Science.gov

Sample records for important item fire

  1. Estimating the Importance of Differential Item Functioning.

    ERIC Educational Resources Information Center

    Rudas, Tamas; Zwick, Rebecca

    1997-01-01

    The mixture index of fit (T. Rudas et al, 1994) is used to estimate the fraction of a population for which differential item functioning (DIF) occurs, and this approach is compared to the Mantel Haenszel test of DIF. The proposed noniterative procedure provides information about data portions contributing to DIF. (SLD)

  2. Fire ant-detecting canines: a complementary method in detecting red imported fire ants.

    PubMed

    Lin, Hui-Min; Chi, Wei-Lien; Lin, Chung-Chi; Tseng, Yu-Ching; Chen, Wang-Ting; Kung, Yu-Ling; Lien, Yi-Yang; Chen, Yang-Yuan

    2011-02-01

    In this investigation, detection dogs are trained and used in identifying red imported fire ants, Solenopsis invicta Buren, and their nests. The methodology could assist in reducing the frequency and scope of chemical treatments for red imported fire ant management and thus reduce labor costs and chemical use as well as improve control and quarantine efficiency. Three dogs previously trained for customs quarantine were retrained to detect the scents of red imported fire ants. After passing tests involving different numbers of live red imported fire ants and three other ant species--Crematogaster rogenhoferi Mayr, Paratrechina longicornis Latreille, and Pheidole megacephala F.--placed in containers, ajoint field survey for red imported fire ant nests by detection dogs and bait traps was conducted to demonstrate their use as a supplement to conventional detection methods. The most significant findings in this report are (1) with 10 or more red imported fire ants in scent containers, the dogs had >98% chance in tracing the red imported fire ant. Upon the introduction of other ant species, the dogs still achieved on average, a 93% correct red imported fire ant indication rate. Moreover, the dogs demonstrated great competence in pinpointing emerging and smaller red imported fire ant nests in red imported fire ant-infested areas that had been previously confirmed by bait trap stations. (2) Along with the bait trap method, we also discovered that approximately 90% of red imported fire ants foraged within a distance of 14 m away from their nests. The results prove detection dogs to be most effective for red imported fire ant control in areas that have been previously treated with pesticides and therefore containing a low density of remaining red imported fire ant nests. Furthermore, as a complement to other red imported fire ant monitoring methods, this strategy will significantly increase the efficacy of red imported fire ant control in cases of individual mount treatment.

  3. 78 FR 70530 - Notice of Determination; New and Revised Treatments for the Imported Fire Ant Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-26

    ... No. APHIS-2012-0064] Notice of Determination; New and Revised Treatments for the Imported Fire Ant... the public that we are adding or revising certain treatment schedules for the Imported Fire Ant... revised treatments in the imported fire ant program. Based on the treatment evaluation document,...

  4. Estimating the Importance of Differential Item Functioning. Program Statistics Research Technical Report No. 95-3.

    ERIC Educational Resources Information Center

    Rudas, Tamas; Zwick, Rebecca

    A method is proposed to assess the importance of differential item functioning (DIF) by estimating the largest possible fraction of the population in which DIF does not occur, or equivalently, the smallest possible portion of the population in which DIF may occur. The approach is based on latent class (C. C. Clogg, 1981) or mixture concepts, and…

  5. Raft Formation by the Red Imported Fire Ant, Solenopsis invicta

    PubMed Central

    Adams, Benjamin J.; Hooper-Bùi, Linda M.; Strecker, Rachel M.; O'Brien, Daniel M.

    2011-01-01

    The raft behavior of the invasive red imported fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae), has been documented for over a century. However, no rigorous tests have been performed elucidating the structure, limits, and important characteristics of this behavior. Rafting makes S. invicta competitive in both native and foreign environments. Further understanding of this behavior will provide critical advancement to the comprehension of this ant's global invasion ecology. Though speculations exist, no one has looked at the movements of individuals within the raft formation, the longevity of rafts, raft success rate, or the importance of different life stages and varying types of adults to raft formation. Furthermore, bubble use has been extensively studied in arthropods, but it has never been documented in social insects. The use of bubbles as a means of floatation has never before been noted in raft formation. This study shows that ants trapped under water escape by lifting themselves to the air-water interface through the use of bubbles collected from submerged substrate. The presence of larvae was noted to increase colony survival and maximize raft longevity due in part their ability to hold bubbles under hydrophobic setae. PMID:22950473

  6. Dynamic thermal structure of imported fire ant mounds.

    PubMed

    Vogt, James T; Wallet, Bradley; Coy, Steven

    2008-01-01

    A study was undertaken to characterize surface temperatures of mounds of imported fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae) and S. richteri Forel, and their hybrid, as it relates to sun position and shape of the mounds, to better understand factors that affect absorption of solar radiation by the nest mound and to test feasibility of using thermal infrared imagery to remotely sense mounds. Mean mound surface temperature peaked shortly after solar noon and exceeded mean surface temperature of the surrounding surface. Temperature range for mounds and their surroundings peaked near solar noon, and the temperature range of the mound surface exceeded that of the surrounding area. The temperature difference between mounds and their surroundings peaked around solar noon and ranged from about 2 to 10 degrees C. Quadratic trends relating temperature measurements to time of day (expressed as percentage of daylight hours from apparent sunrise to apparent sunset) explained 77 to 88% of the variation in the data. Mounds were asymmetrical, with the apex offset on average 81.5 +/- 1.2 mm to the north of the average center. South facing aspects were about 20% larger than north facing aspects. Mound surface aspect and slope affected surface temperature; this affect was greatly influenced by time of day. Thermal infrared imagery was used to illustrate the effect of mound shape on surface temperature. These results indicate that the temperature differences between mounds and their surroundings are sufficient for detection using thermal infrared remote sensing, and predictable temporal changes in surface temperature may be useful for classifying mounds in images.

  7. Development of fire-resistant, low smoke generating, thermally stable end items for aircraft and spacecraft

    NASA Technical Reports Server (NTRS)

    Gagliani, J.

    1978-01-01

    A new approach to the problem of flammability by the use of materials obtained from foamy polyimide resins is developed. The ability of these materials to provide fire protection is demonstrated. The development of processes for producing resilient cell foam for use in aircraft seating, thermal acoustical insulation, floor and wall panels, coated glass fabrics, and molded hardware.

  8. The importance of geoethics in the "Land of Fires"

    NASA Astrophysics Data System (ADS)

    Manzo, Ciro

    2014-05-01

    How was it possible that one of the most fertile soil worldwide called by Romans "Campania Felix", became one of the largest mass poisoning in a Western country? Answer is in the tons of toxic wastes illegally dumped into the fields all around area between Naples and Caserta, which now is known as "Terra dei Fuochi" (The Land of Fires - due to illegal wastes burning). In last 25 years two main emergencies affected Campania, one official started in 1994 due to local waste management system problems, another more hidden and older due to criminal gangs which earn money by illegal disposal of toxic wastes. Those two emergencies are interconnected and have grown in absence of respect for people's health and unknowledge of environmental themes. Apart from judging legal issues, the only evidence visible to public opinion is that during waste emergencies in Campania, decision makers, admitting also their good faith, didn't consider enough environmental risks and decided, in order to solve emergency, to dump wastes in not geological feasible sites, such as landfills at the feet of Vesuvio national park or in abandoned quarries such as Chiaiano tuff pit, exposing local inhabitant and economic activities to high risks. This work wants to underline that geoethics is fundamental as much as the need of geologists participation to whole remediation processes and to raising environmental awareness in the society. Maybe these themes seems to be trivial but geological competences are very important in understanding of pollution risks. This knowledge is practically obscure to decision makers and people, often media provides uncorrected informations which improve the fear of population. In example the idea that whole groundwater in the area is polluted is wrong and is strongly reducing the purchase of agricultural products of the area, and the only way to assess real contamination is site-specific characterization. Indeed Campania plain has a complex stratigraphic architecture with

  9. Positive-strand RNA viruses infecting the Red Imported Fire Ant, Solenopsis invicta

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The black imported fire ant (Solenopsis richteri) and red imported fire ant (S. invicta) are invasive species that were introduced into the United States between 1918 and 1945. Since that time, they have expanded their U.S. range to include some 138 million hectares from Virginia, south to Florida,...

  10. Esterase in imported fire ants, Solenopsis invicata and S. richteri (Hymenoptera: Formicidae): activity, kinetics and variation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Black imported fire ant, Solenopsis richteri, is closely related to the notorious red imported fire ant, Solenopsis invicta. Despite being very similar in biology and behavior, S. invicta is a much more successful invader. In contrast to S. invicta that has invaded numberous countries and regions,...

  11. Arthropod prey of imported fire ants (Hymenopter: formicidae) in Mississippi sweetpotato fields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Imported fire ants, Solenopsis invicta (Buren) are generally considered pests. They have also been viewed as beneficial predators feeding on other insect pests of agricultural and medical importance in various agroecosystems. This study documents the foraging habits of fire ants in sweetpotato. Swee...

  12. Study on the Repellency of Callicarpenal and Intermedeol against Workers of Imported Fire Ants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Repellency of callicarpenal and intermedeol, two terpenoids isolated from American beautyberry and Japanese beautyberry, were tested against workers of red imported fire ants, Solenopsis invicta Buren, black imported fire ants, Solenopsis richteri Forel, and a hybrid of these two species using diggi...

  13. An investigation into effective methodologies for latent fingerprint enhancement on items recovered from fire.

    PubMed

    Gardner, Sarah Jane; Cordingley, Thomas H; Francis, Sean C

    2016-07-01

    A common assumption is that fire destroys fingerprint evidence. Recent studies have sought to challenge this assumption. This study presents a comparative evaluation of soot removal and fingerprint enhancement techniques, following fire(s) to ascertain optimal process efficacy for recovering fingerprints. Two car burns and a cremation oven were used to determine the temperature range. Temperatures of 300, 450 and 600°C were used in simulated, controlled fires wherein cars had prints deposited on rear view mirrors. Burning occurred in a shipping container designed to approximate the variables relating to car arson. Soot removal was undertaken by tape lifting, sodium hydroxide solution, or liquid latex casting. The fingerprint enhancement techniques comprised black magnetic, aluminium and black suspension powders, or cyanoacrylate fuming with BY40 dye. A fingerprint expert classified prints as un/identifiable according to standards to be submitted as evidence in court. Multinomial logistic regression analyses were performed on the data using a p value of <0.05 to determine statistical significance. Temperature was the biggest factor affecting fingerprint recovery. There were no statistically significant differences found between any of the soot removal methods used. Higher counts of identifiable prints were recovered with black magnetic powder and cyanoacrylate/BY40 compared to the other methods used but these findings were not statistically significant. It is recommended that recovery of fire-exposed fingerprints (which are not protected) is undertaken where suspected maximum temperatures are <450°C. Evaluation of optimal soot removal and fingerprint enhancement techniques should be conducted on a case by case basis.

  14. Embedded Materials: Strategic Materials Associated with U.S. Imports of Parts and End-Items

    DTIC Science & Technology

    2015-12-01

    I N S T I T U T E F O R D E F E N S E A N A L Y S E S Embedded Materials: Strategic Materials Associated with U.S. Imports of Parts and End...Government pursuant to the copyright license under the clause at DFARS 252.227-7013 (a)(16) [Jun 2013]. I N S T I T U T E F O R D E F E N S E A N A L...Y S E S IDA Document D-5535 Embedded Materials: Strategic Materials Associated with U.S. Imports of Parts and End-Items Eleanor L. Schwartz James S

  15. Trail pheromone disruption of red imported fire ant.

    PubMed

    Suckling, David M; Stringer, Lloyd D; Bunn, Barry; El-Sayed, Ashraf M; Vander Meer, Robert K

    2010-07-01

    The fire ant, Solenopsis invicta (Hymenoptera: Formicidae), is considered one of the most aggressive and invasive species in the world. Toxic bait systems are used widely for control, but they also affect non-target ant species and cannot be used in sensitive ecosystems such as organic farms and national parks. The fire ant uses recruitment pheromones to organize the retrieval of large food resources back to the colony, with Z,E-alpha-farnesene responsible for the orientation of workers along trails. We prepared Z,E-alpha-farnesene, (91% purity) from extracted E,E-alpha-farnesene and demonstrated disruption of worker trail orientation after presentation of an oversupply of this compound from filter paper point sources (30 microg). Trails were established between queen-right colony cells and food sources in plastic tubs. Trail-following behavior was recorded by overhead webcam, and ants were digitized before and after presentation of the treatment, using two software approaches. The linear regression statistic, r(2) was calculated. Ants initially showed high linear trail integrity (r(2) = 0.75). Within seconds of presentation of the Z,E-alpha-farnesene treatment, the trailing ants showed little or no further evidence of trail following behavior in the vicinity of the pheromone source. These results show that trailing fire ants become disorientated in the presence of large amounts of Z,E-alpha-farnesene. Disrupting fire ant recruitment to resources may have a negative effect on colony size or other effects yet to be determined. This phenomenon was demonstrated recently for the Argentine ant, where trails were disrupted for two weeks by using their formulated trail pheromone, Z-9-hexadecenal. Further research is needed to establish the long term effects and control potential for trail disruption in S. invicta.

  16. Release and establishment of the little decapitating fly Pseudacteon cultellatus on imported fire ants in Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The little decapitating fly Pseudacteon cultellatus from Argentina was released as a self-sustaining biological control agent against the red imported fire ant, Solenopsis invicta, in Florida to parasitize small fire ant workers associated with multiple-queen colonies. This fly appears to be establi...

  17. Development of fire-resistant, low smoke generating, thermally stable end items for aircraft and spacecraft

    NASA Technical Reports Server (NTRS)

    Gagliani, J.; Sorathia, U. A. K.; Wilcoxson, A. L.

    1977-01-01

    Materials were developed to improve aircraft interior materials by modifying existing polymer structures, refining the process parameters, and by the use of mechanical configurations designed to overcome specific deficiencies. The optimization, selection, and fabrication of five fire resistant, low smoke emitting open cell foams are described for five different types of aircraft cabin structures. These include: resilient foams, laminate floor and wall paneling, thermal/acoustical insulation, molded shapes, and coated fabrics. All five have been produced from essentially the same polyimide precursor and have resulted in significant benefits from transfer of technology between the various tasks.

  18. Impact of imidacloprid on new queens of imported fire ants, Solenopsis invicta (Hymenoptera: Formicidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Neonicotinoid insecticides are commonly used in managing pest ants, including the imported fire ant, Solenopsis invicta Buren. There is increasing evidence that neonicotinoid insecticides at sublethal concentrations have profound effects on social insects. However, the sublethal effect of neonicot...

  19. Red imported fire ant impacts on upland arthropods in Southern Mississippi

    USGS Publications Warehouse

    Epperson, D.M.; Allen, C.R.

    2010-01-01

    Red imported fire ants (Solenopsis invicta) have negative impacts on a broad array of invertebrate species. We investigated the impacts of fire ants on the upland arthropod community on 20???40 ha study sites in southern Mississippi. Study sites were sampled from 19972000 before, during, and after fire ant bait treatments to reduce fire ant populations. Fire ant abundance was assessed with bait transects on all sites, and fire ant population indices were estimated on a subset of study sites. Species richness and diversity of other ant species was also assessed from bait transects. Insect biomass and diversity was determined from light trap samples. Following treatments, fire ant abundance and population indices were significantly reduced, and ant species diversity and richness were greater on treated sites. Arthropod biomass, species diversity and species richness estimated from light trap samples were negatively correlated with fire ant abundance, but there were no observable treatment effects. Solenopsis invicta has the potential to negatively impact native arthropod communities resulting in a potential loss of both species and function.

  20. 7 CFR 301.81-11 - Imported fire ant detection, control, exclusion, and enforcement program for nurseries producing...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 5 2012-01-01 2012-01-01 false Imported fire ant detection, control, exclusion, and..., DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Imported Fire Ant Quarantine and Regulations § 301.81-11 Imported fire ant detection, control, exclusion, and enforcement program for nurseries...

  1. 7 CFR 301.81-11 - Imported fire ant detection, control, exclusion, and enforcement program for nurseries producing...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 5 2011-01-01 2011-01-01 false Imported fire ant detection, control, exclusion, and..., DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Imported Fire Ant Quarantine and Regulations § 301.81-11 Imported fire ant detection, control, exclusion, and enforcement program for nurseries...

  2. 7 CFR 301.81-11 - Imported fire ant detection, control, exclusion, and enforcement program for nurseries producing...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 5 2013-01-01 2013-01-01 false Imported fire ant detection, control, exclusion, and..., DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Imported Fire Ant Quarantine and Regulations § 301.81-11 Imported fire ant detection, control, exclusion, and enforcement program for nurseries...

  3. 7 CFR 301.81-11 - Imported fire ant detection, control, exclusion, and enforcement program for nurseries producing...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 5 2014-01-01 2014-01-01 false Imported fire ant detection, control, exclusion, and..., DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Imported Fire Ant Quarantine and Regulations § 301.81-11 Imported fire ant detection, control, exclusion, and enforcement program for nurseries...

  4. Ant-seed mutualisms: Can red imported fire ants sour the relationship?

    USGS Publications Warehouse

    Zettler, J.A.; Spira, T.P.; Allen, C.R.

    2001-01-01

    Invasion by the red imported fire ant, Solenopsis invicta, has had negative impacts on individual animal and plant species, but little is known about how S. invicta affects complex mutualistic relationships. In some eastern forests of North America, 30% of herbaceous species have ant-dispersed seeds. We conducted experiments to determine if fire ants are attracted to seeds of these plant species and assessed the amount of scarification or damage that results from handling by fire ants. Fire ants removed nearly 100% of seeds of the ant-dispersed plants Trillium undulatum, T. discolor, T. catesbaei, Viola rotundifolia, and Sanguinaria canadensis. In recovered seeds fed to ant colonies, fire ants scarified 80% of S. canadensis seeds and destroyed 86% of V. rotundifolia seeds. Our study is the first to document that red imported fire ants are attracted to and remove seeds of species adapted for ant dispersal. Moreover, fire ants might damage these seeds and discard them in sites unfavorable for germination and seedling establishment. ?? 2001 Elsevier Science Ltd. All rights reserved.

  5. 78 FR 29392 - Embedded Digital Devices in Safety-Related Systems, Systems Important to Safety, and Items Relied...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-20

    ... COMMISSION Embedded Digital Devices in Safety-Related Systems, Systems Important to Safety, and Items Relied... Regulatory Issue Summary (RIS) 2013-XX, ``Embedded Digital Devices in Safety-Related Systems, Systems... basic components with embedded digital devices. DATES: Submit comments by July 19, 2013....

  6. Fire!

    ERIC Educational Resources Information Center

    Jones, Rebecca

    1996-01-01

    The number of school fires is up nationwide. This article describes unsafe school conditions, problems with new fire codes, and the factors that contribute to school fires. Installation of sprinkler systems is recommended. A fire-safety checklist is included. (LMI)

  7. Antimicrobial properties of nest volatiles in red imported fire ants, Solenopsis invicta (Hymenoptera: Formicidae).

    PubMed

    Wang, Lei; Elliott, Brad; Jin, Xixuan; Zeng, Ling; Chen, Jian

    2015-12-01

    The antimicrobial property of volatiles produced by red imported fire ants, Solenopsis invicta, against Beauveria bassiana, a common entomopathogenic fungus, was demonstrated. The germination rate of B. bassiana spores was significantly reduced after they were exposed to volatiles within an artificial ant nest. Since the air that contained the same level of O2 and CO2 as that in artificial fire ant nests did not suppress the germination rate of B. bassiana, the observed reduction of germination rate must be caused by the toxicity of nest volatiles. Nest fumigation may be an important component of the social immune system in S. invicta.

  8. Antimicrobial properties of nest volatiles in red imported fire ants, Solenopsis invicta (hymenoptera: formicidae)

    NASA Astrophysics Data System (ADS)

    Wang, Lei; Elliott, Brad; Jin, Xixuan; Zeng, Ling; Chen, Jian

    2015-12-01

    The antimicrobial property of volatiles produced by red imported fire ants, Solenopsis invicta, against Beauveria bassiana, a common entomopathogenic fungus, was demonstrated. The germination rate of B. bassiana spores was significantly reduced after they were exposed to volatiles within an artificial ant nest. Since the air that contained the same level of O2 and CO2 as that in artificial fire ant nests did not suppress the germination rate of B. bassiana, the observed reduction of germination rate must be caused by the toxicity of nest volatiles. Nest fumigation may be an important component of the social immune system in S. invicta.

  9. Tyramides in male alates of black imported fire ants, Solenopsis richetri

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tyramides were recently reported to exist in males of many ant species in the subfamily Myrmicinae. N-(4-hydroxyphenethyl)ethanamide and N-(4-hydroxyphenethyl)hexanamide were found in S. invicta . Transfer of tyramides from male to newly mated queen was demonstrated in the red imported fire ants. ...

  10. Seasonal Shifts in the Hyperspectral Characterization of Imported Fire Ant (Hymenoptera: Formicidae) Mound Features in Turfgrass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Safe, expedient, and cost-effective field- to landscape-scale treatments of imported fire ant (IFA) infestations require technological developments that exploit the use of remotely-sensed contrasting features to detect cryptic mounds in heavily-managed turfgrass. Ground-based implementation of hyper...

  11. SEASONAL SHIFTS IN THE HYPERSPECTRAL CHARACTERIZATION OF IMPORTED FIRE ANT (HYMENOPTERA: FORMICIDAE) MOUND FEATURES IN TURFGRASS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Safe, expedient, and cost-effective field- to landscape-scale treatments of imported fire ant (IFA) infestations require technological developments that exploit the use of remotely-sensed contrasting features to detect cryptic mounds in heavily-managed turfgrass. Ground-based implementation of hyper...

  12. Piperideine Alkaloids from the Poison Gland of the Red Imported Fire Ant (Hymenoptera: Formicidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It is well known that the major chemical components in the venom of the red imported fire ants, Solenopsis invicta Buren, are 2-methyl-6-alkyl or alkenyl piperidines. After isolating the extracts of poison glands and whole worker bodies with a column chromatography, we have obtained fractions conta...

  13. Toxicity of formic acid against red imported fire ants, Solenopsis invicta Buren

    Technology Transfer Automated Retrieval System (TEKTRAN)

    BACKGROUND: Formic acid is a common defensive chemical of formicine ants. Ants often compete with other ants for resources. However, the toxicity of formic acid to any ant species has not been well understood. This study examined the toxicity of formic acid against the red imported fire ants, Sole...

  14. Invasion Biology on Your Campus: Investigating the Red Imported Fire Ant in the Southeastern United States.

    ERIC Educational Resources Information Center

    Forys, Elizabeth A.; Kelly, William B.; Ward, David T.

    2003-01-01

    Describes a laboratory activity on invasion biology to improve students' cognitive skills as well as manual skills. Requires students to develop hypotheses in which a common invasive species will succeed. Focuses on the red imported fire ant in the Southeastern United States, which is a non-native invasive species. (Contains 17 references.) (YDS)

  15. Contact toxicities of Anuran Skin Alkaloids against the Red Imported Fire Ant (Solenopsis invicta)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nearly 500 alkaloids, representing over 20 structural classes, have been identified from the skin of poison frogs (Dendrobatidae). These cutaneous compounds, which are derived from leaf-litter arthropods eaten by the frogs, generally are believed to deter predators. We tested the red imported fire a...

  16. Sampling High-Altitude and Stratified Mating Flights of Red Imported Fire Ant

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With the exception of an airplane equipped with nets, no method has been developed that successfully samples red imported fire ant, Solenopsis invicta Buren, sexuals in mating/dispersal flights throughout their potential altitudinal trajectories. We developed and tested a method for sampling queens ...

  17. IMPORTED FIRE ANT (HYMENOPTERA: FORMICIDAE) MOUND SHAPE CHARACTERISTICS ALONG A NORTH-SOUTH GRADIENT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Imported fire ant mound shape characteristics (south facing slope angle and area, mound height, and basal elongation in the plane of the ground) were quantified in 2005 and 2006 at a number of locations from about 30° 25’ N (Long Beach, Mississippi, USA) to 35° 3’ N (Fayetteville, Tennessee, USA). ...

  18. FIRE

    Atmospheric Science Data Center

    2017-03-16

    Projects:  FIRE Definition/Description:  The F irst I SCCP R egional E xperiments (FIRE) have been designed to improve data products and cloud/radiation ... circulation models (GCMs). Specifically, the goals of FIRE are (1) to improve basic understanding of the interaction of physical ...

  19. Red imported fire ant impacts on wildlife: A decade of research

    USGS Publications Warehouse

    Allen, C.R.; Epperson, D.M.; Garmestani, A.S.

    2004-01-01

    The negative impacts of biological invasion are economically and ecologically significant and, while incompletely quantified, they are clearly substantial. Ants (family Formicidae) are an important, although often overlooked, component of many terrestrial ecosystems. Six species of ants are especially striking in their global ability to invade, and their impacts. This paper focuses on the impacts of the most destructive of those species, the red imported fire ant (Solenopsis invicta), and focuses on impacts on native vertebrates. Red imported fire ants often become the dominant ant species in infested areas outside of their native range due to their aggressive foraging behavior, high reproductive capability and lack of predators and/or other strong competitors. The evidence suggests that mammals, birds and herpetofauna are vulnerable to negative impacts from fire ants, and some species are more likely to experience negative population-level impacts than other species. Assessing the ecological impacts of fire ants on wild animal populations is logistically difficult, and very few studies have combined replicated experimental manipulation with adequate spatial (>10 ha) and temporal (>1 y) scale. Thus, most studies have been observational, opportunistic, small-scale or 'natural' experiments. However, significant research, including an increase in experimental and mechanistic investigations, has occurred during the past decade, and this has led to information that can lead to better management of potentially affected species.

  20. Are Springs Important in the Post-fire Revegetation of Semiarid, Snow-dominated, Mountainous Watersheds?

    NASA Astrophysics Data System (ADS)

    Tsinnajinnie, L.; Frisbee, M. D.; Wilson, J. L.

    2015-12-01

    Semiarid, mountainous watersheds are particularly susceptible to wildfires due to their dense forests and dry conditions. These watersheds are critically important sources of water and habitat for human and ecological communities in an otherwise water-scarce environment. Forest fires severely impact these watersheds through loss of vegetation, increases in erosion, decreases in water quality, and decreases in recharge. In addition, soil hydrophobicity, overland runoff, and erosion in post-fire watersheds create conditions where it is difficult for burned areas to re-vegetate within the months following a wildfire. What role do perennial springs play in post-fire re-vegetation? We hypothesize that revegetation originates around perennial springs since the springs and spring-runs are continual sources of water where new seeds can sprout and where burned vegetation can recover. We test this hypothesis in a snow-dominated, semiarid, mountainous watershed in the Chuska Mountains, located on the Navajo Nation in New Mexico and Arizona, following a wildfire that occurred in June 2014. NDVI was estimated in the watershed before and after the June 2014 fire using remotely sensed data. Photographs from digital trail cameras were used to capture the growth of vegetation/absence of growth on burned slopes with/without springs following the fire. The remote sensing data and trail camera photos indicate that revegetation is concentrated around springs. Springs act as "fountains" for regrowth of vegetation in the watershed following wildfires since they are dependable sources of clean water in a post-fire landscape commonly characterized by decreased infiltration and decreased water quality. An improved understanding of the role of springs in post-wildfire revegetation may enhance and prioritize watershed restoration and protection practices following a wildfire.

  1. Indirect effects of red imported fire ants on Attwater's prairie‐chicken brood survival

    PubMed Central

    Chester, Rebecca E.; Lehnen, Sarah E.; Drees, Bastiaan M.; Toepfer, John E.

    2015-01-01

    ABSTRACT The invasive red imported fire ant (Solenopsis invicta) has negatively affected a host of taxonomic groups throughout its acquired North American range. Many studies have hypothesized indirect trophic impacts, but few documented those impacts. We evaluated invertebrate abundance as a factor limiting juvenile survival of the endangered Attwater's prairie‐chicken (Tympanuchus cupido attwateri), and whether fire ants reduce invertebrate numbers and biomass. From 2009–2013, we monitored survival of Attwater's prairie‐chicken broods (n = 63) with radio telemetry during the first 2 weeks post‐hatch and collected daily invertebrate samples at brood sites. Broods located in areas with the highest median invertebrate count (338 invertebrates/25 sweeps) had a survival probability of 0.83 at 2 weeks post‐hatch compared to 0.07 for broods located in areas with the lowest median invertebrate count (18 invertebrates/25 sweeps). During 2011–2012, we evaluated the reduction of fire ants on invertebrate numbers and biomass by aerially treating areas with Extinguish Plus™ in an impact‐reference study design. Treated fields had 27% more individual invertebrates and 26% higher invertebrate biomass than reference fields. Our results clearly document that invertebrate abundance affects Attwater's prairie‐chicken brood survival and that fire ants may indirectly contribute to low brood survival by suppressing invertebrate abundance. We posit that within the fire ant's acquired North American range, fire ants are likely contributing to declines of other insectivorous species. Published 2015. This article is a U.S. Government work and is in the public domain in the USA. PMID:26900176

  2. Key factors controlling microbial community response after a fire: importance of severity and recurrence

    NASA Astrophysics Data System (ADS)

    Lombao, Alba; Barreiro, Ana; Martín, Ángela; Díaz-Raviña, Montserrat

    2015-04-01

    Microorganisms play an important role in forest ecosystems, especially after fire when vegetation is destroyed and soil is bared. Fire severity and recurrence might be one of main factors controlling the microbial response after a wildfire but information about this topic is scarce. The aim of this study is to evaluate the influence of fire regimen (recurrence and severity) on soil microbial community structure by means of the analysis of phospholipid fatty acid (PLFA). The study was performed with unburned and burned samples collected from the top layer of a soil affected by a high severity fire (Laza, NW Spain) heated under laboratory conditions at different temperatures (50°C, 75°C, 100°C, 125°C, 150°C, 175°C, 200°C, 300°C) to simulate different fire intensities; the process was repeated after further soil recovery (1 month incubation) to simulate fire recurrence. The soil temperature was measured with thermocouples and used to calculate the degree-hours as estimation of the amount of heat supplied to the samples (fire severity). The PLFA analysis was used to estimate total biomass and the biomass of specific groups (bacteria, fungi, gram-positive bacteria and gram-negative bacteria) as well as microbial community structure (PLFA pattern) and PLFA data were analyzed by means of principal component analysis (PCA) in order to identify main factors determining microbial community structure. The results of PCA, performed with the whole PLFA data set, showed that first component explained 35% of variation and clearly allow us to differentiate unburned samples from the corresponding burned samples, while the second component, explaining 16% of variation, separated samples according the heating temperature. A marked impact of fire regimen on soil microorganisms was detected; the microbial community response varied depending on previous history of soil heating and the magnitude of changes in the PLFA pattern was related to the amount of heat supplied to the

  3. Integrated pest management concepts for red imported fire ants Solenopsis invicta (Hymenoptera: Formicidae).

    PubMed

    Drees, Bastiaan M; Calixto, Alejandro A; Nester, Paul R

    2013-08-01

    Management of imported fire ant species has evolved since their accidental introduction into the United States and currently uses integrated pest management concepts to design, implement, and evaluate suppression programs. Although eradication is the management goal in certain isolated infestation sites, localized goals vary dramatically in larger infestations where reinvasion of treated areas is likely. These goals are influenced by regulatory policies, medical liabilities, ecological impact, and/or economic considerations. Tactics employed in fire ant management programs presented here include cultural and biological control options along with judicious use of site-specific insecticide products. In addition, program design considerations that include management goal(s), action level(s), ant form (monogyne or polygyne), presence of nontarget ant species, size of treatment area, seasonality, implementation cost, and environmental impact are also presented. Optimally, elegant IPM programs are target specific, threshold driven, environmentally friendly and cost-effective.

  4. The Importance of the Item Format with Respect to Gender Differences in Test Performance: A Study of Open-Format Items in the DTM Test.

    ERIC Educational Resources Information Center

    Wester, Anita

    1995-01-01

    The effect of different item formats (multiple choice and open) on gender differences in test performance was studied for the Swedish Diagrams, Tables, and Maps (DTM) test with 90 secondary school students. The change to open format resulted in no reduction in gender differences on the DTM. (SLD)

  5. Intercontinental differences in resource use reveal the importance of mutualisms in fire ant invasions

    PubMed Central

    Wilder, Shawn M.; Holway, David A.; Suarez, Andrew V.; LeBrun, Edward G.; Eubanks, Micky D.

    2011-01-01

    Mutualisms play key roles in the functioning of ecosystems. However, reciprocally beneficial interactions that involve introduced species also can enhance invasion success and in doing so compromise ecosystem integrity. For example, the growth and competitive ability of introduced plant species can increase when fungal or microbial associates provide limiting nutrients. Mutualisms also may aid animal invasions, but how such systems may promote invasion success has received relatively little attention. Here we examine how access to food-for-protection mutualisms involving the red imported fire ant (Solenopsis invicta) aids the success of this prominent invader. Intense interspecific competition in its native Argentina constrained the ability of S. invicta to benefit from honeydew-producing Hemiptera (and other accessible sources of carbohydrates), whereas S. invicta dominated these resources in its introduced range in the United States. Consistent with this strong pattern, nitrogen isotopic data revealed that fire ants from populations in the United States occupy a lower trophic position than fire ants from Argentina. Laboratory and field experiments demonstrated that honeydew elevated colony growth, a crucial determinant of competitive performance, even when insect prey were not limiting. Carbohydrates, obtained largely through mutualistic partnerships with other organisms, thus represent critical resources that may aid the success of this widespread invasive species. These results illustrate the potential for mutualistic interactions to play a fundamental role in the establishment and spread of animal invasions. PMID:22143788

  6. The Importance of Item Wording: The Distinction Between Measuring High Standards versus Measuring Perfectionism and Why It Matters

    ERIC Educational Resources Information Center

    Blasberg, Jonathan S.; Hewitt, Paul L.; Flett, Gordon L.; Sherry, Simon B.; Chen, Chang

    2016-01-01

    In the current research, we illustrate the impact that item wording has on the content of personality scales and how differences in item wording influence empirical results. We present evidence indicating that items in certain scales used to measure "adaptive" perfectionism fail to capture the disabling all-or-nothing approach that is…

  7. Parasitoids and competitors influence colony-level responses in the red imported fire ant, Solenopsis invicta

    NASA Astrophysics Data System (ADS)

    Mehdiabadi, Natasha J.; Kawazoe, Elizabeth A.; Gilbert, Lawrence E.

    2004-11-01

    Social insect colonies respond to challenges set by a variable environment by reallocating work among colony members. In many social insects, such colony-level task allocation strategies are achieved through individual decisions that produce a self-organized adapting group. We investigated colony responses to parasitoids and native ant competitors in the red imported fire ant (Solenopsis invicta). Parasitoid flies affected fire ants by decreasing the proportion of workers engaged in foraging. Competitors also altered colony-level behaviours by reducing the proportion of foraging ants and by increasing the proportion of roaming majors, whose role is colony defence. Interestingly, the presence of both parasitism and competition almost always had similar effects on task allocation in comparison to each of the biotic factors on its own. Thus, our study uniquely demonstrates that the interactive effect of both parasitism and competition is not necessarily additive, implying that these biotic factors alter colony behaviour in distinct ways. More generally, our work demonstrates the importance of studying the dynamics of species interactions in a broader context.

  8. Impact of red imported fire ant infestation on northern bobwhite quail abundance trends in southeastern United States

    USGS Publications Warehouse

    Allen, C.R.; Willey, R.D.; Myers, P.E.; Horton, P.M.; Buffa, J.

    2000-01-01

    Northern bobwhite quail (Colinus virginianus L.) populations are declining throughout their range. One factor contributing to the decline in the southeastern United States may be the red imported fire ant (Solenopsis invicta Buren). Recent research in Texas has documented that red imported fire ants can have a significant impact on northern bobwhite quail. That research was conducted in areas where fire ants are predominately polygynous (multiple queen). Polygynous infestations have much higher mound densities than the monogynous (single queen) form. In most of the southeastern United States, fire ants are predominately monogynous. We determined if there was a relationship between the invasion of monogynous red imported fire ants and abundance trends in northern bobwhite quail in the southeastern United States. For Florida, Georgia, and South Carolina we compared average northern bobwhite quail abundance based on Christmas Bird Count data for each county before and after fire ant invasion, and conducted regression analyses on bobwhite quail abundance and year preinvasion, and abundance and year postinvasion. Regionally, northern bobwhite quail were more abundant before (0.067 ??0.018 bobwhite quail per observer hour) than after fire ants invaded (0.019 ?? 0.006; Z = -3.746, df = 18, P 30-yr variation in invasion dates.

  9. Impact of imidacloprid on new queens of imported fire ants, Solenopsis invicta (Hymenoptera: Formicidae)

    PubMed Central

    Wang, Lei; Zeng, Ling; Chen, Jian

    2015-01-01

    Neonicotinoid insecticides are commonly used in managing pest insects, including the imported fire ant, Solenopsis invicta Buren. There is increasing evidence that neonicotinoid insecticides at sublethal concentrations have profound effects on social insects. However, the sublethal effect of neonicotinoids on S. invicta has never been investigated. In this study, the newly mated queens were fed with water containing 0.01 or 0.25 μg/ml imidacloprid. Imidacloprid at both concentrations did not cause any increase in queen mortality during the founding stage; however, it significantly reduced queens’ brood tending ability. In the 0.25 μg/ml imidacloprid treatment, the time to larval emergence was significantly delayed and no pupae or adult workers were produced. This study provides clear evidence that imidacloprid at sublethal concentrations has a significant detrimental impact on S. invicta queens and the development of incipient colonies. PMID:26643971

  10. Ecological dominance of the red imported fire ant, Solenopsis invicta, in its native range.

    PubMed

    Calcaterra, Luis A; Livore, Juan P; Delgado, Alicia; Briano, Juan A

    2008-05-01

    Despite the widespread impacts invasive species can have in introduced populations, little is known about competitive mechanisms and dominance hierarchies between invaders and similar taxa in their native range. This study examines interactions between the red imported fire ant, Solenopsis invicta, and other above-ground foraging ants in two habitats in northeastern Argentina. A combination of pitfall traps and baits was used to characterize the ant communities, their dominance relationships, and to evaluate the effect of phorid flies on the interactions. Twenty-eight ant species coexisted with S. invicta in a gallery forest gap, whereas only ten coexisted with S. invicta in a xerophytic forest grassland. S. invicta was the most numerically dominant species in the richest and complex habitat (gallery forest); however it performed better as discoverer and dominator in the simpler habitat. S. invicta was active during day and night. In spite of its poor capacity to discover resources, S. invicta showed the highest ecological dominance and the second-best behavioral dominance after Camponotus blandus. S. invicta won 78% of the interactions with other ants, mostly against its most frequent competitor, Pheidole cf. obscurithorax, dominating baits via mass recruitment and chemical aggression. P. cf. obscurithorax was the best food discoverer. S. invicta won 80% of the scarce interactions with Linepithema humile. Crematogaster quadriformis was one of the fastest foragers and the only ant that won an equal number of contests against S. invicta. The low presence of phorid flies affected the foraging rate of S. invicta, but not the outcome of interspecific interactions. This study revealed that the red imported fire ant ecologically dominated other terrestrial ants in its native range; however, other species were able to be numerically dominant or co-dominant in its presence.

  11. Toxicity and repellency of compounds from clove (Syzygium aromaticum) to red imported fire ants Solenopsis invicta (Hymenoptera: Formicidae).

    PubMed

    Kafle, Lekhnath; Shih, Cheng Jen

    2013-02-01

    The toxicity and repellency of the bioactive chemicals of clove (Syzygium aromaticum) powder, eugenol, eugenol acetate, and beta-caryophyllene were evaluated against workers of the red imported fire ant, Solenopsis invicta Buren. Clove powder applied at 3 and 12 mg/cm2 provided 100% ant mortality within 6 h, and repelled 99% within 3 h. Eugenol was the fastest acting compound against red imported fire ant compared with eugenol acetate, beta-caryophyllene, and clove oil. The LT50 values inclined exponentially with the increase in the application rate of the chemical compounds tested. However, repellency did not increase with the increase in the application rate of the chemical compounds tested, but did with the increase in exposure time. Eugenol, eugenol acetate, as well as beta-caryophyllene and clove oil may provide another tool for red imported fire ant integrated pest management, particularly in situations where conventional insecticides are inappropriate.

  12. Dose response of red imported fire ant colonies treated with Solenopsis invicta virus 3

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Baiting tests were conducted to evaluate the effect of increasing Solenopsis invicta virus 3 (SINV-3) doses on fire ant colonies. Actively growing, early stage, fire ant (Solenopsis invicta) laboratory colonies were pulse-exposed to six concentrations of SINV-3 in a 10% sucrose bait and monitored r...

  13. The importance of mammalian torpor for survival in a post-fire landscape.

    PubMed

    Stawski, Clare; Körtner, Gerhard; Nowack, Julia; Geiser, Fritz

    2015-06-01

    Wildfires have increased in frequency and intensity worldwide with climate change as a main driving factor. While a number of studies have focused on population changes in regard to fires, there are essentially no quantitative data on behavioural and physiological adjustments that are vital for the persistence of individuals during and after fires. Here we show that brown antechinus, a small insectivorous marsupial mammal, (i) endured a prescribed fire in situ, (ii) remained in their scorched home range despite unburned areas nearby, and (iii) substantially increased post-fire torpor use and thus reduced foraging requirements and exposure to predators. Hence, torpor is a physiological adaptation that, although not quantified in this context previously, appears to play a key role in post-fire survival for this and other heterothermic species.

  14. Sampling high-altitude and stratified mating flights of red imported fire ant.

    PubMed

    Fritz, Gary N; Fritz, Ann H; Vander Meer, Robert K

    2011-05-01

    With the exception of an airplane equipped with nets, no method has been developed that successfully samples red imported fire ant, Solenopsis invicta Buren, sexuals in mating/dispersal flights throughout their potential altitudinal trajectories. We developed and tested a method for sampling queens and males during mating flights at altitudinal intervals reaching as high as "140 m. Our trapping system uses an electric winch and a 1.2-m spindle bolted to a swiveling platform. The winch dispenses up to 183 m of Kevlar-core, nylon rope and the spindle stores 10 panels (0.9 by 4.6 m each) of nylon tulle impregnated with Tangle-Trap. The panels can be attached to the rope at various intervals and hoisted into the air by using a 3-m-diameter, helium-filled balloon. Raising or lowering all 10 panels takes approximately 15-20 min. This trap also should be useful for altitudinal sampling of other insects of medical importance.

  15. Toxicity and sublethal effects of sulfoxaflor on the red imported fire ant, Solenopsis invicta.

    PubMed

    Pan, Fengxiang; Lu, Yongyue; Wang, Lei

    2017-05-01

    To understand whether sulfoxaflor, a novel neonicotinoid, poses unacceptable risks to the environment, it is important to assess its effects on nontarget insects. Therefore, the effects of short-term exposure (28 days) of free-feeding sublethal concentrations (1-2μg/ml) of sulfoxaflor to the red imported fire ant, Solenopsis invicta, were investigated. The following parameters were evaluated to determine the impact of exposure: colony growth, food consumption (sugar water and locusts), and interspecific interactions. Sulfoxaflor exposure produced significant negative effects on S. invicta colony growth, with cumulative colony weight losses of 83.36% and 100.00% after treatment with 1μg/ml and 2μg/ml, respectively. The consumption of sugar water (containing sulfoxaflor) of surviving colonies decreased with increasing sulfoxaflor concentration. Moreover, the consumption of locusts decreased after treatment with 2μg/ml, but not 1μg/ml, sulfoxaflor. Sulfoxaflor treatment for 14 days led to reduced aggressiveness of S. invicta workers in interspecific confrontations (S. invicta vs. unexposed Pheidole fervida), and their probability of survival of aggressive encounters was reduced significantly to 48% of that of control ants. Our results indicate that sublethal concentrations of sulfoxaflor are likely to have a negative impact on ants.

  16. Relative effects of disturbance on red imported fire ants and native ant species in a longleaf pine ecosystem.

    PubMed

    Stuble, Katharine L; Kirkman, L Katherine; Carroll, C Ronald; Sanders, Nathan J

    2011-06-01

    The degree to which changes in community composition mediate the probability of colonization and spread of non-native species is not well understood, especially in animal communities. High species richness may hinder the establishment of non-native species. Distinguishing between this scenario and cases in which non-native species become established in intact (lacking extensive anthropogenic soil disturbance) communities and subsequently diminish the abundance and richness of native species is challenging on the basis of observation alone. The red imported fire ant (Solenopsis invicta), an invasive species that occurs throughout much of the southeastern United States, is such an example. Rather than competitively displacing native species, fire ants may become established only in disturbed areas in which native species richness and abundance are already reduced. We used insecticide to reduce the abundance of native ants and fire ants in four experimental plots. We then observed the reassembly and reestablishment of the ants in these plots for 1 year after treatment. The abundance of fire ants in treated plots did not differ from abundance in control plots 1 year after treatment. Likewise, the abundance of native ants increased to levels comparable to those in control plots after 1 year. Our findings suggest that factors other than large reductions in ant abundance and species density (number of species per unit area) may affect the establishment of fire ants and that the response of native ants and fire ants to disturbance can be comparable.

  17. Action Items

    ERIC Educational Resources Information Center

    Baker, Mark; Keane, Brian

    2009-01-01

    Maximizing school resources and managing a shrinking budget--these are two important items affected when a building's roofing system does not perform properly. Rather than acting in haste, school and university administrators should do what every teacher tells a student prior to answering any question: think through the research and studies to…

  18. Activity of bifenthrin, chlorfenapyr, fipronil, and thiamethoxam against red imported fire ants (Hymenoptera: Formicidae).

    PubMed

    Wiltz, B A; Suiter, D R; Gardner, W A

    2010-06-01

    Bifenthrin, chlorfenapyr, fipronil, and thiamethoxam were evaluated for activity against the red imported fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae). Mobility impairment and lethal times were determined after topical treatments. Both immobilization and mortality occurred most quickly with bifenthrin, followed by thiamethoxam, chlorfenapyr, and fipronil. Mortality due to horizontal exposure was evaluated at 10, 20, or 30 degrees C, with three ratios of topically treated donor ant corpses to live recipients (5, 10, or 20% donors). Bifenthrin had the greatest horizontal activity of the chemicals tested. For chlorfenapyr, the only treatments having higher mortality than controls were the highest percentage donors at either 10 or 30 degrees C. Horizontal activity of fipronil was temperature dependent only with the highest proportion of donors and was lower than that ofbifenthrin but higher than that of chlorfenapyr or thiamethoxam. Mean mortality due to thiamethoxam was similar to that with chlorfenapyr. Significant mortality occurred in all of the 20 and 30 degrees C thiamethoxam treatments, but none of the 10 degrees C treatments. Effectiveness as a barrier was evaluated by providing a choice between bridges treated with insecticide or water. Although bifenthrin did not provide an impenetrable barrier, it was the only treatment having fewer ants than its paired control bridge. Mortality data suggest that a reduction in recruitment rather than repellency account for this result.

  19. Solenopsis invicta virus (sinv-1) infection and insecticide interactions in the red imported fire ant (Hymenoptera: Formicidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Controlling invasive species is a growing concern; however, pesticides can be detrimental for non-target organisms. The red imported fire ant (Solenopsis invicta Buren; Hymenoptera: Formicidae) has aggressively invaded approximately 138 million ha in the USA and causes over $6 billion in damage and ...

  20. Development of a lateral flow immunoassay for rapid field detection of the red imported fire ant, Solenopsis invicta (Hymenoptera: Formicidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The red imported fire ant, Solenopsis invicta, is an aggressive, highly invasive pest ant species from South America that has been introduced into North America, Asia and Australia. Quarantine efforts have been imposed in the United States to minimize the spread of the ant. There remains an acute ...

  1. Potential economic impact of introduction and spread of the red imported fire ant, Solenopsis invicta, in Hawaii

    USGS Publications Warehouse

    Gutrich, J.J.; VanGelder, E.; Loope, L.

    2007-01-01

    Globally, many invasive alien species have caused extensive ecological and economic damage from either accidental or intentional introduction. The red imported fire ant, Solenopsis invicta, has created billions of dollars in costs annually, spreading as an invasive species across the southern United States. In 1998, the red imported fire ant spread into California creating a highly probable future introduction via shipped products to Hawaii. This paper presents the estimation of potential economic impacts of the red imported fire ant (RIFA) to the state of Hawaii. Evaluation of impacts focuses on the economic sectors of (1) households, (2) agriculture (cattle and crop production), (3) infrastructure (cemeteries, churches, cities, electrical, telephone, and cable services, highways, hospitals and schools), (4) recreation, tourism and business (hotels/resort areas, golf courses, commercial businesses and tourists), and (5) government expenditures (with minimal intervention). The full annual economic costs of the red imported fire ant to Hawaii are estimated (in US$ 2006) to be $211 million/year, comprised of $77 million in damages and expenditures and $134 million in foregone outdoor opportunities to households and tourists. The present value of the projected costs of RIFA over a 20-year period after introduction total $2.5 billion. RIFA invasions across the globe indicate that economic cost-effective action in Hawaii entails implementation of prevention, early detection and rapid response treatment programs for RIFA. ?? 2007 Elsevier Ltd. All rights reserved.

  2. Extracted Venom and Cuticular Compounds of Imported Fire Ants, Solenopsis spp., and Chemotaxonomic Applications Across a Persistent Hybrid Zone

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Characterization of cuticular biomolecular assemblages for imported fire ants permit basic distinctions among colonies of S. invicta, S. richteri, and their hybrids; thus, providing opportunities to investigate details of landscape ecology for this species complex as well as to assess levels of inva...

  3. Quantifying the Relative Importance and Potential Interactive Effects of Multiple Indices When Predicting Fire Risk and Severity in the Western US.

    NASA Astrophysics Data System (ADS)

    Keyser, A. R.; Westerling, A.

    2007-12-01

    The national fire plan was implemented after the landmark fire season of 2000 as a response to a perceived increasing threat of severe wildfires. Subsequently, the Landfire project was initiated to develop a national dataset comprising vegetation condition, wildland fuels and fire regimes, and ecosystem status to support the national fire plan. A key product in this dataset to predict areas at risk for severe fires is the fire regime condition class (FRCC). The FRCC is an index of the degree of departure from the historical fire regime. This departure is a metric of the difference between current landscape vegetation composition and the range of historical reference vegetation characteristics; this difference can result from changes in vegetation characteristics and/or the spatial fire regime. The FRCC index is derived relative to simulated reference conditions, which in turn are based on Landsum, a landscape fire succession model. In addition to land management decisions, factors such as nitrogen deposition, ozone and climate affect both reference and current vegetation characteristics. It is an open question as to whether FRCC is sensitive enough to capture the full suite of potential effects on fire regimes. We are interested in examining vegetation change (via FRCC), nitrogen deposition, ozone concentration and climate variability in terms of their utility in predicting spatial variability in fire regime characteristics. Our analysis includes statistical examination of the multiple effects of nitrogen deposition, ozone, climate indices, and FRCC on fire frequency, size, and severity in California and the Western United States. We will assess how these four factors might act alone to influence fire, and their relative importance as co-determinants of fire risks. Our results will quantify how distinct FRCC is from climate and its efficacy as a predictor of fire risk and severity. Of particular interest is the extent to which FRCC predicts spatial variability in

  4. Dose response of red imported fire ant colonies to Solenopsis invicta virus 3.

    PubMed

    Valles, Steven M; Porter, Sanford D

    2015-10-01

    Baiting tests were conducted to evaluate the effect of increasing Solenopsis invicta virus 3 (SINV-3) dose on fire ant colonies. Actively growing early-stage fire ant (Solenopsis invicta Buren) laboratory colonies were pulse-exposed for 24 hours to six concentrations of SINV-3 (10(1), 10(3), 10(5), 10(7), 10(9) genome equivalents/μl) in 1 ml of a 10 % sucrose bait and monitored regularly for two months. SINV-3 concentration had a significant effect on colony health. Brood rating (proportion of brood to worker ants) began to depart from the control group at 19 days for the 10(9) concentration and 26 days for the 10(7) concentration. At 60 days, brood rating was significantly lower among colonies treated with 10(9), 10(7), and 10(5) SINV-3 concentrations. The intermediate concentration, 10(5), appeared to cause a chronic, low-level infection with one colony (n = 9) supporting virus replication. Newly synthesized virus was not detected in any fire ant colonies treated at the 10(1) concentration, indicating that active infections failed to be established at this level of exposure. The highest bait concentration chosen, 10(9), appeared most effective from a control aspect; mean colony brood rating at this concentration (1.1 ± 0.9 at the 60 day time point) indicated poor colony health with minimal brood production. No clear relationship was observed between the quantity of plus genome strand detected and brood rating. Conversely, there was a strong relationship between the presence of the replicative genome strand and declining brood rating, which may serve as a predictor of disease severity. Recommendations for field treatment levels to control fire ants with SINV-3 are discussed.

  5. Topography and climate are more important drivers of long-term, post-fire vegetation assembly than time-since-fire in the Sonoran Desert, US

    USGS Publications Warehouse

    Shryock, Daniel F.; Esque, Todd C.; Chen, Felicia

    2015-01-01

    We find substantial evidence that environmental filters, rather than TSF, drive the majority of variability in long-term, post-fire vegetation assembly within the Sonoran Desert. Careful consideration of spatial variability in abiotic conditions may benefit post-fire vegetation modelling, as well as fire management and restoration strategies.

  6. Importance of climate, forest fires and human population size on the long-term boreal forest dynamics in Northern Europe

    NASA Astrophysics Data System (ADS)

    Kuosmanen, Niina; Seppä, Heikki; Alenius, Teija; Bradshaw, Richard; Clear, Jennifer; Filimonova, Fludmila; Heikkilä, Maija; Renssen, Hans; Tallavaara, Miikka; Reitalu, Triin

    2016-04-01

    Palaeoecological data provides valuable information for understanding the processes behind the past changes in forest composition, and hence can provide important knowledge regarding the potential effects of future changes in climate on boreal vegetation. Furthermore, it is essential to consider both regional and local factors in order to better understand the processes behind the boreal forest dynamics. The relative importance of climate, forest fires and human population size on long-term boreal forest composition were statistically investigated at regional and local scales in Fennoscandia. Statistical method variation partitioning was employed to assess the relative importance of these three variables. Fossil pollen data reflecting long-term boreal forest composition, at both regional (lake records) and local (small hollow records) scales from Russia, Finland and Sweden, were used as response matrix. Climate, generated from a climate model and oxygen isotope data, past forest fires generated from sedimentary charcoal data and human population size derived from radiocarbon dated archaeological findings were used as potential drivers of long-term boreal vegetation. Though the results clearly demonstrate that climate is the main driver of long-term vegetation changes at the regional scale, the role of climate notably is smaller at local scale and the influence of local site specific factors increases. However, the relative importance of forest fires on long-term changes in boreal forest composition remain generally low both at regional and local scale. The relatively low importance of both climate and forest fires on the variation in long-term boreal forest composition at local scale demonstrates the complexity of factors affecting stand-scale forest dynamics. In general, the relative importance of human population size on long-term changes in boreal vegetation was low. However, this was the first time that this type of human population size data was statistically

  7. Development of a lateral flow immunoassay for rapid field detection of the red imported fire ant, Solenopsis invicta (Hymenoptera: Formicidae).

    PubMed

    Valles, Steven M; Strong, Charles A; Callcott, Anne-Marie A

    2016-07-01

    The red imported fire ant, Solenopsis invicta, is an aggressive, highly invasive pest ant species from South America that has been introduced into North America, Asia, and Australia. Quarantine efforts have been imposed in the USA to minimize further spread of the ant. To aid the quarantine efforts, there remains an acute need for a rapid, field portable method for the identification of these ants. In this report, we describe two novel monoclonal antibodies that specifically bind the S. invicta venom protein 2 produced by S. invicta. Using these monoclonal antibodies we developed a lateral flow immunoassay that provides a rapid and portable method for the identification of S. invicta ants. The lateral flow immunoassay was validated against purified S. invicta venom protein 2 and 33 unique ant species (representing 15 % of the total species and 42 % of the Myrmicinae genera found in Florida), and only S. invicta and the S. invicta/richteri hybrid produced a positive result. These monoclonal antibodies were selective to S. invicta venom protein 2 and did not bind to proteins from congeners (i.e., S. geminata or S. richteri) known to produce a S. invicta venom protein 2 ortholog. This S. invicta lateral flow immunoassay provides a new tool for regulatory agencies in the USA to enforce quarantine protocols and limit the spread of this invasive ant. Graphical Abstract Field method to detect and identify the red imported fire ant, Solenopsis invicta.

  8. Influence of the proximity and amount of human development and roads on the occurrence of the red imported fire ant in the lower Florida Keys

    USGS Publications Warehouse

    Forys, E.A.; Allen, C.R.; Wojcik, D.P.

    2002-01-01

    We examined the influence of both the proximity and extent of human developments and paved roads on the presence of the predatory, non-indigenous, red imported fire ant (Solenopsis invicta). This species was inadvertently introduced into the United States at the port of Mobile, Alabama, around 1930 and rapidly spread to many southeastern states, including Florida. More recently, S. invicta colonized the Florida Keys, an area with a high proportion of rare and endemic vertebrate and invertebrate species. We placed bait transects in transitional salt-marsh, pineland, and hardwood hammocks on 13 of the lower Florida Keys and compared habitat type, the shortest distance of the bait transect to a development or road, and area of development and roads 50, 70, 100, and 150 m around each bait transect for areas with and without red imported fire ants. Red imported fire ants were detected on 21 of the 80 transects and were equally abundant in all habitat types. While all of the development and road variables differed significantly between bait transects with and without red imported fire ants, transects that were closest to roads and that had the largest amount of development within a 150 m radii had the highest probability of presence of red imported fire ants. Recovery efforts for endangered species in areas invaded by red imported fire ants should include analyses of the cumulative impacts of roads and developments in areas near protected lands. ?? 2002 Elsevier Science Ltd. All rights reserved.

  9. Effects of fire on decomposition: assessing the relative importance of soil environment versus charring on decomposition in boreal conifer forests

    NASA Astrophysics Data System (ADS)

    Manies, K.; Turetsky, M. R.; Harden, J. W.

    2014-12-01

    Boreal forests are experiencing significant changes in climate and disturbance regimes, including increases in the frequency and severity of fires. Fires impact the carbon (C) cycle of this region in many ways, including through changes to C inputs to the ecosystem (i.e., loss of all living vegetation, followed post-fire regrowth), changes in mycorrhizal relationships, the altering soil temperature and moisture regimes, and the charring of surface organic soil. All of these factors have the potential to impact decomposition rates. We were interested in comparing the relative importance of changes in soil temperature and moisture (soil environmental conditions) versus surface organic soil quality (charring) on decomposition rates. To disentangle the effects of environmental factors versus charring on mass loss, we performed a reciprocal transplant experiment. Our design included burned and unburned feather moss litter, collected from the field and placed within litterbags, which were then placed into triplicate burned and unburned black spruce dominated stands in interior Alaska. Litterbags were collected after one, three, and seven years, after which mass loss and changes in C and N pools were quantified. Exponential decomposition (k) values varied with litter type (burned/unburned) by environment (burned/unburned site) interactions. Averaged across both types of environments, decomposition rates were almost double for unburned versus burned litter. Decomposition rates were approximately 30 percent faster for unburned versus burned sites. Our results to date show that changes to soil quality due to charring have a larger effect in controlling post-burn decomposition rates than changes in soil environmental conditions.

  10. Interaction of RECQ4 and MCM10 is important for efficient DNA replication origin firing in human cells

    PubMed Central

    Kliszczak, Maciej; Sedlackova, Hana; Pitchai, Ganesha P.; Streicher, Werner W.; Krejci, Lumir; Hickson, Ian D.

    2015-01-01

    DNA replication is a highly coordinated process that is initiated at multiple replication origins in eukaryotes. These origins are bound by the origin recognition complex (ORC), which subsequently recruits the Mcm2-7 replicative helicase in a Cdt1/Cdc6-dependent manner. In budding yeast, two essential replication factors, Sld2 and Mcm10, are then important for the activation of replication origins. In humans, the putative Sld2 homolog, RECQ4, interacts with MCM10. Here, we have identified two mutants of human RECQ4 that are deficient in binding to MCM10. We show that these RECQ4 variants are able to complement the lethality of an avian cell RECQ4 deletion mutant, indicating that the essential function of RECQ4 in vertebrates is unlikely to require binding to MCM10. Nevertheless, we show that the RECQ4-MCM10 interaction is important for efficient replication origin firing. PMID:26588054

  11. Body size, but not cooling rate, affects supercooling points in the red imported fire ant, Solenopsis invicta.

    PubMed

    Hahn, Daniel A; Martin, Adam R; Porter, Sanford D

    2008-10-01

    The level of an animal's stress resistance is set by multiple intrinsic physiological and extrinsic environmental parameters. Body size is a critical intrinsic parameter that affects numerous fitness-related organismal traits including fecundity, survival, mating success, and stress resistance. The rate of cooling is a critical extrinsic environmental factor that can affect thermal stress resistance. Workers of the red imported fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae), display considerable variation in adult body size. Therefore, developing ecologically realistic models of thermotolerance in this species requires a consideration of body size. We tested the hypothesis that body size and cooling rate would interact to set the supercooling point in fire ant workers by exposing workers of a range of body sizes to three different cooling regimens: a very fast ramp of -10 degrees C/min, an intermediate ramp of -1 degrees C/min, and an ecologically relevant slow ramp of -0.1 degrees C/min. Specifically, we asked whether large workers were more susceptible to differences in cooling rate than smaller workers. We found that body size had a considerable effect on supercooling point with the largest workers freezing at a temperature approximately 3 degrees C higher than the smallest workers. Cooling rate had a very small effect on supercooling point, and there was no interaction between the two factors. Therefore, the allometry of supercooling points across the range of worker body sizes does not change with cooling rate.

  12. Quantifying Responses of Dung Beetles to Fire Disturbance in Tropical Forests: The Importance of Trapping Method and Seasonality

    PubMed Central

    de Andrade, Rafael Barreto; Barlow, Jos; Louzada, Julio; Vaz-de-Mello, Fernando Zagury; Souza, Mateus; Silveira, Juliana M.; Cochrane, Mark A.

    2011-01-01

    Understanding how biodiversity responds to environmental changes is essential to provide the evidence-base that underpins conservation initiatives. The present study provides a standardized comparison between unbaited flight intercept traps (FIT) and baited pitfall traps (BPT) for sampling dung beetles. We examine the effectiveness of the two to assess fire disturbance effects and how trap performance is affected by seasonality. The study was carried out in a transitional forest between Cerrado (Brazilian Savanna) and Amazon Forest. Dung beetles were collected during one wet and one dry sampling season. The two methods sampled different portions of the local beetle assemblage. Both FIT and BPT were sensitive to fire disturbance during the wet season, but only BPT detected community differences during the dry season. Both traps showed similar correlation with environmental factors. Our results indicate that seasonality had a stronger effect than trap type, with BPT more effective and robust under low population numbers, and FIT more sensitive to fine scale heterogeneity patterns. This study shows the strengths and weaknesses of two commonly used methodologies for sampling dung beetles in tropical forests, as well as highlighting the importance of seasonality in shaping the results obtained by both sampling strategies. PMID:22028831

  13. Fatty Amines from Little Black Ants, Monomorium minimum, and Their Biological Activities Against Red Imported Fire Ants, Solenopsis invicta.

    PubMed

    Wang, Lei; Chen, Jian

    2015-08-01

    Red imported fire ants, Solenopsis invicta, are significant invasive pests. Certain native ant species can compete with S. invicta, such as the little black ant, Monomorium minimum. Defensive secretions may contribute to the competition capacity of native ants. The chemistry of ant defensive secretions in the genus Monomorium has been subjected to extensive research. The insecticidal alkaloids, 2,5-dialkyl-pyrrolidines and 2,5-dialkyl-pyrrolines have been reported to dominate the venom of M. minimum. In this study, analysis of defensive secretions of workers and queens of M. minimum revealed two primary amines, decylamine and dodecylamine. Neither amine has been reported previously from natural sources. Toxicity and digging suppression by these two amines against S. invicta were examined. Decylamine had higher toxicity to S. invicta workers than dodecylamine, a quicker knockdown effect, and suppressed the digging behavior of S. invicta workers at lower concentration. However, the amount of fatty amines in an individual ant was not enough to knockdown a fire ant or suppress its digging behavior. These amines most likely work in concert with other components in the chemical defense of M. minimum.

  14. Increased incidence of red imported fire ant (Hymenoptera: Formicidae) presence in loggerhead sea turtle (Testudines: Cheloniidae) nests and observations of hatchling mortality

    USGS Publications Warehouse

    Parris, L.B.; Lamont, M.M.; Carthy, R.R.

    2002-01-01

    Hatching sea turtles may be at risk to fire ant predation during egg incubation, and especially at risk once pipped from the egg, prior to hatchling emergence from the nest. In addition to direct mortality, fire ants have the potential to inflict debilitating injuries that may directly affect survival of the young. The increased incidence of red imported fire ant induced mortality and envenomization of loggerhead sea turtle hatchlings on Cape San Blas suggests this invasive ant species may pose a serious threat to the future of this genetically distinct population.

  15. Antimicrobial properties of nest volatiles in red imported fire ants, Solenopsis invicta (Hymenoptera: Formicidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In social insects, antimicrobial secretions are often used collectively for the benefit of the whole colony, which is an important component in social immunity. Many ant species build nests in which air circulation can be controlled. Volatile antimicrobial agents would be ideal in implementing socia...

  16. Multiplatform inversion of the 2013 Rim Fire smoke emissions using regional-scale modeling: important nocturnal fire activity, air quality, and climate impacts

    NASA Astrophysics Data System (ADS)

    Saide, P. E.; Peterson, D. A.; da Silva, A. M., Jr.; Ziemba, L. D.; Anderson, B.; Diskin, G. S.; Sachse, G. W.; Hair, J. W.; Butler, C. F.; Fenn, M. A.; Jimenez, J. L.; Campuzano Jost, P.; Dibb, J. E.; Yokelson, R. J.; Toon, B.; Carmichael, G. R.

    2014-12-01

    Large wildfire events are increasingly recognized for their adverse effects on air quality and visibility, thus providing motivation for improving smoke emission estimates. The Rim Fire, one of the largest events in California's history, produced a large smoke plume that was sampled by the Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) DC-8 aircraft with a full suite of in-situ and remote sensing measurements on 26-27 August 2013. We developed an inversion methodology which uses the WRF-Chem modeling system to constrain hourly fire emissions, using as initial estimates the NASA Quick Fire Emissions Dataset (QFED). This method differs from the commonly performed top-down estimates that constrain daily (or longer time scale) emissions. The inversion method is able to simultaneously improve the model fit to various SEAC4RS airborne measurements (e.g., organic aerosol, carbon monoxide (CO), aerosol extinction), ground based measurements (e.g., AERONET aerosol optical depth (AOD), CO), and satellite data (MODIS AOD) by modifying fire emissions and utilizing the information content of all these measurements. Preliminary results show that constrained emissions for a 6 day period following the largest fire growth are a factor 2-4 higher than the initial top-down estimates. Moreover, there is a tendency to increase nocturnal emissions by factors sometimes larger than 20, indicating that vigorous fire activity continued during the night. This deviation from a typical diurnal cycle is confirmed using geostationary satellite data. The constrained emissions also have a larger day-to-day variability than the initial emissions and correlate better to daily area burned estimates as observed by airborne infrared measurements (NIROPS). Experiments with the assimilation system show that performing the inversion using only satellite AOD data produces much smaller correction factors than when using all available data

  17. Esterase in Imported Fire Ants, Solenopsis invicta and S. richteri (Hymenoptera: Formicidae): Activity, Kinetics and Variation

    PubMed Central

    Chen, J.; Rashid, T.; Feng, G.

    2014-01-01

    Solenopsis invicta and Solenopsis richteri are two closely related invasive ants native to South America. Despite their similarity in biology and behavior, S. invicta is a more successful invasive species. Toxic tolerance has been found to be important to the success of some invasive species. Esterases play a crucial role in toxic tolerance of insects. Hence, we hypothesized that the more invasive S. invicta would have a higher esterase activity than S. richteri. Esterase activities were measured for workers and male and female alates of both ant species using α-naphthyl acetate and β-naphthyl acetate as substrates. Esterase activities in S. invicta were always significantly higher than those in S. richteri supporting our hypothesis. In S. invicta, male alates had the highest esterase activities followed by workers then female alates for both substrates. In S. richetri, for α-naphthyl acetate, male alates had the highest activity followed by female alates then workers, while for β-naphthyl acetate, female alates had the highest activity followed by male alates then workers. For workers, S. richteri showed significantly higher levels of variation about the mean esterase activity than S. invicta. However, S. invicta showed significantly higher levels of variation in both female and male alates. PMID:25408118

  18. Assessment of differential item functioning.

    PubMed

    Wang, Wen-Chung

    2008-01-01

    This study addresses several important issues in assessment of differential item functioning (DIF). It starts with the definition of DIF, effectiveness of using item fit statistics to detect DIF, and linear modeling of DIF in dichotomous items, polytomous items, facets, and testlet-based items. Because a common metric over groups of test-takers is a prerequisite in DIF assessment, this study reviews three such methods of establishing a common metric: the equal-mean-difficulty method, the all-other-item method, and the constant-item (CI) method. A small simulation demonstrates the superiority of the CI method over the others. As the CI method relies on a correct specification of DIF-free items to serve as anchors, a method of identifying such items is recommended and its effectiveness is illustrated through a simulation. Finally, this study discusses how to assess practical significance of DIF at both item and test levels.

  19. Fire Ant Decapitating Fly Cooperative Release Programs (1994–2008): Two Pseudacteon Species, P. tricuspis and P. curvatus, Rapidly Expand Across Imported Fire Ant Populations in the Southeastern United States

    PubMed Central

    Callcott, Anne-Marie A.; Porter, Sanford D.; Weeks, Ronald D.; “Fudd” Graham, L. C.; Johnson, Seth J.; Gilbert, Lawrence E.

    2011-01-01

    Natural enemies of the imported fire ants, Solenopsis invicta Buren S. richteri Forel (Hymenoptera: Formicidae), and their hybrid, include a suite of more than 20 fire ant decapitating phorid flies from South America in the genus Pseudacteon. Over the past 12 years, many researchers and associates have cooperated in introducing several species as classical or self-sustaining biological control agents in the United States. As a result, two species of flies, Pseudacteon tricuspis Borgmeier and P. curvatus Borgmeier (Diptera: Phoridae), are well established across large areas of the southeastern United States. Whereas many researchers have published local and state information about the establishment and spread of these flies, here distribution data from both published and unpublished sources has been compiled for the entire United States with the goal of presenting confirmed and probable distributions as of the fall of 2008. Documented rates of expansion were also used to predict the distribution of these flies three years later in the fall of 2011. In the fall of 2008, eleven years after the first successful release, we estimate that P. tricuspis covered about 50% of the fire ant quarantined area and that it will occur in almost 65% of the quarantine area by 2011. Complete coverage of the fire ant quarantined area will be delayed or limited by this species' slow rate of spread and frequent failure to establish in more northerly portions of the fire ant range and also, perhaps, by its preference for red imported fire ants (S. invicta). Eight years after the first successful release of P. curvatus, two biotypes of this species (one biotype occurring predominantly in the black and hybrid imported fire ants and the other occurring in red imported fire ants) covered almost 60% of the fire ant quarantined area. We estimate these two biotypes will cover almost 90% of the quarantine area by 2011 and 100% by 2012 or 2013. Strategic selection of several distributional gaps

  20. Fire ant decapitating fly cooperative release programs (1994-2008): Two Pseudacteon species (P. tricuspis, P. curvatus) rapidly expand across imported fire and populations in the southeastern United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Natural enemies of the imported fire ants (Solenopsis invicta Buren, S. richteri Forel, and their hybrid; Hymenoptera: Formicidae) include a suite of more than 20 phorid decapitating flies from South America in the genus Pseudacteon. Over the past 12 years, many researchers and associates have coop...

  1. Effects of periplocoside X on midgut cells and digestive enzymes activity of the soldiers of red imported fire ant.

    PubMed

    Li, Yan; Zeng, Xin-Nian

    2013-07-01

    The pathological effects of ingested periplocoside X, an insecticidal component isolated from the root of Periploca sepium Bunge, on the midgut epithelial cells of the soldiers of red imported fire ant were studied and the symptom was described. The results showed that periplocoside X could induce a severe, time-dependent cytotoxicity in the midgut epithelial cells. An optical microscopy showed that epithelial cells swelled firstly and then lysed. Transmission electron microscopy (TEM) showed that numerous swollen lysosomes were appeared, microvilli were disrupted and sloughed off, and the numbers of the rough endoplasmic reticulum and the mitochondria decreased sharply in earlier stage. Numerous vacuoles were observed in the later stage. Finally, periplocoside X resulted in cell death by cytolysis. Assay of main three digestive enzymes activity indicated that amylase activity was significantly inhibited, but no significant changes were seen for lipase activity and total protease activity. So it is suggested that periplocoside X induced mainly to organic damage of midgut epithelium cells of insect. In all, insect midgut is one of targets for periplocoside X.

  2. Decreased small mammal and on-host tick abundance in association with invasive red imported fire ants (Solenopsis invicta).

    PubMed

    Castellanos, Adrian A; Medeiros, Matthew C I; Hamer, Gabriel L; Morrow, Michael E; Eubanks, Micky D; Teel, Pete D; Hamer, Sarah A; Light, Jessica E

    2016-09-01

    Invasive species may impact pathogen transmission by altering the distributions and interactions among native vertebrate reservoir hosts and arthropod vectors. Here, we examined the direct and indirect effects of the red imported fire ant (Solenopsis invicta) on the native tick, small mammal and pathogen community in southeast Texas. Using a replicated large-scale field manipulation study, we show that small mammals were more abundant on treatment plots where S. invicta populations were experimentally reduced. Our analysis of ticks on small mammal hosts demonstrated a threefold increase in the ticks caught per unit effort on treatment relative to control plots, and elevated tick loads (a 27-fold increase) on one common rodent species. We detected only one known human pathogen (Rickettsia parkeri), present in 1.4% of larvae and 6.7% of nymph on-host Amblyomma maculatum samples but with no significant difference between treatment and control plots. Given that host and vector population dynamics are key drivers of pathogen transmission, the reduced small mammal and tick abundance associated with S. invicta may alter pathogen transmission dynamics over broader spatial scales.

  3. Decreased small mammal and on-host tick abundance in association with invasive red imported fire ants (Solenopsis invicta)

    PubMed Central

    Medeiros, Matthew C. I.; Hamer, Gabriel L.; Morrow, Michael E.; Eubanks, Micky D.; Teel, Pete D.

    2016-01-01

    Invasive species may impact pathogen transmission by altering the distributions and interactions among native vertebrate reservoir hosts and arthropod vectors. Here, we examined the direct and indirect effects of the red imported fire ant (Solenopsis invicta) on the native tick, small mammal and pathogen community in southeast Texas. Using a replicated large-scale field manipulation study, we show that small mammals were more abundant on treatment plots where S. invicta populations were experimentally reduced. Our analysis of ticks on small mammal hosts demonstrated a threefold increase in the ticks caught per unit effort on treatment relative to control plots, and elevated tick loads (a 27-fold increase) on one common rodent species. We detected only one known human pathogen (Rickettsia parkeri), present in 1.4% of larvae and 6.7% of nymph on-host Amblyomma maculatum samples but with no significant difference between treatment and control plots. Given that host and vector population dynamics are key drivers of pathogen transmission, the reduced small mammal and tick abundance associated with S. invicta may alter pathogen transmission dynamics over broader spatial scales. PMID:27651533

  4. Prevention of retained surgical items.

    PubMed

    Feldman, David L

    2011-01-01

    Reduction in retained surgical items is an important part of any operating room patient-safety effort. Any item used in an operation can result in a retained surgical item, but sponges are the most frequent and the abdomen is the most common location. Retained sponges can cause significant morbidity, and the costs associated with both prevention and treatment of retained surgical items, including legal costs, can be considerable. This review will examine counting, teamwork, radiography, and new technology as methods used to prevent retained surgical items. Even though none of these techniques individually is likely to completely prevent retained surgical items, when used together the numbers can be reduced.

  5. Development of fire-resistant, low smoke generating, thermally stable end items for commercial aircraft and spacecraft using a basic polyimide resin

    NASA Technical Reports Server (NTRS)

    Gagliani, J.; Lee, R.; Sorathia, U. A.; Wilcoxson, A. L.

    1980-01-01

    A terpolyimide precursor was developed which can be foamed by microwave methods and yields foams possessing the best seating properties. A continuous process, based on spray drying techniques, permits production of polyimide powder precursors in large quantities. The constrained rise foaming process permits fabrication of rigid foam panels with improved mechanical properties and almost unlimited density characteristics. Polyimide foam core rigid panels were produced by this technique with woven fiberglass fabric bonded to each side of the panel in a one step microwave process. The fire resistance of polyimide foams was significantly improved by the addition of ceramic fibers to the powder precursors. Foams produced from these compositions are flexible, possess good acoustical attenuation and meet the minimum burnthrough requirements when impinged by high flux flame sources.

  6. Swedish forensic data 1992-2009 suggest hydrogen cyanide as an important cause of death in fire victims.

    PubMed

    Stamyr, Kristin; Thelander, Gunilla; Ernstgård, Lena; Ahlner, Johan; Johanson, Gunnar

    2012-02-01

    Between 60 and 80% of all deaths related to fire are attributed to toxic fumes. Carbon monoxide (CO) is commonly thought to be the major cause. However, hydrogen cyanide (HCN) is also formed. Still, the exact contribution of HCN to fire-related fatalities is unknown. The aim of the study was to investigate the impact of HCN in relation to CO as a cause of death in fire victims. Data on carboxyhemoglobin (COHb) and blood cyanide from deceased fire victims in the period 1992-2009 were collected from two Swedish nationwide forensic databases (ToxBase and RättsBase). The databases contain data on COHb and/or cyanide from 2303 fire victims, whereof 816 on both COHb and cyanide. Nonparametric statistical tests were used. Seventeen percent of the victims had lethal or life-threatening blood cyanide levels (>1 µg/g) and 32% had lethal COHb levels (>50% COHb). Over 31% had cyanide levels above 0.5 µg/g, an indication of significant HCN exposure. The percentages may be underestimates, as cyanide is quickly eliminated in blood also after death. Our results support the notion that HCN contributes more to the cause of death among fire victims than previously thought.

  7. BEHAVIORAL INTERACTIONS OF THE BLACK IMPORTED FIRE ANT (SOLENOPSIS RICHTERI FOREL) AND ITS PARASITOID FLY (PSEUDACTEON CURVATUS BORGMEIER) AS REVEALED BY HIGH-SPEED VIDEO.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    High-speed video recordings were used to study the interactions between the phorid fly (Pseudacteon curvatus), and the black imported fire ant (Solenopsis richteri) in the field. Phorid flies are extremely fast agile fliers that can hover and fly in all directions. Wingbeat frequency recorded with...

  8. Carbon dynamics in the future forest: the importance of long-term successional legacy and climate-fire interactions.

    PubMed

    Loudermilk, E Louise; Scheller, Robert M; Weisberg, Peter J; Yang, Jian; Dilts, Thomas E; Karam, Sarah L; Skinner, Carl

    2013-11-01

    Understanding how climate change may influence forest carbon (C) budgets requires knowledge of forest growth relationships with regional climate, long-term forest succession, and past and future disturbances, such as wildfires and timber harvesting events. We used a landscape-scale model of forest succession, wildfire, and C dynamics (LANDIS-II) to evaluate the effects of a changing climate (A2 and B1 IPCC emissions; Geophysical Fluid Dynamics Laboratory General Circulation Models) on total forest C, tree species composition, and wildfire dynamics in the Lake Tahoe Basin, California, and Nevada. The independent effects of temperature and precipitation were assessed within and among climate models. Results highlight the importance of modeling forest succession and stand development processes at the landscape scale for understanding the C cycle. Due primarily to landscape legacy effects of historic logging of the Comstock Era in the late 1880s, C sequestration may continue throughout the current century, and the forest will remain a C sink (Net Ecosystem Carbon Balance > 0), regardless of climate regime. Climate change caused increases in temperatures limited simulated C sequestration potential because of augmented fire activity and reduced establishment ability of subalpine and upper montane trees. Higher temperatures influenced forest response more than reduced precipitation. As the forest reached its potential steady state, the forest could become C neutral or a C source, and climate change could accelerate this transition. The future of forest ecosystem C cycling in many forested systems worldwide may depend more on major disturbances and landscape legacies related to land use than on projected climate change alone.

  9. Computerized Adaptive Testing with Item Clones. Research Report.

    ERIC Educational Resources Information Center

    Glas, Cees A. W.; van der Linden, Wim J.

    To reduce the cost of item writing and to enhance the flexibility of item presentation, items can be generated by item-cloning techniques. An important consequence of cloning is that it may cause variability on the item parameters. Therefore, a multilevel item response model is presented in which it is assumed that the item parameters of a…

  10. Importance of transboundary transport of biomass burning emissions to regional air quality in Southeast Asia during a high fire event

    NASA Astrophysics Data System (ADS)

    Aouizerats, B.; van der Werf, G. R.; Balasubramanian, R.; Betha, R.

    2015-01-01

    Smoke from biomass and peat burning has a notable impact on ambient air quality and climate in the Southeast Asia (SEA) region. We modeled a large fire-induced haze episode in 2006 stemming mostly from Indonesia using the Weather Research and Forecasting model coupled with chemistry (WRF-Chem). We focused on the evolution of the fire plume composition and its interaction with the urbanized area of the city state of Singapore, and on comparisons of modeled and measured aerosol and carbon monoxide (CO) concentrations. Two simulations were run with WRF-Chem using the complex volatility basis set (VBS) scheme to reproduce primary and secondary aerosol evolution and concentration. The first simulation referred to as WRF-FIRE included anthropogenic, biogenic and biomass burning emissions from the Global Fire Emissions Database (GFED3) while the second simulation referred to as WRF-NOFIRE was run without emissions from biomass burning. To test model performance, we used three independent data sets for comparison including airborne measurements of particulate matter (PM) with a diameter of 10 μm or less (PM10) in Singapore, CO measurements in Sumatra, and aerosol optical depth (AOD) column observations from four satellite-based sensors. We found reasonable agreement between the model runs and both ground-based measurements of CO and PM10. The comparison with AOD was less favorable and indicated the model underestimated AOD, although the degree of mismatch varied between different satellite data sets. During our study period, forest and peat fires in Sumatra were the main cause of enhanced aerosol concentrations from regional transport over Singapore. Analysis of the biomass burning plume showed high concentrations of primary organic aerosols (POA) with values up to 600 μg m-3 over the fire locations. The concentration of POA remained quite stable within the plume between the main burning region and Singapore while the secondary organic aerosol (SOA) concentration

  11. Fire Safety Technician

    ERIC Educational Resources Information Center

    Moore, Pam

    2007-01-01

    Fire protection is one of the most important considerations in the construction and operation of industrial plants and commercial buildings. Fire insurance rates are determined by fire probability factors, such as the type of construction, ease of transporting personnel, and the quality and quantity of fire protection equipment available. Because…

  12. Revealing important nocturnal and day-to-day variations in fire smoke emissions through a multiplatform inversion

    SciTech Connect

    Saide, Pablo E.; Peterson, David A.; de Silva, Arlindo; Anderson, Bruce; Ziemba, Luke D.; Diskin, Glenn; Sachse, Glen; Hair, Jonathan; Butler, Carolyn; Fenn, Marta; Jimenez, Jose L.; Campuzano-Jost, Pedro; Perring, Anne E.; Schwarz, Joshua P.; Markovic, Milos Z.; Russell, Phil; Redemann, Jens; Shinozuka, Yohei; Streets, David G.; Yan, Fang; Dibb, Jack; Yokelson, Robert; Toon, O. Brian; Hyer, Edward; Carmichael, Gregory R.

    2015-05-16

    We couple airborne, ground-based, and satellite observations; conduct regional simulations; and develop and apply an inversion technique to constrain hourly smoke emissions from the Rim Fire, the third largest observed in California, USA. Emissions constrained with multiplatform data show notable nocturnal enhancements (sometimes over a factor of 20), correlate better with daily burned area data, and are a factor of 2–4 higher than a priori estimates, highlighting the need for improved characterization of diurnal profiles and day-to-day variability when modeling extreme fires. Constraining only with satellite data results in smaller enhancements mainly due to missing retrievals near the emissions source, suggesting that top-down emission estimates for these events could be underestimated and a multiplatform approach is required to resolve them. Predictions driven by emissions constrained with multiplatform data present significant variations in downwind air quality and in aerosol feedback on meteorology, emphasizing the need for improved emissions estimates during exceptional events.

  13. Reading Current Events Items.

    ERIC Educational Resources Information Center

    Ediger, Marlow

    People who live in a democracy should be well informed of local, state, national, and international happenings. Students should become curious about news items and relate current happenings to the personal self. They must possess skills in word recognition and in diverse kinds of comprehension since reading is an important way to glean current…

  14. Electroantennogram and behavioral responses of the imported fire ant, Solenopsis invicta Buren, to an alarm pheromone component and its analogues.

    PubMed

    Guan, Di; Lu, Yong-Yue; Liao, Xiao-Lan; Wang, Lei; Chen, Li

    2014-12-10

    A characteristic behavior in ants is to move rapidly to emission sources of alarm pheromones. The addition of ant alarm pheromones to bait is expected to enhance its attractiveness. To search for candidate compounds for bait enhancement in fire ant control, 13 related alkylpyrazine analogues in addition to synthetic alarm pheromone component were evaluated for electroantennogram (EAG) and behavioral activities in Solenopsis invicta. Most compounds elicited dose-dependent EAG and behavioral responses. There exists a correlation between the EAG and behavioral responses. Among the 14 tested alkylpyrazines, three compounds, 2-ethyl-3,6(5)-dimethyl pyrazine (1), 2,3,5-trimethylpyrazine (7), and 2,3-diethyl-5-methylpyrazine (12), elicited significant alarm responses at a dose range of 0.1-1000 ng. Further bait discovery bioassay with the three most active alkylpyrazines demonstrated that food bait accompanied by sample-treated filter paper disk attracted significantly more fire ant workers in the first 15 min period. EAG and behavioral bioassays with pure pheromone isomers accumulated by semi-preparative high-performance liquid chromatography demonstrated that 2-ethyl-3,6-dimethylpyrazine was significantly more active than 2-ethyl-3,5-dimethylpyrazine.

  15. Item Difficulty Modeling of Paragraph Comprehension Items

    ERIC Educational Resources Information Center

    Gorin, Joanna S.; Embretson, Susan E.

    2006-01-01

    Recent assessment research joining cognitive psychology and psychometric theory has introduced a new technology, item generation. In algorithmic item generation, items are systematically created based on specific combinations of features that underlie the processing required to correctly solve a problem. Reading comprehension items have been more…

  16. Growth and patterning are evolutionarily dissociated in the vestigial wing discs of workers of the red imported fire ant, Solenopsis invicta.

    PubMed

    Bowsher, Julia H; Wray, Gregory A; Abouheif, Ehab

    2007-12-15

    Over the last decade, it has become clear that organismal form is largely determined by developmental and evolutionary changes in the growth and pattern formation of tissues. Yet, there is little known about how these two integrated processes respond to environmental cues or how they evolve relative to one another. Here, we present the discovery of vestigial wing imaginal discs in worker larvae of the red imported fire ant, Solenopsis invicta. These vestigial wing discs are present in all worker larvae, which is uncommon for a species with a large worker size distribution. Furthermore, the growth trajectory of these vestigial discs is distinct from all of the ant species examined to date because they grow at a rate slower than the leg discs. We predicted that the growth trajectory of the vestigial wing discs would be mirrored by evolutionary changes in their patterning. We tested this prediction by examining the expression of three patterning genes, extradenticle, ultrabithorax, and engrailed, known to underlie the wing polyphenism in ants. Surprisingly, the expression patterns of these three genes in the vestigial wing discs was the same as those found in ant species with different worker size distributions and wing disc growth than fire ants. We conclude that growth and patterning are evolutionarily dissociated in the vestigial wing discs of S. invicta because patterning in these discs is conserved, whereas their growth trajectories are not. The evolutionary dissociation of growth and patterning may be an important feature of gene networks that underlie polyphenic traits.

  17. The red imported fire ant (Solenopsis invicta Buren) kept Y not F: predicted sNPY endogenous ligands deorphanize the short NPF (sNPF) receptor.

    PubMed

    Bajracharya, Prati; Lu, Hsiao-Ling; Pietrantonio, Patricia V

    2014-01-01

    Neuropeptides and their receptors play vital roles in controlling the physiology and behavior of animals. Short neuropeptide F (sNPF) signaling regulates several physiological processes in insects such as feeding, locomotion, circadian rhythm and reproduction, among others. Previously, the red imported fire ant (Solenopsis invicta) sNPF receptor (S. invicta sNPFR), a G protein-coupled receptor, was immunolocalized in queen and worker brain and queen ovaries. Differential distribution patterns of S. invicta sNPFR protein in fire ant worker brain were associated both with worker subcastes and with presence or absence of brood in the colony. However, the cognate ligand for this sNPFR has not been characterized and attempts to deorphanize the receptor with sNPF peptides from other insect species which ended in the canonical sequence LRLRFamide, failed. Receptor deorphanization is an important step to understand the neuropeptide receptor downstream signaling cascade. We cloned the full length cDNA of the putative S. invicta sNPF prepropeptide and identified the putative "sNPF" ligand within its sequence. The peptide ends with an amidated Tyr residue whereas in other insect species sNPFs have an amidated Phe or Trp residue at the C-terminus. We stably expressed the HA-tagged S. invicta sNPFR in CHO-K1 cells. Two S. invicta sNPFs differing at their N-terminus were synthesized that equally activated the sNPFR, SLRSALAAGHLRYa (EC50 = 3.2 nM) and SALAAGHLRYa (EC50 = 8.6 nM). Both peptides decreased the intracellular cAMP concentration, indicating signaling through the Gαi-subunit. The receptor was not activated by sNPF peptides from other insect species, honey bee long NPF (NPY) or mammalian PYY. Further, a synthesized peptide otherwise identical to the fire ant sequence but in which the C-terminal amidated amino acid residue 'Y' was switched to 'F', failed to activate the sNPFR. This discovery will now allow us to investigate the function of sNPY and its cognate

  18. Computational fire modeling for aircraft fire research

    SciTech Connect

    Nicolette, V.F.

    1996-11-01

    This report summarizes work performed by Sandia National Laboratories for the Federal Aviation Administration. The technical issues involved in fire modeling for aircraft fire research are identified, as well as computational fire tools for addressing those issues, and the research which is needed to advance those tools in order to address long-range needs. Fire field models are briefly reviewed, and the VULCAN model is selected for further evaluation. Calculations are performed with VULCAN to demonstrate its applicability to aircraft fire problems, and also to gain insight into the complex problem of fires involving aircraft. Simulations are conducted to investigate the influence of fire on an aircraft in a cross-wind. The interaction of the fuselage, wind, fire, and ground plane is investigated. Calculations are also performed utilizing a large eddy simulation (LES) capability to describe the large- scale turbulence instead of the more common k-{epsilon} turbulence model. Additional simulations are performed to investigate the static pressure and velocity distributions around a fuselage in a cross-wind, with and without fire. The results of these simulations provide qualitative insight into the complex interaction of a fuselage, fire, wind, and ground plane. Reasonable quantitative agreement is obtained in the few cases for which data or other modeling results exist Finally, VULCAN is used to quantify the impact of simplifying assumptions inherent in a risk assessment compatible fire model developed for open pool fire environments. The assumptions are seen to be of minor importance for the particular problem analyzed. This work demonstrates the utility of using a fire field model for assessing the limitations of simplified fire models. In conclusion, the application of computational fire modeling tools herein provides both qualitative and quantitative insights into the complex problem of aircraft in fires.

  19. 14 CFR 121.221 - Fire precautions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Fire precautions. 121.221 Section 121.221..., FLAG, AND SUPPLEMENTAL OPERATIONS Special Airworthiness Requirements § 121.221 Fire precautions. (a... the compartment and so that damage to or failure of the item would not create a fire hazard in...

  20. Generalized Full-Information Item Bifactor Analysis

    ERIC Educational Resources Information Center

    Cai, Li; Yang, Ji Seung; Hansen, Mark

    2011-01-01

    Full-information item bifactor analysis is an important statistical method in psychological and educational measurement. Current methods are limited to single-group analysis and inflexible in the types of item response models supported. We propose a flexible multiple-group item bifactor analysis framework that supports a variety of…

  1. Designing fire safe interiors.

    PubMed

    Belles, D W

    1992-01-01

    Any product that causes a fire to grow large is deficient in fire safety performance. A large fire in any building represents a serious hazard. Multiple-death fires almost always are linked to fires that grow quickly to a large size. Interior finishes have large, continuous surfaces over which fire can spread. They are regulated to slow initial fire growth, and must be qualified for use on the basis of fire tests. To obtain meaningful results, specimens must be representative of actual installation. Variables--such as the substrate, the adhesive, and product thickness and density--can affect product performance. The tunnel test may not adequately evaluate some products, such as foam plastics or textile wall coverings, thermoplastic materials, or materials of minimal mass. Where questions exist, products should be evaluated on a full-scale basis. Curtains and draperies are examples of products that ignite easily and spread flames readily. The present method for testing curtains and draperies evaluates one fabric at a time. Although a fabric tested alone may perform well, fabrics that meet test standards individually sometimes perform poorly when tested in combination. Contents and furnishings constitute the major fuels in many fires. Contents may involve paper products and other lightweight materials that are easily ignited and capable of fast fire growth. Similarly, a small source may ignite many items of furniture that are capable of sustained fire growth. Upholstered furniture can reach peak burning rates in less than 5 minutes. Furnishings have been associated with many multiple-death fires.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. The Importance of Permafrost Thaw, Fire and Logging Disturbances as Driving Factors of Historical and Projected Carbon Dynamics in Alaskan Ecosystems

    NASA Astrophysics Data System (ADS)

    Genet, H.; Zhang, Y.; McGuire, A. D.; He, Y.; Johnson, K. D.; D'Amore, D. V.; Zhou, X.; Bennett, A.; Breen, A. L.; Biles, F. E.; Bliss, N. B.; Euskirchen, E. S.; Kurkowski, T. A.; Pastick, N.; Rupp, S. T.; Wylie, B. K.; Zhu, Z.; Zhuang, Q.

    2014-12-01

    Carbon dynamics of natural ecosystems are influenced by disturbance regimes of various frequencies and magnitudes. With global change, these disturbances are projected to increase in frequency and/or magnitude and may have significant effects on future net carbon balance, especially in high latitude ecosystems where carbon stocks are among the largest on Earth and climate change is substantial. In Alaska, permafrost degradation and fire in the boreal and arctic regions and logging in the southern coastal region are the main disturbances that affect ecosystems. Large uncertainties related to the effects of these disturbances on the capacity of these regions to store carbon still exist mainly due to difficulty in representing permafrost degradation in current ecosystem models. We ran the Terrestrial Ecosystem Model (TEM), which explicitly simulates the carbon cycle and permafrost dynamics, coupled with a disturbance model (the Alaska Frame Based Ecosystem Code, ALFRESCO) to assess the relative importance of permafrost thaw, wildfire, and forest management on historical and projected carbon balance and carbon stocks in Alaska, from 1950 to 2100, at a 1-km resolution. Our simulations showed that the increase in plant productivity in response to warming in boreal and arctic regions is offset by soil carbon loss due to permafrost degradation and wildfire combustion during both historical and future simulations. Fire disturbances act as a catalyst accelerating permafrost degradation and associated soil carbon loss. In addition, our preliminary results for south coastal regions of Alaska indicate that logging of second growth forests could influence carbon dynamics in that region. Overall, these results have implications for land management strategies and illustrate the importance of taking into account multiple types of disturbance regimes in ecosystem models for Alaska.

  3. Isolation and characterization of Solenopsis invicta virus 3, a new positive-strand RNA virus infecting the red imported fire ant, Solenopsis invicta

    SciTech Connect

    Valles, Steven M.; Hashimoto, Yoshifumi

    2009-06-05

    We report the discovery of a new virus from the red imported fire ant, Solenopsis invicta. Solenopsis invicta virus 3 (SINV-3) represents the third virus discovered from this ant species using the metagenomics approach. The single (positive)-strand RNA, monopartite, bicistronic genome of SINV-3 was sequenced in entirety (GenBank accession number (FJ528584)), comprised of 10,386 nucleotides, and polyadenylated at the 3' terminus. This genome size was confirmed by Northern analysis. The genome revealed 2 large open reading frames (ORFs) in the sense orientation with an untranslated region (UTR) at each end and between the two ORFs. The 5' proximal ORF (ORF 1) encoded a predicted protein of 299.1 kDa (2580 amino acids). The 3' proximal ORF (ORF 2) encoded a predicted protein of 73.2 kDa (651 amino acids). RNA-dependent RNA polymerase (RdRp), helicase, and protease domains were recognized in ORF 1. SDS-PAGE separation of purified SINV-3 particles yielded 2 bands (ostensibly capsid proteins) with a combined molecular mass of 77.3 kDa which was similar to the mass predicted by ORF 2 (73.2 kDa). Phylogenetic analysis of the conserved amino acid sequences containing domains I to VIII of the RdRp from dicistroviruses, iflaviruses, plant small RNA viruses, picornaviruses, and 4 unassigned positive-strand RNA viruses revealed a trichotomous phenogram with SINV-3 and Kelp fly virus comprising a unique cluster. Electron microscopic examination of negatively stained samples of SINV-3 revealed isometric particles with apparent projections and a diameter of 27.3 +- 1.3 nm. SINV-3 was successfully transmitted to uninfected workers by feeding. The minus (replicative) strand of SINV-3 was detected in worker ants indicating replication of the virus. The possibility of using SINV-3 as a microbial control agent for fire ants is discussed.

  4. Effects of piperidine and piperideine alkaloids from the venom of red imported fire ants, Solenopsis invicta Buren, on Pythium ultimum Trow growth in vitro and the application of piperideine alkaloids to control cucumber..

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pythium ultimum Trow is a plant pathogen that causes significant yield losses on many economically important crops. Chemical seed treatment has been used for disease control. In searching for alternatives, the venom alkaloids from red imported fire ant were tested against P. ultimum in vitro and to ...

  5. Screening Test Items for Differential Item Functioning

    ERIC Educational Resources Information Center

    Longford, Nicholas T.

    2014-01-01

    A method for medical screening is adapted to differential item functioning (DIF). Its essential elements are explicit declarations of the level of DIF that is acceptable and of the loss function that quantifies the consequences of the two kinds of inappropriate classification of an item. Instead of a single level and a single function, sets of…

  6. Fire in the Earth system

    USGS Publications Warehouse

    Bowman, David M.J.S.; Balch, Jennifer; Artaxo, Paulo; Bond, William J.; Carlson, Jean M.; Cochrane, Mark A.; D'Antonio, Carla M.; DeFries, Ruth S.; Doyle, John C.; Harrison, Sandy P.; Johnston, Fay H.; Keeley, Jon E.; Krawchuk, Meg A.; Kull, Christian A.; Marston, J. Brad; Moritz, Max A.; Prentice, I. Colin; Roos, Christopher I.; Scott, Andrew C.; Swetnam, Thomas W.; van der Werf, Guido R.; Pyne, Stephen

    2009-01-01

    Fire is a worldwide phenomenon that appears in the geological record soon after the appearance of terrestrial plants. Fire influences global ecosystem patterns and processes, including vegetation distribution and structure, the carbon cycle, and climate. Although humans and fire have always coexisted, our capacity to manage fire remains imperfect and may become more difficult in the future as climate change alters fire regimes. This risk is difficult to assess, however, because fires are still poorly represented in global models. Here, we discuss some of the most important issues involved in developing a better understanding of the role of fire in the Earth system.

  7. Fire in the Earth system.

    PubMed

    Bowman, David M J S; Balch, Jennifer K; Artaxo, Paulo; Bond, William J; Carlson, Jean M; Cochrane, Mark A; D'Antonio, Carla M; Defries, Ruth S; Doyle, John C; Harrison, Sandy P; Johnston, Fay H; Keeley, Jon E; Krawchuk, Meg A; Kull, Christian A; Marston, J Brad; Moritz, Max A; Prentice, I Colin; Roos, Christopher I; Scott, Andrew C; Swetnam, Thomas W; van der Werf, Guido R; Pyne, Stephen J

    2009-04-24

    Fire is a worldwide phenomenon that appears in the geological record soon after the appearance of terrestrial plants. Fire influences global ecosystem patterns and processes, including vegetation distribution and structure, the carbon cycle, and climate. Although humans and fire have always coexisted, our capacity to manage fire remains imperfect and may become more difficult in the future as climate change alters fire regimes. This risk is difficult to assess, however, because fires are still poorly represented in global models. Here, we discuss some of the most important issues involved in developing a better understanding of the role of fire in the Earth system.

  8. Imported fire ants near the edge of their range: disturbance and moisture determine prevalence and impact of an invasive social insect.

    PubMed

    LeBrun, Edward G; Plowes, Robert M; Gilbert, Lawrence E

    2012-07-01

    1. Habitat disturbance and species invasions interact in natural systems, making it difficult to isolate the primary cause of ecosystem degradation. A general understanding requires case studies of how disturbance and invasion interact across a variety of ecosystem - invasive species combinations. 2. Dramatic losses in ant diversity followed the invasion of central Texas by red imported fire ants (Solenopsis invicta). However, recent manipulative studies in Florida revealed no effect on ant diversity following the removal of S. invicta from a disturbed pasture habitat, but moderate loss of diversity associated with their introduction into undisturbed habitat and no invasion occurred without disturbance. Thus, the importance of S. invicta in driving diversity loss and its ability to invade undisturbed systems is unresolved. 3. We examine the distribution and abundance of a large monogyne S. invicta population and its association with the co-occurring ant assemblage at a site in south Texas close to the aridity tolerance limit of S. invicta. 4. We document that moisture modulates S. invicta densities. Further, soil disturbing habitat manipulations greatly increase S. invicta population densities. However, S. invicta penetrates all habitats regardless of soil disturbance history. In contrast, controlled burns depress S. invicta densities. 5. In habitats where S. invicta is prevalent, it completely replaces native fire ants. However, S. invicta impacts native ants as a whole less strongly. Intriguingly, native ants responded distinctly to S. invicta in different environments. In wet, undisturbed environments, high S. invicta abundance disrupts the spatial structure of the ant assemblage by increasing clumping and is associated with reduced species density, while in dry-disturbed habitats, sites with high S. invicta abundance possess high numbers of native species. Analyses of co-occurrence indicate that reduced species density in wet

  9. Prevalence and impact of the microsporidium Thelohania solenopsae (Microsporidia) on wild populations of red imported fire ants, Solenopsis invicta, in Louisiana.

    PubMed

    Milks, Maynard L; Fuxa, James R; Richter, Arthur R

    2008-02-01

    We surveyed 165 sites to determine the ecological factors that might influence the distribution and prevalence of Thelohania solenopsae, and its effect on the demography of the red imported fire ant (Solenopsis invicta) in Louisiana. The microsporidium was found in 9.9% of colonies and at 16% of sites. Its distribution was clumped within the state with the majority of infected colonies and sites occurring in two infection patches. The proportion of polygyne colonies was a strong (positive) predictor of the proportion of infected colonies at a site. Infected monogyne colonies, however, still accounted for nearly 20% of infected colonies, a much higher proportion than anticipated. Several other factors, including the numbers of colonies at a site, precipitation, proximity to commercial waterways and ports, and type of habitat were also retained in the multiple logistic regression model describing T. solenopsae prevalence. The microsporidium appears to adversely affect the occurrence of brood, and possibly the size of S. invicta colonies and the mass of workers. It, however, was not included in the multiple regression model of the number of colonies or the density of ants at a site. Although our findings do not imply causation, they have identified several variables that might influence the epizootiology of T. solenopsae. Future work should concentrate on experimentally manipulating these variables to confirm these relationships.

  10. Insecticidal, fumigant, and repellent activities of sweet wormwood oil and its individual components against red imported fire ant workers (Hymenoptera: Formicidae).

    PubMed

    Zhang, Ning; Tang, Liang; Hu, Wei; Wang, Kun; Zhou, You; Li, Hong; Huang, Congling; Chun, Jiong; Zhang, Zhixiang

    2014-01-01

    In total, 29 compounds from sweet wormwood (Artemisia annua L.) oil were identified using gas chromatography-mass spectrometry. The five active components were D-camphor, linalool, cineole, α-terpineol, and L(-)-borneol. The effectiveness of A. annua oil, as well as d-camphor, linalool, cineole, α-terpineol, and L(-)-borneol, as fumigants, contact insecticides, and repellents, were tested on the red imported fire ant Solenopsis invicta Buren. The results indicated that A. annua oil has no significant topical toxicity; however, the spray contact test revealed that it has strong insecticidal activity and the inhibitory effect is stronger during closed exposure than during open exposure. In the fumigant test, cineole and D-camphor exhibited strong fumigant toxicity on minor and major S. invicta workers. They also caused 100% mortality at 5, 3, 2, and 1 mg/centrifuge tube but not at 0.5 mg/centrifuge tube. The mortality rates of linalool, α-terpineol, and L(-)-borneol exceeded 80% at 5, 3, and 2 mg/centrifuge tube. In the repellent test, cineole and d-camphor showed significant repellency at 100, 10, and 1 mg/kg. However, linalool, α-terpineol, and L(-)-borneol significantly facilitated digging at 10 and 1 mg/kg.

  11. Identification, expression, and immuno-reactivity of Sol i 2 & Sol i 4 venom proteins of queen red imported fire ants, Solenopsis invicta Buren (Hymenoptera: Formicidae).

    PubMed

    Lockwood, Stephanie A; Haghipour-Peasley, Jilla; Hoffman, Donald R; Deslippe, Richard J

    2012-10-01

    We report on two low-molecular weight proteins that are stored in the venom of queen red imported fire ants (Solenopsis invicta). Translated amino acid sequences identified one protein to have 74.8% identity with the Sol i 2w worker allergen, and the other protein was found to have 96/97% identity with Sol i 4.01w/4.02w worker allergens. Both Sol i 2 and Sol i 4 queen and worker proteins were expressed using pEXP1-DEST vector in SHuffle™ T7 Express lysY Escherichia coli. Proteins were expressed at significant concentrations, as opposed to the μg/ml amounts by our previous expression methods, enabling further study of these proteins. Sol i 2q protein bound weakly to human IgE, sera pooled from allergic patients, whereas Sol i 2w, Sol i 4.01w, and Sol i 4q proteins bound strongly. Despite Sol i 2w and Sol i 2q proteins having 74.8% identity, the queen protein is less immuno-reactive than the worker allergen. This finding is consistent with allergic individuals being less sensitive to queen than worker venom.

  12. Tissue, developmental, and caste-specific expression of odorant binding proteins in a eusocial insect, the red imported fire ant, Solenopsis invicta.

    PubMed

    Zhang, Wei; Wanchoo, Arun; Ortiz-Urquiza, Almudena; Xia, Yuxian; Keyhani, Nemat O

    2016-10-21

    Insects interact with the surrounding environment via chemoreception, and in social insects such as ants, chemoreception functions to mediate diverse behaviors including food acquisition, self/non-self recognition, and intraspecific communication. The invasive red imported fire ant, Solenopsis invicta, has spread worldwide, displaying a remarkable environmental adaptability. Odorant binding proteins (OBPs) are chemical compound carriers, involved in diverse physiological processes including odor detection and chemical transport. S. invicta contains a highly divergent 17-member OBP gene family, that includes an ant-specific expansion and the social organization implicated Gp-9 (OBP3) gene. A systematic gene expression analysis of the SiOBP repertoire was performed across social caste (workers, male and female alates), tissues (antennae, head, thorax, and abdomen), and developmental stages (egg, larvae, and pupae), revealing that although SiOBPs were expressed in the antennae, the major regions of expression were in the head and thorax across all castes, and the abdomen in male and female alates. SiOBPs were very highly expressed in female alates and at somewhat lower levels in male alates and workers. SiOBPs were differentially expressed, with unique signatures in various castes and tissues, suggesting functionality of SiOBPs beyond olfaction Expression patterns of SiOBP subgroups also showed relationships with their evolutionary relatedness.

  13. Tissue, developmental, and caste-specific expression of odorant binding proteins in a eusocial insect, the red imported fire ant, Solenopsis invicta

    PubMed Central

    Zhang, Wei; Wanchoo, Arun; Ortiz-Urquiza, Almudena; Xia, Yuxian; Keyhani, Nemat O.

    2016-01-01

    Insects interact with the surrounding environment via chemoreception, and in social insects such as ants, chemoreception functions to mediate diverse behaviors including food acquisition, self/non-self recognition, and intraspecific communication. The invasive red imported fire ant, Solenopsis invicta, has spread worldwide, displaying a remarkable environmental adaptability. Odorant binding proteins (OBPs) are chemical compound carriers, involved in diverse physiological processes including odor detection and chemical transport. S. invicta contains a highly divergent 17-member OBP gene family, that includes an ant-specific expansion and the social organization implicated Gp-9 (OBP3) gene. A systematic gene expression analysis of the SiOBP repertoire was performed across social caste (workers, male and female alates), tissues (antennae, head, thorax, and abdomen), and developmental stages (egg, larvae, and pupae), revealing that although SiOBPs were expressed in the antennae, the major regions of expression were in the head and thorax across all castes, and the abdomen in male and female alates. SiOBPs were very highly expressed in female alates and at somewhat lower levels in male alates and workers. SiOBPs were differentially expressed, with unique signatures in various castes and tissues, suggesting functionality of SiOBPs beyond olfaction Expression patterns of SiOBP subgroups also showed relationships with their evolutionary relatedness. PMID:27765943

  14. Fire fatalities in elderly people.

    PubMed

    Elder, A T; Squires, T; Busuttil, A

    1996-05-01

    Fatal dwelling-house fires account for 10% of all accidental deaths in the United Kingdom with one-quarter of the deaths being of elderly people. No study had described the characteristics of elderly individuals who die in fires. We report results from a retrospective review of all fatal dwelling-house fires in Scotland from 1980 to 1990. Of 1096 people dying in fires, 243 (23%) were aged over 75. When compared with patients under the age of 75, older patients were significantly less likely to be smokers. Significantly more fires killing elderly people were caused by faulty or misused electrical items in the house, particularly electric blankets. These differences between elderly and younger individuals dying in dwelling-house fires may suggest that preventive strategies for the elderly population require a different emphasis from those for younger people.

  15. GP-9s are ubiquitous proteins unlikely involved in olfactory mediation of social organization in the red imported fire ant, Solenopsis invicta.

    PubMed

    Leal, Walter S; Ishida, Yuko

    2008-01-01

    The red imported fire ant (RIFA), Solenopsis invicta, is an invasive species, accidentally introduced in the United States that can cause painful (sometimes life-threatening) stings to human, pets, and livestock. Their colonies have two social forms: monogyne and polygyne that have a single and multiple functional queens, respectively. A major gene (Gp-9), identified as a putative pheromone-binding protein on the basis of a modest amino acid sequence identity, has been suggested to influence the expression of colony social organization. Monogyne queens are reported to possess only the GP-9B alleles, whereas polygyne queens possess both GP-9B and GP-9b. Thus, both social forms are reported to express GP-9B, with GP-9b being a marker expressed in polygynes but it is absent in monogynes. Here, we report two types of polygyne colonies, one that does not express GP-9b (monogyne-like) and the other expressing both proteins, GP-9B and GP-9b. Given their expression pattern, GP-9s are hemolymph proteins, which are more likely to be involved in the transport of lipids and small ligands within the homocoel. GP-9B existed in two forms, one of them is phosphorylated. The helical-rich content of the protein resembles the secondary structures of a beetle hemolymph protein and moth pheromone-binding proteins. An olfactory role is unlikely given the lack of specific expression in the sensillar lymph. In marked contrast to GP-9s, a chemosensory protein, SinvCSP, is demonstrated to be specifically expressed in the antennae. Within the antennae, expression of SinvCSP is restricted to the last two segments, which are known to house olfactory sensilla.

  16. Fighting Fire with Fire.

    ERIC Educational Resources Information Center

    Spoor, Dana L.

    1996-01-01

    School districts are integrating security and life-safety systems into school buildings to protect students and property. This proactive approach includes sprinkler systems, fire alarms, and security systems that monitor door movement. Some school districts that are incorporating the latest life-safety technology are in Missouri, Ohio, California,…

  17. 14 CFR 125.119 - Fire precautions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Fire precautions. 125.119 Section 125.119....119 Fire precautions. (a) Each compartment must be designed so that, when used for storing cargo or... movement of cargo in the compartment and so that damage to or failure of the item would not create a...

  18. Writing better test items.

    PubMed

    Aucoin, Julia W

    2005-01-01

    Professional development specialists have had little opportunity to learn how to write test items to meet the expectations of today's graduate nurse. Schools of nursing have moved away from knowledge-level test items and have had to develop more application and analysis items to prepare graduates for the National Council Licensure Examination (NCLEX). This same type of question can be used effectively to support a competence assessment system and document critical thinking skills.

  19. Reversed item bias: an integrative model.

    PubMed

    Weijters, Bert; Baumgartner, Hans; Schillewaert, Niels

    2013-09-01

    In the recent methodological literature, various models have been proposed to account for the phenomenon that reversed items (defined as items for which respondents' scores have to be recoded in order to make the direction of keying consistent across all items) tend to lead to problematic responses. In this article we propose an integrative conceptualization of three important sources of reversed item method bias (acquiescence, careless responding, and confirmation bias) and specify a multisample confirmatory factor analysis model with 2 method factors to empirically test the hypothesized mechanisms, using explicit measures of acquiescence and carelessness and experimentally manipulated versions of a questionnaire that varies 3 item arrangements and the keying direction of the first item measuring the focal construct. We explain the mechanisms, review prior attempts to model reversed item bias, present our new model, and apply it to responses to a 4-item self-esteem scale (N = 306) and the 6-item Revised Life Orientation Test (N = 595). Based on the literature review and the empirical results, we formulate recommendations on how to use reversed items in questionnaires.

  20. Phase 2 fire hazard analysis for the canister storage building

    SciTech Connect

    Sadanaga, C.T., Westinghouse Hanford

    1996-07-01

    The fire hazard analysis assesses the risk from fire in a facility to ascertain whether the fire protection policies are met. This document provides a preliminary FHA for the CSB facility. Open items have been noted in the document. A final FHA will be required at the completion of definitive design, prior to operation of the facility.

  1. Fire investigation

    NASA Astrophysics Data System (ADS)

    Gomberg, A.

    There was considerable progress made on several fronts of fire investigation in the United States in recent years. Progress was made in increasing the quantity of fire investigation and reporting, through efforts to develop the National Fire Incident Reporting System. Improving overall quality of fire investigation is the objective of efforts such as the Fire Investigation Handbook, which was developed and published by the National Bureau of Standards, and the upgrading and expanding of the ""dictionary'' of fire investigation and reporting, the NFPA 901, Uniform Coding for Fire Protection, system. The science of fire investigation as furthered also by new approaches to post fire interviews being developed at the University of Washington, and by in-depth research into factors involved in several large loss fires, including the MGM Grand Hotel in Las Vegas. Finally, the use of special study fire investigations - in-depth investigations concentrating on specific fire problems - is producing new glimpses into the nature of the national fire problem. A brief description of the status of efforts in each of these areas is discussed.

  2. Fire ants

    MedlinePlus

    ... please enable JavaScript. Fire ants are red-colored insects. A sting from a fire ant delivers a ... poison control. Those who have an allergy to insect bites or stings should carry a bee sting ...

  3. Understory Fires

    NASA Video Gallery

    The flames of understory fires in the southern Amazon reach on average only a few feet tall, but the fire type can claim anywhere from 10 to 50 percent of a burn area's trees. Credit: NASA/Doug Morton

  4. MODIS NDVI Response Following Fires in Siberia

    NASA Technical Reports Server (NTRS)

    Ranson, K. Jon; Sun, G.; Kovacs, K.; Kharuk, V. I.

    2003-01-01

    The Siberian boreal forest is considered a carbon sink but may become an important source of carbon dioxide if climatic warming predictions are correct. The forest is continually changing through various disturbance mechanisms such as insects, logging, mineral exploitation, and especially fires. Patterns of disturbance and forest recovery processes are important factors regulating carbon flux in this area. NASA's Terra MODIS provides useful information for assessing location of fires and post fire changes in forests. MODIS fire (MOD14), and NDVI (MOD13) products were used to examine fire occurrence and post fire variability in vegetation cover as indicated by NDVI. Results were interpreted for various post fire outcomes, such as decreased NDVI after fire, no change in NDVI after fire and positive NDVI change after fire. The fire frequency data were also evaluated in terms of proximity to population centers, and transportation networks.

  5. Detecting Differential Item Functioning of Polytomous Items for an Ideal Point Response Process

    ERIC Educational Resources Information Center

    Wang, Wei; Tay, Louis; Drasgow, Fritz

    2013-01-01

    There has been growing use of ideal point models to develop scales measuring important psychological constructs. For meaningful comparisons across groups, it is important to identify items on such scales that exhibit differential item functioning (DIF). In this study, the authors examined several methods for assessing DIF on polytomous items…

  6. Enhanced Fire Events Database to Support Fire PRA

    SciTech Connect

    Patrick Baranowsky; Ken Canavan; Shawn St. Germain

    2010-06-01

    Abstract: This paper provides a description of the updated and enhanced Fire Events Data Base (FEDB) developed by the Electric Power Research Institute (EPRI) in cooperation with the U.S. Nuclear Regulatory Commission (NRC). The FEDB is the principal source of fire incident operational data for use in fire PRAs. It provides a comprehensive and consolidated source of fire incident information for nuclear power plants operating in the U.S. The database classification scheme identifies important attributes of fire incidents to characterize their nature, causal factors, and severity consistent with available data. The database provides sufficient detail to delineate important plant specific attributes of the incidents to the extent practical. A significant enhancement to the updated FEDB is the reorganization and refinement of the database structure and data fields and fire characterization details added to more rigorously capture the nature and magnitude of the fire and damage to the ignition source and nearby equipment and structures

  7. Evaluation of Item Candidates: The PROMIS Qualitative Item Review

    PubMed Central

    DeWalt, Darren A.; Rothrock, Nan; Yount, Susan; Stone, Arthur A.

    2009-01-01

    One of the PROMIS (Patient-Reported Outcome Measurement Information System) network's primary goals is the development of a comprehensive item bank for patient-reported outcomes of chronic diseases. For its first set of item banks, PROMIS chose to focus on pain, fatigue, emotional distress, physical function, and social function. An essential step for the development of an item pool is the identification, evaluation, and revision of extant questionnaire items for the core item pool. In this work, we also describe the systematic process wherein items are classified for subsequent statistical processing by the PROMIS investigators. Six phases of item development are documented: identification of extant items, item classification and selection, item review and revision, focus group input on domain coverage, cognitive interviews with individual items, and final revision before field testing. Identification of items refers to the systematic search for existing items in currently available scales. Expert item review and revision was conducted by trained professionals who reviewed the wording of each item and revised as appropriate for conventions adopted by the PROMIS network. Focus groups were used to confirm domain definitions and to identify new areas of item development for future PROMIS item banks. Cognitive interviews were used to examine individual items. Items successfully screened through this process were sent to field testing and will be subjected to innovative scale construction procedures. PMID:17443114

  8. 75 FR 62307 - Fire Prevention Week, 2010

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-08

    ... 8577 of October 1, 2010 Fire Prevention Week, 2010 By the President of the United States of America A Proclamation During Fire Prevention Week, we reaffirm the importance of fire safety and awareness, and we pay... our loved ones from the hazards of fire. Smoke alarms are vital detection devices, and...

  9. Evolution of a Test Item

    ERIC Educational Resources Information Center

    Spaan, Mary

    2007-01-01

    This article follows the development of test items (see "Language Assessment Quarterly", Volume 3 Issue 1, pp. 71-79 for the article "Test and Item Specifications Development"), beginning with a review of test and item specifications, then proceeding to writing and editing of items, pretesting and analysis, and finally selection of an item for a…

  10. Item Banking. Basic Testing Series.

    ERIC Educational Resources Information Center

    Childs, Roy

    This pamphlet describes the exciting potential of item banking--a new approach to testing which combines both comparability of scores with flexibility of test format. Item banks are collections of items where the characteristics of each item is known and these characteristics can be summated to described a test made from such items. The principle…

  11. Novelty and Promotional Items

    EPA Pesticide Factsheets

    Small novelty or promotional products, primarily used for outreach and educational purposes, must effectively convey a message, and their purchase will only be allowed if the item will contribute to the accomplishment of the Agency's mission.

  12. Relative Spectral Mixture Analysis for monitoring natural hazards that impact vegetation cover: the importance of the nonphotosynthetic fraction in understanding landscape response to drought, fire, and hurricane damage

    NASA Astrophysics Data System (ADS)

    Okin, G. S.

    2007-12-01

    Remote sensing provides a unique ability to monitor natural hazards that impact vegetation hydrologically. Here, the use of a new multitemporal remote sensing technique that employs free, coarse multispectral remote sensing data is demonstrated in monitoring short- and long-term drought, fire occurrence and recovery, and damage to hurricane-related mangrove ecosystems and subsequent recovery of these systems. The new technique, relative spectral mixture analysis (RSMA), provides information about the nonphotosynthetic fraction (nonphotosynthetic vegetation plus litter) of ground cover in addition to the green vegetation fraction. In some cases, RSMA even provides an improved ability to monitor changes in the green fraction compared to traditional vegetation indices or standard remote sensing products. In arid and semiarid regions, the nonphotosynthetic fraction can vary on an annual basis significantly more than the green fraction and is thus perfectly suited for monitoring drought in these regions. Mortality of evergreen trees due to long-term drought also shows up strongly in the nonphotosynthetic fraction as green vegetation is replaced by dry needles and bare trunks. The response of the nonphotosynthetic fraction to fire is significantly different from that of drought because of the combustion of nonphotosynthetic material. Finally, damage to mangrove ecosystems from hurricane damage, and their subsequent recovery, is readily observable in both the green and nonphotosynthetic fractions as estimated by RSMA.

  13. Using a Linear Regression Method to Detect Outliers in IRT Common Item Equating

    ERIC Educational Resources Information Center

    He, Yong; Cui, Zhongmin; Fang, Yu; Chen, Hanwei

    2013-01-01

    Common test items play an important role in equating alternate test forms under the common item nonequivalent groups design. When the item response theory (IRT) method is applied in equating, inconsistent item parameter estimates among common items can lead to large bias in equated scores. It is prudent to evaluate inconsistency in parameter…

  14. Robust Scale Transformation Methods in IRT True Score Equating under Common-Item Nonequivalent Groups Design

    ERIC Educational Resources Information Center

    He, Yong

    2013-01-01

    Common test items play an important role in equating multiple test forms under the common-item nonequivalent groups design. Inconsistent item parameter estimates among common items can lead to large bias in equated scores for IRT true score equating. Current methods extensively focus on detection and elimination of outlying common items, which…

  15. A Stepwise Test Characteristic Curve Method to Detect Item Parameter Drift

    ERIC Educational Resources Information Center

    Guo, Rui; Zheng, Yi; Chang, Hua-Hua

    2015-01-01

    An important assumption of item response theory is item parameter invariance. Sometimes, however, item parameters are not invariant across different test administrations due to factors other than sampling error; this phenomenon is termed item parameter drift. Several methods have been developed to detect drifted items. However, most of the…

  16. Item Pool Design for an Operational Variable-Length Computerized Adaptive Test

    ERIC Educational Resources Information Center

    He, Wei; Reckase, Mark D.

    2014-01-01

    For computerized adaptive tests (CATs) to work well, they must have an item pool with sufficient numbers of good quality items. Many researchers have pointed out that, in developing item pools for CATs, not only is the item pool size important but also the distribution of item parameters and practical considerations such as content distribution…

  17. Evaluating Item Discrimination Power of WHOQOL-BREF from an Item Response Model Perspectives

    ERIC Educational Resources Information Center

    Lin, Ting Hsiang; Yao, Grace

    2009-01-01

    Quality of life (QOL) has become an important component of health. By using the methodology of psychometric theory, we examine the item properties of the WHOQOL-BRIEF. Samejima's graded response model with natural metrics of the logistic response function was fitted. The results showed items with negative natures were less discriminating. Items…

  18. Mokken Scale Analysis for Dichotomous Items Using Marginal Models

    ERIC Educational Resources Information Center

    van der Ark, L. Andries; Croon, Marcel A.; Sijtsma, Klaas

    2008-01-01

    Scalability coefficients play an important role in Mokken scale analysis. For a set of items, scalability coefficients have been defined for each pair of items, for each individual item, and for the entire scale. Hypothesis testing with respect to these scalability coefficients has not been fully developed. This study introduces marginal modelling…

  19. Fire clay

    USGS Publications Warehouse

    Virta, R.L.

    2011-01-01

    The article discusses the latest developments in the fire clay industry, particularly in the U.S., as of June 2011. It claims that the leading fire clay producer in the U.S. is the state of Missouri. The other major producers include California, Texas and Washington. It reports that the use of heavy clay products made of fire clay like brick, cement and lightweight aggregate has increased slightly in 2010.

  20. Fire clay

    USGS Publications Warehouse

    Virta, R.L.

    2006-01-01

    In 2005, six companies mined fire clay in Missouri, Ohio and South Carolina. Production was estimate to be 300 kt with a value of $8.3 million. Missouri was the leading producer state followed by Ohio and South Carolina. For the third consecutive year, sales and use of fire clays have been relatively unchanged. For the next few years, sales of fire clay is forecasted to remain around 300 kt/a.

  1. Investigating an Invariant Item Ordering for Polytomously Scored Items

    ERIC Educational Resources Information Center

    Ligtvoet, Rudy; van der Ark, L. Andries; te Marvelde, Janneke M.; Sijtsma, Klaas

    2010-01-01

    This article discusses the concept of an invariant item ordering (IIO) for polytomously scored items and proposes methods for investigating an IIO in real test data. Method manifest IIO is proposed for assessing whether item response functions intersect. Coefficient H[superscript T] is defined for polytomously scored items. Given that an IIO…

  2. The Role of Item Models in Automatic Item Generation

    ERIC Educational Resources Information Center

    Gierl, Mark J.; Lai, Hollis

    2012-01-01

    Automatic item generation represents a relatively new but rapidly evolving research area where cognitive and psychometric theories are used to produce tests that include items generated using computer technology. Automatic item generation requires two steps. First, test development specialists create item models, which are comparable to templates…

  3. Fire clay

    USGS Publications Warehouse

    Virta, R.L.

    2013-01-01

    Four companies mined fire clay in three states in 2012. Production, based on a preliminary survey of the fire clay industry, was estimated to be 230 kt (254,000 st) valued at $6.98 million, an increase from 215 kt (237,000 st) valued at $6.15 million in 2011. Missouri was the leading producing state, followed by Colorado and Texas, in decreasing order by quantity. The number of companies mining fire clay declined in 2012 because several common clay producers that occasionally mine fire clay indicated that they did not do so in 2012.

  4. Relevance of Item Analysis in Standardizing an Achievement Test in Teaching of Physical Science in B.Ed Syllabus

    ERIC Educational Resources Information Center

    Marie, S. Maria Josephine Arokia; Edannur, Sreekala

    2015-01-01

    This paper focused on the analysis of test items constructed in the paper of teaching Physical Science for B.Ed. class. It involved the analysis of difficulty level and discrimination power of each test item. Item analysis allows selecting or omitting items from the test, but more importantly item analysis is a tool to help the item writer improve…

  5. A Study on Detecting of Differential Item Functioning of PISA 2006 Science Literacy Items in Turkish and American Samples

    ERIC Educational Resources Information Center

    Çikirikçi Demirtasli, Nükhet; Ulutas, Seher

    2015-01-01

    Problem Statement: Item bias occurs when individuals from different groups (different gender, cultural background, etc.) have different probabilities of responding correctly to a test item despite having the same skill levels. It is important that tests or items do not have bias in order to ensure the accuracy of decisions taken according to test…

  6. Fire Power

    ERIC Educational Resources Information Center

    Denker, Deb; West, Lee

    2009-01-01

    For education administrators, campus fires are not only a distressing loss, but also a stark reminder that a campus faces risks that require special vigilance. In many ways, campuses resemble small communities, with areas for living, working and relaxing. A residence hall fire may raise the specter of careless youth, often with the complication of…

  7. Returning Fire

    ERIC Educational Resources Information Center

    Gould, Jon B.

    2007-01-01

    Last December saw another predictable report from the Foundation for Individual Rights in Education (FIRE), a self-described watchdog group, highlighting how higher education is supposedly under siege from a politically correct plague of so-called hate-speech codes. In that report, FIRE declared that as many as 96 percent of top-ranked colleges…

  8. Arizona Fires

    Atmospheric Science Data Center

    2014-05-15

    ... and is currently the second largest fire in Arizona history. More than 2,000 people are working to contain the fire, which is being ... bright desert background. The areas with no data (shown in black and present at the oblique angles) are locations where the variable ...

  9. California Fires

    Atmospheric Science Data Center

    2014-05-15

    article title:  Smoke Blankets Northern California     View Larger Image ... strikes sparked more than a thousand fires in northern California. This image was captured by the Multi-angle Imaging ... June 27, 2008 - Smoke from fires in northern California. project:  MISR category:  gallery ...

  10. Fire and smoke retardants

    NASA Astrophysics Data System (ADS)

    Drews, M. J.

    Despite a reduction in Federal regulatory activity, research concerned with flame retardancy and smoke suppression in the private sector appears to be increasing. This trend seem related to the increased utilization of plastics for end uses which traditionally have employed metal or wood products. As a result, new markets have appeared for thermally stable and fire resistance thermoplastic materials, and this in turn has spurred research and development activity. In addition, public awareness of the dangers associated with fire has increased as a result of several highly publicized hotel and restaurant fires within the past two years. The consumers recognition of flammability characteristics as important materials property considerations has increased. The current status of fire and smoke retardant chemistry and research are summarized.

  11. Limited life item management

    NASA Technical Reports Server (NTRS)

    Eaglen, R. L.

    1971-01-01

    Plans are available for age-sensitive hardware management. Control plan identifies shelf life or age control requirements for materials considered age sensitive, use sensitive, or time service or shelf life controlled items, and describes methods of arriving at age controls through adherence to detailed specifications.

  12. 46 CFR 28.315 - Fire pumps, fire mains, fire hydrants, and fire hoses.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Fire pumps, fire mains, fire hydrants, and fire hoses... After September 15, 1991, and That Operate With More Than 16 Individuals on Board § 28.315 Fire pumps, fire mains, fire hydrants, and fire hoses. (a) Each vessel 36 feet (11.8 meters) or more in length...

  13. 46 CFR 28.315 - Fire pumps, fire mains, fire hydrants, and fire hoses.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Fire pumps, fire mains, fire hydrants, and fire hoses... After September 15, 1991, and That Operate With More Than 16 Individuals on Board § 28.315 Fire pumps, fire mains, fire hydrants, and fire hoses. (a) Each vessel 36 feet (11.8 meters) or more in length...

  14. Examining Differential Item Functions of Different Item Ordered Test Forms According to Item Difficulty Levels

    ERIC Educational Resources Information Center

    Çokluk, Ömay; Gül, Emrah; Dogan-Gül, Çilem

    2016-01-01

    The study aims to examine whether differential item function is displayed in three different test forms that have item orders of random and sequential versions (easy-to-hard and hard-to-easy), based on Classical Test Theory (CTT) and Item Response Theory (IRT) methods and bearing item difficulty levels in mind. In the correlational research, the…

  15. Spacecraft Fire Safety

    NASA Technical Reports Server (NTRS)

    Margle, Janice M. (Editor)

    1987-01-01

    Fire detection, fire standards and testing, fire extinguishment, inerting and atmospheres, fire-related medical science, aircraft fire safety, Space Station safety concerns, microgravity combustion, spacecraft material flammability testing, and metal combustion are among the topics considered.

  16. Hydrogen Fire Spectroscopy Issues Project

    NASA Technical Reports Server (NTRS)

    Youngquist, Robert C. (Compiler)

    2014-01-01

    The detection of hydrogen fires is important to the aerospace community. The National Aeronautics and Space Administration (NASA) has devoted significant effort to the development, testing, and installation of hydrogen fire detectors based on ultraviolet, near-infrared, mid-infrared, andor far-infrared flame emission bands. Yet, there is no intensity calibrated hydrogen-air flame spectrum over this range in the literature and consequently, it can be difficult to compare the merits of different radiation-based hydrogen fire detectors.

  17. Development and assessment of floor and ceiling items for the PROMIS physical function item bank

    PubMed Central

    2013-01-01

    Introduction Disability and Physical Function (PF) outcome assessment has had limited ability to measure functional status at the floor (very poor functional abilities) or the ceiling (very high functional abilities). We sought to identify, develop and evaluate new floor and ceiling items to enable broader and more precise assessment of PF outcomes for the NIH Patient-Reported-Outcomes Measurement Information System (PROMIS). Methods We conducted two cross-sectional studies using NIH PROMIS item improvement protocols with expert review, participant survey and focus group methods. In Study 1, respondents with low PF abilities evaluated new floor items, and those with high PF abilities evaluated new ceiling items for clarity, importance and relevance. In Study 2, we compared difficulty ratings of new floor items by low functioning respondents and ceiling items by high functioning respondents to reference PROMIS PF-10 items. We used frequencies, percentages, means and standard deviations to analyze the data. Results In Study 1, low (n = 84) and high (n = 90) functioning respondents were mostly White, women, 70 years old, with some college, and disability scores of 0.62 and 0.30. More than 90% of the 31 new floor and 31 new ceiling items were rated as clear, important and relevant, leaving 26 ceiling and 30 floor items for Study 2. Low (n = 246) and high (n = 637) functioning Study 2 respondents were mostly White, women, 70 years old, with some college, and Health Assessment Questionnaire (HAQ) scores of 1.62 and 0.003. Compared to difficulty ratings of reference items, ceiling items were rated to be 10% more to greater than 40% more difficult to do, and floor items were rated to be about 12% to nearly 90% less difficult to do. Conclusions These new floor and ceiling items considerably extend the measurable range of physical function at either extreme. They will help improve instrument performance in populations with broad functional ranges and those concentrated at

  18. Extending item response theory to online homework

    NASA Astrophysics Data System (ADS)

    Kortemeyer, Gerd

    2014-06-01

    Item response theory (IRT) becomes an increasingly important tool when analyzing "big data" gathered from online educational venues. However, the mechanism was originally developed in traditional exam settings, and several of its assumptions are infringed upon when deployed in the online realm. For a large-enrollment physics course for scientists and engineers, the study compares outcomes from IRT analyses of exam and homework data, and then proceeds to investigate the effects of each confounding factor introduced in the online realm. It is found that IRT yields the correct trends for learner ability and meaningful item parameters, yet overall agreement with exam data is moderate. It is also found that learner ability and item discrimination is robust over a wide range with respect to model assumptions and introduced noise. Item difficulty is also robust, but over a narrower range.

  19. Parents of preschool fire setters: perceptions of the child-play fire hazard.

    PubMed

    Pollack-Nelson, Carol; Faranda, Donna M; Porth, Don; Lim, Nicholas K

    2006-09-01

    The present study sought to learn about risk perceptions held by parents of preschool fire-setters. A 41-item survey was distributed to 60 parents whose children, aged 6 years and younger, had previously set fires and who were involved in intervention programmes throughout the US. Most parents did not think their children would play with matches/lighters, or knew how to use these items, although some had witnessed their children playing with matches/lighters previously. Most parents reported having taken precautions to keep matches/lighters out of reach and also educating their children about fire. Regardless, children not only set fires, but in 40% of cases climbed to access the match/lighter. Parents' perceptions of their children's proclivity for fire play were not consistent with their actual fire-play behaviour. Parents underestimated the likelihood that their children would play with matches/lighters. Although most reportedly undertook preventative measures aimed at thwarting fire play, these strategies were ineffective. Traditionally relied upon precautionary techniques, such as storing lighters out of reach and discussing the dangers of fire, were not sufficient to stem interest and resultant fire play.

  20. Fire and climate in Mongolia (1532-2010 Common Era)

    NASA Astrophysics Data System (ADS)

    Hessl, Amy E.; Brown, Peter; Byambasuren, Oyunsanaa; Cockrell, Shawn; Leland, Caroline; Cook, Ed; Nachin, Baatarbileg; Pederson, Neil; Saladyga, Thomas; Suran, Byambagerel

    2016-06-01

    Recent increases in wildland fire, warming temperatures, and land use change have coincided in many forested regions, making it difficult to parse causes of elevated fire activity. Here we use 20 multicentury fire scar chronologies (464 fire scar samples) from Mongolia to evaluate the role of climate forcing of fire in the context of livestock grazing and minimal fire suppression. We observe no change in fire return intervals post-1900; however, since the 1500s, periods of drought are coincident with more fire and shorter fire return intervals. We observe same year and some antecedent year effects of drought on fire, a pattern typical of semiarid forests elsewhere. During the instrumental period, drought remains an important driver of fire; however, limited fire activity in recent decades may be due to the coincidence of drought and intensive grazing that have synergized to reduce fuel continuity and fire spread.

  1. Montana Fires

    Atmospheric Science Data Center

    2014-05-15

    ... fires raging in Montana and Hurricane Hector swirling in the Pacific. These two unrelated, large-scale examples of nature's fury were ... location:  United States Pacific Ocean region:  Western United States Order:  55 ...

  2. Texas Fires

    Atmospheric Science Data Center

    2014-05-15

    article title:  Wind-Whipped Fires in East Texas     View Larger Image ... one-year drought on record and the warmest month in Texas history. The Multi-angle Imaging SpectroRadiometer (MISR) instrument on ...

  3. The Impact of Item Characteristics on Item and Scale Validity

    ERIC Educational Resources Information Center

    Johnson, John A.

    2004-01-01

    This study describes the relation between personality items' validities, defined as the items' correlations with acquaintance ratings on the Big 5 personality factors, and other itemmetric properties including ambiguity, syntactic complexity, social desirability, content, and trait indicativity. Five external validity coefficients for each item on…

  4. IRT Item Parameter Scaling for Developing New Item Pools

    ERIC Educational Resources Information Center

    Kang, Hyeon-Ah; Lu, Ying; Chang, Hua-Hua

    2017-01-01

    Increasing use of item pools in large-scale educational assessments calls for an appropriate scaling procedure to achieve a common metric among field-tested items. The present study examines scaling procedures for developing a new item pool under a spiraled block linking design. The three scaling procedures are considered: (a) concurrent…

  5. Component Identification and Item Difficulty of Raven's Matrices Items.

    ERIC Educational Resources Information Center

    Green, Kathy E.; Kluever, Raymond C.

    Item components that might contribute to the difficulty of items on the Raven Colored Progressive Matrices (CPM) and the Standard Progressive Matrices (SPM) were studied. Subjects providing responses to CPM items were 269 children aged 2 years 9 months to 11 years 8 months, most of whom were referred for testing as potentially gifted. A second…

  6. Item Context Factors Affecting Students' Performance on Mathematics Items

    ERIC Educational Resources Information Center

    Salgado, Felipe Almuna; Stacey, Kaye

    2014-01-01

    This paper reports how the context in which a mathematics item is embedded impacts on students' performance. The performance of Year 10 students on four PISA items was compared with performance on variants with more familiar contexts. Performance was not better when they solved items with more familiar contexts but there was some evidence that…

  7. Real and Artificial Differential Item Functioning in Polytomous Items

    ERIC Educational Resources Information Center

    Andrich, David; Hagquist, Curt

    2015-01-01

    Differential item functioning (DIF) for an item between two groups is present if, for the same person location on a variable, persons from different groups have different expected values for their responses. Applying only to dichotomously scored items in the popular Mantel-Haenszel (MH) method for detecting DIF in which persons are classified by…

  8. Fire clay

    USGS Publications Warehouse

    Virta, R.L.

    2012-01-01

    Five companies mined fire clay in four states in 2011. Production, based on a preliminary survey of the fire clay industry, was estimated to be 240 kt (265,000 st), valued at $7.68 million, an increase from 216 kt (238,000 st), valued at $6.12 million in 2010. Missouri was the leading producing state, followed by Texas, Washington and Ohio, in decreasing order by quantity.

  9. Glass fabric fire barrier for silicone rubber parts

    NASA Technical Reports Server (NTRS)

    Blackmer, K. L.

    1969-01-01

    Preformed knitted glass-fabric covers are placed about silicone rubber items in such a way as to completely isolate them from the effects of adjacent fire. These covers permit retention of the desirable resilient properties of the silicone rubber while forming a very effective fire barrier.

  10. Assessing European wild fire vulnerability

    NASA Astrophysics Data System (ADS)

    Oehler, F.; Oliveira, S.; Barredo, J. I.; Camia, A.; Ayanz, J. San Miguel; Pettenella, D.; Mavsar, R.

    2012-04-01

    Wild fire vulnerability is a measure of potential socio-economic damage caused by a fire in a specific area. As such it is an important component of long-term fire risk management, helping policy-makers take informed decisions about adequate expenditures for fire prevention and suppression, and to target those regions at highest risk. This paper presents a first approach to assess wild fire vulnerability at the European level. A conservative approach was chosen that assesses the cost of restoring the previous land cover after a potential fire. Based on the CORINE Land Cover, a restoration cost was established for each land cover class at country level, and an average restoration time was assigned according to the recovery capacity of the land cover. The damage caused by fire was then assessed by discounting the cost of restoring the previous land cover over the restoration period. Three different vulnerability scenarios were considered assuming low, medium and high fire severity causing different levels of damage. Over Europe, the potential damage of wild land fires ranges from 10 - 13, 732 Euro*ha-1*yr-1 for low fire severity, 32 - 45,772 Euro*ha-1*yr-1 for medium fire severity and 54 - 77,812 Euro*ha-1*yr-1 for high fire severity. The least vulnerable are natural grasslands, moors and heathland and sclerophyllous vegetation, while the highest cost occurs for restoring broad-leaved forest. Preliminary validation comparing these estimates with official damage assessments for past fires shows reasonable results. The restoration cost approach allows for a straightforward, data extensive assessment of fire vulnerability at European level. A disadvantage is the inherent simplification of the evaluation procedure with the underestimation of non-markets goods and services. Thus, a second approach has been developed, valuing individual wild land goods and services and assessing their annual flow which is lost for a certain period of time in case of a fire event. However

  11. Research on fire hose couplings damages

    NASA Astrophysics Data System (ADS)

    Babut, C.; Ungureanu, N.; Ungureanu, M.

    2017-01-01

    This paper presents a part of a research on the damaging of fire hose coupling. These are important components of the hydraulic systems used by firefighters to deliver one or more suppression agents into the fire. The operating regime parameters, working environment and general functioning conditions during fire suppression operations may lead to malfunctions and/or damaging of the couplings.

  12. Post-fire vegetation and fuel development influences fire severity patterns in reburns.

    PubMed

    Coppoletta, Michelle; Merriam, Kyle E; Collins, Brandon M

    2016-04-01

    In areas where fire regimes and forest structure have been dramatically altered, there is increasing concern that contemporary fires have the potential to set forests on a positive feedback trajectory with successive reburns, one in which extensive stand-replacing fire could promote more stand-replacing fire. Our study utilized an extensive set of field plots established following four fires that occurred between 2000 and 2010 in the northern Sierra Nevada, California, USA that were subsequently reburned in 2012. The information obtained from these field plots allowed for a unique set of analyses investigating the effect of vegetation, fuels, topography, fire weather, and forest management on reburn severity. We also examined the influence of initial fire severity and time since initial fire on influential predictors of reburn severity. Our results suggest that high- to moderate-severity fire in the initial fires led to an increase in standing snags and shrub vegetation, which in combination with severe fire weather promoted high-severity fire effects in the subsequent reburn. Although fire behavior is largely driven by weather, our study demonstrates that post-fire vegetation composition and structure are also important drivers of reburn severity. In the face of changing climatic regimes and increases in extreme fire weather, these results may provide managers with options to create more fire-resilient ecosystems. In areas where frequent high-severity fire is undesirable, management activities such as thinning, prescribed fire, or managed wildland fire can be used to moderate fire behavior not only prior to initial fires, but also before subsequent reburns.

  13. Decisions that Make a Difference in Detecting Differential Item Functioning

    ERIC Educational Resources Information Center

    Sireci, Stephen G.; Rios, Joseph A.

    2013-01-01

    There are numerous statistical procedures for detecting items that function differently across subgroups of examinees that take a test or survey. However, in endeavouring to detect items that may function differentially, selection of the statistical method is only one of many important decisions. In this article, we discuss the important decisions…

  14. The largest forest fires in Portugal: the constraints of burned area size on the comprehension of fire severity.

    PubMed

    Tedim, Fantina; Remelgado, Ruben; Martins, João; Carvalho, Salete

    2015-01-01

    Portugal is a European country with highest forest fires density and burned area. Since beginning of official forest fires database in 1980, an increase in number of fires and burned area as well as appearance of large and catastrophic fires have characterized fire activity in Portugal. In 1980s, the largest fires were just a little bit over 10,000 ha. However, in the beginning of 21st century several fires occurred with a burned area over 20,000 ha. Some of these events can be classified as mega-fires due to their ecological and socioeconomic severity. The present study aimed to discuss the characterization of large forest fires trend, in order to understand if the largest fires that occurred in Portugal were exceptional events or evidences of a new trend, and the constraints of fire size to characterize fire effects because, usually, it is assumed that larger the fire higher the damages. Using Portuguese forest fire database and satellite imagery, the present study showed that the largest fires could be seen at the same time as exceptional events and as evidence of a new fire regime. It highlighted the importance of size and patterns of unburned patches within fire perimeter as well as heterogeneity of fire ecological severity, usually not included in fire regime description, which are critical to fire management and research. The findings of this research can be used in forest risk reduction and suppression planning.

  15. Seasonal distribution of African savanna fires

    NASA Technical Reports Server (NTRS)

    Cahoon, Donald R., Jr.; Stocks, Brian J.; Levine, Joel S.; Cofer, Wesley R., III; O'Neill, Katherine P.

    1992-01-01

    The temporal and spatial distribution of savanna fires over the entire African continent, as determined from nighttime satellite imagery, is described. It is found that, contrary to expectations, most fires are left to burn uncontrolled, so that there is no strong diurnal cycle in the fire frequency. The knowledge gained from this study regarding the distribution and variability of fires is helpful in the monitoring of climatically important trace gases emitted from burning biomass.

  16. Effects of Ignoring Item Interaction on Item Parameter Estimation and Detection of Interacting Items

    ERIC Educational Resources Information Center

    Chen, Cheng-Te; Wang, Wen-Chung

    2007-01-01

    This study explores the effects of ignoring item interaction on item parameter estimation and the efficiency of using the local dependence index Q[subscript 3] and the SAS NLMIXED procedure to detect item interaction under the three-parameter logistic model and the generalized partial credit model. Through simulations, it was found that ignoring…

  17. Halon fire extinguishants

    SciTech Connect

    Tapscott, R.

    1991-12-31

    Concerns about depletion of stratospheric ozone has forced restrictions on the production and use of some of our most important chemicals -- the chlorofluorocarbons (CFCs) and halon. Halons, the subject of this paper, are used for fire extinguishment, inertion, and explosion suppression. Assessment of business opportunities with halon replacement agents must take into account three uncertainties: (1) future regulatory activities, (2) a decreasing market due to conversion to alternative fire protection approaches, and (3) the unsettle technologies. The alternative approaches that will reduce the market for halons and halon-like agents include new procedures, equipment, engineering, and alternative agents (carbon dioxide, water, foam, dry chemical).

  18. A Framework for Examining the Utility of Technology-Enhanced Items

    ERIC Educational Resources Information Center

    Russell, Michael

    2016-01-01

    Interest in and use of technology-enhanced items has increased over the past decade. Given the additional time required to administer many technology-enhanced items and the increased expense required to develop them, it is important for testing programs to consider the utility of technology-enhanced items. The Technology-Enhanced Item Utility…

  19. Predicting Item Difficulty of Science National Curriculum Tests: The Case of Key Stage 2 Assessments

    ERIC Educational Resources Information Center

    El Masri, Yasmine H.; Ferrara, Steve; Foltz, Peter W.; Baird, Jo-Anne

    2017-01-01

    Predicting item difficulty is highly important in education for both teachers and item writers. Despite identifying a large number of explanatory variables, predicting item difficulty remains a challenge in educational assessment with empirical attempts rarely exceeding 25% of variance explained. This paper analyses 216 science items of key stage…

  20. The National Item Analysis Program. Metropolitan Achievement Tests, 1978 Edition. Special Report Number 7.

    ERIC Educational Resources Information Center

    Psychological Corp., New York, NY.

    The following information on the development of the 1978 Metropolitan Achievement Tests (MAT), fifth edition, is given; the purpose and importance of item analysis, steps preceding item tryout, characteristics of the sample population, and data obtained. Item analysis allows elimination of undesirable items, adjustment of the difficulty level of…

  1. Characterization of fire regime in Sardinia (Italy)

    NASA Astrophysics Data System (ADS)

    Bacciu, V. M.; Salis, M.; Mastinu, S.; Masala, F.; Sirca, C.; Spano, D.

    2012-12-01

    In the last decades, a number of Authors highlighted the crucial role of forest fires within Mediterranean ecosystems, with impacts both negative and positive on all biosphere components and with reverberations on different scales. Fire determines the landscape structure and plant composition, but it is also the cause of enormous economic and ecological damages, beside the loss of human life. In Sardinia (Italy), the second largest island of the Mediterranean Basin, forest fires are perceived as one of the main environmental and social problems, and data are showing that the situation is worsening especially within the rural-urban peripheries and the increasing number of very large forest fires. The need for information concerning forest fire regime has been pointed out by several Authors (e.g. Rollins et al., 2002), who also emphasized the importance of understanding the factors (such as weather/climate, socio-economic, and land use) that determine spatial and temporal fire patterns. These would be used not only as a baseline to predict the climate change effect on forest fires, but also as a fire management and mitigation strategy. The main aim of this paper is, thus, to analyze the temporal and spatial patterns of fire occurrence in Sardinia (Italy) during the last three decades (1980-2010). For the analyzed period, fire statistics were provided by the Sardinian Forest Service (CFVA - Corpo Forestale e di Vigilanza Ambientale), while weather data for eight weather stations were obtained from the web site www.tutiempo.it. For each station, daily series of precipitation, mean, maximum and minimum temperature, relative humidity and wind speed were available. The present study firstly analyzed fire statistics (burned area and number of fires) according to the main fire regime characteristics (seasonality, fire return interval, fire incidence, fire size distribution). Then, fire and weather daily values were averaged to obtain monthly, seasonal and annual values, and

  2. Techniques for fire detection

    NASA Technical Reports Server (NTRS)

    Bukowski, Richard W.

    1987-01-01

    An overview is given of the basis for an analysis of combustable materials and potential ignition sources in a spacecraft. First, the burning process is discussed in terms of the production of the fire signatures normally associated with detection devices. These include convected and radiated thermal energy, particulates, and gases. Second, the transport processes associated with the movement of these from the fire to the detector, along with the important phenomena which cause the level of these signatures to be reduced, are described. Third, the operating characteristics of the individual types of detectors which influence their response to signals, are presented. Finally, vulnerability analysis using predictive fire modeling techniques is discussed as a means to establish the necessary response of the detection system to provide the level of protection required in the application.

  3. The importance of SO{sub 2} and SO{sub 3} for sulphation of gaseous KCl - An experimental investigation in a biomass fired CFB boiler

    SciTech Connect

    Kassman, Haakan; Baefver, Linda; Aamand, Lars-Erik

    2010-09-15

    This paper is based on results obtained during co-combustion of wood pellets and straw in a 12 MW circulating fluidised bed (CFB) boiler. Elemental sulphur (S) and ammonium sulphate ((NH{sub 4}){sub 2}SO{sub 4}) were used as additives to convert the alkali chlorides (mainly KCl) to less corrosive alkali sulphates. Their performance was then evaluated using several measurement tools including, IACM (on-line measurements of gaseous alkali chlorides), a low-pressure impactor (particle size distribution and chemical composition of extracted fly ash particles), and deposit probes (chemical composition in deposits collected). The importance of the presence of either SO{sub 2} or SO{sub 3} for gas phase sulphation of KCl is also discussed. Ammonium sulphate performed significantly better than elemental sulphur. A more efficient sulphation of gaseous KCl was achieved with (NH{sub 4}){sub 2}SO{sub 4} even when the S/Cl molar ratio was less than half compared to sulphur. Thus the presence of gaseous SO{sub 3} is of greater importance than that of SO{sub 2} for the sulphation of gaseous KCl. (author)

  4. [Analysis of human tissue samples for volatile fire accelerants].

    PubMed

    Treibs, Rudolf

    2014-01-01

    In police investigations of fires, the cause of a fire and the fire debris analysis regarding traces of fire accelerants are important aspects for forensic scientists. Established analytical procedures were recently applied to the remains of fire victims. When examining lung tissue samples, vapors inhaled from volatile ignitable liquids could be identified and differentiated from products of pyrolysis caused by the fire. In addition to the medico-legal results this evidence allowed to draw conclusions as to whether the fire victim was still alive when the fire started.

  5. Active Fire Mapping Program

    MedlinePlus

    Active Fire Mapping Program Current Large Incidents (Home) New Large Incidents Fire Detection Maps MODIS Satellite Imagery VIIRS Satellite Imagery Fire Detection GIS Data Fire Data in Google Earth ...

  6. Fire frequency, area burned, and severity: A quantitative approach to defining a normal fire year

    USGS Publications Warehouse

    Lutz, J.A.; Key, C.H.; Kolden, C.A.; Kane, J.T.; van Wagtendonk, J.W.

    2011-01-01

    Fire frequency, area burned, and fire severity are important attributes of a fire regime, but few studies have quantified the interrelationships among them in evaluating a fire year. Although area burned is often used to summarize a fire season, burned area may not be well correlated with either the number or ecological effect of fires. Using the Landsat data archive, we examined all 148 wildland fires (prescribed fires and wildfires) >40 ha from 1984 through 2009 for the portion of the Sierra Nevada centered on Yosemite National Park, California, USA. We calculated mean fire frequency and mean annual area burned from a combination of field- and satellite-derived data. We used the continuous probability distribution of the differenced Normalized Burn Ratio (dNBR) values to describe fire severity. For fires >40 ha, fire frequency, annual area burned, and cumulative severity were consistent in only 13 of 26 years (50 %), but all pair-wise comparisons among these fire regime attributes were significant. Borrowing from long-established practice in climate science, we defined "fire normals" to be the 26 year means of fire frequency, annual area burned, and the area under the cumulative probability distribution of dNBR. Fire severity normals were significantly lower when they were aggregated by year compared to aggregation by area. Cumulative severity distributions for each year were best modeled with Weibull functions (all 26 years, r2 ??? 0.99; P < 0.001). Explicit modeling of the cumulative severity distributions may allow more comprehensive modeling of climate-severity and area-severity relationships. Together, the three metrics of number of fires, size of fires, and severity of fires provide land managers with a more comprehensive summary of a given fire year than any single metric.

  7. IRT Model Selection Methods for Dichotomous Items

    ERIC Educational Resources Information Center

    Kang, Taehoon; Cohen, Allan S.

    2007-01-01

    Fit of the model to the data is important if the benefits of item response theory (IRT) are to be obtained. In this study, the authors compared model selection results using the likelihood ratio test, two information-based criteria, and two Bayesian methods. An example illustrated the potential for inconsistency in model selection depending on…

  8. Item Effects in Recognition Memory for Words

    ERIC Educational Resources Information Center

    Freeman, Emily; Heathcote, Andrew; Chalmers, Kerry; Hockley, William

    2010-01-01

    We investigate the effects of word characteristics on episodic recognition memory using analyses that avoid Clark's (1973) "language-as-a-fixed-effect" fallacy. Our results demonstrate the importance of modeling word variability and show that episodic memory for words is strongly affected by item noise (Criss & Shiffrin, 2004), as measured by the…

  9. Extending Item Response Theory to Online Homework

    ERIC Educational Resources Information Center

    Kortemeyer, Gerd

    2014-01-01

    Item response theory (IRT) becomes an increasingly important tool when analyzing "big data" gathered from online educational venues. However, the mechanism was originally developed in traditional exam settings, and several of its assumptions are infringed upon when deployed in the online realm. For a large-enrollment physics course for…

  10. How Item Writers Understand Depth of Knowledge

    ERIC Educational Resources Information Center

    Wyse, Adam E.; Viger, Steven G.

    2011-01-01

    An important part of test development is ensuring alignment between test forms and content standards. One common way of measuring alignment is the Webb (1997, 2007) alignment procedure. This article investigates (a) how well item writers understand components of the definition of Depth of Knowledge (DOK) from the Webb alignment procedure and (b)…

  11. Hazardous metals in yellow items used in RCAs

    SciTech Connect

    Brown, K.F.; Rankin, W.N.

    1992-04-21

    Yellow items used in Radiologically Controlled Areas (RCAs) that could contain hazardous metals were identified. X-ray fluorescence analyses indicated that thirty of the fifty-two items do contain hazardous metals. It is important to minimize the hazardous metals put into the wastes. The authors recommend that the specifications for all yellow items stocked in Stores be changed to specify that they contain no hazardous metals.

  12. Development of the PROMIS® Health Expectancies of Smoking Item Banks

    PubMed Central

    Tucker, Joan S.; Shadel, William G.; Stucky, Brian D.; Cerully, Jennifer; Li, Zhen; Hansen, Mark; Cai, Li

    2014-01-01

    Introduction: Smokers’ health-related outcome expectancies are associated with a number of important constructs in smoking research, yet there are no measures currently available that focus exclusively on this domain. This paper describes the development and evaluation of item banks for assessing the health expectancies of smoking. Methods: Using data from a sample of daily (N = 4,201) and nondaily (N = 1,183) smokers, we conducted a series of item factor analyses, item response theory analyses, and differential item functioning analyses (according to gender, age, and race/ethnicity) to arrive at a unidimensional set of health expectancies items for daily and nondaily smokers. We also evaluated the performance of short forms (SFs) and computer adaptive tests (CATs) to efficiently assess health expectancies. Results: A total of 24 items were included in the Health Expectancies item banks; 13 items are common across daily and nondaily smokers, 6 are unique to daily, and 5 are unique to nondaily. For both daily and nondaily smokers, the Health Expectancies item banks are unidimensional, reliable (reliability = 0.95 and 0.96, respectively), and perform similarly across gender, age, and race/ethnicity groups. A SF common to daily and nondaily smokers consists of 6 items (reliability = 0.87). Results from simulated CATs showed that health expectancies can be assessed with good precision with an average of 5–6 items adaptively selected from the item banks. Conclusions: Health expectancies of smoking can be assessed on the basis of these item banks via SFs, CATs, or through a tailored set of items selected for a specific research purpose. PMID:25118229

  13. 46 CFR 28.820 - Fire pumps, fire mains, fire hydrants, and fire hoses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Fire pumps, fire mains, fire hydrants, and fire hoses... REQUIREMENTS FOR COMMERCIAL FISHING INDUSTRY VESSELS Aleutian Trade Act Vessels § 28.820 Fire pumps, fire mains... pump connected to a fixed piping system. This pump must be capable of delivering an effective stream...

  14. 46 CFR 28.315 - Fire pumps, fire mains, fire hydrants, and fire hoses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Fire pumps, fire mains, fire hydrants, and fire hoses... After September 15, 1991, and That Operate With More Than 16 Individuals on Board § 28.315 Fire pumps... be equipped with a self-priming, power driven fire pump connected to a fixed piping system. (1)...

  15. 46 CFR 28.315 - Fire pumps, fire mains, fire hydrants, and fire hoses.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... fire pump on a vessel 79 feet (24 meters) or more in length must be capable of delivering water... 46 Shipping 1 2012-10-01 2012-10-01 false Fire pumps, fire mains, fire hydrants, and fire hoses... After September 15, 1991, and That Operate With More Than 16 Individuals on Board § 28.315 Fire...

  16. Oregon Fires

    Atmospheric Science Data Center

    2014-05-15

    ... (MISR). When the data were acquired, the Booth and Bear Butte Fires had been underway for 16 days and had consumed about 70,000 ... or other factors precluded a retrieval the map is colored black. The  animation  depicts a "multi-angle fly-over" of the plumes, ...

  17. Idaho Fires

    NASA Technical Reports Server (NTRS)

    2001-01-01

    [figure removed for brevity, see original site] Figure 1 Click on image for larger version

    This full-frame ASTER image, acquired August 30, 2000, covers an area of 60 by 60 km in the Salmon River Mountains, Idaho. In this color infrared composite, vegetation is red, clouds are white, and smoke from forest fires is blue. An enlargement (Figure 1) covers an area of 12 x 15 km. A thermal infrared band is displayed in red, a short wave infrared band is displayed in green, and a visible band is displayed in blue. In this combination, fires larger than about 50 m appear yellow because they are bright in both infrared bands. Smaller fires appear green because they are too small to be seen by the 90 m thermal pixels, but large enough to be detected in the 30 m short wave infrared pixels. We are able to see through the smoke in the infrared bands, whereas in the visible bands, the smoke obscures detection of the active fires. This image is located at 44.8 degrees north latitude and 114.8 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.

  18. Dalhousie Fire

    ERIC Educational Resources Information Center

    Matthews, Fred W.

    1986-01-01

    Describes steps taken by the Weldon Law Library at Dalhousie University in salvaging books damaged in a major fire, including procedures and processes used in packing, sorting, drying, and cleaning the books. The need for a disaster plan for specific libraries is emphasized, and some suggestions are made. (CDD)

  19. California Fires

    Atmospheric Science Data Center

    2014-05-15

    ... began August 26, 2009, in La Canada/Flintridge, not far from NASA's Jet Propulsion Laboratory. The fire reportedly burned 105,000 acres (164 ... D.C. The Terra spacecraft is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. The MISR data were obtained from the NASA ...

  20. A model of hippocampal spiking responses to items during learning of a context-dependent task

    PubMed Central

    Raudies, Florian; Hasselmo, Michael E.

    2014-01-01

    Single unit recordings in the rat hippocampus have demonstrated shifts in the specificity of spiking activity during learning of a contextual item-reward association task. In this task, rats received reward for responding to different items dependent upon the context an item appeared in, but not dependent upon the location an item appears at. Initially, neurons in the rat hippocampus primarily show firing based on place, but as the rat learns the task this firing became more selective for items. We simulated this effect using a simple circuit model with discrete inputs driving spiking activity representing place and item followed sequentially by a discrete representation of the motor actions involving a response to an item (digging for food) or the movement to a different item (movement to a different pot for food). We implemented spiking replay in the network representing neural activity observed during sharp-wave ripple events, and modified synaptic connections based on a simple representation of spike-timing dependent synaptic plasticity. This simple network was able to consistently learn the context-dependent responses, and transitioned from dominant coding of place to a gradual increase in specificity to items consistent with analysis of the experimental data. In addition, the model showed an increase in specificity toward context. The increase of selectivity in the model is accompanied by an increase in binariness of the synaptic weights for cells that are part of the functional network. PMID:25294991

  1. 10 CFR 74.55 - Item monitoring.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... days for Category IA items and 60 calendar days for Category IB items contained in a vault or in a... days for Category IA items and seven calendar days for Category BI items located elsewhere in the...

  2. 10 CFR 74.55 - Item monitoring.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... days for Category IA items and 60 calendar days for Category IB items contained in a vault or in a... days for Category IA items and seven calendar days for Category BI items located elsewhere in the...

  3. 10 CFR 74.55 - Item monitoring.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... days for Category IA items and 60 calendar days for Category IB items contained in a vault or in a... days for Category IA items and seven calendar days for Category BI items located elsewhere in the...

  4. 10 CFR 74.55 - Item monitoring.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... days for Category IA items and 60 calendar days for Category IB items contained in a vault or in a... days for Category IA items and seven calendar days for Category BI items located elsewhere in the...

  5. 10 CFR 74.55 - Item monitoring.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... days for Category IA items and 60 calendar days for Category IB items contained in a vault or in a... days for Category IA items and seven calendar days for Category BI items located elsewhere in the...

  6. Decreasing Fires in Mediterranean Europe.

    PubMed

    Turco, Marco; Bedia, Joaquín; Di Liberto, Fabrizio; Fiorucci, Paolo; von Hardenberg, Jost; Koutsias, Nikos; Llasat, Maria-Carmen; Xystrakis, Fotios; Provenzale, Antonello

    2016-01-01

    Forest fires are a serious environmental hazard in southern Europe. Quantitative assessment of recent trends in fire statistics is important for assessing the possible shifts induced by climate and other environmental/socioeconomic changes in this area. Here we analyse recent fire trends in Portugal, Spain, southern France, Italy and Greece, building on a homogenized fire database integrating official fire statistics provided by several national/EU agencies. During the period 1985-2011, the total annual burned area (BA) displayed a general decreasing trend, with the exception of Portugal, where a heterogeneous signal was found. Considering all countries globally, we found that BA decreased by about 3020 km2 over the 27-year-long study period (i.e. about -66% of the mean historical value). These results are consistent with those obtained on longer time scales when data were available, also yielding predominantly negative trends in Spain and France (1974-2011) and a mixed trend in Portugal (1980-2011). Similar overall results were found for the annual number of fires (NF), which globally decreased by about 12600 in the study period (about -59%), except for Spain where, excluding the provinces along the Mediterranean coast, an upward trend was found for the longer period. We argue that the negative trends can be explained, at least in part, by an increased effort in fire management and prevention after the big fires of the 1980's, while positive trends may be related to recent socioeconomic transformations leading to more hazardous landscape configurations, as well as to the observed warming of recent decades. We stress the importance of fire data homogenization prior to analysis, in order to alleviate spurious effects associated with non-stationarities in the data due to temporal variations in fire detection efforts.

  7. Decreasing Fires in Mediterranean Europe

    PubMed Central

    Turco, Marco; Bedia, Joaquín; Di Liberto, Fabrizio; Fiorucci, Paolo; von Hardenberg, Jost; Koutsias, Nikos; Llasat, Maria-Carmen; Xystrakis, Fotios; Provenzale, Antonello

    2016-01-01

    Forest fires are a serious environmental hazard in southern Europe. Quantitative assessment of recent trends in fire statistics is important for assessing the possible shifts induced by climate and other environmental/socioeconomic changes in this area. Here we analyse recent fire trends in Portugal, Spain, southern France, Italy and Greece, building on a homogenized fire database integrating official fire statistics provided by several national/EU agencies. During the period 1985-2011, the total annual burned area (BA) displayed a general decreasing trend, with the exception of Portugal, where a heterogeneous signal was found. Considering all countries globally, we found that BA decreased by about 3020 km2 over the 27-year-long study period (i.e. about -66% of the mean historical value). These results are consistent with those obtained on longer time scales when data were available, also yielding predominantly negative trends in Spain and France (1974-2011) and a mixed trend in Portugal (1980-2011). Similar overall results were found for the annual number of fires (NF), which globally decreased by about 12600 in the study period (about -59%), except for Spain where, excluding the provinces along the Mediterranean coast, an upward trend was found for the longer period. We argue that the negative trends can be explained, at least in part, by an increased effort in fire management and prevention after the big fires of the 1980’s, while positive trends may be related to recent socioeconomic transformations leading to more hazardous landscape configurations, as well as to the observed warming of recent decades. We stress the importance of fire data homogenization prior to analysis, in order to alleviate spurious effects associated with non-stationarities in the data due to temporal variations in fire detection efforts. PMID:26982584

  8. Seasonality of fire weather strongly influences fire regimes in South Florida savanna-grassland landscapes.

    PubMed

    Platt, William J; Orzell, Steve L; Slocum, Matthew G

    2015-01-01

    Fire seasonality, an important characteristic of fire regimes, commonly is delineated using seasons based on single weather variables (rainfall or temperature). We used nonparametric cluster analyses of a 17-year (1993-2009) data set of weather variables that influence likelihoods and spread of fires (relative humidity, air temperature, solar radiation, wind speed, soil moisture) to explore seasonality of fire in pine savanna-grassland landscapes at the Avon Park Air Force Range in southern Florida. A four-variable, three-season model explained more variation within fire weather variables than models with more seasons. The three-season model also delineated intra-annual timing of fire more accurately than a conventional rainfall-based two-season model. Two seasons coincided roughly with dry and wet seasons based on rainfall. The third season, which we labeled the fire season, occurred between dry and wet seasons and was characterized by fire-promoting conditions present annually: drought, intense solar radiation, low humidity, and warm air temperatures. Fine fuels consisting of variable combinations of pyrogenic pine needles, abundant C4 grasses, and flammable shrubs, coupled with low soil moisture, and lightning ignitions early in the fire season facilitate natural landscape-scale wildfires that burn uplands and across wetlands. We related our three season model to fires with different ignition sources (lightning, military missions, and prescribed fires) over a 13-year period with fire records (1997-2009). Largest wildfires originate from lightning and military ignitions that occur within the early fire season substantially prior to the peak of lightning strikes in the wet season. Prescribed ignitions, in contrast, largely occur outside the fire season. Our delineation of a pronounced fire season provides insight into the extent to which different human-derived fire regimes mimic lightning fire regimes. Delineation of a fire season associated with timing of

  9. Seasonality of Fire Weather Strongly Influences Fire Regimes in South Florida Savanna-Grassland Landscapes

    PubMed Central

    Platt, William J.; Orzell, Steve L.; Slocum, Matthew G.

    2015-01-01

    Fire seasonality, an important characteristic of fire regimes, commonly is delineated using seasons based on single weather variables (rainfall or temperature). We used nonparametric cluster analyses of a 17-year (1993–2009) data set of weather variables that influence likelihoods and spread of fires (relative humidity, air temperature, solar radiation, wind speed, soil moisture) to explore seasonality of fire in pine savanna-grassland landscapes at the Avon Park Air Force Range in southern Florida. A four-variable, three-season model explained more variation within fire weather variables than models with more seasons. The three-season model also delineated intra-annual timing of fire more accurately than a conventional rainfall-based two-season model. Two seasons coincided roughly with dry and wet seasons based on rainfall. The third season, which we labeled the fire season, occurred between dry and wet seasons and was characterized by fire-promoting conditions present annually: drought, intense solar radiation, low humidity, and warm air temperatures. Fine fuels consisting of variable combinations of pyrogenic pine needles, abundant C4 grasses, and flammable shrubs, coupled with low soil moisture, and lightning ignitions early in the fire season facilitate natural landscape-scale wildfires that burn uplands and across wetlands. We related our three season model to fires with different ignition sources (lightning, military missions, and prescribed fires) over a 13-year period with fire records (1997–2009). Largest wildfires originate from lightning and military ignitions that occur within the early fire season substantially prior to the peak of lightning strikes in the wet season. Prescribed ignitions, in contrast, largely occur outside the fire season. Our delineation of a pronounced fire season provides insight into the extent to which different human-derived fire regimes mimic lightning fire regimes. Delineation of a fire season associated with timing of

  10. MIMIC Methods for Assessing Differential Item Functioning in Polytomous Items

    ERIC Educational Resources Information Center

    Wang, Wen-Chung; Shih, Ching-Lin

    2010-01-01

    Three multiple indicators-multiple causes (MIMIC) methods, namely, the standard MIMIC method (M-ST), the MIMIC method with scale purification (M-SP), and the MIMIC method with a pure anchor (M-PA), were developed to assess differential item functioning (DIF) in polytomous items. In a series of simulations, it appeared that all three methods…

  11. 48 CFR 852.214-72 - Alternate item(s).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 5 2014-10-01 2014-10-01 false Alternate item(s). 852.214-72 Section 852.214-72 Federal Acquisition Regulations System DEPARTMENT OF VETERANS AFFAIRS CLAUSES AND FORMS SOLICITATION PROVISIONS AND CONTRACT CLAUSES Texts of Provisions and Clauses...

  12. Differential Item Functioning Analysis Using Rasch Item Information Functions

    ERIC Educational Resources Information Center

    Wyse, Adam E.; Mapuranga, Raymond

    2009-01-01

    Differential item functioning (DIF) analysis is a statistical technique used for ensuring the equity and fairness of educational assessments. This study formulates a new DIF analysis method using the information similarity index (ISI). ISI compares item information functions when data fits the Rasch model. Through simulations and an international…

  13. Evaluating Item Fit for Multidimensional Item Response Models

    ERIC Educational Resources Information Center

    Zhang, Bo; Stone, Clement A.

    2008-01-01

    This research examines the utility of the s-x[superscript 2] statistic proposed by Orlando and Thissen (2000) in evaluating item fit for multidimensional item response models. Monte Carlo simulation was conducted to investigate both the Type I error and statistical power of this fit statistic in analyzing two kinds of multidimensional test…

  14. A Mixed Effects Randomized Item Response Model

    ERIC Educational Resources Information Center

    Fox, J.-P.; Wyrick, Cheryl

    2008-01-01

    The randomized response technique ensures that individual item responses, denoted as true item responses, are randomized before observing them and so-called randomized item responses are observed. A relationship is specified between randomized item response data and true item response data. True item response data are modeled with a (non)linear…

  15. Developing an Improved Wildland Fire Emissions Inventory

    NASA Astrophysics Data System (ADS)

    Larkin, S.; Raffuse, S. M.; Strand, T.; Drury, S.; Solomon, R. C.; Wheeler, N.

    2010-12-01

    Smoke from wildland fire is a growing concern as air quality regulations tighten and public acceptance declines. Wildland fire emissions inventories are not only important for understanding air quality impacts from smoke but also in quantifying sources of greenhouse gas emissions. Calculation of wildland fire emissions can be done using a number of models and methods. Under the Smoke and Emissions Model Intercomparison Project, comparisons between different methodologies are presented allowing for direct model-to-model variability calculations. Additionally, the relative importance of uncertainties in fire size information, available fuels information, consumption modeling techniques, and emissions factors can be compared. This work shows the local need for accurate fire information and a new effort to integrate both ground and satellite information into the the SMARTFIRE-BlueSky framework is presented. This DOI/USFS effort is designed to provide constraints on fire information and other errors in the modeling chain, resulting in an improved wildland fire emissions inventory.

  16. A Full-Scale Fire Program to Evaluate New Furnishings and Textile Materials Developed by the National Aeronautics and Space Administration

    NASA Technical Reports Server (NTRS)

    Hillenbrand, L. J.; Wray, J. A.

    1973-01-01

    The plans for the present series of full-scale experimental fires were initiated at the suggestion of NASA following the presentation of a film and discussion illustrating Battelle-Columbus' recent work in fire research. That film showed bedroom-type fires carried out as a part of a program to determine the influence of the cyclic characteristics of real fires under limited ventilation on the burning and pyrolysis properties of the room furnishings. A new series of fires was suggested by NASA designed to show the performance of new fire resistant and fire retardant materials by providing comparative fire and smoldering environmental conditions. More recently, the goal for the new series of fires was written in a meeting with NASA personnel and others at Battelle on May 3 and 4, 1972. The goal was as follows: To establish the need for special materials of improved fire safety in domiciliary settings of public concern, and to assess, in a professionally acceptable manner, the potential of materials arising from the new space-age technology for this purpose. It was anticipated that some new materials arising from the space-age technology and not yet available through conventional commercial channels might provide significant improvements in fire safety if the best of the commercially available materials showed important shortcomings in this area. It was the intent of this program to assess the benefits that could accrue from the use of these new materials. Fire safety is a matter requiring the evaluation of a number of factors. For example, fire resistance and fire spread, visibility during the fire, toxicity of evolved gases, and the fire-fighting problem that is created must be evaluated before the relative hazard can be assessed. The plan of the program provided for sampling and instrumentation to evaluate these factors, consistent with the goal of technological utilization that has been specified. Arrangements were made with the Columbus Fire Department to use an

  17. Localized enhancements in fire danger during the 'Black Saturday' fires

    NASA Astrophysics Data System (ADS)

    Lane, T. P.; Engel, C. B.; Reeder, M. J.

    2011-12-01

    On Saturday 7 February 2009 a series of fire complexes occurred over the state of Victoria, Australia. The fires caused more than 150 fatalities, the destruction of more than 2000 residences, and decimated a number of townships. The meteorological conditions on 7 February for the region were categorized as the worst fire weather conditions on record. Specifically, the maximum temperature exceeded 45 C (113 F) and gusty surface winds were sustained at 15 m/s (30 knots) for most of the day. These conditions were followed by the passage of a strong cold front in the late afternoon / early evening. Moreover, vegetation and fuels had suffered significant drying over the prior weeks due to a sequence of hot days and a record heatwave. In addition to these broad scale meteorological conditions, numerous mesoscale atmospheric processes contributed to localized enhancement in fire danger in the vicinity of many of the fires; these phenomena may have contributed to the extraordinary nature of some of the fires occurring that day. This study documents these localized processes using a combination of surface observations and an extremely high-resolution numerical weather prediction model with a horizontal resolution of 500 m. The observations and model forecast identify many notable phenomena of relevance to fire danger that persist throughout the day. These include enhanced down-slope surface winds and organized boundary layer horizontal convective rolls (HCRs). The HCRs are responsible for significant spatial variability in surface winds and forest fire danger index (FFDI). The model forecast elucidates the complex interaction between the cold front and the terrain, including the large variability in the timing and direction of the cool change. Finally, two nocturnal bores are identified that propagate ahead of the cool change; such bores have the potential to cause rapid, yet unexpected, changes to fire danger. In addition to documenting these important phenomena, the model

  18. Distributed Item Review: Administrator User Guide. Technical Report #1603

    ERIC Educational Resources Information Center

    Irvin, P. Shawn

    2016-01-01

    The Distributed Item Review (DIR) is a secure and flexible, web-based system designed to present test items to expert reviewers across a broad geographic area for evaluation of important dimensions of quality (e.g., alignment with standards, bias, sensitivity, and student accessibility). The DIR is comprised of essential features that allow system…

  19. Editorial Changes and Item Performance: Implications for Calibration and Pretesting

    ERIC Educational Resources Information Center

    Stoffel, Heather; Raymond, Mark R.; Bucak, S. Deniz; Haist, Steven A.

    2014-01-01

    Previous research on the impact of text and formatting changes on test-item performance has produced mixed results. This matter is important because it is generally acknowledged that "any" change to an item requires that it be recalibrated. The present study investigated the effects of seven classes of stylistic changes on item…

  20. Fire Maintenance and Logistics Analysis (Fire Main)

    DTIC Science & Technology

    1989-07-01

    medical evacuation, (2) supply transportation, (3) fire / water bucket support, (4) troop movement, and (&) miscei~areojs. Tabi .1-1. shows the...operation. On average, for the 4-12 September fierce fire fighting period, 44 percent of the helicopters were used for fire / water bucket operations, 2P...the operation. As expected the largest percentage of the helicopters were used for fire / water bucket operations during both the fierce fire fighting

  1. Career and Occupational Development Items.

    ERIC Educational Resources Information Center

    Education Commission of the States, Denver, CO. National Assessment of Educational Progress.

    The career and occupational development items contained in this document are part of a kit consisting of four documents which bring together different types of items that measure a number of career and occupational development (COD) objectives developed by the National Assessment of Educational Progress (NAEP). (NAEP--which completed a national…

  2. Generalizability in Item Response Modeling

    ERIC Educational Resources Information Center

    Briggs, Derek C.; Wilson, Mark

    2007-01-01

    An approach called generalizability in item response modeling (GIRM) is introduced in this article. The GIRM approach essentially incorporates the sampling model of generalizability theory (GT) into the scaling model of item response theory (IRT) by making distributional assumptions about the relevant measurement facets. By specifying a random…

  3. Smouldering Fires in the Earth System

    NASA Astrophysics Data System (ADS)

    Rein, G.

    2012-04-01

    Smouldering fires, the slow, low-temperature, flameless burning, represent the most persistent type of combustion phenomena and the longest continuously fires on Earth system. Indeed, smouldering mega-fires of peatlands occur with some frequency during the dry session in, for example, Indonesia, Canada, Russia, UK and USA. Smouldering fires propagate slowly through organic layers of the ground and can reach depth >5 m if large cracks, natural piping or channel systems exist. It threatens to release sequestered carbon deep into the soil. Once ignited, they are particularly difficult to extinguish despite extensive rains, weather changes or fire-fighting attempts, and can persist for long periods of time (months, years) spreading deep and over extensive areas. Recent figures at the global scale estimate that average annual greenhouse gas emissions from smouldering fires are equivalent to 15% of man-made emissions. These fires are difficult or impossible to detect with current remote sensing methods because the chemistry is significantly different, their thermal radiation signature is much smaller, and the plume is much less buoyant. These wildfires burn fossil fuels and thus are a carbon-positive fire phenomena. This creates feedbacks in the climate system because soil moisture deficit and self-heating are enchanted under warmer climate scenarios and lead to more frequent fires. Warmer temperatures at high latitudes are resulting in more frequent Artic fires. Unprecedented permafrost thaw is leaving large soil carbon pools exposed to smouldering fires for the fist time since millennia. Although interactions between flaming fires and the Earth system have been a central focus, smouldering fires are as important but have received very little attention. DBut differences with flaming fires are important. This paper reviews the current knowledge on smouldering fires in the Earth system regarding combustion dynamics, damage to the soil, emissions, remote sensing and

  4. Zaca Fire

    NASA Technical Reports Server (NTRS)

    2007-01-01

    On August 7, 2007, the Zaca fire continued to burn in the Los Padres National Forest near Santa Barbara, California. The fire started more than a month ago, on July 4, and has burned 69,800 acres. The fire remains in steep, rocky terrain with poor access. The continued poor access makes containment difficult in the wilderness area on the eastern flank. So far only one outbuilding has been destroyed; but over 450 homes are currently threatened. Over 2300 fire personnel, aided by four air tankers and 15 helicopters, are working to contain this massive fire. Full containment is expected on September 1.

    The image covers 45.2 x 46.1 km, and is centered near 34.6 degrees north latitude, 119.7 degrees west longitude.

    With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet.

    ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra spacecraft. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products.

    The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance.

    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

  5. Fire Characterization and Fire-Related Land Cover Classification Using Hyperion Data over Selected Alaskan Boreal Forest Fires

    NASA Astrophysics Data System (ADS)

    Waigl, C. F.; Prakash, A.; Stuefer, M.; Dennison, P. E.

    2014-12-01

    In this study, NIR and SWIR EO-1 Hyperion data acquired over two large Alaskan forest fires are used to detect active fires, map their immediate vicinity, and retrieve fire temperatures. The study sites are located in black spruce stands within the 2004 Boundary fire (215,000 ha total affected area) and the 2009 Wood River 1 fire (50,000 ha). Even though fires in the North American boreal forest ecosystem contribute greatly to global carbon cycling and large-scale air pollution, they have been less studied so far using satellite-borne imaging spectroscopy. We adapted the Hyperspectral Fire Detection Index (HFDI) so that it worked well for the high-latitude Hyperion data. This involved selecting suitable bands which best separated fire from non-fire pixels and averaging them to further improve the detection signal. Resulting fire detection maps compare favorably to uniform radiance thresholding of the Hyperion data and are consistent with fires detected on near-simultaneous Landsat 7 ETM+ data. Unsupervised classification of the vicinity of the active fire zones served to delineate 5 to 6 well separated classes: high- and low-intensity fire, various unburnt vegetation classes, recent fire scar, and a transitional zone ahead of the active fire front that shows evidence of fire impact but no emitted radiance component. Furthermore, MODTRAN5 was used for atmospheric correction to retrieve fire temperatures by modeling a mixture of emitted and reflected radiance signatures of the fire and background areas, respectively. As most of the carbon consumption and subsequent emissions in boreal forest fires stem from the combustion of dead plant material on the forest floor, estimates on fire intensities and high/low intensity burn areas provide valuable insight into the amount of carbon cycling in the system. Imaging spectroscopy can therefore contribute an important step forward in quantitative studies of boreal fires and their impacts. These techniques are set to advance

  6. Fire suppressing apparatus. [sodium fires

    DOEpatents

    Buttrey, K.E.

    1980-12-19

    Apparatus for smothering a liquid sodium fire comprises a pan, a perforated cover on the pan, and tubed depending from the cover and providing communication between the interior of the pan and the ambient atmosphere through the perforations in the cover. Liquid caught in the pan rises above the lower ends of the tubes and thus serves as a barrier which limits the amount of air entering the pan.

  7. Fire Safety Training Handbook.

    ERIC Educational Resources Information Center

    Montgomery County Dept. of Fire and Rescue Services, Rockville, MD. Div. of Fire Prevention.

    Designed for a community fire education effort, particularly in which local volunteers present general information on fire safety to their fellow citizens, this workbook contains nine lessons. Included are an overview of the household fire problem; instruction in basic chemistry and physics of fire, flammable liquids, portable fire extinguishers,…

  8. FIRE ALARM SYSTEM OUTDATED.

    ERIC Educational Resources Information Center

    CHANDLER, L.T.

    AN EFFICIENT FIRE ALARM SYSTEM SHOULD--(1) PROVIDE WARNING OF FIRES THAT START IN HIDDEN OR UNOCCUPIED LOCATIONS, (2) INDICATE WHERE THE FIRE IS, (3) GIVE ADVANCE WARNING TO FACULTY AND ADMINISTRATION SO THAT PANIC AND CONFUSION CAN BE AVOIDED AND ORDERLY EVACUATION OCCUR, (4) AUTOMATICALLY NOTIFY CITY FIRE HEADQUARTERS OF THE FIRE, (5) OPERATE BY…

  9. 46 CFR 28.820 - Fire pumps, fire mains, fire hydrants, and fire hoses.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... water from a hose connected to the highest outlet. The minimum capacity of the power fire pump shall be 50 gallons per minute at a pressure of not less than 60 pounds per square inch at the pump outlet. (1... 46 Shipping 1 2011-10-01 2011-10-01 false Fire pumps, fire mains, fire hydrants, and fire...

  10. 46 CFR 28.820 - Fire pumps, fire mains, fire hydrants, and fire hoses.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... water from a hose connected to the highest outlet. The minimum capacity of the power fire pump shall be 50 gallons per minute at a pressure of not less than 60 pounds per square inch at the pump outlet. (1... 46 Shipping 1 2014-10-01 2014-10-01 false Fire pumps, fire mains, fire hydrants, and fire...

  11. 46 CFR 28.820 - Fire pumps, fire mains, fire hydrants, and fire hoses.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... water from a hose connected to the highest outlet. The minimum capacity of the power fire pump shall be 50 gallons per minute at a pressure of not less than 60 pounds per square inch at the pump outlet. (1... 46 Shipping 1 2012-10-01 2012-10-01 false Fire pumps, fire mains, fire hydrants, and fire...

  12. 46 CFR 28.820 - Fire pumps, fire mains, fire hydrants, and fire hoses.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... water from a hose connected to the highest outlet. The minimum capacity of the power fire pump shall be 50 gallons per minute at a pressure of not less than 60 pounds per square inch at the pump outlet. (1... 46 Shipping 1 2013-10-01 2013-10-01 false Fire pumps, fire mains, fire hydrants, and fire...

  13. Where's the Fire?

    ERIC Educational Resources Information Center

    Needham, Dorothy

    1977-01-01

    National Fire Protection Week is a perfect time for launching a fire safety learning center. The activities described here are intended to help children recognize fire hazards in their homes, play areas and public buildings; learn how to act intelligently in fire emergencies; be able to share their knowledge of fire safety with others and…

  14. Fire Protection for Buildings

    ERIC Educational Resources Information Center

    Edmunds, Jane

    1972-01-01

    Reviews attack on fire safety in high rise buildings made by a group of experts representing the iron and steel industry at a recent conference. According to one expert, fire problems are people oriented, which calls for emphasis on fire prevention rather than reliance on fire suppression and for fire pretection to be built into a structure.…

  15. Assessing item fit for unidimensional item response theory models using residuals from estimated item response functions.

    PubMed

    Haberman, Shelby J; Sinharay, Sandip; Chon, Kyong Hee

    2013-07-01

    Residual analysis (e.g. Hambleton & Swaminathan, Item response theory: principles and applications, Kluwer Academic, Boston, 1985; Hambleton, Swaminathan, & Rogers, Fundamentals of item response theory, Sage, Newbury Park, 1991) is a popular method to assess fit of item response theory (IRT) models. We suggest a form of residual analysis that may be applied to assess item fit for unidimensional IRT models. The residual analysis consists of a comparison of the maximum-likelihood estimate of the item characteristic curve with an alternative ratio estimate of the item characteristic curve. The large sample distribution of the residual is proved to be standardized normal when the IRT model fits the data. We compare the performance of our suggested residual to the standardized residual of Hambleton et al. (Fundamentals of item response theory, Sage, Newbury Park, 1991) in a detailed simulation study. We then calculate our suggested residuals using data from an operational test. The residuals appear to be useful in assessing the item fit for unidimensional IRT models.

  16. Pigments which reflect infrared radiation from fire

    DOEpatents

    Berdahl, P.H.

    1998-09-22

    Conventional paints transmit or absorb most of the intense infrared (IR) radiation emitted by fire, causing them to contribute to the spread of fire. The present invention comprises a fire retardant paint additive that reflects the thermal IR radiation emitted by fire in the 1 to 20 micrometer ({micro}m) wavelength range. The important spectral ranges for fire control are typically about 1 to about 8 {micro}m or, for cool smoky fires, about 2 {micro}m to about 16 {micro}m. The improved inventive coatings reflect adverse electromagnetic energy and slow the spread of fire. Specific IR reflective pigments include titanium dioxide (rutile) and red iron oxide pigments with diameters of about 1 {micro}m to about 2 {micro}m and thin leafing aluminum flake pigments. 4 figs.

  17. Pigments which reflect infrared radiation from fire

    DOEpatents

    Berdahl, Paul H.

    1998-01-01

    Conventional paints transmit or absorb most of the intense infrared (IR) radiation emitted by fire, causing them to contribute to the spread of fire. The present invention comprises a fire retardant paint additive that reflects the thermal IR radiation emitted by fire in the 1 to 20 micrometer (.mu.m) wavelength range. The important spectral ranges for fire control are typically about 1 to about 8 .mu.m or, for cool smoky fires, about 2 .mu.m to about 16 .mu.m. The improved inventive coatings reflect adverse electromagnetic energy and slow the spread of fire. Specific IR reflective pigments include titanium dioxide (rutile) and red iron oxide pigments with diameters of about 1 .mu.m to about 2 .mu.m and thin leafing aluminum flake pigments.

  18. Bison and fire: Landscape analysis of ungulate response to Yellowstone`s fires

    SciTech Connect

    Wallace, L.L.; Turner, M.G.; Wu, Yegang; Romme, W.H.

    1993-10-01

    A simulation model of bison survival under different scenarios of winter severity, fire size, fire pattern and population size was run. Previous work had shown the model to be realistic. The overriding factor influencing bison winter survival in the model was winter severity. This factor had significant interactions with fire size and population size as well, further reducing survival in all cases. Increasing fire size reduced survival the first year after a simulated fire, but increased survival two years after the fire. This was due to enhanced forage production in burned areas the second year. A threshold effect on survival was noted at fire sizes greater than 60% of the simulated landscape, a number which is critical in disturbance propagation in landscapes. There was no biologically important effect of fire pattern (random vs. clumped) on survival.

  19. Controls on fire activity over the Holocene

    NASA Astrophysics Data System (ADS)

    Kloster, S.; Brücher, T.; Brovkin, V.; Wilkenskjeld, S.

    2014-11-01

    Changes in fire activity over the last 8000 years are simulated with a global fire model driven by changes in climate and vegetation cover. The changes were separated into those caused through variations in fuel availability, fuel moisture or wind speed which react differently to changes in climate. Disentangling these controlling factors helps to understand the overall climate control on fire activity over the Holocene. Globally the burned area is simulated to increase by 2.5% between 8000 and 200 cal yr BP with larger regional changes compensating on a global scale. Despite the absence of anthropogenic fire ignitions, the simulated trends in fire activity agree reasonably well with continental scale reconstructions from charcoal records, with the exception of Europe. For some regions the change in fire activity is predominantly controlled through changes in fuel availability (Australia-Monsoon, American Tropics/Subtropics). For other regions changes in fuel moisture are more important for the overall trend in fire activity (North America, Sub-Saharan Africa, Europe, Asia-Monsoon). In Sub-Saharan Africa, for example, changes in fuel moisture alone lead to an increase in fire activity between 8000 and 200 cal yr BP, while changes in fuel availability lead to a decrease. Overall, the fuel moisture control is dominating the simulated fire activity for Sub-Saharan Africa. The simulations clearly demonstrate that both changes in fuel availability and changes in fuel moisture are important drivers for the fire activity over the Holocene. Fuel availability and fuel moisture do, however, have different climate controls. As such observed changes in fire activity can not be related to single climate parameters such as precipitation or temperature alone. Fire models, as applied in this study, in combination with observational records can help to understand the climate control on fire activity, which is essential to project future fire activity.

  20. Controls on fire activity over the Holocene

    NASA Astrophysics Data System (ADS)

    Kloster, S.; Brucher, T.; Brovkin, V.; Wilkenskjeld, S.

    2015-05-01

    Changes in fire activity over the last 8000 years are simulated with a global fire model driven by changes in climate and vegetation cover. The changes were separated into those caused through variations in fuel availability, fuel moisture or wind speed, which react differently to changes in climate. Disentangling these controlling factors helps in understanding the overall climate control on fire activity over the Holocene. Globally the burned area is simulated to increase by 2.5% between 8000 and 200 cal yr BP, with larger regional changes compensating nearly evening out on a global scale. Despite the absence of anthropogenic fire ignitions, the simulated trends in fire activity agree reasonably well with continental-scale reconstructions from charcoal records, with the exception of Europe. For some regions the change in fire activity is predominantly controlled through changes in fuel availability (Australia monsoon, Central America tropics/subtropics). For other regions changes in fuel moisture are more important for the overall trend in fire activity (North America, Sub-Saharan Africa, Europe, Asia monsoon). In Sub-Saharan Africa, for example, changes in fuel moisture alone lead to an increase in fire activity between 8000 and 200 cal yr BP, while changes in fuel availability lead to a decrease. Overall, the fuel moisture control is dominating the simulated fire activity for Sub-Saharan Africa. The simulations clearly demonstrate that both changes in fuel availability and changes in fuel moisture are important drivers for the fire activity over the Holocene. Fuel availability and fuel moisture do, however, have different climate controls. As such, observed changes in fire activity cannot be related to single climate parameters such as precipitation or temperature alone. Fire models, as applied in this study, in combination with observational records can help in understanding the climate control on fire activity, which is essential to project future fire

  1. Fire safety at home

    MedlinePlus

    ... over the smoke alarm as needed. Using a fire extinguisher can put out a small fire to keep it from getting out of control. Tips for use include: Keep fire extinguishers in handy locations, at least one on ...

  2. FIRE Data and Information

    Atmospheric Science Data Center

    2015-11-13

    ... a series of field missions which have collected cirrus and marine stratocumulus cloud parameters from aircraft, satellite and ... FIRE I - Cirrus Home Page FIRE I - Marine Stratocumulus Home Page FIRE I - Extended Time Observations ...

  3. Home Fires Involving Grills

    MedlinePlus

    ... fires were fueled by gas while 13% used charcoal or other solid fuel. Gas grills were involved ... structure fires and 4,300 outdoor fires annually. Charcoal or other solid-fueled grills were involved in ...

  4. Multilevel Modeling of Item Position Effects

    ERIC Educational Resources Information Center

    Albano, Anthony D.

    2013-01-01

    In many testing programs it is assumed that the context or position in which an item is administered does not have a differential effect on examinee responses to the item. Violations of this assumption may bias item response theory estimates of item and person parameters. This study examines the potentially biasing effects of item position. A…

  5. Item Banking. ERIC/AE Digest.

    ERIC Educational Resources Information Center

    Rudner, Lawrence

    This digest discusses the advantages and disadvantages of using item banks, and it provides useful information for those who are considering implementing an item banking project in their school districts. The primary advantage of item banking is in test development. Using an item response theory method, such as the Rasch model, items from multiple…

  6. Effects of Incorporating Humor in Test Items.

    ERIC Educational Resources Information Center

    McMorris, Robert F.; And Others

    1985-01-01

    Two matched forms of a 50 item grammar test were developed. Twenty items designed to be humorous were included in one form. Inclusion of humorous items did not affect grammar scores on matched humorous/nonhumorous items, nor on commmon post-treatment items. Inclusion did not affect results of anxiety measures. (Author/DWH)

  7. Computerized Adaptive Testing with Item Cloning.

    ERIC Educational Resources Information Center

    Glas, Cees A. W.; van der Linden, Wim J.

    2003-01-01

    Developed a multilevel item response (IRT) model that allows for differences between the distributions of item parameters of families of item clones. Results from simulation studies based on an item pool from the Law School Admission Test illustrate the accuracy of the item pool calibration and adaptive testing procedures based on the model. (SLD)

  8. 7 CFR 2902.5 - Item designation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... availability of such items and the economic and technological feasibility of using such items, including life cycle costs. USDA will gather information on individual products within an item and extrapolate that product information to the item level for consideration in designating items. In considering these...

  9. Printed Comments With Item Analyses

    ERIC Educational Resources Information Center

    Reid, J. Christopher

    1970-01-01

    The author suggests that a computer program be designed which not only computes item statistics, but also provides a running commetary in English to assist teachers in their analysis of test results. (PR)

  10. Binding agent for molding ceramic items

    NASA Technical Reports Server (NTRS)

    Beshentsev, B. D.; Vityuk, N. P.; Volkov, A. V.; Yevdokimov, A. I.; Novikov, M. N.; Piskunov, Y. G.; Pobortsev, E. P.; Sadovnichaya, L. M.

    1983-01-01

    The invention refers to the fabrication of ceramic items by the molding method. It can be used to produce items of complicated configuration, in particular composition of binding agent for electroceramic items.

  11. Fire ecology in the southeastern United States

    USGS Publications Warehouse

    ,

    2000-01-01

    Fire has played an important role in the structure of natural ecosystems throughout North America. As a natural process, fire helps clear away dead and dying plant matter and increases the production of native species that occur in fire prone habitats. It also reduces the invasion of exotic species and the succession to woody species in pitcher plant bogs, pine savannas, coastal prairies, marshes, and other natural plant communities of the southeastern United States.

  12. Fire Suppression and Response

    NASA Technical Reports Server (NTRS)

    Ruff, Gary A.

    2004-01-01

    This report is concerned with the following topics regarding fire suppression:What is the relative effectiveness of candidate suppressants to extinguish a representative fire in reduced gravity, including high-O2 mole fraction, low -pressure environments? What are the relative advantages and disadvantages of physically acting and chemically-acting agents in spacecraft fire suppression? What are the O2 mole fraction and absolute pressure below which a fire cannot exist? What effect does gas-phase radiation play in the overall fire and post-fire environments? Are the candidate suppressants effective to extinguish fires on practical solid fuels? What is required to suppress non-flaming fires (smoldering and deep seated fires) in reduced gravity? How can idealized space experiment results be applied to a practical fire scenario? What is the optimal agent deployment strategy for space fire suppression?

  13. Fire clay

    USGS Publications Warehouse

    Virta, R.L.

    2004-01-01

    Seven companies mined fire clay in four states during 2003. From 1984 to 1992, production declined to 383 kt (422,000 st) from a high of 1.04 Mt (1.14 million st) as markets for clay-based refractories declined. Since 1992, production levels have been erratic, ranging from 383 kt (422,000 st) in 1992 and 2001 to 583 kt (642,000 st) in 1995. Production in 2003, based on preliminary data, was estimated to be around 450 kt (496,000 st) with a value of about $10.5 million. This was about the same as in 2002. Missouri remained the leading producer state, followed by South Carolina, Ohio and California.

  14. Using unplanned fires to help suppressing future large fires in Mediterranean forests.

    PubMed

    Regos, Adrián; Aquilué, Núria; Retana, Javier; De Cáceres, Miquel; Brotons, Lluís

    2014-01-01

    Despite the huge resources invested in fire suppression, the impact of wildfires has considerably increased across the Mediterranean region since the second half of the 20th century. Modulating fire suppression efforts in mild weather conditions is an appealing but hotly-debated strategy to use unplanned fires and associated fuel reduction to create opportunities for suppression of large fires in future adverse weather conditions. Using a spatially-explicit fire-succession model developed for Catalonia (Spain), we assessed this opportunistic policy by using two fire suppression strategies that reproduce how firefighters in extreme weather conditions exploit previous fire scars as firefighting opportunities. We designed scenarios by combining different levels of fire suppression efficiency and climatic severity for a 50-year period (2000-2050). An opportunistic fire suppression policy induced large-scale changes in fire regimes and decreased the area burnt under extreme climate conditions, but only accounted for up to 18-22% of the area to be burnt in reference scenarios. The area suppressed in adverse years tended to increase in scenarios with increasing amounts of area burnt during years dominated by mild weather. Climate change had counterintuitive effects on opportunistic fire suppression strategies. Climate warming increased the incidence of large fires under uncontrolled conditions but also indirectly increased opportunities for enhanced fire suppression. Therefore, to shift fire suppression opportunities from adverse to mild years, we would require a disproportionately large amount of area burnt in mild years. We conclude that the strategic planning of fire suppression resources has the potential to become an important cost-effective fuel-reduction strategy at large spatial scale. We do however suggest that this strategy should probably be accompanied by other fuel-reduction treatments applied at broad scales if large-scale changes in fire regimes are to be

  15. Item Selection in Computerized Adaptive Testing: Improving the a-Stratified Design with the Sympson-Hetter Algorithm

    ERIC Educational Resources Information Center

    Leung, Chi-Keung; Chang, Hua-Hua; Hau, Kit-Tai

    2002-01-01

    Item exposure control, test-overlap minimization, and the efficient use of item pool are some of the important issues in computerized adaptive testing (CAT) designs. The overexposure of some items and high test-overlap rate may cause both item and test security problems. Previously these problems associated with the maximum information (Max-I)…

  16. Temporal trends in mammal responses to fire reveals the complex effects of fire regime attributes.

    PubMed

    Lindenmayer, David B; Blanchard, Wade; MacGregor, Christopher; Barton, Philip; Banks, Sam C; Crane, Mason; Michael, Damian; Okada, Sachiko; Berry, Laurence; Florance, Daniel; Gill, Malcolm

    2016-03-01

    Fire is a major ecological process in many ecosystems worldwide. We sought to identify which attributes of fire regimes affect temporal change in the presence and abundance of Australian native mammals. Our detailed study was underpinned by time series data on 11 mammal species at 97 long-term sites in southeastern Australia between 2003 and 2013. We explored how temporal aspects of fire regimes influenced the presence and conditional abundance of species. The key fire regime components examined were: (1) severity of a major fire in 2003, (2) interval between the last major fire (2003) and the fire prior to that, and (3) number of past fires. Our long-term data set enabled quantification of the interactions between survey year and each fire regime variable: an ecological relationship missing from temporally restricted studies. We found no evidence of any appreciable departures from the assumption of independence of the sites. Multiple aspects of fire regimes influenced temporal variation in the presence and abundance of mammals. The best models indicated that six of the 11 species responded to two or more fire regime variables, with two species influenced by all three fire regime attributes. Almost all species responded to time since fire, either as an interaction with survey year or as a main effect. Fire severity or its interaction with survey year was important for most terrestrial rodents. The number of fires at a site was significant for terrestrial rodents and several other species. Our findings contain evidence of the effects on native mammals of heterogeneity in fire regimes. Temporal response patterns of mammal species were influenced by multiple fire regime attributes, often in conjunction with survey year. This underscores the critical importance of long-term studies of biota that are coupled with data sets characterized by carefully documented fire history, severity, and frequency. Long-term studies are essential to predict animal responses to fires and

  17. Idaho National Engineering and Environmental Laboratory Wildland Fire Management Environmental Assessment - April 2003

    SciTech Connect

    Irving, J.S.

    2003-04-30

    DOE prepared an environmental assessment (EA)for wildland fire management activities on the Idaho National Engineering and Environmental Laboratory (INEEL) (DOE/EA-1372). The EA was developed to evaluate wildland fire management options for pre-fire, fire suppression, and post fire activities. Those activities have an important role in minimizing the conversion of the native sagebrush steppe ecosystem found on the INEEL to non-native weeds. Four alternative management approaches were analyzed: Alternative 1 - maximum fire protection; Alternative 2 - balanced fire protection; Alternative 2 - balanced fire protection; Alternative 3 - protect infrastructure and personnel; and Alternative 4 - no action/traditional fire protection.

  18. Idaho National Engineering and Environmental Laboratory Wildland Fire Management Environmental Assessment

    SciTech Connect

    Irving, John S

    2003-04-01

    DOE prepared an environmental assessment (EA)for wildland fire management activities on the Idaho National Engineering and Environmental Laboratory (INEEL) (DOE/EA-1372). The EA was developed to evaluate wildland fire management options for pre-fire, fire suppression, and post fire activities. Those activities have an important role in minimizing the conversion of the native sagebrush steppe ecosystem found on the INEEL to non-native weeds. Four alternative management approaches were analyzed: Alternative 1 - maximum fire protection; Alternative 2 - balanced fire protection; Alternative 2 - balanced fire protection; Alternative 3 - protect infrastructure and personnel; and Alternative 4 - no action/traditional fire protection.

  19. Fire Resistance Testing of Bulkhead and Deck Penetrations.

    DTIC Science & Technology

    1985-10-01

    consisted of a steel plate identical to that used in the Class A-0 assembly, but rockwool insulation was applied to the fire side of the steel plate and...penetration samples were then insulated with rockwool batts to form a Class A-60 assembly (Figure 2). Between nine and twenty-eight temperature readings...representative of Class A-O construction. The UL staff secured insulation ( rockwool batts) to the fire side of the steel plates and penetrating items to prepare

  20. A Study of the Homogeneity of Items Produced From Item Forms Across Different Taxonomic Levels.

    ERIC Educational Resources Information Center

    Weber, Margaret B.; Argo, Jana K.

    This study determined whether item forms ( rules for constructing items related to a domain or set of tasks) would enable naive item writers to generate multiple-choice items at three taxonomic levels--knowledge, comprehension, and application. Students wrote 120 multiple-choice items from 20 item forms, corresponding to educational objectives…

  1. Fire severity and ecosytem responses following crown fires in California shrublands.

    PubMed

    Keeley, Jon E; Brennan, Teresa; Pfaff, Anne H

    2008-09-01

    Chaparral shrublands burn in large high-intensity crown fires. Managers interested in how these wildfires affect ecosystem processes generally rely on surrogate measures of fire intensity known as fire severity metrics. In shrublands burned in the autumn of 2003, a study of 250 sites investigated factors determining fire severity and ecosystem responses. Using structural equation modeling we show that stand age, prefire shrub density, and the shortest interval of the prior fire history had significant direct effects on fire severity, explaining > 50% of the variation in severity. Fire severity per se is of interest to resource managers primarily because it is presumed to be an indicator of important ecosystem processes such as vegetative regeneration, community recovery, and erosion. Fire severity contributed relatively little to explaining patterns of regeneration after fire. Two generalizations can be drawn: fire severity effects are mostly shortlived, i.e., by the second year they are greatly diminished, and fire severity may have opposite effects on different functional types. Species richness exhibited a negative relationship to fire severity in the first year, but fire severity impacts were substantially less in the second postfire year and varied by functional type. Much of this relationship was due to alien plants that are sensitive to high fire severity; at all scales from 1 to 1000 m2, the percentage of alien species in the postfire flora declined with increased fire severity. Other aspects of disturbance history are also important determinants of alien cover and richness as both increased with the number of times the site had burned and decreased with time since last fire. A substantial number of studies have shown that remote-sensing indices are correlated with field measurements of fire severity. Across our sites, absolute differenced normalized burn ratio (dNBR) was strongly correlated with field measures of fire severity and with fire history at a

  2. Fire severity and ecosytem responses following crown fires in California shrublands.

    USGS Publications Warehouse

    Keeley, J.E.; Brennan, T.; Pfaff, A.H.

    2008-01-01

    Chaparral shrublands burn in large high-intensity crown fires. Managers interested in how these wildfires affect ecosystem processes generally rely on surrogate measures of fire intensity known as fire severity metrics. In shrublands burned in the autumn of 2003, a study of 250 sites investigated factors determining fire severity and ecosystem responses. Using structural equation modeling we show that stand age, prefire shrub density, and the shortest interval of the prior fire history had significant direct effects on fire severity, explaining > 50% of the variation in severity. Fire severity per se is of interest to resource managers primarily because it is presumed to be an indicator of important ecosystem processes such as vegetative regeneration, community recovery, and erosion. Fire severity contributed relatively little to explaining patterns of regeneration after fire. Two generalizations can be drawn: fire severity effects are mostly shortlived, i.e., by the second year they are greatly diminished, and fire severity may have opposite effects on different functional types. Species richness exhibited a negative relationship to fire severity in the first year, but fire severity impacts were substantially less in the second postfire year and varied by functional type. Much of this relationship was due to alien plants that are sensitive to high fire severity; at all scales from 1 to 1000 m2, the percentage of alien species in the postfire flora declined with increased fire severity. Other aspects of disturbance history are also important determinants of alien cover and richness as both increased with the number of times the site had burned and decreased with time since last fire. A substantial number of studies have shown that remote-sensing indices are correlated with field measurements of fire severity. Across our sites, absolute differenced normalized burn ratio (dNBR) was strongly correlated with field measures of fire severity and with fire history at a

  3. FIRE SERVICE TRAINING.

    ERIC Educational Resources Information Center

    BERNDT, WILLIAM M.; AND OTHERS

    STUDENTS MAY USE THIS REVISED MANUAL IN FIRE STATION OR TRAINING CENTER EXTENSION PROGRAMS FOR IMPROVING THE COMPETENCIES AND SKILLS OF LOCAL FIRE PERSONNEL IN THE SPECIALIZED FIELD OF FIRE SERVICE. IT WAS DEVELOPED BY A STATEWIDE COMMITTEE OF FIRE-FIGHTING CONSULTANTS AND ADVISORY GROUPS. THE 26 CHAPTERS PROVIDE BOTH BASIC AND ADVANCED TECHNICAL…

  4. Children and Home Fires

    MedlinePlus

    CHILDREN AND HOME FIRES Fast Facts Children under the age of five are twice as likely to die in a home fire than the rest of the population, and child-playing fires are the leading cause of fire deaths among ...

  5. Regulation of Irregular Neuronal Firing by Autaptic Transmission

    NASA Astrophysics Data System (ADS)

    Guo, Daqing; Wu, Shengdun; Chen, Mingming; Perc, Matjaž; Zhang, Yangsong; Ma, Jingling; Cui, Yan; Xu, Peng; Xia, Yang; Yao, Dezhong

    2016-05-01

    The importance of self-feedback autaptic transmission in modulating spike-time irregularity is still poorly understood. By using a biophysical model that incorporates autaptic coupling, we here show that self-innervation of neurons participates in the modulation of irregular neuronal firing, primarily by regulating the occurrence frequency of burst firing. In particular, we find that both excitatory and electrical autapses increase the occurrence of burst firing, thus reducing neuronal firing regularity. In contrast, inhibitory autapses suppress burst firing and therefore tend to improve the regularity of neuronal firing. Importantly, we show that these findings are independent of the firing properties of individual neurons, and as such can be observed for neurons operating in different modes. Our results provide an insightful mechanistic understanding of how different types of autapses shape irregular firing at the single-neuron level, and they highlight the functional importance of autaptic self-innervation in taming and modulating neurodynamics.

  6. Regulation of Irregular Neuronal Firing by Autaptic Transmission

    PubMed Central

    Guo, Daqing; Wu, Shengdun; Chen, Mingming; Perc, Matjaž; Zhang, Yangsong; Ma, Jingling; Cui, Yan; Xu, Peng; Xia, Yang; Yao, Dezhong

    2016-01-01

    The importance of self-feedback autaptic transmission in modulating spike-time irregularity is still poorly understood. By using a biophysical model that incorporates autaptic coupling, we here show that self-innervation of neurons participates in the modulation of irregular neuronal firing, primarily by regulating the occurrence frequency of burst firing. In particular, we find that both excitatory and electrical autapses increase the occurrence of burst firing, thus reducing neuronal firing regularity. In contrast, inhibitory autapses suppress burst firing and therefore tend to improve the regularity of neuronal firing. Importantly, we show that these findings are independent of the firing properties of individual neurons, and as such can be observed for neurons operating in different modes. Our results provide an insightful mechanistic understanding of how different types of autapses shape irregular firing at the single-neuron level, and they highlight the functional importance of autaptic self-innervation in taming and modulating neurodynamics. PMID:27185280

  7. Issues in Numerical Simulation of Fire Suppression

    SciTech Connect

    Tieszen, S.R.; Lopez, A.R.

    1999-04-12

    This paper outlines general physical and computational issues associated with performing numerical simulation of fire suppression. Fire suppression encompasses a broad range of chemistry and physics over a large range of time and length scales. The authors discuss the dominant physical/chemical processes important to fire suppression that must be captured by a fire suppression model to be of engineering usefulness. First-principles solutions are not possible due to computational limitations, even with the new generation of tera-flop computers. A basic strategy combining computational fluid dynamics (CFD) simulation techniques with sub-grid model approximations for processes that have length scales unresolvable by gridding is presented.

  8. Selection and maintenance key to fire protection

    SciTech Connect

    Briese, B.L.

    1996-11-01

    Petroleum product and chemical storage terminals, because of the combustible products they handle, face severe fire exposure potentials. A fire at a terminal can grow rapidly and release damaging and deadly heat, threatening personnel, facilities, the adjoining environment and revenue. To combat this danger, terminals employ several types of fire protection systems, both fixed and mobile. All adhere to consensus codes and standards. Following installation of automatic fire protection equipment, its acceptance (sometimes referred to as commissioning) testing, ongoing maintenance and periodic inspection is vitally important to assure that it reliably functions when required.

  9. Thermal response based item identification.

    SciTech Connect

    Smith, M. K.; Hypes, P. A.; Bracken, D. S.

    2001-01-01

    One of the most difficult problems in NDA of nuclear materials is identifying the chemical form of the nuclear material and the surrounding matrix. Recent work analyzing the calorimeter response of sources embedded in a variety of matrices has led to a possible solution to this problem. The wide range of thermal time constants exhibited by typical matrix materials lends itself to permitting the differentiation between materials, based on time constants extracted from the measured response. Potential applications include simple item identification, item fingerprinting as part of shipper-receiver measurements, and distinguishing between Pu metal and Pu oxide as required under certain proposed attribute measurements. The results of applying this technique to a variety of items will be presented and discussed.

  10. Fire safety concerns in space operations

    NASA Technical Reports Server (NTRS)

    Friedman, Robert

    1987-01-01

    This paper reviews the state-of-the-art in fire control techniques and identifies important issues for continuing research, technology, and standards. For the future permanent orbiting facility, the space station, fire prevention and control calls for not only more stringent fire safety due to the long-term and complex missions, but also for simplified and flexible safety rules to accommodate the variety of users. Future research must address a better understanding of the microgravity space environment as it influences fire propagation and extinction and the application of the technology of fire detection, extinguishment, and material assessment. Spacecraft fire safety should also consider the adaptation of methods and concepts derived from aircraft and undersea experience.

  11. On the fluid mechanics of fires

    SciTech Connect

    TIESZEN,SHELDON R.

    2000-02-29

    Fluid mechanics research related to fire is reviewed with focus on canonical flows, multiphysics coupling aspects, experimental and numerical techniques. Fire is a low-speed, chemically-reacting, flow in which buoyancy plans an important role. Fire research has focused on two canonical flows, the reacting boundary-layer and the reacting free plume. There is rich, multi-lateral, bi-directional, coupling among fluid mechanics and scalar transport, combustion, and radiation. There is only a limited experimental fluid-mechanics database for fire due to measurement difficulties in the harsh environment, and the focus within the fire community on thermal/chemical consequences. Increasingly, computational fluid dynamics techniques are being used to provide engineering guidance on thermal/chemical consequences and to study fire phenomenology.

  12. Using satellite fire detection to calibrate components of the fire weather index system in Malaysia and Indonesia.

    PubMed

    Dymond, Caren C; Field, Robert D; Roswintiarti, Orbita; Guswanto

    2005-04-01

    Vegetation fires have become an increasing problem in tropical environments as a consequence of socioeconomic pressures and subsequent land-use change. In response, fire management systems are being developed. This study set out to determine the relationships between two aspects of the fire problems in western Indonesia and Malaysia, and two components of the Canadian Forest Fire Weather Index System. The study resulted in a new method for calibrating components of fire danger rating systems based on satellite fire detection (hotspot) data. Once the climate was accounted for, a problematic number of fires were related to high levels of the Fine Fuel Moisture Code. The relationship between climate, Fine Fuel Moisture Code, and hotspot occurrence was used to calibrate Fire Occurrence Potential classes where low accounted for 3% of the fires from 1994 to 2000, moderate accounted for 25%, high 26%, and extreme 38%. Further problems arise when there are large clusters of fires burning that may consume valuable land or produce local smoke pollution. Once the climate was taken into account, the hotspot load (number and size of clusters of hotspots) was related to the Fire Weather Index. The relationship between climate, Fire Weather Index, and hotspot load was used to calibrate Fire Load Potential classes. Low Fire Load Potential conditions (75% of an average year) corresponded with 24% of the hotspot clusters, which had an average size of 30% of the largest cluster. In contrast, extreme Fire Load Potential conditions (1% of an average year) corresponded with 30% of the hotspot clusters, which had an average size of 58% of the maximum. Both Fire Occurrence Potential and Fire Load Potential calibrations were successfully validated with data from 2001. This study showed that when ground measurements are not available, fire statistics derived from satellite fire detection archives can be reliably used for calibration. More importantly, as a result of this work, Malaysia and

  13. Australian Item Bank Program: Science Item Bank. Book 3: Biology.

    ERIC Educational Resources Information Center

    Australian Council for Educational Research, Hawthorn.

    The Australian Science Item Bank consists of three volumes of multiple-choice questions. Book 3 contains questions on the biological sciences. The questions are designed to be suitable for high school students (year 8 to year 12 in Australian schools). The questions are classified by the subject content of the question, the cognitive skills…

  14. Evaluating the Magnitude of Differential Item Functioning in Polytomous Items.

    ERIC Educational Resources Information Center

    Zwick, Rebecca; Thayer, Dorothy T.

    1996-01-01

    Two possible standard error formulas for the polytomous differential item functioning index proposed by N. J. Dorans and A. P. Schmitt (1991) were derived. These standard errors, and associated hypothesis-testing procedures, were evaluated through simulated data. The standard error that performed better is based on N. Mantel's (1963)…

  15. Fire-Walking

    ERIC Educational Resources Information Center

    Willey, David

    2010-01-01

    This article gives a brief history of fire-walking and then deals with the physics behind fire-walking. The author has performed approximately 50 fire-walks, took the data for the world's hottest fire-walk and was, at one time, a world record holder for the longest fire-walk (www.dwilley.com/HDATLTW/Record_Making_Firewalks.html). He currently…

  16. DOE Fire Protection Handbook, Volume I

    SciTech Connect

    1996-08-01

    The Department of Energy (DOE) Fire Protection Program is delineated in a number of source documents including; the Code of Federal Regulations (CFR), DOE Policy Statements and Orders, DOE and national consensus standards (such as those promulgated by the National Fire Protection Association), and supplementary guidance, This Handbook is intended to bring together in one location as much of this material as possible to facilitate understanding and ease of use. The applicability of any of these directives to individual Maintenance and Operating Contractors or to given facilities and operations is governed by existing contracts. Questions regarding applicability should be directed to the DOE Authority Having Jurisdiction for fire safety. The information provided within includes copies of those DOE directives that are directly applicable to the implementation of a comprehensive fire protection program. They are delineated in the Table of Contents. The items marked with an asterisk (*) are included on the disks in WordPerfect 5.1 format, with the filename noted below. The items marked with double asterisks are provided as hard copies as well as on the disk. For those using MAC disks, the files are in Wordperfect 2.1 for MAC.

  17. Fire intensity, fire severity and burn severity: A brief review and suggested usage

    USGS Publications Warehouse

    Keeley, J.E.

    2009-01-01

    Several recent papers have suggested replacing the terminology of fire intensity and fire severity. Part of the problem with fire intensity is that it is sometimes used incorrectly to describe fire effects, when in fact it is justifiably restricted to measures of energy output. Increasingly, the term has created confusion because some authors have restricted its usage to a single measure of energy output referred to as fireline intensity. This metric is most useful in understanding fire behavior in forests, but is too narrow to fully capture the multitude of ways fire energy affects ecosystems. Fire intensity represents the energy released during various phases of a fire, and different metrics such as reaction intensity, fireline intensity, temperature, heating duration and radiant energy are useful for different purposes. Fire severity, and the related term burn severity, have created considerable confusion because of recent changes in their usage. Some authors have justified this by contending that fire severity is defined broadly as ecosystem impacts from fire and thus is open to individual interpretation. However, empirical studies have defined fire severity operationally as the loss of or change in organic matter aboveground and belowground, although the precise metric varies with management needs. Confusion arises because fire or burn severity is sometimes defined so that it also includes ecosystem responses. Ecosystem responses include soil erosion, vegetation regeneration, restoration of community structure, faunal recolonization, and a plethora of related response variables. Although some ecosystem responses are correlated with measures of fire or burn severity, many important ecosystem processes have either not been demonstrated to be predicted by severity indices or have been shown in some vegetation types to be unrelated to severity. This is a critical issue because fire or burn severity are readily measurable parameters, both on the ground and with

  18. Archaeology of fire: Methodological aspects of reconstructing fire history of prehistoric archaeological sites

    NASA Astrophysics Data System (ADS)

    Alperson-Afil, Nira

    2012-07-01

    Concepts which are common in the reconstruction of fire histories are employed here for the purpose of interpreting fires identified at archaeological sites. When attempting to evaluate the fire history of ancient occupations we are limited by the amount and quality of the available data. Furthermore, the identification of archaeological burned materials, such as stone, wood, and charcoal, is adequate for the general assumption of a "fire history", but the agent responsible - anthropogenic or natural - cannot be inferred from the mere presence of burned items. The large body of scientific data that has accumulated, primarily through efforts to prevent future fire disasters, enables us to reconstruct scenarios of past natural fires. Adopting this line of thought, this paper attempts to evaluate the circumstances in which a natural fire may have ignited and spread at the 0.79 Ma occupation site of Gesher Benot Ya'aqov (Israel), resulting with burned wood and burned flint within the archaeological layers. At Gesher Benot Ya'aqov, possible remnants of hearths are explored through analyses of the spatial distribution of burned flint-knapping waste products. These occur in dense clusters in each of the archaeological occupations throughout the long stratigraphic sequence. In this study, the combination between the spatial analyses results, paleoenvironmental information, and various factors involved in the complex process of fire ignition, combustion, and behavior, has enabled the firm rejection of recurrent natural fires as the responsible agent for the burned materials. In addition, it suggested that mainly at early sites, where evidence for burning is present yet scarce, data on fire ecology can be particularly useful when it is considered in relation to paleoenvironmental information.

  19. Hazard analysis on one-room building fires

    NASA Astrophysics Data System (ADS)

    Yu, Deming; Feng, Changgen

    1998-12-01

    First, a calculation method for available safety egress time (shortly called ASET) and requirement safety egress time (shortly called RSET) in a one-room building fire is proposed and a model for predicting the death number caused by the fire is established in this paper. Then, numerical simulations are performed, and the following laws are discovered: (1) At the beginning of the fire, the smoke layer falls slowly; as the fire develops, it falls rapidly. (2) The hypotheses on the fire source, the combustion properties of the combustibles, and the width of the exit and the person number in the room are important factors which affect the death number in the fire.

  20. Fire fatality study: demographics of fire victims.

    PubMed

    Barillo, D J; Goode, R

    1996-03-01

    Injury or death caused by fire is frequent and largely preventable. This study was undertaken to define the populations, locations, times and behaviours associated with fatal fires. Seven hundred and twenty-seven fatalities occurring within the State of New Jersey, between the years 1985 and 1991, were examined retrospectively. Most deaths were attributed to a combination of smoke inhalation and burn injury. Five hundred and seventy-four fatalities occurred in residential fires. Smoking materials were the most common source of ignition for residential fires. More than half of the fatal residential fires started between the hours of 11 p.m. and 7 a.m. Children and the elderly represented a disproportionate percentage of fire victims. Victims under the age of 11 years or over the age of 70 years constituted 22.1 per cent of the state population but 39.5 per cent of all fire fatalities. Fire-prevention efforts should target home fire safety, and should concentrate on children and the elderly. The development of fire-safe smoking materials should be encouraged.

  1. Psychometric Consequences of Subpopulation Item Parameter Drift

    ERIC Educational Resources Information Center

    Huggins-Manley, Anne Corinne

    2017-01-01

    This study defines subpopulation item parameter drift (SIPD) as a change in item parameters over time that is dependent on subpopulations of examinees, and hypothesizes that the presence of SIPD in anchor items is associated with bias and/or lack of invariance in three psychometric outcomes. Results show that SIPD in anchor items is associated…

  2. A Monte Carlo Study Investigating the Influence of Item Discrimination, Category Intersection Parameters, and Differential Item Functioning Patterns on the Detection of Differential Item Functioning in Polytomous Items

    ERIC Educational Resources Information Center

    Thurman, Carol

    2009-01-01

    The increased use of polytomous item formats has led assessment developers to pay greater attention to the detection of differential item functioning (DIF) in these items. DIF occurs when an item performs differently for two contrasting groups of respondents (e.g., males versus females) after controlling for differences in the abilities of the…

  3. Adaptable Learning Assistant for Item Bank Management

    ERIC Educational Resources Information Center

    Nuntiyagul, Atorn; Naruedomkul, Kanlaya; Cercone, Nick; Wongsawang, Damras

    2008-01-01

    We present PKIP, an adaptable learning assistant tool for managing question items in item banks. PKIP is not only able to automatically assist educational users to categorize the question items into predefined categories by their contents but also to correctly retrieve the items by specifying the category and/or the difficulty level. PKIP adapts…

  4. Item-Writing Guidelines for Physics

    ERIC Educational Resources Information Center

    Regan, Tom

    2015-01-01

    A teacher learning how to write test questions (test items) will almost certainly encounter item-writing guidelines--lists of item-writing do's and don'ts. Item-writing guidelines usually are presented as applicable across all assessment settings. Table I shows some guidelines that I believe to be generally applicable and two will be briefly…

  5. Fighting fire - with teamwork.

    PubMed

    McKerron, Kim

    2013-04-01

    Team work is a process of working collaboratively and an important aspect of inter professional team success. This article is a reflective account, following eight midwifery students who participated in group dynamics training with a team of airport fire officers. It highlights howyou can borrow teamwork and communication strategies from other high profile industries and adapt it to midwifery practice. The experience demonstrated how a team approach brought together a cluster of skills, experience and understanding, something that cannot exist in one individual. It also demonstrated that when team work is successful the results are amazing.

  6. Application of Optimal Designs to Item Calibration

    PubMed Central

    Lu, Hung-Yi

    2014-01-01

    In computerized adaptive testing (CAT), examinees are presented with various sets of items chosen from a precalibrated item pool. Consequently, the attrition speed of the items is extremely fast, and replenishing the item pool is essential. Therefore, item calibration has become a crucial concern in maintaining item banks. In this study, a two-parameter logistic model is used. We applied optimal designs and adaptive sequential analysis to solve this item calibration problem. The results indicated that the proposed optimal designs are cost effective and time efficient. PMID:25188318

  7. The three Rs of fire safety, emergency action, and fire prevention planning: promoting safety at the worksite.

    PubMed

    Thompson, Marcella R

    2003-04-01

    Fire safety is of paramount importance for everyone. In many workplaces, the occupational health nurse's scope of practice encompasses safety related activities. Included within this role is the responsibility for fire safety, emergency action, and fire prevention planning. The Three Rs of fire safety, emergency action, and fire prevention plans are rules, responsibilities, and resources. Myriad building and fire safety codes, regulations, and standards exist with which an employer must comply. An employer's responsibility for installing, testing, inspecting, and maintaining fire safety related equipment is extensive. Emergency action and fire prevention planning begins with conducting a detailed physical survey and preparing site maps. It includes making key policy decisions, writing procedures, and training employees in those procedures by practicing and executing site drills. The best resources available for emergency planning are the local fire department and the property insurer. Planning ahead means an efficient emergency response if disaster strikes. It saves lives, limits property damage, and preserves the environment.

  8. Paradoxical Results and Item Bundles

    ERIC Educational Resources Information Center

    Hooker, Giles; Finkelman, Matthew

    2010-01-01

    Hooker, Finkelman, and Schwartzman ("Psychometrika," 2009, in press) defined a paradoxical result as the attainment of a higher test score by changing answers from correct to incorrect and demonstrated that such results are unavoidable for maximum likelihood estimates in multidimensional item response theory. The potential for these results to…

  9. Recovery of fingerprints from fire scenes and associated evidence.

    PubMed

    Deans, J

    2006-01-01

    A lack of information concerning the potential recovery of fingerprints from fire scenes and related evidence prompted several research projects. Latent prints from good secretors and visible prints (in blood) were placed on a variety of different surfaces and subsequently subjected to "real life" fires in fully furnished compartments used for fire investigation training purposes. The items were placed in various locations and at different heights within the compartments. After some initial success, further tests were undertaken using both latent and dirt/grease marks on different objects within the same types of fire compartments. Subsequent sets of tests involved the recovery of latent and visual fingerprints (in blood, dirt and grease) from different types of weapons, lighters, plastic bags, match boxes, tapers, plastic bottles and petrol bombs that had been subjected to the same fire conditions as previously. Throughout the entire series of projects one of the prime considerations was how the resultant findings could be put into practice by fire scene examiners in an attempt to assist the police in their investigations. This research demonstrates that almost one in five items recovered from fire scenes yielded fingerprint ridge detail following normal development treatments.

  10. Topographic and fire weather controls of fire refugia in forested ecosystems of northwestern North America

    USGS Publications Warehouse

    Krawchuk, Meg A; Haire, Sandra L; Coop, Jonathan; Parisien, Marc-Andre; Whitman, Ellen; Chong, Geneva W.; Miller, Carol

    2016-01-01

    for seven study fires that burned in conifer-dominated forested landscapes of the Western Cordillera of Canada between 2001 and 2014. We fit nine models, each for distinct levels of fire weather and terrain ruggedness. Our framework revealed that the predictability and abundance of fire refugia varied among these environmental settings. We observed highest predictability under moderate fire weather conditions and moderate terrain ruggedness (ROC-AUC = 0.77), and lowest predictability in flatter landscapes and under high fire weather conditions (ROC-AUC = 0.63–0.68). Catchment slope, local aspect, relative position, topographic wetness, topographic convergence, and local slope all contributed to discriminating where refugia occur but the relative importance of these topographic controls differed among environments. Our framework allows us to characterize the predictability of contemporary fire refugia across multiple environmental settings and provides important insights for ecosystem resilience, wildfire management, conservation planning, and climate change adaptation.

  11. Efficient algorithms for wildland fire simulation

    NASA Astrophysics Data System (ADS)

    Kondratenko, Volodymyr Y.

    In this dissertation, we develop the multiple-source shortest path algorithms and examine their application importance in real world problems, such as wildfire modeling. The theoretical basis and its implementation in the Weather Research Forecasting (WRF) model coupled with the fire spread code SFIRE (WRF-SFIRE model) are described. We present a data assimilation method that gives the fire spread model the ability to start the fire simulation from an observed fire perimeter instead of an ignition point. While the model is running, the fire state in the model changes in accordance with the new arriving data by data assimilation. As the fire state changes, the atmospheric state (which is strongly effected by heat flux) does not stay consistent with the fire state. The main difficulty of this methodology occurs in coupled fire-atmosphere models, because once the fire state is modified to match a given starting perimeter, the atmospheric circulation is no longer in sync with it. One of the possible solutions to this problem is a formation of the artificial time of ignition history from an earlier fire state, which is later used to replay the fire progression to the new perimeter with the proper heat fluxes fed into the atmosphere, so that the fire induced circulation is established. In this work, we develop efficient algorithms that start from the fire arrival times given at the set of points (called a perimeter) and create the artificial fire time of ignition and fire spread rate history. Different algorithms were developed in order to suit possible demands of the user, such as implementation in parallel programming, minimization of the required amount of iterations and memory use, and use of the rate of spread as a time dependent variable. For the algorithms that deal with the homogeneous rate of spread, it was proven that the values of fire arrival times they produce are optimal. It was also shown that starting from arbitrary initial state the algorithms have

  12. Modelling the meteorological forest fire niche in heterogeneous pyrologic conditions.

    PubMed

    De Angelis, Antonella; Ricotta, Carlo; Conedera, Marco; Pezzatti, Gianni Boris

    2015-01-01

    Fire regimes are strongly related to weather conditions that directly and indirectly influence fire ignition and propagation. Identifying the most important meteorological fire drivers is thus fundamental for daily fire risk forecasting. In this context, several fire weather indices have been developed focussing mainly on fire-related local weather conditions and fuel characteristics. The specificity of the conditions for which fire danger indices are developed makes its direct transfer and applicability problematic in different areas or with other fuel types. In this paper we used the low-to-intermediate fire-prone region of Canton Ticino as a case study to develop a new daily fire danger index by implementing a niche modelling approach (Maxent). In order to identify the most suitable weather conditions for fires, different combinations of input variables were tested (meteorological variables, existing fire danger indices or a combination of both). Our findings demonstrate that such combinations of input variables increase the predictive power of the resulting index and surprisingly even using meteorological variables only allows similar or better performances than using the complex Canadian Fire Weather Index (FWI). Furthermore, the niche modelling approach based on Maxent resulted in slightly improved model performance and in a reduced number of selected variables with respect to the classical logistic approach. Factors influencing final model robustness were the number of fire events considered and the specificity of the meteorological conditions leading to fire ignition.

  13. Modelling the Meteorological Forest Fire Niche in Heterogeneous Pyrologic Conditions

    PubMed Central

    De Angelis, Antonella; Ricotta, Carlo; Conedera, Marco; Pezzatti, Gianni Boris

    2015-01-01

    Fire regimes are strongly related to weather conditions that directly and indirectly influence fire ignition and propagation. Identifying the most important meteorological fire drivers is thus fundamental for daily fire risk forecasting. In this context, several fire weather indices have been developed focussing mainly on fire-related local weather conditions and fuel characteristics. The specificity of the conditions for which fire danger indices are developed makes its direct transfer and applicability problematic in different areas or with other fuel types. In this paper we used the low-to-intermediate fire-prone region of Canton Ticino as a case study to develop a new daily fire danger index by implementing a niche modelling approach (Maxent). In order to identify the most suitable weather conditions for fires, different combinations of input variables were tested (meteorological variables, existing fire danger indices or a combination of both). Our findings demonstrate that such combinations of input variables increase the predictive power of the resulting index and surprisingly even using meteorological variables only allows similar or better performances than using the complex Canadian Fire Weather Index (FWI). Furthermore, the niche modelling approach based on Maxent resulted in slightly improved model performance and in a reduced number of selected variables with respect to the classical logistic approach. Factors influencing final model robustness were the number of fire events considered and the specificity of the meteorological conditions leading to fire ignition. PMID:25679957

  14. Controls on variations in MODIS fire radiative power in Alaskan boreal forests: implications for fire severity conditions

    USGS Publications Warehouse

    Barrett, Kirsten; Kasischke, Eric S.

    2013-01-01

    is the most fire prone, but deciduous vegetation is not particularly fire resistant, as the proportion of active fire detections in deciduous stands is roughly the same as the fraction of deciduous vegetation in the region. Qualitative differences between periods of high and low fire activity are likely to reflect important differences in fire severity. Large fire years are likely to be more severe, characterized by more late season fires and a greater proportion of residual burning. Given the potential for severe fires to effect changes in vegetation cover, the shift toward a greater proportion of area burning during large fire years may influence vegetation patterns in the region over the medium to long term.

  15. Fire and deforestation dynamics in Amazonia (1973-2014).

    PubMed

    van Marle, Margreet J E; Field, Robert D; van der Werf, Guido R; Estrada de Wagt, Ivan A; Houghton, Richard A; Rizzo, Luciana V; Artaxo, Paulo; Tsigaridis, Kostas

    2017-01-01

    Consistent long-term estimates of fire emissions are important to understand the changing role of fire in the global carbon cycle and to assess the relative importance of humans and climate in shaping fire regimes. However, there is limited information on fire emissions from before the satellite era. We show that in the Amazon region, including the Arc of Deforestation and Bolivia, visibility observations derived from weather stations could explain 61% of the variability in satellite-based estimates of bottom-up fire emissions since 1997 and 42% of the variability in satellite-based estimates of total column carbon monoxide concentrations since 2001. This enabled us to reconstruct the fire history of this region since 1973 when visibility information became available. Our estimates indicate that until 1987 relatively few fires occurred in this region and that fire emissions increased rapidly over the 1990s. We found that this pattern agreed reasonably well with forest loss data sets, indicating that although natural fires may occur here, deforestation and degradation were the main cause of fires. Compared to fire emissions estimates based on Food and Agricultural Organization's Global Forest and Resources Assessment data, our estimates were substantially lower up to the 1990s, after which they were more in line. These visibility-based fire emissions data set can help constrain dynamic global vegetation models and atmospheric models with a better representation of the complex fire regime in this region.

  16. Fire and deforestation dynamics in Amazonia (1973–2014)

    PubMed Central

    Field, Robert D.; van der Werf, Guido R.; Estrada de Wagt, Ivan A.; Houghton, Richard A.; Rizzo, Luciana V.; Artaxo, Paulo; Tsigaridis, Kostas

    2017-01-01

    Abstract Consistent long‐term estimates of fire emissions are important to understand the changing role of fire in the global carbon cycle and to assess the relative importance of humans and climate in shaping fire regimes. However, there is limited information on fire emissions from before the satellite era. We show that in the Amazon region, including the Arc of Deforestation and Bolivia, visibility observations derived from weather stations could explain 61% of the variability in satellite‐based estimates of bottom‐up fire emissions since 1997 and 42% of the variability in satellite‐based estimates of total column carbon monoxide concentrations since 2001. This enabled us to reconstruct the fire history of this region since 1973 when visibility information became available. Our estimates indicate that until 1987 relatively few fires occurred in this region and that fire emissions increased rapidly over the 1990s. We found that this pattern agreed reasonably well with forest loss data sets, indicating that although natural fires may occur here, deforestation and degradation were the main cause of fires. Compared to fire emissions estimates based on Food and Agricultural Organization's Global Forest and Resources Assessment data, our estimates were substantially lower up to the 1990s, after which they were more in line. These visibility‐based fire emissions data set can help constrain dynamic global vegetation models and atmospheric models with a better representation of the complex fire regime in this region. PMID:28286373

  17. LNG fire and vapor control system technologies

    SciTech Connect

    Konzek, G.J.; Yasutake, K.M.; Franklin, A.L.

    1982-06-01

    This report provides a review of fire and vapor control practices used in the liquefied natural gas (LNG) industry. Specific objectives of this effort were to summarize the state-of-the-art of LNG fire and vapor control; define representative LNG facilities and their associated fire and vapor control systems; and develop an approach for a quantitative effectiveness evaluation of LNG fire and vapor control systems. In this report a brief summary of LNG physical properties is given. This is followed by a discussion of basic fire and vapor control design philosophy and detailed reviews of fire and vapor control practices. The operating characteristics and typical applications and application limitations of leak detectors, fire detectors, dikes, coatings, closed circuit television, communication systems, dry chemicals, water, high expansion foam, carbon dioxide and halogenated hydrocarbons are described. Summary descriptions of a representative LNG peakshaving facility and import terminal are included in this report together with typical fire and vapor control systems and their locations in these types of facilities. This state-of-the-art review identifies large differences in the application of fire and vapor control systems throughout the LNG industry.

  18. Optimal fire histories for biodiversity conservation.

    PubMed

    Kelly, Luke T; Bennett, Andrew F; Clarke, Michael F; McCarthy, Michael A

    2015-04-01

    Fire is used as a management tool for biodiversity conservation worldwide. A common objective is to avoid population extinctions due to inappropriate fire regimes. However, in many ecosystems, it is unclear what mix of fire histories will achieve this goal. We determined the optimal fire history of a given area for biological conservation with a method that links tools from 3 fields of research: species distribution modeling, composite indices of biodiversity, and decision science. We based our case study on extensive field surveys of birds, reptiles, and mammals in fire-prone semi-arid Australia. First, we developed statistical models of species' responses to fire history. Second, we determined the optimal allocation of successional states in a given area, based on the geometric mean of species relative abundance. Finally, we showed how conservation targets based on this index can be incorporated into a decision-making framework for fire management. Pyrodiversity per se did not necessarily promote vertebrate biodiversity. Maximizing pyrodiversity by having an even allocation of successional states did not maximize the geometric mean abundance of bird species. Older vegetation was disproportionately important for the conservation of birds, reptiles, and small mammals. Because our method defines fire management objectives based on the habitat requirements of multiple species in the community, it could be used widely to maximize biodiversity in fire-prone ecosystems.

  19. Modelling Variable Fire Severity in Boreal Forests: Effects of Fire Intensity and Stand Structure.

    PubMed

    Miquelajauregui, Yosune; Cumming, Steven G; Gauthier, Sylvie

    2016-01-01

    It is becoming clear that fires in boreal forests are not uniformly stand-replacing. On the contrary, marked variation in fire severity, measured as tree mortality, has been found both within and among individual fires. It is important to understand the conditions under which this variation can arise. We integrated forest sample plot data, tree allometries and historical forest fire records within a diameter class-structured model of 1.0 ha patches of mono-specific black spruce and jack pine stands in northern Québec, Canada. The model accounts for crown fire initiation and vertical spread into the canopy. It uses empirical relations between fire intensity, scorch height, the percent of crown scorched and tree mortality to simulate fire severity, specifically the percent reduction in patch basal area due to fire-caused mortality. A random forest and a regression tree analysis of a large random sample of simulated fires were used to test for an effect of fireline intensity, stand structure, species composition and pyrogeographic regions on resultant severity. Severity increased with intensity and was lower for jack pine stands. The proportion of simulated fires that burned at high severity (e.g. >75% reduction in patch basal area) was 0.80 for black spruce and 0.11 for jack pine. We identified thresholds in intensity below which there was a marked sensitivity of simulated fire severity to stand structure, and to interactions between intensity and structure. We found no evidence for a residual effect of pyrogeographic region on simulated severity, after the effects of stand structure and species composition were accounted for. The model presented here was able to produce variation in fire severity under a range of fire intensity conditions. This suggests that variation in stand structure is one of the factors causing the observed variation in boreal fire severity.

  20. Modelling Variable Fire Severity in Boreal Forests: Effects of Fire Intensity and Stand Structure

    PubMed Central

    Miquelajauregui, Yosune; Cumming, Steven G.; Gauthier, Sylvie

    2016-01-01

    It is becoming clear that fires in boreal forests are not uniformly stand-replacing. On the contrary, marked variation in fire severity, measured as tree mortality, has been found both within and among individual fires. It is important to understand the conditions under which this variation can arise. We integrated forest sample plot data, tree allometries and historical forest fire records within a diameter class-structured model of 1.0 ha patches of mono-specific black spruce and jack pine stands in northern Québec, Canada. The model accounts for crown fire initiation and vertical spread into the canopy. It uses empirical relations between fire intensity, scorch height, the percent of crown scorched and tree mortality to simulate fire severity, specifically the percent reduction in patch basal area due to fire-caused mortality. A random forest and a regression tree analysis of a large random sample of simulated fires were used to test for an effect of fireline intensity, stand structure, species composition and pyrogeographic regions on resultant severity. Severity increased with intensity and was lower for jack pine stands. The proportion of simulated fires that burned at high severity (e.g. >75% reduction in patch basal area) was 0.80 for black spruce and 0.11 for jack pine. We identified thresholds in intensity below which there was a marked sensitivity of simulated fire severity to stand structure, and to interactions between intensity and structure. We found no evidence for a residual effect of pyrogeographic region on simulated severity, after the effects of stand structure and species composition were accounted for. The model presented here was able to produce variation in fire severity under a range of fire intensity conditions. This suggests that variation in stand structure is one of the factors causing the observed variation in boreal fire severity. PMID:26919456

  1. In the Line of Fire.

    ERIC Educational Resources Information Center

    Kennedy, Mike

    2001-01-01

    Highlights the importance of using sprinkler systems in school residence halls to prevent fire fatalities. Understanding the risks involved, retrofitting schools to meet these risks, and realizing the need to extend safety education to off-campus housing are discussed. (GR)

  2. A New Item Selection Procedure for Mixed Item Type in Computerized Classification Testing.

    ERIC Educational Resources Information Center

    Lau, C. Allen; Wang, Tianyou

    This paper proposes a new Information-Time index as the basis for item selection in computerized classification testing (CCT) and investigates how this new item selection algorithm can help improve test efficiency for item pools with mixed item types. It also investigates how practical constraints such as item exposure rate control, test…

  3. Hidden item variance in multiple mini-interview scores.

    PubMed

    Zaidi, Nikki L Bibler; Swoboda, Christopher M; Kelcey, Benjamin M; Manuel, R Stephen

    2017-05-01

    The extant literature has largely ignored a potentially significant source of variance in multiple mini-interview (MMI) scores by "hiding" the variance attributable to the sample of attributes used on an evaluation form. This potential source of hidden variance can be defined as rating items, which typically comprise an MMI evaluation form. Due to its multi-faceted, repeated measures format, reliability for the MMI has been primarily evaluated using generalizability (G) theory. A key assumption of G theory is that G studies model the most important sources of variance to which a researcher plans to generalize. Because G studies can only attribute variance to the facets that are modeled in a G study, failure to model potentially substantial sources of variation in MMI scores can result in biased estimates of variance components. This study demonstrates the implications of hiding the item facet in MMI studies when true item-level effects exist. An extensive Monte Carlo simulation study was conducted to examine whether a commonly used hidden item, person-by-station (p × s|i) G study design results in biased estimated variance components. Estimates from this hidden item model were compared with estimates from a more complete person-by-station-by-item (p × s × i) model. Results suggest that when true item-level effects exist, the hidden item model (p × s|i) will result in biased variance components which can bias reliability estimates; therefore, researchers should consider using the more complete person-by-station-by-item model (p × s × i) when evaluating generalizability of MMI scores.

  4. The fire at Cocoanut Grove.

    PubMed

    Stewart, Camille L

    2015-01-01

    On November 28, 1942, a fire broke out at The Cocoanut Grove Nightclub, in Boston, Massachusetts. The fire claimed the lives of hundreds, and injured 170 patients who were treated at either Boston City Hospital or the Massachusetts General Hospital. With extraordinary leadership and scientific focus, this tragedy led to many important advances in burn management, including improvements in burn wound care, the first descriptions of inhalation injury, formulas to guide fluid resuscitation, and the initial studies of antimicrobial therapy with burns. This overview describes the treatment of the Cocoanut Gove victims, and how it transformed the management of burns forever.

  5. A survey of anatomical items relevant to the practice of rheumatology: upper extremity, head, neck, spine, and general concepts.

    PubMed

    Villaseñor-Ovies, Pablo; Navarro-Zarza, José Eduardo; Saavedra, Miguel Ángel; Hernández-Díaz, Cristina; Canoso, Juan J; Biundo, Joseph J; Kalish, Robert A; de Toro Santos, Francisco Javier; McGonagle, Dennis; Carette, Simon; Alvarez-Nemegyei, José

    2016-12-01

    This study aimed to identify the anatomical items of the upper extremity and spine that are potentially relevant to the practice of rheumatology. Ten rheumatologists interested in clinical anatomy who published, taught, and/or participated as active members of Clinical Anatomy Interest groups (six seniors, four juniors), participated in a one-round relevance Delphi exercise. An initial, 560-item list that included 45 (8.0 %) general concepts items; 138 (24.8 %) hand items; 100 (17.8 %) forearm and elbow items; 147 (26.2 %) shoulder items; and 130 (23.2 %) head, neck, and spine items was compiled by 5 of the participants. Each item was graded for importance with a Likert scale from 1 (not important) to 5 (very important). Thus, scores could range from 10 (1 × 10) to 50 (5 × 10). An item score of ≥40 was considered most relevant to competent practice as a rheumatologist. Mean item Likert scores ranged from 2.2 ± 0.5 to 4.6 ± 0.7. A total of 115 (20.5 %) of the 560 initial items reached relevance. Broken down by categories, this final relevant item list was composed by 7 (6.1 %) general concepts items; 32 (27.8 %) hand items; 20 (17.4 %) forearm and elbow items; 33 (28.7 %) shoulder items; and 23 (17.6 %) head, neck, and spine items. In this Delphi exercise, a group of practicing academic rheumatologists with an interest in clinical anatomy compiled a list of anatomical items that were deemed important to the practice of rheumatology. We suggest these items be considered curricular priorities when training rheumatology fellows in clinical anatomy skills and in programs of continuing rheumatology education.

  6. Estimation of carbon emissions from crown fires in Turkey

    NASA Astrophysics Data System (ADS)

    Kucuk, O.; Bilgili, E.

    2009-04-01

    Forest biomass consumption is an important index for carbon cycling. Forest fire represents one of the important sources of greenhouse gas (GHG) emissions due to biomass burning processes. Forest fire contribute to increasing atmospheric CO2 concentration therefore, role of forest fires in the global carbon cycle has received increasing interest. Various methods were used to estimation of carbon emission. IPCC methodology is commonly used for the calculation of GHG amounts released at forest fire in Europe especially on a national basis. Many European countries have done many studies relation to estimation of carbon emissions from forest fires. However, carbon emissions from forest fires were not estimated in Turkey. The objective of this paper was to estimate carbon emission from forest fires from 1997 to 2006 in three forest district directorate of Turkey. We have used IPCC methodology for estimation of carbon emission form forest fire in Turkey. The emission calculations associated with forest fires were carried out using the IPCC methodology for estimating emissions from biomass burning. According to IPCC methodology, the annual carbon release of gas is the product of parameters: Annual biomass loss by burning (kt), fraction of biomass oxidized on-site, carbon content (CC), emission ratio, N/C ratio. A set of forest fire data during 1997-2006 obtained from the Turkish Ministry of Environment and Forestry-General Directorate of Forestry Service. Fuel biomass and fuel consumption data were provided from experimental fires and biomass studies in Turkey. The highest carbon emission amount was CO2 gas. A wide range in carbon emissions of 0.37-94.85 Gg was caused by variability in pre-fire fuel characteristics (fuel size, distribution, fuel moisture and total load), fire type, fire season and fire weather, which affected fuel moisture and fire behavior. Keywords: Carbon emissions, Forest fire, Fuel consumption, IPCC, Turkey

  7. School Fires. Topical Fire Research Series. Volume 8, Issue 1

    ERIC Educational Resources Information Center

    US Department of Homeland Security, 2007

    2007-01-01

    Using the past 3 years of data, for 2003 to 2005, from the National Fire Incident Reporting System (NFIRS) database, the yearly national fire loss for fires on nonadult school properties is estimated at $85 million. Such losses are the result of an estimated annual average of 14,700 fires that required a fire department response. Fires on school…

  8. Nuclear power plant fire protection: philosophy and analysis. [PWR; BWR

    SciTech Connect

    Berry, D. L.

    1980-05-01

    This report combines a fire severity analysis technique with a fault tree methodology for assessing the importance to nuclear power plant safety of certain combinations of components and systems. Characteristics unique to fire, such as propagation induced by the failure of barriers, have been incorporated into the methodology. By applying the resulting fire analysis technique to actual conditions found in a representative nuclear power plant, it is found that some safety and nonsafety areas are both highly vulnerable to fire spread and impotant to overall safety, while other areas prove to be of marginal importance. Suggestions are made for further experimental and analytical work to supplement the fire analysis method.

  9. Data for Room Fire Model Comparisons

    PubMed Central

    Peacock, Richard D.; Davis, Sanford; Babrauskas, Vytenis

    1991-01-01

    With the development of models to predict fire growth and spread in buildings, there has been a concomitant evolution in the measurement and analysis of experimental data in real-scale fires. This report presents the types of analyses that can be used to examine large-scale room fire test data to prepare the data for comparison with zone-based fire models. Five sets of experimental data which can be used to test the limits of a typical two-zone fire model are detailed. A standard set of nomenclature describing the geometry of the building and the quantities measured in each experiment is presented. Availability of ancillary data (such as smaller-scale test results) is included. These descriptions, along with the data (available in computer-readable form) should allow comparisons between the experiment and model predictions. The base of experimental data ranges in complexity from one room tests with individual furniture items to a series of tests conducted in a multiple story hotel equipped with a zoned smoke control system. PMID:28184121

  10. Seerley Road Fire Site

    EPA Pesticide Factsheets

    A barn caught fire at on Seerley Road, Indianapolis. Five storage drums believed to contain metallic potassium were involved in the fire. EPA will perform additional sampling as part of removal operations and safe offsite transportation.

  11. South America Fire Observations

    NASA Video Gallery

    From space, we can understand fires in ways that are impossible from the ground. NASA research has contributed to much improved detection of fire for scientific purposes using satellite remote sens...

  12. FIRE II Cirrus Info

    Atmospheric Science Data Center

    2014-03-18

    ... Page:  FIRE II Main Grouping:  Cirrus Description:  First ISCCP Regional Experiment (FIRE) ... stratocumulus systems, the radiative properties of these clouds and their interactions. Data Products:  Cirrus ...

  13. Campus Fire Safety Today.

    ERIC Educational Resources Information Center

    Thompson, Mike

    2001-01-01

    Reviews information on recent college and university dormitory fire fatalities, and highlights five examples of building features reported to be major contributing factors in residence-hall fires. Explains how public awareness and expectations are affecting school dormitory safety. (GR)

  14. Wild Fire Safety Checklist

    MedlinePlus

    ... small fires before emergency responders arrive. Ë Select building materials and plants that resist fire. Ë Regularly clean ... and dust. Ë Listen and watch for air quality reports and health warnings about smoke. Ë Keep ...

  15. Fire Service Training. Fire Apparatus Practices. (Revised).

    ERIC Educational Resources Information Center

    North Carolina State Dept. of Community Colleges, Raleigh.

    One of a set of fourteen instructional outlines for use in a course to train novice firemen, this guide covers the topic of motorized fire apparatus. The fire fighter is instructed on the maintenance, maneuvering, and operation of equipment such as pumps, aerial ladders, and elevating platforms. Designed to be used with the Robert J. Brady…

  16. Identifying predictors of physics item difficulty: A linear regression approach

    NASA Astrophysics Data System (ADS)

    Mesic, Vanes; Muratovic, Hasnija

    2011-06-01

    Large-scale assessments of student achievement in physics are often approached with an intention to discriminate students based on the attained level of their physics competencies. Therefore, for purposes of test design, it is important that items display an acceptable discriminatory behavior. To that end, it is recommended to avoid extraordinary difficult and very easy items. Knowing the factors that influence physics item difficulty makes it possible to model the item difficulty even before the first pilot study is conducted. Thus, by identifying predictors of physics item difficulty, we can improve the test-design process. Furthermore, we get additional qualitative feedback regarding the basic aspects of student cognitive achievement in physics that are directly responsible for the obtained, quantitative test results. In this study, we conducted a secondary analysis of data that came from two large-scale assessments of student physics achievement at the end of compulsory education in Bosnia and Herzegovina. Foremost, we explored the concept of “physics competence” and performed a content analysis of 123 physics items that were included within the above-mentioned assessments. Thereafter, an item database was created. Items were described by variables which reflect some basic cognitive aspects of physics competence. For each of the assessments, Rasch item difficulties were calculated in separate analyses. In order to make the item difficulties from different assessments comparable, a virtual test equating procedure had to be implemented. Finally, a regression model of physics item difficulty was created. It has been shown that 61.2% of item difficulty variance can be explained by factors which reflect the automaticity, complexity, and modality of the knowledge structure that is relevant for generating the most probable correct solution, as well as by the divergence of required thinking and interference effects between intuitive and formal physics knowledge

  17. Detecting Gender Bias Through Test Item Analysis

    NASA Astrophysics Data System (ADS)

    González-Espada, Wilson J.

    2009-03-01

    Many physical science and physics instructors might not be trained in pedagogically appropriate test construction methods. This could lead to test items that do not measure what they are intended to measure. A subgroup of these items might show bias against some groups of students. This paper describes how the author became aware of potentially biased items against females in his examinations, which led to the exploration of fundamental issues related to item validity, gender bias, and differential item functioning, or DIF. A brief discussion of DIF in the context of university courses, as well as practical suggestions to detect possible gender-biased items, follows.

  18. Understanding key factors of users' intentions to repurchase and recommend digital items in social virtual worlds.

    PubMed

    Kim, Byoungsoo

    2012-10-01

    Given to the remarkable profitability of digital items in social virtual worlds (SVWs), such as SecondLife, Cyworld, and Habbo Hotel, it has become crucial to understand SVW users' postadoption behaviors toward digital items. This study develops a theoretical framework to examine key antecedents of users' intentions to repurchase and recommend digital items. Data collected from 256 users of digital items were empirically tested against the research model. The analysis results indicate that both user satisfaction and a perceived value play an important role in establishing users' postadoption intentions about digital items. Moreover, the results clearly show what roles perceived usefulness, perceived enjoyment, and perceived fee play in SVW environments.

  19. Hydrogen Fire Imager

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Through NASA's Technology Transfer Office at Stennis Space Center, two SSC engineers were able to market their hand-held fire imager. Called FIRESCAPE, the device allows firefighters to 'see' the invisible flames of hydrogen and alcohol fires in the daylight, as well as to find victims and burning embers in dense smoke and fog. SafetySCAN, which specializes in fire safety electronic products, will make the device the first affordable commercial product for fire imaging.

  20. Using burned area data to explore fire spread in coupled fire and ecosystem models

    NASA Astrophysics Data System (ADS)

    Gomez-Dans, J. L.; Lewis, P.; Wooster, M.; Spessa, A.

    2009-04-01

    Fire is a major driver of change in many ecosystems, and ecosystem models should try to understand and model the feedbacks between vegetation and fire. To achieve this, work has started on coupling fire and ecosystem models. The fire model receives modelled vegetation as input for its fuel loads, and simulates ignitions and fire spread from a number of assumptions on fire processes. The fire model simulates fire behaviour, and also estimates how vegetation is killed by the fire. This disturbance is fed back into the ecosystem model. In the current work, we focus on the LPJ ecosystem model and on the SPITFIRE fire model. Both models haven been used in conjunction in the past to model emissions over Southern Africa. SPITFIRE makes assumptions about ignitions (either anthropogenic or due to lightning strikes), live fuel moisture, fuel load and type derived from the ecosystem model, and about fire dynamics. In a typical run at daily temporal resolution, SPITFIRE will simulate an "average fire" in terms of fire dynamics, which is combined with the estimated daily number of ignitions to calculate the burned area on that day. The use of an average fire simplifies modelling at the coarse resolutions (grid cell spacing is often around 0.5 - 1 °) often used in these studies, but the associated penalty of a number of important fire limiting factors, such as human-driven suppression efforts or landscape elements that act as fire blocks. In the current study, we aim to explore landscape fragmentation in fire spread. To this end, we compare LPJ+SPITFIRE simulations fire area distributions with actual fire area observations from spaceborne sensors over a large region in Southern Africa. We introduce the concept of "landscape impedance", a metric that describes the difficulty of a fire spreading due to fragmentation, and estimate it spatially using satellite data. Finally, we introduce these concepts into the SPITFIRE fire model. Recently, burned area data from the MODIS sensor

  1. Fire Safety Fundamentals

    ERIC Educational Resources Information Center

    Roy, Ken

    2004-01-01

    Planning and prevention is the best defense against fires in school. This is particularly true in the science laboratory due to the presence of flammable gases, liquids, combustibles, and other potential sources of fire. Teachers can prevent fires from starting by maintaining prudent lab practices when dealing with combustible and flammable…

  2. Fire Department Emergency Response

    SciTech Connect

    Blanchard, A.; Bell, K.; Kelly, J.; Hudson, J.

    1997-09-01

    In 1995 the SRS Fire Department published the initial Operations Basis Document (OBD). This document was one of the first of its kind in the DOE complex and was widely distributed and reviewed. This plan described a multi-mission Fire Department which provided fire, emergency medical, hazardous material spill, and technical rescue services.

  3. Fire as Technology

    ERIC Educational Resources Information Center

    Rudolph, Robert N.

    2011-01-01

    In this article, the author describes a project that deals with fire production as an aspect of technology. The project challenges students to be survivors in a five-day classroom activity. Students research various materials and methods to produce fire without the use of matches or other modern combustion devices, then must create "fire" to keep…

  4. Occupancy Fire Record: Schools.

    ERIC Educational Resources Information Center

    National Fire Protection Association, Boston, MA.

    The considerations of human safety and preservation of facilities are examined in relation to school fires. Various aspects of planning which would decrease the probability of fires and thereby save life and property are reviewed and include--(1) causes, (2) automatic protection devices, (3) evacuation and fire drills, and (4) construction…

  5. Fire Prevention Education.

    ERIC Educational Resources Information Center

    Ehmann, Jeanne; Claus, William C.

    The fire prevention education bulletin helps schools continue their work to make the home, school, and community safe places in which to live and to help children and young people live in safe ways without developing undue fears. Briefly discussed are the goals of a fire prevention program, who should be concerned with fire prevention education,…

  6. Fire Prevention Inspection Procedures.

    ERIC Educational Resources Information Center

    Pribyl, Paul F.

    Lesson plans are provided for a fire prevention inspection course of the Wisconsin Fire Service Training program. Objectives for the course are to enable students to describe and conduct fire prevention inspections, to identify and correct hazards common to most occupancies, to understand the types of building construction and occupancy, and to…

  7. Risks and issues in fire safety on the Space Station

    NASA Technical Reports Server (NTRS)

    Friedman, Robert

    1993-01-01

    A fire in the inhabited portion of a spacecraft is a greatly feared hazard, but fire protection in space operations is complicated by two factors. First, the spacecraft cabin is an enclosed volume, which limits the resources for fire fighting and the options for crew escape. Second, an orbiting spacecraft experiences a balance of forces, creating a near-zero-gravity (microgravity) environment that profoundly affects the characteristics of fire initiation, spread, and suppression. The current Shuttle Orbiter is protected by a fire-detection and suppression system whose requirements are derived of necessity from accepted terrestrial and aircraft standards. While experience has shown that Shuttle fire safety is adequate, designers recognize that improved systems to respond specifically to microgravity fire characteristics are highly desirable. Innovative technology is particularly advisable for the Space Station, a forthcoming space community with a complex configuration and long-duration orbital missions, in which the effectiveness of current fire-protection systems is unpredictable. The development of risk assessments to evaluate the probabilities and consequences of fire incidents in spacecraft are briefly reviewed. It further discusses the important unresolved issues and needs for improved fire safety in the Space Station, including those of material selection, spacecraft atmospheres, fire detection, fire suppression, and post-fire restoration.

  8. Risks and issues in fire safety on the Space Station

    NASA Astrophysics Data System (ADS)

    Friedman, Robert

    1993-12-01

    A fire in the inhabited portion of a spacecraft is a greatly feared hazard, but fire protection in space operations is complicated by two factors. First, the spacecraft cabin is an enclosed volume, which limits the resources for fire fighting and the options for crew escape. Second, an orbiting spacecraft experiences a balance of forces, creating a near-zero-gravity (microgravity) environment that profoundly affects the characteristics of fire initiation, spread, and suppression. The current Shuttle Orbiter is protected by a fire-detection and suppression system whose requirements are derived of necessity from accepted terrestrial and aircraft standards. While experience has shown that Shuttle fire safety is adequate, designers recognize that improved systems to respond specifically to microgravity fire characteristics are highly desirable. Innovative technology is particularly advisable for the Space Station, a forthcoming space community with a complex configuration and long-duration orbital missions, in which the effectiveness of current fire-protection systems is unpredictable. The development of risk assessments to evaluate the probabilities and consequences of fire incidents in spacecraft are briefly reviewed. It further discusses the important unresolved issues and needs for improved fire safety in the Space Station, including those of material selection, spacecraft atmospheres, fire detection, fire suppression, and post-fire restoration.

  9. Forest fire spatial pattern analysis in Galicia (NW Spain).

    PubMed

    Fuentes-Santos, I; Marey-Pérez, M F; González-Manteiga, W

    2013-10-15

    Knowledge of fire behaviour is of key importance in forest management. In the present study, we analysed the spatial structure of forest fire with spatial point pattern analysis and inference techniques recently developed in the Spatstat package of R. Wildfires have been the primary threat to Galician forests in recent years. The district of Fonsagrada-Ancares is one of the most seriously affected by fire in the region and, therefore, the central focus of the study. Our main goal was to determine the spatial distribution of ignition points to model and predict fire occurrence. These data are of great value in establishing enhanced fire prevention and fire fighting plans. We found that the spatial distribution of wildfires is not random and that fire occurrence may depend on ownership conflicts. We also found positive interaction between small and large fires and spatial independence between wildfires in consecutive years.

  10. Foam composite structures. [for fire retardant airframe materials

    NASA Technical Reports Server (NTRS)

    Delano, C. B.; Milligan, R. J.

    1976-01-01

    The need to include fire resistant foams into state of the art aircraft interior paneling to increase passenger safety in aircraft fires was studied. Present efforts were directed toward mechanical and fire testing of panels with foam inclusions. Skinned foam filled honeycomb and PBI structural foams were the two constructions investigated with attention being directed toward weight/performance/cost trade-off. All of the new panels demonstrated improved performance in fire and some were lighter weight but not as strong as the presently used paneling. Continued efforts should result in improved paneling for passenger safety. In particular the simple partial filling (fire side) of state-of-the-art honeycomb with fire resistant foams with little sacrifice in weight would result in panels with increased fire resistance. More important may be the retarded rate of toxic gas evolution in the fire due to the protection of the honeycomb by the foam.

  11. Comparison of the radiological dose from the Cerro Grande fire to a natural wildfire.

    PubMed

    Volkerding, John M

    2004-01-01

    Since the Cerro Grande fire burned portions of a Department of Energy facility where nuclear weapons research occurs, it is important to determine if the fire posed greater risk to the public than a natural fire. All wildfires release radioactive as well as other toxic pollutants into the atmosphere. Thus, it is important to determine if the radioactive air emissions from the Cerro Grande fire were statistically different than those from a natural wildfire, specifically the Viveash fire.

  12. A Bifactor Multidimensional Item Response Theory Model for Differential Item Functioning Analysis on Testlet-Based Items

    ERIC Educational Resources Information Center

    Fukuhara, Hirotaka; Kamata, Akihito

    2011-01-01

    A differential item functioning (DIF) detection method for testlet-based data was proposed and evaluated in this study. The proposed DIF model is an extension of a bifactor multidimensional item response theory (MIRT) model for testlets. Unlike traditional item response theory (IRT) DIF models, the proposed model takes testlet effects into…

  13. Spatial and temporal dimensions of fire activity in the fire-prone eastern Canadian taiga.

    PubMed

    Erni, Sandy; Arseneault, Dominique; Parisien, Marc-André; Bégin, Yves

    2017-03-01

    The forest age mosaic is a fundamental attribute of the North American boreal forest. Given that fires are generally lethal to trees, the time since last fire largely determines the composition and structure of forest stands and landscapes. Although the spatiotemporal dynamics of such mosaics has long been assumed to be random under the overwhelming influence of severe fire weather, no long-term reconstruction of mosaic dynamics has been performed from direct field evidence. In this study, we use fire length as a proxy for fire extent across the fire-prone eastern Canadian taiga and systematically reconstruct the spatiotemporal variability of fire extent and fire intervals, as well as the resulting forest age along a 340-km transect for the 1840-2013 time period. Our results indicate an extremely active fire regime over the last two centuries, with an overall burn rate of 2.1% of the land area yr(-1) , mainly triggered by seasonal anomalies of high temperature and severe drought. However, the rejuvenation of the age mosaic was strongly patterned in space and time due to the intrinsically lower burn rates in wetland-dominated areas and, more importantly, to the much-reduced likelihood of burning of stands up to 50 years postfire. An extremely high burn rate of ~5% yr(-1) would have characterized our study region during the last century in the absence of such fuel age effect. Although recent burn rates and fire sizes are within their range of variability of the last 175 years, a particularly severe weather event allowed a 2013 fire to spread across a large fire refuge, thus shifting the abundance of mature and old forest to a historic low. These results provide reference conditions to evaluate the significance and predict the spatiotemporal dynamics and impacts of the currently strengthening fire activity in the North American boreal forest.

  14. Fire and amphibians in North America

    USGS Publications Warehouse

    Pilliod, D.S.; Bury, R.B.; Hyde, E.J.; Pearl, C.A.; Corn, P.S.

    2003-01-01

    Information on amphibian responses to fire and fuel reduction practices is critically needed due to potential declines of species and the prevalence of new, more intensive fire management practices in North American forests. The goals of this review are to summarize the known and potential effects of fire and fuels management on amphibians and their aquatic habitats, and to identify information gaps to help direct future scientific research. Amphibians as a group are taxonomically and ecologically diverse; in turn, responses to fire and associated habitat alteration are expected to vary widely among species and among geographic regions. Available data suggest that amphibian responses to fire are spatially and temporally variable and incompletely understood. Much of the limited research has addressed short-term (1-3 years) effects of prescribed fire on terrestrial life stages of amphibians in the southeastern United States. Information on the long-term negative effects of fire on amphibians and the importance of fire for maintaining amphibian communities is sparse for the majority of taxa in North America. Given the size and severity of recent wildland fires and the national effort to reduce fuels on federal lands, future studies are needed to examine the effects of these landscape disturbances on amphibians. We encourage studies to address population-level responses of amphibians to fire by examining how different life stages are affected by changes in aquatic, riparian, and upland habitats. Research designs need to be credible and provide information that is relevant for fire managers and those responsible for assessing the potential effects of various fuel reduction alternatives on rare, sensitive, and endangered amphibian species. ?? 2003 Elsevier Science B.V. All rights reserved.

  15. The Heavens on Fire

    NASA Astrophysics Data System (ADS)

    Littmann, Mark

    1998-10-01

    Meteor succeeded meteor in such rapid succession that it was impossible to count them; at times the sky seemed full of them, and the earth was illuminated as with a morning light. Eye-witness accounts such as this, and every spectacular detail of the Leonids, the greatest meteor showers of all, can be found in the acclaimed The Heavens on Fire. In this volume, author Mark Littmann vividly tells the history of meteors, and especially the Leonids, whose terrifying beauty established meteor science. He traces the history and mythology of meteors, profiles the fascinating figures whose discoveries advanced the field, and explores how meteors have changed the course of life on Earth. Crisp illustrations capture the excitement of past meteor showers and help elucidate important concepts. The returning Leonids are now reaching their peak with great activity expected in 1999 and 2000. For all those who wish to take part in this rare experience, Littmann offers advice on how and where to find the best view. Filled with practical tips, clear explanations, and descriptions of a sight that more than one observer has called "brilliant beyond conception," The Heavens on Fire will delight every reader. Mark Littmann teaches astronomy at the University of Tennessee. His previous books include Comet Halley: Once in a Lifetime and Planets Beyond: Discovering the Outer Solar System. Both books were chosen by the Astronomical Society of the Pacific as Astronomy Books of the Year.

  16. Impact of forest fires on particulate matter and ozone levels during the 2003, 2004 and 2005 fire seasons in Portugal.

    PubMed

    Martins, V; Miranda, A I; Carvalho, A; Schaap, M; Borrego, C; Sá, E

    2012-01-01

    The main purpose of this work is to estimate the impact of forest fires on air pollution applying the LOTOS-EUROS air quality modeling system in Portugal for three consecutive years, 2003-2005. Forest fire emissions have been included in the modeling system through the development of a numerical module, which takes into account the most suitable parameters for Portuguese forest fire characteristics and the burnt area by large forest fires. To better evaluate the influence of forest fires on air quality the LOTOS-EUROS system has been applied with and without forest fire emissions. Hourly concentration results have been compared to measure data at several monitoring locations with better modeling quality parameters when forest fire emissions were considered. Moreover, hourly estimates, with and without fire emissions, can reach differences in the order of 20%, showing the importance and the influence of this type of emissions on air quality.

  17. Promoting cold-start items in recommender systems.

    PubMed

    Liu, Jin-Hu; Zhou, Tao; Zhang, Zi-Ke; Yang, Zimo; Liu, Chuang; Li, Wei-Min

    2014-01-01

    As one of the major challenges, cold-start problem plagues nearly all recommender systems. In particular, new items will be overlooked, impeding the development of new products online. Given limited resources, how to utilize the knowledge of recommender systems and design efficient marketing strategy for new items is extremely important. In this paper, we convert this ticklish issue into a clear mathematical problem based on a bipartite network representation. Under the most widely used algorithm in real e-commerce recommender systems, the so-called item-based collaborative filtering, we show that to simply push new items to active users is not a good strategy. Interestingly, experiments on real recommender systems indicate that to connect new items with some less active users will statistically yield better performance, namely, these new items will have more chance to appear in other users' recommendation lists. Further analysis suggests that the disassortative nature of recommender systems contributes to such observation. In a word, getting in-depth understanding on recommender systems could pave the way for the owners to popularize their cold-start products with low costs.

  18. Promoting Cold-Start Items in Recommender Systems

    PubMed Central

    Liu, Jin-Hu; Zhou, Tao; Zhang, Zi-Ke; Yang, Zimo; Liu, Chuang; Li, Wei-Min

    2014-01-01

    As one of the major challenges, cold-start problem plagues nearly all recommender systems. In particular, new items will be overlooked, impeding the development of new products online. Given limited resources, how to utilize the knowledge of recommender systems and design efficient marketing strategy for new items is extremely important. In this paper, we convert this ticklish issue into a clear mathematical problem based on a bipartite network representation. Under the most widely used algorithm in real e-commerce recommender systems, the so-called item-based collaborative filtering, we show that to simply push new items to active users is not a good strategy. Interestingly, experiments on real recommender systems indicate that to connect new items with some less active users will statistically yield better performance, namely, these new items will have more chance to appear in other users' recommendation lists. Further analysis suggests that the disassortative nature of recommender systems contributes to such observation. In a word, getting in-depth understanding on recommender systems could pave the way for the owners to popularize their cold-start products with low costs. PMID:25479013

  19. Development of Elderly Quality of Life Index – Eqoli: Item Reduction and Distribution into Dimensions

    PubMed Central

    Paschoal, Sérgio Márcio Pacheco; Filho, Wilson Jacob; Litvoc, Júlio

    2008-01-01

    OBJECTIVE To describe item reduction and its distribution into dimensions in the construction process of a quality of life evaluation instrument for the elderly. METHODS The sampling method was chosen by convenience through quotas, with selection of elderly subjects from four programs to achieve heterogeneity in the “health status”, “functional capacity”, “gender”, and “age” variables. The Clinical Impact Method was used, consisting of the spontaneous and elicited selection by the respondents of relevant items to the construct Quality of Life in Old Age from a previously elaborated item pool. The respondents rated each item’s importance using a 5-point Likert scale. The product of the proportion of elderly selecting the item as relevant (frequency) and the mean importance score they attributed to it (importance) represented the overall impact of that item in their quality of life (impact). The items were ordered according to their impact scores and the top 46 scoring items were grouped in dimensions by three experts. A review of the negative items was performed. RESULTS One hundred and ninety three people (122 women and 71 men) were interviewed. Experts distributed the 46 items into eight dimensions. Closely related items were grouped and dimensions not reaching the minimum expected number of items received additional items resulting in eight dimensions and 43 items. DISCUSSION The sample was heterogeneous and similar to what was expected. The dimensions and items demonstrated the multidimensionality of the construct. The Clinical Impact Method was appropriate to construct the instrument, which was named Elderly Quality of Life Index - EQoLI. An accuracy process will be examined in the future. PMID:18438571

  20. Fighting Forest Fires

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Firefly is an airborne system for imaging forest fires. It uses satellite-based navigation for greater positioning accuracy and offers timeliness in fire location data delivery with on board data processing and a direct aircraft-to-fire camp communications link. Developed by Jet Propulsion Laboratory and the USFS, it has an infrared line scanner to identify fire boundaries and an infrared sensor system that can penetrate smoke to image the ground. Firefly is an outgrowth of a previous collaboration that produced FLAME, an airborne fire mapping instrument. Further refinements are anticipated by NASA and the United States Forest Service (USFS).

  1. Fire Protection Program Manual

    SciTech Connect

    Sharry, J A

    2012-05-18

    This manual documents the Lawrence Livermore National Laboratory (LLNL) Fire Protection Program. Department of Energy (DOE) Orders 420.1B, Facility Safety, requires LLNL to have a comprehensive and effective fire protection program that protects LLNL personnel and property, the public and the environment. The manual provides LLNL and its facilities with general information and guidance for meeting DOE 420.1B requirements. The recommended readers for this manual are: fire protection officers, fire protection engineers, fire fighters, facility managers, directorage assurance managers, facility coordinators, and ES and H team members.

  2. Spatial probability models of fire in the desert grasslands of the southwestern USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fire is an important driver of ecological processes in semiarid environments; however, the role of fire in desert grasslands of the Southwestern US is controversial and the regional fire distribution is largely unknown. We characterized the spatial distribution of fire in the desert grassland region...

  3. The interaction of fire and mankind: Introduction†

    PubMed Central

    Chaloner, William G.

    2016-01-01

    Fire has been an important part of the Earth system for over 350 Myr. Humans evolved in this fiery world and are the only animals to have used and controlled fire. The interaction of mankind with fire is a complex one, with both positive and negative aspects. Humans have long used fire for heating, cooking, landscape management and agriculture, as well as for pyrotechnologies and in industrial processes over more recent centuries. Many landscapes need fire but population expansion into wildland areas creates a tension between different interest groups. Extinguishing wildfires may not always be the correct solution. A combination of factors, including the problem of invasive plants, landscape change, climate change, population growth, human health, economic, social and cultural attitudes that may be transnational make a re-evaluation of fire and mankind necessary. The Royal Society meeting on Fire and mankind was held to address these issues and the results of these deliberations are published in this volume. This article is part of the themed issue ‘The interaction of fire and mankind’. PMID:27216519

  4. The interaction of fire and mankind: Introduction.

    PubMed

    Scott, Andrew C; Chaloner, William G; Belcher, Claire M; Roos, Christopher I

    2016-06-05

    Fire has been an important part of the Earth system for over 350 Myr. Humans evolved in this fiery world and are the only animals to have used and controlled fire. The interaction of mankind with fire is a complex one, with both positive and negative aspects. Humans have long used fire for heating, cooking, landscape management and agriculture, as well as for pyrotechnologies and in industrial processes over more recent centuries. Many landscapes need fire but population expansion into wildland areas creates a tension between different interest groups. Extinguishing wildfires may not always be the correct solution. A combination of factors, including the problem of invasive plants, landscape change, climate change, population growth, human health, economic, social and cultural attitudes that may be transnational make a re-evaluation of fire and mankind necessary. The Royal Society meeting on Fire and mankind was held to address these issues and the results of these deliberations are published in this volume.This article is part of the themed issue 'The interaction of fire and mankind'.

  5. Spatial patterns of large natural fires in Sierra Nevada wilderness areas

    USGS Publications Warehouse

    Collins, B.M.; Kelly, M.; van Wagtendonk, J.W.; Stephens, S.L.

    2007-01-01

    The effects of fire on vegetation vary based on the properties and amount of existing biomass (or fuel) in a forest stand, weather conditions, and topography. Identifying controls over the spatial patterning of fire-induced vegetation change, or fire severity, is critical in understanding fire as a landscape scale process. We use gridded estimates of fire severity, derived from Landsat ETM+ imagery, to identify the biotic and abiotic factors contributing to the observed spatial patterns of fire severity in two large natural fires. Regression tree analysis indicates the importance of weather, topography, and vegetation variables in explaining fire severity patterns between the two fires. Relative humidity explained the highest proportion of total sum of squares throughout the Hoover fire (Yosemite National Park, 2001). The lowest fire severity corresponded with increased relative humidity. For the Williams fire (Sequoia/Kings Canyon National Parks, 2003) dominant vegetation type explains the highest proportion of sum of squares. Dominant vegetation was also important in determining fire severity throughout the Hoover fire. In both fires, forest stands that were dominated by lodgepole pine (Pinus contorta) burned at highest severity, while red fir (Abies magnifica) stands corresponded with the lowest fire severities. There was evidence in both fires that lower wind speed corresponded with higher fire severity, although the highest fire severity in the Williams fire occurred during increased wind speed. Additionally, in the vegetation types that were associated with lower severity, burn severity was lowest when the time since last fire was fewer than 11 and 17 years for the Williams and Hoover fires, respectively. Based on the factors and patterns identified, managers can anticipate the effects of management ignited and naturally ignited fires at the forest stand and the landscape levels. ?? 2007 Springer Science+Business Media, Inc.

  6. Human influence on California fire regimes

    USGS Publications Warehouse

    Syphard, A.D.; Radeloff, V.C.; Keeley, J.E.; Hawbaker, T.J.; Clayton, M.K.; Stewart, S.I.; Hammer, R.B.

    2007-01-01

    Periodic wildfire maintains the integrity and species composition of many ecosystems, including the mediterranean-climate shrublands of California. However, human activities alter natural fire regimes, which can lead to cascading ecological effects. Increased human ignitions at the wildland-urban interface (WUI) have recently gained attention, but fire activity and risk are typically estimated using only biophysical variables. Our goal was to determine how humans influence fire in California and to examine whether this influence was linear, by relating contemporary (2000) and historic (1960-2000) fire data to both human and biophysical variables. Data for the human variables included fine-resolution maps of the WUI produced using housing density and land cover data. Interface WUI, where development abuts wildland vegetation, was differentiated from intermix WUI, where development intermingles with wildland vegetation. Additional explanatory variables included distance to WUI, population density, road density, vegetation type, and ecoregion. All data were summarized at the county level and analyzed using bivariate and multiple regression methods. We found highly significant relationships between humans and fire on the contemporary landscape, and our models explained fire frequency (R2 = 0.72) better than area burned (R2 = 0.50). Population density, intermix WUI, and distance to WUI explained the most variability in fire frequency, suggesting that the spatial pattern of development may be an important variable to consider when estimating fire risk. We found nonlinear effects such that fire frequency and area burned were highest at intermediate levels of human activity, but declined beyond certain thresholds. Human activities also explained change in fire frequency and area burned (1960-2000), but our models had greater explanatory power during the years 1960-1980, when there was more dramatic change in fire frequency. Understanding wildfire as a function of the

  7. 7 CFR 2902.5 - Item designation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ..., USDA will use life cycle cost information only from tests using the BEES analytical method. (c... availability of such items and the economic and technological feasibility of using such items, including life cycle costs. USDA will gather information on individual products within an item and extrapolate...

  8. Using Multimedia Technology To Create Innovative Items.

    ERIC Educational Resources Information Center

    French, Ann; Godwin, Janet

    The development of innovative test item types that use multimedia technology to improve item authenticity and interaction and allow for objective scoring through partial-credit scoring methodologies was studied. Science test items were developed for community college developmental students using "Authorware 3.0," an instructional compact disc. The…

  9. On the Relationship between Differential Item Functioning and Item Difficulty: An Issue of Methods? Item Response Theory Approach to Differential Item Functioning

    ERIC Educational Resources Information Center

    Santelices, Maria Veronica; Wilson, Mark

    2012-01-01

    The relationship between differential item functioning (DIF) and item difficulty on the SAT is such that more difficult items tended to exhibit DIF in favor of the focal group (usually minority groups). These results were reported by Kulick and Hu, and Freedle and have been enthusiastically discussed by more recent literature. Examining the…

  10. Effects of Assigning Raters to Items

    ERIC Educational Resources Information Center

    Sykes, Robert C.; Ito, Kyoko; Wang, Zhen

    2008-01-01

    Student responses to a large number of constructed response items in three Math and three Reading tests were scored on two occasions using three ways of assigning raters: single reader scoring, a different reader for each response (item-specific), and three readers each scoring a rater item block (RIB) containing approximately one-third of a…

  11. Item Response Methods for Educational Assessment.

    ERIC Educational Resources Information Center

    Mislevy, Robert J.; Rieser, Mark R.

    Multiple matrix sampling (MMS) theory indicates how data may be gathered to most efficiently convey information about levels of attainment in a population, but standard analyses of these data require random sampling of items from a fixed pool of items. This assumption proscribes the retirement of flawed or obsolete items from the pool as well as…

  12. Effects of Including Humor in Test Items.

    ERIC Educational Resources Information Center

    McMorris, Robert F.; And Others

    Two 50-item multiple-choice forms of a grammar test were developed differing only in humor being included in 20 items of one form. One hundred twenty-six (126) eighth graders received the test plus alternate forms of a questionnaire. Humor inclusion did not affect grammar scores on matched humorous/nonhumorous items nor on common post-treatment…

  13. Automatic Item Generation of Probability Word Problems

    ERIC Educational Resources Information Center

    Holling, Heinz; Bertling, Jonas P.; Zeuch, Nina

    2009-01-01

    Mathematical word problems represent a common item format for assessing student competencies. Automatic item generation (AIG) is an effective way of constructing many items with predictable difficulties, based on a set of predefined task parameters. The current study presents a framework for the automatic generation of probability word problems…

  14. Binomial Test Models and Item Difficulty.

    ERIC Educational Resources Information Center

    van der Linden, Wim J.

    1979-01-01

    The restrictions on item difficulties that must be met when binomial models are applied to domain-referenced testing are examined. Both a deterministic and a stochastic conception of item responses are discussed with respect to difficulty and Guttman-type items. (Author/BH)

  15. Are All Item Response Functions Monotonically Increasing?

    ERIC Educational Resources Information Center

    Wang, Wenhao

    2012-01-01

    Item response functions of the parametric logistic IRT models follow the logistic form which is monotonically increasing. However, item response functions of some real items are nonmonotonic which might lead to examinees with lower proficiency levels receiving higher scores. This study compared three nonparametric IRF estimation methods--the…

  16. Computer Equipment Repair Test Item Bank.

    ERIC Educational Resources Information Center

    Reneau, Fred; And Others

    This guide contains 321 test items for use in teaching a course in repairing computer equipment. All test items were reviewed, revised, and validated by incumbent workers and subject matter instructors. Items are provided for assessing student achievement in the following skill areas (with selected skills mentioned in brackets): performing…

  17. 76 FR 60474 - Commercial Item Handbook

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-29

    ... Defense Acquisition Regulations System Commercial Item Handbook AGENCY: Defense Acquisition Regulations... Commercial Item Handbook. The purpose of the Handbook is to help acquisition personnel develop sound business strategies for procuring commercial items. DoD is seeking industry input on the contents before...

  18. A Balance Sheet for Educational Item Banking.

    ERIC Educational Resources Information Center

    Hiscox, Michael D.

    Educational item banking presents observers with a considerable paradox. The development of test items from scratch is viewed as wasteful, a luxury in times of declining resources. On the other hand, item banking has failed to become a mature technology despite large amounts of money and the efforts of talented professionals. The question of which…

  19. Processing Polarity Items: Contrastive Licensing Costs

    ERIC Educational Resources Information Center

    Saddy, Douglas; Drenhaus, Heiner; Frisch, Stefan

    2004-01-01

    We describe an experiment that investigated the failure to license polarity items in German using event-related brain potentials (ERPs). The results reveal distinct processing reflexes associated with failure to license positive polarity items in comparison to failure to license negative polarity items. Failure to license both negative and…

  20. Criterion-Referenced Test Items for Welding.

    ERIC Educational Resources Information Center

    Davis, Diane, Ed.

    This test item bank on welding contains test questions based upon competencies found in the Missouri Welding Competency Profile. Some test items are keyed for multiple competencies. These criterion-referenced test items are designed to work with the Vocational Instructional Management System. Questions have been statistically sampled and validated…

  1. Differential Item Functioning from a Multilevel Perspective.

    ERIC Educational Resources Information Center

    van den Bergh, Huub; And Others

    The term differential item functioning (DIF) refers to whether or not the same psychological constructs are measured across different groups. If an item does not measure the same skills or subskills in different populations, it is said to function differentially or to display item bias. A multilevel approach to DIF is proposed. In such a model,…

  2. Identification of a Semiparametric Item Response Model

    ERIC Educational Resources Information Center

    Peress, Michael

    2012-01-01

    We consider the identification of a semiparametric multidimensional fixed effects item response model. Item response models are typically estimated under parametric assumptions about the shape of the item characteristic curves (ICCs), and existing results suggest difficulties in recovering the distribution of individual characteristics under…

  3. The Multidimensionality of Verbal Analogy Items

    ERIC Educational Resources Information Center

    Ullstadius, Eva; Carlstedt, Berit; Gustafsson, Jan-Eric

    2008-01-01

    The influence of general and verbal ability on each of 72 verbal analogy test items were investigated with new factor analytical techniques. The analogy items together with the Computerized Swedish Enlistment Battery (CAT-SEB) were given randomly to two samples of 18-year-old male conscripts (n = 8566 and n = 5289). Thirty-two of the 72 items had…

  4. Ramsay-Curve Differential Item Functioning

    ERIC Educational Resources Information Center

    Woods, Carol M.

    2011-01-01

    Differential item functioning (DIF) occurs when an item on a test, questionnaire, or interview has different measurement properties for one group of people versus another, irrespective of true group-mean differences on the constructs being measured. This article is focused on item response theory based likelihood ratio testing for DIF (IRT-LR or…

  5. Real and Artificial Differential Item Functioning

    ERIC Educational Resources Information Center

    Andrich, David; Hagquist, Curt

    2012-01-01

    The literature in modern test theory on procedures for identifying items with differential item functioning (DIF) among two groups of persons includes the Mantel-Haenszel (MH) procedure. Generally, it is not recognized explicitly that if there is real DIF in some items which favor one group, then as an artifact of this procedure, artificial DIF…

  6. 15 CFR 742.15 - Encryption items.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... encryption software are distinguished from controls on other software regulated under the EAR. (a) Licensing... items (“EI”) classified under 5A002.a.1, .a.2, .a.5, .a.6, .a.9, and .b; 5D002.a, .c.1 or .d for... items and terms. Most encryption items may be exported under the provisions of License Exception ENC...

  7. 15 CFR 742.15 - Encryption items.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... encryption software are distinguished from controls on other software regulated under the EAR. (a) Licensing... items (“EI”) classified under 5A002.a.1, .a.2, .a.5, .a.6, .a.9, and .b; 5D002.a, .c.1 or .d for... items and terms. Most encryption items may be exported under the provisions of License Exception ENC...

  8. 15 CFR 742.15 - Encryption items.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... encryption software are distinguished from controls on other software regulated under the EAR. (a) Licensing... items (“EI”) classified under 5A002.a.1, .a.2, .a.5, .a.6, .a.9, and .b; 5D002.a, .c.1 or .d for... items and terms. Most encryption items may be exported under the provisions of License Exception ENC...

  9. Computerized Numerical Control Test Item Bank.

    ERIC Educational Resources Information Center

    Reneau, Fred; And Others

    This guide contains 285 test items for use in teaching a course in computerized numerical control. All test items were reviewed, revised, and validated by incumbent workers and subject matter instructors. Items are provided for assessing student achievement in such aspects of programming and planning, setting up, and operating machines with…

  10. Item Selection in Computerized Classification Testing

    ERIC Educational Resources Information Center

    Thompson, Nathan A.

    2009-01-01

    Several alternatives for item selection algorithms based on item response theory in computerized classification testing (CCT) have been suggested, with no conclusive evidence on the substantial superiority of a single method. It is argued that the lack of sizable effect is because some of the methods actually assess items very similarly through…

  11. Linking Item Parameters to a Base Scale

    ERIC Educational Resources Information Center

    Kang, Taehoon; Petersen, Nancy S.

    2012-01-01

    This paper compares three methods of item calibration--concurrent calibration, separate calibration with linking, and fixed item parameter calibration--that are frequently used for linking item parameters to a base scale. Concurrent and separate calibrations were implemented using BILOG-MG. The Stocking and Lord in "Appl Psychol Measure"…

  12. Drivers of recent trends in African landscape fires

    NASA Astrophysics Data System (ADS)

    Andela, Niels; van der Werf, Guido R.

    2014-05-01

    Wildfires play an important role in savannah ecosystem dynamics and are an important source of emissions of (greenhouse) gasses and aerosols. Africa is nowadays responsible for about 70% of global burned area and about 50% of fire carbon emissions. Although it has been reported that fire activity varies according to climatic and anthropogenic influences, much remains unclear about the drivers of the spatial distribution of fire activity over the continent and its temporal dynamics. Resolving the drivers of this spatiotemporal variability is crucial to understand the future role of fire on the African continent. Satellite observations are the preferred way to monitor fire activity at this scale and the satellite fire record starts to be long enough to study recent trends in fire occurrence, the subject of our work. We developed a model to account for variations in fire activity due to climate, and investigated the role of sea surface temperatures on rainfall patterns and thus fire dynamics. Spatial variation and trends in land cover were used to improve understanding of underlying trends caused by socio-economic changes. Results elucidate the importance of various drivers on recent trends in African landscape fires and allow new insights in the future of African fire dynamics.

  13. Approximation Preserving Reductions among Item Pricing Problems

    NASA Astrophysics Data System (ADS)

    Hamane, Ryoso; Itoh, Toshiya; Tomita, Kouhei

    When a store sells items to customers, the store wishes to determine the prices of the items to maximize its profit. Intuitively, if the store sells the items with low (resp. high) prices, the customers buy more (resp. less) items, which provides less profit to the store. So it would be hard for the store to decide the prices of items. Assume that the store has a set V of n items and there is a set E of m customers who wish to buy those items, and also assume that each item i ∈ V has the production cost di and each customer ej ∈ E has the valuation vj on the bundle ej ⊆ V of items. When the store sells an item i ∈ V at the price ri, the profit for the item i is pi = ri - di. The goal of the store is to decide the price of each item to maximize its total profit. We refer to this maximization problem as the item pricing problem. In most of the previous works, the item pricing problem was considered under the assumption that pi ≥ 0 for each i ∈ V, however, Balcan, et al. [In Proc. of WINE, LNCS 4858, 2007] introduced the notion of “loss-leader, ” and showed that the seller can get more total profit in the case that pi < 0 is allowed than in the case that pi < 0 is not allowed. In this paper, we derive approximation preserving reductions among several item pricing problems and show that all of them have algorithms with good approximation ratio.

  14. A new model of landscape-scale fire connectivity applied to resource and fire management in the Sonoran Desert, USA.

    PubMed

    Gray, Miranda E; Dickson, Brett G

    2015-06-01

    Understanding where and when on the landscape fire is likely to burn (fire likelihood) and the predicted responses of valued resources (fire effects) will lead to more effective management of wildfire risk in multiple ecosystem types. Fire is a contagious and highly unpredictable process, and an analysis of fire connectivity that incorporates stochasticity may help predict fire likelihood across large extents. We developed a model of fire connectivity based on electrical circuit theory, which is a probabilistic approach to modeling ecological flows. We first parameterized our model to reflect the synergistic influences of fuels, landscape properties, and winds on fire spread in the lower Sonoran Desert of southwestern Arizona, and then defined this landscape as an interconnected network through which to model flow (i.e., fire spread). We interpreted the mapped outputs as fire likelihood and used historical burned area data to evaluate our results. Expected fire effects were characterized based on the degree to which future fire exposure might negatively impact native plant community recovery, taking into account the impact of repeated fire and major vegetation associations. We explored fire effects within habitat for the endangered Sonoran pronghorn antelope and designated wilderness. Model results indicated that fire likelihood was higher in lower elevations, and in areas with lower slopes and topographic roughness. Fire likelihood and effects were predicted to be high in 21% of the currently occupied range of the Sonoran pronghorn and 15% of the additional habitat considered suitable. Across 16 designated wilderness areas, highest predicted fire likelihood and effects fell within low elevation wilderness areas that overlapped large fire perimeters that occurred in 2005. As ongoing changes in climate and land cover are poised to alter the fire regime across extensive and ecologically important areas in the lower Sonoran Desert, an analysis of fire likelihood and

  15. Emergency Power For Critical Items

    NASA Astrophysics Data System (ADS)

    Young, William R.

    2009-07-01

    Natural disasters, such as hurricanes, floods, tornados, and tsunami, are becoming a greater problem as climate change impacts our environment. Disasters, whether natural or man made, destroy lives, homes, businesses and the natural environment. Such disasters can happen with little or no warning, leaving hundreds or even thousands of people without medical services, potable water, sanitation, communications and electrical services for up to several weeks. In our modern world, the need for electricity has become a necessity. Modern building codes and new disaster resistant building practices are reducing the damage to homes and businesses. Emergency gasoline and diesel generators are becoming common place for power outages. Generators need fuel, which may not be available after a disaster, but Photovoltaic (solar-electric) systems supply electricity without petroleum fuel as they are powered by the sun. Photovoltaic (PV) systems can provide electrical power for a home or business. PV systems can operate as utility interactive or stand-alone with battery backup. Determining your critical load items and sizing the photovoltaic system for those critical items, guarantees their operation in a disaster.

  16. Assessing the Item Response Theory with Covariate (IRT-C) Procedure for Ascertaining Differential Item Functioning

    ERIC Educational Resources Information Center

    Tay, Louis; Vermunt, Jeroen K.; Wang, Chun

    2013-01-01

    We evaluate the item response theory with covariates (IRT-C) procedure for assessing differential item functioning (DIF) without preknowledge of anchor items (Tay, Newman, & Vermunt, 2011). This procedure begins with a fully constrained baseline model, and candidate items are tested for uniform and/or nonuniform DIF using the Wald statistic.…

  17. Optimal Calibration Designs for Tests of Polytomously Scored Items Described by Item Response Theory Models.

    ERIC Educational Resources Information Center

    Holman, Rebecca; Berger, Martijn P. F.

    2001-01-01

    Studied calibration designs that maximize the determinants of Fisher's information matrix on the item parameters for sets of polytomously scored items. Analyzed these items using a number of item response theory models. Results show that for the data and models used, a D-optimal calibration design for an answer or set of answers can reduce the…

  18. Instructional Topics in Educational Measurement (ITEMS) Module: Using Automated Processes to Generate Test Items

    ERIC Educational Resources Information Center

    Gierl, Mark J.; Lai, Hollis

    2013-01-01

    Changes to the design and development of our educational assessments are resulting in the unprecedented demand for a large and continuous supply of content-specific test items. One way to address this growing demand is with automatic item generation (AIG). AIG is the process of using item models to generate test items with the aid of computer…

  19. When Do Item Response Function and Mantel-Haenszel Definitions of Differential Item Functioning Coincide?

    ERIC Educational Resources Information Center

    Zwick, Rebecca

    1990-01-01

    Use of the Mantel-Haenszel procedure as a test for differential item functioning under the Rasch model of item-response theory is examined. Results of the procedure cannot be generalized to the class of items for which item-response functions are monotonic and local independence holds. (TJH)

  20. An Item Response Theory Model for Incorporating Response Time Data in Binary Personality Items

    ERIC Educational Resources Information Center

    Ferrando, Pere J.; Lorenzo-Seva, Urbano

    2007-01-01

    This article describes a general item response theory model for personality items that allows the information provided by the item response times to be used to estimate the individual trait levels. The submodel describing the item response times is a modification of Thissen's log-linear model and is based on the distance-difficulty hypothesis in…

  1. Effects of fire on small mammal communities in frequent-fire forests in California

    USGS Publications Warehouse

    Roberts, Susan L.; Kelt, Douglas A.; Van Wagtendonk, Jan W.; Miles, A. Keith; Meyer, Marc D.

    2015-01-01

    Fire is a natural, dynamic process that is integral to maintaining ecosystem function. The reintroduction of fire (e.g., prescribed fire, managed wildfire) is a critical management tool for protecting many frequent-fire forests against stand-replacing fires while restoring an essential ecological process. Understanding the effects of fire on forests and wildlife communities is important in natural resource planning efforts. Small mammals are key components of forest food webs and essential to ecosystem function. To investigate the relationship of fire to small mammal assemblages, we live trapped small mammals in 10 burned and 10 unburned forests over 2 years in the central Sierra Nevada, California. Small mammal abundance was higher in unburned forests, largely reflecting the greater proportion of closed-canopy species such as Glaucomys sabrinus in unburned forests. The most abundant species across the entire study area was the highly adaptable generalist species, Peromyscus maniculatus. Species diversity was similar between burned and unburned forests, but burned forests were characterized by greater habitat heterogeneity and higher small mammal species evenness. The use and reintroduction of fire to maintain a matrix of burn severities, including large patches of unburned refugia, creates a heterogeneous and resilient landscape that allows for fire-sensitive species to proliferate and, as such, may help maintain key ecological functions and diverse small mammal assemblages.

  2. Eco-hydrology driven fire regime in savanna.

    PubMed

    Ursino, Nadia

    2014-08-21

    Fire is an important evolutionary force and ecosystem consumer that shapes savanna composition. However, ecologists have not comprehensively explained the functioning and maintenance of flammable savannas. A new minimal model accounting for the interdependence between soil saturation, biomass growth, fuel availability and fire has been used to predict the increasing tree density and fire frequency along a Mean Annual Rainfall (MAR) gradient for a typical savanna. Cyclic fire recurrence is reproduced using a predator prey approach in which fire is the "predator" and vegetation is the "prey". For the first time, fire frequency is not defined a priori but rather arises from the composition of vegetation, which determines fuel availability and water limitation. Soil aridity affects fuel production and fuel composition, thus indirectly affecting the ecosystem vulnerability to fire and fire frequency. The model demonstrates that two distinct eco-hydrological states correspond to different fire frequencies: (i) at low MAR, grass is abundant and the impact of fire on the environment is enhanced by the large fuel availability, (ii) at higher MAR, tree density progressively increases and provides less fuel for fire, leading to more frequent and less destructive fires, and (iii) the threshold MAR that determines the transition between the two states and the fire frequency at high MAR are affected by the vulnerability of trees to grass fire. The eco-hydrology-driven predator-prey model originally predicts that the transition between dry and wet savanna is characterized by a shift in wildfire frequency driven by major differences in soil moisture available for plants and savanna structure. The shift and the role of fire in conserving savanna ecosystems could not have been predicted if fire was considered as an external forcing rather than an intrinsic property of the ecosystem.

  3. RESTRICTED INTERESTS AND TEACHER PRESENTATION OF ITEMS

    PubMed Central

    Stocco, Corey S; Thompson, Rachel H; Rodriguez, Nicole M

    2011-01-01

    Restricted and repetitive behavior (RRB) is more pervasive, prevalent, frequent, and severe in individuals with autism spectrum disorders (ASDs) than in their typical peers. One subtype of RRB is restricted interests in items or activities, which is evident in the manner in which individuals engage with items (e.g., repetitious wheel spinning), the types of items or activities they select (e.g., preoccupation with a phone book), or the range of items or activities they select (i.e., narrow range of items). We sought to describe the relation between restricted interests and teacher presentation of items. Overall, we observed 5 teachers interacting with 2 pairs of students diagnosed with an ASD. Each pair included 1 student with restricted interests. During these observations, teachers were free to present any items from an array of 4 stimuli selected by experimenters. We recorded student responses to teacher presentation of items and analyzed the data to determine the relation between teacher presentation of items and the consequences for presentation provided by the students. Teacher presentation of items corresponded with differential responses provided by students with ASD, and those with restricted preferences experienced a narrower array of items. PMID:21941381

  4. Restricted interests and teacher presentation of items.

    PubMed

    Stocco, Corey S; Thompson, Rachel H; Rodriguez, Nicole M

    2011-01-01

    Restricted and repetitive behavior (RRB) is more pervasive, prevalent, frequent, and severe in individuals with autism spectrum disorders (ASDs) than in their typical peers. One subtype of RRB is restricted interests in items or activities, which is evident in the manner in which individuals engage with items (e.g., repetitious wheel spinning), the types of items or activities they select (e.g., preoccupation with a phone book), or the range of items or activities they select (i.e., narrow range of items). We sought to describe the relation between restricted interests and teacher presentation of items. Overall, we observed 5 teachers interacting with 2 pairs of students diagnosed with an ASD. Each pair included 1 student with restricted interests. During these observations, teachers were free to present any items from an array of 4 stimuli selected by experimenters. We recorded student responses to teacher presentation of items and analyzed the data to determine the relation between teacher presentation of items and the consequences for presentation provided by the students. Teacher presentation of items corresponded with differential responses provided by students with ASD, and those with restricted preferences experienced a narrower array of items.

  5. PREFER: a European service providing forest fire management support products

    NASA Astrophysics Data System (ADS)

    Eftychidis, George; Laneve, Giovanni; Ferrucci, Fabrizio; Sebastian Lopez, Ana; Lourenco, Louciano; Clandillon, Stephen; Tampellini, Lucia; Hirn, Barbara; Diagourtas, Dimitris; Leventakis, George

    2015-06-01

    PREFER is a Copernicus project of the EC-FP7 program which aims developing spatial information products that may support fire prevention and burned areas restoration decisions and establish a relevant web-based regional service for making these products available to fire management stakeholders. The service focuses to the Mediterranean region, where fire risk is high and damages from wildfires are quite important, and develop its products for pilot areas located in Spain, Portugal, Italy, France and Greece. PREFER aims to allow fire managers to have access to online resources, which shall facilitate fire prevention measures, fire hazard and risk assessment, estimation of fire impact and damages caused by wildfire as well as support monitoring of post-fire regeneration and vegetation recovery. It makes use of a variety of products delivered by space borne sensors and develop seasonal and daily products using multi-payload, multi-scale and multi-temporal analysis of EO data. The PREFER Service portfolio consists of two main suite of products. The first refers to mapping products for supporting decisions concerning the Preparedness/Prevention Phase (ISP Service). The service delivers Fuel, Hazard and Fire risk maps for this purpose. Furthermore the PREFER portfolio includes Post-fire vegetation recovery, burn scar maps, damage severity and 3D fire damage assessment products in order to support relative assessments required in context of the Recovery/Reconstruction Phase (ISR Service) of fire management.

  6. Libby South Fire, Washington

    NASA Technical Reports Server (NTRS)

    2002-01-01

    On July 9, 2001, a fire burned about 15 miles south of Twisp, Washington, that officials believe was caused by human error. NASA's Moderate-resolution Imaging Spectroradiometer on the Terra satellite observed the fire, indicated with a red dot in this image, on July 10, after the fire had already consumed about 1,240 acres. On July 10, another fire-called the Thirty Mile Fire-trapped 21 firefighters and 2 civilians in a narrow canyon in the Chewuch River Valley, north of Winthrop, WA. (That fire did not erupt until later in the day after this image was acquired and is therefore not visible.) Tragically, four firefighters were killed and six people were injured, including the two civilians. Rolling debris, rugged and steep terrain, and limited access are impeding efforts to contain the now 8,200-acre fire, which according to current fire incident reports, is completely uncontained. Nearly all the areas in the full-size image, including Washington (center), Idaho (right), Oregon (bottom) are in a state of severe drought, which means the region could be in for another devastating fire season. Another fire is visible in Idaho in the full-size image just east of where Idaho borders with Washington and Oregon. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team

  7. Fires in Amazonia

    NASA Astrophysics Data System (ADS)

    Aragão, Luiz E. O. C.; Anderson, Liana O.; Lima, André; Arai, Egidio

    2016-11-01

    Fire has been used since the first humans arrived in Amazonia; however, it has recently become a widely used instrument for large-scale forest clearance. Patterns of fire incidence in the region have been exacerbated by recent drought events. Understanding temporal and spatial fire patterns as well as their consequences for forest structure, species composition, and the carbon cycle is critical for minimising global change impacts on Amazonian ecosystems and people. In this chapter, we provide an overview of the state of our knowledge on the spatial and temporal patterns of fire incidence in Amazonia, depicting the historical fire usage in the region, their relationship with land use and land cover, and their responses to climate seasonality and droughts. We subsequently focus on the impacts of fire, by quantifying the extent of burnt forests during major droughts and describing the main impacts on forest structure, composition, and carbon stocks. Finally, we present an overview of modelling initiatives for forecasting fire incidence in the region. We conclude by providing a comprehensive view of the processes that influence fire occurrence, potential feedbacks, and impacts in Amazonia. We also highlight how key areas within fire ecology must be improved for a better understanding of the long-term effect of fire on the Amazon forest 'biome'.

  8. Fires in Amazonia

    NASA Astrophysics Data System (ADS)

    Aragão, Luiz E. O. C.; Anderson, Liana O.; Lima, André Arai, Egidio

    2016-01-01

    Fire has been used since the first humans arrived in Amazonia; however, it has recently become a widely used instrument for large-scale forest clearance. Patterns of fire incidence in the region have been exacerbated by recent drought events. Understanding temporal and spatial fire patterns as well as their consequences for forest structure, species composition, and the carbon cycle is critical for minimising global change impacts on Amazonian ecosystems and people. In this chapter, we provide an overview of the state of our knowledge on the spatial and temporal patterns of fire incidence in Amazonia, depicting the historical fire usage in the region, their relationship with land use and land cover, and their responses to climate seasonality and droughts. We subsequently focus on the impacts of fire, by quantifying the extent of burnt forests during major droughts and describing the main impacts on forest structure, composition, and carbon stocks. Finally, we present an overview of modelling initiatives for forecasting fire incidence in the region. We conclude by providing a comprehensive view of the processes that influence fire occurrence, potential feedbacks, and impacts in Amazonia. We also highlight how key areas within fire ecology must be improved for a better understanding of the long-term effect of fire on the Amazon forest 'biome'.

  9. Multisensor Fire Observations

    NASA Technical Reports Server (NTRS)

    Boquist, C.

    2004-01-01

    This DVD includes animations of multisensor fire observations from the following satellite sources: Landsat, GOES, TOMS, Terra, QuikSCAT, and TRMM. Some of the animations are included in multiple versions of a short video presentation on the DVD which focuses on the Hayman, Rodeo-Chediski, and Biscuit fires during the 2002 North American fire season. In one version of the presentation, MODIS, TRMM, GOES, and QuikSCAT data are incorporated into the animations of these wildfires. These data products provided rain, wind, cloud, and aerosol data on the fires, and monitored the smoke and destruction created by them. Another presentation on the DVD consists of a panel discussion, in which experts from academia, NASA, and the U.S. Forest Service answer questions on the role of NASA in fighting forest fires, the role of the Terra satellite and its instruments, including the Moderate Resolution Imaging Spectroradiometer (MODIS), in fire fighting decision making, and the role of fire in the Earth's climate. The third section of the DVD features several animations of fires over the years 2001-2003, including animations of global and North American fires, and specific fires from 2003 in California, Washington, Montana, and Arizona.

  10. Fires in Southern Georgia

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Several large fires were burning in southern Georgia on April 29, 2007, when the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite passed overhead and captured this image. Places where MODIS detected actively burning fires are outlined in red. The Roundabout Fire sprang up on April 27, according to the U.S. Southern Area Coordination Center, and was about 3,500 acres as of April 30. That fire was threatening homes in the community of Kirkland. Meanwhile, south of Waycross, two large blazes were burning next to each other in the northern part of Okefenokee Swamp. The Sweat Farm Road Fire threatened the town of Waycross in previous weeks, but at the end of April, activity had moved to the southeastern perimeter. The fire had affected more than 50,000 acres of timber (including pine tree plantations) and swamps. Scores of residences scattered throughout the rural area are threatened. The Big Turnaround Complex is burning to the east. The 26,000-acre fire was extremely active over the weekend, with flame lengths more than 60 feet (just over 18 meters) in places. The two blazes appeared to overlap in fire perimeter maps available from the U.S. Geospatial Multi-Agency Coordination Team. According to the Southern Area Coordination Center morning report on April 30, the Sweat Farm Road Fire 'will be a long term fire. Containment and control will depend on significant rainfall, due to the inaccessible swamp terrain.' No expected containment date was available for the Big Turnaround Complex Fire, either. Describing that fire, the report stated, 'Heavy fuel loading, high fire danger, and difficulty of access continue to hamper suppression efforts.' The large image provided above has a spatial resolution (level of detail) of 250 meters per pixel. The MODIS Rapid Response Team provides twice-daily images of the region in additional resolutions. They also provide a version of the image that shows smoke plumes stretching out across the Atlantic Ocean.

  11. Fire regimes of quaking aspen in the Mountain West

    USGS Publications Warehouse

    Shinneman, Douglas J.; Baker, William L.; Rogers, Paul C.; Kulakowski, Dominik

    2013-01-01

    Quaking aspen (Populus tremuloides Michx.) is the most widespread tree species in North America, and it is found throughout much of the Mountain West (MW) across a broad range of bioclimatic regions. Aspen typically regenerates asexually and prolifically after fire, and due to its seral status in many western conifer forests, aspen is often considered dependent upon disturbance for persistence. In many landscapes, historical evidence for post-fire aspen establishment is clear, and following extended fire-free periods senescing or declining aspen overstories sometimes lack adequate regeneration and are succeeding to conifers. However, aspen also forms relatively stable stands that contain little or no evidence of historical fire. In fact, aspen woodlands range from highly fire-dependent, seral communities to relatively stable, self-replacing, non-seral communities that do not require fire for persistence. Given the broad geographic distribution of aspen, fire regimes in these forests likely co-vary spatially with changing community composition, landscape setting, and climate, and temporally with land use and climate – but relatively few studies have explicitly focused on these important spatiotemporal variations. Here we reviewed the literature to summarize aspen fire regimes in the western US and highlight knowledge gaps. We found that only about one-fourth of the 46 research papers assessed for this review could be considered fire history studies (in which mean fire intervals were calculated), and all but one of these were based primarily on data from fire-scarred conifers. Nearly half of the studies reported at least some evidence of persistent aspen in the absence of fire. We also found that large portions of the MW have had little or no aspen fire history research. As a result of this review, we put forth a classification framework for aspen that is defined by key fire regime parameters (fire severity and probability), and that reflects underlying biophysical

  12. Adding Fuel to the Fire: The Impacts of Non-Native Grass Invasion on Fire Management at a Regional Scale

    PubMed Central

    Setterfield, Samantha A.; Rossiter-Rachor, Natalie A.; Douglas, Michael M.; Wainger, Lisa; Petty, Aaron M.; Barrow, Piers; Shepherd, Ian J.; Ferdinands, Keith B.

    2013-01-01

    Background Widespread invasion by non-native plants has resulted in substantial change in fire-fuel characteristics and fire-behaviour in many of the world's ecosystems, with a subsequent increase in the risk of fire damage to human life, property and the environment. Models used by fire management agencies to assess fire risk are dependent on accurate assessments of fuel characteristics but there is little evidence that they have been modified to reflect landscape-scale invasions. There is also a paucity of information documenting other changes in fire management activities that have occurred to mitigate changed fire regimes. This represents an important limitation in information for both fire and weed risk management. Methodology/Principal Findings We undertook an aerial survey to estimate changes to landscape fuel loads in northern Australia resulting from invasion by Andropogon gayanus (gamba grass). Fuel load within the most densely invaded area had increased from 6 to 10 t ha−1 in the past two decades. Assessment of the effect of calculating the Grassland Fire Danger Index (GFDI) for the 2008 and 2009 fire seasons demonstrated that an increase from 6 to 10 t ha−1 resulted in an increase from five to 38 days with fire risk in the ‘severe’ category in 2008 and from 11 to 67 days in 2009. The season of severe fire weather increased by six weeks. Our assessment of the effect of increased fuel load on fire management practices showed that fire management costs in the region have increased markedly (∼9 times) in the past decade due primarily to A. gayanus invasion. Conclusions/Significance This study demonstrated the high economic cost of mitigating fire impacts of an invasive grass. This study demonstrates the need to quantify direct and indirect invasion costs to assess the risk of further invasion and to appropriately fund fire and weed management strategies. PMID:23690917

  13. Examining the relative effects of fire weather, suppression and fuel treatment on fire behaviour--a simulation study.

    PubMed

    Penman, T D; Collins, L; Price, O F; Bradstock, R A; Metcalf, S; Chong, D M O

    2013-12-15

    Large budgets are spent on both suppression and fuel treatments in order to reduce the risk of wildfires. There is little evidence regarding the relative contribution of fire weather, suppression and fuel treatments in determining the risk posed from wildfires. Here we undertake a simulation study in the Sydney Basin, Australia, to examine this question using a fire behaviour model (Phoenix Rapidfire). Results of the study indicate that fire behaviour is most strongly influenced by fire weather. Suppression has a greater influence on whether a fire reaches 5 ha in size compared to fuel treatments. In contrast, fuel treatments have a stronger effect on the fire size and maximum distance the fire travels. The study suggests that fire management agencies will receive additional benefits from fuel treatment if they are located in areas which suppression resources can respond rapidly and attempt to contain the fires. No combination of treatments contained all fires, and the proportion of uncontained fires increased under more severe fire weather when the greatest number of properties are lost. Our study highlights the importance of alternative management strategies to reduce the risk of property loss.

  14. Fire safety of LPG in marine transportation

    SciTech Connect

    Martinsen, W.E.; Johnson, D.W.; Welker, J.R.

    1980-08-01

    This report contains an analytical examination of cargo spill and fire hazard potential associated with the marine handling of liquefied petroleum gas (LPG) as cargo. Principal emphasis was on cargo transfer operations for ships unloading at receiving terminals, and barges loading or unloading at a terminal. Major safety systems, including emergency shutdown systems, hazard detection systems, and fire extinguishment and control systems were included in the analysis. Spill probabilities were obtained from fault tree analyses utilizing composite LPG tank ship and barge designs. Failure rates for hardware in the analyses were generally taken from historical data on similar generic classes of hardware, there being very little historical data on the specific items involved. Potential consequences of cargo spills of various sizes are discussed and compared to actual LPG vapor cloud incidents. The usefulness of hazard mitigation systems (particularly dry chemical fire extinguishers and water spray systems) in controlling the hazards posed by LPG spills and spill fires is also discussed. The analysis estimates the probability of fatality for a terminal operator is about 10/sup -6/ to 10/sup -5/ per cargo transfer operation. The probability of fatality for the general public is substantially less.

  15. A comparison of geospatially modeled fire behavior and fire management utility of three data sources in the southeastern United States.

    SciTech Connect

    Hollingsworth, LaWen T.; Kurth, Laurie,; Parresol, Bernard, R.; Ottmar, Roger, D.; Prichard, Susan J.

    2012-01-01

    Landscape-scale fire behavior analyses are important to inform decisions on resource management projects that meet land management objectives and protect values from adverse consequences of fire. Deterministic and probabilistic geospatial fire behavior analyses are conducted with various modeling systems including FARSITE, FlamMap, FSPro, and Large Fire Simulation System. The fundamental fire intensity algorithms in these systems require surface fire behavior fuel models and canopy cover to model surface fire behavior. Canopy base height, stand height, and canopy bulk density are required in addition to surface fire behavior fuel models and canopy cover to model crown fire activity. Several surface fuel and canopy classification efforts have used various remote sensing and ecological relationships as core methods to develop the spatial layers. All of these methods depend upon consistent and temporally constant interpretations of crown attributes and their ecological conditions to estimate surface fuel conditions. This study evaluates modeled fire behavior for an 80,000 ha tract of land in the Atlantic Coastal Plain of the southeastern US using three different data sources. The Fuel Characteristic Classification System (FCCS) was used to build fuelbeds from intensive field sampling of 629 plots. Custom fire behavior fuel models were derived from these fuelbeds. LANDFIRE developed surface fire behavior fuel models and canopy attributes for the US using satellite imagery informed by field data. The Southern Wildfire Risk Assessment (SWRA) developed surface fire behavior fuel models and canopy cover for the southeastern US using satellite imagery. Differences in modeled fire behavior, data development, and data utility are summarized to assist in determining which data source may be most applicable for various land management activities and required analyses. Characterizing fire behavior under different fuel relationships provides insights for natural ecological

  16. Boating Accident Investigations 1974, Fire and Explosion

    DTIC Science & Technology

    1975-04-15

    specifically pin-point the cause. In the case of a fuel tank failure, it is necessary to know the specific alloy and thickness, how long the tank was in...steel tank and one fiberglass tank. Li 16 (2) Column 8 "Base Alloy " - This column has been added to supplement Column 6 by recording the actual alloy ...items listed provide a means of recording the presence of • ontaiIeIrU at-various cooking fuels involved in the fire. wSeondary RxloeLonO - The column

  17. Post-fire vegetation dynamics in Portugal

    NASA Astrophysics Data System (ADS)

    Gouveia, C.; Dacamara, C. C.; Trigo, R. M.

    2009-04-01

    The number of fires and the extent of the burned surface in Mediterranean Europe have increased significantly during the last three decades. This may be due either to modifications in land-use (e.g. land abandonment and fuel accumulation) or to climatic changes (e.g. reduction of fuel humidity), both factors leading to an increase of fire risk and fire spread. As in the Mediterranean ecosystems, fires in Portugal have an intricate effect on vegetation regeneration due to the complexity of landscape structures as well as to the different responses of vegetation to the variety of fire regimes. A thorough evaluation of vegetation recovery after fire events becomes therefore crucial in land management. In the above mentioned context remote sensing plays an important role because of its ability to monitor and characterise post-fire vegetation dynamics. A number of fire recovery studies, based on remote sensing, have been conducted in regions characterised by Mediterranean climates and the use of NDVI to monitor plant regeneration after fire events was successfully tested (Díaz-Delgado et al., 1998). In particular, several studies have shown that rapid regeneration occurs within the first 2 years after the fire occurrences, with distinct recovery rates according to the geographical facing of the slopes (Pausas and Vallejo, 1999). In 2003 Portugal was hit by the most devastating sequence of large fires, responsible by a total burnt area of 450 000 ha (including 280 000 ha of forest), representing about 5% of the Portuguese mainland (Trigo et al., 2006). The aim of the present work is to assess and monitor the vegetation behaviour over Portugal following the 2003 fire episodes. For this purpose we have used the regional fields of the Normalized Difference Vegetation Index (NDVI) as obtained from the VEGETATION-SPOT5 instrument, from 1999 to 2008. We developed a methodology to identify large burnt scars in Portugal for the 2003 fire season. The vegetation dynamics was then

  18. Hydrocarbon characterization experiments in fully turbulent fires.

    SciTech Connect

    Ricks, Allen; Blanchat, Thomas K.

    2007-05-01

    As the capabilities of numerical simulations increase, decision makers are increasingly relying upon simulations rather than experiments to assess risks across a wide variety of accident scenarios including fires. There are still, however, many aspects of fires that are either not well understood or are difficult to treat from first principles due to the computational expense. For a simulation to be truly predictive and to provide decision makers with information which can be reliably used for risk assessment the remaining physical processes must be studied and suitable models developed for the effects of the physics. The model for the fuel evaporation rate in a liquid fuel pool fire is significant because in well-ventilated fires the evaporation rate largely controls the total heat release rate from the fire. A set of experiments are outlined in this report which will provide data for the development and validation of models for the fuel regression rates in liquid hydrocarbon fuel fires. The experiments will be performed on fires in the fully turbulent scale range (> 1 m diameter) and with a number of hydrocarbon fuels ranging from lightly sooting to heavily sooting. The importance of spectral absorption in the liquid fuels and the vapor dome above the pool will be investigated and the total heat flux to the pool surface will be measured. The importance of convection within the liquid fuel will be assessed by restricting large scale liquid motion in some tests. These data sets will provide a sound, experimentally proven basis for assessing how much of the liquid fuel needs to be modeled to enable a predictive simulation of a fuel fire given the couplings between evaporation of fuel from the pool and the heat release from the fire which drives the evaporation.

  19. Effects of fire intensity on vital rates of an endemic herb of the Florida keys, USA

    USGS Publications Warehouse

    Liu, H.; Menges, E.S.; Snyder, J.R.; Koptur, S.; Ross, M.S.

    2005-01-01

    Fire intensity is one of the important components of a fire regime. However, relatively few studies have linked fire intensity with post-fire population vital rates. In this study, we explored the effects of fire intensity on population vital rates of Chamaecrista keyensis Pennell (Fabaceae) up to two years post-fire. C. keyensis is an endemic understory plant of pine rockland, a fire-dependent ecosystem of the Lower Florida Keys. We measured one fire intensity indicator, fire temperature reached by steel plates on the ground, during three prescribed fires at different sites. We followed marked individuals up to two years post-fire to derive annual survival, annual growth rate, percentage of fruiting plants, mean number of fruits per reproductive plant, and number of seedlings per census plot (1 m2) of C. keyensis. We found fire intensity had significant effects on reproduction in the first year post-fire only. More specifically, mean number of fruits and percentage of fruiting plants increased as fire intensity increased. Results from this study suggest that extremely low fire intensity caused by very short fire return intervals (e.g., less than three years) may not provide sufficient stimulation to reproduction to achieve the best post-fire recovery for C. keyensis.

  20. New technologies for item monitoring

    SciTech Connect

    Abbott, J.A.; Waddoups, I.G.

    1993-12-01

    This report responds to the Department of Energy`s request that Sandia National Laboratories compare existing technologies against several advanced technologies as they apply to DOE needs to monitor the movement of material, weapons, or personnel for safety and security programs. The authors describe several material control systems, discuss their technologies, suggest possible applications, discuss assets and limitations, and project costs for each system. The following systems are described: WATCH system (Wireless Alarm Transmission of Container Handling); Tag system (an electrostatic proximity sensor); PANTRAK system (Personnel And Material Tracking); VRIS (Vault Remote Inventory System); VSIS (Vault Safety and Inventory System); AIMS (Authenticated Item Monitoring System); EIVS (Experimental Inventory Verification System); Metrox system (canister monitoring system); TCATS (Target Cueing And Tracking System); LGVSS (Light Grid Vault Surveillance System); CSS (Container Safeguards System); SAMMS (Security Alarm and Material Monitoring System); FOIDS (Fiber Optic Intelligence & Detection System); GRADS (Graded Radiation Detection System); and PINPAL (Physical Inventory Pallet).

  1. Identifying Predictors of Physics Item Difficulty: A Linear Regression Approach

    ERIC Educational Resources Information Center

    Mesic, Vanes; Muratovic, Hasnija

    2011-01-01

    Large-scale assessments of student achievement in physics are often approached with an intention to discriminate students based on the attained level of their physics competencies. Therefore, for purposes of test design, it is important that items display an acceptable discriminatory behavior. To that end, it is recommended to avoid extraordinary…

  2. Alignment of Content and Effectiveness of Mathematics Assessment Items

    ERIC Educational Resources Information Center

    Kulm, Gerald; Dager Wilson, Linda; Kitchen, Richard

    2005-01-01

    Alignment has taken on increased importance given the current high-stakes nature of assessment. To make well-informed decisions about student learning on the basis of test results, assessment items need to be well aligned with standards. Project 2061 of the American Association for the Advancement of Science (AAAS) has developed a procedure for…

  3. How Does Calibration Timing and Seasonality Affect Item Parameter Estimates?

    ERIC Educational Resources Information Center

    Wyse, Adam E.; Babcock, Ben

    2016-01-01

    Continuously administered examination programs, particularly credentialing programs that require graduation from educational programs, often experience seasonality where distributions of examine ability may differ over time. Such seasonality may affect the quality of important statistical processes, such as item response theory (IRT) item…

  4. Marketing: Giveaways that Give Back--Marketing with Promotional Items

    ERIC Educational Resources Information Center

    Germain, Carol Anne

    2006-01-01

    In marketing one's library wares, an effective publicity strategy is to use promotional giveaway materials, mainly personalized items that promote one's resources and services. As with any marketing effort, it is important to be clear about the promotional initiative and whom librarians are attempting to reach. This author emphasizes that…

  5. Airborne forest fire research

    NASA Technical Reports Server (NTRS)

    Mattingly, G. S.

    1974-01-01

    The research relating to airborne fire fighting systems is reviewed to provide NASA/Langley Research Center with current information on the use of aircraft in forest fire operations, and to identify research requirements for future operations. A literature survey, interview of forest fire service personnel, analysis and synthesis of data from research reports and independent conclusions, and recommendations for future NASA-LRC programs are included.

  6. Secondary Fire Analysis.

    DTIC Science & Technology

    1981-09-01

    Warehouses and distribution centers - 5.3 Communications Facilities Textile Manufacturing Fire, police communication facilities - 5.0 Textile and garment...manufacturing - 5A Radio and television stations - 5.0 Textile mills using cotton and synthetics - 6.8 Radio and television transmitters - 8.0...electrical fires accounted for 44% of all reported industria ~l fires in 1975 in the State of California (Ref. 8). This is taken as a sample large

  7. Cascading effects of fire exclusion in Rocky Mountain ecosystems: a literature review

    USGS Publications Warehouse

    Keane, R.E.; Ryan, K.C.; Veblen, T.T.; Allen, C.D.; Logan, J.; Hawkes, B.

    2002-01-01

    The health of many Rocky Mountain ecosystems is in decline because of the policy of excluding fire in the management of these ecosystems. Fire exclusion has actually made it more difficult to fight fires, and this poses greater risks to the people who fight fires and for those who live in and around Rocky Mountain forests and rangelands. This paper discusses the extent of fire exclusion in the Rocky Mountains, then details the diverse and cascading effects of suppressing fires in the Rocky Mountain landscape by spatial scale, ecosystem characteristic, and vegetation type. Also discussed are the varied effects of fire exclusion on some important, keystone ecosystems and human concerns.

  8. The 12 Item Social and Economic Conservatism Scale (SECS)

    PubMed Central

    Everett, Jim A. C.

    2013-01-01

    Recent years have seen a surge in psychological research on the relationship between political ideology (particularly conservatism) and cognition, affect, behaviour, and even biology. Despite this flurry of investigation, however, there is as yet no accepted, validated, and widely used multi-item scale of conservatism that is concise, that is modern in its conceptualisation, and that includes both social and economic conservatism subscales. In this paper the 12-Item Social and Economic Conservatism Scale (SECS) is proposed and validated to help fill this gap. The SECS is suggested to be an important and useful tool for researchers working in political psychology. PMID:24349200

  9. Fire protection design criteria

    SciTech Connect

    1997-03-01

    This Standard provides supplemental fire protection guidance applicable to the design and construction of DOE facilities and site features (such as water distribution systems) that are also provided for fire protection. It is intended to be used in conjunction with the applicable building code, national Fire Protection Association Codes and Standards, and any other applicable DOE construction criteria. This Standard, along with other delineated criteria, constitutes the basic criteria for satisfying DOE fire and life safety objectives for the design and construction or renovation of DOE facilities.

  10. Forest Fire Mapping

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The Fire Logistics Airborne Mapping Equipment (FLAME) system, mounted in a twin-engine and airplane operated by the U.S. Forest Service (USFS) of the U.S. Department of Agriculture (USDA), is an airborne instrument for detecting and pinpointing forest fires that might escape ground detection. The FLAME equipment rack includes the operator interface, a video monitor, the system's control panel and film output. FLAME's fire detection sensor is an infrared line scanner system that identifies fire boundaries. Sensor's information is correlated with the aircraft's position and altitude at the time the infrared imagery is acquired to fix the fire's location on a map. System can be sent to a fire locale anywhere in the U.S. at the request of a regional forester. USFS felt a need for a more advanced system to deliver timely fire information to fire management personnel in the decade of the 1990s. The Jet Propulsion Laboratory (JPL) conducted a study, jointly sponsored by NASA and USDA, on what advanced technologies might be employed to produce an end-to-end thermal infrared fire detection and mapping system. That led to initiation of the Firefly system, currently in development at JPL and targeted for operational service beginning in 1992. Firefly will employ satellite-reference position fixing and provide performance superior to FLAME.

  11. Fire Ant Bites

    MedlinePlus

    ... be wary of these systemic reactions. They are: serum sickness, seizures, mononeuritis, nephrotic syndrome, and worsening of preexisting cardiopulmonary disease. When you first identify the fire ant you ...

  12. Determination of Survivable Fires

    NASA Technical Reports Server (NTRS)

    Dietrich, D. L.; Niehaus, J. E.; Ruff, G. A.; Urban, D. L.; Takahashi, F.; Easton, J. W.; Abbott, A. A.; Graf, J. C.

    2012-01-01

    At NASA, there exists no standardized design or testing protocol for spacecraft fire suppression systems (either handheld or total flooding designs). An extinguisher's efficacy in safely suppressing any reasonable or conceivable fire is the primary benchmark. That concept, however, leads to the question of what a reasonable or conceivable fire is. While there exists the temptation to over-size' the fire extinguisher, weight and volume considerations on spacecraft will always (justifiably) push for the minimum size extinguisher required. This paper attempts to address the question of extinguisher size by examining how large a fire a crew member could successfully survive and extinguish in the confines of a spacecraft. The hazards to the crew and equipment during an accidental fire include excessive pressure rise resulting in a catastrophic rupture of the vehicle skin, excessive temperatures that burn or incapacitate the crew (due to hyperthermia), carbon dioxide build-up or other accumulation of other combustion products (e.g. carbon monoxide). Estimates of these quantities are determined as a function of fire size and mass of material burned. This then becomes the basis for determining the maximum size of a target fire for future fire extinguisher testing.

  13. NASA Fire Protection

    NASA Technical Reports Server (NTRS)

    Clark, Theodore

    2001-01-01

    This viewgraph presentation provides information on fire protection operations and administration at Stennis Space Center (SSC). The presentation also lists innovative practices and recent improvements.

  14. Intumescent Coatings as Fire Retardants

    NASA Technical Reports Server (NTRS)

    Parker, J. A.; Fohlen, G. M.; Sawko, P. M.; Fish, R. H.

    1970-01-01

    The development of fire-retardant coatings to protect surfaces which may be exposed to fire or extreme heat is a subject of intense interest to many industries. A fire-retardant paint has been developed which represents a new chemical approach for preparing intumescent coatings, and potentially, is very important to fire-prevention authorities. The requirements for a superior coating include ease of application, suitability to a wide variety of surfaces and finishes, and stability over an extended period of time within a broad range of ambient temperature and humidity conditions. These innovative coatings, when activated by the heat of a fire, react to form a thick, low-density, polymeric coating or char layer. Water vapor and sulphur dioxide are released during the intumescent reaction. Two fire-protection mechanisms thus become available: (1) the char layer retards the flow of heat, due to the extremely low thermal conductivity; and (2) water vapor and sulfur dioxide are released, providing fire quenching properties. Still another mechanism functions in cases where the char, by virtue of its high oxidation resistance and low thermal conductivity, reaches a sufficiently high temperature to re-radiate much of the incident heat load. The coatings consist of dispersions of selective salts of a nitro-amino-arornatic compound. Specifically, para-nitroaniline bisulfate and the ammonium salt of para-nitroaniline-ortho sulphuric acid (2-amino-5-nitrobenzenesulphuric acid) are used. Suitable vehicles are cellulose nitrate of lacquer grade, a nitrite-phenolic modified rubber, or epoxy-polysulfide copolymer. Three separate formulations have been developed. A solvent is usually employed, such as methylethyl ketone, butyl acetate, or toluene, which renders the coatings suitably thin and which evaporates after the coatings are applied. Generally, the intumescent material is treated as insoluble in the vehicle, and is ground and dispersed in the vehicle and solvent like an

  15. Impact of Eliminating Anchor Items Flagged from Statistical Criteria on Test Score Classifications in Common Item Equating

    ERIC Educational Resources Information Center

    Karkee, Thakur; Choi, Seung

    2005-01-01

    Proper maintenance of a scale established in the baseline year would assure the accurate estimation of growth in subsequent years. Scale maintenance is especially important when the state performance standards must be preserved for future administrations. To ensure proper maintenance of a scale, the selection of anchor items and evaluation of…

  16. Nonrestricted multiple-choice examination items.

    PubMed

    Kolstad, R; Goaz, P; Kolstad, R

    1982-08-01

    Multiple-choice items are frequently used in objective examinations. The format chosen should conform to the nature of the instruction. Knowledge about cumulative information, such as lists of attributes, can be tested efficiently by means of multiple-choice items that include a variable number of correct answers. In contrast to conventional, single-answer questions, nonrestricted multiple-choice items are capable of including more facts and fewer incorrect responses. In addition, the nonrestricted format is not burdened with the repetitious pattern of one correct answer coupled with several incorrect responses, a cue that may promote successful guessing. Item analyses can be performed on examinations that include both conventional and nonrestricted items. The reliability of one examination constructed totally with nonrestricted items was analyzed by means of the Kuder-Richardson Formula No. 20. The value 0.72 proved this examination to be both discriminating and consistent.

  17. Where there's smoking, there's fire: the effects of smoking policies on the incidence of fires in the USA.

    PubMed

    Markowitz, Sara

    2014-11-01

    Fires and burns are among the leading causes of unintentional death in the USA. Most of these deaths occur in residences, and cigarettes are a primary cause. In this paper, I explore the relationship between smoking, cigarette policies, and fires. As smoking rates decline, there are fewer opportunities for fires; however, the magnitude of any reduction is in question. Using a state-level panel, I find that increases in cigarette prices are associated with fewer residential fires and deaths. However, laws regulating indoor smoking are associated with more fires; in particular, restaurant and bar smoking bans are associated with an increase in fires at eating and drinking establishments. This increase is important given the growing popularity of smoking bans in the USA and around the world. As workplaces, schools, and businesses ban smoking and remove ashtrays, smokers who continue to smoke are left without safe options for disposal of cigarettes, leading to more opportunities for fires to start.

  18. Metallographic analysis and fire dynamics simulation for electrical fire scene reconstruction.

    PubMed

    Chi, Jen-Hao

    2012-01-01

    This study demonstrated the use of metallographic analysis and NIST's Fire Dynamics Simulator (FDS) program to identify the cause of an actual electrical fire. A severely carbonized steel plate and a cable with a bead were found inside a damaged switchboard from the debris of a factory fire. By metallographic analysis, the copper spatter on the steel plate was found to imply a short circuit has occurred and that this was the probable ignition source of the fire was supported by the presence of a small amount of copper oxide and by the cavities with the tree-like grain microstructures in the bead. The heat estimated to have been released per unit area of the switchboard in question (approximately 236.29 MJ/m(2)) served as key input data for applying the FDS simulation of the blaze. The simulation indicated that thermal insulation polyethylene (PE) played an important role in the rapid fire spread.

  19. FIRE II - Cirrus Data Sets

    Atmospheric Science Data Center

    2013-07-26

    FIRE II - Cirrus Data Sets First ISCCP Regional Experiment (FIRE) II Cirrus was conducted in southeastern Kansas. It was designed to improve the ... stratocumulus systems, the radiative properties of these clouds and their interactions. Relevant Documents:  FIRE ...

  20. Fire-Retardant, Decorative Inks

    NASA Technical Reports Server (NTRS)

    Kourtides, D.; Nir, Z.; Mikroyannidis, J.

    1987-01-01

    Effectiveness of fire-retardant additives evaluated. Fire retardance of decorative acrylic printing inks for aircraft interiors enhanced by certain commercial and experimental fire-retardant additives, according to study.

  1. School Fire Protection: Contents Count

    ERIC Educational Resources Information Center

    American School and University, 1976

    1976-01-01

    The heart of a fire protection system is the sprinkler system. National Fire Protection Association (NFPA) statistics show that automatic sprinklers dramatically reduce fire damage and loss of life. (Author)

  2. NASA Fire Protection Coordinators' Conference

    NASA Technical Reports Server (NTRS)

    Clark, Theodore

    2001-01-01

    Fire prevention activities at NASA's Stennis Space Center are reviewed in this viewgraph presentation. The Fire Prevention Office of the Fire Department at NASA Stennis conducts inspections and issues small appliance permits, while the Operations Section responds to emergencies.

  3. Modeling fire occurrence as a function of landscape

    NASA Astrophysics Data System (ADS)

    Loboda, T. V.; Carroll, M.; DiMiceli, C.

    2011-12-01

    area impacted by fire from the total available area within a given value of the Fire Occurrence Index (FOI) increased from 9.e-06 at FOI < 3 to 28.e-06 at 25 < FOI <= 28. Additionally, the model has revealed a new important relationship between fire occurrence, anthropogenic activity, and fire weather. Data analysis has demonstrated that human activity can alter the expected weather/fire occurrence relationships and result in considerable modifications of fire regimes contrary to the assumed ecological parameters. Specifically, between 2001 and 2009 over 50% of total fire impacted area burned during the low fire danger conditions (Canadian Fire Weather Index < 5). These findings and the FOM capabilities offer a new theoretical construct and an advanced tool for assessing the potential impacts of climate changes on fire regimes, particularly within landscapes which are impacted strongly by human activities. Future development of the FOM will focus on ingesting and internal downscaling of climate variables produced by General or Regional Circulation Models to develop scenarios of potential future change in fire occurrence under the influence of projected climate change at the appropriate regional or landscape scales.

  4. Fire-resistant aircraft materials development and evaluation program

    NASA Technical Reports Server (NTRS)

    Bricker, R. W.; Stuckey, R. N.

    1974-01-01

    The overall objectives of this program are to provide a more fire-resistant commercial aircraft interior and to improve the fuselage insulation barrier between the cabin interior and an exterior fuel fire. Significant secondary objectives are to reduce the smoke and toxic gas production of the materials and to meet the end item use requirements pertaining to wearability, color fastness, and aesthetic appeal. It is shown that the fuselage insulation materials must meet stringent requirements pertaining to acoustic attenuation, low density, and water repellency.

  5. Impact of antecedent climate on fire regimes in coastal California

    USGS Publications Warehouse

    Keeley, J.E.

    2004-01-01

    Severe fire weather is a major determinant of fire size in coastal California; however, it is unclear to what extent antecedent climate also controls fire activity. This study investigates the relationship between fire activity and climate in central coastal and southern California. Climate variables included the Palmer Drought Severity Index (PDSI), total monthly precipitation, mean monthly maximum temperature and the autumn and winter Southern Oscillation Indices (SOI). For both the central coast and the south coast regions there was no significant relationship between growing season PDSI, precipitation or temperature and number of fires. When examined by season, summer temperatures were positively correlated with number of fires in the central coast and autumn PDSI and precipitation were negatively correlated with fire occurrence in the south coast region. Area burned was not correlated with any current year climate variables in southern California although, in the central coast, drought during spring and autumn were correlated, but explained less than 10% of the variation in the area burned. Although there was a modest relationship between the Southern Oscillation Index (SOI) and local climate parameters, there was only a relatively weak relationship with fire activity. The importance of autumn foehn winds is illustrated by the observation that large fires occur most commonly during the autumn, regardless of PDSI. Antecedent climate, however, does appear to play some role in determining the length of the fire season on these landscape as PDSI is consistently related to the occurrence of large fires that occur before or after the autumn months.

  6. Effect of personality item writing on psychometric properties of ideal-point and likert scales.

    PubMed

    Huang, Jialin; Mead, Alan D

    2014-12-01

    The present study was designed to investigate personality item-writing practices and their effect on the psychometric properties of personality items and scales. Personality items were developed based on ideal-point and dominance models, analyzed using the generalized graded unfolding model, and empirically classified as having an ideal-point or dominance form. Results suggested that writing dominance items were slightly easier (more successful) than writing ideal-point items, but this varied slightly by personality dimensions. Of 3 ideal-point item writing tactics, the "neutral" tactic was least successful; success writing "double-barreled" and "average" ideal-point items was comparable to that of dominance items. Three personality scales were then constructed using successful ideal-point and dominance items. Scales constructed using ideal-point items had substantially inferior psychometric properties, including lower score reliability, lower correlations with important criteria, and mixed test information results. However, lower predictive validity of ideal-point scale scores may be due to lower reliability of the scores. Practical and methodological implications were also discussed. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

  7. Fire and Microtopography in Peatlands: Feedbacks and Carbon Dynamics

    NASA Astrophysics Data System (ADS)

    Benscoter, B.; Turetsky, M. R.

    2011-12-01

    Fire is the dominant natural disturbance in peatland ecosystems. Over the past decade, peat fires have emerged as an important issue for global climate change, human health, and economic loss, largely due to the extreme peat fire events in Indonesia and Russia that severely impacted metropolitan areas and social infrastructure. However, the impact and importance of fire in peatland ecosystems are more far-reaching. Combustion of vegetation and soil organic matter releases an average of 2.2 kg C m-2 to the atmosphere, primarily as CO2, as well as a number of potentially harmful emissions such as fine particulate matter and mercury. Additionally, while peatlands are generally considered to be net sinks of atmospheric carbon, the removal of living vegetation by combustion halts primary production following fire resulting in a net loss of ecosystem carbon to the atmosphere for several years. The recovery of carbon sink function is linked to plant community succession and development, which can vary based on combustion severity and the resulting post-fire microhabitat conditions. Microtopography has a strong influence on fire behavior and combustion severity during peatland wildfires. In boreal continental peatlands, combustion severity is typically greatest in low-lying hollows while raised hummocks are often lightly burned or unburned. The cross-scale influence of microtopography on landscape fire behavior is due to differences in plant community composition between microforms. The physiological and ecohydrological differences among plant communities result in spatial patterns in fuel availability and condition, influencing the spread, severity, and type of combustion over local to landscape scales. In addition to heterogeneous combustion loss of soil carbon, this differential fire behavior creates variability in post-fire microhabitat conditions, resulting in differences in post-fire vegetation succession and carbon exchange trajectories. These immediate and legacy

  8. Modeling Payload Stowage Impacts on Fire Risks On-Board the International Space Station

    NASA Technical Reports Server (NTRS)

    Anton, Kellie e.; Brown, Patrick F.

    2010-01-01

    The purpose of this presentation is to determine the risks of fire on-board the ISS due to non-standard stowage. ISS stowage is constantly being reexamined for optimality. Non-standard stowage involves stowing items outside of rack drawers, and fire risk is a key concern and is heavily mitigated. A Methodology is needed to account for fire risk due to non-standard stowage to capture the risk. The contents include: 1) Fire Risk Background; 2) General Assumptions; 3) Modeling Techniques; 4) Event Sequence Diagram (ESD); 5) Qualitative Fire Analysis; 6) Sample Qualitative Results for Fire Risk; 7) Qualitative Stowage Analysis; 8) Sample Qualitative Results for Non-Standard Stowage; and 9) Quantitative Analysis Basic Event Data.

  9. Research in fire prevention.

    PubMed

    Pearce, N

    1985-10-01

    This paper describes in broad terms, the fire testing programme we carried out on whole bed assemblies in 1984. It should be clear that the tests were carried out in a thoroughly rigorous scientific manner. As always there is more to be done. The immediate task of finding the so called 'safe' bed assembly is proceeding with the search this year for safer pillows. Softer barrier foams are now being produced and it may be that the NHS could use full depth foam mattresses rather than a barrier foam wrap. On the engineering side I have explained the false alarm problem, and I have reviewed some of the research we are doing to see that new technology is used to give us better systems in future. Life safety sprinkler systems give the possibility of truly active fire protection in patient areas. They will enhance fire safety but at the moment no trade-offs can be offered in other areas of fire protection--either active or passive. My final point is that although I have considered the Department's fire research by looking separately at specific projects, the fire safety of a hospital must always be considered as a total package. To be effective, individual components of fire safety must not be considered in isolation but as part of the overall fire safety system.

  10. Residence Hall Fires.

    ERIC Educational Resources Information Center

    Wright, Dorothy

    1999-01-01

    Discusses how one college's experience with a tragic fire in one of its residence halls prompted a reevaluation of its fire-prevention-and-response strategies. Staff training, sprinkler installation, new alarm systems, and exit hardware to help make building exiting more efficient are discussed. (GR)

  11. Industrial Fire Brigade Training.

    ERIC Educational Resources Information Center

    North Carolina State Dept. of Community Colleges, Raleigh.

    Organized as a teaching outline for an industrial plant fire brigade course, this manual contains a rationale for an industrial plant brigade as an adjunct to the local firefighting services; information to the instructor concerning the implementation of an industrial fire brigade program; and a teaching outline consisting of eleven sections: (1)…

  12. Chisholm Forest Fire

    Atmospheric Science Data Center

    2013-04-17

    ... Larger Image A new look at smoke from the Chisholm forest fire, which ignited on May 23, 2001 about 160 kilometers north of ... in detail by M. Fromm and R. Servranckx, "Transport of forest fire smoke above the tropopause by supercell convection", Geophys. Res. ...

  13. Fire Science Curriculum Guide.

    ERIC Educational Resources Information Center

    Oregon State Board of Education, Salem.

    This curriculum guide, developed in cooperation with the State Advisory Committee on Fireman Training for Post-High School Preparatory Programs, summarizes the need for formal training programs in fire protection and offers guidelines for their establishment. It is also a practical handbook for the planning of fire protection curriculums and…

  14. Applying Item Response Theory methods to design a learning progression-based science assessment

    NASA Astrophysics Data System (ADS)

    Chen, Jing

    the defined boundaries. This ensures the accuracy of the classification. Third, when item threshold parameters vary a bit, the scoring rubrics and the items need to be reviewed to make the threshold parameters similar across items. This is because one important design criterion of the learning progression-based items is that ideally, a student should be at the same level across items, which means that the item threshold parameters (d1, d 2 and d3) should be similar across items. To design a learning progression-based science assessment, we need to understand whether the assessment measures a single construct or several constructs and how items are associated with the constructs being measured. Results from dimension analyses indicate that items of different carbon transforming processes measure different aspects of the carbon cycle construct. However, items of different practices assess the same construct. In general, there are high correlations among different processes or practices. It is not clear whether the strong correlations are due to the inherent links among these process/practice dimensions or due to the fact that the student sample does not show much variation in these process/practice dimensions. Future data are needed to examine the dimensionalities in terms of process/practice in detail. Finally, based on item characteristics analysis, recommendations are made to write more discriminative CR items and better OMC, MTF options. Item writers can follow these recommendations to write better learning progression-based items.

  15. 41 CFR 101-30.701-1 - Item reduction study.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 41 Public Contracts and Property Management 2 2012-07-01 2012-07-01 false Item reduction study....7-Item Reduction Program § 101-30.701-1 Item reduction study. Item reduction study means the study... so identified, a replacement item shall be proposed. The result of item reduction studies...

  16. 41 CFR 101-30.701-1 - Item reduction study.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 41 Public Contracts and Property Management 2 2014-07-01 2012-07-01 true Item reduction study. 101....7-Item Reduction Program § 101-30.701-1 Item reduction study. Item reduction study means the study... so identified, a replacement item shall be proposed. The result of item reduction studies...

  17. 41 CFR 101-30.701-1 - Item reduction study.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Item reduction study. 101....7-Item Reduction Program § 101-30.701-1 Item reduction study. Item reduction study means the study... so identified, a replacement item shall be proposed. The result of item reduction studies...

  18. 41 CFR 101-30.701-1 - Item reduction study.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 41 Public Contracts and Property Management 2 2013-07-01 2012-07-01 true Item reduction study. 101....7-Item Reduction Program § 101-30.701-1 Item reduction study. Item reduction study means the study... so identified, a replacement item shall be proposed. The result of item reduction studies...

  19. 41 CFR 101-30.701-1 - Item reduction study.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 41 Public Contracts and Property Management 2 2011-07-01 2007-07-01 true Item reduction study. 101....7-Item Reduction Program § 101-30.701-1 Item reduction study. Item reduction study means the study... so identified, a replacement item shall be proposed. The result of item reduction studies...

  20. 41 CFR 101-30.701-2 - Item standardization code.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Item standardization code....7-Item Reduction Program § 101-30.701-2 Item standardization code. Item standardization code (ISC) means a code assigned an item in the supply system which identifies the item as authorized...

  1. Software Note: Using BILOG for Fixed-Anchor Item Calibration

    ERIC Educational Resources Information Center

    DeMars, Christine E.; Jurich, Daniel P.

    2012-01-01

    The nonequivalent groups anchor test (NEAT) design is often used to scale item parameters from two different test forms. A subset of items, called the anchor items or common items, are administered as part of both test forms. These items are used to adjust the item calibrations for any differences in the ability distributions of the groups taking…

  2. Detection of Differential Item Functioning Using the Lasso Approach

    ERIC Educational Resources Information Center

    Magis, David; Tuerlinckx, Francis; De Boeck, Paul

    2015-01-01

    This article proposes a novel approach to detect differential item functioning (DIF) among dichotomously scored items. Unlike standard DIF methods that perform an item-by-item analysis, we propose the "LR lasso DIF method": logistic regression (LR) model is formulated for all item responses. The model contains item-specific intercepts,…

  3. Estimation of Fire Radiative Energy in Siberia Using MODIS Data

    NASA Astrophysics Data System (ADS)

    Shvetsov, Eugene; Ponomarev, Evgenii

    2014-05-01

    The intensity of heat release during biomass combustion is an important characteristic of wildfires. Space-borne systems, such as MODIS radiometer, provide observations of fire locations, as well as an estimate of the amount of radiant energy emitted by the fire. Such measures of fire radiative power (FRP) provide information on the fireline heat release intensity and on the rate of biomass combustion in large scale and are important for the analysis of fire impact on vegetation. In this study we analyzed the spatial distribution and temporal dynamics of detected wildfires in Siberia considering their radiative power. For the analysis we used database of fire detections made by MODIS instrument located on TERRA and AQUA satellites for 2002- 2013. For the detected fire pixels the frequency of their occurrence was calculated depending on the radiative power. More than 80% of all detected pixels had radiative power less than 100 MW. The distribution of fires according to their radiative power values was obtained for different regions of Siberia characterized by various vegetation and climatic conditions. Geospatial analysis performed using vegetation maps for the territory of Siberia and GIS layers of active fire detections showed that fires in deciduous and pine forests generally had lower intensities than fires in larch and spruce/fir forests. The rate of biomass combustion and the amount of heat emitted are strongly related to fuel moisture and therefore to weather conditions. In this study weather conditions were characterized using Russian and Canadian weather fire danger indices. Using images obtained during day and night satellite passes daily and long-term dynamics of fire radiative power was calculated. The long-term dynamics of fire radiative power measured by MODIS sensor was compared to weather fire danger indices calculated using on-ground weather stations data located in several Siberian regions mostly liable to fires. For most of the weather stations

  4. Emissions from Coal Fires and Their Impact on the Environment

    USGS Publications Warehouse

    Kolker, Allan; Engle, Mark; Stracher, Glenn; Hower, James; Prakash, Anupma; Radke, Lawrence; ter Schure, Arnout; Heffern, Ed

    2009-01-01

    extinguishing underground fires (fig. 2) (see 'Controlling Coal Fires'). In this fact sheet we review how coal fires occur, how they can be detected by airborne and remote surveys, and, most importantly, the impact coal-fire emissions may have on the environment and human health. In addition, we describe recent efforts by the U.S. Geological Survey (USGS) and collaborators to measure fluxes of CO2, CO, CH4, and Hg, using groundbased portable detectors, and combining these approaches with airborne thermal imaging and CO2 measurements. The goal of this research is to develop approaches that can be extrapolated to large fires and to extrapolate results for individual fires in order to estimate the contribution of coal fires as a category of global emissions.

  5. Fires in Chile

    NASA Technical Reports Server (NTRS)

    2002-01-01

    On February 5, 2002, the dense smoke from numerous forest fires stretched out over the Pacific Ocean about 400 miles south of Santiago, Chile. This true-color Moderate-resolution Imaging Spectroradiometer (MODIS) image shows the fires, which are located near the city of Temuco. The fires are indicated with red dots (boxes in the high-resolution imagery). The fires were burning near several national parks and nature reserves in an area of the Chilean Andes where tourism is very popular. Southeast of the fires, the vegetation along the banks of the Rio Negro in Argentina stands out in dark green. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  6. Partially Premixed Flame (PPF) Research for Fire Safety

    NASA Technical Reports Server (NTRS)

    Puri, Ishwar K.; Aggarwal, Suresh K.; Lock, Andrew J.; Hegde, Uday

    2004-01-01

    Incipient fires typically occur after the partial premixing of fuel and oxidizer. The mixing of product species into the fuel/oxidizer mixture influences flame stabilization and fire spread. Therefore, it is important to characterize the impact of different levels of fuel/oxidizer/product mixing on flame stabilization, liftoff and extinguishment under different gravity conditions. With regard to fire protection, the agent concentration required to achieve flame suppression is an important consideration. The initial stage of an unwanted fire in a microgravity environment will depend on the level of partial premixing and the local conditions such as air currents generated by the fire itself and any forced ventilation (that influence agent and product mixing into the fire). The motivation of our investigation is to characterize these impacts in a systematic and fundamental manner.

  7. Social and Biophysical Predictors of Public Perceptions of Extreme Fires

    NASA Astrophysics Data System (ADS)

    Hall, T. E.; Kooistra, C. M.; Paveglio, T.; Gress, S.; Smith, A. M.

    2013-12-01

    composite dependent variables: (1) subjective perceptions of the atypicality of the fire; and (2) perceptions of the fire's impact to individual and community well-being. The impact measures were adapted from the hazards and disasters literature and used a multi-item measure of emotional response during and immediately after the fire. Independent variables included both biophysical characteristics of each fire (such as size, duration, and burn severity), obtained from remotely sensed imagery, and perceptual variables measured in the survey. All measures were pilot tested for adequate psychometric properties using a sample of 150 individuals from an on-line panel who had been affected by a wildfire within the past two years. Factor analysis techniques will be used to reduce the data to latent constructs for use in regression modeling. Hierarchical linear modeling will be used to identify factors predicting the impact of fires on individuals (level 1) and whether those factors differ by fire (level 2). Our study provides a unique interdisciplinary perspective on extreme disturbance events, and findings will help land managers and community leaders anticipate how individuals may respond to future fires, as well as how to ameliorate the negative impacts of those fires.

  8. Item Selection in Multidimensional Computerized Adaptive Testing--Gaining Information from Different Angles

    ERIC Educational Resources Information Center

    Wang, Chun; Chang, Hua-Hua

    2011-01-01

    Over the past thirty years, obtaining diagnostic information from examinees' item responses has become an increasingly important feature of educational and psychological testing. The objective can be achieved by sequentially selecting multidimensional items to fit the class of latent traits being assessed, and therefore Multidimensional…

  9. Background and Attitude Questionnaire Items and A Priori Weights. Table 4.

    ERIC Educational Resources Information Center

    Michigan State Dept. of Education, Lansing. Research, Evaluation, and Assessment Services.

    Background and attitude questionnaire items used in the Michigan Educational Assessment battery to measure socioeconomic status and attitudes toward self, school, and the importance of school achievement are presented. A priori weights for item responses are provided. (For related document, see TM 002 329.) (KM)

  10. Applying a Score Confidence Interval to Aiken's Item Content-Relevance Index

    ERIC Educational Resources Information Center

    Penfield, Randall D.; Giacobbi, Peter R., Jr

    2004-01-01

    Item content-relevance is an important consideration for researchers when developing scales used to measure psychological constructs. Aiken (1980) proposed a statistic, "V," that can be used to summarize item content-relevance ratings obtained from a panel of expert judges. This article proposes the application of the Score confidence interval to…

  11. Do multiple fires interact to affect vegetation structure in temperate eucalypt forests?

    PubMed

    Haslem, Angie; Leonard, Steve W J; Bruce, Matthew J; Christie, Fiona; Holland, Greg J; Kelly, Luke T; MacHunter, Josephine; Bennett, Andrew F; Clarke, Michael F; York, Alan

    2016-12-01

    Fire plays an important role in structuring vegetation in fire-prone regions worldwide. Progress has been made towards documenting the effects of individual fire events and fire regimes on vegetation structure; less is known of how different fire history attributes (e.g., time since fire, fire frequency) interact to affect vegetation. Using the temperate eucalypt foothill forests of southeastern Australia as a case study system, we examine two hypotheses about such interactions: (1) post-fire vegetation succession (e.g., time-since-fire effects) is influenced by other fire regime attributes and (2) the severity of the most recent fire overrides the effect of preceding fires on vegetation structure. Empirical data on vegetation structure were collected from 540 sites distributed across central and eastern Victoria, Australia. Linear mixed models were used to examine these hypotheses and determine the relative influence of fire and environmental attributes on vegetation structure. Fire history measures, particularly time since fire, affected several vegetation attributes including ground and canopy strata; others such as low and sub-canopy vegetation were more strongly influenced by environmental characteristics like rainfall. There was little support for the hypothesis that post-fire succession is influenced by fire history attributes other than time since fire; only canopy regeneration was influenced by another variable (fire type, representing severity). Our capacity to detect an overriding effect of the severity of the most recent fire was limited by a consistently weak effect of preceding fires on vegetation structure. Overall, results suggest the primary way that fire affects vegetation structure in foothill forests is via attributes of the most recent fire, both its severity and time since its occurrence; other attributes of fire regimes (e.g., fire interval, frequency) have less influence. The strong effect of environmental drivers, such as rainfall and

  12. An Item Analysis and Validity Investigation of Bender Visual Motor Gestalt Test Score Items

    ERIC Educational Resources Information Center

    Lambert, Nadine M.

    1971-01-01

    This investigation attempted to demonstrate the utility of standard item analysis procedures for selecting the most reliable and valid items for scoring Bender Visual Motor Gestalt Test test records. (Author)

  13. Fire science at LLNL: A review

    SciTech Connect

    Hasegawa, H.K.

    1990-03-01

    This fire sciences report from LLNL includes topics on: fire spread in trailer complexes, properties of welding blankets, validation of sprinkler systems, fire and smoke detectors, fire modeling, and other fire engineering and safety issues. (JEF)

  14. Toxicity of fire smoke.

    PubMed

    Alarie, Yves

    2002-07-01

    This review is an attempt to present and describe the major immediate toxic threats in fire situations. These are carbon monoxide, a multitude of irritating organic chemicals in the smoke, oxygen depletion, and heat. During the past 50 years, synthetic polymers have been introduced in buildings in very large quantities. Many contain nitrogen or halogens, resulting in the release of hydrogen cyanide and inorganic acids in fire smoke as additional toxic threats. An analysis of toxicological findings in fire and nonfire deaths and the results of animal exposures to smoke from a variety of burning materials indicate that carbon monoxide is still likely to be the major toxicant in modern fires. However, the additional toxic threats mentioned above can sometimes be the principal cause of death or their addition can result in much lower than expected carboxyhemoglobin levels in fire victims. This analysis also revealed that hydrogen cyanide is likely to be present in appreciable amounts in the blood of fire victims in modern fires. The mechanisms of action of acute carbon monoxide and hydrogen cyanide poisonings are reviewed, with cases presented to illustrate how each chemical can be a major contributor or how they may interact. Also, lethal levels of carboxyhemoglobin and cyanide in blood are suggested from an analysis of the results of a large number of fire victims from different fire scenarios. The contribution of oxygen depletion and heat stress are more difficult to establish. From the analysis of several fire scenarios, they may play a major role in the room of origin at the beginning of a fire. The results in animal studies indicate that when major oxygen depletion (<10%) is added to lethal or sublethal levels of carbon monoxide or hydrogen cyanide its major role is to substantially reduce the time to death. In these experiments the carboxyhemoglobin level at death was slightly reduced from the expected level with exposure to carbon monoxide alone. However, blood

  15. Fire impacts on European Boreal soils: A review

    NASA Astrophysics Data System (ADS)

    Pereira, Paulo; Oliva, Marc; Cerda, Artemi

    2016-04-01

    Fire is an important natural disturbance in boreal ecosystems, fundamental to understand plant distribution (Ryan, 2002; Wallenius et al., 2004; Granstrom, 2001). Nevertheless, nowadays the intense and successful, fire suppression measures are changing their ecological role (Pereira et al., 2013a,b). This is consequence of the lack of understanding of stakeholders and decision makers about the role of the fire in the ecosystems (Mierasukas and Pereira, 2013; Pereira et al., 2016). This fire suppression measures are increasing the amount of fuel accumulation and the risk of severe wildfires, which can increase of frequency and severity in a context of climate change. Fire is a good tool for landscape management and restoration of degraded ecosystems (Toivanen and Kotiaho, 2007). Fire is considered a soil forming factor (Certini, 2014) and in boreal environments it has been observed that low fire severities, do not change importantly soil properties, mean fire severities induce positive impacts on soil, since add an important amounts of nutrients into soil profile and high severity fires had negative impacts due to the high consumption of organic matter (Vanha-Majamaa et al., 2007; Pereira et al., 2014). References Certini, G., 2014. Fire as a soil-forming factor. Ambio, 43, 191-195 Granstrom A. 2001. Fire management for biodiversity in the European Boreal forest. Scandinavian Journal of Forest Research 3: 62-69. Mierauskas, P., Pereira, P. (2013) Stakeholders perception about prescribed fire use in Lithuania. First results, Flamma, 4(3), 157-161. Pereira, P., Cerdà, A., Jordán, A., Bolutiene, V., Úbeda, X., Pranskevicius, M., Mataix-Solera, J. (2013) Spatio-temporal vegetation recuperation after a grassland fire in Lithuania, Procedia Environmental Sciences, 19:856-864 Pereira, P., Mierauskas, P., Ubeda, X., Mataix-Solera, J.,Cerda, A. (2012) Fire in protected areas - the effect of the protection and importance of fire management, Environmental Research

  16. 38 CFR 3.1606 - Transportation items.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Burial Benefits § 3.1606 Transportation items. The transportation costs of those persons who come within... case. In any such instance any excess amount would be an acceptable item to be included in the burial...) is used as a shipping case and also for burial, an allowance of $30 may be made thereon in lieu of...

  17. 38 CFR 3.1606 - Transportation items.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Burial Benefits § 3.1606 Transportation items. The transportation costs of those persons who come within... case. In any such instance any excess amount would be an acceptable item to be included in the burial...) is used as a shipping case and also for burial, an allowance of $30 may be made thereon in lieu of...

  18. 38 CFR 3.1606 - Transportation items.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Burial Benefits § 3.1606 Transportation items. The transportation costs of those persons who come within... case. In any such instance any excess amount would be an acceptable item to be included in the burial...) is used as a shipping case and also for burial, an allowance of $30 may be made thereon in lieu of...

  19. 38 CFR 3.1606 - Transportation items.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Burial Benefits § 3.1606 Transportation items. The transportation costs of those persons who come within... case. In any such instance any excess amount would be an acceptable item to be included in the burial...) is used as a shipping case and also for burial, an allowance of $30 may be made thereon in lieu of...

  20. 38 CFR 3.1606 - Transportation items.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Burial Benefits § 3.1606 Transportation items. The transportation costs of those persons who come within... case. In any such instance any excess amount would be an acceptable item to be included in the burial...) is used as a shipping case and also for burial, an allowance of $30 may be made thereon in lieu of...

  1. Modeling Rule-Based Item Generation

    ERIC Educational Resources Information Center

    Geerlings, Hanneke; Glas, Cees A. W.; van der Linden, Wim J.

    2011-01-01

    An application of a hierarchical IRT model for items in families generated through the application of different combinations of design rules is discussed. Within the families, the items are assumed to differ only in surface features. The parameters of the model are estimated in a Bayesian framework, using a data-augmented Gibbs sampler. An obvious…

  2. Invariant Ordering of Item-Total Regressions

    ERIC Educational Resources Information Center

    Tijmstra, Jesper; Hessen, David J.; van der Heijden, Peter G. M.; Sijtsma, Klaas

    2011-01-01

    A new observable consequence of the property of invariant item ordering is presented, which holds under Mokken's double monotonicity model for dichotomous data. The observable consequence is an invariant ordering of the item-total regressions. Kendall's measure of concordance "W" and a weighted version of this measure are proposed as measures for…

  3. Geography Library of Test Items. Volume Six.

    ERIC Educational Resources Information Center

    Kouimanos, John, Ed.

    As one in a series of test item collections developed by the Assessment and Evaluation Unit of the Directorate of Studies, items of value from past tests are made available to teachers for the construction of unit tests, term examinations or as a basis for class discussion. Each collection was reviewed for content validity and reliability. The…

  4. Geography Library of Test Items. Volume One.

    ERIC Educational Resources Information Center

    Kouimanos, John, Ed.

    As one in a series of test item collections developed by the Assessment and Evaluation Unit of the Directorate of Studies, items of value from past tests are made available to teachers for the construction of unit tests, term examinations or as a basis for class discussion. Each collection was reviewed for content validity and reliability. The…

  5. Factoring handedness data: I. Item analysis.

    PubMed

    Messinger, H B; Messinger, M I

    1995-12-01

    Recently in this journal Peters and Murphy challenged the validity of factor analyses done on bimodal handedness data, suggesting instead that right- and left-handers be studied separately. But bimodality may be avoidable if attention is paid to Oldfield's questionnaire format and instructions for the subjects. Two characteristics appear crucial: a two-column LEFT-RIGHT format for the body of the instrument and what we call Oldfield's Admonition: not to indicate strong preference for handedness item, such as write, unless "... the preference is so strong that you would never try to use the other hand unless absolutely forced to...". Attaining unimodality of an item distribution would seem to overcome the objections of Peters and Murphy. In a 1984 survey in Boston we used Oldfield's ten-item questionnaire exactly as published. This produced unimodal item distributions. With reflection of the five-point item scale and a logarithmic transformation, we achieved a degree of normalization for the items. Two surveys elsewhere based on Oldfield's 20-item list but with changes in the questionnaire format and the instructions, yielded markedly different item distributions with peaks at each extreme and sometimes in the middle as well.

  6. 47 CFR 65.830 - Deducted items.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Deducted items. 65.830 Section 65.830 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES (CONTINUED) INTERSTATE RATE OF RETURN PRESCRIPTION PROCEDURES AND METHODOLOGIES Rate Base § 65.830 Deducted items. (a)...

  7. Restricted Interests and Teacher Presentation of Items

    ERIC Educational Resources Information Center

    Stocco, Corey S.; Thompson, Rachel H.; Rodriguez, Nicole M.

    2011-01-01

    Restricted and repetitive behavior (RRB) is more pervasive, prevalent, frequent, and severe in individuals with autism spectrum disorders (ASDs) than in their typical peers. One subtype of RRB is restricted interests in items or activities, which is evident in the manner in which individuals engage with items (e.g., repetitious wheel spinning),…

  8. Geography Library of Test Items. Volume Three.

    ERIC Educational Resources Information Center

    Kouimanos, John, Ed.

    As one in a series of test item collections developed by the Assessment and Evaluation Unit of the Directorate of Studies, items of value from past tests are made available to teachers for the construction of unit tests, term examinations or as a basis for class discussion. Each collection was reviewed for content validity and reliability. The…

  9. Effects of Item Disclosure on TOEFL Performance.

    ERIC Educational Resources Information Center

    Hale, Gordon A.; And Others

    To ascertain how the Test of English as a Foreign Language (TOEFL) would be affected if candidates had access to some of the items before administration of a test containing those items, a number of specially constructed TOEFL forms were made available to 945 foreign students in intensive English language programs. The students were later…

  10. Geography: Library of Test Items. Volume II.

    ERIC Educational Resources Information Center

    Kouimanos, John, Ed.

    As one in a series of test item collections developed by the Assessment and Evaluation Unit of the Directorate of Studies, items of value from past tests are made available to teachers for the construction of unit tests, term examinations or as a basis for class discussion. Each collection was reviewed for content validity and reliability. The…

  11. Similarity of Various Item Discrimination Indices.

    ERIC Educational Resources Information Center

    Oosterhof, Albert C.

    1976-01-01

    The purpose of this study was to investigate the degree to which various selected test item discrimination indices reflect a common factor. The indices used include the point-biserial, biserial, phi and tetrachoric coefficients, Flanagan's approximation of the product-moment correlation, Gulliksen's item reliability index, and Findley's difference…

  12. Item Calibration in Incomplete Testing Designs

    ERIC Educational Resources Information Center

    Eggen, Theo J. H. M.; Verhelst, Norman D.

    2011-01-01

    This study discusses the justifiability of item parameter estimation in incomplete testing designs in item response theory. Marginal maximum likelihood (MML) as well as conditional maximum likelihood (CML) procedures are considered in three commonly used incomplete designs: random incomplete, multistage testing and targeted testing designs.…

  13. Fire disturbance and climate change: implications for Russian forests

    NASA Astrophysics Data System (ADS)

    Shuman, Jacquelyn K.; Foster, Adrianna C.; Shugart, Herman H.; Hoffman-Hall, Amanda; Krylov, Alexander; Loboda, Tatiana; Ershov, Dmitry; Sochilova, Elena

    2017-03-01

    Change in the Russian boreal forest has the capacity to alter global carbon and climate dynamics. Fire disturbance is an integral determinant of the forest’s composition and structure, and changing climate conditions are expected to create more frequent and severe fires. Using the individual tree-based forest gap model UVAFME, along with an updated fire disturbance module that tracks mortality based on tree-species and –size level effects, biomass and species dynamics are simulated across Russia for multiple scenarios: with and without fire, and with and without altered climate. Historical fire return intervals and percent of forest stand mortality are calculated for the Russian eco-regions and applied to 31 010 simulation points across Russia. Simulation results from the scenarios are compared to assess changes in biomass, composition, and stand structure after 600 years of successional change following bare-ground initiation. Simulations that include fire disturbance show an increase in biomass across the region compared to equivalent simulations without fire. Fire disturbance allows the deciduous needle-leaved conifer larch to maintain dominance across much of the region due to their high growth rate and fire tolerance relative to other species. Larch remain dominant under the scenario of altered climate conditions with fire disturbance. The distribution of age cohorts shifts for the scenario of altered climate with fire disturbance, displaying a bimodal distribution with a peak of 280-year-old trees and another of 100-year-old cohorts. In these simulations, fire disturbance acts to increase the turnover rate and patterns of biomass accumulation, though species and tree size are also important factors in determining mortality and competitive success. These results reinforce the importance of the inclusion of complex competition at the species level in evaluating forest response to fire and climate.

  14. Modelling of fire count data: fire disaster risk in Ghana.

    PubMed

    Boadi, Caleb; Harvey, Simon K; Gyeke-Dako, Agyapomaa

    2015-01-01

    Stochastic dynamics involved in ecological count data require distribution fitting procedures to model and make informed judgments. The study provides empirical research, focused on the provision of an early warning system and a spatial graph that can detect societal fire risks. It offers an opportunity for communities, organizations, risk managers, actuaries and governments to be aware of, and understand fire risks, so that they will increase the direct tackling of the threats posed by fire. Statistical distribution fitting method that best helps identify the stochastic dynamics of fire count data is used. The aim is to provide a fire-prediction model and fire spatial graph for observed fire count data. An empirical probability distribution model is fitted to the fire count data and compared to the theoretical probability distribution of the stochastic process of fire count data. The distribution fitted to the fire frequency count data helps identify the class of models that are exhibited by the fire and provides time leading decisions. The research suggests that fire frequency and loss (fire fatalities) count data in Ghana are best modelled with a Negative Binomial Distribution. The spatial map of observed fire frequency and fatality measured over 5 years (2007-2011) offers in this study a first regional assessment of fire frequency and fire fatality in Ghana.

  15. Comparing Methods for Item Analysis: The Impact of Different Item-Selection Statistics on Test Difficulty

    ERIC Educational Resources Information Center

    Jones, Andrew T.

    2011-01-01

    Practitioners often depend on item analysis to select items for exam forms and have a variety of options available to them. These include the point-biserial correlation, the agreement statistic, the B index, and the phi coefficient. Although research has demonstrated that these statistics can be useful for item selection, no research as of yet has…

  16. Ramsay-Curve Item Response Theory for the Three-Parameter Logistic Item Response Model

    ERIC Educational Resources Information Center

    Woods, Carol M.

    2008-01-01

    In Ramsay-curve item response theory (RC-IRT), the latent variable distribution is estimated simultaneously with the item parameters of a unidimensional item response model using marginal maximum likelihood estimation. This study evaluates RC-IRT for the three-parameter logistic (3PL) model with comparisons to the normal model and to the empirical…

  17. Investigating Separate and Concurrent Approaches for Item Parameter Drift in 3PL Item Response Theory Equating

    ERIC Educational Resources Information Center

    Arce-Ferrer, Alvaro J.; Bulut, Okan

    2017-01-01

    This study examines separate and concurrent approaches to combine the detection of item parameter drift (IPD) and the estimation of scale transformation coefficients in the context of the common item nonequivalent groups design with the three-parameter item response theory equating. The study uses real and synthetic data sets to compare the two…

  18. Item Purification in Differential Item Functioning Using Generalized Linear Mixed Models

    ERIC Educational Resources Information Center

    Liu, Qian

    2011-01-01

    For this dissertation, four item purification procedures were implemented onto the generalized linear mixed model for differential item functioning (DIF) analysis, and the performance of these item purification procedures was investigated through a series of simulations. Among the four procedures, forward and generalized linear mixed model (GLMM)…

  19. Psychometric Changes on Item Difficulty Due to Item Review by Examinees

    ERIC Educational Resources Information Center

    Papanastasiou, Elena C.

    2015-01-01

    If good measurement depends in part on the estimation of accurate item characteristics, it is essential that test developers become aware of discrepancies that may exist on the item parameters before and after item review. The purpose of this study was to examine the answer changing patterns of students while taking paper-and-pencil multiple…

  20. Designing P-Optimal Item Pools in Computerized Adaptive Tests with Polytomous Items

    ERIC Educational Resources Information Center

    Zhou, Xuechun

    2012-01-01

    Current CAT applications consist of predominantly dichotomous items, and CATs with polytomously scored items are limited. To ascertain the best approach to polytomous CAT, a significant amount of research has been conducted on item selection, ability estimation, and impact of termination rules based on polytomous IRT models. Few studies…

  1. Asymptotic Standard Errors for Item Response Theory True Score Equating of Polytomous Items

    ERIC Educational Resources Information Center

    Cher Wong, Cheow

    2015-01-01

    Building on previous works by Lord and Ogasawara for dichotomous items, this article proposes an approach to derive the asymptotic standard errors of item response theory true score equating involving polytomous items, for equivalent and nonequivalent groups of examinees. This analytical approach could be used in place of empirical methods like…

  2. Improvement in Detection of Differential Item Functioning Using a Mixture Item Response Theory Model

    ERIC Educational Resources Information Center

    Maij-de Meij, Annette M.; Kelderman, Henk; van der Flier, Henk

    2010-01-01

    Usually, methods for detection of differential item functioning (DIF) compare the functioning of items across manifest groups. However, the manifest groups with respect to which the items function differentially may not necessarily coincide with the true source of the bias. It is expected that DIF detection under a model that includes a latent DIF…

  3. Developing and evaluating innovative items for the NCLEX: Part 2, item characteristics and cognitive processing.

    PubMed

    Wendt, Anne; Harmes, J Christine

    2009-01-01

    This article is a continuation of the research on the development and evaluation of innovative item formats for the NCLEX examinations that was published in the March/April 2009 edition of Nurse Educator. The authors discuss the innovative item templates and evaluate the statistical characteristics and level of cognitive processing required to answer the examination items.

  4. Descriptive and Inferential Procedures for Assessing Differential Item Functioning in Polytomous Items.

    ERIC Educational Resources Information Center

    Zwick, Rebecca; Thayer, Dorothy T.; Mazzeo, John

    1997-01-01

    Differential item functioning (DIF) assessment procedures for items with more than two ordered score categories, referred to as polytomous items, were evaluated. Three descriptive statistics (standardized mean difference and two procedures based on the SIBTEST computer program) and five inferential procedures were used. Conditions under which the…

  5. Estimating fire radiative power obscuration by tree canopies through laboratory experiments: Estimating fire radiative energy in a longleaf pine forest from airborne thermal imagery

    NASA Astrophysics Data System (ADS)

    Mathews, William

    Remote sensing has been proven as a useful tool in characterizing the effects of fire on a landscape scale. The radiant energy released during biomass burning can be measured remotely, and is directly related to the rate biomass consumed from the fire. This is an important measurement as it can characterize fire effects on the ground along with provide important information about the amount of gases produced by the fire. One source of error associated with estimating the fire radiative energy (FRE) remotely is the obscuration of the signal by the forest canopy. We quantify the relationship between canopy cover and the amount of energy observed by a sensor rom laboratory experiments. A prescribed fire was conducted in northwestern Florida and a suite of pre-, active, and post-fire measurements were taken by an interdisciplinary team. From those data we measured the amount of biomass consumed by the fire FRE estimates.

  6. Fires in Myanmar (2007)

    NASA Technical Reports Server (NTRS)

    2007-01-01

    In Southeast Asia, fires are common and widespread throughout the dry season, which roughly spans the northern hemisphere winter months. People set fires to clear crop stubble and brush and to prepare grazing land for a new flush of growth when the rainy season arrives. These intentional fires are too frequently accompanied by accidental fires that invade nearby forests and woodlands. The combination of fires produces a thick haze that alternately lingers and disperses, depending on the weather. This image from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Aqua satellite shows fire activity on March 19, 2007, across eastern India, Myanmar, Thailand, Laos, and China. Places where MODIS detected actively burning fires are marked in red on the image. The darker green areas are generally more wooded areas or forests, while the paler green and tan areas are agricultural land. Smoke pools over low-lying areas of the hilly terrain in gray pockets. The green tops of rolling hills in Thailand emerge from a cloud of low-lying smoke. According to news reports from Thailand, the smoke blanket created air quality conditions that were considered unhealthy for all groups, and it prompted the Thai Air Force to undertake cloud-seeding attempts in an effort to cleanse the skies with rain. Commercial air traffic was halted due to poor visibility.

  7. Electronic firing systems and methods for firing a device

    DOEpatents

    Frickey, Steven J [Boise, ID; Svoboda, John M [Idaho Falls, ID

    2012-04-24

    An electronic firing system comprising a control system, a charging system, an electrical energy storage device, a shock tube firing circuit, a shock tube connector, a blasting cap firing circuit, and a blasting cap connector. The control system controls the charging system, which charges the electrical energy storage device. The control system also controls the shock tube firing circuit and the blasting cap firing circuit. When desired, the control system signals the shock tube firing circuit or blasting cap firing circuit to electrically connect the electrical energy storage device to the shock tube connector or the blasting cap connector respectively.

  8. Fire retardant polyetherimide nanocomposites

    SciTech Connect

    Lee, J.; Takekoshi, T.; Giannelis, E.P.

    1997-09-01

    Polyetherimide-layered silicates nanocomposites with increased char yield and fire retardancy are described. The use of nanocomposites is a new, environmentally-benign approach to improve fire resistance of polymers. An increase in the aromaticity yields high char residues that normally correlate with higher oxygen index and lower flammability. The often high cost of these materials and the specialized processing techniques required, however, have limited the use of these polymers to certain specialized applications. The effectiveness of fire retardant fillers is also limited since the large amounts required make processing difficult and might inadvertently affect mechanical properties.

  9. Fire research publications, 1983

    NASA Astrophysics Data System (ADS)

    Jason, N. H.

    1984-04-01

    Approximately 130 articles are cited addressing topics in fire fighting and prevention, combustion physics, and fire related hazards. Only publications prepared by members of the Center for Fire Research (CFR), by other National Bureau of Standards (NBS) personnel for CFR, or by external laboratories under contract or grant from the CFR are cited. For documents that are available for purchase from either the Government Printing Office (GPO) or the National Technical Information Service (NTIS), the specific order number has been included in the citation.

  10. Fires in Central Africa

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Hundreds of fires are set every year during the dry season in Central Africa. This true color image from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) shows dozens of smoke plumes in the Democratic Republic of the Congo on June 29, 2000. Residents burn away scrub and brush annually in the woody savanna to clear land for farming and grazing. For more information, visit the SeaWiFS Home Page, Global Fire Monitoring Fact Sheet, and 4km2 Fire Data Image Provided by the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

  11. Future Integrated Fire Control

    DTIC Science & Technology

    2005-06-01

    this illustration, the remote unit provides fire control quality ( FCQ ) data of the threat to the firing unit throughout the engagement. The firing...interceptor; tasking sensors & communication resources; ensuring resources are committed; monitoring resource performance; ensuring FCQ data is...FC LoR EoR FP RF PSD Object Observ. R R R L or R R L or R Object Trking/ID L & R R R L or R R L or R FCQ Data Attain. L R& L R L or R

  12. Ash in fire affected ecosystems

    NASA Astrophysics Data System (ADS)

    Pereira, Paulo; Jordan, Antonio; Cerda, Artemi; Martin, Deborah

    2015-04-01

    Ash in fire affected ecosystems Ash lefts an important footprint in the ecosystems and has a key role in the immediate period after the fire (Bodi et al., 2014; Pereira et al., 2015). It is an important source of nutrients for plant recover (Pereira et al., 2014a), protects soil from erosion and controls soil hydrological process as runoff, infiltration and water repellency (Cerda and Doerr, 2008; Bodi et al., 2012, Pereira et al., 2014b). Despite the recognition of ash impact and contribution to ecosystems recuperation, it is assumed that we still have little knowledge about the implications of ash in fire affected areas. Regarding this situation we wanted to improve our knowledge in this field and understand the state of the research about fire ash around world. The special issue about "The role of ash in fire affected ecosystems" currently in publication in CATENA born from the necessity of joint efforts, identify research gaps, and discuss future cooperation in this interdisciplinary field. This is the first special issue about fire ash in the international literature. In total it will be published 10 papers focused in different aspects of the impacts of ash in fire affected ecosystems from several parts of the world: • Fire reconstruction using charcoal particles (Burjachs and Espositio, in press) • Ash slurries impact on rheological properties of Runoff (Burns and Gabet, in press) • Methods to analyse ash conductivity and sorbtivity in the laboratory and in the field (Balfour et al., in press) • Termogravimetric and hydrological properties of ash (Dlapa et al. in press) • Effects of ash cover in water infiltration (Leon et al., in press) • Impact of ash in volcanic soils (Dorta Almenar et al., in press; Escuday et al., in press) • Ash PAH and Chemical extracts (Silva et al., in press) • Microbiology (Barreiro et al., in press; Lombao et al., in press) We believe that this special issue will contribute importantly to the better understanding of

  13. Fire-probability maps for the Brazilian Amazonia

    NASA Astrophysics Data System (ADS)

    Cardoso, Manoel; Sampaio, Gilvan; Obregon, Guillermo; Nobre, Carlos

    2010-05-01

    Most fires in Amazonia result from the combination between climate and land-use factors. They occur mainly in the dry season and are used as an inexpensive tool for land clearing and management. However, their unintended consequences are of important concern. Fire emissions are the most important sources of greenhouse gases and aerosols in the region, accidental fires are a major threat to protected areas, and frequent fires may lead to permanent conversion of forest areas into savannas. Fire-activity models have thus become important tools for environmental analyses in Amazonia. They are used, for example, in warning systems for monitoring the risk of burnings in protected areas, to improve the description of biogeochemical cycles and vegetation composition in ecosystem models, and to help estimate the long-term potential for savannas in biome models. Previous modeling studies for the whole region were produced in units of satellite fire pixels, which complicate their direct use for environmental applications. By reinterpreting remote-sensing based data using a statistical approach, we were able to calibrate models for the whole region in units of probability, or chance of fires to occur. The application of these models for years 2005 and 2006 provided maps of fire potential at 3-month and 0.25-deg resolution as a function of precipitation and distance from main roads. In both years, the performance of the resulting maps was better for the period July-September. During these months, most of satellite-based fire observations were located in areas with relatively high chance of fire, as determined by the modeled probability maps. In addition to reproduce reasonably well the areas presenting maximum fire activity as detected by remote sensing, the new results in units of probability are easier to apply than previous estimates from fire-pixel models.

  14. Fire-probability maps for the Brazilian Amazonia

    NASA Astrophysics Data System (ADS)

    Cardoso, M.; Nobre, C.; Obregon, G.; Sampaio, G.

    2009-04-01

    Most fires in Amazonia result from the combination between climate and land-use factors. They occur mainly in the dry season and are used as an inexpensive tool for land clearing and management. However, their unintended consequences are of important concern. Fire emissions are the most important sources of greenhouse gases and aerosols in the region, accidental fires are a major threat to protected areas, and frequent fires may lead to permanent conversion of forest areas into savannas. Fire-activity models have thus become important tools for environmental analyses in Amazonia. They are used, for example, in warning systems for monitoring the risk of burnings in protected areas, to improve the description of biogeochemical cycles and vegetation composition in ecosystem models, and to help estimate the long-term potential for savannas in biome models. Previous modeling studies for the whole region were produced in units of satellite fire pixels, which complicate their direct use for environmental applications. By reinterpreting remote-sensing based data using a statistical approach, we were able to calibrate models for the whole region in units of probability, or chance of fires to occur. The application of these models for years 2005 and 2006 provided maps of fire potential at 3-month and 0.25-deg resolution as a function of precipitation and distance from main roads. In both years, the performance of the resulting maps was better for the period July-September. During these months, most of satellite-based fire observations were located in areas with relatively high chance of fire, as determined by the modeled probability maps. In addition to reproduce reasonably well the areas presenting maximum fire activity as detected by remote sensing, the new results in units of probability are easier to apply than previous estimates from fire-pixel models.

  15. FIREhose: Reducing Data from FIRE

    NASA Astrophysics Data System (ADS)

    Fica, Haley Diane; Lambrides, Erini; Faherty, Jackie; Cruz, Kelle L.; BDNYC

    2016-01-01

    Brown dwarfs are stellar objects that do not have enough mass to ignite hydrogen fusion in their core. Their mass is between 0.08 solar masses and the mass of our sun. Brown dwarfs are very bright in the near-infrared wavelength band (0.8- 2.5 microns). We reduced data from the Folded-port InfraRed Echellette (FIRE) instrument on the Magellan Telescope at the Las Campanas Observatory. FIRE is a medium-resolution echelle spectrometer, whose data reduction results in a spectrum of a star. When reducing FIRE data, it is important to account for inconsistencies in the data, such as bad pixels, cosmic rays, and the effects of our atmosphere. Using the FIREhose pipeline, these inconsistencies can be accounted for and corrected using a A0 telluric with a known spectrum. After telluric correcting, the data reduction results in a primed spectrum for an object, which can then be used to determine an object's physical properties, such as atmospheric composition, radial velocity, effective temperature and surface gravity.

  16. Seasonal Distribution of African Savanna Fires

    NASA Technical Reports Server (NTRS)

    Cahoon, Donald R.; Stocks, Brian J.; Levine, Joel S.; Cofer, Wesley R., III; O'Neill, Katherine P.

    1992-01-01

    Savannas consist of a continuous layer of grass interspersed with scattered trees or shrubs, and cover approx. 10 million square kilometers of tropical Africa. African savanna fires, almost all resulting from human activities, may produce as much as a third of the total global emissions from biomass burning. Little is known, however, about the frequency and location of these fires, and the area burned each year. Emissions from African savanna burning are known to be transported over the mid-Atlantic, south Pacific and Indian oceans; but to study fully the transport of regional savanna burning and the seasonality of the atmospheric circulation must be considered simultaneously. Here we describe the temporal and spatial distribution of savanna fires over the entire African continent, as determined from night-time satellite imagery. We find that, contrary to expectations, most fires are left to burn uncontrolled, so that there is no strong diurnal cycle in the fire frequency. The knowledge gained from this study regarding the distribution and variability of fires will aid monitoring of the climatically important trace gases emitted from burning biomass.

  17. Soldiers and marksmen under fire: monitoring performance with neural correlates of small arms fire localization

    PubMed Central

    Sherwin, Jason; Gaston, Jeremy

    2013-01-01

    Important decisions in the heat of battle occur rapidly and a key aptitude of a good combat soldier is the ability to determine whether he is under fire. This rapid decision requires the soldier to make a judgment in a fraction of a second, based on a barrage of multisensory cues coming from multiple modalities. The present study uses an oddball paradigm to examine listener ability to differentiate shooter locations from audio recordings of small arms fire. More importantly, we address the neural correlates involved in this rapid decision process by employing single-trial analysis of electroencephalography (EEG). In particular, we examine small arms expert listeners as they differentiate the sounds of small arms firing events recorded at different observer positions relative to a shooter. Using signal detection theory, we find clear neural signatures related to shooter firing angle by identifying the times of neural discrimination on a trial-to-trial basis. Similar to previous results in oddball experiments, we find common windows relative to the response and the stimulus when neural activity discriminates between target stimuli (forward fire: observer 0° to firing angle) vs. standards (off-axis fire: observer 90° to firing angle). We also find, using windows of maximum discrimination, that auditory target vs. standard discrimination yields neural sources in Brodmann Area 19 (BA 19), i.e., in the visual cortex. In summary, we show that single-trial analysis of EEG yields informative scalp distributions and source current localization of discriminating activity when the small arms experts discriminate between forward and off-axis fire observer positions. Furthermore, this perceptual decision implicates brain regions involved in visual processing, even though the task is purely auditory. Finally, we utilize these techniques to quantify the level of expertise in these subjects for the chosen task, having implications for human performance monitoring in combat. PMID

  18. Teach Children Fire Will Burn.

    ERIC Educational Resources Information Center

    Children's Bureau (DHEW), Washington, DC.

    This handbook, addressed to parents and others responsible for the safety of children, presents information on fire hazards, prevention and protection. Emphasizing an early start to fire safety training, it outlines the basic facts of fire safety education, listing the most frequent causes of fire and suggesting the organization of a Family Fire…

  19. [Relationships of forest fire with lightning in Daxing' anling Mountains, Northeast China].

    PubMed

    Lei, Xiao-Li; Zhou, Guang-Sheng; Jia, Bing-Rui; Li, Shuai

    2012-07-01

    Forest fire is an important factor affecting forest ecosystem succession. Recently, forest fire, especially forest lightning fire, shows an increasing trend under global warming. To study the relationships of forest fire with lightning is essential to accurately predict the forest fire in time. Daxing' anling Mountains is a region with high frequency of forest lightning fire in China, and an important experiment site to study the relationships of forest fire with lightning. Based on the forest fire records and the corresponding lightning and meteorological observation data in the Mountains from 1966 to 2007, this paper analyzed the relationships of forest fire with lightning in this region. In the period of 1966-2007, both the lightning fire number and the fired forest area in this region increased significantly. The meteorological factors affecting the forest lighting fire were related to temporal scales. At yearly scale, the forest lightning fire was significantly correlated with precipitation, with a correlation coefficient of -0.489; at monthly scale, it had a significant correlation with air temperature, the correlation coefficient being 0.18. The relationship of the forest lightning fire with lightning was also related to temporal scales. At yearly scale, there was no significant correlation between them; at monthly scale, the forest lightning fire was strongly correlated with lightning and affected by precipitation; at daily scale, a positive correlation was observed between forest lightning fire and lightning when the precipitation was less than 5 mm. According to these findings, a fire danger index based on ADTD lightning detection data was established, and a forest lightning fire forecast model was developed. The prediction accuracy of this model for the forest lightning fire in Daxing' anling Mountains in 2005-2007 was > 80%.

  20. Seasonal changes in the human alteration of fire regimes beyond the climate forcing

    NASA Astrophysics Data System (ADS)

    Fréjaville, Thibaut; Curt, Thomas

    2017-03-01

    Human activities have altered fire regimes for millennia by suppressing or enhancing natural fire activity. However, whether these anthropogenic pressures on fire activity have exceeded and will surpass climate forcing still remains uncertain. We tested if, how and the extent to which seasonal fire activity in southern France has recently (1976–2009) deviated from climate-expected trends. The latter were simulated using an ensemble of detrended fire–climate models. We found both seasonal and regional contrasts in climatic effects through a mixture of drought-driven and fuel-limited fire regimes. Dry contemporary conditions chiefly drove fire frequency and burned area, although higher fire activity was related to wetter conditions in the last three years. Surprisingly, the relative importance of preceding wet conditions was higher in winter than in summer, illustrating the strong potential dependency of regional fire–climate relationships on the human use and control of fires. In the Mediterranean mountains, warm winters and springs favour extensive fires in the following dry summer. These results highlight that increasing dryness with climate change could have antagonistic effects on fire regime by leading to larger fires in summer (moisture-limited), but lower fire activity in winter (fuel-limited fire regime). Furthermore, fire trends have significantly diverged from climatic expectations, with a strong negative alteration in fire activity in the Mediterranean lowlands and the summer burned area in the mountains. In contrast, alteration of winter fire frequency in the Mediterranean and Temperate mountains has shifted from positive to negative (or null) trends during the mid-1990s, a period when fire suppression policy underwent major revisions. Our findings demonstrate that changes in land-use and fire suppression policy have probably exceeded the strength of climate change effects on changing fire regime in southern Europe, making regional predictions of