribution."
"Its greatest value is just the sheer comprehensive nature of the work, which allows both the public and researchers to have access to huge amounts of information in one place," she said. "I think this effort will really move us forward."
Known and Probable Carcinogens
Including Industrial Processes, Occupational Exposures, Infectious Agents, Chemicals, and Radiation)
What Is a Carcinogen?
Cancer is caused by abnormalities in a cell’s DNA (its genetic "blueprint"). These may be inherited from parents, or they may be caused by outside exposures to the body such as chemicals, radiation, or even infectious agents.
Substances that can cause changes that can lead to cancer are called carcinogens. Some carcinogens do not act on DNA directly, but lead to cancer in other ways, such as causing cells to divide at a faster rate, which could increase the chances that DNA changes will occur.
Carcinogens do not cause cancer in every case, all the time. Substances classified as carcinogens may have different levels of cancer-causing potential. Some may cause cancer only after prolonged, high levels of exposure. And for any particular person, the risk of developing cancer depends on many factors, including the length and intensity of exposure to the carcinogen and the person’s genetic makeup.
How Do We Determine if Something Is a Carcinogen? Scientists get much of their data about whether something might cause cancer from laboratory (cell culture and animal) studies. Although it isn’t possible to predict with certainty which substances will cause cancer in humans based on animal studies alone, virtually all known human carcinogens that have been adequately tested produce cancer in lab animals. In many cases, carcinogens are first found to cause cancer in lab animals and are later found to cause cancer in people. Because there are far too many substances (natural and manmade) to test each one in lab animals, scientists use knowledge about chemical structure, other types of lab tests, and information about the extent of human exposure to select chemicals for testing.
Most studies of potential carcinogens expose the lab animals to doses that are higher than common human exposures. This is so that cancer risk can be detected in relatively small groups of animals. For most carcinogens, it is assumed that those that cause cancer at larger doses in animals will also cause cancer in people. Although it isn’t always possible to know the relationship between exposure dose and risk, it is reasonable for public health purposes to assume that lowering human exposure will reduce risk.
Another important way to identify carcinogens is through epidemiologic studies, which look at human populations to determine which factors might be linked to cancer. While these studies also provide useful information, they also have their limitations. Humans do not live in a controlled environment. People are exposed to numerous substances at any one time, including those they encounter at work, school, or home; in the food they eat; and the air they breathe. And it is usually many years (often decades) between exposure to a carcinogen and the development of cancer. Therefore, it can be very hard to single out any particular exposure as having a definite link to cancer.
By combining data from both types of studies, scientists are able to make an educated assessment of a substance’s cancer-causing ability. When the available evidence is compelling but not felt to be conclusive, the substance may be considered to be a probable carcinogen.
How Are Carcinogens Classified?
International Agency for Research on Cancer (IARC)
The most widely used system for classifying carcinogens comes from the IARC, which is part if the World Health Organization (WHO). In the past 30 years, the IARC has evaluated the cancer-causing potential of about 900 likely candidates, placing them into one of the following groups:
Group 1: Carcinogenic to humans
Group 2A: Probably carcinogenic to humans
Group 2B: Possibly carcinogenic to humans
Group 3: Unclassifiable as to carcinogenicity in humans
Group 4: Probably not carcinogenic to humans
Perhaps not surprisingly, most of the agents are of probable, possible, or unknown risk. Only about 90 are classified as "carcinogenic to humans."
National Toxicology Program (NTP)
In the United States, the NTP releases the Report on Carcinogens about every 2 years. The NTP is formed from parts of several different government agencies, including the National Institutes of Health (NIH), the Centers for Disease Control and Prevention (CDC), and the Food and Drug Administration (FDA).
The Report on Carcinogens (RoC) identifies 2 groups of agents:
"Known to be human carcinogens"
"Reasonably anticipated to be human carcinogens"
Unlike the IARC’s list, the RoC does not list substances that have been studied and found not to be carcinogens. Below are the lists of known and probable human carcinogens from both groups.
Known Human Carcinogens
International Agency for Research on Cancer (IARC) "Carcinogenic to Humans" (Group 1)
Agents and Groups of Agents
Aflatoxins (naturally occurring mixtures of)
4-Aminobiphenyl
Arsenic and arsenic compounds (Note: This evaluation applies to the group of compounds as a whole and not necessarily to all individual compounds within the group)
Estrogens, nonsteroidal (Note: This evaluation applies to the group of compounds as a whole and not necessarily to all individual compounds within the group)
Estrogens, steroidal (Note: This evaluation applies to the group of compounds as a whole and not necessarily to all individual compounds within the group)
Ethylene oxide
Etoposide in combination with cisplatin and bleomycin
Formaldehyde
Gallium arsenide
Gamma radiation
Helicobacter pylori (infection with)
Hepatitis B virus (chronic infection with)
Hepatitis C virus (chronic infection with)
Herbal remedies containing plant species of the genus Aristolochia
Human immunodeficiency virus type 1 (infection with)
Human papillomavirus type 16
Human papillomavirus type 18
Human T-cell lymphotropic virus type I
Melphalan
8-Methoxypsoralen (Methoxsalen) plus ultraviolet A radiation
MOPP and other combined chemotherapy including alkylating agents
Mustard gas (Sulfur mustard)
2-Naphthylamine
Neutrons
Nickel compounds
Opisthorchis viverrini (infection with)
Oral contraceptives, combined (Note: There is also conclusive evidence that these agents have a protective effect against cancers of the ovary and endometrium)
Oral contraceptives, sequential
Phosphorus-32, as phosphate
Plutonium-239 and its decay products (may contain plutonium-240 and other isotopes), as aerosols
Radioiodines, short-lived isotopes, including iodine-131, from atomic reactor accidents and nuclear weapons detonation (exposure during childhood)
Radionuclides, alpha-particle-emitting, internally deposited (Note: Specific radionuclides for which there is sufficient evidence for carcinogenicity to humans are also listed individually as Group 1 agents)
Radionuclides, beta-particle-emitting, internally deposited (Note: Specific radionuclides for which there is sufficient evidence for carcinogenicity to humans are also listed individually as Group 1 agents)
Radium-224 and its decay products
Radium-226 and its decay products
Radium-228 and its decay products
Radon-222 and its decay products
Schistosoma haematobium (infection with)
Silica, crystalline (inhaled in the form of quartz or cristobalite from occupational sources)
Solar radiation
Talc containing asbestiform fibers
Tamoxifen (Note: There is also conclusive evidence that this agent (tamoxifen) reduces the risk of contralateral breast cancer)
2,3,7,8-Tetrachlorodibenzo-para-dioxin
Thiotepa
Thorium-232 and its decay products, administered intravenously as a colloidal dispersion of thorium-232 dioxide
Treosulfan
Vinyl chloride
X- and Gamma radiation
Mixtures
Alcoholic beverages
Analgesic mixtures containing phenacetin
Areca nut
Betel quid with tobacco
Betel quid without tobacco
Coal-tar pitches
Coal-tars
Mineral oils, untreated and mildly treated
Salted fish (Chinese-style)
Shale-oils
Soots
Tobacco products, oral tobacco products
Wood dust
Exposure Circumstances
Aluminum production
Arsenic in drinking water
Auramine, manufacture of
Boot and shoe manufacture and repair
Coal gasification
Coke production
Furniture and cabinet making
Hematite mining (underground) with exposure to radon
