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Sample records for las especies vegetales

  1. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    1999-05-01

    assigned as a take-home activity. JCE Classroom Activity #15, "Liver and Onions: DNA Extraction from Animal and Plant Tissues" (p 400A, March 1999) also integrates chemical and biological concepts. The JCE Software videotape HIV-1 Protease: An Enzyme at Work is another useful resource. It can be used in any classroom where kinetics, catalysis, proteins, or enzymes are discussed. Information about JCE Software products can be found in recent issues of the Journal or by accessing JCE Online (http://jchemed.chem.wisc.edu). Because most high school students complete at least one year of biology before enrolling in chemistry, developing the connections between biology and chemistry can be especially productive. Connections between chemistry and biology often seem to be more real to students than do many of the phenomena we cite as applications. For example, students often are not able to make the connection between the excitation of electrons to produce electromagnetic radiation and anything that is personally relevant. The light given off by sodium or mercury vapor lights provides a common example of relating atomic emission to a useful process, but many students do not seem to find that particularly interesting. The need to make a connection between biology and chemistry becomes especially meaningful to students when the chemical change occurs within the human body. As an example, the interaction of emitted electromagnetic radiation with human cells to cause well-tanned skin seems more relevant to a greater number of students than the color of lights in a parking lot. This issue contains an article that describes a useful application of light to kill cancer cells through use of photosensitizers (p 592). The process of photodynamic therapy (PDT) provides another example that could help students make a connection between the emission of electromagnetic radiation and the challenge of killing cancer cells without harming healthy cells. Certainly this example is not a magic

  2. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    1999-09-01

    Secondary School Feature Articles * Authentic Research within the Grasp of High School Students, by Annis Hapkiewicz, p 1212 * JCE Classroom Activity #19: Blueprint Photography by the Cyanotype Process, by Glen D. Lawrence and Stuart Fishelson, p 1216A Author Recognition A new program has been instituted to recognize high school teachers who are authors or coauthors of manuscripts published in the Journal. In May, letters were sent to teachers who wrote articles published in JCE beginning with Volume 74 (1997). If you were an author, you should have received a letter from us in late May or early June stating that your high school principal has been sent a Certificate of High School Author Recognition to be presented to you at a suitable occasion. Because the letters were sent late in the school year, you may not see the certificate until fall, or you may not receive your letter until then if we had only your school address. If you have authored or coauthored an article published in JCE and did not receive a letter, please contact me using the information about the Secondary School Chemistry Editor appearing on the Information Page in this issue. Syllabus Swap In the August issue, this column contained an invitation to exchange high school syllabi. The day after my copy of the August issue arrived, I received an email from a teacher indicating an interest in participating in an exchange. If you are interested, check the August "Especially for High School Chemistry Teachers" column for a brief discussion of the informal exchange program, or contact me. Research Conducted by High School Students In his June 1999 editorial "Learning Is a Do-It-Yourself Activity", p 725, John Moore wrote about the need to engage students actively in the learning process. As I have mentioned in this column previously, research conducted by students is one means of accomplishing this goal. In this issue, p 1212, Annis Hapkiewicz explains how she has drawn her Okemos [Michigan] High

  3. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    1999-05-01

    assigned as a take-home activity. JCE Classroom Activity #15, "Liver and Onions: DNA Extraction from Animal and Plant Tissues" (p 400A, March 1999) also integrates chemical and biological concepts. The JCE Software videotape HIV-1 Protease: An Enzyme at Work is another useful resource. It can be used in any classroom where kinetics, catalysis, proteins, or enzymes are discussed. Information about JCE Software products can be found in recent issues of the Journal or by accessing JCE Online (http://jchemed.chem.wisc.edu). Because most high school students complete at least one year of biology before enrolling in chemistry, developing the connections between biology and chemistry can be especially productive. Connections between chemistry and biology often seem to be more real to students than do many of the phenomena we cite as applications. For example, students often are not able to make the connection between the excitation of electrons to produce electromagnetic radiation and anything that is personally relevant. The light given off by sodium or mercury vapor lights provides a common example of relating atomic emission to a useful process, but many students do not seem to find that particularly interesting. The need to make a connection between biology and chemistry becomes especially meaningful to students when the chemical change occurs within the human body. As an example, the interaction of emitted electromagnetic radiation with human cells to cause well-tanned skin seems more relevant to a greater number of students than the color of lights in a parking lot. This issue contains an article that describes a useful application of light to kill cancer cells through use of photosensitizers (p 592). The process of photodynamic therapy (PDT) provides another example that could help students make a connection between the emission of electromagnetic radiation and the challenge of killing cancer cells without harming healthy cells. Certainly this example is not a magic

  4. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    2000-01-01

    Classroom Activity #23 (pp 40A-40B) and in an article by Robert Goldsmith (p 41). The 1999 Nobel Prize in chemistry and the research that led to the awards are discussed in an article beginning on p 14. An account of the 1998 winners appeared in last January's issue (5), providing the basis for another convenient resource file. Water droplets on a surface of Magic Sand. For many students electrochemistry is among the least favorite of the topics included in first- or second-year high school chemistry - despite the many interesting applications that students encounter every day. There are many reasons why students find the topic difficult, but misconceptions about current flow seem to present the largest obstacle to developing a conceptual understanding of electrochemical processes. Two university faculty members and a high school teacher, Huddle, White, and Rogers, have developed a teaching model to help students confront and overcome their misconceptions (pp 104-110). They have conducted studies of the impact of the model's use on student learning in both high school and introductory college chemistry courses. Particularly encouraging were the learning gains made by students with weak academic backgrounds. An action research project focused on student perspectives of small-group learning is described by Towns, Kreke, and Fields (pp 111-119). Although the project involved upper-division undergraduate university students, action research can be useful to any chemistry teacher who wishes to systematically examine and improve instructional methods and strategies. This article may be especially interesting to readers who frequently employ small-group learning techniques in their classroom. Advances in the technology of multimedia delivery are having an impact on the format in which new JCE Software releases are available. In particular, CD-ROM and Internet browsers are becoming increasingly important as the medium and method of access respectively. To better understand what is

  5. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    1999-06-01

    Secondary School Feature Article * JCE Classroom Activity #18: Photochemistry and Pinhole Photography: An Interdisciplinary Experiment, by Angeliki A. Rigos and Kevin Salemme, p 736A High School Program at Anaheim ACS Meeting Congratulations to Barbara Sitzman of Chatsworth High School (Los Angeles) and her committee for organizing an outstanding day of activities! With support from the Southern California Section of the American Chemical Society and the encouragement of Tom Wildeman, CHED Program Committee Chair, the program attracted a large number of Southern California teachers and some from much greater distances. A synopsis of some of the day's activities is included in the Chemical Education Program Meeting Report, p 747. Other workshop topics included gel chromatography, forensic chemistry, art preservation and authentication, well water purification, and toxins in waste water. Also, a workshop on fitting polymers into the chemistry course was conducted by the Polymer Ambassadors. I thank Mickey Sarquis, founding editor of the JCE Secondary School Chemistry Section, for joining me in conducting an information workshop. The pictures appearing on this page were taken at the High School/College Interface Luncheon, which featured an address by Paul Boyer. In addition to the opportunity to visit with colleagues, enjoy a meal together, and win door prizes, those in attendance enjoyed a lively hands-on workshop led by Michael Tinnesand, Department Head of K-12 Science, ACS Education Division. Don't you wish you could have attended the High School Program? Plan Now: High School Program in New Orleans Mark your calendar for Sunday, August 22, 1999. The Fall ACS National Meeting will be held in New Orleans and the High School Program is scheduled on Sunday so that teachers will be able to avoid conflicts with the opening of the school year. Teachers in the Mid-South region are especially encouraged

  6. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    1999-07-01

    Secondary School Feature Articles * Super Science Connections, by Patricia B. McKean, p 916 * A pHorseshoe, by Roger Plumsky, p 935 National Conferences in Your Part of the Country For the past several months, considerable space in this column has been devoted to forthcoming national conferences and conventions and to highlights of conferences past. For some of us, location is fairly unimportant; but for most of us travel costs and time are both factors to consider when choosing a conference. The community of high school chemistry teachers is favored by the number of national conventions and conferences that are held each year in different locations. In 1999, for example, the spring National Meeting of the American Chemical Society was in Anaheim and the National Science Teachers Association National Convention was in Boston. This summer CHEMED '99 will be held in Fairfield, CT, August 1-5, and the fall National ACS Meeting will be in New Orleans. Teachers from the mid-South especially should consider attending the High School Program at New Orleans, described below by Lillie Tucker Akin, Chairperson of the Division's High School Program Committee. The event will be held on Sunday to minimize conflicts with the beginning of the school year. JCE at CHEMED '99 Stop by the JCE booth at CHEMED '99 in the exhibits area to learn more about the wide array of print and nonprint resources you can use in your classroom and laboratory. Members of the editorial staff will be on hand to talk with you. You are invited to participate in a workshop, "Promoting Active Learning through JCE Activity Sheets and Software", on Monday, August 1, 8:30-10:30. The free hands-on workshop is number WT11 and we encourage you to include it among your choices in the blanks provided on the third page of the registration form. We will also conduct an interactive session to listen to ideas for making the Journal more useful to you. Check the final program for location and time or inquire at the JCE

  7. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    2000-01-01

    Classroom Activity #23 (pp 40A-40B) and in an article by Robert Goldsmith (p 41). The 1999 Nobel Prize in chemistry and the research that led to the awards are discussed in an article beginning on p 14. An account of the 1998 winners appeared in last January's issue (5), providing the basis for another convenient resource file. Water droplets on a surface of Magic Sand. For many students electrochemistry is among the least favorite of the topics included in first- or second-year high school chemistry - despite the many interesting applications that students encounter every day. There are many reasons why students find the topic difficult, but misconceptions about current flow seem to present the largest obstacle to developing a conceptual understanding of electrochemical processes. Two university faculty members and a high school teacher, Huddle, White, and Rogers, have developed a teaching model to help students confront and overcome their misconceptions (pp 104-110). They have conducted studies of the impact of the model's use on student learning in both high school and introductory college chemistry courses. Particularly encouraging were the learning gains made by students with weak academic backgrounds. An action research project focused on student perspectives of small-group learning is described by Towns, Kreke, and Fields (pp 111-119). Although the project involved upper-division undergraduate university students, action research can be useful to any chemistry teacher who wishes to systematically examine and improve instructional methods and strategies. This article may be especially interesting to readers who frequently employ small-group learning techniques in their classroom. Advances in the technology of multimedia delivery are having an impact on the format in which new JCE Software releases are available. In particular, CD-ROM and Internet browsers are becoming increasingly important as the medium and method of access respectively. To better understand what is

  8. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    1999-07-01

    Secondary School Feature Articles * Super Science Connections, by Patricia B. McKean, p 916 * A pHorseshoe, by Roger Plumsky, p 935 National Conferences in Your Part of the Country For the past several months, considerable space in this column has been devoted to forthcoming national conferences and conventions and to highlights of conferences past. For some of us, location is fairly unimportant; but for most of us travel costs and time are both factors to consider when choosing a conference. The community of high school chemistry teachers is favored by the number of national conventions and conferences that are held each year in different locations. In 1999, for example, the spring National Meeting of the American Chemical Society was in Anaheim and the National Science Teachers Association National Convention was in Boston. This summer CHEMED '99 will be held in Fairfield, CT, August 1-5, and the fall National ACS Meeting will be in New Orleans. Teachers from the mid-South especially should consider attending the High School Program at New Orleans, described below by Lillie Tucker Akin, Chairperson of the Division's High School Program Committee. The event will be held on Sunday to minimize conflicts with the beginning of the school year. JCE at CHEMED '99 Stop by the JCE booth at CHEMED '99 in the exhibits area to learn more about the wide array of print and nonprint resources you can use in your classroom and laboratory. Members of the editorial staff will be on hand to talk with you. You are invited to participate in a workshop, "Promoting Active Learning through JCE Activity Sheets and Software", on Monday, August 1, 8:30-10:30. The free hands-on workshop is number WT11 and we encourage you to include it among your choices in the blanks provided on the third page of the registration form. We will also conduct an interactive session to listen to ideas for making the Journal more useful to you. Check the final program for location and time or inquire at the JCE

  9. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    1999-06-01

    Secondary School Feature Article * JCE Classroom Activity #18: Photochemistry and Pinhole Photography: An Interdisciplinary Experiment, by Angeliki A. Rigos and Kevin Salemme, p 736A High School Program at Anaheim ACS Meeting Congratulations to Barbara Sitzman of Chatsworth High School (Los Angeles) and her committee for organizing an outstanding day of activities! With support from the Southern California Section of the American Chemical Society and the encouragement of Tom Wildeman, CHED Program Committee Chair, the program attracted a large number of Southern California teachers and some from much greater distances. A synopsis of some of the day's activities is included in the Chemical Education Program Meeting Report, p 747. Other workshop topics included gel chromatography, forensic chemistry, art preservation and authentication, well water purification, and toxins in waste water. Also, a workshop on fitting polymers into the chemistry course was conducted by the Polymer Ambassadors. I thank Mickey Sarquis, founding editor of the JCE Secondary School Chemistry Section, for joining me in conducting an information workshop. The pictures appearing on this page were taken at the High School/College Interface Luncheon, which featured an address by Paul Boyer. In addition to the opportunity to visit with colleagues, enjoy a meal together, and win door prizes, those in attendance enjoyed a lively hands-on workshop led by Michael Tinnesand, Department Head of K-12 Science, ACS Education Division. Don't you wish you could have attended the High School Program? Plan Now: High School Program in New Orleans Mark your calendar for Sunday, August 22, 1999. The Fall ACS National Meeting will be held in New Orleans and the High School Program is scheduled on Sunday so that teachers will be able to avoid conflicts with the opening of the school year. Teachers in the Mid-South region are especially encouraged

  10. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    1999-09-01

    Secondary School Feature Articles * Authentic Research within the Grasp of High School Students, by Annis Hapkiewicz, p 1212 * JCE Classroom Activity #19: Blueprint Photography by the Cyanotype Process, by Glen D. Lawrence and Stuart Fishelson, p 1216A Author Recognition A new program has been instituted to recognize high school teachers who are authors or coauthors of manuscripts published in the Journal. In May, letters were sent to teachers who wrote articles published in JCE beginning with Volume 74 (1997). If you were an author, you should have received a letter from us in late May or early June stating that your high school principal has been sent a Certificate of High School Author Recognition to be presented to you at a suitable occasion. Because the letters were sent late in the school year, you may not see the certificate until fall, or you may not receive your letter until then if we had only your school address. If you have authored or coauthored an article published in JCE and did not receive a letter, please contact me using the information about the Secondary School Chemistry Editor appearing on the Information Page in this issue. Syllabus Swap In the August issue, this column contained an invitation to exchange high school syllabi. The day after my copy of the August issue arrived, I received an email from a teacher indicating an interest in participating in an exchange. If you are interested, check the August "Especially for High School Chemistry Teachers" column for a brief discussion of the informal exchange program, or contact me. Research Conducted by High School Students In his June 1999 editorial "Learning Is a Do-It-Yourself Activity", p 725, John Moore wrote about the need to engage students actively in the learning process. As I have mentioned in this column previously, research conducted by students is one means of accomplishing this goal. In this issue, p 1212, Annis Hapkiewicz explains how she has drawn her Okemos [Michigan] High

  11. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    1999-12-01

    published in a feature titled the 50-Minute Experiment. Block scheduling has brought an end to the 50-minute period in many classrooms, but the experiment is valid and potentially useful in providing experience with real-world samples. Write Now! With the coming of December days are shorter and nights are longer, and for many readers in the United States and Canada winter weather has set in. If you have been thinking about writing an article for JCE perhaps now is a good time to be doing it. I would like to call your attention to four feature columns designed especially for high school teachers: Chemical Principles Revisited Cary Kilner, Editor Exeter High School, 7 Salmon Street, Newmarket, NH 03857 Phone: 603/659-6825; Fax: 603/772-8287; email: CaryPQ@aol.com Interdisciplinary Connections Mark Alber, Editor Darlington School, 1014 Cave Spring Road, Rome, GA 30161 Phone: 706/236-0442; Fax: 706/236-0443; email: malber@darlington.rome.ga.us Second Year and Advanced Placement Chemistry John Fischer, Editor Ashwaubenon High School, 2391 Ridge Road, Green Bay, WI 54304 Phone: 414/492-2955 ext 2020; email: fischer@netnet.net View from My Classroom David Byrum, Editor Flowing Wells High School, 3301 E. Ft. Lowell Rd., Tucson, AZ 85716 Phone: 520/795-2928; email: DavidB1032@aol.com The titles are descriptive of the content sought for each feature, whose mission statement can be found at the JCE Web site, jchemed.chem.wisc.edu. Click on "Features" in the left-hand frame on your screen. All these editors will be happy to discuss your ideas for an article. Secondary School Feature Articles JCE Classroom Activity #22: Colors to Dye for: Preparation of Natural Dyes, p 1688A Applications of Biocatalysis to Industrial Processes, by John T. Sime, p 1658

  12. Having a Baby (Especially for Teens)

    MedlinePlus

    ... FAQs Having a Baby (Especially for Teens) Patient Education Pamphlets - Spanish Having a Baby (Especially for Teens) Especially for ... Your Practice Patient Safety & Quality Payment Reform (MACRA) Education & Events Annual ... Pamphlets Teen Health About ACOG About Us Leadership & ...

  13. Especial skills: specificity embedded within generality.

    PubMed

    Keetch, Katherine M; Lee, Timothy D; Schmidt, Richard A

    2008-12-01

    Recent evidence suggests that massive amounts of practice of the basketball free throw (a "set shot") results in the development of a specific memory representation that is unique to this one shot distance and angle, and that is distinct from set shots taken at locations other than the free throw line. We termed this unique capability an especial skill. In this article, we review the evidence and provide new data regarding the existence of especial skills. These findings are discussed in terms of their implications for motor control theory and in terms of the broader context of specificity versus generality in the learning of motor skills.

  14. Las Vegas

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This image of Las Vegas, NV was acquired on August, 2000 and covers an area 42 km (25 miles) wide and 30 km (18 miles) long. The image displays three bands of the reflected visible and infrared wavelength region, with a spatial resolution of 15 m. McCarran International Airport to the south and Nellis Air Force Base to the NE are the two major airports visible. Golf courses appear as bright red areas of worms. The first settlement in Las Vegas (which is Spanish for The Meadows) was recorded back in the early 1850s when the Mormon church, headed by Brigham Young, sent a mission of 30 men to construct a fort and teach agriculture to the Indians. Las Vegas became a city in 1905 when the railroad announced this city was to be a major division point. Prior to legalized gambling in 1931, Las Vegas was developing as an agricultural area. Las Vegas' fame as a resort area became prominent after World War II. The image is located at 36.1 degrees north latitude and 115.1 degrees west longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  15. Visual uncertainty influences the extent of an especial skill.

    PubMed

    Czyż, S H; Kwon, O-S; Marzec, J; Styrkowiec, P; Breslin, G

    2015-12-01

    An especial skill in basketball emerges through highly repetitive practice at the 15 ft free throw line. The extent of the role vision plays in the emergence of an especial skill is unknown. We examined the especial skills of ten skilled basketball players in normal and blurred vision conditions where participants wore corrective lenses. As such, we selectively manipulated visual information without affecting the participants' explicit knowledge that they were shooting free throws. We found that shot efficiency was significantly lower in blurred vision conditions as expected, and that the concave shape of shot proficiency function in normal vision conditions became approximately linear in blurred vision conditions. By applying a recently proposed generalization model of especial skills, we suggest that the linearity of shot proficiency function reflects the participants' lesser dependence on especial skill in blurred vision conditions. The findings further characterize the role of visual context in the emergence of an especial skill.

  16. Visual uncertainty influences the extent of an especial skill.

    PubMed

    Czyż, S H; Kwon, O-S; Marzec, J; Styrkowiec, P; Breslin, G

    2015-12-01

    An especial skill in basketball emerges through highly repetitive practice at the 15 ft free throw line. The extent of the role vision plays in the emergence of an especial skill is unknown. We examined the especial skills of ten skilled basketball players in normal and blurred vision conditions where participants wore corrective lenses. As such, we selectively manipulated visual information without affecting the participants' explicit knowledge that they were shooting free throws. We found that shot efficiency was significantly lower in blurred vision conditions as expected, and that the concave shape of shot proficiency function in normal vision conditions became approximately linear in blurred vision conditions. By applying a recently proposed generalization model of especial skills, we suggest that the linearity of shot proficiency function reflects the participants' lesser dependence on especial skill in blurred vision conditions. The findings further characterize the role of visual context in the emergence of an especial skill. PMID:26342796

  17. 3. OVERALL VIEW OF THE MEDICAL CENTER (ESPECIALLY BUILDING 2 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. OVERALL VIEW OF THE MEDICAL CENTER (ESPECIALLY BUILDING 2 & BUILDING 1) FROM THE 'CAMPUS' GROUNDS; LOOKING NW. (Harms) - Veterans Administration Medical Center, Old State Route 13 West, Marion, Williamson County, IL

  18. 2. OVERALL VIEW OF THE MEDICAL CENTER (ESPECIALLY BUILDING 1) ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. OVERALL VIEW OF THE MEDICAL CENTER (ESPECIALLY BUILDING 1) FROM THE 'CAMPUS' GROUNDS; LOOKING SW. (Harms) - Veterans Administration Medical Center, Old State Route 13 West, Marion, Williamson County, IL

  19. 4. OVERALL VIEW OF THE MEDICAL CENTER (ESPECIALLY BUILDING 2 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. OVERALL VIEW OF THE MEDICAL CENTER (ESPECIALLY BUILDING 2 & BUILDING 1) FROM THE 'CAMPUS' GROUNDS; LOOKING NE. (Harms) - Veterans Administration Medical Center, Old State Route 13 West, Marion, Williamson County, IL

  20. Poorer Heart Attack Victims, Especially Women, Fare Worse: Study

    MedlinePlus

    ... https://medlineplus.gov/news/fullstory_161722.html Poorer Heart Attack Victims, Especially Women, Fare Worse: Study Doctors need ... 2016 THURSDAY, Oct. 27, 2016 (HealthDay News) -- Younger heart attack survivors who struggle to afford health care and ...

  1. An especial skill: Support for a learned parameters hypothesis.

    PubMed

    Breslin, Gavin; Hodges, Nicola J; Kennedy, Rodney; Hanlon, Michael; Williams, A Mark

    2010-05-01

    We tested the 'learned parameters' hypothesis as an explanation of the 'especial skill effect'. Outcome attainment and movement kinematics were recorded for 10 expert and 10 novice players performing basketball free-throw shots at five distances (11-19 ft) with a regular and heavy weight basketball. As predicted, experts performed better than expected relative to the regression equation at the 15 ft, free-throw line with the regular basketball, supporting the 'especial skill effect'. This effect was not present for the experts when shooting with the heavy ball. Novices did not show an advantage at the free-throw line when performing with either ball. Although the outcome attainment scores support the 'learned parameters' hypotheses, kinematic analysis failed to identify differences in the movement pattern for the especial skill, suggesting that these skills (i.e., shooting at different distances) are not governed by separate motor programs.

  2. Constant or variable practice: recreating the especial skill effect.

    PubMed

    Breslin, Gavin; Hodges, Nicola J; Steenson, Andrew; Williams, A Mark

    2012-06-01

    An especial skill occurs when performance of a single action from within a class of actions produces an advantage in performance. This advantage in a single action over others in the class is presumed to result from large amounts of practice performing the specific action (Keetch, Schmidt, Lee, & Young, 2005). In an experiment involving the learning of a basketball set shot, practice was manipulated to identify whether an especial skill effect emerges at the free-throw line as a result of constant practice conditions in novice performers. After a pretest, which involved set shots across five distances, participants were randomly assigned to one of two intervention groups. A constant practice group (n=10) performed 300 trials of the set shot at the 15 ft free throw line only, whereas a variable practice group (n=10) performed 300 trials across five distances. Shot accuracy increased for both groups as a result of practice at the 15' distance. However, on the posttest, a significant difference was reported between actual and expected scores for the constant practice group only. This finding provided evidence that an effect similar to that seen for especial skills emerges as a result of constant practice. Although an especial skill effect could result from massive amounts of practice, we show it can emerge as a result of short term repetitive practice, indicating that the type, rather than amount, of practice is important.

  3. Conexiones: Guia para Padres y Estudiantes. Directorio de Servicios y Programas de Educacion Especial de las Escuelas Publicas de Boston.

    ERIC Educational Resources Information Center

    Celuzza, Paul W., Ed.; Clayton, Shelley Bakst, Ed.

    Intended for handicapped students and their parents, the booklet presents a guide in Spanish to special education services in the Boston public schools. Chapter 766, the Massachusetts law guaranteeing free appropriate public education to every child, is focused on. Section 1 discusses such evaluation aspects as early childhood screening, referral,…

  4. An especial skill in elite wheelchair basketball players.

    PubMed

    Fay, K; Breslin, G; Czyż, S H; Pizlo, Z

    2013-08-01

    We aimed to investigate whether an especial skill is present in elite wheelchair basketball players when taking twenty shots with a regular basketball from five different distances (11 ft, 13 ft, 17 ft, & 19 ft) from the basket including the free throw line (15 ft). Twelve elite male basketball players participated. The results showed that as distance increased shot accuracy decreased in line with force by variability predictions for the 11 ft, 13 ft, 17 ft, & 19 ft distances. However, shot performance at the free throw line where players are more familiar with practicing free throw shots did not follow this trend. A linear regression line was drawn to predict performance at the free throw line based on nearer (11 ft & 13 ft) and farer (17 ft & 19 ft) distances to the basket, this was then compared to actual performance. A significant difference between actual and predicted scores was found (p<.05) supporting the presence of an especial skill. Significant positive correlations were found for the 11 ft and 17 ft distance, age, years of playing, and accumulated practice hours with performance at the 15 ft line (p<.05). These correlations imply the operation of generalization in the especial skill. This observation received support from applying a model in which shot accuracy as a function of distance was approximated by two regression lines. PMID:23981485

  5. An especial skill in elite wheelchair basketball players.

    PubMed

    Fay, K; Breslin, G; Czyż, S H; Pizlo, Z

    2013-08-01

    We aimed to investigate whether an especial skill is present in elite wheelchair basketball players when taking twenty shots with a regular basketball from five different distances (11 ft, 13 ft, 17 ft, & 19 ft) from the basket including the free throw line (15 ft). Twelve elite male basketball players participated. The results showed that as distance increased shot accuracy decreased in line with force by variability predictions for the 11 ft, 13 ft, 17 ft, & 19 ft distances. However, shot performance at the free throw line where players are more familiar with practicing free throw shots did not follow this trend. A linear regression line was drawn to predict performance at the free throw line based on nearer (11 ft & 13 ft) and farer (17 ft & 19 ft) distances to the basket, this was then compared to actual performance. A significant difference between actual and predicted scores was found (p<.05) supporting the presence of an especial skill. Significant positive correlations were found for the 11 ft and 17 ft distance, age, years of playing, and accumulated practice hours with performance at the 15 ft line (p<.05). These correlations imply the operation of generalization in the especial skill. This observation received support from applying a model in which shot accuracy as a function of distance was approximated by two regression lines.

  6. Specificity vs. Generalizability: Emergence of Especial Skills in Classical Archery

    PubMed Central

    Czyż, Stanisław H.; Moss, Sarah J.

    2016-01-01

    There is evidence that the recall schema becomes more refined after constant practice. It is also believed that massive amounts of constant practice eventually leads to the emergence of especial skills, i.e., skills that have an advantage in performance over other actions from within the same class of actions. This advantage in performance was noticed when one-criterion practice, e.g., basketball free throws, was compared to non-practiced variations of the skill. However, there is no evidence whether multi-criterion massive amounts of practice would give an advantage to the trained variations of the skill over non-trained, i.e., whether such practice would eventually lead to the development of (multi)-especial skills. The purpose of this study was to determine whether massive amount of practice involving four criterion variations of the skill will give an advantage in performance to the criterions over the class of actions. In two experiments, we analyzed data from female (n = 8) and male classical archers (n = 10), who were required to shoot 30 shots from four accustomed distances, i.e., males at 30, 50, 70, and 90 m and females at 30, 50, 60, and 70 m. The shooting accuracy for the untrained distances (16 distances in men and 14 in women) was used to compile a regression line for distance over shooting accuracy. Regression determined (expected) values were then compared to the shooting accuracy of the trained distances. Data revealed no significant differences between real and expected results at trained distances, except for the 70 m shooting distance in men. The F-test for lack of fit showed that the regression computed for trained and non-trained shooting distances was linear. It can be concluded that especial skills emerge only after very specific practice, i.e., constant practice limited to only one variation of the skill. PMID:27547196

  7. Specificity vs. Generalizability: Emergence of Especial Skills in Classical Archery.

    PubMed

    Czyż, Stanisław H; Moss, Sarah J

    2016-01-01

    There is evidence that the recall schema becomes more refined after constant practice. It is also believed that massive amounts of constant practice eventually leads to the emergence of especial skills, i.e., skills that have an advantage in performance over other actions from within the same class of actions. This advantage in performance was noticed when one-criterion practice, e.g., basketball free throws, was compared to non-practiced variations of the skill. However, there is no evidence whether multi-criterion massive amounts of practice would give an advantage to the trained variations of the skill over non-trained, i.e., whether such practice would eventually lead to the development of (multi)-especial skills. The purpose of this study was to determine whether massive amount of practice involving four criterion variations of the skill will give an advantage in performance to the criterions over the class of actions. In two experiments, we analyzed data from female (n = 8) and male classical archers (n = 10), who were required to shoot 30 shots from four accustomed distances, i.e., males at 30, 50, 70, and 90 m and females at 30, 50, 60, and 70 m. The shooting accuracy for the untrained distances (16 distances in men and 14 in women) was used to compile a regression line for distance over shooting accuracy. Regression determined (expected) values were then compared to the shooting accuracy of the trained distances. Data revealed no significant differences between real and expected results at trained distances, except for the 70 m shooting distance in men. The F-test for lack of fit showed that the regression computed for trained and non-trained shooting distances was linear. It can be concluded that especial skills emerge only after very specific practice, i.e., constant practice limited to only one variation of the skill.

  8. Specificity vs. Generalizability: Emergence of Especial Skills in Classical Archery.

    PubMed

    Czyż, Stanisław H; Moss, Sarah J

    2016-01-01

    There is evidence that the recall schema becomes more refined after constant practice. It is also believed that massive amounts of constant practice eventually leads to the emergence of especial skills, i.e., skills that have an advantage in performance over other actions from within the same class of actions. This advantage in performance was noticed when one-criterion practice, e.g., basketball free throws, was compared to non-practiced variations of the skill. However, there is no evidence whether multi-criterion massive amounts of practice would give an advantage to the trained variations of the skill over non-trained, i.e., whether such practice would eventually lead to the development of (multi)-especial skills. The purpose of this study was to determine whether massive amount of practice involving four criterion variations of the skill will give an advantage in performance to the criterions over the class of actions. In two experiments, we analyzed data from female (n = 8) and male classical archers (n = 10), who were required to shoot 30 shots from four accustomed distances, i.e., males at 30, 50, 70, and 90 m and females at 30, 50, 60, and 70 m. The shooting accuracy for the untrained distances (16 distances in men and 14 in women) was used to compile a regression line for distance over shooting accuracy. Regression determined (expected) values were then compared to the shooting accuracy of the trained distances. Data revealed no significant differences between real and expected results at trained distances, except for the 70 m shooting distance in men. The F-test for lack of fit showed that the regression computed for trained and non-trained shooting distances was linear. It can be concluded that especial skills emerge only after very specific practice, i.e., constant practice limited to only one variation of the skill. PMID:27547196

  9. Effects of radiation on development, especially of the nervous system

    SciTech Connect

    Hicks, S.P.; D'Amato, C.J.

    1980-12-01

    Humans and other organisms are exposed to ionizing radiations from a variety of natural and man-made sources. Radiation may cause mutations and chromosome abnormalities, cell-killing, alterations and transformations in cell growth, and carcinogenetic changes. This paper considers principally the cell-killing and nonlethal cell alterations in developing laboratory mammals and humans, especially the nervous system, that follow irradiation and often lead to malformation and disturbed function, but at certain stages to restitution of the injury. Most of what researchers know about the mechanisms of these radiation effects in man is derived from animal experiments, especially with rats. The few observations in humans have corresponded closely to them. Researchers illustrate the cellular effects and malformative results with an example of cell-killing in the developing cortex of a human fetus exposed to therapeutic radiation in utero; a current timetable of the malformative and other effects of radiation on rats during development from which expectations of human effects might be extrapolated; examples of hydrocephalus produced in rats; low-dose alterations of nerve cells in rats; and a microcephalic Japanese boy exposed in utero to the atomic bomb at Hiroshima in 1945.

  10. Effects of radiation on development, especially of the nervous system.

    PubMed

    Hicks, S P; D'Amato, C J

    1980-12-01

    Humans and other organisms are exposed to ionizing radiations from a variety of natural and man-made sources. Radiation may cause mutations and chromosome abnormalities, cell-killing, alterations and transformations in cell growth, and carcinogenetic changes. This paper considers principally the cell-killing and nonlethal cell alterations in developing laboratory mammals and humans, especially the nervous system, that follow irradiation and often lead to malformation and disturbed function, but at certain stages to restitution of the injury. Most of what we know about the mechanisms of these radiation effects in man is derived from animal experiments, especially with rats. The few observations in humans have corresponded closely to them. We illustrate the cellular effects and malformative results with an example of cell-killing in the developing cortex of a human fetus exposed to therapeutic radiation in utero; a current timetable of the malformative and other effects of radiation on rats during development from which expectations of human effects might be extrapolated; examples of hydrocephalus produced in rats; low-dose alterations of nerve cells in rats; and a microcephalic Japanese boy exposed in utero to the atomic bomb at Hiroshima in 1945.

  11. Especial skills: their emergence with massive amounts of practice.

    PubMed

    Keetch, Katherine M; Schmidt, Richard A; Lee, Timothy D; Young, Douglas E

    2005-10-01

    Differing viewpoints concerning the specificity and generality of motor skill representations in memory were compared by contrasting versions of a skill having either extensive or minimal specific practice. In Experiments 1 and 2, skilled basketball players more accurately performed set shots at the foul line than would be predicted on the basis of the performance at the nearby locations, suggesting considerable specificity at this distance. This effect was replicated even when the lines on the court were obscured (in Experiment 2). However, the effect was absent when jump shots were executed in Experiment 3. The authors argue that massive levels of practice at 1 particular member of a class of actions produce specific effects that allow this skill to stand out from the other members of the class, giving it the status of an especial skill. Various theoretical views are proposed to account for the development of these skills. PMID:16262492

  12. Especial skills: their emergence with massive amounts of practice.

    PubMed

    Keetch, Katherine M; Schmidt, Richard A; Lee, Timothy D; Young, Douglas E

    2005-10-01

    Differing viewpoints concerning the specificity and generality of motor skill representations in memory were compared by contrasting versions of a skill having either extensive or minimal specific practice. In Experiments 1 and 2, skilled basketball players more accurately performed set shots at the foul line than would be predicted on the basis of the performance at the nearby locations, suggesting considerable specificity at this distance. This effect was replicated even when the lines on the court were obscured (in Experiment 2). However, the effect was absent when jump shots were executed in Experiment 3. The authors argue that massive levels of practice at 1 particular member of a class of actions produce specific effects that allow this skill to stand out from the other members of the class, giving it the status of an especial skill. Various theoretical views are proposed to account for the development of these skills.

  13. Land Analysis System (LAS)

    NASA Technical Reports Server (NTRS)

    Pease, P. B.

    1989-01-01

    Version 4.1 of LAS provides flexible framework for algorithm development and processing and analysis of image data. Over 500,000 lines of code enable image repair, clustering, classification, film processing, geometric registration, radiometric correction, and manipulation of image statistics.

  14. A Total Water Management Analysis of the Las Vegas Wash Watershed, Nevada

    EPA Science Inventory

    Climate change, land use change, and population growth are fundamental factors affecting future hydrologic conditions in streams, especially in arid regions with scarce water resources. Located in the arid southwest, Las Vegas Valley located within the Las Vegas Wash watershed is...

  15. Las Campanas Stellar Library

    NASA Astrophysics Data System (ADS)

    Chilingarian, Igor; Zolotukhin, Ivan; Beletsky, Yuri; Worthey, Guy

    2015-08-01

    Stellar libraries are fundamental tools required to understand stellar populations in star clusters and galaxies as well as properties of individual stars. Comprehensive libraries exist in the optical domain, but the near-infrared (NIR) domain stays a couple of decades behind. Here we present the Las Campanas Stellar Library project aiming at obtaining high signal-to-noise intermediate-resolution (R=8000) NIR spectra (0.83<λ<2.5μm) for a sample of 1200 stars in the Southern sky using the Folded-port InfraRed Echelette spectrograph at the 6.5-m Magellan Baade telescope. We developed a dedicated observing strategy and customized the telescope control software in order to achieve the highest possible level of data homogeniety. As of 2015, we observed about 600 stars of all spectral types and luminosity classes making our library the largest homogeneous collection of stellar spectra covering the entire NIR domain. We also re-calibrated in flux and wavelength the two existing optical stellar libraries, INDO-US and UVES-POP and followed up about 400 non-variable stars in the NIR in order to get complete optical-NIR coverage. Worth mentioning that our current sample includes about 80 AGB stars and a few dozens of bulge/LMC/SMC stars.

  16. Challenges to cognitive bases for an especial motor skill at the regulation baseball pitching distance.

    PubMed

    Simons, Jeffery P; Wilson, Jacob M; Wilson, Gabriel J; Theall, Stephen

    2009-09-01

    We tested expert baseball pitchers for evidence of especial skills at the regulation pitching distance. Seven college pitchers threw indoors to a target placed at 60.5 feet (18.44 m) and four closer and four further distances away. Accuracy at the regulation distance was significantly better than predicted by regression on the nonregulation distances (p < .02), indicating an especial skill effect emerged despite the absence of normal contextual cues. Self-efficacy data failed to support confidence as a mediating factor in especial skill effect. We concluded that cognitive theories fail to fully account for the patterns of observed data, and therefore theoretical explanations of the especial skills must address noncognitive aspects of motor learning and control.

  17. Especial skill effect across age and performance level: the nature and degree of generalization.

    PubMed

    Czyż, S H; Breslin, G; Kwon, O; Mazur, M; Kobiałka, K; Pizlo, Z

    2013-01-01

    It has been claimed that an especial skill emerges after massive amounts of basketball practice. Despite this no direct evidence is available to support this claim. The authors aimed to shed light on this question. Thirty-seven male basketball players took part representing four groups: 2 groups of senior players, a cadet group, and a group of juniors. Players performed free throw shots from 7 distances including shots from the free throw line (15 ft). It was shown that an especial skill was present in senior players, but not in junior players who had only 3 years of playing experience. The authors present a descriptive model of especial skill and express it using the formalism of a hierarchical Bayesian model to fit the data and estimate the parameters. This model can account not only for the results, which indicate the presence and a substantial degree of generalizability of especial skill to nearby distances, but also for results of the original study on especial skill where it was proposed that specificity in practice leads to the emergence of the especial skill.

  18. Challenges to Cognitive Bases for an Especial Motor Skill at the Regulation Baseball Pitching Distance

    ERIC Educational Resources Information Center

    Simons, Jeffery P.; Wilson, Jacob M.; Wilson, Gabriel J.; Theall, Stephen

    2009-01-01

    We tested expert baseball pitchers for evidence of especial skills at the regulation pitching distance. Seven college pitchers threw indoors to a target placed at 60.5 feet (18.44 m) and four closer and four further distances away. Accuracy at the regulation distance was significantly better than predicted by regression on the nonregulation…

  19. EMPACT: THE LAS VEGAS INTERAGENCY PILOT PROGRAM

    EPA Science Inventory

    ENPACT: The Las Vegas Interagency Pilot Project

    The Las Vegas Interagency Pilot Project of the EMPACT program has involved eleven efforts. These efforts are described in brief on the poster presentation. They include: Las Vegas Environmental Monitoring Inventory, the Qual...

  20. Optimization of linear alkylbenzene sulfonate (LAS) degradation in UASB reactors by varying bioavailability of LAS, hydraulic retention time and specific organic load rate.

    PubMed

    Okada, Dagoberto Y; Delforno, Tiago P; Esteves, Andressa S; Sakamoto, Isabel K; Duarte, Iolanda C S; Varesche, Maria B A

    2013-01-01

    Degradation of linear alkylbenzene sulfonate (LAS) in UASB reactors was optimized by varying the bioavailability of LAS based on the concentration of biomass in the system (1.3-16 g TS/L), the hydraulic retention time (HRT), which was operated at 6, 35 or 80 h, and the concentration of co-substrates as specific organic loading rates (SOLR) ranging from 0.03-0.18 g COD/g TVS.d. The highest degradation rate of LAS (76%) was related to the lowest SOLR (0.03 g COD/g TVS.d). Variation of the HRT between 6 and 80 h resulted in degradation rates of LAS ranging from 18% to 55%. Variation in the bioavailability of LAS resulted in discrete changes in the degradation rates (ranging from 37-53%). According to the DGGE profiles, the archaeal communities exhibited greater changes than the bacterial communities, especially in biomass samples that were obtained from the phase separator. The parameters that exhibited more influence on LAS degradation were the SOLR followed by the HRT. PMID:23196232

  1. The Present Status of Airship Construction, Especially of Airship-framing Construction

    NASA Technical Reports Server (NTRS)

    Ebner, Hans

    1938-01-01

    This work proposes to sketch, in broad outline, the status of airship construction in the various countries, at a time when commerce over great distances might be finally opened up to the airship through the performances of the "Graf Zeppelin." After a short historical review, a survey of the most important rigid and semirigid airships built since 1925, their differences and special problems, is made. In more detailed treatment, the framing construction of the more recent rigid airships and some especially interesting structural questions are investigated.

  2. Medical history and progress in infectious diseases, especially systemic fungal infections in Japan.

    PubMed

    Mori, Takeshi

    2008-01-01

    This paper reports on medical history from the end of the Edo period to the present and development of studies on infectious diseases, especially medical mycology including systemic fungal diseases. With the inflow of Dutch studies at the end of the Edo period and the adoption of European, mainly German, medicine in the Meiji Restoration, Japanese medical studies gradually developed. However, evolution in the medical field as well as other scientific fields was prevented during the 2nd World War. After the War, there was marked progress in scientific fields and medical research made strong advances. In the past 20 years, basic fungal studies and clinical fungal diseases, especially clinical analysis, clinical diagnosis and treatment of systemic fungal infections have progressed. The level in this field is now equivalent to or higher than that in European countries. Further development is necessary, however, to relieve patients suffering from systemic fungal infections. Members of the Japanese Association of Medical Mycology must be leaders among international medical mycologists.

  3. The diagnostic criteria of Graves' disease and especially the thyrotropin receptor antibody; our own experience.

    PubMed

    Paunkovic, Nebojsa; Paunkovic, Jane

    2007-01-01

    It is generally accepted that the thyrotropin receptor antibody (TRAb) has a stimulating activity and is the major pathogenic factor in Graves' disease (GD). In spite of that, TRAb is not routinely examined in clinical practice. The aim of this article is to briefly review the subject and suggest protocols for the diagnosis, treatment and follow-up of patients with GD based on our own studies and referring especially to TRAb. Clinical symptoms and signs and thyroid hormones may have poor sensitivity or specificity, especially in cases of endocrine ophthalmopathy and subclinical hyperthyroidism. In these cases the TRAb test is 98% sensitive and specific with a diagnostic accuracy of almost 99%. By this test it is possible to differentiate between autoimmune and other forms of thyrotoxicosis such as autonomous hyperthyroidism, destructive thyroiditis, iodine induced hyperthyroidism etc. Antithyroid drugs decrease serum TRAb levels and also induce immune remission. If after treatment TRAb remains increased as in about 30%of our cases, patients will relapse. In pregnant women with GD the follow-up of serum TRAb levels is also important as predictive of immune thyroid disease in the newborn. Data presented in this article confirm that the determination of serum TRAb levels in some rare hyperthyroid disorders, such as associated autoimmune and autonomous forms and in epidemiological studies, is also justified.

  4. Basic types of nonuniformities and their manifestation in the galvanomagnetic properties of especially pure silicon

    NASA Astrophysics Data System (ADS)

    Ostroborodova, V. V.

    1987-06-01

    A method is proposed for analyzing the type of nonuniformities in a single-crystalline pure material based on the changes in the “asymmetry resistances,” determined from the magnitudes of the external potentials on the Hall contacts, in a magnetic field. By comparing their magnetic-field dependences with the analogous dependences of the Hall constant and of the resistivity, measured with different polarities of the voltage applied to the sample, it is shown that the asymmetry resistances are the parameters which are most sensitive to nonuniformity. It was found that nonuniformities of the “compensation” type, i.e., space-charge regions in which the minority carriers make an appreciable contribution to the Hall constant, are systematically manifested in crystals of especially pure high-resistance silicon. The effective Hall factors were calculated under the conditions of Hall bipolarity of the impurity conductivity and the results are compared with the experimental data.

  5. The Dominant Robot: Threatening Robots Cause Psychological Reactance, Especially When They Have Incongruent Goals

    NASA Astrophysics Data System (ADS)

    Roubroeks, M. A. J.; Ham, J. R. C.; Midden, C. J. H.

    Persuasive technology can take the form of a social agent that persuades people to change behavior or attitudes. However, like any persuasive technology, persuasive social agents might trigger psychological reactance, which can lead to restoration behavior. The current study investigated whether interacting with a persuasive robot can cause psychological reactance. Additionally, we investigated whether goal congruency plays a role in psychological reactance. Participants programmed a washing machine while a robot gave threatening advice. Confirming expectations, participants experienced more psychological reactance when receiving high-threatening advice compared to low-threatening advice. Moreover, when the robot gave high-threatening advice and expressed an incongruent goal, participants reported the highest level of psychological reactance (on an anger measure). Finally, high-threatening advice led to more restoration, and this relationship was partially mediated by psychological reactance. Overall, results imply that under certain circumstances persuasive technology can trigger opposite effects, especially when people have incongruent goal intentions.

  6. Protoplasts: a useful research system for plant cell biology, especially dedifferentiation.

    PubMed

    Jiang, Fangwei; Zhu, Jian; Liu, Hai-Liang

    2013-12-01

    As protoplasts have the characteristics of no cell walls, rapid population growth, and synchronicity, they are useful tools for research in many fields, especially cellular biology (Table 1). This article is an overview that focuses on the application of protoplasts to investigate the mechanisms of dedifferentiation, including changes in hormone signals, epigenetic changes, and organelle distribution during the dedifferentiation process. The article also emphasizes the wide range of uses for protoplasts in studying protein positions and signaling during different stresses. The examples provided help to show that protoplast systems, for example the mesophyll protoplast system of Arabidopsis, represent promising tools for studying developmental biology. Meanwhile, specific analysis of protoplast, which comes from different tissue, has specific advantages and limitations (Table 2), and it can provide recommendations to use this system.

  7. Theories of Strongly Nonequilibrium Phenomena, Especially Deformation and Fracture of Solids

    SciTech Connect

    Langer, J. S.

    2013-02-13

    The major focus of the research program supported by this grant was the development of the shear-transformation-zone (STZ) theory of amorphous plasticity and its application to theories of dynamic fracture. In retrospect, the project was remarkably successful. It produced a deep understanding of the formability and strength of bulk metallic glasses [see, especially, refs 5, 6, 19] , and a predictive theory of shear-banding instabilities [17] . The shear-band analysis led, peripherally, to a first understanding of the origin of sharp stress drops during large earthquakes [22]. An important theme that emerged during these studies was the role of an effective temperature as a quantitative measure of the state of disorder induced by shear deformations. This theme led to what now appears to be a fundamental advance in nonequilibrium thermodynamics [6,23,24,25]. Much of this work has been summarized in a review article [26].

  8. Inappropriate management conditions, especially for the regressed class, are related to sperm quality in Prochilodus lineatus.

    PubMed

    De Souza, Thiago G; Hainfellner, Patrick; Kuradomi, Rafael Y; Muñoz, Mario E; Honji, Renato M; Moreira, Renata G; Batlouni, Sergio R

    2015-03-15

    The aims of this study were to evaluate the characteristics of the reproductive classes and semen quality in curimbatá (Prochilodus lineatus) breeders maintained in two different rearing systems. To achieve this goal, cages (Cs) and earthen ponds (EPs) were used as experimental systems to provide unsuitable and suitable conditions, respectively. The fish were maintained under the experimental conditions for 18 months. During this period, males were randomly sampled every 2 months for biometric analysis (n = 30 per sample) and for an evaluation of selected characteristics of the testes (n = 5 per sample). After this period, males maintained in EPs and males maintained in Cs (CMs) were evaluated in induced breeding experiments. We observed that rearing P. lineatus in a C at a high stocking density for the long 18-month period of study produced reductions in growth, testis development, gonadosomatic index values, and sperm quality in the fish. We found differences between the groups in all the reproductive classes examined, especially in the regression class, which showed a pronounced accumulation of immature germ cells in the CMs. In this group, we also noted a less intense transition from a continuous to discontinuous germinal epithelium, with an extended and abnormal but less intense spermatogenic period resulting in decreases in semen volume and sperm concentration in the breeding season. Together, such dysfunctions resulted in the production of low-quality sperm in the CMs, as demonstrated by lower-quality DNA (as evaluated by the comet assay), low fertilization success, and low hatching success. In conclusion, to ensure high-quality semen in P. lineatus, appropriate management conditions must be provided throughout the reproductive cycle, especially for the regressed class, even in winter, two seasons before the breeding season. PMID:25515362

  9. La Función de Luminosidad de las poblaciones de cúmulos globulares alrededor de NGC 1399

    NASA Astrophysics Data System (ADS)

    Ostrov, P. G.; Forte, J. C.; Geisler, D.

    Mediante el empleo de una técnica especial para filtrar el pattern de fringing, se ha obtenido una función de luminosidad de los cúmulos globulares de NGC 1399 superando por ~ 1 mag el turn-over en la banda T1 del sistema de Washington. El análisis de los resultados de la fotometría multibanda (C, M, T1) permite determinar que las mitades mas brillantes de las funciones de luminosidad de las dos principales poblaciones de cúmulos globulares asociadas con esta galaxia son similares.

  10. Plasmid-Encoded Metallo-β-Lactamase (IMP-6) Conferring Resistance to Carbapenems, Especially Meropenem

    PubMed Central

    Yano, Hisakazu; Kuga, Akio; Okamoto, Ryoichi; Kitasato, Hidero; Kobayashi, Toshimitsu; Inoue, Matsuhisa

    2001-01-01

    In 1996, Serratia marcescens KU3838 was isolated from the urine of a patient with a urinary tract infection at a hospital in northern Japan and was found to contain the plasmid pKU501. Previously, we determined that pKU501 carries blaIMP and the genes for TEM-1-type β-lactamases as well as producing both types of β-lactamases (H. Yano, A. Kuga, K. Irinoda, R. Okamoto, T. Kobayashi, and M. Inoue, J. Antibiot. 52:1135–1139, 1999). pKU502 is a recombinant plasmid that contains a 1.5-kb DNA fragment, including the metallo-β-lactamase gene, and is obtained by PCR amplification of pKU501. The sequence of the metallo-β-lactamase gene in pKU502 was determined and revealed that this metallo-β-lactamase gene differed from the gene encoding IMP-1 by one point mutation, leading to one amino acid substitution: 640-A in the base sequence of the IMP-1 gene was replaced by G, and Ser-196 was replaced by Gly in the mature enzyme. This enzyme was designated IMP-6. The strains that produced IMP-6 were resistant to carbapenems. The MICs of panipenem and especially meropenem were higher than the MIC of imipenem for these strains. The kcat/Km value of IMP-6 was about sevenfold higher against meropenem than against imipenem, although the MIC of meropenem for KU1917, which produced IMP-1, was lower than that of imipenem, and the MIC of panipenem was equal to that of imipenem. These results support the hypothesis that IMP-6 has extended substrate profiles against carbapenems. However, the activity of IMP-6 was very low against penicillin G and piperacillin. These results suggest that IMP-6 acquired high activity against carbapenems, especially meropenem, via the point mutation but in the process lost activity against penicillins. Although IMP-6 has reduced activity against penicillins due to this point mutation, pKU501 confers resistance to a variety of antimicrobial agents because it also produces TEM-1-type enzyme. PMID:11302793

  11. Low molecular weight heparin improves healing of chronic venous ulcers especially in the elderly.

    PubMed

    Serra, Raffaele; Buffone, Gianluca; Molinari, Vincenzo; Montemurro, Rossella; Perri, Paolo; Stillitano, Domenico M; Amato, Bruno; de Franciscis, Stefano

    2015-04-01

    Venous ulcers are common, especially in the elderly, accounting for more than 50% of all lower extremity ulcers with important socioeconomic problems. Improving extracellular matrix functioning, by heparin administration, seems to be a way to support wound healing. A total of 284 patients with venous ulcers were recruited in a 4-year period. All patients were subjected to the most appropriate treatment after considering their preference (compression therapy followed or not by vein surgery). Patients were randomised into two groups of 142 persons in each (group A and group B as cases and controls, respectively). Patients of group A, in addition to the basic treatment as described earlier, received administration of nadroparin 2850 IU/0.3 ml through subcutaneous injection once a day for 12 months, whereas group B patients received basic treatment alone. Healing was assessed by means of direct ulcer tracing with computerised planimetry. Group A showed a healing rate of 83·80% at 12 months, whereas that of group B was 60·56%. Results by age group surprisingly showed that the group of older patients took the most advantage from long-term treatment with low molecular weight heparin; this group also had lowest recurrence rate.

  12. A new specific method to detect cyanide in body fluids, especially whole blood, by fluorimetry.

    PubMed

    Felscher, D; Wulfmeyer, M

    1998-09-01

    This study shows a simple, rapid, and specific method for the quantitative determination of cyanide ion in body fluids, especially blood, by fluorimetry. It is based upon the transformation of cyanide ion into hydrocyanic acid, which then reacts with 2,3-naphthalenedialdehyde and taurine in a self-contained system. The 1-cyano-2-benzoisoindole derivate thus formed is suitable for fluorimetric measurement (lambdaEX = 418 nm; lambdaEM = 460 nm). The fluorescence intensity can be determined by spectrophotometry or by high-performance liquid chromatography (HPLC) with fluorescence detection. The detection limit is 0.002 microg/mL. Linearity was excellent from 0.002 to 1 microg/mL for spectrophotometry and from 0.002 to 5 microg/mL for HPLC with fluorescence detection. The coefficient of variation for repeatability was 8% or less. Thiocyanate and sulfide did not interfere, even at high concentrations (200 microg/mL). The method was applicable to whole blood, so it should be suitable for both clinical and forensic purposes. PMID:9737330

  13. Seasonal variability of meiofauna, especially harpacticoid copepods, in Posidonia oceanica macrophytodetritus accumulations

    NASA Astrophysics Data System (ADS)

    Mascart, Thibaud; Lepoint, Gilles; Deschoemaeker, Silke; Binard, Marc; Remy, François; De Troch, Marleen

    2015-01-01

    The overall aim of this study was (1) to assess the diversity and density of meiofauna taxa, especially harpacticoid copepod species, present within accumulated seagrass macrophytodetritus on unvegetated sand patches and (2) to elucidate the community structure of detritus-associated harpacticoid copepods in relation to natural temporal variability of physico-chemical characteristics of accumulations. This was investigated in a Posidonia oceanica (L.) Delile seagrass ecosystem in the northwest Mediterranean Sea (Bay of Calvi, Corsica, 42°35‧N, 8°43‧E) using a triplicate macrophytodetritus core field sampling in two contrasting sites over the four seasons of 2011. Meiofauna higher taxa consisted of 50% Copepoda, of which 87% belonged to the Harpacticoida order. Nematoda was the second most abundant taxa. The copepod community displayed a wide variety of morphologically similar and ecologically different species (i.e. mesopsammic, phytal, phytal-swimmers, planktonic and parasitic). The harpacticoid copepod community followed a strong seasonal pattern with highest abundances and species diversity in May-August, revealing a link with the leaf litter epiphyte primary production cycle. Aside from the important role in sheltering, housing and feeding potential of macrophytodetritus, a harpacticoid community BEST analysis demonstrated a positive correlation with habitat complexity and a negative correlation with water movements and P. oceanica leaf litter accumulation.

  14. Iron-binding compounds impair Pseudomonas aeruginosa biofilm formation, especially under anaerobic conditions.

    PubMed

    O'May, Che Y; Sanderson, Kevin; Roddam, Louise F; Kirov, Sylvia M; Reid, David W

    2009-06-01

    The success of Pseudomonas aeruginosa in cystic fibrosis (CF) and other chronic infections is largely attributed to its ability to grow in antibiotic-resistant biofilm communities. This study investigated the effects of limiting iron levels as a strategy for preventing/disrupting P. aeruginosa biofilms. A range of synthetic and naturally occurring iron-chelating agents were examined. Biofilm development by P. aeruginosa strain PAO1 and CF sputum isolates from chronically infected individuals was significantly decreased by iron removal under aerobic atmospheres. CF strains formed poor biofilms under anaerobic conditions. Strain PAO1 was also tested under anaerobic conditions. Biofilm formation by this model strain was almost totally prevented by several of the chelators tested. The ability of synthetic chelators to impair biofilm formation could be reversed by iron addition to cultures, providing evidence that these effective chelating compounds functioned by directly reducing availability of iron to P. aeruginosa. In contrast, the biological chelator lactoferrin demonstrated enhanced anti-biofilm effects as iron supplementation increased. Hence biofilm inhibition by lactoferrin appeared to occur through more complex mechanisms to those of the synthetic chelators. Overall, our results demonstrate the importance of iron availability to biofilms and that iron chelators have potential as adjunct therapies for preventing biofilm development, especially under low oxygen conditions such as encountered in the chronically infected CF lung. PMID:19429753

  15. Size and Depth Determination of Defects in Plastic Materials, Especially in CFRP, by Means of Shearography

    NASA Astrophysics Data System (ADS)

    Hendorfer, G.; Reiter, C.; Mayr, G.

    2009-03-01

    Interferometric methods are known to be very sensitive, allowing metrology with resolutions better than the wavelength of the light used for illumination. On the other hand, those methods are susceptible to environmental and mechanical noise, usually. We use Shearography, a version of Speckle interferometry, which, in contrast, is a robust method, resistant to noise and vibrations and compatible to industrial applications. We survey thermally-induced Shearography in order to detect defects in plastic materials, especially in carbon fiber reinforced plastics. We show that by analyzing out-of-plane-deformations, it is possible to evaluate those data quantitatively, enabling the determination of the size as well as the depth of defects. The method of depth determination is based on a gray-scale evaluation with respect to the deformations induced. It has been applied for defects localized in depths up to 10 mm, so far. The method of size determination is based on modeling the dependence of the apparent defect size as a function of the amount of shearing. Simulations of the out-of-plane-deformations for specific defects in different materials have been performed as well. The simulations' results help to understand how to interpret the experimental data. In addition they suggest that the sensitivity for the detection of defects is essentially higher in thermally-induced shearography- than in thermography-experiments.

  16. Etologia aplicada al manejo de especies amenazadas: el caso del turon de patas negras (Mustela nigripes)

    USGS Publications Warehouse

    Vargas, A.; Biggins, D.; Miller, B.

    1999-01-01

    de esta especie de un modo más eficaz y rentable. Black-footed ferrets are considered one of the world's most endangered mammals. The last wild population was discovered in 1981 in Meteetsee, Wyoming, and, in 1985 it collapsed due to an epizootic of canine distemper in combination with sylvatic plague. Prior to the extinction of the last remnant population, 18 wild black-footed ferrets were captured to initiate captive propagation efforts. Captive breeding has been successful and, during the last 11 years, more than 2600 black-footed ferrets have been born in captive breeding centers. Since 1991, approximately 870 ferrets have been reintroduced in 5 areas located within the ferret's original geographic distribution, including sites in Wyoming, Montana, South Dakota, and Arizona. Scientific research has been, and continues to be, a critical tool to direct recovery efforts. Studies in applied ethology conducted on captive and reintroduced ferret populations have demonstrated that a naturalistic captive environment, particularly during early developmental periods, enhances the expression of behaviors necessary for survival in nature. Ferrets raised in a naturalistic environment develop better predatory skills, are able to recognize prairie dog burrows as a home and shelter from predators, and are more physically fit. Results from these studies have been adapted into management strategies to help implement a more cost-effective road to black-footed ferret recovery.

  17. The influence of visual contextual information on the emergence of the especial skill in basketball.

    PubMed

    Stöckel, Tino; Breslin, Gavin

    2013-10-01

    We examined whether basketball throwing performance in general and motor skill specificity from the free throw distance in particular are influenced by visual contextual information. Experienced basketball players (N = 36) performed basketball set shots at five distances from the basket. Of particular interest was the performance from the free throw distance (4.23 m), at which experienced basketball players are expected to show superior performance compared with nearby locations as a result of massive amounts of practice. Whereas a control group performed the shots on a regular basketball court, the distance between the rim and the free throw line was either increased or decreased by 30 cm in two experimental groups. Findings showed that only the control group had a superior performance from the free throw distance, and the experimental groups did not. Moreover, all groups performed more accurately from the perceived free throw line (independent of its location) compared with nearby locations. The findings suggest that visual context information influences the presence of specificity effects in experienced performers. The findings have theoretical implications for explaining the memory representation underlying the especial skill effect in basketball.

  18. The influence of visual contextual information on the emergence of the especial skill in basketball.

    PubMed

    Stöckel, Tino; Breslin, Gavin

    2013-10-01

    We examined whether basketball throwing performance in general and motor skill specificity from the free throw distance in particular are influenced by visual contextual information. Experienced basketball players (N = 36) performed basketball set shots at five distances from the basket. Of particular interest was the performance from the free throw distance (4.23 m), at which experienced basketball players are expected to show superior performance compared with nearby locations as a result of massive amounts of practice. Whereas a control group performed the shots on a regular basketball court, the distance between the rim and the free throw line was either increased or decreased by 30 cm in two experimental groups. Findings showed that only the control group had a superior performance from the free throw distance, and the experimental groups did not. Moreover, all groups performed more accurately from the perceived free throw line (independent of its location) compared with nearby locations. The findings suggest that visual context information influences the presence of specificity effects in experienced performers. The findings have theoretical implications for explaining the memory representation underlying the especial skill effect in basketball. PMID:24197721

  19. (Re)cognizing postmodernity: helps for historians--of science especially.

    PubMed

    Forman, Paul

    2010-06-01

    Postmodernity, a historical era demarcated from modernity by a broad reversal in cultural presuppositions, is distinguished from postmodernism, an intellectual posture adopted by self-identified postmodernists early in postmodernity. Two principal features of postmodernity are addressed: first, the downgrading of science and the upgrading of technology in cultural rank--on which postmodernity and postmodernism are in accord; second, the displacement of the methodical, disinterested scientist, modernity's beau ideal, not by a fragmented subject as postmodernism claims, but by the single-minded entrepreneur, resourcefully pursuing his self-interest in disregard of all rules. The reversal in rank and role as between science and technology, setting in circa 1980, is a marker of the transition from modernity to postmodernity. That reversal is to be cognized primarily as rejection of rule-following, of proceeding methodically--'methodism' being the cultural perspective that uniquely distinguished modernity--but also as rejection of disinterestedness, the quality of mind especially highly esteemed in modernity. Postmodernity is constituted by this transvaluation of values, whose well-spring is the egocentric, transgressive (hence 'risk taking'), postmodern personality and its anti-social presumptions regarding personhood. Within the history of science itself there has been since circa 1980 a corresponding turn of scholarly attention away from science to technology, and a growing distaste for social perspectives, reflected, i.a., in the rejection of causalist 'influence' explanations in favor of voluntarist 'resource' explanations.

  20. Marked elevation of adrenal steroids, especially androgens, in saliva of prepubertal autistic children.

    PubMed

    Majewska, Maria Dorota; Hill, Martin; Urbanowicz, Ewa; Rok-Bujko, Paulina; Bieńkowski, Przemysław; Namysłowska, Irena; Mierzejewski, Paweł

    2014-06-01

    Autism is diagnosed on the basis of behavioral manifestations, but its biomarkers are not well defined. A strong gender bias typifying autism (it is 4-5 times more prevalent in males) suggests involvement of steroid hormones in autism pathobiology. In order to evaluate the potential roles of such hormones in autism, we compared the salivary levels of 22 steroids in prepubertal autistic male and female children from two age groups (3-4 and 7-9 years old) with those in healthy controls. The steroids were analyzed using gas chromatography-mass spectrometry and radioimmunoassay. Statistical analysis (ANOVA) revealed that autistic children had significantly higher salivary concentrations of many steroid hormones (both C21 and C19) than control children. These anomalies were more prominent in older autistic children and in boys. The levels of androgens (androstenediol, dehydroepiandrosterone, androsterone and their polar conjugates) were especially increased, indicative of precocious adrenarche and predictive of early puberty. The concentrations of the steroid precursor, pregnenolone, and of several pregnanolones were also higher in autistic than in healthy children, but cortisol levels were not different. Some steroids, whose levels are raised in autism (allopregnanolone, androsterone, pregnenolone, dehydroepiandrosterone and their sulfate conjugates) are neuroactive and modulate GABA, glutamate, and opioid neurotransmission, affecting brain development and functioning. These steroids may contribute to autism pathobiology and symptoms such as elevated anxiety, sleep disturbances, sensory deficits, and stereotypies among others. We suggest that salivary levels of selected steroids may serve as biomarkers of autism pathology useful for monitoring the progress of therapy.

  1. On the Chemical Synthesis and Physical Properties of Iron Pyrite, Especially the (100) Surface

    NASA Astrophysics Data System (ADS)

    Macpherson, Hector Alexander

    Given that iron pyrite (cubic FeS2, fool's gold) is a semiconductor with a ˜1 eV band gap, it has long been investigated for use in technological applications, especially photovoltaics. Unfortunately, numerous measurements indicate that it's properties, as currently synthesized at least, do not allow for effective devices. Photovoltages far below theoretical expectation are found as well as below band gap optical absorption. From a scientific standpoint, our understanding of the cause of these observations, the form of the density of states for instance, remains mired in uncertainty. In this work we have attempted to gain insight into this problem by creating ensembles of pyrite nanocrystals that can then be treated and measured with well-developed wet-chemical nanocrystal techniques. Specifically, we interpret the existing literature to advocate that the surface states of this material dominate its observed electrical properties. In an effort to better understand the most prevalent surface, the (100) face, we developed a synthesis that nucleates small (< 20 nm) pyrite nanoparticles and then changes chemical conditions to grow all other faces besides {100} to extinction, creating ˜37 nm nanocubes. The optical properties of these nanocubes are measured and the phenomenon of resonance light scattering (RLS) is observed. This phenomenon, along with the poor colloidal dispersibility of these nanocubes is then used to promote the idea that an unusual dynamic electronic phenomenon exists on these surfaces. This phenomenon is found to be passivated by introducing charged ligands to the surfaces of these particles. Additionally, after this surface treatment, two very sharp absorption features are observed at 0.73 and 0.88 eV. In connection with recent theoretical work, these transitions are taken as evidence that the (100) surface of pyrite is spin-polarized with each absorption peak being the signal of band edge absorption across a spin-selected direct band gap. A

  2. Negative association between metabolic syndrome and bone mineral density in Koreans, especially in men.

    PubMed

    Kim, Ha Young; Choe, Jae Won; Kim, Hong Kyu; Bae, Sung Jin; Kim, Beom Jun; Lee, Seung Hun; Koh, Jung-Min; Han, Ki Ok; Park, Hyoung Moo; Kim, Ghi Su

    2010-05-01

    Cardiovascular disease and osteoporosis are thought to share common risk factors, and metabolic syndrome (MS) is composed of major risk factors for cardiovascular disease. This study was performed to investigate the relationships between specific MS components and bone mineral density (BMD). BMD was measured at the femoral neck of Korean men aged 40 years or more (n = 1,780) and postmenopausal women (n = 1,108) using dual-energy X-ray absorptiometry. We identified subjects with MS as defined by two criteria, International Diabetes Federation (IDF) and American Heart Association/National Heart, Lung, and Blood Institute (AHA/NHLBI). Body fat and lean mass were measured via bioimpedance analysis. The prevalence of MS was 19.8% and 7.7% in men and 20.8% and 11.6% in postmenopausal women according to the AHA/NHLBI definition and the IDF definition, respectively. After multivariate adjustment, femoral neck BMD was significantly lower in subjects with MS regardless of diagnostic criteria. BMD decreased as the number of MS components increased (P < 0.001 for trends in both sexes). Among MS components, waist circumference was the most important factor in this negative association. When multiple linear regression models were applied to each 5-kg weight stratum to test for a linear trend, waist circumference and fat mass were negatively associated with BMD and lean mass was positively associated with BMD in men but not in women. MS was associated with a lower BMD in Korean men and postmenopausal women, suggesting that visceral fat may lead to bone loss, especially in men. PMID:20354685

  3. Denaturation fingerprinting: two related mutation detection methods especially advantageous for high G + C regions.

    PubMed

    Liu, Q; Weinshenker, B G; Wingerchuk, D M; Sommer, S S

    1998-01-01

    Two versions of denaturation fingerprinting (dnF2R and dnF1R are described for detecting mutations. DnF2R is a sensitive screening method in which fingerprints are generated by performing denaturing gel electrophoresis on bidirectional "cycle-sequencing" reactions with each of two dideoxy terminators, e.g. ddATP and ddCTP. When the fingerprints generated by ddATP and ddCTP are combined, all sequence changes are expected to result in one extra and one absent segment. DnF2R was performed on 246- and 318-bp segments of the human factor IX gene, and the products were electrophoresed through a 6% Long Ranger gel with 7 M urea. All 32 single-base mutations were detected in hemizygous males with hemophilia B. DnF2R has been applied to detect a total of seven heterozygous sequence changes in large-scale screening and was found to be especially suitable for high G+C regions. In a blinded analysis, all of twenty-four additional single-base mutations were detected, but 7 of 31 heterozygous mutations were missed (23%). To reduce the effort of dnF2R by almost twofold while retaining the ability to detect all types of single-base changes, one fingerprint (dnF1R) was generated by performing a single reaction with ddATP and a second chemically modified terminator (e.g., ROX-conjugated ddCTP), which retards the mobility of the same termination products. The sensitivity and specificity of dnF1R equaled that of dnF2R, with the exception that the blinded analysis of heterozygotes in the 318-bp segment, which revealed the presence of an additional mutation. DnF under partially denaturing conditions may have optimal sensitivity for the detection of heterozygotes.

  4. Apolipoprotein E, especially apolipoprotein E4, increases the oligomerization of amyloid β peptide.

    PubMed

    Hashimoto, Tadafumi; Serrano-Pozo, Alberto; Hori, Yukiko; Adams, Kenneth W; Takeda, Shuko; Banerji, Adrian Olaf; Mitani, Akinori; Joyner, Daniel; Thyssen, Diana H; Bacskai, Brian J; Frosch, Matthew P; Spires-Jones, Tara L; Finn, Mary Beth; Holtzman, David M; Hyman, Bradley T

    2012-10-24

    Alzheimer's disease (AD) is the most common progressive neurodegenerative disorder causing dementia. Massive deposition of amyloid β peptide (Aβ) as senile plaques in the brain is the pathological hallmark of AD, but oligomeric, soluble forms of Aβ have been implicated as the synaptotoxic component. The apolipoprotein E ε 4 (apoE ε4) allele is known to be a genetic risk factor for developing AD. However, it is still unknown how apoE impacts the process of Aβ oligomerization. Here, we found that the level of Aβ oligomers in APOE ε4/ε4 AD patient brains is 2.7 times higher than those in APOE ε3/ε3 AD patient brains, matched for total plaque burden, suggesting that apoE4 impacts the metabolism of Aβ oligomers. To test this hypothesis, we examined the effect of apoE on Aβ oligomer formation. Using both synthetic Aβ and a split-luciferase method for monitoring Aβ oligomers, we observed that apoE increased the level of Aβ oligomers in an isoform-dependent manner (E2 < E3 < E4). This effect appears to be dependent on the ApoE C-terminal domain. Moreover, these results were confirmed using endogenous apoE isolated from the TBS-soluble fraction of human brain, which increased the formation of Aβ oligomers. Together, these data show that lipidated apoE, especially apoE4, increases Aβ oligomers in the brain. Higher levels of Aβ oligomers in the brains of APOE ε4/ε4 carriers compared with APOE ε3/ε3 carriers may increase the loss of dendritic spines and accelerate memory impairments, leading to earlier cognitive decline in AD.

  5. Modeling treatment couches in the Pinnacle treatment planning system: Especially important for arc therapy.

    PubMed

    Duggar, William Neil; Nguyen, Alex; Stanford, Jason; Morris, Bart; Yang, Claus C

    2016-01-01

    treatment delivery after couch modeling with both thermoluminescent dosimeter doses and film analysis. Furthermore, analysis of treatment plans with and without using the couch model showed a statistically significant reduction in planning target volume coverage and increase in skin dose. In conclusion, ignoring the treatment couch, a common practice when generating a patient treatment plan, can overestimate the dose delivered especially for arc therapy. This work shows that explicitly modeling the couch during planning can meaningfully improve the agreement between calculated and measured dose distributions. Because of this project, we have implemented the couch models clinically across all treatment plans.

  6. Las ideologias, las ciencias naturales y sus implicaciones en la educacion cientifica

    NASA Astrophysics Data System (ADS)

    Lozada Roldan, Sandra

    Este estudio ausculto las concepciones epistemologicas de los docentes de ciencia del nivel secundario con relacion a las ideologias y las ciencias naturales. Tambien examino las posiciones de los docentes ante asuntos publicos relacionados a la ciencia. Para propositos de este estudio se diseno y se valido el cuestionario con el cual se obtuvieron los resultados. La investigacion es de tipo cuantitativa y se utilizo como diseno la encuesta. El cuestionario se administro en varias actividades de desarrollo profesional para maestros de ciencia. Un total de 78 maestros del nivel secundario respondieron el cuestionario. Para analizar los datos obtenidos se utilizaron estadisticas descriptivas como la distribucion de frecuencia y el porciento. Ademas se establecieron codigos y categorias para describir las posiciones de los maestros ante asuntos publicos relacionados a la ciencia. Los analisis demostraron que entre los docentes participantes de este estudio prevalecen ciertas concepciones epistemologicas adecuadas acerca de las ciencias naturales, a la luz de la literatura consultada. Entre estas concepciones se destacan las siguientes: a) la filosofia materialista de las ciencias naturales, b) la naturaleza tentativa y constructivista del conocimiento cientifico, c) el uso de una metodologia que garantiza cierto grado de objetividad y con el que se justifican y validan los enunciados cientificos y d) la funcion instrumental del conocimiento cientifico. Sin embargo, entre los docentes participantes de este estudio prevalecen ciertas concepciones epistemologicas erroneas acerca de las ciencias naturales, a la luz de la literatura consultada. Entre estas concepciones se destacan las siguientes: a) tendencia inductivista en el que las teorias cientificas comienzan con observaciones que establecen generalizaciones, b) secuencia jerarquica de la metodologia cientifica. Ademas, entre los docentes participantes de este estudio prevalecen concepciones epistemologicas adecuadas

  7. Graduate Enrollment Increases in Science and Engineering Fields, Especially in Engineering and Computer Sciences. InfoBrief: Science Resources Statistics.

    ERIC Educational Resources Information Center

    Burrelli, Joan S.

    This brief describes graduate enrollment increases in the science and engineering fields, especially in engineering and computer sciences. Graduate student enrollment is summarized by enrollment status, citizenship, race/ethnicity, and fields. (KHR)

  8. Overview of the land analysis system (LAS)

    USGS Publications Warehouse

    Quirk, Bruce K.; Olseson, Lyndon R.

    1987-01-01

    The Land Analysis System (LAS) is a fully integrated digital analysis system designed to support remote sensing, image processing, and geographic information systems research. LAS is being developed through a cooperative effort between the National Aeronautics and Space Administration Goddard Space Flight Center and the U. S. Geological Survey Earth Resources Observation Systems (EROS) Data Center. LAS has over 275 analysis modules capable to performing input and output, radiometric correction, geometric registration, signal processing, logical operations, data transformation, classification, spatial analysis, nominal filtering, conversion between raster and vector data types, and display manipulation of image and ancillary data. LAS is currently implant using the Transportable Applications Executive (TAE). While TAE was designed primarily to be transportable, it still provides the necessary components for a standard user interface, terminal handling, input and output services, display management, and intersystem communications. With TAE the analyst uses the same interface to the processing modules regardless of the host computer or operating system. LAS was originally implemented at EROS on a Digital Equipment Corporation computer system under the Virtual Memorial System operating system with DeAnza displays and is presently being converted to run on a Gould Power Node and Sun workstation under the Berkeley System Distribution UNIX operating system.

  9. Regulating device for an electromagnetic control element especially in an internal combustion engine with auto-ignition

    SciTech Connect

    Locher, J.; Schaller, D.

    1985-02-12

    A regulating device for an electromagnetic control element, especially for an internal combustion engine with auto-ignition, is proposed in which a non-linear regulator with preferably a PD characteristic is coupled with a pulse regulator, preferably a two-point regulator with PID characteristic. Of special advantage is the interposition of a limiting device, which allows an increase in the D portion of the non-linear regulator, while at the same time suppressing interference. This results in an excellent control behavoir, especially in the face of small control deviations and in a control element or control circuit afflicted with friction and/or (magnetic) hysteresis.

  10. lasA and lasB genes of Pseudomonas aeruginosa: analysis of transcription and gene product activity.

    PubMed Central

    Toder, D S; Ferrell, S J; Nezezon, J L; Rust, L; Iglewski, B H

    1994-01-01

    The lasA gene was the first of the Pseudomonas aeruginosa genes involved in proteolysis and elastolysis to be cloned and sequenced. Its function and significance have been studied by genetic approaches (D. S. Toder, M. J. Gambello, and B. H. Iglewski, Mol. Microbiol. 5:2003-2010, 1991) and by attempts to purify an active fragment of the protein (J. E. Peters and D. R. Galloway, J. Bacteriol. 172:2236-2240, 1990). To further study LasA in vivo, we have constructed and characterized an insertional mutant in the lasA gene in strain PAO1 (PAO-A1) and in the lasB insertional mutant, PAO-B1. Analysis of these isogenic strains demonstrates that the lasA lesion diminished elastolysis more than proteolysis and that LasA is required for staphylolytic activity. Despite previous suggestions that lasB elastase cleaves the LasA protein, the size of the LasA protein was the same whether or not lasB elastase was present. Expression of lasA in a lasR-negative mutant, PAO-R1, demonstrated that the LasA protein is produced in an active form in the absence of (lasB) elastase or alkaline protease and is itself a protease with elastolytic activity. We also observed that PAO-A1 was closer to the parental phenotype, with respect to elastolytic and proteolytic activities, than the previously characterized, chemically induced lasA mutant PAO-E64. Quantification of promoter activity with lasA::lacZ and lasB::lacZ fusions suggests that PAO-E64 harbors a mutation in a gene which regulates expression of both lasA and lasB. Images PMID:8132339

  11. Methyl Eugenol: Its Occurrence, Distribution, and Role in Nature, Especially in Relation to Insect Behavior and Pollination

    PubMed Central

    Tan, Keng Hong; Nishida, Ritsuo

    2012-01-01

    This review discusses the occurrence and distribution (within a plant) of methyl eugenol in different plant species (> 450) from 80 families spanning many plant orders, as well as various roles this chemical plays in nature, especially in the interactions between tephritid fruit flies and plants. PMID:22963669

  12. [Bone and joint diseases in children. Adequate calcium intake and dietary habit especially breakfast in children and adolescents].

    PubMed

    Kodama, Momoko; Uenishi, Kazuhiro

    2010-06-01

    Childhood and adolescence are important periods for body growth. Calcium is one of the critical dietary factors especially for bone growth. Although recommended dietary allowance (RDA) of calcium has been determined higher in Dietary reference intakes for Japanese, 2010, calcium intake of Japanese children and adolescent are not necessarily adequate. Furthermore, breakfast skippers in this period tend to increase. So, it is very important to acquire an adequate dietary habit from childhood and adolescent. PMID:20513944

  13. Pressure leaching las cruces copper ore

    NASA Astrophysics Data System (ADS)

    Berezowsky, R. M.; Xue, T.; Collins, M. J.; Makwana, M.; Barton-Jones, I.; Southgate, M.; Maclean, J. K.

    1999-12-01

    A hydrometallurgical process was developed for treating the Las Cruces massive sulfide-ore deposit located near Seville, Spain. A two-stage countercurrent leach process, consisting of an atmospheric leach and a pressure leach, was developed to effectively leach copper from the copper-bearing minerals and to generate a solution suitable for the subsequent solvent-extraction and copper-electrowinning operations. The results of batch and continuous miniplant tests are presented.

  14. LANDSCAPE CHANGE OF THE LAS VEGAS VALLEY, 1972 TO 1998

    EPA Science Inventory

    Las Vegas has become one of the fastest growing metropolitan areas in the United States. The cities population has doubled from 1980 to 1994 and in 1995 Las Vegas has surpassed the one million mark. The population of Las Vegas is currently growing at a rate of 7 percent annually....

  15. ?Cuales son las amenazas o peligros volcanicos?

    USGS Publications Warehouse

    Myers, Bobbie; Brantley, Steven R.; Stauffer, Peter; Hendley, James W.

    2000-01-01

    Los volcanes son capaces de producir numerosos peligros geologicos e hidrologicos. Los cientificos del Servicio Geologico de los EE. UU. (USGS, por sus siglas en ingles) y de otras instituciones alrededor del mundo estan estudiando los peligros de muchos de los centenares de volcanes activos y potencialmente activos del mundo. Estos cientificos vigilan muy de cerca la actividad de algunos de los volcanes mas peligrosos, por lo que estan preparados para alertar a las autoridades y/o a la poblacion en caso de que aumente sustancialmente la probabilidad de que ocurra una erupcion u otro evento peligroso.

  16. [Obligations and penal responsibilities of physicians, especially factory doctors, in regard to the protection of workers' health].

    PubMed

    Cottinelli, V

    1987-01-01

    The paper comments on the rôle of health surveillance as a tool for the safeguarding of workers' health on the basis of constitutional principles. The author discusses the concept of health status and disease from the forensic medicine and juridical viewpoint and describes the obligations that are common to all medical practitioners (diagnosis, notification to the Local Health Unit) and the particular obligations of some categories of physicians, especially factory doctors. The responsibility of the physician in the case of crimes of omission of duty is considered. In responsibility for crimes of injury, the author deals with the professional responsibility of both the general practitioner and of the factory doctor in particular, the general liabilities of the employer, and the relationship between the liabilities of the employer and the physician. The paper conclude with comments on some aspects of negligence of the physician appointed to carry out health surveillance of the workers.

  17. Energy Metabolism of the Brain, Including the Cooperation between Astrocytes and Neurons, Especially in the Context of Glycogen Metabolism

    PubMed Central

    Falkowska, Anna; Gutowska, Izabela; Goschorska, Marta; Nowacki, Przemysław; Chlubek, Dariusz; Baranowska-Bosiacka, Irena

    2015-01-01

    Glycogen metabolism has important implications for the functioning of the brain, especially the cooperation between astrocytes and neurons. According to various research data, in a glycogen deficiency (for example during hypoglycemia) glycogen supplies are used to generate lactate, which is then transported to neighboring neurons. Likewise, during periods of intense activity of the nervous system, when the energy demand exceeds supply, astrocyte glycogen is immediately converted to lactate, some of which is transported to the neurons. Thus, glycogen from astrocytes functions as a kind of protection against hypoglycemia, ensuring preservation of neuronal function. The neuroprotective effect of lactate during hypoglycemia or cerebral ischemia has been reported in literature. This review goes on to emphasize that while neurons and astrocytes differ in metabolic profile, they interact to form a common metabolic cooperation. PMID:26528968

  18. Energy Metabolism of the Brain, Including the Cooperation between Astrocytes and Neurons, Especially in the Context of Glycogen Metabolism.

    PubMed

    Falkowska, Anna; Gutowska, Izabela; Goschorska, Marta; Nowacki, Przemysław; Chlubek, Dariusz; Baranowska-Bosiacka, Irena

    2015-10-29

    Glycogen metabolism has important implications for the functioning of the brain, especially the cooperation between astrocytes and neurons. According to various research data, in a glycogen deficiency (for example during hypoglycemia) glycogen supplies are used to generate lactate, which is then transported to neighboring neurons. Likewise, during periods of intense activity of the nervous system, when the energy demand exceeds supply, astrocyte glycogen is immediately converted to lactate, some of which is transported to the neurons. Thus, glycogen from astrocytes functions as a kind of protection against hypoglycemia, ensuring preservation of neuronal function. The neuroprotective effect of lactate during hypoglycemia or cerebral ischemia has been reported in literature. This review goes on to emphasize that while neurons and astrocytes differ in metabolic profile, they interact to form a common metabolic cooperation.

  19. Las Vegas Basin Seismic Response Project: Preliminary Results From Seismic Refraction Experiments, Las Vegas, NV.

    NASA Astrophysics Data System (ADS)

    Zaragoza, S. A.; Snelson, C. M.; Harder, S. H.; Kaip, G.; Luke, B.; Buck, B. J.; Hanson, A. D.

    2002-12-01

    In May and September 2002, seismic refraction data were acquired in the Las Vegas basin. Located in the southern Basin and Range province, the cities of Las Vegas, North Las Vegas, and Henderson sit atop a fault-bounded basin with a depth of up to 5 km and basin dimensions of roughly 60 km wide (east-west) by 50 km in length (north-south). Previous isostatic gravity, seismic reflection, and aeromagnetic studies indicate that a series of sub-basins exist beneath the unconsolidated basin fill, with the deepest sub-basin occurring 5 km west of the fault block bounding the eastern edge of the basin (Frenchman Mountain). The basin is significantly deeper along its northern extremity, following the path of the fault block bounding the northern edge of the basin (Las Vegas Valley Shear Zone), and along the western edge of Frenchman Mountain. Recent, paleoseismic studies have indicated that faults in the Las Vegas region have the potential for an earthquake of M6.5 to 7.0. It is estimated that a M6.9 earthquake in the basin could produce about 11 billion dollars in damage and a significant number of deaths and/or injuries. In addition, an equivalent or larger event in the Death Valley fault zone, 150 km distance, would also be devastating to the metropolitan area of approximately 1.5 million residents. Therefore, it is essential to understand the seismic hazard posed to the Las Vegas region. This project is part of a larger collaborative effort to characterize the basin and its response to ground shaking. The University of Nevada, Las Vegas with assistance from the University of Texas at El Paso, students from UNLV and UTEP, volunteers from the community and several students from Centennial High school deployed 432 portable seismic recorders ("Texans") throughout the valley. Shot point locations were located at three quarries in the valley, one to the north, one to the east and one to the southwest. The profiles cross the Las Vegas Valley Shear zone as well as a prominent

  20. Gesturing during mental problem solving reduces eye movements, especially for individuals with lower visual working memory capacity.

    PubMed

    Pouw, Wim T J L; Mavilidi, Myrto-Foteini; van Gog, Tamara; Paas, Fred

    2016-08-01

    Non-communicative hand gestures have been found to benefit problem-solving performance. These gestures seem to compensate for limited internal cognitive capacities, such as visual working memory capacity. Yet, it is not clear how gestures might perform this cognitive function. One hypothesis is that gesturing is a means to spatially index mental simulations, thereby reducing the need for visually projecting the mental simulation onto the visual presentation of the task. If that hypothesis is correct, less eye movements should be made when participants gesture during problem solving than when they do not gesture. We therefore used mobile eye tracking to investigate the effect of co-thought gesturing and visual working memory capacity on eye movements during mental solving of the Tower of Hanoi problem. Results revealed that gesturing indeed reduced the number of eye movements (lower saccade counts), especially for participants with a relatively lower visual working memory capacity. Subsequent problem-solving performance was not affected by having (not) gestured during the mental solving phase. The current findings suggest that our understanding of gestures in problem solving could be improved by taking into account eye movements during gesturing.

  1. Glitter-Like Iridescence within the Bacteroidetes Especially Cellulophaga spp.: Optical Properties and Correlation with Gliding Motility

    PubMed Central

    Kientz, Betty; Ducret, Adrien; Luke, Stephen; Vukusic, Peter; Mignot, Tâm; Rosenfeld, Eric

    2012-01-01

    Iridescence results from structures that generate color. Iridescence of bacterial colonies has recently been described and illustrated. The glitter-like iridescence class, created especially for a few strains of Cellulophaga lytica, exhibits an intense iridescence under direct illumination. Such color appearance effects were previously associated with other bacteria from the Bacteroidetes phylum, but without clear elucidation and illustration. To this end, we compared various bacterial strains to which the iridescent trait was attributed. All Cellulophaga species and additional Bacteroidetes strains from marine and terrestrial environments were investigated. A selection of bacteria, mostly marine in origin, were found to be iridescent. Although a common pattern of reflected wavelengths was recorded for the species investigated, optical spectroscopy and physical measurements revealed a range of different glitter-like iridescence intensity and color profiles. Importantly, gliding motility was found to be a common feature of all iridescent colonies. Dynamic analyses of “glitter” formation at the edges of C. lytica colonies showed that iridescence was correlated with layer superposition. Both gliding motility, and unknown cell-to-cell communication processes, may be required for the establishment, in time and space, of the necessary periodic structures responsible for the iridescent appearance of Bacteroidetes. PMID:23300811

  2. Single-Unit Muscle Sympathetic Nerve Activity Reflects Sleep Apnea Severity, Especially in Severe Obstructive Sleep Apnea Patients

    PubMed Central

    Hamaoka, Takuto; Murai, Hisayoshi; Kaneko, Shuichi; Usui, Soichiro; Okabe, Yoshitaka; Tokuhisa, Hideki; Kato, Takeshi; Furusho, Hiroshi; Sugiyama, Yu; Nakatsumi, Yasuto; Takata, Shigeo; Takamura, Masayuki

    2016-01-01

    Obstructive sleep apnea syndrome (OSAS) is associated with augmented sympathetic nerve activity, as assessed by multi-unit muscle sympathetic nerve activity (MSNA). However, it is still unclear whether single-unit MSNA is a better reflection of sleep apnea severity according to the apnea-hypopnea index (AHI). One hundred and two OSAS patients underwent full polysomnography and single- and multi-unit MSNA measurements. Univariate and multivariate regression analysis were performed to determine which parameters correlated with OSAS severity, which was defined by the AHI. Single- and multi-unit MSNA were significantly and positively correlated with AHI severity. The AHI was also significantly correlated with multi-unit MSNA burst frequency (r = 0.437, p < 0.0001) and single-unit MSNA spike frequency (r = 0.632, p < 0.0001). Multivariable analysis revealed that SF was correlated most significantly with AHI (T = 7.27, p < 0.0001). The distributions of multiple single-unit spikes per one cardiac interval did not differ between patients with an AHI of <30 and those with and AHI of 30–55 events/h; however, the pattern of each multiple spike firing were significantly higher in patients with an AHI of >55. These results suggest that sympathetic nerve activity is associated with sleep apnea severity. In addition, single-unit MSNA is a more accurate reflection of sleep apnea severity with alternation of the firing pattern, especially in patients with very severe OSAS. PMID:26973534

  3. Potential Involvement of Draxin in the Axonal Projection of Cranial Nerves, Especially Cranial Nerve X, in the Chick Hindbrain.

    PubMed

    Zhang, Sanbing; Cui, Huixian; Wang, Lei; Kang, Lin; Huang, Guannan; Du, Juan; Li, Sha; Tanaka, Hideaki; Su, Yuhong

    2016-07-01

    The appropriate projection of axons within the nervous system is a crucial component of the establishment of neural circuitry. Draxin is a repulsive axon guidance protein. Draxin has important functions in the guidance of three commissures in the central nervous system and in the migration of neural crest cells and dI3 interneurons in the chick spinal cord. Here, we report that the distribution of the draxin protein and the location of 23C10-positive areas have a strong temporal and spatial correlation. The overexpression of draxin, especially transmembrane draxin, caused 23C10-positive axon bundles to misproject in the dorsal hindbrain. In addition, the overexpression of transmembrane draxin caused abnormal formation of the ganglion crest of the IX and X cranial nerves, misprojection of some anti-human natural killer-1 (HNK-1)-stained structures in the dorsal roof of the hindbrain, and a simultaneous reduction in the efferent nerves of some motoneuron axons inside the hindbrain. Our data reveal that draxin might be involved in the fascicular projection of cranial nerves in the hindbrain. PMID:27199282

  4. Histone H3 N-terminal acetylation sites especially K14 are important for rDNA silencing and aging.

    PubMed

    Xu, Heng-hao; Su, Trent; Xue, Yong

    2016-02-24

    Histone variants and histone modifications are essential components in the establishment and maintenance of the repressed status of heterochromatin. Among these histone variants and modifications, acetylation at histone H4K16 is uniquely important for the maintenance of silencing at telomere and mating type loci but not at the ribosomal DNA locus. Here we show that mutations at H3 N-terminal acetylation site K14 specifically disrupt rDNA silencing. However, the mutant ion at H3K14R doesn't affect the recruitment of Pol II repressor RENT (regulator of nucleolar silencing and telophase exit) complex at the rDNA region. Instead, the CAF-1(chromatin assembly factor I) subunit Cac2 level decreased in the H3K14R mutant. Further experiments revealed that the single mutation at H3K14 and multi-site mutations at H3 N-terminus including K14 also delayed replication-depend nucleosome assembly and advanced replicative life span. In conclusion, our data suggest that histone H3 N-terminal acetylation sites especially at K14 are important for rDNA silencing and aging.

  5. Histone H3 N-terminal acetylation sites especially K14 are important for rDNA silencing and aging

    PubMed Central

    Xu, Heng-hao; Su, Trent; Xue, Yong

    2016-01-01

    Histone variants and histone modifications are essential components in the establishment and maintenance of the repressed status of heterochromatin. Among these histone variants and modifications, acetylation at histone H4K16 is uniquely important for the maintenance of silencing at telomere and mating type loci but not at the ribosomal DNA locus. Here we show that mutations at H3 N-terminal acetylation site K14 specifically disrupt rDNA silencing. However, the mutant ion at H3K14R doesn’t affect the recruitment of Pol II repressor RENT (regulator of nucleolar silencing and telophase exit) complex at the rDNA region. Instead, the CAF-1(chromatin assembly factor I) subunit Cac2 level decreased in the H3K14R mutant. Further experiments revealed that the single mutation at H3K14 and multi-site mutations at H3 N-terminus including K14 also delayed replication-depend nucleosome assembly and advanced replicative life span. In conclusion, our data suggest that histone H3 N-terminal acetylation sites especially at K14 are important for rDNA silencing and aging. PMID:26906758

  6. Gesturing during mental problem solving reduces eye movements, especially for individuals with lower visual working memory capacity.

    PubMed

    Pouw, Wim T J L; Mavilidi, Myrto-Foteini; van Gog, Tamara; Paas, Fred

    2016-08-01

    Non-communicative hand gestures have been found to benefit problem-solving performance. These gestures seem to compensate for limited internal cognitive capacities, such as visual working memory capacity. Yet, it is not clear how gestures might perform this cognitive function. One hypothesis is that gesturing is a means to spatially index mental simulations, thereby reducing the need for visually projecting the mental simulation onto the visual presentation of the task. If that hypothesis is correct, less eye movements should be made when participants gesture during problem solving than when they do not gesture. We therefore used mobile eye tracking to investigate the effect of co-thought gesturing and visual working memory capacity on eye movements during mental solving of the Tower of Hanoi problem. Results revealed that gesturing indeed reduced the number of eye movements (lower saccade counts), especially for participants with a relatively lower visual working memory capacity. Subsequent problem-solving performance was not affected by having (not) gestured during the mental solving phase. The current findings suggest that our understanding of gestures in problem solving could be improved by taking into account eye movements during gesturing. PMID:26993293

  7. Single-Unit Muscle Sympathetic Nerve Activity Reflects Sleep Apnea Severity, Especially in Severe Obstructive Sleep Apnea Patients.

    PubMed

    Hamaoka, Takuto; Murai, Hisayoshi; Kaneko, Shuichi; Usui, Soichiro; Okabe, Yoshitaka; Tokuhisa, Hideki; Kato, Takeshi; Furusho, Hiroshi; Sugiyama, Yu; Nakatsumi, Yasuto; Takata, Shigeo; Takamura, Masayuki

    2016-01-01

    Obstructive sleep apnea syndrome (OSAS) is associated with augmented sympathetic nerve activity, as assessed by multi-unit muscle sympathetic nerve activity (MSNA). However, it is still unclear whether single-unit MSNA is a better reflection of sleep apnea severity according to the apnea-hypopnea index (AHI). One hundred and two OSAS patients underwent full polysomnography and single- and multi-unit MSNA measurements. Univariate and multivariate regression analysis were performed to determine which parameters correlated with OSAS severity, which was defined by the AHI. Single- and multi-unit MSNA were significantly and positively correlated with AHI severity. The AHI was also significantly correlated with multi-unit MSNA burst frequency (r = 0.437, p < 0.0001) and single-unit MSNA spike frequency (r = 0.632, p < 0.0001). Multivariable analysis revealed that SF was correlated most significantly with AHI (T = 7.27, p < 0.0001). The distributions of multiple single-unit spikes per one cardiac interval did not differ between patients with an AHI of <30 and those with and AHI of 30-55 events/h; however, the pattern of each multiple spike firing were significantly higher in patients with an AHI of >55. These results suggest that sympathetic nerve activity is associated with sleep apnea severity. In addition, single-unit MSNA is a more accurate reflection of sleep apnea severity with alternation of the firing pattern, especially in patients with very severe OSAS. PMID:26973534

  8. Deregulated Copper Transport Affects Arabidopsis Development Especially in the Absence of Environmental Cycles1[C][W

    PubMed Central

    Andrés-Colás, Nuria; Perea-García, Ana; Puig, Sergi; Peñarrubia, Lola

    2010-01-01

    Copper is an essential cofactor for key processes in plants, but it exerts harmful effects when in excess. Previous work has shown that the Arabidopsis (Arabidopsis thaliana) COPT1 high-affinity copper transport protein participates in copper uptake through plant root tips. Here, we show that COPT1 protein localizes to the plasma membrane of Arabidopsis cells and the phenotypic effects of transgenic plants overexpressing either COPT1 or COPT3, the latter being another high-affinity copper transport protein family member. Both transgenic lines exhibit increased endogenous copper levels and are sensitive to the copper in the growth medium. Additional phenotypes include decreased hypocotyl growth in red light and differentially affected flowering times depending on the photoperiod. Furthermore, in the absence of environmental cycles, such as light and temperature, the survival of plants overexpressing COPT1 or COPT3 is compromised. Consistent with altered circadian rhythms, the expression of the nuclear circadian clock genes CIRCADIAN CLOCK-ASSOCIATED1 (CCA1) and LATE ELONGATED HYPOCOTYL (LHY) is substantially reduced in either COPT1- or COPT3-overexpressing plants. Copper affects the amplitude and the phase, but not the period, of the CCA1 and LHY oscillations in wild-type plants. Copper also drives a reduction in the expression of circadian clock output genes. These results reveal that the spatiotemporal control of copper transport is a key aspect of metal homeostasis that is required for Arabidopsis fitness, especially in the absence of environmental cues. PMID:20335405

  9. Potential Involvement of Draxin in the Axonal Projection of Cranial Nerves, Especially Cranial Nerve X, in the Chick Hindbrain.

    PubMed

    Zhang, Sanbing; Cui, Huixian; Wang, Lei; Kang, Lin; Huang, Guannan; Du, Juan; Li, Sha; Tanaka, Hideaki; Su, Yuhong

    2016-07-01

    The appropriate projection of axons within the nervous system is a crucial component of the establishment of neural circuitry. Draxin is a repulsive axon guidance protein. Draxin has important functions in the guidance of three commissures in the central nervous system and in the migration of neural crest cells and dI3 interneurons in the chick spinal cord. Here, we report that the distribution of the draxin protein and the location of 23C10-positive areas have a strong temporal and spatial correlation. The overexpression of draxin, especially transmembrane draxin, caused 23C10-positive axon bundles to misproject in the dorsal hindbrain. In addition, the overexpression of transmembrane draxin caused abnormal formation of the ganglion crest of the IX and X cranial nerves, misprojection of some anti-human natural killer-1 (HNK-1)-stained structures in the dorsal roof of the hindbrain, and a simultaneous reduction in the efferent nerves of some motoneuron axons inside the hindbrain. Our data reveal that draxin might be involved in the fascicular projection of cranial nerves in the hindbrain.

  10. Relevamiento de HI en las Nubes de Magallanes

    NASA Astrophysics Data System (ADS)

    Bajaja, E.; Morras, R.; Arnal, E. M.; Pöppel, W. G. L.

    El relevamiento de HI en el hemisferio sur, que se está realizando desde el IAR con el nuevo receptor enfriado, abarca, en su rango de velocidades, las velocidades desplegadas por el hidrógeno neutro de las Nubes de Magallanes. Esto permite obtener los perfiles de velocidad correspondientes a estas galaxias con una sensibilidad y una completitud de grilla excepcionales para el estudio de la distribución y de la cinemática del gas a gran escala y con una resolución angular de 30' y una resolución en velocidad de 1 km/s. Estas condiciones permiten el estudio de los campos de velocidad, de las componentes múltiples en velocidad, de las asimetrías, concentraciones y burbujas en la distribución del gas, los puentes entre las Nubes y entre las Nubes y la Galaxia, etc. Estas características son de particular importancia para su correlación con los mapas obtenidos con las emisiones en el radio-continuo, el IR y el CO (relacionable con el hidrógeno molecular) todas las cuales permiten el estudio de la dinámica de las Nubes y su relación con la Galaxia, de la formación y evolución estelar y de la evolución de la Nubes mismas.

  11. Isolation of a potent antibiotic producer bacterium, especially against MRSA, from northern region of the Persian Gulf

    PubMed Central

    Darabpour, Esmaeil; Ardakani, Mohammad Roayaei; Motamedi, Hossein; Ronagh, Mohammad Taghi

    2012-01-01

    Nowadays, emergence and prevalence of MRSA (Methicillin Resistant Staphylococcus aureus) strain have become a great global concern in 21st century, so, it is necessary to discover new antibiotics against this pathogen. The aim of this study was isolation and evaluation marine bacteria from the Persian Gulf in order to finding antibiotic compounds against some pathogenic bacteria. For this purpose, water and sediment samples were collected from the Persian Gulf during March to October 2009. The antibacterial activity of the isolated bacteria was assessed using disc diffusion method. The Growth Curve Interference (GCI) parameter against MRSA was determined for the high potential antibiotic producing strain. The most important factors affecting fermentation conditions in antibiotic production were also optimized. Definite identification of intended isolate was confirmed by 16S rRNA sequencing. Altogether, 51 bacterial colony was isolated and among them only 3 bacterium showed antibacterial activity. Pseudoalteromonaspiscicida PG-01 isolated from a sediment sample was chosen as the best antibiotic producing strain. This strain was effective against all tested Gram-positive bacteria, had good anti-MRSA activity and also GCI value against MRSA was two times lower than MIC value. Among the optimized fermentation parameters, carbon and nitrogen sources play major role in efficacy of optimized antibiotic production. Ultrastructural study on the effect of intended antibiotic compounds on MRSA using TEM revealed that the target site for this compound is cell wall. Considering the antibacterial effect of PG-01 strain especially against MRSA, intended antibiotic compounds can gives hope for treatment of diseases caused by multi-drug resistant bacteria. PMID:22642595

  12. Cost-effectiveness analysis should continually assess competing health care options especially in high volume environments like cataract surgery

    PubMed Central

    Khan, Ashiya; Amitava, Abadan Khan; Rizvi, Syed Ali Raza; Siddiqui, Ziya; Kumari, Namita; Grover, Shivani

    2015-01-01

    Context: Cost-effectiveness analysis should continually assess competing health care options especially in high volume environments like cataract surgery. Aims: To compare the cost effectiveness of phacoemulsification (PE) versus manual small-incision cataract surgery (MSICS). Settings and Design: Prospective randomized controlled trial. Tertiary care hospital setting. Subjects and Methods: A total of 52 consenting patients with age-related cataracts, were prospectively recruited, and block randomized to PE or MSICS group. Preoperative and postoperative LogMAR visual acuity (VA), visual function-14 (VF-14) score and their quality-adjusted life years (QALYs) were obtained, and the change in their values calculated. These were divided by the total cost incurred in the surgery to calculate and compare the cost effectiveness and cost utility. Surgery duration was also compared. Statistical Analysis Used: Two group comparison with Student's t-test. Significance set at P < 0.05; 95% confidence interval (CI) quoted where appropriate. Results: Both the MSICS and PE groups achieved comparative outcomes in terms of change (difference in mean [95% CI]) in LogMAR VA (0.03 [−0.05−0.11]), VF-14 score (7.92 [−1.03−16.86]) and QALYs (1.14 [−0.89−3.16]). However, with significantly lower costs (INR 3228 [2700–3756]), MSICS was more cost effective, with superior cost utility value. MSICS was also significantly quicker (10.58 min [6.85–14.30]) than PE. Conclusions: MSICS provides comparable visual and QALY improvement, yet takes less time, and is significantly more cost-effective, compared with PE. Greater push and penetration of MSICS, by the government, is justifiably warranted in our country. PMID:26265639

  13. Households across All Income Quintiles, Especially the Poorest, Increased Animal Source Food Expenditures Substantially during Recent Peruvian Economic Growth

    PubMed Central

    Humphries, Debbie L.; Behrman, Jere R.; Crookston, Benjamin T.; Dearden, Kirk A.; Schott, Whitney; Penny, Mary E.

    2014-01-01

    Background Relative to plant-based foods, animal source foods (ASFs) are richer in accessible protein, iron, zinc, calcium, vitamin B-12 and other nutrients. Because of their nutritional value, particularly for childhood growth and nutrition, it is important to identify factors influencing ASF consumption, especially for poorer households that generally consume less ASFs. Objective To estimate differential responsiveness of ASF consumption to changes in total household expenditures for households with different expenditures in a middle-income country with substantial recent income increases. Methods The Peruvian Young Lives household panel (n = 1750) from 2002, 2006 and 2009 was used to characterize patterns of ASF expenditures. Multivariate models with controls for unobserved household fixed effects and common secular trends were used to examine nonlinear relationships between changes in household expenditures and in ASF expenditures. Results Households with lower total expenditures dedicated greater percentages of expenditures to food (58.4% vs.17.9% in 2002 and 24.2% vs. 21.5% in 2009 for lowest and highest quintiles respectively) and lower percentages of food expenditures to ASF (22.8% vs. 33.9% in 2002 and 30.3% vs. 37.6% in 2009 for lowest and highest quintiles respectively). Average percentages of overall expenditures spent on food dropped from 47% to 23.2% between 2002 and 2009. Households in the lowest quintiles of expenditures showed greater increases in ASF expenditures relative to total consumption than households in the highest quintiles. Among ASF components, meat and poultry expenditures increased more than proportionately for households in the lowest quintiles, and eggs and fish expenditures increased less than proportionately for all households. Conclusions Increases in household expenditures were associated with substantial increases in consumption of ASFs for households, particularly households with lower total expenditures. Increases in ASF

  14. Variación temporal de las constantes fundamentales

    NASA Astrophysics Data System (ADS)

    Landau, S. J.; Vucetich, H.

    La variación temporal de las constantes fundamentales es un problema que ha motivado numerosos trabajos teóricos y experimentales desde la hipótesis de los grandes números de Dirac en 1937. Entre los métodos experimentales y observacionales para establecer restricciones sobre la variación de las constantes fundamentes es importante mencionar: comparación entre relojes atómicos[1], métodos geofísicos[2][3], análisis de sistemas de absorción en quasares[4][5][6] y cotas provenientes de la nucleosíntesis primordial[7]. En un trabajo reciente[5], se reportó una significativa variación en la constante de estructura fina. Intentos de unificar las cuatro interacciones fundamentales dieron como resultado teorías con múltiples dimensiones como las teorías de Kaluza-Klein y teorías de supercuerdas. Estas teorías proporcionan un marco teórico natural para el estudio de la variación temporal de las constantes fundamentales. A su vez, un modelo sencillo para estudiar la variación de la constante de estructura fina, fue propuesto en [8], a partir de premisas muy generales como ser covarianza, invarianza de gauge, causalidad y invarianza ante reversiones temporales en el electromagnetismo. Diferentes versiones de las teorías antes mencionadas coinciden en predecir variaciones temporales de las constantes fundamentales pero difieren en la forma de esta variación[9][10]. De esta manera, las restricciones establecidas experimentalmente sobre la variación de las constantes fundamentales pueden ser una herramienta importante para testear estas diferentes teorías. En este trabajo, utilizamos las cotas provenientes de diversas técnicas experimentales, para testear si las mismas son consistentes con alguna de las teorías antes mencionadas. En particular, establecemos cotas sobre la variación de los parámentros libres de las diferentes teorías como por ejemplo el radio de las dimensiones extras en las teorías tipo Kaluza-Klein.

  15. StalAge - A new algorithm especially designed for the construction of speleothem age-depth models

    NASA Astrophysics Data System (ADS)

    Scholz, Denis; Hoffmann, Dirk

    2010-05-01

    A standard approach to construct age-depth models for speleothems on the basis of 230Th/U-ages is not available yet. Some studies apply linear interpolation between dated depths; others use least squares polynomial fits. Other authors, in turn, use various kinds of splines or even more sophisticated methods based on the general growth mechanisms of speleothems. A general approach to estimate the uncertainty of stalagmite age models has neither been developed yet. Since the exact determination of the timing and duration of climatic events recorded in speleothem calcite depends on the method used to calculate the age model, a general technique for the calculation of both the age model and its uncertainty is urgently needed. Here we present a new algorithm, especially designed for constructing age-depth models based on speleothem 230Th/U-ages. The algorithm relies on two basic assumptions: (i) the age model must increase monotonically with increasing distance from top of the stalagmite, and (ii) if possible within the associated error bars, the simplest age-depth relationship (i.e., a straight line) is fitted to the age data. Whereas the first assumption simply arises from the absolute constraint of increasing age with increasing distance from top, the second assumption avoids over-interpretation of the age data. The performance of the algorithm was tested using synthetic speleothem age data. For this purpose, a numerical model simulating (i) speleothem growth, (ii) incorporation and temporal evolution of U-series isotopes and (iii) mass spectrometric analysis was developed. This allows simulation of extreme scenarios, such as stalagmite sections including obvious outliers, age inversions and pronounced detrital contamination, and also to test the performance and robustness of the algorithm under these conditions. The developed algorithm has distinct advantages in comparison with the existing methods. Firstly, it is very robust. Outliers and age inversions are

  16. Las Cumbres Observatory Global Telescope Network

    NASA Astrophysics Data System (ADS)

    Brown, T. M.; Baliber, N.; Bianco, F. B.; Bowman, M.; Burleson, B.; Conway, P.; Crellin, M.; Depagne, É.; De Vera, J.; Dilday, B.; Dragomir, D.; Dubberley, M.; Eastman, J. D.; Elphick, M.; Falarski, M.; Foale, S.; Ford, M.; Fulton, B. J.; Garza, J.; Gomez, E. L.; Graham, M.; Greene, R.; Haldeman, B.; Hawkins, E.; Haworth, B.; Haynes, R.; Hidas, M.; Hjelstrom, A. E.; Howell, D. A.; Hygelund, J.; Lister, T. A.; Lobdill, R.; Martinez, J.; Mullins, D. S.; Norbury, M.; Parrent, J.; Paulson, R.; Petry, D. L.; Pickles, A.; Posner, V.; Rosing, W. E.; Ross, R.; Sand, D. J.; Saunders, E. S.; Shobbrook, J.; Shporer, A.; Street, R. A.; Thomas, D.; Tsapras, Y.; Tufts, J. R.; Valenti, S.; Vander Horst, K.; Walker, Z.; White, G.; Willis, M.

    2013-09-01

    Las Cumbres Observatory Global Telescope (LCOGT) is a young organization dedicated to time-domain observations at optical and (potentially) near-IR wavelengths. To this end, LCOGT is constructing a worldwide network of telescopes, including the two 2 m Faulkes telescopes, as many as 17 × 1 m telescopes, and as many as 23 × 40 cm telescopes. These telescopes initially will be outfitted for imaging and (excepting the 40 cm telescopes) spectroscopy at wavelengths between the atmospheric UV cutoff and the roughly 1-μm limit of silicon detectors. Since the first of LCOGT's 1 m telescopes are now being deployed, we lay out here LCOGT's scientific goals and the requirements that these goals place on network architecture and performance, we summarize the network's present and projected level of development, and we describe our expected schedule for completing it. In the bulk of the paper, we describe in detail the technical approaches that we have adopted to attain desired performance. In particular, we discuss our choices for the number and location of network sites, for the number and sizes of telescopes, for the specifications of the first generation of instruments, for the software that will schedule and control the network's telescopes and reduce and archive its data, and for the structure of the scientific and educational programs for which the network will provide observations.

  17. Radioxenon Atmospheric Measurements in North Las Vegas

    SciTech Connect

    Milbrath, Brian D.; Cooper, Matthew W.; Lidey, Lance S.; Bowyer, Ted W.; Hayes, James C.; McIntyre, Justin I.; Karr, L.; Shafer, David S.; Tappen, J.

    2007-09-25

    Pacific Northwest National Laboratory (PNNL) deployed the Automated Radioxenon Sampler/Analyzer (ARSA) in North Las Vegas for two weeks in February and March 2006 for the purpose of measuring the radioxenon background at a level of sensitivity much higher than previously done in the vicinity of the Nevada Test Site (NTS). The measurements establish what might be expected if future measurements are taken at NTS itself and investigate improved methods of environmental monitoring of NTS for test site readiness. Also, such radioxenon measurements have not previously been performed in a United States location considered to be as remote from nuclear reactors. A second detector, the Portable Environmental Monitoring Station (PEMS), built and operated by the Desert Research Institute (DRI), was deployed in conjunction with the ARSA and contained a pressure ion chamber, aerosol collection filters, and meteorological sensors. Some of the radioxenon measurements detected 133Xe at levels up to 3 mBq/m3. This concentration of radioxenon is consistent with the observation of low levels of radioxenon emanating from distance nuclear reactors. Previous measurements in areas of high nuclear reactor concentration have shown similar results, but the western US, in general, does not have many nuclear reactors. Measurements of the wind direction indicate that the air carrying the radioxenon came from south of the detector and not from the NTS.

  18. LAS - LAND ANALYSIS SYSTEM, VERSION 5.0

    NASA Technical Reports Server (NTRS)

    Pease, P. B.

    1994-01-01

    The Land Analysis System (LAS) is an image analysis system designed to manipulate and analyze digital data in raster format and provide the user with a wide spectrum of functions and statistical tools for analysis. LAS offers these features under VMS with optional image display capabilities for IVAS and other display devices as well as the X-Windows environment. LAS provides a flexible framework for algorithm development as well as for the processing and analysis of image data. Users may choose between mouse-driven commands or the traditional command line input mode. LAS functions include supervised and unsupervised image classification, film product generation, geometric registration, image repair, radiometric correction and image statistical analysis. Data files accepted by LAS include formats such as Multi-Spectral Scanner (MSS), Thematic Mapper (TM) and Advanced Very High Resolution Radiometer (AVHRR). The enhanced geometric registration package now includes both image to image and map to map transformations. The over 200 LAS functions fall into image processing scenario categories which include: arithmetic and logical functions, data transformations, fourier transforms, geometric registration, hard copy output, image restoration, intensity transformation, multispectral and statistical analysis, file transfer, tape profiling and file management among others. Internal improvements to the LAS code have eliminated the VAX VMS dependencies and improved overall system performance. The maximum LAS image size has been increased to 20,000 lines by 20,000 samples with a maximum of 256 bands per image. The catalog management system used in earlier versions of LAS has been replaced by a more streamlined and maintenance-free method of file management. This system is not dependent on VAX/VMS and relies on file naming conventions alone to allow the use of identical LAS file names on different operating systems. While the LAS code has been improved, the original capabilities

  19. La edad de las familias Eos, Themis y Koronis

    NASA Astrophysics Data System (ADS)

    Gil-Hutton, R.

    Las familias de asteroides son el producto de la disrupción colisional de objetos destruídos por impactos ocurridos en el cinturón principal. Las colisiones posteriores han modificado los tamaños y las órbitas de los miembros de estas familias, por lo que las distribuciones que vemos hoy en día pueden ser muy diferentes de aquellas producidas inmediatamente después de la fragmentación del objeto original. En esta hipótesis, puede ser difícil reconstruir la evolución colisional de la familia basándose sólo en las actuales distribuciones y puede ser necesario hacer ciertas suposiciones para obtener información sobre las condiciones iniciales. En este trabajo se deriva una estimación de la edad de las familias Eos, Themis y Koronis obtenida de una simulación de la evolución colisional de un cuerpo original teórico para cada familia usando un modelo de distribución para el cinturón propuesto por Gil-Hutton (1996).

  20. Fate of linear alkylbenzene sulfonate (LAS) in activated sludge plants.

    PubMed

    Temmink, H; Klapwijk, Bram

    2004-02-01

    Monitoring data were collected in a pilot-scale municipal activated sludge plant to assess the fate of the C12-homologue of linear alkyl benzene sulfonate (LAS-C12). The pilot-plant was operated at influent LAS-C12 concentrations between 2 and 12 mg l(-1) and at sludge retention times of 10 and 27 days. Effluent and waste sludge concentrations varied between 5 and 10 microg l(-1) and between 37 and 69 microg g(-1) VSS, respectively. In the sludge samples only 2-8% was present as dissolved LAS-C12, whereas the remaining 92-98% was found to be adsorbed to the sludge. In spite of this high degree of sorption, more than 99% of the LAS-C12 load was removed by biodegradation, showing that not only the soluble fraction but also the adsorbed fraction of LAS-C12 is readily available for biodegradation. Sorption and biodegradation of LAS-C12 were also investigated separately. Sorption was an extremely fast and reversible process and could be described by a linear isotherm with a partition coefficient of 3.2 l g(-1) volatile suspended solids. From the results of biodegradation kinetic tests it was concluded that primary biodegradation of LAS-C12 cannot be described by a (growth) Monod model, but a secondary utilisation model should be used instead. The apparent affinity of the sludge to biodegrade LAS-C12 increased when the sludge was loaded with higher influent concentrations of LAS-C12.

  1. The Land Analysis System (LAS) for multispectral image processing

    USGS Publications Warehouse

    Wharton, S. W.; Lu, Y. C.; Quirk, Bruce K.; Oleson, Lyndon R.; Newcomer, J. A.; Irani, Frederick M.

    1988-01-01

    The Land Analysis System (LAS) is an interactive software system available in the public domain for the analysis, display, and management of multispectral and other digital image data. LAS provides over 240 applications functions and utilities, a flexible user interface, complete online and hard-copy documentation, extensive image-data file management, reformatting, conversion utilities, and high-level device independent access to image display hardware. The authors summarize the capabilities of the current release of LAS (version 4.0) and discuss plans for future development. Particular emphasis is given to the issue of system portability and the importance of removing and/or isolating hardware and software dependencies.

  2. Log ASCII Standard (LAS) Files for Geophysical (Gamma Ray) Wireline Well Logs and Their Application to Geologic Cross Section C-C' Through the Central Appalachian Basin

    USGS Publications Warehouse

    Trippi, Michael H.; Crangle, Robert D.

    2009-01-01

    U.S. Geological Survey (USGS) regional geologic cross section C-C' (Ryder and others, 2008) displays key stratigraphic intervals in the central Appalachian basin. For this cross section, strata were correlated by using descriptions of well cuttings and gamma ray well log traces. This report summarizes the procedures used to convert gamma ray curves on paper well logs to the digital Log ASCII (American Standard Code for Information Interchange) Standard (LAS) format using the third-party software application Neuralog. The procedures could be used with other geophysical wireline logs also. The creation of digital LAS files from paper well logs by using Neuralog is very helpful, especially when dealing with older logs with limited or nonexistent digital data. The LAS files from the gamma ray logs of 11 wells used to construct cross section C-C' are included in this report. They may be downloaded from the index page as a single ZIP file.

  3. Environmental behavior of linear alkylbenzene sulfonate (LAS) in aquatic ecosystem

    NASA Astrophysics Data System (ADS)

    Zhang, Yongyuan; Tan, Yuyun; Korte, F.

    1991-03-01

    LAS degradation rate in Donghu Lake water under aerobic was much faster than under anaerobic condition. The half life of LAS in aerobic and anaerobic environment was 3.2 days and 57 days, respectively. The degradation rate at 25 27°C was approximately 20 times higher than that at 1.5 3.5 °C. In a laboratory model aquatic ecosystem, two stages of bioconcentration in fish, daphnia and snail were observed. The first stage, on second day exposure, resulted from accumulation of intact LAS, and the second stage, on 16th day exposure, was due to metabolites. The bioconcentration factor (BCF) of LAS was extremely low in the muscle of hybrid carp (0.64), but rather high (2485) in the gall bladder.

  4. Actitudes de los candidatos y maestros de ciencias en servicio acerca del uso de las herramientas computadorizadas en las clases de ciencias

    NASA Astrophysics Data System (ADS)

    Bayuelo, Ezequiel

    Este estudio examino y comparo las actitudes de los candidatos a maestros de ciencias y los maestros de ciencias en servicio acerca de la utilizacion de las herramientas computadorizadas en las clases de ciencias. Tambien identifico y diferencio el uso que ellos dan a estas herramientas en las clases de ciencias. Este estudio presenta un diseno descriptivo exploratorio. Constituyeron la muestra trescientos diez sujetos que fueron candidatos a maestros de ciencias o maestros de ciencias en servicio. Para recoger los datos se construyo y valido un cuestionario de treinta y un itemes. Se utilizaron las pruebas estadisticas no parametricas Kruskal Wallis y Chi-cuadrado (test de homogeneidad) para establecer las diferencias entre las actitudes de los sujetos con relacion al uso de las herramientas computadorizadas en las clases de ciencias. Los hallazgos evidenciaron que son positivas y muy parecidas las actitudes de los candidatos a maestros y maestros en servicio hacia el uso de las herramientas computadorizadas. No hubo diferencias entre los candidatos y maestros en servicio en terminos de las actitudes de confianza y empatia hacia el uso de las herramientas computadorizadas en las clases de ciencias. En aspectos como el uso del banco de datos bibliografico Eric y el uso de las herramientas computadorizadas en actividades educativas como explorar conceptos, conceptuar, aplicar lo aprendido y hacer asignaciones hubo diferencias estadisticamente significativas entre los candidatos y los maestros en servicio. Al comparar las frecuencias observadas con las esperadas hubo mas maestros en servicio y menos candidatos que indicaron usar el anterior banco de datos y las herramientas computadorizadas en las mencionadas actividades educativas.

  5. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    1999-02-01

    Secondary School Feature Articles * Building the Interest of High School Students for Science-A PACT Ambassador Program To Investigate Soap Manufacturing and Industrial Chemistry, by Matthew Lynch, Nicholas Geary, Karen Hagaman, Ann Munson, and Mark Sabo, p 191. * Promoting Chemistry at the Elementary Level, by Larry L. Louters and Richard D. Huisman, p 196. * Is It Real Gold? by Harold H. Harris, p 198. * The "Big Dog-Puppy Dog" Analogy for Resonance, by Todd P. Silverstein, p 206. * The Fizz Keeper, a Case Study in Chemical Education, Equilibrium, and Kinetics, by Reed A. Howald, p 208. Staying on Top: Curricular Projects, Relativistic Effects, and Standard-State Pressure You may wonder why some articles are identified with the Secondary School Chemistry logo (*) this month even though at first glance they appear to be of greater interest to college faculty.1 The three articles discussed below are representative of three broad categories: (i) the interrelatedness of science teaching and learning, K-16+; (ii) new understandings of chemical phenomena; and (iii) information about the use of SI units. For each article I have highlighted the major point(s) and the reasons it may be of interest to high school teachers. First, the article "The NSF 'Systemic' Projects- A New Tradition" (G. M. Barrow, p 158) is a commentary on changes in post-secondary introductory chemistry courses in which a distinction is drawn between information management and individual understanding. The author is of the opinion that most students expect the former and that the NSF-funded systemic projects "will thrive only if they are consistent with their information-management mission". Three individuals provided responses to the commentary from their perspective. Has a student asked you why mercury is a liquid, or why gold is the most electronegative metal? "Gold Chemistry: The Aurophilic Attraction" by J. Bardají and A. Laguna (p 201) and "Why Gold and Copper Are Colored but Silver Is Not" by A. H. Guerreor, H. J. Fasoli, and J. L. Costa (p 200) provide useful information in answering these questions. Have you thought about the effect of changing the standard-state pressure from 1 atm to the SI unit of 1 bar? The question is addressed in "How Thermodynamic Data and Equilibrium Constants Changed When the Standard-State Pressure Became 1 Bar" by R. S. Treptow (p 212). The author points out that although textbook authors have not yet abandoned use of 1 atm as standard-state pressure, thermodynamic data are reported in the research literature on the basis of 1 bar standard-state pressure. The author provides the information needed to readily convert thermodynamic data from one standard to the other. These articles represent just a few that may be of interest to you. I encourage you to explore other articles within the Journal that are not noted with the secondary school section logo. As we each continue to broaden our knowledge of chemistry and chemical education, JCE will continue to serve as an invaluable resource in our educational quest. Anaheim and Boston in March; Fairfield in August JCE will have a booth in the exhibition hall both at the ACS National Meeting in Anaheim, March 21-24, and at the NSTA National Convention in Boston, March 25-29. Additionally, the all-day High School Program on Monday, March 22, will be held as part of the ACS meeting. More details will be provided in the March issue of JCE. Make your plans to attend now. Registration information may be found at http://www.acs.org/meetings/anaheim/welcome.htm and http://www.nsta.org/conv/natgen.htm. Another outstanding event, ChemEd '99, will held on the campus of Sacred Heart University, Fairfield, CT, August 1-5, 1999. Information, including a call for presentation proposals, is available at http://www.sacredheart.edu/chemed/. The deadline for abstracts is March 1, 1999, so don't delay. Chemistry for Kids-Looking for New Ideas Over the life of the Chemistry for Kids (CFK) feature a relatively large number of articles have been published that describe outreach by college or high school faculty and students. The majority of these have dwelt on the details of delivery-be it demonstrations or hands-on activities. An article in this issue, "Promoting Chemistry at the Elementary Level: A Low-Maintenance Program of Chemical Demonstration" by Larry L. Louters and Richard D. Huisman (p 196), details an on-campus program that could be a model for others to use. We believe that almost every combination of interaction has been described in CFK articles. What we would like now are more CFK articles with an emphasis on science instruction in the elementary classroom. Learner-centered activities and teaching strategies that integrate chemistry into the curriculum, successful curricula, and applications of software or other technological innovations are among topics that could be of interest to readers. If you have an idea for a manuscript, the co-editors of the CFK feature would be happy to discuss it with you. Any suggestions regarding types of articles that you think would be helpful within this section are welcomed too. To contact the CFK feature editors: John T. Moore, Stephen F. Austin State University Department of Chemistry, Box 13006 SFA Station, Nacogdoches, TX 75962; 409/468-2384; jmoore@sfasu.edu; David Tolar, Ennis Intermediate School, Ennis, TX 75120; 903/872-5364; TolarD@ennis.ednet10.net. Note 1. Comments from readers regarding the appropriateness of the recommendations are always welcome (j.e.howell@usm.edu).

  6. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    1998-06-01

    Secondary School Feature Articles * Why Do Alcoholic Beverages Have "Legs"?, by Todd P. Silverstein, p 723. * Audience-Appropriate Analogies: Collision Theory, by Kent W. Piepgrass, p 724. * Using Balls from Different Sports To Model the Variation of Atomic Sizes, by Gabriel Pinto, p 725. * The Convergent Evolution of a Chemistry Project: Using Laboratory Posters as a Platform for Web Page Construction, by Sally Rigeman, p 727. * Process Development in the Teaching Laboratory, by Leonard C. Klein and Susanne M. Dana, p 745.

  7. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    2001-11-01

    It is not necessary to be a subscriber in order to use the index. However, there is a definite advantage to being a subscriber because full-text download of any article published from September 1996 to date is possible from the abstract page. Thus, these articles may be read from your computer screen or printed on your printer. Supplemental material to an article is also available for download by subscribers.

    Literature Cited

    1. National Science Education Standards, National Academy Press: Washington, DC, 1996: pp 190-193.
    2. J. Chem. Educ. 2001, 78, 328A.
    3. J. Chem. Educ. 2000, 77, 40A.
    4. J. Chem. Educ. 1999, 76, 1688A.
    5. J. Chem. Educ. 1999, 76, 1416A.
    6. J. Chem. Educ. 1999, 76, 192A.
    7. J. Chem. Educ. 1997, 74, 1176A.
    8. Houghton, Peter J. J. Chem. Educ. 2001, 78, 175.
    9. Ward, Michael D. J. Chem. Educ. 2001, 78, 321.
    10. Pellenbarg, Robert E. J. Chem. Educ. 2001, 78, 896.
    11. Chisholm, Michael S. J. Chem. Educ. 2000, 77, 841.
    12. Oriakhi, Christopher O. J. Chem. Educ. 2000, 77, 1138.

  8. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    2001-06-01

    My five-year term as Secondary School Chemistry Editor is coming to a close. I am excited about the direction the Journal has taken in relation to high school teachers, and challenge my successor to remain focused on the changing needs of high school teachers so that the Journal may continue to be the resource for teachers, both new and seasoned. If you have a vision of how to carry on JCE's mission for high school teachers, I encourage you to refer here for more information about the position and how to apply for it. Literature Cited

    1. National Commission on Mathematics and Science Education for the 21st Century, Before It's Too Late (accessed Apr 2001).
    2. Moore, J. W. J. Chem. Educ. 2000, 77, 1535.
    3. Bush, G. W. No Child Left Behind (accessed Apr 2001).

  9. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    2001-09-01

    Looking for great National Chemistry Week 2001 resources on Chemistry and Art? Watch for the October and November issues of JCE. For more details about what to expect see pages 1158 and 1194 of this issue. Note 1. Solid State Model Kit. Available from the Institute for Chemical Education, Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, WI 53706-1396; phone 608/262-3033; fax 608/265-8094. Literature Cited 1. Cady, S. G. J. Chem. Educ. 1997, 74, 794. 2. Laing, M. J. Chem. Educ. 1997, 74, 795. 3. Mattson, B. J. Chem. Educ. 2000, 77, 622.

  10. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    2001-05-01

    Literature Cited

    1. National Science Education Standards; National Academy Press: Washington, DC, 1996; http://www. nap.edu/readingroom/books/nses/.
    2. Principles and Standards for School Mathematics; National Council of Teachers of Mathematics: Washington, DC, 2000; http://standards.nctm.org/.
    Visit CLIC, an Online Resource for High School Teachers at http://jchemed.chem.wisc.edu/HS/

  11. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    2000-02-01

    Secondary School Feature Articles JCE Classroom Activity: #24. The Write Stuff: Using Paper Chromatography to Separate an Ink Mixture, p 176A Teaching Chemistry in the Midwinter Every year, forecasters around the world provide us with long-range predictions of what the seasons will afford us in the coming year. And each year, the weather provides a few surprises that the forecasters did not predict - such as a record amount of snow or record heat indexes, depending on where you live. Although the weatherman didn't predict it, we still must pull out our snow shovels or sun block and take the necessary steps to adapt to the situation. As teachers, we make predictions of teaching and learning goals that we aspire to achieve during a given year, and like the weather, the year brings surprises that aren't in line with our predictions. With that in mind, I would like to offer JCE as the scholastic snow shovel or sun shield you need to jump-start your class and reach the goals you have set. So find a warm (or cool) place, get comfortable, and spend some time with the February issue of JCE. Articles of General Interest in This Issue For readers living where snow falls, Williams's article on page 148 offers some historical background on the use of calcium chloride as a deicer. A diver that depends for its buoyancy upon gas given off by a chemical reaction is described by Derr, Lewis, and Derr in the article beginning on page 171. In her article appearing on pages 249-250, Wang describes a laboratory exercise that makes the mastery of solution preparation skills fun. The students' skill is tested by using the solutions they make to carry out the Briggs-Rauscher oscillating reaction. For high school class applications I recommend use of 3% hydrogen peroxide, described as an option in the article. A well-organized approach to separating an ink mixture, with some possibly new twists, is laid out in the student- and teacher-friendly format of JCE Classroom Activity: #24, pages 176A-176B. Addressing Some Specialized Interests As in any issue of the Journal, there are several articles that are not designated with the secondary school mark (?) but are likely to be of interest to some high school teachers. For example, if you are interested in staying abreast of educational applications of computational chemistry, the articles on pages 199-221 will be among those you will wish to examine even though the focus is on meeting the learning needs of college students. For those with an interest in electronics, there are several articles on pages 252-262, on building on modifying useful devices. Among the topics: building a digital monitor for analyzing spectrophotometer signals, building a digital interface for a graphing calculator, and using an inexpensive commercial analog-to-digital converter. JCE Reviewers The standard of quality in JCE articles is due in great measure to the careful scrutiny and helpful suggestions of reviewers. I am proud to note that the names of several high school teachers are in the list of individuals who have reviewed manuscripts for JCE recently. This month's list, which appears on page 152, is a continuation from page 24 of the January issue. Keep watching if your name has not yet appeared. If you are not currently serving as a reviewer, I encourage you to sign up today. As a reviewer, you would review potential articles that have been submitted to the Journal. You may choose from a variety of subject areas to review and choose as few or as many manuscripts as you can handle. To find out how to become a reviewer, read the information on page 162 or visit our Web site at jchemed.chem.wisc.edu/Journal/Reviewers. NACS 3/2000 Reminder NACS 3/2000 is the heading Carolyn Abbott uses in email correspondence about the High School Day program, which be held Monday, March 27, 2000, at the American Chemical Society National Meeting in San Francisco. Carolyn is High School Program Chair and she and her committee have assembled a full day of interesting and useful sessions for teachers. Among the sessions will be three worksh

  12. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    2001-10-01

    JCE publications regularly make connections to a wide variety of interests, of which art is but one. Interdisciplinary Connections is a High School Feature Column designed to meet this challenge. Articles have been published relating literature (2) and writing (3) to chemistry. If you have developed interdisciplinary connections that you would like to share with other teachers, I encourage you to contact the feature editor, Mark Alber.2 Additional examples of annotated bibliographies on chemical connections to other disciplines or applications include food science (4), environmental concerns (5), and writing (6,7). The online "Search" link in the left-hand column of the home page of HS CLIC can lead to the discovery of articles relevant to many other interests. Happy connecting!

    Note

    1. For more information about NCW, visit their Web site.
    2. For the feature mission statement and contact information see the HS CLIC Web site.

    Literature Cited

    1. Chem. Eng. News 2001, 79 (Feb 26), 50.
    2. Thoman, C. J. J. Chem. Educ. 1998, 75, 495.
    3. Alber, M. J. Chem. Educ. 2001, 78, 478.
    4. Jacobsen, E. K. J. Chem. Educ.2000, 77, 1256.
    5. Moore, J. W.; Moore, E. A. J. Chem. Educ. 1976, 53, 167; 1976, 53, 240; 1975, 52, 288.
    6. Shires, N. P. J. Chem. Educ. 1991, 68, 494.
    7. Waterman, E. L. J. Chem. Educ. 1981, 58, 826.

  13. Especially for Teens: Birth Control

    MedlinePlus

    ... which controls the function of female reproductive organs. Human Immunodeficiency Virus (HIV): A virus that attacks certain cells of the body’s immune system and causes acquired immunodeficiency syndrome (AIDS). Pelvic Exam: ...

  14. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    2000-10-01

    Garfield, the feline creation of comic strip artist Jim Davis, hates Mondays with a passion. Many individuals-including chemistry teachers and their students-can identify with Garfield's animosity toward Mondays. But October 23 is a Monday that everyone should look forward to because it is Mole Day. This year's theme is Celebrate the MOLEnnium, and as anticipated, CEO Maury Oheler, President Art Logan, and the foundation board members have done their usual great job of planning an event for building student interest. Check out the National Mole Day Foundation Web site to find more information about the MOLEnnium Celebration and obtain a membership form so that you may obtain the full packet of Mole Day activities. If you do not have access to the Web, you may send 15 new membership (or 10 renewal) with your name, address, telephone number, and email address to National Mole Day Foundation, Inc., 1220 South 5th Street, Prairie du Chien, Wisconsin 53821.

  15. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    2000-02-01

    Secondary School Feature Articles JCE Classroom Activity: #24. The Write Stuff: Using Paper Chromatography to Separate an Ink Mixture, p 176A Teaching Chemistry in the Midwinter Every year, forecasters around the world provide us with long-range predictions of what the seasons will afford us in the coming year. And each year, the weather provides a few surprises that the forecasters did not predict - such as a record amount of snow or record heat indexes, depending on where you live. Although the weatherman didn't predict it, we still must pull out our snow shovels or sun block and take the necessary steps to adapt to the situation. As teachers, we make predictions of teaching and learning goals that we aspire to achieve during a given year, and like the weather, the year brings surprises that aren't in line with our predictions. With that in mind, I would like to offer JCE as the scholastic snow shovel or sun shield you need to jump-start your class and reach the goals you have set. So find a warm (or cool) place, get comfortable, and spend some time with the February issue of JCE. Articles of General Interest in This Issue For readers living where snow falls, Williams's article on page 148 offers some historical background on the use of calcium chloride as a deicer. A diver that depends for its buoyancy upon gas given off by a chemical reaction is described by Derr, Lewis, and Derr in the article beginning on page 171. In her article appearing on pages 249-250, Wang describes a laboratory exercise that makes the mastery of solution preparation skills fun. The students' skill is tested by using the solutions they make to carry out the Briggs-Rauscher oscillating reaction. For high school class applications I recommend use of 3% hydrogen peroxide, described as an option in the article. A well-organized approach to separating an ink mixture, with some possibly new twists, is laid out in the student- and teacher-friendly format of JCE Classroom Activity: #24, pages 176A-176B. Addressing Some Specialized Interests As in any issue of the Journal, there are several articles that are not designated with the secondary school mark (?) but are likely to be of interest to some high school teachers. For example, if you are interested in staying abreast of educational applications of computational chemistry, the articles on pages 199-221 will be among those you will wish to examine even though the focus is on meeting the learning needs of college students. For those with an interest in electronics, there are several articles on pages 252-262, on building on modifying useful devices. Among the topics: building a digital monitor for analyzing spectrophotometer signals, building a digital interface for a graphing calculator, and using an inexpensive commercial analog-to-digital converter. JCE Reviewers The standard of quality in JCE articles is due in great measure to the careful scrutiny and helpful suggestions of reviewers. I am proud to note that the names of several high school teachers are in the list of individuals who have reviewed manuscripts for JCE recently. This month's list, which appears on page 152, is a continuation from page 24 of the January issue. Keep watching if your name has not yet appeared. If you are not currently serving as a reviewer, I encourage you to sign up today. As a reviewer, you would review potential articles that have been submitted to the Journal. You may choose from a variety of subject areas to review and choose as few or as many manuscripts as you can handle. To find out how to become a reviewer, read the information on page 162 or visit our Web site at jchemed.chem.wisc.edu/Journal/Reviewers. NACS 3/2000 Reminder NACS 3/2000 is the heading Carolyn Abbott uses in email correspondence about the High School Day program, which be held Monday, March 27, 2000, at the American Chemical Society National Meeting in San Francisco. Carolyn is High School Program Chair and she and her committee have assembled a full day of interesting and useful sessions for teachers. Among the sessions will be three workshops: CBL (John Heil), Laboratory Safety (James Kaufman), and ICE: Chemistry and Material Science (Kathleen Shanks and David Shaw). John Moore and I will conduct a session in which you are invited to share your thoughts about how the Journal could be made more useful to you. We will also provide an update on the breadth of resources available through JCE. The High School/College Interface Luncheon will feature Michael Tinnesand speaking about teaching resources available from the American Chemical Society. Also, there will be sessions on teaching organic and polymer chemistry, developing survival skills for teaching, and "Living by Chemistry". Several outstanding California teachers are among the presenters of these sessions. NACS 3/2000 is a concise way of reminding those of you who can attend, particularly those teaching in the San Francisco Bay area, to put this important date on the calendar now. More details about the High School Day program, as well as other Division of Chemical Education sessions, will appear in the March issue of JCE.

  16. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    1999-08-01

    Care to Share? An Informal Syllabus Exchange A recent email message from Thomas Shiland, who teaches at Saratoga Springs Senior High School, noted that the process of revising the high school chemistry syllabus is underway in New York State. He expressed a strong interest in helping construct a chemistry syllabus that represents the best thinking about appropriate content. He wondered if it would be possible to develop a way in which different secondary chemistry syllabi could easily be exchanged. It is likely that readers from other states and countries are involved in a similar process and might also be interested in exchanging syllabi. Many states do not use the term syllabus to describe their guiding curricular document for chemistry but rather refer to it as a framework or as guidelines. In most cases, the document includes a list of key ideas or topics, performance indicators, and the major understandings associated with each key idea. Such documents would be appropriate for exchange among those of you involved in the revision process. If you are interested in arranging an exchange please contact me by email at j.e.howell@usm.edu or by mail at J. E. Howell, Box 5043, USM, Hattiesburg, MS39406-5043, USA. High School Day Information The High School Chemistry Program at the American Chemical Society National Meeting in New Orleans, Louisiana will be held Sunday, August 22, 1999, at the Doubletree Hotel, 300 Canal Street. If you wish to register only for the High School Day activities, which includes a pass to the ACS Exposition, a special registration form is available from Lillie Tucker-Akin, 2800 Reynard Dr., Tupelo, MS38801; sci4me@aol.com; fax: 662/566-7906. Advance registration is 25 and the cost of the High School Luncheon is 12. Register in advance by August 1, 1999, or from 7:45 to 8:30 a.m. at the High School Day table in the conference room area of the Doubletree. The workshop schedule is shown below. Secondary School Feature Articles * Exploring the Ocean-Stating the Case for Chemistry, by Paul J. Scheuer, p 1075 * Distillation Apparatuses Using Household Items, by Danielle R. D. Campanizzi, Brenda Mason, Christine K. F. Hermann, p 1079 New Orleans Concurrent Workshops, High School Program 8:30 a.m.-9:20 a.m. A. A Teaching Resource for You: The Journal of Chemical Education, J. E. Howell, J. W. Moore, and A. M. Sarquis B. Electrical Conductivity, J. M. Manion and P. F. Krause, and The Properties of Gases, J.-M. Whitfield and K. A. Woodling C. Chemistry with Calculators for Beginners, P. Sconzo (3 hours) D. Spectrum of Activities for Chemistry Teachers, Carolina Biological Supply, S. Mitchell, F. Cherry, and L. Akin (3 hours) 9:30 a.m.-10:20 a.m. A. Applying Chemical Education Research to the Classroom, L. Akin and J. Valasek B. Another Look at the Deflection of Falling Liquids, H. H. Harris and J. Newstrum, and Encouraging Students to Investigate Acids and Bases Using Plant Indicators, P. K. Kerrigan C. Chemistry with Calculators (continued) D. Spectrum of Activities (continued) E. Science Education for Public Understanding (SEPUP) and Chemistry, Health, Environment, and Me, M. Koker and L. Akin (2 hours) 10:30 a.m.-11:30 a.m. A. Increasing Aptitude and Interest of High School Students through Summer Camp, C. E. Fulton, and Energy Teaching Introduction to High School Chemistry, L.-M. Trejo B. Chemistry in Science Museum Exhibits: Opportunities and Challenges and Cooking with Chemistry, D. Katz C. Chemistry with Calculators (continued) D. Spectrum of Activities (continued) E. SEPUP (continued) 12:00 noon-1:15 p.m., High School Luncheon Educating High School Teachers for the 21st Century, Glenn Crosby 1:30 p.m.-2:20 p.m. A. Customized Mastery Learning in First-Year Chemistry and Computer Software for Chemistry Teachers Who Require Mastery Learning of Their Students, J. Bedenbaugh and A. Bedenbaugh B. Can One Teach Chemistry with Everyday Substances? A. Sae, and SourceBook Activities Using Everyday Substances, C. Ayers, J. Schreck, and M. V. Orna C. Chemistry with Calculators II, P. Sconzo (3 hours) D. An Enlightening Afternoon of Lab Safety, Carolina Biological Supply, J. Kaufman E. Alabama Science in Motion, T. Boman and C. Nassar (90 minutes) 2:30 p.m.-3:20 p.m. A. An Activity to Show Chemistry Students How to Organize Experimentally Determined Information and Using Chemistry to Teach Reasoning Skills, A. Bedenbaugh B. Demonstrations with Gases, M. D. Alexander, and The Ring of Fire with Rubbing Alcohol and a Couple of Others, W. Deese C. Chemistry with Calculators II (continued) D. An Enlightening Afternoon of Lab Safety (continued) E. Alabama Science in Motion (continued) and Buck Scientific, J. DeMenna 3:30 p.m.-4:30 p.m. A. How Flawed Textbook Experiment Can Lead to an Opportunity for Guided Discovery by Students and a Simpler, Better Experiment, J. Bedenbaugh B. Demonstrating Applications of Chemistry with Everyday Substances, D. Katz C. Chemistry with Calculators II (continued) D. An Enlightening Afternoon of Lab Safety (continued) E. Buck Scientific (continued)

  17. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    1999-10-01

    Writing Across the Curriculum The notion that student learning is enhanced through writing is widely accepted at all educational levels if the product is fairly assessed and the learner is provided with feedback. Finding the time to critically evaluate student papers is difficult at best and competes with time needed to prepare laboratory investigations. A few weeks ago a teacher who has extensive extracurricular responsibilities that include extensive interaction with parents and community members shared with me his frustration in not being able to grade written reports. This teacher is the head football coach at his school, but many readers experience the same difficulties due to a variety of duties. There are no easy or completely satisfying answers to this problem, but this issue contains an account of a successful approach (Writing in Chemistry: An Effective Learning Tool, pp 1399-1403). Although they are based on experience in college courses, several ideas described in the article could be applied in high school chemistry courses. In another article, the author of Precise Writing for a Precise Science (pp 1407-1408) identifies 20 examples of familiar, but incorrect, grammatical constructions and explains how to phrase each one correctly. Chemical Education Research: Improving Chemistry Learning The results from research on how students learn have greatly increased our understanding of cognition in recent years. However, the results are often published in the science education research literature and are not readily accessible to the classroom teacher. Additionally, the research reports are couched in specialized terminology. This issue contains a Viewpoints article (pp 1353-1361) that bridges the gap between research results and classroom application. It was written by two veteran chemical educators, Dudley Herron and Susan Nurrenbern. The shift from behaviorism to constructivism as the dominant theory of learning is described briefly to provide a context for constructivist approaches. In the section titled "What Research Has Revealed", the authors provide a succinct summary of specific research findings under three tantalizing subheadings: "What You Think You Know May Not Be the Way It Is", "Learning Is Not a Spectator Sport!", and "Appropriate Outcomes Must Be Identified and Measured". The authors' insight into future research challenges is detailed in a sidebar. ChemEd'99: A Great Success The 1999 ChemEd Conference was a great success, judging by the many very favorable comments of high school teachers who attended. Thanks and congratulations go to Babu George and to the many volunteers who made this event possible through a great deal of hard work, ingenuity, and creativity. Many of the volunteers who gave so generously of their time, before and during the conference, are high school teachers. The program reflected the broad range of needs and interests of high school teachers. Credit for the success also should go to the many presenters. The workshops, demonstrations, papers, and posters that I attended were of high quality and useful to teachers. Conversation with other attendees convinced me that the same degree of quality and utility was characteristic of the entire conference program. Demonstrations are always an outstanding feature of ChemEd conferences and the Signature Demonstrations continued this tradition, as did the large number of demonstration sessions scheduled throughout the general program. The Reg Friesen Memorial Lecture, delivered by Steve Spangler, featured spectacular and stimulating demonstrations in the context of building connections between chemical concepts and real-world applications. Some other themes that permeated the general program were Internet applications, methods of assessment, safety and waste disposal, calculator and computer based laboratory methods, and ideas for making classroom instruction interesting and effective. Thank you to each reader who visited the JCE Exhibit or participated in our workshop on using JCE Activities. We enjoyed talking with you and appreciate the many helpful suggestions and comments. We want to express special thanks to the large number of new subscribers. Finally, the conference was fun. The opening ceremony parade included flags of all countries represented at the conference, individual element flags carried students, and moles of all descriptions. The Lobster/Clam Bake was an obvious success, evidenced by the mountains of mouth-watering food that was consumed. Seeing the periodic table emerge from the assemblage of large blocks of ice was a fitting sequel to witnessing the world's largest periodic table being put together at ChemEd'95 in Norfolk. It is exciting to anticipate how the periodic table might be represented at future ChemEd conferences. Start planning now to attend ChemEd'2001 in Toronto. Mole Day 1999 Remember National Mole Day is October 23! Read about the mole of the year on page 1335. National Chemistry Week 1999 Celebrate National Chemistry Week! starting on November 7th. An announcement on page 1338 describes this year's activity on finding creative uses for sodium polyacrylate. Secondary School Feature Articles * JCE Classroom Activity #20: Cleaning Up with Chemistry: Investigating the Action of Zeolite in Laundry Detergent, p 1416A. * Experiments with Zeolites at the Secondary-School Level: Experience from the Netherlands, by Eric N. Coker, Pamela J. Davis, Aonne Kerkstra, Herman van Bekkum, p 1417.

  18. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    2000-05-01

    JCE Classroom Activity: #27. How Does Your Garden Grow? Investigating the "Magic Salt Crystal Garden", edited by Nancy S. Gettys and Erica K. Jacobsen, p 624A. Some Articles of Interest photos by Jerrold J. Jacobsen and Nancy S. Gettys This month's issue covers a wide variety of topics, from historical notes to the latest software from JCE. Gas burners are such familiar items in the laboratory that little thought is given to their development. An interesting article by Kathryn Williams (pp 558-559) explains how these humble devices came into being, beginning with Robert Bunsen's invention in 1857, through their adaptation in the United States in the 1930s to burn natural gas. Bunsen, in collaboration with Gustav Kirchhoff, used his invention in constructing an emission spectrometer that could be used in chemical analysis. A drawing of the instrument appears in the Williams article. The spectrometer is described in more detail in an article titled "A Brief History of Atomic Emission Spectrochemical Analysis, 1666-1950". Author Richard Jarrell traces the history of this important and lasting method of analysis from Isaac Newton's discovery of the visible spectrum to the development of the powerful analytical instruments that were in use in the 1950s. For readers who have a deeper interest in atomic emission spectroscopy, Jarrell's article is the first of five that are based on a symposium conducted in 1999 (pp 573-607). Visualizing the structure of ionic crystals is the topic of articles by Keenan Dungey (pp 618-619), Bruce Mattson (pp 622-623), and J. Kamenícek and M. Melichárek (pp 623-624). The ionic crystal theme is also carried out in JCE Classroom Activity #27 (pp 624A-B) and a demonstration on the preparation of sodium iodide, written by Zelek Herman (pp 619-621). Together, the five articles provide an interesting combination of ideas for investigating and describing both the macroscopic and the submicroscopic views of ionic crystals. Is It the "Write" Time for You? The end of the school year is approaching quickly. In previous years, several readers have submitted manuscripts soon after the end of the school year, while ideas were fresh in their mind and there was relief from the demands of daily classes. If you have an idea for an article, I encourage you to think about writing as soon as the school term ends. I can probably guess what you are saying, "I don't have anything that readers would be interested in." This is a common reaction, to which we frequently respond by reminding high school teachers that this is "your journal" and the only way to ensure that topics of interest to you are considered or published is by your active participation. In this presidential election year I am reminded of the familiar sentiment, "I voted in the election, so I have earned the right to complain about the politicians." I do not wish to encourage complaining, but there is a relevant correlation. By submitting manuscripts to the Journal, you are ensuring that you will continue to get your money's worth because it will include topics of interest to you. When considering a submission, many prospective authors are overwhelmed at the thought of preparing a complete manuscript. Don't let that stop you. If you have an idea, an outline, or a rough draft, any of the feature editors or I would be happy to discuss it with you. This one-on-one interaction during the development process will help you express your ideas more effectively. Many teachers across the country who are faced with similar situations and problems each day would benefit from an article discussing innovative teaching strategies or a new way to look at principles we teach every year. As you begin to formulate your ideas, I would like to emphasize five features whose editors are fellow teachers:

    • JCE Classroom Activities. An invitation for contributions was issued in the April issue of this column (JCE, 2000, 77, 431).
    • Chemical Principles Revisited, edited by Cary Kilner
    • Interdisciplinary Connections, edited by Mark Alber
    • Second Year and Advanced Placement Chemistry, edited by John Fischer
    • View From My Classroom, edited by David Byrum
    Information about the expectations for each feature and contact information for each feature editor may be found online, http://jchemed.chem.wisc.edu/AboutJCE/Features/index.html. So review the various features today, and drop one of the editors or me an email briefly discussing your idea. We will begin a dialogue to explore the topic more thoroughly and do our best to provide feedback to help you submit the best possible manuscript. If you have selected a topic and are ready to prepare a manuscript for submission, be sure to consult the Guide to Submissions (JCE 2000, 77, 29-30 or http://jchemed.chem.wisc.edu/Journal/Authors/Guidelines.html). If you are considering writing about a laboratory experiment, consult Supplemental Guidelines, JCE Lab-Experiment Manuscripts ( this issue, p 562). We look forward to hearing from you soon.

  19. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    2000-09-01

    Alternative Assessment The trend in several states to use high-stakes achievement test scores to evaluate districts, schools, and teachers appears to be at odds with the intent of the National Science Education Assessment Standards. Recently I read several postings on an Internet discussion list in which several high school teachers expressed differing opinions on how to deal with the situation. There seemed to be general agreement, however, that as increased emphasis is placed on preparation for high-stakes end-of-course examinations it becomes more difficult to assess conceptual understanding. High school chemistry teachers are an innovative lot, and I am confident that ways will be found to evaluate understanding no matter what. This month's issue contains two examples of using student-constructed posters as a means of assessment. Although we most often associate poster presentations with research, such as a science fair project, these articles show that posters may also be used to assess student learning in class settings. The examples are from lower-division college courses, but they may be equally useful in high school chemistry courses. An article titled Using Poster Sessions as an Alternative to Written ExaminationsThe Poster Exam by Pamela Mills and four co-authors contains a detailed explanation of how student-constructed posters can be used to assess student learning. A number of related articles are listed in the Literature Cited section. Another example is found in A Poster Session in Organic Chemistry That Markedly Enhanced Student Learning by P. A. Huddle. The same author also contributed the article How to Present a Paper or Poster in which useful, straightforward suggestions for communicating information and ideas clearly are provided.

  20. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    1999-12-01

    Chemistry and the Environment This issue contains more than 20 articles relating to the environment. Several articles of potential interest are indicated in the Table of Contents with the SSC mark (). Others are not so indicated because they depict use of expensive instrumentation or costly procedures, but if you have an interest in environmental chemistry you may wish to examine all the environmentally related articles. While many of the articles, both marked and unmarked, are targeted to college-level environmental chemistry curricula or to introductory courses for non-major, the methods described in several could be readily adapted to high school chemistry courses. One article likely to be of interest to teachers is found in News from Online, pp 1608-1609. The author explains how to use the U.S. Environment Protection Agency's EnviroMapper Web site to view and query environmental information. She mentioned finding a hazardous waste handler located near her home, so I decided to check the area near my home. I quickly located a natural gas salt dome storage facility marked on the map and, with a few more mouse clicks, I found information that included status of compliance with regulations, amounts of each compound released to the air in tons per year, and how to contact the corporation owning the site. Email and Web site addresses were included for the convenience of anyone wishing to contact the corporation. Students could learn a great deal about where they live that is relevant to chemistry by using the EPA site. Additional Web sites dealing with environmental issues and chemistry are cited in the sidebar at the bottom of p 1609. Among the articles that could be adapted to an advanced high school chemistry class or possibly even to an introductory class is one titled Bridge of Mandolin County (pp 1671-1672). It describes a case-study strategy similar to the scenarios used in ChemStudy. Students analyze information from various sources, including laboratory experiments if desired, discuss their findings, and make a recommendation regarding which of two road deicers should be used on the bridge. The article Pesticides in Drinking Water: Project-Based Learning within the Introductory Chemistry Curriculum (pp 1673-1667) describes class involvement in field data collection and analysis. Since more sophisticated instrumentation than is possessed by many schools is required, 6th grade science and high school chemistry classes work with a college class to obtain and analyze data. Everyone involved in this approach wins. The 6th graders, high school students, and college students all gain experience in sampling, preparing samples for analysis, determining pollutant levels, and drawing conclusions, each at an appropriate level of understanding. Plus, the high school students are exposed to instrumentation that otherwise would not be accessible, such as gas chromatography coupled with mass spectrometry (GC-MS). Although the project described was started by the college faculty members who wrote the article, such an approach to many interesting environmental chemistry problems could be initiated by a high school teacher by seeking out a nearby college or university with whom to partner. An article that probably would not have received the SSC mark had I not noticed that two of the coauthors are high school students, is titled Remediation of Water Contaminated with an Azo Dye (pp 1680-1683). In addition to being interesting, the article is a good reminder that research opportunities for high school students exist. Still another article that received the SSC mark because of a high school connection is Chemical Analysis of Soils (pp 1693-1694). The authors mention that with modification their techniques could be used in high school chemistry. They cite a reference to an article published several years ago, titled Soil Analysis for High School Chemistry Students (J. Chem. Educ. 1980, 57, 897-899). It was published in a feature titled the 50-Minute Experiment. Block scheduling has brought

  1. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    1999-08-01

    Care to Share? An Informal Syllabus Exchange A recent email message from Thomas Shiland, who teaches at Saratoga Springs Senior High School, noted that the process of revising the high school chemistry syllabus is underway in New York State. He expressed a strong interest in helping construct a chemistry syllabus that represents the best thinking about appropriate content. He wondered if it would be possible to develop a way in which different secondary chemistry syllabi could easily be exchanged. It is likely that readers from other states and countries are involved in a similar process and might also be interested in exchanging syllabi. Many states do not use the term syllabus to describe their guiding curricular document for chemistry but rather refer to it as a framework or as guidelines. In most cases, the document includes a list of key ideas or topics, performance indicators, and the major understandings associated with each key idea. Such documents would be appropriate for exchange among those of you involved in the revision process. If you are interested in arranging an exchange please contact me by email at j.e.howell@usm.edu or by mail at J. E. Howell, Box 5043, USM, Hattiesburg, MS39406-5043, USA. High School Day Information The High School Chemistry Program at the American Chemical Society National Meeting in New Orleans, Louisiana will be held Sunday, August 22, 1999, at the Doubletree Hotel, 300 Canal Street. If you wish to register only for the High School Day activities, which includes a pass to the ACS Exposition, a special registration form is available from Lillie Tucker-Akin, 2800 Reynard Dr., Tupelo, MS38801; sci4me@aol.com; fax: 662/566-7906. Advance registration is 25 and the cost of the High School Luncheon is 12. Register in advance by August 1, 1999, or from 7:45 to 8:30 a.m. at the High School Day table in the conference room area of the Doubletree. The workshop schedule is shown below. Secondary School Feature Articles * Exploring the Ocean-Stating the Case for Chemistry, by Paul J. Scheuer, p 1075 * Distillation Apparatuses Using Household Items, by Danielle R. D. Campanizzi, Brenda Mason, Christine K. F. Hermann, p 1079 New Orleans Concurrent Workshops, High School Program 8:30 a.m.-9:20 a.m. A. A Teaching Resource for You: The Journal of Chemical Education, J. E. Howell, J. W. Moore, and A. M. Sarquis B. Electrical Conductivity, J. M. Manion and P. F. Krause, and The Properties of Gases, J.-M. Whitfield and K. A. Woodling C. Chemistry with Calculators for Beginners, P. Sconzo (3 hours) D. Spectrum of Activities for Chemistry Teachers, Carolina Biological Supply, S. Mitchell, F. Cherry, and L. Akin (3 hours) 9:30 a.m.-10:20 a.m. A. Applying Chemical Education Research to the Classroom, L. Akin and J. Valasek B. Another Look at the Deflection of Falling Liquids, H. H. Harris and J. Newstrum, and Encouraging Students to Investigate Acids and Bases Using Plant Indicators, P. K. Kerrigan C. Chemistry with Calculators (continued) D. Spectrum of Activities (continued) E. Science Education for Public Understanding (SEPUP) and Chemistry, Health, Environment, and Me, M. Koker and L. Akin (2 hours) 10:30 a.m.-11:30 a.m. A. Increasing Aptitude and Interest of High School Students through Summer Camp, C. E. Fulton, and Energy Teaching Introduction to High School Chemistry, L.-M. Trejo B. Chemistry in Science Museum Exhibits: Opportunities and Challenges and Cooking with Chemistry, D. Katz C. Chemistry with Calculators (continued) D. Spectrum of Activities (continued) E. SEPUP (continued) 12:00 noon-1:15 p.m., High School Luncheon Educating High School Teachers for the 21st Century, Glenn Crosby 1:30 p.m.-2:20 p.m. A. Customized Mastery Learning in First-Year Chemistry and Computer Software for Chemistry Teachers Who Require Mastery Learning of Their Students, J. Bedenbaugh and A. Bedenbaugh B. Can One Teach Chemistry with Everyday Substances? A. Sae, and SourceBook Activities Using Everyday Substances, C. Ayers, J

  2. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    1998-12-01

    Secondary School Feature Articles * Demonstrations of the Enormity of Avogadro's Number, by Damon Diemente, p 1565. * The Egg in the Bottle Revisited: Air Pressure and Amontons' Law (Charles' Law), by Louis H. Adcock, p 1567 * CD-ROM Spectroscope: A Simple and Inexpensive Tool for Classroom Demonstrations on Chemical Spectroscopy, by Fumitaka Wakabayashi, Kiyohito Hamada, Kozo Sone, p 1569 Environmental Chemistry Resources

  3. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    1999-04-01

    Secondary School Feature Articles * Amino Acid Wordsearch, by Terry L. Helser, p 495. Games, Puzzles, and Humor In honor of April Fools' Day this issue contains 22 pages devoted to games and puzzles that can be used to teach aspects of chemistry. Most are designed for high school and first-year college students. The lead article, p 481, contains an annotated bibliography of chemistry games, complete with a vendor list. Many of the annotated games must be purchased, but the other articles that follow in this issue describe some games and puzzles that require minimal preparation using a word processor and readily available materials. Actually, JCE has a long tradition of publishing games and puzzles for chemistry teachers and their students. Read the letter by Helser and the Editor's response, p 468, for some recent background. Not having counted articles over past years, I became curious and turned to the online index, accessed by way of http://jchemed.chem.wisc.edu/. Because I wanted to search the entire 75-year life of the Journal, I searched titles for the words "game", "puzzle", and "humor" and obtained a total of 85 hits from the three searches. After eliminating titles of articles that were not applicable, I found that at least 25 games, 48 puzzles, and 5 humor articles have appeared during the past 75 years. At an average of one per year, the JCE editors hardly can be accused of frivolity, but game, puzzle, and humor articles have been published. The term "game" did not appear in any titles during 1945-1970, "puzzle" did not appear from 1927 to 1953, and there was no mention of humor (in the titles) prior to 1974. What appears to be the earliest article (1929) about a game was authored by an undergraduate student at the University of Colorado (1). It was titled "Chemical Bank", and the game pieces were tokens cut from cork stoppers. Wire hooks were inserted in the side of the token to represent valence electrons available for bonding. Carbon contained 4 hooks at 90° relative to each other, nitrogen contained three hooks at 120°, etc. The wires were sufficiently long and flexible that multiple bonding could be represented. Each player was dealt several game pieces and the first player received an extra carbon. The objective was to hook pieces together to make an acceptable molecule. Players took turns and the first player to use all his or her pieces was declared the winner. The first crossword puzzle to appear in JCE was written by a high school teacher from Hollywood, California (2). Ruth Van Vleet had observed that her students were caught up in the popularity of crossword puzzles of the time (1925) and used that interest to help students learn chemical facts. The puzzle published in the article was submitted by one of her students after completing one year of chemistry. The first article which carried the term "humor" in the title was published in 1974 (3). To meet the requirements of a class assignment to compare two elements, one student wrote an imaginary dialog between ytterbium and lutetium. Word play and puns were used to described similar and differing properties of the two elements. This article, however, was not the first account of using humor as a vehicle for stimulating student interest. Games, puzzles, and humor certainly can be overused. Usually they do not lead to the development of conceptual understanding. However, appropriate use, as many JCE readers have discovered, can stimulate student interest and reinforce factual knowledge. Some strategy games may help develop problem-solving and critical-thinking skills. The games, humor, and puzzles published in JCE are peer-reviewed so that inaccuracies and errors are not perpetuated. So why not take advantage of this resource? And look forward to next April, or whenever, for more games, puzzles, and humor. Feedback Requested for View from My Classroom Feature David Byrum, editor of the View From My Classroom feature, requests the assistance of readers. During a recent conference on the preparation of new teachers, a question was asked about what specific ideas, procedures, concepts, and skills teachers wished that they had known more about as they started their first job. Some of the responses at the conference were:

    • How to choose which concepts/ideas/skills to teach
    • How to justify which concepts/ideas/skills to leave out
    • How to set up the equipment and supplies needed for common experiments
    • How to choose, set up, and perform useful demonstrations
    • How to order materials and supplies for the classroom and laboratory
    • How district, school, and department budgets work and how to order for the classroom or laboratory
    David would like to know what your thoughts are in regard to the question posed. What would you have liked to know more about as you started your teaching career? What information would have allowed you to miss a few of those potholes in your first few years of teaching? What information would have helped you raise your teaching to a higher level? Please take a few minutes to write your thoughts down and send them to David. Since this should be as quick and painless as possible, email is the preferred method. His email address is DavidB1032@aol.com. If you are without email, please send your comments to David L. Byrum, Flowing Wells High School, 3725 N. Flowing Wells Road, Tucson, AZ 85705. Literature Cited 1. James, H. J. Chem. Educ. 1929, 6, 1790-1792. 2. Van Vleet, R. C. J. Chem. Educ. 1925, 2, 292-294. 3. Levine, B; Myers, S. C. J. Chem. Educ. 1974, 51, 564.

  4. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Emory Howell, J.

    1999-11-01

    More Feature Articles This Month This issue contains a larger-than-usual number of Secondary School Chemistry feature articles (see side-bar). Mary Harris, who teaches in St. Louis, Missouri, and her student, Lauren Picard, contributed an account of student research on the cuprammonium rayon process (p 1512). In addition to being informative and interesting, the article provides a model for student-teacher interaction in carrying out an independent research project. Two North Carolina teachers, Charles Roser and Catherine McCluskey, describe how to use a Calculator Based Laboratory (interface) to measure the kinetics of the reaction that occurs when a lightstick is activated (p 1514). The method and the easy-to-construct device they made could be used with other systems, as well. Don't Throw Away the Carrier Sheet All areas of JCE Online are now accessible to all JCE subscribers. To find out how you can benefit, read the article appearing on p 1599, Now That I Have It, What Can I Do with It? Jon Holmes, Editor of JCE Online, explains in the article how you can use this resource most effectively. Access to several areas, such as full text access to articles, requires that you log in. The mailing label on the carrier sheet that accompanies your Journal each month contains a password that you need to log in. That is why you need to keep the carrier sheet, at least until you have logged in for the first time and either memorized the number or written it in a safe place. Detailed instructions for logging on are found by clicking on the "How to Log On" link, which appears near the upper left corner of the JCE Online Home Page, jchemed.chem.wisc.edu. If you read a school library copy you need to ask your librarian what password you need to log in. Congratulations Among the recipients of the most prestigious American Society Awards (p 1481) are two individuals who have given generously of their time and energy to the cause of chemical education. Both are familiar names to many of our readers. The High School/College Interface Luncheon was part of the very rich day-long High School Program at the New Orleans ACS Meeting. Shown here (from left) are Glenn Crosby, the luncheon speaker; Lillie Tucker-Akin, the High School Day program chair; and Fred Johnson, Assistant Superintendent of Shelby County (TN) schools and Immediate Past President of NSTA. The recipient of the James Bryant Conant Award in High School Chemistry Teaching is Frank G. Cardulla, who taught for many years at Niles North High School, Skokie, Illinois. His extensive record of service to fellow teachers includes editing the JCE "View from My Classroom" feature for several years and writing several articles, as well as his recent appointment to the JCE Board of Publication. The recipient of the George C. Pimentel Award in Chemical Education is Jerry A. Bell of the American Chemical Society in Washington, DC. An author of numerous articles appearing in JCE and a member of the JCE Board of Publication for several years, he currently serves as Board Chair. The 16th Biennial Conference on Chemical Education Readers who attended the 15th BCCE in Waterloo, Ontario, know that much of the programming at these conferences is of interest to high school teachers. Many work shops, papers, and demonstrations are presented by high school teachers. There are many other outstanding papers and posters, plenary speakers, and exciting demonstrations. The 16th BCCE will be held at the University of Michigan in Ann Arbor, July 30-August 3, 2000. Among the high school teachers already scheduled to present workshops at the 16th BCCE are George Hague, Lynn Hershey, and Jack Randall, and there will be many more before the program is completed. The High School Chemistry Program Chair is Tim Graham, Roosevelt High School (MI). The Organizing Committee is seeking the assistance of local sections of the American Chemical Society within a 300-mile radius of

  5. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    1999-04-01

    Secondary School Feature Articles * Amino Acid Wordsearch, by Terry L. Helser, p 495. Games, Puzzles, and Humor In honor of April Fools' Day this issue contains 22 pages devoted to games and puzzles that can be used to teach aspects of chemistry. Most are designed for high school and first-year college students. The lead article, p 481, contains an annotated bibliography of chemistry games, complete with a vendor list. Many of the annotated games must be purchased, but the other articles that follow in this issue describe some games and puzzles that require minimal preparation using a word processor and readily available materials. Actually, JCE has a long tradition of publishing games and puzzles for chemistry teachers and their students. Read the letter by Helser and the Editor's response, p 468, for some recent background. Not having counted articles over past years, I became curious and turned to the online index, accessed by way of http://jchemed.chem.wisc.edu/. Because I wanted to search the entire 75-year life of the Journal, I searched titles for the words "game", "puzzle", and "humor" and obtained a total of 85 hits from the three searches. After eliminating titles of articles that were not applicable, I found that at least 25 games, 48 puzzles, and 5 humor articles have appeared during the past 75 years. At an average of one per year, the JCE editors hardly can be accused of frivolity, but game, puzzle, and humor articles have been published. The term "game" did not appear in any titles during 1945-1970, "puzzle" did not appear from 1927 to 1953, and there was no mention of humor (in the titles) prior to 1974. What appears to be the earliest article (1929) about a game was authored by an undergraduate student at the University of Colorado (1). It was titled "Chemical Bank", and the game pieces were tokens cut from cork stoppers. Wire hooks were inserted in the side of the token to represent valence electrons available for bonding. Carbon contained 4 hooks at 90° relative to each other, nitrogen contained three hooks at 120°, etc. The wires were sufficiently long and flexible that multiple bonding could be represented. Each player was dealt several game pieces and the first player received an extra carbon. The objective was to hook pieces together to make an acceptable molecule. Players took turns and the first player to use all his or her pieces was declared the winner. The first crossword puzzle to appear in JCE was written by a high school teacher from Hollywood, California (2). Ruth Van Vleet had observed that her students were caught up in the popularity of crossword puzzles of the time (1925) and used that interest to help students learn chemical facts. The puzzle published in the article was submitted by one of her students after completing one year of chemistry. The first article which carried the term "humor" in the title was published in 1974 (3). To meet the requirements of a class assignment to compare two elements, one student wrote an imaginary dialog between ytterbium and lutetium. Word play and puns were used to described similar and differing properties of the two elements. This article, however, was not the first account of using humor as a vehicle for stimulating student interest. Games, puzzles, and humor certainly can be overused. Usually they do not lead to the development of conceptual understanding. However, appropriate use, as many JCE readers have discovered, can stimulate student interest and reinforce factual knowledge. Some strategy games may help develop problem-solving and critical-thinking skills. The games, humor, and puzzles published in JCE are peer-reviewed so that inaccuracies and errors are not perpetuated. So why not take advantage of this resource? And look forward to next April, or whenever, for more games, puzzles, and humor. Feedback Requested for View from My Classroom Feature David Byrum, editor of the View From My Classroom feature, requests the assistance of readers. During a recent conference o

  6. Especially for High School Teachers

    NASA Astrophysics Data System (ADS)

    Howell, J. Emory

    2000-05-01

    JCE Classroom Activity: #27. How Does Your Garden Grow? Investigating the "Magic Salt Crystal Garden", edited by Nancy S. Gettys and Erica K. Jacobsen, p 624A. Some Articles of Interest photos by Jerrold J. Jacobsen and Nancy S. Gettys This month's issue covers a wide variety of topics, from historical notes to the latest software from JCE. Gas burners are such familiar items in the laboratory that little thought is given to their development. An interesting article by Kathryn Williams (pp 558-559) explains how these humble devices came into being, beginning with Robert Bunsen's invention in 1857, through their adaptation in the United States in the 1930s to burn natural gas. Bunsen, in collaboration with Gustav Kirchhoff, used his invention in constructing an emission spectrometer that could be used in chemical analysis. A drawing of the instrument appears in the Williams article. The spectrometer is described in more detail in an article titled "A Brief History of Atomic Emission Spectrochemical Analysis, 1666-1950". Author Richard Jarrell traces the history of this important and lasting method of analysis from Isaac Newton's discovery of the visible spectrum to the development of the powerful analytical instruments that were in use in the 1950s. For readers who have a deeper interest in atomic emission spectroscopy, Jarrell's article is the first of five that are based on a symposium conducted in 1999 (pp 573-607). Visualizing the structure of ionic crystals is the topic of articles by Keenan Dungey (pp 618-619), Bruce Mattson (pp 622-623), and J. Kamenícek and M. Melichárek (pp 623-624). The ionic crystal theme is also carried out in JCE Classroom Activity #27 (pp 624A-B) and a demonstration on the preparation of sodium iodide, written by Zelek Herman (pp 619-621). Together, the five articles provide an interesting combination of ideas for investigating and describing both the macroscopic and the submicroscopic views of ionic crystals. Is It the "Write" Time for You? The end of the school year is approaching quickly. In previous years, several readers have submitted manuscripts soon after the end of the school year, while ideas were fresh in their mind and there was relief from the demands of daily classes. If you have an idea for an article, I encourage you to think about writing as soon as the school term ends. I can probably guess what you are saying, "I don't have anything that readers would be interested in." This is a common reaction, to which we frequently respond by reminding high school teachers that this is "your journal" and the only way to ensure that topics of interest to you are considered or published is by your active participation. In this presidential election year I am reminded of the familiar sentiment, "I voted in the election, so I have earned the right to complain about the politicians." I do not wish to encourage complaining, but there is a relevant correlation. By submitting manuscripts to the Journal, you are ensuring that you will continue to get your money's worth because it will include topics of interest to you. When considering a submission, many prospective authors are overwhelmed at the thought of preparing a complete manuscript. Don't let that stop you. If you have an idea, an outline, or a rough draft, any of the feature editors or I would be happy to discuss it with you. This one-on-one interaction during the development process will help you express your ideas more effectively. Many teachers across the country who are faced with similar situations and problems each day would benefit from an article discussing innovative teaching strategies or a new way to look at principles we teach every year. As you begin to formulate your ideas, I would like to emphasize five features whose editors are fellow teachers:

    • JCE Classroom Activities. An invitation for contributions was issued in the April issue of this column (JCE, 2000, 77, 431).
    • Chemical Principles Revisited,

    • Especially for High School Teachers

      NASA Astrophysics Data System (ADS)

      Emory Howell, J.

      1999-11-01

      More Feature Articles This Month This issue contains a larger-than-usual number of Secondary School Chemistry feature articles (see side-bar). Mary Harris, who teaches in St. Louis, Missouri, and her student, Lauren Picard, contributed an account of student research on the cuprammonium rayon process (p 1512). In addition to being informative and interesting, the article provides a model for student-teacher interaction in carrying out an independent research project. Two North Carolina teachers, Charles Roser and Catherine McCluskey, describe how to use a Calculator Based Laboratory (interface) to measure the kinetics of the reaction that occurs when a lightstick is activated (p 1514). The method and the easy-to-construct device they made could be used with other systems, as well. Don't Throw Away the Carrier Sheet All areas of JCE Online are now accessible to all JCE subscribers. To find out how you can benefit, read the article appearing on p 1599, Now That I Have It, What Can I Do with It? Jon Holmes, Editor of JCE Online, explains in the article how you can use this resource most effectively. Access to several areas, such as full text access to articles, requires that you log in. The mailing label on the carrier sheet that accompanies your Journal each month contains a password that you need to log in. That is why you need to keep the carrier sheet, at least until you have logged in for the first time and either memorized the number or written it in a safe place. Detailed instructions for logging on are found by clicking on the "How to Log On" link, which appears near the upper left corner of the JCE Online Home Page, jchemed.chem.wisc.edu. If you read a school library copy you need to ask your librarian what password you need to log in. Congratulations Among the recipients of the most prestigious American Society Awards (p 1481) are two individuals who have given generously of their time and energy to the cause of chemical education. Both are familiar names to many of our readers. The High School/College Interface Luncheon was part of the very rich day-long High School Program at the New Orleans ACS Meeting. Shown here (from left) are Glenn Crosby, the luncheon speaker; Lillie Tucker-Akin, the High School Day program chair; and Fred Johnson, Assistant Superintendent of Shelby County (TN) schools and Immediate Past President of NSTA. The recipient of the James Bryant Conant Award in High School Chemistry Teaching is Frank G. Cardulla, who taught for many years at Niles North High School, Skokie, Illinois. His extensive record of service to fellow teachers includes editing the JCE "View from My Classroom" feature for several years and writing several articles, as well as his recent appointment to the JCE Board of Publication. The recipient of the George C. Pimentel Award in Chemical Education is Jerry A. Bell of the American Chemical Society in Washington, DC. An author of numerous articles appearing in JCE and a member of the JCE Board of Publication for several years, he currently serves as Board Chair. The 16th Biennial Conference on Chemical Education Readers who attended the 15th BCCE in Waterloo, Ontario, know that much of the programming at these conferences is of interest to high school teachers. Many work shops, papers, and demonstrations are presented by high school teachers. There are many other outstanding papers and posters, plenary speakers, and exciting demonstrations. The 16th BCCE will be held at the University of Michigan in Ann Arbor, July 30-August 3, 2000. Among the high school teachers already scheduled to present workshops at the 16th BCCE are George Hague, Lynn Hershey, and Jack Randall, and there will be many more before the program is completed. The High School Chemistry Program Chair is Tim Graham, Roosevelt High School (MI). The Organizing Committee is seeking the assistance of local sections of the American Chemical Society within a 300-mile radius of Ann Arbor in providing support for high school teachers to attend the conference. High school teachers who wish to attend, whether within the 300-mile radius or beyond, are encouraged to contact their local section of the ACS. Information about local sections can be found on the Web at www.acs.org. See p 1482 for more information about the conference, including deadlines for proposals and abstracts and for the conference Web site address. Secondary School Feature Articles * The Chemistry of Modern Dental Filling Materials, by John W. Nicholson and H. Mary Anstice, p 1497 * JCE Classroom Activity #21: Hunting for Chemicals in Consumer Products, p 1504A, by Arthur M. Last * Science for Kids Outreach Programs, by Birgit G. Koehler, Lee Y. Park, and Lawrence J. Kaplan, p 1505 *Henry's Law and Noisy Knuckles by Doris R. Kimbrough, p 1509 *Investigating the Cuprammonium Rayon Process in a High School Laboratory, by Lauren J. Pickard and Mary E. Harris, p 1512 * Lightstick Kinetics, by Charles E. Roser and Catherine L. McCluskey, p 1514

    • Especially for High School Teachers

      NASA Astrophysics Data System (ADS)

      Howell, J. Emory

      2000-06-01

      It Was Nice to See You It was great to meet and talk to so many high school chemistry teachers who attended the High School Program at the ACS National Meeting in San Francisco or attended the NSTA National Convention in Orlando. Thank you to every teacher who visited the JCE Booth at either meeting and to the approximately 100 individuals who attended the JCE workshop early Monday morning at the ACS. At the NSTA meeting, the Mole Day Breakfast was a special occasion that was made very enjoyable by National Mole Day Foundation leaders Art Logan and Maury Oehler and the enthusiasm and camaraderie of the audience. For more about NMDF activities check out the website http://gamstcweb.gisd.k12.mi.us/~nmdf. Bringing Quality Visualization into the Classroom Turn to page 799 of this issue to learn about the release of Chemistry Comes Alive! Volume 4. The Chemistry Comes Alive! series of CD-ROMs are packed with Quicktime movies and still photos depicting chemical reactions, many of which are too hazardous or expensive to carry out in the classroom or laboratory. Many of the demonstrations are accompanied by background information, and they are also correlated with popular chemistry textbooks. An innovation appearing in Volume 4 is an interactive section on reactions in aqueous solution. Among the appealing features of the CCA! series is the ability to incorporate QuickTime movies of these demonstrations into your own presentations. The Reprise of Chemical Principles Revisited I am very pleased that Cary Kilner has agreed to edit the Chemical Principles Revisited feature. Please read his Mission Statement below. If you have an idea for a manuscript that fits this feature, now is the time to take action either by discussing it with Cary or by submitting a manuscript for review. This feature has the potential to be very useful to teachers, but it can reach its potential only through your suggestions and submissions. Let us hear from you soon. Scenes from High School Day at the ACS meeting in San Francisco. (Top photo, left to right) Carolyn Abbott, chair of the program, with Michael Tinnesand and Mare Taagepera. (Bottom photo) Michael Tinnesand speaking at the Luncheon. Photo by Morton Z. Hoffman. Mission Statement for Chemical Principles Revisited W. Cary Kilner, Feature Editor Exeter High School, 7 Salmon Street, Newmarket, NH 03857; 603/659-6825; CaryPQ@aol.com Through this feature, teachers are invited to share how they introduce and present a specific chemical principle, how students investigate the principle or its applications in the laboratory, and how student understanding of this principle is assessed. In most cases the principle would be one that is difficult for students to learn or apply, or one in which chemical research has led to a new understanding that has not yet appeared in textbooks. Discussion of content underlying the principle should provide insight that goes beyond the treatment of high school or general chemistry texts, providing depth that will enable the teacher to become confident in his or her understanding. The account may be a brief vignette that will inspire the reader to try something new and that can be easily implemented. Alternatively, it may be a longer discussion of phenomena that have been neglected or misinterpreted and to which a fresh, reflective, and informed view is provided. An example of a brief article is "The Disappearing Act: Teaching Students to Expect the Unexpected" (J. Chem. Educ. 1987, 64, 155). An example of a longer article is "Studying the Activity Series of Metals" (J. Chem. Educ. 1995, 72, 51), although a current submission should also include discussion of assessment and actual outcomes whenever possible. Teachers who have an idea for an article that fits this mission may contact the feature editor if they have questions.

    • Especially for High School Teachers

      NASA Astrophysics Data System (ADS)

      Howell, J. Emory

      1998-01-01

      Secondary School Feature Articles * Heat Capacity, Body Temperature, and Hypothermia, by Doris Kimbrough, p 48. * The Electromotive Series and Other Non-Absolute Scales, by Gavin Peckham, p 49. * Demonstrations on Paramagnetism with an Electronic Balance, by Adolf Cortel, p 61. * Toward More Performance Evaluation in Chemistry, by Sharon Rasp, p 64. A Wealth of Useful Information

    • Las dificultades de sentir: el rol de las emociones en la estigmatización del VIH/SIDA

      PubMed Central

      MARZÁN-RODRÍGUEZ, Melissa; VARAS-DÍAZ, Nelson

      2009-01-01

      Resumen El Virus de Inmunodeficiencia Humana (VIH) y el Síndrome de Inmunodeficiencia Adquirida (SIDA) han sido motivo de estigmatización para las personas que viven con ellos. Esta estigmatización se ha estudiado consecuentemente desde la perspectiva de opiniones de agentes estigmatizantes. Estas opiniones han obviado sistemáticamente el rol de las emociones en el proceso de estigmatización. Llevamos a cabo este estudio con el propósito de identificar el rol de las emociones en el proceso de estigmatización de las personas que viven con el virus (PVVS) por parte de profesionales de la salud. Para lograr este objetivo utilizamos un diseño exploratorio y cualitativo en el cual utilizamos la técnica de entrevistas semiestructuradas a profundidad. La muestra estuvo compuesta por 80 profesionales de la salud y estudiantes de las siguientes especialidades: psicología, trabajo social, medicina y enfermería. Los resultados reflejaron la existencia de emociones asociadas al VIH/SIDA tales como pena, lástima, compasión, asco, fobia y miedo entre los/as profesionales y estudiantes que participaron. Las personas participantes evidenciaron la necesidad de controlar sus emociones al interactuar con PVVS. Los resultados apuntan a la necesidad de explorar aquellos factores que mediatizan las emociones, tales como el contexto social en que se manifiestan y ante quiénes se revelan, para lograr entender a cabalidad el estigma que rodea al VIH/SIDA. PMID:20212916

    • LAS: a software platform to support oncological data management.

      PubMed

      Baralis, Elena; Bertotti, Andrea; Fiori, Alessandro; Grand, Alberto

      2012-11-01

      The rapid technological evolution in the biomedical and molecular oncology fields is providing research laboratories with huge amounts of complex and heterogeneous data. Automated systems are needed to manage and analyze this knowledge, allowing the discovery of new information related to tumors and the improvement of medical treatments. This paper presents the Laboratory Assistant Suite (LAS), a software platform with a modular architecture designed to assist researchers throughout diverse laboratory activities. The LAS supports the management and the integration of heterogeneous biomedical data, and provides graphical tools to build complex analyses on integrated data. Furthermore, the LAS interfaces are designed to ease data collection and management even in hostile environments (e.g., in sterile conditions), so as to improve data quality.

    • [My interpretation as a pediatrician of "Las Meninas"].

      PubMed

      Valtueña Borque, O

      1999-01-01

      Las Meninas from Velázquez is one of the most important pictures in the world nevertheless, there is not an interpretation out of doubt of his meaning, in spite of all the studies written about it. After an original study of the history of Las Meninas, the persons painted, what are they doing, the Spanish culture on the time in what was painted and the historical life of the Infanta Margarita, the central personage of the picture, the author arrives to the conclusion about the possibility that she had a precocious puberty.

    • Chrysomelids American diabroticines Hosts and natural enemies. Biology-feasibility for control of pest species (Crisomelidos Diabroticinos americanos Hospederos y enemigos naturales Biologia y factibili manejo especies plagas

      Technology Transfer Automated Retrieval System (TEKTRAN)

      The chrysomelids in the Diabroticites include some of the most important pest species of the American continent. The chemical and management techniques used to date to control them are: crop rotation to prevent re-infection of host crops, especially in the species that display an egg diapause; insec...

    • The Role and Tasks of Education in the Politic of Evolution of the Modern World (with Especial Regard to the Developing Countries).

      ERIC Educational Resources Information Center

      Podoski, Kazimierz

      This paper, one of several on the theme of economy and culture in the politics of nation building, was written for the Ninth World Congress of the International Political Science Association. The author's aim is to indicate the role of modern education policy in the world's socio-economic development, especially in developing countries. Access to…

    • The Las Vegas Sustainability Atlas: Modeling Place-based Interactions and Implications in the Las Vegas Valley Bioregion

      NASA Astrophysics Data System (ADS)

      Ego, H.; McCown, K.; Saghafi, N.; Gross, E.; Hunter, W.; Zawarus, P.; Gann, A.; Piechota, T. C.

      2014-12-01

      Las Vegas, Nevada, with 2 million residents and 40 million annual visitors, is one of the driest metropolitan environments of its size in the world. The metro imports nearly all of its resources, including energy, water and food. Rapid population increases, drought, and temperature increases due to climate change create challenges for planning resilient systems in the Las Vegas Valley. Because of its growth rate, aridity, Las Vegas, Nevada is a significant and relevant region for the study of the water, energy, food and climate nexus. Cities in the United States and the world are seeing increasing trends in urbanization and water scarcity. How does the water-energy-climate-food nexus affect each metropolitan area? How can this complex information be used for resiliency planning? How can it be related to the public, so they can understand the issues in a way that makes them meaningful participants in the planning process? The topic of our presentation is a 'resiliency atlas.' The atlas is a place-based model tested in Las Vegas to explore bioregional distinctiveness of the water-energy-climate-food nexus, including regional transportation systems. The atlas integrates the systems within a utilitarian organization of information. Systems in this place-based model demonstrate how infrastructure services are efficiently provided for the Las Vegas Valley population. This resiliency atlas can clarify how the nexus applies to place; and how it can be used to spur geographically germane adaption strategies. In the Las Vegas Valley, climate change (drought and high sustained temperatures) and population affect water, energy, and food systems. This clarity of a place based model can help educate the public about the resilience of their place, and facilitate and organize the planning process in the face of uncertainty.

    • Reading "Las Meninas": An Ekphrastic Approach to Teaching "Don Quijote"

      ERIC Educational Resources Information Center

      Ortuno, Marian

      2012-01-01

      Reading and teaching "Don Quijote" present multiple challenges to twenty-first century students and instructors who are culturally and historically distanced from the seventeenth century. With "Las Meninas" serving as a visual lexicon for cuing correlative themes and events in "Don Quijote", the instructor, through an ekphrastic, interdisciplinary…

    • Disminuyen en los Estados Unidos las infecciones por VPH.

      Cancer.gov

      La infección por los tipos del virus del papiloma humano (VPH) en el blanco de la vacuna cuadrivalente se redujo en casi dos tercios en las adolescentes desde que se recomendó la vacunación en los Estados Unidos.

    • Las Rocas Nos Cuentan (Rocks Tell Their Stories)

      ERIC Educational Resources Information Center

      Llerandi-Roman, Pablo A.

      2012-01-01

      Many Earth science lessons today still focus on memorizing the names of rocks and minerals. This led the author to develop a lesson that reveals the fascinating stories told by rocks through the study of their physical properties. He first designed the lesson for Puerto Rican teachers, hence its Spanish title: "Las Rocas Nos Cuentan Su Historia."…

    • Aeromagnetic map of Nevada: Las Vegas sheet, Map 95

      SciTech Connect

      Saltus, R.W.; Ponce, D.A.

      1988-01-01

      A 1:250,000-scale map showing total intensity of the Earth's magnetic field at intervals of 10 to 500 nanoteslas, and a 1:1,000,000-scale merged aeromagnetic map. The topographic base with drainage pattern and cultural information is from the Las Vegas 1/degree/ by 2/degree/ Quadrangle. (6 refs.)

    • Solar Hot Water for a Motor Inn -- Las Vegas, Nevada

      NASA Technical Reports Server (NTRS)

      1982-01-01

      Solar hot-water installation at motor inn in Las Vegas, Nevada is described in report containing descriptions of design, philosophy, operation of system and problems and solutions. Provides drawings of solar roof plan, operator's instructions, manufacturers' brochures and copy of acceptance report.

  1. Astronomía para ciegos y amblíopes. Proyecto de construcción de un planetario especial en la ciudad de Mar del Plata

    NASA Astrophysics Data System (ADS)

    Musso, S.

    ?`Qué es la Astronomía para Ciegos?. El trabajo es una adaptación en base a la escala de magnitudes de Hipparco que cambia el concepto de luz por una adaptación sonora, donde las estrellas de magnitud 6 se escuchan en 10 dB, más o menos lo que consideramos el umbral de la audición humana. Quienes no escuchan muy bien no pueden escuchar las magnitudes 6, de la misma manera que muchos de nosotros, que no poseemos una visión perfecta, no podemos observar esas mismas estrellas en el cielo (más allá de la polución). A los astros de magnitud 5 vamos a relacionarlos a un sonido en 20 dB. Y así sucesivamente. También los colores estarán representados en una convención de graves a agudos y lo mismo algunas características del cielo. Por ejemplo, la Vía Láctea se mostrará como un ``ruido", como bien nos lo hicieron ver nuestros futuros destinatarios. En Mar del Plata nos encontramos ya trabajando en un proyecto que tiene como objetivo final la construcción del Primer Planetario Acústico del Mundo, una herramienta para la enseñanza de la astronomía, un espacio para la lucha contra la discriminación del discapacitado y una posibilidad de ``ver el cielo de un modo diferente".

  2. Informe Anual a la Nación sobre el Estado del Cáncer con una sección especial sobre la prevalencia d

    Cancer.gov

    El Informe Anual a la Nación sobre el Estado del Cáncer (1975 a 2010), mostró un descenso más acelerado que en años anteriores de los índices de mortalidad por cáncer de pulmón. También contiene una sección especial que destaca los efectos significativos

  3. Perchlorate uptake by salt cedar (Tamarix ramosissima) in the Las Vegas wash riparian ecosystem.

    PubMed

    Urbansky, E T; Magnuson, M L; Kelty, C A; Brown, S K

    2000-07-10

    Perchlorate ion (ClO4-) has been identified in samples of dormant salt cedar (Tamarix ramosissima) growing in the Las Vegas Wash. Perchlorate is an oxidant, but its reduction is kinetically hindered. Concern over thyroid effects caused the Environmental Protection Agency (EPA) to add perchlorate to the drinking water Contaminant Candidate List (CCL). Beginning in 2001, utilities will look for perchlorate under the Unregulated Contaminants Monitoring Rule (UCMR). In wood samples acquired from the same plant growing in a contaminated stream, perchlorate concentrations were found as follows: 5-6 microg g(-1) in dry twigs extending above the water and 300 microg g(-1) in stalks immersed in the stream. Perchlorate was leached from samples of wood, and the resulting solutions were analyzed by ion chromatography after clean-up. The identification was confirmed by electrospray ionization mass spectrometry after complexation of perchlorate with decyltrimethylammonium cation. Because salt cedar is regarded as an invasive species, there are large scale programs aimed at eliminating it. However, this work suggests that salt cedar might play a role in the ecological distribution of perchlorate as an environmental contaminant. Consequently, a thorough investigation of the fate and transport of perchlorate in tamarisks is required to assess the effects that eradication might have on perchlorate-tainted riparian ecosystems, such as the Las Vegas Wash. This is especially important since water from the wash enters Lake Mead and the Colorado River and has the potential to affect the potable water source of tens of millions of people as well as irrigation water used on a variety of crops, including much of the lettuce produced in the USA. PMID:10902849

  4. Regiones de formación de estrellas masivas en las Nubes de Magallanes

    NASA Astrophysics Data System (ADS)

    Barbá, R.; Maíz Apellániz, J.; Rubio, M.; Walborn, N.

    Las Nubes de Magallanes son un laboratorio formidable para el estudio de regiones de formación estelar. A diferencia de lo que sucede en el plano galáctico, ambas galaxias contienen poco polvo que nos afecte la visión directa de dichas regiones. Por otra parte, la menor metalicidad de las Nubes, nos permiten hacer un estudio comparativo de la formación estelar en ambientes de baja metalicidad. El presente trabajo da una revisión de los progresos notables que hemos alcanzado en el conocimiento del contenido estelar de algunas regiones de formación de estrellas masivas en ambas Nubes, en base a la utilización de imágenes del Telescopio Espacial Hubble, Gemini Sur, y Very Large Telescope, entre otros. En especial, nos concentramos en 30 Doradus y N11 en la Nube Mayor, y en NGC 346 en la Nube Menor. Nuevas imágenes de N11 obtenidas en los últimos meses con la Advanced Camera for Surveys del Hubble (óptico), y con Flamingos en Gemini Sur (infrarrojo), nos han permitido descubrir un nuevo `jet' con origen en una fuente infrarroja sumergida en un pilar polvoriento similar al objeto Herbig-Haro de M20 en nuestra galaxia. Este `jet' (junto a otros tres que hemos descubierto en 30 Doradus), es el cuarto ejemplo confirmado de `jet' asociado a una protoestrella fuera de nuestra galaxia. Además, presentamos el descubrimiento del primer objeto estelar joven masivo de la Nube Menor confirmado espectroscópicamente.

  5. Regulatory T cells, especially ICOS+ FOXP3+ regulatory T cells, are increased in the hepatocellular carcinoma microenvironment and predict reduced survival

    PubMed Central

    Tu, Jian-Fei; Ding, Ya-Hui; Ying, Xi-Hui; Wu, Fa-Zong; Zhou, Xin-Mu; Zhang, Deng-Ke; Zou, Hai; Ji, Jian-Song

    2016-01-01

    Hepatocellular carcinoma (HCC) is a common malignant tumour, especially in Asia. Its prognosis is poor, and there are limited methods for predicting patient survival. This study was carried out to analyse the prognostic value of tumour-infiltrating lymphocytes (TILs), especially regulatory T cells (Tregs), in HCC patients. TILs were analysed in 57 randomly selected HCC patients. The prognostic effects of groups with high and low numbers were evaluated by the Kaplan-Meier and Cox model analyses. Although higher densities of CD3+, CD4+, and CD8+ cytotoxic lymphocytes (CTLs) as well as CD56+ NK cells and CD68+ macrophages were observed in peritumoural tissue, increased numbers of forkhead/winged helix transcription factor P3+ (FOXP3+) Tregs were found in intratumoural tissue. Additionally, regarding ICOS+ FOXP3+ Tregs, an increased prevalence in carcinoma was not only associated with the absolute number but also with the percentage of FOXP3+ cells. Higher Treg levels in tumour tissues indicated a worse prognosis, and the FOXP3+ Tregs/CD4+ T cells ratio was an independent prognostic factor for OS. Therefore, FOXP3+ Tregs, especially ICOS+ FOXP3+ Tregs, contribute to the immunosuppressive HCC microenvironment. High tumour-infiltrating Tregs are thought to be an unfavourable prognostic indicator of HCC. PMID:27725696

  6. Near-Ground optical turbulence measurements at Cerro Las Campanas

    NASA Astrophysics Data System (ADS)

    Prieto, G.; Berdja, A.; Thomas-Osip, J. E.

    2011-11-01

    We report preliminary results from Near-Ground optical turbulence measurements carried out at Cerro Las Campanas, the future site of the Giant Magellan Telescope (GMT), using MooSci (Moon Scintillomenter), DIMM (Differential Image Motion Monitor) and MASS (Multiple Aperture Scintillation Sensor), focusing on the effects above the future GMT enclosure. This campaign will continue with future observations of the NGL turbulence in order to better model the adaptive optics performance and aid in the design of the GMT AO instrumentation

  7. Solar hot water system installed at Las Vegas, Nevada

    NASA Technical Reports Server (NTRS)

    1981-01-01

    A solar energy hot water system installed in a motor inn at Las Vegas, Nevada is described. The inn is a three story building with a flat roof for installation of the solar panels. The system consists of 1,200 square feet of liquid flat plate collectors, a 2,500 gallon insulated vertical steel storage tank, two heat exchangers, and pumps and controls. The system was designed to supply approximately 74 percent of the total hot water load.

  8. GIS methodology for quantifying channel change in Las Vegas, Nevada

    USGS Publications Warehouse

    Buckingham, S.E.; Whitney, J.W.

    2007-01-01

    This study applies spatial analyses to examine the consequences of accelerated urban expansion on a hydrologic system over a period of 24 years. Three sets of historical aerial photos are used in a GIS analysis to document the geomorphic history of Las Vegas Wash, which drains the rapidly growing Las Vegas urban area in southern Nevada. New spatial techniques are introduced to make quantitative measurements of the erosion at three specific time intervals in the hydrologic evolution of the channel and floodplain. Unlike other erosion studies that use two different elevation surfaces to assess erosion, this study used a single elevation surface to remove systematic and nonsystemic elevation errors. The spatial analysis quantifies channel changes for discrete time periods, calculates erosion volumes, and provides a foundation to examine how the specific mechanisms related to urban expansion have affected Las Vegas Wash. The erosion calculated over 24 years is the largest documented sediment loss attributed to the effect of rapid urban growth. ?? 2007 American Water Resources Association.

  9. Geology of Las Vegas, Nevada, United States of America

    SciTech Connect

    Wyman, R.V.; Karakouzian, M. ); Bax-Valentine, V. ); Peterson, L.; Palmer, S. ); Slemmons, D.B.

    1993-03-01

    Las Vegas is one of the fastest growing cities in the US. Its regional geologic setting is in the Basin and Range geomorphic province and in the Sevier orogenic belt. The city itself lies in a broad north-south valley formed by coalescing alluvial fans and lake beds which give rise to several soil and foundation problems. Although destructive earthquakes have not occurred in the Las Vegas area in modern times, the record is very short. Major earthquakes could have taken place in the past when the area was unoccupied except for a few nomadic tribes. Studies are underway to better define the seismicity. Although the climate is hot and dry, flash flooding occurs frequently from late summer thunderstorms and torrential rains. The Regional Flood Control District is actively constructing retention basins and drainage improvements for diversion and protection from such floods. Water supply is a problem for the increasing population. The groundwater supply has long been overdrawn, and the allotment to Nevada under the Colorado River Compact will be completely utilized in the near future. Las Vegas has faced the problems of solid waste disposal, water treatment, rational water use, flooding and earthquakes - all of which are related to the unique geologic and geomorphic setting.

  10. Genotyping NUDT15 can predict the dose reduction of 6-MP for children with acute lymphoblastic leukemia especially at a preschool age.

    PubMed

    Suzuki, Hisato; Fukushima, Hiroko; Suzuki, Ryoko; Hosaka, Sho; Yamaki, Yuni; Kobayashi, Chie; Sakai, Aiko; Imagawa, Kazuo; Iwabuchi, Atsushi; Yoshimi, Ai; Nakao, Tomohei; Kato, Keisuke; Tsuchida, Masahiro; Kiyokawa, Nobutaka; Koike, Kazutoshi; Noguchi, Emiko; Fukushima, Takashi; Sumazaki, Ryo

    2016-09-01

    The pharmacokinetics among children has been altered dynamically. The difference between children and adults is caused by immaturity in things such as metabolic enzymes and transport proteins. The periods when these alterations happen vary from a few days to some years after birth. We hypothesized that the effect of gene polymorphisms associated with the dose of medicine could be influenced by age. In this study, we analyzed 51 patients with childhood acute lymphoblastic leukemia (ALL) retrospectively. We examined the associations between the polymorphism in NUDT15 and clinical data, especially the dose of 6-mercaptopurine (6-MP). Ten of the patients were heterozygous for the variant allele in NUDT15. In patients under 7 years old with NUDT15 variant allele, the average administered dose of 6-MP was lower than that for the patients homozygous for the wild-type allele (P=0.04). Genotyping of NUDT15 could be a beneficial to estimate the tolerated dose of 6-MP for patients with childhood ALL, especially at a preschool age in Japan. Furthermore, the analysis with stratification by age might be useful in pharmacogenomics among children.

  11. 40 CFR 81.80 - Las Vegas Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 18 2012-07-01 2012-07-01 false Las Vegas Intrastate Air Quality...) AIR PROGRAMS (CONTINUED) DESIGNATION OF AREAS FOR AIR QUALITY PLANNING PURPOSES Designation of Air Quality Control Regions § 81.80 Las Vegas Intrastate Air Quality Control Region. The Las Vegas...

  12. 40 CFR 81.80 - Las Vegas Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Quality Control Regions § 81.80 Las Vegas Intrastate Air Quality Control Region. The Las Vegas Intrastate Air Quality Control Region (Nevada) has been revised to consist of the territorial area encompassed by... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Las Vegas Intrastate Air...

  13. Source Water Assessment for the Las Vegas Valley Surface Waters

    NASA Astrophysics Data System (ADS)

    Albuquerque, S. P.; Piechota, T. C.

    2003-12-01

    The 1996 amendment to the Safe Drinking Water Act of 1974 created the Source Water Assessment Program (SWAP) with an objective to evaluate potential sources of contamination to drinking water intakes. The development of a Source Water Assessment Plan for Las Vegas Valley surface water runoff into Lake Mead is important since it will guide future work on source water protection of the main source of water. The first step was the identification of the watershed boundary and source water protection area. Two protection zones were delineated. Zone A extends 500 ft around water bodies, and Zone B extends 3000 ft from the boundaries of Zone A. These Zones extend upstream to the limits of dry weather flows in the storm channels within the Las Vegas Valley. After the protection areas were identified, the potential sources of contamination in the protection area were inventoried. Field work was conducted to identify possible sources of contamination. A GIS coverage obtained from local data sources was used to identify the septic tank locations. Finally, the National Pollutant Discharge Elimination System (NPDES) Permits were obtained from the State of Nevada, and included in the inventory. After the inventory was completed, a level of risk was assigned to each potential contaminating activity (PCA). The contaminants of concern were grouped into five categories: volatile organic compounds (VOCs), synthetic organic compounds (SOCs), inorganic compounds (IOCs), microbiological, and radionuclides. The vulnerability of the water intake to each of the PCAs was assigned based on these five categories, and also on three other factors: the physical barrier effectiveness, the risk potential, and the time of travel. The vulnerability analysis shows that the PCAs with the highest vulnerability rating include septic systems, golf courses/parks, storm channels, gas stations, auto repair shops, construction, and the wastewater treatment plant discharges. Based on the current water quality

  14. Posible culto al sol en los grabados rupestres de Las Hurdes (Cáceres).

    NASA Astrophysics Data System (ADS)

    Sevillano, C.

    The author presents a set of rock engravings located in the region of Las Hurdes (Cäceres) a mountainous region to the west of the Central System of the Iberian Peninsula, which present some characteristics different from the other rock engravings known in the Península. In first place the total lack of a narrative character must be underlined, implying that the idea is transmitted through symbols. Essentially the set is formed by geometric scenes, mainly cycles associated with pictures of steps and standing stones. There do exist several schematic motives of weapons and feet as well. On one of the rocks there exists a Roman inscription. The study centers on the circular motives and their associations with other geometric motives, which suggest a possible solar cult, especially in view of the steps which can define the image of a cart, which could be identified with the image of the solar cart. Similarly, on other rock there appear a series of five-spiked stars associated in one case to weapons and in another with foot prints, which provide evidence for a solar cult. In any case, the symbolic character of the figures represented seems to imply the abstraction of a cult, with a magic religious character, in which the idea of the star cult presides the rock symbolism. From the study of the arms represented and because of the Roman inscription one could assign to the set of engravings a chronology which could go from the megalithic to the time of romanization.

  15. Computed tomography imaging spectrometer (CTIS) with 2D reflective grating for ultraviolet to long-wave infrared detection especially useful for surveying transient events

    NASA Technical Reports Server (NTRS)

    Wilson, Daniel W. (Inventor); Maker, Paul D. (Inventor); Muller, Richard E. (Inventor); Mouroulis, Pantazis Z. (Inventor)

    2003-01-01

    The optical system of this invention is an unique type of imaging spectrometer, i.e. an instrument that can determine the spectra of all points in a two-dimensional scene. The general type of imaging spectrometer under which this invention falls has been termed a computed-tomography imaging spectrometer (CTIS). CTIS's have the ability to perform spectral imaging of scenes containing rapidly moving objects or evolving features, hereafter referred to as transient scenes. This invention, a reflective CTIS with an unique two-dimensional reflective grating, can operate in any wavelength band from the ultraviolet through long-wave infrared. Although this spectrometer is especially useful for rapidly occurring events it is also useful for investigation of some slow moving phenomena as in the life sciences.

  16. Single-walled carbon nanohorn (SWNH) aggregates inhibited proliferation of human liver cell lines and promoted apoptosis, especially for hepatoma cell lines

    PubMed Central

    Zhang, Jinqian; Sun, Qiang; Bo, Jian; Huang, Rui; Zhang, Mengran; Xia, Zhenglin; Ju, Lili; Xiang, Guoan

    2014-01-01

    Single-walled carbon nanohorns (SWNHs) may be useful as carriers for anticancer drugs due to their particular structure. However, the interactions between the material itself and cancerous or normal cells have seldom been studied. To address this problem, the effects of raw SWNH material on the biological functions of human liver cell lines were studied. Our results showed that unmodified SWNHs inhibited mitotic entry, growth, and proliferation of human liver cell lines and promoted their apoptosis, especially in hepatoma cell lines. Individual spherical SWNH particles were found inside the nuclei of human hepatoma HepG2 cells and the lysosomes of normal human liver L02 cells, implying that SWNH particles could penetrate into human liver cells_and the different interacted mechanisms on human normal cell lines compared to hepatoma cell lines. Further research on the mechanisms and application in treatment of hepatocellular carcinoma with SWNHs is needed. PMID:24523586

  17. Computed Tomography Imaging Spectrometer (CTIS) with 2D Reflective Grating for Ultraviolet to Long-Wave Infrared Detection Especially Useful for Surveying Transient Events

    NASA Technical Reports Server (NTRS)

    Wilson, Daniel W. (Inventor); Maker, Paul D. (Inventor); Muller, Richard E. (Inventor); Mouroulis, Pantazis Z. (Inventor)

    2003-01-01

    The optical system of this invention is an unique type of imaging spectrometer, i.e. an instrument that can determine the spectra of all points in a two-dimensional scene. The general type of imaging spectrometer under which this invention falls has been termed a computed-tomography imaging spectrometer (CTIS). CTIS's have the ability to perform spectral imaging of scenes containing rapidly moving objects or evolving features, hereafter referred to as transient scenes. This invention, a reflective CTIS with an unique two-dimensional reflective grating, can operate in any wavelength band from the ultraviolet through long-wave infrared. Although this spectrometer is especially useful for events it is also for investigation of some slow moving phenomena as in the life sciences.

  18. Bevacizumab Addition in Neoadjuvant Treatment Increases the Pathological Complete Response Rates in Patients with HER-2 Negative Breast Cancer Especially Triple Negative Breast Cancer: A Meta-Analysis

    PubMed Central

    Zhang, Jing; Zhang, Binglan; Shi, Changle; Liu, Lei

    2016-01-01

    Background Neoadjuvant therapy is administered to breast cancer patients as an induction process before surgery or radiotherapy to reduce tumor size. Human epidermal growth factor receptor-2 (HER-2) negative breast cancer lacks effective standard target therapy. Bevacizumab has a controversial role in the treatment of breast cancer and we conduct a meta-analysis to evaluate the value of adding bevacizumab in neoadjuvant regimen. Methods Potentially eligible studies were retrieved using PubMed, EMBASE and Medline. Clinical characteristics of patients and statistical data with pathological complete response (pCR) data were collected. Then a meta-analysis model was established to investigate the correlation between administration of bevacizumab in neoadjuvant therapy and pCR rates in HER-2 negative breast cancer. Results Seven eligible studies and 5408 patients were yielded. The pCR rates for “breast” or “breast plus lymph node” were similar. In subgroup analysis, we emphasized on patients with triple-negative breast cancer (TNBC). In the criterion of “lesions in breast” the pooled ORs was 1.55 [1.29, 1.86], P<0.00001 and regarding to the evaluation criterion of “lesions in breast and lymph nodes”, the pooled ORs was 1.48 [1.23, 1.78], P<0.0001, in favor of bevacizumab administration. Conclusion According to our pooled results, we finally find that bevacizumab addition as a neoadjuvant chemotherapy component, for induction use with limited cycle to improve the pCR rates and patients may avoid long-term adverse event and long-term invalid survival improvement. Especially in subgroup analysis, pCR rates could be improved significantly and physicians could consider bevacizumab with caution. As patients could avoid the adverse event caused by long-term using of bevacizumab, long-term quality of life improvement may be achieved, especially in TNBC. PMID:27579484

  19. Anaerobic treatment of sludge: focusing on reduction of LAS concentration in sludge.

    PubMed

    Haggensen, F; Mogensen, A S; Angelidaki, I; Ahring, B K

    2002-01-01

    Anaerobic degradation of linear alkylbenzene sulfonates (LAS) was tested in continuous stirred tank reactors (CSTR). LAS12 was used as a model compound and was spiked on sewage sludge. The experiments clearly showed that transformation of LAS12 occurred under anaerobic conditions. The degree oftransformation varied between 14% and 25%. HPLC analysis showed that disappearance of LAS12 was followed by the formation of a metabolite. The experiments indicated that there is a clear correlation between degradation of organic matter contained in sludge and transformation of LAS 12. When the reduction degree of the organic matter increased from 22% to 28%, the transformation degree of LAS12 also increased, from 14% to 20%. Decreasing the total solids concentration of the influent sludge or increasing the spiked concentration of LAS12 did not alter the degree of LAS12 transformation significantly. A clear correlation between transformed and bioavailable LAS12 was found, indicating that it is merely the bioavailable fraction of LAS12 that is transformed by anaerobic digestion. The results from the present study are promising and indicate that a great potential for biological degradation of LAS is possible even at anaerobic conditions.

  20. Las1 Is an Essential Nuclear Protein Involved in Cell Morphogenesis and Cell Surface Growth

    PubMed Central

    Doseff, A. I.; Arndt, K. T.

    1995-01-01

    Saccharomyces cerevisiae mutations that cause a requirement for SSD1-v for viability were isolated, yielding one new gene, LAS1, and three previously identified genes, SIT4, BCK1/SLK1, and SMP3. Three of these genes, LAS1, SIT4, and BCK1/SLK1, encode proteins that have roles in bud formation or morphogenesis. LAS1 is essential and loss of LAS1 function causes the cells to arrest as 80% unbudded cells and 20% large budded cells that accumulate many vesicles at the mother-daughter neck. Overexpression of LAS1 results in extra cell surface projections in the mother cell, alterations in actin and SPA2 localization, and the accumulation of electron-dense structures along the periphery of both the mother cell and the bud. The nuclear localization of LAS1 suggests a role of LAS1 for regulating bud formation and morphogenesis via the expression of components that function directly in these processes. PMID:8582632

  1. Linear alkyl benzene sulphonate (LAS) degradation by immobilized Pseudomonas aeruginosa under low intensity ultrasound.

    PubMed

    Lijun, Xiang; Bochu, Wang; Zhimin, Li; Chuanren, Duan; Qinghong, Wang; Liu, Liu

    2005-01-15

    We studied the LAS degradation of immobilized Pseudomonas aeruginosa with low-intensity ultrasonic and the influence of original LAS concentration, pH, rotary velocity and different conditions of low-intensity ultrasonic irradiation on the degradation of LAS. In our experiment, the degradation rate of LAS was the main index. We found that low-intensity ultrasonic irradiation could improve the metabolism of microorganism cells and promote the LAS biodegradation of immobilized cells. In the experiment, 50 mg/l LAS were used to simulate wastewater, and low-intensity ultrasonic was considered. We found the influence was obvious, and the optimal degradation rate was acquired when the conditions of ultrasonic were frequency 24 kHz, power 8 W, stimulation time 5 s, intermissive time 30 s, and total time 10 min. The LAS degradation rate of immobilized cells with ultrasonic were respectively 40% and 9.5% higher than that of the suspending cells and immobilized cells without irradiation.

  2. Geological Mapping Using Legacy Geophysical Data in Las Vegas Valley

    NASA Astrophysics Data System (ADS)

    Donovan, D.; O'Donnell, J.; McLin, K.

    2014-12-01

    In 2008-2011, Clark County, Building Department contracted with Optim to collect 10,700 Reflection Microtremor (ReMi) 600 ft seismic lines that cover most of the metropolitan area of Las Vegas and other outlying communities such as Moapa, Laughlin, Primm, and Coyote Spring. The County completed their goal of characterizing seismic susceptibility of the top 100 ft and the results are posted at http://gisgate.co.clark.nv.us/openweb/. The research question of the authors is: What additional geologic information can be inferred from the data, either through reprocessing, cross correlation of drill hole data or additional data collection? An advantage of geophysical data is that it can be reprocessed to provide additional insight into the local geologic setting. The interpretation is also improved if combined with drill hole data and / or hydrologic information. It should be noted that there is also legacy geophysical data in limited areas collected by the USGS, primarily in conjunction with water well drilling, where some of the ReMi seismic data was collected. An unexpected result of the ReMi survey was a clear delineation of current and paleo channels in Laughlin, Moapa, and Las Vegas. The geometry of the paleochanel, of the Colorado River, is well away from the current position. however the signal is very similar to modern streams such as the Muddy River. Although the surficial geologic mapping in Las Vegas Valley was very detailed, and importantly, was performed prior to development; the new geophysical data provides better details of the lithologic properties of the units. That is it may be an excellent basis for remapping for specific properties related to engineering and hydrologic modeling.

  3. El libro del Relogio del Palacio de las Horas

    NASA Astrophysics Data System (ADS)

    Morales, J. D.

    2009-08-01

    This paper resume the investigation entitled ``El libro del Relogio del Palacio de las Horas''. That consist in an edition of the original text of the book of the Clock of the Palace of the Hours from the Books of the knowledge of Astronomy of Alfonso X (Manuscript 156, Complutense University). And a description of the astronomical functionality of the Clock of the Palace of the Hours. It includes a geometric description of the positional astronomy on which the operation of the Palace is based.

  4. Characteristics of the Las Vegas/Clark County visitor economy

    SciTech Connect

    1988-06-01

    The purpose of this report is to present the results of a review of the Clark County visitor economy and the Clark County visitor. The review, undertaken in support of NWPO`s two objectives mentioned above, addressed a number of topics including performance of the Clark County visitor economy as a generator of employment, earnings and tax base; importance of the Clark County visitor economy to the Nevada economy as a whole; elements of the Clark County visitor economy outside the Las Vegas strip and downtown areas; current trends in the Clark County visitor industry; and indirect economic effects of Clark County casino/hotel purchases.

  5. Insulin-like growth factor-I (IGF-I) and especially IGF-I variants are anabolic in dexamethasone-treated rats.

    PubMed

    Tomas, F M; Knowles, S E; Owens, P C; Chandler, C S; Francis, G L; Read, L C; Ballard, F J

    1992-02-15

    The administration of insulin-like growth factor-I (IGF-I) via subcutaneously implanted osmotic pumps partially reversed a catabolic state produced by the co-administration of 20 micrograms of dexamethasone/day to 150 g male rats. Marked dose-dependent effects on body weight and nitrogen retention were produced, with the highest IGF-I dose, 695 micrograms/day, giving a 6 g increase in body weight over 7 days, compared with a 19 g loss in the dexamethasone-only group and an 18 g gain in pair-fed controls. Two IGF-I analogues that bind poorly to IGF-binding proteins, the truncated form, des(1-3)IGF-I, and a variant with an N-terminal extension as well as arginine at residue 3, LR3IGF-I, were approx. 2.5-fold more potent than IGF-I. The response with LR3IGF-I was particularly striking because this peptide binds 3-fold less well than IGF-I to the type 1 IGF receptor. The increased potencies of the IGF-I variants may relate to the substantially increased plasma levels of IGF-binding proteins, particularly IGFBP-3, produced by the combined treatment of dexamethasone with IGF-I or the variants. These binding proteins would be expected to decrease the transfer of IGF-I, but not that of the variants, from blood to tissue sites of action. Measurements of muscle protein synthesis at the end of the treatment period and muscle protein breakdown by 3-methylhistidine (3MH) excretion throughout the experiment indicated coordinate anabolic effects of the IGF peptides on both processes. Thus 3MH excretion was decreased at the highest IGF-I dose from 83.5 +/- 4.2 (S.E.M.) mumol/kg per 7 days to 65.1 +/- 2.2, compared with 54.9 +/- 1.2 in the pair-fed controls. Part of this response in 3MH excretion may have reflected a decrease in gut protein breakdown, because IGF-I and especially the IGF analogues increased the gut weight by up to 45%. Notwithstanding the effects on protein synthesis and breakdown, the fractional carcass weights remained low in the IGF-treated groups, although the

  6. Hormonal interference with pheromone systems in parasitic acarines, especially ixodid ticks. Annual technical report No. 4, 1 May 1983-30 April 1984

    SciTech Connect

    Sonenshine, D.E.; Oliver, J.H. Jr.; Homsher, P.J.

    1984-05-01

    The most important result of recent project research was the demonstration of the juvenoid JH III by radioimmunoassay. This assay revealed an estimated 78 pg/tick in the hemolymph of partially fed Hyalomma dromedarii females, and an estimated 3 pg/tick in the hemolymph of partially fed D. variabilis. Other studies, especially digestion of tritium labelled JH III, provided additional evidence suggesting the presence of this hormone in adult ticks. The implications of these findings for our understanding of sex pheromone regulation in ticks is discussed. Other studies described in this report deal with the source of ecdysteroid in teh camel tick, Hyalomma dromedarii, the American dog tick, Dermacentor variabilis, and the soft tick, Ornithodoros parkeri. Studies done at ODU, using radioimmunoassay high performance liquid chromatography, and autoradiography, provide new evidence implicating the tick synganglion - lateral nerve plexus as an important site of ecdysteroid activity in the ixodid ticks. Other studies with ecdysteriods suggest that metabolism of ecdysone or 20-hydroxyecdysone (or both) to inactive metabolites, possibly including polar conjugates. If confirmed, these findings indicate the presence of only a single active ecdysteriod hormone in ticks, 20-hydroxyecdysone.

  7. AM fungi root colonization increases the production of essential isoprenoids vs. nonessential isoprenoids especially under drought stress conditions or after jasmonic acid application.

    PubMed

    Asensio, Dolores; Rapparini, Francesca; Peñuelas, Josep

    2012-05-01

    Previous studies have shown that root colonization by arbuscular mycorrhiza (AM) fungi enhances plant resistance to abiotic and biotic stressors and finally plant growth. However, little is known about the effect of AM on isoprenoid foliar and root content. In this study we tested whether the AM symbiosis affects carbon resource allocation to different classes of isoprenoids such as the volatile nonessential isoprenoids (monoterpenes and sesquiterpenes) and the non-volatile essential isoprenoids (abscisic acid, chlorophylls and carotenoids). By subjecting the plants to stressors such as drought and to exogenous application of JA, we wanted to test their interaction with AM symbiosis in conditions where isoprenoids usually play a role in resistance to stress and in plant defence. Root colonization by AM fungi favoured the leaf production of essential isoprenoids rather than nonessential ones, especially under drought stress conditions or after JA application. The increased carbon demand brought on by AM fungi might thus influence not only the amount of carbon allocated to isoprenoids, but also the carbon partitioning between the different classes of isoprenoids, thus explaining the not previously shown decrease of root volatile isoprenoids in AM plants. We propose that since AM fungi are a nutrient source for the plant, other carbon sinks normally necessary to increase nutrient uptake can be avoided and therefore the plant can devote more resources to synthesize essential isoprenoids for plant growth.

  8. Revision curricular a partir de un analisis comparativo de las discrepancias en los curriculos de una escuela de optometria en Puerto Rico con las competencias requeridas para las agencias de revalida y acreditacion 2004

    NASA Astrophysics Data System (ADS)

    Rivera Pacheco, Andres

    El proposito de esta investigacion, un estudio cualitativo de caso, fue comparar y contrastar el curriculo vigente de la Escuela de Optometria de la UIAPR con las competencias y estandares requeridos por las agencias de acreditacion y de revalida. Con este proposito, decidimos realizar una revision y un analisis de documentos: el prontuario de cada uno de los cursos de los curriculos implantados en el 1993 y en el 2001; las competencias y estandares establecidos por las agencias de revalida y de acreditacion; y las estadisticas en las que se analiza el porcentaje de estudiantes que aprueban cada una de las partes de los examenes de revalida entre el 1998 al 2003. Se realizaron entrevistas dirigidas para dar apoyo y complementar la revision y el analisis de estos documentos. Los participantes de las entrevistas fueron tres estudiantes de la clase de optometria del 2004 (ultima clase del curriculo del 1993); tres estudiantes de la clase de optometria del 2005 (primera clase graduanda del curriculo vigente) y tres profesores y/o directores de los Departamentos de Ciencias Basicas, Ciencias Clinicas y Cuidado al Paciente. Esta investigacion se enmarco en el modelo de evaluacion curricular de discrepancia de Malcolm Provus y en el modelo de desarrollo basado en competencias. Uno de los hallazgos mas importantes del estudio es que los cambios que se implantaron al curriculo del 2001 no han logrado que los estudiantes mejoren su ejecucion en los examenes de revalida. Por otro lado, se encontro que el curriculo vigente atiende completamente los estandares de la practica de Optometria, pero no las competencias. Esta informacion fue validada mediante el uso de una tabla de cotejo para el analisis de los cursos y de la informacion obtenida de las entrevistas. El estudio determina y concluye que existen discrepancias entre los prontuarios de los cursos del curriculo y las competencias requeridas por la agencia de revalida. Segundo, que el Departamento de Ciencias Basicas es el

  9. Insulin-like growth factor-I (IGF-I) and especially IGF-I variants are anabolic in dexamethasone-treated rats.

    PubMed Central

    Tomas, F M; Knowles, S E; Owens, P C; Chandler, C S; Francis, G L; Read, L C; Ballard, F J

    1992-01-01

    The administration of insulin-like growth factor-I (IGF-I) via subcutaneously implanted osmotic pumps partially reversed a catabolic state produced by the co-administration of 20 micrograms of dexamethasone/day to 150 g male rats. Marked dose-dependent effects on body weight and nitrogen retention were produced, with the highest IGF-I dose, 695 micrograms/day, giving a 6 g increase in body weight over 7 days, compared with a 19 g loss in the dexamethasone-only group and an 18 g gain in pair-fed controls. Two IGF-I analogues that bind poorly to IGF-binding proteins, the truncated form, des(1-3)IGF-I, and a variant with an N-terminal extension as well as arginine at residue 3, LR3IGF-I, were approx. 2.5-fold more potent than IGF-I. The response with LR3IGF-I was particularly striking because this peptide binds 3-fold less well than IGF-I to the type 1 IGF receptor. The increased potencies of the IGF-I variants may relate to the substantially increased plasma levels of IGF-binding proteins, particularly IGFBP-3, produced by the combined treatment of dexamethasone with IGF-I or the variants. These binding proteins would be expected to decrease the transfer of IGF-I, but not that of the variants, from blood to tissue sites of action. Measurements of muscle protein synthesis at the end of the treatment period and muscle protein breakdown by 3-methylhistidine (3MH) excretion throughout the experiment indicated coordinate anabolic effects of the IGF peptides on both processes. Thus 3MH excretion was decreased at the highest IGF-I dose from 83.5 +/- 4.2 (S.E.M.) mumol/kg per 7 days to 65.1 +/- 2.2, compared with 54.9 +/- 1.2 in the pair-fed controls. Part of this response in 3MH excretion may have reflected a decrease in gut protein breakdown, because IGF-I and especially the IGF analogues increased the gut weight by up to 45%. Notwithstanding the effects on protein synthesis and breakdown, the fractional carcass weights remained low in the IGF-treated groups, although the

  10. Treatment with insulin analogs, especially Glargine and Lispro, associates with better renal function and higher hemoglobin levels in Type 1 diabetic patients with impaired kidney function

    PubMed Central

    Hasslacher, Christoph; Kulozik, Felix; Lorenzo Bermejo, Justo

    2016-01-01

    Objectives: The influence of type of insulin treatment - insulin analogs versus human insulin - on the development of diabetes related vascular complications has been sparsely investigated. We examine here possible differences regarding kidney function and hemoglobin levels. Methods: Multiple linear regression was used to investigate the relationship between the following characteristics measured in 509 type 1 diabetic patients who were recruited in an outpatient practice: current clinical status and treatment modalities, type of injected insulin and the routine laboratory parameters hemoglobin, HbA1c, serum creatinine, eGFR, hs CRP and urinary albumin/creatinine ratio. Results: Compared with human insulin, multiple regression analysis taking into account possible confounders revealed that treatment with insulin analogs was associated with increased eGFR (+7.1 ml/min; P=0.0002), lower urinary albumin/creatinine ratio (ratio logarithm -0.4; P=0.003) and higher hemoglobin concentration (+0.31 g/dl; P=0.04). Stratification by type of insulin showed the best renal status for treatment with insulins Glargine and Lispro. Differences were consistent both for patients with normal (eGFR → 90 ml/min) and with an impaired (eGFR ← 90 ml/min) kidney function. Conclusions: Present results suggest that treatment of type 1 diabetic patients with normal and impaired renal function with insulin analogs, especially Glargine and Lispro, is associated with better kidney function, lower urinary albumin/creatinine ratio and lower hemoglobin concentration compared to therapy with human insulin. If confirmed by other studies, treatment with insulin analogs may be a further possibility in delaying progression of nephropathy and in preventing early hemoglobin decline. PMID:27540462

  11. TERT rs2736100T/G polymorphism upregulates interleukin 6 expression in non-small cell lung cancer especially in adenocarcinoma.

    PubMed

    Wang, Fuxia; Fu, Ping; Pang, Yixin; Liu, Chengxiang; Shao, Zhulin; Zhu, Jingyan; Li, Jie; Wang, Ti; Zhang, Xia; Liu, Jie

    2014-05-01

    Telomerase reverse transcriptase (TERT) is the catalytic component of telomerase, especially the rate-limiting determinant of telomerase activity. Accumulating evidence has suggested that TERT could modulate the expression of numerous genes including interleukin 6 (IL-6), an important cytokine for the development of lung cancer. It has been reported that TERT polymorphism rs2736100T/G is associated with increased susceptibility to non-small cell lung cancer (NSCLC). However, the mechanism remains unclear. In the current study, we investigated the association between rs2736100T/G and NSCLC in 1,552 NSCLC and 1,602 healthy controls. Data revealed that the prevalence of TG and GG genotypes were significantly elevated in patients than in controls (odds ratio (OR) = 1.18; 95% confidence interval (CI), 1.01-1.39; p = 0.040 and OR = 1.46; 95% CI, 1.19-1.78; p < 0.001, respectively). The association was more prominent in patients with lung adenocarcinoma than those with squamous cell carcinoma (p = 0.039). When analyzing the function of the polymorphism, we observed a significantly augmented level of IL-6 in subjects with GG genotype than those with GT and TT genotypes. Interestingly, the upregulation of IL-6 by GG genotype was 2.3-fold higher in lung adenocarcinoma compared to squamous cell carcinoma. These results suggest that the rs2736100T/G polymorphism modulates IL-6 expression and may play a unique role in lung adenocarcinoma.

  12. Oral administration of ethanol with aspirin increases the concentration of salicylic acid in plasma and organs, especially the brain, in mice.

    PubMed

    Kato, Hideaki; Yoshimoto, Kanji; Kobayashi, Masaki; Sakabe, Masaaki; Funaki, Hironao; Ikegaya, Hiroshi

    2010-06-10

    Aspirin (acetylsalicylic acid) has been widely used as an over-the-counter drug to relieve pain throughout the world. In suicide attempts, aspirin is one of the most common drugs taken in large quantities. The concentration of salicylic acid shows a low-level distribution in the mouse brain, a site that may be critical regarding the expression of symptoms (e.g. hyperpnea, coma, convulsion and tremor) during acute aspirin toxicity. Therefore, it was suggested that sensitivity to salicylic acid concerning acute toxicity was higher in the brain than in other organs. Moreover, it is thought that it is common for aspirin and ethanol to be ingested at the same time. Therefore, the present study was designed to investigate the influence of ethanol on the distribution of salicylic acid, which is a primary metabolite of aspirin, and its related metabolite, salicyluric acid. The oral co-administration of aspirin (0.5g/kg) and ethanol (2.5g/kg; 10ml/kg of 25% (w/v)) enhanced the concentrations of salicylic acid in the plasma and organs, especially in the brain, compared with the aspirin alone-treated group. On the other hand, ethanol did not influence the concentrations of salicyluric acid in the plasma and kidney compared with the aspirin alone-treated group. These results suggest that ethanol enhances aspirin absorption from the gastrointestinal tract but has no influence on its metabolism. Thus, it is dangerous to ingest the alcohol and aspirin at the same time, as this may exacerbate the acute toxicity of aspirin.

  13. In intergroup conflict, self-sacrifice is stronger among pro-social individuals, and parochial altruism emerges especially among cognitively taxed individuals.

    PubMed

    Dreu, Carsten K W De; Dussel, D Berno; Velden, Femke S Ten

    2015-01-01

    Parochial altruism is decomposed in a tendency to benefit the in-group along with a tendency to ignore, derogate, and harm rivaling out-groups. Building off recent work suggesting that decisions to cooperate can be relatively fast and intuitive, we examine parochial altruism in intergroup conflict when cognitive deliberation is rendered difficult or not. Predictions were tested in an experiment using an incentivized Intergroup Prisoner's Dilemma-Maximizing Differences Game with 95 subjects classified as either pro-social or pro-self being randomly allocated to high vs. low impulse-control conditions. Results showed, first of all, that self-sacrificial decisions to contribute were made faster than decisions not to contribute, and that faster decision time associated with more positive expectations of in-group members. Second, we observed that lowering impulse control with a difficult rather than easy Stroop Task increased the amount contributed to a pool that benefited in-group members while harming out-group members; thus reducing deliberation increased parochial altruism. Finally, results replicated earlier work showing that especially pro-social (vs. pro-self) individuals contributed more to the in-group and did not lower their contributions to the between-group pool that benefitted their in-group and, simultaneously, hurt the out-group. This pattern emerged independent of their impulse control. Thus, (in-group bounded) cooperation is more prominent among individuals with strong rather than weak other-regarding preferences. Moreover, the intuitive tendency to cooperate may have evolved in the context of intergroup conflict and therefore is sharp-edged-in-group bounded and including willingness to aggress out-groups.

  14. In intergroup conflict, self-sacrifice is stronger among pro-social individuals, and parochial altruism emerges especially among cognitively taxed individuals

    PubMed Central

    Dreu, Carsten K. W. De; Dussel, D. Berno; Velden, Femke S. Ten

    2015-01-01

    Parochial altruism is decomposed in a tendency to benefit the in-group along with a tendency to ignore, derogate, and harm rivaling out-groups. Building off recent work suggesting that decisions to cooperate can be relatively fast and intuitive, we examine parochial altruism in intergroup conflict when cognitive deliberation is rendered difficult or not. Predictions were tested in an experiment using an incentivized Intergroup Prisoner’s Dilemma–Maximizing Differences Game with 95 subjects classified as either pro-social or pro-self being randomly allocated to high vs. low impulse-control conditions. Results showed, first of all, that self-sacrificial decisions to contribute were made faster than decisions not to contribute, and that faster decision time associated with more positive expectations of in-group members. Second, we observed that lowering impulse control with a difficult rather than easy Stroop Task increased the amount contributed to a pool that benefited in-group members while harming out-group members; thus reducing deliberation increased parochial altruism. Finally, results replicated earlier work showing that especially pro-social (vs. pro-self) individuals contributed more to the in-group and did not lower their contributions to the between-group pool that benefitted their in-group and, simultaneously, hurt the out-group. This pattern emerged independent of their impulse control. Thus, (in-group bounded) cooperation is more prominent among individuals with strong rather than weak other-regarding preferences. Moreover, the intuitive tendency to cooperate may have evolved in the context of intergroup conflict and therefore is sharp-edged—in-group bounded and including willingness to aggress out-groups. PMID:25999888

  15. The motirod: a novel physical skill task that enhances motivation to learn and thereby increases neurogenesis especially in the female hippocampus.

    PubMed

    DiFeo, Gina; Curlik, Daniel M; Shors, Tracey J

    2015-09-24

    Males and females perform differently on a variety of training tasks. In the present study we examined performance of male and female rats while they were trained with a gross motor skill in which they learn to maintain their balance on an accelerating rotating rod (the accelerating rotarod). During training, many animals simply step off the rod, thus terminating the training. This problem was addressed by placing cold water below the rod. We termed the new training procedure "motirod" training because the trained animals were apparently motivated to remain on the rod for longer periods of time. Groups of male and female adult Sprague-Dawley rats were trained on either the standard accelerating rotarod or the motirod for four trials per day on four consecutive days. Latency to fall from the rod (in seconds) was recorded. The motivating feature increased performance especially in females (p=.001). As a consequence of enhanced performance, females retained significantly more new cells in the dentate gyrus of the hippocampus than those trained on the accelerating rotarod or those that received no training. In addition, individuals that learned well retained more new cells, irrespective of sex or task conditions. Previous studies have established that new cells rescued from death by learning remain in the hippocampus for months and mature into neurons (Leuner et al., 2004a; Shors, 2014). These data suggest that sex differences in physical skill learning can arise from sex differences in motivation, which thereby influence how many new neurons survive in the adult brain. This article is part of a Special Issue entitled SI: Brain and Memory.

  16. Plasma brain natriuretic peptide level in older outpatients with heart failure is associated with physical frailty, especially with the slowness domain

    PubMed Central

    Nishiguchi, Shu; Nozaki, Yuma; Yamaji, Masayuki; Oya, Kanako; Hikita, Yuki; Aoyama, Tomoki; Mabuchi, Hiroshi

    2016-01-01

    Objective To determine the association between plasma brain natriuretic peptide (BNP) level in patients with heart failure (HF) and physical frailty as well as with each domain of physical frailty. Methods Two hundred and six outpatients of cardiovascular medicine aged 60 years and older who had been hospitalized for HF or had been given a prescription medication for HF were included. Physical frailty was assessed using the following five domains: slowness, weakness, exhaustion, low activity, and shrinking, according to the Cardiovascular Health Study. Patients were divided into nonfrailty and frailty groups according to frailty scores. Plasma BNP level was measured. The 6-min walk test was performed to measure endurance. Results Plasma BNP was significantly different between the two groups (frailty group: 158.0 ± 214.7 pg/mL, nonfrailty group: 65.2 ± 88.0 pg/mL, P < 0.01). Multivariate logistic regression analysis revealed log-transformed plasma BNP (Log BNP) was significantly associated with physical frailty (OR: 1.68, 95% CI: 1.11–2.56), and Log BNP was significantly associated with the slowness domain (walking speed < 1.0 m/s) of physical frailty (OR: 1.75, 95% CI: 1.15–2.67). Additionally, Log BNP was negatively correlated to the 6-minute walk distance (6MWD) (ρ = −0.37, P < 0.01), while 6MWD was positively correlated to walking speed (ρ = 0.66, P < 0.01). Conclusions Plasma BNP level was related to physical frailty, especially in the slowness domain. Endurance may intervene in the associations between plasma BNP level and walking speed.

  17. How our practice of histopathology, especially tumour pathology has changed in the last two decades: reflections from a major referral center in Pakistan.

    PubMed

    Ahmad, Zubair; Idrees, Romana; Fatima, Saira; Arshad, Huma; Din, Nasir-ud; Memon, Aisha; Minhas, Khurram; Ahmed, Arsalan; Fatima, Syeda Samia; Arif, Muhammad; Ahmed, Rashida; Haroon, Saroona; Pervez, Shahid; Hassan, Sheema; Kayani, Naila

    2014-01-01

    Continued advances in the field of histo-pathology (and cyto-pathology) over the past two decades have resulted in dramatic changes in the manner in which these disciplines are now practiced. This is especially true in the setting of a large university hospital where the role of pathologists as clinicians (diagnosticians), undergraduate and postgraduate educators, and researchers has evolved considerably. The world around us has changed significantly during this period bringing about a considerable change in our lifestyles and the way we live. This is the world of the internet and the world-wide web, the world of Google and Wikipedia, of Youtube and Facebook where anyone can obtain any information one desires at the push of a button. The practice of histo (and cyto) pathology has also evolved in line with these changes. For those practicing this discipline in a poor, developing country these changes have been breathtaking. This is an attempt to document these changes as experienced by histo (and cyto) pathologists practicing in the biggest center for Histopathology in Pakistan, a developing country in South Asia with a large (180 million) and ever growing population. The Section of Histopathology, Department of Pathology and Microbiology at the Aga Khan University Hospital (AKUH) in Karachi, Pakistan's largest city has since its inception in the mid-1980s transformed the way histopathology is practiced in Pakistan by incorporating modern methods and rescuing histopathology in Pakistan from the primitive and outdated groove in which it was stuck for decades. It set histopathology in Pakistan firmly on the path of modernity and change which are essential for better patient management and care through accurate and complete diagnosis and more recently prognostic and predictive information as well.

  18. Plasma brain natriuretic peptide level in older outpatients with heart failure is associated with physical frailty, especially with the slowness domain

    PubMed Central

    Nishiguchi, Shu; Nozaki, Yuma; Yamaji, Masayuki; Oya, Kanako; Hikita, Yuki; Aoyama, Tomoki; Mabuchi, Hiroshi

    2016-01-01

    Objective To determine the association between plasma brain natriuretic peptide (BNP) level in patients with heart failure (HF) and physical frailty as well as with each domain of physical frailty. Methods Two hundred and six outpatients of cardiovascular medicine aged 60 years and older who had been hospitalized for HF or had been given a prescription medication for HF were included. Physical frailty was assessed using the following five domains: slowness, weakness, exhaustion, low activity, and shrinking, according to the Cardiovascular Health Study. Patients were divided into nonfrailty and frailty groups according to frailty scores. Plasma BNP level was measured. The 6-min walk test was performed to measure endurance. Results Plasma BNP was significantly different between the two groups (frailty group: 158.0 ± 214.7 pg/mL, nonfrailty group: 65.2 ± 88.0 pg/mL, P < 0.01). Multivariate logistic regression analysis revealed log-transformed plasma BNP (Log BNP) was significantly associated with physical frailty (OR: 1.68, 95% CI: 1.11–2.56), and Log BNP was significantly associated with the slowness domain (walking speed < 1.0 m/s) of physical frailty (OR: 1.75, 95% CI: 1.15–2.67). Additionally, Log BNP was negatively correlated to the 6-minute walk distance (6MWD) (ρ = −0.37, P < 0.01), while 6MWD was positively correlated to walking speed (ρ = 0.66, P < 0.01). Conclusions Plasma BNP level was related to physical frailty, especially in the slowness domain. Endurance may intervene in the associations between plasma BNP level and walking speed. PMID:27605942

  19. LAS homolog distribution shift during wastewater treatment and composting ecological implications

    SciTech Connect

    Prats, D.; Ruiz, F.; Vazquez, B.; Zarzo, D. . Div. Chemical Engineering); Berna, J.L.; Moreno, A. )

    1993-09-01

    The behavior of LAS (linear alkylbenzene sulfonate) in different environmental compartments was studied through wastewater treatment process steps in sewage treatment plants of Alicante and Benidorm (activated sludge type) as well as in Guardamar (lagoons). The fate of LAS, using a specific HPLC method, was monitored during treatment sludge compostage and soil amendment operations. Finally, the marine sediments close to a submarine wastewater sewer outfall were analyzed. The results show significant differences between distribution of LAS homologs in water and solids (sludges, sediments, and soils), as compared to the original distribution in detergent formulations, yielding a lower LAS average molecular weight in water samples. The change observed in the homolog distribution of LAS implies a reduction in the toxicity to Daphnia, because a lower average molecular weight of LAS is less toxic.

  20. [LOW-FAT, FERMENTED MILK ENRICHED WITH PLANT STEROLS, A STRATEGY TO REDUCE HYPERTRIGLYCERIDEMA IN CHILDREN, A DOUBLE-BLIND, RANDOMIZED PLACEBO-COTROLLED TRIAL].

    PubMed

    Blumenfeld Olivares, Javier Andrés; San Mauro Martín, Ismael; Calle, Maria Elisa; Bischofberger Valdés, Cornelia; Perez Arruche, Eva; Arce Delgado, Esperanza; Ciudad, María Jose; Hernández Cabría, Marta; Collado Yurita, Luis

    2015-09-01

    Introducción: en estos últimos años, paralelamente a la epidemia de obesidad, se ha producido un aumento de las dislipemias en la población pediátrica. En estas dislipemias es posible que los triglicéridos sanguíneos también tengan un papel importante. Los esteroles vegetales se han mostrado eficaces en el tratamiento de la hipercolesterolemia, pero no de la hipertrigliceridemia. Nuestro objetivo en este estudio es determinar la eficacia de la leche enriquecida en fitoesteroles para la disminución de la hipertrigliceridemia en la población infantil. Población y método: se diseñó un ensayo clínico, controlado, aleatorizado, y doble ciego, con leche desnatada enriquecida con esteroles vegetales y leche desnatada no enriquecida. Se incluyeron 67 pacientes pediátricos. Resultados: tras la ingesta observamos diferencias en la trigliceridemia final entre la leche desnatada enriquecida con esteroles vegetales y la leche desnatada no enriquecida con esteroles. El efecto atribuible a la ingesta de la leche enriquecida con fitosteroles vegetales fue de una disminución de 5,88 mg/dl. Conclusión: concluimos que la leche enriquecida con esteroles vegetales (2,24 gr de esteroles vegetales al día) podría constituir una estrategia adecuada para el tratamiento de la hipertrigliceridemia en pacientes pediátricos.

  1. Explicación de las disparidades raciales en la salud neonatal en Brasil*

    PubMed Central

    Nyarko, Kwame A.; López-Camelo, Jorge; Castilla, Eduardo E.; Wehby, George L.

    2015-01-01

    Objetivos. Buscamos cuantificar la manera en que los efectos socioeconómicos, demográficos, geográficos y de atención de salud explican las disparidades raciales en las tasas de bajo peso al nacer y prematuridad en Brasil. Métodos. Utilizamos una muestra de 8 949 niños nacidos entre 1995 y el 2009 en 15 ciudades y 7 provincias de Brasil. Nos centramos en las disparidades en la prevalencia de bajo peso al nacer (< 2 500 g) y prematuridad (< 37 semanas de gestación) en recién nacidos de ascendencia solo africana o mezclada con otras ascendencias y de ascendencia solo europea. Usamos un modelo de descomposición para cuantificar la contribución de los factores conceptualmente pertinentes a esas disparidades. Resultados. El modelo permitió explicar entre 45% y 94% de las disparidades en cuanto al bajo peso al nacer y entre 64% y 94% de las disparidades en cuanto a la prematuridad entre los grupos de ascendencia africana y de ascendencia europea. Las diferencias en el uso de atención prenatal y en la ubicación geográfica fueron los factores más importantes, seguidos por las diferencias socioeconómicas. El modelo permitió explicar la mayoría de las disparidades en los recién nacidos de ascendencia africana mezclada y parte de las disparidades en los de ascendencia solo africana. Conclusiones. En las políticas públicas para mejorar la salud infantil se deben abordar las diferencias en cuanto a la atención prenatal y la ubicación geográfica a fin de reducir las disparidades en materia de salud entre los recién nacidos de ascendencia africana y los de ascendencia europea en Brasil.

  2. City of Las Vegas Plug-in Hybrid Electric Vehicle Demonstration Program

    SciTech Connect

    2013-12-31

    The City of Las Vegas was awarded Department of Energy (DOE) project funding in 2009, for the City of Las Vegas Plug-in Hybrid Electric Vehicle Demonstration Program. This project allowed the City of Las Vegas to purchase electric and plug-in hybrid electric vehicles and associated electric vehicle charging infrastructure. The City anticipated the electric vehicles having lower overall operating costs and emissions similar to traditional and hybrid vehicles.

  3. Environmental levels of Linear alkylbenzene Sulfonates (LAS) in sediments from the Tagus estuary (Portugal): environmental implications.

    PubMed

    Hampel, M; Canário, J; Branco, V; Vale, C; Blasco, J

    2009-02-01

    Sediments from the Tagus estuary (Portugal) were collected at 40 stations in July and December 2004. Total LAS concentrations ranged between 0.03 and 17.76 mg LAS.kg(-1) dry weight in July, and between 0.09 and 9.57 mg LAS.kg(-1) in December. Highest LAS concentrations were found at the upper northern part of the estuary, coincident with the localisation of an important waste water treatment station. According to the Predicted No Effect Concentration (PNEC) of 8.1 mg.kg(-1) derived for this compound, Environmental Risk Assessment (ERA) identified a hazard for the ecosystem at the station with the highest LAS concentration, and similar results are obtained by Equilibrium Partitioning Method (EPM). Nevertheless, LAS concentrations decreased significantly between samplings in the stations with the highest LAS concentrations in July, whereas increased LAS concentrations at adjacent stations were found in December. In the remaining stations, LAS concentrations were up to three orders of magnitude lower, representing no hazard for the sediment community. PMID:18228153

  4. Sloan Digital Sky Survey Infrastructure Preparations at Las Campanas Observatory

    NASA Astrophysics Data System (ADS)

    Hearty, Frederick R.; Wilson, J. C.; Majewski, S. R.; Leger, F.; Harding, P.; Parejko, J. K.; Roman, A.; Ebelke, G.; SDSS-IV; APOGEE-1/2

    2014-01-01

    The Sloan Digital Sky Survey, conducted on the Sloan Foundation Telescope at Apache Point Observatory for the last 15 years, is embarking on a dual hemisphere survey. This next iteration of the survey, termed SDSS-IV, will conduct a portion of the galactic evolution experiment APOGEE in Chile on the du Pont Telescope at the Las Campanas Observatory; critical portions of the Galaxy are best or only accessible in southern skies. The infrastructure for the southern survey will be derived from the mature and productive systems at APO, while the concept of operations will significantly depart from the established SDSS model. Presented herein are the elements that comprise the LCO infrastructure and the rationale for the envisioned survey operations.

  5. Proteus aircraft over Las Cruces International Airport in New Mexico.

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The unique Proteus aircraft served as a test bed for NASA-sponsored flight tests designed to validate collision-avoidance technologies proposed for uninhabited aircraft. The tests, flown over southern New Mexico in March, 2002, used the Proteus as a surrogate uninhabited aerial vehicle (UAV) while three other aircraft flew toward the Proteus from various angles on simulated collision courses. Radio-based 'detect, see and avoid' equipment on the Proteus successfully detected the other aircraft and relayed that information to a remote pilot on the ground at Las Cruces Airport. The pilot then transmitted commands to the Proteus to maneuver it away from the potential collisions. The flight demonstration, sponsored by NASA Dryden Flight Research Center, New Mexico State University, Scaled Composites, the U.S. Navy and Modern Technology Solutions, Inc., were intended to demonstrate that UAVs can be flown safely and compatibly in the same skies as piloted aircraft.

  6. Proteus in flight over mountains near Las Cruces, New Mexico.

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The unique Proteus aircraft served as a test bed for NASA-sponsored flight tests designed to validate collision-avoidance technologies proposed for uninhabited aircraft. The tests, flown over southern New Mexico in March, 2002, used the Proteus as a surrogate uninhabited aerial vehicle (UAV) while three other aircraft flew toward the Proteus from various angles on simulated collision courses. Radio-based 'detect, see and avoid' equipment on the Proteus successfully detected the other aircraft and relayed that information to a remote pilot on the ground at Las Cruces Airport. The pilot then transmitted commands to the Proteus to maneuver it away from the potential collisions. The flight demonstration, sponsored by NASA Dryden Flight Research Center, New Mexico State University, Scaled Composites, the U.S. Navy and Modern Technology Solutions, Inc., were intended to demonstrate that UAVs can be flown safely and compatibly in the same skies as piloted aircraft.

  7. Occurrence and weight-of-evidence risk assessment of alkyl sulfates, alkyl ethoxysulfates, and linear alkylbenzene sulfonates (LAS) in river water and sediments.

    PubMed

    Sanderson, Hans; Dyer, Scott D; Price, Bradford B; Nielsen, Allen M; van Compernolle, Remi; Selby, Martin; Stanton, Kathleen; Evans, Alex; Ciarlo, Michael; Sedlak, Richard

    2006-09-15

    Alkyl sulfates (AS), alkyl ethoxysulfates (AES) and linear alkyl benzene sulfonates (LAS) are all High Production Volume (HPV) and 'down-the-drain' chemicals used globally in detergent and personal care products, resulting in low levels ultimately released to the environment via wastewater effluent. Due to their surfactant properties, they preferentially sorb to sediments. Hence, assessment of their levels and potential perturbations on benthos are of interest. The relative levels of AS/AES decreased with distance from the wastewater treatment plant outfall. However, this was not evident for LAS. Short chained AES and especially AS dominated the homologue distribution for AES. There were no evident patterns in LAS homologue distribution. The overall mean margin of exposure (MoE) for AS/AES and LAS is approximately 40 (range: 3 to 100) suggesting no noteworthy perturbation on biota. The findings in this study are in concordance with previous preliminary hazard screening. Comparative sediment contamination analyses principally based on Chapman and Anderson [Chapman PM, Anderson, J. A decision-making framework for sediment contamination. Integr Environ Assess Mana. 2005; 1: 163-173.] and the U.S. Environmental Protection Agency RAPID assessment methods [USEPA. Rapid bioassessment protocols for use in wadeable streams and rivers: Periphyton, benthic, macroinvertebrates, and fish. 1999. Second Edition. U.S. Environmental Protection Agency Office of Water, Washington, D.C. EPA 841-B-99-002.] did not reveal significant correlations between the surfactant concentrations and ecological status of the sampling locations. Several Lines of Evidence (LoE) of the Weight-of-Evidence (WoE) lead to the conclusion of low aquatic risk associated to the monitored compounds.

  8. Site Response in Las Vegas Valley, Nevada from NTS Explosions and Earthquake Data

    NASA Astrophysics Data System (ADS)

    Rodgers, Arthur; Tkalcic, Hrvoje; McCallen, David; Larsen, Shawn; Snelson, Catherine

    2006-01-01

    We report site response in Las Vegas Valley (LVV) from historical recordings of Nevada Test Site (NTS) nuclear explosions and earthquake recordings from permanent and temporary seismic stations. Our data set significantly improves the spatial coverage of LVV over previous studies, especially in the northern, deeper parts of the basin. Site response at stations in LVV was measured for frequencies in the range 0.2 5.0 Hz using Standard Spectral Ratios (SSR) and Horizontal-Vertical Spectral Ratios (HVR). For the SSR measurements we used a reference site (approximately NEHRP B ``rock'' classification) located on Frenchman Mountain outside the basin. Site response at sedimentary sites is variable in LVV with average amplifications approaching a factor of 10 at some frequencies. We observed peaks in the site response curves at frequencies clustered near 0.6, 1.2 and 2.0 Hz, with some sites showing additional lower amplitude peaks at higher frequencies. The spatial pattern of site response is strongly correlated with the reported depth to basement for frequencies between 0.2 and 3.0 Hz, although the frequency of peak amplification does not show a similar correlation. For a few sites where we have geotechnical shear velocities, the amplification shows a correlation with the average upper 30-meter shear velocities, V 30. We performed two-dimensional finite difference simulations and reproduced the observed peak site amplifications at 0.6 and 1.2 Hz with a low velocity near-surface layer with shear velocities 600 750 m/s and a thickness of 100 200 m. These modeling results indicate that the amplitude and frequencies of site response peaks in LVV are strongly controlled by shallow velocity structure.

  9. Influence of LAS on marine calanoid copepod population dynamics and potential reproduction.

    PubMed

    Christoffersen, Kirsten; Hansen, Benni W; Johansson, Liselotte S; Krog, Elisabeth

    2003-05-29

    The toxicity of linear alkyl benzene sulfonate (LAS) to marine invertebrates is well documented under laboratory conditions using single-species tests. It is less known how LAS affects natural populations of aquatic organisms. We hypothesised that LAS was more toxic to the calanoid copepod Acartia sp. under natural conditions than Acartia tonsa under cultured conditions in the laboratory. This hypothesis was checked by a direct comparison of LAS toxicity in single-species and model (mesocosm) studies. The acute and sublethal effects of LAS on the survival and egg production of laboratory reared A. tonsa were examined by standard test, i.e. incubation with LAS without food for 24-72 h. The LC(50) and EC(50) values averaged 1.23 and 0.74 mg l(-1) for survival and egg production, respectively. These values are comparable to previous reports. The effects of LAS on a natural copepod community were also investigated under in situ conditions. A series of seven mesocosms (holding approx. 3 m(3) of seawater each) was established with two mesocosms being controls without LAS and five mesocosms with increasing concentrations of LAS ranging from 0.1 to 6.5 mg l(-1) applied as a single dose. The indigenous copepod community, dominated by Acartia sp. and Centropages sp., responded clearly to LAS concentrations above 0.1 mg l(-1). The calculated no effect value was 0.14 mg LAS l(-1) (95% CI=0.08-1.82 mg LAS l(-1)) for the entire copepod community including all development stages after 24 h exposure. The increased sensitivity under in situ conditions was probably promoted by the suboptimal growth conditions, e.g. no saturated food concentration or inadequate nutritive values of the food. The amount of food expressed as chlorophyll concentration was low (around 2 microg chl. a l(-1)) but was not affected by LAS. It appeared that the naupliar stages of Acartia and Centropages were the least affected by LAS and that new cohorts were able to develop 15 days after the dosing with LAS.

  10. Las propiedades de las estrellas extrañas en el marco de una nueva ecuación de estado para la materia extraña

    NASA Astrophysics Data System (ADS)

    Lugones, G.; Benvenuto, O. G.

    Se estudian las propiedades generales de las estrellas constituídas por materia extraña (ME) en el marco de una nueva ecuación de estado (EOS) en la que consideramos la masa de los quarks como dependiente del número medio de bariones por unidad de volumen. Se asume esta dependencia de forma que los quarks sean livianos (pesados) a densidades altas (bajas). En esta aproximación, la EOS de la ME es similar a la predicha por el modelo de la Bolsa del MIT, pero es significativamente mas dura a bajas densidades. Esta propiedad modifica las propiedades de las estrellas extrañas en forma notable. Encontramos que, con esta nueva EOS, los objetos pueden ser más masivos que en el caso de la EOS de la bolsa del MIT y que, además, pueden presentar mayores redshifts gravitatorios en hasta un 10%. En el caso de las oscilaciones radiales de estos objetos, calculamos la relación período vs. redshift gravitacional y encontramos una expresión analítica simple para el caso de las oscilaciones de objetos de baja masa. Encontramos que, aún con hipótesis muy diferentes en cuanto a la ecuación de estado de la materia extraña, las propiedades generales de estos objetos no se ve afectada en forma fundamental, y, por lo tanto, no deberían ser muy diferentes de las aquí expuestas.

  11. An EXCEL macro for importing log ASCII standard (LAS) files into EXCEL worksheets

    NASA Astrophysics Data System (ADS)

    Özkaya, Sait Ismail

    1996-02-01

    An EXCEL 5.0 macro is presented for converting a LAS text file into an EXCEL worksheet. Although EXCEL has commands for importing text files and parsing text lines, LAS files must be decoded line-by-line because three different delimiters are used to separate fields of differing length. The macro is intended to eliminate manual decoding of LAS version 2.0. LAS is a floppy disk format for storage and transfer of log data as text files. LAS was proposed by the Canadian Well Logging Society. The present EXCEL macro decodes different sections of a LAS file, separates, and places the fields into different columns of an EXCEL worksheet. To import a LAS file into EXCEL without errors, the file must not contain any unrecognized symbols, and the data section must be the last section. The program does not check for the presence of mandatory sections or fields as required by LAS rules. Once a file is incorporated into EXCEL, mandatory sections and fields may be inspected visually.

  12. Inhibition of biogas production by alkyl benzene sulfonates (LAS) in a screening test for anaerobic biodegradability.

    PubMed

    Garcia, M Teresa; Campos, Encarna; Dalmau, Manel; Illán, Patricia; Sánchez-Leal, Joaquin

    2006-02-01

    The effect of the inoculum source on the digestion of linear alkylbenzene sulfonates (LAS) under anaerobic conditions has been investigated. The potential for primary and ultimate LAS biodegradation of anaerobic sludge samples obtained from wastewater treatment plants (WWTPs) of different geographical locations was studied applying a batch test system. It was found that only 4-22% of the LAS added to the batch anaerobic digesters was primarily transformed suggesting a poor primary degradation of the LAS molecule in anaerobic discontinuous systems. Regarding ultimate biodegradation, the addition of LAS to the batch anaerobic digesters caused a reduction on the extent of biogas production. Significant differences in the inhibition extent of the biogas production were observed (4-26%) depending on the sludge used as inoculum. Effect of the surfactant on the anaerobic microorganisms was correlated with its concentration in the aqueous phase. Sorption of LAS on anaerobic sludge affects its toxicity by depletion of the available fraction of the surfactant. LAS content on sludge was related to the total amount of calcium and magnesium extractable ions. The presence of divalent cations promote the association of LAS with anaerobic sludge reducing its bioavailability and the extent of its inhibitory effect on the biogas production. PMID:16453170

  13. REMOTE SENSING OF PERCHLORATE EFFECTS ON SALT CEDAR PRELIMINARY RESULTS FROM THE LAS VEGAS WASH

    EPA Science Inventory



    Sodium Perchlorate and ammonium Perchlorate, major components of solid rocket fuel, have been manufactured in the Las Vegas Valley immediately up gradient from the Las Vegas Wash, since 1945 and 1956, respectively. Measurements of emerging ground water quality in the vici...

  14. La Noche de las Brujas Module. Nivel Primario. [The Night of the Witches Module. Primary Level.

    ERIC Educational Resources Information Center

    Espinoza, Delia

    La Noche de las Brujas (Halloween) is the topic of this primary level unit. The objectives are to enable the child to: (1) draw scenery, using his imagination, about witches, castles, and devils; (2) write compositions on witches, devils, and Halloween; (3) explain the story "La Noche de las Brujas"; (4) tell about any adventures or incidents he…

  15. 40 CFR 81.80 - Las Vegas Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 17 2011-07-01 2011-07-01 false Las Vegas Intrastate Air Quality Control Region. 81.80 Section 81.80 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) DESIGNATION OF AREAS FOR AIR QUALITY PLANNING PURPOSES Designation of Air Quality Control Regions § 81.80 Las...

  16. FLS2 from Solanum tuberosum have interaction with FlaLas from Candidatus Liberibacter asiaticus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Candidatus Liberibacter asiaticus’ (Las) is a Gram-negative and phloem-limited alphaproteobacterium. Las attacks all citrus species and citrus hybrids in the genus of Citrus and other relatives, and causes a systemic disease. Currently, control of this devastating disease is extremely difficult sinc...

  17. Problem-Solving in Las Vegas: Students Are Building Skills and a Global Network.

    ERIC Educational Resources Information Center

    Budd, Gregory; Curry, Don

    1995-01-01

    Describes a project initiated at Silverado High School in Las Vegas, where students from Las Vegas and schools across the United States monitor the levels of radon in the atmosphere. Enables students to learn first hand about the collection, analysis, and interpretation of scientific data and to network with other students from the United States…

  18. What Providers Should Know about Child Care Assistance for Families: A Targeted Effort to Reach Hispanic Families and Providers = Lo que Deben Saber los Proveedores Sobre el Programa de Ayuda de Cuidado Infantil para las Familias: Un Esfuerzo Especial para Alcanzar Familias y Proveedores Hispanos

    ERIC Educational Resources Information Center

    Child Care Bureau, 2004

    2004-01-01

    Federal and State governments can help families pay for child care. The families one serves may be eligible for this assistance, and one may receive this funding for services one provides, thus becoming a "participating provider." This paper provides answers to the following questions: (1) How can parents receive child care assistance?; (2) How do…

  19. Earthquake Hazard Class Mapping by Parcel in Las Vegas Valley

    NASA Astrophysics Data System (ADS)

    Pancha, A.; Pullammanappallil, S.; Louie, J. N.; Hellmer, W. K.

    2011-12-01

    Clark County, Nevada completed the very first effort in the United States to map earthquake hazard class systematically through an entire urban area. The map is used in development and disaster response planning, in addition to its direct use for building code implementation and enforcement. The County contracted with the Nevada System of Higher Education to classify about 500 square miles including urban Las Vegas Valley, and exurban areas considered for future development. The Parcel Map includes over 10,000 surface-wave array measurements accomplished over three years using Optim's SeisOpt° ReMi measurement and processing techniques adapted for large scale data. These array measurements classify individual parcels on the NEHRP hazard scale. Parallel "blind" tests were conducted at 93 randomly selected sites. The rms difference between the Vs30 values yielded by the blind data and analyses and the Parcel Map analyses is 4.92%. Only six of the blind-test sites showed a difference with a magnitude greater than 10%. We describe a "C+" Class for sites with Class B average velocities but soft surface soil. The measured Parcel Map shows a clearly definable C+ to C boundary on the west side of the Valley. The C to D boundary is much more complex. Using the parcel map in computing shaking in the Valley for scenario earthquakes is crucial for obtaining realistic predictions of ground motions.

  20. Loose Groups of Galaxies in the Las Campanas Redshift Survey

    NASA Astrophysics Data System (ADS)

    Tucker, Douglas L.; Oemler, Augustus, Jr.; Hashimoto, Yasuhiro; Shectman, Stephen A.; Kirshner, Robert P.; Lin, Huan; Landy, Stephen D.; Schechter, Paul L.; Allam, Sahar S.

    2000-10-01

    A ``friends-of-friends'' percolation algorithm has been used to extract a catalog of δn/n=80 density enhancements (groups) from the six slices of the Las Campanas Redshift Survey (LCRS). The full catalog contains 1495 groups and includes 35% of the LCRS galaxy sample. A clean sample of 394 groups has been derived by culling groups from the full sample that either are too close to a slice edge, have a crossing time greater than a Hubble time, have a corrected velocity dispersion of zero, or contain a 55" ``orphan'' (a galaxy with a mock redshift that was excluded from the original LCRS redshift catalog due to its proximity to another galaxy-i.e., within 55"). Median properties derived from the clean sample include a line-of-sight velocity dispersion σlos=164 km s-1, crossing time tcr=0.10 H-10, harmonic radius Rh=0.58 h-1 Mpc, pairwise separation Rp=0.64 h-1 Mpc, virial mass Mvir=1.90×1013 h-1 Msolar, total group R-band luminosity Ltot=1.30×1011 h-2 Lsolar, and R-band mass-to-light ratio M/L=171 h Msolar/Lsolar the median number of observed members in a group is three.

  1. Atmospheric Radioxenon Measurements in North Las Vegas, NV

    SciTech Connect

    Milbrath, Brian D.; Cooper, Matthew W.; Lidey, Lance S.; Bowyer, Ted W.; Hayes, James C.; McIntyre, Justin I.; Karr, L.; Shafer, D.; Tappen, J.

    2006-07-31

    PNNL deployed the ARSA radioxenon measurement system in North Las Vegas for two weeks in February and March 2006 for the purpose of measuring the radioxenon background at a level of sensitivity much higher than previously done in the vicinity of the NTS. The measurements establish what might be expected if future measurements are taken at NTS itself. The measurements are also relevant to test site readiness. A second detector, the PEMS, built and operated by DRI, was deployed in conjunction with the ARSA and contained a PIC, aerosol collection filters, and meteorological sensors. Originally, measurements were also to be performed at Mercury, NV on the NTS, but these were canceled due to initial equipment problems with the ARSA detector. Some of the radioxenon measurements detected 133Xe at levels up to 3 mBq/m3. This concentration of radioxenon is consistent with the observation of low levels of radioxenon emanating from distance nuclear reactors. Previous measurements in areas of high nuclear reactor concentration have shown similar results, but the western US, in general, does not have many nuclear reactors. Measurements of the wind direction indicate that the air carrying the radioxenon came from south of the detector and not from the NTS.

  2. The vitamin riboflavin and its derivative lumichrome activate the LasR bacterial quorum sensing receptor

    PubMed Central

    Rajamani, Sathish; Bauer, Wolfgang D.; Robinson, Jayne B.; Farrow, John M.; Pesci, Everett C.; Teplitski, Max; Gao, Mengsheng; Sayre, Richard T.; Phillips, Donald A.

    2013-01-01

    Many bacteria use quorum sensing (QS) as an intercellular signaling mechanism to regulate gene expression in local populations. Plant and algal hosts, in turn, secrete compounds that mimic bacterial QS signals, allowing these hosts to manipulate QS-regulated gene expression in bacteria. Lumichrome, a derivative of the vitamin riboflavin, was purified and chemically identified from culture filtrates of the alga Chlamydomonas as a QS signal-mimic compound capable of stimulating the Pseudomonas aeruginosa LasR QS receptor. LasR normally recognizes the N-acyl homoserine lactone (AHL) signal, N-3-oxo-dodecanoyl homoserine lactone (3-oxo-C12-HSL). Authentic lumichrome and riboflavin stimulated the LasR receptor in bioassays, and lumichrome activated LasR in gel shift experiments. Amino acid substitutions in LasR residues required for AHL binding altered responses to both AHLs and lumichrome/riboflavin. These results and docking studies indicate that the AHL binding pocket of LasR recognizes both AHLs and the structurally dissimilar lumichrome/riboflavin. Bacteria, plants and algae commonly secrete riboflavin and/or lumichrome, raising the possibility that these compounds could serve as either QS signals or as interkingdom signal-mimics capable of manipulating QS in bacteria with a LasR-like receptor. PMID:18700823

  3. European risk assessment of LAS in agricultural soil revisited: species sensitivity distribution and risk estimates.

    PubMed

    Jensen, John; Smith, Stephen R; Krogh, Paul Henning; Versteeg, Donald J; Temara, Ali

    2007-10-01

    Linear alkylbenzene sulphonate (LAS) is used at a rate of approximately 430,000 tons/y in Western Europe, mainly in laundry detergents. It is present in sewage sludge (70-5,600 mg/kg; 5-95th percentile) because of its high usage per capita, its sorption and precipitation in primary settlers, and its lack of degradation in anaerobic digesters. Immediately after amendment, calculated and measured concentrations are <1 to 60 mg LAS/kg soil. LAS biodegrades rapidly in soil with primary and ultimate half-lives of up to 7 and 30 days, respectively. Calculated residual concentrations after the averaging time (30 days) are 0.24-18 mg LAS/kg soil. The long-term ecotoxicity to soil microbiota is relatively low (EC10 >or=26 mg sludge-associated LAS/kg soil). An extensive review of the invertebrate and plant ecotoxicological data, combined with a probabilistic assessment approach, led to a PNEC value of 35 mg LAS/kg soil, i.e. the 5th percentile (HC5) of the species sensitivity distribution (lognormal distribution of the EC10 and NOEC values). Risk ratios were identified to fall within a range of 0.01 (median LAS concentration in sludge) to 0.1 (95th percentile) and always below 0.5 (maximum LAS concentration measured in sludge) according to various scenarios covering different factors such as local sewage influent concentration, water hardness, and sewage sludge stabilisation process. Based on the present information, it can be concluded that LAS does not represent an ecological risk in Western Europe when applied via normal sludge amendment to agricultural soil. PMID:17765285

  4. Managing Floods and Resources at the Arroyo Las Positas

    SciTech Connect

    Sanchez, L; Van Hattem, M; Mathews, S

    2002-03-05

    Engineers and water resource professionals are challenged with protecting facilities from flood events within environmental resource protection, regulatory, and economic constraints. One case in point is the Arroyo Las Positas (ALP), an intermittent stream that traverses the Lawrence Livermore National Laboratory (LLNL) in Livermore, California. Increased runoff from post-drought rainfall, upstream development, and new perennial discharges from LLNL activities have resulted in increased dry weather flows and wetland vegetation. These new conditions have recently begun to provide improved habitat for the federally threatened California red-legged frog (Rana aurora draytonii; CRLF), but the additional vegetation diminishes the channel's drainage capacity and increases flood risk. When LLNL proposed to re-grade the channel to reestablish the 100-year flood capacity, traditional dredging practices were no longer being advocated by environmental regulatory agencies. LLNL therefore designed a desilting maintenance plan to protect LLNL facility areas from flooding, while minimizing impacts to wetland resources and habitat. The result was a combination of structural upland improvements and the ALP Five Year Maintenance Plan (Maintenance Plan), which includes phased desilting in segments so that the entire ALP is desilted after five years. A unique feature of the Maintenance Plan is the variable length of the segments designed to minimize LLNL's impact on CRLF movement. State and federal permits also added monitoring requirements and additional constraints on desilting activities. Two years into the Maintenance Plan, LLNL is examining the lessons learned on the cost-effectiveness of these maintenance measures and restrictions and reevaluating the direction of future maintenance activities.

  5. Effects of linear alkylbenzene sulfonate (LAS) on the interspecific competition between Microcystis and Scenedesmus.

    PubMed

    Zhu, Wei; Chen, Huaimin; Guo, Lili; Li, Ming

    2016-08-01

    The widespread use of detergents increases the concentration of surfactant in lakes and reservoirs. High surfactant loads produces toxicity to algae; however, the influence of the increasing surfactant on the competition between algae is not clear. In this paper, different amounts of linear alkylbenzene sulfonate (LAS) were added to test the effects of LAS on the competition between Microcystis aeruginosa and Scenedesmus obliquus under eutrophic condition. In single culture, the growth of S. obliquus was promoted under lower LAS concentrations (1 and 20 mg L(-1)), but cell density of S. obliquus reduced when treated with higher LAS concentration (100 mg L(-1)). The growth of M. aeruginosa was inhibited markedly with 20 and 100 mg L(-1) LAS. Compared with single culture, the result was opposite in co-cultures and the cell density of S. obliquus increased significantly when treated with LAS of 1, 20, and 100 mg L(-1). The specific growth rates of S. obliquus and M. aeruginosa in both cultures were 0.4-0.5 day(-1) and 0.6-0.7 day(-1), respectively, except that the specific growth rate of M. aeruginosa in both cultures treated with 100 mg L(-1) LAS was about 0.2 day(-1). M. aeruginosa dominated over S. obliquus in the co-culture without LAS, while the competition was completely opposite with the addition of 20 mg L(-1) LAS. The growth of S. obliquus treated with 20 mg L(-1) LAS was not affected significantly in single culture but was promoted by 75 % in co-culture. Moreover, the growth of S. obliquus in co-culture treated with 100 mg L(-1) LAS was promoted by more than 97 %. These results suggested that the increasing LAS would overturn the competition of algae in freshwater ecosystems. PMID:27154838

  6. Effects of linear alkylbenzene sulfonate (LAS) on the interspecific competition between Microcystis and Scenedesmus.

    PubMed

    Zhu, Wei; Chen, Huaimin; Guo, Lili; Li, Ming

    2016-08-01

    The widespread use of detergents increases the concentration of surfactant in lakes and reservoirs. High surfactant loads produces toxicity to algae; however, the influence of the increasing surfactant on the competition between algae is not clear. In this paper, different amounts of linear alkylbenzene sulfonate (LAS) were added to test the effects of LAS on the competition between Microcystis aeruginosa and Scenedesmus obliquus under eutrophic condition. In single culture, the growth of S. obliquus was promoted under lower LAS concentrations (1 and 20 mg L(-1)), but cell density of S. obliquus reduced when treated with higher LAS concentration (100 mg L(-1)). The growth of M. aeruginosa was inhibited markedly with 20 and 100 mg L(-1) LAS. Compared with single culture, the result was opposite in co-cultures and the cell density of S. obliquus increased significantly when treated with LAS of 1, 20, and 100 mg L(-1). The specific growth rates of S. obliquus and M. aeruginosa in both cultures were 0.4-0.5 day(-1) and 0.6-0.7 day(-1), respectively, except that the specific growth rate of M. aeruginosa in both cultures treated with 100 mg L(-1) LAS was about 0.2 day(-1). M. aeruginosa dominated over S. obliquus in the co-culture without LAS, while the competition was completely opposite with the addition of 20 mg L(-1) LAS. The growth of S. obliquus treated with 20 mg L(-1) LAS was not affected significantly in single culture but was promoted by 75 % in co-culture. Moreover, the growth of S. obliquus in co-culture treated with 100 mg L(-1) LAS was promoted by more than 97 %. These results suggested that the increasing LAS would overturn the competition of algae in freshwater ecosystems.

  7. Microbial mineralization of IsoLAS in activated sludge, aquatic and soil systems

    SciTech Connect

    Nielsen, A.M.; Beall, C.E.; Britton, L.N.; Russell, G.L.

    1995-12-31

    IsoLAS is a minor component (< 1 % to 6%) in commercial linear alkylbenzene sulfonate (LAS). It consists of two types (1 and 2). IsoLAS type 1 molecules have a single methyl group attached to non-benzylic carbons of the alkyl chain. IsoLAS type 2 molecules have a single methyl group attached to the benzylic carbon. A [{sup 14}C]-benzene ring-labeled C{sub 12}, LAS and four [{sup 14}C]-benzene ring-labeled single methyl branched alkylbenzene sulfonates (IsoLAS) were synthesized and tested. They were: Type 1A-Sodium 5-methyl-2-undecyl [{sup 14}C]benzene sulfonate, Type 1B-Sodium 5-methyl-5-undecyl [{sup 14}C]benzene sulfonate, Type 2A-Sodium 2-methyl-2undecyl [{sup 14}C]benzene sulfonate, Type 2B-Sodium 5-methyl-5-undecyl [{sup 14}C]benzene sulfonate. Mineralization results during the steady state operation of the continuous flow porous pot activated sludge laboratory test systems were: C{sub 12} LAS-58%, type 1A-53%, type 1B-58%, type 2A-52% and type 2B-8%. All except type 2B showed about 30% of the radioactivity in the biomass and 10--20% in the water soluble effluent; type 2B released 88% of its radioactivity into the effluent. Total recoveries of radioactivity in the porous pot units ranged from 97% to 102%. Since all units showed > 98% primary biodegradation, mineralization of the porous pot effluents in aquatic test systems suggests the ultimate biodegradation if IsoLAS biodegradation intermediates in receiving waters. Rapid and extensive mineralization of LAS and IsoLAS types 1 and 2 was noted in batch activated sludge, soil and aquatic test systems. Half lives were: activated sludge -- 1--3 days, sludge amended soil -- 1.5--5 days, water/periphyton -- 3--8.5 days and water/sediment -- 3.5--12 days. These results demonstrate that the IsoLAS in commercial LAS undergo rapid and ultimately complete mineralization during biological wastewater treatment and downstream exposure to surface waters.

  8. 40 CFR 81.82 - El Paso-Las Cruces-Alamogordo Interstate Air Quality Control Region.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 17 2010-07-01 2010-07-01 false El Paso-Las Cruces-Alamogordo... Designation of Air Quality Control Regions § 81.82 El Paso-Las Cruces-Alamogordo Interstate Air Quality Control Region. The El Paso-Las Cruces-Alamogordo Interstate Air Quality Control Region (New...

  9. Investigaciones en la producción orgánica de vegetales en Oklahoma, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nationally recognized standards for certified organic farming were established in 2002 in the United States. This action stimulated increased scientific research on production methods that can be used in certified organic growing. In 2003, a multi-disciplinary scientific team in Oklahoma that cons...

  10. Seepage carbonate mounds in Cenozoic sedimentary sequences from the Las Minas Basin, SE Spain

    NASA Astrophysics Data System (ADS)

    Pozo, M.; Calvo, J. P.; Scopelliti, G.; González-Acebrón, L.

    2016-04-01

    A number of carbonate mounds composed of indurate, strongly folded and/or brecciated calcite and dolomite beds occur interstratified in Cenozoic sedimentary sequences from the Las Minas Basin. Part of the fabric of the rock forming the carbonate mounds is composed of laminated to banded dolostone similar to the host rock but showing contrasted lithification. Moreover, the carbonate deposits of the mounds display aggrading neomorphism of dolomite, partial replacement of dolomite by calcite, calcite cementation, and extensive silicification, locally resulting in box-work fabric. Eight main lithofacies were distinguished in the carbonate mound deposits. In some lithofacies, chert is present as both microcrystalline to fibro-radial quartz and opal, the latter occurring mainly as cement whereas the former replace the carbonate and infill voids. Yet one of the carbonate mounds shows distinctive petrography and geochemical features thus suggesting a distinctive growth pattern. The carbon isotope compositions of calcite from the mound samples range from - 11.56 to - 5.15 δ‰ whilst dolomite is depleted in 13C, with values of - 12.38 to 3.02 δ‰. Oxygen isotopic compositions vary from - 9.42 to - 4.64 δ‰ for calcite and between - 6.68 and 8.19 δ‰ for dolomite. Carbonate in the mounds shows significant enrichment in Co, Cr, Ni and Pb content, especially in the strongly deformed (F-2-2 lithofacies) and brecciated carbonate (F-4). The carbonate deposits show depletion in REE and Y in contrast to that determined in lutite. The formation of the carbonate mounds was related to local artesian seepage thermal water flows of moderate to relative high temperatures. Pressure differences between the low permeability host rock and the circulating fluids accounted for dilational fracturing and brecciation of the host sediment packages, which combined with precipitation of new carbonate and silica mineral phases. Locally, some carbonate mounds developed where groundwater

  11. 77 FR 77090 - Notice of Public Meeting, Las Cruces District Resource Advisory Council Meeting, New Mexico

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-31

    ...In accordance with the Federal Land Policy and Management Act and the Federal Advisory Committee Act, the Bureau of Land Management's (BLM) Las Cruces District Resource Advisory Council (RAC) will meet as indicated...

  12. 78 FR 65356 - Notice of Public Meeting, Las Cruces District Resource Advisory Council Meeting, New Mexico

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-31

    ...In accordance with the Federal Land Policy and Management Act and the Federal Advisory Committee Act, the Bureau of Land Management's (BLM) Las Cruces District Resource Advisory Council (RAC) will meet as indicated...

  13. Double star images taken by HST WFPC and Las Campanas Observatory

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Comparison of the same area of sky (a double star) taken by the Hubble Space Telescope (HST) wide field planetary camera (WFPC) and ground-based image taken from the Las Campanas Observatory, Carnegie Institute of Washington.

  14. Response-Induced Reversals of Preference in Gambling: An Extended Replication in Las Vegas

    ERIC Educational Resources Information Center

    Lichtenstein, Sarah; Slovic, Paul

    1973-01-01

    The present report describes an expanded replication of the previous experiments in a nonlaboratory real-play setting unique to the experimental literature on decision processes - a casino in downtown Las Vegas. (Author)

  15. Does the spatial arrangement of vegetation and anthropogenic land cover features matter? Case studies of urban warming and cooling in Phoenix and Las Vegas

    NASA Astrophysics Data System (ADS)

    Myint, S. W.; Zheng, B.; Fan, C.; Kaplan, S.; Brazel, A.; Middel, A.; Smith, M.

    2014-12-01

    While the relationship between fractional cover of anthropogenic and vegetation features and the urban heat island has been well studied, the effect of spatial arrangements (e.g., clustered, dispersed) of these features on urban warming or cooling are not well understood. The goal of this study is to examine if and how spatial configuration of land cover features influence land surface temperatures (LST) in urban areas. This study focuses on Phoenix, AZ and Las Vegas, NV that have undergone dramatic urban expansion. The data used to classify detailed urban land cover types include Geoeye-1 (Las Vegas) and QuickBird (Phoenix). The Geoeye-1 image (3 m resolution) was acquired on October 12, 2011 and the QuickBird image (2.4 m resolution) was taken on May 29, 2007. Classification was performed using object based image analysis (OBIA). We employed a spatial autocorrelation approach (i.e., Moran's I) that measures the spatial dependence of a point to its neighboring points and describes how clustered or dispersed points are arranged in space. We used Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data acquired over Phoenix (daytime on June 10, 2011 and nighttime on October 17, 2011) and Las Vegas (daytime on July 6, 2005 and nighttime on August 27, 2005) to examine daytime and nighttime LST with regards to the spatial arrangement of anthropogenic and vegetation features. We spatially correlate Moran's I values of each land cover per surface temperature, and develop regression models. The spatial configuration of grass and trees shows strong negative correlations with LST, implying that clustered vegetation lowers surface temperatures more effectively. In contrast, a clustered spatial arrangement of anthropogenic land-cover features, especially impervious surfaces, significantly elevates surface temperatures. Results from this study suggest that the spatial configuration of anthropogenic and vegetation features influence urban warming and cooling.

  16. Terrestrial risk assessment for linear alkyl benzene sulfonate (LAS) in sludge-amended soils.

    PubMed

    de Wolf, W; Feijtel, T

    1998-03-01

    A comparison of the estimated environmental concentration and the effect concentrations (in the laboratory or field) in the receiving compartment form the basis of environmental risk assessments. This paper reviews processes that critically influence the fate of LAS in the terrestrial environment. Concentrations of LAS in sludge are quite high due to sorption to primary sludge, precipitation of Ca and Mg-salts of LAS, and lack of biodegradation under anaerobic digestion. This implies that when sludge is applied to soil e.g. as a fertilizer, considerable amounts of this important surfactant may enter the terrestrial environment. Influence of aerobic situations on LAS concentrations during sludge storage needs further research to allow incorporation into the risk assessment. Aerobic biodegradation in soil is considered the most important removal mechanism of LAS loading to the terrestrial environment through sludge-amendment. Sorption plays a role in determining the residence time of a chemical in the soil, hereby enabling more time for biodegradation to occur. In addition, sorption may affect the expression of effects of surfactants towards benthic and soil dwelling organisms and plants. Another factor that needs further attention is the form of LAS in the environment, which is not similar to the commercial material applied in detergents. The differential sorption and biodegradation of the LAS components lead to a shift in the alkyl chain length (homologue), and phenylisomer distribution towards increased hydrophobicity. Also, occurrence of Ca/Mg-salts in the environment versus the Na-salt for the commercial material critically impacts the extrapolation of effects data obtained in lab studies (mostly performed with the commercial material) to the field. The literature data were used in combination with strategies and methods provided by the European Union Technical Guidance Document in support of risk assessment of new and notified substances (1996) for the

  17. Russian vaccines against especially dangerous bacterial pathogens

    PubMed Central

    Feodorova, Valentina A; Sayapina, Lidiya V; Corbel, Michael J; Motin, Vladimir L

    2014-01-01

    In response to the epidemiological situation, live attenuated or killed vaccines against anthrax, brucellosis, cholera, glanders, plague and tularemia were developed and used for immunization of at-risk populations in the Former Soviet Union. Certain of these vaccines have been updated and currently they are used on a selective basis, mainly for high risk occupations, in the Russian Federation. Except for anthrax and cholera these vaccines currently are the only licensed products available for protection against the most dangerous bacterial pathogens. Development of improved formulations and new products is ongoing. PMID:26038506

  18. The Book Scene...Especially for Teens.

    ERIC Educational Resources Information Center

    Peskorz, Adela, Comp.; And Others

    This annotated bibliography lists approximately 500 titles that reflect the diversity of interests and levels of sophistication among young adult readers between the ages of 12 and 18. Within each subject division is a varied array of fiction and nonfiction titles, some ideal for middle graders, others more appropriate for adult-level readers. The…

  19. My education in mineral (especially oil) economics

    SciTech Connect

    Adelman, M.A.

    1997-12-31

    The crude oil and natural gas markets have a long colorful history. To understand them, one needs some economic theory. The dominant view, of a fixed mineral stock, implies that a unit produced today means one less in the future. As mankind approaches the limit, it must exert ever more effort per unit recovered. This concept is false, whether stated as common sense or as elegant theory. Under competition, the price results from endless struggle between depletion and increasing knowledge. But sellers may try to control the market in order to offer less and charge more. The political results may feed back upon market behavior. These factors--depletion, knowledge, monopoly, and politics--must be analyzed separately before being put together to capture a slice of a changing history. 68 refs., 1 fig., 1 tab.

  20. REFRIGERATION ESPECIALLY FOR VERY LOW TEMPERATURES

    DOEpatents

    Kennedy, P.B.; Smith, H.R. Jr.

    1960-09-13

    A refrigeration system for producing very low temperatures is described. The system of the invention employs a binary mixture refrigerant in a closed constant volume, e.g., Freon and ethylene. Such mixture is compressed in the gaseous state and is then separated in a fractionating column element of the system. Thenceforth, the first liquid to separate is employed stagewise to cool and liq uefy successive portions of the refrigerant at successively lower temperatures by means of heat exchangers coupled between the successive stages. When shut down, all of the volumes of the system are interconnected and a portion of the refrigerant remains liquid at ambient temperatures so that no dangerous overpressures develop. The system is therefore rugged, simple and dependable in operation.

  1. Physicians practicing other occupations, especially literature.

    PubMed

    Green, J P

    1993-03-01

    Literature has been the favored nonmedical pursuit of physicians probably because the practice of medicine is suffused with narratives, the patient's history being one. Arthur Conan Doyle regarded medicine as a "grim romance," Somerset Maugham as an opportunity to see "life in the raw," and William Carlos Williams treated "the patient as a work of art." These sentiments may be linked to humanistic medicine. At some medical schools, literature is taught in the context of and integrated with medicine in an attempt to enhance ethics and empathy which were explicitly expressed by some physician-writers.

  2. Especially for Teens: You and Your Sexuality

    MedlinePlus

    ... Bisexuality is being attracted to both sexes. Many boys and girls are attracted to members of their own sex ... Gender identity is your sense of being a boy, a girl, or other gendered. Some teens feel that their ...

  3. [Biotechnology, especially genetic modification, and legislation].

    PubMed

    de Sitter, H; Peters, P W J

    2002-05-15

    Biotechnology and genetic modification (GM) related legislation is not yet fully developed in the European Union (EU). New legislation has been recently issued ('Introduction of GMO's in the environment') and recently proposals from the European Commission ('GMO's in food and feed' and 'Traceability and labelling of GMO's') entered the decision-making process in the end of 2001. The proposals for the establishment of the European Food Authority play a role in this respect. GMO legislation is complex not in the least because of the demands for the dossiers, to be submitted with an application, while these procedures for admission must become more transparent. In this paper the relevant legislation will be discussed with the exception of that related to human health. Because of dissatisfaction with the present legislation, the European Commission in the past years granted no new approvals for introductions on the market of GMO's and for GM novel foods. New legislation should suspend the present de-facto moratorium. The tasks and position of the Inspectorate for the Health Protection and Veterinary Public Health is discussed. A provision has been made in the legislation with respect to adventitious or technically unavoidable contamination of raw materials with GMO's up to a maximum of 1%, of which the enforcement is not yet watertight. The analytical methods are being still developed.

  4. Best Practices Case Study: Pulte Homes and Communities of Del Webb, Las Vegas Division

    SciTech Connect

    2009-10-01

    Case study of Pulte Homes Las Vegas Division, who certified nearly 1,200 homes to the DOE Builders Challenge between 2008 and 2012. All of the homes by Las Vegas’ biggest builder achieved HERS scores of lower than 70, and many floor plans got down to the mid 50s, with ducts located in sealed attics insulated along the roof line, advanced framing, and extra attention to air sealing.

  5. Effect of the test media and toxicity of LAS on the growth of Isochrysis galbana.

    PubMed

    Garrido-Perez, M C; Perales-VargasMachuca, J A; Nebot-Sanz, E; Sales-Márquez, D

    2008-11-01

    In this paper, the toxicity of linear alkylbenzene sulfonate (LAS) was evaluated in the marine microalga Isochrysis galbana using data of growth inhibition toxicity tests at 96-h exposure time. Toxicity was examined in standard conditions and by means of the modification of two variables of the test media: (1) the dilution water and (2) the content of nutrients in the test medium. For this purpose, a total of 10 toxicity test were designed: five dilution waters, four natural marine waters and one synthetic seawater; each in two different nutritive conditions, saturated nutrient concentration (SC) by the addition of modified f/2 nutritive medium, and natural nutrient concentration (NC), i.e., without the addition of f/2. At threshold toxicity levels, the dilution waters used in the test and the nutrient concentrations did not affect the toxicity of LAS. At IC50 concentrations, the toxicity of LAS is influenced by both variables: under SC conditions, the toxic effect of LAS diminishes, obtaining in all the tests IC50 > 10 mg/L LAS. Under NC conditions, IC50 concentrations ranging between 3.15 and 9.26 mg/L LAS have been obtained.

  6. Cluster galaxy evolution with the Las Campanas Distant Cluster Survey

    NASA Astrophysics Data System (ADS)

    Nelson, Amy Elizabeth

    Understanding the formation and evolution of galaxies is a principal goal of modern cosmology. In this thesis, we place constraints on galaxy evolution models using the largest sample of high redshift clusters to date. Our sample consists of 63 clusters at 0.3 ≲ z ≲ 0.9 drawn from the Las Campanas Distant Cluster Survey (LCDCS). This survey differs from traditional optical surveys in that we detect clusters as regions of excess surface brightness relative to the background sky rather than selecting overdensities of resolved galaxies. Therefore, not only does this sample result in a significant increase in the number of known clusters at these redshifts, but because our cluster identification criteria is independent of those utilized in previous surveys, this catalog provides an independent, well-defined sample with which to compare the results of more traditional surveys. In this work, we take a two-pronged approach to studying galaxy evolution. First, we examine the luminosity and color evolution of the bright cluster galaxies as a class. Specifically, we measure the evolution of: (1) M*I , the characteristic luminosity of cluster galaxies, (2) the location of the red envelope in V--I and I--K', and (3) the fraction of blue galaxies (i.e. the Butcher-Oemler effect; Butcher & Oemler 1984). Our data suggest that luminous early type galaxies (or the progenitors of current day early type galaxies) form the bulk of their stellar populations at high redshifts ( ≲ 5) and that many of these galaxies, if not all, experience a short term episode of star formation at lower redshifts (1.5 < z < 2). Second, we narrow the focus and study a single type of cluster galaxy, the brightest cluster galaxy (BCG). We constrain the amount of luminosity and color evolution of BCGs, particularly in the context of recent claims in the literature of significant mass accretion since z ˜ 1 (Aragon-Salamanca 1998; Burke, Collins, & Mann 2000). Consistent with previous results (Burke

  7. Monitoring Changes in Channel Morphology in Las Vegas Wash with Global Fiducials Program Imagery

    NASA Astrophysics Data System (ADS)

    Wheeler, D. J.

    2012-12-01

    To borrow from a popular adage, "What happens in Las Vegas [Wash], stays in Las Vegas [Wash]"—but only with a lot of help. This past decade has seen a concerted effort to curb erosion and sediment transport along the 12 mile long channel between East Las Vegas and Lake Mead. Las Vegas Wash is prototypical of an urban river in an arid environment that is being impacted by increasing urban development and impervious surface runoff within its drainage area. Rapid urbanization since the 1970s has increased the flow of water into Las Vegas Wash, causing severe channel destabilization. Within two decades millions of cubic yards of rocks and sediment were scoured out of the wash and transported downstream to Lake Mead. The wetlands that once covered over 2,000 acres within Las Vegas Wash dwindled to 200 acres in the 1990s as the channel became as much as 40 feet deeper and 300 feet wider at some points. In 1999 the Las Vegas Wash Coordination Committee (LVWCC) initiated a 20-year plan to construct erosion control structures (weirs) for channel stabilization and rock riprap for stream bank protection. The hope is to design structures that will slow down the water flow, trap sediments, and to eventually restore much of the wetland environment. Using high-resolution satellite imagery from the Global Fiducials Program Library housed at the U. S. Geological Survey, this transition is being tracked from 1999 to the present. From November 1999 to July 2008 new residential and commercial development has claimed an additional 12 square kilometers (3000 acres) of land in Henderson, NV, along the south side of Las Vegas Wash. Even with the increased volume of surface and groundwater runoff entering the wash, current sediment yields are much lower than the 1999 totals. The imagery documents the construction of 14 of the 22 LVWCC planned weirs by the year 2011. It also shows many miles of stream bank stabilization by riprap, planting of riparian vegetation and placing of

  8. Environmentally Endemic Pseudomonas aeruginosa Strains with Mutations in lasR Are Associated with Increased Disease Severity in Corneal Ulcers.

    PubMed

    Hammond, John H; Hebert, Wesley P; Naimie, Amanda; Ray, Kathryn; Van Gelder, Rachel D; DiGiandomenico, Antonio; Lalitha, Prajna; Srinivasan, Muthiah; Acharya, Nisha R; Lietman, Thomas; Hogan, Deborah A; Zegans, Michael E

    2016-01-01

    The Steroids for Corneal Ulcers Trial (SCUT) was a multicenter, international study of bacterial keratitis in which 101 Pseudomonas aeruginosa infections were treated. Twenty-two of 101 P. aeruginosa isolates collected had a colony morphology characteristic of a loss-of-function mutation in lasR, the gene encoding a quorum-sensing master regulator. Ulcers caused by these 22 strains were associated with larger areas of corneal opacification, worse vision, and a lower rate of vision recovery in response to treatment than ulcers caused by the other isolates. The lasR sequences from these isolates each contained one of three nonsynonymous substitutions, and these strains were deficient in production of LasR-regulated protease and rhamnolipids. Replacement of lasR with either of the two most common lasR alleles from the SCUT isolates was sufficient to decrease protease and rhamnolipid production in PA14. Loss of LasR function is associated with increased production of CupA fimbriae, and the LasR-defective isolates exhibited higher production of CupA fimbriae than LasR-intact isolates. Strains with the same lasR mutation were of the same multilocus sequence type, suggesting that LasR-deficient, environmental P. aeruginosa strains were endemic to the area, and infections caused by these strains were associated with worse patient outcomes in the SCUT study. (This study has been registered at ClinicalTrials.gov under registration no. NCT00324168.) IMPORTANCE The LasR transcription factor is an important regulator of quorum sensing in P. aeruginosa and positively controls multiple virulence-associated pathways. The emergence of strains with lasR loss-of-function alleles in chronic disease is well described and is thought to represent a specific adaptation to the host environment. However, the prevalence and virulence of these strains in acute infections remain unclear. This report describes observations revealing that lasR mutants were common among isolates from a large

  9. Environmentally Endemic Pseudomonas aeruginosa Strains with Mutations in lasR Are Associated with Increased Disease Severity in Corneal Ulcers

    PubMed Central

    Hammond, John H.; Hebert, Wesley P.; Naimie, Amanda; Ray, Kathryn; Van Gelder, Rachel D.; DiGiandomenico, Antonio; Lalitha, Prajna; Srinivasan, Muthiah; Acharya, Nisha R.; Lietman, Thomas; Hogan, Deborah A.

    2016-01-01

    ABSTRACT The Steroids for Corneal Ulcers Trial (SCUT) was a multicenter, international study of bacterial keratitis in which 101 Pseudomonas aeruginosa infections were treated. Twenty-two of 101 P. aeruginosa isolates collected had a colony morphology characteristic of a loss-of-function mutation in lasR, the gene encoding a quorum-sensing master regulator. Ulcers caused by these 22 strains were associated with larger areas of corneal opacification, worse vision, and a lower rate of vision recovery in response to treatment than ulcers caused by the other isolates. The lasR sequences from these isolates each contained one of three nonsynonymous substitutions, and these strains were deficient in production of LasR-regulated protease and rhamnolipids. Replacement of lasR with either of the two most common lasR alleles from the SCUT isolates was sufficient to decrease protease and rhamnolipid production in PA14. Loss of LasR function is associated with increased production of CupA fimbriae, and the LasR-defective isolates exhibited higher production of CupA fimbriae than LasR-intact isolates. Strains with the same lasR mutation were of the same multilocus sequence type, suggesting that LasR-deficient, environmental P. aeruginosa strains were endemic to the area, and infections caused by these strains were associated with worse patient outcomes in the SCUT study. (This study has been registered at ClinicalTrials.gov under registration no. NCT00324168.) IMPORTANCE The LasR transcription factor is an important regulator of quorum sensing in P. aeruginosa and positively controls multiple virulence-associated pathways. The emergence of strains with lasR loss-of-function alleles in chronic disease is well described and is thought to represent a specific adaptation to the host environment. However, the prevalence and virulence of these strains in acute infections remain unclear. This report describes observations revealing that lasR mutants were common among isolates from

  10. Environmentally Endemic Pseudomonas aeruginosa Strains with Mutations in lasR Are Associated with Increased Disease Severity in Corneal Ulcers

    PubMed Central

    Hammond, John H.; Hebert, Wesley P.; Naimie, Amanda; Ray, Kathryn; Van Gelder, Rachel D.; DiGiandomenico, Antonio; Lalitha, Prajna; Srinivasan, Muthiah; Acharya, Nisha R.; Lietman, Thomas; Hogan, Deborah A.

    2016-01-01

    ABSTRACT The Steroids for Corneal Ulcers Trial (SCUT) was a multicenter, international study of bacterial keratitis in which 101 Pseudomonas aeruginosa infections were treated. Twenty-two of 101 P. aeruginosa isolates collected had a colony morphology characteristic of a loss-of-function mutation in lasR, the gene encoding a quorum-sensing master regulator. Ulcers caused by these 22 strains were associated with larger areas of corneal opacification, worse vision, and a lower rate of vision recovery in response to treatment than ulcers caused by the other isolates. The lasR sequences from these isolates each contained one of three nonsynonymous substitutions, and these strains were deficient in production of LasR-regulated protease and rhamnolipids. Replacement of lasR with either of the two most common lasR alleles from the SCUT isolates was sufficient to decrease protease and rhamnolipid production in PA14. Loss of LasR function is associated with increased production of CupA fimbriae, and the LasR-defective isolates exhibited higher production of CupA fimbriae than LasR-intact isolates. Strains with the same lasR mutation were of the same multilocus sequence type, suggesting that LasR-deficient, environmental P. aeruginosa strains were endemic to the area, and infections caused by these strains were associated with worse patient outcomes in the SCUT study. (This study has been registered at ClinicalTrials.gov under registration no. NCT00324168.) IMPORTANCE The LasR transcription factor is an important regulator of quorum sensing in P. aeruginosa and positively controls multiple virulence-associated pathways. The emergence of strains with lasR loss-of-function alleles in chronic disease is well described and is thought to represent a specific adaptation to the host environment. However, the prevalence and virulence of these strains in acute infections remain unclear. This report describes observations revealing that lasR mutants were common among isolates from

  11. Molecular Insights into the Impact of Oxidative Stress on the Quorum-Sensing Regulator Protein LasR.

    PubMed

    Kafle, Prapti; Amoh, Amanda N; Reaves, Jocelyn M; Suneby, Emma G; Tutunjian, Kathryn A; Tyson, Reed L; Schneider, Tanya L

    2016-05-27

    The LasR regulator protein functions at the top of the Pseudomonas aeruginosa quorum-sensing hierarchy and is implicated in promoting bacterial virulence. Of note is recent evidence that this transcription factor may also respond to oxidative stress. Here, all cysteines in LasR were inspected to deduce their redox sensitivity and to probe the connection between stress response and LasR activity using purified LasR and individual LasR domains. Cys(79) in the ligand binding domain of LasR appears to be important for ligand recognition and folding of this domain to potentiate DNA binding but does not seem to be sensitive to oxidative stress when bound to its native ligand. Two cysteines in the DNA binding domain of LasR do form a disulfide bond when treated with hydrogen peroxide, and formation of this Cys(201)-Cys(203) disulfide bond appears to disrupt the DNA binding activity of the transcription factor. Mutagenesis of either of these cysteines leads to expression of a protein that no longer binds DNA. A cell-based reporter assay linking LasR function with β-galactosidase activity gave results consistent with those obtained with purified LasR. This work provides a possible mechanism for oxidative stress response by LasR and indicates that multiple cysteines within the protein may prove to be useful targets for disabling its activity. PMID:27053110

  12. LasR Variant Cystic Fibrosis Isolates Reveal an Adaptable Quorum-Sensing Hierarchy in Pseudomonas aeruginosa

    PubMed Central

    Feltner, John B.; Wolter, Daniel J.; Pope, Christopher E.; Groleau, Marie-Christine; Smalley, Nicole E.; Greenberg, E. Peter; Mayer-Hamblett, Nicole; Burns, Jane; Hoffman, Lucas R.

    2016-01-01

    ABSTRACT Chronic Pseudomonas aeruginosa infections cause significant morbidity in patients with cystic fibrosis (CF). Over years to decades, P. aeruginosa adapts genetically as it establishes chronic lung infections. Nonsynonymous mutations in lasR, the quorum-sensing (QS) master regulator, are common in CF. In laboratory strains of P. aeruginosa, LasR activates transcription of dozens of genes, including that for another QS regulator, RhlR. Despite the frequency with which lasR coding variants have been reported to occur in P. aeruginosa CF isolates, little is known about their consequences for QS. We sequenced lasR from 2,583 P. aeruginosa CF isolates. The lasR sequences of 580 isolates (22%) coded for polypeptides that differed from the conserved LasR polypeptides of well-studied laboratory strains. This collection included 173 unique lasR coding variants, 116 of which were either missense or nonsense mutations. We studied 31 of these variants. About one-sixth of the variant LasR proteins were functional, including 3 with nonsense mutations, and in some LasR-null isolates, genes that are LasR dependent in laboratory strains were nonetheless expressed. Furthermore, about half of the LasR-null isolates retained RhlR activity. Therefore, in some CF isolates the QS hierarchy is altered such that RhlR quorum sensing is independent of LasR regulation. Our analysis challenges the view that QS-silent P. aeruginosa is selected during the course of a chronic CF lung infection. Rather, some lasR sequence variants retain functionality, and many employ an alternate QS strategy involving RhlR. PMID:27703072

  13. El fenotipo de las mucinas en el esófago de Barrett

    PubMed Central

    Torrado, Julio; Piazuelo, María Blanca; Ruiz, Irune; Izarzugaza, María Isabel; Camargo, María Constanza; Delgado, Alberto; Abdirad, Afshin; Correa, Pelayo

    2011-01-01

    Antecedentes El esófago de Barrett es una reconocida lesión precursora de adenocarcinoma esofágico. Aunque generalmente asociada al reflujo gastroesofágico, los mecanismos patogénicos de la enfermedad no son bien conocidos. El objetivo del presente estudio es explorar la historia natural e identificar marcadores de progreso del proceso precanceroso. Material y métodos Se utilizaron cortes histológicos de 67 especímenes de esófago correspondientes a 14 pacientes con esófago de Barrett, a los que se siguió entre 1 – 9 años. Se clasificaron las lesiones en: esófago de Barrett sin displasia, indefinido para displasia o con displasia. Se evaluó la expresión de diferentes mucinas en las células caliciformes y en las columnares usando técnicas de histoquímica e inmunohistoquímica. Resultados En todos los casos se comprobó la presencia de metaplasia intestinal incompleta. Las células columnares dentro del epitelio metaplásico contenían mucinas neutras. A mayor severidad de la lesión se encontró significativamente menor expresión de sialomucinas en las células columnares (p de tendencia igual a 0,03). En sujetos con lesiones indefinidas para displasia se observó un mayor contenido de sulfomucinas en las células caliciformes (p=0,034) y de MUC2 en las células columnares (p=0,029) que en sujetos con esófago de Barrett sin displasia. Se observó expresión de la mucina intestinal MUC2 y de la mucina gástrica MUC5AC en todas las muestras. MUC6, una mucina de las glándulas profundas gástricas, se presentó ocasionalmente. Conclusión La evaluación de los perfiles de mucinas en el esófago de Barrett sugiere una transición gradual del fenotipo del epitelio metaplásico a medida que la lesión avanza en el tiempo. PMID:21804831

  14. Evaluation of Linear Alkylbenzene Sulfonate (LAS) behaviour in agricultural soil through laboratory continuous studies.

    PubMed

    Oliver-Rodríguez, B; Zafra-Gómez, A; Reis, M S; Duarte, B P M; Verge, C; de Ferrer, J A; Pérez-Pascual, M; Vílchez, J L

    2015-07-01

    The behaviour of Linear Alkylbenzene Sulfonate (LAS) in agricultural soil is investigated in the laboratory using continuous-flow soil column studies in order to simultaneously analyze the three main underlying phenomena (adsorption/desorption, degradation and transport). The continuous-flow soil column experiments generated the breakthrough curves for each LAS homologue, C10, C11, C12 and C13, and by adding them up, for total LAS, from which the relevant retention, degradation and transport parameters could be estimated, after proposing adequate models. Several transport equations were considered, including the degradation of the sorbate in solution and its retention by soil, under equilibrium and non-equilibrium conditions between the sorbent and the sorbate. In general, the results obtained for the estimates of those parameters that were common to the various models studied (such as the isotherm slope, first order degradation rate coefficient and the hydrodynamic dispersion coefficient) were rather consistent, meaning that mass transfer limitations are not playing a major role in the experiments. These three parameters increase with the length of the LAS homologue chain. The study will provide the underlying conceptual framework and fundamental parameters to understand, simulate and predict the environmental behaviour of LAS compounds in agricultural soils. PMID:25765258

  15. Cystic fibrosis–adapted Pseudomonas aeruginosa quorum sensing lasR mutants cause hyperinflammatory responses

    PubMed Central

    LaFayette, Shantelle L.; Houle, Daniel; Beaudoin, Trevor; Wojewodka, Gabriella; Radzioch, Danuta; Hoffman, Lucas R.; Burns, Jane L.; Dandekar, Ajai A.; Smalley, Nicole E.; Chandler, Josephine R.; Zlosnik, James E.; Speert, David P.; Bernier, Joanie; Matouk, Elias; Brochiero, Emmanuelle; Rousseau, Simon; Nguyen, Dao

    2015-01-01

    Cystic fibrosis lung disease is characterized by chronic airway infections with the opportunistic pathogen Pseudomonas aeruginosa and severe neutrophilic pulmonary inflammation. P. aeruginosa undergoes extensive genetic adaptation to the cystic fibrosis (CF) lung environment, and adaptive mutations in the quorum sensing regulator gene lasR commonly arise. We sought to define how mutations in lasR alter host-pathogen relationships. We demonstrate that lasR mutants induce exaggerated host inflammatory responses in respiratory epithelial cells, with increased accumulation of proinflammatory cytokines and neutrophil recruitment due to the loss of bacterial protease–dependent cytokine degradation. In subacute pulmonary infections, lasR mutant–infected mice show greater neutrophilic inflammation and immunopathology compared with wild-type infections. Finally, we observed that CF patients infected with lasR mutants have increased plasma interleukin-8 (IL-8), a marker of inflammation. These findings suggest that bacterial adaptive changes may worsen pulmonary inflammation and directly contribute to the pathogenesis and progression of chronic lung disease in CF patients. PMID:26457326

  16. Evaluation of Linear Alkylbenzene Sulfonate (LAS) behaviour in agricultural soil through laboratory continuous studies.

    PubMed

    Oliver-Rodríguez, B; Zafra-Gómez, A; Reis, M S; Duarte, B P M; Verge, C; de Ferrer, J A; Pérez-Pascual, M; Vílchez, J L

    2015-07-01

    The behaviour of Linear Alkylbenzene Sulfonate (LAS) in agricultural soil is investigated in the laboratory using continuous-flow soil column studies in order to simultaneously analyze the three main underlying phenomena (adsorption/desorption, degradation and transport). The continuous-flow soil column experiments generated the breakthrough curves for each LAS homologue, C10, C11, C12 and C13, and by adding them up, for total LAS, from which the relevant retention, degradation and transport parameters could be estimated, after proposing adequate models. Several transport equations were considered, including the degradation of the sorbate in solution and its retention by soil, under equilibrium and non-equilibrium conditions between the sorbent and the sorbate. In general, the results obtained for the estimates of those parameters that were common to the various models studied (such as the isotherm slope, first order degradation rate coefficient and the hydrodynamic dispersion coefficient) were rather consistent, meaning that mass transfer limitations are not playing a major role in the experiments. These three parameters increase with the length of the LAS homologue chain. The study will provide the underlying conceptual framework and fundamental parameters to understand, simulate and predict the environmental behaviour of LAS compounds in agricultural soils.

  17. Nucleotide sequence and expression in Escherichia coli of the Pseudomonas aeruginosa lasA gene.

    PubMed Central

    Schad, P A; Iglewski, B H

    1988-01-01

    Pseudomonas aeruginosa PAO-E64 is a mutant which produces parental levels of elastase antigen but has no elastolytic activity at 37 degrees C. The lesion (lasA1) in PAO-E64 is not a mutation in the structural gene for P. aeruginosa elastase (P.A. Schad, R.A. Bever, T.I. Nicas, F. Leduce, L.F. Hanne, and B.H. Iglewski, J. Bacteriol. 169: 2691-2696, 1987). A 1.7-kilobase segment of DNA that complements the lasA1 lesion was sequenced. Computer analysis of the DNA sequence showed that it contained an open reading frame which encoded a 41,111-dalton protein. The lasA gene was expressed under an inducible PT-7 promoter, and a 40,000-dalton protein was detected in Escherichia coli lysates. The lasA protein was localized in the outer membrane fraction of E. coli. This lasA protein produced in E. coli activated the extracellular elastase produced by the P. aeruginosa mutant, PAO-E64. Images PMID:2836371

  18. Roles of Pseudomonas aeruginosa las and rhl quorum-sensing systems in control of elastase and rhamnolipid biosynthesis genes.

    PubMed Central

    Pearson, J P; Pesci, E C; Iglewski, B H

    1997-01-01

    Two quorum-sensing systems (las and rhl) regulate virulence gene expression in Pseudomonas aeruginosa. The las system consists of a transcriptional activator, LasR, and LasI, which directs the synthesis of the autoinducer N-(3-oxododecanoyl) homoserine lactone (PAI-1). Induction of lasB (encoding elastase) and other virulence genes requires LasR and PAI-1. The rhl system consists of a putative transcriptional activator, RhlR, and RhlI, which directs the synthesis of N-butyryl homoserine lactone (PAI-2). Rhamnolipid production in P. aeruginosa has been reported to require both the rhl system and rhlAB (encoding a rhamnosyltransferase). Here we report the generation of a delta lasI mutant and both delta lasI delta rhlI and delta lasR rhlR::Tn501 double mutants of strain PAO1. Rhamnolipid production and elastolysis were reduced in the delta lasI single mutant and abolished in the double-mutant strains. rhlAB mRNA was not detected in these strains at mid-logarithmic phase but was abundant in the parental strain. Further RNA analysis of the wild-type strain revealed that rhlAB is organized as an operon. The rhlAB transcriptional start was mapped, and putative sigma 54 and sigma 70 promoters were identified upstream. To define components required for rhlAB expression, we developed a bioassay in Escherichia coli and demonstrated that PAI-2 and RhlR are required and sufficient for expression of rhlA. To characterize the putative interaction between PAI-2 and RhlR, we demonstrated that [3H]PAI-2 binds to E. coli cells expressing RhlR and not to those expressing LasR. Finally, the specificity of the las and rhl systems was examined in E. coli bioassays. The las system was capable of mildly activating rhlA, and similarly, the rhl system partly activated lasB. However; these effects were much less than the activation of rhlA by the rhl system and lasB by the las system. The results presented here further characterize the roles of the rhl and las quorum-sensing systems in

  19. Estudio de la transparencia de las nubes de Magallanes a partir de la observación espectroscópica de galaxias ubicadas en dirección a las mismas

    NASA Astrophysics Data System (ADS)

    Dutra, C.; Bica, E.; Clariá, J. J.; Piatti, A. E.:

    Se presentan los primeros resultados obtenidos a partir de observaciones espectroscópicas de galaxias ubicadas en dirección a las Nubes de Magallanes. Los espectros fueron obtenidos con el telescopio de 2.15 m del CASLEO y cubren el rango 3500-7000 Å. El material observacional recolectado permite examinar poblaciones estelares y determinar el enrojecimiento interestelar que afecta a cada una de las galaxias. La distribución angular de la muestra de galaxias observadas permite efectuar el mapeamiento del enrojecimiento que afecta las distintas regiones de las Nubes de Magallanes.

  20. Bioconcentration of the anionic surfactant linear alkylbenzene sulfonate (LAS) in the marine shrimp Palaemonetes varians: a radiotracer study.

    PubMed

    Renaud, Florent; Warnau, Michel; Oberhänsli, François; Teyssié, Jean-Louis; Temara, Ali; Rouleau, Claude; Metian, Marc

    2014-08-15

    Uptake and depuration kinetics of dissolved [(14)C]C₁₂-6-linear alkylbenzene sulfonate (LAS) were determined in the shrimp Palaemonetes varians using environmentally relevant exposure concentration. The shrimp concentrated LAS from seawater with a mean BCF value of 120 L kg(-1) after a 7-day exposure. Uptake biokinetics were best described by a saturation model, with an estimated BCFss, of 159 ± 34 L kg(-1), reached after 11.5 days. Shrimp weight influenced significantly BCF value with smaller individuals presenting higher affinity to LAS. To the light of a whole body autoradiography, major accumulation of LAS occurred in the cephalothorax circulatory system (gills, heart, hepatopancreas) and ocular peduncle, but not in the flesh, limiting potential transfer to human consumers. LAS depuration rate constant value of the shrimp was 1.18 ± 0.08 d(-1) leading to less than 1% of remaining LAS in its tissues after 8 days of depuration.

  1. Sobre las soluciones acotadas del problema instantáneo de dos cuerpos

    NASA Astrophysics Data System (ADS)

    Altavista, C.

    La demostración se basa en el hecho de que las integrales del problema de los N-cuerpos admiten componentes en el campo complejo según las raíces n-ésimas de la unidad. Definida la matriz unitaria correspondiente, la fórmula de Cayley permite transformar la matriz unitaria en una matriz hermitiana. Utilizando como parámetros los cosenos direccionales de un sistema de coordenadas orbitales referidos a un sistema de referencia fijo, puede construirse, utilizando el operador hermitiano antes definido, una forma cuadrática cuyas raíces mínima y máxima definen las cotas respectivas de los movimientos de los mencionados cosenos direccionales.

  2. Carbon Dioxide Laser Absorption Spectrometer (CO2LAS) Aircraft Measurements of CO2

    NASA Technical Reports Server (NTRS)

    Christensen, Lance E.; Spiers, Gary D.; Menzies, Robert T.; Jacob, Joseph C.; Hyon, Jason

    2011-01-01

    The Jet Propulsion Laboratory Carbon Dioxide Laser Absorption Spectrometer (CO2LAS) utilizes Integrated Path Differential Absorption (IPDA) at 2.05 microns to obtain CO2 column mixing ratios weighted heavily in the boundary layer. CO2LAS employs a coherent detection receiver and continuous-wave Th:Ho:YLF laser transmitters with output powers around 100 milliwatts. An offset frequency-locking scheme coupled to an absolute frequency reference enables the frequencies of the online and offline lasers to be held to within 200 kHz of desired values. We describe results from 2009 field campaigns when CO2LAS flew on the Twin Otter. We also describe spectroscopic studies aimed at uncovering potential biases in lidar CO2 retrievals at 2.05 microns.

  3. Identification of methyl triclosan and halogenated analogues in male common carp (Cyprinus carpio) from Las Vegas Bay and semipermeable membrane devices from Las Vegas Wash, Nevada

    USGS Publications Warehouse

    Leiker, T.J.; Abney, S.R.; Goodbred, S.L.; Rosen, Michael R.

    2009-01-01

    Methyl triclosan and four halogenated analogues have been identified in extracts of individual whole-body male carp (Cyprinus carpio) tissue that were collected from Las Vegas Bay, Nevada, and Semipermeable Membrane Devices (SPMD) that were deployed in Las Vegas Wash, Nevada. Methyl triclosan is believed to be the microbially methylated product of the antibacterial agent triclosan (2, 4, 4'-trichloro-4-hydroxydiphenyl ether, Chemical Abstract Service Registry Number 3380-34-5, Irgasan DP300). The presence of methyl triclosan and four halogenated analogues was confirmed in SPMD extracts by comparing low- and high-resolution mass spectral data and Kovats retention indices of methyl triclosan with commercially obtained triclosan that was derivatized to the methyl ether with ethereal diazomethane. The four halogenated analogues of methyl triclosan detected in both whole-body tissue and SPMD extracts were tentatively identified by high resolution mass spectrometry. Methyl triclosan was detected in all 29 male common carp from Las Vegas Bay with a mean concentration of 596????g kg- 1 wet weight (ww) which is more than an order of magnitude higher than previously reported concentrations in the literature. The halogenated analogs were detected less frequently (21%-76%) and at much lower concentrations (< 51????g kg- 1 ww). None of these compounds were detected in common carp from a Lake Mead reference site in Overton Arm, Nevada.

  4. Methanogenic activity inhibition by increasing the linear alkylbenzene sulfonate (LAS) concentration.

    PubMed

    Souza, Luiza F C; Florencio, Lourdinha; Gavazza, Savia; Kato, Mario T

    2016-07-01

    The effect of the initial concentration of linear alkylbenzene sulfonate (LAS) on specific methanogenic activity (SMA) was investigated in this work. Six anaerobic flasks reactors with 1 L of total volume were inoculated with anaerobic sludge (2 g VSS L(-1)). The reactors were assayed for 42 days, and fed with volatile fatty acids, nutrients, and LAS. The initial LAS concentrations were 0, 10, 30, 50, 75, and 100 mg L(-1) for the treatment flasks T1 (control), T2, T3, T4, T5, and T6, respectively. When compared with T1, T2 exhibited a 30% reduction in maximum SMA and total methane production (TMP). In treatment T3 through T6, the reductions were 44-97% (T3-T6) for SMA, and 30-90% (T3-T6) for TMP. Total LAS removal increased following the increase in the initial LAS concentration (from 36% at T1 to 76% at T6), primarily due to the high degree of sludge adsorption. LAS biodegradation also occurred (32% in all treatments), although this was most likely associated with the formation of non-methane intermediates. Greater removal by adsorption was observed in long-chain homologues, when compared to short-chain homologues (C13 > C10), whereas the opposite occurred for biodegradation (C10 > C13). The C13 homologue was adsorbed to a great extent (in mass) in T4, T5 and T6, and may also have inhibited methane formation in these treatments. PMID:27088975

  5. Las fulguraciones como manifestación de reconexión en el campo magnético solar

    NASA Astrophysics Data System (ADS)

    Bagalá, L. G.; Mandrini, M. C.; Rovira, M. G.; Démoulin, P.

    Las fulguraciones solares son fenómenos transitorios de liberación de energía que se desarrollan en las estructuras magnéticas de las regiones activas del Sol. Las fulguraciones pueden llegar a liberar hasta 1032 erg en 100 seg. en todo el rango electromagnético, y acelerar partículas. En este trabajo mostramos que la ubicación de los abrillantamientos en Hα de diversas fulguraciones está relacionado con las propiedades de las conexiones de las líneas del campo magnético de la región, como se espera por las teorías de reconexión en 3D recientemente desarrolladas (Démoulin et al, 1996a). El campo magnético coronal se extrapola del campo fotosférico observado suponiendo una configuración libre de fuerzas lineal. Por medio de un algoritmo se determinan las regiones donde existe un cambio drástico en la conectividad de las líneas de campo (límites ``cuasi-discontinuos'', o cuasi-separatrices CS). Las CS son bandas abiertas que identifican zonas donde el campo magnético se reconectará con más probabilidad y, siempre que las mismas sean lo suficientemente finas, se producirá allíla liberación de energía proveniente del campo magnético. Hemos encontrado que en todas las regiones fulgurantes estudiadas (Démoulin et al, 1996b) existen CS en los mismos lugares donde se observaron los abrillantamientos en Hα. Allídonde coinciden los abrillantamientos con las CS, éstas tienen un espesor menor que 1 Mm. Las líneas de campo coronales extrapoladas de nuestro modelo tienen sus orígenes fotosféricos a ambos lados de las CS, como se espera dados los recientes estudios de reconexión magnética en 3D. Estos resultados ponen a prueba los modelos presentes sobre fulguraciones solares.

  6. El aprendizaje significativo en las ciencias al participar en proyectos de investigacion cientifica

    NASA Astrophysics Data System (ADS)

    Mora Polanco, Miguelena

    La ciencia es el eje fundamental a traves del cual se desarrollan las habilidades necesarias para el pensar cientifico que va a la busqueda del conocimiento cientifico. La intencion de este estudio fue indagar en el tema de investigacion cientifica desde el punto de vista de los participantes en los siguientes aspectos relacionados con la experiencia de investigacion cientifica: a) conceptos, b) proceso, c) destrezas y d) disposicion. Tambien se analizaron: a) las perspectivas del metodo cientifico, b) la estrategia de ensenanza, c) la cultura cientifica y d) la exposicion del proyecto investigativo en la Feria Cientifica; como parte del aprendizaje significativo de la ciencias de los participantes. Esta investigacion cualitativa propuso como diseno el estudio de caso. Los aspectos relacionados a la experiencia de participar en proyecto de investigacion cientifica son el fenomeno o caso bajo estudio. En el estudio participaron cinco (5) estudiantes egresados de escuela publica o privada que cursaban hasta el tercer ano de estudios universitarios, conducentes a un bachillerato en educacion secundaria en ciencias o en ciencias naturales. Las tecnicas utilizadas para recopilar los datos fueron: analisis de documentos del DEPR, revision de artefactos y entrevistas profundas. Para el analisis de los datos de las entrevistas se utilizo el modelo de Wolcott (1994). Del analisis de documentos del DEPR se identificaron areas a mejorar en las guias de las cartas circulares con relacion a la investigacion escolar y la feria cientifica. El analisis de los artefactos proveyo evidencia de como los internados, simposios e investigaciones fomentan el que los estudiantes se superen en el aspecto cognitivo, se conviertan en creadores del conocimiento, al hacer suyo los conceptos para poder explicarlos al publico. De las entrevistas los participantes manifestaron que la experiencia de investigacion fue una de aprendizaje significativo que los marco para toda la vida y les expandio su

  7. A reinterpretation of the Pleistocene human and faunal association at Las Buitreras Cave, Santa Cruz, Argentina

    NASA Astrophysics Data System (ADS)

    Borrero, Luis A.; Martin, Fabiana M.

    2008-12-01

    The faunal assemblage recovered from Layers VIII-VII at Las Buitreras Cave has been considered as associated with human artifacts. On that basis, the previous analysis had concluded that human hunters had exploited ground sloths at the end of the Pleistocene. A reanalysis of the bones as well as the rest of the evidence suggests that there is no basis for that conclusion. On the contrary, it is suggested here that the lower layers at Las Buitreras are the result of the use of the cave as a den by ground sloths.

  8. Discovery of LAS101057: A Potent, Selective, and Orally Efficacious A2B Adenosine Receptor Antagonist

    PubMed Central

    2010-01-01

    The structure−activity relationships for a series of pyrazine-based A2B adenosine receptor antagonists are described. From this work, LAS101057 (17), a potent, selective, and orally efficacious A2B receptor antagonist, was identified as a clinical development candidate. LAS101057 inhibits agonist-induced IL-6 production in human fibroblasts and is active in an ovalbumin (OVA)-sensitized mouse model after oral administration, reducing airway hyperresponsiveness to methacholine, Th2 cytokine production, and OVA-specific IgE levels. PMID:24900298

  9. Sealing 304L to lithia-alumina-silica (LAS) glass-ceramics

    SciTech Connect

    Moddeman, W.E.; Pence, R.E.; Massey, R.T.; Cassidy, R.T.; Kramer, D.P.

    1989-10-01

    Lithia-alumina-silica (LAS) glass-ceramics have been developed whose high coefficient of thermal expansion (CTE) allows the formation of stress-free seals with 300-series stainless steels, by adjusting either the parent glass composition or the sealing/crystallization cycle used in forming seals between LAS glass-ceramics and Ni-base alloys. CTE value and alloy yield strength data are presented which demonstrate the feasibility of feedthroughs and pyrotechnic components based on these materials; the integrity of the glass/steel interfaces is indicated by TEM, metallographic, and wavelength-dispersive spectroscopy results. 10 refs.

  10. Positive correlation of algD transcription to lasB and lasA transcription by populations of Pseudomonas aeruginosa in the lungs of patients with cystic fibrosis.

    PubMed

    Storey, D G; Ujack, E E; Mitchell, I; Rabin, H R

    1997-10-01

    Pseudomonas aeruginosa causes a chronic infection in the lungs of individuals with cystic fibrosis. The P. aeruginosa isolates from these infections, when grown under laboratory conditions, characteristically are mucoid and produce low levels of the more destructive virulence factors, such as exotoxin A and the proteases. We wanted to determine if during the chronic lung infections associated with CF, the expression of alginate was inversely correlated to the expression of exotoxin A, elastase, and the LasA protease. We measured the transcript accumulation of algD, a marker of alginate, toxA, the structural gene for exotoxin A, lasB, the structural gene for elastase, and lasA, the structural gene for LasA protease, from the sputum bacterial populations of 23 patients. In the 131 samples tested, we frequently detected transcripts from the four genes. When a Spearman rank correlation analysis was done on the samples, we found no correlation between algD transcript accumulation and toxA transcript accumulation. This result suggested that toxA was regulated independently of algD. Curiously, we found a positive correlation between algD transcript accumulation and both lasB and lasA transcript accumulation levels. This correlation may not indicate a direct association between algD and either lasA or lasB. More likely, it indicates a common regulatory element in a cascade of regulators or a common environmental cue that triggers transcription. PMID:9317008

  11. Hydrogeochemical and stream sediment reconnaissance basic data for Las Cruces quadrangle, New Mexico

    SciTech Connect

    Not Available

    1981-08-31

    Field and laboratory data are presented for 501 water samples and 1817 sediment samples from the Las Cruces Quadrangle, New Mexico. The samples were collected and uranium analysis performed by Los Alamos National Laboratory; multielement analysis and data reporting were performed by the Uranium Resource Evaluation Project at Oak Ridge, Tennessee.

  12. Crustal structure in the vicinity of Las Vegas, Nevada, from seismic and gravity observations

    USGS Publications Warehouse

    Roller, John C.

    1963-01-01

    A seismic-refraction profile indicates that the crust of the Earth increases in thickness by as much as 5 km over a horizontal distance of less than 25 km northeast of Las Vegas, Nevada. This feature correlates with a decrease in the Bouguer anomaly and an increase in the average surface altitude.

  13. 76 FR 61379 - Notice of Public Meeting, Las Cruces District Resource Advisory Council Meeting, New Mexico

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-04

    ... public land management in New Mexico. Planned agenda items include a welcome and introduction of new... Bureau of Land Management Notice of Public Meeting, Las Cruces District Resource Advisory Council Meeting, New Mexico AGENCY: Bureau of Land Management, Interior. ACTION: Notice of Public Meeting. SUMMARY:...

  14. VizieR Online Data Catalog: L and T dwarfs from UKIDSS LAS (Marocco+, 2015)

    NASA Astrophysics Data System (ADS)

    Marocco, F.; Jones, H. R. A.; Day-Jones, A. C.; Pinfield, D. J.; Lucas, P. W.; Burningham, B.; Zhang, Z. H.; Smart, R. L.; Gomes, J. I.; Smith, L.

    2015-11-01

    The objects presented here have been selected from the UKIDSS LAS 7th Data Release. The details of the selection criteria can be found in Day-Jones et al. (2013, Cat. J/MNRAS/430/1171, hereafter ADJ13). (5 data files).

  15. Hydrologic impacts of climate change and urbanization in Las Vegas Wash Watershed, Nevada

    EPA Science Inventory

    In this study, a cell-based model for the Las Vegas Wash (LVW) Watershed in Clark County, Nevada, was developed by combining the traditional hydrologic modeling methods (Thornthwaite’s water balance model and the Soil Conservation Survey’s Curve Number method) with the pixel-base...

  16. Episodic Impacts from California Wildfires Identified in Las Vegas Near-Road Air Quality Monitoring

    EPA Science Inventory

    Air pollutant concentrations near major highways are usually attributed to a combination of nearby traffic emissions and regional background, and generally presumed to be additive in nature. During a recent year-long near-road monitoring study conducted in Las Vegas, NV, a substa...

  17. Changes in the morphometry of Las Vegas Wash and the impact on water quality

    USGS Publications Warehouse

    Roline, Richard A.; Sartoris, James J.

    1988-01-01

    Las Vegas Wash, a natural wash east of Las Vegas, Nevada, carries stormwater, groundwater drainage, and sewage effluent from two sewage treatment plants to Lake Mean. Over 80 percent of the normal discharge of approximately 3.4 m3/s (120 ft3/s) consists of effluent from the City of Las Vegas and Clark County sewage treatment plants. Beginning in the 1950s, a large wetland area developed along the wash that supported waterfowl populations and contributed to some water quality transformations. Heavy rains and subsequent flooding in the area in 1983 and 1984 resulted in erosion and channelization that greatly reduced the wetland area within Las Vegas Wash. The reduction in wetland area shortened water travel time in the wash and affected water quality. The primary impacts on the water entering Lake Mead have been an increase in temperature, a decrease in dissolved oxygen concentration, and an increase in ammonia levels. Other physical-chemical parameters and changes in nutrient transformations are also discussed.

  18. Builders Challenge High Performance Builder Spotlight - NextGen Home, Las Vegas, Nevada

    SciTech Connect

    2009-01-01

    Building America Builders Challenge fact sheet on the NextGen demo home built in Las Vegas. The home has a Home Energy Rating System (HERS) index score of 44 with R-40 spray foam attic insulation, R-40 insulated concrete walls, and a 4kW DC solar laminate

  19. Perceptions toward the Value of Higher Education for Hotel Professionals in Las Vegas: A Case Study

    ERIC Educational Resources Information Center

    Deel, Gary Lee

    2015-01-01

    This study concerns a qualitative investigation of the views toward higher education and its importance to hospitality career success among hotel professionals in the Las Vegas, Nevada area. Existing literature supported the premise that education may be important to professional career success in several different ways, and that values concerning…

  20. Orion Launch Abort System (LAS) Propulsion on Pad Abort 1 (PA-1)

    NASA Technical Reports Server (NTRS)

    Jones, Daniel S.

    2015-01-01

    This presentation provides a concise overview of the highly successful Orion Pad Abort 1 (PA-1) flight test, and the three rocket motors that contributed to this success. The primary purpose of the Orion PA-1 flight was to help certify the Orion Launch Abort System (LAS), which can be utilized in the unlikely event of an emergency on the launchpad or during mission vehicle ascent. The PA-1 test was the first fully integrated flight test of the Orion LAS, one of the primary systems within the Orion Multi-Purpose Crew Vehicle (MPCV). The Orion MPCV is part of the architecture within the Space Launch System (SLS), which is being designed to transport astronauts beyond low-Earth orbit for future exploration missions. Had the Orion PA-1 flight abort occurred during launch preparations for a real human spaceflight mission, the PA-1 LAS would have saved the lives of the crew. The PA-1 flight test was largely successful due to the three solid rocket motors of the LAS: the Attitude Control Motor (ACM); the Jettison Motor (JM); and the Abort Motor (AM). All three rocket motors successfully performed their required functions during the Orion PA-1 flight test, flown on May 6, 2010 at the White Sands Missile Range in New Mexico, culminating in a successful demonstration of an abort capability from the launchpad.

  1. Builders Challenge High Performance Builder Spotlight - Masco Environments for Living, Las Vegas, Nevada

    SciTech Connect

    2009-01-01

    Building America Builders Challenge fact sheet on Masco’s Environments for Living Certified Green demo home at the 2009 International Builders Show in Las Vegas. The home has a Home Energy Rating System (HERS) index score of 44, a right-sized air conditi

  2. 77 FR 65332 - Proposed Modification of Class B Airspace; Las Vegas, NV

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-26

    ... establishing the Las Vegas, NV, Terminal Control Area (TCA) with an effective date of November 11, 1974 (39 FR... to ensure that turbine-powered aircraft operations were fully contained within the TCA (47 FR 30052). In 1993, as part of the Airspace Reclassification Final Rule (56 FR 65638), the term...

  3. 78 FR 43772 - Modification of Class B Airspace; Las Vegas, NV

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-22

    ... (77 FR 65332). Interested parties were invited to participate in this rulemaking effort by submitting... reopening the comment period until February 13, 2013 (78 FR 2646). The Aircraft Owners and Pilots... to reduce the number of Traffic Alert and Collision Avoidance System (TCAS) alerts between Las...

  4. The Development of Child Subjectivity in "La lengua de las mariposas"

    ERIC Educational Resources Information Center

    Ryan, Lorraine

    2012-01-01

    Jose Luis Cuerda's film "La lengua de las mariposas" is set in rural Galicia in the immediate lead-up to the outbreak of the Spanish Civil War. It portrays the tender relationship between a Republican schoolteacher, Don Gregorio, and a boy named Moncho. Upon the Nationalist capture of the town, the young Moncho hurls stones at his friend, but…

  5. 76 FR 35371 - Proposed Modification of the Las Vegas, NV, Class B Airspace Area; Public Meetings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-17

    ...: (1) The meeting on Thursday, August 18, 2011, will be held at Centennial High School, 10200... Coronado High School, 10 1 Coronado Center Drive, Henderson, NV 89052; (3) The meeting on Thursday, August 25, 2011, will be held at Shadow Ridge High School, 5050 Brent Lane, Las Vegas, NV 89131....

  6. Control del dolor: Apoyo para las personas con cáncer

    Cancer.gov

    Contiene información sobre las medicinas contra el dolor para pacientes con cáncer, los planes para controlarlo, cómo hablar con su equipo de atención médica sobre el dolor que usted siente y qué hacer para controlar los efectos físicos y emocionales del

  7. Hydrologic impacts of climate change and urbanization in Las Vegas Wash Watershed, Nevada

    EPA Science Inventory

    In this study, a cell-based model for the Las Vegas Wash (LVW) Watershed in Clark County, Nevada, was developed by combining the traditional hydrologic modeling methods (Thornthwaite’s water balance model and the Soil Conservation Survey’s Curve Number method) with th...

  8. 75 FR 38778 - Expansion of Foreign-Trade Zone 89 Las Vegas, NV

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-06

    ... the Federal Register (74 FR 59131-59132, 11/17/09) and the application has been processed pursuant to... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE Foreign-Trade Zones Board Expansion of Foreign-Trade Zone 89 Las Vegas, NV Pursuant to its authority...

  9. PERCHLORATE UPTAKE BY SALT CEDAR (TAMARIX RAMOSISSIMA) IN THE LAS VEGAS WASH RIPARIAN ECOSYSTEM

    EPA Science Inventory

    Perchlorate ion (CIO4-) has been identified in samples of dormant salt cedar (Tamarix ramosissima) growing in the Las vegas Wash. Perchlorate is an oxidenat, but its reduction is kineticaly hindered. CXoncern over thyrpoid effects caused the Environmental Protection Agency (EPA...

  10. State-of-the-Art Building Concepts Lower Energy Bills, Pulte Homes - Las Vegas, Nevada

    SciTech Connect

    2002-03-01

    Houses built by Pulte Homes as part of the U.S. Department of Energy's Building America program in Las Vegas, Nevada, save money for the home owners by reducing electric air-conditioning costs and gas heating costs with little or no additional inv

  11. Probabilistic risk assessment for linear alkylbenzene sulfonate (LAS) in sewage sludge used on agricultural soil.

    PubMed

    Schowanek, Diederik; David, Helen; Francaviglia, Rosa; Hall, Jeremy; Kirchmann, Holger; Krogh, Paul Henning; Schraepen, Nathalie; Smith, Stephen; Wildemann, Tanja

    2007-12-01

    Deterministic and probabilistic risk assessments were developed for commercial LAS in agricultural soil amended with sewage sludge. The procedure done according to ILSI Europe's Conceptual Framework [Schowanek, D., Carr, R., David, H., Douben, P., Hall, J., Kirchmann, H., Patria, L., Sequi, P., Smith, S., Webb, S.F., 2004. A risk-based methodology for deriving quality standards for organic contaminants in sewage sludge for use in agriculture-conceptual Framework. Regul. Toxicol. Pharmacol. 40 (3), 227-251], consists of three main steps. First, the most sensitive endpoint was determined. This was found to be the chronic ecotoxicity of LAS to soil invertebrates and plants. Additional endpoints, such as potential for plant uptake and transfer in the food chain, leaching to groundwater, surface erosion run-off, human health risk via drinking water, plant consumption and soil ingestion were also systematically evaluated but were all assessed to be of little toxicological significance. In the second step, a back-calculation was conducted from the Predicted No-Effect Concentration in soil (PNECsoil) to a safe level of LAS in sludge (here called 'Sludge Quality Standard'; SQS). The deterministic approach followed the default agricultural soil exposure scenario in the EU-Technical Guidance Document (TGD). The SQS for LAS was calculated as 49 g/kg sludge Dry Matter (DM). In order to assess the potential variability as a result of varying agricultural practices and local environmental conditions, two probabilistic exposure assessment scenarios were also developed. The mean SQS was estimated at 55 and 27.5 g/kg DM for the homogeneous soil mixing and soil injection scenarios, respectively. In the final step, the resulting SQS values were evaluated for consistency and relevance versus available information from agricultural experience and field tests. No build-up, adverse impact on soil fertility, agronomic performance, or animal/human health have been reported for agricultural

  12. The vitamin riboflavin and its derivative lumichrome activate the LasR bacterial quorum-sensing receptor.

    PubMed

    Rajamani, Sathish; Bauer, Wolfgang D; Robinson, Jayne B; Farrow, John M; Pesci, Everett C; Teplitski, Max; Gao, Mengsheng; Sayre, Richard T; Phillips, Donald A

    2008-09-01

    Many bacteria use quorum sensing (QS) as an intercellular signaling mechanism to regulate gene expression in local populations. Plant and algal hosts, in turn, secrete compounds that mimic bacterial QS signals, allowing these hosts to manipulate QS-regulated gene expression in bacteria. Lumichrome, a derivative of the vitamin riboflavin, was purified and chemically identified from culture filtrates of the alga Chlamydomonas as a QS signal-mimic compound capable of stimulating the Pseudomonas aeruginosa LasR QS receptor. LasR normally recognizes the N-acyl homoserine lactone (AHL) signal, N-3-oxo-dodecanoyl homoserine lactone. Authentic lumichrome and riboflavin stimulated the LasR receptor in bioassays and lumichrome activated LasR in gel shift experiments. Amino acid substitutions in LasR residues required for AHL binding altered responses to both AHLs and lumichrome or riboflavin. These results and docking studies indicate that the AHL binding pocket of LasR recognizes both AHLs and the structurally dissimilar lumichrome or riboflavin. Bacteria, plants, and algae commonly secrete riboflavin or lumichrome, raising the possibility that these compounds could serve as either QS signals or as interkingdom signal mimics capable of manipulating QS in bacteria with a LasR-like receptor.

  13. Estudio comparativo de las moléculas isovalentes de interés atmosférico CF3Cl y CF3Br y sus correspondientes halógenos aislados Cl y Br.

    NASA Astrophysics Data System (ADS)

    Mayor, E.; Velasco, A. M.; Martín, I.; Lavín, C.

    Los estados Rydberg moleculares han suscitado en los últimos años un creciente interés entre los espectroscopistas experimentales, motivado en parte por el desarrollo de nuevas técnicas espectroscópicas capaces de investigar estos estados altamente excitados electrónicamente. Los procesos de fotoabsorción que implican estados Rydberg en los derivados halogenados del metano son de gran importancia, debido a su abundancia en la atmósfera y a sus implicaciones medioambientales. Por ello, la obtención de datos relativos a sus fuerzas de oscilador es de gran interés. En este trabajo se aborda el estudio de dichas propiedades para las moléculas isovalentes CF3Cl y CF3Br. Ambas moléculas presentan idéntica estructura electrónica para el estado fundamental por lo que se espera que sus espectros Rydberg presenten grandes similitudes, en ausencia de perturbaciones. Por ello y dada la escasez de datos relativos a fuerzas de oscilador, hemos establecido la corrección de nuestros resultados en base a las analogías esperadas en las intensidades espectrales correspondientes a transiciones análogas. Por otro lado, Novak y col. [1] han encontrado experimentalmente un marcado carácter atómico en el espectro correspondiente a estas moléculas, siendo muy similar a los de los átomos de Cl y Br. Por ello en el presente trabajo, además de establecer la comparación entre ambas moléculas hemos buscado las similitudes con sus respectivos halógenos. Los cálculos relativos a las especies moleculares se han realizado utilizando la Metodología Molécular de Orbítales de Defecto Cuántico (MQDO) [2], mientras que para el estudio de los átomos de Cl y Br se empleó la versión relativista del método (RQDO) [3].

  14. Sealing 304L to lithia-alumina-silica (LAS) glass-ceramics

    SciTech Connect

    Moddeman, W.E.; Pence, R.E.; Massey, R.T.; Cassidy, R.T.; Kramer, D.P.

    1989-12-31

    The formation of a crack-free between 300 series stainless steel and a glass-ceramic is difficult owing to the high coefficients of thermal expansion of the stainless steels. Lithia-alumina-silica (LAS) glass-ceramics were successfully developed and sealed to 304L stainless steel. These crack-free seals were fabricated by two techniques: by adjusting the parent glass composition (reducing the Al{sub 2}O{sub 3} content), or by adjusting the sealing/crystallization cycle. All seals were hermetic, with leak rates < 10{sup -8} cc/sec STP helium. CTE and alloy yield strengths are given which show the feasibility of using these materials to make feedthroughs, pyrotechnic components, etc. Metallography, SEM, and wavelength dispersive spectroscopy show the quality and integrity of the glass-ceramic/stainless steel interface. These data are compared to those on the Inconel 718/LAS-glass seal system.

  15. Exposure of the marine deposit feeder Hydrobia ulvae to sediment associated LAS.

    PubMed

    Mauffret, A; Rico-Rico, A; Temara, A; Blasco, J

    2010-02-01

    Linear Alkylbenzene Sulfonates (LAS) effects (mortality, egestion rate, behaviour) on the marine deposit feeder Hydrobia ulvae were assessed in whole-sediment and water-only systems. The results were combined with a bioenergetic-based kinetic model of exposure pathways to account for the observed toxicity. The 10-d LC50 value based on the freely dissolved fraction was 9.3 times lower in spiked sediment (0.152 +/- 0.001 (95% CI) mg/L) than in water-only (1.390 +/- 0.020 (95% CI) mg/L). Consequently, the actual 10-d LC50 value (208 mg/kg) was overestimated by the Equilibrium Partitioning calculation (1629 mg/kg). This suggests that the sediment associated LAS fraction was bioavailable to the snails. It could also be due to modifications in physiological parameters in absence of sediment, the organism natural substrate.

  16. Reinterpretation of the stratigraphy and structure of the Rancho Las Norias area, central Sonora, Mexico

    USGS Publications Warehouse

    Page, W.R.; Harris, A.G.; Poole, F.G.; Repetski, J.E.

    2003-01-01

    New geologic mapping and fossil data in the vicinity of Rancho Las Norias, 30 km east of Hermosillo, Sonora, Mexico, show that rocks previously mapped as Precambrian instead are Paleozoic. Previous geologic maps of the Rancho Las Norias area show northeast-directed, southwest-dipping reverse or thrust faults deforming both Precambrian and Paleozoic rocks. The revised stratigraphy requires reinterpretation of some of these faults as high-angle normal or oblique-slip faults and the elimination of other faults. We agree with earlier geologic map interpretations that compressional structures have affected the Paleozoic rocks in the area, but our mapping suggests that the direction of compression is from southeast to northwest. Published by Elsevier Ltd.

  17. Continuous absence of metaphase-defined cytogenetic abnormalities, especially of chromosome 13 and hypodiploidy, ensures long-term survival in multiple myeloma treated with Total Therapy I: interpretation in the context of global gene expression.

    PubMed

    Shaughnessy, John; Jacobson, Joth; Sawyer, Jeff; McCoy, Jason; Fassas, Athanasios; Zhan, Fenghuang; Bumm, Klaus; Epstein, Joshua; Anaissie, Elias; Jagannath, Sundar; Vesole, David; Siegel, David; Desikan, Raman; Munshi, Nikhil; Badros, Ashraf; Tian, Erming; Zangari, Maurizio; Tricot, Guido; Crowley, John; Barlogie, Bart

    2003-05-15

    Metaphase cytogenetic abnormalities (CAs), especially of chromosome 13 (CA 13), confer a grave prognosis in multiple myeloma even with tandem autotransplantations as applied in Total Therapy I, which enrolled 231 patients between 1989 and 1994. With a median follow-up of almost 9 years, the prognostic implications of all individual CAs, detected prior to treatment and at relapse, were investigated. Among all CAs and standard prognostic factors examined prior to therapy, only hypodiploidy and CA 13 (hypo-13 CA), alone or in combination, were associated with shortest event-free survival and overall survival (OS). The shortest postrelapse OS was observed with hypo-13 CA, which was newly detected in 18 of all 28 patients presenting with this abnormality at relapse. Superior prognosis was associated with the absence of any CA at both diagnosis and relapse (10-year OS, 40%). The lack of independent prognostic implications of other CAs points to a uniquely aggressive behavior of hypo-13 CA (present in 16% of patients at diagnosis). With the use of microarray data in 146 patients enrolled in Total Therapy II, overexpression of cell cycle genes distinguished CA from no CA, especially in cases of del(13) detected by interphase fluorescence in situ hybridization (FISH). FISH 13, resulting in a haploinsufficiency of RB1 and other genes mapping to chromosome 13, as well as activation of IGF1R, appears to have an amplifying effect on cell cycle gene expression, thus providing a molecular explanation for the dire outcome of patients with CA 13 compared with those with other CAs.

  18. Comenditic and pantelleritic ash-flow tuffs from Volcan Las Navajas, Nayarit, Mexico

    SciTech Connect

    Nelson, S.A.; Hebre, J.A.

    1985-01-01

    Two distinctive ash-flow tuffs occur around the base of Volcan Las Navajas, a Pleistocene trachyte - peralkaline rhyolite center located in the northwestern segment of the Mexican Volcanic belt. The lower ash-flow unit is locally up to 65 m thick, is lithic rich and contains pumice blocks of comenditic rhyolite. The unit is not extensively exposed, and thus its areal extent and volume cannot be determined. Its chemical characteristics and stratigraphic relationship to other products erupted from Las Navajas suggest that it is related to the formation of the older of the two calderas which occur on Las Navajas. Unconformably overlying this unwelded ash-flow is a pantelleritic airfall pumice unit which is locally welded. This airfall unit is conformably overlain by a welded as-flow tuff that contains fiamme of pantelleritic composition (72 %SiO/sub 2/, 8% FeO*, 900 ppm Zr, agpaitic index of 1.7) as well as pumice blocks that show evidence of various degrees of mixing between pantellerite and trachyte. This suggests eruption from a chemically zoned magma chamber. This unit is locally up to 20 m thick, although its top has been removed by erosion. It is found on all sides of Las Navajas except on the south where it may be covered by Volcan Sanganguey, a Pleistocene to Recent calc-alkaline volcano. The welded ash-flow has been dated by K - Ar at 0.2+/-0.1 m.y. Stratigraphically and chemically this ash-flow appears to be related to the formation of younger of the two calderas.

  19. Quantifying multi-temporal urban development characteristics in Las Vegas from Landsat and ASTER data

    USGS Publications Warehouse

    Xian, G.; Crane, M.; McMahon, C.

    2008-01-01

    Urban development has expanded rapidly in Las Vegas, Nevada of the United States, over the last fifty years. A major environmental change associated with this urbanization trend is the transformation of the landscape from natural cover types to increasingly anthropogenic impervious surface. This research utilizes remote sensing data from both the Landsat and Terra-Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instruments in conjunction with digital orthophotography to estimate urban extent and its temporal changes by determining sub-pixel impervious surfaces. Percent impervious surface area has shown encouraging agreement with urban land extent and development density. Results indicate that total urban land-use increases approximately 110 percent from 1984 to 2002. Most of the increases are associated with medium-to high-density urban development. Places having significant increases in impervious surfaces are in the northwestern and southeastern parts of Las Vegas. Most high-density urban development, however, appears in central Las Vegas. Impervious surface conditions for 2002 measured from Landsat and ASTER satellite data are compared in terms of their accuracy. ?? 2008 American Society for Photogrammetry and Remote Sensing.

  20. Surficial geology and distribution of post-impoundment sediment in Las Vegas Bay, Lake Mead

    USGS Publications Warehouse

    Twichell, David C.; Cross, VeeAnn A.; Rudin, Mark J.; Parolski, Kenneth F.; Rendigs, Richard R.

    2001-01-01

    Sidescan sonar imagery and seismic-reflection profiles were collected in the northwestern part of Las Vegas Bay to map the distribution and volume of sediment that has accumulated in this part of Lake Mead since impoundment. The mapping suggests that three ephemeral streams are the primary source of this sediment, and of these, Las Vegas Wash is the largest. Two deltas off the mouth of Las Vegas Wash formed at different lake elevations and account for 41% of the total volume of post-impoundment sediment within the study area. Deltas off the other two washes (Gypsum and Government) account for only 6% of the total volume. The sediment beyond the front of the deltas is primarily mud, and it only occurs in valley floors, where it forms a flat-lying blanket that is mostly less than 1.5 m thick. Although a thin layer, the fine-grained sediment accounts for approximately 53% of the total post-impoundment sediment volume of 5.7 x 106 m3 that has accumulated in the study area. This sediment appears to have been transported several kilometers from the river sources by density flows.

  1. GRACE and ICESat Data for Estimation of Ice Sheet Surface Changes in LAS, East Antarctica

    NASA Astrophysics Data System (ADS)

    Xie, H.; Ju, X.; Liu, J.; Gu, Z.; Liu, S.; Tian, Y.; Chen, L.; Shen, Y.; Tong, X.; Sun, B.; Li, R.

    2014-12-01

    Knowledge of mass changes of the Antarctic ice sheet is essential for understanding global climate change, specifically, for sea-level change. This presentation reports the the results of a comparative study on changes of regional ice sheet mass and surface elevation based on observations of GRACE and ICESat satellites over the period of 2004 - 2008 in the Lambert Glacier-Amery Ice Shelf System (LAS), East Antarctica. LAS is an important drainage system in East Antarctica and one of the significant contributors to the mass budget of the Antarctic. We fitted the GRACE monthly solutions to a model that contains a linear trend, an acceleration, annual and semiannual terms, and a 161 days tide aliasing term (S2). We employed the IJ05 R2 GIA model. For ICESat observations, we employed a modified spatial-temporal polynomial model to describe the ice surface topography and an annual elevation change rate (trend), which is solved by using repeat-track points within a moving box along the repeating tracks. Uncertainties of the source data and the estimated trends from both GRACE and ICESat data are given. The mass changes from GRACE and ICESat are compared and the differences are analyzed. A number of key issues in the comparison and mass - volume conversion are discussed. Afterwards, spatial and temporal correlations between the results at the annual change level derived from the two data sets are analyzed. Impact of firn models, GIA models, and comparison with other research results in LAS demonstrated.

  2. The Las Vegas Valley Seismic Response Project: Ground Motions in Las Vegas Valley from Nuclear Explosions at the Nevada Test Site

    SciTech Connect

    Rodgers, A; Tkalcic, H; McCallen, D

    2005-03-18

    Between 2001-2004 the Las Vegas Seismic Response Project has sought to understand the response of Las Vegas Valley (LVV) to seismic excitation. In this study, the author report the findings of this project with an emphasis on ground motions in LVV from nuclear explosions at the Nevada Test Site (NTS). These ground motions are used to understand building structural response and damage as well as human perception. Historical nuclear explosion observations are augmented with earthquake recordings from a temporary deployment of seismometers to improve spatial coverage of LVV. The nuclear explosions were conducted between 1968 and 1989 and were recorded at various sites within Las Vegas. The data from past nuclear tests were used to constrain ground motions in LVV and to gain a predictive capability of ground motions for possible future nuclear tests at NTS. Analysis of ground motion data includes peak ground motions (accelerations and velocities) and amplification of basin sites relative to hard rock sites (site response). Site response was measured with the Standard Spectral Ratios (SSR) technique relative to hard rock reference sites on the periphery of LVV. The site response curves indicate a strong basin amplification of up to a factor of ten at frequencies between 0.5-2 Hz. Amplifications are strongest in the central and northern portions of LVV, where the basin is deeper than 1 km based on the reported basin depths of Langenheim et al (2001a). They found a strong correlation between amplification and basin depth and shallow shear wave velocities. Amplification below 1 Hz is strongly controlled by slowness-averaged shear velocities to depths of 30 and 100 meters. Depth averaged shear velocities to 10 meters has modest control of amplifications between 1-3 Hz. Modeling reveals that low velocity material in the shallow layers (< 200 m) effectively controls amplification. They developed a method to scale nuclear explosion ground motion time series to sites around LVV

  3. 40 CFR 51.917 - What is the effective date of designation for the Las Vegas, NV, 8-hour ozone nonattainment area?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... designation for the Las Vegas, NV, 8-hour ozone nonattainment area? 51.917 Section 51.917 Protection of... Air Quality Standard § 51.917 What is the effective date of designation for the Las Vegas, NV, 8-hour ozone nonattainment area? The Las Vegas, NV, 8-hour ozone nonattainment area (designated on September...

  4. 40 CFR 51.917 - What is the effective date of designation for the Las Vegas, NV, 8-hour ozone nonattainment area?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... designation for the Las Vegas, NV, 8-hour ozone nonattainment area? 51.917 Section 51.917 Protection of... Air Quality Standard § 51.917 What is the effective date of designation for the Las Vegas, NV, 8-hour ozone nonattainment area? The Las Vegas, NV, 8-hour ozone nonattainment area (designated on September...

  5. 40 CFR 51.917 - What is the effective date of designation for the Las Vegas, NV, 8-hour ozone nonattainment area?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... designation for the Las Vegas, NV, 8-hour ozone nonattainment area? 51.917 Section 51.917 Protection of... Air Quality Standard § 51.917 What is the effective date of designation for the Las Vegas, NV, 8-hour ozone nonattainment area? The Las Vegas, NV, 8-hour ozone nonattainment area (designated on September...

  6. 40 CFR 51.917 - What is the effective date of designation for the Las Vegas, NV, 8-hour ozone nonattainment area?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... designation for the Las Vegas, NV, 8-hour ozone nonattainment area? 51.917 Section 51.917 Protection of... Air Quality Standard § 51.917 What is the effective date of designation for the Las Vegas, NV, 8-hour ozone nonattainment area? The Las Vegas, NV, 8-hour ozone nonattainment area (designated on September...

  7. 40 CFR 51.917 - What is the effective date of designation for the Las Vegas, NV, 8-hour ozone nonattainment area?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... designation for the Las Vegas, NV, 8-hour ozone nonattainment area? 51.917 Section 51.917 Protection of... Air Quality Standard § 51.917 What is the effective date of designation for the Las Vegas, NV, 8-hour ozone nonattainment area? The Las Vegas, NV, 8-hour ozone nonattainment area (designated on September...

  8. Shear Velocity Structure Beneath the Las Vegas Valley, Nevada From Regional and Teleseismic Events

    NASA Astrophysics Data System (ADS)

    McEwan, D. J.; Snelson, C. M.; Tkalcic, H.; Rodgers, A.

    2004-12-01

    The Las Vegas Valley (LVV), Nevada is located in the central Basin and Range province of western North America. The Valley sits atop a broad sedimentary basin and is susceptible to large earthquakes generated by local and regional faults. During ground motion events, the Las Vegas basin has been found to amplify seismic energy. In addition, the crustal and upper mantle structure of the Valley is poorly understood. Therefore, surface wave data have been used to create shear velocity profiles of the crust and upper mantle beneath LVV using regional and teleseismic events. This project is part of a larger collaborative study, which is characterizing the Las Vegas basin for test site readiness and seismic hazards. Although the frequency of large events is small, the risk associated with such an event is very high for the Valley. As a result, the Las Vegas Valley Broadband array (LVVBB) was deployed in late September 2002 by Lawrence Livermore National Laboratory and the University of Nevada Las Vegas. It consists of a mixture of twelve three-component broadband and short period seismometers deployed in a saw-tooth geometry oriented northeast-southwest across the northeastern and central LVV, above the area estimated to be the deepest portion of the basin. Data examined as part of this study include both regional and global earthquake events recorded within a five-month period on seven of the twelve stations. All seven broadband stations used a three-component Guralp CMG40T sensor with a 40 samples/second sampling rate. Group velocity dispersion curves from Rayleigh waves and Love waves were determined using a multiple filter technique. Rayleigh wave group velocities range from 2.7 to 3.5 km/s for periods from 10 to 30s. Love wave group velocities range from 3.1 to 4.0 km/s for periods from 10 to 100s. In addition, Rg and Lg were examined from local events. 1-D shear velocity profiles of the crust and upper mantle have been produced through inversion along regional

  9. An Aerial Radiological Survey of Selected Areas of the City of North Las Vegas

    SciTech Connect

    Piotr Wasiolek

    2008-06-01

    As part of the proficiency training for the Radiological Mapping mission of the Aerial Measuring System (AMS), a survey team from the Remote Sensing Laboratory-Nellis (RSL-Nellis) conducted an aerial radiological survey of selected areas of the city of North Las Vegas for the purpose of mapping natural radiation background and locating any man-made radioactive sources. Survey areas were selected in collaboration with the City Manager's office and included four separate areas: (1) Las Vegas Motor Speedway (10.6 square miles); (2) North Las Vegas Downtown Area (9.2 square miles); (3) I-15 Industrial Corridor (7.4 square miles); and (4) Future site of University of Nevada Las Vegas campus (17.4 square miles). The survey was conducted in three phases: Phase 1 on December 11-12, 2007 (Areas 1 and 2), Phase 2 on February 28, 2008 (Area 3), and Phase 3 on March 19, 2008 (Area 4). The total completed survey covered a total of 44.6 square miles. The flight lines (without the turns) over the surveyed areas are presented in Figures 1, 2, 3, and 4. A total of eight 2.5-hour-long flights were performed at an altitude of 150 ft above ground level (AGL) with 300 feet of flight-line spacing. Water line and test line flights were conducted over the Lake Mead and Government Wash areas to ensure quality control of the data. The data were collected by the AMS data acquisition system (REDAR V) using an array of twelve 2-inch x 4-inch x 16-inch sodium iodide (NaI) detectors flown on-board a twin-engine Bell 412 helicopter. Data, in the form of gamma energy spectra, were collected continually (every second) over the course of the survey and were geo-referenced using a differential Global Positioning System. Collection of spectral data allows the system to distinguish between ordinary fluctuations in natural background radiation levels and the signature produced by man-made radioisotopes. Spectral data can also be used to identify specific radioactive isotopes. As a courtesy service, with

  10. Final Report for the Arroyo Las Positas Maintenance Impact Study, Lawrence Livermore National Laboratory

    SciTech Connect

    van Hattem, M; Paterson, L

    2006-01-12

    In 2000, the Lawrence Livermore National Laboratory's (LLNL) Environmental Protection Department, in coordination with Plant Engineering (PE), began dredging sections of the Arroyo Las Positas (ALP) to alleviate concerns about flooding of sensitive facilities within the mainsite of Lawrence Livermore National Laboratory. In order to reduce potential impacts on the federally threatened California red-legged frog (Rana aurora draytonii), LLNL proposed to dredge sections of the ALP in a ''checkerboard pattern'', resulting in a mosaic of open water habitat and vegetated sections (Figure 1). The Arroyo Las Positas Management Plan (Plan) was coordinated with both state and federal agencies including the U.S. Fish and Wildlife Service (USFWS), California Department of Fish and Game (CDF&G), San Francisco Regional Water Quality Control Board (SFRWQCB), and the Army Corp of Engineers (ACOE). Water Discharge Requirements (WDRs) were issued for this project on December 30, 1999 (Order No. 99-086) by the SFRWQCB. Provision 19 of the WDRs outlined a five-year (2000 through 2004) Maintenance Impact Study (MIS) that LLNL began in coordination with dredging work that was conducted as part of the Arroyo Las Positas Management Plan. Provision 20 of these WDRs requires LLNL to submit a final report of the results of the Maintenance Impact Study for this project to the SFRWQCB. The purpose of this report is to present the results of the Maintenance Impact Study for Arroyo Las Positas and meet the requirements of Provision 20. A description of the annual monitoring included in this Maintenance Impact Study is included in the methods section of this report. Initially the Plan called for dredging the entire length of the Arroyo Las Positas (approximately 6,981 linear feet) over a 5-year period to minimize temporal impacts on the California red-legged frog. Dredging occurred in 2000 ({approx}1,300 ft.), 2001 ({approx}800 ft.), and 2002 ({approx}1,200 ft.), which constituted approximately

  11. Earthquakes in the Classroom, Las Vegas, NV: The Nevada Educational Seismic Network (NESN)

    NASA Astrophysics Data System (ADS)

    Hopkins, J.; Snelson, C. M.; Zaragoza, S. A.; Smith, K.; Depolo, D.

    2002-12-01

    Geophysics is a term guaranteed to strike fear into the heart of the bravest high school science student. Using math to describe the earth can involve complex equations that can only be deciphered by enigmatic computer programs. But high school science students in the Las Vegas Valley have been given a unique opportunity to gather important research information while learning about geophysics, real-time data collection, and Internet communications in a less threatening environment. Three seismograph stations funded by the Department of Energy and the University of Nevada, Las Vegas have been installed in three different high schools in the Clark County School District. These three stations form a triangle in the Las Vegas Valley basin covering areas where the basin depths change significantly. The geophones are buried outside and a cable connects the sensors and GPS receiver to a digitizer on a local PC. The data is transmitted continuously in real-time via Internet communications protocols to the Seismic Explorer Monitoring Network. There it is available to all schools and to researchers who will analyze the data. These short-period geophones will record small local earthquakes and larger more distant events contributing to real-time seismic network operations in southern Nevada. Students at a school site are able to see live real-time data from other school stations as well as from seismograph stations in southern Nevada, the western US, and the world. Mentored by researchers at the University of Nevada, Reno and University of Nevada, Las Vegas, the teachers and students conduct simple waveform analysis to determine earthquake locations and magnitudes and operate the stations in this cooperative research effort. The goal of this partnership between secondary and university educational systems is to create a successful alliance that will benefit the research community as well as the classroom teacher and his/her students. Researchers will use the data collected

  12. Variaciones seculares de período en las RR Lyrae de ω~Centauri

    NASA Astrophysics Data System (ADS)

    Marraco, H. G.; Milesi, G. E.

    Utilizando 689 observaciones de 35 estrellas RR Lyrae del cúmulo globular ω Centauri hemos obtenido nuevas determinaciones de sus períodos y sus correspondientes variaciones seculares. Las observaciones fueron obtenidas de la literatura con la excepción de un grupo 66 determinaciones que se presentan por vez primera aquí. Utilizando el parámetro testigo σ descripto en Marraco & Muzzio (Publ. Astron. Soc. Pacific 92, 700, 1980), hemos realizado un ajuste bidimensional en P y β (donde β es la variación secular del período). Con este fin la totalidad de las 689 observaciones fueron llevadas a un sistema fotométrico común. Para esto se realizó un cuidadoso análisis de los numerosos errores en la identificación de las estrellas de las series de comparación. Los resultados de los ajustes bidimensionales fueron analizados utilizando técnicas de procesamiento de imágenes. Con este fin el parámetro de ajuste σ fue representado como función de P y β. En las imágenes resultantes se buscaron los mínimos y al menor de ellos se lo aceptó como período instantáneo verdadero y su variación secular β. La determinación precisa de cada parámetro se realizó mediante ajuste de gaussianas y se determinaron sus errores. A modo de ejemplo la variable #8 fue analizada en una matriz de 501 × 501 elementos representando el parámetro σ para valores comprendidos entre 0,521034 < P < 0,521534 dias y -150×10-10 < β < +150×10-10 dias/dia. El mejor período instantáneo (correspondiente a la época DJ=2.426.908) y su variación secular son P = 0,5212859±0,0000001 días y β 14,012±,010×10-10 días/día respectivamente. Con estos valores el parámetro testigo resulta σ= 0,127 . Si no se tiene en cuenta la variación secular del período y se busca aquél de mejor ajuste para β = 0, se obtiene P = 0,5212960 días, pero entonces el parámetro de ajuste resulta tan alto como σ = 0,23 .

  13. Investigaccion-accion en la sala de clases sobre las creencias de la cultura de la ciencia de un grupo de estudiantes universitarios y su relacion reciproca con el aprendizaje de las ciencias biologicas

    NASA Astrophysics Data System (ADS)

    Cordova-Santiago, Lizzette Astrid

    La investigacion---accion que se llevo a cabo en la sala de clases tenia como punto de partida las creencias de la cultura de la ciencia de un grupo de estudiantes universitarios para luego examinar sus implicaciones en el proceso de aprendizaje de las Ciencias Biologicas. ¿Que se supone que hagan las creencias en relacion con el aprendizaje? ¿En que consiste incorporar este aspecto a la practica educativa universitaria? Utilizando el modelo de Kemmis y McTaggart (1987) la investigacion-accion se planteo como un proceso dinamico en cuatro momentos en espiral constituidos por la planificacion, la accion, la observacion y la reflexion. Cada una de las fases tuvo una intencion retrospectiva y prospectiva formando una espiral de autorreflexion del conocimiento y la accion. Se llevaron a cabo audio grabaciones en clases y analisis de documentos. Ademas, la profesora-investigadora hizo un portafolio para reflexionar sobre las creencias de la cultura de la ciencia que tienen los estudiantes y las creencias del aprendizaje que tiene la profesora y sobre como la comprension de estos elementos ayudo a mejorar su practica educativa a traves del tiempo. Los resultados obtenidos apuntan a que las creencias de la cultura de la ciencia que tiene el grupo de estudiantes son diversas. Ellos si creen que la ciencia tiene una cultura la cual describieron como: complicada y desconocida que evoluciona constantemente, que es un conjunto de metodos, que es altamente tecnologica, que resuelve problemas de salud, ayuda a interpretar la realidad del mundo que los rodea y su origen y que existen unas intersecciones entre la ciencia y el poder. Sobre las creencias del proceso de aprendizaje de la profesora-investigadora, estas senalan que el modelaje de actores, la vision de la academia que tiene ella asi como la participacion y negociacion entre todos los involucrados en el proceso educativo, son factores que inciden en el proceso de aprendizaje.

  14. Use of 90° Hopkin’s Telescopic Examination as an OPD Tool to Clinically Evaluate and Record Oral Cavity Lesions: Our Experience in Early Detection, Especially in Patients with Limited Mouth Opening

    PubMed Central

    Gupta, Karan; Patel, Daxesh; Patel, Purvi; Toprani, Rajendra; Patel, Kaustubh

    2015-01-01

    Introduction Restricted mouth opening due to premalignant lesions like oral sub-mucous fibrosis, malignancies of oral cavity and postoperative status is very common in Indian patients. It is very difficult to evaluate, document and biopsy the lesions due to inability to access, vast area and diversity of premalignant lesions and subject variations. 90° Hopkin’s slender out-patient examination telescope was found useful tool in this. Aim The aim of the study was to evaluate the use of magnified view and reach of a slender telescope to document and examine the oral cavity for any premalignant and malignant lesions, especially for patients with restricted mouth opening and to study its impact on management. Materials and Methods A 900 Hopkin’s telescope was used to evaluate and document oral cavity examination in the Out Patients Department (OPD). The data of first 2000 patients was analysed. Results Difficult to reach areas, where mouth opening was severely restricted was the significant subset. A total of 1394 patients approached OPD for primary diagnosis at our tertiary cancer care centre. Six hundred and six patients were the ones in follow up after treatment in form of Surgery, Chemotherapy or Radiotherapy, or combination. Five twenty three patients (of 1394) with mouth opening ≤ 20mm formed the study group. Telescope guided biopsies were also taken in 50 patients from 56 sites. Serial recordings were compared objectively in premalignant, treatment evaluation and close watch groups. An increase of 5.6% in rate of diagnosis of malignancy was made possible with the help of telescopic examination in patients with mouth opening ≤ 20mm. Conclusion A 900 Hopkin’s telescopic examination is a useful tool to evaluate and record oral cavity lesions, especially in patients with restricted mouth openings. It is a useful tool for screening high risk group, giving definite advantage of objective evaluation and recording of the lesion. It can also be used to

  15. Long-term assessment of ultrafine particles on major roadways in Las Vegas, Nevada and Detroit, Michigan

    EPA Science Inventory

    This is a presentation at the National Air Monitoring conference, given at the request of OAQPS partners. The presentation will cover ultrafine particle data collected at three locations - Las Vegas, Detroit, and Research Triangle Park.

  16. Seismic Data for Evaluation of Ground Motion Hazards in Las Vegas in Support of Test Site Readiness Ground Motion

    SciTech Connect

    Rodgers, A

    2008-01-16

    In this report we describe the data sets used to evaluate ground motion hazards in Las Vegas from nuclear tests at the Nevada Test Site. This analysis is presented in Rodgers et al. (2005, 2006) and includes 13 nuclear explosions recorded at the John Blume and Associates network, the Little Skull Mountain earthquake and a temporary deployment of broadband station in Las Vegas. The data are available in SAC format on CD-ROM as an appendix to this report.

  17. Study on the Principle Mechanisms of Heat Transfer for Cryogenic Insulations: Especially Accounting for the Temperature-Dependent Deposition-Evacuation of the Filling Gas (Self-Evacuating Systems)

    NASA Astrophysics Data System (ADS)

    Geisler, Matthias; Vidi, Stephan; Ebert, Hans-Peter

    2016-11-01

    This study concentrates on the principles of heat transfer within cryogenic insulation systems, especially accounting for self-evacuating systems (deposition-evacuation of the filling gas). These principles allow the extrapolation to other temperatures, gases and other materials with the input of only a few experimentally derived or carefully estimated material properties. The type of gas (e.g. air or CO2) within the porous insulation material dominates the behaviour of the effective thermal conductivity during the cooldown of the cryogenic application. This is due to the specific temperature-dependent saturation gas pressure which determines the contribution of the gas conductivity. The selected material classes include powders, fibrous insulations, foams, aerogels and multilayer insulations in the temperature range of 20 K to 300 K. Novel within this study is an analytical function for the total and the mean thermal conductivity with respect to the temperature, type of gas, external pressure and material class of the insulation. Furthermore, the integral mean value of the thermal conductivity, the so-called mean thermal conductivity, is calculated for a mechanically evacuated insulation material and an insulation material evacuated by deposition-evacuation of the filling gas, respectively. This enables a comparison of the total thermal conductivity of cryogenic insulation materials and their applicability for a self-evacuating cryogenic insulation system.

  18. A brief hydrologic appraisal of the July 3-4, 1975, flash flood in Las Vegas Valley, Nevada

    USGS Publications Warehouse

    Katzer, T.L.; Glancy, Patrick A.; Harmsen, Lynn

    1976-01-01

    Heavy thunderstorm precipitation on the afternoon of July 3, 1975, between metropolitan Las Vegas and the mountains to the south, west, and north, caused flash flooding in the city area. Total storm precipitation equaled or exceeded 3 inches (76 mm) in some areas. The total storm yield on the area of significant runoff was probably between 20,000 and 25,000 acre-feet (2.5 x 107 m3 and 3.1 x 107 m3) of water. Of this amount, probably less than 3,000 acre-feet (37 x 106 m3) flowed directly to Lake Mead. Peak flows of Tropicana Wash, Flamingo Wash, Las Vegas Creek, and Las Vegas Wash were the highest ever determined. Flooding caused the loss of two lives and inflicted extensive property damage. Total damage was reportedly estimated by the Clark County Flood Control District at $4-5 million. Problems associated with sediment erosion, transportation, and deposition occurred throughout the flooded area. An unknown amount of the material transported during the flood was deposited in Lake Mead near the mouth of Las Vegas Wash. Lateral erosion appeared more prominent than vertical erosion along most major channels, except on Las Vegas Wash at Northshore Road where downcutting threatened the loss of the highway. Sediment deposits were particularly noticeable and troublesome in Flamingo Wash at Caesars Palace parking lot and on the Winterwood Golf Course near the junction of Flamingo Wash and Las Vegas Wash.

  19. An Aerial Radiological Survey of the City of North Las Vegas (Downtown) and the Motor Speedway

    SciTech Connect

    Piotr Wasiolek

    2007-12-01

    As part of the proficiency training for the Radiological Mapping mission of the Aerial Measuring System (AMS), a survey team from the Remote Sensing Laboratory-Nellis (RSL-Nellis) conducted an aerial radiological survey on December 11-12, 2007, with the purpose of mapping natural radiation background and locating any man-made radioactive sources. The survey covered 19.4 square miles (9.2 square miles over the downtown area of the City of North Las Vegas and 10.2 square miles over the Las Vegas Motor Speedway [LVMS]). The flight lines over the surveyed areas are presented in Figures 1 and 2. A total of four 2.5-hour-long flights were performed at an altitude of 150 ft above ground level (AGL) with 300 ft of flight line spacing. Water line and test line flights were conducted over the Lake Mead and Government Wash areas to ensure quality control of the data. The data were collected by the AMS data acquisition system-REDAR V using an array of twelve 2-inch x 4-inch x 16-inch sodium iodide (NaI) detectors flown on-board a twin-engine Bell 412 helicopter. Data in the form of gamma energy spectra were collected continually (every second) over the course of the survey and were geo-referenced using a differential Global Positioning System. Collection of spectral data allows the system to distinguish between ordinary fluctuations in natural background radiation levels and the signature produced by man-made radioisotopes sources. Spectral data can also be used to identify specific radioactive isotopes. As a courtesy service with the approval of the U.S. Department of Energy, National Nuclear Security Administration, Nevada Site Office, RSL-Nellis is providing this summary to the office of the Mayor of City of North Las Vegas and LVMS security along with the gross counts-based exposure rate and man-made counts maps.

  20. Roles of Pseudomonas aeruginosa las and rhl Quorum-Sensing Systems in Control of Twitching Motility

    PubMed Central

    Glessner, Alex; Smith, Roger S.; Iglewski, Barbara H.; Robinson, Jayne B.

    1999-01-01

    Pseudomonas aeruginosa is a ubiquitous environmental bacterium and an important human pathogen. The production of several virulence factors by P. aeruginosa is controlled through two quorum-sensing systems, las and rhl. We have obtained evidence that both the las and rhl quorum-sensing systems are also required for type 4 pilus-dependent twitching motility and infection by the pilus-specific phage D3112cts. Mutants which lack the ability to synthesize PAI-1, PAI-2, or both autoinducers were significantly or greatly impaired in twitching motility and in susceptibility to D3112cts. Twitching motility and phage susceptibility in the autoinducer-deficient mutants were partially restored by exposure to exogenous PAI-1 and PAI-2. Both twitching motility and infection by pilus-specific phage are believed to be dependent on the extension and retraction of polar type 4 pili. Western blot analysis of whole-cell lysates and enzyme-linked immunosorbent assays of intact cells were used to measure the amounts of pilin on the cell surfaces of las and rhl mutants relative to that of the wild type. It appears that PAI-2 plays a crucial role in twitching motility and phage infection by affecting the export and assembly of surface type 4 pili. The ability of P. aeruginosa cells to adhere to human bronchial epithelial cells was also found to be dependent on the rhl quorum-sensing system. Microscopic analysis of twitching motility indicated that mutants which were unable to synthesize PAI-1 were defective in the maintenance of cellular monolayers and migrating packs of cells. Thus, PAI-1 appears to have an essential role in maintaining cell-cell spacing and associations required for effective twitching motility. PMID:10049396

  1. Seismic Wave Amplification in Las Vegas: Site Response and Empirical Estimates of Ground Motion

    NASA Astrophysics Data System (ADS)

    Rodgers, A.; McCallen, D.; Tkalcic, H.; Wagoner, J.; Louie, J.; Anderson, J.; Luke, B.; Snelson, C.; Taylor, W.

    2004-12-01

    This presentation will summarize a multidisciplinary effort to understand seismic wave amplification in Las Vegas Valley. The project involves weak motion recording and analysis, geotechnical and seismic refraction field studies, geologic and lithologic interpretation and model building. We will provide a brief overview of the project, then focus on specifics of seismic wave amplification including observations and interpretations. We analyzed recordings of nuclear explosions from the Nevada Test Site (NTS) and regional earthquakes to estimate site response in Las Vegas. An empirical transfer function method was used to transform ground motion time-series at one (reference) station to other stations, using frequency dependent site response curves in the band 0.2-5.0 Hz. The method transforms the time-series to the frequency domain by Fast Fourier transform, multiplies the amplitude spectrum by the site response curve and inverse FFT's back to the time domain. The approach is validated by the ability to predict horizontal component S-wave ground motion measures, such as peak and rms ground velocities and accelerations. We then can provide empirical estimates of ground motion for a wider distribution of sites in Las Vegas. Frequency dependent amplifications (site response) and peak ground motions are strongly correlated with measures of shallow shear-wave (geotechnical) velocities. Details of the geotechnical measurements and models will be presented in a companion presentation. This work was performed under the auspices of the U.S. Department of Energy by University of California Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48.

  2. An Aerial Radiological Survey of the Las Vegas Strip and Adjacent Areas

    SciTech Connect

    Wasiolek, Piotr

    2009-02-01

    As proficiency training for the Radiological Mapping mission of the Aerial Measuring System (AMS), a survey team from the Remote Sensing Laboratory–Nellis (RSL-Nellis) conducted an aerial radiological survey of the Las Vegas Strip and adjacent areas on December 29, 2008. This survey was one of the bi-annual surveys carried in support of the city of Las Vegas Police Department (LVPD) before significant events on the Las Vegas Strip: e.g., the annual New Year’s Eve and July Fourth celebrations. The AMS operation and appropriate law enforcement agencies selected this area as an appropriate urban location to exercise AMS capability for mapping environmental radiation and searching for man-made radioactive sources. The surveys covered approximately 11 square miles. Each survey required a 2.5-hour-long flight, performed at an altitude of 300 ft above ground level (AGL) at a line spacing of 600 ft. Water line and test line flights are conducted over the Lake Mead and Government Wash areas to determine the non-terrestrial background contributed by aircraft, radon, and cosmic activity, and to determine the altitude-dependent air mass correction. The data were collected by the AMS data acquisition system (REDAR V) using an array of twelve 2" x 4" x 16" sodium iodide (NaI) detectors flown on-board a twin-engine Bell 412 helicopter. Gamma energy spectral data were collected second-by-second over the survey area. This spectral data allows the system to distinguish between natural terrestrial background contributions and man-made radioisotope contributions. Spectral data can also be used to identify specific man-made radioactive isotopes. Data geo-locations were determined with a Real-Time Differential Global Positioning System (RDGPS).

  3. The Liege Acromegaly Survey (LAS): a new software tool for the study of acromegaly.

    PubMed

    Petrossians, Patrick; Tichomirowa, Maria A; Stevenaert, Achile; Martin, Didier; Daly, Adrian F; Beckers, Albert

    2012-06-01

    Acromegaly is a chronic rare disease associated with negative pathological effects on multiple systems and organs. We designed a new informatics tool to study data from patients with acromegaly, the Liege Acromegaly Survey (LAS). This relational database permits the inclusion of anonymous historical and prospective data on patients and includes pathophysiology, clinical features, responses to therapy and long term outcomes of acromegaly. We deployed the LAS in a validation study at a single center in order to study the characteristics of patients with acromegaly diagnosed at our center from 1970-2011. A total of 290 patients with acromegaly were included (147 males and 143 females). There was a linear relationship between age at diagnosis and the date of diagnosis, indicating that older patients are being diagnosed with acromegaly more frequently. A majority presented with macroadenomas (77.5%) and the median diameter was 14 mm. Patients with macroadenomas were significantly younger than patients with microadenomas (P=0.01). GH values at diagnosis decreased with the age of the patients (P=0.01) and there was a correlation between GH values and tumor size at diagnosis (P=0.02). No correlation existed between insulin-like growth factor 1 (IGF-1) levels and tumor characteristics. The prevalence of diabetes was 21.4% in this population and 41.0% had hypertension. The presence of hypertension and diabetes were significantly associated with one another (P<0.001). There was a linear relation between initial GH and IGF-1 levels at diagnosis and those obtained during SSA analog treatment and the lowest GH and IGF-1 values following SSA therapy were obtained in older patients (GH: P<0.001; IGF-1: P<0.001). The LAS is a new relational database that is feasible to use in the clinical research setting and permits ready pooling of anonymous patient data from multiple study sites to undertake robust statistical analyses of clinical and therapeutic characteristics.

  4. Interferograms showing land subsidence and uplift in Las Vegas Valley, Nevada, 1992-99

    USGS Publications Warehouse

    Pavelko, Michael T.; Hoffmann, Jorn; Damar, Nancy A.

    2006-01-01

    The U.S. Geological Survey, in cooperation with the Nevada Department of Conservation and Natural Resources-Division of Water Resources and the Las Vegas Valley Water District, compiled 44 individual interferograms and 1 stacked interferogram comprising 29 satellite synthetic aperture radar acquisitions of Las Vegas Valley, Nevada, from 1992 to 1999. The interferograms, which depict short-term, seasonal, and long-term trends in land subsidence and uplift, are viewable with an interactive map. The interferograms show that land subsidence and uplift generally occur in localized areas, are responsive to ground-water pumpage and artificial recharge, and, in part, are fault controlled. Information from these interferograms can be used by water and land managers to mitigate land subsidence and associated damage. Land subsidence attributed to ground-water pumpage has been documented in Las Vegas Valley since the 1940s. Damage to roads, buildings, and other engineered structures has been associated with this land subsidence. Land uplift attributed to artificial recharge and reduced pumping has been documented since the 1990s. Measuring these land-surface changes with traditional benchmark and Global Positioning System surveys can be costly and time consuming, and results typically are spatially and temporally sparse. Interferograms are relatively inexpensive and provide temporal and spatial resolutions previously not achievable. The interferograms are viewable with an interactive map. Landsat images from 1993 and 2000 are viewable for frames of reference to locate areas of interest and help determine land use. A stacked interferogram for 1992-99 is viewable to visualize the cumulative vertical displacement for the period represented by the individual interferograms. The interactive map enables users to identify and estimate the magnitude of vertical displacement, visually analyze deformation trends, and view interferograms and Landsat images side by side. The

  5. Elevation Changes of LAS, East Antarctica, Derived From ICESat and CryoSat-2 Altimetric Data

    NASA Astrophysics Data System (ADS)

    Chen, L.; Xie, H.; Hai, G.; Liu, S.; Liu, J.; Tong, X.; Li, R.

    2015-12-01

    Understanding of mass changes of the Antarctic ice sheet is essential for sea level rise study. A research effort has been made to estimate elevation mass changes at Lambert Glacier-Amery Ice Shelf System (LAS), East Antarctica using ICESat data of 2004-2008 and Cryosat-2 data of 2010-2015. A repeat-tack processing method that includes a trend and the first order terrain terms is applied to repeat-track points of all ICESat Campaigns of 2004-2008. The estimated change rate in LAS from 2004-2008 is 3.14±4.13 Gt yr-1. At the basin level, two basins show a combined positive trend of 8.16±2.96 Gt yr-1 while other four basins a combined negative trend of -5.39±6.04 Gt yr-1. Cryosat-2 altimeter works in three modes with the "synthetic aperture interferometer mode" (SARIn) and "low-resolution mode" (LRM) in LAS. Our data coverage is from 2010 to 2015. Cryosat-2 ground tracks do not maintain repeated points. We further divide the entire area into a grid of 5km by 5km. Then we estimate the elevation change rate in each grid cell using a least-squares fitting model with a trend and a second order polynomial. We found that the quality of the estimates is correlated with slopes of cells. The progress of the CryoSat-2 data processing result as well as the analysis with the existing ICESat result will be presented. An integrated model of both ICESat and CryoSat-2 data processing will be developed.

  6. Açaí (Euterpe oleracea Mart.): a tropical fruit with high levels of essential minerals-especially manganese-and its contribution as a source of natural mineral supplementation.

    PubMed

    da Silva Santos, Vivian; de Almeida Teixeira, Gustavo Henrique; Barbosa, Fernando

    2014-01-01

    Açaí is a fruit from the Brazilian Amazon region, with an exotic flavor, possessing high antioxidant and anti-inflammatory properties. Based on these properties, the fruit is classified as one of the new "super fruits." The mean daily consumption of açai pulp may reach 300 ml in several Brazilian regions. Further, this fruit is also gaining popularity in Europe and North America. In this context, the aim of this study was to assess the levels of some essential minerals in freeze-dried açaí pulp obtained in different Brazilian locations. It was found that açaí pulp is rich in essential minerals (Ca, Fe, Mg, Zn), but the levels of copper (Cu) and especially manganese (Mn) are surprisingly markedly higher than the traditional sources of these elements in the human diet. A daily consumption of 300 ml açaí pulp leads to a Mn daily intake exceeding at least sixfold (14.6 mg on average) the reference daily intake for an adult. Consequently, Mn intake may surpass the permitted daily maximum intake of 11 mg, which leads to a special concern, particularly for children, vegetarians, and individuals with anemia, since iron (Fe) absorption is impaired by Mn. Our findings demonstrate that this fruit is a potential source of several nutrients and a good dietary supplement to resolve malnutrition problems. However, due to the expressive levels of Mn, further studies are necessary to evaluate potential adverse effects associated with açaí consumption. PMID:24555649

  7. Açaí (Euterpe oleracea Mart.): a tropical fruit with high levels of essential minerals-especially manganese-and its contribution as a source of natural mineral supplementation.

    PubMed

    da Silva Santos, Vivian; de Almeida Teixeira, Gustavo Henrique; Barbosa, Fernando

    2014-01-01

    Açaí is a fruit from the Brazilian Amazon region, with an exotic flavor, possessing high antioxidant and anti-inflammatory properties. Based on these properties, the fruit is classified as one of the new "super fruits." The mean daily consumption of açai pulp may reach 300 ml in several Brazilian regions. Further, this fruit is also gaining popularity in Europe and North America. In this context, the aim of this study was to assess the levels of some essential minerals in freeze-dried açaí pulp obtained in different Brazilian locations. It was found that açaí pulp is rich in essential minerals (Ca, Fe, Mg, Zn), but the levels of copper (Cu) and especially manganese (Mn) are surprisingly markedly higher than the traditional sources of these elements in the human diet. A daily consumption of 300 ml açaí pulp leads to a Mn daily intake exceeding at least sixfold (14.6 mg on average) the reference daily intake for an adult. Consequently, Mn intake may surpass the permitted daily maximum intake of 11 mg, which leads to a special concern, particularly for children, vegetarians, and individuals with anemia, since iron (Fe) absorption is impaired by Mn. Our findings demonstrate that this fruit is a potential source of several nutrients and a good dietary supplement to resolve malnutrition problems. However, due to the expressive levels of Mn, further studies are necessary to evaluate potential adverse effects associated with açaí consumption.

  8. First results from optical turbulence measurements at Cerro Las Campanas in 2010

    NASA Astrophysics Data System (ADS)

    Berdja, A.; Prieto, G.; Thomas-Osip, J. E.

    2011-09-01

    We report preliminary results from optical turbulence measurements carried out in 2010 at Cerro Las Campanas, the future site for the Giant Magellan Telescope (GMT). The instruments involved are MooSci, a lunar scintillometer for the near-ground optical turbulence profile, Differential Image Motion Monitor (DIMM) for the whole atmosphere total seeing, and MASS Multiple Aperture Scintillation Sensor (MASS) for high-altitude optical turbulence estimation. The main purpose of these measurements is to anticipate the optical turbulence strength above the future GMT enclosure, and to provide a means to model the future adaptive optics performance. We also discuss the significance of such a combination of instruments and some hypothetical limitations.

  9. Las Cumbres Observatory Global Telescope 1-meter Telescope Project: Design, Deployment Plans, Status

    NASA Astrophysics Data System (ADS)

    Brown, Timothy M.; Burleson, B.; Crellin, M.; De Vera, J.; Dubberly, M.; Greene, R.; Falarski, M.; Haldeman, B.; Hausler, S.; Haynes, R.; Hjelstrom, A.; Hygelund, J.; Johnson, D.; Lobdill, R.; Martinez, J.; Mullins, D.; Pickles, A.; Posner, V.; Rosing, W.; Tufts, J.; Vander Horst, K.; Vanderhyden, B.; Walker, Z.

    2010-01-01

    Las Cumbres Observatory Global Telescope (LCOGT) is a privately-funded observatory dedicated to time-domain astronomy. Our main observing tool will be a homogeneous world-wide network of 12 x 1m optical telescopes, each equipped for both imaging and spectroscopy. Here we describe the LCOGT 1m telescope design, its development status, and our plans for deploying a dozen or so such telescopes in a worldwide network capable of continuous observing. We also describe the 80 cm Sedgwick telescope, which is now in regular operation as a research instrument, and which has served as a prototype for many of the 1m mechanical and control systems.

  10. Geodetic leveling data used to define historical height changes between Tonopah Junction and Las Vegas, Nevada

    SciTech Connect

    Gilmore, T.D.

    1992-12-31

    This report documents geodetic leveling data for a survey route following US Highway 95 from Tonopah Junction, approximately 50 km west of Tonopah, Nevada, to Las Vegas, Nevada. The survey route passes immediately south of the potential site for a high-level nuclear waste repository at Yucca Mountain in southern Nevada. Comparisons among the results of the several repeated levelings along this survey route provide a partial basis for evaluating contemporary crustal deformation patterns in the vicinity of the Yucca Mountain site and the relation between any such deformation and geologic structures known or suspected to have been active during Quaternary time.

  11. Crystal Structure of the LasA Virulence Factor from Pseudomonas aeruginosa: Substrate Specificity and Mechanism of M23 Metallopeptidases

    SciTech Connect

    Spencer, James; Murphy, Loretta M.; Conners, Rebecca; Sessions, Richard B.; Gamblin, Steven J.

    2010-09-21

    Pseudomonas aeruginosa is an opportunist Gram-negative bacterial pathogen responsible for a wide range of infections in immunocompromized individuals and is a leading cause of mortality in cystic fibrosis patients. A number of secreted virulence factors, including various proteolytic enzymes, contribute to the establishment and maintenance of Pseudomonas infection. One such is LasA, an M23 metallopeptidase related to autolytic glycylglycine endopeptidases such as Staphylococcus aureus lysostaphin and LytM, and to DD-endopeptidases involved in entry of bacteriophage to host bacteria. LasA is implicated in a range of processes related to Pseudomonas virulence, including stimulating ectodomain shedding of the cell surface heparan sulphate proteoglycan syndecan-1 and elastin degradation in connective tissue. Here we present crystal structures of active LasA as a complex with tartrate and in the uncomplexed form. While the overall fold resembles that of the other M23 family members, the LasA active site is less constricted and utilizes a different set of metal ligands. The active site of uncomplexed LasA contains a five-coordinate zinc ion with trigonal bipyramidal geometry and two metal-bound water molecules. Using these structures as a starting point, we propose a model for substrate binding by LasA that explains its activity against a wider range of substrates than those used by related lytic enzymes, and offer a catalytic mechanism for M23 metallopeptidases consistent with available structural and mutagenesis data. Our results highlight how LasA is a structurally distinct member of this endopeptidase family, consistent with its activity against a wider range of substrates and with its multiple roles in Pseudomonas virulence.

  12. Giant Magellan Telescope Site Testing and Characterization at Las Campanas Observatory

    NASA Astrophysics Data System (ADS)

    Thomas-Osip, Joanna E.; Prieto, Gabriel E.

    2009-09-01

    Las Campanas Observatory has been designated as the location for the Giant Magellan Telescope (GMT). We report results obtained since the commencement, in 2005, of a systematic site testing campaign at LCO. Measurements of the turbulence profile of the free-atmosphere above LCO have been collected with a MASS/DIMM. We examine the contribution to the seeing arising from turbulence in the ground layer (defined here as below an altitude of 500 m) through the difference between the turbulence integrals in the full atmosphere (as measured by DIMM) and in the free atmosphere (as measured by MASS). In preparation to characterize the Giant Magellan Telescope site and guide the development of its adaptive optics system, two campaigns to systematically compare the turbulence profiles obtained independently with three different instruments were conducted at Las Campanas Observatory in September, 2007 and January 2008. Slope detection and ranging (SLODAR) was used on the 2.5-m duPont telescope. SLODAR measures the Cn2 profile as a function of altitude through observations of double stars. The separation of the observed double star sets the maximum altitude and height resolution. Ground layer (altitudes < 1 km) and free atmosphere turbulence profiles are compared with those obtained with a lunar scintillometer (LuSci) and a multi-aperture scintillation sensor (MASS), respectively. In addition, the total atmospheric seeing was measured by both SLODAR and a differential image motion monitor (DIMM).

  13. Seasonal subsidence and rebound in Las Vegas Valley, Nevada, observed by synthetic aperture radar interferometry

    USGS Publications Warehouse

    Hoffmann, J.; Zebker, H.A.; Galloway, D.L.; Amelung, F.

    2001-01-01

    Analyses of areal variations in the subsidence and rebound occurring over stressed aquifer systems, in conjunction with measurements of the hydraulic head fluctuations causing these displacements, can yield valuable information about the compressibility and storage properties of the aquifer system. Historically, stress-strain relationships have been derived from paired extensometer/piezometer installations, which provide only point source data. Because of the general unavailability of spatially detailed deformation data, areal stress-strain relations and their variability are not commonly considered in constraining conceptual and numerical models of aquifer systems. Interferometric synthetic aperture radar (InSAR) techniques can map ground displacements at a spatial scale of tens of meters over 100 km wide swaths. InSAR has been used previously to characterize larger magnitude, generally permanent aquifer system compaction and land subsidence at yearly and longer timescales, caused by sustained drawdown of ground-water levels that produces intergranular stresses consistently greater than the maximum historical stress. We present InSAR measurements of the typically small-magnitude, generally recoverable deformations of the Las Vegas Valley aquifer system occurring at seasonal timescales. From these we derive estimates of the elastic storage coefficient for the aquifer system at several locations in Las Vegas Valley. These high-resolution measurements offer great potential for future investigations into the mechanics of aquifer systems and the spatial heterogeneity of aquifer system structure and material properties as well as for monitoring ongoing aquifer system compaction and land subsidence.

  14. Influence of composition and temperature on hydrocarbon migration through Morrow fluvial reservoirs, Las Animas Arch, Colorado

    SciTech Connect

    Bolyard, D.W.

    1995-06-01

    Precipitation of wax in pores may impair permeability and prohibit the flow of oil. Crude oil composition and temperature are the most important controlling factors. Oils are chemically complex, may contain up to 45 wax compounds and may vary significantly even in the same pool. High-wax oils are common in the Morrow of eastern Colorado. Narrow fluvial sandstones provide migration paths toward the Las Animas Arch from adjacent basins. Temperatures range from less than 110{degrees}F. on the top of the arch to 180{degrees}F at a structural position only 1,400 feet lower. A range of 30{degrees}F has been observed in individual pools. Wax has precipitated in the 120-140{degrees}F range, creating relative permeability barriers which cut across the sandstones. Wax barriers are impermeable to oil, but may be permeable to gas and water. They account for certain dry holes with high porosity, permeability and oil saturation (and low water saturation) in both core and electrical log analysis. They explain why some oil wells with impaired permeability are adjacent to structurally lower gas wells with good permeability. A network of wax barriers around the Las Animas Arch accounts for approximately 300 feet of variation in the structural position of a line separating oil from gas fields. Since the low temperature bands may be short and discontinuous, wax barriers are more effective in narrow fluvial reservoirs than in blanket reservoirs.

  15. Excess air during aquifer storage and recovery in an arid basin (Las Vegas Valley, USA)

    NASA Astrophysics Data System (ADS)

    Solomon, D. Kip; Cole, Erin; Leising, Joseph F.

    2011-02-01

    The Las Vegas Valley Water District in Nevada, USA, has operated an artificial recharge (AR) program since 1989. In summer 2001, observations of gas exsolving from tap water prompted a study that revealed total dissolved gas (TDG) pressures approaching 2 atm with a gas composition that it is predominantly air. Measurements of TDG pressure at well heads and in the distribution system indicated two potential mechanisms for elevated TDG pressures: (1) air entrainment during AR operations, and (2) temperature changes between the winter recharge season and the summer withdrawal season. Air entrainment during pumping was investigated by intentionally allowing the forebay (upstream reservoir) of a large pumping station to drawdown to the point of vortex formation. This resulted in up to a 0.7 atm increase in TDG pressure. In general, the solubility of gases in water decreases as the temperature increases. In the Las Vegas Valley, water that acquired a modest amount of dissolved gas during winter artificial recharge operations experienced an increase in dissolved gas pressure (0.04 atm/°C) as the water warmed in the subsurface. A combination of air entrainment during AR operations and its amplification by temperature increase after recharge can account for most of the observed amounts of excess gas at this site.

  16. MBAS (Methylene Blue Active Substances) and LAS (Linear Alkylbenzene Sulphonates) in Mediterranean coastal aerosols: Sources and transport processes

    NASA Astrophysics Data System (ADS)

    Becagli, S.; Ghedini, C.; Peeters, S.; Rottiers, A.; Traversi, R.; Udisti, R.; Chiari, M.; Jalba, A.; Despiau, S.; Dayan, U.; Temara, A.

    2011-12-01

    Methylene Blue Active Substances (MBAS) and Linear Alkylbenzene Sulphonates (LAS) concentrations, together with organic carbon and ions were measured in atmospheric coastal aerosols in the NW Mediterranean Basin. Previous studies have suggested that the presence of surfactants in coastal aerosols may result in vegetation damage without specifically detecting or quantifying these surfactants. Coastal aerosols were collected at a remote site (Porquerolles Island-Var, France) and at a more anthropised site (San Rossore National Park-Tuscany, Italy). The chemical data were interpreted according to a comprehensive local meteorological analysis aiming to decipher the airborne source and transport processes of these classes of compounds. The LAS concentration (anthropogenic surfactants) was measured in the samples using LC-MS/MS, a specific analytical method. The values were compared with the MBAS concentration, determined by a non-specific analytical method. At Porquerolles, the MBAS concentration (103 ± 93 ng m -3) in the summer samples was significantly higher than in the winter samples. In contrast, LAS concentrations were rarely greater than in the blank filters. At San Rossore, the mean annual MBAS concentration (887 ± 473 ng m -3 in PM10) contributed about 10% to the total atmospheric particulate organic matter. LAS mean concentration in these same aerosol samples was 11.5 ± 10.5 ng m -3. A similar MBAS (529 ± 454 ng m -3) - LAS (7.1 ± 4.1 ng m -3 LAS) ratio of ˜75 was measured in the fine (PM2.5) aerosol fraction. No linear correlation was found between MBAS and LAS concentrations. At San Rossore site the variation of LAS concentrations was studied on a daily basis over a year. The LAS concentrations in the coarse fraction (PM10-2.5) were higher during strong sea storm conditions, characterized by strong air flow coming from the sea sector. These events, occurring with more intensity in winter, promoted the formation of primary marine aerosols containing LAS

  17. The study of ozone variations in the Las Vegas metropolitan area using remote sensing information and ground observations

    USGS Publications Warehouse

    Xian, G.; Crane, M.

    2006-01-01

    Urban development in the Las Vegas Valley, Nevada, has grown rapidly in the past fifty years. Associated with this growth has been a change in landscape from natural cover types to developed urban land mixed with planned vegetation canopy throughout in the metropolitan area. Air quality in the Las Vegas Valley has been affected by increases in anthropogenic emissions and concentrations of carbon monoxide, ozone, and criteria pollutants of particular matter. Ozone concentration in the region is generally influenced by synoptic and mesoscale meteorological conditions, as well as regional transport of pollutants from the western side of Las Vegas. Local influences from ground-level nitrogen oxide emissions and vegetation canopy coverage also affect ozone concentration. Multi-year observational data collected by a network of local air monitoring stations in Clark County, Nevada, indicate that ozone maximums develop in May and June, while minimums exist primarily from November to February. Ozone concentrations are high on the west and northwest sides of the valley. A nighttime ozone reduction in the urban area characterizes the heterogeneous features of spatial distribution for average ozone levels in the Las Vegas urban area. The urban vegetation canopy has a locally positive effect by reducing ozone in urban areas. Decreased ozone levels associated with increased urban development density suggests that the highest ozone concentrations are associated with medium- to low-density urban development in Las Vegas.

  18. Overexpression of the Brassica napus BnLAS gene in Arabidopsis affects plant development and increases drought tolerance.

    PubMed

    Yang, Minggui; Yang, Qingyong; Fu, Tingdong; Zhou, Yongming

    2011-03-01

    The GRAS proteins are a family of transcription regulators found in plants and play diverse roles in plant growth and development. To study the biological roles of GRAS family genes in Brassica napus, an Arabidopsis LAS homologous gene, BnLAS and its two homologs were cloned from B. napus and its two progenitor species, Brassica rapa and Brassica oleracea. Relatively high levels of BnLAS were observed in roots, shoot tips, lateral meristems and flower organs based on the analysis of the transcripts by quantitative RT-PCR and promoter-reporter assays. Constitutive overexpression of BnLAS in Arabidopsis resulted in inhibition of growth, and delays in leaf senescence and flowering time. A large portion of transgenic lines had darker leaf color and higher chlorophyll content than in wild type plants. Interestingly, water lose rates in transgenic leaves were reduced, and transgenic plants exhibited enhanced drought tolerance and increased recovery after exposed to dehydration treatment. The stomatal density on leaves of the transgenic plants increased significantly due to the smaller cell size. However, the stomatal aperture on the leaves of the transgenic plants reduced significantly compared with wild type plants. More epidermal wax deposition on transgenic leaves was observed. Furthermore, several genes involved in wax synthesis and regulation, including CER1, CER2, KCS1 and KCS2, were upregulated in the transgenic plants. Our results indicate a potential to utilize BnLAS in the improvement of drought tolerance in plants.

  19. Wide-range and accurate modeling of linear alkylbenzene sulfonate (LAS) adsorption/desorption on agricultural soil.

    PubMed

    Oliver-Rodríguez, B; Zafra-Gómez, A; Reis, M S; Duarte, B P M; Verge, C; de Ferrer, J A; Pérez-Pascual, M; Vílchez, J L

    2015-11-01

    In this paper, rigorous data and adequate models about linear alkylbenzene sulfonate (LAS) adsorption/desorption on agricultural soil are presented, contributing with a substantial improvement over available adsorption works. The kinetics of the adsorption/desorption phenomenon and the adsorption/desorption equilibrium isotherms were determined through batch studies for total LAS amount and also for each homologue series: C10, C11, C12 and C13. The proposed multiple pseudo-first order kinetic model provides the best fit to the kinetic data, indicating the presence of two adsorption/desorption processes in the general phenomenon. Equilibrium adsorption and desorption data have been properly fitted by a model consisting of a Langmuir plus quadratic term, which provides a good integrated description of the experimental data over a wide range of concentrations. At low concentrations, the Langmuir term explains the adsorption of LAS on soil sites which are highly selective of the n-alkyl groups and cover a very small fraction of the soil surface area, whereas the quadratic term describes adsorption on the much larger part of the soil surface and on LAS retained at moderate to high concentrations. Since adsorption/desorption phenomenon plays a major role in the LAS behavior in soils, relevant conclusions can be drawn from the obtained results. PMID:26070080

  20. The degradation of linear alkylbenzene sulfonate (LAS) in the presence of light and natural biofilms: the important role of photosynthesis.

    PubMed

    Hua, Xiuyi; Li, Ming; Su, Yulong; Dong, Deming; Guo, Zhiyong; Liang, Dapeng

    2012-08-30

    Photosynthesis of algae usually changes the chemical conditions of microenvironment in natural waters. However, few studies have been carried out to examine the effects of diurnal variation and photosynthesis on behavior of organic pollutants in aquatic environments. In this study, linear alkylbenzene sulfonate (LAS) was selected as a representative of non-persistent organic pollutants to investigate the degradation of this type of pollutants in the presence of light and natural biofilms by laboratory batch experiments, with special emphasis on the effect of photosynthesis of the biofilms. The maximum decrease of LAS was observed in the coexistence of both illumination and fully active biofilms, and about 75% of the LAS were removed after a 36-h degradation experiment. The removal of LAS was found to be dominated by photosynthesis of the biofilms, with lesser roles attributed to biodegradation and adsorption by the biofilms, and the role of direct photolysis was negligible. The production of some reactive oxygen species might account for the role of photosynthesis in decomposing the LAS. The study confirms the important roles of algae biofilms and their photosynthesis in determining the fate of organic pollutants in aquatic environments.

  1. Wide-range and accurate modeling of linear alkylbenzene sulfonate (LAS) adsorption/desorption on agricultural soil.

    PubMed

    Oliver-Rodríguez, B; Zafra-Gómez, A; Reis, M S; Duarte, B P M; Verge, C; de Ferrer, J A; Pérez-Pascual, M; Vílchez, J L

    2015-11-01

    In this paper, rigorous data and adequate models about linear alkylbenzene sulfonate (LAS) adsorption/desorption on agricultural soil are presented, contributing with a substantial improvement over available adsorption works. The kinetics of the adsorption/desorption phenomenon and the adsorption/desorption equilibrium isotherms were determined through batch studies for total LAS amount and also for each homologue series: C10, C11, C12 and C13. The proposed multiple pseudo-first order kinetic model provides the best fit to the kinetic data, indicating the presence of two adsorption/desorption processes in the general phenomenon. Equilibrium adsorption and desorption data have been properly fitted by a model consisting of a Langmuir plus quadratic term, which provides a good integrated description of the experimental data over a wide range of concentrations. At low concentrations, the Langmuir term explains the adsorption of LAS on soil sites which are highly selective of the n-alkyl groups and cover a very small fraction of the soil surface area, whereas the quadratic term describes adsorption on the much larger part of the soil surface and on LAS retained at moderate to high concentrations. Since adsorption/desorption phenomenon plays a major role in the LAS behavior in soils, relevant conclusions can be drawn from the obtained results.

  2. 20 years of mass balances on the Piloto glacier, Las Cuevas river basin, Mendoza, Argentina

    NASA Astrophysics Data System (ADS)

    Leiva, J. C.; Cabrera, G. A.; Lenzano, L. E.

    2007-10-01

    Climatic changes of the 20th century have altered the water cycle in the Andean basins of central Argentina. The most visible change is seen in the mountain glaciers, with loss of part of their mass due to decreasing thickness and a substantial recession in the last 100 years. This paper briefly describes the results of glacier mass balance research since 1979 in the Piloto Glacier at the Cajón del Rubio, in the headwaters of Las Cuevas River, presenting new results for the period 1997-2003. Very large interannual variability of net annual specific balance is evident, due largely to variations in winter snow accumulation, with a maximum net annual value of + 151 cm w.e. and a minimum value of - 230 cm w.e. Wet El Niño years are normally associated with positive net annual balances, while dry La Niña years generally result in negative balances. Within the 24-year period, 67% of the years show negative net annual specific balances, with a cumulative mass balance loss of - 10.50 m water equivalent (w.e.). Except for exceptions normally related to El Niño events, a general decreasing trend of winter snow accumulation is evident in the record, particularly after 1992, which has a strong effect in the overall negative mass balance values. The glacier contribution to Las Cuevas River runoff is analysed based on the Punta de Vacas River gauge station for a hypothetical year without snow precipitation (YWSP), when the snowmelt component is zero. Extremely dry years similar to a YWSP have occurred in 1968-1969, 1969-1970 and 1996-1997. The Punta de Vacas gauge station is located 62 km downstream from Piloto Glacier, and the basin contains 3.0% of uncovered glacier ice and 3.7% of debris-covered ice. The total glacier contribution to Las Cuevas River discharge is calculated as 82 ± 8% during extremely dry years. If glacier wastage continues at the present trend as observed during the last 2 decades, it will severely affect the water resources in the arid central Andes of

  3. Sociohydrology of an Arid City: Development of a Coupled Model of Water Management in Las Vegas

    NASA Astrophysics Data System (ADS)

    Garcia, M. E.; Islam, S.; Portney, K. E.

    2014-12-01

    Rapidly growing cities in arid regions present a significant water management challenge. Key to tackling this challenge is understanding how and why some cities transition to more sustainable water management; acknowledging that urban water resources decisions are both responding to and precipitating hydrologic change, this question is best tackled through a sociohydrology approach. While coupling of natural and societal systems is in it's infancy in the field of hydrology, there is a strong tradition of studying coupled systems in the field of Socio-Ecological Systems. We build on Ostrom's Socio-Ecological Systems framework to develop a system dynamics model of water management for the Las Vegas metropolitan area using Vensim. A key objective our proposed modeling framework is to illuminate the dynamic interactions of the sociohydrologic system components and enable testing of various assumptions and strategies. The model of Las Vegas water management consists of five sub-modules: water supply, water demand, finances, public perception and policy making process. The development of the first three modules were based on clearly defined system structure. The public perception sub-module tracks the level public risk perception of a water supply shortage and represents the hypothesis that public risk perception is updated periodically when shortage events are experienced. The policy making process module uses an algorithm capturing the hypothesized decision making process to select policy actions (or in-action) from a set of feasible actions in response to the system states tracked by the model and observable to decision makers. The model was tested and parameterized using mix of quantitative data on water demands, supplies and costs and qualitative data from document analysis and interview data covering 1990 to 2010 period. Given that not only the parameters but also the structure of the public perception and the policy making process sub-systems is contested, a

  4. A design for a new catalog manager and associated file management for the Land Analysis System (LAS)

    NASA Technical Reports Server (NTRS)

    Greenhagen, Cheryl

    1986-01-01

    Due to the larger number of different types of files used in an image processing system, a mechanism for file management beyond the bounds of typical operating systems is necessary. The Transportable Applications Executive (TAE) Catalog Manager was written to meet this need. Land Analysis System (LAS) users at the EROS Data Center (EDC) encountered some problems in using the TAE catalog manager, including catalog corruption, networking difficulties, and lack of a reliable tape storage and retrieval capability. These problems, coupled with the complexity of the TAE catalog manager, led to the decision to design a new file management system for LAS, tailored to the needs of the EDC user community. This design effort, which addressed catalog management, label services, associated data management, and enhancements to LAS applications, is described. The new file management design will provide many benefits including improved system integration, increased flexibility, enhanced reliability, enhanced portability, improved performance, and improved maintainability.

  5. Polycyclic aromatic hydrocarbons in ambient air particles in the city of Las Palmas de Gran Canaria.

    PubMed

    Vera Castellano, A; López Cancio, J; Santana Alemán, P; Santana Rodríguez, J

    2003-07-01

    Concentration levels, seasonal variation and winter/summer ratios of 11 polycyclic aromatic hydrocarbons (PAHs) in the TSP of Las Palmas de Gran Canaria city were determined. The study area is under the influence of heavy traffic (80000 vehicles/day). Pyr/BaA, Pyr/Flt, B(ghi)P/I(cd)P and B(b+k)F/B(ghi)P ratios were calculated; the values of these two last suggest a strong influence of diesel fuel burning. Levels of TSP and TSP-bound PAHs were also established. The hazard potential of PAHs in terms of carcinogenicity of BaP is acceptable. Potential risk on the basis of TEFs is also studied. PMID:12705945

  6. Giant Magellan Telescope site evaluation and characterization at Las Campanas Observatory

    NASA Astrophysics Data System (ADS)

    Thomas-Osip, Joanna E.; Prieto, Gabriel; Johns, Matt; Phillips, Mark M.

    2008-07-01

    Las Campanas Observatory has been designated as the location for the Giant Magellan Telescope (GMT). We report results obtained since the commencement, in 2005, of a systematic site testing campaign at LCO. Meteorological (cloud cover, temperature, pressure, wind, and humidity) and DIMM seeing data have been obtained at three potential sites, and are compared with identical data taken at the site of the twin Magellan 6.5m telescopes. In addition, measurements of the turbulence profile of the free-atmosphere above LCO have been collected with a MASS/DIMM. We examine the contribution to the seeing arising from turbulence in the ground layer (defined here as below an altitude of 500 m) through the difference between the turbulence integrals in the full atmosphere (as measured by DIMM) and in the free atmosphere (as measured by MASS). Additionally, we consider photometric quality, light pollution, and precipitable water vapor at LCO.

  7. Two campaigns to compare three turbulence profiling techniques at Las Campanas Observatory

    NASA Astrophysics Data System (ADS)

    Thomas-Osip, Joanna; Bustos, Edison; Goodwin, Michael; Jenkins, Charles; Lambert, Andrew; Prieto, Gabriel; Tokovinin, Andrei

    2008-07-01

    In preparation to characterize the Giant Magellan Telescope site and guide the development of its adaptive optics system, two campaigns to systematically compare the turbulence profiles obtained independently with three different instruments were conducted at Las Campanas Observatory in September, 2007 and January 2008. Slope detection and ranging (SLODAR) was used on the 2.5-m duPont telescope. SLODAR measures the C2n profile as a function of altitude through observations of double stars. The separation of the observed double star sets the maximum altitude and height resolution. Ground layer (altitudes < 1 km) and free atmosphere turbulence profiles are compared with those obtained with a lunar scintillometer (LuSci) and a multi-aperture scintillation sensor (MASS), respectively. In addition, the total atmospheric seeing was measured by both SLODAR and a differential image motion monitor (DIMM).

  8. Late Neandertals in Southeastern Iberia: Sima de las Palomas del Cabezo Gordo, Murcia, Spain

    PubMed Central

    Walker, Michael J.; Gibert, Josep; López, Mariano V.; Lombardi, A. Vincent; Pérez-Pérez, Alejandro; Zapata, Josefina; Ortega, Jon; Higham, Thomas; Pike, Alistair; Schwenninger, Jean-Luc; Zilhão, João; Trinkaus, Erik

    2008-01-01

    Middle Paleolithic fossil human remains from the Sima de las Palomas in southeastern Iberia (dated to ≤43,000–40,000 calendar years before present) present a suite of derived Neandertal and/or retained ancestral morphological features in the mandibular symphysis, mandibular ramus, dental occlusal morphology, and distal hand phalanx. These traits are combined with variation in the mandibular corpus, discrete dental morphology, tooth root lengths, and anterior dental size that indicate a frequency difference with earlier Iberian and more northern European Neandertals. The Palomas Neandertals therefore confirm the late presence of Neandertals associated with the Iberian persistence of the Middle Paleolithic, but suggest microevolutionary processes and/or population contact with contemporaneous modern humans to the north. PMID:19074275

  9. Las Cumbres Observatory Global Telescope Network: Keeping education in the dark

    NASA Astrophysics Data System (ADS)

    Ross, R.; Roche, P.; Roberts, S.

    2008-06-01

    Las Cumbres Observatory Global Telescope Network (LCOGTN) is a privately-funded, non-profit organisation that is creating a cutting edge science programme paired with an innovative education programme. We are building two networks of telescopes in rings in both the Northern and Southern hemispheres for complete sky coverage, all of which will be equipped with high-quality, science-grade instrumentation. The telescopes will be completely robotic with the ability to be controlled by anyone, from anywhere with a broadband internet connection. Accompanying the observations will be a library of resources and activities including how to plan and carry out an observing session as well as several activities and project ideas to carry out in both formal and informal education settings. The goal is not to produce more astronomers, but to encourage a new understanding of science and technology that people will be able to apply to any field that is studied.

  10. Prevalence of ectoparasitic arthropods on wild animals and cattle in the Las Merindades area (Burgos, Spain)

    PubMed Central

    Domínguez-Peñafiel, G.; Giménez-Pardo, C.; Gegúndez, M.I.; Lledó, L.

    2011-01-01

    This paper reports the prevalence of ectoparasitic arthropods in sampled groups of wild (n = 128; 16 species) and domestic (n = 69; 3 species) animals in the Las Merindades area of the Province of Burgos, Spain. The study revealed that wild animals were more infested and with a wider variety of ectoparasites than domestic animals. The parasitic prevalence was 67% for wild animals and 48% for livestock. In this way, 39% of animals were infected by ticks. Ixodes ricinus and Ixodes hexagonus were the most prevalent species whereas Dermacentor reticulatus showed affinity for the fox and wolf. The overall prevalence of parasitisation by fleas was 27%. Ctenophthalmus spp. showed the wider range host in wild animals, while Pulex irritans was the most frequent specie found. The parasitic prevalences by lice (Trichodectes melis, Trichodectes canis and Trichodectes mustelae) and by mite (Neotrombicula spp., Laelaps agilis and Sarcoptes scabiei) were 4% and 12%, respectively. In both cases only wild animals were found parasited. PMID:21894267

  11. Neighborhood Reputation and Resident Sentiment in the Wake of the Las Vegas Foreclosure Crisis

    PubMed Central

    Pais, Jeremy; Batson, Christie D.; Monnat, Shannon M.

    2014-01-01

    This study examines how two major components of a neighborhood’s reputation—perceived disorder and collective efficacy—shape individuals’ sentiments toward their neighborhoods during the foreclosure crisis triggered by the Great Recession. Of central interest are whether neighborhood reputations are durable in the face of a crisis (neighborhood resiliency hypothesis) or whether neighborhood reputations wane during times of duress (foreclosure crisis hypothesis). Geo-coded individual-level data from the Las Vegas Metropolitan Area Social Survey merged with data on census tract foreclosure rates are used to address this question. The results provide qualified support for both perspectives. In support of the neighborhood resiliency hypothesis, collective efficacy is positively associated with how residents feel about the quality of their neighborhoods, and this relationship is unaltered by foreclosure rates. In support of the foreclosure crisis hypothesis, foreclosure rates mediate the effects of neighborhood disorder on resident sentiment. The implications of these findings for community resiliency are discussed. PMID:25678735

  12. The Proteus aircraft and NASA Dryden's T-34 in flight over Las Cruces, New Mexico.

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The unique Proteus aircraft served as a test bed for NASA-sponsored flight tests designed to validate collision-avoidance technologies proposed for uninhabited aircraft. The tests, flown over southern New Mexico in March, 2002, used the Proteus as a surrogate uninhabited aerial vehicle (UAV) while three other aircraft flew toward the Proteus from various angles on simulated collision courses. Radio-based 'detect, see and avoid' equipment on the Proteus successfully detected the other aircraft and relayed that information to a remote pilot on the ground at Las Cruces Airport. The pilot then transmitted commands to the Proteus to maneuver it away from the potential collisions. The flight demonstration, sponsored by NASA Dryden Flight Research Center, New Mexico State University, Scaled Composites, the U.S. Navy and Modern Technology Solutions, Inc., were intended to demonstrate that UAVs can be flown safely and compatibly in the same skies as piloted aircraft.

  13. Paleoslope, sea-level and climate controls on Upper Miocene platform evolution, Las Negras area, southeastern Spain

    USGS Publications Warehouse

    Franseen, E.K.; Goldstein, R.H.; ,

    1996-01-01

    Carbonate platforms in the Las Negras area evolved from onlapping ramps to fringing reef complexes later draped by cyclic shallow marine strata. Although sea-level history and paleoclimate had an effect on platform evolution, substrate topography played a dominant role. The strata are divided into five depositional sequences of Tortonian and Messinian age. The model of platform evolution provided by the Las Negras area exposures likely has applications for other Miocene carbonate complexes in the Mediterranean and could apply to other carbonate complexes in the rock record.

  14. Stratospheric contribution to surface ozone in the desert Southwest during the 2013 Las Vegas Ozone Study

    NASA Astrophysics Data System (ADS)

    Langford, A. O.; Senff, C. J.; Alvarez, R. J. _II, II; Brioude, J. F.; Cooper, O. R.; Holloway, J. S.; Lin, M.; Marchbanks, R.; Pierce, R. B.; Reddy, P. J.; Sandberg, S.; Weickmann, A. M.; Williams, E. J.; Gustin, M. S.; Iraci, L. T.; Leblanc, T.; Yates, E. L.

    2014-12-01

    The 2013 Las Vegas Ozone Study (LVOS) was designed to investigate the potential impact of stratosphere-troposphere transport (STT) and long-range transport of pollution from Asia on surface O3 concentrations in Clark County, NV. This measurement campaign, which took place in May and June of 2013, was conducted at Angel Peak, NV, a high elevation site about 2.8 km above mean sea level and 45 km west of Las Vegas. The study was organized around the NOAA ESRL truck-based TOPAZ scanning ozone lidar with collocated in situ sampling of O3, CO, and meteorological parameters. These measurements were supported by the NOAA/NESDIS real time modelling system (RAQMS), FLEXPART particle dispersion model, and the NOAA GFDL AM3 model. In this talk, I will describe one of several STT events that occurred during the LVOS campaign. This intrusion, which was profiled by TOPAZ on the night of May 24-25, was also sampled by the NASA Alpha Jet, the Table Mountain ozone lidar, and by an ozonesonde flying above southern California. This event also led to significant ozone increases at surface monitors operated by Clark County, the California Air Resources Board, the U.S. National Park Service, and the Nevada Rural Ozone Initiative (NRVOI), and resulted in exceedances of the 2008 75 ppbv O3 NAAQS both in Clark County and in surrounding areas of Nevada and southern California. The potential implications of this and similar events for air quality compliance in the western U.S. will be discussed.

  15. Precisión de las velocidades radiales obtenidas con el REOSC

    NASA Astrophysics Data System (ADS)

    González, J. F.; Lapasset, E.

    Complementando una línea de trabajo iniciada con anterioridad discutimos la estabilidad del espectrógrafo REOSC de CASLEO en DC para la medición de velocidades radiales en base al análisis de observaciones realizadas en enero y abril de 1997. En esas oportunidades obtuvimos 26 espectros de estrellas patrones y 27 espectros de 3 estrellas usadas como estrellas de referencia en nuestro programa de cúmulos abiertos. Además tomamos 26 espectros de crepúsculo con el telescopio en posiciones cubriendo el rango H=-4,+4 y δ =-90,+30. Mediante correlaciones cruzadas derivamos la velocidad de 19 órdenes en cada uno de estos espectros. En base a un análisis estadístico de los datos obtenidos discutimos la contribución de los distintos factores que afectan a la dispersión de lectura observada. En particular, la flexión del instrumento no introduciría errores significativos cuando se observa con masas de aire menores que 2.0. La dispersión de los valores de velocidad medidos para espectros de alta relación S/N de una misma estrella resultó del orden de 0.5 km/s. La comparación con los valores de velocidad publicados por distintos autores para las estrellas patrones no permite distinguir ninguna diferencia sistemática apreciable de las velocidades de CASLEO, siendo la media cuadrática de los residuos del orden de 1.0 km/s.

  16. Characterization of stormwater discharges from Las Flores Industrial Park, Rio Grande, Puerto Rico, 1998-99

    USGS Publications Warehouse

    Rodriguez, Jose M.

    2000-01-01

    Stormwater discharges from Las Flores Industrial Park, Rio Grande, Puerto Rico, were characterized from June 1998 to July 1999 by measuring the flow rate at two outfalls, delineating the drainage areas for each outfall, and calculating the volume of the stormwater discharges. Stormwater-discharge samples were collected and analyzed to determine the quality of the discharges. Constituent loads and loads per area were estimated for each drainage area. The studied drainage subareas covered approximately 46 percent of the total area of the Las Flores Industrial Park. Industrial groups represented in the study areas include manufacturers of textile, electronics, paper, fabricated metal, plastic, and chemical products. The concentrations of oil and grease (1 to 6 milligrams per liter), biochemical oxygen demand (4.7 to 16 milligrams per liter), total organic carbon (5.8 to 36 milligrams per liter), total suspended solids (28 to 100 milligrams per liter), and total phosphorous (0.11 to 0.78 milligrams per liter) from all the samples collected were less than the U.S. Environmental Protection Agency stormwater benchmark concentrations. Concentrations of chemical oxygen demand (15.8 to 157 milligrams per liter) and nitrate and nitrite (0.06 to 1.75 milligrams per liter) exceeded benchmark concentrations at one of the studied drainage areas. Total Kjeldahl nitrogen concentrations (1.00 to 3.20 milligrams per liter) exceeded the benchmark concentrations at the two studied drainage areas. Maximum concentrations for oil and grease, biochemical oxygen demand, chemical oxygen demand, total organic carbon, total Kjeldahl nitrogen, nitrate plus nitrite, and total phosphorous were detected in an area where electronics, plastics, and chemical products are currently manufactured. The maximum concentration of total suspended solids was detected at an area where textile, paper, plastic, chemical, and fabricated metal products are manufactured.

  17. Fishery of the Green Jack Caranx caballus (Osteichytes: Carangidae) in Las Perlas Archipelago, Pacific Panama.

    PubMed

    Mair, James M; Cipriani, Roberto; Guzman, Hector M; Usan, David

    2012-09-01

    Green Jacks, Caranx caballus, are distributed along the Eastern Pacific coast. In Panama, C. caballus was heavily fished around Las Perlas Archipelago to sustain local markets until 2007, when the archipelago was declared a marine protected area. This first study in Panama, analyzed a sample of 4 990 individuals from Las Perlas, obtained monthly from June 2005 to June 2006, from landings at the central fish market. Average total length was 36.1 +/- 6.4cm and optimum length 38.9cm. Approximately 68% of fish lengths were within +/-10% of the optimal length but only six (15%) were considered mega-spawners. The von Bertalanffy parameters describe a long-lived and fast growing species, while mortality rates revealed that C. caballus is under high fishing pressure. Standard length at which half of the population is mature was 38.8cm, and the size at which individuals matured massively, 33cm. Only 10-13% of the fish were immature. C. caballus reproduces two to three times per year, with peaks in December, April, and probably September, and recruits to the population at least twice per year. Catch per unit effort (CPUE) was best predicted by minimum annual values of the Multivariate ENSO/LNSO Index (MEI) (R2=0.54). Results show that C. caballus in Pacific Panama is overfished. We recommend the raising of the minimum capture/landing size of this species in order to increase the proportion of mega-spawners in the population and guarantee the sustainability of this resource.

  18. Health effects following subacute exposure to geogenic dusts from arsenic-rich sediment at the Nellis Dunes Recreation Area, Las Vegas, NV.

    PubMed

    DeWitt, Jamie; Buck, Brenda; Goossens, Dirk; Hu, Qing; Chow, Rebecca; David, Winnie; Young, Sharon; Teng, Yuanxin; Leetham-Spencer, Mallory; Murphy, Lacey; Pollard, James; McLaurin, Brett; Gerads, Russell; Keil, Deborah

    2016-08-01

    Geogenic dust from arid environments is a possible inhalation hazard for humans, especially when using off-road vehicles that generate significant dust. This study focused on immunotoxicological and neurotoxicological effects following subacute exposure to geogenic dust generated from sediments in the Nellis Dunes Recreation Area near Las Vegas, Nevada that are particularly high in arsenic; the naturally-occurring arsenic concentrations in these surficial sediments ranged from 4.8 to 346μg/g. Dust samples from sediments used in this study had a median diameter of 4.5μm and also were a complex mixture of naturally-occurring metals, including aluminum, vanadium, chromium, manganese, iron, cobalt, copper, zinc, strontium, cesium, lead, uranium, and arsenic. Adult female B6C3F1 mice exposed via oropharyngeal aspiration to 0.01 to 100mg dust/kg body weight, four times, a week apart, for 28days, were evaluated 24h after the last exposure. Peripheral eosinophils were increased at all concentrations, serum creatinine was dose responsively increased beginning at 1.0mg/kg/day, and blood urea nitrogen was decreased at 10 and 100mg/kg/day. Antigen-specific IgM responses and natural killer cell activity were dose-responsively suppressed at 0.1mg/kg/day and above. Splenic CD4+CD25+ T cells were decreased at 0.01, 0.1, 10, and 100mg/kg/day. Antibodies against MBP, NF-68, and GFAP were selectively reduced. A no observed adverse effect level of 0.01mg/kg/day and a lowest observed adverse effect level of 0.1mg/kg/day were determined from IgM responses and natural killer cell activity, indicating that exposure to this dust, under conditions similar to our design, could affect these responses. PMID:27221630

  19. Integración automatizada de las ecuaciones de Lagrange en el movimiento orbital.

    NASA Astrophysics Data System (ADS)

    Abad, A.; San Juan, J. F.

    The new techniques of algebraic manipulation, especially the Poisson Series Processor, permit the analytical integration of the more and more complex problems of celestial mechanics. The authors are developing a new Poisson Series Processor, PSPC, and they use it to solve the Lagrange equation of the orbital motion. They integrate the Lagrange equation by using the stroboscopic method, and apply it to the main problem of the artificial satellite theory.

  20. Can a Spanish Science Education Journal Become International? The Case of "Enseñanza De Las Ciencias"

    ERIC Educational Resources Information Center

    Espinet, Mariona; Izquierdo, Mercè; Garcia-Pujol, Clara

    2015-01-01

    In this paper we discuss the case of the science education research journal "Enseñanza de las Ciencias" ("EC") around the issue of its internationalization and the consequences this process has had and is still having on the use and preservation of different languages and more specifically the Castilian (Spanish) language. We…

  1. Mechanistic analysis of a synthetic inhibitor of the Pseudomonas aeruginosa LasI quorum-sensing signal synthase

    PubMed Central

    Lidor, O.; Al-Quntar, A.; Pesci, E. C.; Steinberg, D.

    2015-01-01

    Pseudomonas aeruginosa is an opportunistic Gram-negative pathogen responsible for many human infections. LasI is an acyl-homoserine lactone synthase that produces a quorum-sensing (QS) signal that positively regulates numerous P. aeruginosa virulence determinants. The inhibition of the LasI protein is therefore an attractive drug target. In this study, a novel in silico to in vitro complementation was applied to screen thiazolidinedione-type compounds for their ability to inhibit biofilm formation at concentrations not affecting bacterial growth. The compound (z)-5-octylidenethiazolidine-2, 4-dione (TZD-C8) was a strong inhibitor of biofilm formation and chosen for further study. Structural exploration of in silico docking predicted that the compound had high affinity for the LasI activity pocket. The TZD-C8 compound was also predicted to create hydrogen bonds with residues Arg30 and Ile107. Site-directed mutagenesis (SDM) of these two sites demonstrated that TZD-C8 inhibition was abolished in the lasI double mutant PAO-R30D, I107S. In addition, in vitro swarming motility and quorum sensing signal production were affected by TZD-C 8, confirming this compound alters the cell to cell signalling circuitry. Overall, this novel inhibitor of P. aeruginosa quorum sensing shows great promise and validates our mechanistic approach to discovering inhibitors of LuxI-type acyl-homoserine lactone synthases. PMID:26593271

  2. Ambient air monitoring during the 2011 Las Conchas wildland fire near Los Alamos, U.S.A.

    SciTech Connect

    Green, Andrew A.; Schlemann, Shea A.; Young, Daniel L.

    2012-08-31

    Air monitoring data collected during the Las Conchas fire near the Los Alamos National Laboratory during 2011 are presented. Data included are for selected radionuclides and selected metals found in particulate matter. None of these analytes were seen at levels which exceeded any state or federal standards.

  3. 76 FR 3678 - Board Meeting: February 16, 2011-Las Vegas, NV, the U.S. Nuclear Waste Technical Review Board...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-20

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR WASTE TECHNICAL REVIEW BOARD Board Meeting: February 16, 2011--Las Vegas, NV, the U.S. Nuclear Waste Technical Review... Radioactive Waste Pursuant to its authority under section 5051 of Public Law 100-203, Nuclear Waste...

  4. Seasonal and diurnal analysis of NO2 concentrations from a long-duration study conducted in Las Vegas, Nevada

    EPA Science Inventory

    A study, conducted in Las Vegas, NV from mid-December 2008 to mid-December 2009 along an interstate highway, collected continuous and integrated ambient air quality samples for a wide variety of species including NO2 and NOX. Previous near-road studies have been short duration, ...

  5. Preliminary information on ambient concentrations measured at the Las Vegas National Near-Road MSAT study site

    EPA Science Inventory

    This paper provides preliminary information on the trends in ambient concentrations observed near a heavily traveled highway in Las Vegas, Nevada. As part of a joint effort by the U.S. Environmental Protection Agency (EPA) and Federal Highway Administration, an air monitoring pro...

  6. El origen de las galaxias en modelos jerárquicos de formación de la estructura

    NASA Astrophysics Data System (ADS)

    Navarro, J. F.

    En esta charla presentaré una revisión de los modelos corrientes de formación de galaxias. En particular, haré énfasis en el origen de la gran variedad de morfologías galácticas y de las correlaciones entre las propiedades estructurales de discos y esferoides, todo dentro del contexto cosmológico jerárquico provisto por teorías como la de materia oscura fría. En este tipo de teorías las correlaciones observadas entre la luminosidad, velocidad de rotación, momento angular, y tamaño de galaxias son el resultado de la falta de escalas naturales en el proceso de formación de los halos de materia oscura que dichas galaxias habitan. Simulaciones numéricas que incorporan efectos gravitacionales, hidrodinámicos y de formación estelar ilustran estas ideas y demuestran las dificultades que aquejan a modelos donde tanto discos como esferoides son el resultado final de una secuencia de fusiones de sistemas protogalácticos.

  7. Female Adolescent Subjectivities in Las Vegas: Poststructural Thoughts on the Intersections of Gender, Sexuality, Consumer Logic and Curriculum

    ERIC Educational Resources Information Center

    Dentith, Audrey M.

    2004-01-01

    In this article, data collected from an ethnographic study of adolescent girls growing up in the city of Las Vegas in the US is used to further our understanding of the role of mediated sex and consumer culture and in relationship to emerging adolescent female identities. Girls in this study articulated a clear sense of their abilities to make…

  8. Un programa innovador busca ayudar a las personas que cuidan a pacientes con cáncer

    Cancer.gov

    Artículo sobre un programa educativo del City of Hope Cancer Center que ofrece a los profesionales de salud la información y las herramientas necesarias para ayudar a los familiares a saber cómo cuidarse a si mismos y a sus seres queridos con cáncer.

  9. What Happens in Vegas Does "Not" Stay in Vegas: Youth Leadership in the Immigrant Rights Movement in Las Vegas, 2006

    ERIC Educational Resources Information Center

    Revilla, Anita Tijerina

    2012-01-01

    Students calling themselves the Las Vegas Activist Crew shut down the city's famed Strip on May 1, 2006, with an immigrant rights protest that was one of the largest demonstrations in Nevada's history. This research analyzes the ways that students engage in activism to improve their own social conditions and those of their communities. The…

  10. A second Las17 monomeric actin-binding motif functions in Arp2/3-dependent actin polymerization during endocytosis.

    PubMed

    Feliciano, Daniel; Tolsma, Thomas O; Farrell, Kristen B; Aradi, Al; Di Pietro, Santiago M

    2015-04-01

    During clathrin-mediated endocytosis (CME), actin assembly provides force to drive vesicle internalization. Members of the Wiskott-Aldrich syndrome protein (WASP) family play a fundamental role stimulating actin assembly. WASP family proteins contain a WH2 motif that binds globular actin (G-actin) and a central-acidic motif that binds the Arp2/3 complex, thus promoting the formation of branched actin filaments. Yeast WASP (Las17) is the strongest of five factors promoting Arp2/3-dependent actin polymerization during CME. It was suggested that this strong activity may be caused by a putative second G-actin-binding motif in Las17. Here, we describe the in vitro and in vivo characterization of such Las17 G-actin-binding motif (LGM) and its dependence on a group of conserved arginine residues. Using the yeast two-hybrid system, GST-pulldown, fluorescence polarization and pyrene-actin polymerization assays, we show that LGM binds G-actin and is necessary for normal Arp2/3-mediated actin polymerization in vitro. Live-cell fluorescence microscopy experiments demonstrate that LGM is required for normal dynamics of actin polymerization during CME. Further, LGM is necessary for normal dynamics of endocytic machinery components that are recruited at early, intermediate and late stages of endocytosis, as well as for optimal endocytosis of native CME cargo. Both in vitro and in vivo experiments show that LGM has relatively lower potency compared to the previously known Las17 G-actin-binding motif, WH2. These results establish a second G-actin-binding motif in Las17 and advance our knowledge on the mechanism of actin assembly during CME.

  11. Human-health pharmaceutical compounds in Lake Mead, Nevada and Arizona, and Las Vegas Wash, Nevada, October 2000-August 2001

    USGS Publications Warehouse

    Boyd, Robert A.; Furlong, Edward T.

    2002-01-01

    The U.S. Geological Survey and the National Park Service conducted a reconnaissance study to investigate the occurrence of selected human-health pharmaceutical compounds in water samples collected from Lake Mead on the Colorado River and Las Vegas Wash, a waterway used to transport treated wastewater from the Las Vegas metropolitan area to Lake Mead. Current research indicates many of these compounds can bioaccumulate and may adversely affect aquatic organisms by disrupting physiological processes, impairing reproductive functions, increasing cancer rates, contributing to the development of antibiotic-resistant strains of bacteria, and acting in undesirable ways when mixed with other substances. These compounds may be present in effluent because a high percentage of prescription and non-prescription drugs used for human-health purposes are excreted from the body as a mixture of parent compounds and degraded metabolite compounds; also, they can be released to the environment when unused products are discarded by way of toilets, sinks, and trash in landfills. Thirteen of 33 targeted compounds were detected in at least one water sample collected between October 2000 and August 2001. All concentrations were less than or equal to 0.20 micrograms per liter. The most frequently detected compounds in samples from Las Vegas Wash were caffeine, carbamazepine (used to treat epilepsy), cotinine (a metabolite of nicotine), and dehydronifedipine (a metabolite of the antianginal Procardia). Less frequently detected compounds in samples collected from Las Vegas Wash were antibiotics (clarithromycin, erythromycin, sulfamethoxazole, and trimethoprim), acetaminophen (an analgesic and anti-inflammatory), cimetidine (used to treat ulcers), codeine (a narcotic and analgesic), diltiazem (an antihypertensive), and 1,7-dimethylxanthine (a metabolite of caffeine). Fewer compounds were detected in samples collected from Lake Mead than from Las Vegas Wash. Caffeine was detected in all samples

  12. Geohydrologic reconnaissance of Lake Mead National Recreation Area; Las Vegas Wash to Virgin River, Nevada

    USGS Publications Warehouse

    Laney, R.L.; Bales, J.T.

    1996-01-01

    This study is the last of a series of eight geohydrologic reconnaissance studies that were done in the Lake Mead National Recreation Area. The studies were done to evaluate the water resources in the recreation area and to identify areas having potential for the development of water supplies that would be adequate for marinas and campgrounds. The study area includes about 250 square miles north of Lake Mead from Las Vegas Wash to the Virgin River (Overton Arm), Nevada. Volcanic rocks, consolidated sedimentary rocks, and unconsolidated to semiconsolidated sedimentary rocks underlie the area. Surface-water sources include the Colorado River, Virgin River, Muddy River, and Las Vegas Wash. Elsewhere in the area, streamflow is meager and extremely variable. Ground water originates from four sources: (1) subsurface flow in local basins, (2) infiltration of water from Lake Mead into permeable rocks near the lake, (3) subsurface flow in valleys of perennial streams, and (4) subsurface flow in consolidated rocks of the Muddy Mountains. The quantity of water from Lake Mead that has saturated rocks adjacent to the lake probably is greater than the quantity of ground water from all the Other sources. Rocks saturated by water from the lake probably extend less than 0.5 mileinland from the lake shore. The quality of virtually all the ground water in the area is not acceptable for drinking purposes. The most favorable areas for obtaining ground water are those underlain by the coarse-grained deposits of the older alluvium and the younger alluvium adjacent to Lake Mead. The least favorable areas are those underlain by the mudstone facies of the Muddy Creek Formation and fine-grained rocks of the Horse Spring Formation. Four areas identified as having potential for ground-water development are (1) near Overton Beach, (2) west of Callville Bay, (3) near Middle Point, and (4) in the lower Moapa Valley. Usable quantities of water probably can be obtained at these sites, but the

  13. Growth and production of Donax striatus (Bivalvia: Donacidae) from Las Balsas beach, Gibara, Cuba.

    PubMed

    Ocaña, Frank A

    2015-09-01

    Clams of the genus Donax are worldwide the dominating group of the invertebrate community on sandy beaches. They are primary consumers that provide a significant abundance and biomass to the ecosystem. In the Caribbean, Donax striatus has an important role for nature and human, nonetheless studies on the population dynamics of this beach clam are scarce and no information exists on secondary production of this species. Growth parameters and secondary production of D. striatus were estimated from February 2008 to November 2009 at Las Balsas beach, Northeastern Cuba, in order to provide basic information for management purposes. In each month 45 samples were taken by means of a PVC corer of 0.025 m2 area and sieved with a 1 mm mesh. Animals were measured and weighted with and without shell. A total of 5 471 specimens were collected during the sampling period. Shell length ranged from 2.7-33.3 mm. Growth parameters estimated from length frequency data were L∞ = 36.1 mm, K= 0.8/yr and t0= 0.2/yr. The growth performance resulted in values of Φ'= 3.02. Life span was 2.4 yrs and mortality rate was 3.07 /yr. In 2008, mean abundance of D. striatus ranged between 17.1 - 770.7 ind./m2. In 2009 the lowest mean abundance was 34.4 and the highest was 892.5 ind./m2. During 2009 biomass and production was more than twice higher in comparison with 2008. Individual production showed highest values in the 24 mm shell size (3.74 g/m2.yr) and 25 mm (0.71 g/m2.yr), considering mass with shell and without shell, respectively. During 2009 abundance of individuals with 15 mm shell length or more increased resulting in higher biomass and production, compared to 2008. Using the conversion factor of wet mass to ash free dry mass (AFDM), annual production ranged between 2.87-6.11 g AFDM/m2.yr, resulting in a turnover rate (P/B) between 5.11 and 3.47 in 2008 and 2009, respectively. The rapid growth and high turnover rate of D. striatus suggest a rapid recovery of the population. These

  14. Growth and production of Donax striatus (Bivalvia: Donacidae) from Las Balsas beach, Gibara, Cuba.

    PubMed

    Ocaña, Frank A

    2015-09-01

    Clams of the genus Donax are worldwide the dominating group of the invertebrate community on sandy beaches. They are primary consumers that provide a significant abundance and biomass to the ecosystem. In the Caribbean, Donax striatus has an important role for nature and human, nonetheless studies on the population dynamics of this beach clam are scarce and no information exists on secondary production of this species. Growth parameters and secondary production of D. striatus were estimated from February 2008 to November 2009 at Las Balsas beach, Northeastern Cuba, in order to provide basic information for management purposes. In each month 45 samples were taken by means of a PVC corer of 0.025 m2 area and sieved with a 1 mm mesh. Animals were measured and weighted with and without shell. A total of 5 471 specimens were collected during the sampling period. Shell length ranged from 2.7-33.3 mm. Growth parameters estimated from length frequency data were L∞ = 36.1 mm, K= 0.8/yr and t0= 0.2/yr. The growth performance resulted in values of Φ'= 3.02. Life span was 2.4 yrs and mortality rate was 3.07 /yr. In 2008, mean abundance of D. striatus ranged between 17.1 - 770.7 ind./m2. In 2009 the lowest mean abundance was 34.4 and the highest was 892.5 ind./m2. During 2009 biomass and production was more than twice higher in comparison with 2008. Individual production showed highest values in the 24 mm shell size (3.74 g/m2.yr) and 25 mm (0.71 g/m2.yr), considering mass with shell and without shell, respectively. During 2009 abundance of individuals with 15 mm shell length or more increased resulting in higher biomass and production, compared to 2008. Using the conversion factor of wet mass to ash free dry mass (AFDM), annual production ranged between 2.87-6.11 g AFDM/m2.yr, resulting in a turnover rate (P/B) between 5.11 and 3.47 in 2008 and 2009, respectively. The rapid growth and high turnover rate of D. striatus suggest a rapid recovery of the population. These

  15. Metallic species in atmospheric particulate matter in Las Palmas de Gran Canaria.

    PubMed

    Cancio, J López; Castellano, A Vera; Hernández, M Chaar; Bethencourt, R García; Ortega, E Macías

    2008-12-30

    In this work, we quantified the total, water-soluble and insoluble fractions of 12 metallic species (Na, Ca, K, Mg, Fe, Zn, Cr, Ni, Cu, Cd, Pb and Mn) present in total suspended particulates (TSP) in an urban area with heavy traffic (about 80 000 vehicles/day) of Las Palmas de Gran Canaria (Canary Islands). Experimental measurements were made from July to December 2003 on a total of 42 samples (7 per month). Particulate matter (TSP) was collected in fiber filters and high volume samplers. PM10 levels were estimated assuming the PM10 fraction is about 70% of all TSP. Total fractions was determined gravimetrically. Water-soluble fraction was extracted by sonication. Concentrations of metallic elements were analyzed by flame atomic absorption spectrophotometer. Temporal changes in the concentrations of the target elements were examined and a multivariate approach used to identify the primary sources for each species. Mean value for TSP is 71.92microg/m3. The water-soluble fraction consisted mainly of Na, Ca, Mg, and K. The insoluble fraction contained higher concentrations of all elements than the soluble except Na. In the water-soluble fraction, Na, K, Ca and Mg were found to come mainly from natural sources; Cr, Pb, Cd, Ni, Zn and Cu from anthropogenic sources. PMID:18440133

  16. Recovery of Durvillaea antarctica (Durvilleales) inside and outside Las Cruces Marine Reserve, Chile.

    PubMed

    Castilla, J C; Campo, M A; Bustamante, R H

    2007-07-01

    We present the results for over two decades of monitoring on intertidal food-gatherers and the population of the low rocky shore dweller kelp Durvillaea antarctica, a short-distance disperser, inside and outside the no-take marine reserve, Estacion Costera de Investigaciones Marinas (ECIM), at Las Cruces, central Chile. It was hypothesized that protection of an initially extremely depleted population would recover by recolonizing first the no-take area and then adjacent non-protected (exploited) areas. We found that recovery of D. antarctica occurred slowly inside ECIM, with increase in density and biomass, of up to three orders of magnitude as compared to an adjacent non-protected area, which showed approximately 2-yr delay. These results suggest that the kelp population inside ECIM was likely regulated via intraspecific competition, which did not occur outside. Results showed no evidence for juvenile vs. adult density dependence other than a weak relationship for the central area of ECIM. These findings also suggest that the population recovery and cross-boundary seeding subsides affected the population dynamics. Understanding these dynamics may enhance management and conservation policies. Our work highlights the critical value of baseline and long-term comparative studies in marine no-take protected and non-protected areas for understanding how population processes respond to human and conservation practices.

  17. Las Cumbres Observatory Global Telescope Network: Keeping Education in the Dark

    NASA Astrophysics Data System (ADS)

    Ross, R. J.; Barton, J. A.; Rosing, W. E.

    2008-06-01

    The Las Cumbres Observatory Global Telescope Network is a privately- funded, non-profit organization that is creating a global network of telescopes ranging in size from 0.4 meter to 2 meters for educational and scientific uses. All will be equipped with high quality CCD imagers with the larger ones with spectrographs. An online interface will be used for observing both in real time and in a queue. Any registered school or group will have the capability to remotely observe using a telescope that is currently in the dark from the comfort of their classroom or science center, half a world away. Accompanying the online telescope-control interface will be a library of resources and activities that will be available in the formal classroom setting, informal groups and clubs, and for public outreach in the community for all age groups and levels of science. Using the LCOGT network as a tool to enjoy real astronomical research will not only create a new awareness and excitement towards science and technology, it will also make visible connections between science and humanities.

  18. Revisiting Brightest Cluster Galaxy Evolution with the Las Campanas Distant Cluster Survey

    NASA Astrophysics Data System (ADS)

    Nelson, Amy E.; Gonzalez, Anthony H.; Zaritsky, Dennis; Dalcanton, Julianne J.

    2002-02-01

    We investigate the influence of environment on brightest cluster galaxy (BCG) evolution using a sample of 63 clusters at 0.3<=z<=0.9 drawn primarily from the Las Campanas Distant Cluster Survey and follow-up V, I, and K' photometry. The luminosity evolution of the entire BCG sample is not adequately described by a single evolutionary model. Using the integrated light from the cluster detection as a proxy for cluster LX and the suggestion by Burke, Collins, & Mann, we set LX=2×1044 ergs s-1 to be the division between high- and low-luminosity clusters. At high redshift (z>0.6) BCGs from low-LX clusters are fainter, on average, than those from high-LX clusters and are best modeled as having constant luminosity with redshift. The BCGs from high-LX clusters are best modeled as having a stellar population that formed at large redshift (zform>5) and is passively evolving. However, for the entire BCG population, the observed V-I and I-K' colors are well described by a single evolutionary model in which the stellar populations have zform>5 and subsequently passively evolve. We conclude that accretion is proportionally more significant for BCGs in lower mass clusters at these redshifts (a factor of 2-4 increase in mass since z~1 for the low-LX systems; Aragon-Salamanca and coworkers) and that the accreted matter is in the form of systems with evolved stellar populations.

  19. Understanding Ground Motion in Las Vegas: Insights from Data Analysis and Two-Dimensional Modeling

    SciTech Connect

    Rodgers, A; Tkalcic, H; McCallen, D

    2004-02-05

    Seismic ground motions are amplified in low velocity sedimentary basins relative to adjacent sites on high velocity hard rock. We used historical recordings of NTS nuclear explosions and earthquake recordings in Las Vegas Valley to quantify frequency-dependent basin amplification using Standard Spectral Ratios. We show that amplifications, referred to as site response, can reach a factor of 10 in the frequency band 0.4-2.0 Hz. Band-averaged site response between 0.4-2.0 Hz is strongly correlated with basin depth. However, it is also well known that site response is related to shallow shear-wave velocity structure. We simulated low frequency (f<1Hz) ground motion and site response with two-dimensional elastic finite difference simulations. We demonstrate that physically plausible models of the shallow subsurface, including low velocity sedimentary structure, can predict relative amplification as well as some of the complexity in the observed waveforms. This study demonstrates that site response can be modeled without invoking complex and computationally expensive three-dimensional structural models.

  20. Indicator pathogens, organic matter and LAS detergent removal from wastewater by constructed subsurface wetlands

    PubMed Central

    2014-01-01

    Background Constructed wetland is one of the natural methods of municipal and industrial wastewater treatments with low initial costs for construction and operation as well as easy maintenance. The main objective of this study is to determine the values of indicator bacteria removal, organic matter, TSS, ammonia and nitrate affecting the wetland removal efficiency. Results The average concentration of E. coli and total coliform in the input is 1.127 × 1014 and 4.41 × 1014 MPN/100 mL that reached 5.03 × 1012 and 1.13 × 1014 MPN/100 mL by reducing 95.5% and 74.4% in wetland 2. Fecal streptococcus reached from the average 5.88 × 1014 in raw wastewater to 9.69 × 1012 in the output of wetland 2. Wetland 2 could reduce 1.5 logarithmic units of E. coli. The removal efficiency of TSS for the wetlands is 68.87%, 71.4%, 57.3%, and 66% respectively. Conclusions The overall results show that wetlands in which herbs were planted had a high removal efficiency about the indicator pathogens, organic matter, LAS detergent in comparison to a control wetland (without canes) and could improve physicochemical parameters (DO, ammonia, nitrate, electrical conductivity, and pH) of wastewater. PMID:24581277

  1. Episodic Impacts from California Wildfires Identified in Las Vegas Near-Road Air Quality Monitoring.

    PubMed

    Kimbrough, Sue; Hays, Michael; Preston, Bill; Vallero, Daniel A; Hagler, Gayle S W

    2016-01-01

    Air pollutant concentrations near major highways are usually attributed to a combination of nearby traffic emissions and regional background, and generally presumed to be additive in nature. During a near-road measurement study conducted in Las Vegas, NV, the effects of distant wildfires on regional air quality were indicated over a several day period in the summer of 2009. Area-wide elevated particulate levoglucosan (maximum of 0.83 μg/m(3)) and roadside measurements of ultraviolet light-absorbing particulate matter (UVPM) in comparison to black carbon (Delta-C) were apparent over the three-day period. Back-trajectory modeling and satellite images supported the measurement results and indicated the transport of air pollutants from wildfires burning in southern California. Separating roadside measurements under apparent biomass burning event (Delta-C > 1000 ng m(-3)) and nonevent (Delta-C < 1000 ng m(-3)) periods, and constraining to specific days of week, wind speed range, wind direction from the road and traffic volume range, roadside carbon monoxide, black carbon, total particle number count (20-200 nm), and accumulation mode particle number count (100-200 nm) increased by 65%, 146%, 58%, and 366%, respectively, when biomass smoke was indicated. Meanwhile, ultrafine particles (20-100 nm) decreased by 35%. This episode indicates that the presence of aged wildfire smoke may interact with freshly emitted ultrafine particles, resulting in a decrease of particles in the ultrafine mode. PMID:26618236

  2. Targeting Planetary Anomalies in Microlensing Events with the Las Cumbres Observatory Global Telescope Network

    NASA Astrophysics Data System (ADS)

    Street, Rachel; RoboNet Microlensing Team

    2007-12-01

    By the nature of these transient, non-repeating phenomena, observing microlensing events requires a fast, responsive system of telescopes distributed over a range of longitudes. The Las Cumbres Observatory Global Telescope Network currently consists of the 2m Faulkes Telescopes North and South. Over the course of the next few years LCOGT will expand this network to a complement of 44, including 2x2m, 18x1m and 24x0.4m which will be sited in clusters of 3-4 telescopes such that at least one site is in the dark at any given time, enabling us to provide 24hr coverage of any transient event. The telescopes are controlled via a robotic scheduler, allowing a fast response to alerts from eStar or other robotic agents or to manual override. Both 2m telescopes have been engaged in robotically-controlled follow-up of 222 OGLE and MOA alerts during the 2007 Bulge season and intensive observations of 2 events displaying clear anomalies. We summarise here the results to date.

  3. [Description of a staphylococcal alimentary poisoning outbreak in Las Rosas, Santa Fe Province, Argentina].

    PubMed

    Brizzio, Aníbal A; Tedeschi, Fabián A; Zalazar, Fabián E

    2011-01-01

    On February 2008, a suspected foodborne outbreak was reported in Las Rosas (Santa Fe Province, Argentina). The formal procedures indicated that an undetermined number of individuals had experienced food poisoning following consumption of vegetable cannelloni bought at a local shop. The manufacturer establishment was audited. Samples from the suspected food, as well as environmental samples and swabs from food handlers were obtained and involved subjects were interviewed. Remnants of ingested food were also obtained. Routine microbiological procedures of the foodborne outbreak revealed the presence of coagulase positive S. aureus subspecies aureus in samples from ingested and raw food, and from manipulators. Indicator microorganisms did not show significant levels and no other foodborne pathogen was isolated. Presence of staphylococcal enterotoxin-producing genes was subsequently investigated, and a positive result for enterotoxin B was shown in S. aureus strains isolated from a food handler as well as from food linked to the outbreak Moreover, these isolates showed 100% similarity by SmaI-PFGE. Timely notification together with coordinated sanitary measures and the availability of appropriate laboratory tools allowed to interrupt the chain of disease transmission by identifying risk and protective factors. PMID:21491063

  4. Generalized Slope Detection and Ranging turbulence profiling at Las Campanas Observatory

    NASA Astrophysics Data System (ADS)

    Goodwin, Michael; Jenkins, Charles; Lambert, Andrew

    2016-09-01

    We present two models of the optical turbulence profile (model-OTP) for Las Campanas Observatory (LCO) based on measurements conducted during 2007 and 2008 using the Generalized Slope Detection and Ranging (SLODAR) method. The model-OTPs can be used as input into simulations to assess the performance of adaptive optics for the Giant Magellan Telescope. Of particular interest is the strength of the ground-layer turbulence for ground-layer adaptive optics. A total of two 1-week observing data was collected using a purpose-built instrument where observations of a bright double star are imaged by 24 × 24 Shack-Hartmann taken with the LCO 100-inch du Pont telescope. The analysis of the data yielded model-OTP consisting of a handful of statistically prominent thin layers that are statistically separated into the ground layer (below 0.5 km) and the free atmosphere for good (25 per cent), typical (50 per cent) and bad (25 per cent) observing conditions. We demonstrate that using the novel technique of Generalized SLODAR we were able to achieve three times the nominal height resolution of SLODAR and uncover important structural details in the ground layer.

  5. Using mixture tuned match filtering to measure changes in subpixel vegetation area in Las Vegas, Nevada

    NASA Astrophysics Data System (ADS)

    Brelsford, Christa; Shepherd, Doug

    2013-09-01

    In desert cities, securing sufficient water supply to meet the needs of both existing population and future growth is a complex problem with few easy solutions. Grass lawns are a major driver of water consumption and accurate measurements of vegetation area are necessary to understand drivers of changes in household water consumption. Measuring vegetation change in a heterogeneous urban environment requires sub-pixel estimation of vegetation area. Mixture Tuned Match Filtering has been successfully applied to target detection for materials that only cover small portions of a satellite image pixel. There have been few successful applications of MTMF to fractional area estimation, despite theory that suggests feasibility. We use a ground truth dataset over ten times larger than that available for any previous MTMF application to estimate the bias between ground truth data and matched filter results. We find that the MTMF algorithm underestimates the fractional area of vegetation by 5-10%, and calculate that averaging over 20 to 30 pixels is necessary to correct this bias. We conclude that with a large ground truth dataset, using MTMF for fractional area estimation is possible when results can be estimated at a lower spatial resolution than the base image. When this method is applied to estimating vegetation area in Las Vegas, NV spatial and temporal trends are consistent with expectations from known population growth and policy goals.

  6. Episodic Impacts from California Wildfires Identified in Las Vegas Near-Road Air Quality Monitoring.

    PubMed

    Kimbrough, Sue; Hays, Michael; Preston, Bill; Vallero, Daniel A; Hagler, Gayle S W

    2016-01-01

    Air pollutant concentrations near major highways are usually attributed to a combination of nearby traffic emissions and regional background, and generally presumed to be additive in nature. During a near-road measurement study conducted in Las Vegas, NV, the effects of distant wildfires on regional air quality were indicated over a several day period in the summer of 2009. Area-wide elevated particulate levoglucosan (maximum of 0.83 μg/m(3)) and roadside measurements of ultraviolet light-absorbing particulate matter (UVPM) in comparison to black carbon (Delta-C) were apparent over the three-day period. Back-trajectory modeling and satellite images supported the measurement results and indicated the transport of air pollutants from wildfires burning in southern California. Separating roadside measurements under apparent biomass burning event (Delta-C > 1000 ng m(-3)) and nonevent (Delta-C < 1000 ng m(-3)) periods, and constraining to specific days of week, wind speed range, wind direction from the road and traffic volume range, roadside carbon monoxide, black carbon, total particle number count (20-200 nm), and accumulation mode particle number count (100-200 nm) increased by 65%, 146%, 58%, and 366%, respectively, when biomass smoke was indicated. Meanwhile, ultrafine particles (20-100 nm) decreased by 35%. This episode indicates that the presence of aged wildfire smoke may interact with freshly emitted ultrafine particles, resulting in a decrease of particles in the ultrafine mode.

  7. [Description of a staphylococcal alimentary poisoning outbreak in Las Rosas, Santa Fe Province, Argentina].

    PubMed

    Brizzio, Aníbal A; Tedeschi, Fabián A; Zalazar, Fabián E

    2011-01-01

    On February 2008, a suspected foodborne outbreak was reported in Las Rosas (Santa Fe Province, Argentina). The formal procedures indicated that an undetermined number of individuals had experienced food poisoning following consumption of vegetable cannelloni bought at a local shop. The manufacturer establishment was audited. Samples from the suspected food, as well as environmental samples and swabs from food handlers were obtained and involved subjects were interviewed. Remnants of ingested food were also obtained. Routine microbiological procedures of the foodborne outbreak revealed the presence of coagulase positive S. aureus subspecies aureus in samples from ingested and raw food, and from manipulators. Indicator microorganisms did not show significant levels and no other foodborne pathogen was isolated. Presence of staphylococcal enterotoxin-producing genes was subsequently investigated, and a positive result for enterotoxin B was shown in S. aureus strains isolated from a food handler as well as from food linked to the outbreak Moreover, these isolates showed 100% similarity by SmaI-PFGE. Timely notification together with coordinated sanitary measures and the availability of appropriate laboratory tools allowed to interrupt the chain of disease transmission by identifying risk and protective factors.

  8. Reference materials and intercomparison samples available from the Environmental Monitoring Systems Laboratory - Las Vegas

    SciTech Connect

    Kantor, E.J.; Laska, P.R.

    1985-06-01

    Reference materials and intercomparison samples may be obtained by laboratories involved in the analysis of environmental samples containing radioactivity, pesticides, toxic inorganic species, or toxic organic species. These reference materials and intercomparison samples are available from the US Environmental Protection Agency's Quality Assurance Division located at the Environmental Monitoring Systems Laboratory in Las Vegas (EMSL-LV). These materials are useful for incorporation into a laboratory's quality control program for the evaluation of the precision and accuracy of analytical work. Media used for radiation reference materials are pitchblende, Monazite ore, uranium mill tailings, Mancos shale, fly ash, and water spiked with radionuclides. Radioactivity intercomparison samples consist of water, milk, air, urine, and a simulated diet slurry spiked with radionuclides. Media available for toxic organic reference materials are sludge, shale oil, and rag oil, and for intercomparison samples are soil and water. Characterized fly ash, foundry sludge, and river sediment serve as reference materials for toxic inorganics, while spiked soil and water serve as intercomparison samples. Finally, spiked adipose tissue, blood plasma, urine, and water comprise the pesticide intercomparison samples, and, after the disclosure of the true pesticide compositions and concentrations of these samples, the laboratory can use the samples as reference materials. The reference materials are generally available continuously, but the intercomparison samples are distributed on a scheduled basis and in some cases only to certain laboratories. 9 tables.

  9. Integrated geophysical methods for studying the karst system of Gruta de las Maravillas (Aracena, Southwest Spain)

    NASA Astrophysics Data System (ADS)

    Martínez-Moreno, F. J.; Galindo-Zaldívar, J.; Pedrera, A.; Teixido, T.; Ruano, P.; Peña, J. A.; González-Castillo, L.; Ruiz-Constán, A.; López-Chicano, M.; Martín-Rosales, W.

    2014-08-01

    In this study we contrast the results of different geophysical methods in order to describe the karst system surrounding of the Gruta de las Maravillas cave (Aracena, Spain). A comprehensive study of the geophysical responses of the known cavity was carried out, after which several sections were studied to detect the karst architecture and cave continuity. To ensure precision, the inner 3D-topography of the cave was determined by classical geodetic techniques and a digital terrain model was performed with differential GPS. The microgravity method was used to obtain the residual gravity map of the entire study zone, whose minima could be related to caves. Then, the negative gravity anomalies were analyzed to plan several lines for implementing further geophysical methods: magnetic profiles (MP), electrical resistivity tomography (ERT), induced polarization (IP), 2D seismic prospection (refraction tomography and reflection sections) and ground penetrating radar (GPR). The resulting models for each line explored were integrated with detailed geological maps to establish the unknown continuity of the caves. Finally, we discuss the suitability of each geophysical technique for cave detection in marble with sulfur host rock and propose the best procedures to constrain their geometries.

  10. A method based on local approximate solutions (LAS) for inverting transient flow in heterogeneous aquifers

    NASA Astrophysics Data System (ADS)

    Jiao, Jianying; Zhang, Ye

    2014-06-01

    An inverse method based on local approximate solutions (LAS inverse method) is proposed to invert transient flows in heterogeneous aquifers. Unlike the objective-function-based inversion techniques, the method does not require forward simulations to assess measurement-to-model misfits; thus the knowledge of aquifer initial conditions (IC) and boundary conditions (BC) is not required. Instead, the method employs a set of local approximate solutions of flow to impose continuity of hydraulic head and Darcy fluxes throughout space and time. Given sufficient (but limited) measurements, it yields well-posed systems of nonlinear equations that can be solved efficiently with optimization. Solution of the inversion includes parameters (hydraulic conductivities, specific storage coefficients) and flow field including the unknown IC and BC. Given error-free measurements, the estimated conductivities and specific storages are accurate within 10% of the true values. When increasing measurement errors are imposed, the estimated parameters become less accurate, but the inverse solution is still stable, i.e., parameter, IC, and BC estimation remains bounded. For a problem where parameter variation is unknown, highly parameterized inversion can reveal the underlying parameter structure, whereas equivalent conductivity and average storage coefficient can also be estimated. Because of the physically-based constraints placed in inversion, the number of measurements does not need to exceed the number of parameters for the inverse method to succeed.

  11. Pseudomonas aeruginosa Las quorum sensing autoinducer suppresses growth and biofilm production in Legionella species.

    PubMed

    Kimura, Soichiro; Tateda, Kazuhiro; Ishii, Yoshikazu; Horikawa, Manabu; Miyairi, Shinichi; Gotoh, Naomasa; Ishiguro, Masaji; Yamaguchi, Keizo

    2009-06-01

    Bacteria commonly communicate with each other by a cell-to-cell signalling mechanism known as quorum sensing (QS). Recent studies have shown that the Las QS autoinducer N-(3-oxododecanoyl)-l-homoserine lactone (3-oxo-C(12)-HSL) of Pseudomonas aeruginosa performs a variety of functions not only in intraspecies communication, but also in interspecies and interkingdom interactions. In this study, we report the effects of Pseudomonas 3-oxo-C(12)-HSL on the growth and suppression of virulence factors in other bacterial species that frequently co-exist with Ps. aeruginosa in nature. It was found that 3-oxo-C(12)-HSL, but not its analogues, suppressed the growth of Legionella pneumophila in a dose-dependent manner. However, 3-oxo-C(12)-HSL did not exhibit a growth-suppressive effect on Serratia marcescens, Proteus mirabilis, Escherichia coli, Alcaligenes faecalis and Stenotrophomonas maltophilia. A concentration of 50 microM 3-oxo-C(12)-HSL completely inhibited the growth of L. pneumophila. Additionally, a significant suppression of biofilm formation was demonstrated in L. pneumophila exposed to 3-oxo-C(12)-HSL. Our results suggest that the Pseudomonas QS autoinducer 3-oxo-C(12)-HSL exerts both bacteriostatic and virulence factor-suppressive activities on L. pneumophila alone.

  12. Approaches to Costing Adult Literacy Programmes, Especially in Africa

    ERIC Educational Resources Information Center

    Carr-Hill, Roy; Roberts, Fiona; Currie, Elizabeth

    2010-01-01

    Background: This study was originally prepared for the African Inter-Ministerial Conference on Literacy (September 2007) with the objective of analysing the costs of successful adult literacy programmes run both by government ministries, as well as international and national non-governmental organisations. Objectives: This study aims to increase…

  13. Progress Lags in High School, Especially for Advanced Achievers

    ERIC Educational Resources Information Center

    Education Digest: Essential Readings Condensed for Quick Review, 2012

    2012-01-01

    This report by the Center on Education Policy (CEP), an independent nonprofit organization, examines trends in the achievement of high school students on the state reading/English language arts (ELA) and mathematics tests used for accountability under the No Child Left Behind Act (NCLB). This study confirms that there is reason for concern about…

  14. PIXE analysis of preconcentrated body fluids, especially urine

    NASA Astrophysics Data System (ADS)

    Pakarinen, Pirjo; Ekholm, Ann-Kristin; Pallon, Jan

    1990-04-01

    A cation exchange resin, Chelex 100, has been used to separate and preconcentrate trace metal ions in urine. A good recovery of several metal ions in doped urine is achieved. The validity of the procedure has been checked by analyzing a certified control urine for metals, Lanonorm. The method is also applicable for amniotic fluid samples.

  15. Outcomes of esophageal surgery, especially of the lower esophageal sphincter.

    PubMed

    Bonavina, Luigi; Siboni, Stefano; Saino, Greta I; Cavadas, Demetrio; Braghetto, Italo; Csendes, Attila; Korn, Owen; Figueredo, Edgar J; Swanstrom, Lee L; Wassenaar, Eelco

    2013-10-01

    This paper includes commentaries on outcomes of esophageal surgery, including the mechanisms by which fundoduplication improves lower esophageal sphincter (LES) pressure; the efficacy of the Linx™ management system in improving LES function; the utility of radiologic characterization of antireflux valves following surgery; the correlation between endoscopic findings and reported symptoms following antireflux surgery; the links between laparoscopic sleeve gastrectomy and decreased LES pressure, endoscopic esophagitis, and gastroesophageal reflux disease (GERD); the less favorable outcomes following fundoduplication among obese patients; the application of bioprosthetic meshes to reinforce hiatal repair and decrease the incidence of paraesophageal hernia; the efficacy of endoluminal antireflux procedures, and the limited efficacy of revisional antireflux operations, underscoring the importance of good primary surgery and diligent work-up to prevent the necessity of revisional procedures. PMID:24117632

  16. Immune mechanisms in atherosclerosis, especially in diabetes type 2.

    PubMed

    Frostegård, Johan

    2013-10-29

    Atherosclerosis and ensuing cardiovascular disease (CVD) are major complications of diabetes type 2. Atherosclerosis is a chronic inflammatory condition involving immunocompetent cells of different types present in the lesions. Even though inflammation and immune activation may be more pronounced in atherosclerosis in diabetes type 2, there does not appear to be any major differences between diabetics and non-diabetics. Similar factors are thus implicated in atherosclerosis-associated immune activation in both groups. The cause of immune activation is not known and different mutually non-exclusive possibilities exist. Oxidized and/or enzymatically modified forms of low-density lipoprotein (OxLDL) and dead cells are present in atherosclerotic plaques. OxLDL could play a role, being pro-inflammatory and immunostimulatory as it activates T-cells and is cytotoxic at higher concentrations. Inflammatory phospholipids in OxLDL are implicated, with phosphorylcholine (PC) as one of the exposed antigens. Antibodies against PC (anti-PC) are anti-atherogenic in mouse studies, and anti-PC is negatively associated with development of atherosclerosis and CVD in humans. Bacteria and virus have been discussed as potential causes of immune activation, but it has been difficult to find direct evidence supporting this hypothesis, and antibiotic trials in humans have been negative or inconclusive. Heat shock proteins (HSP) could be one major target for atherogenic immune reactions. More direct causes of plaque rupture include cytokines such as interleukin 1β (IL-1β), tumor necrosis factor (TNF), and also lipid mediators as leukotrienes. In addition, in diabetes, hyperglycemia and oxidative stress appear to accelerate the development of atherosclerosis, one mechanism could be via promotion of immune reactions. To prove that immune reactions are causative of atherosclerosis and CVD, further studies with immune-modulatory treatments are needed.

  17. Consciousness: a neural capacity for objectivity, especially pronounced in humans.

    PubMed

    Dijker, Anton J M

    2014-01-01

    Consciousness tends to be viewed either as subjective experience of sensations and feelings, or as perception and internal representation of objects. This paper argues that neither view sufficiently acknowledges that consciousness may refer to the brain's most adaptive property: its capacity to produce states of objectivity. It is proposed that this capacity relies on multiple sensorimotor networks for internally representing objects and their properties in terms of expectancies, as well as on motivational and motor mechanisms involved in exploration, play, and care for vulnerable living and non-living objects. States of objectivity are associated with a very special phenomenal aspect; the experience that subjective aspects are absent and one is "just looking" at the world as it really is and can be. However, these states are normally closely preceded and followed by (and tend to be combined or fused with) sensations and feelings which are caused by activation of sensory and motivational mechanisms. A capacity for objectivity may have evolved in different species and can be conceived as a common basis for other elusive psychological properties such as intelligence, conscience, and esthetic experience; all three linked to crucial behaviors in human evolution such as tool making, cooperation, and art. The brain's pervasive tendency to objectify may be responsible for wrongly equating consciousness with feelings and wrongly opposing it to well-learned or habitual ("unconscious") patterns of perception and behavior.

  18. Necrotizing Fasciitis: A Rare Disease, Especially for the Healthy

    MedlinePlus

    ... Emergency Preparedness & Response Environmental Health Healthy Living Injury, Violence & Safety Life Stages & Populations Travelers' Health Workplace Safety & Health Features Media Sign up for Features Get Email Updates To ...

  19. Graph analysis of dream reports is especially informative about psychosis

    NASA Astrophysics Data System (ADS)

    Mota, Natália B.; Furtado, Raimundo; Maia, Pedro P. C.; Copelli, Mauro; Ribeiro, Sidarta

    2014-01-01

    Early psychiatry investigated dreams to understand psychopathologies. Contemporary psychiatry, which neglects dreams, has been criticized for lack of objectivity. In search of quantitative insight into the structure of psychotic speech, we investigated speech graph attributes (SGA) in patients with schizophrenia, bipolar disorder type I, and non-psychotic controls as they reported waking and dream contents. Schizophrenic subjects spoke with reduced connectivity, in tight correlation with negative and cognitive symptoms measured by standard psychometric scales. Bipolar and control subjects were undistinguishable by waking reports, but in dream reports bipolar subjects showed significantly less connectivity. Dream-related SGA outperformed psychometric scores or waking-related data for group sorting. Altogether, the results indicate that online and offline processing, the two most fundamental modes of brain operation, produce nearly opposite effects on recollections: While dreaming exposes differences in the mnemonic records across individuals, waking dampens distinctions. The results also demonstrate the feasibility of the differential diagnosis of psychosis based on the analysis of dream graphs, pointing to a fast, low-cost and language-invariant tool for psychiatric diagnosis and the objective search for biomarkers. The Freudian notion that ``dreams are the royal road to the unconscious'' is clinically useful, after all.

  20. Especially for Women. Programs and Services Offered by School Boards.

    ERIC Educational Resources Information Center

    Canadian Education Association, Toronto (Ontario).

    This report describes programs and services school boards offer to women employees or women in the community. A special focus is innovative, nontraditional courses and services. The first section discusses offerings for school board staff. An overview of affirmative action/employment equity programs addresses their objectives and describes…

  1. Consciousness: a neural capacity for objectivity, especially pronounced in humans

    PubMed Central

    Dijker, Anton J. M.

    2014-01-01

    Consciousness tends to be viewed either as subjective experience of sensations and feelings, or as perception and internal representation of objects. This paper argues that neither view sufficiently acknowledges that consciousness may refer to the brain’s most adaptive property: its capacity to produce states of objectivity. It is proposed that this capacity relies on multiple sensorimotor networks for internally representing objects and their properties in terms of expectancies, as well as on motivational and motor mechanisms involved in exploration, play, and care for vulnerable living and non-living objects. States of objectivity are associated with a very special phenomenal aspect; the experience that subjective aspects are absent and one is “just looking” at the world as it really is and can be. However, these states are normally closely preceded and followed by (and tend to be combined or fused with) sensations and feelings which are caused by activation of sensory and motivational mechanisms. A capacity for objectivity may have evolved in different species and can be conceived as a common basis for other elusive psychological properties such as intelligence, conscience, and esthetic experience; all three linked to crucial behaviors in human evolution such as tool making, cooperation, and art. The brain’s pervasive tendency to objectify may be responsible for wrongly equating consciousness with feelings and wrongly opposing it to well-learned or habitual (“unconscious”) patterns of perception and behavior. PMID:24672506

  2. Graph analysis of dream reports is especially informative about psychosis

    PubMed Central

    Mota, Natália B.; Furtado, Raimundo; Maia, Pedro P. C.; Copelli, Mauro; Ribeiro, Sidarta

    2014-01-01

    Early psychiatry investigated dreams to understand psychopathologies. Contemporary psychiatry, which neglects dreams, has been criticized for lack of objectivity. In search of quantitative insight into the structure of psychotic speech, we investigated speech graph attributes (SGA) in patients with schizophrenia, bipolar disorder type I, and non-psychotic controls as they reported waking and dream contents. Schizophrenic subjects spoke with reduced connectivity, in tight correlation with negative and cognitive symptoms measured by standard psychometric scales. Bipolar and control subjects were undistinguishable by waking reports, but in dream reports bipolar subjects showed significantly less connectivity. Dream-related SGA outperformed psychometric scores or waking-related data for group sorting. Altogether, the results indicate that online and offline processing, the two most fundamental modes of brain operation, produce nearly opposite effects on recollections: While dreaming exposes differences in the mnemonic records across individuals, waking dampens distinctions. The results also demonstrate the feasibility of the differential diagnosis of psychosis based on the analysis of dream graphs, pointing to a fast, low-cost and language-invariant tool for psychiatric diagnosis and the objective search for biomarkers. The Freudian notion that “dreams are the royal road to the unconscious” is clinically useful, after all. PMID:24424108

  3. Why Is It Important to Eat Grains, Especially Whole Grains?

    MedlinePlus

    ... foods or supplements. This reduces the risk of neural tube defects, spina bifida, and anencephaly during fetal ... with folate before and during pregnancy helps prevent neural tube defects during fetal development. Grains All About ...

  4. Graph analysis of dream reports is especially informative about psychosis.

    PubMed

    Mota, Natália B; Furtado, Raimundo; Maia, Pedro P C; Copelli, Mauro; Ribeiro, Sidarta

    2014-01-01

    Early psychiatry investigated dreams to understand psychopathologies. Contemporary psychiatry, which neglects dreams, has been criticized for lack of objectivity. In search of quantitative insight into the structure of psychotic speech, we investigated speech graph attributes (SGA) in patients with schizophrenia, bipolar disorder type I, and non-psychotic controls as they reported waking and dream contents. Schizophrenic subjects spoke with reduced connectivity, in tight correlation with negative and cognitive symptoms measured by standard psychometric scales. Bipolar and control subjects were undistinguishable by waking reports, but in dream reports bipolar subjects showed significantly less connectivity. Dream-related SGA outperformed psychometric scores or waking-related data for group sorting. Altogether, the results indicate that online and offline processing, the two most fundamental modes of brain operation, produce nearly opposite effects on recollections: While dreaming exposes differences in the mnemonic records across individuals, waking dampens distinctions. The results also demonstrate the feasibility of the differential diagnosis of psychosis based on the analysis of dream graphs, pointing to a fast, low-cost and language-invariant tool for psychiatric diagnosis and the objective search for biomarkers. The Freudian notion that "dreams are the royal road to the unconscious" is clinically useful, after all.

  5. Gender Differences, Especially on Fifty College Board Achievement Tests.

    ERIC Educational Resources Information Center

    Stanley, Julian C.; Stumpf, Heinrich

    In a follow-up to findings published by H. Stumpf and J. Stanley (1996), the gender-related differences in enrollment in and scores on the College Board Achievement (SAT II) and Advanced Placement (AP) tests were studied. Differences in scores turned out to be rather stable from 1982 (for the Achievement tests) and 1984 (for the AP tests) through…

  6. Possible energy savings through tribological measures - Especially in automobiles

    NASA Astrophysics Data System (ADS)

    Bartz, W. J.

    1980-02-01

    The efficiency of internal combustion engines and gears is analyzed. Their influence and the state of friction is discussed to assess the order of magnitude of fuel savings that can be achieved through lubricants. These figures are compared with the results achieved elsewhere to establish a practical value for efficiency.

  7. An intelligent rollator for mobility impaired persons, especially stroke patients.

    PubMed

    Hellström, Thomas; Lindahl, Olof; Bäcklund, Tomas; Karlsson, Marcus; Hohnloser, Peter; Bråndal, Anna; Hu, Xiaolei; Wester, Per

    2016-07-01

    An intelligent rollator (IRO) was developed that aims at obstacle detection and guidance to avoid collisions and accidental falls. The IRO is a retrofit four-wheeled rollator with an embedded computer, two solenoid brakes, rotation sensors on the wheels and IR-distance sensors. The value reported by each distance sensor was compared in the computer to a nominal distance. Deviations indicated a present obstacle and caused activation of one of the brakes in order to influence the direction of motion to avoid the obstacle. The IRO was tested by seven healthy subjects with simulated restricted and blurred sight and five stroke subjects on a standardised indoor track with obstacles. All tested subjects walked faster with intelligence deactivated. Three out of five stroke patients experienced more detected obstacles with intelligence activated. This suggests enhanced safety during walking with IRO. Further studies are required to explore the full value of the IRO. PMID:27078084

  8. Apparatus and method for cutting soft materials, especially meat

    DOEpatents

    Spletzer, Barry L.; Callow, Diane S.; Jones, James F.; Kuehl, Michael A.; Shaw, Dick L.; Scalia, Barbara J.

    2005-10-18

    An apparatus and method for cutting soft materials such as meat. Two or more spirally mounted helical blades are situated between two supports, and the supports are mounted to a shank. The shank is rotated to impart rotary action to the spiral shear blades, and the entire device may be used to perform various cutting operations. The distal or bottom one of the supports may also be a cutting blade, and a number of versions of bottom cutting blades are useable in the practice of the invention.

  9. Climate change in California - why is this region especially vulnerable?

    NASA Astrophysics Data System (ADS)

    Cayan, D. R.

    2008-12-01

    It is very likely that global warming has already been affecting the California region., and global model projections indicate that much larger changes will unfold over the coming decades. In this talk we review results from two recent State-sponsored assessments of prospective climate change scenarios for California, which indicate that impacts in this region may be particularly challenging. Among the rest of the United States, the annual delivery of precipitation in this region is remarkably volatile, being prone to multi- year droughts and occasional wet spells and large storms-climate change may exacerbate this. An important part of the water supply that historically has come in the form of snow in mountain watersheds will probably shift to rain, which is harder to manage and save for dry summer irrigation and other forms of consumption. Furthermore, much of the water supply is conveyed through the San Franciso Bay/Delta, a complex estuary that will be impacted by bigger floods and rising sea levels.

  10. Immune mechanisms in atherosclerosis, especially in diabetes type 2.

    PubMed

    Frostegård, Johan

    2013-01-01

    Atherosclerosis and ensuing cardiovascular disease (CVD) are major complications of diabetes type 2. Atherosclerosis is a chronic inflammatory condition involving immunocompetent cells of different types present in the lesions. Even though inflammation and immune activation may be more pronounced in atherosclerosis in diabetes type 2, there does not appear to be any major differences between diabetics and non-diabetics. Similar factors are thus implicated in atherosclerosis-associated immune activation in both groups. The cause of immune activation is not known and different mutually non-exclusive possibilities exist. Oxidized and/or enzymatically modified forms of low-density lipoprotein (OxLDL) and dead cells are present in atherosclerotic plaques. OxLDL could play a role, being pro-inflammatory and immunostimulatory as it activates T-cells and is cytotoxic at higher concentrations. Inflammatory phospholipids in OxLDL are implicated, with phosphorylcholine (PC) as one of the exposed antigens. Antibodies against PC (anti-PC) are anti-atherogenic in mouse studies, and anti-PC is negatively associated with development of atherosclerosis and CVD in humans. Bacteria and virus have been discussed as potential causes of immune activation, but it has been difficult to find direct evidence supporting this hypothesis, and antibiotic trials in humans have been negative or inconclusive. Heat shock proteins (HSP) could be one major target for atherogenic immune reactions. More direct causes of plaque rupture include cytokines such as interleukin 1β (IL-1β), tumor necrosis factor (TNF), and also lipid mediators as leukotrienes. In addition, in diabetes, hyperglycemia and oxidative stress appear to accelerate the development of atherosclerosis, one mechanism could be via promotion of immune reactions. To prove that immune reactions are causative of atherosclerosis and CVD, further studies with immune-modulatory treatments are needed. PMID:24194733

  11. Especial Skills: Their Emergence with Massive Amounts of Practice

    ERIC Educational Resources Information Center

    Keetch, Katherine M.; Schmidt, Richard A.; Lee, Timothy D.; Young, Douglas E.

    2005-01-01

    Differing viewpoints concerning the specificity and generality of motor skill representations in memory were compared by contrasting versions of a skill having either extensive or minimal specific practice. In Experiments 1 and 2, skilled basketball players more accurately performed set shots at the foul line than would be predicted on the basis…

  12. A Film Unit Designed Especially For Developing Countries.

    ERIC Educational Resources Information Center

    Woods, John L.

    An Agency for International Development (AID) project established an educational film production unit in Malawi. The project was designed to deliver extension services and information from the Ministry of Agriculture to rural farmers and had to: 1) produce films which meet the needs of villagers; 2) keep costs to an absolute minimum; and 3) fully…

  13. Variations in alluvial style of Tertiary units in response to tectonism, Las Monas area, middle Magdalena valley, Colombia

    SciTech Connect

    Jordan, D.W.; Siemers, C.T.

    1989-03-01

    Detailed sedimentologic and petrographic analyses of Tertiary alluvial sandstone outcrops within and east of producing oil fields in the Las Monas area in Colombia, South America, indicate that depositional style changed from fluvial-deltaic to braided streams atop alluvial fans to high-sinuosity meandering streams in response to uplifts in the surrounding areas. Diverse paleocurrent trends in the Tertiary formations in the perimeter area demonstrate that streams flowed northeast and northwest. Streams in the oil field had easterly and southerly components. Source areas contributing sediment were different and reflected uplifts to the west and south of the Las Monas area. Petrographic composition of sandstones that have easterly and southerly paleocurrent trends in the field area contain more feldspar and less polycrystalline strained quartz than sandstones having a northerly trend in the perimeter area. Sandstones in the field area represent an unroofing of a western granitic terrain, possibly in the ancestral Central Cordillera.

  14. SOURCE AND PATHWAY DETERMINATION FOR BERYLLIUM FOUND IN BECHTEL NEVADA NORTH LAS VEGAS FACILITIES

    SciTech Connect

    BECHTEL NEVADA

    2004-07-01

    In response to the report ''Investigation of Beryllium Exposure Cases Discovered at the North Las Vegas Facility of the National Nuclear Security Administration'', published by the U.S. Department of Energy (DOE), National Nuclear Security Administration (NNSA) in August 2003, Bechtel Nevada (BN) President and General Manager Dr. F. A. Tarantino appointed the Beryllium Investigation & Assessment Team (BIAT) to identify both the source and pathway for the beryllium found in the North Las Vegas (NLV) B-Complex. From September 8 to December 18, 2003, the BIAT investigated the pathway for beryllium and determined that a number of locations existed at the Nevada Test Site (NTS) which could have contained sufficient quantities of beryllium to result in contamination if transported. Operations performed in the B-1 Building as a result of characterization activities at the Engine Maintenance, Assembly, and Disassembly (EMAD); Reactor Maintenance, Assembly, and Disassembly (RMAD); Test Cells A and C; and the Central Support Facility in Area 25 had the greatest opportunity for transport of beryllium. Investigative monitoring and sampling was performed at these sites with subsequent transport of sample materials, equipment, and personnel from the NTS to the B-1 Building. The timeline established by the BIAT for potential transport of the beryllium contamination into the B-1 Building was from September 1997 through November 2002. Based on results of recently completed swipe sampling, no evidence of transport of beryllium from test areas has been confirmed. Results less than the DOE beryllium action level of 0.2 ???g/100 cm2 were noted for work support facilities located in Area 25. All of the identified sites in Area 25 worked within the B-1 tenant's residency timeline have been remediated. Legacy contaminants have either been disposed of or capped with clean borrow material. As such, no current opportunity exists for release or spread of beryllium contamination. Historical

  15. DISYUNTIVAS EN LAS CONCEPCIONES SOBRE AUTONOMÍA Y BENEFICENCIA QUE AFECTAN LA TERAPÉUTICA DEL INTENTO SUICIDA.

    PubMed

    Mondragón, Liliana; Monroy, Zuraya; Ito, Ma Emily; Medina-Mora, Dra Ma Elena

    2010-06-01

    El objetivo del trabajo es conocer las disyuntivas entre los principios de beneficencia y autonomía, que se presentan en la relación médico-paciente, durante la terapéutica del intento de suicidio.La investigación se realizó en dos hospitales psiquiátricos de la Ciudad de México. La muestra incluyó a tres sujetos con intento de suicidio, mayores de 18 años, que eran atendidos en consulta externa a causa de una lesión autoinfligida en el último año, y a tres psiquiatras que trataban a estos pacientes. La información se obtuvo previo consentimiento informado en entrevistas individuales. Se llevó a cabo un análisis de discurso argumentado para encontrar los significados que los participantes otorgaron a los principios bioéticos y las posibles disyuntivas entre éstos.Las discordancias entre la beneficencia y la autonomía estuvieron relacionadas con el beneficio del tratamiento, el respeto por los valores y las creencias de los pacientes, entre otros. Este trabajo presenta consideraciones éticas relevantes en el escenario clínico, al ofrecer al psiquiatra un análisis bioético que le permita actuar de acuerdo con la beneficencia y respetando la autonomía del paciente frente a casos de intento de suicidio y, de esta forma procurar una mejor atención para ellos.

  16. DISYUNTIVAS EN LAS CONCEPCIONES SOBRE AUTONOMÍA Y BENEFICENCIA QUE AFECTAN LA TERAPÉUTICA DEL INTENTO SUICIDA.

    PubMed

    Mondragón, Liliana; Monroy, Zuraya; Ito, Ma Emily; Medina-Mora, Dra Ma Elena

    2010-06-01

    El objetivo del trabajo es conocer las disyuntivas entre los principios de beneficencia y autonomía, que se presentan en la relación médico-paciente, durante la terapéutica del intento de suicidio.La investigación se realizó en dos hospitales psiquiátricos de la Ciudad de México. La muestra incluyó a tres sujetos con intento de suicidio, mayores de 18 años, que eran atendidos en consulta externa a causa de una lesión autoinfligida en el último año, y a tres psiquiatras que trataban a estos pacientes. La información se obtuvo previo consentimiento informado en entrevistas individuales. Se llevó a cabo un análisis de discurso argumentado para encontrar los significados que los participantes otorgaron a los principios bioéticos y las posibles disyuntivas entre éstos.Las discordancias entre la beneficencia y la autonomía estuvieron relacionadas con el beneficio del tratamiento, el respeto por los valores y las creencias de los pacientes, entre otros. Este trabajo presenta consideraciones éticas relevantes en el escenario clínico, al ofrecer al psiquiatra un análisis bioético que le permita actuar de acuerdo con la beneficencia y respetando la autonomía del paciente frente a casos de intento de suicidio y, de esta forma procurar una mejor atención para ellos. PMID:20830214

  17. Elucidating Key Motifs Required for Arp2/3-Dependent and Independent Actin Nucleation by Las17/WASP

    PubMed Central

    Urbanek, Agnieszka N.; Smaczynska-de Rooij, Iwona I.

    2016-01-01

    Actin nucleation is the key rate limiting step in the process of actin polymerization, and tight regulation of this process is critical to ensure actin filaments form only at specific times and at defined regions of the cell. Arp2/3 is a well-characterised protein complex that can promote nucleation of new filaments, though its activity requires additional nucleation promotion factors (NPFs). The best recognized of these factors are the WASP family of proteins that contain binding motifs for both monomeric actin and for Arp2/3. Previously we demonstrated that the yeast WASP homologue, Las17, in addition to activating Arp2/3 can also nucleate actin filaments de novo, independently of Arp2/3. This activity is dependent on its polyproline rich region. Through biochemical and in vivo analysis we have now identified key motifs within the polyproline region that are required for nucleation and elongation of actin filaments, and have addressed the role of the WH2 domain in the context of actin nucleation without Arp2/3. We have also demonstrated that full length Las17 is able to bind liposomes giving rise to the possibility of direct linkage of nascent actin filaments to specific membrane sites to which Las17 has been recruited. Overall, we propose that Las17 functions as the key initiator of de novo actin filament formation at endocytic sites by nucleating, elongating and tethering nascent filaments which then serve as a platform for Arp2/3 recruitment and function. PMID:27637067

  18. DISYUNTIVAS EN LAS CONCEPCIONES SOBRE AUTONOMÍA Y BENEFICENCIA QUE AFECTAN LA TERAPÉUTICA DEL INTENTO SUICIDA1

    PubMed Central

    Mondragón, Liliana; Monroy, Zuraya; Ito, Ma. Emily; Medina-Mora, Dra. Ma. Elena

    2010-01-01

    El objetivo del trabajo es conocer las disyuntivas entre los principios de beneficencia y autonomía, que se presentan en la relación médico-paciente, durante la terapéutica del intento de suicidio. La investigación se realizó en dos hospitales psiquiátricos de la Ciudad de México. La muestra incluyó a tres sujetos con intento de suicidio, mayores de 18 años, que eran atendidos en consulta externa a causa de una lesión autoinfligida en el último año, y a tres psiquiatras que trataban a estos pacientes. La información se obtuvo previo consentimiento informado en entrevistas individuales. Se llevó a cabo un análisis de discurso argumentado para encontrar los significados que los participantes otorgaron a los principios bioéticos y las posibles disyuntivas entre éstos. Las discordancias entre la beneficencia y la autonomía estuvieron relacionadas con el beneficio del tratamiento, el respeto por los valores y las creencias de los pacientes, entre otros. Este trabajo presenta consideraciones éticas relevantes en el escenario clínico, al ofrecer al psiquiatra un análisis bioético que le permita actuar de acuerdo con la beneficencia y respetando la autonomía del paciente frente a casos de intento de suicidio y, de esta forma procurar una mejor atención para ellos. PMID:20830214

  19. Elucidating Key Motifs Required for Arp2/3-Dependent and Independent Actin Nucleation by Las17/WASP.

    PubMed

    Allwood, Ellen G; Tyler, Joe J; Urbanek, Agnieszka N; Smaczynska-de Rooij, Iwona I; Ayscough, Kathryn R

    2016-01-01

    Actin nucleation is the key rate limiting step in the process of actin polymerization, and tight regulation of this process is critical to ensure actin filaments form only at specific times and at defined regions of the cell. Arp2/3 is a well-characterised protein complex that can promote nucleation of new filaments, though its activity requires additional nucleation promotion factors (NPFs). The best recognized of these factors are the WASP family of proteins that contain binding motifs for both monomeric actin and for Arp2/3. Previously we demonstrated that the yeast WASP homologue, Las17, in addition to activating Arp2/3 can also nucleate actin filaments de novo, independently of Arp2/3. This activity is dependent on its polyproline rich region. Through biochemical and in vivo analysis we have now identified key motifs within the polyproline region that are required for nucleation and elongation of actin filaments, and have addressed the role of the WH2 domain in the context of actin nucleation without Arp2/3. We have also demonstrated that full length Las17 is able to bind liposomes giving rise to the possibility of direct linkage of nascent actin filaments to specific membrane sites to which Las17 has been recruited. Overall, we propose that Las17 functions as the key initiator of de novo actin filament formation at endocytic sites by nucleating, elongating and tethering nascent filaments which then serve as a platform for Arp2/3 recruitment and function. PMID:27637067

  20. Recent variation of the Las Vacas Glacier Mt. Aconcagua region, Central Andes, Argentina, based on ASTER stereoscopic images

    NASA Astrophysics Data System (ADS)

    Lenzano, M. G.; Leiva, J. C.; Lenzano, L.

    2010-01-01

    This work presents the results of the ASTER stereoscopic image processing to calculate the volume changes of Las Vacas Glacier. The processing of medium resolution satellite images (ASTER level 1A - pixel 15 m) from February 2001 and 2007 was performed applying the satellite digital photogrammetry method (Kääb, 2005). The comparison of the two generated DTM returns results that are acceptable within the parameters and precisions that can be obtained with this kind of sensor and the processing methodology.

  1. Mangrove forest composition and structure in Las Perlas Archipelago, Pacific Panama.

    PubMed

    McGowan, Tom; Cunningham, Sarah L; Guzmán, Héctor M; Mair, James M; Guevara, José M; Betts, Tanja

    2010-09-01

    Mangrove forest is an important ecosystem that provides many services, but in Panama, as in other countries, they are under threat due to a variety of human activities. Nowadays, large areas of mangroves continue to be lost without been described and lack of management strategies. This study focused on the mangrove structure in the two largest islands, Isla del Rey and Isla San Jose, of Las Perlas Archipelago (LPA), Pacific Panama. Assessment of Landsat satellite imagery revealed loss of mangroves in the LPA of 965ha in the period 1974-1986, and 248ha in the period 1986-2000. The majority of the loss (>77%) from the two study islands was due to timber extraction and agricultural development. In May 2006, permanent plots following the CARICOMP protocol were established at two sites on Isla del Rey (R1 and R2) and one site on Isla San Jose (SJ) where standardized metrics such as species, height and diameter at breast height of adult trees and seedlings were recorded. Forest structure differed at the three sites, although R1 and R2 were most similar. At R1, Laguncularia racemosa was the important species and R2 was dominated by Pelliciera rhizophorae. Examination of the forest structure and classified imagery indicated that these sites are spatially dynamic and appear to be rejuvenating. The forest structure would indicate that the sites have been growth-limited previously by human activities and possibly by other factors. SJ was dominated by Rhizophora mangle and appears to have a mature forest with large adult trees and few seedlings. It does not appear to have shown the same extent of spatial regrowth as the other two sites between 1986 and 2000 and is relatively static. The establishment of permanent plots and monitoring will be useful as part of the management plan, as the LPA shows a variety of mangrove structures and could be subject to further coastal development. PMID:20737843

  2. Tritium contamination at EG&G/EM in North Las Vegas, Nevada

    SciTech Connect

    Sowell, C.V.; Arent, L.J.

    1996-06-01

    The tritium contamination discovered at the EG&G Energy Measurements (EG&G/EM) facility in North Las Vegas, Nevada, on 20 April 1995, could have been averted by good health physics practices and/or adequate management oversight. Scandium tritide (ScT{sub 3}) targets were installed for use in sealed tube neutron generators at EG&G/EM. In addition, EG&G/EM was also storing zirconium tritide (ZrT{sub 3}) and titanium tritide (TiT{sub 3}) foils. Since the targets were classified as sealed sources, the appropriate administrative and engineering control measures such as relocating targets/sources, air monitoring, bioassay, waste stream management, labeling/posting and training were not implemented. In all there were six unreported incidents of tritium contamination from March 1994 to July 1995. Swipe surveys revealed areas exceeding the action level of 10,000 dpm/100 cm{sup 2} by up to three orders of magnitude. After reclassifying the targets as unsealed sources, a bioassay program was instituted, and the results were higher than expected for three employees. The doses assigned to the three individuals working in the contaminated area were 35, 58, and 61 mrem committed effective dose equivalent. Though the doses were low, the decontamination costs were in excess of $350,000.00. An investigation, was initiated by the U.S. Department of Energy Nevada Operations Office to analyze the events that led to the tritium contamination and recommend actions to prevent recurrence. Event and causal factor charting, Project Evaluation Tree (PET) analysis techniques, and root cause analysis, were used to evaluate management systems, causal sequences, and systems factors contributing to the tritium release.

  3. The Las Cumbres Observatory (LCOGT) Network for NEO and Solar System Science

    NASA Astrophysics Data System (ADS)

    Lister, Tim; Greenstreet, Sarah; Gomez, Edward; Christensen, Eric; Larson, Stephen

    2015-11-01

    Las Cumbres Observatory Global Telescope Network (LCOGT) has deployed a homogeneous telescope network of nine 1-meter telescopes to four locations in the northern and southern hemispheres, with a planned network size of twelve 1-meter telescopes at 6 locations. This 1-meter network is in addition to the two 2-meter Faulkes Telescopes that have been operating since 2005. This network is very versatile and is designed to respond rapidly to target of opportunity events and also to perform long term monitoring of slowly changing astronomical phenomena. The global coverage of the network and the apertures of telescope available make LCOGT ideal for follow-up and characterization of Solar System objects e.g. Near-Earth Objects (NEOs), comets, asteroids and Kuiper Belt Objects and also for the discovery of new objects.LCOGT has completed the first phase of the deployment with the installation and commissioning of the nine 1-meter telescopes at McDonald Observatory (Texas), Cerro Tololo (Chile), SAAO (South Africa) and Siding Spring Observatory (Australia). The telescope network has been fully operational since 2014 May, and observations are being executed remotely and robotically. Future expansion to sites in the Canary Islands and Tibet are planned for 2016-2017.I will describe the Solar System science research that is being carried out using the LCOGT Network with highlights from the LCOGT NEO Follow-up Network, long-term monitoring of the Rosetta spacecraft target comet 67P and comet C/2013 A1 (Siding Spring) and work on Kuiper Belt Object occultation targets, including Pluto.

  4. The Las Cumbres Observatory (LCOGT) Network for NEO and Solar System Science

    NASA Astrophysics Data System (ADS)

    Lister, Tim; Greenstreet, Sarah; Gomez, Edward; Christensen, Eric J.; Larson, Stephen M.

    2016-01-01

    Las Cumbres Observatory Global Telescope Network (LCOGT) has deployed a homogeneous telescope network of nine 1-meter telescopes to four locations in the northern and southern hemispheres, with a planned network size of twelve 1-meter telescopes at 6 locations. This 1-meter network is in addition to the two 2-meter Faulkes Telescopes that have been operating since 2005. This network is very versatile and is designed to respond rapidly to target of opportunity events and also to perform long term monitoring of slowly changing astronomical phenomena. The global coverage of the network and the apertures of telescope available make LCOGT ideal for follow-up and characterization of Solar System objects e.g. Near-Earth Objects (NEOs), comets, asteroids and Kuiper Belt Objects and also for the discovery of new objects.LCOGT has completed the first phase of the deployment with the installation and commissioning of the nine 1-meter telescopes at McDonald Observatory (Texas), Cerro Tololo (Chile), SAAO (South Africa) and Siding Spring Observatory (Australia). The telescope network has been fully operational since 2014 May, and observations are being executed remotely and robotically. Future expansion to sites in the Canary Islands and Tibet are planned for 2016-2017.I will describe the Solar System science research that is being carried out using the LCOGT Network with highlights from the LCOGT NEO Follow-up Network, long-term monitoring of the Rosetta spacecraft target comet 67P and comet C/2013 A1 (Siding Spring) and work on Kuiper Belt Object occultation targets, including Pluto.

  5. Geology of Volcan Las Navajas, a pleistocene trachyte/peralkaline rhyolite volcanic center in Nayarit, Mexico

    SciTech Connect

    Hegre, J.A.; Nelson, S.A.

    1985-01-01

    Volcan Las Navajas, located in the northwestern portion of the Mexican Volcanic Belt has produced a sequence of volcanic rocks with compositions in marked contrast to the predominantly calc-alkaline volcanoes which predominate in this part of Mexico. The oldest exposed lavas consist of trachytes with 63% SiO/sub 2/, 6% FeO*, and 500 ppm Zr along with comenditic rhyolites with 68% SiO/sub 2/, 5% FeO*, 800 ppm Zr, and an agpaitic index of 1.0. These lavas were followed by the eruption of a comenditic ash-flow tuff and the formation of a caldera 2.7 km in diameter. This caldera was subsequently filled by eruptions of pantelleritic rhyolite obsidian lava flows with 72% SiO/sub 2/, 8% FeO*, 1100 ppm Zr, and an agpaitic index of 1.5 to 1.9. A second caldera was then formed which is offset to the south of the main eruptive vents for previous eruptions. This younger caldera has a diameter of about 4.8 km and its southern walls have been covered by calc-alkaline andesitic lavas erupted from nearby Sanganguey volcano. Volcanoclastic sediments in the floor of the younger caldera have been tilted and faulted in a manner suggestive of late stage resurgence. Subsequent eruptions within the caldera, however, have been restricted to calc-alkaline andesites. Tectonically, the area in which this volcano occurs appears to have been undergoing a crustal rifting event since the Pliocene. The occurrence of these peralkaline rocks lends further support to such a hypothesis.

  6. Surface and Airborne Arsenic Concentrations in a Recreational Site near Las Vegas, Nevada, USA

    PubMed Central

    Goossens, Dirk

    2015-01-01

    Elevated concentrations of arsenic, up to 7058 μg g-1 in topsoil and bedrock, and more than 0.03 μg m-3 in air on a 2-week basis, were measured in the Nellis Dunes Recreation Area (NDRA), a very popular off-road area near Las Vegas, Nevada, USA. The elevated arsenic concentrations in the topsoil and bedrock are correlated to outcrops of yellow sandstone belonging to the Muddy Creek Formation (≈ 10 to 4 Ma) and to faults crossing the area. Mineralized fluids moved to the surface through the faults and deposited the arsenic. A technique was developed to calculate airborne arsenic concentrations from the arsenic content in the topsoil. The technique was tested by comparing calculated with measured concentrations at 34 locations in the NDRA, for 3 periods of 2 weeks each. We then applied it to calculate airborne arsenic concentrations for more than 500 locations all over the NDRA. The highest airborne arsenic concentrations occur over sand dunes and other zones with a surficial layer of aeolian sand. Ironically these areas show the lowest levels of arsenic in the topsoil. However, they are highly susceptible to wind erosion and emit very large amounts of sand and dust during episodes of strong winds, thereby also emitting much arsenic. Elsewhere in the NDRA, in areas not or only very slightly affected by wind erosion, airborne arsenic levels equal the background level for airborne arsenic in the USA, approximately 0.0004 μg m-3. The results of this study are important because the NDRA is visited by more than 300,000 people annually. PMID:25897667

  7. Flow and transport at the Las Cruces trench site: Experiment IIb

    SciTech Connect

    Vinson, J.; Hills, R.G.; Wierenga, P.J.; Young, M.H.

    1997-07-01

    The US Nuclear Regulatory Commission (NRC) has been directed by Congress in the Low Level Waste Policy Act of 1980 to develop regulatory guidance and assist the individual states and compacts in siting and assessing future low level radioactive waste (LLW) disposal facilities. Three water flow and solute transport experiments were performed as part of a comprehensive field trench study near Las Cruces, New Mexico to test deterministic and stochastic models of vadose zone flow and transport. This report presents partial results from the third experiment (experiment IIb). Experiments IIa and b were conducted on the North side of the trench, on a plot 1.22 m wide by 12 m long, perpendicular to the trench. The area was drip irrigated during two time periods with water containing a variety of tracers. The advance of the water front during the two irrigation episodes was measured with tensiometers and neutron probes. Solute front positions were determined from soil solution sampling through suction samplers and from disturbed sampling. The results from experiment IIb show predominantly downward water movement through the layered unsaturated soil, as evidenced from neutron probe data and gravimetric sampling. Tritium plumes were only half as deep and half as wide as the water plumes at 310 days after the beginning of experiment IIb. Chromium, applied as Cr(VI), moved a readily as, and similar to tritium, but there was a loss of mass due to reduction of Cr(VI) to Cr(III). Chloride and nitrate, initially present at high concentrations in the soil solution, were displaced by the low concentration irrigation water, resulting in chloride and nitrate concentration distributions that looked like negative images of the tritium distributions. The extensive data presented should serve well as a data base for model testing.

  8. The Membrane Protein LasM Promotes the Culturability of Legionella pneumophila in Water

    PubMed Central

    Li, Laam; Faucher, Sébastien P.

    2016-01-01

    The water-borne pathogen Legionella pneumophila (Lp) strongly expresses the lpg1659 gene in water. This gene encodes a hypothetical protein predicted to be a membrane protein using in silico analysis. While no conserved domains were identified in Lpg1659, similar proteins are found in many Legionella species and other aquatic bacteria. RT-qPCR showed that lpg1659 is positively regulated by the alternative sigma factor RpoS, which is essential for Lp to survive in water. These observations suggest an important role of this novel protein in the survival of Lp in water. Deletion of lpg1659 did not affect cell morphology, membrane integrity or tolerance to high temperature. Moreover, lpg1659 was dispensable for growth of Lp in rich medium, and during infection of the amoeba Acanthamoeba castellanii and of THP-1 human macrophages. However, deletion of lpg1659 resulted in an early loss of culturability in water, while over-expression of this gene promoted the culturability of Lp. Therefore, these results suggest that lpg1659 is required for Lp to maintain culturability, and possibly long-term survival, in water. Since the loss of culturability observed in the absence of Lpg1659 was complemented by the addition of trace metals into water, this membrane protein is likely a transporter for acquiring essential trace metal for maintaining culturability in water and potentially in other metal-deprived conditions. Given its role in the survival of Lp in water, Lpg1659 was named LasM for Legionella aquatic survival membrane protein. PMID:27734007

  9. Estudio del comportamiento tribologico y de las interacciones de superficie de nuevos nanofluidos ionicos

    NASA Astrophysics Data System (ADS)

    Espinosa Rodriguez, Tulia

    tribocorrosion processes. The formation of a coating layer on magnesium alloys from phosphonate imidazolium ionic liquids by immersion and by chronoamperometry has been described. The new coatings reduce the abrasive wear in the magnesium-aluminium alloy but they are not effective in the magnesium-zinc alloy, which prevent the formation of continuous coatings. Los liquidos ionicos son sales liquidas a temperatura ambiente o bajas temperaturas que presentan excelentes propiedades fisico-quimicas. En el presente trabajo se estudian como lubricantes en problemas tribologicos complejos como la lubricacion de metales contra si mismos, el desarrollo de lubricantes base agua y de nuevas superficies autolubricadas. Cuando no es posible reducir la friccion y desgaste mediante lubricacion, como en las aleaciones de magnesio, los liquidos ionicos se han estudiado como precursores de recubrimientos protectores. Se han determinado las interacciones superficiales y los procesos de corrosion sobre cobre y sobre acero con diferentes liquidos ionicos proticos y aproticos para desarrollar nuevos lubricantes y aditivos. En el contacto cobre/cobre, excepto el liquido ionico protico derivado del oleato, todos los liquidos ionicos estudiados presentan mejor comportamiento tribologico que el lubricante comercial Polialfaolefina 6. En el contacto acero/zafiro, los nuevos liquidos ionicos proticos son buenos lubricantes cuando se utilizan en estado puro, y, como aditivos en agua, generan peliculas adsorbidas sobre la superficie del metal reduciendo la friccion y el desgaste tras la evaporacion del agua. Para evitar el periodo de alta friccion inicial en presencia de agua, se han generado peliculas superficiales de liquido ionico sobre el acero en condiciones estaticas. El mejor comportamiento lubricante tanto en el contacto cobre/cobre como en el contacto acero/zafiro se obtiene para el liquido ionico protico derivado del anion adipato, con dos grupos carboxilicos. Las interacciones de los grupos

  10. Evaporite sedimentation in a tectonically active basin: The lacustrine Las Minas Gypsum unit (Late Tortonian, SE Spain)

    NASA Astrophysics Data System (ADS)

    Ortí, Federico; Rosell, Laura; Gibert, Lluís; Moragas, Mar; Playà, Elisabet; Inglès, Montserrat; Rouchy, Jean Marie; Calvo, José Pedro; Gimeno, Domingo

    2014-08-01

    Evaporite successions may undergo significant lithostratigraphic changes laterally and vertically in tectonically-active basins. The Las Minas Gypsum, a lacustrine unit of Late Tortonian age and up to 160 m thick in the Las Minas-Camarillas basin (SE Spain), consists of a number of shallowing-upward cycles. Each cycle is made up of a lower interval with marl and carbonate, and an upper interval with gypsum. In the upper interval, the base displays carbonate-gypsum laminites (couplets, yearly microcycles) showing a large variability of textures and fabrics; gypsum textures are cumulates and bottom-grown crystals. Laminites are overlain by selenitic gypsum. The carbonate is a primary dolomite induced by sulphate-reducing bacterial activity. Native sulphur was formed in early diagenesis and during exhumation was partly transformed into late diagenetic gypsum. The isotopic compositions of gypsum suggest that the sulphate mainly derived from chemical recycling of Triassic evaporites; however, marine sulphate was probably supplied by episodic marine incursions. A perennial saline lake characterized by irregular bottom topography and depositional settings with variable subsidence ratios is interpreted. In addition to climate, saline diapirism, Neogene volcanism, synsedimentary faulting and seismicity influenced the evaporitic deposition. Las Minas-Camarillas basin is an example of how in tectonically active zones different factors interplay to produce significant variability of the evaporitic sedimentation and cyclicity.

  11. The U.S. Department of Energy Office of Indian Energy Policy and Programs Las Vegas, Nevada, Roundtable Summary

    SciTech Connect

    2011-03-16

    LAS VEGAS EXECUTIVE SUMMARY The Las Vegas, Nevada DOE Tribal Roundtable convened on March 16th, at the Las Vegas Hilton. The meeting was hosted by the Department of Energy (DOE) Office of Indian Policy and Programs (DOE Office of Indian Energy) and facilitated by JR Bluehouse, Program Manager, Udall Foundation’s U.S. Institute for Environmental Conflict Resolution (U.S. Institute). Mr. Bluehouse was assisted by Tamara, Underwood, Program Assistant, U.S. Institute.  Tribal leaders and representatives from multiple tribal governments and communities attended the roundtable. Tracey LeBeau, newly appointed Director of the Office of Indian Energy attended.    LaMont Jackson from DOE’s Office of Electricity attended. Also attending from the administration and federal agencies were Kim Teehee, Senior Policy Advisor for Native American Affairs, The White House; Charlie Galbraith, Associate Director of the Office of Public Engagement and Deputy Associate Director of the Office of Intergovernmental Affairs, The White House; Jodi Gillette, Deputy Assistant Secretary for Policy and Economic Development, the Bureau of Indian Affairs.

  12. Analysis of the real estate market in Las Vegas: Bubble, seasonal patterns, and prediction of the CSW indices

    NASA Astrophysics Data System (ADS)

    Zhou, Wei-Xing; Sornette, Didier

    2008-01-01

    We analyze 27 house price indices of Las Vegas from June 1983 to March 2005, corresponding to 27 different zip codes. These analyses confirm the existence of a real estate bubble, defined as a price acceleration faster than exponential, which is found, however, to be confined to a rather limited time interval in the recent past from approximately 2003 to mid-2004 and has progressively transformed into a more normal growth rate comparable to pre-bubble levels in 2005. There has been no bubble till 2002 except for a medium-sized surge in 1990. In addition, we have identified a strong yearly periodicity which provides a good potential for fine-tuned prediction from month to month. A monthly monitoring using a model that we have developed could confirm, by testing the intra-year structure, if indeed the market has returned to “normal” or if more turbulence is expected ahead. We predict the evolution of the indices one year ahead, which is validated with new data up to September 2006. The present analysis demonstrates the existence of very significant variations at the local scale, in the sense that the bubble in Las Vegas seems to have preceded the more global USA bubble and has ended approximately two years earlier (mid-2004 for Las Vegas compared with mid-2006 for the whole of the USA).

  13. Aerosol Light Absorption and Scattering in Mexico City: Comparison With Las Vegas, NV, and Los Angeles, CA.

    NASA Astrophysics Data System (ADS)

    Paredes-Miranda, G.; Arnott, W. P.; Gaffney, J. S.; Marley, N. A.; Campbell, D.; Fujita, E.

    2007-12-01

    Aerosol light scattering and absorption measurements were deployed in and near Mexico City in March 2006 as part of the Megacity Impacts on Regional and Global Environments (MIRAGE). The primary site in Mexico City was an urban site at Instituto Mexicano del Petroleo (Mexican Oil Institute, denoted by IMP). Similar campaigns were held in Las Vegas, NV in January-February, 2003; and Los Angeles, CA at numerous sites during all seasons from 2003 through 2007. The IMP site gave in-situ characterization of the Mexico City plume under favorable wind conditions. The photoacoustic instrument (PAS) used at IMP operates at 532 nm, and conveniently allowed for characterization of gaseous absorption at this wavelength as well. Light scattering measurements are accomplished within the PAS by the reciprocal nephelometery method. In Mexico City the aerosol absorption coefficient typically varies between 20 and 180 Mm-1 during the course of the day and significant diurnal variation of the aerosol single scattering albedo was observed probably as a consequence of secondary aerosol formation. We will present the diurnal variation of the scattering and absorption as well as the single scattering albedo and fraction of absorption due to gases at the IMP site and compare with Las Vegas diurnal variation. Mexico City 'breaths' more during the course of the day than Las Vegas, Nevada in part because the latitude of Mexico City resulted in more direct solar radiation. Further insight on the meteorological connections and population dynamics will be discussed.

  14. Improved estimation of sensible heat flux by a LAS using a Bowen ratio at urban residential area

    NASA Astrophysics Data System (ADS)

    Park, M. S.; Chae, J. H.

    2014-12-01

    A large aperture scintillometer (LAS) data sampled for the period from 1 February to 31 July 2014 at urban residential area in Seoul are modified using the variable Bowen ratio and a net radiation data to determine the space-averaged sensible heat flux (SHF). A LAS system is installed over the rooftop of two buildings with a distance between receiver and transmitter of 535 m, an effective height of 18.4 m, a wind speed sensor at 25.0 m high. The path-averaged building height, roughness length, and displacement length between the receiver and transmitter are 9.2 m, 0.4 m, and 7.1 m, respectively. The Bowen ratio computed at every 30 minute interval by the wind speed and air temperature at 10 and 18 m above the rooftop is found to be well correlated with meteorological variables such as net radiation and mixing ratio. Therefore, it is parameterized as a function of mixing ratio and net radiation. The resulting parameterization is applied to estimate the SHF by LAS. The Monin-Obukhov similarity universal function should be changed according to the atmospheric stability using the sign of net radiation sampled at the same time. It is found that the resulting sensible heat fluxes are available under all atmospheric stability and are much improved compared with those by eddy covariance method.

  15. Contribución al flujo infrarrojo de las estrellas Be de la recombinación dielectrónica del MgII

    NASA Astrophysics Data System (ADS)

    Cruzado, A.; di Rocco, H.; Ringuelet, A.

    Para evaluar la contribución del proceso de recombinación dielectrónica del átomo de MgII al exceso de flujo infrarrojo observado en las estrellas Be, calculamos la energía emitida en las líneas originadas por este proceso. Se evaluaron los efectos de las condiciones físicas del medio, como la temperatura electrónica y la densidad electrónica, sobre el flujo emitido. Se consideró también la influencia de una posible opacidad.

  16. Distribution and origin of dissolved gases of groundwaters at Las Cañadas aquifer, Tenerife, Canary Islands

    NASA Astrophysics Data System (ADS)

    Marrero, R.; Melian, G.; Padron, E.; Sortino, F.; Hernandez Perez, P. A.; Lopez, D. L.; Perez, N.

    2009-12-01

    Volcanic aquifers commonly trap an important fraction of the main soluble components of fluids released from volcanic-hydrothermal system (CO2, SO2, H2S, HCl, HF, etc.). In particular, the interactions between volcanic gases and volcanic aquifers have been studied through hydrogeochemical parameters, as major and minor ions contents and dissolved gases in groundwaters. In the context of hydrogeochemical studies applied to active volcanic areas, studies of dissolved gases species in groundwater could be a useful tool to better understand the subsurface processes as gas-water-rock interaction or to strengthen the geochemical seismic-volcanic surveillance programs. In this work, we report the results of the geochemical characterization of dissolved gases (N2, O2, Ar, CO2, CH4, CO, H2, He, 222Rn, δ13CTDIC) in 96 groundwater samples from Las Cañadas aquifer (around Teide volcano) between May and October, 2006. The main aims of this work are: (1) to determine the background level of magmatic gas input in the aquifer during quiescent periods, (2) to better define the origin of dissolved gases in Las Cañadas aquifer, specially CO2, (3) to evaluate the gas-water-rock interaction processes occurring at depth, and (4) to delineate high permeable pathway of upward migration of volcanic-hydrothermal gases. In general, the dissolved gas phase in groundwaters of Las Cañadas aquifer is relatively enriched in endogenous gases (CO2, He and H2) while it is relatively depleted in atmospheric gases (N2, O2 and Ar). N2-O2-CO2 triangular diagram shows that dissolved gases in most of analyzed groundwater are variable mixtures of CO2-rich fluids from the volcanic-hydrothermal system (as represent the Teide fumaroles) with dissolved air. The relatively high N2/O2 ratio in some groundwater compared to the air saturated water suggests an O2 consumption during gas-water-rock interactions occurring at depth. Spatial distribution maps show anomalous concentration of 222Rn CH4, H2 and CO2

  17. Reconciling Scale Mismatch in Water Governance, Hydro-climatic Processes and Infrastructure Systems of Water Supply in Las Vegas

    NASA Astrophysics Data System (ADS)

    Garcia, M. E.; Alarcon, T.; Portney, K.; Islam, S.

    2013-12-01

    Water resource systems are a classic example of a common pool resource due to the high cost of exclusion and the subtractability of the resource; for common pool resources, the performance of governance systems primarily depends on how well matched the institutional arrangements and rules are to the biophysical conditions and social norms. Changes in water governance, hydro-climatic processes and infrastructure systems occur on disparate temporal and spatial scales. A key challenge is the gap between current climate change model resolution, and the spatial and temporal scale of urban water supply decisions. This gap will lead to inappropriate management policies if not mediated through a carefully crafted decision making process. Traditional decision support and planning methods (DSPM) such as classical decision analysis are not equipped to deal with a non-static climate. While emerging methods such as decision scaling, robust decision making and real options are designed to deal with a changing climate, governance systems have evolved under the assumption of a static climate and it is not clear if these methods are well suited to the existing governance regime. In our study, these questions are contextualized by examining an urban water utility that has made significant changes in policy to adapt to changing conditions: the Southern Nevada Water Authority (SNWA) which serves metropolitan Las Vegas. Like most desert cities, Las Vegas exists because of water; the artesian springs of the Las Vegas Valley once provided an ample water supply for Native Americans, ranchers and later a small railroad city. However, population growth has increased demands far beyond local supplies. The area now depends on the Colorado River for the majority of its water supply. Natural climate variability with periodic droughts has further challenged water providers; projected climate changes and further population growth will exacerbate these challenges. Las Vegas is selected as a case

  18. Integration of aquatic fate and ecological responses to linear alkyl benzene sulfonate (LAS) in model stream ecosystems.

    PubMed

    Belanger, S E; Bowling, J W; Lee, D M; LeBlanc, E M; Kerr, K M; McAvoy, D C; Christman, S C; Davidson, D H

    2002-06-01

    An integrated model stream ecosystem fate and effect study of dodecyl linear alkylbenzene sulfonate (C(12)LAS) was performed in the summer and fall of 1996. The study addressed responses of periphytic microbes, immature benthic fauna including abundance, drift, and emergence of adult insects in a 56-day exposure. Exposures ranged from 126 to 2978 microg/L and were continuously presented in a single-pass, flow-through test system. Microbial heterotrophs acclimated to C(12)LAS exposure quickly (14 days) and biodegraded C(12)LAS at all concentrations. Blue-green algae responded by increasing in abundance with increasing C(12)LAS concentration. Invertebrates responded by increased drift and reduced benthic abundances at concentrations exceeding 293 microg/L. Emergence at 927 microg/L also declined relative to the control. Adverse responses for mayflies and chironomids were indicated using univariate statistical techniques. Multivariate techniques indicated these taxa plus mollusks, aquatic worms, caddisflies, and stoneflies were impaired at some concentrations. Bioavailability of C(12)LAS was investigated in streams as a function of the total suspended solid load in the water column driven by local weather and watershed patterns. A continuous bioavailability model indicated exposure was reduced by an average of 8.5+/-8.9%. A model ecosystem no-observed-effect concentration (NOEC) was concluded to be 293 microg/L based on measured water column exposure and adjusted to 268 microg/L by the bioavailability model. A literature review of 13 available model ecosystem studies was conducted and NOEC conclusions were adjusted by a structure-activity relationship to a dodecyl chain length (sulfophenyl position and distribution being ignored due to lack of information in the reviewed studies). Lentic studies (n=7) were found to have higher NOECs than lotic studies (n=6) and were more variable. Mean NOECs+/-SD for all studies, lentic studies only, and lotic studies only were 3320

  19. Geohydrologic reconnaissance of Lake Mead National Recreation Area; Las Vegas Wash to Opal Mountain, Nevada

    USGS Publications Warehouse

    Laney, R.L.

    1981-01-01

    The study is a geohydrologic reconnaissance of about 170 square miles in the Lake Mead National Recreation Area from Las Vegas Wash to Opal Mountain, Nevada. The study is one of a series that describes the geohydrology of the recreation area and that indentifies areas where water supplies can be developed. Precipitation in this arid area is about 5 inches per year. Streamflow is seasonal and extremely variable except for that in the Colorado River, which adjoins the area. Pan evaporation is more than 20 times greater than precipitation; therefore, regional ground-water supplies are meager except near the Colorado River, Lake Mead, and Lake Mohave. Large ground-water supplies can be developed near the river and lakes, and much smaller supplies may be obtained in a few favorable locations farther from the river and lakes. Ground water in most of the areas probably contains more than 1,000 milligrams per liter of dissolved solids, but water that contains less than 1,000 milligrams per liter of dissolved solids can be obtained within about 1 mile of the lakes. Crystalline rocks of metamorphic, intrusive and volcanic origin crop out in the area. These rocks are overlain by conglomerate and mudstone of the Muddy Creek Formation, gravel and conglomerate of the older alluvium, and sand and gravel of the Chemehuevi Formation and younger alluvium. The crystalline rocks, where sufficiently fractured, yield water to springs and would yield small amounts of water to favorably located wells. The poorly cemented and more permeable beds of the older alluvium, Chemehuevi Formation, and younger alluvium are the better potential aquifers, particularly along the Colorado River and Lakes Mead and Mohave. Thermal springs in the gorge of the Colorado River south of Hoover Dam discharge at least 2,580 acre-feet per year of water from the volcanic rocks and metamorphic and plutonic rocks. The discharge is much greater than could be infiltrated in the drainage basin above the springs

  20. The Las Campanas Infrared Survey: Early-Type Galaxy Progenitors beyond z=1

    NASA Astrophysics Data System (ADS)

    McCarthy, P. J.; Carlberg, R. G.; Chen, H.-W.; Marzke, R. O.; Firth, A. E.; Ellis, R. S.; Persson, S. E.; McMahon, R. G.; Lahav, O.; Wilson, J.; Martini, P.; Abraham, R. G.; Sabbey, C. N.; Oemler, A.; Murphy, D. C.; Somerville, R. S.; Beckett, M. G.; Lewis, J. R.; MacKay, C. D.

    2001-10-01

    We have identified a population of faint red galaxies from a 0.62 deg2 region of the Las Campanas Infrared Survey whose properties are consistent with their being the progenitors of early-type galaxies. The optical and IR colors, number-magnitude relation, and angular clustering together indicate modest evolution and increased star formation rates among the early-type field population at redshifts between 1 and 2. The counts of red galaxies with H magnitudes between 17 and 20 rise with a slope that is much steeper than that of the total H sample. The surface density of red galaxies drops from roughly 3000 deg-2 at H=20.5, I-H>3 to ~20 deg-2 at H=20, I-H>5. The V-I colors are approximately 1.5 mag bluer on average than a pure old population and span a range of more than 3 mag. The strength of the angular clustering of the red galaxies is an order of magnitude larger than that of the full galaxy sample. The colors, and photometric redshifts derived from them, indicate that the red galaxies have redshift distributions adequately described by Gaussians with σz~=0.2 centered near z=1, with the exception that galaxies having V-I<1.6 and I-H>3 are primarily in the 1.5<~z<~2 range. We invert the angular correlation functions using these n(z) and find comoving correlation lengths of r0~=9-10 h-1 Mpc at z~=1, comparable to, or larger than, those found for early-type galaxies at lower redshifts. A simple photometric evolution model reproduces the counts of the red galaxies, with only an ~30% decline in the underlying space density of early-type galaxies at z~1.2. The colors indicate characteristic star formation rates of ~1 Msolar yr-1 per 1010 Msolar. We suggest on the basis of the colors, counts, and clustering that these red galaxies are the bulk of the progenitors of present-day early-type galaxies.

  1. Las Cumbres Observatory Global Telescope Network: Keeping Education in the Dark

    NASA Astrophysics Data System (ADS)

    Ross, R. J.

    2011-09-01

    Las Cumbres Observatory Global Telescope Network (LCOGT) is creating a network of telescopes to be placed around the world providing 24/7 sky coverage of both the Northern and Southern hemispheres. These telescopes will range in size from 0.4 m to 2.0 m and will be available for scientific and educational uses in both real-time and in a queue-scheduler. The educational uses of LCOGT will be primarily online through our website (http://www.lcogt.net) where there will be how-to guides, ideas for activities, opportunities for participating in research projects with our astronomers, full access to the public archive, as well as an online community built through forums and groups. Content will be visible to all, although registered users will have the ability to add resources, post on blogs and forums, comment and rate existing pages and resources, collaborate in world-wide projects, and much more. The current network includes the two 2.0 m Faulkes Telescopes on Haleakala, Maui and at Siding Spring, Australia. A 0.8 m telescope located at Sedgwick Reserve in the Santa Ynez Valley is nearly commissioned and will be used both for local outreach events as well as on the LCOGT network. The first pair of 0.4 m telescopes has been deployed to Maui and are enclosed inside the clamshell dome with Faulkes Telescope North (FTN), but still have some time to go before they are fully commissioned. The site in Chile is currently being prepped for three 1.0 m and two pairs of 0.4 m telescopes with the site in South Africa to follow shortly. Other sites include the Canary Islands, a site in North America, one in Asia, and another site in Australia. The 0.4 m telescopes will be deployed by pair and the 1.0 m telescopes will be deployed in groups of two or three, all with research-grade instrumentation.

  2. In vitro acute toxicity of anionic surfactant linear alkylbenzene sulphonate (LAS) on the motility of gilthead (Sparus aurata L.) sperm.

    PubMed

    Rosety, M; Ordoñez, F J; Rosety-Rodríguez, M; Rosety, J M; Rosety, I

    2003-04-01

    This paper describes the acute toxicity of a known anionic surfactant, Linear Alkylbenzene Sulphonate (LAS), on the quality of gilthead Sparus aurata L. sperm. The parameter used to judge exposure effectiveness was sperm motility as well as its fertilizing ability after being combined with unexposed gilthead eggs. Preincubation of sperm suspensions with concentrations of LAS of 0.1, 0.5, 1, 2 and 4 mg/L caused decrease in sperm motility and fertilizing ability. In this respect, percentages of motile sperm were respectively 89.8+/-9.8, 81.7+/-16.3, 69.5+/-21.3, 57.1+/-19.1 and 21.2+/-10.9%. With regard to the percentage of fertilization success, the results were 85.7+/-8.1, 75.1+/-20.2, 62.9+/-19.7, 52.7+/-19.2 and 14.2+/-7.9% respectively. At concentrations of LAS of 0.5 mg/L or higher, the differences in both percentage of motility and fertilizing ability with controls were significant (p<5%). Although extrapolation from the laboratory to the field requires caution, the results of this work demonstrated that low-level surfactant pollution may impact directly on reproduction of the free gametes (sperm) released into water. It may lead to a long-term decline and eventual extinction of gilthead populations in nature when they are located close to effluents that are either untreated or receive inadequate secondary treatment. It is also quite important because this species constitutes an important link in the food chain and its death via exposure to surfactants may imbalance the littoral ecosystem.

  3. The Evolutionarily Conserved Protein LAS1 Is Required for Pre-rRNA Processing at Both Ends of ITS2

    PubMed Central

    Schillewaert, Stéphanie; Wacheul, Ludivine; Lhomme, Frédéric

    2012-01-01

    Ribosome synthesis entails the formation of mature rRNAs from long precursor molecules, following a complex pre-rRNA processing pathway. Why the generation of mature rRNA ends is so complicated is unclear. Nor is it understood how pre-rRNA processing is coordinated at distant sites on pre-rRNA molecules. Here we characterized, in budding yeast and human cells, the evolutionarily conserved protein Las1. We found that, in both species, Las1 is required to process ITS2, which separates the 5.8S and 25S/28S rRNAs. In yeast, Las1 is required for pre-rRNA processing at both ends of ITS2. It is required for Rrp6-dependent formation of the 5.8S rRNA 3′ end and for Rat1-dependent formation of the 25S rRNA 5′ end. We further show that the Rat1-Rai1 5′-3′ exoribonuclease (exoRNase) complex functionally connects processing at both ends of the 5.8S rRNA. We suggest that pre-rRNA processing is coordinated at both ends of 5.8S rRNA and both ends of ITS2, which are brought together by pre-rRNA folding, by an RNA processing complex. Consistently, we note the conspicuous presence of ∼7- or 8-nucleotide extensions on both ends of 5.8S rRNA precursors and at the 5′ end of pre-25S RNAs suggestive of a protected spacer fragment of similar length. PMID:22083961

  4. Laser Remote Measurements of atmospheric pollutants (Las-R-Map): UV-Visible Laser system description and data processing

    NASA Astrophysics Data System (ADS)

    Sivakumar, V.; Wyk, H. V.

    Laser radar more popularly known as LIDAR LIght Detection And Ranging is becoming one of the most powerful techniques for active remote sensing of the earth s atmosphere Around the globe several new lidar systems have been developed based on the scientific interest Particularly the DIfferential Absorption Lidar DIAL technique is only one which can provide the better accuracy of measuring atmospheric pollutants Using modern advanced techniques and instrumentation a mobile DIAL system called laser remote measurements of atmospheric pollutants hear after referred as Las-R-Map is designed at National Laser Centre NLC --Pretoria 25 r 45 prime S 28 r 17 prime E Las-R-Map is basically used for measuring atmospheric pollutants applying the principle of absorption by constituents The system designed primarily to focus on the following pollutant measurements such as SO 2 CH 4 CO 2 NO 2 and O 3 In future the system could be used to measure few particulate matter between 2 5 mu m and 10 mu m Benzene Hg 1 3-butadiene H 2 S HF and Volatile Organic Compounds VOC Las-R-map comprises of two different laser sources Alexandrite and CO 2 optical receiver data acquisition and signal processor It uses alexandrite laser in the UV-Visible region from 200 nm to 800 nm and CO 2 laser in the Far-IR region from 9 2 mu m to 10 8 mu m Such two different laser sources make feasibility for studying the wide range of atmospheric pollutants The present paper is focused on technical details

  5. Las líneas de aluminio neutro como diagnóstico cromosférico

    NASA Astrophysics Data System (ADS)

    Fernández Borda, R.; Mauas, P. J. D.

    Se presenta un modelo atómico para el cálculo de las lí neas del Aluminio neutro que se forman en la cromósfera solar. En particular, se estudia la línea λ 3961 Å, que, por estar muy próxima a la lí nea H del Ca II y a Hɛ es muy frecuentemente observada. Observaciones en esta lí nea obtenidas con el espectrógrafo a instalarse en el CASLEO, serán utilizadas para el estudio de fulguraciones solares.

  6. Hydrostratigraphic Framework of the Raton, Vermejo, and Trinidad Aquifers in the Raton Basin, Las Animas County, Colorado

    USGS Publications Warehouse

    Watts, Kenneth R.

    2006-01-01

    Exploration for and production of coalbed methane has increased substantially in the Rocky Mountain region of the United States since the 1990s. During 1999-2004, annual production of natural gas (coalbed methane) from the Raton Basin in Las Animas County, Colorado, increased from 28,129,515 to 80,224,130 thousand cubic feet, and the annual volume of ground water coproduced by coalbed methane wells increased from about 949 million gallons to about 2,879 million gallons. Better definition of the hydrostratigraphic framework of the Raton, Vermejo, and Trinidad aquifers in the Raton Basin of southern Colorado is needed to evaluate the long-term effects of coalbed methane development on the availability and sustainability of ground-water resources. In 2001, the U.S. Geological Survey, in cooperation with the Colorado Water Conservation Board, began a study to evaluate the hydrogeology of the Raton Basin in Huerfano and Las Animas Counties, Colorado. Geostatistical methods were used to map the altitude of and depths to the bottoms and tops (structure) and the apparent thicknesses of the Trinidad Sandstone, the Vermejo Formation, and the Raton Formation in Las Animas County, based on completion reports and drillers' logs from about 1,400 coalbed methane wells in the Raton Basin. There was not enough subsurface control to map the structural surfaces and apparent thicknesses of the aquifers in Huerfano County. Geostatistical methods also were used to map the regional water table in the northern part of Las Animas County, based on reported depth to water from completion reports of water-supply wells. Although these maps were developed to better define the hydrostratigraphic framework, they also can be used to determine the contributing aquifer(s) of existing water wells and to estimate drilling depths of proposed water wells. These maps of the hydrostratigraphic framework could be improved with the addition of measured sections and mapping of geologic contacts at outcrops

  7. Distress in the Desert: Neighborhood Disorder, Resident Satisfaction, and Quality of Life during the Las Vegas Foreclosure Crisis

    PubMed Central

    Batson, Christie D.; Monnat, Shannon M.

    2014-01-01

    Using surveys collected from a sample of households nested within ‘naturally occurring’ neighborhoods in Las Vegas, NV during the 2007-2009 economic recession, this study examines the associations between real and perceived measures of neighborhood distress (foreclosure rate, physical decay, crime) and residents' reports of neighborhood quality of life and neighborhood satisfaction. Consistent with social disorganization theory, both real and perceived measures of neighborhood disorder were negatively associated with quality of life and neighborhood satisfaction. Residents' perceptions of neighborliness partially acted as a buffer against the effects of neighborhood distress, including housing foreclosures, on quality of life and neighborhood satisfaction. PMID:25750507

  8. Las Palmeras Molecular Dynamics: A flexible and modular molecular dynamics code

    NASA Astrophysics Data System (ADS)

    Davis, Sergio; Loyola, Claudia; González, Felipe; Peralta, Joaquín

    2010-12-01

    Las Palmeras Molecular Dynamics (LPMD) is a highly modular and extensible molecular dynamics (MD) code using interatomic potential functions. LPMD is able to perform equilibrium MD simulations of bulk crystalline solids, amorphous solids and liquids, as well as non-equilibrium MD (NEMD) simulations such as shock wave propagation, projectile impacts, cluster collisions, shearing, deformation under load, heat conduction, heterogeneous melting, among others, which involve unusual MD features like non-moving atoms and walls, unstoppable atoms with constant-velocity, and external forces like electric fields. LPMD is written in C++ as a compromise between efficiency and clarity of design, and its architecture is based on separate components or plug-ins, implemented as modules which are loaded on demand at runtime. The advantage of this architecture is the ability to completely link together the desired components involved in the simulation in different ways at runtime, using a user-friendly control file language which describes the simulation work-flow. As an added bonus, the plug-in API (Application Programming Interface) makes it possible to use the LPMD components to analyze data coming from other simulation packages, convert between input file formats, apply different transformations to saved MD atomic trajectories, and visualize dynamical processes either in real-time or as a post-processing step. Individual components, such as a new potential function, a new integrator, a new file format, new properties to calculate, new real-time visualizers, and even a new algorithm for handling neighbor lists can be easily coded, compiled and tested within LPMD by virtue of its object-oriented API, without the need to modify the rest of the code. LPMD includes already several pair potential functions such as Lennard-Jones, Morse, Buckingham, MCY and the harmonic potential, as well as embedded-atom model (EAM) functions such as the Sutton-Chen and Gupta potentials. Integrators to

  9. Xenoliths of Cerro las Mercedes, Costa Rica: a Geochemical Record of Arc History?

    NASA Astrophysics Data System (ADS)

    Lindsay, F. N.; Gazel, E.; Herzberg, C. T.; Carr, M. J.; Feigenson, M. D.

    2006-12-01

    Over 70 ultramafic xenoliths, many with diameters of at least 3cm, open a window into the mantle beneath Cerro las Mercedes, Costa Rica. This quaternary vent is 70km behind the active volcanic front and near the northern boundary of the Caribbean Plateau. Both xenoliths and host lava remain well preserved in spite of substantial soil development in a rain forest environment. We analyzed the host lava and a subset of 30 rocks for bulk and mineral chemistry, which include both peridotite and pyroxenite populations. The host rock is Plio-Quaternary potassic alkaline basalt; depleted in SiO2 and Al2O3 and enriched in MgO and P2O5 relative to both present day and Miocene volcanics. In terms of trace elements, the host basalt has enriched LREEs and relative depletion of HFSEs, typical of island-arc basalt, both present and past. The coarse-grained pyroxenites have trace element chemistry akin to the volcanic front lavas of Costa Rica, although they are closer to chondritic values. Truly, they are more similar to basalts from Sarapiquí Miocene arc than to present day volcanic front basalts. Although there is enrichment in incompatible elements such as Ba and U and depletions in HFSEs, common in island arc basalts, the pyroxenites have a strong positive Pb anomaly that is characteristic only of the Miocene arc, not present day lavas. We interpret the pyroxenites as cumulates. The peridotite population includes dunites, spinel lherzolites and lherzolites. These rocks have Mg-numbers ranging from 87 to 92 and Cr-numbers ranging from 6 to 61. Whole rock geochemistry indicates that the peridotite xenoliths are fragments of mantle associated with the western Caribbean Plateau. SiO2, FeO, Al2O3 and MgO contents of several Cerro Mercedes peridotites are similar to those expected of hot residues that would form in a plume environment. Trace elements reveal some samples with enrichment of Ba and U, and depletion in Nb and Ta indicating variable extents of melt-rock reaction and

  10. Morphology and mechanics of large collapses: Sotano de las Golondrinas, Mexico

    NASA Astrophysics Data System (ADS)

    Lauritzen, S.-E.; Hammer, Ø.; Wheeler, W.; Redfield, T.; Blanco, M.; Rosales Lagarde, L.; Jamtveit, B.

    2012-04-01

    The dynamics and mode of formation of large karst pipes are not yet fully understood. We present precise Lidar and structural field data of the 340+ m deep open karst shaft el Sotano de las Golondrinas, and test the geometry on a a simplified 2D evolution model. The Golondrinas shaft is located in the San Luis county, northeastern México and is developed in massive, early cretaceous (Barremian-Coniacian) reef- limestones (El Abra/ El Doctor fm.). It is a bell-shaped breakout dome that has reached the land surface, i.e. a classical Einstrurtzdoline. The dimensions and shape makes it to an interesting case study, as it has similar dimensions as breccia-pipes encountered in many paleokarsts, but is incompletely filled, so that internal structure can be easily inspected. Second, with regard to stress mechanisms controlling roof collapse, the large dimensions (270 - 130 m diameter at the base) reduce the influence (anisotropy) of geological structures in comparison to smaller pipes (e.g. <70 m diameter). We may thus test morphology against the shape of various tectonic and gravitational stress distributions. During our field campaign in 2009, it was decided to re-map the cavity using laser (Lidar and rangefinders) in order to obtain exact dimensions and high-resolution images of morphology and geologic structure. The maximum explored depth is a fissure at -512 m with the main floor between 325 and 400 meters below the skylight entrance of 80 m diameter. Overall, the shaft is cigar-shaped and oval in outline. Its horizontal length/width ratio at floor level is about 2.31, with an azimuth of elongation of about 125 degrees true. The shaft is developed along a major, steep fracture zone (115°, true) which makes up the north wall. The fracture has no detectable off-set, in all very few faults were observed. The strike of the guiding fracture, the azimuth of elongation and the direction of the least horizontal stress direction (111°, true) coincide. Where it occurs

  11. Hacia el consumo informado de tabaco en México: efecto de las advertencias con pictogramas en población fumadora

    PubMed Central

    Thrasher, James F; Pérez-Hernández, Rosaura; Arillo-Santillán, Edna; Barrientos-Gutiérrez, Inti

    2015-01-01

    Resumen Objetivo Evaluar el efecto de las advertencias sanitarias (AS) con pictogramas en las cajetillas de tabaco en adultos fumadores. Material y métodos Cohorte de fumadores con representatividad poblacional de siete ciudades mexi canas, antes (2010) y después (2011) de la implementación de AS con pictogramas (ASP). Para determinar el cambio en las variables sobre el impacto cognitivo y conductual de las advertencias, se estimaron modelos bivariados y ajustados de ecuaciones de estimación generalizada. En el Segundo levantamiento (2011), se estimaron modelos para determiner los factores que se asocian con el reporte de recordar cada advertencia que había entrado al mercado, además de los factores asociados con el autorreporte del impacto de cada advertencia vigente. Resultados Se observaron incrementos importantes de 2010 a 2011 en los conocimientos sobre los riesgos de fumar, los componentes tóxicos del tabaco y el número telefónico para recibir consejos sobre dejar de fumar. La recordación e impacto de las primeras advertencias con pictogramas parecen ser amplios y equitativos a través de la población fumadora. En comparación con 2010, un mayor nivel de ex fumadores entrevistados en 2011 reportaron que las advertencias habían influido mucho en dejar de fumar (RM=2.44, 95% IC 1.27–4.72). Conclusiones Las AS con pictogramas han logrado un impacto importante en el conocimiento y conducta, información relevante para la población y en tomadores de decisiones. PMID:22689162

  12. Subsurface Connections and Magma Mixing as revealed by Olivine- and Pyroxene-Hosted Melt Inclusions from Cerro Negro Volcano and the Las Pilas-El Hoyo Complex, Nicaragua.

    NASA Astrophysics Data System (ADS)

    Venugopal, S.; Moune, S.; Williams-Jones, G.

    2015-12-01

    Cerro Negro, the youngest volcano in the Central American Volcanic Belt, is a polygenetic cinder cone with relatively frequent explosive basaltic eruptions. Las Pilas, on the other hand, is a much larger and older complex with milder and less frequent eruptions. Based on historical data, these two closely spaced volcanoes have shown concurrent eruptive behavior, suggesting a subsurface connection. To further investigate this link, melt inclusions, which are blebs of melt trapped in growing crystals, were the obvious choice for optimal comparison of sources and determination of pre-eruptive volatile contents and magmatic conditions. Olivine-hosted inclusions were chosen for both volcanoes and pyroxene-hosted inclusions were also sampled from Las Pilas to represent the evolved melt. Major, volatile and trace elements reveal a distinct geochemical continuum with Cerro Negro defining the primitive end member and Las Pilas representing the evolved end member. Volatile contents are high for Cerro Negro (up to 1260 ppm CO2, 4.27 wt% H2O and 1700 ppm S) suggesting that volatile exsolution is likely the trigger for Cerro Negro's explosive eruptions. Las Pilas volatile contents are lower but consistent with degassing and evolutionary trends shown by major oxides. Trace element contents are rather unique and suggest Cerro Negro magmas fractionally crystallize while Las Pilas magmas are the products of mixing. Magmatic conditions were estimated with major and volatile contents: at least 2.4 kbar and 1170 °C for Cerro Negro melts and 1.3 kbar and 1130 °C for Las Pilas melts with an overall oxygen fugacity at the NNO buffer. In combination with available literature data, this study suggests an interconnected subsurface plumbing system and thus Cerro Negro should be considered as the newest vent within the Las Pilas-El Hoyo Complex.

  13. An analysis of urban thermal characteristics and associated land cover in Tampa Bay and Las Vegas using Landsat satellite data

    USGS Publications Warehouse

    Xian, G.; Crane, M.

    2006-01-01

    Remote sensing data from both Landsat 5 and Landsat 7 systems were utilized to assess urban area thermal characteristics in Tampa Bay watershed of west-central Florida, and the Las Vegas valley of southern Nevada. To quantitatively determine urban land use extents and development densities, sub-pixel impervious surface areas were mapped for both areas. The urban-rural boundaries and urban development densities were defined by selecting certain imperviousness threshold values and Landsat thermal bands were used to investigate urban surface thermal patterns. Analysis results suggest that urban surface thermal characteristics and patterns can be identified through qualitatively based urban land use and development density data. Results show the urban area of the Tampa Bay watershed has a daytime heating effect (heat-source), whereas the urban surface in Las Vegas has a daytime cooling effect (heat-sink). These thermal effects strongly correlated with urban development densities where higher percent imperviousness is usually associated with higher surface temperature. Using vegetation canopy coverage information, the spatial and temporal distributions of urban impervious surface and associated thermal characteristics are demonstrated to be very useful sources in quantifying urban land use, development intensity, and urban thermal patterns. ?? 2006 Elsevier Inc. All rights reserved.

  14. Long-term assessment of the oil spill at Bahia Las Minas, Panama. Interim report. Volume 1: Executive summary

    SciTech Connect

    Keller, B.D.; Jackson, J.B.C.

    1991-10-01

    On April 27, 1986, at least 8 million liters of medium-weight crude oil spilled from a ruptured storage tank into the Bahia Las Minas on the Caribbean Coast of Panama. Coral reefs, seagrass communities, and mangroves were affected. The area of the spill was also the location of the Smithsonian Tropical Research Institute's Galeta Laboratory where resident and visiting scientists have been studying the ecology of the Bahia Las Minas and the adjacent areas for over 15 years. Because this was a unique opportunity to assess the immediate biological effects following a major spill in the Caribbean region and to monitor the subsequent recovery, the U.S. Department of the Interior Minerals Management Service supported a 5-year environmental study. The objectives of the study are to identify any long-term changes in the marine environment that may have resulted from the spill and to understand the ecological processes causing such changes. This is the first report from the study and addresses the effects observed during the first two years of the effort.

  15. Long-term assessment of the oil spill at Bahia Las Minas, Panama. Interim report. Volume 2: Technical report

    SciTech Connect

    Keller, B.D.; Jackson, J.B.C.

    1991-10-01

    On April 27, 1986, at least 8 million liters of medium-weight crude oil spilled from a ruptured storage tank into the Bahia Las Minas on the Caribbean Coast of Panama. Coral reefs, seagrass communities, and mangroves were affected. The area of the spill was also the location of the Smithsonian Tropical Research Institute's Galeta Laboratory where resident and visiting scientists have been studying the ecology of the Bahia Las Minas and the adjacent areas for over 15 years. Because this was a unique opportunity to assess the immediate biological effects following a major spill in the Caribbean region and to monitor the subsequent recovery, the U.S. Department of the Interior Minerals Management Service supported a 5-year environmental study. The objectives of the study are to identify any long-term changes in the marine environment that may have resulted from the spill and to understand the ecological processes causing such changes. This is the first report from the study and addresses the effects observed during the first two years of the effort.

  16. Morphology, body proportions, and postcranial hypertrophy of a female Neandertal from the Sima de las Palomas, southeastern Spain

    PubMed Central

    Walker, Michael J.; Ortega, Jon; Parmová, Klara; López, Mariano V.; Trinkaus, Erik

    2011-01-01

    Considerations of Neandertal geographical variation have been hampered by the dearth of remains from Mediterranean Europe and the absence there of sufficiently complete associated postcrania. The 2006 and 2007 excavation of an articulated partial skeleton of a small adult female Neandertal at the Sima de las Palomas, Murcia, southeastern Spain (Sima de las Palomas 96) provides substantial and secure information on body proportions among southern European Neandertals, as well as further documenting the nature of Neandertal biology in southern Iberia. The remains exhibit a suite of cranial, mandibular, dental, and postcranial features, of both Neandertals and archaic Homo generally, that distinguish them from contemporary and subsequent early modern humans. Its lower limbs exhibit the robustness of later Pleistocene Homo generally, and its upper limbs conform to the pattern of elevated robustness of the Neandertals. Its body proportions, including relative clavicular length, distal limb segment lengths, and body mass to stature indicators, conform to the “cold-adapted” pattern of more northern Neandertals. Palomas 96 therefore documents the presence of a suite of “Neandertal” characteristics in southern Iberia and, along with its small body size, the more “Arctic” body proportions of other European Neandertals despite the warmer climate of southern Iberia during marine isotope stage 3. PMID:21646528

  17. The emplacement of the granitic Las Tazas complex, northern Chile: the relationship between local and regional strain

    NASA Astrophysics Data System (ADS)

    Wilson, Jeff; Grocott, John

    1999-11-01

    The Coastal batholith of northern Chile grew under transtensional-extensional conditions that prevailed along the Andean margin during the Mesozoic. The batholith hosts the Atacama Fault Zone, a major arc-parallel fault system which was characterised by sinistral transtensional shearing during the Early Cretaceous. The Las Tazas complex is a composite granitoid intrusion that was emplaced syntectonically along the Atacama Fault Zone at ˜130 Ma. Syntectonic emplacement is indicated by a consistent kinematic history between the complex and its wall rocks, together with synchronous crystallisation and shearing ages. In contrast to regional patterns, the Las Tazas complex was emplaced during a local change from vertical east-side-down to dextral transcurrent displacement along the fault zone. During intrusion, strain was partitioned between non-coaxial simple shearing within country-rock mylonites and a flattening strain across the crystallising complex. This combination indicates that the pluton was emplaced under temporary transpressive conditions that were localised around the pluton, probably induced by magma emplacement. Such a difference between local and regional strain suggests that emplacement-related structures should only be related to regional strain-states with great care.

  18. [Consumption of nuts and vegetal oil in people with type 1 diabetes mellitus].

    PubMed

    Ferrer-García, Juan Carlos; Granell Vidal, Lina; Muñoz Izquierdo, Amparo; Sánchez Juan, Carlos

    2015-06-01

    Introducción: estudios recientes han demostrado los beneficios cardiovasculares de la dieta mediterránea enriquecida con aceite de oliva y frutos secos. Las personas con diabetes, que tienen un mayor riesgo de complicaciones cardiovasculares, podrían beneficiarse en gran medida de seguir ese tipo de patrón alimentario. Objetivos: análisis de la ingesta de grasas vegetales procedentes de frutos secos y aceites vegetales en pacientes con diabetes mellitus tipo 1 (DM1). Métodos: estudio transversal descriptivo que compara 60 personas con DM1 y 60 sujetos sanos. Se recoge la frecuencia de consumo de aceites vegetales y de frutos secos y se calcula el aporte procedente de estos alimentos en ácidos grasos mono y poliinsaturados (ácido oleico, linoleico y -linolénico). Se utilizó un cuestionario de frecuencia de consumo diseñado de forma específica. Se recogen variables antropométricas, factores de riesgo cardiovascular y variables relacionadas con la diabetes. Resultados: el consumo total de grasa vegetal procedente de aceites vegetales fue similar en los pacientes con DM1 frente a los sujetos control (3,02 ± 1,14 vs. 3,07 ± 1,27 Raciones (R)/día, P = 0,822) y de frutos secos (1,35 ± 2,24 vs. 1,60 ± 2,44 R/semana, P = 0,560). El grupo DM1 consumió menos aceite de oliva que el grupo control (2,55 ± 1,17 vs. 3,02 ± 1,34 R/día, P = 0,046). Se detectó un menor consumo de ácido -linolénico respecto al grupo control (1,13 ± 2,06 vs. 2,64 ± 4,37 g/día, P = 0,018), mientras que no hubo diferencias en el resto de ácidos grasos (oleico 28,30 ± 18,13 vs. 29,53 ± 16,90 g/día, P = 0,703; linoleico 13,70 ± 16,80 vs. 15,45 ± 19,90 g/día, P = 0,605). En los DM1 no se demostró una influencia del consumo de las grasas vegetales procedentes de aceites y frutos secos en los parámetros antropométricos, metabólicos y variables específicas de la diabetes. Conclusiones: en las personas con DM1 el consumo total de aceites vegetales y frutos secos no

  19. [Effects and mechanisms of inorganic anions in water on degradation of LAS by UV/H2 O2 combination process].

    PubMed

    Pan, Jing; Sun, Tie-Heng; Li, Hai-Bo

    2007-11-01

    Experiments are carried out to study the effects and mechanisms of inorganic anions in water on the degradation of linear alkyl benzene sulfonate (LAS) in UV/H2 O2 process. The results show that UV/H2 O2 process could remove LAS effectively, and the rate of photodegradation follows first-order reaction kinetics model. Under the condition that H2 O2 concentration was 8 mg x L(-1) and a 14 W low pressure mercury vapor discharge lamp irradiated samples, the first-order photodegradation rate constant of LAS in distilled water and tap water were 0.018 0 min(-1) and 0.012 2 min(-1) respectively. NO3-, Cl-, SO4(2-) and HCO3- have inhibitory action on LAS photodegradation. The higher inorganic anions concentration was, the stronger inhibitory action. When their concentrations were 5, 10 and 15 mmol x L(-1) respectively, their inhibitory action order was HCO3- > NO3- > Cl- > SO4(2-) all the time. It was anions synthetical effect that caused photodegradation rate constant of LAS in tap water lower than distilled water.

  20. Log ASCII Standard (LAS) Files for Geophysical Wireline Well Logs and Their Application to Geologic Cross Sections Through the Central Appalachian Basin

    USGS Publications Warehouse

    Crangle, Robert D.

    2007-01-01

    Introduction The U.S. Geological Survey (USGS) uses geophysical wireline well logs for a variety of purposes, including stratigraphic correlation (Hettinger, 2001, Ryder, 2002), petroleum reservoir analyses (Nelson and Bird, 2005), aquifer studies (Balch, 1988), and synthetic seismic profiles (Kulander and Ryder, 2005). Commonly, well logs are easier to visualize, manipulate, and interpret when available in a digital format. In recent geologic cross sections E-E' and D-D', constructed through the central Appalachian basin (Ryder, Swezey, and others, in press; Ryder, Crangle, and others, in press), gamma ray well log traces and lithologic logs were used to correlate key stratigraphic intervals (Fig. 1). The stratigraphy and structure of the cross sections are illustrated through the use of graphical software applications (e.g., Adobe Illustrator). The gamma ray traces were digitized in Neuralog (proprietary software) from paper well logs and converted to a Log ASCII Standard (LAS) format. Once converted, the LAS files were transformed to images through an LAS-reader application (e.g., GeoGraphix Prizm) and then overlain in positions adjacent to well locations, used for stratigraphic control, on each cross section. This report summarizes the procedures used to convert paper logs to a digital LAS format using a third-party software application, Neuralog. Included in this report are LAS files for sixteen wells used in geologic cross section E-E' (Table 1) and thirteen wells used in geologic cross section D-D' (Table 2).

  1. Water-quality data for the Rio Grande between Picacho Bridge near Las Cruces and Calle del Norte Bridge near Mesilla, New Mexico, 1996-97

    USGS Publications Warehouse

    Huff, G.F.

    1998-01-01

    The City of Las Cruces is concerned about water quality in a reach of the Rio Grande that receives outfall from the City of Las Cruces wastewater-treatment plant. Water-quality samples were collected from the Rio Grande at Picacho Bridge near Las Cruces, New Mexico; from the sampling site at the City of Las Cruces wastewater-treatment plant; and from the Rio Grande at Calle del Norte Bridge near Mesilla, New Mexico. The samples were collected on 12 days from August 6, 1996, to February 28, 1997, and were analyzed for a suite of dissolved and total constituents including trace metals. Instantaneous stream discharge was measured concurrently with collection of the Rio Grande samples. At the wastewater- treatment plant, the City of Las Cruces provided instantaneous discharge rates concurrent with sampling. Quality-control measures used in this study to ensure analytical accuracy included replicate sampling, replicate analysis of split samples, ambient blanks, equipment blanks, and analysis of standard reference water samples.

  2. 2LAs, 3LAs, and the enterprise

    SciTech Connect

    Hoffmann, T.

    1998-01-01

    This article is about new things that engineers, facility managers and automation system operators need to learn about and understand when it comes to integrating information throughout an enterprise. The goal is to help one better understand the connection between building systems and building intelligence. The authors set the foundation with an overview of the latest concept in network communications, enterprise computing. Because any new technology spawns a number of acronyms, they`ll also investigate new two-, three-, four- and five-letter acronyms that directly affect the changing role of the building automation system (BAS) as it becomes an integral, contributing part of the business. In each case, one or more Internet URLs will be provided for more information.

  3. Changes in air quality at near-roadway schools after a major freeway expansion in Las Vegas, Nevada.

    PubMed

    Brown, Steven G; McCarthy, Michael C; DeWinter, Jennifer L; Vaughn, David L; Roberts, Paul T

    2014-09-01

    Near-roadway ambient black carbon (BC) and carbon monoxide (CO) concentrations were measured at two schools adjacent to a freeway and at an urban background school 2 km from the freeway to determine the change in concentrations attributable to vehicle emissions after the three-lane expansion of U.S. Highway 95 (US 95) in Las Vegas, Nevada. Between summer 2007 and summer 2008, average weekday small-vehicle volume increased by 40% +/- 2% (standard error). Average weekday large-vehicle volume decreased by 17% +/- 5%, due to a downturn in the economy and an associated decline in goods movement. Average vehicle speed increased from 58 to 69 mph, a 16% +/- 1% increase. The authors compared BC and CO concentrations in summer 2007 with those in summer 2008 to understand what effect the expansion of the freeway may have had on ambient concentrations: BC and CO were measured 17 m north of the freeway sound wall, CO was measured 20 m south of the sound wall, and BC was measured at an urban background site 2 km south of the freeway. Between summer 2007 and summer 2008, median BC decreased at the near-road site by 40% +/- 2% and also decreased at the urban background site by 24% +/- 4%, suggesting that much of the change was due to decreases in emissions throughout Las Vegas, rather than only on US 95. CO concentrations decreased by 14% +/- 2% and 10% +/- 3% at the two near-road sites. The decrease in BC concentrations after the expansion is likely due to the decrease in medium- and heavy-duty-vehicle traffic resulting from the economic recession. The decrease in CO concentrations may be a result of improved traffic flow, despite the increase in light-duty-vehicle traffic. Implications: Monitoring of BC and CO at near-road locations in Las Vegas demonstrated the impacts of changes in traffic volume and vehicle speed on near-road concentrations. However, urban-scale declines in concentrations were larger than near-road changes due to the impacts of the economic recession that

  4. Changes in air quality at near-roadway schools after a major freeway expansion in Las Vegas, Nevada.

    PubMed

    Brown, Steven G; McCarthy, Michael C; DeWinter, Jennifer L; Vaughn, David L; Roberts, Paul T

    2014-09-01

    Near-roadway ambient black carbon (BC) and carbon monoxide (CO) concentrations were measured at two schools adjacent to a freeway and at an urban background school 2 km from the freeway to determine the change in concentrations attributable to vehicle emissions after the three-lane expansion of U.S. Highway 95 (US 95) in Las Vegas, Nevada. Between summer 2007 and summer 2008, average weekday small-vehicle volume increased by 40% +/- 2% (standard error). Average weekday large-vehicle volume decreased by 17% +/- 5%, due to a downturn in the economy and an associated decline in goods movement. Average vehicle speed increased from 58 to 69 mph, a 16% +/- 1% increase. The authors compared BC and CO concentrations in summer 2007 with those in summer 2008 to understand what effect the expansion of the freeway may have had on ambient concentrations: BC and CO were measured 17 m north of the freeway sound wall, CO was measured 20 m south of the sound wall, and BC was measured at an urban background site 2 km south of the freeway. Between summer 2007 and summer 2008, median BC decreased at the near-road site by 40% +/- 2% and also decreased at the urban background site by 24% +/- 4%, suggesting that much of the change was due to decreases in emissions throughout Las Vegas, rather than only on US 95. CO concentrations decreased by 14% +/- 2% and 10% +/- 3% at the two near-road sites. The decrease in BC concentrations after the expansion is likely due to the decrease in medium- and heavy-duty-vehicle traffic resulting from the economic recession. The decrease in CO concentrations may be a result of improved traffic flow, despite the increase in light-duty-vehicle traffic. Implications: Monitoring of BC and CO at near-road locations in Las Vegas demonstrated the impacts of changes in traffic volume and vehicle speed on near-road concentrations. However, urban-scale declines in concentrations were larger than near-road changes due to the impacts of the economic recession that

  5. Aerosol Light Absorption and Scattering at Four Sites in and Near Mexico City: Comparison with Las Vegas, Nevada, USA

    NASA Astrophysics Data System (ADS)

    Arnott, W. P.; Miranda, G. P.; Gaffney, J. S.; Marley, N. A.

    2007-05-01

    Four photoacoustic spectrometers (PAS) for aerosol light scattering and absorption measurements were deployed in and near Mexico City in March 2006 as part of the Megacity Impacts on Regional and Global Environments (MIRAGE). The four sites included: an urban site at Instituto Mexicano del Petroleo (Mexican Oil Institute, denoted by IMP); a suburban site at the Technological University of Tecamac; a rural site at "La Biznaga" ranch; and a site at the Paseo de Cortes (altitude 3,810 meters ASL) in the rural area above Amecameca in the State of Mexico, on the saddle between the volcanoes Popocatepetl and Iztaccihuatl. A similar campaign was held in Las Vegas, Nevada, USA in January-February, 2003. The IMP site gave in-situ characterization of the Mexico City plume under favorable wind conditions while the other sites provided characterization of the plume, mixed in with any local sources. The second and third sites are north of Mexico City, and the fourth site is south. The PAS used at IMP operates at 532 nm, and conveniently allowed for characterization of gaseous absorption at this wavelength as well. Instruments at the second and third sites operate at 870 nm, and the one at the fourth site at 780 nm. Light scattering measurements are accomplished within the PAS by the reciprocal nephelometery method. In the urban site the aerosol absorption coefficient typically varies between 20 and 180 Mm-1 during the course of the day and significant diurnal variation of the aerosol single scattering albedo was observed probably as a consequence of secondary aerosol formation. Comparisons with TSI nephelometer scattering at the T0 site will be presented. We will present the diurnal variation of the scattering and absorption as well as the single scattering albedo and fraction of absorption due to gases at the IMP site and compare with Las Vegas diurnal variation. Mexico City 'breaths' more during the course of the day than Las Vegas, Nevada in part because the latitude of

  6. The Primary Diterpene Synthase Products of Picea abies Levopimaradiene/Abietadiene Synthase (PaLAS) Are Epimers of a Thermally Unstable Diterpenol*

    PubMed Central

    Keeling, Christopher I.; Madilao, Lina L.; Zerbe, Philipp; Dullat, Harpreet K.; Bohlmann, Jörg

    2011-01-01

    The levopimaradiene/abietadiene synthase from Norway spruce (Picea abies; PaLAS) has previously been reported to produce a mixture of four diterpene hydrocarbons when incubated with geranylgeranyl diphosphate as the substrate: levopimaradiene, abietadiene, neoabietadiene, and palustradiene. However, variability in the assay products observed by GC-MS of this and orthologous conifer diterpene synthases over the past 15 years suggested that these diterpenes may not be the initial enzyme assay products but are rather the products of dehydration of an unstable alcohol. We have identified epimers of the thermally unstable allylic tertiary alcohol 13-hydroxy-8(14)-abietene as the products of PaLAS. The identification of these compounds, not previously described in conifers, as the initial products of PaLAS has considerable implications for our understanding of the complexity of the biosynthetic pathway of the structurally diverse diterpene resin acids of conifer defense. PMID:21518766

  7. Informe sobre el avance del proyecto de determinaciones de V sen i para todas las estrellas B más brillantes que 6.5 mag.

    NASA Astrophysics Data System (ADS)

    Abt, H.; Levato, H.

    Se ha finalizado con la determinación de V sen i para todas las estrellas B más brillantes que 6.5 mag y al norte de -30 grados de declinación. Esta muestra involucra casi 1000 estrellas. Las observaciones fueron realizadas desde KPNO. Mientras tanto, se ha completado desde CASLEO la observación de 350 estrellas B más brillantes que 6.5 mag. al sur de -30 grados. Además de la determinación de la rotación axial se determinan, en los casos posibles, los anchos equivalentes de las líneas 4471 Ådel He I y 4481 Ådel Mg II.

  8. Evolución en el tiempo de las relaciones Masa-Luminosidad y Corrección Bolométrica y Temperatura Efectiva contra Índice de Color

    NASA Astrophysics Data System (ADS)

    Miloni, L. A.; Camperi, J. A.

    Analizamos la evolución que en los últimos 70 años han tenido las relaciones M-L, BC vs CI y Teff vs CI. Se discuten las causas de esa evolución, se trata de incorporar los valores más modernos disponibles discutiendo su calidad y se deducen las relaciones que actualmente deberían ser las más confiables. Destacamos los puntos en los que estas relaciones continúan estando pobremente definidas y sería deseable mejorar en el futuro próximo.

  9. Cómo aumentar la actividad física de los niños durante el período del recreo en las escuelas

    PubMed Central

    Ludwig, David

    2014-01-01

    Objetivos. Analizamos si la participación de las escuelas en el Programa de Mejoramiento del Recreo (PMR) en la primavera del año 2011 estuvo asociada a tasas más altas de actividad física intensa en los niños. Métodos. En el PMR, un coordinador dirige a los niños para que practiquen juegos adecuados para la edad a fin de aumentar su nivel de actividad física. Durante el recreo en 25 escuelas primarias públicas de la ciudad de Nueva York (15 participantes en el PMR, 10 no participantes en el PMR) los investigadores observaron algunas áreas predeterminadas (n = 1 339 observaciones) y registraron el número de niños que estaban sedentarios, caminando o muy activos. Resultados. Tras el análisis estadístico con múltiples variables se encontró que la participación en el PMR era una variable predictiva significativa (P = 0,027) de la tasa de actividad física intensa (porcentaje de niños muy activos en las áreas de observación) cuyas medias de los mínimos cuadrados fueron de 41% en las escuelas participantes en el PMR y de 27% en escuelas no participantes en el PMR. En las escuelas participantes en el PMR se siguió registrando una tasa significativamente superior incluso cuando el coordinador de juegos no estaba en el área de observación, lo que sugiere un cambio en la cultura del recreo en las escuelas que participan en este programa. Conclusiones. La tasa de actividad física intensa en las escuelas participantes en el PMR fue 14 puntos porcentuales (o 52%) superior a la tasa registrada en las escuelas no participantes en el PMR. Esta intervención de bajo costo podría ser un agregado valioso a las herramientas para combatir la obesidad infantil y podría valer la pena reproducirla en otros sitios. PMID:24899455

  10. Heavy Metal Contamination and Salt Efflorescence Associated With Decorative Landscaping Rocks, Las Vegas, Nevada: The Need for Regulations

    NASA Astrophysics Data System (ADS)

    Mrozek, S. A.; Buck, B. J.; Brock, A. L.

    2004-12-01

    Las Vegas, Nevada is one of the fastest growing cities in the United States. Faced with water restrictions, decorative rock xeroscaping has become a very popular form of landscaping. Currently, there are no regulations controlling the geochemistry of the decorative rocks that can be used for these purposes. In this study, we examined three sites containing two different decorative rock products. The landscaping rocks, underlying soil, and surface salt crusts were analyzed to determine their mineralogy and chemistry. Methods of analysis include scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDS), X-ray diffraction (XRD), inductively coupled plasma atomic emission spectroscopy (ICP), thin section analysis, and laser particle size analysis (LPSA). Preliminary results indicate the presence of halite (NaCl), bloedite (Na2Mg(SO4)2 4H2O), a hydrated magnesium sulfate, and possibly copper sulfate and copper chloride mineral phases in the surface salt crusts. Both copper minerals are regarded as hazardous substances by the Occupational Safety and Health Administration (OSHA) and the Environmental Protection Agency (EPA); these agencies have established minimum exposure limits for human contact with these substances. Copper sulfate and copper chloride are not naturally occurring minerals in the soils of the Las Vegas Valley, and analyses indicate that their formation may be attributed to the mineralogy of the decorative landscaping rocks. Further testing is needed to characterize this potential health hazard; however the preliminary results of this study demonstrate the need for regulations controlling the geochemistry of decorative rocks used for urban landscaping.

  11. A preliminary assessment of earthquake ground shaking hazard at Yucca Mountain, Nevada and implications to the Las Vegas region

    SciTech Connect

    Wong, I.G.; Green, R.K.; Sun, J.I.; Pezzopane, S.K.; Abrahamson, N.A.; Quittmeyer, R.C.

    1996-12-31

    As part of early design studies for the potential Yucca Mountain nuclear waste repository, the authors have performed a preliminary probabilistic seismic hazard analysis of ground shaking. A total of 88 Quaternary faults within 100 km of the site were considered in the hazard analysis. They were characterized in terms of their probability o being seismogenic, and their geometry, maximum earthquake magnitude, recurrence model, and slip rate. Individual faults were characterized by maximum earthquakes that ranged from moment magnitude (M{sub w}) 5.1 to 7.6. Fault slip rates ranged from a very low 0.00001 mm/yr to as much as 4 mm/yr. An areal source zone representing background earthquakes up to M{sub w} 6 1/4 = 1/4 was also included in the analysis. Recurrence for these background events was based on the 1904--1994 historical record, which contains events up to M{sub w} 5.6. Based on this analysis, the peak horizontal rock accelerations are 0.16, 0.21, 0.28, and 0.50 g for return periods of 500, 1,000, 2,000, and 10,000 years, respectively. In general, the dominant contributor to the ground shaking hazard at Yucca Mountain are background earthquakes because of the low slip rates of the Basin and Range faults. A significant effect on the probabilistic ground motions is due to the inclusion of a new attenuation relation developed specifically for earthquakes in extensional tectonic regimes. This relation gives significantly lower peak accelerations than five other predominantly California-based relations used in the analysis, possibly due to the lower stress drops of extensional earthquakes compared to California events. Because Las Vegas is located within the same tectonic regime as Yucca Mountain, the seismic sources and path and site factors affecting the seismic hazard at Yucca Mountain also have implications to Las Vegas. These implications are discussed in this paper.

  12. Sources and concentrations of mercury and selenium in compartments within the Las Vegas Wash during a period of rapid change.

    PubMed

    Cizdziel, James; Zhou, Xiaoping

    2005-08-01

    The Las Vegas Wash, which drains the Las Vegas valley watershed and provides the second largest inflow to Lake Mead, is being dramatically altered with erosion control structures and wetland restoration efforts. The impact of these changes on the cycling and distribution of Hg and Se is of particular interest because of their tendency to bioaccumulate and because of a lack of information on these contaminants in the Wash. In this study, we determined concentrations of Hg and Se in surface water (monthly), groundwater (once) and sediments (quarterly) from strategic locations within and along the Wash during 2002 and 2003. The data was used to characterize Se sources and loading into the Wash. Samples containing resurfacing groundwater and urban runoff (LW10.75 and Duck Creek) had significantly higher yearly means (13.7 +/- 4.4 and 23.8 +/- 4.1 microg/L, respectively) compared with mainstream samples containing primarily treated wastewater (2.8 +/- 0.8 microg/L). Investigation of Se in tributaries, street runoff and rain suggest that the source of the elevated Se is likely groundwater seeps located within a relatively narrow geographic band on the southeast side of the valley. Se content of sediments was similar, except for LW10.75 which was rich in organic matter. Hg concentrations in the water and sediments were low, averaging 4 +/- 5 ng/L and 34 +/- 20 ng/g, dw, respectively. Overall, this study suggests that water quality remains relatively stable despite changes in the Wash and managers of developing wetlands should not use tributary water as source water.

  13. The influence of faults in basin-fill deposits on land subsidence, Las Vegas Valley, Nevada, USA

    NASA Astrophysics Data System (ADS)

    Burbey, Thomas

    2002-07-01

    The role of horizontal deformation caused by pumping of confined-aquifer systems is recognized as contributing to the development of earth fissures in semiarid regions, including Las Vegas Valley, Nevada. In spite of stabilizing water levels, new earth fissures continue to develop while existing ones continue to lengthen and widen near basin-fill faults. A three-dimensional granular displacement model based on Biot's consolidation theory (Biot, MA, 1941, General theory of three-dimensional consolidation. Jour. Applied Physics 12:155-164) has been used to evaluate the nature of displacement in the vicinity of two vertical faults. The fault was simulated as (1) a low-permeability barrier to horizontal flow, (2) a gap or structural break in the medium, but where groundwater flow is not obstructed, and (3) a combination of conditions (1) and (2). Results indicate that the low-permeability barrier greatly enhances horizontal displacement. The fault plane also represents a location of significant differential vertical subsidence. Large computed strains in the vicinity of the fault may suggest high potential for failure and the development of earth fissures when the fault is assumed to have low permeability. Results using a combination of the two boundaries suggest that potential fissure development may be great at or near the fault plane and that horizontal deformation is likely to play a key role in this development. Résumé. On considère que la déformation horizontale provoquée par un pompage dans un aquifère captif joue un rôle dans le développement des fissures du sol en régions semi-arides, comme la vallée de Las Vegas (Nevada). Malgré des niveaux d'eau stabilisés, de nouvelles fissures du sol continuent de se développer en longueur et en largeur au voisinage de failles dans les bassins sédimentaires. Un modèle de déplacement granulaire tri-dimensionnel, basé sur la théorie de la consolidation de Biot (Biot, M A, 1941, General theory of three

  14. The influence of faults in basin-fill deposits on land subsidence, Las Vegas Valley, Nevada, USA

    NASA Astrophysics Data System (ADS)

    Burbey, Thomas

    2002-07-01

    The role of horizontal deformation caused by pumping of confined-aquifer systems is recognized as contributing to the development of earth fissures in semiarid regions, including Las Vegas Valley, Nevada. In spite of stabilizing water levels, new earth fissures continue to develop while existing ones continue to lengthen and widen near basin-fill faults. A three-dimensional granular displacement model based on Biot's consolidation theory (Biot, MA, 1941, General theory of three-dimensional consolidation. Jour. Applied Physics 12:155-164) has been used to evaluate the nature of displacement in the vicinity of two vertical faults. The fault was simulated as (1) a low-permeability barrier to horizontal flow, (2) a gap or structural break in the medium, but where groundwater flow is not obstructed, and (3) a combination of conditions (1) and (2). Results indicate that the low-permeability barrier greatly enhances horizontal displacement. The fault plane also represents a location of significant differential vertical subsidence. Large computed strains in the vicinity of the fault may suggest high potential for failure and the development of earth fissures when the fault is assumed to have low permeability. Results using a combination of the two boundaries suggest that potential fissure development may be great at or near the fault plane and that horizontal deformation is likely to play a key role in this development. Résumé. On considère que la déformation horizontale provoquée par un pompage dans un aquifère captif joue un rôle dans le développement des fissures du sol en régions semi-arides, comme la vallée de Las Vegas (Nevada). Malgré des niveaux d'eau stabilisés, de nouvelles fissures du sol continuent de se développer en longueur et en largeur au voisinage de failles dans les bassins sédimentaires. Un modèle de déplacement granulaire tri-dimensionnel, basé sur la théorie de la consolidation de Biot (Biot, M A, 1941, General theory of three

  15. Exploring the effects of population growth on future land use change in the Las Vegas Wash watershed: an integrated approach of geospatial modeling and analytics

    EPA Science Inventory

    The Las Vegas Valley metropolitan area is one of the fastest growing areas in the southwestern United States. The rapid urbanization has led to many environmental problems. For instance, as population growth and urbanization continue, there will be a problem with water shortage. ...

  16. Integrating NASA's Land Analysis System (LAS) image processing software with an appropriate Geographic Information System (GIS): A review of candidates in the public domain

    NASA Technical Reports Server (NTRS)

    Rochon, Gilbert L.

    1989-01-01

    A user requirements analysis (URA) was undertaken to determine and appropriate public domain Geographic Information System (GIS) software package for potential integration with NASA's LAS (Land Analysis System) 5.0 image processing system. The necessity for a public domain system was underscored due to the perceived need for source code access and flexibility in tailoring the GIS system to the needs of a heterogenous group of end-users, and to specific constraints imposed by LAS and its user interface, Transportable Applications Executive (TAE). Subsequently, a review was conducted of a variety of public domain GIS candidates, including GRASS 3.0, MOSS, IEMIS, and two university-based packages, IDRISI and KBGIS. The review method was a modified version of the GIS evaluation process, development by the Federal Interagency Coordinating Committee on Digital Cartography. One IEMIS-derivative product, the ALBE (AirLand Battlefield Environment) GIS, emerged as the most promising candidate for integration with LAS. IEMIS (Integrated Emergency Management Information System) was developed by the Federal Emergency Management Agency (FEMA). ALBE GIS is currently under development at the Pacific Northwest Laboratory under contract with the U.S. Army Corps of Engineers' Engineering Topographic Laboratory (ETL). Accordingly, recommendations are offered with respect to a potential LAS/ALBE GIS linkage and with respect to further system enhancements, including coordination with the development of the Spatial Analysis and Modeling System (SAMS) GIS in Goddard's IDM (Intelligent Data Management) developments in Goddard's National Space Science Data Center.

  17. The Birth of a New Vocational-Technical Center. National Vocational-Technical Facility Planning Conference (Las Vegas, Nevada, May, 1967).

    ERIC Educational Resources Information Center

    Farnsworth, Clayton

    The principal of the Southern Nevada Vocational-Technical Center at Las Vegas, Nevada, briefly outlines its development and function. The facility cost approximately 3 million dollars and was built on 390 acres of land purchased from the Federal government. The PERT method was used in planning. Instructional facilities, including those for auto…

  18. A McOndo Writer's Take on Literature in the Era of Audiovisual and Digital Communication: The Case of Alberto Fuguet's "Las Peliculas de mi vida"

    ERIC Educational Resources Information Center

    Maier, Linda S.

    2011-01-01

    Alberto Fuguet, one of the leaders of the McOndo writers who seek cultural direction from the United States and exploit mass-media formulas, is a polarizing figure in contemporary Latin American culture. His most recent full-length novel, the semi-autobiographical "Las peliculas de mi vida" (2003), has led many to conclude that Fuguet is simply a…

  19. NCI adopta el sendero científico para lograr las metas de la Misión Nacional contra el Cáncer

    Cancer.gov

    El director interino del NCI, doctor Douglas Lowy, aceptó hoy las recomendaciones de un Panel Listón Azul para 10 planteamientos científicos que en cinco años lograrán un progreso contra el cáncer equivalente a una década de trabajo.

  20. Long-term continuous measurement of near-road air pollution in Las Vegas: Seasonal variability in traffic emissions impact on local air quality

    EPA Science Inventory

    Excess air pollution along roadways is an issue of public health concern and motivated a long-term measurement effort established by the U.S. Environmental Protection Agency in Las Vegas, Nevada. Measurements of air pollutants – including black carbon (BC), carbon monoxide (CO),...

  1. Abundancias químicas de las estrellas CP del grupo HgMn μ Leporis y 53 Tauri. II. Boro, Berilio, Carbono, Magnesio, Aluminio y Silicio

    NASA Astrophysics Data System (ADS)

    López García, Z.; Malaroda, S. M.; Faraggiana, R.

    Se determinan las abundancias químicas de los elementos más livianos presentes en dos estrellas CP del grupo HgMn, μ Lep y 53 Tau, utilizando espectros IUE de alta resolución y técnicas de cálculo de espectros sintéticos. Para el cálculo de las líneas se utiliza la lista mas completa de datos atómicos disponible y el programa SYNTHE. Para el cálculo de la abundancia de un elemento se comparan, para cada imagen, los perfiles observados del mayor número de líneas presentes con los perfiles calculados obtenidos por variación de las abundancias iniciales, reteniendo la abundancia para la cual el acuerdo entre las líneas observadas y calculadas es considerado visualmente el mejor. Los resultados obtenidos son comparados con los estimados por la teoría de la difusión.

  2. Explorations of Colleges, Universities, and Career Training Centers in Las Vegas, Nevada: Creating Educational and Training Programs for Displaced Workers to Learn Marketable Employment Skills

    ERIC Educational Resources Information Center

    Gonyea, Jacob Patrick

    2012-01-01

    The city of Las Vegas, Nevada has experienced a slowdown in tourism, a drop in property taxes and consolidated tax revenue used to support the city's operating budget, and a lack of economic diversification. Because of these changes, the ability of displaced workers to learn marketable employment skills continues to be an important issue for…

  3. Summary of chemical data from onsite and laboratory analyses of groundwater samples from the surficial aquifer, Las Vegas, Nevada, April and August 1993 and September 1994

    USGS Publications Warehouse

    Reddy, Michael M.; Gunther, Charmaine D.

    2012-01-01

    Samples were collected from groundwater wells in and about the city of Las Vegas, Nevada, and were analyzed for selected major, minor and trace constituents. Analyses of blank and reference samples are summarized as mean and standard deviation values for all positive results.

  4. Six month progress report on the Waste Package Project at the University of Nevada, Las Vegas, July 1991--January 1992: Management, quality assurance and overview

    SciTech Connect

    Ladkany, S.G.

    1991-12-31

    The progress of the waste package project at the University of Nevada, Las Vegas was the subject of this report. It covered aspects of management and quality assurance, container design, application of ASME Pressure Vessel Codes, structural analysis of containers, design of rock tunnels for storage, and heat transfer phenomena. (MB)

  5. Six month progress report on the Waste Package Project at the University of Nevada, Las Vegas, July 1991--January 1992: Management, quality assurance and overview

    SciTech Connect

    Ladkany, S.G.

    1991-01-01

    The progress of the waste package project at the University of Nevada, Las Vegas was the subject of this report. It covered aspects of management and quality assurance, container design, application of ASME Pressure Vessel Codes, structural analysis of containers, design of rock tunnels for storage, and heat transfer phenomena. (MB)

  6. School Resegregation in the Mississippi of the West: Community Counternarratives on the Return to Neighborhood Schools in Las Vegas, 1968-1994

    ERIC Educational Resources Information Center

    Horsford, Sonya Douglass; Sampson, Carrie; Forletta, Felicia

    2013-01-01

    Background: School desegregation and resegregation in the Mountain West remain understudied despite the substantial impact the region's growth and demographic change have had on racial balance and diversity in schools. Home to the largest school district in the Mountain West and fifth largest school district in the country, Las Vegas's…

  7. Full House: The Las Vegas building boom has stretched the creativity and resources of the fastest-growing school district in the nation. Edutopia, September/October 2004

    ERIC Educational Resources Information Center

    Furger, Roberta

    2004-01-01

    This once sleepy community, founded by Mormon missionaries in 1855 and jumpstarted by gambling 85 years later, now gobbles up real estate faster than a conventioneer chowing down at a midnight buffet. Every day of the week, two acres of Las Vegas area land are developed for commercial or residential use in a frenetic drive to accommodate the…

  8. BEA Annual Convention: A Look Back at BEA 97 and Preparing for BEA 98, April 3-6, Las Vegas, Nevada.

    ERIC Educational Resources Information Center

    Feedback, 1997

    1997-01-01

    The 42nd annual Broadcast Education Association (BEA) Convention ("Reinventing Electronic Media: Multimedia in the New Millennium") for electronic media educators was held April 3-6, 1997 in Las Vegas, Nevada. This article outlines events at the 1997 convention and provides a "sneak peek" at planning for the 1998 convention, "Electronic Media:…

  9. NCI adopta el sendero científico para lograr las metas de la Misión contra el Cáncer

    Cancer.gov

    El director interino del NCI, doctor Douglas Lowy, aceptó hoy las recomendaciones de un Panel Listón Azul para 10 planteamientos científicos que en cinco años lograrán un progreso contra el cáncer equivalente a una década de trabajo.

  10. Reproductive Responses of Common Carp Cyprinus carpio in Cages to Influent of the Las Vegas Wash in Lake Mead, Nevada, from late Winter to early Spring

    EPA Science Inventory

    To investigate the potential for contaminants in Las Vegas Wash (LW) influent to produce effects indicative of endocrine disruption in vivo, adult male and female common carp were exposed in cages for 42-48 d at four sites and two reference locations in Lake Mead.

  11. PA01.43. In-vitro cyto chemical & flow-cytometry studies with las02- a coded herbo-mineral compound

    PubMed Central

    Asthana, Aditi; Saxena, R C; Singh, Vandana; Sharma, Vinamra; Srivastava, Ashok; Trivedi, V. P.

    2012-01-01

    Purpose: The drug optimization and understanding the mechanisms of action of drugs on the deregulation of cell cycle which is frequently considered as the cause of progression in cancer can provide important insights for new cancer treatment strategies. The drug LAS02 is a herbo mineral drug prepared as per ancient Ayurvedic literature. Method: In this study the effect of LAS02 was studied by analyzing the effect on cell cycle by flow cytometery on cancer cell lines breast cancer (MCF7), cervical cancer (HELA), colon cancer (COLO 205) and prostate cancer (DU 145), procured from NCCS, Pune. The cells were treated by different doses of LAS02, and assay for proliferation was performed by MTT assay test, subsequently, these were analyzed by flow cytometer for cell cycle analysis. Result: The results showed inhibition of proliferation in MCF7 by 77% and HELA cells by 78% at dose of 500μg/ml in MTT assay. In cell cycle analysis for COLO 205 treated with LAS02, the percentage retention of the cells in G0/ G1 phase was 73.07% at 300μg/ml as compared to 52.16% in the control after 24hrs. In DU 145, treated with LAS02, cells that retained at G0/G1 phase were 79.28% at a dose of 400μg/ml after 48hrs; as compared to control of 62.41%. The apoptosis observed at 400μg/ml drug concentration was 43.51%. Conclusion: The study shows that LAS02 acts as a potent anti cancerous compound by inhibiting proliferation as well as by inducing retention of cells in G0/G1 phase along with apoptosis significantly at in vitro level. Therefore, LAS02 arrests the cancerous cells in G0/G1 phase and prevented the entry of pre cancerous stem cells from G0/G1 phase into G2, the subsequent proliferative stage and inhibits cancer cells from completing the cell cycle. Such a finding is unique with this new drug, which holds a great promise as one of the most effective and safest cancerostatic drug.

  12. Enhancement of archaeological heritage. El Risco de las Cuevas at Perales de Tajuña, Madrid (Spain)

    NASA Astrophysics Data System (ADS)

    Freire-Lista, David Martin; Alvarez de Buergo, Mónica; Fort, Rafael

    2016-04-01

    Heritage conservation has a great impact on the economy of a country. The enhancement of archaeological sites is an investment that promotes tourism and culture. The interdisciplinary knowledge of heritage should be the basis of its management. Preventive actions, non-destructive analytical techniques and monitoring for the conservation of these assets should be promoted. "El Risco de las Cuevas" is a highly decayed and nearly vertical gypsum escarpment which contains a series of dwellings excavated during the Chalcolithic and much more recent times. It is located at Perales de Tajuña, 40 km southeast of Madrid, Spain. This monument is approximately 70 metres high and 500 metres wide. It was listed as a cultural and monumental heritage site by the regional government of Madrid in 1998. The gypsum escarpment housing the dwellings forms part of a lower Miocene unit (Madrid Basin). Debris cones with a mixture of debris from the lower, medium and upper units are found at the bottom of the rockwall. The vulnerability of this monument to atmospheric agents has been studied using "in situ" monitoring techniques of humidity, temperature and rate of rockfalls. Drones have been used for aerial photography in the highest areas of the escarpment and have provided an information network of fractures likely to cause rockfall. Gypsum artificial accelerated ageing has been carried out in the laboratory, including freeze/thaw, wet/dry, thermal shock and dissolution tests. To determine the response of these accelerated ageing processes, density, micro-roughness, ultrasound velocities (Vp and Vs), air permeability and microscopy measurements were made before, during and after ageing tests. Geomorphological studies, rates of decay, material characteristics and durability tests indicate that the decay is controlled by the mineralogy, clay content and porosity of the gypsum rock, as well as microclimate, temperature changes and rock fractures. Rockfalls are particularly relevant in the

  13. Sedimentology and paleoenvironments of the Las Chacritas carbonate paleolake, Cañadón Asfalto Formation (Jurassic), Patagonia, Argentina

    NASA Astrophysics Data System (ADS)

    Cabaleri, Nora G.; Benavente, Cecilia A.

    2013-02-01

    The Las Chacritas Member is the lower part of the Cañadón Asfalto Formation (Jurassic). The unit is a completely continental limestone succession with volcanic contributions that were deposited during the development of the Cañadón Asfalto Rift Basin (Chubut province, Patagonia, Argentina). A detailed sedimentological analysis was performed in the Fossati depocenter to determine the paleoenvironments that developed in the context of this rift. The Las Chacritas Member represents a carbonate paleolake system with ramp-shaped margins associated with wetlands that were eventually affected by subaerial exposure and pedogenesis. This process is represented by three main subenvironments: a) a lacustrine setting sensu stricto (lacustrine limestone facies association), represented by Mudstones/Wackestones containing porifera spicules (F1), Intraclastic packstones (F6) and Tabular stromatolites (F10) in which deposition and diagenesis were entirely subaqueous; b) a palustrine setting (palustrine limestone facies association) containing Microbial Mudstones (F2), Intraclastic sandy packstone with ostracode remains (F3), Oncolitic packstone (F5), Brecciated limestone (F7) and Nodular-Mottled limestone (F8) representing shallow marginal areas affected by groundwater fluctuations and minor subaerial exposure; and c) a pedogenic paleoenvironment (pedogenic limestone facies association) including Intraclastic limestone (F4) and Packstones containing Microcodium (F9) facies displaying the major features of subaerial exposure, pedogenic diagenesis and the development of paleosols. The fluvial-palustrine-lacustrine succession shows a general shallow upward trend in which contraction-expansion cycles are represented (delimited by exposure and surface erosion). The variations in the successive formations reflect the responses to fluctuations in a combination of two major controls, the tectonic and local climatic variables. The predominance of the palustrine facies associations was

  14. Integrating Collaboration, Adaptive Management, and Scenario-Planning to Address Rapid Change: Experiences at Las Cienegas National Conservation Area

    NASA Astrophysics Data System (ADS)

    Caves, J. K.; Bodner, G.; Simms, K.; Fisher, L.; Robertson, T.

    2012-12-01

    There is growing recognition that public lands cannot be managed as islands; rather, land management must address the ecological, social, and temporal complexity that often spans jurisdictions and traditional planning horizons. Collaborative decision-making and adaptive management (CAM) have been promoted as methods to reconcile competing societal demands and respond to complex ecosystem dynamics. We present the experiences of land managers and stakeholders in using CAM at Las Cienegas National Conservation Area (LCNCA), a highly valued site under the jurisdiction of the Bureau of Land Management (BLM). The CAM process at Las Cienegas is marked by strong stakeholder engagement, with four core elements: 1) shared watershed goals with measurable resource objectives; 2) mechanisms to incorporate new information into decision-making; 3) efforts to make information increasingly relevant and reliable; and 4) shared learning to improve both the process and management actions. The combination of stakeholder engagement and adaptive management has led to agreement on contentious issues, more innovative solutions, and more effective land management. Yet the region is now experiencing rapid changes outside managers' control—including climate change, human population growth, and reduced federal budgets—with large but unpredictable impacts on natural resources. While CAM experience provides a strong foundation for making the difficult and contentious management decisions that such changes are likely to require, neither collaboration nor adaptive management provides a sufficient structure for addressing uncontrollable and unpredictable change. As a result, LCNCA is exploring two specific modifications to CAM that may better address emerging challenges, including: 1) Creating nested resource objectives to distinguish between those objectives which may be crucial from those which may hinder a flexible response to climate change, and 2) Incorporating scenario planning into CAM

  15. Seismic activity and stress tensor inversion at Las Tres Vírgenes Volcanic and Geothermal Field (México)

    NASA Astrophysics Data System (ADS)

    Antayhua-Vera, Yanet; Lermo-Samaniego, Javier; Quintanar-Robles, Luis; Campos-Enríquez, Oscar

    2015-10-01

    We analyze local earthquakes occurring between 2003 and 2012 at the Las Tres Vírgenes Volcanic and Geothermal Field (TVVGF) to establish their temporal and spatial distribution, and relationships with local and regional fault systems, water injection, acid stimulation and steam production tests. We obtained focal mechanisms and inverted data for the stress tensor to understand the local and regional stress fields. We analyzed 423 local earthquakes with magnitudes between 0.1 and 2.9 Mc and hypocentral depths from 0.2 to 7.4 km b.s.l. The cutoff depth at ~ 7.4 km possibly delineates the brittle-ductile transition zone. We identified seven swarms (from 1 to 7). Swarms 1 (December 2009), 2 (May 2010), 3 (June-July 2010) and 7 (December 2012) are strongly correlated with injection processes; whereas swarms 5 (April 2012) and 6 (September 2012) are correlated with local tectonic faults. Stress inversion showed NW-SE, E-W and NE-SW extensional orientations (Shmin), in agreement with the local tectonic stress field; while NE-SW compressional orientations (SHmax) are correlated with the regional tectonic stress field.

  16. Can a Spanish science education journal become international? the case of Enseñanza de las Ciencias

    NASA Astrophysics Data System (ADS)

    Espinet, Mariona; Izquierdo, Mercè; Garcia-Pujol, Clara

    2015-12-01

    In this paper we discuss the case of the science education research journal Enseñanza de las Ciencias (EC) around the issue of its internationalization and the consequences this process has had and is still having on the use and preservation of different languages and more specifically the Castilian (Spanish) language. We first frame the concept of globalization and internationalization, and identify three important dimensions involved in the process of internationalization of EC such as language use, actors involved and resources available. Secondly, we address the historical evolution of EC along three phases of internationalization. In each phase we discuss the tensions experienced in relevant internationalization dimensions focusing particularly on the use of languages. We conclude by advocating a plurilingual and multicultural model for a science education research journal as an alternative to the hegemony of international English written journals. In doing so we want to continue the conversation on the role that local and national science education research journals have in promoting science education around the world.

  17. Pedostratigraphy and pedological and geochemical characterization of Las Carreras loess paleosol sequence, Valle de Tafí, NW-Argentina

    NASA Astrophysics Data System (ADS)

    Schellenberger, Andreas; Veit, Heinz

    2006-04-01

    The Las Carreras loess-paleosol sequence is considered the most complete Quaternary pedostratigraphic record in South America. It consists of 32 paleosols formed during the past 1.15 Ma. Chronological control is provided by magnetostratigraphy. Sediment and paleosol characterization is based on a variety of methods, including soil chemistry, geochemistry, and micromorphology. The main pedogenic processes identified are carbonate leaching and reprecipitation, ped formation, and translocation of clay and organic matter. In many cases, the boundaries between individual paleosols are not clearly defined due to indistinct transitional zones. Based on both pedological and sedimentological characteristics the sequence was subdivided into three units, with paleosols in Units I and III designated as Luvisols and paleosols in Unit II tentatively classified as (Luvic) Kastanozems. This subdivision reflects environmental changes associated with the mid-Pleistocene transition. Overall geochemical variability is low and largely related to pedogenesis. The homogeneity suggests a rather constant provenance that seems to be linked to the Central Andes pursuant to the Chaco Model of Iriondo [1997. Models of deposition of loess and loessoids in the Upper Quaternary of South America. Journal of South American Earth Sciences 10, 71-79], and includes direct volcanic ash falls and local sources in a subordinate manner. In a paleoclimatic context, loess-paleosol alternation is interpreted to reflect climatic cycles that were primarily caused by the variability of the South American Monsoon System.

  18. Application of PALSAR Data to Classify Vegetation in an Anthropogenically Affected Wetland Area in Central Spain (Las Tablas de Daimiel)

    NASA Astrophysics Data System (ADS)

    Schmid, Thomas; Koch, Magaly; Solana, Jesus; Gumuzzio, Jose

    2008-11-01

    Semiarid wetlands are very dynamic ecosystems as the different characteristics (areal extension, water depth and salinity, seasonal flooding, vegetation and fauna) that define them vary greatly in the short and long term. The objective of this work is the incorporation of ALOS PALSAR and AVNIR2 data within ongoing work for a semi-arid wetland area in the National Park of Las Tablas de Daimiel and were ample information (obtained from spaceborne, airborne and field data) already exist. An intergrated methodology is presented where ALOS data is used to characterise wetland components and will be used for monitoring purposes. Preliminary results suggest that the multipolarized SAR data enables a better separation of the vegetation structure and fragmentation than with the optical data. Multispectral data from the AVNIR2 has the advantage of improved spatial resolution. Therefore, a combination of the radar and optical data can be used to assess the wetland degradation status, so that appropriate measures can be designed for a sustainable management of the wetland.

  19. Continuous Hidden Markov Models: Application to automatic earthquake detection and classification at Las Canãdas caldera, Tenerife

    NASA Astrophysics Data System (ADS)

    Beyreuther, Moritz; Carniel, Roberto; Wassermann, Joachim

    2008-10-01

    A possible interaction of (volcano-) tectonic earthquakes with the continuous seismic noise recorded in the volcanic island of Tenerife was recently suggested. Also recently the zone close to Las Canadas caldera shows unusual high number of near (< 25 km), possibly volcano-tectonic, earthquakes indicating signs of reawakening of the volcano putting high pressure on the risk analyst. Certainly for both tasks consistent earthquake catalogues provide valuable information and thus there is a strong demand for automatic detection and classification methodologies generating such catalogues. Therefore we adopt methodologies of speech recognition where statistical models, called Hidden Markov Models (HMMs), are widely used for spotting words in continuous audio data. In this study HMMs are used to detect and classify volcano-tectonic and/or tectonic earthquakes in continuous seismic data. Further the HMM detection and classification is evaluated and discussed for a one month period of continuous seismic data at a single seismic station. Being a stochastic process, HMMs provide the possibility to add a confidence measure to each classification made, basically evaluating how "sure" the algorithm is when classifying a certain earthquake. Moreover, this provides helpful information for the seismological analyst when cataloguing earthquakes. Combined with the confidence measure the HMM detection and classification can provide precise enough earthquake statistics, both for further evidence on the interaction between seismic noise and (volcano-) tectonic earthquakes as well as for incorporation in an automatic early warning system.

  20. Nuevos escenarios de la migración México-Estados Unidos. Las consecuencias de la guerra antiinmigrante

    PubMed Central

    MASSEY, Douglas S.; PREN, Karen A.; DURAND, Jorge

    2010-01-01

    La historia de la migración México-Estados Unidos se caracteriza por una serie de periodos durante los cuales los patrones migratorios se transforman y evolucionan como respuesta a los cambios en la política migratoria de Estados Unidos. En la década de 1990 se dio uno de estos cambios, lo que provocó el paso de la ‘era de la contradicción’ a la ‘era de la marginalización’. Actualmente, un gran número de migrantes indocumentados permanecen al margen de la ley, precisamente en un periodo en el que las penas se han incrementado y la persecución ha alcanzado niveles récord. De manera cada vez más notoria, los migrantes indocumentados, por la represión interna y fronteriza, quedan obligados a romper los lazos que los vinculaban con sus lugares de destino, pero al mismo tiempo se sienten cada vez más extraños en una tierra donde la aplicación de políticas antiinmigrantes es cosa de todos los días, lo que los sitúa en una posición de marginalización y gran vulnerabilidad. PMID:21209790

  1. Using mixture-tuned match filtering to measure changes in subpixel vegetation area in Las Vegas, Nevada

    NASA Astrophysics Data System (ADS)

    Brelsford, Christa; Shepherd, Doug

    2014-01-01

    In desert cities, accurate measurements of vegetation area within residential lots are necessary to understand drivers of change in water consumption. Most residential lots are smaller than an individual 30-m pixel from Landsat satellite images and have a mixture of vegetation and other land covers. Quantifying vegetation change in this environment requires estimating subpixel vegetation area. Mixture-tuned match filtering (MTMF) has been successfully used for subpixel target detection. There have been few successful applications of MTMF to subpixel abundance estimation because the relationship observed between MTMF estimates and ground measurements of abundance is noisy. We use a ground truth dataset over 10 times larger than that available for any previous MTMF application to estimate the bias between ground data and MTMF results. We find that MTMF underestimates the fractional area of vegetation by 5% to 10% and show that averaging over multiple pixels is necessary to reduce noise in the dataset. We conclude that MTMF is a viable technique for fractional area estimation when a large dataset is available for calibration. When this method is applied to estimating vegetation area in Las Vegas, Nevada, spatial and temporal trends are consistent with expectations from known population growth and policy changes.

  2. Environmental and social determinants of youth physical activity intensity levels at neighborhood parks in Las Vegas, NV.

    PubMed

    Coughenour, Courtney; Coker, Lisa; Bungum, Tim J

    2014-12-01

    Parks can play an important role in youth activity. This study used observational data to evaluate the relationship of environmental and social determinants to youth physical activity intensity levels in Las Vegas neighborhood parks. System for observing play and leisure activity in youth was used to code activity levels as sedentary, walking, or vigorous in five low-income and five high-income parks. Environmental determinants included amenities, incivilities, size, high-speed streets, sidewalk condition, and temperature. Social determinants included percent minority and Hispanic, gender, and income. A multinomial logistic regression model was performed. We observed 1,421 youth, 59% male, 41% female; 21% were sedentary, 38% walking, and 41% vigorous. Males were more likely to be observed walking (OR 1.42) and vigorous (OR 2.21) when compared to sedentary. High-speed streets (OR 0.76), sidewalks condition (OR 0.34), and low-income neighborhoods (OR 0.07) was associated with decreased odds of vigorous activity; incivilities (OR 1.34) and amenities (OR 1.27) were associated with greater odds of being vigorous. Environmental and social determinants are associated with physical activity intensity levels at parks. Stakeholders should ensure quality parks, as they relate to physical activity levels in youth. Understanding environmental and social determinants that influence physical activity at parks is critical to utilizing their full potential in an effort to combat childhood obesity.

  3. Characterization and prediction of spatial variability of unsaturated hydraulic properties in a field soil: Las Cruces, New Mexico

    SciTech Connect

    Yeh, T.C.J.; Greenholtz, D.E.; Nash, M.S.; Wierenga, P.J.

    1991-12-31

    A 91-m transect was set up in an irrigated field near Las Cruces, New Mexico to investigate the spatial variability of unsaturated soil properties. A total of 455 sampling points were monitored along a grid consisting of 91 stations placed 1 m apart by 5 depths per station. Post-irrigation soil water tension and water content measurements were recorded over 45 days at 11 time periods. The instantaneous profile was used to estimate the unsaturated hydraulic conductivity at the 455 sampling points. Fifty soil samples were also taken for analyzing sand, silt, and clay content distributions. The spatial and temporal variability of soil water tension and water content were investigated along with the spatial variability of parameters of an unsaturated hydraulic conductivity model. Results of the analysis show that spatial variation in soil water tension and water content is consistent with the soil texture spatial variability. In addition, the spatial distribution of the estimated parameter value of unsaturated hydraulic conductivity reflects the soil texture distribution. Using the statistics of the estimated hydraulic parameter values, a stochastic soil water tension model was employed to reproduce the variability of observed soil water tension. Although many assumptions were made, the results of the simulation appear promising.

  4. Characterization and prediction of spatial variability of unsaturated hydraulic properties in a field soil: Las Cruces, New Mexico

    SciTech Connect

    Yeh, T.C.J.; Greenholtz, D.E. . Dept. of Hydrology and Water Resources); Nash, M.S. . Dept. of Crop and Soil Sciences); Wierenga, P.J. . Dept. of Soil and Water Science)

    1991-01-01

    A 91-m transect was set up in an irrigated field near Las Cruces, New Mexico to investigate the spatial variability of unsaturated soil properties. A total of 455 sampling points were monitored along a grid consisting of 91 stations placed 1 m apart by 5 depths per station. Post-irrigation soil water tension and water content measurements were recorded over 45 days at 11 time periods. The instantaneous profile was used to estimate the unsaturated hydraulic conductivity at the 455 sampling points. Fifty soil samples were also taken for analyzing sand, silt, and clay content distributions. The spatial and temporal variability of soil water tension and water content were investigated along with the spatial variability of parameters of an unsaturated hydraulic conductivity model. Results of the analysis show that spatial variation in soil water tension and water content is consistent with the soil texture spatial variability. In addition, the spatial distribution of the estimated parameter value of unsaturated hydraulic conductivity reflects the soil texture distribution. Using the statistics of the estimated hydraulic parameter values, a stochastic soil water tension model was employed to reproduce the variability of observed soil water tension. Although many assumptions were made, the results of the simulation appear promising.

  5. Geologic and geophysical maps of the Las Vegas 30' x 60' quadrangle, Clark and Nye counties, Nevada, and Inyo County, California

    USGS Publications Warehouse

    Page, William R.; Lundstrom, Scott C.; Harris, Anita G.; Langenheim, V.E.; Workman, Jeremiah B.; Mahan, Shannon; Paces, James B.; Dixon, Gary L.; Rowley, Peter D.; Burchfiel, B.C.; Bell, John W.; Smith, Eugene I.

    2005-01-01

    Las Vegas and Pahrump are two of the fastest growing cities in the US, and the shortage of water looms as among the greatest future problems for these cities. These new maps of the Las Vegas 30 x 60-minute quadrangle provide a geologic and geophysical framework and fundamental earth science database needed to address societal issues such as ground water supply and contamination, surface flood, landslide, and seismic hazards, and soil properties and their changing impact by and on urbanization. The mountain ranges surrounding Las Vegas and Pahrump consist of Mesozoic, Paleozoic and Proterozoic rocks. A majority of these rocks are Paleozoic carbonate rocks that are part of Nevada's carbonate rock aquifer province. The Spring Mountains represent a major recharge site in the province, where maximum altitude is 3,632 m (Charleston Peak) above sea level. Rocks in the Sheep and Las Vegas Ranges and Spring Mountains contain correlative, northeast-striking, southeast-verging thrust faults that are part of the Cretaceous, Sevier orogenic belt. These thrusts were offset during the Miocene by the Las Vegas Valley shear system (LVVSZ). We conducted new mapping in the Blue Diamond area, highlighting refined work on the Bird Spring thrust, newly studied ancient landslides, and gravity-slide blocks. We conducted new mapping in the Las Vegas Range and mapped previously unrecognized structures such as the Valley thrust and fold belt; recognition of these structures has led to a refined correlation of Mesozoic thrust faults across the LVVSZ. New contributions in the quadrangle also include a greatly refined stratigraphy of Paleozoic bedrock units based on conodont biostragraphy. We collected over 200 conodont samples in the quadrangle and established stratigraphic reference sections used to correlate units across the major Mesozoic thrust faults. Quaternary deposits cover about half of the map area and underlie most of the present urbanized area. Deposits consist of large coalescing

  6. Estructura espacial de las órbitas caóticas en un modelo autoconsistente de galaxia elíptica

    NASA Astrophysics Data System (ADS)

    Muzzio, J. C.

    Hemos logrado construir modelos autoconsistentes de sistemas estelares utilizando una aproximación cuadrupolar para el potencial. Esto nos permite determinar órbitas y exponentes de Lyapunov de objetos que tienen posiciones y velocidades equivalentes a las que se obtienen de la funcón de distribución del sistema. La distribución espacial de las órbitas caóticas exhibe considerable estructura y, lo que es más importante aún, los valores de los exponentes de Lyapunov calculados sobre intervalos finitos de tiempo, muestran una fuerte correlación con el comportamiento de la órbita en esos mismos intervalos, por lo que permiten reconocer distintos subsistemas con diferentes distribuciones espaciales.

  7. Toxicity of a Novel Herbomineral Preparation Las01 on Human Cancer Cell Lines and Its Safety Profile in Humans and Animals

    PubMed Central

    Sheikh, Saba; Srivastava, Ashok; Tripathi, Rajesh; Tripathi, Shalini; Trivedi, V. P.; Saxena, R. C.

    2012-01-01

    Polyhedral formulations based on Rasayana therapy described in Charaka Samhita showed remarkable improvement in quality of life of various cancer patients who have been found to be refractory or poor responders to modern chemotherapy and radiation treatment. One of the most recent novel herbomineral preparation, Las01 prepared absolutely as per the instruction given in the ancient Ayurvedic literature has been found to be effective as a potent anticancer drug in the human cell lines, the MCF-7 and Hela cancer cell lines. This novel preparation of Las01 is also found to be devoid of toxicity both in animals as well as in human subjects, which is the main drawback of chemotherapeutic agents used in modern system of medicine. Our results warrant multicentric clinical trials on a large scale which seems to be a future promising drug to cure incurables cancer patients. PMID:22969832

  8. Effect of Y2O3 on the crystallization kinetics of TiO2 nucleated LAS glass for the production of nanocrystalline transparent glass ceramics

    NASA Astrophysics Data System (ADS)

    Shakeri, Mohammad Sadegh

    2013-05-01

    Crystallization kinetics of metastable β-quartz solid solution as a desirable phase for the production of transparent lithium aluminosilicate (LAS) glass ceramics was investigated in the presence of Y2O3. Accordingly, differential thermal analysis scans were performed thoroughly to study the mechanism of crystallization kinetics. The aim of this investigation is to discover the complicated mechanism of crystallization process in the presence of co-additives and accordingly find a way for increasing the transparency of glass ceramics. It is shown that the bulk (3D) growth is intensively increased by the enhancement of Y2O3. Then again, reducing nucleation and increasing growth mechanisms were recognized for the LAS system in the presence of Y2O3. Results of the investigation illustrate that when co-additives are added to glasses, it is necessary to nucleate the optical component separately before the growth process.

  9. Hydrologic, water-quality, and biological assessment of Laguna de las Salinas, Ponce, Puerto Rico, January 2003-September 2004

    USGS Publications Warehouse

    Soler-López, Luis R.; Gómez-Gómez, Fernando; Rodríguez-Martínez, Jesús

    2005-01-01

    The Laguna de Las Salinas is a shallow, 35-hectare, hypersaline lagoon (depth less than 1 meter) in the municipio of Ponce, located on the southern coastal plain of Puerto Rico. Hydrologic, water-quality, and biological data in the lagoon were collected between January 2003 and September 2004 to establish baseline conditions. During the study period, rainfall was about 1,130 millimeters, with much of the rain recorded during three distinct intense events. The lagoon is connected to the sea by a shallow, narrow channel. Subtle tidal changes, combined with low rainfall and high evaporation rates, kept the lagoon at salinities above that of the sea throughout most of the study. Water-quality properties measured on-site (temperature, pH, dissolved oxygen, specific conductance, and Secchi disk transparency) exhibited temporal rather than spatial variations and distribution. Although all physical parameters were in compliance with current regulatory standards for Puerto Rico, hyperthermic and hypoxic conditions were recorded during isolated occasions. Nutrient concentrations were relatively low and in compliance with current regulatory standards (less than 5.0 and 1.0 milligrams per liter for total nitrogen and total phosphorus, respectively). The average total nitrogen concentration was 1.9 milligrams per liter and the average total phosphorus concentration was 0.4 milligram per liter. Total organic carbon concentrations ranged from 12.0 to 19.0 milligrams per liter. Chlorophyll a was the predominant form of photosynthetic pigment in the water. The average chlorophyll a concentration was 13.4 micrograms per liter. Chlorophyll b was detected (detection limits 0.10 microgram per liter) only twice during the study. About 90 percent of the primary productivity in the Laguna de Las Salinas was generated by periphyton such as algal mats and macrophytes such as seagrasses. Of the average net productivity of 13.6 grams of oxygen per cubic meter per day derived from the diel

  10. Conceptuaciones de los estudiantes de las facultades de educacion y ciencias naturales de la Universidad de Puerto Rico, recinto de Rio Piedras, acerca de la ciencia y la pseudociencia

    NASA Astrophysics Data System (ADS)

    Reyes Medina, Hector A.

    Esta investigacion describe las conceptuaciones de los estudiantes de tercer ano o mas a nivel de bachillerato de los programas de Educacion en Ciencia y Ciencias Naturales de la Universidad de Puerto Rico, Recinto de Rio Piedras, acerca de lo establecido en la literatura para distinguir el conocimiento cientifico de las creencias pseudocientificas. Este estudio se guio por un diseno tipo encuesta transversal que permitio conocer de manera consistente las conceptuaciones de los estudiantes encuestados acerca de la Ciencia y la Pseudociencia. Ademas, permitio desarrollar inferencias estadisticas relacionadas a la poblacion de estudio, sus conceptuaciones y su inclinacion teorica en torno al Realismo y al Racionalismo cientifico moderados. El instrumento utilizado fue el Cuestionario acerca de las concepciones de la ciencia y la pseudocienca en estudiantes universitarios, Reyes (2015). Este cuestionario fue validado mediante la recopilacion de diversas fuentes de evidencias, entre estas se encuentran las evidencias basadas en el contenido, el proceso de respuesta, la estructura interna y de constructo. Tambien, se calculo el Alfa de Crombach para la escala total y para cada componente y se realizo un analisis de factores que demostro la presencia de seis componentes claramente definidos de acuerdo a lo esperado sobre las caracteristicas originales del instrumento. Las estadisticas utilizadas fueron descriptivas. Participaron 302 alumnos, de las facultades de educacion y ciencias naturales. Se encontro que las conceptuaciones de los estudiantes de ambas facultades se inclinan en un 66.2% a favor con lo establecido en el modelo teorico en torno al Realismo y al Racionalismo cientifico moderados. Sin embargo, aun hay un 33.8% de los estudiantes de ambas facultades que poseen conceptuaciones distintas al modelo teorico propuesto.

  11. American Recovery and Reinvestment Act (ARRA) FEMP Technical Assistance Federal Aviation Administration Project 209 - Control Tower and Support Building, Las Vegas, NV

    SciTech Connect

    Arends, J.; Sandusky, William F.

    2010-03-31

    This report represents findings of a design review team that evaluated construction documents (at the 70% level) and operating specifications for a new control tower and support building that will be built in Las Vegas, Nevada by the Federal Aviation Administration (FAA). The focus of the review was to identify measures that could be incorporated into the final design and operating specification that would result in additional energy savings for the FAA that would not have otherwise occurred.

  12. The high-grade Las Cruces copper deposit, Spain: a product of secondary enrichment in an evolving basin

    NASA Astrophysics Data System (ADS)

    Tornos, Fernando; Velasco, Francisco; Slack, John F.; Delgado, Antonio; Gomez-Miguelez, Nieves; Escobar, Juan Manuel; Gomez, Carmelo

    2016-04-01

    The Las Cruces deposit (Iberian Pyrite Belt) includes a large, high-grade cementation zone capped by unusual rocks that contain carbonates, galena, iron sulphides, and quartz. Between the Late Cretaceous(?) and Tortonian, the volcanogenic massive sulphides were exhumed and affected by subaerial oxidation that formed paired cementation and gossan zones. Onset of Alpine extension produced accelerated growth of the cementation zone along extensional faults, leading to formation of the high-grade copper ore at ca. 11 Ma. Later, replacement of the overlying gossan by sulphide- and carbonate-rich rocks beneath sealing marl sediments is thought to have involved microbial processes, occurring between the Messinian (ca. 7.2 Ma) and today. Isotope data show that the cementation zone formed by the mixing of descending acidic waters derived from oxidation of the massive sulphides, with upwelling geothermal waters flowing at temperatures above 100 °C. The C, O, and Sr isotope values of the mineralization (87Sr/86Sr 0.7101-0.7104) and of the local groundwater (0.7102-0.7104) reflect equilibration with basement rocks, and indicate that influence on the ore-forming process by marl-equilibrated water (0.7091-0.7093) or Miocene seawater (0.7086-0.7092) was negligible. The high sulphur isotope values of the sulphides in the biogenic zone (most +19 to +24 ‰) are well above those of the primary sulphides (δ34S ca. -6.8 to +10.3 ‰) and likely reflect formation of the biogenic sulphides by reduction of aqueous sulphate in the groundwaters. Sulphur isotope values of the cementation zone (δ34S ca. -2.4 to +21.7 ‰) are also consistent with some contribution of sulphur from the biogenic reduction of aqueous sulphate.

  13. Computer graphics synthesis for inferring artist studio practice: an application to Diego Velázquez's Las Meninas[

    NASA Astrophysics Data System (ADS)

    Stork, David G.; Furuichi, Yasuo

    2009-02-01

    Diego Velázquez's Las meninas (1656) has been called by some art experts "the most important painting of the 17th century," "a theology of painting," and even "the world's greatest painting"; it has been the subject of intensive study. The work depicts a complex scene in the Alcázar palace of King Philip IV of Spain, and includes mirror reflections of the king and queen, apparently standing in place of the viewer, as well as the artist himself standing before an enormous canvas on an easel. Nevertheless, questions remain about the studio and the proper viewing configuration: Is the artist looking toward the perspectivally correct position of the viewer in the museum space (center of projection), outside the picture space? Does the perspectivally correct position correspond to the locations of the king and queen seen reflected in the mirror? Is the bright illumination on the king and queen (as revealed in the mirror) consistent with the lighting in the tableau itself? We addressed these questions in a new way: by building a full computer graphics model of the figures and tableau as well as the viewer's space outside the painting. In our full model, the painting itself is represented as a translucent window onto which the picture space is projected toward the center of projection, that is, the viewer. Our geometric and (new) lighting evidence confirm Janson's and Snyder's contention that the plane mirror on the back wall reflects the other side of the large painting depicted within the tableau, not the king and queen themselves in the studio. We believe our computer graphics synthesis of both the tableau within the painting and the viewer's space in the real world is the first of its kind to address such problems in the history of art.

  14. Palinspastic reconstruction of Lower Mesozoic stratigraphic sequences near the latitude of Las Vegas: Implications for the entire Great Basin

    SciTech Connect

    Marzolf, J.E. . Dept. of Geology)

    1993-04-01

    On the Colorado Plateau, lower Mesozoic stratigraphy is subdivided by regional unconformities into the Lower Triassic Moenkopi, Upper Triassic Chinle, Lower and Middle( ) Jurassic Glen Canyon, and Middle Jurassic lower San Rafael tectonosequences. Palinspastic reconstruction for Cenozoic extensional and mesozoic compressional deformations near the latitude of Las Vegas indicates the Moenkopi tectono-sequence constructed a passive-margin-like architecture of modest width overlapping folded. Thrust-faulted, and intruded Permian strata, with state boundaries fixed relative to the Colorado Plateau, comparison of the location of the Early Triassic shelf-slope break near latitude 36[degree] with the palinspastically restored location of the shelf-slope break in southeastern Idaho implies strata of the Moenkopi tectonosequence in the Mesozoic marine province of northwest NV lay in western utah in the Early Triassic. This reconstruction: suggests that the Galconda and Last Chance faults are part of the same thrust system; aligns late Carnian paleovalleys of the chinle tectonosequence on the Colorado Plateau with a coeval northwest-trending paleovalley cut across the Star Pea, and the Norian Cottonwood paleovalley with the coeval Grass Valley delta; defines a narrow, northward deepening back-arc basin in which the Glen Canyon tectonosequence was deposited; aligns east-facing half grabens along the back side of the arc from the Cowhole Mountains to the Clan Alpine Range; projects the volcan-arc/back-arc transition from northwest Arizona to the east side of the Idaho batholith; and predicts the abrupt facies change from silicic volcanics to marine strata of the lower San Rafael sequence lay in western Utah. The paleogeographic was altered in the late Bathonian to Callovian by back-arc extension north of a line extending from Cedar City, UT to Mina, NV. The palinspastic reconstruction implies the Paleozoic was tectonically stacked at the close of the Paleozoic.

  15. Sr Isotopes and Migration of Prairie Mammoths (Mammuthus columbi) from Laguna de las Cruces, San Luis Potosi, Mexico

    NASA Astrophysics Data System (ADS)

    Solis-Pichardo, G.; Perez-Crespo, V.; Schaaf, P. E.; Arroyo-Cabrales, J.

    2011-12-01

    Asserting mobility of ancient humans is a major issue for anthropologists. For more than 25 years, Sr isotopes have been used as a resourceful tracer tool in this context. A comparison of the 87Sr/86Sr ratios found in tooth enamel and in bone is performed to determine if the human skeletal remains belonged to a local or a migrant. Sr in bone approximately reflects the isotopic composition of the geological region where the person lived before death; whereas the Sr isotopic system in tooth enamel is thought to remain as a closed system and thus conserves the isotope ratio acquired during childhood. Sr isotope ratios are obtained through the geologic substrate and its overlying soil, from where an individual got hold of food and water; these ratios are in turn incorporated into the dentition and skeleton during tissue formation. In previous studies from Teotihuacan, Mexico we have shown that a three-step leaching procedure on tooth enamel samples is important to assure that only the biogenic Sr isotope contribution is analyzed. The same Sr isotopic tools can function concerning ancient animal migration patterns. To determine or to discard the mobility of prairie mammoths (Mammuthus columbi) found at Laguna de las Cruces, San Luis Potosi, México the leaching procedure was applied on six molar samples from several fossil remains. The initial hypothesis was to use 87Sr/86Sr values to verify if the mammoth population was a mixture of individuals from various herds and further by comparing their Sr isotopic composition with that of plants and soils, to confirm their geographic origin. The dissimilar Sr results point to two distinct mammoth groups. The mammoth population from Laguna de Cruces was then not a family unit because it was composed by individuals originated from different localities. Only one individual was identified as local. Others could have walked as much as 100 km to find food and water sources.

  16. Proximal record of the 273 ka Poris caldera-forming eruption, Las Cañadas, Tenerife

    NASA Astrophysics Data System (ADS)

    Smith, Natasha J.; Kokelaar, B. Peter

    2013-11-01

    Lithofacies architecture analysis is applied to the most proximal exposures of the 273 ka Poris Formation, in the Diego Hernandez caldera wall of Las Cañadas. Here, the succession records an opening Plinian phase followed by generation of a pyroclastic density current (PDC) that was partly blocked by near-vent topography. The upper part of the current surmounted the barrier and deposited an ignimbrite veneer. During a hiatus in energetic flow, ash and various ash aggregates were deposited from a hybrid cloud comprising parts of both the Plinian and the co-ignimbrite plumes. Phreatomagmatic explosions then generated currents rich in fine-grained lithics; current waxing with local erosion was followed by pulsing-unsteady waning, recorded in repeated sets of graded tuff. Reversion to magmatic activity was marked by hybrid deposition, as coarse pumice fallout and juvenile ballistics entered pyroclastic currents to form stratified pumice-block tuff. Increasingly energetic flow is recorded in 9 m of mainly massive lapilli tuff that includes evidence of widespread scour and bypass; lithic-rich layers record incremental onset of edifice disruption due to magma withdrawal. Laterally variable stratification and load structures show that the PDC was unsteady and highly non-uniform at times, with locally rapid aggradation of gas-rich ignimbrite. Climactic edifice disruption is marked by a lithic-block layer in erosional contact with the underlying ignimbrite, recording intense pyroclastic current activity and widespread bypass of material to distal volcano slopes. Pumice-block breccia, 10 m thick and with blocks up to 1.2 m in diameter, forms the top of the succession and registers modification of the magmatic plumbing. The timing of collapse to form a major summit depression is uncertain. However, the abrupt termination of the proximal aggradation of coarse breccia, with no record there of any waning-stage pyroclastic currents, suggests subsidence at that time, conceivably

  17. The Las Vegas Thesis

    ERIC Educational Resources Information Center

    Sughrua, William

    2010-01-01

    Following "reflexive ethnography" and utilizing an approach of "performative narrative" and "layered text", this article explores how Bachelor of Arts students in the Teaching of English as a Foreign Language program at a public university in Mexico successfully manage the writing of an inductive-oriented thesis in English by resisting…

  18. Analysis of impacts of urban land use and land cover on air quality in the Las Vegas region using remote sensing information and ground observations

    USGS Publications Warehouse

    Xian, G.

    2007-01-01

    Urban development in the Las Vegas Valley of Nevada (USA) has expanded rapidly over the past 50 years. The air quality in the valley has suffered owing to increases from anthropogenic emissions of carbon monoxide, ozone and criteria pollutants of particular matter. Air quality observations show that pollutant concentrations have apparent heterogeneous characteristics in the urban area. Quantified urban land use and land cover information derived from satellite remote sensing data indicate an apparent local influence of urban development density on air pollutant distributions. Multi-year observational data collected by a network of local air monitoring stations specify that ozone maximums develop in the May and June timeframe, whereas minimum concentrations generally occur from November to February. The fine particulate matter maximum occurs in July. Ozone concentrations are highest on the west and northwest sides of the valley. Night-time ozone reduction contributes to the heterogeneous features of the spatial distribution for average ozone levels in the Las Vegas metropolitan area. Decreased ozone levels associated with increased urban development density suggest that the highest ozone and lowest nitrogen oxides concentrations are associated with medium to low density urban development in Las Vegas.

  19. Perspectivas para mejorar la salud sexual de las minorías sexuales y de identidad de género en Guatemala

    PubMed Central

    Alonzo, Jorge; Mann, Lilli; Simán, Florence; Sun, Christina J.; Andrade, Mario; Villatoro, Guillermo; Rhodes, Scott D.

    2016-01-01

    Resumen Las minorías sexuales y de identidad de género en Guatemala son afectadas de manera desproporcionada por el VIH y otras infecciones transmitidas sexualmente (ITS). Sin embargo, poco se sabe de los factores que contribuyen al riesgo de infección en estas minorías. Investigadores de Estados Unidos y Guatemala quisimos informarnos sobre las necesidades de salud sexual e identificar características de programas de prevención de VIH/ITS para estas minorías. Llevamos a cabo 8 grupos focales con hombres gay, bisexuales y personas transgénero y entrevistas en profundidad con líderes comunitarios. Utilizamos el Método Comparativo Constante para analizar las transcripciones. Identificamos 24 factores que influyen en la salud sexual y 16 características de programas para reducir el riesgo de VIH/ITS en estas poblaciones. La identificación de factores de conductas sexuales de riesgo y de características de programas potencialmente efectivos ofrece gran potencial para desarrollar intervenciones que contribuyan a reducir el riesgo de infección por VIH/ITS en estas minorías en Guatemala. PMID:27494000

  20. New 40Ar/39Ar isotopic dates from Miocene volcanic rocks in the Lake Mead area and southern Las Vegas Range, Nevada

    USGS Publications Warehouse

    Harlan, S.S.; Duebendorfer, E.M.; Deibert, J.E.

    1998-01-01

    New 40Ar/39Ar dates on volcanic rocks interlayered with synextensional Miocene sedimentary rocks in the western Lake Mead area and southern end of the Las Vegas Range provide tight constraints on magmatism, basin formation, and extensional deformation in the Basin and Range province of southern Nevada. Vertical axis rotations associated with movement along the Las Vegas Valley shear zone occurred after 15.67??0.10 Ma (2??), based on a 40Ar/39Ar date from a tuff in the Gass Peak formation in the southern Las Vegas Range. Basaltic magmatism in the western Lake Mead area began as early as 13.28??0.09 Ma, based on a date from a basalt flow in the Lovell Wash Member of the Horse Spring Formation. Isotopic dating of a basalt from the volcanic rocks of Callville Mesa indicates that these rocks are as old as 11.41??0.14 Ma, suggesting that volcanic activity began shortly after formation of the Boulder basin, the extensional basin in which the informally named red sandstone unit was deposited. The red sandstone unit is at least as old as 11.70??0.08 Ma and contains megabreccia deposits younger than 12.93??0.10 Ma. This results shows that formation of the Boulder basin was associated with development of topographic relief that was probably generated by movement along the Saddle Island low-angle normal fault. Stratal tilting associated with extension occurred both prior to and after 11.5 Ma.