WorldWideScience

Sample records for maximum recorded burrowing

  1. Maximum Acceleration Recording Circuit

    Science.gov (United States)

    Bozeman, Richard J., Jr.

    1995-01-01

    Coarsely digitized maximum levels recorded in blown fuses. Circuit feeds power to accelerometer and makes nonvolatile record of maximum level to which output of accelerometer rises during measurement interval. In comparison with inertia-type single-preset-trip-point mechanical maximum-acceleration-recording devices, circuit weighs less, occupies less space, and records accelerations within narrower bands of uncertainty. In comparison with prior electronic data-acquisition systems designed for same purpose, circuit simpler, less bulky, consumes less power, costs and analysis of data recorded in magnetic or electronic memory devices. Circuit used, for example, to record accelerations to which commodities subjected during transportation on trucks.

  2. Early Pliocene anuran fossils from Kanapoi, Kenya, and the first fossil record for the African burrowing frog Hemisus (Neobatrachia: Hemisotidae).

    Science.gov (United States)

    Delfino, Massimo

    2017-07-13

    Isolated amphibian bones from the early Pliocene of Kanapoi (West Turkana, Kenya) help to improve the scarce fossil record of the late Neogene and Quaternary amphibians from East Africa. All currently available 579 bones are referable exclusively to the Anura (frogs and toads). More than half of the remains (366) are identified as Hemisus cf. Hemisus marmoratus, an extant species that still inhabits Kenya, but apparently not the northwest of the country and the Turkana area in particular. The rest of the remains are identified simply as Anura indet. because of poor preservation or non congruence with the relatively few African extant taxa whose osteology is known in detail. The Hemisus material represents the first fossil record for Hemisotidae, an endemic African family of peculiar, head-first burrowing frogs, whose sister taxon relationships indicate a divergence from brevicipitids in the Late Cretaceous or early Paleocene. The ecological requirements of extant H. marmoratus suggest that the Kanapoi area surrounding the fluvial and deltaic settings, from where the fossil remains of vertebrates were buried, was likely a grassland or relatively dry, open low tree-shrub savanna. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Habitat requirements and burrowing depths of rodents in relation to shallow waste burial sites

    Energy Technology Data Exchange (ETDEWEB)

    Gano, K.A.; States, J.B.

    1982-05-01

    The purpose of this paper is to provide a review of the literature and summarize information on factors affecting habitat selection and maximum recorded burrowing depths for representative small mammals that we consider most likely to inhibit waste burial sites in arid and semi-arid regions of the West. The information is intended for waste management designers who need to know what to expect from small mammals that may be present at a particular site. Waste repositories oculd be designed to exclude the deep burrowing rodents of a region by creating an unattractive habitat over the waste. Summaries are given for habitat requirements of each group along with generalized modifications that could be employed to deter habitation. Representatives from the major groups considered to be deep burrowers are discussed. Further, detailed information about a particular species can be obtained from the references cited.

  4. Habitat requirements and burrowing depths of rodents in relation to shallow waste burial sites

    International Nuclear Information System (INIS)

    Gano, K.A.; States, J.B.

    1982-05-01

    The purpose of this paper is to provide a review of the literature and summarize information on factors affecting habitat selection and maximum recorded burrowing depths for representative small mammals that we consider most likely to inhibit waste burial sites in arid and semi-arid regions of the West. The information is intended for waste management designers who need to know what to expect from small mammals that may be present at a particular site. Waste repositories oculd be designed to exclude the deep burrowing rodents of a region by creating an unattractive habitat over the waste. Summaries are given for habitat requirements of each group along with generalized modifications that could be employed to deter habitation. Representatives from the major groups considered to be deep burrowers are discussed. Further, detailed information about a particular species can be obtained from the references cited

  5. Ventilation of multi-entranced rodent burrows by boundary layer eddies.

    Science.gov (United States)

    Brickner-Braun, Inbal; Zucker-Milwerger, Daniel; Braun, Avi; Turner, J Scott; Pinshow, Berry; Berliner, Pedro

    2014-12-01

    Rodent burrows are often assumed to be environments wherein the air has a high concentration of CO₂. Although high burrow [CO₂] has been recorded, many studies report burrow [CO₂] that differs only slightly from atmospheric concentrations. Here, we advocate that one of the reasons for these differences is the penetration into burrows of air gusts (eddies), which originate in the turbulent boundary layer and prevent build-up of CO₂. We have characterized the means by which burrows of Sundevall's jird, which are representative of the burrows of many rodent species with more than one entrance, are ventilated. Our results demonstrate that, even at low wind speeds, the random penetration of eddies into a burrow through its openings is sufficient to keep the burrow [CO₂] low enough to be physiologically inconsequential, even in its deep and remote parts. © 2014. Published by The Company of Biologists Ltd.

  6. Use of Artificial Burrows by Burrowing Owls (Athene cunicularia) at the HAMMER Facility on the U.S. Department of Energy Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, Amanda K.; Sackschewsky, Michael R.; Duberstein, Corey A.

    2005-09-30

    In 2003 the U.S. Department of Energy (DOE) constructed an Emergency Vehicle Operations Course (EVOC) at the Hazardous Material Management and Emergency Response Training and Education Center (HAMMER) in the southern portion of the Hanford Site. Preliminary surveys during 2001 identified an active burrowing owl (Athene cunicularia) burrow and three burrowing owls within the proposed development area. Burrowing owls were classified as a federal species of concern, a Washington State ?candidate? species, a Washington Department of Fish and Wildlife priority species, and a Hanford Site Biological Resources Management Plan Level III resource. Therefore, the mitigation action plan for the project included the installation of twenty artificial burrows around EVOC in the spring of 2003. The mitigation plan established a success criterion of five percent annual use of the burrows by owls. In July 2005, a field survey of the EVOC burrow complex was conducted to determine use and demography at each site. Burrow locations were mapped and signs of activity (feces, owl tracks, castings, feathers) were recorded. Out of the twenty burrows, twelve were found to be active. Of the eight inactive burrows three appeared to have been active earlier in the 2005 breeding season. A total of nineteen owls were counted but demography could not be determined. It appears that the EVOC mitigation exceeded burrow use goals during 2005. Continued site monitoring and maintenance, according to mitigation plan guidelines should be conducted as prescribed.

  7. Like night and day: Reversals of thermal gradients across ghost crab burrows and their implications for thermal ecology

    Science.gov (United States)

    Watson, Gregory S.; Gregory, Emily A.; Johnstone, Charmaine; Berlino, Manuel; Green, David W.; Peterson, Nicola R.; Schoeman, David S.; Watson, Jolanta A.

    2018-04-01

    Ghost crabs, Ocypode cordimanus, inhabit relatively hostile environments subject to thermal fluctuations, including both diurnal and seasonal cycles. For many ectotherms, including ghost crabs, a major challenge is to remain cool during hot daytime temperatures. This can be achieved by adopting a fossorial lifestyle, taking advantage of thermal refuge afforded by burrows of sufficient depth. Another consideration, often overlooked, is the potential advantage associated with ready access to a thermal energy source (a "charging station") when surface temperatures are cooler. Being able to rapidly elevate body temperature during cool periods would enhance the crab's ability to maintain rate processes and carry out essential activities. We have measured ghost crab burrow temperature profiles at two times of the day with contrasting sun exposure (06:00 and 14:00), demonstrating how effective burrow depth (up to a maximum of 40 cm) provides thermal regulation below the surface of the sand (e.g., at dawn (06:00) and early afternoon (14:00) at a depth of 5 cm, temperatures (±SD) of 16.32 ± 0.96 °C and 25.04 ± 1.47 °C were recorded, respectively. Corresponding temperatures at a depth of 30 cm were 19.17 ± 0.59 °C and 19.78 ± 1.60 °C, respectively). This demonstrates that while temperature conditions at the surface vary dramatically from night to day, ghost crab burrows can maintain relatively constant temperatures at the burrow base throughout the diurnal cycle, at least during winter. As a consequence, the burrow heat signatures undergo a corresponding thermal gradient reversal between night and day, as revealed by infra-red photography. Complementing these field observations, we also determined heating and cooling times/constants for O. cordimanus in the laboratory (τ = 17.54 and 16.59 JK-1, respectively), and analysed chemical composition of their carapace (external (with β Chitin evident) and internal (predominance of α Chitin)), which is the primary thermal

  8. A New Maximum Length Record of the Bluefish (Pomatomus saltatrix Linnaeus, 1766) for Turkey Seas

    OpenAIRE

    Cengiz, Özgür

    2014-01-01

    One specimen of the bluefish (Pomatomus saltatrix Linnaeus, 1766) with 76.5 cm in total length and 4800.0 g in total weight was photographed in the Çanakkale Fish Market. The given length is second maximum length record of the bluefish for Turkish waters

  9. Large mammal burrows in late Miocene calcic paleosols from central Argentina: paleoenvironment, taphonomy and producers

    Directory of Open Access Journals (Sweden)

    María Cristina Cardonatto

    2018-05-01

    Full Text Available Large cylindrical sediment-filled structures interpreted as mammal burrows occur within the loess-paleosol sequence of the late Miocene Cerro Azul Formation of central Argentina. A total of 115 burrow fills from three localities were measured. They are typically shallowly dipping, subcylindrical, unbranched structures with rounded ends and lacking enlargements. The horizontal diameter of the burrows range between 0.15 and 1.50 m, with most of the burrows in the interval of 0.39 to 0.98 m. Geometric morphometric analysis of transverse cross-sections support their distinct subcircular and elliptical (horizontally flattened shapes. Burrow fills are typically laminated in the lower part and massive in the upper part. The laminated intervals reflect pulses of flowing water entering the abandoned burrow during moderate rains, whereas massive intervals reflect mass flow input of dense sediment-water mixtures during heavy rains that produced sheet floods. Approximately 1% of the burrows contained fragmentary, disarticulated and weathered mammal bones that were introduced in the open burrow by currents along with other sedimentary particles. Analysis of the tetrapod burrow fossil record suggests that Miocene burrows, including those studied herein, reflect a remarkable increase in the average size of the fossorial fauna. We conclude that large late Miocene mammals dug burrows essentially as a shelter against environmental extremes and to escape predation. The simple architecture of the burrows suggests that the producers essentially foraged aboveground. Several mammal groups acquired fossorial habits in response to cold and seasonally dry climatic conditions that prevailed during the late Miocene in southern South America. The considerable range of horizontal diameters of the studied burrows can be attributed to a variety of producers, including dasypodids, the notoungulate Paedotherium minor, Glyptodontidae and Proscelidodon sp.

  10. Aardvark burrows: a potential resource for animals in arid and semi ...

    African Journals Online (AJOL)

    Twenty-seven vertebrate species (21 mammals, two birds, three reptiles and one amphibian) were recorded making use of the burrows and it is likely that these species accrue benefits (e.g. a buffered microclimate) from burrow use. However, our sampling was biased towards mammals and nocturnal species. Consequently ...

  11. Burgess shale-type biotas were not entirely burrowed away

    DEFF Research Database (Denmark)

    Gaines, Robert R.; Droser, Mary L.; Orr, Patrick J.

    2012-01-01

    environments is that soft-bodied biotas were literally burrowed away from the fossil record by increasing infaunal activity in muddy substrate environments; this would have affected geochemical gradients and increased the efficiency of organic matter recycling in sediments. New and recently published data...

  12. Impact of dissolution on the sedimentary record of the Paleocene-Eocene thermal maximum

    Science.gov (United States)

    Bralower, Timothy J.; Kelly, D. Clay; Gibbs, Samantha; Farley, Kenneth; Eccles, Laurie; Lindemann, T. Logan; Smith, Gregory J.

    2014-09-01

    The input of massive amounts of carbon to the atmosphere and ocean at the Paleocene-Eocene Thermal Maximum (PETM; ˜55.53 Ma) resulted in pervasive carbonate dissolution at the seafloor. At many sites this dissolution also penetrated into the underlying sediment column. The magnitude of dissolution at and below the seafloor, a process known as chemical erosion, and its effect on the stratigraphy of the PETM, are notoriously difficult to constrain. Here, we illuminate the impact of dissolution by analyzing the complete spectrum of sedimentological grain sizes across the PETM at three deep-sea sites characterized by a range of bottom water dissolution intensity. We show that the grain size spectrum provides a measure of the sediment fraction lost during dissolution. We compare these data with dissolution and other proxy records, electron micrograph observations of samples and lithology. The complete data set indicates that the two sites with slower carbonate accumulation, and less active bioturbation, are characterized by significant chemical erosion. At the third site, higher carbonate accumulation rates, more active bioturbation, and possibly winnowing have limited the impacts of dissolution. However, grain size data suggest that bioturbation and winnowing were not sufficiently intense to diminish the fidelity of isotopic and microfossil assemblage records.

  13. Burrowing owl nesting productivity: A comparison between artificial and natural burrows on and off golf courses

    Science.gov (United States)

    Smith, M.D.; Conway, C.J.; Ellis, L.A.

    2005-01-01

    Burrowing owl (Athene cunicularia) populations are declining in many portions of their range, and lack of suitable nesting burrows is thought to be one reason for observed declines. Burrowing owls are attracted to golf courses because the birds generally nest and forage in short-grass, open areas, yet golf courses seldom have suitable nesting burrows. We examined the efficacy of installing artificial nesting burrows on golf courses as a way to help restore local burrowing owl populations. From 2001-2004 we monitored over 175 natural burrows off golf courses, 14 natural burrows on golf courses, 86 artificial burrows off golf courses, and 130 artificial burrows on golf courses. Owls located and used 8 of the 130 artificial burrows installed on golf courses (4 were used as nests). Owls selected burrows that were closer to existing natural burrows, farther from maintained areas (areas receiving turf maintenance by golf course staff), and farther from sprinkler heads. All 4 of the artificial burrows used as nests successfully fledged young, and annual site fidelity for owls nesting on golf courses was higher than for owls nesting off golf courses. However, annual fecundity of owls nesting on golf courses was lower than that of owls nesting off golf courses. If golf courses have sufficiently large nonmaintained areas and there are nesting owls nearby, course managers potentially can help in restoring local burrowing owl populations by installing artificial nesting burrows on the periphery of the course. However, the low fecundity on golf courses reported here should be more thoroughly examined before artificial burrows are used to attract owls to golf courses.

  14. High resolution record of the Last Glacial Maximum in eastern Australia

    Science.gov (United States)

    Petherick, Lynda; Moss, Patrick; McGowan, Hamish

    2010-05-01

    A continuous, high resolution (average ca. 22 year) record encompassing the Last Glacial Maximum (LGM) has been developed using multiple proxies (aeolian sediment flux, grain size, pollen and charcoal) in lake sediment from Tortoise Lagoon (TOR), North Stradbroke Island, Queensland, Australia. The presence of Asteraceae tubilifloreae and spineless Asteraceae (common indicators of glacial conditions in Australia) at TOR indicates significantly cooler temperatures (mean annual temperature up to 6oC lower than today). In addition to the palaeoclimatic reconstruction, a record of palaeodust transport pathways for eastern Australia was developed using ICP-MS trace element analysis and geochemical "fingerprinting" of TOR aeolian sediment to continental dust source areas. Vectors between dominant dust source areas and North Stradbroke Island allowed the reconstruction of the position and intensity of LGM dust transport pathways. Furthermore, changes in likely synpotic scale conditions can be postulated based on the position of the dust transport corridors. Similarities between the vegetation at TOR during the LGM and that at temperate sites e.g. Caledonia Fen, Victoria (Kershaw et al. 2007), Redhead Lagoon, New South Wales (Williams et al. 2006) and Barrington Tops, New South Wales (Sweller and Martin 2001) suggests that this record reflects regional conditions across southeastern Australia. The TOR record also correlates well with that from nearby Native Companion Lagoon which suggests that the LGM was actually an extended period of ca. 8 - 10 kyr, characterised by 2 periods of increased aridity (ca. 30 - 26.5 kyr and 21 - 19.5 kyr) (Petherick et al. 2008). A growing number of records from across the Southern Hemisphere e.g. New Zealand (Suggate and Almond 2003; Alloway et al. 2007; Newnham et al. 2007), Chile (Denton et al. 1999), Antarctica (Röthlisberger et al. 2002; EPICA 2006) and Australia (Smith 2009) also show evidence that the LGM encompassed a longer period of

  15. Large-Diameter Burrows of the Triassic Ischigualasto Basin, NW Argentina: Paleoecological and Paleoenvironmental Implications

    Science.gov (United States)

    Colombi, Carina E.; Fernández, Eliana; Currie, Brian S.; Alcober, Oscar A.; Martínez, Ricardo; Correa, Gustavo

    2012-01-01

    Large-diameter ichnofossils comprising three morphotypes have been identified in the Upper Triassic Ischigualasto and Los Colorados formations of northwestern Argentina. These burrows add to the global record of the early appearance of fossorial behavior during early Mesozoic time. Morphotypes 1 and 2 are characterized by a network of tunnels and shafts that can be assigned to tetrapod burrows given similarities with previously described forms. However, differences in diameter, overall morphology, and stratigraphic occurrence allow their independent classification. Morphotype 3 forms a complex network of straight branches that intersect at oblique angles. Their calcareous composition and surface morphology indicate these structures have a composite biogenic origin likely developed due to combined plant/animal interactions. The association of Morphotypes 1 and 2 with fluvial overbank lithologies deposited under an extremely seasonal arid climate confirms interpretations that the early appearance of burrowing behavior was employed by vertebrates in response to both temperature and moisture-stress associated with seasonally or perpetually dry Pangean paleoclimates. Comparisons of burrow morphology and biomechanical attributes of the abundant paleovertebrate fauna preserved in both formations permit interpretations regarding the possible burrow architects for Morphotypes 1 and 2. In the case of the Morphotype 1, the burrow constructor could be one of the small carnivorous cynodonts, Ecteninion or Probelesodon. Assigning an architect for Morphotype 2 is more problematic due to mismatches between the observed burrow morphology and the size of the known Los Colorados vertebrates. PMID:23227195

  16. Synchrotron Reveals Early Triassic Odd Couple: Injured Amphibian and Aestivating Therapsid Share Burrow.

    Directory of Open Access Journals (Sweden)

    Vincent Fernandez

    Full Text Available Fossorialism is a beneficial adaptation for brooding, predator avoidance and protection from extreme climate. The abundance of fossilised burrow casts from the Early Triassic of southern Africa is viewed as a behavioural response by many tetrapods to the harsh conditions following the Permo-Triassic mass-extinction event. However, scarcity of vertebrate remains associated with these burrows leaves many ecological questions unanswered. Synchrotron scanning of a lithified burrow cast from the Early Triassic of the Karoo unveiled a unique mixed-species association: an injured temnospondyl amphibian (Broomistega that sheltered in a burrow occupied by an aestivating therapsid (Thrinaxodon. The discovery of this rare rhinesuchid represents the first occurrence in the fossil record of a temnospondyl in a burrow. The amphibian skeleton shows signs of a crushing trauma with partially healed fractures on several consecutive ribs. The presence of a relatively large intruder in what is interpreted to be a Thrinaxodon burrow implies that the therapsid tolerated the amphibian's presence. Among possible explanations for such unlikely cohabitation, Thrinaxodon aestivation is most plausible, an interpretation supported by the numerous Thrinaxodon specimens fossilised in curled-up postures. Recent advances in synchrotron imaging have enabled visualization of the contents of burrow casts, thus providing a novel tool to elucidate not only anatomy but also ecology and biology of ancient tetrapods.

  17. Burrowing Owls, Pulex irritans, and Plague.

    Science.gov (United States)

    Belthoff, James R; Bernhardt, Scott A; Ball, Christopher L; Gregg, Michael; Johnson, David H; Ketterling, Rachel; Price, Emily; Tinker, Juliette K

    2015-09-01

    Western Burrowing Owls (Athene cunicularia hypugaea) are small, ground-dwelling owls of western North America that frequent prairie dog (Cynomys spp.) towns and other grasslands. Because they rely on rodent prey and occupy burrows once or concurrently inhabited by fossorial mammals, the owls often harbor fleas. We examined the potential role of fleas found on burrowing owls in plague dynamics by evaluating prevalence of Yersinia pestis in fleas collected from burrowing owls and in owl blood. During 2012-2013, fleas and blood were collected from burrowing owls in portions of five states with endemic plague-Idaho, Oregon, Washington, Colorado, and South Dakota. Fleas were enumerated, taxonomically identified, pooled by nest, and assayed for Y. pestis using culturing and molecular (PCR) approaches. Owl blood underwent serological analysis for plague antibodies and nested PCR for detection of Y. pestis. Of more than 4750 fleas collected from owls, Pulex irritans, a known plague vector in portions of its range, comprised more than 99.4%. However, diagnostic tests for Y. pestis of flea pools (culturing and PCR) and owl blood (PCR and serology) were negative. Thus, even though fleas were prevalent on burrowing owls and the potential for a relationship with burrowing owls as a phoretic host of infected fleas exists, we found no evidence of Y. pestis in sampled fleas or in owls that harbored them. We suggest that studies similar to those reported here during plague epizootics will be especially useful for confirming these results.

  18. Automatically quantifying the scientific quality and sensationalism of news records mentioning pandemics: validating a maximum entropy machine-learning model.

    Science.gov (United States)

    Hoffman, Steven J; Justicz, Victoria

    2016-07-01

    To develop and validate a method for automatically quantifying the scientific quality and sensationalism of individual news records. After retrieving 163,433 news records mentioning the Severe Acute Respiratory Syndrome (SARS) and H1N1 pandemics, a maximum entropy model for inductive machine learning was used to identify relationships among 500 randomly sampled news records that correlated with systematic human assessments of their scientific quality and sensationalism. These relationships were then computationally applied to automatically classify 10,000 additional randomly sampled news records. The model was validated by randomly sampling 200 records and comparing human assessments of them to the computer assessments. The computer model correctly assessed the relevance of 86% of news records, the quality of 65% of records, and the sensationalism of 73% of records, as compared to human assessments. Overall, the scientific quality of SARS and H1N1 news media coverage had potentially important shortcomings, but coverage was not too sensationalizing. Coverage slightly improved between the two pandemics. Automated methods can evaluate news records faster, cheaper, and possibly better than humans. The specific procedure implemented in this study can at the very least identify subsets of news records that are far more likely to have particular scientific and discursive qualities. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Burrowing Owl - Palo Verde Valley [ds197

    Data.gov (United States)

    California Natural Resource Agency — These burrowing owl observations were collected during the spring and early summer of 1976 in the Palo Verde Valley, eastern Riverside County, California. This is an...

  20. Mammalian mesocarnivore visitation at tortoise burrows in a wind farm

    Science.gov (United States)

    Agha, Mickey; Smith, Amanda L.; Lovich, Jeffrey E.; Delaney, David F.; Ennen, Joshua R.; Briggs, Jessica R.; Fleckenstein, Leo J.; Tennant, Laura A.; Puffer, Shellie R.; Walde, Andrew D.; Arundel, Terry; Price, Steven J.; Todd, Brian D.

    2017-01-01

    There is little information on predator–prey interactions in wind energy landscapes in North America, especially among terrestrial vertebrates. Here, we evaluated how proximity to roads and wind turbines affect mesocarnivore visitation with desert tortoises (Gopherus agassizii) and their burrows in a wind energy landscape. In 2013, we placed motion-sensor cameras facing the entrances of 46 active desert tortoise burrows in a 5.2-km2 wind energy facility near Palm Springs, California, USA. Cameras recorded images of 35 species of reptiles, mammals, and birds. Counts for 4 species of mesocarnivores at desert tortoise burrows increased closer to dirt roads, and decreased closer to wind turbines. Our results suggest that anthropogenic infrastructure associated with wind energy facilities could influence the general behavior of mammalian predators and their prey. Further investigation of proximate mechanisms that underlie road and wind turbine effects (i.e., ground vibrations, sound emission, and traffic volume) and on wind energy facility spatial designs (i.e., road and wind turbine configuration) could prove useful for better understanding wildlife responses to wind energy development. © 2017 The Wildlife Society.

  1. A new record of the Paleocene Carbon Isotope Maximum from the Mississippi Embayment

    Science.gov (United States)

    Platt, B. F.; Gerweck, E. D.

    2017-12-01

    The Paleocene-Eocene interval is well known as a time of climatic transitions, especially hyperthermals associated with disturbances in the carbon cycle that are used as proxies for impacts of projected anthropogenic global climate change. A recent roadcut in Benton County, Mississippi exposes a disconformity between the Paleocene Naheola Formation and the Eocene Meridian Sand. The disconformity is developed on a thick, kaolinitic paleosol, which we interpret as a mature Oxisol that supported tropical rainforest vegetation (as evidenced by associated well preserved leaf fossils). The nature of the paleosol at the disconformity led us to hypothesize that the strata might contain evidence of the Paleocene Eocene Thermal Maximum (PETM). We sampled two Mississippi Mineral Resources Institute (MMRI) cores from the equivalent stratigraphic interval from Benton and Tippah Counties, Mississippi, for bulk organic carbon stable isotopes at 25-cm intervals. Results showed no evidence of the negative excursion characteristic of the PETM. Instead, we found a gradual upsection enrichment that we interpret as the positive trend characteristic of the lower Paleocene Carbon Isotope Maximum (PCIM). This is reasonable based on published biostratigraphy and absolute ages from elsewhere in the Naheola Formation. Further analyses will be performed to determine whether the PCIM trend continues throughout the remainder of the core. The identification of the PCIM in Mississippi Embayment (ME) sediments is important because stable carbon isotope data may be useful for improving chronostratigraphy in the ME. Also, the PCIM is associated with a gradual warming trend as indicated by previously published stable oxygen isotopes from benthic foraminifera. Studying successive ME paleosols throughout the PCIM may yield information about the impacts of gradual atmospheric warming on soils and associated terrestrial systems.

  2. Maximum rates of climate change are systematically underestimated in the geological record.

    Science.gov (United States)

    Kemp, David B; Eichenseer, Kilian; Kiessling, Wolfgang

    2015-11-10

    Recently observed rates of environmental change are typically much higher than those inferred for the geological past. At the same time, the magnitudes of ancient changes were often substantially greater than those established in recent history. The most pertinent disparity, however, between recent and geological rates is the timespan over which the rates are measured, which typically differ by several orders of magnitude. Here we show that rates of marked temperature changes inferred from proxy data in Earth history scale with measurement timespan as an approximate power law across nearly six orders of magnitude (10(2) to >10(7) years). This scaling reveals how climate signals measured in the geological record alias transient variability, even during the most pronounced climatic perturbations of the Phanerozoic. Our findings indicate that the true attainable pace of climate change on timescales of greatest societal relevance is underestimated in geological archives.

  3. Detection of surface electromyography recording time interval without muscle fatigue effect for biceps brachii muscle during maximum voluntary contraction.

    Science.gov (United States)

    Soylu, Abdullah Ruhi; Arpinar-Avsar, Pinar

    2010-08-01

    The effects of fatigue on maximum voluntary contraction (MVC) parameters were examined by using force and surface electromyography (sEMG) signals of the biceps brachii muscles (BBM) of 12 subjects. The purpose of the study was to find the sEMG time interval of the MVC recordings which is not affected by the muscle fatigue. At least 10s of force and sEMG signals of BBM were recorded simultaneously during MVC. The subjects reached the maximum force level within 2s by slightly increasing the force, and then contracted the BBM maximally. The time index of each sEMG and force signal were labeled with respect to the time index of the maximum force (i.e. after the time normalization, each sEMG or force signal's 0s time index corresponds to maximum force point). Then, the first 8s of sEMG and force signals were divided into 0.5s intervals. Mean force, median frequency (MF) and integrated EMG (iEMG) values were calculated for each interval. Amplitude normalization was performed by dividing the force signals to their mean values of 0s time intervals (i.e. -0.25 to 0.25s). A similar amplitude normalization procedure was repeated for the iEMG and MF signals. Statistical analysis (Friedman test with Dunn's post hoc test) was performed on the time and amplitude normalized signals (MF, iEMG). Although the ANOVA results did not give statistically significant information about the onset of the muscle fatigue, linear regression (mean force vs. time) showed a decreasing slope (Pearson-r=0.9462, pfatigue starts after the 0s time interval as the muscles cannot attain their peak force levels. This implies that the most reliable interval for MVC calculation which is not affected by the muscle fatigue is from the onset of the EMG activity to the peak force time. Mean, SD, and range of this interval (excluding 2s gradual increase time) for 12 subjects were 2353, 1258ms and 536-4186ms, respectively. Exceeding this interval introduces estimation errors in the maximum amplitude calculations

  4. Artificially evolved functional shell morphology of burrowing bivalves

    DEFF Research Database (Denmark)

    Germann, D. P.; Schatz, W.; Hotz, Peter Eggenberger

    2014-01-01

    The morphological evolution of bivalves is documented by a rich fossil record. It is believed that the shell shape and surface sculpture play an important role for the burrowing performance of endobenthic species. While detailed morphometric studies of bivalve shells have been done...... dimensional (3D) objects, the first ever artificial evolution of a physical bivalve shell was performed. The result was a vertically flattened shell occupying only the top sediment layers. Insufficient control of the sediment was the major limitation of the setup and restricted the significance of the results...

  5. Influence of vegetation on the nocturnal foraging behaviors and vertebrate prey capture by endangered Burrowing Owls

    Directory of Open Access Journals (Sweden)

    Alan Marsh

    2014-06-01

    Full Text Available Restrictions in technology have limited past habitat selection studies for many species to the home-range level, as a finer-scale understanding was often not possible. Consequently, these studies may not identify the true mechanism driving habitat selection patterns, which may influence how such results are applied in conservation. We used GPS dataloggers with digital video recorders to identify foraging modes and locations in which endangered Burrowing Owls (Athene cunicularia captured prey. We measured the coarse and fine-scale characteristics of vegetation at locations in which owls searched for, versus where they caught, vertebrate prey. Most prey items were caught using hover-hunting. Burrowing Owls searched for, and caught, vertebrate prey in all cover types, but were more likely to kill prey in areas with sparse and less dense vegetative cover. Management strategies designed to increase Burrowing Owl foraging success in the Canadian prairies should try to ensure a mosaic of vegetation heights across cover types.

  6. Effect of environmental conditions on variation in the sediment-water interface created by complex macrofaunal burrows on a tidal flat

    Science.gov (United States)

    Koo, Bon Joo; Kwon, Kae Kyoung; Hyun, Jung-Ho

    2007-11-01

    We quantified the increase in the sediment-water interface created by the burrowing activities of the resident macrofaunal community and its variation with respect to the physical conditions of the habitat on a tidal fat. We investigated environmental factors and dimensions of macrofaunal burrows with respect to tidal height and vegetation during spring and summer at three sites. A resin-casting method was used to quantify the dimensions of all burrows at each site. The dimensions of macrofaunal burrows varied both temporally and spatially and the increase in the sediment-water interface reached a maximum of 311%, ranging from 20 to 255% under different habitat conditions. The sediment-water interface depended on the duration of exposure resulting from tidal height, increased temperatures resulting from seasonality, and marsh plant density. Burrows were deeper and more expansive at both higher tidal levels and higher temperatures in summer. Burrow dimensions were sharply reduced with the disappearance of adult macrofauna in areas where the roots of the marsh plant Suaeda japonica were dense. The significance of this study lies in quantifying the burrow dimensions of the entire macrofaunal community, rather than just a single population, and confirming their spatial and temporal variation with respect to physical conditions of the habitat. Environmental factors responsible for variation in burrow dimensions are discussed.

  7. Effects of ocean acidification on the marine calcium isotope record at the Paleocene-Eocene Thermal Maximum

    Science.gov (United States)

    Griffith, Elizabeth M.; Fantle, Matthew S.; Eisenhauer, Anton; Paytan, Adina; Bullen, Thomas D.

    2015-06-01

    Carbonates are used extensively to reconstruct paleoclimate and paleoceanographic conditions over geologic time scales. However, these archives are susceptible to diagenetic alteration via dissolution, recrystallization and secondary precipitation, particularly during ocean acidification events when intense dissolution can occur. Despite the possible effects of diagenesis on proxy fidelity, the impacts of diagenesis on the calcium isotopic composition (δ44Ca) of carbonates are unclear. To shed light on this issue, bulk carbonate δ44Ca was measured at high resolution in two Pacific deep sea sediment cores (ODP Sites 1212 and 1221) with considerably different dissolution histories over the Paleocene-Eocene Thermal Maximum (PETM, ∼ 55 Ma). The δ44Ca of marine barite was also measured at the deeper Site 1221, which experienced severe carbonate dissolution during the PETM. Large variations (∼ 0.8 ‰) in bulk carbonate δ44Ca occur in the deeper of the two sites at depths corresponding to the peak carbon isotope excursion, which correlate with a large drop in carbonate weight percent. Such an effect is not observed in either the 1221 barite record or the bulk carbonate record at the shallower Site 1212, which is also less affected by dissolution. We contend that ocean chemical changes associated with abrupt and massive carbon release into the ocean-atmosphere system and subsequent ocean acidification at the PETM affected the bulk carbonate δ44Ca record via diagenesis in the sedimentary column. Such effects are considerable, and need to be taken into account when interpreting Ca isotope data and, potentially, other geochemical proxies over extreme climatic events that drive sediment dissolution.

  8. A study of burrow morphology in representative axiidean and gebiidean mud shrimps, from the Persian Gulf and Gulf of Oman, Iran

    Directory of Open Access Journals (Sweden)

    Vahid Sepahvand

    Full Text Available Mud shrimps (formerly Thalassinidea are common burrow dwelling decapod crustaceans in the littoral zone of the Persian Gulf and Gulf of Oman. Their burrow morphology was investigated using foam casting methods. The present study shows that the burrow morphology in Upogebia carinicauda is not consistent and the recorded variations are based on habitat type and some physical characteristics of sediments. Adult burrow morphology in sandy-muddy substrate with shells, and boulder field habitats were Y-shaped and complex burrows of horizontal channels with turning chambers and vertical connections to internal passages or crevices of boulders, respectively. In burrows of U. carinicauda, some narrow passages, connected to the upper part of adult burrows in sandy-muddy habitats, belong to juveniles. Another species, Neocallichirus jousseaumei was found under boulders in sandy-muddy habitats of the Gulf of Oman and Qeshm Island, Persian Gulf. Since this type of habitat is special in some features, no conspicuous ex-current openings (usually obvious as conical mounds of extruded sediment have been observed on the sediment surface; as these were hidden among the boulders surrounded by mixed sand and shells. The only method for observing this type of burrow was to remove the boulders by hand or lever.

  9. Transient dwarfism of soil fauna during the Paleocene-Eocene Thermal Maximum.

    Science.gov (United States)

    Smith, Jon J; Hasiotis, Stephen T; Kraus, Mary J; Woody, Daniel T

    2009-10-20

    Soil organisms, as recorded by trace fossils in paleosols of the Willwood Formation, Wyoming, show significant body-size reductions and increased abundances during the Paleocene-Eocene Thermal Maximum (PETM). Paleobotanical, paleopedologic, and oxygen isotope studies indicate high temperatures during the PETM and sharp declines in precipitation compared with late Paleocene estimates. Insect and oligochaete burrows increase in abundance during the PETM, suggesting longer periods of soil development and improved drainage conditions. Crayfish burrows and molluscan body fossils, abundant below and above the PETM interval, are significantly less abundant during the PETM, likely because of drier floodplain conditions and lower water tables. Burrow diameters of the most abundant ichnofossils are 30-46% smaller within the PETM interval. As burrow size is a proxy for body size, significant reductions in burrow diameter suggest that their tracemakers were smaller bodied. Smaller body sizes may have resulted from higher subsurface temperatures, lower soil moisture conditions, or nutritionally deficient vegetation in the high-CO(2) atmosphere inferred for the PETM. Smaller soil fauna co-occur with dwarf mammal taxa during the PETM; thus, a common forcing mechanism may have selected for small size in both above- and below-ground terrestrial communities. We predict that soil fauna have already shown reductions in size over the last 150 years of increased atmospheric CO(2) and surface temperatures or that they will exhibit this pattern over the next century. We retrodict also that soil fauna across the Permian-Triassic and Triassic-Jurassic boundary events show significant size decreases because of similar forcing mechanisms driven by rapid global warming.

  10. Transient dwarfism of soil fauna during the Paleocene-Eocene Thermal Maximum

    Science.gov (United States)

    Smith, J.J.; Hasiotis, S.T.; Kraus, M.J.; Woody, D.T.

    2009-01-01

    Soil organisms, as recorded by trace fossils in paleosols of the Willwood Formation, Wyoming, show significant body-size reductions and increased abundances during the Paleocene-Eocene Thermal Maximum (PETM). Paleobotanical, paleopedologic, and oxygen isotope studies indicate high temperatures during the PETM and sharp declines in precipitation compared with late Paleocene estimates. Insect and oligochaete burrows increase in abundance during the PETM, suggesting longer periods of soil development and improved drainage conditions. Crayfish burrows and molluscan body fossils, abundant below and above the PETM interval, are significantly less abundant during the PETM, likely because of drier floodplain conditions and lower water tables. Burrow diameters of the most abundant ichnofossils are 30-46% smaller within the PETM interval. As burrow size is a proxy for body size, significant reductions in burrow diameter suggest that their tracemakers were smaller bodied. Smaller body sizes may have resulted from higher subsurface temperatures, lower soil moisture conditions, or nutritionally deficient vegetation in the high-CO2 atmosphere inferred for the PETM. Smaller soil fauna co-occur with dwarf mammal taxa during the PETM; thus, a common forcing mechanism may have selected for small size in both above- and below-ground terrestrial communities. We predict that soil fauna have already shown reductions in size over the last 150 years of increased atmospheric CO2 and surface temperatures or that they will exhibit this pattern over the next century. We retrodict also that soil fauna across the Permian-Triassic and Triassic-Jurassic boundary events show significant size decreases because of similar forcing mechanisms driven by rapid global warming.

  11. The role of burrowing sponges in bioerosion.

    Science.gov (United States)

    Rützler, Klaus

    1975-09-01

    Among the large number of limestone-eroding organisms, sponges, mainly of the family Clinonidae are of special interest because of their efficient means of substratum penetration by cellular etching and because they release characteristically shaped calcium carbonate chips which can be detected in the mud-size fraction of many sediments. Identifiable trace fossils and sediments are of great ecological and paleoecological significance.As new data on the excavating mechanism have become available, the questions of burrowing rates and sediment production have gained importance. Extrapolation from shortterm experiments (under 6 months) on substrate invasion are inconclusive because of high initial penetration rates resulting from mechanical stimulation and lack of competition. New experiments show that the rate curve flattens after 6 months and that optimum longterm erosion of CaCO 3 does not exceed 700 mg m -2 year -1 (Cliona lampa and C. aprica). Substrate limitations and competition will further reduce this rate.By monitoring the production of CaCO 3 chips by Cliona lampa, it was possible to link activity patterns to certain environmental factors. Mechanical stimuli, high light intensity, strong currents and, possibly, low temperature seem to accelerate the burrowing process. Sponge-generated chips can make up over 40% of coral mud when deposited in the current shadow of the reef framework.Using transect counts and sponge area-biomass conversion factors, the mean abundance of burrowing sponges on the Bermuda platform could be calculated. On suitable hard bottom substrates it averages 16 g dry weight per m 2 . From this value the burrowing potential of sponges can be estimated as 256 g CaCO 3 per m 2 substrate per year. Since 97-98% of the eroded limestone remains in particulate form, the contribution of fine sediments can amount to 250 g m -2 year -1 .Attention is called to the fact that erosion rates by burrowers can not directly be compared with those of borers or

  12. Deep circulation changes in the South Atlantic since the Last Glacial Maximum from Nd isotope and multi-proxy records

    Science.gov (United States)

    Wei, R.; Abouchami, W.; Zahn, R.; Masque, P.

    2016-01-01

    We report down-core sedimentary Nd isotope (εNd) records from two South Atlantic sediment cores, MD02-2594 and GeoB3603-2, located on the western South African continental margin. The core sites are positioned downstream of the present-day flow path of North Atlantic Deep Water (NADW) and close to the Southern Ocean, which makes them suitable for reconstructing past variability in NADW circulation over the last glacial cycle. The Fe-Mn leachates εNd records show a coherent decreasing trend from glacial radiogenic values towards less radiogenic values during the Holocene. This trend is confirmed by εNd in fish debris and mixed planktonic foraminifera, albeit with an offset during the Holocene to lower values relative to the leachates, matching the present-day composition of NADW in the Cape Basin. We interpret the εNd changes as reflecting the glacial shoaling of Southern Ocean waters to shallower depths combined with the admixing of southward flowing Northern Component Water (NCW). A compilation of Atlantic εNd records reveals increasing radiogenic isotope signatures towards the south and with increasing depth. This signal is most prominent during the Last Glacial Maximum (LGM) and of similar amplitude across the Atlantic basin, suggesting continuous deep water production in the North Atlantic and export to the South Atlantic and the Southern Ocean. The amplitude of the εNd change from the LGM to Holocene is largest in the southernmost cores, implying a greater sensitivity to the deglacial strengthening of NADW at these sites. This signal impacted most prominently the South Atlantic deep and bottom water layers that were particularly deprived of NCW during the LGM. The εNd variations correlate with changes in 231Pa/230Th ratios and benthic δ13C across the deglacial transition. Together with the contrasting 231Pa/230Th: εNd pattern of the North and South Atlantic, this indicates a progressive reorganization of the AMOC to full strength during the Holocene.

  13. Burrowing Owl Monitoring Report for Calendar Year 2012

    Energy Technology Data Exchange (ETDEWEB)

    Wilde, Justin W.; Lindsey, Cole T.; Nugent, John J.

    2013-03-14

    The monitoring during 2012 focused on documenting the status of known burrows. Newly identified burrows were documented while examining historical locations, during ecological resource reviews, or discovered during other monitoring efforts. The timing of the monitoring effort allowed staff to perform the surveys without disrupting any breeding or hatching, while also allowing for easy discernment of adults from juveniles, which helped in determining burrow-use type.

  14. Climate and Provenance Evolution Recorded in the Sub-aqueous Indus Delta since the Last Glacial Maximum

    Science.gov (United States)

    Limmer, D. R.; Clift, P. D.; Koehler, C.; Giosan, L.; Ponton, C.; Henstock, T.; Tabrez, A.

    2010-12-01

    Source to sink processes in large fluvial systems are complicated by large transport distances and the potential to store and rework material on route to the submarine fan. We target the Indus river system and assess how climate change since the Last Glacial Maximum (LGM) may have affected the storage and deposition of sediment in the nearshore shelf setting. While sediment reworking within the floodplain appears to have been strong during the Holocene, it is unclear whether this can be observed in the deep sea or in the submarine delta. We present a multi-proxy record of mineralogical and geochemical change from two cores obtained from the Indus Shelf during Winter 2008/9, one located close to the modern river and one located in the north-west shelf. Results show a strong contrast in the geochemistry, reflectance spectroscopy and clay mineralogy between Holocene sediments from the two cores. We propose that these differences are caused by both local variations in sediment source and transport mechanisms. Trends common in both cores could be related to climatic processes, such as low values in the chemical alteration index (CIA) and low 87Sr/86Sr that rise between 11 and 8ka suggests more intense chemical weathering at that time. This period coincides with presumed warmer, wet conditions and a stronger summer monsoon. A small decline in chemical weathering after 8ka could be caused by an apparent weakening of the monsoon since that time. These data suggest that sediment weathered in the floodplains is transported quickly to the submarine delta during the Holocene, but that this material has not yet been re-deposited into the deep water via the Indus Canyon.

  15. Orofacial neuropathic pain reduces spontaneous burrowing behavior in rats.

    Science.gov (United States)

    Deseure, K; Hans, G

    2018-07-01

    It was recently reported that spontaneous burrowing behavior is decreased after tibial nerve transection, spinal nerve transection and partial sciatic nerve ligation. It was proposed that spontaneous burrowing could be used as a measure of the impact of neuropathic pain after peripheral nerve injury. It has remained unclear whether the reduction in burrowing behavior is caused directly by pain or hypersensitivity in the affected limbs, making it more difficult to perform burrowing, or by a pain induced decrease in the general wellbeing, thus reducing the motivation to burrow. We studied burrowing behavior after infraorbital nerve injury, a model of orofacial neuropathic pain that does not affect the limbs. Burrowing behavior was significantly reduced after infraorbital nerve injury. Isolated face grooming and responsiveness to mechanical von Frey stimulation of the infraorbital nerve territory were significantly increased after infraorbital nerve injury, indicative, respectively, of spontaneous pain and mechanical allodynia. It is concluded that spontaneous burrowing may provide a measure of the global impact of pain on the animal's wellbeing after peripheral nerve injury and incorporation of this behavioral assay in preclinical drug testing may improve the predictive validity of currently used pain models. Copyright © 2018 Elsevier Inc. All rights reserved.

  16. Burrow architecture of the Damaraland mole-rat ( Fukomys ...

    African Journals Online (AJOL)

    The burrow architecture (length, internal dimensions, fractal dimension of tunnel systems, number of nesting chambers and surface mounds) was investigated in the Damaraland mole-rat (Fukomys damarensis). A total of 31 animals were caught from five different colonies and their burrow systems were excavated in their ...

  17. Stalagmite-derived Last Glacial Maximum - Mid Holocene Indian Monsoon Record from Krem Mawmluh, Meghalaya, NE India

    Science.gov (United States)

    Lone, M. A.; Routh, J.; Kumar, V.; Mangini, A.; Rangarajan, R.; Ghosh, P.; Munnuru Singamshetty, K.; Shen, C. C.; Ahmad, S. M.; Mii, H. S.

    2016-12-01

    Seasonal reversals in monsoon winds strongly influence rainfall patterns on the Indian sub-continent regulating the socio-economy of south Asian region. High-resolution centennial-millennial scale records of climate change from the core zone of the monsoon impacted region are nonetheless very few. Here, we report Indian summer monsoon (ISM) variability record from an 87-cm long stalagmite (KM-1) from Krem Mawmluh in the Khasi Hills, Meghalaya. The absolute dated stalagmite record ranges from 22.7 (LGM) to 6.7 ka (Mid Holocene), revealing last glacial-interglacial paleoclimatic changes over the Indian sub-continent. A sharp change in δ18O ( 5‰) and growth rate post Younger Dryas (YD) is marked by continued rapid speleogenesis in KM-1 and coincides with monsoon intensification during the early Holocene. Prominent multi-centennial to millennial scale dry phases in ISM activity are observed from LGM to YD. During early to mid-Holocene, the record shows significant multi-decadal to centennial scale changes. The high frequency δ18O variations referring to abrupt changes in ISM activity are believed to be driven by changes in temperature and shifting of Inter-Tropical Convergence Zone.

  18. Traces and burrowing behaviors of the Cicada nymph Cicadetta calliope: Neoichnology and paleoecological significance of extant soil-dwelling insects

    Science.gov (United States)

    Smith, J.J.; Hasiotis, S.T.

    2008-01-01

    This study documents the traces and burrowing behaviors of nymphs of the prairie cicada Cicadetta calliope (Hemiptera: Cicadidae), as observed in neoichnological experiments. Cicada nymphs were collected from the C horizons of sandy Fluvents along the Kansas River east of Lawrence, Kansas. The nymphs appeared to be fifth instars, 13-17 mm long and 6-7 mm wide. Nymphs were placed in plastic enclosures containing layers of colored, moist, very fine-grained sand. They burrowed immediately, excavating air-filled, sediment-enclosed cells between 20 mm and 40 mm long and averaging 9 mm wide. Burrowing was completed in three stages: (1) sediment in the forward portion of the cell was excavated and rolled into a ball with the forelimbs; (2) the nymph turned 180?? using a forward roll, and moved to the back of the cell; and (3) the sediment ball was pushed up against the back wall of the cell and kneaded with the forelimbs into a thin layer. Resulting burrow traces are sinuous and distinctly meniscate and demonstrate that insect larvae construct meniscate, backfilled burrows in well-drained terrestrial settings. Cicadetta calliope nymphs and their traces are excellent analogs for meniscate trace fossils commonly found in late Paleozoic-Cenozoic alluvial deposits and paleosols. Such meniscate trace fossils are useful for interpreting the paleoenvironment and paleohydrogeology of the units in which they are found. In addition, such backfilled burrows can be used to supplement the fossil record of cicada-like hemipterans, currently known only from the latest Permian to the Early Triassic. Copyright ?? 2008, SEPM (Society for Sedimentary Geology).

  19. Vegetation history since the last glacial maximum in the Ozark highlands (USA): A new record from Cupola Pond, Missouri

    Science.gov (United States)

    Jones, Rachel A.; Williams, John W.; Jackson, Stephen T.

    2017-01-01

    The timing and drivers of vegetation dynamics and formation of no-analog plant communities during the last deglaciation in the unglaciated southeastern US are poorly understood. We present a multi-proxy record spanning the past 19,800 years from Cupola Pond in the Ozarks Mountains, consisting of replicate high-resolution pollen records, 25 AMS radiocarbon dates, and macrofossil, charcoal, and coprophilous spore analyses. Full-glacial Pinus and Picea forests gave way to no-analog vegetation after 17,400 yr BP, followed by development of Quercus-dominated Holocene forests, with late Holocene rises in Pinus and Nyssa. Vegetation transitions, replicated in different cores, are closely linked to hemispheric climate events. Rising Quercus abundances coincide with increasing Northern Hemisphere temperatures and CO2 at 17,500 yr BP, declining Pinus and Picea at 14,500 yr BP are near the Bølling-Allerød onset, and rapid decline of Fraxinus and rise of Ostrya/Carpinus occur 12,700 yr BP during the Younger Dryas. The Cupola no-analog vegetation record is unusual for its early initiation (17,000 yr BP) and for its three vegetation zones, representing distinct rises of Fraxinus and Ostrya/Carpinus. Sporormiella was absent and sedimentary charcoal abundances were low throughout, suggesting that fire and megaherbivores were not locally important agents of disturbance and turnover. The Cupola record thus highlights the complexity of the late-glacial no-analog communities and suggests direct climatic regulation of their formation and disassembly.

  20. Vegetation history since the last glacial maximum in the Ozark highlands (USA): A new record from Cupola Pond, Missouri

    Science.gov (United States)

    Jones, Rachel A.; Williams, John W.; Jackson, Stephen T.

    2017-08-01

    The timing and drivers of vegetation dynamics and formation of no-analog plant communities during the last deglaciation in the unglaciated southeastern US are poorly understood. We present a multi-proxy record spanning the past 19,800 years from Cupola Pond in the Ozarks Mountains, consisting of replicate high-resolution pollen records, 25 AMS radiocarbon dates, and macrofossil, charcoal, and coprophilous spore analyses. Full-glacial Pinus and Picea forests gave way to no-analog vegetation after 17,400 yr BP, followed by development of Quercus-dominated Holocene forests, with late Holocene rises in Pinus and Nyssa. Vegetation transitions, replicated in different cores, are closely linked to hemispheric climate events. Rising Quercus abundances coincide with increasing Northern Hemisphere temperatures and CO2 at 17,500 yr BP, declining Pinus and Picea at 14,500 yr BP are near the Bølling-Allerød onset, and rapid decline of Fraxinus and rise of Ostrya/Carpinus occur 12,700 yr BP during the Younger Dryas. The Cupola no-analog vegetation record is unusual for its early initiation (17,000 yr BP) and for its three vegetation zones, representing distinct rises of Fraxinus and Ostrya/Carpinus. Sporormiella was absent and sedimentary charcoal abundances were low throughout, suggesting that fire and megaherbivores were not locally important agents of disturbance and turnover. The Cupola record thus highlights the complexity of the late-glacial no-analog communities and suggests direct climatic regulation of their formation and disassembly.

  1. Incorporation of microplastics from litter into burrows of Lumbricus terrestris.

    Science.gov (United States)

    Huerta Lwanga, Esperanza; Gertsen, Hennie; Gooren, Harm; Peters, Piet; Salánki, Tamás; van der Ploeg, Martine; Besseling, Ellen; Koelmans, Albert A; Geissen, Violette

    2017-01-01

    Pollution caused by plastic debris is an urgent environmental problem. Here, we assessed the effects of microplastics in the soil surface litter on the formation and characterization of burrows built by the anecic earthworm Lumbricus terrestris in soil and quantified the amount of microplastics that was transported and deposited in L. terrestris burrows. Worms were exposed to soil surface litter treatments containing microplastics (Low Density Polyethylene) for 2 weeks at concentrations of 0%, 7%, 28%, 45% and 60%. The latter representing environmentally realistic concentrations found in hot spot soil locations. There were significantly more burrows found when soil was exposed to the surface treatment composed of 7% microplastics than in all other treatments. The highest amount of organic matter in the walls of the burrows was observed after using the treatments containing 28 and 45% microplastics. The highest microplastic bioturbation efficiency ratio (total microplastics (mg) in burrow walls/initial total surface litter microplastics (mg)) was found using the concentration of 7% microplastics, where L. terrestris introduced 73.5% of the surface microplastics into the burrow walls. The highest burrow wall microplastic content per unit weight of soil (11.8 ± 4.8 g kg- 1 ) was found using a concentration of 60% microplastics. L. terrestris was responsible for size-selective downward transport when exposed to concentrations of 7, 28 and 45% microplastics in the surface litter, as the fraction ≤50 μm microplastics in burrow walls increased by 65% compared to this fraction in the original surface litter plastic. We conclude that the high biogenic incorporation rate of the small-fraction microplastics from surface litter into burrow walls causes a risk of leaching through preferential flow into groundwater bodies. Furthermore, this leaching may have implications for the subsequent availability of microplastics to terrestrial organisms or for the transport

  2. The burrowing characteristics of three common earthworm species

    International Nuclear Information System (INIS)

    Francis, G.S.; Tabley, F.J.; Butler, R.C.; Fraser, P.M.

    2001-01-01

    The burrowing characteristics of 3 common earthworm species were studied using X-ray computed tomography (CT) scanning in large cylinders (24.1 cm diameter) packed with topsoil (0-25 cm) and subsoil (25-50 cm) to representative field bulk density values and sown with ryegrass. Replicated cylinders (n 3), kept under constant moisture and temperature conditions, were inoculated with mature species of Lumbricus rubellus, Aporrectodea caliginosa, or Octolasion cyaneum earthworms at rates similar to their population density in the field. A non-inoculated, unreplicated control was also included. The number, biomass, and activity of the 3 species were then examined. X-ray CT scanning of large-diameter soil cylinders offers an alternative method for obtaining information on the burrowing characteristics of earthworms (Jegou et al. 1999). As this method is non-destructive, repeat measurements can be made and the use of large cylinders minimises edge effects. The objectives of this study were to: (i) assess the burrowing characteristics of 3 earthworm species (under artificial conditions) through measurement of 2-D porosity using X-ray CT scanning, (ii) estimate the extent of burrow backfilling between sequential scans, and (iii) estimate the continuity of earthworm burrows with depth through hydraulic conductivity measurements. Copyright (2001) CSIRO Publishing

  3. Plant cover effect on Bolson tortoise (Gopherus flavomarginatus Legler 1959, Testudinidae burrow use

    Directory of Open Access Journals (Sweden)

    Jorge Luis Becerra-López

    2017-03-01

    Full Text Available The Bolson tortoise, Gopherus flavomarginatus, occurs within a restricted geographical area in the Mexican Chihuahuan Desert. We analyzed the variation in surface microhabitat with relation to the burrow occupancy for this tortoise at the Mapimí Biosphere Reserve, Mexico. In summer 2010, we monitored burrow activity (active, inactive, or abandoned and measured environmental factors that might influence the burrow’s occupancy by tortoises (air temperature, relative humidity and substrate temperature, both inside and outside the burrow, and the plant cover around it. Discriminant analysis was used to identify the importance of these variables influencing burrow occupancy. Correlation and linear regression analyses were performed to quantify the relation between environmental factors in the sampled burrows. Results. Sixty-one burrows were identified at the Tortugas locality. The first function’s auto-value analysis indicates that this function explains 97.9% of the variation in burrow activity status; high occupancy scores were associated with low substrate temperature inside the burrow. Plant cover was inversely proportional to substrate temperature inside the burrow. These results suggest the importance the density of plants surrounding the tortoise’s burrow as a key factor influencing the burrow microclimate and occupancy by the tortoises. Conclusions. Gopherus flavomarginatus inhabits burrows, in part, based on microhabitat structure, with plant cover being a main factor influencing burrow occupancy. Our findings indicate that human land use and vegetation management are important for conserving Bolson tortoises, and for understanding habitat conditions necessary for the successful establishment of populations elsewhere.

  4. Exposure of burrowing mammals to {sup 222}Rn

    Energy Technology Data Exchange (ETDEWEB)

    Beresford, N.A., E-mail: nab@ceh.ac.uk [NERC Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Av. Bailrigg, Lancaster LA1 4AP (United Kingdom); Barnett, C.L. [NERC Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Av. Bailrigg, Lancaster LA1 4AP (United Kingdom); Vives i Batlle, J. [Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, 2400 Mol (Belgium); Potter, E.D. [NERC Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Av. Bailrigg, Lancaster LA1 4AP (United Kingdom); Ibrahimi, Z.-F. [Health Protection Agency, Centre for Radiation, Chemical and Environmental Hazards, Chilton, Didcot OX11 0RQ (United Kingdom); Barlow, T.S.; Schieb, C.; Jones, D.G. [British Geological Survey, Environmental Science Centre, Keyworth, Nottingham NG12 5GG (United Kingdom); Copplestone, D. [School of Natural Sciences, University of Stirling, Stirling FK9 4LA (United Kingdom)

    2012-08-01

    Estimates of absorbed dose rates to wildlife from exposure to natural background radionuclides are required to put estimates of dose rates arising from regulated releases of radioactivity and proposed benchmarks into context. Recent review papers have estimated dose rates to wildlife from {sup 40}K, and {sup 238}U and {sup 232}Th series radionuclides. However, only one study previous has considered the potential dose rates to burrowing animals from inhaled {sup 222}Rn and its daughter products. In this paper we describe a study conducted at seven sites in northwest England. Passive track etch detectors were used to measure the {sup 222}Rn concentrations in artificial burrows over a period of approximately one year. Results suggest that absorbed dose rates to burrowing mammals as a consequence of exposure to {sup 222}Rn are likely to be at least an order of magnitude higher than those suggested in previous evaluations of natural background exposure rates which had omitted this radionuclide and exposure pathway. Dose rates in some areas of Great Britain will be considerably in excess of incremental no-effects benchmark dose rates suggested for use as screening levels. Such advised benchmark dose rates need to be better put into context with background dose rates, including exposure to {sup 222}Rn, to ensure credibility; although the context will be determined by the purpose of the benchmark and the assessment level. - Highlights: Black-Right-Pointing-Pointer Determined {sup 222}Rn concentrations in artificial burrows. Black-Right-Pointing-Pointer Estimated dose rates to burrowing mammals from inhaled {sup 222}Rn and daughter products. Black-Right-Pointing-Pointer {sup 222}Rn likely to dominate exposure of burrowing mammals due to natural radionuclides.

  5. Hydroclimate of the Last Glacial Maximum and deglaciation in southern Australia's arid margin interpreted from speleothem records (23–15 ka

    Directory of Open Access Journals (Sweden)

    P. C. Treble

    2017-06-01

    Full Text Available Terrestrial data spanning the Last Glacial Maximum (LGM and deglaciation from the southern Australian region are sparse and limited to discontinuous sedimentological and geomorphological records with relatively large chronological uncertainties. This dearth of records has hindered a critical assessment of the role of the Southern Hemisphere mid-latitude westerly winds on the region's climate during this time period. In this study, two precisely dated speleothem records for Mairs Cave, Flinders Ranges, are presented, providing for the first time a detailed terrestrial hydroclimatic record for the southern Australian drylands during 23–15 ka. Recharge to Mairs Cave is interpreted from the speleothem record by the activation of growth, physical flood layering, and δ18O and δ13C minima. Periods of lowered recharge are indicated by 18O and 13C enrichment, primarily affecting δ18O, argued to be driven by evaporation of shallow soil/epikarst water in this water-limited environment. A hydrological driver is supported by calcite fabric changes. These include the presence of laminae, visible organic colloids, and occasional dissolution features, related to recharge, as well as the presence of sediment bands representing cave floor flooding. A shift to slower-growing, more compact calcite and an absence of lamination is interpreted to represent reduced recharge. The Mairs Cave record indicates that the Flinders Ranges were relatively wet during the LGM and early deglaciation, particularly over the interval 18.9–15.8 ka. This wetter phase ended abruptly with a shift to drier conditions at 15.8 ka. These findings are in agreement with the geomorphic archives for this region, as well as the timing of events in records from the broader Australasian region. The recharge phases identified in the Mairs Cave record are correlated with, but antiphase to, the position of the westerly winds interpreted from marine core MD03-2611, located 550 km south

  6. Modeling seasonal detection patterns for burrowing owl surveys

    Science.gov (United States)

    Quresh S. Latif; Kathleen D. Fleming; Cameron Barrows; John T. Rotenberry

    2012-01-01

    To guide monitoring of burrowing owls (Athene cunicularia) in the Coachella Valley, California, USA, we analyzed survey-method-specific seasonal variation in detectability. Point-based call-broadcast surveys yielded high early season detectability that then declined through time, whereas detectability on driving surveys increased through the season. Point surveys...

  7. Incorporation of microplastics from litter into burrows of Lumbricus terrestris

    NARCIS (Netherlands)

    Huerta Lwanga, Esperanza; Gertsen, H.F.; Gooren, H.; Peters, P.; Salanki, T.E.; Ploeg, van der M.; Besseling, E.; Koelmans, A.A.; Geissen, V.

    2017-01-01

    Pollution caused by plastic debris is an urgent environmental problem. Here, we assessed the effects of microplastics in the soil surface litter on the formation and characterization of burrows built by the anecic earthworm Lumbricus terrestris in soil and quantified the amount of microplastics that

  8. Daily and seasonal temperatures in the burrows of African rodent ...

    African Journals Online (AJOL)

    1987-03-02

    Mar 2, 1987 ... temperature extremes, containing a nest and a bolt-hole. (Jarvis & Sale 1971; Davies & Jarvis 1986; Lovegrove &. Painting 1987). In the burrow systems of Cryptomys damarensis we have found nests as deep as 2,5 m below ground. Dissimilarities in ..... The live-trap in which it was confined was shaded ...

  9. Protozoal hepatitis in a western burrowing owl (Athene cunicularia hypugaea)

    Science.gov (United States)

    Franson, J. Christian

    2017-01-01

    A western burrowing owl (Athene cunicularia hypugaea) found dead in southern California had many light-colored lesions visible grossly on its liver, and histopathology revealed extensive necrosis throughout the hepatic parenchyma. Single-celled organisms were seen in clear spaces within the areas of necrosis. The owl was diagnosed with protozoal hepatitis.

  10. Oxygen penetration around burrows and roots in aquatic sediments

    DEFF Research Database (Denmark)

    Meysman, Filip J.R.; Galaktionov, O.S.; Glud, Ronnie N.

    2010-01-01

    Diffusion is the dominant physical mechanism for the transfer of oxygen into fine-grained aquatic sediments. This diffusive uptake occurs at the sediment-water interface, but also at internal interfaces, such as along ventilated burrows or O2 releasing plant roots. Here, we present a systematic...

  11. An example of burrow system architecture of dispersing Damaraland ...

    African Journals Online (AJOL)

    The Damaraland mole-rat (Fukomys damarensis) is a social, subterranean rodent that occurs in the red Kalahari sands. This species exhibits extreme reproductive skew with a single breeding female whereas reproduction in subordinate group members is completely blocked. Rainfall, as it greatly facilitates burrowing, ...

  12. Seasonal effects on digging activity and burrow architecture in the ...

    African Journals Online (AJOL)

    Most polygynous male mammals exhibit little or no parental care or involvement raising young. Instead, they invest indirectly in their own morphological and physiological attributes which enhance their chance of reproduction. Such secondary morphological sex traits may contribute to differences in the burrow architecture ...

  13. Shrimp burrow in tropical seagrass meadows: An important sink for litter

    Science.gov (United States)

    Vonk, Jan Arie; Kneer, Dominik; Stapel, Johan; Asmus, Harald

    2008-08-01

    The abundance, burrow characteristics, and in situ behaviour of the burrowing shrimps Neaxius acanthus (Decapoda: Strahlaxiidae) and Alpheus macellarius (Decapoda: Alpheidae) were studied to quantify the collection of seagrass material, to identify the fate of this collected material, and to determine the importance of these burrowing crustaceans in the nutrient (nitrogen and phosphorus) cycling of two tropical seagrass meadows on Bone Batang, South Sulawesi, Indonesia. Alpheus macellarius harvested 0.70 g dry weight (DW) burrow -1 d -1 seagrass material, dominantly by active cutting of fresh seagrass leaves. Neaxius acanthus collected 1.66 g DW burrow -1 d -1, mainly detached leaves which floated past the burrow opening. The A. macellarius and N. acanthus communities together collected in their burrows an amount of seagrass leaf material corresponding to more than 50% of the leaf production in the meadows studied. The crustacean species studied might therefore fulfil an important function in the nutrient cycling of tropical meadows. In the burrow most of the collected material is shredded into pieces. The burrows of both species had special chambers which serve as a storage for seagrass leaf material. Neaxius acanthus incorporated most of the material into the burrow wall lining, which is made of small sediment particles and macerated seagrass leaves. Phosphate concentrations measured in N. acanthus burrows compared with pore-water and water-column concentrations suggests that a substantial amount of the seagrass material undergoes decomposition in the burrows. Oxygen levels measured in these water bodies are indicative for a possible exchange of water between the burrow and its surroundings, most likely supported by the shrimps irrigating their burrows. By collecting leaf material in their burrows, nutrients that are otherwise lost from the seagrass meadow associated with detached leaves and leaf fragments carried away in the water column, are maintained in the

  14. Estimating population size of a nocturnal burrow-nesting seabird using acoustic monitoring and habitat mapping

    Directory of Open Access Journals (Sweden)

    Steffen Oppel

    2014-04-01

    Full Text Available Population size assessments for nocturnal burrow-nesting seabirds are logistically challenging because these species are active in colonies only during darkness and often nest on remote islands where manual inspections of breeding burrows are not feasible. Many seabird species are highly vocal, and recent technological innovations now make it possible to record and quantify vocal activity in seabird colonies. Here we test the hypothesis that remotely recorded vocal activity in Cory’s shearwater (Calonectris borealis breeding colonies in the North Atlantic increases with nest density, and combined this relationship with cliff habitat mapping to estimate the population size of Cory’s shearwaters on the island of Corvo (Azores. We deployed acoustic recording devices in 9 Cory’s shearwater colonies of known size to establish a relationship between vocal activity and local nest density (slope = 1.07, R2 = 0.86, p < 0.001. We used this relationship to predict the nest density in various cliff habitat types and produced a habitat map of breeding cliffs to extrapolate nest density around the island of Corvo. The mean predicted nest density on Corvo ranged from 6.6 (2.1–16.2 to 27.8 (19.5–36.4 nests/ha. Extrapolation of habitat-specific nest densities across the cliff area of Corvo resulted in an estimate of 6326 Cory’s shearwater nests (95% confidence interval: 3735–10,524. This population size estimate is similar to previous assessments, but is too imprecise to detect moderate changes in population size over time. While estimating absolute population size from acoustic recordings may not be sufficiently precise, the strong positive relationship that we found between local nest density and recorded calling rate indicates that passive acoustic monitoring may be useful to document relative changes in seabird populations over time.

  15. Origin of tropical American burrowing reptiles by transatlantic rafting.

    Science.gov (United States)

    Vidal, Nicolas; Azvolinsky, Anna; Cruaud, Corinne; Hedges, S Blair

    2008-02-23

    Populations of terrestrial or freshwater taxa that are separated by oceans can be explained by either oceanic dispersal or fragmentation of a previously contiguous land mass. Amphisbaenians, the worm lizards (approx. 165 species), are small squamate reptiles that are uniquely adapted to a burrowing lifestyle and inhabit Africa, South America, Caribbean Islands, North America, Europe and the Middle East. All but a few species are limbless and they rarely leave their subterranean burrows. Given their peculiar habits, the distribution of amphisbaenians has been assumed to be primarily the result of two land-mass fragmentation events: the split of the supercontinent Pangaea starting 200 Myr ago, separating species on the northern land mass (Laurasia) from those on the southern land mass (Gondwana), and the split of South America from Africa 100 Myr ago. Here we show with molecular evidence that oceanic dispersal-on floating islands-played a more prominent role, and that amphisbaenians crossed the Atlantic Ocean in the Eocene (40 Myr ago) resulting in a tropical American radiation representing one-half of all known amphisbaenian species. Until now, only four or five transatlantic dispersal events were known in terrestrial vertebrates. Significantly, this is the first such dispersal event to involve a group that burrows, an unexpected lifestyle for an oceanic disperser.

  16. Does petroleum development affect burrowing owl nocturnal space-use?

    Energy Technology Data Exchange (ETDEWEB)

    Scobie, Corey; Wellicome, Troy; Bayne, Erin [Department of Biological Sciences, University of Alberta (Canada)], email: cscobie@ualberta.ca, email: tiw@ualberta.ca, email: bayne@ualberta.ca

    2011-07-01

    Decline all over Canada in the population of burrowing owls, a federally listed endangered species, has raised concerns about the possible influence of petroleum infrastructure development on owl nocturnal space-use while foraging. Roads, wells, pipelines and sound-producing facilities related to petroleum development change the landscape and can influence the owls' mortality risk. For 3 years, 27 breeding adult male burrowing owls with nests close to different petroleum infrastructures were captured and fitted with a miniature GPS datalogger in order to track their nocturnal foraging. Data from these GPS devices were fed into a geographical information system and showed that pipelines and wells did not alter the foraging habits of the owls. Dirt and gravel roads, with little traffic, were preferentially selected by the owls, conceivably because of higher owl mortality risk along paved roads. Sound-producing facilities did not change owls' foraging behaviour, implying that sound may not affect their nocturnal space-use. Traffic data and sound power measurements will be used in further studies in an effort to better understand burrowing owls' nocturnal foraging habits.

  17. Artificial Crab Burrows Facilitate Desalting of Rooted Mangrove Sediment in a Microcosm Study

    Directory of Open Access Journals (Sweden)

    Nathalie Pülmanns

    2015-07-01

    Full Text Available Water uptake by mangrove trees can result in salt accumulation in sediment around roots, negatively influencing growth. Tidal pumping facilitates salt release and can be enhanced by crab burrows. Similarly, flushing of burrows by incoming tidal water decreases sediment salinity. In contrast to burrows with multiple entrances, the role of burrows with one opening for salinity reduction is largely unknown. In a microcosm experiment we studied the effect of artificial, burrow-like macro-pores with one opening on the desalting of mangrove sediment and growth of Rhizophora mangle L. seedlings. Sediment salinity, seedling leaf area and seedling growth were monitored over six months. Artificial burrows facilitated salt release from the sediment after six weeks, but seedling growth was not influenced. To test whether crab burrows with one opening facilitate salt release in mangrove forests, sediment salinities were measured in areas with and without R. mangle stilt roots in North Brazil at the beginning and end of the wet season. In addition, burrows of Ucides cordatus were counted. High crab burrow densities and sediment salinities were associated with stilt root occurrence. Precipitation and salt accumulation by tree roots seem to have a larger effect on sediment salinity than desalting by U. cordatus burrows.

  18. Rodent burrows in late Pleistocene paleosols at Korean Palaeolithic sites and their implications for paleoclimate changes

    Science.gov (United States)

    Lim, H.; Park, S.; Lee, J.; Lee, Y.

    2013-12-01

    Rodent burrows are commonly found at many Paleolithic archaeological sites in Korea. They are nearly straight in horizontal view and gently inclined in lateral view. Burrow diameters are mostly 7 - 10cm, and burrow length may reach a few meters. Vertical penetration depths are generally about 1 m from the surface, and the thickness of the burrow-bearing layer is about 1-2 m. Although no remains (bones, teeth, claws, and coprolites) were found within burrows, they are interpreted to have been produced by rodent-like mammals (probably ground squirrels) based on the size and architecture. According to the previous study, the age of these burrows was constrained to be between ca. 40,000 and 25,000 yr BP by tephrochronology, radiocarbon and optically stimulated luminescence dating results (Lim et al., 2007). However, little is known about the reason why these burrows have disappeared after late Pleistocene time. For this question, two explanations can be considered: extinction or migration. Since same kinds of burrows are still found in the high-latitude regions, such as Mongolia and North America, the possibility of extinction can be ruled out. Therefore, migration seems to be the most likely explanation. Our results show that the destruction of habitat caused by climate change during this period is the main reason for the northward migration of burrowing animals. This study suggests that rodent burrows found in the late Pleistocene paleosols can provide useful information on paleoclimate and paleoenvironmental changes.

  19. Subsurface Sampling and Sensing Using Burrowing Moles

    Science.gov (United States)

    Stoker, C. R.; Richter, L.; Smith, W. H.

    2004-01-01

    , light sources, and control electronics for the instrument are on the surface. The DSS sensor is capable of sensing a wide range of minerals relevant to Mars Astrobiology objectives including hydrated minerals, clays, carbonates, sulfates, and ice. Additionally, Raman spectroscopy is effective for detecting organics. The MUM is designed to achieve a maximum depth of penetration of 5 m in Mars regolith and can be repeatedly deployed and retrieved. The ability to perform repeated sampling, combined with the low mass and power requirements, means that Moles could be incorporated into a rover mission as well as used on a stationary platform. The Mole mechanism is a pointed slender cylinder that advances into soil by way of an internal sliding hammer mechanism. Part of the energy released by the spring-loaded hammer with each shock is transferred to the Mole casing and from there to the soil, resulting in penetration by displacing and compressing the surrounding soil. A backwards-directed impulse as a re- action to each forward shock is transferred via a suppressor mass against a second weaker spring allowing forward motion without requiring reactive forces provided by the lander. The Mole tip can be opened to collect soil samples. The Mole casing is tethered to a supporting mechanism that supplies power. Components supporting the Mole on the surface include a launch tube, tether reel and winch for pulling in tether, in addition to the tether itself.

  20. Artificially evolved functional shell morphology of burrowing bivalves

    DEFF Research Database (Denmark)

    Germann, D. P.; Schatz, W.; Hotz, Peter Eggenberger

    2014-01-01

    dimensional (3D) objects, the first ever artificial evolution of a physical bivalve shell was performed. The result was a vertically flattened shell occupying only the top sediment layers. Insufficient control of the sediment was the major limitation of the setup and restricted the significance of the results......, there are almost no studies experimentally testing their dynamic properties. To investigate the functional morphology of the bivalve shell, we employed a synthetic methodology and built an experimental setup to simulate the burrowing process. Using an evolutionary algorithm and a printer that prints three...

  1. The vibrational signals that male fiddler crabs ( Uca lactea) use to attract females into their burrows

    Science.gov (United States)

    Takeshita, Fumio; Murai, Minoru

    2016-06-01

    In some fiddler crab species, males emit vibrations from their burrows to mate-searching females after they have attracted a female to the burrow entrance using a waving display. Although the vibrations are considered acoustic signals to induce mating, it has not been demonstrated whether the vibrations attract the females into the burrow and, consequently, influence females' mating decisions. We investigated the structures and patterns of the vibrations using a dummy female and demonstrated experimentally a female preference for male vibrations in Uca lactea in the field. The acoustic signals consisted of repetitions of pulses. The dominant frequency of the pulses decreased with male carapace width. The pulse length decreased slightly with an increasing number of vibrational repetitions, and the pulse interval increased with increasing repetitions. These factors imply that the vibrations convey information on male characteristics, such as body size and stamina. In the experiment on female mate choice, the females significantly preferred males with higher pulse repetition rates when they were positioned at the entrance of the burrow, indicating that the females use the male vibrational signals to decide whether to enter the burrow. However, females showed no preference for the vibrations once they were inside a burrow, i.e., whether they decided to copulate, suggesting that the vibrations do not independently affect a female's final decision of mate choice. The vibrations inside the burrow might influence a female's decision by interaction with other male traits such as the burrow structure.

  2. Sand moisture as a factor determining depth of burrowing in the ...

    African Journals Online (AJOL)

    Tylos granulatus, a sandy-beach isopod, prefers an environmental moisture range exceeding 3,4% but less than 13%. The depths to which the animals burrow are, at least partly, determined by the moisture gradient in the sand. They are, however, incapable of burrowing into lotally dry sand. Animals alter their position in ...

  3. COMPARISON OF CARBON AND NITROGEN FLUXES IN TIDEFLAT FOOD WEBS DOMINATED BY BURROWING SHRIMP OR BY CULTURED OYSTERS

    Science.gov (United States)

    Two species of indigenous, thalassinid burrowing shrimps are pests to the benthic culture of Pacific oysters (Crassostrea gigas) because deposition of sediment excavated by the shrimps buries or smothers the oysters. Carbaryl pesticide is used to reduce burrowing shrimp densitie...

  4. Burrowing behavior as an indicator of post-laparotomy pain in mice

    Directory of Open Access Journals (Sweden)

    Paulin Jirkof

    2010-10-01

    Full Text Available Detection of persistent pain of a mild-to-moderate degree in laboratory mice is difficult because mice do not show unambiguous symptoms of pain or suffering using standard methods of short-term observational or clinical monitoring. This study investigated the potential use of burrowing performance — a spontaneous and highly motivated behavior — as a measure of post-operative pain in laboratory mice. The influence of minor surgery on burrowing was investigated in adult C57BL/6J mice of both genders in a modified rodent burrowing test (displacement of food pellets from a pellet-filled tube within the animal’s home cage. Almost all (98% healthy mice burrowed (mean latency 1.3 h, SEM 0.5 h. After surgery without pain treatment, latency of burrowing was significantly prolonged (mean ∆ latency 10 h. Analgesic treatment using the anti-inflammatory drug carprofen (5 mg/kg bodyweight decreased latency of burrowing after surgery (mean ∆ latency 5.5 h to the level found in mice that had been anaesthetised (mean ∆ latency 5.3 h or had received anaesthesia and analgesia (mean ∆ latency 4.6 h. Analgesia during surgery was associated with a significantly earlier onset of burrowing compared to surgery without pain treatment. A distinct gradation in burrowing performance was found ranging from the undisturbed pre-operative status to the intermediate level following anaesthesia/analgesia and surgery with analgesia, to the pronounced prolongation of latency to burrow after surgery without pain relief. In conclusion, post-surgical impairment of general condition, probably mainly attributable to pain, can be conveniently assessed in laboratory mice on the basis of the burrowing test.

  5. Pre-Migratory Movements by Juvenile Burrowing Owls in a Patchy Landscape

    Directory of Open Access Journals (Sweden)

    L. Danielle. Todd

    2007-12-01

    Full Text Available Dispersal is a fundamental aspect of population dynamics, and can have direct implications on processes such as the colonization of habitat patches. Pre-migratory movements, landscape fragmentation, and body condition have all been hypothesized as key factors influencing dispersal in birds, but little direct evidence exists to support these ideas. We used radio-telemetry and supplementary feeding to test if body condition or landscape pattern influenced pre-migratory movements of juvenile Burrowing Owls (Athene cunicularia in a fragmented landscape. We categorized grassland patches as either large (≥95 ha or small and isolated (≤58 ha and ≥1.5 km to next nearest grassland patch, and young owls were either provided supplemental food as nestlings or not. Owlets receiving supplemental food and residing in large grassland patches moved a greater maximum distance from their nest than similarly fed owlets residing in small patches (large = 1605 ± 443 m; small = 373 ± 148 m. In contrast, non-supplemented owlets from large and small patches did not differ in their maximum distance moved from the nest (large = 745 ± 307 m; small 555 ± 286 m. Only two of 32 individuals from small patches moved >800 m, whereas ten of 23 owlets from large patches moved >800 m. In addition, owlets from large patches continued to move farther and farther from their nest before migration, whereas owlets in small, isolated patches ultimately moved

  6. Population structure of the burrowing crab Neohelice granulata (Brachyura, Varunidae in a southwestern Atlantic salt marsh

    Directory of Open Access Journals (Sweden)

    Sabrina Angeletti

    2015-07-01

    Full Text Available Neohelice granulata inhabits estuarine and protected coastal areas in temperate regions and is the most dominant decapod crustacean in the Bahía Blanca Estuary, Argentina. The population structure was studied during a year in a SW Atlantic salt marsh located in the Bahía Blanca Estuary. Crabs were sampled monthly from August 2010 to July 2011. The maximum observed density was 30 crabs m-2 in February and 70 burrows m-2 in May. The maximum carapace width (CW was 32 and 27.5 mm in males and females respectively. Medium size crabs were between 16 and 20 mm CW. Significantly smaller sized crabs were observed at the lower intertidal regions (P < 0.05. The sex ratio was favorable for males and was significantly different from the expected 1:1 (P < 0.05. The recruitment of unsexed juveniles crabs (CW <6.5 mm was observed throughout the year and the presence of ovigerous females from October to February indicated seasonal reproduction. The average size of ovigerous females was CW = 20.8 mm and the smallest ovigerous female measured was 16 mm CW. For the first time, the population structure of the most important macro-invertebrate is analyzed in the Bahía Blanca Estuary. This study may help to make decisions in the area, where anthropic action is progressing day by day.

  7. Priming effect in topsoil and subsoil induced by earthworm burrows

    Science.gov (United States)

    Thu, Duyen Hoang Thi

    2017-04-01

    Earthworms (Lumbricus terrestris L.) not only affect soil physics, but they also boost microbial activities and consequently important hotspots of microbial mediated carbon and C turnover through their burrowing activity. However, it is still unknown to which extend earthworms affect priming effect in top- and subsoil horizons. More labile C inputs in earthworm burrows were hypothesized to trigger higher priming of soil organic matter (SOM) decomposition compared to rhizosphere and bulk soil. Moreover, this effect was expected to be more pronounced in subsoil due to its greater C and nutrient limitation. To test these hypotheses, biopores and bulk soil were sampled from topsoil (0-30 cm) and two subsoil depths (45-75 and 75-105 cm). Additionally, rhizosphere samples were taken from the topsoil. Total organic C (Corg), total N (TN), total P (TP) and enzyme activities involved in C-, N-, and P-cycling (cellobiohydrolase, β-glucosidase, xylanase, chitinase, leucine aminopeptidase and phosphatase) were measured. Priming effects were calculated as the difference in SOM-derived CO2 from soil with or without 14C-labelled glucose addition. Enzyme activities in biopores were positively correlated with Corg, TN and TP, but in bulk soil this correlation was negative. The more frequent fresh and labile C inputs to biopores caused 4 to 20 time higher absolute priming of SOM turnover due to enzyme activities that were one order of magnitude higher than in bulk soil. In subsoil biopores, reduced labile C inputs and lower N availability stimulated priming twofold greater than in topsoil. In contrast, a positive priming effect in bulk soil was only detected at 75-105 cm depth. We conclude that earthworm burrows provide not only the linkage between top- and subsoil for C and nutrients, but strongly increase microbial activities and accelerate SOM turnover in subsoil, contributing to nutrient mobilization for roots and CO2 emission increase as a greenhouse gas. Additionally, the

  8. Spilled oil and infaunal activity - Modification of burrowing behavior and redistribution of oil

    Science.gov (United States)

    Clifton, H.E.; Kvenvolden, K.A.; Rapp, J.B.

    1984-01-01

    A series of experiments in Willapa Bay, Washington, indicates the degree to which the presence of spilled oil modifies the burrowing behavior of infauna and the extent to which the animals redistribute oil into intertidal sediment. Small amounts of North Slope crude oil introduced at low tide directly into burrow openings (mostly made by the crustacean Callianassa) resulted in a limited and temporary reduction in the number of burrow openings. In contrast, a layer of oil-saturated sand 1 cm thick buried about 5 cm below the sediment surface sharply reduced the number of burrow openings. After a year, the few new burrows penetrated only the margins of the experimental plot, and bioturbation below the buried oil-saturated sand layer declined dramatically. The experiments suggest that small amounts of oil temporarily stranded by tides in themselves have no long-range effect on burrowing behavior. The fauna, however, are capable of introducing measurable amounts of oil into the subsurface, where it is retained long after the rest of the stranded oil had washed away. A buried layer of oil-saturated sand greatly reduces infaunal activity; the oil presents an effective barrier that can persist for years. The oil incorporated into the sediment from burrow openings showed evidence of degradation after 7 months. In contrast the layer of buried oil remained essentially undergraded after a period of two years, even though oil in lower concentrations above the layer was degraded after a period of one year. This variation in degree of degradation of the buried oil, as well as the heterogeneity of oil distribution wherever the oil has been incorporated from the surface, emphasises the importance of careful sampling in any attempt to locate or monitor the presence of spilled oil in the substrate.In a series of experiments in Willapa Bay, Washington, small amounts of North Slope crude oil introduced at low tide directly into burrow openings resulted in a limited and temporary

  9. The influence of small mammal burrowing activity on water storage at the Hanford Site

    International Nuclear Information System (INIS)

    Landeen, D.S.

    1994-09-01

    The amount and rate at which water may penetrate a protective barrier and come into contact with buried radioactive waste is a major concern. Because burrowing animals eventually will reside on the surface of any protective barrier, the effect these burrow systems may have on the loss or retention of water needs to be determined. The first section of this document summarizes the known literature relative to small mammals and the effects that burrowing activities have on water distribution, infiltration, and the overall impact of burrows on the ecosystem. Topics that are summarized include burrow air pressures, airflow, burrow humidity, microtopography, mounding, infiltration, climate, soil evaporation, and discussions of large pores relative to water distribution. The second section of this document provides the results of the study that was conducted at the Hanford Site to determine what effect small mammal burrows have on water storage. This Biointrusion task is identified in the Permanent Isolation Surface Barrier Development Plan in support of protective barriers. This particular animal intrusion task is one part of the overall animal intrusion task identified in Animal Intrusion Test Plan

  10. Burrow characteristics and habitat associations of armadillos in Brazil and the United States of America

    OpenAIRE

    Colleen M. McDonough; Michael J. DeLaney; Phu Quoc Le; Mark S. Blackmore; W. J. Loughry

    2000-01-01

    We censused and measured armadillo burrows in ten 10 m x 40 m plots in each of four habitat types at a study site in northern Florida and one in the Atlantic coastal rainforest of Brazil. The nine-banded armadillo (Dasypus novemcinctus) was the only species of armadillo found in Florida, but several additional species were present in Brazil. Burrows were more numerous but smaller in Brazil than in the U. S., probably due to the inclusion of burrows dug by the smaller congener D. septemcinctus...

  11. Observations on burrowing rates and comments on host specificity in the endangered mussel Lampsilis higginsi

    Science.gov (United States)

    Sylvester, J.R.; Holland, L.E.; Kamer, T.K.

    1984-01-01

    In preliminary laboratory studies, the endangered mussel Lampsilis higginsi was unable to burrow into rocky substrates, but did burrow into substrates comprised of silt, clay, sand, and/or pebble-gravel. Burrowing times were shortest in silt and longest in pebble-gravel. As judged by longevity of glochidial infection, walleye (Stizostedion vitreum) and largemouth bass (Micropterus salmoides) may be suitable hosts for the parasitic stage. When glochidia were placed in water without host fish, half had died after 48 hours, and all had died after 72 hours. (DBO).

  12. Behavioural adaptations to moisture as an environmental constraint in a nocturnal burrow-inhabiting Kalahari detritivore Parastizopus armaticeps Peringuey (Coleoptera: Tenebrionidae

    Directory of Open Access Journals (Sweden)

    O.A.E. Rasa

    1994-08-01

    Full Text Available The nocturnal desert detritivore Parastiz.opus armaticeps shows differences in surface activity patterns and burrow fidelity depending on surface humidity. After rain approximately half of the beetle population, independent of sex, is highly vagile and disperses over long distances. During drought, beetles are more sedentary and show higher burrow fidelity. They also inhabit burrows that are longer and deeper than non-inhabited ones, such burrows being relatively scarce. Burrow fidelity and the adoption of a more sedentary habit during drought are considered strategies to avoid the risks of not locating a suitable burrow before sunrise and subsequent desiccation in shallow burrows.

  13. Genetic characterization of the burrowing shrimp (Neotrypaea californiensis) in Washington and Oregon estuaries

    Science.gov (United States)

    The Ghost shrimp, (Neotrypaea californiensis) are burrowers, which have a wide demographic distribution along the United States Pacific Coast. Our study used genetic analysis to estimate the source populations of larvae recruiting into estuaries to allow a greater understanding ...

  14. Mechanics and Energetics of Excavation by Burrowing Wolf Spiders, Geolycosa spp.

    Science.gov (United States)

    Suter, Robert B.; Stratton, Gail E.; Miller, Patricia R.

    2011-01-01

    Burrowing wolf spiders, Geolycosa sp. (Araneae:Lycosidae), excavate vertical burrows and inhabit them throughout their lives or, in the case of males, until they mature and wander in search of mates. Three species: G. fatifera Kurata, G. missouriensis Banks, and G. rogersi Wallace were studied to understand how and at what expense the burrowing is accomplished. Normal and high-speed videography coupled with scanning electron microscopy revealed (a) that the convex surfaces of the two fangs, together, constitute the digging tool, (b) that boluses of soil are transported to the burrow entrance on the anterior surfaces of the chelicerae held there by the pedipalps, and (c) that each bolus is either incorporated into the growing turret or flung away, propelled by the forelegs. To elucidate the energetics of burrow construction, burrow volumes were calculated and then the costs associated with dislodging, elevating, and throwing the known volumes of soil were measured. A typical Geolycosa burrow, at a volume of 23.6 ± 2.0 ml and a depth of 13.2 ± 0.7 cm, required the removal of 918 boluses each weighing about 34 mg. The aggregate dislodging cost was close to 1.9 Joules in sand/sandy loam and 5.6 J in clayey subsoil, the work against gravity necessary to raise all of the boluses to the surface was about 0.13 J, and the aggregate cost of flinging the boluses was close to 0.014 J. Assuming that the ratio of external work to metabolic cost of external work is between 0.20 and 0.25 in spiders, the real cost of burrow construction would be between 8 J and 29 J, depending primarily on soil type. This is a small but not negligible cost when placed in the context of reproductive effort: a single Geolycosa egg, dozens to hundreds of which are produced in a clutch, contains about 10 J. PMID:21529154

  15. Vegetation change and terrestrial carbon storage in eastern Asia during the Last Glacial Maximum as indicated by a new pollen record from central Taiwan

    Energy Technology Data Exchange (ETDEWEB)

    Liew, P.M.; Kuo, C.M.; Huang, S.Y.; Tseng, M.H. [Geological Department, National Taiwan Univ. 245, Chou-shan Rd., Taipei (Taiwan, Province of China)

    1998-05-01

    Last Glacial Maximum (LGM) carbon storage in eastern Asia is a key issue for understanding the sinks and sources of paleocarbon. Palynological data with good time constraint for the LGM in a peat bog from a site at 650 m above mean sea level in central Taiwan, together with data from low-lying deltaic and basin deposits of Taiwan and South China, increase our understanding about vegetational evolution and possible terrestrial carbon storage in this area and probably eastern Asia. Contrasting to today`s Machilus-Castanopsis forest zone around the peat bog, the vegetation before the LGM was dominated by Alnus, a relatively xerophytic element in Taiwan. An increase in herbs and decrease in spores during the LGM is recognized when compared with Holocene and modern assemblages. A less humid interval dominated by herbs (>50%) occurred between 21 and 15.8 ka. Basin deposits in northern Taiwan and deltaic deposits in central Taiwan show that during the LGM Artemisia, Umbelliferae and Gramineae were the main components contrasting with the Pinus or Cyclobalanopsis-dominant assemblages in the rest of the last glacial. Thus, less humid conditions lasted about 5000 to 6000 years in the LGM even on this very humid island. This may also be true in eastern Asia where a large area of the widely exposed continental shelf may have been occupied by grasslands and the uplands of South China were occupied by less dense coniferous or temperate forests during the LGM in contrast to the modern subtropical forest. This scenario improves our understanding of the terrestrial paleocarbon storage

  16. Vegetation change and terrestrial carbon storage in eastern Asia during the Last Glacial Maximum as indicated by a new pollen record from central Taiwan

    Science.gov (United States)

    Liew, P. M.; Kuo, C. M.; Huang, S. Y.; Tseng, M. H.

    1998-05-01

    Last Glacial Maximum (LGM) carbon storage in eastern Asia is a key issue for understanding the sinks and sources of paleocarbon. Palynological data with good time constraint for the LGM in a peat bog from a site at 650 m above mean sea level in central Taiwan, together with data from low-lying deltaic and basin deposits of Taiwan and South China, increase our understanding about vegetational evolution and possible terrestrial carbon storage in this area and probably eastern Asia. Contrasting to today's Machilus-Castanopsis forest zone around the peat bog, the vegetation before the LGM was dominated by Alnus, a relatively xerophytic element in Taiwan. An increase in herbs and decrease in spores during the LGM is recognized when compared with Holocene and modern assemblages. A less humid interval dominated by herbs (>50%) occurred between 21 and 15.8 ka. Basin deposits in northern Taiwan and deltaic deposits in central Taiwan show that during the LGM Artemisia, Umbelliferae and Gramineae were the main components contrasting with the Pinus or Cyclobalanopsis-dominant assemblages in the rest of the last glacial. Thus, less humid conditions lasted about 5000 to 6000 years in the LGM even on this very humid island. This may also be true in eastern Asia where a large area of the widely exposed continental shelf may have been occupied by grasslands and the uplands of South China were occupied by less dense coniferous or temperate forests during the LGM in contrast to the modern subtropical forest. This scenario improves our understanding of the terrestrial paleocarbon storage.

  17. Burrow characteristics and habitat associations of armadillos in Brazil and the United States of America

    Directory of Open Access Journals (Sweden)

    Colleen M. McDonough

    2000-03-01

    Full Text Available We censused and measured armadillo burrows in ten 10 m x 40 m plots in each of four habitat types at a study site in northern Florida and one in the Atlantic coastal rainforest of Brazil. The nine-banded armadillo (Dasypus novemcinctus was the only species of armadillo found in Florida, but several additional species were present in Brazil. Burrows were more numerous but smaller in Brazil than in the U. S., probably due to the inclusion of burrows dug by the smaller congener D. septemcinctus. In Brazil, burrows were larger and more numerous in swamp and forest habitats than in grassland or disturbed areas, suggesting that D. novemcinctus is found primarily in forests and swamps while D. septemcinctus is located in the other areas. This was supported by data from sightings of live animals. In Florida, burrows were more numerous in hardwood hammocks than in wetlands, fields or upland pine areas, but burrow dimensions did not vary across habitat types. In Florida, armadillos were seen more frequently than expected in hammocks and wetlands and less frequently than expected in fields and upland pine areas. There were also age (juvenile versus adult, sex, and yearly differences in habitat use in Florida. Biomass, abundance, and species diversity of terrestrial invertebrates did not vary significantly between habitat types in Florida, suggesting that habitat associations of armadillos were not influenced by prey availability.

  18. Integration of ice-core, marine and terrestrial records for the Australian Last Glacial Maximum and Termination: a contribution from the OZ INTIMATE group

    Science.gov (United States)

    Turney, C. S. M.; Haberle, S.; Fink, D.; Kershaw, A. P.; Barbetti, M.; Barrows, T. T.; Black, M.; Cohen, T. J.; Corrège, T.; Hesse, P. P.; Hua, Q.; Johnston, R.; Morgan, V.; Moss, P.; Nanson, G.; van Ommen, T.; Rule, S.; Williams, N. J.; Zhao, J.-X.; D'Costa, D.; Feng, Y.-X.; Gagan, M.; Mooney, S.; Xia, Q.

    2006-10-01

    The degree to which Southern Hemisphere climatic changes during the end of the last glacial period and early Holocene (30-8 ka) were influenced or initiated by events occurring in the high latitudes of the Northern Hemisphere is a complex issue. There is conflicting evidence for the degree of hemispheric teleconnection and an unresolved debate as to the principle forcing mechanism(s). The available hypotheses are difficult to test robustly, however, because the few detailed palaeoclimatic records in the Southern Hemisphere are widely dispersed and lack duplication. Here we present climatic and environmental reconstructions from across Australia, a key region of the Southern Hemisphere because of the range of environments it covers and the potentially important role regional atmospheric and oceanic controls play in global climate change. We identify a general scheme of events for the end of the last glacial period and early Holocene but a detailed reconstruction proved problematic. Significant progress in climate quantification and geochronological control is now urgently required to robustly investigate change through this period. Copyright

  19. Population models of burrowing mayfly recolonization in Western Lake Erie

    Science.gov (United States)

    Madenjian, C.P.; Schloesser, D.W.; Krieger, K.A.

    1998-01-01

    Burrowing mayflies, Hexagenia spp. (H. limbata and H. rigida), began recolonizing western Lake Erie during the 1990s. Survey data for mayfly nymph densities indicated that the population experienced exponential growth between 1991 and 1997. To predict the time to full recovery of the mayfly population, we fitted logistic models, ranging in carrying capacity from 600 to 2000 nymphs/m2, to these survey data. Based on the fitted logistic curves, we forecast that the mayfly population in western Lake Erie would achieve full recovery between years 1998 and 2000, depending on the carrying capacity of the western basin. Additionally, we estimated the mortality rate of nymphs in western Lake Erie during 1994 and then applied an age-based matrix model to the mayfly population. The results of the matrix population modeling corroborated the exponential growth model application in that both methods yielded an estimate of the population growth rate, r, in excess of 0.8 yr-1. This was the first evidence that mayfly populations are capable of recolonizing large aquatic ecosystems at rates comparable with those observed in much smaller lentic ecosystems. Our model predictions should prove valuable to managers of power plant facilities along the western basin in planning for mayfly emergences and to managers of the yellow perch (Perca flavescens) fishery in western Lake Erie.

  20. A new macrofaunal limit in the deep biosphere revealed by extreme burrow depths in ancient sediments.

    Science.gov (United States)

    Cobain, S L; Hodgson, D M; Peakall, J; Wignall, P B; Cobain, M R D

    2018-01-10

    Macrofauna is known to inhabit the top few 10s cm of marine sediments, with rare burrows up to two metres below the seabed. Here, we provide evidence from deep-water Permian strata for a previously unrecognised habitat up to at least 8 metres below the sediment-water interface. Infaunal organisms exploited networks of forcibly injected sand below the seabed, forming living traces and reworking sediment. This is the first record that shows sediment injections are responsible for hosting macrofaunal life metres below the contemporaneous seabed. In addition, given the widespread occurrence of thick sandy successions that accumulate in deep-water settings, macrofauna living in the deep biosphere are likely much more prevalent than considered previously. These findings should influence future sampling strategies to better constrain the depth range of infaunal animals living in modern deep-sea sands. One Sentence Summary: The living depth of infaunal macrofauna is shown to reach at least 8 metres in new habitats associated with sand injections.

  1. Burrow architecture, family composition and habitat characteristics of the largest social African mole-rat: the giant mole-rat constructs really giant burrow systems

    Czech Academy of Sciences Publication Activity Database

    Šumbera, R.; Mazoch, V.; Patzenhauerová, Hana; Lövy, M.; Šklíba, J.; Bryja, Josef; Burda, H.

    2012-01-01

    Roč. 57, č. 2 (2012), s. 121-130 ISSN 0001-7051 R&D Projects: GA AV ČR IAA601410802 Institutional research plan: CEZ:AV0Z60930519 Keywords : Fukomys mechowii * subterranean rodent * burrow system * kin structure * Bathyergidae Subject RIV: EG - Zoology Impact factor: 0.949, year: 2012

  2. The burrows of Parastacus defossus (Decapoda: Parastacidae, a fossorial freshwater crayfish from southern Brazil

    Directory of Open Access Journals (Sweden)

    Clarissa K. Noro

    2010-06-01

    Full Text Available Parastacus defossus Faxon, 1898 is a fossorial crayfish species, which constructs its burrows in swampy areas in southeast Uruguay and in the state of Rio Grande do Sul, Brazil. The present field study was carried out in Lami, Porto Alegre, Rio Grande do Sul, Brazil, from May 2003 through August 2005. Environmental measurements (temperature, pH, dissolved oxygen, and water-table depth of the water in the galleries were made monthly. Burrow morphology was analyzed by means of resin and gypsum casts. The spatial distribution and changes in the number and shape of the surface openings over time were observed in a 100 m² area. To estimate the spatial distribution of the openings, the observed distribution was compared with the expected distribution predicted by the Poisson and Negative Binomial frequency-distribution models. The adult population density was estimated by direct observation of burrows and counts in the study area. Inside the burrows of P. defossus, the water temperature ranged between 16.6°C (autumn 2004 and 23°C (spring 2003. The water was hypoxic and slightly acidic, and the dissolved oxygen content was very low (mean 1.43 mg/l (18.2% saturation. The soil with burrows had higher percentages of coarse sand, fine sand, and silt. The spatial distribution of the openings showed a significant fit to the Negative Binomial distribution, indicating that the distribution of the openings is aggregated, as confirmed from the burrow morphology. The galleries are always formed by a central tunnel with multiple branchings that connect the underground water to the soil surface by one or more openings, which can be recognized by the chimneys. From knowledge of the burrow morphology, the population density was estimated to be about 120 individuals/100 m².

  3. Map-Based Repowering and Reorganization of a Wind Resource Area to Minimize Burrowing Owl and Other Bird Fatalities

    Directory of Open Access Journals (Sweden)

    Lee Neher

    2009-10-01

    Full Text Available Wind turbines in the Altamont Pass Wind Resource Area (Alameda/Contra Costa Counties, California, USA generate about 730 GWh of electricity annually, but have been killing thousands of birds each year, including >2,000 raptors and hundreds of burrowing owls. We have developed collision hazard maps and hazard ratings of wind turbines to guide relocation of existing wind turbines and careful repowering to modern turbines to reduce burrowing owl fatalities principally, and other birds secondarily. Burrowing owls selected burrow sites lower on slopes and on smaller, shallower slopes than represented by the average 10 × 10 m2 grid cell among 187,908 grid cells sampled from 2,281,169 grid cells comprising a digital elevation model (DEM of the study area. Fuzzy logic and discriminant function analysis produced likelihood surfaces encompassing most burrowing owl burrows within a fraction of the study area, and the former corresponded with burrowing owl fatalities and the latter with other raptor fatalities. Our ratings of wind turbine hazard were more predictive of burrowing owl fatalities, but would be more difficult to implement. Careful repowering to modern wind turbines would most reduce fatalities of burrowing owls and other birds while adding about 1,000 GWh annually toward California’s 33% Renewable Portfolio Standard.

  4. BURROW ARCHITECTURE OF RED GHOST CRAB OCYPODE MACROCERA (H. MILNE-EDWARDS, 1852) : A CASE STUDY IN INDIAN SUNDARBANS

    OpenAIRE

    Sourabh Kumar Dubey; Deep Chandan Chakraborty; Sudipta Chakraborty; Amalesh Choudhury

    2013-01-01

    A study on burrow architecture and burrow morphology of the red ghost crab (Ocypode macrocera) was carried out at the southern proximity of the Sagar island (21°37.973' N, to E 88° 04.195'), western sector of Indian Sundarbans that faces the regular tidal influences of Bay of Bengal. Ocypode macrocera constructs burrows that are highly species specific and used by single individual. Four types of burrow patterns were observed like ‘I’, ‘J’ ‘U’ and ‘semi-U’ type with different size...

  5. Map-based repowering and reorganization of a wind resource area to minimize burrowing owl and other bird fatalities

    Energy Technology Data Exchange (ETDEWEB)

    Smallwood, K. S. [Research Ecologist, 3108 Finch Street, Davis, CA 95616 (United States); Neher, L. [Gis Specialist, Neher Consulting, 7241 34th Street, North Highlands, CA 95660 (United States); Bell, D. A. [East Bay Regional Park District, 2950 Peralta Oaks Court, Oakland, CA 94605-0381 (United States)

    2009-07-01

    Wind turbines in the Altamont Pass Wind Resource Area (Alameda/Contra Costa Counties, California, USA) generate about 730 GWh of electricity annually, but have been killing thousands of birds each year, including >2,000 raptors and hundreds of burrowing owls. We have developed collision hazard maps and hazard ratings of wind turbines to guide relocation of existing wind turbines and careful repowering to modern turbines to reduce burrowing owl fatalities principally, and other birds secondarily. Burrowing owls selected burrow sites lower on slopes and on smaller, shallower slopes than represented by the average 10 x 10 m{sup 2} grid cell among 187,908 grid cells sampled from 2,281,169 grid cells comprising a digital elevation model (DEM) of the study area. Fuzzy logic and discriminant function analysis produced likelihood surfaces encompassing most burrowing owl burrows within a fraction of the study area, and the former corresponded with burrowing owl fatalities and the latter with other raptor fatalities. Our ratings of wind turbine hazard were more predictive of burrowing owl fatalities, but would be more difficult to implement. Careful repowering to modern wind turbines would most reduce fatalities of burrowing owls and other birds while adding about 1,000 GWh annually toward California's 33% Renewable Portfolio Standard. (author)

  6. Burrowing inhibition by fine textured beach fill: Implications for recovery of beach ecosystems

    Science.gov (United States)

    Viola, Sloane M.; Hubbard, David M.; Dugan, Jenifer E.; Schooler, Nicholas K.

    2014-10-01

    Beach nourishment is often considered the most environmentally sound method of maintaining eroding shorelines. However, the ecological consequences are poorly understood. Fill activities cause intense disturbance and high mortality and have the potential to alter the diversity, abundance, and distribution of intertidal macroinvertebrates for months to years. Ecological recovery following fill activities depends on successful recolonization and recruitment of the entire sandy intertidal community. The use of incompatible sediments as fill material can strongly affect ecosystem recovery. We hypothesized that burrowing inhibition of intertidal animals by incompatible fine fill sediments contributes to ecological impacts and limits recovery in beach ecosystems. We experimentally investigated the influence of intertidal zone and burrowing mode on responses of beach invertebrates to altered sediment texture (28-38% fines), and ultimately the potential for colonization and recovery of beaches disturbed by beach filling. Using experimental trials in fill material and natural beach sand, we found that the mismatched fine fill sediments significantly inhibited burrowing of characteristic species from all intertidal zones, including sand crabs, clams, polychaetes, isopods, and talitrid amphipods. Burrowing performance of all five species we tested was consistently reduced in the fill material and burrowing was completely inhibited for several species. The threshold for burrowing inhibition by fine sediment content in middle and lower beach macroinvertebrates varied by species, with highest sensitivity for the polychaete (4% fines, below the USA regulatory limit of 10% fines), followed by sand crabs and clams (20% fines). These results suggest broader investigation of thresholds for burrowing inhibition in fine fill material is needed for beach animals. Burrowing inhibition caused by mismatched fill sediments exposes beach macroinvertebrates to stresses, which could depress

  7. Observations on the use of tarantula burrows by the anurans Leptodactylus bufonius (Leptodactylidae and Rhinella major (Bufonidae in the Dry Chaco ecoregion of Bolivia

    Directory of Open Access Journals (Sweden)

    Christopher M. Schalk

    2014-06-01

    Full Text Available Some species of anurans have been observed utilizing burrows of other animals, such as rodents and tarantulas. Here we report the observations of two anuran species, Leptodactylus bufonius and Rhinella major, utilizing the burrows of tarantulas (Acanthoscurria sp.; Family Theraphosidae in the dry Chaco ecoregion of Bolivia. Both species of anurans never co-occurred with tarantulas in the burrows and used burrows that were wider in diameter and closer to breeding ponds as compared to the total available tarantula burrows in the area. These burrows may serve as refuges from predators, especially for conspicuous, calling males.

  8. Footprints in the sand: independent reduction of subdigital lamellae in the Namib–Kalahari burrowing geckos

    Science.gov (United States)

    Lamb, Trip; Bauer, Aaron M

    2005-01-01

    Many desert organisms exhibit convergence, and certain physical factors such as windblown sands have generated remarkably similar ecomorphs across divergent lineages. The burrowing geckos Colopus, Chondrodactylus and Palmatogecko occupy dune ecosystems in the Namib and Kalahari deserts of southwest Africa. Considered closely related, they share several putative synapomorphies, including reduced subdigital pads (toe pads) and spinose digital scales. Though recognized as part of Africa's ecologically diverse Pachydactylus Group, the burrowing geckos' precise phylogenetic affinities remain elusive. Convergent pedal modification provides a tenable alternative explaining the geckos' derived terrestriality and adaptation to Namib and Kalahari sands. We generated a molecular phylogeny for the Pachydactylus Group to examine evolutionary relationships among the burrowing geckos and infer historical patterns of pedal character change. Bayesian and parsimony analyses revealed all three burrowing genera to be deeply nested within Pachydactylus, each genus belonging to a separate clade. Strong support for these distinct clades indicates ecomorphological adaptations for burrowing have evolved independently three times in the southern Pachydactylus Group. We argue that the physical properties of Namib and Kalahari sands played a principal role in selecting for pedal similarity. PMID:16618680

  9. Footprints in the sand: independent reduction of subdigital lamellae in the Namib-Kalahari burrowing geckos.

    Science.gov (United States)

    Lamb, Trip; Bauer, Aaron M

    2006-04-07

    Many desert organisms exhibit convergence, and certain physical factors such as windblown sands have generated remarkably similar ecomorphs across divergent lineages. The burrowing geckos Colopus, Chondrodactylus and Palmatogecko occupy dune ecosystems in the Namib and Kalahari deserts of southwest Africa. Considered closely related, they share several putative synapomorphies, including reduced subdigital pads (toe pads) and spinose digital scales. Though recognized as part of Africa's ecologically diverse Pachydactylus Group, the burrowing geckos' precise phylogenetic affinities remain elusive. Convergent pedal modification provides a tenable alternative explaining the geckos' derived terrestriality and adaptation to Namib and Kalahari sands. We generated a molecular phylogeny for the Pachydactylus Group to examine evolutionary relationships among the burrowing geckos and infer historical patterns of pedal character change. Bayesian and parsimony analyses revealed all three burrowing genera to be deeply nested within Pachydactylus, each genus belonging to a separate clade. Strong support for these distinct clades indicates ecomorphological adaptations for burrowing have evolved independently three times in the southern Pachydactylus Group. We argue that the physical properties of Namib and Kalahari sands played a principal role in selecting for pedal similarity.

  10. Dusk but not dawn burrow emergence rhythms of Nephrops norvegicus (Crustacea: Decapoda

    Directory of Open Access Journals (Sweden)

    Valerio Sbragaglia

    2013-10-01

    Full Text Available The Norway lobster, Nephrops norvegicus, can be captured by haul nets only during the emergence from its burrow. In the last few decades, an extensive field research revealed distinct diel (24-h–based catchability patterns at different depths. Laboratory experiments suggested that burrow emergence (used as a proxy of catchability is endogenously controlled via a circadian system. Results were usually presented in terms of mean effects without a quantification of inter-individual variability and arrhythmia. Here, we studied the burrow emergence of 52 adult Nephrops by an infrared actograph endowed with an artificial burrow. Animals were exposed to 12-12 h light-darkness cycle, simulating photic condition of the lower shelf. Forty-five animals showed rhythmic emergence (87%, while seven were arrhythmic (13%. Rhythmic animals were clustered according to their timing of emergence: 54% at dusk and 4% at dawn. Moreover, other animals showed fully diurnal or nocturnal emergence (10% and 19%, respectively. The comparison of our results with those derived from temporally scheduled trawling indicates that bimodal catch patterns observed in shelf populations are poorly observed during individual experiments in the laboratory, where the same light conditions are simulated. Nephrops burrow emergence seems to be the result of a mixed endogenous-exogenous control, while arrhythmia could also be present in the wild.

  11. Burrow ventilation and associated porewater irrigation by the polychaete Marenzelleria viridis

    DEFF Research Database (Denmark)

    Quintana, Cintia Organo; Hansen, Torben; Delefosse, Matthieu

    2011-01-01

    presented muscular pumping in time averaged rates of 0.15 ml min−1. Oxygen needle electrodes positioned above the burrow openings revealed that muscular undulation of the worm body pumps anoxic water out of the burrow. On the other hand, microscope observations of the animal showed that ventilation...... be about 0.16 ml min−1. Since the cilia pumping into the burrow occurs in periods of 24±12 min and at 50–70% of the measured time, considerable amounts of water from deeper sediments may percolate upwards to the sediment surface. This water is rich in reduced compounds and nutrients and may have important...

  12. Breeding-season food habits of burrowing owls (Athene cunicularia) in southwestern Dominican Republic

    Science.gov (United States)

    Wiley, J.W.

    1998-01-01

    Diet data from 20 Burrowing Owl (Athene cunicularia) nests were collected in southwestern Dominican Republic in 1976, 1982, and 1996. Invertebrates (53.3%) comprised the most numerous prey items (N = 396) delivered to nests by adult owls, but vertebrates (46.7%) were much better represented than in other studies of Burrowing Owl diet. Among vertebrates, birds (28.3% of all items) and reptiles (14.9%) were most important, whereas mammals (1.0%) and amphibians (2.5%) were less commonly delivered to nests. Vertebrates, however, comprised more than twice (69.2%) of the total biomass as invertebrates (30.8%), with birds (50.4%) and reptiles (12.8%) the most important of the vertebrate prey classes. A positive relationship was observed between bird species abundance and number of individuals taken as prey by Burrowing Owls.

  13. Belted kingfishers: Under surveillance and sampled in the privacy of their own burrow

    International Nuclear Information System (INIS)

    Baron, L.A.; Ashwood, T.L.

    1995-01-01

    The belted kingfisher, a common piscivore of the Oak Ridge Reservation (ORR), bioaccumulates contaminants from consumption of aquatic prey. Three kingfisher carcasses found near contaminated streams on the ORR were analyzed. Mercury, cadmium, and selenium bioaccumulated within the liver, kidney, and feathers. Additionally, PCB-1254 accumulated in muscle and lipid tissue, while Cesium-137 accumulated within the muscle and whole body. These contaminant levels have been shown to produce a variety of toxicological effects (i.e., reproductive impairment, central nervous system dysfunction) within other species of birds. In addition to use of this data for ecological risk assessment, kingfishers can also be monitored as a viable bioindicator species reflecting environmental contaminant levels over time. However, current sampling methods of burrow excavation or the use of mist nets can be detrimental to the reproductive success of the birds. The authors present a method for obtaining adequate samples of feathers and other remnants (i.e., egg shells, dried regurgitant) found in the burrow during or following the nesting season. The collection of samples following surveillance of the burrow and its contents was performed with the use of a 15 ft-long flexible, portable probe containing a video camera. Once sighted with the probe, contents of the burrow were collected by insertion of an additional tube attached to a hand held vacuum cleaner (Dirt Devil reg-sign). Feathers collected from a nest at an uncontaminated site contained selenium, lead and mercury. Cesium-137 was found in an egg shell collected from a nest at a radiologically contaminated site. Close-up photos of a kingfisher mother incubating her eggs and nestlings within two burrows will also be shown. This surveillance and sampling technique can also be used for monitoring other burrowing terrestrial species

  14. Pisodonophis boro (ophichthidae: anguilliformes): specialization for head-first and tail-first burrowing?

    Science.gov (United States)

    De Schepper, Natalie; De Kegel, Barbara; Adriaens, Dominique

    2007-02-01

    The rice paddy eel, Pisodonophis boro (P. boro), is of special interest because of its peculiar burrowing habits. P. boro penetrates the substrate tail-first, a technique common for ophichthids, but it is able to burrow head-first as well. P. boro exhibits three feeding modes: inertial feeding, grasping, and spinning. Rotational feeding is a highly specialized feeding mode, adopted by several elongate, aquatic vertebrates and it is likely that some morphological modifications are related to this feeding mode. The detailed morphology of the head and tail of P. boro is examined with the goal to apportion the anatomical specializations among head-first burrowing, tail-first burrowing, and rotational feeding. The reduced eyes, covered with thick corneas may be beneficial for protection during head-first burrowing, but at the same time decreased visual acuity may have an impact on other sensory systems (e.g. cephalic lateral line system). The elongated and pointed shape of the skull is beneficial for substrate penetration. The cranial bones and their joints, which are fortified, are advantageous for resisting high mechanical loads during head-first burrowing. The aponeurotic connection between epaxial and jaw muscles is considered beneficial for transferring these forces from the body to the head during rotational feeding. Hypertrophied jaw muscles facilitate a powerful bite, which is required to hold prey during spinning movements and variability in the fiber angles of subdivisions of jaw muscles may be beneficial for preventing the lower jaw from being dislodged or opened. Furthermore, firm upper (premaxillo-ethmovomerine complex) and lower jaws (with robust coronoid processes) and high neurocranial rigidity are advantageous for a solid grip to hold prey during rotational feeding. The pointed shape of the tail and the consolidated caudal skeleton are beneficial for their tail-first burrowing habits. It is quite likely that the reduction of the caudal musculature is

  15. Variations in the Foraging Behaviour and Burrow Structures of the Damara Molerat Cryptomys damarensis in the Kalahari Gemsbok National Park

    Directory of Open Access Journals (Sweden)

    B.G. Lovegrove

    1987-10-01

    Full Text Available Aspects of two habitat-specific foraging behaviours of the social subterranean rodent Cryptomys damarensis, are discussed in terms of burrow structure, resource dispersion patterns, sand moisture content, burrow temperature regimes, and predatory pressures, in the Kalahari Gemsbok National Park, South Africa.

  16. Non-Native Suckermouth Armored Catfishes in Florida: Description of Nest Borrows and Burrow Colonies with Assessment of Shoreline Conditions

    Science.gov (United States)

    2009-04-01

    clubhouses and other residences with boat docks, and a mix of other land uses. Most waterway reaches surveyed were located in rural or low-density...were excavated to obtain in- formation on burrow dimensions. In contrast to what Grier (1980) had described for Hypostomus burrows in Florida, Devick

  17. Detecting plague-host abundance from space: Using a spectral vegetation index to identify occupancy of great gerbil burrows

    NARCIS (Netherlands)

    Wilschut, Liesbeth I.; Heesterbeek, Johan A.P.; Begon, Mike; de Jong, Steven M.; Ageyev, Vladimir; Laudisoit, Anne; Addink, Elisabeth A.

    2018-01-01

    In Kazakhstan, plague outbreaks occur when its main host, the great gerbil, exceeds an abundance threshold. These live in family groups in burrows, which can be mapped using remote sensing. Occupancy (percentage of burrows occupied) is a good proxy for abundance and hence the possibility of an

  18. Detecting plague-host abundance from space: Using a spectral vegetation index to identify occupancy of great gerbil burrows

    Science.gov (United States)

    Wilschut, Liesbeth I.; Heesterbeek, Johan A. P.; Begon, Mike; de Jong, Steven M.; Ageyev, Vladimir; Laudisoit, Anne; Addink, Elisabeth A.

    2018-02-01

    In Kazakhstan, plague outbreaks occur when its main host, the great gerbil, exceeds an abundance threshold. These live in family groups in burrows, which can be mapped using remote sensing. Occupancy (percentage of burrows occupied) is a good proxy for abundance and hence the possibility of an outbreak. Here we use time series of satellite images to estimate occupancy remotely. In April and September 2013, 872 burrows were identified in the field as either occupied or empty. For satellite images acquired between April and August, 'burrow objects' were identified and matched to the field burrows. The burrow objects were represented by 25 different polygon types, then classified (using a majority vote from 10 Random Forests) as occupied or empty, using Normalized Difference Vegetation Indices (NDVI) calculated for all images. Throughout the season NDVI values were higher for empty than for occupied burrows. Occupancy status of individual burrows that were continuously occupied or empty, was classified with producer's and user's accuracy values of 63 and 64% for the optimum polygon. Occupancy level was predicted very well and differed 2% from the observed occupancy. This establishes firmly the principle that occupancy can be estimated using satellite images with the potential to predict plague outbreaks over extensive areas with much greater ease and accuracy than previously.

  19. Current status, distribution, and conservation of the Burrowing Owl (Speotyto cunicularia) in midwestern and western North America

    Science.gov (United States)

    Steven R. Sheffield

    1997-01-01

    The Burrowing Owl (Speotyto cunicularia) inhabits open prairie grassland habitat in the midwestern and western US and Canada. For several years now, numbers of this species in North America have been declining at an alarming rate. Currently, Burrowing Owls are listed as endangered in Canada and threatened in Mexico. In the United States, the...

  20. Interplanetary variability recorded by the sled instrument aboard the Phobos spacecraft during that period of solar cycle 22 characterized by a transition from solar minimum- to solar maximum-dominated conditions

    Energy Technology Data Exchange (ETDEWEB)

    McKenna-Lawlor, S.M.P. (Saint Patrick' s Coll., Maynooth (Ireland)); Afonin, V.V.; Gringauz, K.I. (AN SSSR, Moscow (USSR). Space Research Inst.) (and others)

    Twin telescope particle detector systems SLED-1 and SLED-2, with the capability of monitoring electron and ion fluxes within an energy range spanning approximately 30 keV to a few megaelectron volts, were individually launched on the two spacecraft (Phobos-2 and Phobos-1, respectively) of the Soviet Phobos Mission to Mars and its moons in July 1988. A short description of the SLED instrument and a preliminary account of representative solar-related particle enhancements recorded by SLED-1 and SLED-2 during the Cruise Phase, and by SLED-1 in the near Martian environment (within the interval 25 July 1988-26 March 1989) are presented. These observations were made while the interplanetary medium was in the course of changing over from solar minimum- to solar maximum-dominated conditions and examples are presented of events associated with each of these phenomenological states. (author).

  1. Burrows of the semi-terrestrial crab Ucides cordatus enhance CO2 release in a North Brazilian mangrove forest.

    Directory of Open Access Journals (Sweden)

    Nathalie Pülmanns

    Full Text Available Ucides cordatus is an abundant mangrove crab in Brazil constructing burrows of up to 2 m depth. Sediment around burrows may oxidize during low tides. This increase in sediment-air contact area may enhance carbon degradation processes. We hypothesized that 1 the sediment CO2 efflux rate is greater with burrows than without and 2 the reduction potential in radial profiles in the sediment surrounding the burrows decreases gradually, until approximating non-bioturbated conditions. Sampling was conducted during the North Brazilian wet season at neap tides. CO2 efflux rates of inhabited burrows and plain sediment were measured with a CO2/H2O gas analyzer connected to a respiration chamber. Sediment redox potential, pH and temperature were measured in the sediment surrounding the burrows at horizontal distances of 2, 5, 8 and 15 cm at four sediment depths (1, 10, 30 and 50 cm and rH values were calculated. Sediment cores (50 cm length were taken to measure the same parameters for plain sediment. CO2 efflux rates of plain sediment and individual crab burrows with entrance diameters of 7 cm were 0.7-1.3 µmol m(-2 s(-1 and 0.2-0.4 µmol burrows(-1 s(-1, respectively. CO2 released from a Rhizophora mangle dominated forest with an average of 1.7 U. cordatus burrows(-1 m(-2 yielded 1.0-1.7 µmol m(-2 s(-1, depending on the month and burrow entrance diameter. Laboratory experiments revealed that 20-60% of the CO2 released by burrows originated from crab respiration. Temporal changes in the reduction potential in the sediment surrounding the burrows did not influence the CO2 release from burrows. More oxidized conditions of plain sediment over time may explain the increase in CO2 release until the end of the wet season. CO2 released by U. cordatus and their burrows may be a significant pathway of CO2 export from mangrove sediments and should be considered in mangrove carbon budget estimates.

  2. Burrows of the semi-terrestrial crab Ucides cordatus enhance CO2 release in a North Brazilian mangrove forest.

    Science.gov (United States)

    Pülmanns, Nathalie; Diele, Karen; Mehlig, Ulf; Nordhaus, Inga

    2014-01-01

    Ucides cordatus is an abundant mangrove crab in Brazil constructing burrows of up to 2 m depth. Sediment around burrows may oxidize during low tides. This increase in sediment-air contact area may enhance carbon degradation processes. We hypothesized that 1) the sediment CO2 efflux rate is greater with burrows than without and 2) the reduction potential in radial profiles in the sediment surrounding the burrows decreases gradually, until approximating non-bioturbated conditions. Sampling was conducted during the North Brazilian wet season at neap tides. CO2 efflux rates of inhabited burrows and plain sediment were measured with a CO2/H2O gas analyzer connected to a respiration chamber. Sediment redox potential, pH and temperature were measured in the sediment surrounding the burrows at horizontal distances of 2, 5, 8 and 15 cm at four sediment depths (1, 10, 30 and 50 cm) and rH values were calculated. Sediment cores (50 cm length) were taken to measure the same parameters for plain sediment. CO2 efflux rates of plain sediment and individual crab burrows with entrance diameters of 7 cm were 0.7-1.3 µmol m(-2) s(-1) and 0.2-0.4 µmol burrows(-1) s(-1), respectively. CO2 released from a Rhizophora mangle dominated forest with an average of 1.7 U. cordatus burrows(-1) m(-2) yielded 1.0-1.7 µmol m(-2) s(-1), depending on the month and burrow entrance diameter. Laboratory experiments revealed that 20-60% of the CO2 released by burrows originated from crab respiration. Temporal changes in the reduction potential in the sediment surrounding the burrows did not influence the CO2 release from burrows. More oxidized conditions of plain sediment over time may explain the increase in CO2 release until the end of the wet season. CO2 released by U. cordatus and their burrows may be a significant pathway of CO2 export from mangrove sediments and should be considered in mangrove carbon budget estimates.

  3. Nelson's big horn sheep (Ovis canadensis nelsoni) trample Agassiz's desert tortoise (Gopherus agassizii) burrow at a California wind energy facility

    Science.gov (United States)

    Agha, Mickey; Delaney, David F.; Lovich, Jeffrey E.; Briggs, Jessica; Austin, Meaghan; Price, Steven J.

    2015-01-01

    Research on interactions between Agassiz's desert tortoises (Gopherus agassizii) and ungulates has focused exclusively on the effects of livestock grazing on tortoises and their habitat (Oldemeyer, 1994). For example, during a 1980 study in San Bernardino County, California, 164 desert tortoise burrows were assessed for vulnerability to trampling by domestic sheep (Ovis aries). Herds of grazing sheep damaged 10% and destroyed 4% of the burrows (Nicholson and Humphreys 1981). In addition, a juvenile desert tortoise was trapped and an adult male was blocked from entering a burrow due to trampling by domestic sheep. Another study found that domestic cattle (Bos taurus) trampled active desert tortoise burrows and vegetation surrounding burrows (Avery and Neibergs 1997). Trampling also has negative impacts on diversity of vegetation and intershrub soil crusts in the desert southwest (Webb and Stielstra 1979). Trampling of important food plants and overgrazing has the potential to create competition between desert tortoises and domestic livestock (Berry 1978; Coombs 1979; Webb and Stielstra 1979).

  4. Lizard burrows provide thermal refugia for larks in the Arabian desert

    NARCIS (Netherlands)

    Williams, JB; Tieleman, BI; Shobrak, M

    A common perception is that desert birds experience greater extremes of heat and aridity than their mammalian counterparts, in part, because birds do not use burrows as a refuge from the desert environment. We report observations of Dunn's Larks (Eremalauda dunni), Bar-tailed Desert Larks (Ammomanes

  5. Strong population genetic structure and larval dispersal capability of the burrowing ghost shrimp (Neotrypaea californiensis)

    Science.gov (United States)

    The burrowing ghost shrimp, Neotrypaea californiensis, is a vital member of the estuarine benthic community. Dense populations of shrimp are found in the major estuaries of Washington and Oregon. Our study determines the genetic structure of shrimp populations in order to gain ...

  6. Burrowing Behavior of a Deposit Feeding Bivalve Predicts Change in Intertidal Ecosystem State

    NARCIS (Netherlands)

    Compton, T.J.; Bodnar, W.; Koolhaas, A.; Dekinga, A.; Holthuijsen, S.; Ten Horn, J.; McSweeney, N.; van Gils, J.A.; Piersma, T.

    2016-01-01

    Behavior has a predictive power that is often underutilized as a tool for signaling ecological change. The burrowing behavior of the deposit feeding bivalve Macoma balthica reflects a typical food-safety trade-off. The choice to live close to the sediment surface comes at a risk of predation and is

  7. Burrowing behavior of a deposit feeding bivalve predicts change in intertidal ecosystem state

    NARCIS (Netherlands)

    Compton, Tanya J.; Bodnar, Wanda; Koolhaas, Anita; Dekinga, Anne; Holthuijsen, Sander; ten Horn, Job; McSweeney, Niamh; van Gils, Jan; Piersma, Theunis

    2016-01-01

    Behavior has a predictive power that is often underutilized as a tool for signaling ecological change. The burrowing behavior of the deposit feeding bivalve Macoma balthica reflects a typical food-safety trade-off. The choice to live close to the sediment surface comes at a risk of predation and is

  8. The influence of small-mammal burrowing activity on water storage at the Hanford Site

    International Nuclear Information System (INIS)

    Landeen, D.S.

    1994-01-01

    This paper summarizes the activities that were conducted in support of the long-term surface barrier development program by Westinghouse Hanford Company to determine the degree that small-mammal burrow systems affect the loss or retention of water in the soils at the Hanford Site in Washington state. An animal intrusion lysimeter facility was constructed, consisting of two outer boxes buried at grade, which served as receptacles for six animal intrusion lysimeters. Small burrowing animals common the Hanford Site were introduced over a 3- to 4-month period. Supplemental precipitation was added monthly to three of the lysimeters with a rainfall simulator (rainulator). Information collected from the five tests indicated that (1) during summer months, water was lost in all the lysimeters, including the supplemental precipitation added with the rainulator; and (2) during winter months, all lysimeters gained water. The data indicate little difference in the amount of water stored between control and animal lysimeters. The overall water loss was attributed to surface evaporation, a process that occurred equally in control and treatment lysimeters. Other causes of water loss are a result of (1) constant soil turnover and subsequent drying, and (2) burrow ventilation effects. This suggests that burrow systems will not contribute to any significant water storage at depth and, in fact, may enhance the removal of water from the soil

  9. Burrowing herbivores alter soil carbon and nitrogen dynamics in a semi-arid ecosystem, Argentina

    Science.gov (United States)

    Kenneth L. Clark; Lyn C. Branch; Jose L. Hierro; Diego Villarreal

    2016-01-01

    Activities of burrowing herbivores, including movement of soil and litter and deposition of waste material, can alter the distribution of labile carbon (C) and nitrogen (N) in soil, affecting spatial patterning of nutrient dynamics in ecosystems where they are abundant. Their role in ecosystem processes in surface soil has been studied extensively, but effects of...

  10. Burrowing and avoidance behaviour in marine organisms exposed to pesticide-contaminated sediment

    DEFF Research Database (Denmark)

    Møhlenberg, Flemming; Kiørboe, Thomas

    1983-01-01

    Behavioural effects of marine sediment contaminated with pesticides (6000 ppm parathion, 200 ppm methyl parathion, 200 ppm malathion) were studied in a number of marine organisms in laboratory tests and in situ. The burrowing behaviour in Macoma baltica, Cerastoderma edule, Abra alba, Nereis...

  11. Living in a ``stethoscope'': burrow-acoustics promote auditory specializations in subterranean rodents

    Science.gov (United States)

    Lange, Simone; Burda, Hynek; Wegner, Regina E.; Dammann, Philip; Begall, Sabine; Kawalika, Mathias

    2007-02-01

    Subterranean mammals rely to a great extent on audition for communication and to be alerted to danger. The only hitherto published report on burrow acoustics revealed that in tunnels of blind mole-rats ( Spalax ehrenbergi), airborne sounds of 440 Hz propagated best whereas lower and higher frequencies were effectively attenuated. Morpho-functional analyses classify the ear of subterranean mammals as a low-sensitivity and low-frequency device. Concordantly, hearing is characterized by low sensitivity and a restricted frequency range tuned to low frequencies (0.5-4 kHz). Some authors considered the restricted hearing in subterranean mammals vestigial and degenerate due to under-stimulation. In contrast to this view stand a rich (mostly low-frequency) vocal repertoire and progressive structural specializations of the middle and inner ear. Thus, other authors considered these hearing characteristics adaptive. To test the hypothesis that acoustical environment in burrows of different species of subterranean mammals is similar, we measured sound attenuation in burrows of Fukomys mole-rats (formerly known as Cryptomys, cf. Kock et al. 2006) of two differently sized species at different locations in Zambia. We show that in these burrows, low-frequency sounds (200-800 Hz) are not only least attenuated but also their amplitude may be amplified like in a stethoscope (up to two times over 1 m). We suggest that hearing sensitivity has decreased during evolution of subterranean mammals to avoid over-stimulation of the ear in their natural environment.

  12. Organic matter composition and the protist and nematode communities around anecic earthworm burrows

    NARCIS (Netherlands)

    Andriuzzi, Walter S.; Ngo, Phuong-Thi; Geisen, Stefan; Keith, Aidan M.; Dumack, Kenneth; Bolger, Thomas; Bonkowski, Michael; Brussaard, Lijbert; Faber, Jack H.; Chabbi, Abad; Rumpel, Cornelia; Schmidt, Olaf

    2016-01-01

    By living in permanent burrows and incorporating organic detritus from the soil surface, anecic earthworms contribute to soil heterogeneity, but their impact is still under-studied in natural field conditions. We investigated the effects of the anecic earthworm Lumbricus centralis on fresh carbon

  13. Development of earthworm burrow systems and the influence of earthworms on soil hydrology

    NARCIS (Netherlands)

    Ligthart, T.N.

    1996-01-01


    Inoculation of earthworms can help to restore or ameliorate land qualities. Earthworms create burrows and alter the structure of the soil matrix, which influence the water infiltration, drainage, water retention and the aeration of the soil. The way and rate of the development of

  14. Sedimentary organic matter distributions, burrowing activity, and biogeochemical cycling: Natural patterns and experimental artifacts

    Science.gov (United States)

    Michaud, Emma; Aller, Robert, C.; Stora, Georges

    2010-11-01

    The coupling between biogenic reworking activity and reactive organic matter patterns within deposits is poorly understood and often ignored. In this study, we examined how common experimental treatments of sediment affect the burrowing behavior of the polychaete Nephtys incisa and how these effects may interact with reactive organic matter distributions to alter diagenetic transport - reaction balances. Sediment and animals were recovered from a subtidal site in central Long Island Sound, USA. The upper 15 cm of the sediment was sectioned into sub-intervals, and each interval separately sieved and homogenized. Three initial distributions of sediment and organic substrate reactivity were setup in a series of microcosms: (1) a reconstituted natural pattern with surface-derived sediment overlying sediment obtained from progressively deeper material to a depth of 15 cm (Natural); (2) a 15 cm thick sediment layer composed only of surface-derived sediment (Rich); and (3) a 15 cm thick layer composed of uniformally mixed sediment from the original 15 cm sediment profile (Averaged). The two last treatments are comparable to that used in microcosms in many previous studies of bioturbation and interspecific functional interaction experiments. Sediment grain size distributions were 97.5% silt-clay and showed no depth dependent patterns. Sediment porosity gradients were slightly altered by the treatments. Nepthys were reintroduced and aquariums were X-rayed regularly over 5 months to visualize and quantify spatial and temporal dynamics of burrows. The burrowing behaviour of adult populations having similar total biovolume, biomass, abundance, and individual sizes differed substantially as a function of treatment. Burrows in sediment with natural property gradients were much shallower and less dense than those in microcosms with altered gradients. The burrow volume/biovolume ratio was also lower in the substrate with natural organic reactivity gradients. Variation in food

  15. Development of homeothermy in chicks of sub-Antarctic burrowing ...

    African Journals Online (AJOL)

    On average, chicks of grey petrels, great-winged petrels and Salvin's prions attained homeothermy within five days of hatching, but some individuals exhibited well-developed homeothermy within 24 h of hatching. Chicks demonstrated a high capacity for heat production and maximum cold-induced oxygen consumptions ...

  16. Under the weather?-The direct effects of climate warming on a threatened desert lizard are mediated by their activity phase and burrow system.

    Science.gov (United States)

    Moore, Danae; Stow, Adam; Kearney, Michael Ray

    2018-05-01

    For ectotherms such as lizards, the importance of behavioural thermoregulation in avoiding thermal extremes is well-established and is increasingly acknowledged in modern studies of climate warming and its impacts. Less appreciated and understood are the buffering roles of retreat sites and activity phase, in part because of logistical challenges of studying below-ground activity. Burrowing and nocturnal activity are key behavioural adaptations that have enabled a diverse range of reptiles to survive extreme environmental temperatures within hot desert regions. Yet, the direct impact of recent global warming on activity potential has been hypothesised to have caused extinctions in desert lizards, including the Australian arid zone skink Liopholis kintorei. We test the relevance of this hypothesis through a detailed characterisation of the above- and below-ground thermal and hydric microclimates available to, and used by, L. kintorei. We integrate operative temperatures with observed body temperatures to construct daily activity budgets, including the inference of subterranean behaviour. We then assess the likelihood that contemporary and future local extinctions in this species, and those of similar burrowing habits, could be explained by the direct effects of warming on its activity budget and exposure to thermal extremes. We found that L. kintorei spent only 4% of its time active on the surface, primarily at dusk, and that overall potential surface activity will be increased, not restricted, with climate warming. The burrow system provides an exceptional buffer to current and future maximum extremes of temperature (≈40°C reduction from potential surface temperatures), and desiccation (burrows near 100% humidity). Therefore, any climate warming impacts on this species are likely to be indirect. Our findings reflect the general buffering capacity of underground microclimates, therefore, our conclusions for L. kintorei are more generally applicable to

  17. Effect of mangrove restoration on crab burrow density in Luoyangjiang Estuary, China

    Directory of Open Access Journals (Sweden)

    Wei Li

    2015-07-01

    Full Text Available Background Mangrove restoration seeks to restore or rebuild degraded mangrove systems. The methods of mangrove restoration include ecological projects and restoration-oriented technologies, the latter of which are designed to restore the structure, processes as well as related physical, chemical and biological characteristics of wetlands and to ensure the provision of ecosystem services. As important components of mangrove ecosystem, benthic organisms and crabs play a key role in nutrient cycling. In addition, mangrove restoration, such as vegetation restoration measures, can lead to changes in the benthic faunal communities. This study investigates whether the presence of different mangrove species, age and canopy cover of mangrove communities affect the density of crab burrows. Methods The Luoyangjiang Estuary, in the southeast of Fujian Province, was selected as our research area. A survey, covering 14 sites, was conducted to investigate the impacts of mangrove restoration on the density of crab burrows in four rehabilitated forests with different stand ages and canopy. Results It was found that differences in vegetation types had a large impact on crab density and that the density of crab burrows was lower on exposed beaches (non-mangrove than under mature Kandelia candel, Aegiceras corniculatum and Avicennia marina communities. In general, the amount of leaf litter and debris on mangrove mudflats was greater than on the beaches as food sources for crabs. Two-factor analysis of variance (ANOVA shows that changes in mangrove species and age since restoration had different effects on crab burrow density. The effect of canopy cover was highly significant on crab burrow density. Conclusions The results suggest that in the process of mangrove restoration the combined effects of mangrove stand age, canopy cover and other factors should be taken into account. This study further supports the findings of the future scientific research and practice on

  18. Burrowing with a kinetic snout in a snake (Elapidae: Aspidelaps scutatus).

    Science.gov (United States)

    Deufel, Alexandra

    2017-12-01

    Of the few elongate, fossorial vertebrates that have been examined for their burrowing mechanics, all were found to use an akinetic, reinforced skull to push into the soil, powered mostly by trunk muscles. Reinforced skulls were considered essential for head-first burrowing. In contrast, I found that the skull of the fossorial shield-nosed cobra (Aspidelaps scutatus) is not reinforced and retains the kinetic potential typical of many non-fossorial snakes. Aspidelaps scutatus burrows using a greatly enlarged rostral scale that is attached to a kinetic snout that is independently mobile with respect to the rest of the skull. Two mechanisms of burrowing are used: (1) anteriorly directed head thrusts from a loosely bent body that is anchored against the walls of the tunnel by friction, and (2) side-to-side shovelling using the head and rostral scale. The premaxilla, to which the rostral scale is attached, lacks any direct muscle attachments. Rostral scale movements are powered by, first, retractions of the palato-pterygoid bar, mediated by a ligament that connects the anterior end of the palatine to the transverse process of the premaxilla and, second, by contraction of a previously undescribed muscle slip of the m. retractor pterygoidei that inserts on the skin at the edge of the rostral scale. In derived snakes, palatomaxillary movements are highly conserved and power prey capture and transport behaviors. Aspidelaps scutatus has co-opted those mechanisms for the unrelated function of burrowing without compromising the original feeding functions, showing the potential for evolution of functional innovations in highly conserved systems. © 2017 Wiley Periodicals, Inc.

  19. No pain, no gain: Male plasticity in burrow digging according to female rejection in a sand-dwelling wolf spider.

    Science.gov (United States)

    Carballo, Matilde; Baldenegro, Fabiana; Bollatti, Fedra; Peretti, Alfredo V; Aisenberg, Anita

    2017-07-01

    Behavioral plasticity allows individuals to reversibly respond to short-term variations in their ecological and social environment in order to maximize their fitness. Allocosa senex is a burrow-digging spider that inhabits the sandy coasts of South America. This species shows a reversal in typical sex roles expected in spiders: females are wanderers that visit males at their burrows and initiate courtship. They prefer males with long burrows for mating, and males prefer virgin over mated females. We tested whether female sexual rejection induced males to enlarge their burrows and if female reproductive status affected males' responses. We exposed males who had constructed burrows to: a) virgin females or b) mated females, (n=16 for each category). If female rejection occurred, we repeated the trial 48h later with the same female. As control, we maintained a group of males without female exposure (unexposed group, n=32). Rejected males enlarged their burrows more frequently and burrows were longer compared to unexposed males. However, frequency and length of enlargement did not differ according to female reproductive status. Males of A. senex showed plasticity in digging behavior in response to the availability of females, as a way to maximize the possibilities of future mating. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. BURROW ARCHITECTURE OF RED GHOST CRAB OCYPODE MACROCERA (H. MILNE-EDWARDS, 1852 : A CASE STUDY IN INDIAN SUNDARBANS

    Directory of Open Access Journals (Sweden)

    Sourabh Kumar Dubey

    2013-12-01

    Full Text Available A study on burrow architecture and burrow morphology of the red ghost crab (Ocypode macrocera was carried out at the southern proximity of the Sagar island (21°37.973' N, to E 88° 04.195', western sector of Indian Sundarbans that faces the regular tidal influences of Bay of Bengal. Ocypode macrocera constructs burrows that are highly species specific and used by single individual. Four types of burrow patterns were observed like ‘I’, ‘J’ ‘U’ and ‘semi-U’ type with different sizes as revealed by POP casting. Important physic-chemical parameters like air temperature, temperature and salinity of the water were significantly varied (P < 0.05 throughout seasons in the Ocypode zone. Burrow sand column temperature were also significantly varied from ambient air temperature thus exhibiting preference for cooler subterranean residential compartment. The digging behaviour of Ocypodes enhances oxygenation in the ground soil and facilitates decomposition of organic materials, nutrient recycling, entrapping the sediments and mangrove seedlings and helps the process of bioturbation. As per the preliminary observations it was suggested that burrow shape is directly related to tidal action and metabolic activities of the crab are strongly correlated with burrow microenvironment. They are adapted to the different sediment conditions, tidal fluctuations, varying salinity gradients, air and water temperatures and other environmental fluctuations.

  1. Population biology of the burrowing crab Neohelice granulata, (Crustacea: Decapoda: Varunidae from a tropical mangrove in Brazil

    Directory of Open Access Journals (Sweden)

    Rafael A. Gregati

    2009-03-01

    Full Text Available The population biology of the burrowing crab Neohelice granulata (Dana, 1851 from a mangrove in Jabaquara Beach, Paraty, state of Rio de Janeiro, Brazil (23º13'04"S and 44º42'47"W, was studied with respect to the following traits: size-frequency distribution, recruitment, reproductive period, fecundity, and sex ratio. Specimens were sampled monthly from April, 2003 to March, 2004, at the river margins during low tide periods. Size, sex, presence of eggs, and stage of the female gonad were recorded. Ovigerous females had their eggs removed and counted. The reproductive period was continuous and the highest frequency of ovigerous females was recorded in the fall and winter. Mature gonads were found throughout the year and recruitment was continuous but more intense during the summer. The fecundity of N. granulata (30028.3 ± 10861.2 eggs was high in comparison to studies in other localities. In general, the proportion of males was similar to that of females (1:0.92; however, males were predominant in the fall (1:0.77 and winter (1:0.75. All the information available so far on the reproduction of N. granulata involves populations from subtropical salt marshes; therefore, comparative studies including other habitats, such as mangrove forests, are needed to further understand the environmental influences on the population and reproductive biology of semiterrestrial crabs.

  2. Burrows of the Semi-Terrestrial Crab Ucides cordatus Enhance CO2 Release in a North Brazilian Mangrove Forest

    Science.gov (United States)

    Pülmanns, Nathalie; Diele, Karen; Mehlig, Ulf; Nordhaus, Inga

    2014-01-01

    Ucides cordatus is an abundant mangrove crab in Brazil constructing burrows of up to 2 m depth. Sediment around burrows may oxidize during low tides. This increase in sediment-air contact area may enhance carbon degradation processes. We hypothesized that 1) the sediment CO2 efflux rate is greater with burrows than without and 2) the reduction potential in radial profiles in the sediment surrounding the burrows decreases gradually, until approximating non-bioturbated conditions. Sampling was conducted during the North Brazilian wet season at neap tides. CO2 efflux rates of inhabited burrows and plain sediment were measured with a CO2/H2O gas analyzer connected to a respiration chamber. Sediment redox potential, pH and temperature were measured in the sediment surrounding the burrows at horizontal distances of 2, 5, 8 and 15 cm at four sediment depths (1, 10, 30 and 50 cm) and rH values were calculated. Sediment cores (50 cm length) were taken to measure the same parameters for plain sediment. CO2 efflux rates of plain sediment and individual crab burrows with entrance diameters of 7 cm were 0.7–1.3 µmol m−2 s−1 and 0.2–0.4 µmol burrows−1 s−1, respectively. CO2 released from a Rhizophora mangle dominated forest with an average of 1.7 U. cordatus burrows−1 m−2 yielded 1.0–1.7 µmol m−2 s−1, depending on the month and burrow entrance diameter. Laboratory experiments revealed that 20–60% of the CO2 released by burrows originated from crab respiration. Temporal changes in the reduction potential in the sediment surrounding the burrows did not influence the CO2 release from burrows. More oxidized conditions of plain sediment over time may explain the increase in CO2 release until the end of the wet season. CO2 released by U. cordatus and their burrows may be a significant pathway of CO2 export from mangrove sediments and should be considered in mangrove carbon budget estimates. PMID:25313661

  3. A documentation on burrows in hard substrates of ferromanganese crusts and associated soft sediments from the Central Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Banerjee, R

    , which are extensively bioturbated. Both the ferromanganese-coated and uncoated relict burrows have been collected from the same locality. Mobile epibenthic megafauna, e.g. molluscs, echinoderms, etc. seem to be main bioturbating organisms. The adjacent...

  4. Water pumping and analysis of flow in burrowing zoobenthos - a short overview

    DEFF Research Database (Denmark)

    Riisgård, Hans Ulrik; Larsen, Poul Scheel

    2005-01-01

    with the measuring of water pumping and the analysis of flow generated by burrowing deposit- and filter-feeding zoobenthos in order to determine the type of pump and mechanisms involved, flow rate, pump pressure, and pumping power. The practical use of fluid mechanical principles is examined, and it is stressed......-feeding animals. In stagnant situations the near-bottom water may be depleted of food particles, depending on the population filtration rate and the intensity of the biomixing induced by the filtering activity. But moderate currents and the biomixing can presumably generate enough turbulence to facilitate mixing...... of water layers at the sea bed with the layers above where food particle concentrations are relatively higher. Following a brief summary of types of burrowing benthic animals, common methods for measuring pumping rates are described along with examples. For estimating the required pump pressure, biofluid...

  5. Black-footed ferrets and recreational shooting influence the attributes of black-tailed prairie dog burrows

    Science.gov (United States)

    Biggins, Dean E.; Ramakrishnan, Shantini; Goldberg, Amanda R.; Eads, David A.

    2012-01-01

    Black-tailed prairie dogs (Cynomys ludovicianus) plug burrows occupied by black-footed ferrets (Mustela nigripes), and they also plug burrows to entomb dead prairie dogs. We further evaluated these phenomena by sampling connectivity and plugging of burrow openings on prairie dog colonies occupied by ferrets, colonies where recreational shooting was allowed, and colonies with neither shooting nor ferrets. We counted burrow openings on line surveys and within plots, classified surface plugging, and used an air blower to examine subsurface connectivity. Colonies with ferrets had lower densities of openings, fewer connected openings (suggesting increased subsurface plugging), and more surface plugs compared to colonies with no known ferrets. Colonies with recreational shooting had the lowest densities of burrow openings, and line-survey data suggested colonies with shooting had intermediate rates of surface plugging. The extent of surface and subsurface plugging could have consequences for the prairie dog community by changing air circulation and escape routes of burrow systems and by altering energetic relationships. Burrow plugging might reduce prairie dogs' risk of predation by ferrets while increasing risk of predation by American badgers (Taxidea taxus); however, the complexity of the trade-off is increased if plugging increases the risk of predation on ferrets by badgers. Prairie dogs expend more energy plugging and digging when ferrets or shooting are present, and ferrets increase their energy expenditures when they dig to remove those plugs. Microclimatic differences in plugged burrow systems may play a role in flea ecology and persistence of the flea-borne bacterium that causes plague (Yersinia pestis).

  6. Effects of pocket gopher burrowing on cesium-133 distribution on engineered test plots

    International Nuclear Information System (INIS)

    Gonzales, G.J.; Saladen, M.T.; Hakonson, T.E.

    1995-01-01

    Very low levels of radionuclides exist on soil surfaces. Biological factors including vegetation and animal burrowing can influence the fate of these surface contaminants. Animal burrowing introduces variability in radionuclide migration that confounds estimation of nuclide migration pathways, risk assessment, and assessment of waste burial performance. A field study on the surface and subsurface erosional transport of surface-applied 133 Cs as affected by pocket gopher (Thomomys bottae) burrowing was conducted on simulated waste landfill caps at the Los Alamos National Laboratory in north central New Mexico. Surface loss of Cs, adhered to five soil particle size ranges, was measured several times over an 18-mo period while simulated rainfalls were in progress. Gophers reduced Cs surface loss by significant amounts, 43%. Cesium surface loss on plots with only gophers was 0.8 kg totalled for the study period. This compared with 1.4 kg for control plots, 0.5 kg for vegetated plots, and 0.2 kg for plots with both gophers and vegetation. The change in Cs surface loss over time was significant (P -1 ). Vegetation-bearing plots bad significant more total subsurface Cs (μ = 1.7 g kg -1 ) than plots without vegetation (μ = 0.8 g kg -1 ). An average of 97% of the subsurface Cs in plots with vegetation was located in the upper 15 cm of soil (SDR1 + SDR2) compared with 67% for plots without vegetation. Vegetation moderated the influence of gopher activity on the transport of Cs to soil subsurface, and stabilized subsurface Cs by concentrating it in the rhizosphere. Gopher activity may have caused Cs transport to depths below that sampled, 30 cm. The results provide distribution coefficients for models of contaminant migration where animal burrowing occurs. 35 refs., 2 figs., 3 tabs

  7. Burrowing by Sailfin Catfish (Pterygoplichthys sp.): A Potential Cause of Erosion in Disturbed Environments

    Science.gov (United States)

    2014-03-01

    originates at a large levee, which was built to create a water retention (to control excess water) and water bird management area. The levee and canal...each sample was dried in stainless steel trays in a 60 °C convection oven . Two methods of quantitative analysis were performed to determine the...ERDC/TN ANSRP-14-1 March 2014 Approved for public release; distribution is unlimited. Burrowing by Sailfin Catfish (Pterygoplichthys sp.): A

  8. Burrowing Owl and Other Migratory Bird Mitigation for a Runway Construction Project at Edwards AFB

    OpenAIRE

    Hoehn, Amber L.; Hagan, Mark; Bratton, Mark

    2009-01-01

    Edwards Air Force Base (AFB) scheduled the construction of a runway in the spring of 2007. The runway would be in an area that contained migratory birds and their habitat. The construction project would be near Edwards AFB main runway and had the potential not only to impact species protected under the Migratory Bird Treaty Act (MBTA), including the burrowing owl (Athene cunicularia), but also to increase bird and wildlife–aircraft strike hazards in the active flightline areas. To discourage ...

  9. Razor clam to RoboClam: burrowing drag reduction mechanisms and their robotic adaptation

    International Nuclear Information System (INIS)

    Winter, A G; V; Dorsch, D S; Slocum, A H; Hosoi, A E; Deits, R L H

    2014-01-01

    Estimates based on the strength, size, and shape of the Atlantic razor clam (Ensis directus) indicate that the animal's burrow depth should be physically limited to a few centimeters; yet razor clams can dig as deep as 70 cm. By measuring soil deformations around burrowing E. directus, we have found the animal reduces drag by contracting its valves to initially fail, and then fluidize, the surrounding substrate. The characteristic contraction time to achieve fluidization can be calculated directly from soil properties. The geometry of the fluidized zone is dictated by two commonly-measured geotechnical parameters: coefficient of lateral earth pressure and friction angle. Calculations using full ranges for both parameters indicate that the fluidized zone is a local effect, occurring between 1–5 body radii away from the animal. The energy associated with motion through fluidized substrate—characterized by a depth-independent density and viscosity—scales linearly with depth. In contrast, moving through static soil requires energy that scales with depth squared. For E. directus, this translates to a 10X reduction in the energy required to reach observed burrow depths. For engineers, localized fluidization offers a mechanically simple and purely kinematic method to dramatically reduce energy costs associated with digging. This concept is demonstrated with RoboClam, an E. directus-inspired robot. Using a genetic algorithm to find optimal digging kinematics, RoboClam has achieved localized fluidization burrowing performance comparable to that of the animal, with a linear energy-depth relationship, in both idealized granular glass beads and E. directus' native cohesive mudflat habitat. (paper)

  10. Long-term population dynamics of a managed burrowing owl colony

    Science.gov (United States)

    Barclay, John H.; Korfanta, Nicole M.; Kauffman, Matthew J.

    2011-01-01

    We analyzed the population dynamics of a burrowing owl (Athene cunicularia) colony at Mineta San Jose International Airport in San Jose, California, USA from 1990-2007. This colony was managed by using artificial burrows to reduce the occurrence of nesting owls along runways and within major airport improvement projects during the study period. We estimated annual reproduction in natural and artificial burrows and age-specific survival rates with mark-recapture techniques, and we estimated the relative contribution of these vital rates to population dynamics using a life table response experiment. The breeding colony showed 2 distinct periods of change: high population growth from 7 nesting pairs in 1991 to 40 pairs in 2002 and population decline to 17 pairs in 2007. Reproduction was highly variable: annual nesting success (pairs that raised =1 young) averaged 79% and ranged from 36% to 100%, whereas fecundity averaged 3.36 juveniles/pair and ranged from 1.43 juveniles/pair to 4.54 juveniles/pair. We estimated annual adult survival at 0.710 during the period of colony increase from 1996 to 2001 and 0.465 during decline from 2002 to 2007, but there was no change in annual survival of juveniles between the 2 time periods. Long-term population growth rate (lambda) estimated from average vital rates was lambdaa=1.072 with lambdai=1.288 during colony increase and lambdad=0.921 (DELTA lambda=0.368) during decline. A life table response experiment showed that change in adult survival rate during increasing and declining phases explained more than twice the variation in growth rate than other vital rates. Our findings suggest that management and conservation of declining burrowing owl populations should address factors that influence adult survival.

  11. Distribution of the Chuckwalla, Western Burrowing Owl, and Six Bat Species on the Nevada Test Site

    Energy Technology Data Exchange (ETDEWEB)

    Cathy A. Willis

    1997-05-01

    Field Surveys were conducted in 1996 to determine the current distribution of several animal species of concern on the Nevada Test Site (NTS). They included the chuckwall (Sauromalus obesus), western burrowing owl (Speotyto cunicularia), and six species of bats. Nineteen chuckwallas and 118 scat locations were found during the chuckwalla field study. Eighteen western burrowing owls were found at 12 sighting locations during the 1996 field study. Of the eleven bat species of concern which might occur on the NTS, five, and possibly six, were captured during this survey. The U.S. Department of Energy, Nevada Operations Office, takes certain management actions to protect and conserve the chuckwalla, western burrowing owl, and bats on the NTS. These actions are described and include: (1) conducting surveys at sites of proposed land-disturbing activities (2) altering projects whenever possible to avoid or minimize impacts to these species (3) maintaining a geospatial database of known habitat for species of concern (4) sharing sighting and trap location data gathered on the NTS with other local land and resource managers, and (5) conducting periodic field surveys to monitor these species distribution and relative abundance on the NTS.

  12. Regional and Seasonal Diet of the Western Burrowing Owl in South-Central Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Derek B. Hall, Paul D. Greger, Jeffrey R. Rosier

    2009-04-01

    We examined diets of Western Burrowing Owls (Athene cunicularia hypugaea) based on contents of pellets and large prey remains collected year-round at burrows in each of the 3 regions in south central Nevada (Mojave Desert, Great Basin Desert, and Transition region). The most common prey items, based on percent frequency of occurrence, were crickets and grasshoppers, beetles, rodents, sun spiders, and scorpions. The most common vertebrate prey was kangaroo rats (Dipodomys spp.). True bugs (Hemiptera), scorpions, and western harvest mice (Reithrodontomys megalotis) occurred most frequently in pellets from the Great Basin Desert region. Kangaroo rats (Dipodomys spp.) and pocket mice (Perognathinae) were the most important vertebrate prey items in the Transition and Mojave Desert regions, respectively. Frequency of occurrence of any invertebrate prey was high (>80%) in samples year-round but dropped in winter samples, with scorpions and sun spiders exhibiting the steepest declines. Frequency of occurrence of any vertebrate prey peaked in spring samples, was intermediate for winter and summer samples, and was lowest in fall samples. With the possible exception of selecting for western harvest mice in the Great Basin Desert region, Western Burrowing Owls in our study appeared to be opportunistic foragers with a generalist feeding strategy.

  13. N2 production and fixation in deep-tier burrows of Squilla empusa in muddy sediments of Great Peconic Bay

    Science.gov (United States)

    Waugh, Stuart; Aller, Robert C.

    2017-11-01

    Global marine N budgets often show deficits due to dominance of benthic N2 production relative to pelagic N2 fixation. Recent studies have argued that benthic N2 fixation in shallow water environments has been underestimated. In particular, N2 fixation associated with animal burrows may be significant as indicated by high rates of N2 fixation reported in muddy sands populated by the ghost shrimp, Neotrypaea californiensis (Bertics et al., 2010). We investigated whether N2 fixation occurs at higher rates in the burrow-walls of the deep-burrowing ( 0.5-4 m) mantis shrimp, Squilla empusa, compared to ambient, estuarine muds and measured seasonal in-situ N2 concentrations in burrow-water relative to bottom-water. Acetylene reduction assays showed lower N2 fixation in burrow-walls than in un-populated sediments, likely due to inhibitory effects of O2 on ethylene production. Dissolved N2 was higher in burrow-water than proximate bottom-water at all seasons, demonstrating a consistent balance of net N2 production relative to fixation in deep-tier biogenic structures.

  14. Approximate maximum parsimony and ancestral maximum likelihood.

    Science.gov (United States)

    Alon, Noga; Chor, Benny; Pardi, Fabio; Rapoport, Anat

    2010-01-01

    We explore the maximum parsimony (MP) and ancestral maximum likelihood (AML) criteria in phylogenetic tree reconstruction. Both problems are NP-hard, so we seek approximate solutions. We formulate the two problems as Steiner tree problems under appropriate distances. The gist of our approach is the succinct characterization of Steiner trees for a small number of leaves for the two distances. This enables the use of known Steiner tree approximation algorithms. The approach leads to a 16/9 approximation ratio for AML and asymptotically to a 1.55 approximation ratio for MP.

  15. Maximum permissible dose

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    This chapter presents a historic overview of the establishment of radiation guidelines by various national and international agencies. The use of maximum permissible dose and maximum permissible body burden limits to derive working standards is discussed

  16. Burrowing behavior of a deposit feeding bivalve predicts change in intertidal ecosystem state

    Directory of Open Access Journals (Sweden)

    Tanya Joan Compton

    2016-03-01

    Full Text Available Behavior has a predictive power that is often underutilized as a tool for signaling ecological change. The burrowing behavior of the deposit feeding bivalve Macoma balthica reflects a typical food-safety trade-off. The choice to live close to the sediment surface comes at a risk of predation and is a decision made when predation danger, food intake rates or future fitness prospects are low. In parts of the Dutch Wadden Sea, Macoma populations declined by 90% in the late 1990s, in parallel with large-scale mechanical cockle-dredging activities. During this decline, the burrowing depth of Macoma became shallow and was correlated with the population decline in the following year, indicating that it forecasted population change. Recently, there has been a series of large recruitment events in Macoma. According to the food-safety trade-off, we expected that Macoma should now live deeper, and have a higher body condition in association with this change in depth of living. Indeed, we observed that Macoma now lives deeper and that living depth in a given year forecasted population growth to the next year, especially in individuals larger than 14 mm. As living depth and body condition were strongly correlated in individuals larger than 14 mm, larger Macoma could be living deeper to protect their reproductive assets. Our results confirmed that burrowing depth signals impending population change and, together with body condition, can provide an early warning signal of ecological change. We suggest that population recovery is being driven by improved intertidal habitat quality in the Dutch Wadden Sea, rather than by the proposed climate-change related effects. This shift in ecosystem state is suggested to include the recovery of diatom habitat in the top layer of the sediment after cockle-dredging ended.

  17. Importance of agricultural landscapes to nesting burrowing owls in the Northern Great Plains, USA

    Science.gov (United States)

    Restani, M.; Davies, J.M.; Newton, W.E.

    2008-01-01

    Anthropogenic habitat loss and fragmentation are the principle factors causing declines of grassland birds. Declines in burrowing owl (Athene cunicularia) populations have been extensive and have been linked to habitat loss, primarily the decline of black-tailed prairie dog (Cynomys ludovicianus) colonies. Development of habitat use models is a research priority and will aid conservation of owls inhabiting human-altered landscapes. From 2001 to 2004 we located 160 burrowing owl nests on prairie dog colonies on the Little Missouri National Grassland in North Dakota. We used multiple linear regression and Akaike's Information Criterion to estimate the relationship between cover type characteristics surrounding prairie dog colonies and (1) number of owl pairs per colony and (2) reproductive success. Models were developed for two spatial scales, within 600 m and 2,000 m radii of nests for cropland, crested wheatgrass (Agropyron cristatum), grassland, and prairie dog colonies. We also included number of patches as a metric of landscape fragmentation. Annually, fewer than 30% of prairie dog colonies were occupied by owls. None of the models at the 600 m scale explained variation in number of owl pairs or reproductive success. However, models at the 2,000 m scale did explain number of owl pairs and reproductive success. Models included cropland, crested wheatgrass, and prairie dog colonies. Grasslands were not included in any of the models and had low importance values, although percentage grassland surrounding colonies was high. Management that protects prairie dog colonies bordering cropland and crested wheatgrass should be implemented to maintain nesting habitat of burrowing owls. ?? 2008 Springer Science+Business Media B.V.

  18. Habitat selection by two species of burrowing mayfly nymphs in the Les Cheneaux Islands region of northern Lake Huron

    Science.gov (United States)

    Blouin, Marc A.; Hudson, Patrick; Chriscinske, Margret

    2004-01-01

    This study focused primarily on the habitat preferences of Hexagenia limbata andEphemera simulans, two species prevalent in northern Lake Huron, to gain a better understanding of the key components that determined their distribution and abundance. Both species preferred habitats based upon depth and sediment type. In addition, the burrowing activity of H. limbata was examined using in-situ, underwater sampling techniques specifically designed for the study. SCUBA divers made resin casts and took clear sediment cores in order to study how the burrow densities of H. limbata related to the sediment: water volume ratios. H. limbata contributed to the bioturbation and sediment porosity in specific, fine-sediment habitats. Younger age classes of this species utilized the burrows of their larger cohorts, an adaptation that could allow for energy savings and optimized growth.

  19. The Analysis of Burrows Recognition Accuracy in XINJIANG'S Pasture Area Based on Uav Visible Images with Different Spatial Resolution

    Science.gov (United States)

    Sun, D.; Zheng, J. H.; Ma, T.; Chen, J. J.; Li, X.

    2018-04-01

    The rodent disaster is one of the main biological disasters in grassland in northern Xinjiang. The eating and digging behaviors will cause the destruction of ground vegetation, which seriously affected the development of animal husbandry and grassland ecological security. UAV low altitude remote sensing, as an emerging technique with high spatial resolution, can effectively recognize the burrows. However, how to select the appropriate spatial resolution to monitor the calamity of the rodent disaster is the first problem we need to pay attention to. The purpose of this study is to explore the optimal spatial scale on identification of the burrows by evaluating the impact of different spatial resolution for the burrows identification accuracy. In this study, we shoot burrows from different flight heights to obtain visible images of different spatial resolution. Then an object-oriented method is used to identify the caves, and we also evaluate the accuracy of the classification. We found that the highest classification accuracy of holes, the average has reached more than 80 %. At the altitude of 24 m and the spatial resolution of 1cm, the accuracy of the classification is the highest We have created a unique and effective way to identify burrows by using UAVs visible images. We draw the following conclusion: the best spatial resolution of burrows recognition is 1 cm using DJI PHANTOM-3 UAV, and the improvement of spatial resolution does not necessarily lead to the improvement of classification accuracy. This study lays the foundation for future research and can be extended to similar studies elsewhere.

  20. Seasonal temperature acclimatization in a semi-fossorial mammal and the role of burrows as thermal refuges

    Science.gov (United States)

    Rachlow, Janet L.; Chappell, Mark A.; Camp, Meghan J.; Johnson, Timothy R.; Shipley, Lisa A.; Paul, David R.; Forbey, Jennifer S.

    2018-01-01

    Small mammals in habitats with strong seasonal variation in the thermal environment often exhibit physiological and behavioral adaptations for coping with thermal extremes and reducing thermoregulatory costs. Burrows are especially important for providing thermal refuge when above-ground temperatures require high regulatory costs (e.g., water or energy) or exceed the physiological tolerances of an organism. Our objective was to explore the role of burrows as thermal refuges for a small endotherm, the pygmy rabbit (Brachylagus idahoensis), during the summer and winter by quantifying energetic costs associated with resting above and below ground. We used indirect calorimetry to determine the relationship between energy expenditure and ambient temperature over a range of temperatures that pygmy rabbits experience in their natural habitat. We also measured the temperature of above- and below-ground rest sites used by pygmy rabbits in eastern Idaho, USA, during summer and winter and estimated the seasonal thermoregulatory costs of resting in the two microsites. Although pygmy rabbits demonstrated seasonal physiological acclimatization, the burrow was an important thermal refuge, especially in winter. Thermoregulatory costs were lower inside the burrow than in above-ground rest sites for more than 50% of the winter season. In contrast, thermal heterogeneity provided by above-ground rest sites during summer reduced the role of burrows as a thermal refuge during all but the hottest periods of the afternoon. Our findings contribute to an understanding of the ecology of small mammals in seasonal environments and demonstrate the importance of burrows as thermal refuge for pygmy rabbits. PMID:29576977

  1. Effects of change in primary forest cover on armadillo (Cingulata, Mammalia burrow use in the Central Amazon Efectos del cambio en la cobertura de bosque primario sobre el uso de las madrigueras por los armadillos (Cingulata, Mammalia en la Amazonia Central

    Directory of Open Access Journals (Sweden)

    María Clara Arteaga

    2012-03-01

    Full Text Available Transformation of primary forest to other vegetation types alters the availability and distribution of resources, and thus affects their use by species that inhabit the forest. Although armadillos are important earthmover mammals in the Amazon forest, and their burrows play an important physical and ecological role in the ecosystem, the impact of loss of primary forest cover on these organisms has been poorly understood. In order to evaluate the effects of change in the primary forest cover on burrow use by armadillos, we performed 2 censuses in 33 plots within 12 sites of different vegetation cover characteristics, and recorded burrow density and current use. A total of 109 armadillo burrows were found; the sites with higher percentages of primary forest cover showed a larger number of active burrows, although burrow density and the probability of establishing new burrows remained unaffected by this variable. Our results show that areas with higher quantities of primary forest habitat show more intense use by armadillos, probably due to the permanence time of individuals. These findings suggest that the viability of armadillo populations, as well as the role that these animals play within the ecosystem, may be affected in disturbed areas.La transformación del bosque primario a otro tipo de vegetación cambia la disponibilidad y distribución de los recursos, afectando su uso por especies que habitan el bosque. Los armadillos son el principal grupo de mamíferos escavadores del Amazonas y sus madrigueras cumplen un papel físico y ecológico en el ecosistema. Sin embargo, no se conoce el impacto de la pérdida del bosque sobre estos organismos. Con el fin de evaluar el efecto de los cambios en la cobertura de bosque primario sobre el uso de sus madrigueras, realizamos 2 censos en 33 parcelas dentro de 12 localidades con diferentes coberturas vegetales y reportamos la densidad y el estado de uso de las madrigueras. Encontramos 109 madrigueras y

  2. Real estate ads in Emei music frog vocalizations: female preference for calls emanating from burrows.

    Science.gov (United States)

    Cui, Jianguo; Tang, Yezhong; Narins, Peter M

    2012-06-23

    During female mate choice, both the male's phenotype and resources (e.g. his nest) contribute to the chooser's fitness. Animals other than humans are not known to advertise resource characteristics to potential mates through vocal communication; although in some species of anurans and birds, females do evaluate male qualities through vocal communication. Here, we demonstrate that calls of the male Emei music frog (Babina dauchina), vocalizing from male-built nests, reflect nest structure information that can be recognized by females. Inside-nest calls consisted of notes with energy concentrated at lower frequency ranges and longer note durations when compared with outside-nest calls. Centre frequencies and note durations of the inside calls positively correlate with the area of the burrow entrance and the depth of the burrow, respectively. When given a choice between outside and inside calls played back alternately, more than 70 per cent of the females (33/47) chose inside calls. These results demonstrate that males of this species faithfully advertise whether or not they possess a nest to potential mates by vocal communication, which probably facilitates optimal mate selection by females. These results revealed a novel function of advertisement calls, which is consistent with the wide variation in both call complexity and social behaviour within amphibians.

  3. Using ground penetrating radar in levee assessment to detect small scale animal burrows

    Science.gov (United States)

    Chlaib, Hussein K.; Mahdi, Hanan; Al-Shukri, Haydar; Su, Mehmet M.; Catakli, Aycan; Abd, Najah

    2014-04-01

    Levees are civil engineering structures built to protect human lives, property, and agricultural lands during flood events. To keep these important structures in a safe condition, continuous monitoring must be performed regularly and thoroughly. Small rodent burrows are one of the major defects within levees; however, their early detection and repair helps in protecting levees during flooding events. A set of laboratory experiments was conducted to analyze the polarity change in GPR signals in the presence of subsurface voids and water-filled cavities. Ground Penetrating Radar (GPR) surveys using multi frequency antennas (400 MHz and 900 MHz) were conducted along an 875 meter section of the Lollie Levee near Conway, Arkansas, USA, to assess the levee's structural integrity. Many subsurface animal burrows, water-filled cavities, clay clasts, and metallic objects were investigated and identified. These anomalies were located at different depths and have different sizes. To ground truth the observations, hand dug trenches were excavated to confirm several anomalies. Results show an excellent match between GPR interpreted anomalies and the observed features. In-situ dielectric constant measurements were used to calculate the feature depths. The results of this research show that the 900 MHz antenna has more advantages over the 400 MHz antenna.

  4. From LZ77 to the run-length encoded burrows-wheeler transform, and back

    DEFF Research Database (Denmark)

    Policriti, Alberto; Prezza, Nicola

    2017-01-01

    The Lempel-Ziv factorization (LZ77) and the Run-Length encoded Burrows-Wheeler Transform (RLBWT) are two important tools in text compression and indexing, being their sizes z and r closely related to the amount of text self-repetitiveness. In this paper we consider the problem of converting the t......(r + z) words of working space. Note that r and z can be constant if the text is highly repetitive, and our algorithms can operate with (up to) exponentially less space than naive solutions based on full decompression.......The Lempel-Ziv factorization (LZ77) and the Run-Length encoded Burrows-Wheeler Transform (RLBWT) are two important tools in text compression and indexing, being their sizes z and r closely related to the amount of text self-repetitiveness. In this paper we consider the problem of converting the two...... representations into each other within a working space proportional to the input and the output. Let n be the text length. We show that RLBWT can be converted to LZ77 in O(n log r) time and O(r) words of working space. Conversely, we provide an algorithm to convert LZ77 to RLBWT in O(n(log r + log z)) time and O...

  5. The effects of two free-floating plants (Eichhornia crassipes and Pistia stratiotes on the burrow morphology and water quality characteristics of pond loach (Misgurnus anguillicaudatus habitat

    Directory of Open Access Journals (Sweden)

    Jinqing Wang

    2018-01-01

    Full Text Available Loach exhibit conspicuous drilling behaviors in the mud of shallow waters, yet their burrow morphology and the factors affecting this behavior have received little attention. We characterized the burrow morphology and water quality of the pond loach Misgurnus anguillicaudatus in three scenarios: in tanks without plants, tanks with the free-floating plant water hyacinth Eichhornia crassipes, and tanks with water lettuce Pistia stratiotes. Water hyacinth effectively removed water TN, COD, NO3-N and NH4-N, and water lettuce removed water TP and NH4-N. Water hyacinth and water lettuce markedly reduced water turbidity and DO, increased TOC and EC. Water hyacinth purified water more effectively than water lettuce, providing a suitable habitat for loach feeding, living and burrowing. The burrow structures were V-shaped, Y-shaped, inverted L-shaped, or complicated dendritic networks composed of multiple V shapes. The hyacinth treatment was characterized by the greatest burrow volume, length, depth, and structural complexity, but the opening size was reduced by dense root mat coverage. Burrows in the water lettuce treatment were characterized by intermediate volume, length, branches and sinuosity, but they had the largest opening and pit size. The control treatment had a flat bottom with the smallest, shortest burrows. This study indicates that free-floating plants improve habitat suitability and change burrow morphology and may be used to improve loach breeding methods.

  6. Maximum Quantum Entropy Method

    OpenAIRE

    Sim, Jae-Hoon; Han, Myung Joon

    2018-01-01

    Maximum entropy method for analytic continuation is extended by introducing quantum relative entropy. This new method is formulated in terms of matrix-valued functions and therefore invariant under arbitrary unitary transformation of input matrix. As a result, the continuation of off-diagonal elements becomes straightforward. Without introducing any further ambiguity, the Bayesian probabilistic interpretation is maintained just as in the conventional maximum entropy method. The applications o...

  7. Maximum power demand cost

    International Nuclear Information System (INIS)

    Biondi, L.

    1998-01-01

    The charging for a service is a supplier's remuneration for the expenses incurred in providing it. There are currently two charges for electricity: consumption and maximum demand. While no problem arises about the former, the issue is more complicated for the latter and the analysis in this article tends to show that the annual charge for maximum demand arbitrarily discriminates among consumer groups, to the disadvantage of some [it

  8. PARTICLE REMOVAL RATES BY THE MUD SHRIMP UPOGEBIA PUGETTENSIS, ITS BURROW, AND A COMMENSAL CLAM: EFFECTS ON ESTUARINE PHYTOPLANKTON ABUNDANCE

    Science.gov (United States)

    The burrowing shrimp Upogebia pugettensis is an abundant intertidal inhabitant of Pacific Northwest bays and estuaries where it lives commensally with the bivalve Cryptomya californica. Suspension-feeding activities by the shrimp and by its commensal clam, as well as particle se...

  9. Distributional changes in the western Burrowing Owl (Athene cunicularia hypugaea) in North America from 1967 to 2008

    Science.gov (United States)

    Macias-Duarte, Alberto; Conway, Courtney J.

    2015-01-01

    The quantification of shifts in bird distributions in response to climate change provides an opportunity to gain a deeper understanding of the processes that influence species persistence. We used data from the North American Breeding Bird Survey (BBS) to document changes in the distributional limits of the western Burrowing Owl (Athene cunicularia hypugaea) from 1967 to 2008. We used logistic regression to model presence probability (p) as a function of longitude, latitude, and year. We modeled a linear trend in logit(p) through time with slope and intercept modeled as a double Fourier series of longitude and latitude. We found that the western Burrowing Owl has experienced an intriguing southward shift in the northern half of its breeding range, contrary to what is predicted by most species niche models and what has been observed for many other species in North America. The breeding range of the Burrowing Owl has been shrinking near its northern, western, and eastern edges. Our model detected the population declines that were observed in California and eastern Washington, in locations where maps based on route-specific estimating equations had predicted significant population increases. We suggest that the northern boundary of the breeding distribution of the western Burrowing Owl has contracted southward and the southern boundary of the species' breeding distribution has expanded southward into areas of northern Mexico that were formerly used only by wintering migrants.

  10. A maze-lover's dream: Burrow architecture, natural history and habitat characteristics of Ansell's mole-rat (Fukomys anselli)

    Czech Academy of Sciences Publication Activity Database

    Šklíba, J.; Mazoch, V.; Patzenhauerová, Hana; Hrouzková, E.; Lövy, M.; Kott, O.; Šumbera, R.

    2012-01-01

    Roč. 77, č. 6 (2012), s. 420-427 ISSN 1616-5047 R&D Projects: GA AV ČR IAA601410802 Institutional support: RVO:68081766 Keywords : Bathyergidae * Burrow system * Sociality * Habitat characteristics * Subterranean mammal * Fukomys anselli Subject RIV: EG - Zoology Impact factor: 1.246, year: 2012

  11. Burrow characteristics of the co-existing sibling species Mus booduga and Mus terricolor and the genetic basis of adaptation to hypoxic/hypercapnic stress

    Directory of Open Access Journals (Sweden)

    Narayan Gopeshwar

    2009-04-01

    Full Text Available Abstract Background The co-existing, sibling species Mus booduga and Mus terricolor show a difference in site-preference for burrows. The former build them in flat portion of the fields while the latter make burrows in earthen mounds raised for holding water in cultivated fields. In northern India which experiences great variation in climatic condition between summer and winter, M. booduga burrows have an average depth of 41 cm, as against 30 cm in southern India with less climatic fluctuation. M. terricolor burrows are about 20 cm deep everywhere. The three chromosomal species M. terricolor I, II and III have identical burrows, including location of the nest which is situated at the highest position. In contrast, in M. booduga burrows, the nest is at the lowest position. Results The nest chamber of M. booduga is located at greater depth than the nest chamber of M. terricolor. Also, in the burrows of M. booduga the exchange of air takes place only from one side (top surface in contrast to the burrows of M. terricolor where air exchange is through three sides. Hence, M. booduga lives in relatively more hypoxic and hypercapnic conditions than M. terricolor. We observed the fixation of alternative alleles in M. booduga and M. terricolor at Superoxide dismutase-1 (Sod-1, Transferrin (Trf and Hemoglobin beta chain (Hbb loci. All the three are directly or indirectly dependent on oxygen concentration for function. In addition to these, there are differences in burrow patterns and site-preference for burrows suggesting difference in probable adaptive strategy in these co-existing sibling species. Conclusion The burrow structure and depth of nest of the chromosomal species M. terricolor I, II and III are same everywhere probably due to the recency of their evolutionary divergence. Moreover, there is lack of competition for the well-adapted 'microhabitats' since they are non-overlapping in distribution. However, the co-existing sibling species M. booduga

  12. Maximum likely scale estimation

    DEFF Research Database (Denmark)

    Loog, Marco; Pedersen, Kim Steenstrup; Markussen, Bo

    2005-01-01

    A maximum likelihood local scale estimation principle is presented. An actual implementation of the estimation principle uses second order moments of multiple measurements at a fixed location in the image. These measurements consist of Gaussian derivatives possibly taken at several scales and/or ...

  13. Robust Maximum Association Estimators

    NARCIS (Netherlands)

    A. Alfons (Andreas); C. Croux (Christophe); P. Filzmoser (Peter)

    2017-01-01

    textabstractThe maximum association between two multivariate variables X and Y is defined as the maximal value that a bivariate association measure between one-dimensional projections αX and αY can attain. Taking the Pearson correlation as projection index results in the first canonical correlation

  14. Scent gland constituents of the Middle American burrowing python, Loxocemus bicolor (Serpentes: Loxocemidae).

    Science.gov (United States)

    Schulze, Thies; Weldon, Paul J; Schulz, Stefan

    2017-07-14

    Analysis by gas chromatography/mass spectrometry of the scent gland secretions of male and female Middle American burrowing pythons (Loxocemus bicolor) revealed the presence of over 300 components including cholesterol, fatty acids, glyceryl monoalkyl ethers, and alcohols. The fatty acids, over 100 of which were identified, constitute most of the compounds in the secretions and show the greatest structural diversity. They include saturated and unsaturated, unbranched and mono-, di-, and trimethyl-branched compounds ranging in carbon-chain length from 13 to 24. The glyceryl monoethers possess saturated or unsaturated, straight or methyl-branched alkyl chains ranging in carbon-chain length from 13 to 24. Alcohols, which have not previously been reported from the scent glands, possess straight, chiefly saturated carbon chains ranging in length from 13 to 24. Sex or individual differences in secretion composition were not observed. Compounds in the scent gland secretions of L. bicolor may deter offending arthropods, such as ants.

  15. The rhinoceros among Serpents: Comparative anatomy and experimental biophysics of Calabar burrowing python (Calabaria reinhardtii) skin.

    Science.gov (United States)

    Han, Dawei; Young, Bruce A

    2018-01-01

    The Calabar burrowing python (Calabaria reinhardtii) has a unique combination of marked thickness of the integumentary layers, a highly organized lamellate arrangement of the dermal collagen bundles, and a reduction in the size of the interscale hinge region of the integument. Biomechanical testing demonstrates that the skin of C. reinhardtii is more resistant to penetration than the skin of other snakes. The laminar arrangement of the collagen bundles provides for penetrative resistance, even while maintaining the flexibility characteristic of snake skin. Considering the life history of this species, it is hypothesized that the specialized integument of C. reinhardtii is a passive defensive mechanism against penetrative bites from maternal rodents and predators. © 2017 Wiley Periodicals, Inc.

  16. Effects of radiotransmitter necklaces on behaviors of adult male western burrowing owls

    Science.gov (United States)

    Chipman, E.D.; McIntyre, N.E.; Ray, J.D.; Wallace, M.C.; Boal, C.W.

    2007-01-01

    We studied the behavioral effects of necklace-style radiotransmitters on breeding male western burrowing owls (Athene cunicularia hypugaea) in 2 areas of northwestern Texas, USA, in 2004 and 2005. We tested the hypothesis that transmittered owls would spend time interacting with their necklaces and as a result spend less time in vigilance and resting activities than would nontransmittered owls. Nontransmittered owls (n = 6) spent significantly more time being vigilant (P = 0.007) than did transmittered owls (n = 3) in 2004, who spent significant amounts of time interacting with their necklaces. In 2005, behaviors of transmittered owls (n = 8) were significantly different (P of time interacting with their necklaces, they appeared to habituate to the presence of the transmitters within a relatively short period (<1 week), and necklaces did not affect survivorship or fitness in the short-term.

  17. Patterns of surface burrow plugging in a colony of black-tailed prairie dogs occupied by black-footed ferrets

    Science.gov (United States)

    Eads, David E.; Biggins, Dean E.

    2012-01-01

    Black-tailed prairie dogs (Cynomys ludovicianus) can surface-plug openings to a burrow occupied by a black-footed ferret (Mustela nigripes). At a coarse scale, surface plugs are more common in colonies of prairie dogs occupied by ferrets than in colonies without ferrets. However, little is known about spatial and temporal patterns of surface plugging in a colony occupied by ferrets. In a 452-ha colony of black-tailed prairie dogs in South Dakota, we sampled burrow openings for surface plugs and related those data to locations of ferrets observed during spotlight surveys. Of 67,574 burrow openings in the colony between June and September 2007, 3.7% were plugged. In a colony-wide grid of 80 m × 80 m cells, the occurrence of surface plugging (≥1 opening plugged) was greater in cells used by ferrets (93.3% of cells) than in cells not observably used by ferrets (70.6%). Rates of surface plugging (percentages of openings plugged) were significantly higher in cells used by ferrets (median = 3.7%) than in cells without known ferret use (median = 3.2%). Also, numbers of ferret locations in cells correlated positively with numbers of mapped surface plugs in the cells. To investigate surface plugging at finer temporal and spatial scales, we compared rates of surface plugging in 20-m-radius circle-plots centered on ferret locations and in random plots 1–4 days after observing a ferret (Jun–Oct 2007 and 2008). Rates of surface plugging were greater in ferret-plots (median = 12.0%) than in random plots (median = 0%). For prairie dogs and their associates, the implications of surface plugging could be numerous. For instance, ferrets must dig to exit or enter plugged burrows (suggesting energetic costs), and surface plugs might influence microclimates in burrows and consequently influence species that cannot excavate soil (e.g., fleas that transmit the plague bacterium Yersinia pestis).

  18. Burrowing as a novel voluntary strength training method for mice: A comparison of various voluntary strength or resistance exercise methods.

    Science.gov (United States)

    Roemers, P; Mazzola, P N; De Deyn, P P; Bossers, W J; van Heuvelen, M J G; van der Zee, E A

    2018-04-15

    Voluntary strength training methods for rodents are necessary to investigate the effects of strength training on cognition and the brain. However, few voluntary methods are available. The current study tested functional and muscular effects of two novel voluntary strength training methods, burrowing (digging a substrate out of a tube) and unloaded tower climbing, in male C57Bl6 mice. To compare these two novel methods with existing exercise methods, resistance running and (non-resistance) running were included. Motor coordination, grip strength and muscle fatigue were measured at baseline, halfway through and near the end of a fourteen week exercise intervention. Endurance was measured by an incremental treadmill test after twelve weeks. Both burrowing and resistance running improved forelimb grip strength as compared to controls. Running and resistance running increased endurance in the treadmill test and improved motor skills as measured by the balance beam test. Post-mortem tissue analyses revealed that running and resistance running induced Soleus muscle hypertrophy and reduced epididymal fat mass. Tower climbing elicited no functional or muscular changes. As a voluntary strength exercise method, burrowing avoids the confounding effects of stress and positive reinforcers elicited in forced strength exercise methods. Compared to voluntary resistance running, burrowing likely reduces the contribution of aerobic exercise components. Burrowing qualifies as a suitable voluntary strength training method in mice. Furthermore, resistance running shares features of strength training and endurance (aerobic) exercise and should be considered a multi-modal aerobic-strength exercise method in mice. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Maximum power point tracking

    International Nuclear Information System (INIS)

    Enslin, J.H.R.

    1990-01-01

    A well engineered renewable remote energy system, utilizing the principal of Maximum Power Point Tracking can be m ore cost effective, has a higher reliability and can improve the quality of life in remote areas. This paper reports that a high-efficient power electronic converter, for converting the output voltage of a solar panel, or wind generator, to the required DC battery bus voltage has been realized. The converter is controlled to track the maximum power point of the input source under varying input and output parameters. Maximum power point tracking for relative small systems is achieved by maximization of the output current in a battery charging regulator, using an optimized hill-climbing, inexpensive microprocessor based algorithm. Through practical field measurements it is shown that a minimum input source saving of 15% on 3-5 kWh/day systems can easily be achieved. A total cost saving of at least 10-15% on the capital cost of these systems are achievable for relative small rating Remote Area Power Supply systems. The advantages at larger temperature variations and larger power rated systems are much higher. Other advantages include optimal sizing and system monitor and control

  20. Infusion of low dose glyceryl trinitrate has no consistent effect on burrowing behavior, running wheel activity and light sensitivity in female rats

    DEFF Research Database (Denmark)

    Christensen, Sarah Louise T; Petersen, Steffen; Sørensen, Dorte Bratbo

    2016-01-01

    . In the current paper we have studied the effect of glyceryl trinitrate infusion on three different rat behaviors. Methods: The stability of burrowing behavior, running wheel activity and light sensitivity towards repeated testing was evaluated also with respect to estrous cycle. Finally, the effect of glyceryl...... trinitrate on these behaviors in female rats was observed. Results: Burrowing behavior and running wheel activity were stable in the individual rat between experiments. The burrowing behavior was significantly affected by the stage of estrous cycle. The other assays were stable throughout the cycle. None...

  1. Maximum entropy methods

    International Nuclear Information System (INIS)

    Ponman, T.J.

    1984-01-01

    For some years now two different expressions have been in use for maximum entropy image restoration and there has been some controversy over which one is appropriate for a given problem. Here two further entropies are presented and it is argued that there is no single correct algorithm. The properties of the four different methods are compared using simple 1D simulations with a view to showing how they can be used together to gain as much information as possible about the original object. (orig.)

  2. The last glacial maximum

    Science.gov (United States)

    Clark, P.U.; Dyke, A.S.; Shakun, J.D.; Carlson, A.E.; Clark, J.; Wohlfarth, B.; Mitrovica, J.X.; Hostetler, S.W.; McCabe, A.M.

    2009-01-01

    We used 5704 14C, 10Be, and 3He ages that span the interval from 10,000 to 50,000 years ago (10 to 50 ka) to constrain the timing of the Last Glacial Maximum (LGM) in terms of global ice-sheet and mountain-glacier extent. Growth of the ice sheets to their maximum positions occurred between 33.0 and 26.5 ka in response to climate forcing from decreases in northern summer insolation, tropical Pacific sea surface temperatures, and atmospheric CO2. Nearly all ice sheets were at their LGM positions from 26.5 ka to 19 to 20 ka, corresponding to minima in these forcings. The onset of Northern Hemisphere deglaciation 19 to 20 ka was induced by an increase in northern summer insolation, providing the source for an abrupt rise in sea level. The onset of deglaciation of the West Antarctic Ice Sheet occurred between 14 and 15 ka, consistent with evidence that this was the primary source for an abrupt rise in sea level ???14.5 ka.

  3. Maximum Entropy Fundamentals

    Directory of Open Access Journals (Sweden)

    F. Topsøe

    2001-09-01

    Full Text Available Abstract: In its modern formulation, the Maximum Entropy Principle was promoted by E.T. Jaynes, starting in the mid-fifties. The principle dictates that one should look for a distribution, consistent with available information, which maximizes the entropy. However, this principle focuses only on distributions and it appears advantageous to bring information theoretical thinking more prominently into play by also focusing on the "observer" and on coding. This view was brought forward by the second named author in the late seventies and is the view we will follow-up on here. It leads to the consideration of a certain game, the Code Length Game and, via standard game theoretical thinking, to a principle of Game Theoretical Equilibrium. This principle is more basic than the Maximum Entropy Principle in the sense that the search for one type of optimal strategies in the Code Length Game translates directly into the search for distributions with maximum entropy. In the present paper we offer a self-contained and comprehensive treatment of fundamentals of both principles mentioned, based on a study of the Code Length Game. Though new concepts and results are presented, the reading should be instructional and accessible to a rather wide audience, at least if certain mathematical details are left aside at a rst reading. The most frequently studied instance of entropy maximization pertains to the Mean Energy Model which involves a moment constraint related to a given function, here taken to represent "energy". This type of application is very well known from the literature with hundreds of applications pertaining to several different elds and will also here serve as important illustration of the theory. But our approach reaches further, especially regarding the study of continuity properties of the entropy function, and this leads to new results which allow a discussion of models with so-called entropy loss. These results have tempted us to speculate over

  4. Probable maximum flood control

    International Nuclear Information System (INIS)

    DeGabriele, C.E.; Wu, C.L.

    1991-11-01

    This study proposes preliminary design concepts to protect the waste-handling facilities and all shaft and ramp entries to the underground from the probable maximum flood (PMF) in the current design configuration for the proposed Nevada Nuclear Waste Storage Investigation (NNWSI) repository protection provisions were furnished by the United States Bureau of Reclamation (USSR) or developed from USSR data. Proposed flood protection provisions include site grading, drainage channels, and diversion dikes. Figures are provided to show these proposed flood protection provisions at each area investigated. These areas are the central surface facilities (including the waste-handling building and waste treatment building), tuff ramp portal, waste ramp portal, men-and-materials shaft, emplacement exhaust shaft, and exploratory shafts facility

  5. Introduction to maximum entropy

    International Nuclear Information System (INIS)

    Sivia, D.S.

    1988-01-01

    The maximum entropy (MaxEnt) principle has been successfully used in image reconstruction in a wide variety of fields. We review the need for such methods in data analysis and show, by use of a very simple example, why MaxEnt is to be preferred over other regularizing functions. This leads to a more general interpretation of the MaxEnt method, and its use is illustrated with several different examples. Practical difficulties with non-linear problems still remain, this being highlighted by the notorious phase problem in crystallography. We conclude with an example from neutron scattering, using data from a filter difference spectrometer to contrast MaxEnt with a conventional deconvolution. 12 refs., 8 figs., 1 tab

  6. Solar maximum observatory

    International Nuclear Information System (INIS)

    Rust, D.M.

    1984-01-01

    The successful retrieval and repair of the Solar Maximum Mission (SMM) satellite by Shuttle astronauts in April 1984 permitted continuance of solar flare observations that began in 1980. The SMM carries a soft X ray polychromator, gamma ray, UV and hard X ray imaging spectrometers, a coronagraph/polarimeter and particle counters. The data gathered thus far indicated that electrical potentials of 25 MeV develop in flares within 2 sec of onset. X ray data show that flares are composed of compressed magnetic loops that have come too close together. Other data have been taken on mass ejection, impacts of electron beams and conduction fronts with the chromosphere and changes in the solar radiant flux due to sunspots. 13 references

  7. Introduction to maximum entropy

    International Nuclear Information System (INIS)

    Sivia, D.S.

    1989-01-01

    The maximum entropy (MaxEnt) principle has been successfully used in image reconstruction in a wide variety of fields. The author reviews the need for such methods in data analysis and shows, by use of a very simple example, why MaxEnt is to be preferred over other regularizing functions. This leads to a more general interpretation of the MaxEnt method, and its use is illustrated with several different examples. Practical difficulties with non-linear problems still remain, this being highlighted by the notorious phase problem in crystallography. He concludes with an example from neutron scattering, using data from a filter difference spectrometer to contrast MaxEnt with a conventional deconvolution. 12 refs., 8 figs., 1 tab

  8. Functional Maximum Autocorrelation Factors

    DEFF Research Database (Denmark)

    Larsen, Rasmus; Nielsen, Allan Aasbjerg

    2005-01-01

    MAF outperforms the functional PCA in concentrating the interesting' spectra/shape variation in one end of the eigenvalue spectrum and allows for easier interpretation of effects. Conclusions. Functional MAF analysis is a useful methods for extracting low dimensional models of temporally or spatially......Purpose. We aim at data where samples of an underlying function are observed in a spatial or temporal layout. Examples of underlying functions are reflectance spectra and biological shapes. We apply functional models based on smoothing splines and generalize the functional PCA in......\\verb+~+\\$\\backslash\\$cite{ramsay97} to functional maximum autocorrelation factors (MAF)\\verb+~+\\$\\backslash\\$cite{switzer85,larsen2001d}. We apply the method to biological shapes as well as reflectance spectra. {\\$\\backslash\\$bf Methods}. MAF seeks linear combination of the original variables that maximize autocorrelation between...

  9. Regularized maximum correntropy machine

    KAUST Repository

    Wang, Jim Jing-Yan; Wang, Yunji; Jing, Bing-Yi; Gao, Xin

    2015-01-01

    In this paper we investigate the usage of regularized correntropy framework for learning of classifiers from noisy labels. The class label predictors learned by minimizing transitional loss functions are sensitive to the noisy and outlying labels of training samples, because the transitional loss functions are equally applied to all the samples. To solve this problem, we propose to learn the class label predictors by maximizing the correntropy between the predicted labels and the true labels of the training samples, under the regularized Maximum Correntropy Criteria (MCC) framework. Moreover, we regularize the predictor parameter to control the complexity of the predictor. The learning problem is formulated by an objective function considering the parameter regularization and MCC simultaneously. By optimizing the objective function alternately, we develop a novel predictor learning algorithm. The experiments on two challenging pattern classification tasks show that it significantly outperforms the machines with transitional loss functions.

  10. Regularized maximum correntropy machine

    KAUST Repository

    Wang, Jim Jing-Yan

    2015-02-12

    In this paper we investigate the usage of regularized correntropy framework for learning of classifiers from noisy labels. The class label predictors learned by minimizing transitional loss functions are sensitive to the noisy and outlying labels of training samples, because the transitional loss functions are equally applied to all the samples. To solve this problem, we propose to learn the class label predictors by maximizing the correntropy between the predicted labels and the true labels of the training samples, under the regularized Maximum Correntropy Criteria (MCC) framework. Moreover, we regularize the predictor parameter to control the complexity of the predictor. The learning problem is formulated by an objective function considering the parameter regularization and MCC simultaneously. By optimizing the objective function alternately, we develop a novel predictor learning algorithm. The experiments on two challenging pattern classification tasks show that it significantly outperforms the machines with transitional loss functions.

  11. Synthesis of Pt nanoparticles and their burrowing into Si due to synergistic effects of ion beam energy losses

    Directory of Open Access Journals (Sweden)

    Pravin Kumar

    2014-10-01

    Full Text Available We report the synthesis of Pt nanoparticles and their burrowing into silicon upon irradiation of a Pt–Si thin film with medium-energy neon ions at constant fluence (1.0 × 1017 ions/cm2. Several values of medium-energy neon ions were chosen in order to vary the ratio of the electronic energy loss to the nuclear energy loss (Se/Sn from 1 to 10. The irradiated films were characterized using Rutherford backscattering spectroscopy (RBS, atomic force microscopy (AFM, scanning electron microscopy (SEM, X-ray diffraction (XRD and high resolution transmission electron microscopy (HRTEM. A TEM image of a cross section of the film irradiated with Se/Sn = 1 shows ≈5 nm Pt NPs were buried up to ≈240 nm into the silicon. No silicide phase was detected in the XRD pattern of the film irradiated at the highest value of Se/Sn. The synergistic effect of the energy losses of the ion beam (molten zones are produced by Se, and sputtering and local defects are produced by Sn leading to the synthesis and burrowing of Pt NPs is evidenced. The Pt NP synthesis mechanism and their burrowing into the silicon is discussed in detail.

  12. ECOBIOLOGICAL STUDY ON BURROWING MUD LOBSTER THALASSINA ANOMALA (HERBST, 1804 (DECAPODA : THALASSINIDEA IN THE INTERTIDAL MANGROVE MUDFLAT OF DELTAIC SUNDARBANS

    Directory of Open Access Journals (Sweden)

    S. K. Dubey

    2012-07-01

    Full Text Available Populations of mud lobster Thalassina anomala were studied on tidal flats in the Sagar island of Indian Sundarbans. Ecologically they are recognized as the 'friends of mangrove' and a 'Biological Marvel' of the system. They turn up the deep soil to the surface by regular night shift burrowing exercise and help to import aerated tidal water in the burrows 2 to 2.5 meter deep. They have extra ordinary morphological adaptation and structural changes and completely resort to detritivore diet. Being thigmotactic it seldom exposes to atmospheric oxygen and forms its palace underground with a central chamber having 5 to 6 radiated tunnels opening to the surface covered with earth mounds. It displays its engineering skill of bioturbation in tunneling. During tunneling the shrimp feeds on the mud packed with detritus and derived its required micronutrients. Being mud dwelling and mud eating habits, it's respiratory and food manipulating apparatus underwent transformations which demands intensive investigation. Thalassinid burrow associates comprising mieo and microorganisms also provide good subject of study of species specific interaction, exchanging of materials between associate partners.

  13. Incidence of plastic fragments among burrow-nesting seabird colonies on offshore islands in northern New Zealand.

    Science.gov (United States)

    Buxton, Rachel T; Currey, Caitlin A; Lyver, Philip O'B; Jones, Christopher J

    2013-09-15

    Marine plastic pollution is ubiquitous throughout the world's oceans, and has been found in high concentrations in oceanic gyres of both the northern and southern hemispheres. The number of studies demonstrating plastic debris at seabird colonies and plastic ingestion by adult seabirds has increased over the past few decades. Despite the recent discovery of a large aggregation of plastic debris in the South Pacific subtropical gyre, the incidence of plastics at seabird colonies in New Zealand is unknown. Between 2011 and 2012 we surveyed six offshore islands on the northeast coast of New Zealand's North Island for burrow-nesting seabird colonies and the presence of plastic fragments. We found non-research related plastic fragments (0.031 pieces/m(2)) on one island only, Ohinau, within dense flesh-footed shearwater (Puffinus carneipes) colonies. On Ohinau, we found a linear relationship between burrow density and plastic density, with 3.5 times more breeding burrows in areas with plastic fragments found. From these data we conclude that plastic ingestion is a potentially a serious issue for flesh-footed shearwaters in New Zealand. Although these results do not rule out plastic ingestion by other species, they suggest the need for further research on the relationship between New Zealand's pelagic seabirds and marine plastic pollution. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Failure to Burrow and Tunnel Reveals Roles for jim lovell in the Growth and Endoreplication of the Drosophila Larval Tracheae.

    Directory of Open Access Journals (Sweden)

    Fanli Zhou

    Full Text Available The Drosophila protein Jim Lovell (Lov is a putative transcription factor of the BTB/POZ (Bric- a-Brac/Tramtrack/Broad/ Pox virus and Zinc finger domain class that is expressed in many elements of the developing larval nervous system. It has roles in innate behaviors such as larval locomotion and adult courtship. In performing tissue-specific knockdown with the Gal4-UAS system we identified a new behavioral phenotype for lov: larvae failed to burrow into their food during their growth phase and then failed to tunnel into an agarose substratum during their wandering phase. We determined that these phenotypes originate in a previously unrecognized role for lov in the tracheae. By using tracheal-specific Gal4 lines, Lov immunolocalization and a lov enhancer trap line, we established that lov is normally expressed in the tracheae from late in embryogenesis through larval life. Using an assay that monitors food burrowing, substrate tunneling and death we showed that lov tracheal knockdown results in tracheal fluid-filling, producing hypoxia that activates the aberrant behaviors and inhibits development. We investigated the role of lov in the tracheae that initiates this sequence of events. We discovered that when lov levels are reduced, the tracheal cells are smaller, more numerous and show lower levels of endopolyploidization. Together our findings indicate that Lov is necessary for tracheal endoreplicative growth and that its loss in this tissue causes loss of tracheal integrity resulting in chronic hypoxia and abnormal burrowing and tunneling behavior.

  15. Role of burrowing activities of the Great Basin pocket mouse (Perognathus parvus) in the dispersal of radionuclides on a decommissioned pond

    International Nuclear Information System (INIS)

    Landeen, D.S.; Mitchell, R.M.

    1982-08-01

    The intrusion of waste burial sites by animals is a common occurrence at nuclear waste facilities. This study identifies parameters associated with burrowing activities of the Great Basin Pocket Mouse at the Hanford Site in southeastern Washington. The objectives of the study were to: (1) document and compare burrow depths on a control site and a decommissioned radioactive waste pond and (2) document 137 Cs concentrations in pocket mice and the soil mounds created by their burrowing activities. Pocket mice burrowed deeper in the backfilled burial site (anti x = 72 cm) than they did in the control site (anti x = 38 cm). The small amounts of 137 Cs found in the mice were an order of magnitude below what was present in the mounds. This indicates that the burrowing habits of these mice and subsequent mound construction may be more important in terms of radionuclide dispersal than the small amounts contained within their bodies. The 137 Cs values reported in the mice and mounds are below Rockwell Hanford Operations (Rockwell) surface soil contamination limits. Information received from test plots will be used in formulating appropriate control mechanisms which may be deployed in the future. In the interim, surface stabilization efforts are being conducted on waste sites to control and deter burrowing animals

  16. Isotopic signatures (13C/12C; 15N/14N) of blue penguin burrow soil invertebrates : carbon sources and trophic relationships

    International Nuclear Information System (INIS)

    Hawke, D.J.; Clark, J.M.

    2010-01-01

    Seabird burrows provide a soil environment for processing discards such as feathers and guano, hence constituting a primary interface between the sea and the land. This study involved collection and culturing of soil invertebrates from three blue penguin (Eudyptula minor) burrows, and examined their 13 C/ 12 C and 15 N/ 14 N isotopic composition in relation to potential burrow resources (terrestrial plant litter, burrow soil, guano, blue penguin feathers). Two taxa (cerylonid beetles and small tineid moth larvae) had a depleted 13 C/ 12 C indicative of a level of dependence on C from terrestrial soil. Tineid moth larvae (Monopis crocicapitella and (or) M. ethelella) substantially increased their 13 C/ 12 C enrichment during development, implying increasing dependence on marine C. Remaining taxa, both decomposers and predators, had 13 C/ 12 C intermediate between guano and feathers. Larval and emergent fleas had the most enriched 13 C/ 12 C , indicative of a greater dependence on feather C and the likelihood of co-processing with guano. Pseudoscorpions and histerid beetles had overlapping isotopic enrichments implying competition for prey, but were spatially separated in burrow soil. With their highly enriched 15 N/ 14 N and marine 13 C/ 12 C, larvae and protonymphs of the histiostomatid mite Myianoetus antipodus stood alone. Blue penguin burrows therefore support a diverse invertebrate fauna that incorporates terrestrial soil as well as varying proportions of the various blue penguin discards. (author). 45 refs., 1 fig., 1 tab.

  17. Effects of radiotransmitter necklaces on behaviors of adult male western burrowing owls

    Science.gov (United States)

    Chipman, E.D.; McIntyre, N.E.; Ray, J.D.; Wallace, M.C.; Boal, C.W.

    2007-01-01

    We studied the behavioral effects of necklace-style radiotransmitters on breeding male western burrowing owls (Athene cunicularia hypugaea) in 2 areas of northwestern Texas, USA, in 2004 and 2005. We tested the hypothesis that transmittered owls would spend time interacting with their necklaces and as a result spend less time in vigilance and resting activities than would nontransmittered owls. Nontransmittered owls (n = 6) spent significantly more time being vigilant (P = 0.007) than did transmittered owls (n = 3) in 2004, who spent significant amounts of time interacting with their necklaces. In 2005, behaviors of transmittered owls (n = 8) were significantly different (P < 0.001) from control individuals (n = 4), but behaviors did not vary consistently by treatment period (prenecklace vs. necklace vs. postnecklace periods). Behavioral activity budgets varied considerably among individuals. Although the owls spent a significant amount of time interacting with their necklaces, they appeared to habituate to the presence of the transmitters within a relatively short period (<1 week), and necklaces did not affect survivorship or fitness in the short-term.

  18. Solar maximum mission

    International Nuclear Information System (INIS)

    Ryan, J.

    1981-01-01

    By understanding the sun, astrophysicists hope to expand this knowledge to understanding other stars. To study the sun, NASA launched a satellite on February 14, 1980. The project is named the Solar Maximum Mission (SMM). The satellite conducted detailed observations of the sun in collaboration with other satellites and ground-based optical and radio observations until its failure 10 months into the mission. The main objective of the SMM was to investigate one aspect of solar activity: solar flares. A brief description of the flare mechanism is given. The SMM satellite was valuable in providing information on where and how a solar flare occurs. A sequence of photographs of a solar flare taken from SMM satellite shows how a solar flare develops in a particular layer of the solar atmosphere. Two flares especially suitable for detailed observations by a joint effort occurred on April 30 and May 21 of 1980. These flares and observations of the flares are discussed. Also discussed are significant discoveries made by individual experiments

  19. Association of the "IUCN vulnerable "spiny rat Clyomys bishopi (Rodentia:Echimyidaewith palm trees and armadillo burrows in southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Adriana A Bueno

    2004-12-01

    Full Text Available The globally vulnerable Clyomys bishopi ,a semi-fossorial and colonial rodent,is apparently limited to cerrado (savannah-like vegetationphysiognomies in São Paulo State,Brazil.The aim of the study was to verify whether the presence of C.bishopi is associated to the occurrence of palm trees (Attalea gearensis, Syagrus loefgrenii and armadillo burrows.Thirty six quadrats were placed in different physiognomies of cerrado vegetation at Itirapina Ecological Station,southeastern Brazil to survey the number of C.bishopi burrows of individuals of palm trees and burrows of armadillos.There was a strong dependence and association between the number of C.bishopi burrows and all measured variables (Contingency tables and Spearman rank correlations.It is suggested that this rodent can be found in great numbers where palm trees are abundant.The use of armadillo burrows possibly makes the movement of the rodents easier inside their own galleries.Rev.Biol. Trop. 52(4:1009-1011.Epub 2005 Jun 24.El roedor colonial Clyomys bishopi está aparentemente limitado a vegetación de semi-sabana (cerradoen el estado de São Paulo,Brasil.El objetivo de este estudio fue verificar si la presencia de C.bishopi está asociada a la individuos de las palmeras Attalea gearensis,Syagrus loefgrenii y madrigueras de armadillos.El estudio fue realizado en la Estación Ecológica de Itirapina,en el sureste de Brasil.Treinta y seis cuadrantes fueron dispuestos en diferentes fisionomías del la vegetación del cerrado para encuestar el número de madrigueras de C.bishopi, árboles individuales de palma y madrigueras de armadillos.Se calcularon tablas de contingencia y correlaciones de Sperman para evaluar, respectivamente, la dependencia y asociación entre el número de madrigueras de C.bishopi y las otras variables.Se encontró una fuerte dependencia y asociación entre el número de madrigueras de C.bishopi y todas las variables medidas.Esto sugiere que este roedor alcanza grandes

  20. Investigation of plutonium concentration and distribution in burrowing crayfish from the White Oak Creek floodplain

    Energy Technology Data Exchange (ETDEWEB)

    Delaney, M.S.; Dahlman, R.C.; Craig, R.B.

    1979-01-01

    The White Oak floodplain was contaminated with several radionuclides, including /sup 239/Pu, during the Manhattan Project in 1944. Plutonium distribution in the soil is nonhomogeneous. An investigation was conducted to deterine Pu accumulation in a resident animal population. Crayfish were chosen because they complete their life-cycle within the contaminated environment, they directly contact contaminated muds, and they function in a food chain of significance to man. Two major conclusions of the research were that Pu concentrations in contaminated crayfish typically exceed those of control crayfish by two orders of magnitude and that if an incident were to occur in which a standard man ingested the soft tissues of ten crayfish from the floodplain, an insignificant whole body dose would accrue over the subsequent 50 years of life. The digestive tract of contaminated crayfish contained 21 to 33% of the Pu body burden, soft tissues contained 11 to 31% of the Pu body burden, and 48 to 62% of the Pu body burden of contaminated crayfish was associated with the carapace. Therefore, at a molt a large proportion of its accumulated Pu is deposited in the environment. A supplementary laboratory investigation using /sup 237/Pu included a chronic Pu uptake study by uncontaminated crayfish. In these crayfish, from 64 to 82% of the /sup 237/Pu was associated with the body tissues. Complementary data for /sup 237/Pu associated with the carapace ranged from 18 to 37% of the distribution. An inventory of /sup 239/Pu in crayfish at two sites on the floodplain was calculated by multiplying the estimated biomass of the crayfish by their average /sup 239/Pu concentration. This evaluation of Pu associated with the crayfish population was compared to an inventory of /sup 239/Pu in the soil in which they burrow and was found to be eight orders of magnitude less.

  1. Behavioral Correlations Associated with Fear of Humans Differ between Rural and Urban Burrowing Owls

    Directory of Open Access Journals (Sweden)

    Martina Carrete

    2017-05-01

    Full Text Available Behavioral studies are fundamental to understanding how animal populations face global change. Although much research has centered upon the idea that individuals can adaptively modify their behaviors to cope with environmental changes, recent evidence supports the existence of individual differences in suites of correlated behaviors. However, little is known about how selection can change these behavioral structures in populations subject to different environmental constraints. The colonization of urban environments by birds has been related to their inter-individual variability in their fear of humans, measured as their flight initiation distance to an approaching human, such that urban life would select for fearless individuals. This behavior has been demonstrated to be heritable and highly consistent throughout the adult lifespan of burrowing owls (Athene cunicularia. Here, we experimentally assessed, in field conditions, whether urban life involves changes in other behaviors such as exploration and antipredatory response through their correlation with fear of humans. Breeding urban birds were more fearless toward humans and were quicker to explore a new food resource and defend their nests from predators than their rural counterparts. However, while fear of humans positively correlated with exploration and antipredatory response in the rural population, it only correlated with exploration in the urban one. Predator release in urban environments could relax—and even counterselect—antipredator behaviors, thus dismantling the behavioral correlation existent in natural populations. Altogether, our results suggest that rural and urban animals may differ in some behavioral aspects, may be as a consequence of the selection processes acting during the colonization of urban areas as well as the different ecological environments encountered by individuals.

  2. Investigation of plutonium concentration and distribution in burrowing crayfish from the White Oak Creek floodplain

    International Nuclear Information System (INIS)

    Delaney, M.S.; Dahlman, R.C.; Craig, R.B.

    1979-01-01

    The White Oak floodplain was contaminated with several radionuclides, including 239 Pu, during the Manhattan Project in 1944. Plutonium distribution in the soil is nonhomogeneous. An investigation was conducted to deterine Pu accumulation in a resident animal population. Crayfish were chosen because they complete their life-cycle within the contaminated environment, they directly contact contaminated muds, and they function in a food chain of significance to man. Two major conclusions of the research were that Pu concentrations in contaminated crayfish typically exceed those of control crayfish by two orders of magnitude and that if an incident were to occur in which a standard man ingested the soft tissues of ten crayfish from the floodplain, an insignificant whole body dose would accrue over the subsequent 50 years of life. The digestive tract of contaminated crayfish contained 21 to 33% of the Pu body burden, soft tissues contained 11 to 31% of the Pu body burden, and 48 to 62% of the Pu body burden of contaminated crayfish was associated with the carapace. Therefore, at a molt a large proportion of its accumulated Pu is deposited in the environment. A supplementary laboratory investigation using 237 Pu included a chronic Pu uptake study by uncontaminated crayfish. In these crayfish, from 64 to 82% of the 237 Pu was associated with the body tissues. Complementary data for 237 Pu associated with the carapace ranged from 18 to 37% of the distribution. An inventory of 239 Pu in crayfish at two sites on the floodplain was calculated by multiplying the estimated biomass of the crayfish by their average 239 Pu concentration. This evaluation of Pu associated with the crayfish population was compared to an inventory of 239 Pu in the soil in which they burrow and was found to be eight orders of magnitude less

  3. Body and skull morphometric variations between two shovel-headed species of Amphisbaenia (Reptilia: Squamata with morphofunctional inferences on burrowing

    Directory of Open Access Journals (Sweden)

    Leandro dos Santos Lima Hohl

    2017-07-01

    Full Text Available Background Morphological descriptions comparing Leposternon microcephalum and L. scutigerum have been made previously. However, these taxa lack a formal quantitative morphological characterization, and comparative studies suggest that morphology and burrowing performance are be related. The excavatory movements of L. microcephalum have been described in detail. However, there is a lack of studies comparing locomotor patterns and/or performance among different amphisbaenids sharing the same skull shape. This paper presents the first study of comparative morphometric variations between two closely related amphisbaenid species, L. microcephalum and L. scutigerum, with functional inferences on fossorial locomotion efficiency. Methods Inter-specific morphometric variations were verified through statistical analyses of body and cranial measures of L. microcephalum and L. scutigerum specimens. Their burrowing activity was assessed through X-ray videofluoroscopy and then compared. The influence of morphological variation on the speed of digging was tested among Leposternon individuals. Results Leposternon microcephalum and L. scutigerum are morphometrically distinct species. The first is shorter and robust with a wider head while the other is more elongated and slim with a narrower head. They share the same excavatory movements. The animals analyzed reached relatively high speeds, but individuals with narrower skulls dug faster. A negative correlation between the speed and the width of skull was determined, but not with total length or diameter of the body. Discussion The morphometric differences between L. microcephalum and L. scutigerum are in accord with morphological variations previously described. Since these species performed the same excavation pattern, we may infer that closely related amphisbaenids with the same skull type would exhibit the same excavatory pattern. The negative correlation between head width and excavation speed is also

  4. The chemistry and mineralogy of haloed burrows in pelagic sediment at DOMES Site A: The equatorial North Pacific

    Science.gov (United States)

    Piper, D.Z.; Rude, P.D.; Monteith, S.

    1987-01-01

    The chemical and mineralogical composition of burrowed sediment, recovered in 66 box cores at latitude 9??25???N and longitude 151??15???W in the equatorial Pacific, demonstrates the important role of infauna in determining the geochemistry of pelagic sediment. Haloed burrows, approximately 3 cm across, were present in many of the cores. Within early Tertiary sediment that was covered by less than 5 cm of surface Quaternary sediment in several cores, the burrows in cross-section consist of three units: (1) a dark yellowish-brown central zone of Quaternary sediment surrounded, by (2) a pale yellowish-orange zone (the halo) of Tertiary sediment, which is surrounded by (3) a metal-oxide precipitate; the enclosing Tertiary sediment is dusky brown. Several elements - Mn, Ni, Cu, Co, Zn, Sb and Ce - have been leached from the light-colored halo, whereas Cr, Cs, Hf, Rb, Sc, Ta, Th, U, the rare earth elements exclusive of Ce, and the major oxides have not been leached. The metal-oxide zone, 1-5 mm thick, contains as much as 16% MnO2, as the mineral todorokite. The composition of the todorokite, exclusive of the admixed Tertiary sediment, resembles the composition of the metal deficit of the halo and also the composition of surface ferromanganese nodules that have been interpreted as having a predominantly diagenetic origin. Thus bioturbation contributes not only to the redistribution of metals within pelagic sediment, but also to the accretion of ferromanganese nodules on the sea floor. ?? 1987.

  5. Comparison of hydraulics and particle removal efficiencies in a mixed cell raceway and Burrows pond rearing system

    Science.gov (United States)

    Moffitt, Christine M.

    2016-01-01

    We compared the hydrodynamics of replicate experimental mixed cell and replicate standard Burrows pond rearing systems at the Dworshak National Fish Hatchery, ID, in an effort to identify methods for improved solids removal. We measured and compared the hydraulic residence time, particle removal efficiency, and measures of velocity using several tools. Computational fluid dynamics was used first to characterize hydraulics in the proposed retrofit that included removal of the traditional Burrows pond dividing wall and establishment of four counter rotating cells with appropriate drains and inlet water jets. Hydraulic residence time was subsequently established in the four full scale test tanks using measures of conductivity of a salt tracer introduced into the systems both with and without fish present. Vertical and horizontal velocities were also measured with acoustic Doppler velocimetry in transects across each of the rearing systems. Finally, we introduced ABS sinking beads that simulated fish solids then followed the kinetics of their removal via the drains to establish relative purge rates. The mixed cell raceway provided higher mean velocities and a more uniform velocity distribution than did the Burrows pond. Vectors revealed well-defined, counter-rotating cells in the mixed cell raceway, and were likely contributing factors in achieving a relatively high particle removal efficiency-88.6% versus 8.0% during the test period. We speculate retrofits of rearing ponds to mixed cell systems will improve both the rearing environments for the fish and solids removal, improving the efficiency and bio-security of fish culture. We recommend further testing in hatchery production trials to evaluate fish physiology and growth.

  6. Urban pollution of sediments: Impact on the physiology and burrowing activity of tubificid worms and consequences on biogeochemical processes

    Energy Technology Data Exchange (ETDEWEB)

    Pigneret, M., E-mail: mathilde.pigneret@univ-lyon1.fr [LEHNA, UMR CNRS 5023, Ecologie des Hydrosystèmes Naturels et Anthropisés, Université de Lyon, Université Lyon 1, ENTPE, 6 rue Raphael Dubois, 69622 Villeurbanne (France); Mermillod-Blondin, F.; Volatier, L.; Romestaing, C. [LEHNA, UMR CNRS 5023, Ecologie des Hydrosystèmes Naturels et Anthropisés, Université de Lyon, Université Lyon 1, ENTPE, 6 rue Raphael Dubois, 69622 Villeurbanne (France); Maire, E.; Adrien, J. [MATEIS, UMR CNRS 5510, INSA de Lyon, 25 avenue Jean Capelle, 69621 Villeurbanne (France); Guillard, L.; Roussel, D.; Hervant, F. [LEHNA, UMR CNRS 5023, Ecologie des Hydrosystèmes Naturels et Anthropisés, Université de Lyon, Université Lyon 1, ENTPE, 6 rue Raphael Dubois, 69622 Villeurbanne (France)

    2016-10-15

    In urban areas, infiltration basins are designed to manage stormwater runoff from impervious surfaces and allow the settling of associated pollutants. The sedimentary layer deposited at the surface of these structures is highly organic and multicontaminated (mainly heavy metals and hydrocarbons). Only few aquatic species are able to maintain permanent populations in such an extreme environment, including the oligochaete Limnodrilus hoffmeisteri. Nevertheless, the impact of urban pollutants on these organisms and the resulting influence on infiltration basin functioning remain poorly studied. Thus, the aim of this study was to determine how polluted sediments could impact the survival, the physiology and the bioturbation activity of L. hoffmeisteri and thereby modify biogeochemical processes occurring at the water-sediment interface. To this end, we conducted laboratory incubations of worms, in polluted sediments from infiltration basins or slightly polluted sediments from a stream. Analyses were performed to evaluate physiological state and burrowing activity (X-ray micro-tomography) of worms and their influences on biogeochemical processes (nutrient fluxes, CO{sub 2} and CH{sub 4} degassing rates) during 30-day long experiments. Our results showed that worms exhibited physiological responses to cope with high pollution levels, including a strong ability to withstand the oxidative stress linked to contamination with heavy metals. We also showed that the presence of urban pollutants significantly increased the burrowing activity of L. hoffmeisteri, demonstrating the sensitivity and the relevance of such a behavioural response as biomarker of sediment toxicity. In addition, we showed that X-ray micro-tomography was an adequate technique for accurate and non-invasive three-dimensional investigations of biogenic structures formed by bioturbators. The presence of worms induced stimulations of nutrient fluxes and organic matter recycling (between + 100% and 200% of CO

  7. Ichnofabrics and Facies in the Paleocene of Chicxulub: A Record of the Recovery of Life Post-Impact

    Science.gov (United States)

    Whalen, M. T.; O'Malley, K.; Lowery, C. M.; Rodriguez-Tovar, F. J.; Gulick, S. P. S.; Morgan, J. V.

    2017-12-01

    IODP/ICDP Expedition 364 recovered 829 m of core at Site M0077 including 110 m of post-impact, (hemi)pelagic Paleogene sedimentary rocks overlying the Chicxulub impact crater peak ring formed from suevite, melt rock, and granitic basement. The transition between suevite and Paleocene limestone (Unit 1F) is a remarkable fining upward package of gravel to sand-sized suevite (Unit 2A) overlain by the laminated carbonate-rich Unit 1G that records deposition of fine-grained material post-impact and contains a mix of Late Cretaceous and earliest Danian taxa. This study concentrates on the overlying Unit 1F. The ichnofabric index (ii, 1-6 indicating no bioturbation to complete homogenization), provides a semiquantitative estimate of burrow density to help assess the return of life to the crater. Unit 1F is 10 m thick with a sharp contact at the base of a green claystone (ii 2) that overlies Unit 1G. It consists of cm-dm interbedded blue-gray marlstone (ii 2) grading upward into gray to blue-gray wacke/packstone (ii 3-5). Contacts between facies are mostly gradational due to burrowing. The upper 3 m of the unit is a yellow-brown burrowed packstone (ii 4) intercalated with gray marlstone (ii 2). The uppermost 7.5 cm is calcite cemented with 1 cm wide burrows (ii 3-4) and fine to coarse sand size clasts including foraminifera. The upper surface of the unit is a hardground with an 2 Myr unconformity overlain by Eocene rocks. The first well-defined burrows occur in the upper 30 cm of Unit 1G. Unequivocal burrows (ii 2) that disturb sedimentary facies occur in overlying Unit 1F with values of 3-5 recorded in the overlying 10 cm indicating significant disruption of primary sedimentary structures. The iis in Unit 1F vary between 2 and 5 with rare laminated intervals without bioturbation (ii 1). Values of ii correlate well with facies changes, i.e. marlstones display lower iis than more carbonate-rich facies, implying a depth and/or redox control on burrower distribution. The ii

  8. Trait aggressiveness does not predict social dominance of rats in the Visible Burrow System.

    Science.gov (United States)

    Buwalda, Bauke; Koolhaas, Jaap M; de Boer, Sietse F

    2017-09-01

    Hierarchical social status greatly influences health and well-being in mammals, including humans. The social rank of an individual is established during competitive encounters with conspecifics. Intuitively, therefore, social dominance and aggressiveness may seem intimately linked. Yet, whether an aggressive personality trait may predispose individuals to a particular rank in a social colony setting remains largely unclear. Here we tested the hypothesis that high trait aggressiveness in Wildtype Groningen (WTG) rats, as assessed in a classic resident-intruder offensive aggression paradigm predicts social dominance in a mixed-sex colony housing using the Visible Burrow System (VBS). We also hypothesized that hierarchical steepness, as reflected in the number and intensity of the social conflicts, positively correlates with the average level of trait aggressiveness of the male subjects in the VBS. Clear and stable hierarchical ranking was formed within a few days in VBS colonies as indicated and reflected by a rapid loss of body weight in subordinates which stabilized after 2-3days. Social conflicts, that occurred mainly during these first few days, also resulted in bite wounds in predominantly subordinate males. Data clearly showed that trait aggressiveness does not predict dominance status. The most aggressive male in a mixed sex group of conspecifics living in a closed VBS environment does not always become the dominant male. In addition, data did not convincingly indicate that in colonies with only highly aggressive males, agonistic interactions were more intense. Number of bite wounds and body weight loss did not positively correlate with trait-aggressiveness of subordinates. In this study, rats from this wild-derived rat strain behave differently from Long-Evans laboratory rats that have been studied up till now in many experiments using the VBS. Strain dependent differences in the capacity to display appropriate social behavior fitting an adaptive strategy to

  9. Credal Networks under Maximum Entropy

    OpenAIRE

    Lukasiewicz, Thomas

    2013-01-01

    We apply the principle of maximum entropy to select a unique joint probability distribution from the set of all joint probability distributions specified by a credal network. In detail, we start by showing that the unique joint distribution of a Bayesian tree coincides with the maximum entropy model of its conditional distributions. This result, however, does not hold anymore for general Bayesian networks. We thus present a new kind of maximum entropy models, which are computed sequentially. ...

  10. Comparison of burrowing and stimuli-evoked pain behaviors as end-points in rat models of inflammatory pain and peripheral neuropathic pain

    Directory of Open Access Journals (Sweden)

    Arjun eMuralidharan

    2016-05-01

    Full Text Available Establishment and validation of ethologically-relevant, non-evoked behavioral end-points as surrogate measures of spontaneous pain in rodent pain models has been proposed as a means to improve preclinical to clinical research translation in the pain field. Here, we compared the utility of burrowing behavior with hypersensitivity to applied mechanical stimuli for pain assessment in rat models of chronic inflammatory and peripheral neuropathic pain. Briefly, groups of male Sprague-Dawley rats were habituated to the burrowing environment and trained over a 5-day period. Rats that burrowed ≤450g of gravel on any two days of the individual training phase were excluded from the study. The remaining rats received either a unilateral intraplantar injection of Freund’s complete adjuvant (FCA or saline, or underwent unilateral chronic constriction injury (CCI of the sciatic nerve- or sham-surgery. Baseline burrowing behavior and evoked pain behaviors were assessed prior to model induction, and twice-weekly until study completion on day 14. For FCA- and CCI-rats, but not the corresponding groups of sham-rats, evoked mechanical hypersensitivity developed in a temporal manner in the ipsilateral hindpaws. Although burrowing behavior also decreased in a temporal manner for both FCA- and CCI-rats, there was considerable inter-animal variability. By contrast, mechanical hyperalgesia and mechanical allodynia in the ipsilateral hindpaws of FCA- and CCI-rats respectively, exhibited minimal inter-animal variability. Our data collectively show that burrowing behavior is altered in rodent models of chronic inflammatory pain and peripheral neuropathic pain. However, large group sizes are needed to ensure studies are adequately powered due to considerable inter-animal variability.

  11. Oribatid mites (Acari: Oribatida) in casts and burrows of an endemic earthworm .i.Dendrobaena mrazeki./i. and in litter of thermophilous oak forests

    Czech Academy of Sciences Publication Activity Database

    Starý, Josef; Pižl, Václav

    2007-01-01

    Roč. 26, č. 4 (2007), s. 390-397 ISSN 1335-342X R&D Projects: GA ČR GA206/03/0056 Institutional research plan: CEZ:AV0Z60660521 Keywords : soil oribatid mites * earthworms * casts and burrows Subject RIV: EH - Ecology, Behaviour Impact factor: 0.085, year: 2005

  12. Flea abundance, diversity, and plague in Gunnison's prairie dogs (Cynomys gunnisoni) and their burrows in montane grasslands in northern New Mexico

    Science.gov (United States)

    Megan M. Friggens; Robert R. Parmenter; Michael Boyden; Paulette L. Ford; Kenneth Gage; Paul Keim

    2010-01-01

    Plague, a flea-transmitted infectious disease caused by the bacterium Yersinia pestis, is a primary threat to the persistence of prairie dog populations (Cynomys spp.). We conducted a 3-yr survey (2004-2006) of fleas from Gunnison's prairie dogs (Cynomys gunnisoni) and their burrows in montane grasslands in Valles Caldera National Preserve in New Mexico. Our...

  13. Locomotory behaviour and functional morphology of Nematostella vectensis (Anthozoa: Actiniaria: Edwardsiidae): a contribution to a comparative study of burrowing behaviour in athenarian sea anemones

    NARCIS (Netherlands)

    Williams, R.B.

    2003-01-01

    The locomotory behaviour and functional morphology of English populations of a small (<2 cm long), burrowing athenarian sea anemone, Nematostella vectensis Stephenson, 1935 (= N. pellucida Crowell, 1946), which lives in soft mud in salt marshes and creeks, are described. Objectives were to ascertain

  14. Composite Phymatoderma from Neogene deep-marine deposits in Japan: Implications for Phanerozoic benthic interactions between burrows and the trace-makers of Chondrites and Phycosiphon

    Directory of Open Access Journals (Sweden)

    Kentaro Izumi

    2015-12-01

    Full Text Available Among composite trace fossils, one of the most common structures throughout the Phanerozoic are structures (e.g., dwelling trace, feeding trace reworked by Chondrites and/or Phycosiphon. However, differences in the nature of the reworking behaviors of these two ichnogenera remain unknown. Thus, in this study, composite Phymatoderma specimens from the Neogene deep-marine Shiramazu Formation in Japan, particularly those reworked by Chondrites and Phycosiphon, were analyzed to reveal the specific conditions that might control the activities of these trace-makers. Phymatoderma reworked by Phycosiphon is significantly larger than non-reworked Phymatoderma, whereas Phymatoderma reworked by Chondrites shows no significant difference in burrow diameter compared with non-reworked Phymatoderma. The recognized size selectivity (i.e., preference for larger burrows by the Phycosiphon trace-maker can be explained by considering the different feeding strategies of these two ichnogenera; namely deposit-feeding Phycosiphon-makers, which must have processed a significant mass of sediment to obtain sufficient organic matter, whereas chemosymbiotic Chondrites-producers did not require a lot of sediment to obtain nutrients. In order to test these interpretations, a dataset of Phanerozoic trace fossils reworked by Chondrites/Phycosiphon were compiled. Consequently, the Phycosiphon-producers’ preference toward relatively larger burrows was recognized, quantitatively supporting the results of this study. The compilation also indicates that the burrow size might have become one of the important limiting factors for the Phycosiphon-producers that tried to rework the sediments within previous subsurface burrows, at least for 80 million years.

  15. Burrower bugs (Heteroptera: Cydnidae) in peanut: seasonal species abundance, tillage effects, grade reduction effects, insecticide efficacy, and management.

    Science.gov (United States)

    Chapin, Jay W; Thomas, James S

    2003-08-01

    Pitfall traps placed in South Carolina peanut, Arachis hypogaea (L.), fields collected three species of burrower bugs (Cydnidae): Cyrtomenus ciliatus (Palisot de Beauvois), Sehirus cinctus cinctus (Palisot de Beauvois), and Pangaeus bilineatus (Say). Cyrtomenus ciliatus was rarely collected. Sehirus cinctus produced a nymphal cohort in peanut during May and June, probably because of abundant henbit seeds, Lamium amplexicaule L., in strip-till production systems. No S. cinctus were present during peanut pod formation. Pangaeus bilineatus was the most abundant species collected and the only species associated with peanut kernel feeding injury. Overwintering P. bilineatus adults were present in a conservation tillage peanut field before planting and two to three subsequent generations were observed. Few nymphs were collected until the R6 (full seed) growth stage. Tillage and choice of cover crop affected P. bilineatus populations. Peanuts strip-tilled into corn or wheat residue had greater P. bilineatus populations and kernel-feeding than conventional tillage or strip-tillage into rye residue. Fall tillage before planting a wheat cover crop also reduced burrower bug feeding on peanut. At-pegging (early July) granular chlorpyrifos treatments were most consistent in suppressing kernel feeding. Kernels fed on by P. bilineatus were on average 10% lighter than unfed on kernels. Pangaeus bilineatus feeding reduced peanut grade by reducing individual kernel weight, and increasing the percentage damaged kernels. Each 10% increase in kernels fed on by P. bilineatus was associated with a 1.7% decrease in total sound mature kernels, and kernel feeding levels above 30% increase the risk of damaged kernel grade penalties.

  16. Maximum Entropy in Drug Discovery

    Directory of Open Access Journals (Sweden)

    Chih-Yuan Tseng

    2014-07-01

    Full Text Available Drug discovery applies multidisciplinary approaches either experimentally, computationally or both ways to identify lead compounds to treat various diseases. While conventional approaches have yielded many US Food and Drug Administration (FDA-approved drugs, researchers continue investigating and designing better approaches to increase the success rate in the discovery process. In this article, we provide an overview of the current strategies and point out where and how the method of maximum entropy has been introduced in this area. The maximum entropy principle has its root in thermodynamics, yet since Jaynes’ pioneering work in the 1950s, the maximum entropy principle has not only been used as a physics law, but also as a reasoning tool that allows us to process information in hand with the least bias. Its applicability in various disciplines has been abundantly demonstrated. We give several examples of applications of maximum entropy in different stages of drug discovery. Finally, we discuss a promising new direction in drug discovery that is likely to hinge on the ways of utilizing maximum entropy.

  17. Maximum stellar iron core mass

    Indian Academy of Sciences (India)

    60, No. 3. — journal of. March 2003 physics pp. 415–422. Maximum stellar iron core mass. F W GIACOBBE. Chicago Research Center/American Air Liquide ... iron core compression due to the weight of non-ferrous matter overlying the iron cores within large .... thermal equilibrium velocities will tend to be non-relativistic.

  18. Maximum entropy beam diagnostic tomography

    International Nuclear Information System (INIS)

    Mottershead, C.T.

    1985-01-01

    This paper reviews the formalism of maximum entropy beam diagnostic tomography as applied to the Fusion Materials Irradiation Test (FMIT) prototype accelerator. The same formalism has also been used with streak camera data to produce an ultrahigh speed movie of the beam profile of the Experimental Test Accelerator (ETA) at Livermore. 11 refs., 4 figs

  19. Maximum entropy beam diagnostic tomography

    International Nuclear Information System (INIS)

    Mottershead, C.T.

    1985-01-01

    This paper reviews the formalism of maximum entropy beam diagnostic tomography as applied to the Fusion Materials Irradiation Test (FMIT) prototype accelerator. The same formalism has also been used with streak camera data to produce an ultrahigh speed movie of the beam profile of the Experimental Test Accelerator (ETA) at Livermore

  20. A portable storage maximum thermometer

    International Nuclear Information System (INIS)

    Fayart, Gerard.

    1976-01-01

    A clinical thermometer storing the voltage corresponding to the maximum temperature in an analog memory is described. End of the measurement is shown by a lamp switch out. The measurement time is shortened by means of a low thermal inertia platinum probe. This portable thermometer is fitted with cell test and calibration system [fr

  1. Neutron spectra unfolding with maximum entropy and maximum likelihood

    International Nuclear Information System (INIS)

    Itoh, Shikoh; Tsunoda, Toshiharu

    1989-01-01

    A new unfolding theory has been established on the basis of the maximum entropy principle and the maximum likelihood method. This theory correctly embodies the Poisson statistics of neutron detection, and always brings a positive solution over the whole energy range. Moreover, the theory unifies both problems of overdetermined and of underdetermined. For the latter, the ambiguity in assigning a prior probability, i.e. the initial guess in the Bayesian sense, has become extinct by virtue of the principle. An approximate expression of the covariance matrix for the resultant spectra is also presented. An efficient algorithm to solve the nonlinear system, which appears in the present study, has been established. Results of computer simulation showed the effectiveness of the present theory. (author)

  2. On Maximum Entropy and Inference

    Directory of Open Access Journals (Sweden)

    Luigi Gresele

    2017-11-01

    Full Text Available Maximum entropy is a powerful concept that entails a sharp separation between relevant and irrelevant variables. It is typically invoked in inference, once an assumption is made on what the relevant variables are, in order to estimate a model from data, that affords predictions on all other (dependent variables. Conversely, maximum entropy can be invoked to retrieve the relevant variables (sufficient statistics directly from the data, once a model is identified by Bayesian model selection. We explore this approach in the case of spin models with interactions of arbitrary order, and we discuss how relevant interactions can be inferred. In this perspective, the dimensionality of the inference problem is not set by the number of parameters in the model, but by the frequency distribution of the data. We illustrate the method showing its ability to recover the correct model in a few prototype cases and discuss its application on a real dataset.

  3. Maximum Water Hammer Sensitivity Analysis

    OpenAIRE

    Jalil Emadi; Abbas Solemani

    2011-01-01

    Pressure waves and Water Hammer occur in a pumping system when valves are closed or opened suddenly or in the case of sudden failure of pumps. Determination of maximum water hammer is considered one of the most important technical and economical items of which engineers and designers of pumping stations and conveyance pipelines should take care. Hammer Software is a recent application used to simulate water hammer. The present study focuses on determining significance of ...

  4. Maximum Gene-Support Tree

    Directory of Open Access Journals (Sweden)

    Yunfeng Shan

    2008-01-01

    Full Text Available Genomes and genes diversify during evolution; however, it is unclear to what extent genes still retain the relationship among species. Model species for molecular phylogenetic studies include yeasts and viruses whose genomes were sequenced as well as plants that have the fossil-supported true phylogenetic trees available. In this study, we generated single gene trees of seven yeast species as well as single gene trees of nine baculovirus species using all the orthologous genes among the species compared. Homologous genes among seven known plants were used for validation of the finding. Four algorithms—maximum parsimony (MP, minimum evolution (ME, maximum likelihood (ML, and neighbor-joining (NJ—were used. Trees were reconstructed before and after weighting the DNA and protein sequence lengths among genes. Rarely a gene can always generate the “true tree” by all the four algorithms. However, the most frequent gene tree, termed “maximum gene-support tree” (MGS tree, or WMGS tree for the weighted one, in yeasts, baculoviruses, or plants was consistently found to be the “true tree” among the species. The results provide insights into the overall degree of divergence of orthologous genes of the genomes analyzed and suggest the following: 1 The true tree relationship among the species studied is still maintained by the largest group of orthologous genes; 2 There are usually more orthologous genes with higher similarities between genetically closer species than between genetically more distant ones; and 3 The maximum gene-support tree reflects the phylogenetic relationship among species in comparison.

  5. LCLS Maximum Credible Beam Power

    International Nuclear Information System (INIS)

    Clendenin, J.

    2005-01-01

    The maximum credible beam power is defined as the highest credible average beam power that the accelerator can deliver to the point in question, given the laws of physics, the beam line design, and assuming all protection devices have failed. For a new accelerator project, the official maximum credible beam power is determined by project staff in consultation with the Radiation Physics Department, after examining the arguments and evidence presented by the appropriate accelerator physicist(s) and beam line engineers. The definitive parameter becomes part of the project's safety envelope. This technical note will first review the studies that were done for the Gun Test Facility (GTF) at SSRL, where a photoinjector similar to the one proposed for the LCLS is being tested. In Section 3 the maximum charge out of the gun for a single rf pulse is calculated. In Section 4, PARMELA simulations are used to track the beam from the gun to the end of the photoinjector. Finally in Section 5 the beam through the matching section and injected into Linac-1 is discussed

  6. The importance of scale-dependent ravine characteristics on breeding-site selection by the Burrowing Parrot, Cyanoliseus patagonus

    Directory of Open Access Journals (Sweden)

    Myriam Ramirez-Herranz

    2017-04-01

    Full Text Available In birds, the environmental variables and intrinsic characteristics of the nest have important fitness consequences through its influence on the selection of nesting sites. However, the extent to which these variables interact with variables that operate at the landscape scale, and whether there is a hierarchy among the different scales that influences nest-site selection, is unknown. This interaction could be crucial in burrowing birds, which depend heavily on the availability of suitable nesting locations. One representative of this group is the burrowing parrot, Cyanoliseus patagonus that breeds on specific ravines and forms large breeding colonies. At a particular site, breeding aggregations require the concentration of adequate environmental elements for cavity nesting, which are provided by within ravine characteristics. Therefore, intrinsic ravine characteristics should be more important in determining nest site selection compared to landscape level characteristics. Here, we assess this hypothesis by comparing the importance of ravine characteristics operating at different scales on nest-site selection and their interrelation with reproductive success. We quantified 12 characteristics of 105 ravines in their reproductive habitat. For each ravine we quantified morphological variables, distance to resources and disturbance as well as nest number and egg production in order to compare selected and non-selected ravines and determine the interrelationship among variables in explaining ravine differences. In addition, the number of nests and egg production for each reproductive ravine was related to ravine characteristics to assess their relation to reproductive success. We found significant differences between non-reproductive and reproductive ravines in both intrinsic and extrinsic characteristics. The multidimensional environmental gradient of variation between ravines, however, shows that differences are mainly related to intrinsic

  7. Effects of the burrowing crab Chasmagnathus granulata (Dana on meiofauna of estuarine intertidal habitats of Patos Lagoon, Southern Brazil

    Directory of Open Access Journals (Sweden)

    Leonardo Cruz Rosa

    2005-03-01

    Full Text Available This study aimed to evaluate the effects of the burrowing crab Chasmagnathus granulata on meiofauna at three intertidal habitats across a tidal exposure gradient (i.e., an emerged salt marsh, an emerged mudflat and a submerged mudflat in an estuarine embayment of Patos Lagoon, Southern Brazil. Meiofauna community was dominated by nematodes and ostracods, following by copepods and turbellarians. Densities of all studied organisms varied significantly among habitats. Highest values were observed in submerged mudflat while lower in salt marsh. Nematodes were unaffected by crab in either habitat, whereas ostracod, copepod and turbellarian densities were significantly lower in disturbed than control areas in both mudflat habitats. Any meiofaunal group was affected in salt marsh, probably due to a less intense disturbance. The results showed that the burrowing crab C. granulata could play an important role on meiofauna community structure in estuarine intertidal habitats of Patos Lagoon, because crab disturbance seemed to affect mainly surface populations, especially in mudflat. However, the meiofauna response to crab disturbance was variable among habitats depending of the intensity and the frequency of the disturbance.Este trabalho avalia os efeitos do caranguejo Chasmagnathus granulata sobre a meiofauna em três ambientes intermareais, durante um prolongado período de exposição (uma marisma emersa, um plano de lama emerso e outro submerso, numa enseada estuarina da Lagoa dos Patos. Nematódeos e ostrácodes foram os organismos dominantes, seguidos por copépodes e turbelários. As densidades dos organismos variam significativamente entre os hábitats. As maiores densidades foram registradas no plano de lama submerso e as menores na marisma. Os nematódeos não foram afetados pelo caranguejo em nenhum hábitat. As densidades dos ostrácodes, copépodes e turbelários foram significativamente menores nos sedimentos perturbados do que nas

  8. Generic maximum likely scale selection

    DEFF Research Database (Denmark)

    Pedersen, Kim Steenstrup; Loog, Marco; Markussen, Bo

    2007-01-01

    in this work is on applying this selection principle under a Brownian image model. This image model provides a simple scale invariant prior for natural images and we provide illustrative examples of the behavior of our scale estimation on such images. In these illustrative examples, estimation is based......The fundamental problem of local scale selection is addressed by means of a novel principle, which is based on maximum likelihood estimation. The principle is generally applicable to a broad variety of image models and descriptors, and provides a generic scale estimation methodology. The focus...

  9. Cydninae (Hemiptera, Heteroptera, Cydnidae) in Brazil: updated checklist, new records, and description of Tominotus ondulatus sp. nov.

    Science.gov (United States)

    Avendaño, José Mauricio; Grazia, Jocelia; Schwertner, Cristiano Feldens

    2017-10-09

    Cydninae is the largest subfamily among burrower bugs all around the world and for Brazil the genera Cyrtomenus, Dallasiellus, Ectinopus, Melanaethus, Onalips, Pangaeus, Prolobodes and Tominotus were reported with a total of 39 species, so far. Basing on the material of nine entomological collections, we updated the list to 47 species including new records and a new species, Tominotus ondulatus sp. nov. described from Restinga, Rio Grande do Sul. Distribution maps and photos of dorsal habits for several species are also provided.

  10. Extreme Maximum Land Surface Temperatures.

    Science.gov (United States)

    Garratt, J. R.

    1992-09-01

    There are numerous reports in the literature of observations of land surface temperatures. Some of these, almost all made in situ, reveal maximum values in the 50°-70°C range, with a few, made in desert regions, near 80°C. Consideration of a simplified form of the surface energy balance equation, utilizing likely upper values of absorbed shortwave flux (1000 W m2) and screen air temperature (55°C), that surface temperatures in the vicinity of 90°-100°C may occur for dry, darkish soils of low thermal conductivity (0.1-0.2 W m1 K1). Numerical simulations confirm this and suggest that temperature gradients in the first few centimeters of soil may reach 0.5°-1°C mm1 under these extreme conditions. The study bears upon the intrinsic interest of identifying extreme maximum temperatures and yields interesting information regarding the comfort zone of animals (including man).

  11. A case of leucism in the burrowing owl Athene cunicularia (Aves: Strigiformes with confirmation of species identity using cytogenetic analysis

    Directory of Open Access Journals (Sweden)

    Denise M Nogueira

    2011-02-01

    Full Text Available Leucism is an inherited disorder, characterized by the lack of pigments in part or all of the body, normal coloration of the eyes and, in birds, in naked parts such as the bill and legs. This kind of disorder is sometimes erroneously designated as albinism or partial albinism. In this study, we present a case of leucism in a wild owl. The studied individual presented completely white plumage, light-yellow coloration of legs and bill and normal coloration of eyes. According to morphological features, this owl is a specimen of burrowing owl, Athene cunicularia (Molina, 1782. To confirm the species identity, we used cytogenetic analyses for karyotypic determination, comparing it to the previously described one in the literature. We also studied a captive female of A. cunicularia to complement the species karyotype, which was described in the literature based only on a single male. The karyotype of the leucistic owl individual was compatible with the previously published one for A. cunicularia, confirming the bird was a male specimen. Cytogenetic analysis of the captive female showed that the W sex chromosome is metacentric and comparable to the seventh pair in size. This is the first description of a case of leucism in A. cunicularia for South America. Long-term studies are needed in the Neotropical region to evaluate survival and breeding success in leucistic birds.

  12. System for memorizing maximum values

    Science.gov (United States)

    Bozeman, Richard J., Jr.

    1992-08-01

    The invention discloses a system capable of memorizing maximum sensed values. The system includes conditioning circuitry which receives the analog output signal from a sensor transducer. The conditioning circuitry rectifies and filters the analog signal and provides an input signal to a digital driver, which may be either linear or logarithmic. The driver converts the analog signal to discrete digital values, which in turn triggers an output signal on one of a plurality of driver output lines n. The particular output lines selected is dependent on the converted digital value. A microfuse memory device connects across the driver output lines, with n segments. Each segment is associated with one driver output line, and includes a microfuse that is blown when a signal appears on the associated driver output line.

  13. Remarks on the maximum luminosity

    Science.gov (United States)

    Cardoso, Vitor; Ikeda, Taishi; Moore, Christopher J.; Yoo, Chul-Moon

    2018-04-01

    The quest for fundamental limitations on physical processes is old and venerable. Here, we investigate the maximum possible power, or luminosity, that any event can produce. We show, via full nonlinear simulations of Einstein's equations, that there exist initial conditions which give rise to arbitrarily large luminosities. However, the requirement that there is no past horizon in the spacetime seems to limit the luminosity to below the Planck value, LP=c5/G . Numerical relativity simulations of critical collapse yield the largest luminosities observed to date, ≈ 0.2 LP . We also present an analytic solution to the Einstein equations which seems to give an unboundedly large luminosity; this will guide future numerical efforts to investigate super-Planckian luminosities.

  14. Maximum mutual information regularized classification

    KAUST Repository

    Wang, Jim Jing-Yan

    2014-09-07

    In this paper, a novel pattern classification approach is proposed by regularizing the classifier learning to maximize mutual information between the classification response and the true class label. We argue that, with the learned classifier, the uncertainty of the true class label of a data sample should be reduced by knowing its classification response as much as possible. The reduced uncertainty is measured by the mutual information between the classification response and the true class label. To this end, when learning a linear classifier, we propose to maximize the mutual information between classification responses and true class labels of training samples, besides minimizing the classification error and reducing the classifier complexity. An objective function is constructed by modeling mutual information with entropy estimation, and it is optimized by a gradient descend method in an iterative algorithm. Experiments on two real world pattern classification problems show the significant improvements achieved by maximum mutual information regularization.

  15. Scintillation counter, maximum gamma aspect

    International Nuclear Information System (INIS)

    Thumim, A.D.

    1975-01-01

    A scintillation counter, particularly for counting gamma ray photons, includes a massive lead radiation shield surrounding a sample-receiving zone. The shield is disassembleable into a plurality of segments to allow facile installation and removal of a photomultiplier tube assembly, the segments being so constructed as to prevent straight-line access of external radiation through the shield into radiation-responsive areas. Provisions are made for accurately aligning the photomultiplier tube with respect to one or more sample-transmitting bores extending through the shield to the sample receiving zone. A sample elevator, used in transporting samples into the zone, is designed to provide a maximum gamma-receiving aspect to maximize the gamma detecting efficiency. (U.S.)

  16. Maximum mutual information regularized classification

    KAUST Repository

    Wang, Jim Jing-Yan; Wang, Yi; Zhao, Shiguang; Gao, Xin

    2014-01-01

    In this paper, a novel pattern classification approach is proposed by regularizing the classifier learning to maximize mutual information between the classification response and the true class label. We argue that, with the learned classifier, the uncertainty of the true class label of a data sample should be reduced by knowing its classification response as much as possible. The reduced uncertainty is measured by the mutual information between the classification response and the true class label. To this end, when learning a linear classifier, we propose to maximize the mutual information between classification responses and true class labels of training samples, besides minimizing the classification error and reducing the classifier complexity. An objective function is constructed by modeling mutual information with entropy estimation, and it is optimized by a gradient descend method in an iterative algorithm. Experiments on two real world pattern classification problems show the significant improvements achieved by maximum mutual information regularization.

  17. Maximum spectral demands in the near-fault region

    Science.gov (United States)

    Huang, Yin-Nan; Whittaker, Andrew S.; Luco, Nicolas

    2008-01-01

    The Next Generation Attenuation (NGA) relationships for shallow crustal earthquakes in the western United States predict a rotated geometric mean of horizontal spectral demand, termed GMRotI50, and not maximum spectral demand. Differences between strike-normal, strike-parallel, geometric-mean, and maximum spectral demands in the near-fault region are investigated using 147 pairs of records selected from the NGA strong motion database. The selected records are for earthquakes with moment magnitude greater than 6.5 and for closest site-to-fault distance less than 15 km. Ratios of maximum spectral demand to NGA-predicted GMRotI50 for each pair of ground motions are presented. The ratio shows a clear dependence on period and the Somerville directivity parameters. Maximum demands can substantially exceed NGA-predicted GMRotI50 demands in the near-fault region, which has significant implications for seismic design, seismic performance assessment, and the next-generation seismic design maps. Strike-normal spectral demands are a significantly unconservative surrogate for maximum spectral demands for closest distance greater than 3 to 5 km. Scale factors that transform NGA-predicted GMRotI50 to a maximum spectral demand in the near-fault region are proposed.

  18. Maximum entropy and Bayesian methods

    International Nuclear Information System (INIS)

    Smith, C.R.; Erickson, G.J.; Neudorfer, P.O.

    1992-01-01

    Bayesian probability theory and Maximum Entropy methods are at the core of a new view of scientific inference. These 'new' ideas, along with the revolution in computational methods afforded by modern computers allow astronomers, electrical engineers, image processors of any type, NMR chemists and physicists, and anyone at all who has to deal with incomplete and noisy data, to take advantage of methods that, in the past, have been applied only in some areas of theoretical physics. The title workshops have been the focus of a group of researchers from many different fields, and this diversity is evident in this book. There are tutorial and theoretical papers, and applications in a very wide variety of fields. Almost any instance of dealing with incomplete and noisy data can be usefully treated by these methods, and many areas of theoretical research are being enhanced by the thoughtful application of Bayes' theorem. Contributions contained in this volume present a state-of-the-art overview that will be influential and useful for many years to come

  19. Recolonization and possible recovery of burrowing mayflies (Ephemeroptera: Ephemeridae: Hexagenia spp.) in Lake Erie of the Laurentian Great Lakes

    Science.gov (United States)

    Schloesser, Don W.; Krieger, Kenneth A.; Ciborowski, Jan J.H.; Corkum, Lynda D.

    2000-01-01

    Burrowing mayflies of the genus Hexagenia spp. were widely distributed (ca. 80% of sites) and abundant (ca. 160 nymphs/m2) in the western basin of Lake Erie of the Laurentian Great Lakes in 1929–1930, prior to a period of anoxia in the mid 1950s. Nymphs were absent or rare in the basin between 1961 and 1973–1975. In 1979–1991, nymphs were infrequently found (13–46% of sites) in low abundance (3–40 nymphs/m2) near shore (recolonized sediments of western Lake Erie and that their abundance may be similar to levels observed before their disappearance in the mid 1950s. However, prior to the mid 1950s, densities were greater in offshore than nearshore waters, but between 1979 and 1998 greater densities occurred near shore than offshore. In addition, there were two areas in the 1990s where low densities consistently occurred. Therefore, recovery of nymphs in western Lake Erie may not have been complete in 1998. At present we do not know the cause for the sudden recolonization of nymphs in large portions of western Lake Erie. Undoubtedly, pollution-abatement programs contributed to improved conditions that would have ultimately led to mayfly recovery in the future. However, the explosive growth of the exotic zebra mussel, Dreissena polymorpha, undoubtedly diverted plankton foods to bottom substrates which could have increased the speed at which Hexagenia spp. nymphs recolonized sediments in western Lake Erie in the 1990s.

  20. Maximum entropy principal for transportation

    International Nuclear Information System (INIS)

    Bilich, F.; Da Silva, R.

    2008-01-01

    In this work we deal with modeling of the transportation phenomenon for use in the transportation planning process and policy-impact studies. The model developed is based on the dependence concept, i.e., the notion that the probability of a trip starting at origin i is dependent on the probability of a trip ending at destination j given that the factors (such as travel time, cost, etc.) which affect travel between origin i and destination j assume some specific values. The derivation of the solution of the model employs the maximum entropy principle combining a priori multinomial distribution with a trip utility concept. This model is utilized to forecast trip distributions under a variety of policy changes and scenarios. The dependence coefficients are obtained from a regression equation where the functional form is derived based on conditional probability and perception of factors from experimental psychology. The dependence coefficients encode all the information that was previously encoded in the form of constraints. In addition, the dependence coefficients encode information that cannot be expressed in the form of constraints for practical reasons, namely, computational tractability. The equivalence between the standard formulation (i.e., objective function with constraints) and the dependence formulation (i.e., without constraints) is demonstrated. The parameters of the dependence-based trip-distribution model are estimated, and the model is also validated using commercial air travel data in the U.S. In addition, policy impact analyses (such as allowance of supersonic flights inside the U.S. and user surcharge at noise-impacted airports) on air travel are performed.

  1. Modelling maximum likelihood estimation of availability

    International Nuclear Information System (INIS)

    Waller, R.A.; Tietjen, G.L.; Rock, G.W.

    1975-01-01

    Suppose the performance of a nuclear powered electrical generating power plant is continuously monitored to record the sequence of failure and repairs during sustained operation. The purpose of this study is to assess one method of estimating the performance of the power plant when the measure of performance is availability. That is, we determine the probability that the plant is operational at time t. To study the availability of a power plant, we first assume statistical models for the variables, X and Y, which denote the time-to-failure and the time-to-repair variables, respectively. Once those statistical models are specified, the availability, A(t), can be expressed as a function of some or all of their parameters. Usually those parameters are unknown in practice and so A(t) is unknown. This paper discusses the maximum likelihood estimator of A(t) when the time-to-failure model for X is an exponential density with parameter, lambda, and the time-to-repair model for Y is an exponential density with parameter, theta. Under the assumption of exponential models for X and Y, it follows that the instantaneous availability at time t is A(t)=lambda/(lambda+theta)+theta/(lambda+theta)exp[-[(1/lambda)+(1/theta)]t] with t>0. Also, the steady-state availability is A(infinity)=lambda/(lambda+theta). We use the observations from n failure-repair cycles of the power plant, say X 1 , X 2 , ..., Xsub(n), Y 1 , Y 2 , ..., Ysub(n) to present the maximum likelihood estimators of A(t) and A(infinity). The exact sampling distributions for those estimators and some statistical properties are discussed before a simulation model is used to determine 95% simulation intervals for A(t). The methodology is applied to two examples which approximate the operating history of two nuclear power plants. (author)

  2. Last Glacial Maximum Salinity Reconstruction

    Science.gov (United States)

    Homola, K.; Spivack, A. J.

    2016-12-01

    It has been previously demonstrated that salinity can be reconstructed from sediment porewater. The goal of our study is to reconstruct high precision salinity during the Last Glacial Maximum (LGM). Salinity is usually determined at high precision via conductivity, which requires a larger volume of water than can be extracted from a sediment core, or via chloride titration, which yields lower than ideal precision. It has been demonstrated for water column samples that high precision density measurements can be used to determine salinity at the precision of a conductivity measurement using the equation of state of seawater. However, water column seawater has a relatively constant composition, in contrast to porewater, where variations from standard seawater composition occur. These deviations, which affect the equation of state, must be corrected for through precise measurements of each ion's concentration and knowledge of apparent partial molar density in seawater. We have developed a density-based method for determining porewater salinity that requires only 5 mL of sample, achieving density precisions of 10-6 g/mL. We have applied this method to porewater samples extracted from long cores collected along a N-S transect across the western North Atlantic (R/V Knorr cruise KN223). Density was determined to a precision of 2.3x10-6 g/mL, which translates to salinity uncertainty of 0.002 gms/kg if the effect of differences in composition is well constrained. Concentrations of anions (Cl-, and SO4-2) and cations (Na+, Mg+, Ca+2, and K+) were measured. To correct salinities at the precision required to unravel LGM Meridional Overturning Circulation, our ion precisions must be better than 0.1% for SO4-/Cl- and Mg+/Na+, and 0.4% for Ca+/Na+, and K+/Na+. Alkalinity, pH and Dissolved Inorganic Carbon of the porewater were determined to precisions better than 4% when ratioed to Cl-, and used to calculate HCO3-, and CO3-2. Apparent partial molar densities in seawater were

  3. Maximum Parsimony on Phylogenetic networks

    Science.gov (United States)

    2012-01-01

    Background Phylogenetic networks are generalizations of phylogenetic trees, that are used to model evolutionary events in various contexts. Several different methods and criteria have been introduced for reconstructing phylogenetic trees. Maximum Parsimony is a character-based approach that infers a phylogenetic tree by minimizing the total number of evolutionary steps required to explain a given set of data assigned on the leaves. Exact solutions for optimizing parsimony scores on phylogenetic trees have been introduced in the past. Results In this paper, we define the parsimony score on networks as the sum of the substitution costs along all the edges of the network; and show that certain well-known algorithms that calculate the optimum parsimony score on trees, such as Sankoff and Fitch algorithms extend naturally for networks, barring conflicting assignments at the reticulate vertices. We provide heuristics for finding the optimum parsimony scores on networks. Our algorithms can be applied for any cost matrix that may contain unequal substitution costs of transforming between different characters along different edges of the network. We analyzed this for experimental data on 10 leaves or fewer with at most 2 reticulations and found that for almost all networks, the bounds returned by the heuristics matched with the exhaustively determined optimum parsimony scores. Conclusion The parsimony score we define here does not directly reflect the cost of the best tree in the network that displays the evolution of the character. However, when searching for the most parsimonious network that describes a collection of characters, it becomes necessary to add additional cost considerations to prefer simpler structures, such as trees over networks. The parsimony score on a network that we describe here takes into account the substitution costs along the additional edges incident on each reticulate vertex, in addition to the substitution costs along the other edges which are

  4. New Mediterranean Marine biodiversity records (June 2013

    Directory of Open Access Journals (Sweden)

    I. SIOKOU

    2013-04-01

    Full Text Available This paper concerns records of species that have extended their distribution in the Mediterranean Sea. The finding of the rare brackish angiosperm Althenia filiformis in the island of Cyprus is interesting since its insertion in the Red Data Book of the Flora of Cyprus is suggested. The following species enriched the flora or fauna lists of the relevant countries: the red alga Sebdenia dichotoma (Greece, the hydrachnid mite Pontarachna adriatica (Slovenia, and the thalassinid Gebiacantha talismani (Turkey. Several alien species were recorded in new Mediterranean localities. The record of the burrowing goby Trypauchen vagina in the North Levantine Sea (Turkish coast, suggests the start of spreading of this Lessepsian immigrant in the Mediterranean Sea. The findings of the following species indicate the extension of their occurrence in the Mediterranean Sea: the foraminifer Amphistegina lobifera (island of Zakynthos, Greece, the medusa Cassiopea andromeda (Syria, the copepod Centropages furcatus (Aegean Sea, the decapod shrimp Melicertus hathor (island of Kastellorizo, Greece, the crab Menoethius monoceros (Gulf of Tunis, the barnacles Balanus trigonus, Megabalanus tintinnabulum, Megabalanus coccopoma and the bivalves Chama asperella, Cucurbitula cymbium (Saronikos Gulf, Greece.

  5. Mammographic image restoration using maximum entropy deconvolution

    International Nuclear Information System (INIS)

    Jannetta, A; Jackson, J C; Kotre, C J; Birch, I P; Robson, K J; Padgett, R

    2004-01-01

    An image restoration approach based on a Bayesian maximum entropy method (MEM) has been applied to a radiological image deconvolution problem, that of reduction of geometric blurring in magnification mammography. The aim of the work is to demonstrate an improvement in image spatial resolution in realistic noisy radiological images with no associated penalty in terms of reduction in the signal-to-noise ratio perceived by the observer. Images of the TORMAM mammographic image quality phantom were recorded using the standard magnification settings of 1.8 magnification/fine focus and also at 1.8 magnification/broad focus and 3.0 magnification/fine focus; the latter two arrangements would normally give rise to unacceptable geometric blurring. Measured point-spread functions were used in conjunction with the MEM image processing to de-blur these images. The results are presented as comparative images of phantom test features and as observer scores for the raw and processed images. Visualization of high resolution features and the total image scores for the test phantom were improved by the application of the MEM processing. It is argued that this successful demonstration of image de-blurring in noisy radiological images offers the possibility of weakening the link between focal spot size and geometric blurring in radiology, thus opening up new approaches to system optimization

  6. Effects of human disturbance on a burrow nesting seabird Efectos de la presencia de humanos en aves marinas que anidan en madrigueras

    Directory of Open Access Journals (Sweden)

    Yuri V. Albores-Barajas

    2011-12-01

    Full Text Available During 2004, we followed 72 natural burrows to determine the effects of disturbance on breeding success of Cassin's auklets (Ptychoramphus aleuticus. We used distance from a human settlement or path in the analysis of disturbance. Birds whose burrows were closer to the path or the village had a higher rate of nest abandonment and lower breeding success compared to birds nesting further away from the path or the village. Also, older and more experienced individuals represented a larger proportion of the breeding population on less disturbed areas than on highly disturbed ones, probably as older individuals tend to arrive earlier at the breeding grounds, and failed breeders may change burrow sites to move away from disturbance. P. aleuticus are adversely affected by human activity at colonies even if birds are not handled and burrows are not opened, and this has implications for conservation, and planning of ecotourism. On the long term, this can have negative consequences for this species and others with similar characteristics.Durante el 2004 seguimos 72 nidos de la alcuela (Ptychoramphus aleuticus para determinar los efectos de disturbio en el éxito reproductivo. Utilizamos la distancia del nido a áreas asentamientos humanos o al camino como medidas de disturbio. Los nidos que estaban más cerca de los asentamientos o del camino tuvieron una tasa de abandono mayor y un éxito reproductivo menor en comparación con los nidos que estaban más alejados de las fuentes de disturbio. También observamos que en las zonas menos expuestas la proporción de adultos, con mayor experiencia, era más alta, posiblemente porque los individuos con mayor experiencia llegan antes a la zona de anidación. Las alcuelas son afectadas negativamente por la presencia de los humanos y sus actividades, aunque las aves no entren en contacto directo con los humanos. A largo plazo, esto puede acarrear consecuencias graves para esta especie y otras con caracter

  7. Presence of the fire ant Solenopsis invicta (Westwood) (Hymenoptera: Formicidae) stimulates burrowing behavior by larvae of the sandfly Lutzomyia longipalpis (Lutz and Neiva) (Diptera: Psychodidae)

    Energy Technology Data Exchange (ETDEWEB)

    Harvey, Jeffrey A. [Netherlands Institute of Ecology, Heteren (Netherlands). Dept. of Terrestrial Ecology; Hamilton, James G.C.; Ward, Richard D. [University of Keele, Staffordshire (United Kingdom). Centre for Applied Entomology and Parasitology. Dept. of Biological Sciences

    2010-01-15

    The sandfly Lutzomyia longipalpis (Lutz and Neiva) vectors leishmaniasis in the neotropics. Although much is known about the biology of adult flies, little is known about interactions with its natural enemies. Here, we examined behavior of larvae of L4 L. longipalpis on a soil substrate when exposed to the fire ant Solenopsis invicata (Westwood). When ants were absent, most larvae tended to remain at or close to the soil surface, but when ants were present the larvae burrowed into the soil. Sandflies seek refuges in the presence of generalist predators, thus rendering them immune to attack from many potential enemies. (author)

  8. Presence of the fire ant Solenopsis invicta (Westwood) (Hymenoptera: Formicidae) stimulates burrowing behavior by larvae of the sandfly Lutzomyia longipalpis (Lutz and Neiva) (Diptera: Psychodidae)

    International Nuclear Information System (INIS)

    Harvey, Jeffrey A.; Hamilton, James G.C.; Ward, Richard D.

    2010-01-01

    The sandfly Lutzomyia longipalpis (Lutz and Neiva) vectors leishmaniasis in the neotropics. Although much is known about the biology of adult flies, little is known about interactions with its natural enemies. Here, we examined behavior of larvae of L4 L. longipalpis on a soil substrate when exposed to the fire ant Solenopsis invicata (Westwood). When ants were absent, most larvae tended to remain at or close to the soil surface, but when ants were present the larvae burrowed into the soil. Sandflies seek refuges in the presence of generalist predators, thus rendering them immune to attack from many potential enemies. (author)

  9. Presence of the fire ant Solenopsis invicta (Westwood) (Hymenoptera: Formicidae) stimulates burrowing behavior by larvae of the sandfly Lutzomyia longipalpis (Lutz & Neiva) (Diptera: Psychodidae).

    Science.gov (United States)

    Harvey, Jeffrey A; Hamilton, James G C; Ward, Richard D

    2010-01-01

    The sandfly Lutzomyia longipalpis (Lutz & Neiva) vectors leishmaniasis in the neotropics. Although much is known about the biology of adult flies, little is known about interactions with its natural enemies. Here, we examined behavior of larvae of L4 L.longipalpis on a soil substrate when exposed to the fire ant Solenopsis invicata (Westwood). When ants were absent, most larvae tended to remain at or close to the soil surface, but when ants were present the larvae burrowed into the soil. Sandflies seek refuges in the presence of generalist predators, thus rendering them immune to attack from many potential enemies.

  10. Redescription, distribution and status of the Karwar Large Burrowing Spider Thrigmopoeus truculent us Pocock, 1899 (Araneae: Theraphosidae, a Western Ghats endemic ground mygalomorph

    Directory of Open Access Journals (Sweden)

    M. Siliwal

    2009-06-01

    Full Text Available The genus Thrigmopoeus is endemic to the Western Ghats of India, and is so far represented by two species: Thrigmopoeus truculentus Pocock, 1899 and T. insignis Pocock, 1899. The distribution of T. truculentus was considered to be restricted to its type locality until a few populations were identified in other places. In this paper we provide detail morphometry and characters used in modern-day taxonomy to redescribe the female of T. truculentus, with additional notes on its distribution, range extension, burrow and habitat.

  11. Two-dimensional maximum entropy image restoration

    International Nuclear Information System (INIS)

    Brolley, J.E.; Lazarus, R.B.; Suydam, B.R.; Trussell, H.J.

    1977-07-01

    An optical check problem was constructed to test P LOG P maximum entropy restoration of an extremely distorted image. Useful recovery of the original image was obtained. Comparison with maximum a posteriori restoration is made. 7 figures

  12. Receiver function estimated by maximum entropy deconvolution

    Institute of Scientific and Technical Information of China (English)

    吴庆举; 田小波; 张乃铃; 李卫平; 曾融生

    2003-01-01

    Maximum entropy deconvolution is presented to estimate receiver function, with the maximum entropy as the rule to determine auto-correlation and cross-correlation functions. The Toeplitz equation and Levinson algorithm are used to calculate the iterative formula of error-predicting filter, and receiver function is then estimated. During extrapolation, reflective coefficient is always less than 1, which keeps maximum entropy deconvolution stable. The maximum entropy of the data outside window increases the resolution of receiver function. Both synthetic and real seismograms show that maximum entropy deconvolution is an effective method to measure receiver function in time-domain.

  13. Biogeochemistry: Oxygen burrowed away

    NARCIS (Netherlands)

    Meysman, F.J.R.

    2014-01-01

    Multicellular animals probably evolved at the seafloor after a rise in oceanic oxygen levels. Biogeochemical model simulations suggest that as these animals started to rework the seafloor, they triggered a negative feedback that reduced global oxygen.

  14. Maximum Power from a Solar Panel

    Directory of Open Access Journals (Sweden)

    Michael Miller

    2010-01-01

    Full Text Available Solar energy has become a promising alternative to conventional fossil fuel sources. Solar panels are used to collect solar radiation and convert it into electricity. One of the techniques used to maximize the effectiveness of this energy alternative is to maximize the power output of the solar collector. In this project the maximum power is calculated by determining the voltage and the current of maximum power. These quantities are determined by finding the maximum value for the equation for power using differentiation. After the maximum values are found for each time of day, each individual quantity, voltage of maximum power, current of maximum power, and maximum power is plotted as a function of the time of day.

  15. Phenological Records

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Phenology is the scientific study of periodic biological phenomena, such as flowering, breeding, and migration, in relation to climatic conditions. The few records...

  16. Assessing the risk to green sturgeon from application of imidacloprid to control burrowing shrimp in Willapa Bay, Washington-Part I: exposure characterization.

    Science.gov (United States)

    Frew, John A; Sadilek, Martin; Grue, Christian E

    2015-11-01

    Willapa Bay and Grays Harbor (WA, USA) comprise the largest region of commercial oyster cultivation on the Pacific Coast. The activities of 2 species of burrowing shrimp impair growth and survival of oysters reared on the intertidal mudflats. To maintain viable harvests, the oyster growers have proposed controlling the shrimp by applying the insecticide imidacloprid onto harvested beds. Green sturgeon (listed in the Endangered Species Act) forage on burrowing shrimp and could be exposed to imidacloprid in the sediment porewater and through consumed prey. Studies were conducted to evaluate the likelihood that green sturgeon would be exposed to imidacloprid and to characterize the subsequent environmental exposure. Comparisons between treated and untreated control beds following test application of the insecticide suggested that green sturgeon fed opportunistically on imidacloprid-impaired shrimp. The highest interpolated imidacloprid residue concentrations in field samples following chemical application were 27.8 µg kg(-1) and 31.4 µg kg(-1) in porewater and shrimp, respectively. Results from modeled branchial and dietary uptake, based on conservative assumptions, indicated that the porewater exposure route had the greatest contribution to systemic absorption of imidacloprid. The highest average daily uptake from porewater (177.9 µg kg(-1) body wt) was 9.5-fold greater than total dietary uptake (18.8 µg kg(-1) body wt). Concentrations and durations of exposure would be lower than the levels expected to elicit direct acute or chronic toxic effects. © 2015 SETAC.

  17. Assessing the risk to green sturgeon from application of imidacloprid to control burrowing shrimp in Willapa Bay, Washington--Part II: controlled exposure studies.

    Science.gov (United States)

    Frew, John A; Grue, Christian E

    2015-11-01

    The activities of 2 species of burrowing shrimp have a negative impact on the growth and survival of oysters reared on intertidal mudflats in Willapa Bay and Grays Harbor, Washington (USA). To maintain viable harvests, oyster growers proposed the application of the neonicotinoid insecticide imidacloprid onto harvested beds for the control of burrowing shrimp. In test applications, water column concentrations of imidacloprid were relatively low and dissipated rapidly. The foraging activities of the green sturgeon (listed in the US Endangered Species Act) could result in exposure to higher, more sustained imidacloprid concentrations within sediment porewater and from the consumption of contaminated shrimp. Controlled experiments were conducted using surrogate white sturgeon to determine acute and chronic effect concentrations, to examine overt effects at more environmentally realistic concentrations and durations of exposure, and to assess chemical depuration. The 96-h median lethal concentration was 124 mg L(-1) , and the predicted 35-d no-observed-adverse-effect concentration was 0.7 mg L(-1) . No overt effects were observed following environmentally relevant exposures. Imidacloprid half-life in plasma was greater than 32 h. Measured concentrations of imidacloprid in porewater were significantly lower than the derived acute and chronic effect concentrations for white sturgeon. Exposure risk quotients were calculated using the effect concentrations and estimated environmental exposure. The resulting values were considerably below the level of concern for direct effects from either acute or chronic exposure to an endangered species. © 2015 SETAC.

  18. Population traits of the burrowing toad Rhinella fernandezae (Gallardo, 1957 (Anura, Bufonidae Características populacionais do sapo Rhinella fernandezae (Anura, Bufonidae

    Directory of Open Access Journals (Sweden)

    LC. Sanchez

    2008-02-01

    Full Text Available Size distribution, sex ratio and use of burrows of the burrowing toad Rhinella fernandezae were studied in Buenos Aires province, Argentina. Two sites separated by approximately 300 m were studied: one was a road next to a swamp, and the other a garden of a country house located further from the swamp. We identified toad burrows, and individuals were sexed, measured and given an individual mark. Burrows were examined in subsequent months after the first sampling to assess the presence of toads. We found significant differences in the size distribution between areas, being the proportion of juveniles greater at the site next to the swamp where the reproduction of the species was observed. This result may suggest that the site located near to the swamp functions as a source habitat of individuals that migrate to the other site, where recruitment would be very scarce. Sex proportion of adults did not differ from 1:1 in neither the total population nor in each site, suggesting that there was not differential mortality by sex. Some toads changed burrows throughout the study period, but there were not differences in the frequency of change between adults and juveniles.Distribuição de tamanho, razão sexual operacional, e uso de covas do sapo Rhinella fernandezae foram estudados na província de Buenos Aires, Argentina, em dois sítios afastados 300 m. Um deles é uma trilha próxima a um pântano, o outro, um jardim de uma casa rural, mais afastado do pântano. Identificamos as covas dos sapos, e os indivíduos dentro delas foram sexados, medidos e marcados individualmente. As covas foram monitoradas mensalmente, depois da primeira amostragem para avaliar a presença dos sapos. Achamos diferenças na distribuição de tamanhos entres os sítios, sendo a proporção de juvenis maior naquele próximo ao pântano, onde a reprodução da espécie foi observada. O resultado sugere que o sítio próximo ao pântano funciona como um habitat fonte de indiv

  19. The impact of olive leaves, mosses and the burrowing of wild boars on soil erosion in olive orchards

    Science.gov (United States)

    Cerdà, Artemi; Nadal-Romero, Estela; Brevik, Eric C.; Pulido, Manuel; Maestre, Fermando T.; Taguas, Tani; Novara, Agata; Keesstra, Saskia; Cammeraat, Erik; Parras-Alcantara, Luis

    2017-04-01

    The main factor controlling soil erosion is vegetation cover (Cerdà and Doerr, 2005; Van Eck et al., 2016; van Hall et al., 2017). However, due to the removal of the vegetation in agricultural fields and the increase in soil erosion rates other factors arise as keys to control soil erosion rates and mechanisms (Ochoa-Cueva et al., 2016; Rodrigo Comino et al., 2016). Soil erosion rates in olive plantations are high due to the lack of vegetation cover as a consequence of intensive tillage and herbicides abuse (Taguas et al., 2015; Parras-Alcantara et al., 2016; Zema et al., 2016). This is also found in vineyards and other orchards around the world (Prosdocimi et al., 2016; Rodrígo Comino et al., 2016), and the reason to look for sustainable management techniques such as geotextiles, mulches or catch crops that will stop the accelerated soil erosion (Giménez Morera et al., 2010; Mwango et al., 2016; Nawaz et al., 2016a; 2016b; Nishigaki et al., 2016). All these management techniques are difficult to apply and have high costs. Natural solutions such as weeds to provide cover are very efficient and have no cost (Cerdà et al., 2016; Keesstra et al., 2016) and they can be adapted to the management of the farmers. In olive orchards under herbicide treatment there is a natural growth of mosses and the development of a litter layer composed of olive leaves. There is also burrowing by wild boars that "ploughs" the soil. This research evaluates the impact of the three items above on soil erosion. The measurements were carried out using simulated rainfall experiments over an area of 0.25 m2 at a rainfall rate of 55 mm h-1 during one hour (Cerdà, 1996; Prosdocimi et al., 2017) on 15 plots of mosses, 15 wild boar burrowed surfaces and 15 leaf covered surfaces during the winter of 2015. The soil erosion rates were 34 times greater in the wild boar burrowed soils, meanwhile the litter and mosses covered soils showed similar erosional responses and the soil erosion rates were

  20. Maximum permissible voltage of YBCO coated conductors

    Energy Technology Data Exchange (ETDEWEB)

    Wen, J.; Lin, B.; Sheng, J.; Xu, J.; Jin, Z. [Department of Electrical Engineering, Shanghai Jiao Tong University, Shanghai (China); Hong, Z., E-mail: zhiyong.hong@sjtu.edu.cn [Department of Electrical Engineering, Shanghai Jiao Tong University, Shanghai (China); Wang, D.; Zhou, H.; Shen, X.; Shen, C. [Qingpu Power Supply Company, State Grid Shanghai Municipal Electric Power Company, Shanghai (China)

    2014-06-15

    Highlights: • We examine three kinds of tapes’ maximum permissible voltage. • We examine the relationship between quenching duration and maximum permissible voltage. • Continuous I{sub c} degradations under repetitive quenching where tapes reaching maximum permissible voltage. • The relationship between maximum permissible voltage and resistance, temperature. - Abstract: Superconducting fault current limiter (SFCL) could reduce short circuit currents in electrical power system. One of the most important thing in developing SFCL is to find out the maximum permissible voltage of each limiting element. The maximum permissible voltage is defined as the maximum voltage per unit length at which the YBCO coated conductors (CC) do not suffer from critical current (I{sub c}) degradation or burnout. In this research, the time of quenching process is changed and voltage is raised until the I{sub c} degradation or burnout happens. YBCO coated conductors test in the experiment are from American superconductor (AMSC) and Shanghai Jiao Tong University (SJTU). Along with the quenching duration increasing, the maximum permissible voltage of CC decreases. When quenching duration is 100 ms, the maximum permissible of SJTU CC, 12 mm AMSC CC and 4 mm AMSC CC are 0.72 V/cm, 0.52 V/cm and 1.2 V/cm respectively. Based on the results of samples, the whole length of CCs used in the design of a SFCL can be determined.

  1. Revealing the Maximum Strength in Nanotwinned Copper

    DEFF Research Database (Denmark)

    Lu, L.; Chen, X.; Huang, Xiaoxu

    2009-01-01

    boundary–related processes. We investigated the maximum strength of nanotwinned copper samples with different twin thicknesses. We found that the strength increases with decreasing twin thickness, reaching a maximum at 15 nanometers, followed by a softening at smaller values that is accompanied by enhanced...

  2. Modelling maximum canopy conductance and transpiration in ...

    African Journals Online (AJOL)

    There is much current interest in predicting the maximum amount of water that can be transpired by Eucalyptus trees. It is possible that industrial waste water may be applied as irrigation water to eucalypts and it is important to predict the maximum transpiration rates of these plantations in an attempt to dispose of this ...

  3. RECORDS REACHING RECORDING DATA TECHNOLOGIES

    Directory of Open Access Journals (Sweden)

    G. W. L. Gresik

    2013-07-01

    Full Text Available The goal of RECORDS (Reaching Recording Data Technologies is the digital capturing of buildings and cultural heritage objects in hard-to-reach areas and the combination of data. It is achieved by using a modified crane from film industry, which is able to carry different measuring systems. The low-vibration measurement should be guaranteed by a gyroscopic controlled advice that has been , developed for the project. The data were achieved by using digital photography, UV-fluorescence photography, infrared reflectography, infrared thermography and shearography. Also a terrestrial 3D laser scanner and a light stripe topography scanner have been used The combination of the recorded data should ensure a complementary analysis of monuments and buildings.

  4. Records Reaching Recording Data Technologies

    Science.gov (United States)

    Gresik, G. W. L.; Siebe, S.; Drewello, R.

    2013-07-01

    The goal of RECORDS (Reaching Recording Data Technologies) is the digital capturing of buildings and cultural heritage objects in hard-to-reach areas and the combination of data. It is achieved by using a modified crane from film industry, which is able to carry different measuring systems. The low-vibration measurement should be guaranteed by a gyroscopic controlled advice that has been , developed for the project. The data were achieved by using digital photography, UV-fluorescence photography, infrared reflectography, infrared thermography and shearography. Also a terrestrial 3D laser scanner and a light stripe topography scanner have been used The combination of the recorded data should ensure a complementary analysis of monuments and buildings.

  5. Burrow ventilation in the tube-dwelling shrimp callianassa subterranea (Decapoda: thalassinidea). II. The flow in the vicinity of the shrimp and the energetic advantages of a laminar non-pulsating ventilation current.

    NARCIS (Netherlands)

    Stamhuis, Eize; Videler, Johannes

    1998-01-01

    The ventilation flow in the vicinity of the pleopod-pumping thalassinid shrimp Callianassa subterranea in an artificial transparent burrow has been mapped using particle image velocimetry. The flow in the tube in front of the shrimp was unidirectional, laminar and steady, with a parabolic

  6. The cuticular hydrocarbons of the giant soil-burrowing cockroach Macropanesthia rhinoceros saussure (Blattodea: Blaberidae: Geoscapheinae): analysis with respect to age, sex and location.

    Science.gov (United States)

    Brown, W V; Rose, H A; Lacey, M J; Wright, K

    2000-11-01

    The cuticular hydrocarbons of a widespread species of soil-burrowing cockroach, Macropanesthia rhinoceros, have been sampled from most of its known geographical locations. Analysis of extracts from individual insects has enabled a study of differences within a population as well as among geographical locations. In the case of M. rhinoceros, except for newly hatched first-instar nymphs, variations in hydrocarbon composition among individuals of different cohorts of M. rhinoceros, based on age and sex, are no greater than those among individuals of a single cohort. Geographical populations of this species are variable in hydrocarbon composition unless they occur within a few kilometres of each other. A few populations showed very different hydrocarbon patterns but, in the absence of any correlating biological differences, it is uncertain whether this signifies the presence of otherwise unrecognizable sibling species or just extreme examples of the geographical variation characteristic of this group of insects.

  7. MXLKID: a maximum likelihood parameter identifier

    International Nuclear Information System (INIS)

    Gavel, D.T.

    1980-07-01

    MXLKID (MaXimum LiKelihood IDentifier) is a computer program designed to identify unknown parameters in a nonlinear dynamic system. Using noisy measurement data from the system, the maximum likelihood identifier computes a likelihood function (LF). Identification of system parameters is accomplished by maximizing the LF with respect to the parameters. The main body of this report briefly summarizes the maximum likelihood technique and gives instructions and examples for running the MXLKID program. MXLKID is implemented LRLTRAN on the CDC7600 computer at LLNL. A detailed mathematical description of the algorithm is given in the appendices. 24 figures, 6 tables

  8. The Visible Burrow System: A behavioral paradigm to assess sociability and social withdrawal in BTBR and C57BL/6J mice strains.

    Science.gov (United States)

    Bove, Maria; Ike, Kevin; Eldering, Adriaan; Buwalda, Bauke; de Boer, Sietse F; Morgese, Maria Grazia; Schiavone, Stefania; Cuomo, Vincenzo; Trabace, Luigia; Kas, Martien J H

    2018-05-15

    Disrupted sociability and consequent social withdrawal are (early) symptoms of a wide variety of neuropsychiatric diseases, such as schizophrenia, autism spectrum disorders, depressive disorders and Alzheimer's disease. The paucity of objective measures to translationally assess social withdrawal characteristics has been an important limitation to study this behavioral phenotype, both in human and rodents. The aim of the present study was to investigate sociability and social withdrawal in rodents using an ethologically valid behavioral paradigm, the Visible Burrow System (VBS). The VBS mimics a natural environment, with male and female rodents housed together in an enclosure where a large open arena is connected to a continuously dark burrow system that includes 4 nest boxes. In this study, mixed-sex colonies of C57BL/6J and of BTBR mice have been investigated (n = 8 mice per colony). Results showed marked differences between the two strains, in terms of sociability as well as social withdrawal behaviors. In particular, BTBR mice performed less social behaviors and have a preference for non-social behaviors compared to C57BL/6J mice. Neurobiologically, the decreased sociability of BTBR was accompanied by reduced GABA and increased glutamate concentrations in brain prefrontal cortex (PFC) and amygdala regions. In conclusion, our study validated the use of the VBS as an ethologically relevant behavioral paradigm in group-housed mice to investigate individual sociability and social withdrawal features and their underlying neurobiology. This paradigm may provide new insights to develop new therapeutic treatments for behavioral dysfunctions that may be relevant across neuropsychiatric diseases. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

  9. Influence of maximum bite force on jaw movement during gummy jelly mastication.

    Science.gov (United States)

    Kuninori, T; Tomonari, H; Uehara, S; Kitashima, F; Yagi, T; Miyawaki, S

    2014-05-01

    It is known that maximum bite force has various influences on chewing function; however, there have not been studies in which the relationships between maximum bite force and masticatory jaw movement have been clarified. The aim of this study was to investigate the effect of maximum bite force on masticatory jaw movement in subjects with normal occlusion. Thirty young adults (22 men and 8 women; mean age, 22.6 years) with good occlusion were divided into two groups based on whether they had a relatively high or low maximum bite force according to the median. The maximum bite force was determined according to the Dental Prescale System using pressure-sensitive sheets. Jaw movement during mastication of hard gummy jelly (each 5.5 g) on the preferred chewing side was recorded using a six degrees of freedom jaw movement recording system. The motion of the lower incisal point of the mandible was computed, and the mean values of 10 cycles (cycles 2-11) were calculated. A masticatory performance test was conducted using gummy jelly. Subjects with a lower maximum bite force showed increased maximum lateral amplitude, closing distance, width and closing angle; wider masticatory jaw movement; and significantly lower masticatory performance. However, no differences in the maximum vertical or maximum anteroposterior amplitudes were observed between the groups. Although other factors, such as individual morphology, may influence masticatory jaw movement, our results suggest that subjects with a lower maximum bite force show increased lateral jaw motion during mastication. © 2014 John Wiley & Sons Ltd.

  10. Maximum neutron flux in thermal reactors

    International Nuclear Information System (INIS)

    Strugar, P.V.

    1968-12-01

    Direct approach to the problem is to calculate spatial distribution of fuel concentration if the reactor core directly using the condition of maximum neutron flux and comply with thermal limitations. This paper proved that the problem can be solved by applying the variational calculus, i.e. by using the maximum principle of Pontryagin. Mathematical model of reactor core is based on the two-group neutron diffusion theory with some simplifications which make it appropriate from maximum principle point of view. Here applied theory of maximum principle are suitable for application. The solution of optimum distribution of fuel concentration in the reactor core is obtained in explicit analytical form. The reactor critical dimensions are roots of a system of nonlinear equations and verification of optimum conditions can be done only for specific examples

  11. Maximum allowable load on wheeled mobile manipulators

    International Nuclear Information System (INIS)

    Habibnejad Korayem, M.; Ghariblu, H.

    2003-01-01

    This paper develops a computational technique for finding the maximum allowable load of mobile manipulator during a given trajectory. The maximum allowable loads which can be achieved by a mobile manipulator during a given trajectory are limited by the number of factors; probably the dynamic properties of mobile base and mounted manipulator, their actuator limitations and additional constraints applied to resolving the redundancy are the most important factors. To resolve extra D.O.F introduced by the base mobility, additional constraint functions are proposed directly in the task space of mobile manipulator. Finally, in two numerical examples involving a two-link planar manipulator mounted on a differentially driven mobile base, application of the method to determining maximum allowable load is verified. The simulation results demonstrates the maximum allowable load on a desired trajectory has not a unique value and directly depends on the additional constraint functions which applies to resolve the motion redundancy

  12. Maximum phytoplankton concentrations in the sea

    DEFF Research Database (Denmark)

    Jackson, G.A.; Kiørboe, Thomas

    2008-01-01

    A simplification of plankton dynamics using coagulation theory provides predictions of the maximum algal concentration sustainable in aquatic systems. These predictions have previously been tested successfully against results from iron fertilization experiments. We extend the test to data collect...

  13. Vinyl Record

    DEFF Research Database (Denmark)

    Bartmanski, Dominik; Woodward, Ian

    2018-01-01

    . This relational process means that both the material affordances and entanglements of vinyl allow us to feel, handle, experience, project, and share its iconicity. The materially mediated meanings of vinyl enabled it to retain currency in independent and collector’s markets and thus resist the planned......In this paper, we use the case of the vinyl record to show that iconic objects become meaningful via a dual process. First, they offer immersive engagements which structure user interpretations through various material experiences of handling, use, and extension. Second, they always work via...

  14. Maximum-Likelihood Detection Of Noncoherent CPM

    Science.gov (United States)

    Divsalar, Dariush; Simon, Marvin K.

    1993-01-01

    Simplified detectors proposed for use in maximum-likelihood-sequence detection of symbols in alphabet of size M transmitted by uncoded, full-response continuous phase modulation over radio channel with additive white Gaussian noise. Structures of receivers derived from particular interpretation of maximum-likelihood metrics. Receivers include front ends, structures of which depends only on M, analogous to those in receivers of coherent CPM. Parts of receivers following front ends have structures, complexity of which would depend on N.

  15. Record Club

    CERN Multimedia

    Record Club

    2011-01-01

    http://cern.ch/Record.Club November  Selections Just in time for the holiday season, we have added a number of new CDs and DVDs into the Club. You will find the full lists at http://cern.ch/record.club; select the "Discs of the Month" button on the left side on the left panel of the web page and then Nov 2011. New films include the all 5 episodes of Fast and Furious, many of the most famous films starring Jean-Paul Belmondo and those of Louis de Funes and some more recent films such as The Lincoln Lawyer and, according to some critics, Woody Allen’s best film for years – Midnight in Paris. For the younger generation there is Cars 2 and Kung Fu Panda 2. New CDs include the latest releases by Adele, Coldplay and the Red Hot Chili Peppers. We have also added the new Duets II CD featuring Tony Bennett singing with some of today’s pop stars including Lady Gaga, Amy Winehouse and Willy Nelson. The Club is now open every Monday, Wednesday and Friday ...

  16. Record Club

    CERN Multimedia

    Record Club

    2011-01-01

    http://cern.ch/Record.Club June Selections We have put a significant number of new CDs and DVDs into the Club You will find the full lists at http://cern.ch/record.club and select the «Discs of the Month» button on the left side on the left panel of the web page and then June 2011. New films include the latest Action, Suspense and Science Fiction film hits, general drama movies including the Oscar-winning The King’s Speech, comedies including both chapter of Bridget Jones’s Diary, seven films for children and a musical. Other highlights include the latest Harry Potter release and some movies from the past you may have missed including the first in the Terminator series. New CDs include the latest releases by Michel Sardou, Mylene Farmer, Jennifer Lopez, Zucchero and Britney Spears. There is also a hits collection from NRJ. Don’t forget that the Club is now open every Monday, Wednesday and Friday lunchtimes from 12h30 to 13h00 in Restaurant 2, Building 504. (C...

  17. Record club

    CERN Document Server

    Record club

    2010-01-01

      Bonjour a tous, Voici les 24 nouveaux DVD de Juillet disponibles depuis quelques jours, sans oublier les 5 CD Pop musique. Découvrez la saga du terroriste Carlos, la vie de Gainsbourg et les aventures de Lucky Luke; angoissez avec Paranormal Activity et évadez vous sur Pandora dans la peau d’Avatar. Toutes les nouveautés sont à découvrir directement au club. Pour en connaître la liste complète ainsi que le reste de la collection du Record Club, nous vous invitons sur notre site web: http://cern.ch/crc. Toutes les dernières nouveautés sont dans la rubrique « Discs of the Month ». Rappel : le club est ouvert les Lundis, Mercredis, Vendredis de 12h30 à 13h00 au restaurant n°2, bâtiment 504. A bientôt chers Record Clubbers.  

  18. Record Club

    CERN Multimedia

    Record Club

    2011-01-01

    http://cern.ch/Record.Club Nouveautés été 2011 Le club de location de CDs et de DVDs vient d’ajouter un grand nombre de disques pour l’été 2011. Parmi eux, Le Discours d’un Roi, oscar 2011 du meilleur film et Harry Potter les reliques de la mort (1re partie). Ce n’est pas moins de 48 DVDs et 10 CDs nouveaux qui vous sont proposés à la location. Il y en a pour tous les genres. Alors n’hésitez pas à consulter notre site http://cern.ch/record.club, voir Disc Catalogue, Discs of the month pour avoir la liste complète. Le club est ouvert tous les Lundi, Mercredi, Vendredi de 12h30 à 13h dans le bâtiment du restaurent N°2 (Cf. URL: http://www.cern.ch/map/building?bno=504) A très bientôt.  

  19. RECORD CLUB

    CERN Multimedia

    Record Club

    2010-01-01

    DVD James Bond – Series Complete To all Record Club Members, to start the new year, we have taken advantage of a special offer to add copies of all the James Bond movies to date, from the very first - Dr. No - to the latest - Quantum of Solace. No matter which of the successive 007s you prefer (Sean Connery, George Lazenby, Roger Moore, Timothy Dalton, Pierce Brosnan or Daniel Craig), they are all there. Or perhaps you have a favourite Bond Girl, or even perhaps a favourite villain. Take your pick. You can find the full selection listed on the club web site http://cern.ch/crc; use the panel on the left of the page “Discs of the Month” and select Jan 2010. We remind you that we are open on Mondays, Wednesdays and Fridays from 12:30 to 13:00 in Restaurant 2 (Bldg 504).

  20. Record dynamics

    DEFF Research Database (Denmark)

    Robe, Dominic M.; Boettcher, Stefan; Sibani, Paolo

    2016-01-01

    When quenched rapidly beyond their glass transition, colloidal suspensions fall out of equilibrium. The pace of their dynamics then slows down with the system age, i.e., with the time elapsed after the quench. This breaking of time translational invariance is associated with dynamical observables...... which depend on two time-arguments. The phenomenology is shared by a broad class of aging systems and calls for an equally broad theoretical description. The key idea is that, independent of microscopic details, aging systems progress through rare intermittent structural relaxations that are de......-facto irreversible and become increasingly harder to achieve. Thus, a progression of record-sized dynamical barriers are traversed in the approach to equilibration. Accordingly, the statistics of the events is closely described by a log-Poisson process. Originally developed for relaxation in spin glasses...

  1. Record breakers

    CERN Multimedia

    Antonella Del Rosso

    2012-01-01

    In the sixties, CERN’s Fellows were but a handful of about 50 young experimentalists present on site to complete their training. Today, their number has increased to a record-breaking 500. They come from many different fields and are spread across CERN’s different activity areas.   “Diversifying the Fellowship programme has been the key theme in recent years,” comments James Purvis, Head of the Recruitment, Programmes and Monitoring group in the HR Department. “In particular, the 2005 five-yearly review introduced the notion of ‘senior’ and ‘junior’ Fellowships, broadening the target audience to include those with Bachelor-level qualifications.” Diversification made CERN’s Fellowship programme attractive to a wider audience but the number of Fellows on site could not have increased so much without the support of EU-funded projects, which were instrumental in the growth of the programme. ...

  2. Maximum gravitational redshift of white dwarfs

    International Nuclear Information System (INIS)

    Shapiro, S.L.; Teukolsky, S.A.

    1976-01-01

    The stability of uniformly rotating, cold white dwarfs is examined in the framework of the Parametrized Post-Newtonian (PPN) formalism of Will and Nordtvedt. The maximum central density and gravitational redshift of a white dwarf are determined as functions of five of the nine PPN parameters (γ, β, zeta 2 , zeta 3 , and zeta 4 ), the total angular momentum J, and the composition of the star. General relativity predicts that the maximum redshifts is 571 km s -1 for nonrotating carbon and helium dwarfs, but is lower for stars composed of heavier nuclei. Uniform rotation can increase the maximum redshift to 647 km s -1 for carbon stars (the neutronization limit) and to 893 km s -1 for helium stars (the uniform rotation limit). The redshift distribution of a larger sample of white dwarfs may help determine the composition of their cores

  3. Maximum entropy analysis of EGRET data

    DEFF Research Database (Denmark)

    Pohl, M.; Strong, A.W.

    1997-01-01

    EGRET data are usually analysed on the basis of the Maximum-Likelihood method \\cite{ma96} in a search for point sources in excess to a model for the background radiation (e.g. \\cite{hu97}). This method depends strongly on the quality of the background model, and thus may have high systematic unce...... uncertainties in region of strong and uncertain background like the Galactic Center region. Here we show images of such regions obtained by the quantified Maximum-Entropy method. We also discuss a possible further use of MEM in the analysis of problematic regions of the sky....

  4. The Maximum Resource Bin Packing Problem

    DEFF Research Database (Denmark)

    Boyar, J.; Epstein, L.; Favrholdt, L.M.

    2006-01-01

    Usually, for bin packing problems, we try to minimize the number of bins used or in the case of the dual bin packing problem, maximize the number or total size of accepted items. This paper presents results for the opposite problems, where we would like to maximize the number of bins used...... algorithms, First-Fit-Increasing and First-Fit-Decreasing for the maximum resource variant of classical bin packing. For the on-line variant, we define maximum resource variants of classical and dual bin packing. For dual bin packing, no on-line algorithm is competitive. For classical bin packing, we find...

  5. Shower maximum detector for SDC calorimetry

    International Nuclear Information System (INIS)

    Ernwein, J.

    1994-01-01

    A prototype for the SDC end-cap (EM) calorimeter complete with a pre-shower and a shower maximum detector was tested in beams of electrons and Π's at CERN by an SDC subsystem group. The prototype was manufactured from scintillator tiles and strips read out with 1 mm diameter wave-length shifting fibers. The design and construction of the shower maximum detector is described, and results of laboratory tests on light yield and performance of the scintillator-fiber system are given. Preliminary results on energy and position measurements with the shower max detector in the test beam are shown. (authors). 4 refs., 5 figs

  6. Topics in Bayesian statistics and maximum entropy

    International Nuclear Information System (INIS)

    Mutihac, R.; Cicuttin, A.; Cerdeira, A.; Stanciulescu, C.

    1998-12-01

    Notions of Bayesian decision theory and maximum entropy methods are reviewed with particular emphasis on probabilistic inference and Bayesian modeling. The axiomatic approach is considered as the best justification of Bayesian analysis and maximum entropy principle applied in natural sciences. Particular emphasis is put on solving the inverse problem in digital image restoration and Bayesian modeling of neural networks. Further topics addressed briefly include language modeling, neutron scattering, multiuser detection and channel equalization in digital communications, genetic information, and Bayesian court decision-making. (author)

  7. Density estimation by maximum quantum entropy

    International Nuclear Information System (INIS)

    Silver, R.N.; Wallstrom, T.; Martz, H.F.

    1993-01-01

    A new Bayesian method for non-parametric density estimation is proposed, based on a mathematical analogy to quantum statistical physics. The mathematical procedure is related to maximum entropy methods for inverse problems and image reconstruction. The information divergence enforces global smoothing toward default models, convexity, positivity, extensivity and normalization. The novel feature is the replacement of classical entropy by quantum entropy, so that local smoothing is enforced by constraints on differential operators. The linear response of the estimate is proportional to the covariance. The hyperparameters are estimated by type-II maximum likelihood (evidence). The method is demonstrated on textbook data sets

  8. Record Club

    CERN Document Server

    Record Club

    2012-01-01

      March  Selections By the time this appears, we will have added a number of new CDs and DVDs into the Club. You will find the full lists at http://cern.ch/record.club; select the "Discs of the Month" button on the left panel of the web page and then Mar 2012. New films include recent releases such as Johnny English 2, Bad Teacher, Cowboys vs Aliens, and Super 8. We are also starting to acquire some of the classic films we missed when we initiated the DVD section of the club, such as appeared in a recent Best 100 Films published by a leading UK magazine; this month we have added Spielberg’s Jaws and Scorsese’s Goodfellas. If you have your own ideas on what we are missing, let us know. For children we have no less than 8 Tin-Tin DVDs. And if you like fast moving pop music, try the Beyonce concert DVD. New CDs include the latest releases from Paul McCartney, Rihanna and Amy Winehouse. There is a best of Mylene Farmer, a compilation from the NRJ 201...

  9. Maximum Aerobic Capacity of Underground Coal Miners in India

    Directory of Open Access Journals (Sweden)

    Ratnadeep Saha

    2011-01-01

    Full Text Available Miners fitness test was assessed in terms of determination of maximum aerobic capacity by an indirect method following a standard step test protocol before going down to mine by taking into consideration of heart rates (Telemetric recording and oxygen consumption of the subjects (Oxylog-II during exercise at different working rates. Maximal heart rate was derived as 220−age. Coal miners reported a maximum aerobic capacity within a range of 35–38.3 mL/kg/min. It also revealed that oldest miners (50–59 yrs had a lowest maximal oxygen uptake (34.2±3.38 mL/kg/min compared to (42.4±2.03 mL/kg/min compared to (42.4±2.03 mL/kg/min the youngest group (20–29 yrs. It was found to be negatively correlated with age (r=−0.55 and −0.33 for younger and older groups respectively and directly associated with the body weight of the subjects (r=0.57 – 0.68, P≤0.001. Carriers showed maximum cardio respiratory capacity compared to other miners. Indian miners VO2max was found to be lower both compared to their abroad mining counterparts and various other non-mining occupational working groups in India.

  10. Nonsymmetric entropy and maximum nonsymmetric entropy principle

    International Nuclear Information System (INIS)

    Liu Chengshi

    2009-01-01

    Under the frame of a statistical model, the concept of nonsymmetric entropy which generalizes the concepts of Boltzmann's entropy and Shannon's entropy, is defined. Maximum nonsymmetric entropy principle is proved. Some important distribution laws such as power law, can be derived from this principle naturally. Especially, nonsymmetric entropy is more convenient than other entropy such as Tsallis's entropy in deriving power laws.

  11. Maximum speed of dewetting on a fiber

    NARCIS (Netherlands)

    Chan, Tak Shing; Gueudre, Thomas; Snoeijer, Jacobus Hendrikus

    2011-01-01

    A solid object can be coated by a nonwetting liquid since a receding contact line cannot exceed a critical speed. We theoretically investigate this forced wetting transition for axisymmetric menisci on fibers of varying radii. First, we use a matched asymptotic expansion and derive the maximum speed

  12. Maximum potential preventive effect of hip protectors

    NARCIS (Netherlands)

    van Schoor, N.M.; Smit, J.H.; Bouter, L.M.; Veenings, B.; Asma, G.B.; Lips, P.T.A.M.

    2007-01-01

    OBJECTIVES: To estimate the maximum potential preventive effect of hip protectors in older persons living in the community or homes for the elderly. DESIGN: Observational cohort study. SETTING: Emergency departments in the Netherlands. PARTICIPANTS: Hip fracture patients aged 70 and older who

  13. Maximum gain of Yagi-Uda arrays

    DEFF Research Database (Denmark)

    Bojsen, J.H.; Schjær-Jacobsen, Hans; Nilsson, E.

    1971-01-01

    Numerical optimisation techniques have been used to find the maximum gain of some specific parasitic arrays. The gain of an array of infinitely thin, equispaced dipoles loaded with arbitrary reactances has been optimised. The results show that standard travelling-wave design methods are not optimum....... Yagi–Uda arrays with equal and unequal spacing have also been optimised with experimental verification....

  14. correlation between maximum dry density and cohesion

    African Journals Online (AJOL)

    HOD

    represents maximum dry density, signifies plastic limit and is liquid limit. Researchers [6, 7] estimate compaction parameters. Aside from the correlation existing between compaction parameters and other physical quantities there are some other correlations that have been investigated by other researchers. The well-known.

  15. Weak scale from the maximum entropy principle

    Science.gov (United States)

    Hamada, Yuta; Kawai, Hikaru; Kawana, Kiyoharu

    2015-03-01

    The theory of the multiverse and wormholes suggests that the parameters of the Standard Model (SM) are fixed in such a way that the radiation of the S3 universe at the final stage S_rad becomes maximum, which we call the maximum entropy principle. Although it is difficult to confirm this principle generally, for a few parameters of the SM, we can check whether S_rad actually becomes maximum at the observed values. In this paper, we regard S_rad at the final stage as a function of the weak scale (the Higgs expectation value) vh, and show that it becomes maximum around vh = {{O}} (300 GeV) when the dimensionless couplings in the SM, i.e., the Higgs self-coupling, the gauge couplings, and the Yukawa couplings are fixed. Roughly speaking, we find that the weak scale is given by vh ˜ T_{BBN}2 / (M_{pl}ye5), where ye is the Yukawa coupling of electron, T_BBN is the temperature at which the Big Bang nucleosynthesis starts, and M_pl is the Planck mass.

  16. The maximum-entropy method in superspace

    Czech Academy of Sciences Publication Activity Database

    van Smaalen, S.; Palatinus, Lukáš; Schneider, M.

    2003-01-01

    Roč. 59, - (2003), s. 459-469 ISSN 0108-7673 Grant - others:DFG(DE) XX Institutional research plan: CEZ:AV0Z1010914 Keywords : maximum-entropy method, * aperiodic crystals * electron density Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.558, year: 2003

  17. Achieving maximum sustainable yield in mixed fisheries

    NARCIS (Netherlands)

    Ulrich, Clara; Vermard, Youen; Dolder, Paul J.; Brunel, Thomas; Jardim, Ernesto; Holmes, Steven J.; Kempf, Alexander; Mortensen, Lars O.; Poos, Jan Jaap; Rindorf, Anna

    2017-01-01

    Achieving single species maximum sustainable yield (MSY) in complex and dynamic fisheries targeting multiple species (mixed fisheries) is challenging because achieving the objective for one species may mean missing the objective for another. The North Sea mixed fisheries are a representative example

  18. 5 CFR 534.203 - Maximum stipends.

    Science.gov (United States)

    2010-01-01

    ... maximum stipend established under this section. (e) A trainee at a non-Federal hospital, clinic, or medical or dental laboratory who is assigned to a Federal hospital, clinic, or medical or dental... Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY UNDER OTHER SYSTEMS Student...

  19. Minimal length, Friedmann equations and maximum density

    Energy Technology Data Exchange (ETDEWEB)

    Awad, Adel [Center for Theoretical Physics, British University of Egypt,Sherouk City 11837, P.O. Box 43 (Egypt); Department of Physics, Faculty of Science, Ain Shams University,Cairo, 11566 (Egypt); Ali, Ahmed Farag [Centre for Fundamental Physics, Zewail City of Science and Technology,Sheikh Zayed, 12588, Giza (Egypt); Department of Physics, Faculty of Science, Benha University,Benha, 13518 (Egypt)

    2014-06-16

    Inspired by Jacobson’s thermodynamic approach, Cai et al. have shown the emergence of Friedmann equations from the first law of thermodynamics. We extend Akbar-Cai derivation http://dx.doi.org/10.1103/PhysRevD.75.084003 of Friedmann equations to accommodate a general entropy-area law. Studying the resulted Friedmann equations using a specific entropy-area law, which is motivated by the generalized uncertainty principle (GUP), reveals the existence of a maximum energy density closed to Planck density. Allowing for a general continuous pressure p(ρ,a) leads to bounded curvature invariants and a general nonsingular evolution. In this case, the maximum energy density is reached in a finite time and there is no cosmological evolution beyond this point which leaves the big bang singularity inaccessible from a spacetime prospective. The existence of maximum energy density and a general nonsingular evolution is independent of the equation of state and the spacial curvature k. As an example we study the evolution of the equation of state p=ωρ through its phase-space diagram to show the existence of a maximum energy which is reachable in a finite time.

  20. Maximum concentrations at work and maximum biologically tolerable concentration for working materials 1991

    International Nuclear Information System (INIS)

    1991-01-01

    The meaning of the term 'maximum concentration at work' in regard of various pollutants is discussed. Specifically, a number of dusts and smokes are dealt with. The valuation criteria for maximum biologically tolerable concentrations for working materials are indicated. The working materials in question are corcinogeneous substances or substances liable to cause allergies or mutate the genome. (VT) [de

  1. 75 FR 43840 - Inflation Adjustment of the Ordinary Maximum and Aggravated Maximum Civil Monetary Penalties for...

    Science.gov (United States)

    2010-07-27

    ...-17530; Notice No. 2] RIN 2130-ZA03 Inflation Adjustment of the Ordinary Maximum and Aggravated Maximum... remains at $250. These adjustments are required by the Federal Civil Penalties Inflation Adjustment Act [email protected] . SUPPLEMENTARY INFORMATION: The Federal Civil Penalties Inflation Adjustment Act of 1990...

  2. Zipf's law, power laws and maximum entropy

    International Nuclear Information System (INIS)

    Visser, Matt

    2013-01-01

    Zipf's law, and power laws in general, have attracted and continue to attract considerable attention in a wide variety of disciplines—from astronomy to demographics to software structure to economics to linguistics to zoology, and even warfare. A recent model of random group formation (RGF) attempts a general explanation of such phenomena based on Jaynes' notion of maximum entropy applied to a particular choice of cost function. In the present paper I argue that the specific cost function used in the RGF model is in fact unnecessarily complicated, and that power laws can be obtained in a much simpler way by applying maximum entropy ideas directly to the Shannon entropy subject only to a single constraint: that the average of the logarithm of the observable quantity is specified. (paper)

  3. Maximum-entropy description of animal movement.

    Science.gov (United States)

    Fleming, Chris H; Subaşı, Yiğit; Calabrese, Justin M

    2015-03-01

    We introduce a class of maximum-entropy states that naturally includes within it all of the major continuous-time stochastic processes that have been applied to animal movement, including Brownian motion, Ornstein-Uhlenbeck motion, integrated Ornstein-Uhlenbeck motion, a recently discovered hybrid of the previous models, and a new model that describes central-place foraging. We are also able to predict a further hierarchy of new models that will emerge as data quality improves to better resolve the underlying continuity of animal movement. Finally, we also show that Langevin equations must obey a fluctuation-dissipation theorem to generate processes that fall from this class of maximum-entropy distributions when the constraints are purely kinematic.

  4. Pareto versus lognormal: a maximum entropy test.

    Science.gov (United States)

    Bee, Marco; Riccaboni, Massimo; Schiavo, Stefano

    2011-08-01

    It is commonly found that distributions that seem to be lognormal over a broad range change to a power-law (Pareto) distribution for the last few percentiles. The distributions of many physical, natural, and social events (earthquake size, species abundance, income and wealth, as well as file, city, and firm sizes) display this structure. We present a test for the occurrence of power-law tails in statistical distributions based on maximum entropy. This methodology allows one to identify the true data-generating processes even in the case when it is neither lognormal nor Pareto. The maximum entropy approach is then compared with other widely used methods and applied to different levels of aggregation of complex systems. Our results provide support for the theory that distributions with lognormal body and Pareto tail can be generated as mixtures of lognormally distributed units.

  5. Maximum likelihood estimation for integrated diffusion processes

    DEFF Research Database (Denmark)

    Baltazar-Larios, Fernando; Sørensen, Michael

    We propose a method for obtaining maximum likelihood estimates of parameters in diffusion models when the data is a discrete time sample of the integral of the process, while no direct observations of the process itself are available. The data are, moreover, assumed to be contaminated...... EM-algorithm to obtain maximum likelihood estimates of the parameters in the diffusion model. As part of the algorithm, we use a recent simple method for approximate simulation of diffusion bridges. In simulation studies for the Ornstein-Uhlenbeck process and the CIR process the proposed method works...... by measurement errors. Integrated volatility is an example of this type of observations. Another example is ice-core data on oxygen isotopes used to investigate paleo-temperatures. The data can be viewed as incomplete observations of a model with a tractable likelihood function. Therefore we propose a simulated...

  6. A Maximum Radius for Habitable Planets.

    Science.gov (United States)

    Alibert, Yann

    2015-09-01

    We compute the maximum radius a planet can have in order to fulfill two constraints that are likely necessary conditions for habitability: 1- surface temperature and pressure compatible with the existence of liquid water, and 2- no ice layer at the bottom of a putative global ocean, that would prevent the operation of the geologic carbon cycle to operate. We demonstrate that, above a given radius, these two constraints cannot be met: in the Super-Earth mass range (1-12 Mearth), the overall maximum that a planet can have varies between 1.8 and 2.3 Rearth. This radius is reduced when considering planets with higher Fe/Si ratios, and taking into account irradiation effects on the structure of the gas envelope.

  7. Maximum parsimony on subsets of taxa.

    Science.gov (United States)

    Fischer, Mareike; Thatte, Bhalchandra D

    2009-09-21

    In this paper we investigate mathematical questions concerning the reliability (reconstruction accuracy) of Fitch's maximum parsimony algorithm for reconstructing the ancestral state given a phylogenetic tree and a character. In particular, we consider the question whether the maximum parsimony method applied to a subset of taxa can reconstruct the ancestral state of the root more accurately than when applied to all taxa, and we give an example showing that this indeed is possible. A surprising feature of our example is that ignoring a taxon closer to the root improves the reliability of the method. On the other hand, in the case of the two-state symmetric substitution model, we answer affirmatively a conjecture of Li, Steel and Zhang which states that under a molecular clock the probability that the state at a single taxon is a correct guess of the ancestral state is a lower bound on the reconstruction accuracy of Fitch's method applied to all taxa.

  8. Maximum entropy analysis of liquid diffraction data

    International Nuclear Information System (INIS)

    Root, J.H.; Egelstaff, P.A.; Nickel, B.G.

    1986-01-01

    A maximum entropy method for reducing truncation effects in the inverse Fourier transform of structure factor, S(q), to pair correlation function, g(r), is described. The advantages and limitations of the method are explored with the PY hard sphere structure factor as model input data. An example using real data on liquid chlorine, is then presented. It is seen that spurious structure is greatly reduced in comparison to traditional Fourier transform methods. (author)

  9. A Maximum Resonant Set of Polyomino Graphs

    Directory of Open Access Journals (Sweden)

    Zhang Heping

    2016-05-01

    Full Text Available A polyomino graph P is a connected finite subgraph of the infinite plane grid such that each finite face is surrounded by a regular square of side length one and each edge belongs to at least one square. A dimer covering of P corresponds to a perfect matching. Different dimer coverings can interact via an alternating cycle (or square with respect to them. A set of disjoint squares of P is a resonant set if P has a perfect matching M so that each one of those squares is M-alternating. In this paper, we show that if K is a maximum resonant set of P, then P − K has a unique perfect matching. We further prove that the maximum forcing number of a polyomino graph is equal to the cardinality of a maximum resonant set. This confirms a conjecture of Xu et al. [26]. We also show that if K is a maximal alternating set of P, then P − K has a unique perfect matching.

  10. Automatic maximum entropy spectral reconstruction in NMR

    International Nuclear Information System (INIS)

    Mobli, Mehdi; Maciejewski, Mark W.; Gryk, Michael R.; Hoch, Jeffrey C.

    2007-01-01

    Developments in superconducting magnets, cryogenic probes, isotope labeling strategies, and sophisticated pulse sequences together have enabled the application, in principle, of high-resolution NMR spectroscopy to biomolecular systems approaching 1 megadalton. In practice, however, conventional approaches to NMR that utilize the fast Fourier transform, which require data collected at uniform time intervals, result in prohibitively lengthy data collection times in order to achieve the full resolution afforded by high field magnets. A variety of approaches that involve nonuniform sampling have been proposed, each utilizing a non-Fourier method of spectrum analysis. A very general non-Fourier method that is capable of utilizing data collected using any of the proposed nonuniform sampling strategies is maximum entropy reconstruction. A limiting factor in the adoption of maximum entropy reconstruction in NMR has been the need to specify non-intuitive parameters. Here we describe a fully automated system for maximum entropy reconstruction that requires no user-specified parameters. A web-accessible script generator provides the user interface to the system

  11. maximum neutron flux at thermal nuclear reactors

    International Nuclear Information System (INIS)

    Strugar, P.

    1968-10-01

    Since actual research reactors are technically complicated and expensive facilities it is important to achieve savings by appropriate reactor lattice configurations. There is a number of papers, and practical examples of reactors with central reflector, dealing with spatial distribution of fuel elements which would result in higher neutron flux. Common disadvantage of all the solutions is that the choice of best solution is done starting from the anticipated spatial distributions of fuel elements. The weakness of these approaches is lack of defined optimization criteria. Direct approach is defined as follows: determine the spatial distribution of fuel concentration starting from the condition of maximum neutron flux by fulfilling the thermal constraints. Thus the problem of determining the maximum neutron flux is solving a variational problem which is beyond the possibilities of classical variational calculation. This variational problem has been successfully solved by applying the maximum principle of Pontrjagin. Optimum distribution of fuel concentration was obtained in explicit analytical form. Thus, spatial distribution of the neutron flux and critical dimensions of quite complex reactor system are calculated in a relatively simple way. In addition to the fact that the results are innovative this approach is interesting because of the optimization procedure itself [sr

  12. Darwin taxonomist: Barnacles and shell burrowing barnacles Darwin taxónomo: cirrípedos y cirrípedos perforadores de conchas

    Directory of Open Access Journals (Sweden)

    JUAN CARLOS CASTILLA

    2009-12-01

    Full Text Available This bibliographic review revisits circumstances in which the wharf, shell burrowing barnacle, Cryptophialus minutus, was first collected by Charles Darwin in southern Chile, in 1836. Further, explores how its collection marked Darwin's taxonomical interest in Cirripedia. A short review analyzes the initial number of extant species of Cirripedia, as described by Darwin and the present situation, with emphasis on recent collections of C. minutus in the southern tip of South America.Esta revisión bibliográfica describe las circunstancias en el que el cirrípedo enano, Crypophialus minutus, perforador de conchas, fue recolectado por Charles Darwin en el sur de Chile, en 1836. Además, cómo esta recolección marcó el interés taxonómico de Darwin en Cirripedia. Se presenta una revisión resumida sobre el número inicial de especies vivas de Cirripedia, como fueron descritas por Darwin, y la situación actual, con énfasis en recolecciones recientes de C. minutus en el cono sur de Suramérica.

  13. Probable Maximum Earthquake Magnitudes for the Cascadia Subduction

    Science.gov (United States)

    Rong, Y.; Jackson, D. D.; Magistrale, H.; Goldfinger, C.

    2013-12-01

    The concept of maximum earthquake magnitude (mx) is widely used in seismic hazard and risk analysis. However, absolute mx lacks a precise definition and cannot be determined from a finite earthquake history. The surprising magnitudes of the 2004 Sumatra and the 2011 Tohoku earthquakes showed that most methods for estimating mx underestimate the true maximum if it exists. Thus, we introduced the alternate concept of mp(T), probable maximum magnitude within a time interval T. The mp(T) can be solved using theoretical magnitude-frequency distributions such as Tapered Gutenberg-Richter (TGR) distribution. The two TGR parameters, β-value (which equals 2/3 b-value in the GR distribution) and corner magnitude (mc), can be obtained by applying maximum likelihood method to earthquake catalogs with additional constraint from tectonic moment rate. Here, we integrate the paleoseismic data in the Cascadia subduction zone to estimate mp. The Cascadia subduction zone has been seismically quiescent since at least 1900. Fortunately, turbidite studies have unearthed a 10,000 year record of great earthquakes along the subduction zone. We thoroughly investigate the earthquake magnitude-frequency distribution of the region by combining instrumental and paleoseismic data, and using the tectonic moment rate information. To use the paleoseismic data, we first estimate event magnitudes, which we achieve by using the time interval between events, rupture extent of the events, and turbidite thickness. We estimate three sets of TGR parameters: for the first two sets, we consider a geographically large Cascadia region that includes the subduction zone, and the Explorer, Juan de Fuca, and Gorda plates; for the third set, we consider a narrow geographic region straddling the subduction zone. In the first set, the β-value is derived using the GCMT catalog. In the second and third sets, the β-value is derived using both the GCMT and paleoseismic data. Next, we calculate the corresponding mc

  14. Energetics of the Ventilatory Piston Pump of the Lugworm, a Deposit-feeding Polychaete Living in a Burrow.

    Science.gov (United States)

    Toulmond, A; Dejours, P

    1994-04-01

    The aim of this study was to tentatively estimate the energy cost of breathing in the lugworm, Arenicola marina (L.), a gallery-dwelling, piston-pump breather that moves water in a tail-to-head direction. Each tested lugworm was placed in a horizontal glass tube. The caudal end of the tube was connected to a well-aerated seawater reservoir at 20{deg}C, and the cephalic end attached to a drop meter through a tube resistance. At the exit of the cephalic chamber the O2 tension was recorded via an in situ O2 electrode, and the hydrostatic pressure of the exhaled water was also recorded. Water flow rate, total O2 uptake rate {Mdot}TOTO2, O2 extraction coefficient, and the mechanical power necessary to pump water through the resistive anterior exit of the apparatus ({Wdot}MEC), were computed. The basal metabolic rate of each animal ({Mdot}CONFO2) was separately estimated by the confinement method. {Mdot}CONFO2 subtracted from {Mdot}TOTO2 approximates {Mdot}CBO2, the O2 uptake rate necessary to activate the piston-pump breathing mechanism and to ensure the corresponding mechanical work rate, {Wdot}MEC. The results show that the energy cost of breathing, {Mdot}CBO2, of the piston-pump-breathing Arenicola is very high, with mean values approximating 47% of the {Mdot}TOTO2 value; that the mechanical power we measured, {Wdot}MEC, is very low; and that the mechanical-to-metabolic efficiency, the ratio {Wdot}MEC/{Mdot}CBO2, does not exceed 1%. These observations are compared to those obtained in other piston-pump breathers, such as Chaetopterus variopedatus and Urechis caupo, and in ciliary filter feeders including polychaetes, bivalves, and ascidians.

  15. Records Management Directive

    Data.gov (United States)

    Office of Personnel Management — The Office of Personnel Management (OPM) Records Management Directive provides guidelines for the management of OPM records, and identifies the records management...

  16. The spectrum of R Cygni during its exceptionally low maximum of 1983

    International Nuclear Information System (INIS)

    Wallerstein, G.; Dominy, J.F.; Mattei, J.A.; Smith, V.V.

    1985-01-01

    In 1983 R Cygni experienced its faintest maximum ever recorded. A study of the light curve shows correlations between brightness at maximum and interval from the previous cycle, in the sense that fainter maxima occur later than normal and are followed by maxima that occur earlier than normal. Emission and absorption lines in the optical and near infrared (2.2 μm region) reveal two significant correlations. The amplitude of line doubling is independent of the magnitude at maximum for msub(v)(max)=7.1 to 9.8. The velocities of the emission lines, however, correlate with the magnitude at maximum, in that during bright maxima they are negatively displaced by 15 km s -1 with respect to the red component of absorption lines, while during the faintest maximum there is no displacement. (author)

  17. Maximum entropy decomposition of quadrupole mass spectra

    International Nuclear Information System (INIS)

    Toussaint, U. von; Dose, V.; Golan, A.

    2004-01-01

    We present an information-theoretic method called generalized maximum entropy (GME) for decomposing mass spectra of gas mixtures from noisy measurements. In this GME approach to the noisy, underdetermined inverse problem, the joint entropies of concentration, cracking, and noise probabilities are maximized subject to the measured data. This provides a robust estimation for the unknown cracking patterns and the concentrations of the contributing molecules. The method is applied to mass spectroscopic data of hydrocarbons, and the estimates are compared with those received from a Bayesian approach. We show that the GME method is efficient and is computationally fast

  18. Maximum power operation of interacting molecular motors

    DEFF Research Database (Denmark)

    Golubeva, Natalia; Imparato, Alberto

    2013-01-01

    , as compared to the non-interacting system, in a wide range of biologically compatible scenarios. We furthermore consider the case where the motor-motor interaction directly affects the internal chemical cycle and investigate the effect on the system dynamics and thermodynamics.......We study the mechanical and thermodynamic properties of different traffic models for kinesin which are relevant in biological and experimental contexts. We find that motor-motor interactions play a fundamental role by enhancing the thermodynamic efficiency at maximum power of the motors...

  19. Maximum entropy method in momentum density reconstruction

    International Nuclear Information System (INIS)

    Dobrzynski, L.; Holas, A.

    1997-01-01

    The Maximum Entropy Method (MEM) is applied to the reconstruction of the 3-dimensional electron momentum density distributions observed through the set of Compton profiles measured along various crystallographic directions. It is shown that the reconstruction of electron momentum density may be reliably carried out with the aid of simple iterative algorithm suggested originally by Collins. A number of distributions has been simulated in order to check the performance of MEM. It is shown that MEM can be recommended as a model-free approach. (author). 13 refs, 1 fig

  20. On the maximum drawdown during speculative bubbles

    Science.gov (United States)

    Rotundo, Giulia; Navarra, Mauro

    2007-08-01

    A taxonomy of large financial crashes proposed in the literature locates the burst of speculative bubbles due to endogenous causes in the framework of extreme stock market crashes, defined as falls of market prices that are outlier with respect to the bulk of drawdown price movement distribution. This paper goes on deeper in the analysis providing a further characterization of the rising part of such selected bubbles through the examination of drawdown and maximum drawdown movement of indices prices. The analysis of drawdown duration is also performed and it is the core of the risk measure estimated here.

  1. Multi-Channel Maximum Likelihood Pitch Estimation

    DEFF Research Database (Denmark)

    Christensen, Mads Græsbøll

    2012-01-01

    In this paper, a method for multi-channel pitch estimation is proposed. The method is a maximum likelihood estimator and is based on a parametric model where the signals in the various channels share the same fundamental frequency but can have different amplitudes, phases, and noise characteristics....... This essentially means that the model allows for different conditions in the various channels, like different signal-to-noise ratios, microphone characteristics and reverberation. Moreover, the method does not assume that a certain array structure is used but rather relies on a more general model and is hence...

  2. Conductivity maximum in a charged colloidal suspension

    Energy Technology Data Exchange (ETDEWEB)

    Bastea, S

    2009-01-27

    Molecular dynamics simulations of a charged colloidal suspension in the salt-free regime show that the system exhibits an electrical conductivity maximum as a function of colloid charge. We attribute this behavior to two main competing effects: colloid effective charge saturation due to counterion 'condensation' and diffusion slowdown due to the relaxation effect. In agreement with previous observations, we also find that the effective transported charge is larger than the one determined by the Stern layer and suggest that it corresponds to the boundary fluid layer at the surface of the colloidal particles.

  3. Dynamical maximum entropy approach to flocking.

    Science.gov (United States)

    Cavagna, Andrea; Giardina, Irene; Ginelli, Francesco; Mora, Thierry; Piovani, Duccio; Tavarone, Raffaele; Walczak, Aleksandra M

    2014-04-01

    We derive a new method to infer from data the out-of-equilibrium alignment dynamics of collectively moving animal groups, by considering the maximum entropy model distribution consistent with temporal and spatial correlations of flight direction. When bird neighborhoods evolve rapidly, this dynamical inference correctly learns the parameters of the model, while a static one relying only on the spatial correlations fails. When neighbors change slowly and the detailed balance is satisfied, we recover the static procedure. We demonstrate the validity of the method on simulated data. The approach is applicable to other systems of active matter.

  4. Maximum Temperature Detection System for Integrated Circuits

    Science.gov (United States)

    Frankiewicz, Maciej; Kos, Andrzej

    2015-03-01

    The paper describes structure and measurement results of the system detecting present maximum temperature on the surface of an integrated circuit. The system consists of the set of proportional to absolute temperature sensors, temperature processing path and a digital part designed in VHDL. Analogue parts of the circuit where designed with full-custom technique. The system is a part of temperature-controlled oscillator circuit - a power management system based on dynamic frequency scaling method. The oscillator cooperates with microprocessor dedicated for thermal experiments. The whole system is implemented in UMC CMOS 0.18 μm (1.8 V) technology.

  5. Maximum entropy PDF projection: A review

    Science.gov (United States)

    Baggenstoss, Paul M.

    2017-06-01

    We review maximum entropy (MaxEnt) PDF projection, a method with wide potential applications in statistical inference. The method constructs a sampling distribution for a high-dimensional vector x based on knowing the sampling distribution p(z) of a lower-dimensional feature z = T (x). Under mild conditions, the distribution p(x) having highest possible entropy among all distributions consistent with p(z) may be readily found. Furthermore, the MaxEnt p(x) may be sampled, making the approach useful in Monte Carlo methods. We review the theorem and present a case study in model order selection and classification for handwritten character recognition.

  6. Multiperiod Maximum Loss is time unit invariant.

    Science.gov (United States)

    Kovacevic, Raimund M; Breuer, Thomas

    2016-01-01

    Time unit invariance is introduced as an additional requirement for multiperiod risk measures: for a constant portfolio under an i.i.d. risk factor process, the multiperiod risk should equal the one period risk of the aggregated loss, for an appropriate choice of parameters and independent of the portfolio and its distribution. Multiperiod Maximum Loss over a sequence of Kullback-Leibler balls is time unit invariant. This is also the case for the entropic risk measure. On the other hand, multiperiod Value at Risk and multiperiod Expected Shortfall are not time unit invariant.

  7. Maximum a posteriori decoder for digital communications

    Science.gov (United States)

    Altes, Richard A. (Inventor)

    1997-01-01

    A system and method for decoding by identification of the most likely phase coded signal corresponding to received data. The present invention has particular application to communication with signals that experience spurious random phase perturbations. The generalized estimator-correlator uses a maximum a posteriori (MAP) estimator to generate phase estimates for correlation with incoming data samples and for correlation with mean phases indicative of unique hypothesized signals. The result is a MAP likelihood statistic for each hypothesized transmission, wherein the highest value statistic identifies the transmitted signal.

  8. Improved Maximum Parsimony Models for Phylogenetic Networks.

    Science.gov (United States)

    Van Iersel, Leo; Jones, Mark; Scornavacca, Celine

    2018-05-01

    Phylogenetic networks are well suited to represent evolutionary histories comprising reticulate evolution. Several methods aiming at reconstructing explicit phylogenetic networks have been developed in the last two decades. In this article, we propose a new definition of maximum parsimony for phylogenetic networks that permits to model biological scenarios that cannot be modeled by the definitions currently present in the literature (namely, the "hardwired" and "softwired" parsimony). Building on this new definition, we provide several algorithmic results that lay the foundations for new parsimony-based methods for phylogenetic network reconstruction.

  9. Ancestral sequence reconstruction with Maximum Parsimony

    OpenAIRE

    Herbst, Lina; Fischer, Mareike

    2017-01-01

    One of the main aims in phylogenetics is the estimation of ancestral sequences based on present-day data like, for instance, DNA alignments. One way to estimate the data of the last common ancestor of a given set of species is to first reconstruct a phylogenetic tree with some tree inference method and then to use some method of ancestral state inference based on that tree. One of the best-known methods both for tree inference as well as for ancestral sequence inference is Maximum Parsimony (...

  10. Objective Bayesianism and the Maximum Entropy Principle

    Directory of Open Access Journals (Sweden)

    Jon Williamson

    2013-09-01

    Full Text Available Objective Bayesian epistemology invokes three norms: the strengths of our beliefs should be probabilities; they should be calibrated to our evidence of physical probabilities; and they should otherwise equivocate sufficiently between the basic propositions that we can express. The three norms are sometimes explicated by appealing to the maximum entropy principle, which says that a belief function should be a probability function, from all those that are calibrated to evidence, that has maximum entropy. However, the three norms of objective Bayesianism are usually justified in different ways. In this paper, we show that the three norms can all be subsumed under a single justification in terms of minimising worst-case expected loss. This, in turn, is equivalent to maximising a generalised notion of entropy. We suggest that requiring language invariance, in addition to minimising worst-case expected loss, motivates maximisation of standard entropy as opposed to maximisation of other instances of generalised entropy. Our argument also provides a qualified justification for updating degrees of belief by Bayesian conditionalisation. However, conditional probabilities play a less central part in the objective Bayesian account than they do under the subjective view of Bayesianism, leading to a reduced role for Bayes’ Theorem.

  11. Efficient heuristics for maximum common substructure search.

    Science.gov (United States)

    Englert, Péter; Kovács, Péter

    2015-05-26

    Maximum common substructure search is a computationally hard optimization problem with diverse applications in the field of cheminformatics, including similarity search, lead optimization, molecule alignment, and clustering. Most of these applications have strict constraints on running time, so heuristic methods are often preferred. However, the development of an algorithm that is both fast enough and accurate enough for most practical purposes is still a challenge. Moreover, in some applications, the quality of a common substructure depends not only on its size but also on various topological features of the one-to-one atom correspondence it defines. Two state-of-the-art heuristic algorithms for finding maximum common substructures have been implemented at ChemAxon Ltd., and effective heuristics have been developed to improve both their efficiency and the relevance of the atom mappings they provide. The implementations have been thoroughly evaluated and compared with existing solutions (KCOMBU and Indigo). The heuristics have been found to greatly improve the performance and applicability of the algorithms. The purpose of this paper is to introduce the applied methods and present the experimental results.

  12. [Evolutionary process unveiled by the maximum genetic diversity hypothesis].

    Science.gov (United States)

    Huang, Yi-Min; Xia, Meng-Ying; Huang, Shi

    2013-05-01

    As two major popular theories to explain evolutionary facts, the neutral theory and Neo-Darwinism, despite their proven virtues in certain areas, still fail to offer comprehensive explanations to such fundamental evolutionary phenomena as the genetic equidistance result, abundant overlap sites, increase in complexity over time, incomplete understanding of genetic diversity, and inconsistencies with fossil and archaeological records. Maximum genetic diversity hypothesis (MGD), however, constructs a more complete evolutionary genetics theory that incorporates all of the proven virtues of existing theories and adds to them the novel concept of a maximum or optimum limit on genetic distance or diversity. It has yet to meet a contradiction and explained for the first time the half-century old Genetic Equidistance phenomenon as well as most other major evolutionary facts. It provides practical and quantitative ways of studying complexity. Molecular interpretation using MGD-based methods reveal novel insights on the origins of humans and other primates that are consistent with fossil evidence and common sense, and reestablished the important role of China in the evolution of humans. MGD theory has also uncovered an important genetic mechanism in the construction of complex traits and the pathogenesis of complex diseases. We here made a series of sequence comparisons among yeasts, fishes and primates to illustrate the concept of limit on genetic distance. The idea of limit or optimum is in line with the yin-yang paradigm in the traditional Chinese view of the universal creative law in nature.

  13. Noise and physical limits to maximum resolution of PET images

    Energy Technology Data Exchange (ETDEWEB)

    Herraiz, J.L.; Espana, S. [Dpto. Fisica Atomica, Molecular y Nuclear, Facultad de Ciencias Fisicas, Universidad Complutense de Madrid, Avda. Complutense s/n, E-28040 Madrid (Spain); Vicente, E.; Vaquero, J.J.; Desco, M. [Unidad de Medicina y Cirugia Experimental, Hospital GU ' Gregorio Maranon' , E-28007 Madrid (Spain); Udias, J.M. [Dpto. Fisica Atomica, Molecular y Nuclear, Facultad de Ciencias Fisicas, Universidad Complutense de Madrid, Avda. Complutense s/n, E-28040 Madrid (Spain)], E-mail: jose@nuc2.fis.ucm.es

    2007-10-01

    In this work we show that there is a limit for the maximum resolution achievable with a high resolution PET scanner, as well as for the best signal-to-noise ratio, which are ultimately related to the physical effects involved in the emission and detection of the radiation and thus they cannot be overcome with any particular reconstruction method. These effects prevent the spatial high frequency components of the imaged structures to be recorded by the scanner. Therefore, the information encoded in these high frequencies cannot be recovered by any reconstruction technique. Within this framework, we have determined the maximum resolution achievable for a given acquisition as a function of data statistics and scanner parameters, like the size of the crystals or the inter-crystal scatter. In particular, the noise level in the data as a limitation factor to yield high-resolution images in tomographs with small crystal sizes is outlined. These results have implications regarding how to decide the optimal number of voxels of the reconstructed image or how to design better PET scanners.

  14. Noise and physical limits to maximum resolution of PET images

    International Nuclear Information System (INIS)

    Herraiz, J.L.; Espana, S.; Vicente, E.; Vaquero, J.J.; Desco, M.; Udias, J.M.

    2007-01-01

    In this work we show that there is a limit for the maximum resolution achievable with a high resolution PET scanner, as well as for the best signal-to-noise ratio, which are ultimately related to the physical effects involved in the emission and detection of the radiation and thus they cannot be overcome with any particular reconstruction method. These effects prevent the spatial high frequency components of the imaged structures to be recorded by the scanner. Therefore, the information encoded in these high frequencies cannot be recovered by any reconstruction technique. Within this framework, we have determined the maximum resolution achievable for a given acquisition as a function of data statistics and scanner parameters, like the size of the crystals or the inter-crystal scatter. In particular, the noise level in the data as a limitation factor to yield high-resolution images in tomographs with small crystal sizes is outlined. These results have implications regarding how to decide the optimal number of voxels of the reconstructed image or how to design better PET scanners

  15. Maximum surface level and temperature histories for Hanford waste tanks

    International Nuclear Information System (INIS)

    Flanagan, B.D.; Ha, N.D.; Huisingh, J.S.

    1994-01-01

    Radioactive defense waste resulting from the chemical processing of spent nuclear fuel has been accumulating at the Hanford Site since 1944. This waste is stored in underground waste-storage tanks. The Hanford Site Tank Farm Facilities Interim Safety Basis (ISB) provides a ready reference to the safety envelope for applicable tank farm facilities and installations. During preparation of the ISB, tank structural integrity concerns were identified as a key element in defining the safety envelope. These concerns, along with several deficiencies in the technical bases associated with the structural integrity issues and the corresponding operational limits/controls specified for conduct of normal tank farm operations are documented in the ISB. Consequently, a plan was initiated to upgrade the safety envelope technical bases by conducting Accelerated Safety Analyses-Phase 1 (ASA-Phase 1) sensitivity studies and additional structural evaluations. The purpose of this report is to facilitate the ASA-Phase 1 studies and future analyses of the single-shell tanks (SSTs) and double-shell tanks (DSTs) by compiling a quantitative summary of some of the past operating conditions the tanks have experienced during their existence. This report documents the available summaries of recorded maximum surface levels and maximum waste temperatures and references other sources for more specific data

  16. Hydraulic Limits on Maximum Plant Transpiration

    Science.gov (United States)

    Manzoni, S.; Vico, G.; Katul, G. G.; Palmroth, S.; Jackson, R. B.; Porporato, A. M.

    2011-12-01

    Photosynthesis occurs at the expense of water losses through transpiration. As a consequence of this basic carbon-water interaction at the leaf level, plant growth and ecosystem carbon exchanges are tightly coupled to transpiration. In this contribution, the hydraulic constraints that limit transpiration rates under well-watered conditions are examined across plant functional types and climates. The potential water flow through plants is proportional to both xylem hydraulic conductivity (which depends on plant carbon economy) and the difference in water potential between the soil and the atmosphere (the driving force that pulls water from the soil). Differently from previous works, we study how this potential flux changes with the amplitude of the driving force (i.e., we focus on xylem properties and not on stomatal regulation). Xylem hydraulic conductivity decreases as the driving force increases due to cavitation of the tissues. As a result of this negative feedback, more negative leaf (and xylem) water potentials would provide a stronger driving force for water transport, while at the same time limiting xylem hydraulic conductivity due to cavitation. Here, the leaf water potential value that allows an optimum balance between driving force and xylem conductivity is quantified, thus defining the maximum transpiration rate that can be sustained by the soil-to-leaf hydraulic system. To apply the proposed framework at the global scale, a novel database of xylem conductivity and cavitation vulnerability across plant types and biomes is developed. Conductivity and water potential at 50% cavitation are shown to be complementary (in particular between angiosperms and conifers), suggesting a tradeoff between transport efficiency and hydraulic safety. Plants from warmer and drier biomes tend to achieve larger maximum transpiration than plants growing in environments with lower atmospheric water demand. The predicted maximum transpiration and the corresponding leaf water

  17. Analogue of Pontryagin's maximum principle for multiple integrals minimization problems

    OpenAIRE

    Mikhail, Zelikin

    2016-01-01

    The theorem like Pontryagin's maximum principle for multiple integrals is proved. Unlike the usual maximum principle, the maximum should be taken not over all matrices, but only on matrices of rank one. Examples are given.

  18. Lake Basin Fetch and Maximum Length/Width

    Data.gov (United States)

    Minnesota Department of Natural Resources — Linear features representing the Fetch, Maximum Length and Maximum Width of a lake basin. Fetch, maximum length and average width are calcuated from the lake polygon...

  19. Maximum Likelihood Reconstruction for Magnetic Resonance Fingerprinting.

    Science.gov (United States)

    Zhao, Bo; Setsompop, Kawin; Ye, Huihui; Cauley, Stephen F; Wald, Lawrence L

    2016-08-01

    This paper introduces a statistical estimation framework for magnetic resonance (MR) fingerprinting, a recently proposed quantitative imaging paradigm. Within this framework, we present a maximum likelihood (ML) formalism to estimate multiple MR tissue parameter maps directly from highly undersampled, noisy k-space data. A novel algorithm, based on variable splitting, the alternating direction method of multipliers, and the variable projection method, is developed to solve the resulting optimization problem. Representative results from both simulations and in vivo experiments demonstrate that the proposed approach yields significantly improved accuracy in parameter estimation, compared to the conventional MR fingerprinting reconstruction. Moreover, the proposed framework provides new theoretical insights into the conventional approach. We show analytically that the conventional approach is an approximation to the ML reconstruction; more precisely, it is exactly equivalent to the first iteration of the proposed algorithm for the ML reconstruction, provided that a gridding reconstruction is used as an initialization.

  20. Maximum Profit Configurations of Commercial Engines

    Directory of Open Access Journals (Sweden)

    Yiran Chen

    2011-06-01

    Full Text Available An investigation of commercial engines with finite capacity low- and high-price economic subsystems and a generalized commodity transfer law [n ∝ Δ (P m] in commodity flow processes, in which effects of the price elasticities of supply and demand are introduced, is presented in this paper. Optimal cycle configurations of commercial engines for maximum profit are obtained by applying optimal control theory. In some special cases, the eventual state—market equilibrium—is solely determined by the initial conditions and the inherent characteristics of two subsystems; while the different ways of transfer affect the model in respects of the specific forms of the paths of prices and the instantaneous commodity flow, i.e., the optimal configuration.

  1. The worst case complexity of maximum parsimony.

    Science.gov (United States)

    Carmel, Amir; Musa-Lempel, Noa; Tsur, Dekel; Ziv-Ukelson, Michal

    2014-11-01

    One of the core classical problems in computational biology is that of constructing the most parsimonious phylogenetic tree interpreting an input set of sequences from the genomes of evolutionarily related organisms. We reexamine the classical maximum parsimony (MP) optimization problem for the general (asymmetric) scoring matrix case, where rooted phylogenies are implied, and analyze the worst case bounds of three approaches to MP: The approach of Cavalli-Sforza and Edwards, the approach of Hendy and Penny, and a new agglomerative, "bottom-up" approach we present in this article. We show that the second and third approaches are faster than the first one by a factor of Θ(√n) and Θ(n), respectively, where n is the number of species.

  2. Shifts in the diets of slimy sculpin (Cottus cognatus) and lake whitefish (Coregonus clupeaformis) in Lake Ontario following the collapse of the burrowing amphipod Diporeia

    Science.gov (United States)

    Owens, Randall W.; Dittman, Dawn E.

    2003-01-01

    In Lake Ontario, the diets of slimy sculpin Cottus cognatus and lake whitefish Coregonus clupeaformis shifted from a diet dominated by the burrowing amphipod, Diporeia, and to a lesser extent, Mysis, to a more diverse diet, after Diporeia collapsed, to one dominated by Mysis and prey that were formerly less important or uncommon such as Chironomidae, Oligochaeta, and Ostracoda. Additionally, lake whitefish still preyed on native mollusks like Sphaeriidae and Gastropoda, but also preyed on exotic mollusks, Dreissena spp., which are swallowed intact and subsequently crushed in its muscular stomach. Whether Diporeia was abundant (1992) or scarce (1999), selection indices for Diporeia by slimy sculpins was positive, suggesting that Diporeia was a preferred prey. Unlike lake whitefish, slimy sculpins avoided Dreissena; therefore, energy diverted to Dreissena production was a real loss for slimy sculpins. The shifts in the diet of these benthic fishes corresponded with drastic changes in the benthic community between 1992 and 1999. The collapse of Diporeia, formerly the most abundant macroinvertebrate in the benthic community, along with sharp declines in the abundance of Oligochaeta and Sphaeriidae, coincided with the establishment and rapid expansion of Dreissena bugensis, the quagga mussel, and to a lesser degree Dreissena polymorpha, the zebra mussel. It appears that the Diporeia population first collapsed at depths >70 m in southeastern Lake Ontario by autumn 1992, at shallower depths in the eastern Lake Ontario by 1995, and along the entire south shore line at depths 100 m by 1999. In response to the disappearance of Diporeia, populations of two native benthivores, slimy sculpin and lake whitefish, collapsed in eastern Lake Ontario, perhaps due in part to starvation, because Diporeia was their principal prey. Presently, alternative food resources do not appear sufficient to sustain these two benthivores at their former levels of abundance. We do not expect slimy

  3. A maximum power point tracking for photovoltaic-SPE system using a maximum current controller

    Energy Technology Data Exchange (ETDEWEB)

    Muhida, Riza [Osaka Univ., Dept. of Physical Science, Toyonaka, Osaka (Japan); Osaka Univ., Dept. of Electrical Engineering, Suita, Osaka (Japan); Park, Minwon; Dakkak, Mohammed; Matsuura, Kenji [Osaka Univ., Dept. of Electrical Engineering, Suita, Osaka (Japan); Tsuyoshi, Akira; Michira, Masakazu [Kobe City College of Technology, Nishi-ku, Kobe (Japan)

    2003-02-01

    Processes to produce hydrogen from solar photovoltaic (PV)-powered water electrolysis using solid polymer electrolysis (SPE) are reported. An alternative control of maximum power point tracking (MPPT) in the PV-SPE system based on the maximum current searching methods has been designed and implemented. Based on the characteristics of voltage-current and theoretical analysis of SPE, it can be shown that the tracking of the maximum current output of DC-DC converter in SPE side will track the MPPT of photovoltaic panel simultaneously. This method uses a proportional integrator controller to control the duty factor of DC-DC converter with pulse-width modulator (PWM). The MPPT performance and hydrogen production performance of this method have been evaluated and discussed based on the results of the experiment. (Author)

  4. Large temperature variability in the southern African tropics since the Last Glacial Maximum

    NARCIS (Netherlands)

    Powers, L.A.; Johnson, T.C.; Werne, J.P.; Castañeda, I.S.; Hopmans, E.; Sinninghe Damsté, J.S.; Schouten, S.

    2005-01-01

    The role of the tropics in global climate change is actively debated, particularly in regard to the timing and magnitude of thermal and hydrological response. Continuous, high-resolution temperature records through the Last Glacial Maximum (LGM) from tropical oceans have provided much insight

  5. Maximum mass of magnetic white dwarfs

    International Nuclear Information System (INIS)

    Paret, Daryel Manreza; Horvath, Jorge Ernesto; Martínez, Aurora Perez

    2015-01-01

    We revisit the problem of the maximum masses of magnetized white dwarfs (WDs). The impact of a strong magnetic field on the structure equations is addressed. The pressures become anisotropic due to the presence of the magnetic field and split into parallel and perpendicular components. We first construct stable solutions of the Tolman-Oppenheimer-Volkoff equations for parallel pressures and find that physical solutions vanish for the perpendicular pressure when B ≳ 10 13 G. This fact establishes an upper bound for a magnetic field and the stability of the configurations in the (quasi) spherical approximation. Our findings also indicate that it is not possible to obtain stable magnetized WDs with super-Chandrasekhar masses because the values of the magnetic field needed for them are higher than this bound. To proceed into the anisotropic regime, we can apply results for structure equations appropriate for a cylindrical metric with anisotropic pressures that were derived in our previous work. From the solutions of the structure equations in cylindrical symmetry we have confirmed the same bound for B ∼ 10 13 G, since beyond this value no physical solutions are possible. Our tentative conclusion is that massive WDs with masses well beyond the Chandrasekhar limit do not constitute stable solutions and should not exist. (paper)

  6. TRENDS IN ESTIMATED MIXING DEPTH DAILY MAXIMUMS

    Energy Technology Data Exchange (ETDEWEB)

    Buckley, R; Amy DuPont, A; Robert Kurzeja, R; Matt Parker, M

    2007-11-12

    Mixing depth is an important quantity in the determination of air pollution concentrations. Fireweather forecasts depend strongly on estimates of the mixing depth as a means of determining the altitude and dilution (ventilation rates) of smoke plumes. The Savannah River United States Forest Service (USFS) routinely conducts prescribed fires at the Savannah River Site (SRS), a heavily wooded Department of Energy (DOE) facility located in southwest South Carolina. For many years, the Savannah River National Laboratory (SRNL) has provided forecasts of weather conditions in support of the fire program, including an estimated mixing depth using potential temperature and turbulence change with height at a given location. This paper examines trends in the average estimated mixing depth daily maximum at the SRS over an extended period of time (4.75 years) derived from numerical atmospheric simulations using two versions of the Regional Atmospheric Modeling System (RAMS). This allows for differences to be seen between the model versions, as well as trends on a multi-year time frame. In addition, comparisons of predicted mixing depth for individual days in which special balloon soundings were released are also discussed.

  7. Maximum Margin Clustering of Hyperspectral Data

    Science.gov (United States)

    Niazmardi, S.; Safari, A.; Homayouni, S.

    2013-09-01

    In recent decades, large margin methods such as Support Vector Machines (SVMs) are supposed to be the state-of-the-art of supervised learning methods for classification of hyperspectral data. However, the results of these algorithms mainly depend on the quality and quantity of available training data. To tackle down the problems associated with the training data, the researcher put effort into extending the capability of large margin algorithms for unsupervised learning. One of the recent proposed algorithms is Maximum Margin Clustering (MMC). The MMC is an unsupervised SVMs algorithm that simultaneously estimates both the labels and the hyperplane parameters. Nevertheless, the optimization of the MMC algorithm is a non-convex problem. Most of the existing MMC methods rely on the reformulating and the relaxing of the non-convex optimization problem as semi-definite programs (SDP), which are computationally very expensive and only can handle small data sets. Moreover, most of these algorithms are two-class classification, which cannot be used for classification of remotely sensed data. In this paper, a new MMC algorithm is used that solve the original non-convex problem using Alternative Optimization method. This algorithm is also extended for multi-class classification and its performance is evaluated. The results of the proposed algorithm show that the algorithm has acceptable results for hyperspectral data clustering.

  8. Paving the road to maximum productivity.

    Science.gov (United States)

    Holland, C

    1998-01-01

    "Job security" is an oxymoron in today's environment of downsizing, mergers, and acquisitions. Workers find themselves living by new rules in the workplace that they may not understand. How do we cope? It is the leader's charge to take advantage of this chaos and create conditions under which his or her people can understand the need for change and come together with a shared purpose to effect that change. The clinical laboratory at Arkansas Children's Hospital has taken advantage of this chaos to down-size and to redesign how the work gets done to pave the road to maximum productivity. After initial hourly cutbacks, the workers accepted the cold, hard fact that they would never get their old world back. They set goals to proactively shape their new world through reorganizing, flexing staff with workload, creating a rapid response laboratory, exploiting information technology, and outsourcing. Today the laboratory is a lean, productive machine that accepts change as a way of life. We have learned to adapt, trust, and support each other as we have journeyed together over the rough roads. We are looking forward to paving a new fork in the road to the future.

  9. Maximum power flux of auroral kilometric radiation

    International Nuclear Information System (INIS)

    Benson, R.F.; Fainberg, J.

    1991-01-01

    The maximum auroral kilometric radiation (AKR) power flux observed by distant satellites has been increased by more than a factor of 10 from previously reported values. This increase has been achieved by a new data selection criterion and a new analysis of antenna spin modulated signals received by the radio astronomy instrument on ISEE 3. The method relies on selecting AKR events containing signals in the highest-frequency channel (1980, kHz), followed by a careful analysis that effectively increased the instrumental dynamic range by more than 20 dB by making use of the spacecraft antenna gain diagram during a spacecraft rotation. This analysis has allowed the separation of real signals from those created in the receiver by overloading. Many signals having the appearance of AKR harmonic signals were shown to be of spurious origin. During one event, however, real second harmonic AKR signals were detected even though the spacecraft was at a great distance (17 R E ) from Earth. During another event, when the spacecraft was at the orbital distance of the Moon and on the morning side of Earth, the power flux of fundamental AKR was greater than 3 x 10 -13 W m -2 Hz -1 at 360 kHz normalized to a radial distance r of 25 R E assuming the power falls off as r -2 . A comparison of these intense signal levels with the most intense source region values (obtained by ISIS 1 and Viking) suggests that multiple sources were observed by ISEE 3

  10. Maximum likelihood window for time delay estimation

    International Nuclear Information System (INIS)

    Lee, Young Sup; Yoon, Dong Jin; Kim, Chi Yup

    2004-01-01

    Time delay estimation for the detection of leak location in underground pipelines is critically important. Because the exact leak location depends upon the precision of the time delay between sensor signals due to leak noise and the speed of elastic waves, the research on the estimation of time delay has been one of the key issues in leak lovating with the time arrival difference method. In this study, an optimal Maximum Likelihood window is considered to obtain a better estimation of the time delay. This method has been proved in experiments, which can provide much clearer and more precise peaks in cross-correlation functions of leak signals. The leak location error has been less than 1 % of the distance between sensors, for example the error was not greater than 3 m for 300 m long underground pipelines. Apart from the experiment, an intensive theoretical analysis in terms of signal processing has been described. The improved leak locating with the suggested method is due to the windowing effect in frequency domain, which offers a weighting in significant frequencies.

  11. Ancestral Sequence Reconstruction with Maximum Parsimony.

    Science.gov (United States)

    Herbst, Lina; Fischer, Mareike

    2017-12-01

    One of the main aims in phylogenetics is the estimation of ancestral sequences based on present-day data like, for instance, DNA alignments. One way to estimate the data of the last common ancestor of a given set of species is to first reconstruct a phylogenetic tree with some tree inference method and then to use some method of ancestral state inference based on that tree. One of the best-known methods both for tree inference and for ancestral sequence inference is Maximum Parsimony (MP). In this manuscript, we focus on this method and on ancestral state inference for fully bifurcating trees. In particular, we investigate a conjecture published by Charleston and Steel in 1995 concerning the number of species which need to have a particular state, say a, at a particular site in order for MP to unambiguously return a as an estimate for the state of the last common ancestor. We prove the conjecture for all even numbers of character states, which is the most relevant case in biology. We also show that the conjecture does not hold in general for odd numbers of character states, but also present some positive results for this case.

  12. Maximum neutron yeidls in experimental fusion devices

    International Nuclear Information System (INIS)

    Jassby, D.L.

    1979-02-01

    The optimal performances of 12 types of fusion devices are compared with regard to neutron production rate, neutrons per pulse, and fusion energy multiplication, Q/sub p/ (converted to the equivalent value in D-T operation). The record values in all categories are held by the beam-injected tokamak plasma, followed by other beam-target systems. The achieved values of Q/sub p/ for nearly all laboratory plasma fusion devices (magnetically or inertially confined) are found to roughly satisfy a common empirical scaling, Q/sub p/ approx. 10 -6 E/sub in//sup 3/2/, where E/sub in/ is the energy (in kilojoules) injected into the plasma during one or two energy confinement times, or the total energy delivered to the target for inertially confined systems. Fusion energy break-even (Q/sub p/ = 1) in any system apparently requires E/sub in/ approx. 10,000 kJ

  13. Interactions of juvenile Lumbricus terrestris with adults and their burrow systems in a two-dimensional microcosm Interações de juvenis de Lumbricus terrestris com adultos e seus sistemas de galerias em um microcosmo bidimensional

    Directory of Open Access Journals (Sweden)

    Niki Grigoropoulou

    2009-08-01

    Full Text Available The objective of this work was to evaluate interactions of Lumbricus terrestris juveniles with adults and with inherited burrow systems. An experiment was set up using a two dimensional Evans' boxes microcosm. Adult L. terrestris were added to 16 boxes (one individual per box and kept in darkness at 17ºC along with eight unoccupied boxes for two months. The adult L. terrestris were removed from eight randomly selected boxes, and L. terrestris juveniles were added (one juvenile per box, composing three treatments with eight replicates: 1, with an adult in an inherited burrow (ABJ; 2, alone in an inherited burrow (BJ; and 3, alone in a previously uninhabited box (J. The proportion of juveniles occupying adult burrows observed was significantly different in treatments ABJ (48% and BJ (75%. The mean mass of juveniles at experimental termination differed significantly among treatments and was greater in treatment J (4.04±0.39 g in comparison to the BJ (3.09±0.93 g and ABJ treatments (2.13±0.64 g. Results suggest a negative influence of both the presence of an adult and its burrow system on juvenile growth. Intraspecific competition partially explained this, but further investigation is required to examine how an inherited environment (i.e. burrow could negatively affect the growth of juveniles.O objetivo deste trabalho foi avaliar as interações de juvenis de Lumbricus terrestris com indivíduos adultos e com sistemas de galerias herdados. O experimento foi realizado usando microcosmos bidimensionais de Evans como unidades experimentais. Adultos de L. terrestris foram colocados em 16 unidades experimentais (um indivíduo por unidade e mantidos no escuro a 17ºC juntamente com oito unidades experimentais inabitadas, por dois meses. Os adultos foram removidos de oito unidades selecionadas aleatoriamente e juvenis foram adicionados a todas as unidades experimentais (um indivíduo por unidade, em três tratamentos, com oito repetições: 1, com um

  14. Quality assurance records and records' system

    International Nuclear Information System (INIS)

    Link, M.; Martinek, J.

    1980-01-01

    For nuclear power plants extensive proof of quality is required which has to be documented reliably by quality records. With respect to the paper volume it is the most comprehensive 'curriculum vitae' of the technique. Traditional methods of information and recording are unsatisfactory for meeting regulatory requirements for maintaining the QA-aspects of status reporting, completeness, traceability and retrieval. Therefore KWU has established a record (documentation) subsystem within the overall component qualification system. Examples of the general documentation requirements, the procedure and handling in accordance with this subsystem for mechanical equipment are to be described examplarily. Topics are: - National and international requirements - Definition of QA records - Modular and product orientated KWU-record subsystem - Criteria for developing records - Record control, distribution, collection, storage - New documentation techniques (microfilm, data processing) - Education and training of personnel. (orig./RW)

  15. 49 CFR 230.24 - Maximum allowable stress.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Maximum allowable stress. 230.24 Section 230.24... Allowable Stress § 230.24 Maximum allowable stress. (a) Maximum allowable stress value. The maximum allowable stress value on any component of a steam locomotive boiler shall not exceed 1/4 of the ultimate...

  16. 20 CFR 226.52 - Total annuity subject to maximum.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Total annuity subject to maximum. 226.52... COMPUTING EMPLOYEE, SPOUSE, AND DIVORCED SPOUSE ANNUITIES Railroad Retirement Family Maximum § 226.52 Total annuity subject to maximum. The total annuity amount which is compared to the maximum monthly amount to...

  17. Half-width at half-maximum, full-width at half-maximum analysis

    Indian Academy of Sciences (India)

    addition to the well-defined parameter full-width at half-maximum (FWHM). The distribution of ... optical side-lobes in the diffraction pattern resulting in steep central maxima [6], reduc- tion of effects of ... and broad central peak. The idea of.

  18. Neuroethological validation of an experimental apparatus to evaluate oriented and non-oriented escape behaviours: Comparison between the polygonal arena with a burrow and the circular enclosure of an open-field test.

    Science.gov (United States)

    Biagioni, Audrey Francisco; dos Anjos-Garcia, Tayllon; Ullah, Farhad; Fisher, Isaac René; Falconi-Sobrinho, Luiz Luciano; de Freitas, Renato Leonardo; Felippotti, Tatiana Tocchini; Coimbra, Norberto Cysne

    2016-02-01

    Inhibition of GABAergic neural inputs to dorsal columns of the periaqueductal grey matter (dPAG), posterior (PH) and dorsomedial (DMH) hypothalamic nuclei elicits distinct types of escape behavioural reactions. To differentiate between the variety and intensity of panic-related behaviours, the pattern of defensive behaviours evoked by blockade of GABAA receptors in the DMH, PH and dPAG were compared in a circular open-field test and in a recently designed polygonal arena. In the circular open-field, the defensive behaviours induced by microinjection of bicuculline into DMH and PH were characterised by defensive alertness behaviour and vertical jumps preceded by rearing exploratory behaviour. On the other hand, explosive escape responses interspersed with horizontal jumps and freezing were observed after the blockade of GABAA receptors on dPAG neurons. In the polygonal arena apparatus, the escape response produced by GABAergic inhibition of DMH and PH neurons was directed towards the burrow. In contrast, the blockade of GABAA receptors in dPAG evoked non-oriented escape behaviour characterised by vigorous running and horizontal jumps in the arena. Our findings support the hypothesis that the hypothalamic nuclei organise oriented escape behavioural responses whereas non-oriented escape is elaborated by dPAG neurons. Additionally, the polygonal arena with a burrow made it easy to discriminate and characterise these two different patterns of escape behavioural responses. In this sense, the polygonal arena with a burrow can be considered a good methodological tool to discriminate between these two different patterns of escape behavioural responses and is very useful as a new experimental animal model of panic attacks. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Cosmic shear measurement with maximum likelihood and maximum a posteriori inference

    Science.gov (United States)

    Hall, Alex; Taylor, Andy

    2017-06-01

    We investigate the problem of noise bias in maximum likelihood and maximum a posteriori estimators for cosmic shear. We derive the leading and next-to-leading order biases and compute them in the context of galaxy ellipticity measurements, extending previous work on maximum likelihood inference for weak lensing. We show that a large part of the bias on these point estimators can be removed using information already contained in the likelihood when a galaxy model is specified, without the need for external calibration. We test these bias-corrected estimators on simulated galaxy images similar to those expected from planned space-based weak lensing surveys, with promising results. We find that the introduction of an intrinsic shape prior can help with mitigation of noise bias, such that the maximum a posteriori estimate can be made less biased than the maximum likelihood estimate. Second-order terms offer a check on the convergence of the estimators, but are largely subdominant. We show how biases propagate to shear estimates, demonstrating in our simple set-up that shear biases can be reduced by orders of magnitude and potentially to within the requirements of planned space-based surveys at mild signal-to-noise ratio. We find that second-order terms can exhibit significant cancellations at low signal-to-noise ratio when Gaussian noise is assumed, which has implications for inferring the performance of shear-measurement algorithms from simplified simulations. We discuss the viability of our point estimators as tools for lensing inference, arguing that they allow for the robust measurement of ellipticity and shear.

  20. A maximum likelihood framework for protein design

    Directory of Open Access Journals (Sweden)

    Philippe Hervé

    2006-06-01

    Full Text Available Abstract Background The aim of protein design is to predict amino-acid sequences compatible with a given target structure. Traditionally envisioned as a purely thermodynamic question, this problem can also be understood in a wider context, where additional constraints are captured by learning the sequence patterns displayed by natural proteins of known conformation. In this latter perspective, however, we still need a theoretical formalization of the question, leading to general and efficient learning methods, and allowing for the selection of fast and accurate objective functions quantifying sequence/structure compatibility. Results We propose a formulation of the protein design problem in terms of model-based statistical inference. Our framework uses the maximum likelihood principle to optimize the unknown parameters of a statistical potential, which we call an inverse potential to contrast with classical potentials used for structure prediction. We propose an implementation based on Markov chain Monte Carlo, in which the likelihood is maximized by gradient descent and is numerically estimated by thermodynamic integration. The fit of the models is evaluated by cross-validation. We apply this to a simple pairwise contact potential, supplemented with a solvent-accessibility term, and show that the resulting models have a better predictive power than currently available pairwise potentials. Furthermore, the model comparison method presented here allows one to measure the relative contribution of each component of the potential, and to choose the optimal number of accessibility classes, which turns out to be much higher than classically considered. Conclusion Altogether, this reformulation makes it possible to test a wide diversity of models, using different forms of potentials, or accounting for other factors than just the constraint of thermodynamic stability. Ultimately, such model-based statistical analyses may help to understand the forces

  1. Presidential Electronic Records Library

    Data.gov (United States)

    National Archives and Records Administration — PERL (Presidential Electronic Records Library) used to ingest and provide internal access to the Presidential electronic Records of the Reagan, Bush, and Clinton...

  2. CMS Records Schedule

    Data.gov (United States)

    U.S. Department of Health & Human Services — The CMS Records Schedule provides disposition authorizations approved by the National Archives and Records Administration (NARA) for CMS program-related records...

  3. Maximum entropy production rate in quantum thermodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Beretta, Gian Paolo, E-mail: beretta@ing.unibs.i [Universita di Brescia, via Branze 38, 25123 Brescia (Italy)

    2010-06-01

    In the framework of the recent quest for well-behaved nonlinear extensions of the traditional Schroedinger-von Neumann unitary dynamics that could provide fundamental explanations of recent experimental evidence of loss of quantum coherence at the microscopic level, a recent paper [Gheorghiu-Svirschevski 2001 Phys. Rev. A 63 054102] reproposes the nonlinear equation of motion proposed by the present author [see Beretta G P 1987 Found. Phys. 17 365 and references therein] for quantum (thermo)dynamics of a single isolated indivisible constituent system, such as a single particle, qubit, qudit, spin or atomic system, or a Bose-Einstein or Fermi-Dirac field. As already proved, such nonlinear dynamics entails a fundamental unifying microscopic proof and extension of Onsager's reciprocity and Callen's fluctuation-dissipation relations to all nonequilibrium states, close and far from thermodynamic equilibrium. In this paper we propose a brief but self-contained review of the main results already proved, including the explicit geometrical construction of the equation of motion from the steepest-entropy-ascent ansatz and its exact mathematical and conceptual equivalence with the maximal-entropy-generation variational-principle formulation presented in Gheorghiu-Svirschevski S 2001 Phys. Rev. A 63 022105. Moreover, we show how it can be extended to the case of a composite system to obtain the general form of the equation of motion, consistent with the demanding requirements of strong separability and of compatibility with general thermodynamics principles. The irreversible term in the equation of motion describes the spontaneous attraction of the state operator in the direction of steepest entropy ascent, thus implementing the maximum entropy production principle in quantum theory. The time rate at which the path of steepest entropy ascent is followed has so far been left unspecified. As a step towards the identification of such rate, here we propose a possible

  4. Determination of the maximum-depth to potential field sources by a maximum structural index method

    Science.gov (United States)

    Fedi, M.; Florio, G.

    2013-01-01

    A simple and fast determination of the limiting depth to the sources may represent a significant help to the data interpretation. To this end we explore the possibility of determining those source parameters shared by all the classes of models fitting the data. One approach is to determine the maximum depth-to-source compatible with the measured data, by using for example the well-known Bott-Smith rules. These rules involve only the knowledge of the field and its horizontal gradient maxima, and are independent from the density contrast. Thanks to the direct relationship between structural index and depth to sources we work out a simple and fast strategy to obtain the maximum depth by using the semi-automated methods, such as Euler deconvolution or depth-from-extreme-points method (DEXP). The proposed method consists in estimating the maximum depth as the one obtained for the highest allowable value of the structural index (Nmax). Nmax may be easily determined, since it depends only on the dimensionality of the problem (2D/3D) and on the nature of the analyzed field (e.g., gravity field or magnetic field). We tested our approach on synthetic models against the results obtained by the classical Bott-Smith formulas and the results are in fact very similar, confirming the validity of this method. However, while Bott-Smith formulas are restricted to the gravity field only, our method is applicable also to the magnetic field and to any derivative of the gravity and magnetic field. Our method yields a useful criterion to assess the source model based on the (∂f/∂x)max/fmax ratio. The usefulness of the method in real cases is demonstrated for a salt wall in the Mississippi basin, where the estimation of the maximum depth agrees with the seismic information.

  5. Comparing maximum intercuspal contacts of virtual dental patients and mounted dental casts.

    Science.gov (United States)

    Delong, Ralph; Ko, Ching-Chang; Anderson, Gary C; Hodges, James S; Douglas, W H

    2002-12-01

    Quantitative measures of occlusal contacts are of paramount importance in the study of chewing dysfunction. A tool is needed to identify and quantify occlusal parameters without occlusal interference caused by the technique of analysis. This laboratory simulation study compared occlusal contacts constructed from 3-dimensional images of dental casts and interocclusal records with contacts found by use of conventional methods. Dental casts of 10 completely dentate adults were mounted in a semi-adjustable Denar articulator. Maximum intercuspal contacts were marked on the casts using red film. Intercuspal records made with an experimental vinyl polysiloxane impression material recorded maximum intercuspation. Three-dimensional virtual models of the casts and interocclusal records were made using custom software and an optical scanner. Contacts were calculated between virtual casts aligned manually (CM), aligned with interocclusal records scanned seated on the mandibular casts (C1) or scanned independently (C2), and directly from virtual interocclusal records (IR). Sensitivity and specificity calculations used the marked contacts as the standard. Contact parameters were compared between method pairs. Statistical comparisons used analysis of variance and the Tukey-Kramer post hoc test (P= CM/C1 = CM/C2 > C2/IR > CM/IR > C1/IR, where ">" means "closer than." Within the limits of this study, occlusal contacts calculated from aligned virtual casts accurately reproduce articulator contacts.

  6. Burrowing behavior of penaeid shrimps

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Brown shrimp, Farfantepenaeus aztecus, and white shrimp, Litopenaeus setiferus, were held were held under natural light conditions before experiments. Experiments...

  7. Weighted Maximum-Clique Transversal Sets of Graphs

    OpenAIRE

    Chuan-Min Lee

    2011-01-01

    A maximum-clique transversal set of a graph G is a subset of vertices intersecting all maximum cliques of G. The maximum-clique transversal set problem is to find a maximum-clique transversal set of G of minimum cardinality. Motivated by the placement of transmitters for cellular telephones, Chang, Kloks, and Lee introduced the concept of maximum-clique transversal sets on graphs in 2001. In this paper, we study the weighted version of the maximum-clique transversal set problem for split grap...

  8. Providing a complete online multimedia patient record.

    Science.gov (United States)

    Dayhoff, R. E.; Kuzmak, P. M.; Kirin, G.; Frank, S.

    1999-01-01

    Seamless integration of all types of patient data is a critical feature for clinical workstation software. The Dept. of Veterans Affairs has developed a multimedia online patient record that includes traditional medical chart information as well as a wide variety of medical images from specialties such as cardiology, pulmonary and gastrointestinal medicine, pathology, radiology, hematology, and nuclear medicine. This online patient record can present data in ways not possible with a paper chart or other physical media. Obtaining a critical mass of information online is essential to achieve the maximum benefits from an integrated patient record system. Images Figure 1 Figure 2 PMID:10566357

  9. Pattern formation, logistics, and maximum path probability

    Science.gov (United States)

    Kirkaldy, J. S.

    1985-05-01

    The concept of pattern formation, which to current researchers is a synonym for self-organization, carries the connotation of deductive logic together with the process of spontaneous inference. Defining a pattern as an equivalence relation on a set of thermodynamic objects, we establish that a large class of irreversible pattern-forming systems, evolving along idealized quasisteady paths, approaches the stable steady state as a mapping upon the formal deductive imperatives of a propositional function calculus. In the preamble the classical reversible thermodynamics of composite systems is analyzed as an externally manipulated system of space partitioning and classification based on ideal enclosures and diaphragms. The diaphragms have discrete classification capabilities which are designated in relation to conserved quantities by descriptors such as impervious, diathermal, and adiabatic. Differentiability in the continuum thermodynamic calculus is invoked as equivalent to analyticity and consistency in the underlying class or sentential calculus. The seat of inference, however, rests with the thermodynamicist. In the transition to an irreversible pattern-forming system the defined nature of the composite reservoirs remains, but a given diaphragm is replaced by a pattern-forming system which by its nature is a spontaneously evolving volume partitioner and classifier of invariants. The seat of volition or inference for the classification system is thus transferred from the experimenter or theoretician to the diaphragm, and with it the full deductive facility. The equivalence relations or partitions associated with the emerging patterns may thus be associated with theorems of the natural pattern-forming calculus. The entropy function, together with its derivatives, is the vehicle which relates the logistics of reservoirs and diaphragms to the analog logistics of the continuum. Maximum path probability or second-order differentiability of the entropy in isolation are

  10. Surgical medical record

    DEFF Research Database (Denmark)

    Bulow, S.

    2008-01-01

    A medical record is presented on the basis of selected linguistic pearls collected over the years from surgical case records Udgivelsesdato: 2008/12/15......A medical record is presented on the basis of selected linguistic pearls collected over the years from surgical case records Udgivelsesdato: 2008/12/15...

  11. Electronic records management in the public health sector of the ...

    African Journals Online (AJOL)

    Ngulup

    records) ... cally related administrative decision-making and problem-solving. ... This implies that a successful e-health system needs maximum support from proper ...... disaster backup for recovery in case it is affected by disaster like fire and water.

  12. Accurate modeling and maximum power point detection of ...

    African Journals Online (AJOL)

    Accurate modeling and maximum power point detection of photovoltaic ... Determination of MPP enables the PV system to deliver maximum available power. ..... adaptive artificial neural network: Proposition for a new sizing procedure.

  13. Maximum power per VA control of vector controlled interior ...

    Indian Academy of Sciences (India)

    Thakur Sumeet Singh

    2018-04-11

    Apr 11, 2018 ... Department of Electrical Engineering, Indian Institute of Technology Delhi, New ... The MPVA operation allows maximum-utilization of the drive-system. ... Permanent magnet motor; unity power factor; maximum VA utilization; ...

  14. Electron density distribution in Si and Ge using multipole, maximum ...

    Indian Academy of Sciences (India)

    Si and Ge has been studied using multipole, maximum entropy method (MEM) and ... and electron density distribution using the currently available versatile ..... data should be subjected to maximum possible utility for the characterization of.

  15. 40 CFR 141.13 - Maximum contaminant levels for turbidity.

    Science.gov (United States)

    2010-07-01

    ... turbidity. 141.13 Section 141.13 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER... Maximum contaminant levels for turbidity. The maximum contaminant levels for turbidity are applicable to... part. The maximum contaminant levels for turbidity in drinking water, measured at a representative...

  16. Maximum Power Training and Plyometrics for Cross-Country Running.

    Science.gov (United States)

    Ebben, William P.

    2001-01-01

    Provides a rationale for maximum power training and plyometrics as conditioning strategies for cross-country runners, examining: an evaluation of training methods (strength training and maximum power training and plyometrics); biomechanic and velocity specificity (role in preventing injury); and practical application of maximum power training and…

  17. 13 CFR 107.840 - Maximum term of Financing.

    Science.gov (United States)

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Maximum term of Financing. 107.840... COMPANIES Financing of Small Businesses by Licensees Structuring Licensee's Financing of An Eligible Small Business: Terms and Conditions of Financing § 107.840 Maximum term of Financing. The maximum term of any...

  18. 7 CFR 3565.210 - Maximum interest rate.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Maximum interest rate. 3565.210 Section 3565.210... AGRICULTURE GUARANTEED RURAL RENTAL HOUSING PROGRAM Loan Requirements § 3565.210 Maximum interest rate. The interest rate for a guaranteed loan must not exceed the maximum allowable rate specified by the Agency in...

  19. Characterizing graphs of maximum matching width at most 2

    DEFF Research Database (Denmark)

    Jeong, Jisu; Ok, Seongmin; Suh, Geewon

    2017-01-01

    The maximum matching width is a width-parameter that is de ned on a branch-decomposition over the vertex set of a graph. The size of a maximum matching in the bipartite graph is used as a cut-function. In this paper, we characterize the graphs of maximum matching width at most 2 using the minor o...

  20. Standard values of maximum tongue pressure taken using newly developed disposable tongue pressure measurement device.

    Science.gov (United States)

    Utanohara, Yuri; Hayashi, Ryo; Yoshikawa, Mineka; Yoshida, Mitsuyoshi; Tsuga, Kazuhiro; Akagawa, Yasumasa

    2008-09-01

    It is clinically important to evaluate tongue function in terms of rehabilitation of swallowing and eating ability. We have developed a disposable tongue pressure measurement device designed for clinical use. In this study we used this device to determine standard values of maximum tongue pressure in adult Japanese. Eight hundred fifty-three subjects (408 male, 445 female; 20-79 years) were selected for this study. All participants had no history of dysphagia and maintained occlusal contact in the premolar and molar regions with their own teeth. A balloon-type disposable oral probe was used to measure tongue pressure by asking subjects to compress it onto the palate for 7 s with maximum voluntary effort. Values were recorded three times for each subject, and the mean values were defined as maximum tongue pressure. Although maximum tongue pressure was higher for males than for females in the 20-49-year age groups, there was no significant difference between males and females in the 50-79-year age groups. The maximum tongue pressure of the seventies age group was significantly lower than that of the twenties to fifties age groups. It may be concluded that maximum tongue pressures were reduced with primary aging. Males may become weaker with age at a faster rate than females; however, further decreases in strength were in parallel for male and female subjects.

  1. Maximum possible age of a petrel breeding colony near Punakaiki (South Island, New Zealand) from radiocarbon and stable isotope analysis of soil

    International Nuclear Information System (INIS)

    Hawke, D.J.

    2004-01-01

    The lifetime of individual petrel colonies is poorly known. This study used radiocarbon, 13 C, and 15 N analysis of soil to determine the maximum possible age of a colony presently occupied by Westland petrels. A sample of Ap horizon soil in lithic contact was selected for analysis, as soil least likely to have been redistributed by petrel burrowing. Chemical removal of mobile organic matter decreased δ 15 N from 14.0 permille (typical of breeding colony soils) to 6.1 permille (within the range of temperate forest soils without sea-bird breeding). δ 13 C values changed little, from -27.1 permille (untreated soil) to -28.4 permille (treated soil), and were typical of forest soil with with C 3 vegetation and no incorporation of marine C. Duplicate AMS radiocarbon analysis of treated sample yielded a combined conventional radiocarbon age of 864 ± 32 BP, indicating that sea-bird breeding could not have occurred at the site for more than 740-960 calendar years. Initial colony occupation may have occurred much later than this, and not been continuous. Sea bird species other than Westland petrels may also have used the site. (author). 30 refs., 2 figs

  2. Subtropical Climate Variability since the Last Glacial Maximum from Speleothem Precipitation Reconstructions in Florida

    Science.gov (United States)

    Polk, J.; van Beynen, P.; DeLong, K. L.; Asmerom, Y.; Polyak, V. J.

    2017-12-01

    Teleconnections between the tropical-subtropical regions of the Americas since the Last Glacial Maximum (LGM), particularly the Mid- to Late-Holocene, and high-resolution proxy records refining climate variability over this period continue to receive increasing attention. Here, we present a high-resolution, precisely dated speleothem record spanning multiple periods of time since the LGM ( 30 ka) for the Florida peninsula. The data indicate that the amount effect plays a significant role in determining the isotopic signal of the speleothem calcite. Collectively, the records indicate distinct differences in climate in the region between the LGM, Mid-Holocene, and Late Holocene, including a progressive shift in ocean composition and precipitation isotopic values through the period, suggesting Florida's sensitivity to regional and global climatic shifts. Comparisons between speleothem δ18O values and Gulf of Mexico marine records reveal a strong connection between the Gulf region and the terrestrial subtropical climate in the Late Holocene, while the North Atlantic's influence is clear in the earlier portions of the record. Warmer sea surface temperatures correspond to enhanced evaporation, leading to more intense atmospheric convection in Florida, and thereby modulating the isotopic composition of rainfall above the cave. These regional signals in climate extend from the subtropics to the tropics, with a clear covariance between the speleothem signal and other proxy records from around the region, as well as global agreement during the LGM period with other records. These latter connections appear to be driven by changes in the mean position of the Intertropical Convergence Zone and time series analysis of the δ18O values reveals significant multidecadal periodicities in the record, which are evidenced by agreement with the AMV and other multidecadal influences (NAO and PDO) likely having varying influence throughout the period of record. The climate variability

  3. Accurate computations of monthly average daily extraterrestrial irradiation and the maximum possible sunshine duration

    International Nuclear Information System (INIS)

    Jain, P.C.

    1985-12-01

    The monthly average daily values of the extraterrestrial irradiation on a horizontal plane and the maximum possible sunshine duration are two important parameters that are frequently needed in various solar energy applications. These are generally calculated by solar scientists and engineers each time they are needed and often by using the approximate short-cut methods. Using the accurate analytical expressions developed by Spencer for the declination and the eccentricity correction factor, computations for these parameters have been made for all the latitude values from 90 deg. N to 90 deg. S at intervals of 1 deg. and are presented in a convenient tabular form. Monthly average daily values of the maximum possible sunshine duration as recorded on a Campbell Stoke's sunshine recorder are also computed and presented. These tables would avoid the need for repetitive and approximate calculations and serve as a useful ready reference for providing accurate values to the solar energy scientists and engineers

  4. Table for monthly average daily extraterrestrial irradiation on horizontal surface and the maximum possible sunshine duration

    International Nuclear Information System (INIS)

    Jain, P.C.

    1984-01-01

    The monthly average daily values of the extraterrestrial irradiation on a horizontal surface (H 0 ) and the maximum possible sunshine duration are two important parameters that are frequently needed in various solar energy applications. These are generally calculated by scientists each time they are needed and by using the approximate short-cut methods. Computations for these values have been made once and for all for latitude values of 60 deg. N to 60 deg. S at intervals of 1 deg. and are presented in a convenient tabular form. Values of the maximum possible sunshine duration as recorded on a Campbell Stoke's sunshine recorder are also computed and presented. These tables should avoid the need for repetition and approximate calculations and serve as a useful ready reference for solar energy scientists and engineers. (author)

  5. 40 CFR 1042.140 - Maximum engine power, displacement, power density, and maximum in-use engine speed.

    Science.gov (United States)

    2010-07-01

    ... cylinders having an internal diameter of 13.0 cm and a 15.5 cm stroke length, the rounded displacement would... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Maximum engine power, displacement... Maximum engine power, displacement, power density, and maximum in-use engine speed. This section describes...

  6. Maximum on the electrical conductivity polytherm of molten TeCl{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Salyulev, Alexander B.; Potapov, Alexei M. [Russian Academy of Sciences, Ekaterinburg (Russian Federation). Inst. of High-Temperature Electrochemistry

    2017-09-01

    The electrical conductivity of molten TeCl{sub 4} was measured up to 761 K, i.e. 106 degrees above the normal boiling point of the salt. For the first time it was found that TeCl{sub 4} electrical conductivity polytherm has a maximum. It was recorded at 705 K (Κ{sub max}=0.245 Sm/cm), whereupon the conductivity decreases as the temperature rises. The activation energy of electrical conductivity was calculated.

  7. Maximum on the electrical conductivity polytherm of molten TeCl4

    International Nuclear Information System (INIS)

    Salyulev, Alexander B.; Potapov, Alexei M.

    2017-01-01

    The electrical conductivity of molten TeCl 4 was measured up to 761 K, i.e. 106 degrees above the normal boiling point of the salt. For the first time it was found that TeCl 4 electrical conductivity polytherm has a maximum. It was recorded at 705 K (Κ max =0.245 Sm/cm), whereupon the conductivity decreases as the temperature rises. The activation energy of electrical conductivity was calculated.

  8. Your Medical Records

    Science.gov (United States)

    ... hear medical people call these EHRs — short for electronic health records . Electronic records make it easier for all your doctors ... doctor's office is trying to protect a patient's privacy or safety. For example, they may say no ...

  9. Climate Record Books

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Climate Record Books contain daily, monthly, seasonal, and annual averages, extremes, or occurrences. Most data are sequential by period of record 1871-1910,...

  10. Daily Weather Records

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These daily weather records were compiled from a subset of stations in the Global Historical Climatological Network (GHCN)-Daily dataset. A weather record is...

  11. Iraq Radiosonde Launch Records

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Iraqi upper air records loaned to NCDC from the Air Force 14th Weather Squadron. Scanned notebooks containing upper air radiosonde launch records and data. Launches...

  12. The maximum entropy production and maximum Shannon information entropy in enzyme kinetics

    Science.gov (United States)

    Dobovišek, Andrej; Markovič, Rene; Brumen, Milan; Fajmut, Aleš

    2018-04-01

    We demonstrate that the maximum entropy production principle (MEPP) serves as a physical selection principle for the description of the most probable non-equilibrium steady states in simple enzymatic reactions. A theoretical approach is developed, which enables maximization of the density of entropy production with respect to the enzyme rate constants for the enzyme reaction in a steady state. Mass and Gibbs free energy conservations are considered as optimization constraints. In such a way computed optimal enzyme rate constants in a steady state yield also the most uniform probability distribution of the enzyme states. This accounts for the maximal Shannon information entropy. By means of the stability analysis it is also demonstrated that maximal density of entropy production in that enzyme reaction requires flexible enzyme structure, which enables rapid transitions between different enzyme states. These results are supported by an example, in which density of entropy production and Shannon information entropy are numerically maximized for the enzyme Glucose Isomerase.

  13. Solar Maximum Mission Experiment - Ultraviolet Spectroscopy and Polarimetry on the Solar Maximum Mission

    Science.gov (United States)

    Tandberg-Hanssen, E.; Cheng, C. C.; Woodgate, B. E.; Brandt, J. C.; Chapman, R. D.; Athay, R. G.; Beckers, J. M.; Bruner, E. C.; Gurman, J. B.; Hyder, C. L.

    1981-01-01

    The Ultraviolet Spectrometer and Polarimeter on the Solar Maximum Mission spacecraft is described. It is pointed out that the instrument, which operates in the wavelength range 1150-3600 A, has a spatial resolution of 2-3 arcsec and a spectral resolution of 0.02 A FWHM in second order. A Gregorian telescope, with a focal length of 1.8 m, feeds a 1 m Ebert-Fastie spectrometer. A polarimeter comprising rotating Mg F2 waveplates can be inserted behind the spectrometer entrance slit; it permits all four Stokes parameters to be determined. Among the observing modes are rasters, spectral scans, velocity measurements, and polarimetry. Examples of initial observations made since launch are presented.

  14. Record Statistics and Dynamics

    DEFF Research Database (Denmark)

    Sibani, Paolo; Jensen, Henrik J.

    2009-01-01

    with independent random increments. The term record dynamics covers the rather new idea that records may, in special situations, have measurable dynamical consequences. The approach applies to the aging dynamics of glasses and other systems with multiple metastable states. The basic idea is that record sizes...... fluctuations of e. g. the energy are able to push the system past some sort of ‘edge of stability’, inducing irreversible configurational changes, whose statistics then closely follows the statistics of record fluctuations....

  15. Interpreting land records

    CERN Document Server

    Wilson, Donald A

    2014-01-01

    Base retracement on solid research and historically accurate interpretation Interpreting Land Records is the industry's most complete guide to researching and understanding the historical records germane to land surveying. Coverage includes boundary retracement and the primary considerations during new boundary establishment, as well as an introduction to historical records and guidance on effective research and interpretation. This new edition includes a new chapter titled "Researching Land Records," and advice on overcoming common research problems and insight into alternative resources wh

  16. Managing electronic records

    CERN Document Server

    McLeod, Julie

    2005-01-01

    For records management courses, this book covers the theory and practice of managing electronic records as business and information assets. It focuses on the strategies, systems and procedures necessary to ensure that electronic records are appropriately created, captured, organized and retained over time to meet business and legal requirements.

  17. Comparative evaluation of the efficacy of occlusal splints fabricated in centric relation or maximum intercuspation in temporomandibular disorders patients

    OpenAIRE

    Hamata,Marcelo Matida; Zuim,Paulo Renato Junqueira; Garcia,Alicio Rosalino

    2009-01-01

    Fabrication of occlusal splints in centric relation for temporomandibular disorders (TMD) patients is arguable, since this position has been defined for asymptomatic stomatognathic system. Thus, maximum intercuspation might be employed in patients with occlusal stability, eliminating the need for interocclusal records. This study compared occlusal splints fabricated in centric relation and maximum intercuspation in muscle pain reduction of TMD patients. Twenty patients with TMD of myogenous o...

  18. Read/write properties of oriented longitudinal recording media

    International Nuclear Information System (INIS)

    Uesaka, Y.; Nakatani, Y.; Hayashi, N.; Fukushima, H.

    2001-01-01

    The effect of orientation on the maximum recording density including the thermal stability effect was investigated using computer simulation. The necessary head current for a highly oriented medium is at most 10% larger than that for a 2D random medium. A recording density larger than 300 Gb/in 2 can be achieved with highly oriented media with 30 nm flying height

  19. Benefits of the maximum tolerated dose (MTD) and maximum tolerated concentration (MTC) concept in aquatic toxicology

    International Nuclear Information System (INIS)

    Hutchinson, Thomas H.; Boegi, Christian; Winter, Matthew J.; Owens, J. Willie

    2009-01-01

    There is increasing recognition of the need to identify specific sublethal effects of chemicals, such as reproductive toxicity, and specific modes of actions of the chemicals, such as interference with the endocrine system. To achieve these aims requires criteria which provide a basis to interpret study findings so as to separate these specific toxicities and modes of action from not only acute lethality per se but also from severe inanition and malaise that non-specifically compromise reproductive capacity and the response of endocrine endpoints. Mammalian toxicologists have recognized that very high dose levels are sometimes required to elicit both specific adverse effects and present the potential of non-specific 'systemic toxicity'. Mammalian toxicologists have developed the concept of a maximum tolerated dose (MTD) beyond which a specific toxicity or action cannot be attributed to a test substance due to the compromised state of the organism. Ecotoxicologists are now confronted by a similar challenge and must develop an analogous concept of a MTD and the respective criteria. As examples of this conundrum, we note recent developments in efforts to validate protocols for fish reproductive toxicity and endocrine screens (e.g. some chemicals originally selected as 'negatives' elicited decreases in fecundity or changes in endpoints intended to be biomarkers for endocrine modes of action). Unless analogous criteria can be developed, the potentially confounding effects of systemic toxicity may then undermine the reliable assessment of specific reproductive effects or biomarkers such as vitellogenin or spiggin. The same issue confronts other areas of aquatic toxicology (e.g., genotoxicity) and the use of aquatic animals for preclinical assessments of drugs (e.g., use of zebrafish for drug safety assessment). We propose that there are benefits to adopting the concept of an MTD for toxicology and pharmacology studies using fish and other aquatic organisms and the

  20. Microprocessor Controlled Maximum Power Point Tracker for Photovoltaic Application

    International Nuclear Information System (INIS)

    Jiya, J. D.; Tahirou, G.

    2002-01-01

    This paper presents a microprocessor controlled maximum power point tracker for photovoltaic module. Input current and voltage are measured and multiplied within the microprocessor, which contains an algorithm to seek the maximum power point. The duly cycle of the DC-DC converter, at which the maximum power occurs is obtained, noted and adjusted. The microprocessor constantly seeks for improvement of obtained power by varying the duty cycle

  1. Practical recording techniques the step-by-step approach to professional audio recording

    CERN Document Server

    Bartlett, Bruce

    2013-01-01

    Hands-on practical guide covering all aspects of recording, ideal for beginning and intermediate recording engineers, producers, musicians and audio enthusiasts. Filled with tips and shortcuts, this book offers advice on equipping a home studio (both low-budget and advanced), suggestions for set-up, acoustics, choosing monitor speakers, and preventing hum. This best-selling guide also tells how to judge recordings and improve them to produce maximum results. New material covered in the 5th edition to include: * complete revision and update of dig

  2. MEGA5: Molecular Evolutionary Genetics Analysis Using Maximum Likelihood, Evolutionary Distance, and Maximum Parsimony Methods

    Science.gov (United States)

    Tamura, Koichiro; Peterson, Daniel; Peterson, Nicholas; Stecher, Glen; Nei, Masatoshi; Kumar, Sudhir

    2011-01-01

    Comparative analysis of molecular sequence data is essential for reconstructing the evolutionary histories of species and inferring the nature and extent of selective forces shaping the evolution of genes and species. Here, we announce the release of Molecular Evolutionary Genetics Analysis version 5 (MEGA5), which is a user-friendly software for mining online databases, building sequence alignments and phylogenetic trees, and using methods of evolutionary bioinformatics in basic biology, biomedicine, and evolution. The newest addition in MEGA5 is a collection of maximum likelihood (ML) analyses for inferring evolutionary trees, selecting best-fit substitution models (nucleotide or amino acid), inferring ancestral states and sequences (along with probabilities), and estimating evolutionary rates site-by-site. In computer simulation analyses, ML tree inference algorithms in MEGA5 compared favorably with other software packages in terms of computational efficiency and the accuracy of the estimates of phylogenetic trees, substitution parameters, and rate variation among sites. The MEGA user interface has now been enhanced to be activity driven to make it easier for the use of both beginners and experienced scientists. This version of MEGA is intended for the Windows platform, and it has been configured for effective use on Mac OS X and Linux desktops. It is available free of charge from http://www.megasoftware.net. PMID:21546353

  3. A novel algorithm for single-axis maximum power generation sun trackers

    International Nuclear Information System (INIS)

    Lee, Kung-Yen; Chung, Chi-Yao; Huang, Bin-Juine; Kuo, Ting-Jung; Yang, Huang-Wei; Cheng, Hung-Yen; Hsu, Po-Chien; Li, Kang

    2017-01-01

    Highlights: • A novel algorithm for a single-axis sun tracker is developed to increase the efficiency. • Photovoltaic module is rotated to find the optimal angle for generating the maximum power. • Electric energy increases up to 8.3%, compared with that of the tracker with three fixed angles. • The rotation range is optimized to reduce energy consumption from the rotation operations. - Abstract: The purpose of this study is to develop a novel algorithm for a single-axis maximum power generation sun tracker in order to identify the optimal stopping angle for generating the maximum amount of daily electric energy. First, the photovoltaic modules of the single-axis maximum power generation sun tracker are automatically rotated from 50° east to 50° west. During the rotation, the instantaneous power generated at different angles is recorded and compared, meaning that the optimal angle for generating the maximum power can be determined. Once the rotation (detection) is completed, the photovoltaic modules are then rotated to the resulting angle for generating the maximum power. The photovoltaic module is rotated once per hour in an attempt to detect the maximum irradiation and overcome the impact of environmental effects such as shading from cloud cover, other photovoltaic modules and surrounding buildings. Furthermore, the detection range is halved so as to reduce the energy consumption from the rotation operations and to improve the reliability of the sun tracker. The results indicate that electric energy production is increased by 3.4% in spring and autumn, 5.4% in summer, and 8.3% in winter, compared with that of the same sun tracker with three fixed angles of 50° east in the morning, 0° at noon and 50° west in the afternoon.

  4. Record values from a family of J-shaped distributions

    Directory of Open Access Journals (Sweden)

    Ahmad A. Zghoul

    2013-05-01

    Full Text Available A family of J-shaped distributions has applications in life testing modeling. In this paper we study record values from this family of distributions. Based on lower records, recurrence relations and bounds as well as expressions for moments and product moments of record values are obtained, the maximum likelihood estimator of the shape parameter is derived and shown to be consistent, sufficient, complete and UMVU estimator. In addition, an application in reliability is given.

  5. 49 CFR 195.406 - Maximum operating pressure.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Maximum operating pressure. 195.406 Section 195.406 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS... HAZARDOUS LIQUIDS BY PIPELINE Operation and Maintenance § 195.406 Maximum operating pressure. (a) Except for...

  6. 78 FR 49370 - Inflation Adjustment of Maximum Forfeiture Penalties

    Science.gov (United States)

    2013-08-14

    ... ``civil monetary penalties provided by law'' at least once every four years. DATES: Effective September 13... increases the maximum civil monetary forfeiture penalties available to the Commission under its rules... maximum civil penalties established in that section to account for inflation since the last adjustment to...

  7. 22 CFR 201.67 - Maximum freight charges.

    Science.gov (United States)

    2010-04-01

    ..., commodity rate classification, quantity, vessel flag category (U.S.-or foreign-flag), choice of ports, and... the United States. (2) Maximum charter rates. (i) USAID will not finance ocean freight under any... owner(s). (4) Maximum liner rates. USAID will not finance ocean freight for a cargo liner shipment at a...

  8. Maximum penetration level of distributed generation without violating voltage limits

    NARCIS (Netherlands)

    Morren, J.; Haan, de S.W.H.

    2009-01-01

    Connection of Distributed Generation (DG) units to a distribution network will result in a local voltage increase. As there will be a maximum on the allowable voltage increase, this will limit the maximum allowable penetration level of DG. By reactive power compensation (by the DG unit itself) a

  9. Particle Swarm Optimization Based of the Maximum Photovoltaic ...

    African Journals Online (AJOL)

    Photovoltaic electricity is seen as an important source of renewable energy. The photovoltaic array is an unstable source of power since the peak power point depends on the temperature and the irradiation level. A maximum peak power point tracking is then necessary for maximum efficiency. In this work, a Particle Swarm ...

  10. Maximum-entropy clustering algorithm and its global convergence analysis

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Constructing a batch of differentiable entropy functions touniformly approximate an objective function by means of the maximum-entropy principle, a new clustering algorithm, called maximum-entropy clustering algorithm, is proposed based on optimization theory. This algorithm is a soft generalization of the hard C-means algorithm and possesses global convergence. Its relations with other clustering algorithms are discussed.

  11. Application of maximum entropy to neutron tunneling spectroscopy

    International Nuclear Information System (INIS)

    Mukhopadhyay, R.; Silver, R.N.

    1990-01-01

    We demonstrate the maximum entropy method for the deconvolution of high resolution tunneling data acquired with a quasielastic spectrometer. Given a precise characterization of the instrument resolution function, a maximum entropy analysis of lutidine data obtained with the IRIS spectrometer at ISIS results in an effective factor of three improvement in resolution. 7 refs., 4 figs

  12. The regulation of starch accumulation in Panicum maximum Jacq ...

    African Journals Online (AJOL)

    ... decrease the starch level. These observations are discussed in relation to the photosynthetic characteristics of P. maximum. Keywords: accumulation; botany; carbon assimilation; co2 fixation; growth conditions; mesophyll; metabolites; nitrogen; nitrogen levels; nitrogen supply; panicum maximum; plant physiology; starch; ...

  13. 32 CFR 842.35 - Depreciation and maximum allowances.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Depreciation and maximum allowances. 842.35... LITIGATION ADMINISTRATIVE CLAIMS Personnel Claims (31 U.S.C. 3701, 3721) § 842.35 Depreciation and maximum allowances. The military services have jointly established the “Allowance List-Depreciation Guide” to...

  14. The maximum significant wave height in the Southern North Sea

    NARCIS (Netherlands)

    Bouws, E.; Tolman, H.L.; Holthuijsen, L.H.; Eldeberky, Y.; Booij, N.; Ferier, P.

    1995-01-01

    The maximum possible wave conditions along the Dutch coast, which seem to be dominated by the limited water depth, have been estimated in the present study with numerical simulations. Discussions with meteorologists suggest that the maximum possible sustained wind speed in North Sea conditions is

  15. PTree: pattern-based, stochastic search for maximum parsimony phylogenies

    OpenAIRE

    Gregor, Ivan; Steinbr?ck, Lars; McHardy, Alice C.

    2013-01-01

    Phylogenetic reconstruction is vital to analyzing the evolutionary relationship of genes within and across populations of different species. Nowadays, with next generation sequencing technologies producing sets comprising thousands of sequences, robust identification of the tree topology, which is optimal according to standard criteria such as maximum parsimony, maximum likelihood or posterior probability, with phylogenetic inference methods is a computationally very demanding task. Here, we ...

  16. 5 CFR 838.711 - Maximum former spouse survivor annuity.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Maximum former spouse survivor annuity... Orders Awarding Former Spouse Survivor Annuities Limitations on Survivor Annuities § 838.711 Maximum former spouse survivor annuity. (a) Under CSRS, payments under a court order may not exceed the amount...

  17. Modern recording techniques

    CERN Document Server

    Huber, David Miles

    2013-01-01

    As the most popular and authoritative guide to recording Modern Recording Techniques provides everything you need to master the tools and day to day practice of music recording and production. From room acoustics and running a session to mic placement and designing a studio Modern Recording Techniques will give you a really good grounding in the theory and industry practice. Expanded to include the latest digital audio technology the 7th edition now includes sections on podcasting, new surround sound formats and HD and audio.If you are just starting out or looking for a step up

  18. Maximum physical capacity testing in cancer patients undergoing chemotherapy

    DEFF Research Database (Denmark)

    Knutsen, L.; Quist, M; Midtgaard, J

    2006-01-01

    BACKGROUND: Over the past few years there has been a growing interest in the field of physical exercise in rehabilitation of cancer patients, leading to requirements for objective maximum physical capacity measurement (maximum oxygen uptake (VO(2max)) and one-repetition maximum (1RM)) to determin...... early in the treatment process. However, the patients were self-referred and thus highly motivated and as such are not necessarily representative of the whole population of cancer patients treated with chemotherapy....... in performing maximum physical capacity tests as these motivated them through self-perceived competitiveness and set a standard that served to encourage peak performance. CONCLUSION: The positive attitudes in this sample towards maximum physical capacity open the possibility of introducing physical testing...

  19. Maximum Principles for Discrete and Semidiscrete Reaction-Diffusion Equation

    Directory of Open Access Journals (Sweden)

    Petr Stehlík

    2015-01-01

    Full Text Available We study reaction-diffusion equations with a general reaction function f on one-dimensional lattices with continuous or discrete time ux′  (or  Δtux=k(ux-1-2ux+ux+1+f(ux, x∈Z. We prove weak and strong maximum and minimum principles for corresponding initial-boundary value problems. Whereas the maximum principles in the semidiscrete case (continuous time exhibit similar features to those of fully continuous reaction-diffusion model, in the discrete case the weak maximum principle holds for a smaller class of functions and the strong maximum principle is valid in a weaker sense. We describe in detail how the validity of maximum principles depends on the nonlinearity and the time step. We illustrate our results on the Nagumo equation with the bistable nonlinearity.

  20. Predicting the Maximum Earthquake Magnitude from Seismic Data in Israel and Its Neighboring Countries.

    Science.gov (United States)

    Last, Mark; Rabinowitz, Nitzan; Leonard, Gideon

    2016-01-01

    This paper explores several data mining and time series analysis methods for predicting the magnitude of the largest seismic event in the next year based on the previously recorded seismic events in the same region. The methods are evaluated on a catalog of 9,042 earthquake events, which took place between 01/01/1983 and 31/12/2010 in the area of Israel and its neighboring countries. The data was obtained from the Geophysical Institute of Israel. Each earthquake record in the catalog is associated with one of 33 seismic regions. The data was cleaned by removing foreshocks and aftershocks. In our study, we have focused on ten most active regions, which account for more than 80% of the total number of earthquakes in the area. The goal is to predict whether the maximum earthquake magnitude in the following year will exceed the median of maximum yearly magnitudes in the same region. Since the analyzed catalog includes only 28 years of complete data, the last five annual records of each region (referring to the years 2006-2010) are kept for testing while using the previous annual records for training. The predictive features are based on the Gutenberg-Richter Ratio as well as on some new seismic indicators based on the moving averages of the number of earthquakes in each area. The new predictive features prove to be much more useful than the indicators traditionally used in the earthquake prediction literature. The most accurate result (AUC = 0.698) is reached by the Multi-Objective Info-Fuzzy Network (M-IFN) algorithm, which takes into account the association between two target variables: the number of earthquakes and the maximum earthquake magnitude during the same year.

  1. Disturbance recording system

    International Nuclear Information System (INIS)

    Chandra, A.K.; Deshpande, S.V.; Mayya, A.; Vaidya, U.W.; Premraj, M.K.; Patil, N.B.

    1994-01-01

    A computerized system for disturbance monitoring, recording and display has been developed for use in nuclear power plants and is versatile enough to be used where ever a large number of parameters need to be recorded, e.g. conventional power plants, chemical industry etc. The Disturbance Recording System (DRS) has been designed to continuously monitor a process plant and record crucial parameters. The DRS provides a centralized facility to monitor and continuously record 64 process parameters scanned every 1 sec for 5 days. The system also provides facility for storage of 64 parameters scanned every 200 msec during 2 minutes prior to and 3 minutes after a disturbance. In addition the system can initiate, on demand, the recording of 8 parameters at a fast rate of every 5 msec for a period of 5 sec. and thus act as a visicorder. All this data is recorded in non-volatile memory and can be displayed, printed/plotted and used for subsequent analysis. Since data can be stored densely on floppy disks, the volume of space required for archival storage is also low. As a disturbance recorder, the DRS allows the operator to view the state of the plant prior to occurrence of the disturbance and helps in identifying the root cause. (author). 10 refs., 7 figs

  2. Privacy and Library Records

    Science.gov (United States)

    Bowers, Stacey L.

    2006-01-01

    This paper summarizes the history of privacy as it relates to library records. It commences with a discussion of how the concept of privacy first originated through case law and follows the concept of privacy as it has affected library records through current day and the "USA PATRIOT Act."

  3. Visual patient records

    NARCIS (Netherlands)

    Luu, M.D.

    2015-01-01

    Patient information is often complex and fragmented; visualization can help to obtain and communicate insights. To move from paper medical records to interactive and visual patient records is a big challenge. This project aims to move towards this ultimate goal by providing an interactive prototype

  4. Record Keeping Guidelines

    Science.gov (United States)

    American Psychologist, 2007

    2007-01-01

    These guidelines are designed to educate psychologists and provide a framework for making decisions regarding professional record keeping. State and federal laws, as well as the American Psychological Association's "Ethical Principles of Psychologists and Code of Conduct," generally require maintenance of appropriate records of psychological…

  5. 78 FR 9845 - Minimum and Ordinary Maximum and Aggravated Maximum Civil Monetary Penalties for a Violation of...

    Science.gov (United States)

    2013-02-12

    ... maximum penalty amount of $75,000 for each violation, except that if the violation results in death... the maximum civil penalty for a violation is $175,000 if the violation results in death, serious... Penalties for a Violation of the Hazardous Materials Transportation Laws or Regulations, Orders, Special...

  6. Usage Record Format Recommendation

    CERN Document Server

    Nilsen, J.K.; Muller-Pfeerkorn, R

    2013-01-01

    For resources to be shared, sites must be able to exchange basic accounting and usage data in a common format. This document describes a common format which enables the exchange of basic accounting and usage data from different resources. This record format is intended to facilitate the sharing of usage information, particularly in the area of the accounting of jobs, computing, memory, storage and cloud usage but with a structure that allows an easy extension to other resources. This document describes the Usage Record components both in natural language form and annotated XML. This document does not address how these records should be used, nor does it attempt to dictate the format in which the accounting records are stored. Instead, it denes a common exchange format. Furthermore, nothing is said regarding the communication mechanisms employed to exchange the records, i.e. transport layer, framing, authentication, integrity, etc.

  7. Laser color recording unit

    Science.gov (United States)

    Jung, E.

    1984-05-01

    A color recording unit was designed for output and control of digitized picture data within computer controlled reproduction and picture processing systems. In order to get a color proof picture of high quality similar to a color print, together with reduced time and material consumption, a photographic color film material was exposed pixelwise by modulated laser beams of three wavelengths for red, green and blue light. Components of different manufacturers for lasers, acousto-optic modulators and polygon mirrors were tested, also different recording methods as (continuous tone mode or screened mode and with a drum or flatbed recording principle). Besides the application for the graphic arts - the proof recorder CPR 403 with continuous tone color recording with a drum scanner - such a color hardcopy peripheral unit with large picture formats and high resolution can be used in medicine, communication, and satellite picture processing.

  8. The power and robustness of maximum LOD score statistics.

    Science.gov (United States)

    Yoo, Y J; Mendell, N R

    2008-07-01

    The maximum LOD score statistic is extremely powerful for gene mapping when calculated using the correct genetic parameter value. When the mode of genetic transmission is unknown, the maximum of the LOD scores obtained using several genetic parameter values is reported. This latter statistic requires higher critical value than the maximum LOD score statistic calculated from a single genetic parameter value. In this paper, we compare the power of maximum LOD scores based on three fixed sets of genetic parameter values with the power of the LOD score obtained after maximizing over the entire range of genetic parameter values. We simulate family data under nine generating models. For generating models with non-zero phenocopy rates, LOD scores maximized over the entire range of genetic parameters yielded greater power than maximum LOD scores for fixed sets of parameter values with zero phenocopy rates. No maximum LOD score was consistently more powerful than the others for generating models with a zero phenocopy rate. The power loss of the LOD score maximized over the entire range of genetic parameters, relative to the maximum LOD score calculated using the correct genetic parameter value, appeared to be robust to the generating models.

  9. Connectivity dynamics since the Last Glacial Maximum in the northern Andes: a pollen-driven framework to assess potential migration

    NARCIS (Netherlands)

    Flantua, S.G.A.; Hooghiemstra, H.; van Boxel, J.H.; Cabrera, M.; González-Carranza, Z.; González-Arango, C.; Stevens, W.D.; Montiel, O.M.; Raven, P.H.

    2014-01-01

    We provide an innovative pollen-driven connectivity framework of the dynamic altitudinal distribution of North Andean biomes since the Last Glacial Maximum (LGM). Altitudinally changing biome distributions reconstructed from a pollen record from Lake La Cocha (2780 m) are assessed in terms of their

  10. Global correlations between maximum magnitudes of subduction zone interface thrust earthquakes and physical parameters of subduction zones

    NARCIS (Netherlands)

    Schellart, W. P.; Rawlinson, N.

    2013-01-01

    The maximum earthquake magnitude recorded for subduction zone plate boundaries varies considerably on Earth, with some subduction zone segments producing giant subduction zone thrust earthquakes (e.g. Chile, Alaska, Sumatra-Andaman, Japan) and others producing relatively small earthquakes (e.g.

  11. Estimativas de repetibilidade para caracteres forrageiros em Panicum maximum Repeatability estimates for forage characters in Panicum maximum

    Directory of Open Access Journals (Sweden)

    Francisco José da Silva Lédo

    2008-08-01

    Full Text Available Objetiva-se com este trabalho estimar a repetibilidade para caracteres forrageiros de Panicum, e determinar o número de cortes de avaliação necessários para a seleção de genótipos de Panicum, com confiabilidade. Utilizaram-se os dados de um ensaio conduzido no período de 21/11/2002 a 08/04/2005, no Campo Experimental da Embrapa Gado de Leite, localizado em Valença-RJ, onde foram realizados 15 cortes de avaliação. No ensaio, foram avaliados 23 genótipos de Panicum maximum, em parcelas experimentais, dispostas no delineamento de blocos casualizados, com três repetições. Foram estimados os coeficientes de repetibilidade para as características produção de matéria verde de forragem (PMV; produção de matéria seca de forragem (PMS e de folhas (PMSF; porcentagem de folhas na PMS (%FOL e altura da planta (AP, utilizando os métodos da análise de variância, componentes principais e análise estrutural. Para todas as características avaliadas os efeitos de genótipos, cortes e interação genótipos x cortes foram significativos (PThe objective of this work was to estimate the repeatability for forage characters of Panicum and to determinate the necessary number of evaluation cuts to select Panicum genotypes with confidence. Data of a trial with 15 cuts, carried out between 21/11/2002 and 08/04/2005 in the experimental station of Embrapa Gado de Leite located in Valença, RJ, Brazil, were used. In this study. 23 genotypes of " Panicum maximum" were evaluated, in a complete randomized block, with three replications. The coefficient of repeatability for fresh forage production (PMV, total plant dry matter production (PMS and leaves dry matter production (PMSF were recorded along with leaves percentage in PMS (%FOL and plant hight (AP, using the variance analysis, main components and structural analysis methods. For all evaluated parameters the effects of genotype, cut and genotype x cut interaction were significant (P<0.01. When

  12. Parameters determining maximum wind velocity in a tropical cyclone

    International Nuclear Information System (INIS)

    Choudhury, A.M.

    1984-09-01

    The spiral structure of a tropical cyclone was earlier explained by a tangential velocity distribution which varies inversely as the distance from the cyclone centre outside the circle of maximum wind speed. The case has been extended in the present paper by adding a radial velocity. It has been found that a suitable combination of radial and tangential velocities can account for the spiral structure of a cyclone. This enables parametrization of the cyclone. Finally a formula has been derived relating maximum velocity in a tropical cyclone with angular momentum, radius of maximum wind speed and the spiral angle. The shapes of the spirals have been computed for various spiral angles. (author)

  13. Electronic health records

    DEFF Research Database (Denmark)

    Kierkegaard, Patrick

    2011-01-01

    that a centralised European health record system will become a reality even before 2020. However, the concept of a centralised supranational central server raises concern about storing electronic medical records in a central location. The privacy threat posed by a supranational network is a key concern. Cross......-border and Interoperable electronic health record systems make confidential data more easily and rapidly accessible to a wider audience and increase the risk that personal data concerning health could be accidentally exposed or easily distributed to unauthorised parties by enabling greater access to a compilation...... of the personal data concerning health, from different sources, and throughout a lifetime....

  14. Environmental Monitoring, Water Quality - Total Maximum Daily Load (TMDL)

    Data.gov (United States)

    NSGIC Education | GIS Inventory — The Clean Water Act Section 303(d) establishes the Total Maximum Daily Load (TMDL) program. The purpose of the TMDL program is to identify sources of pollution and...

  15. Probabilistic maximum-value wind prediction for offshore environments

    DEFF Research Database (Denmark)

    Staid, Andrea; Pinson, Pierre; Guikema, Seth D.

    2015-01-01

    statistical models to predict the full distribution of the maximum-value wind speeds in a 3 h interval. We take a detailed look at the performance of linear models, generalized additive models and multivariate adaptive regression splines models using meteorological covariates such as gust speed, wind speed......, convective available potential energy, Charnock, mean sea-level pressure and temperature, as given by the European Center for Medium-Range Weather Forecasts forecasts. The models are trained to predict the mean value of maximum wind speed, and the residuals from training the models are used to develop...... the full probabilistic distribution of maximum wind speed. Knowledge of the maximum wind speed for an offshore location within a given period can inform decision-making regarding turbine operations, planned maintenance operations and power grid scheduling in order to improve safety and reliability...

  16. Combining Experiments and Simulations Using the Maximum Entropy Principle

    DEFF Research Database (Denmark)

    Boomsma, Wouter; Ferkinghoff-Borg, Jesper; Lindorff-Larsen, Kresten

    2014-01-01

    are not in quantitative agreement with experimental data. The principle of maximum entropy is a general procedure for constructing probability distributions in the light of new data, making it a natural tool in cases when an initial model provides results that are at odds with experiments. The number of maximum entropy...... in the context of a simple example, after which we proceed with a real-world application in the field of molecular simulations, where the maximum entropy procedure has recently provided new insight. Given the limited accuracy of force fields, macromolecular simulations sometimes produce results....... Three very recent papers have explored this problem using the maximum entropy approach, providing both new theoretical and practical insights to the problem. We highlight each of these contributions in turn and conclude with a discussion on remaining challenges....

  17. Parametric optimization of thermoelectric elements footprint for maximum power generation

    DEFF Research Database (Denmark)

    Rezania, A.; Rosendahl, Lasse; Yin, Hao

    2014-01-01

    The development studies in thermoelectric generator (TEG) systems are mostly disconnected to parametric optimization of the module components. In this study, optimum footprint ratio of n- and p-type thermoelectric (TE) elements is explored to achieve maximum power generation, maximum cost......-performance, and variation of efficiency in the uni-couple over a wide range of the heat transfer coefficient on the cold junction. The three-dimensional (3D) governing equations of the thermoelectricity and the heat transfer are solved using the finite element method (FEM) for temperature dependent properties of TE...... materials. The results, which are in good agreement with the previous computational studies, show that the maximum power generation and the maximum cost-performance in the module occur at An/Ap

  18. Ethylene Production Maximum Achievable Control Technology (MACT) Compliance Manual

    Science.gov (United States)

    This July 2006 document is intended to help owners and operators of ethylene processes understand and comply with EPA's maximum achievable control technology standards promulgated on July 12, 2002, as amended on April 13, 2005 and April 20, 2006.

  19. ORIGINAL ARTICLES Surgical practice in a maximum security prison

    African Journals Online (AJOL)

    Prison Clinic, Mangaung Maximum Security Prison, Bloemfontein. F Kleinhans, BA (Cur) .... HIV positivity rate and the use of the rectum to store foreign objects. ... fruit in sunlight. Other positive health-promoting factors may also play a role,.

  20. A technique for estimating maximum harvesting effort in a stochastic ...

    Indian Academy of Sciences (India)

    Unknown

    Estimation of maximum harvesting effort has a great impact on the ... fluctuating environment has been developed in a two-species competitive system, which shows that under realistic .... The existence and local stability properties of the equi-.

  1. Water Quality Assessment and Total Maximum Daily Loads Information (ATTAINS)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Water Quality Assessment TMDL Tracking And Implementation System (ATTAINS) stores and tracks state water quality assessment decisions, Total Maximum Daily Loads...

  2. Post optimization paradigm in maximum 3-satisfiability logic programming

    Science.gov (United States)

    Mansor, Mohd. Asyraf; Sathasivam, Saratha; Kasihmuddin, Mohd Shareduwan Mohd

    2017-08-01

    Maximum 3-Satisfiability (MAX-3SAT) is a counterpart of the Boolean satisfiability problem that can be treated as a constraint optimization problem. It deals with a conundrum of searching the maximum number of satisfied clauses in a particular 3-SAT formula. This paper presents the implementation of enhanced Hopfield network in hastening the Maximum 3-Satisfiability (MAX-3SAT) logic programming. Four post optimization techniques are investigated, including the Elliot symmetric activation function, Gaussian activation function, Wavelet activation function and Hyperbolic tangent activation function. The performances of these post optimization techniques in accelerating MAX-3SAT logic programming will be discussed in terms of the ratio of maximum satisfied clauses, Hamming distance and the computation time. Dev-C++ was used as the platform for training, testing and validating our proposed techniques. The results depict the Hyperbolic tangent activation function and Elliot symmetric activation function can be used in doing MAX-3SAT logic programming.

  3. Maximum likelihood estimation of finite mixture model for economic data

    Science.gov (United States)

    Phoong, Seuk-Yen; Ismail, Mohd Tahir

    2014-06-01

    Finite mixture model is a mixture model with finite-dimension. This models are provides a natural representation of heterogeneity in a finite number of latent classes. In addition, finite mixture models also known as latent class models or unsupervised learning models. Recently, maximum likelihood estimation fitted finite mixture models has greatly drawn statistician's attention. The main reason is because maximum likelihood estimation is a powerful statistical method which provides consistent findings as the sample sizes increases to infinity. Thus, the application of maximum likelihood estimation is used to fit finite mixture model in the present paper in order to explore the relationship between nonlinear economic data. In this paper, a two-component normal mixture model is fitted by maximum likelihood estimation in order to investigate the relationship among stock market price and rubber price for sampled countries. Results described that there is a negative effect among rubber price and stock market price for Malaysia, Thailand, Philippines and Indonesia.

  4. Encoding Strategy for Maximum Noise Tolerance Bidirectional Associative Memory

    National Research Council Canada - National Science Library

    Shen, Dan

    2003-01-01

    In this paper, the Basic Bidirectional Associative Memory (BAM) is extended by choosing weights in the correlation matrix, for a given set of training pairs, which result in a maximum noise tolerance set for BAM...

  5. Narrow band interference cancelation in OFDM: Astructured maximum likelihood approach

    KAUST Repository

    Sohail, Muhammad Sadiq; Al-Naffouri, Tareq Y.; Al-Ghadhban, Samir N.

    2012-01-01

    This paper presents a maximum likelihood (ML) approach to mitigate the effect of narrow band interference (NBI) in a zero padded orthogonal frequency division multiplexing (ZP-OFDM) system. The NBI is assumed to be time variant and asynchronous

  6. Maximum Acceptable Vibrato Excursion as a Function of Vibrato Rate in Musicians and Non-musicians

    DEFF Research Database (Denmark)

    Vatti, Marianna; Santurette, Sébastien; Pontoppidan, Niels H.

    2014-01-01

    and, in most listeners, exhibited a peak at medium vibrato rates (5–7 Hz). Large across-subject variability was observed, and no significant effect of musical experience was found. Overall, most listeners were not solely sensitive to the vibrato excursion and there was a listener-dependent rate...... for which larger vibrato excursions were favored. The observed interaction between maximum excursion thresholds and vibrato rate may be due to the listeners’ judgments relying on cues provided by the rate of frequency changes (RFC) rather than excursion per se. Further studies are needed to evaluate......Human vibrato is mainly characterized by two parameters: vibrato extent and vibrato rate. These parameters have been found to exhibit an interaction both in physical recordings of singers’ voices and in listener’s preference ratings. This study was concerned with the way in which the maximum...

  7. Maximum entropy deconvolution of low count nuclear medicine images

    International Nuclear Information System (INIS)

    McGrath, D.M.

    1998-12-01

    Maximum entropy is applied to the problem of deconvolving nuclear medicine images, with special consideration for very low count data. The physics of the formation of scintigraphic images is described, illustrating the phenomena which degrade planar estimates of the tracer distribution. Various techniques which are used to restore these images are reviewed, outlining the relative merits of each. The development and theoretical justification of maximum entropy as an image processing technique is discussed. Maximum entropy is then applied to the problem of planar deconvolution, highlighting the question of the choice of error parameters for low count data. A novel iterative version of the algorithm is suggested which allows the errors to be estimated from the predicted Poisson mean values. This method is shown to produce the exact results predicted by combining Poisson statistics and a Bayesian interpretation of the maximum entropy approach. A facility for total count preservation has also been incorporated, leading to improved quantification. In order to evaluate this iterative maximum entropy technique, two comparable methods, Wiener filtering and a novel Bayesian maximum likelihood expectation maximisation technique, were implemented. The comparison of results obtained indicated that this maximum entropy approach may produce equivalent or better measures of image quality than the compared methods, depending upon the accuracy of the system model used. The novel Bayesian maximum likelihood expectation maximisation technique was shown to be preferable over many existing maximum a posteriori methods due to its simplicity of implementation. A single parameter is required to define the Bayesian prior, which suppresses noise in the solution and may reduce the processing time substantially. Finally, maximum entropy deconvolution was applied as a pre-processing step in single photon emission computed tomography reconstruction of low count data. Higher contrast results were

  8. What controls the maximum magnitude of injection-induced earthquakes?

    Science.gov (United States)

    Eaton, D. W. S.

    2017-12-01

    Three different approaches for estimation of maximum magnitude are considered here, along with their implications for managing risk. The first approach is based on a deterministic limit for seismic moment proposed by McGarr (1976), which was originally designed for application to mining-induced seismicity. This approach has since been reformulated for earthquakes induced by fluid injection (McGarr, 2014). In essence, this method assumes that the upper limit for seismic moment release is constrained by the pressure-induced stress change. A deterministic limit is given by the product of shear modulus and the net injected fluid volume. This method is based on the assumptions that the medium is fully saturated and in a state of incipient failure. An alternative geometrical approach was proposed by Shapiro et al. (2011), who postulated that the rupture area for an induced earthquake falls entirely within the stimulated volume. This assumption reduces the maximum-magnitude problem to one of estimating the largest potential slip surface area within a given stimulated volume. Finally, van der Elst et al. (2016) proposed that the maximum observed magnitude, statistically speaking, is the expected maximum value for a finite sample drawn from an unbounded Gutenberg-Richter distribution. These three models imply different approaches for risk management. The deterministic method proposed by McGarr (2014) implies that a ceiling on the maximum magnitude can be imposed by limiting the net injected volume, whereas the approach developed by Shapiro et al. (2011) implies that the time-dependent maximum magnitude is governed by the spatial size of the microseismic event cloud. Finally, the sample-size hypothesis of Van der Elst et al. (2016) implies that the best available estimate of the maximum magnitude is based upon observed seismicity rate. The latter two approaches suggest that real-time monitoring is essential for effective management of risk. A reliable estimate of maximum

  9. Maximum organic carbon limits at different melter feed rates (U)

    International Nuclear Information System (INIS)

    Choi, A.S.

    1995-01-01

    This report documents the results of a study to assess the impact of varying melter feed rates on the maximum total organic carbon (TOC) limits allowable in the DWPF melter feed. Topics discussed include: carbon content; feed rate; feed composition; melter vapor space temperature; combustion and dilution air; off-gas surges; earlier work on maximum TOC; overview of models; and the results of the work completed

  10. A tropospheric ozone maximum over the equatorial Southern Indian Ocean

    Directory of Open Access Journals (Sweden)

    L. Zhang

    2012-05-01

    Full Text Available We examine the distribution of tropical tropospheric ozone (O3 from the Microwave Limb Sounder (MLS and the Tropospheric Emission Spectrometer (TES by using a global three-dimensional model of tropospheric chemistry (GEOS-Chem. MLS and TES observations of tropospheric O3 during 2005 to 2009 reveal a distinct, persistent O3 maximum, both in mixing ratio and tropospheric column, in May over the Equatorial Southern Indian Ocean (ESIO. The maximum is most pronounced in 2006 and 2008 and less evident in the other three years. This feature is also consistent with the total column O3 observations from the Ozone Mapping Instrument (OMI and the Atmospheric Infrared Sounder (AIRS. Model results reproduce the observed May O3 maximum and the associated interannual variability. The origin of the maximum reflects a complex interplay of chemical and dynamic factors. The O3 maximum is dominated by the O3 production driven by lightning nitrogen oxides (NOx emissions, which accounts for 62% of the tropospheric column O3 in May 2006. We find the contribution from biomass burning, soil, anthropogenic and biogenic sources to the O3 maximum are rather small. The O3 productions in the lightning outflow from Central Africa and South America both peak in May and are directly responsible for the O3 maximum over the western ESIO. The lightning outflow from Equatorial Asia dominates over the eastern ESIO. The interannual variability of the O3 maximum is driven largely by the anomalous anti-cyclones over the southern Indian Ocean in May 2006 and 2008. The lightning outflow from Central Africa and South America is effectively entrained by the anti-cyclones followed by northward transport to the ESIO.

  11. Dinosaur Metabolism and the Allometry of Maximum Growth Rate

    OpenAIRE

    Myhrvold, Nathan P.

    2016-01-01

    The allometry of maximum somatic growth rate has been used in prior studies to classify the metabolic state of both extant vertebrates and dinosaurs. The most recent such studies are reviewed, and their data is reanalyzed. The results of allometric regressions on growth rate are shown to depend on the choice of independent variable; the typical choice used in prior studies introduces a geometric shear transformation that exaggerates the statistical power of the regressions. The maximum growth...

  12. MAXIMUM PRINCIPLE FOR SUBSONIC FLOW WITH VARIABLE ENTROPY

    Directory of Open Access Journals (Sweden)

    B. Sizykh Grigory

    2017-01-01

    Full Text Available Maximum principle for subsonic flow is fair for stationary irrotational subsonic gas flows. According to this prin- ciple, if the value of the velocity is not constant everywhere, then its maximum is achieved on the boundary and only on the boundary of the considered domain. This property is used when designing form of an aircraft with a maximum critical val- ue of the Mach number: it is believed that if the local Mach number is less than unit in the incoming flow and on the body surface, then the Mach number is less then unit in all points of flow. The known proof of maximum principle for subsonic flow is based on the assumption that in the whole considered area of the flow the pressure is a function of density. For the ideal and perfect gas (the role of diffusion is negligible, and the Mendeleev-Clapeyron law is fulfilled, the pressure is a function of density if entropy is constant in the entire considered area of the flow. Shows an example of a stationary sub- sonic irrotational flow, in which the entropy has different values on different stream lines, and the pressure is not a function of density. The application of the maximum principle for subsonic flow with respect to such a flow would be unreasonable. This example shows the relevance of the question about the place of the points of maximum value of the velocity, if the entropy is not a constant. To clarify the regularities of the location of these points, was performed the analysis of the com- plete Euler equations (without any simplifying assumptions in 3-D case. The new proof of the maximum principle for sub- sonic flow was proposed. This proof does not rely on the assumption that the pressure is a function of density. Thus, it is shown that the maximum principle for subsonic flow is true for stationary subsonic irrotational flows of ideal perfect gas with variable entropy.

  13. On semidefinite programming relaxations of maximum k-section

    NARCIS (Netherlands)

    de Klerk, E.; Pasechnik, D.V.; Sotirov, R.; Dobre, C.

    2012-01-01

    We derive a new semidefinite programming bound for the maximum k -section problem. For k=2 (i.e. for maximum bisection), the new bound is at least as strong as a well-known bound by Poljak and Rendl (SIAM J Optim 5(3):467–487, 1995). For k ≥ 3the new bound dominates a bound of Karisch and Rendl

  14. Direct maximum parsimony phylogeny reconstruction from genotype data

    OpenAIRE

    Sridhar, Srinath; Lam, Fumei; Blelloch, Guy E; Ravi, R; Schwartz, Russell

    2007-01-01

    Abstract Background Maximum parsimony phylogenetic tree reconstruction from genetic variation data is a fundamental problem in computational genetics with many practical applications in population genetics, whole genome analysis, and the search for genetic predictors of disease. Efficient methods are available for reconstruction of maximum parsimony trees from haplotype data, but such data are difficult to determine directly for autosomal DNA. Data more commonly is available in the form of ge...

  15. Maximum power point tracker based on fuzzy logic

    International Nuclear Information System (INIS)

    Daoud, A.; Midoun, A.

    2006-01-01

    The solar energy is used as power source in photovoltaic power systems and the need for an intelligent power management system is important to obtain the maximum power from the limited solar panels. With the changing of the sun illumination due to variation of angle of incidence of sun radiation and of the temperature of the panels, Maximum Power Point Tracker (MPPT) enables optimization of solar power generation. The MPPT is a sub-system designed to extract the maximum power from a power source. In the case of solar panels power source. the maximum power point varies as a result of changes in its electrical characteristics which in turn are functions of radiation dose, temperature, ageing and other effects. The MPPT maximum the power output from panels for a given set of conditions by detecting the best working point of the power characteristic and then controls the current through the panels or the voltage across them. Many MPPT methods have been reported in literature. These techniques of MPPT can be classified into three main categories that include: lookup table methods, hill climbing methods and computational methods. The techniques vary according to the degree of sophistication, processing time and memory requirements. The perturbation and observation algorithm (hill climbing technique) is commonly used due to its ease of implementation, and relative tracking efficiency. However, it has been shown that when the insolation changes rapidly, the perturbation and observation method is slow to track the maximum power point. In recent years, the fuzzy controllers are used for maximum power point tracking. This method only requires the linguistic control rules for maximum power point, the mathematical model is not required and therefore the implementation of this control method is easy to real control system. In this paper, we we present a simple robust MPPT using fuzzy set theory where the hardware consists of the microchip's microcontroller unit control card and

  16. Bistability, non-ergodicity, and inhibition in pairwise maximum-entropy models.

    Science.gov (United States)

    Rostami, Vahid; Porta Mana, PierGianLuca; Grün, Sonja; Helias, Moritz

    2017-10-01

    Pairwise maximum-entropy models have been used in neuroscience to predict the activity of neuronal populations, given only the time-averaged correlations of the neuron activities. This paper provides evidence that the pairwise model, applied to experimental recordings, would produce a bimodal distribution for the population-averaged activity, and for some population sizes the second mode would peak at high activities, that experimentally would be equivalent to 90% of the neuron population active within time-windows of few milliseconds. Several problems are connected with this bimodality: 1. The presence of the high-activity mode is unrealistic in view of observed neuronal activity and on neurobiological grounds. 2. Boltzmann learning becomes non-ergodic, hence the pairwise maximum-entropy distribution cannot be found: in fact, Boltzmann learning would produce an incorrect distribution; similarly, common variants of mean-field approximations also produce an incorrect distribution. 3. The Glauber dynamics associated with the model is unrealistically bistable and cannot be used to generate realistic surrogate data. This bimodality problem is first demonstrated for an experimental dataset from 159 neurons in the motor cortex of macaque monkey. Evidence is then provided that this problem affects typical neural recordings of population sizes of a couple of hundreds or more neurons. The cause of the bimodality problem is identified as the inability of standard maximum-entropy distributions with a uniform reference measure to model neuronal inhibition. To eliminate this problem a modified maximum-entropy model is presented, which reflects a basic effect of inhibition in the form of a simple but non-uniform reference measure. This model does not lead to unrealistic bimodalities, can be found with Boltzmann learning, and has an associated Glauber dynamics which incorporates a minimal asymmetric inhibition.

  17. Deploying Electronic Health Record

    African Journals Online (AJOL)

    SOFTLINKS DIGITAL

    [11] Verisign Whitepaper (2005) Managing Application Security in Business ... health record (EHR) and Information Technology and the subsequent impact of ... advancements, said that IT must play a ... and history of medical status and other.

  18. Acoustic ambient noise recorder

    Digital Repository Service at National Institute of Oceanography (India)

    Saran, A.K.; Navelkar, G.S.; Almeida, A.M.; More, S.R.; Chodankar, P.V.; Murty, C.S.

    with a robust outfit that can withstand high pressures and chemically corrosion resistant materials. Keeping these considerations in view, a CMOS micro-controller-based marine acoustic ambient noise recorder has been developed with a real time clock...

  19. Lagos Notes and Records

    African Journals Online (AJOL)

    PROMOTING ACCESS TO AFRICAN RESEARCH ... Lagos Notes and Records is an annual, interdisciplinary journal of the humanities. ... Insuring the Nation: Europeans and the Emergence of Modern Insurance Business in Colonial Nigeria ...

  20. Pervasive Electronic Medical Record

    African Journals Online (AJOL)

    Nafiisah

    independent web service connected to database of medical records or Worldwide. Interoperability ... allows wireless monitoring and tracking of patients and first responders using sensor nodes .... All these network security threats arise mainly ...

  1. Records Management Database

    Data.gov (United States)

    US Agency for International Development — The Records Management Database is tool created in Microsoft Access specifically for USAID use. It contains metadata in order to access and retrieve the information...

  2. Environmental Review Records

    Data.gov (United States)

    Department of Housing and Urban Development — HUD’s Environmental Review Records page houses environmental reviews made publicly available through the HUD Environmental Review Online System (HEROS). This...

  3. Vaccination Records for Kids

    Science.gov (United States)

    ... Immunization Information System (IIS). An IIS is a computer system your doctor or public health clinic may use ... preventable diseases. Immunization Records for Adoption and Foster Care You should ask your adoption coordinator for your ...

  4. Microcomputer sunshine recorder

    International Nuclear Information System (INIS)

    Benincasa, F.; Fasano, G.; Materassi, A.

    1986-01-01

    The Campbell-Stokes recorder is the most frequently used sunshine recorder. However, it cannot be used for automatic data acquisitions and the threshold level is not well defined. This paper describes an instrument in which the threshold for minimum sunshine is strictly established. The instrument not only gives the parameter but three other analogical signals: direct, diffuse and global radiation. All of this as been done with only two silicon cells [it

  5. The intelligent data recorder

    International Nuclear Information System (INIS)

    Kojima, Mamoru; Hidekuma, Sigeru.

    1985-01-01

    The intelligent data recorder has been developed to data acquisition for a microwave interferometer. The 'RS-232C' which is the standard interface is used for data transmission to the host computer. Then, it's easy to connect with any computer which has general purpose serial port. In this report, the charcteristics of the intelligent data recorder and the way of developing the software are described. (author)

  6. Probabilistic record linkage.

    Science.gov (United States)

    Sayers, Adrian; Ben-Shlomo, Yoav; Blom, Ashley W; Steele, Fiona

    2016-06-01

    Studies involving the use of probabilistic record linkage are becoming increasingly common. However, the methods underpinning probabilistic record linkage are not widely taught or understood, and therefore these studies can appear to be a 'black box' research tool. In this article, we aim to describe the process of probabilistic record linkage through a simple exemplar. We first introduce the concept of deterministic linkage and contrast this with probabilistic linkage. We illustrate each step of the process using a simple exemplar and describe the data structure required to perform a probabilistic linkage. We describe the process of calculating and interpreting matched weights and how to convert matched weights into posterior probabilities of a match using Bayes theorem. We conclude this article with a brief discussion of some of the computational demands of record linkage, how you might assess the quality of your linkage algorithm, and how epidemiologists can maximize the value of their record-linked research using robust record linkage methods. © The Author 2015; Published by Oxford University Press on behalf of the International Epidemiological Association.

  7. Digital recording system

    International Nuclear Information System (INIS)

    Chandra, A.K.; Deshpande, S.V.; Iyer, A.; Vaidya, U.W.

    1987-01-01

    A large number of critical process parameters in nuclear power plants have hitherto been monitored using electromechanical chart recorders. The reducing costs of electronics systems have led to a trend towards modernizing power plant control rooms by computerizing all the panel instrumentation. As a first step, it has been decided to develop a digital recording system to record the values of 48 process parameters. The system as developed and described in this report is more than a replacement for recorders; it offers substantial advantages in terms of lower overall system cost, excellent time resolution, accurate data and absolute synchronization for correlated signals. The system provides high speed recording of 48 process parameters, maintains historical records and permits retrieval and display of archival information on a colour monitor, a plotter and a printer. It is implemented using a front end data acquisition unit connected on a serial link to a PC-XT computer with 20 MB Winchester. The system offers an extremely user friendly man machine interaction, based on a hierarchical paged menu driven scheme. Softwre development for this system has been carried out using the C language. (author). 9 figs

  8. Could brown bears (Ursus arctos) have survived in Ireland during the Last Glacial Maximum?

    OpenAIRE

    Leonard, Saoirse A.; Risley, Claire L.; Turvey, Samuel T.

    2013-01-01

    Brown bears are recorded from Ireland during both the Late Pleistocene and early?mid Holocene. Although most of the Irish landmass was covered by an ice sheet during the Last Glacial Maximum (LGM), Irish brown bears are known to have hybridized with polar bears during the Late Pleistocene, and it is suggested that the Irish brown bear population did not become extinct but instead persisted in situ through the LGM in a southwestern ice-free refugium. We use historical population modelling to d...

  9. Characterising Record Flooding in the United Kingdom

    Science.gov (United States)

    Cox, A.; Bates, P. D.; Smith, J. A.

    2017-12-01

    Though the most notable floods in history have been carefully explained, there remains a lack of literature that explores the nature of record floods as a whole in the United Kingdom. We characterise the seasonality, statistical and spatial distribution, and meteorological causes of peak river flows for 521 gauging stations spread across the British Isles. We use annual maximum data from the National River Flow Archive, catchment descriptors from the Flood Estimation Handbook, and historical records of large floods. What we aim to find is in what ways, if any, the record flood for a station is different from more 'typical' floods. For each station, we calculate two indices: the seasonal anomaly and the flood index. Broadly, the seasonal anomaly is the degree to which a station's record flood happens at a different time of year compared to typical floods at that site, whilst the flood index is a station's record flood discharge divided by the discharge of the 1-in-10-year return period event. We find that while annual maximum peaks are dominated by winter frontal rainfall, record floods are disproportionately caused by summer convective rainfall. This analysis also shows that the larger the seasonal anomaly, the higher the flood index. Additionally, stations across the country have record floods that occur in the summer with no notable spatial pattern, yet the most seasonally anomalous record events are concentrated around the south and west of the British Isles. Catchment descriptors tell us little about the flood index at a particular station, but generally areas with lower mean annual precipitation have a higher flood index. The inclusion of case studies from recent and historical examples of notable floods across the UK supplements our analysis and gives insight into how typical these events are, both statistically and meteorologically. Ultimately, record floods in general happen at relatively unexpected times and with unpredictable magnitudes, which is a

  10. Maximum vehicle cabin temperatures under different meteorological conditions

    Science.gov (United States)

    Grundstein, Andrew; Meentemeyer, Vernon; Dowd, John

    2009-05-01

    A variety of studies have documented the dangerously high temperatures that may occur within the passenger compartment (cabin) of cars under clear sky conditions, even at relatively low ambient air temperatures. Our study, however, is the first to examine cabin temperatures under variable weather conditions. It uses a unique maximum vehicle cabin temperature dataset in conjunction with directly comparable ambient air temperature, solar radiation, and cloud cover data collected from April through August 2007 in Athens, GA. Maximum cabin temperatures, ranging from 41-76°C, varied considerably depending on the weather conditions and the time of year. Clear days had the highest cabin temperatures, with average values of 68°C in the summer and 61°C in the spring. Cloudy days in both the spring and summer were on average approximately 10°C cooler. Our findings indicate that even on cloudy days with lower ambient air temperatures, vehicle cabin temperatures may reach deadly levels. Additionally, two predictive models of maximum daily vehicle cabin temperatures were developed using commonly available meteorological data. One model uses maximum ambient air temperature and average daily solar radiation while the other uses cloud cover percentage as a surrogate for solar radiation. From these models, two maximum vehicle cabin temperature indices were developed to assess the level of danger. The models and indices may be useful for forecasting hazardous conditions, promoting public awareness, and to estimate past cabin temperatures for use in forensic analyses.

  11. Fractal Dimension and Maximum Sunspot Number in Solar Cycle

    Directory of Open Access Journals (Sweden)

    R.-S. Kim

    2006-09-01

    Full Text Available The fractal dimension is a quantitative parameter describing the characteristics of irregular time series. In this study, we use this parameter to analyze the irregular aspects of solar activity and to predict the maximum sunspot number in the following solar cycle by examining time series of the sunspot number. For this, we considered the daily sunspot number since 1850 from SIDC (Solar Influences Data analysis Center and then estimated cycle variation of the fractal dimension by using Higuchi's method. We examined the relationship between this fractal dimension and the maximum monthly sunspot number in each solar cycle. As a result, we found that there is a strong inverse relationship between the fractal dimension and the maximum monthly sunspot number. By using this relation we predicted the maximum sunspot number in the solar cycle from the fractal dimension of the sunspot numbers during the solar activity increasing phase. The successful prediction is proven by a good correlation (r=0.89 between the observed and predicted maximum sunspot numbers in the solar cycles.

  12. Size dependence of efficiency at maximum power of heat engine

    KAUST Repository

    Izumida, Y.; Ito, N.

    2013-01-01

    We perform a molecular dynamics computer simulation of a heat engine model to study how the engine size difference affects its performance. Upon tactically increasing the size of the model anisotropically, we determine that there exists an optimum size at which the model attains the maximum power for the shortest working period. This optimum size locates between the ballistic heat transport region and the diffusive heat transport one. We also study the size dependence of the efficiency at the maximum power. Interestingly, we find that the efficiency at the maximum power around the optimum size attains a value that has been proposed as a universal upper bound, and it even begins to exceed the bound as the size further increases. We explain this behavior of the efficiency at maximum power by using a linear response theory for the heat engine operating under a finite working period, which naturally extends the low-dissipation Carnot cycle model [M. Esposito, R. Kawai, K. Lindenberg, C. Van den Broeck, Phys. Rev. Lett. 105, 150603 (2010)]. The theory also shows that the efficiency at the maximum power under an extreme condition may reach the Carnot efficiency in principle.© EDP Sciences Società Italiana di Fisica Springer-Verlag 2013.

  13. Size dependence of efficiency at maximum power of heat engine

    KAUST Repository

    Izumida, Y.

    2013-10-01

    We perform a molecular dynamics computer simulation of a heat engine model to study how the engine size difference affects its performance. Upon tactically increasing the size of the model anisotropically, we determine that there exists an optimum size at which the model attains the maximum power for the shortest working period. This optimum size locates between the ballistic heat transport region and the diffusive heat transport one. We also study the size dependence of the efficiency at the maximum power. Interestingly, we find that the efficiency at the maximum power around the optimum size attains a value that has been proposed as a universal upper bound, and it even begins to exceed the bound as the size further increases. We explain this behavior of the efficiency at maximum power by using a linear response theory for the heat engine operating under a finite working period, which naturally extends the low-dissipation Carnot cycle model [M. Esposito, R. Kawai, K. Lindenberg, C. Van den Broeck, Phys. Rev. Lett. 105, 150603 (2010)]. The theory also shows that the efficiency at the maximum power under an extreme condition may reach the Carnot efficiency in principle.© EDP Sciences Società Italiana di Fisica Springer-Verlag 2013.

  14. How long do centenarians survive? Life expectancy and maximum lifespan.

    Science.gov (United States)

    Modig, K; Andersson, T; Vaupel, J; Rau, R; Ahlbom, A

    2017-08-01

    The purpose of this study was to explore the pattern of mortality above the age of 100 years. In particular, we aimed to examine whether Scandinavian data support the theory that mortality reaches a plateau at particularly old ages. Whether the maximum length of life increases with time was also investigated. The analyses were based on individual level data on all Swedish and Danish centenarians born from 1870 to 1901; in total 3006 men and 10 963 women were included. Birth cohort-specific probabilities of dying were calculated. Exact ages were used for calculations of maximum length of life. Whether maximum age changed over time was analysed taking into account increases in cohort size. The results confirm that there has not been any improvement in mortality amongst centenarians in the past 30 years and that the current rise in life expectancy is driven by reductions in mortality below the age of 100 years. The death risks seem to reach a plateau of around 50% at the age 103 years for men and 107 years for women. Despite the rising life expectancy, the maximum age does not appear to increase, in particular after accounting for the increasing number of individuals of advanced age. Mortality amongst centenarians is not changing despite improvements at younger ages. An extension of the maximum lifespan and a sizeable extension of life expectancy both require reductions in mortality above the age of 100 years. © 2017 The Association for the Publication of the Journal of Internal Medicine.

  15. Modeling multisite streamflow dependence with maximum entropy copula

    Science.gov (United States)

    Hao, Z.; Singh, V. P.

    2013-10-01

    Synthetic streamflows at different sites in a river basin are needed for planning, operation, and management of water resources projects. Modeling the temporal and spatial dependence structure of monthly streamflow at different sites is generally required. In this study, the maximum entropy copula method is proposed for multisite monthly streamflow simulation, in which the temporal and spatial dependence structure is imposed as constraints to derive the maximum entropy copula. The monthly streamflows at different sites are then generated by sampling from the conditional distribution. A case study for the generation of monthly streamflow at three sites in the Colorado River basin illustrates the application of the proposed method. Simulated streamflow from the maximum entropy copula is in satisfactory agreement with observed streamflow.

  16. Quality, precision and accuracy of the maximum No. 40 anemometer

    Energy Technology Data Exchange (ETDEWEB)

    Obermeir, J. [Otech Engineering, Davis, CA (United States); Blittersdorf, D. [NRG Systems Inc., Hinesburg, VT (United States)

    1996-12-31

    This paper synthesizes available calibration data for the Maximum No. 40 anemometer. Despite its long history in the wind industry, controversy surrounds the choice of transfer function for this anemometer. Many users are unaware that recent changes in default transfer functions in data loggers are producing output wind speed differences as large as 7.6%. Comparison of two calibration methods used for large samples of Maximum No. 40 anemometers shows a consistent difference of 4.6% in output speeds. This difference is significantly larger than estimated uncertainty levels. Testing, initially performed to investigate related issues, reveals that Gill and Maximum cup anemometers change their calibration transfer functions significantly when calibrated in the open atmosphere compared with calibration in a laminar wind tunnel. This indicates that atmospheric turbulence changes the calibration transfer function of cup anemometers. These results call into question the suitability of standard wind tunnel calibration testing for cup anemometers. 6 refs., 10 figs., 4 tabs.

  17. Beat the Deviations in Estimating Maximum Power of Thermoelectric Modules

    DEFF Research Database (Denmark)

    Gao, Junling; Chen, Min

    2013-01-01

    Under a certain temperature difference, the maximum power of a thermoelectric module can be estimated by the open-circuit voltage and the short-circuit current. In practical measurement, there exist two switch modes, either from open to short or from short to open, but the two modes can give...... different estimations on the maximum power. Using TEG-127-2.8-3.5-250 and TEG-127-1.4-1.6-250 as two examples, the difference is about 10%, leading to some deviations with the temperature change. This paper analyzes such differences by means of a nonlinear numerical model of thermoelectricity, and finds out...... that the main cause is the influence of various currents on the produced electromotive potential. A simple and effective calibration method is proposed to minimize the deviations in specifying the maximum power. Experimental results validate the method with improved estimation accuracy....

  18. Mass mortality of the vermetid gastropod Ceraesignum maximum

    Science.gov (United States)

    Brown, A. L.; Frazer, T. K.; Shima, J. S.; Osenberg, C. W.

    2016-09-01

    Ceraesignum maximum (G.B. Sowerby I, 1825), formerly Dendropoma maximum, was subject to a sudden, massive die-off in the Society Islands, French Polynesia, in 2015. On Mo'orea, where we have detailed documentation of the die-off, these gastropods were previously found in densities up to 165 m-2. In July 2015, we surveyed shallow back reefs of Mo'orea before, during and after the die-off, documenting their swift decline. All censused populations incurred 100% mortality. Additional surveys and observations from Mo'orea, Tahiti, Bora Bora, and Huahine (but not Taha'a) suggested a similar, and approximately simultaneous, die-off. The cause(s) of this cataclysmic mass mortality are currently unknown. Given the previously documented negative effects of C. maximum on corals, we expect the die-off will have cascading effects on the reef community.

  19. Stationary neutrino radiation transport by maximum entropy closure

    International Nuclear Information System (INIS)

    Bludman, S.A.

    1994-11-01

    The authors obtain the angular distributions that maximize the entropy functional for Maxwell-Boltzmann (classical), Bose-Einstein, and Fermi-Dirac radiation. In the low and high occupancy limits, the maximum entropy closure is bounded by previously known variable Eddington factors that depend only on the flux. For intermediate occupancy, the maximum entropy closure depends on both the occupation density and the flux. The Fermi-Dirac maximum entropy variable Eddington factor shows a scale invariance, which leads to a simple, exact analytic closure for fermions. This two-dimensional variable Eddington factor gives results that agree well with exact (Monte Carlo) neutrino transport calculations out of a collapse residue during early phases of hydrostatic neutron star formation

  20. Keeping electronic records secure.

    Science.gov (United States)

    Easton, David

    2013-10-01

    Are electronic engineering maintenance records relating to the hospital estate or a medical device as important as electronic patient records? Computer maintenance management systems (CMMS) are increasingly being used to manage all-round maintenance activities. However, the accuracy of the data held on them, and a level of security that prevents tampering with records, or other unauthorised changes to them to 'cover' poor practice, are both essential, so that, should an individual be injured or killed on hospital grounds, and a law suit follow, the estates team can be confident that it has accurate data to prove it has fulfilled its duty of care. Here David Easton MSc CEng FIHEEM MIET, director of Zener Engineering Services, and chair of IHEEM's Medical Devices Advisory Group, discusses the issues around maintenance databases, and the security and integrity of maintenance data.

  1. Documentation: Records and Reports.

    Science.gov (United States)

    Akers, Michael J

    2017-01-01

    This article deals with documentation to include the beginning of documentation, the requirements of Good Manufacturing Practice reports and records, and the steps that can be taken to minimize Good Manufacturing Practice documentation problems. It is important to remember that documentation for 503a compounding involves the Formulation Record, Compounding Record, Standard Operating Procedures, Safety Data Sheets, etc. For 503b outsourcing facilities, compliance with Current Good Manufacturing Practices is required, so this article is applicable to them. For 503a pharmacies, one can see the development and modification of Good Manufacturing Practice and even observe changes as they are occurring in 503a documentation requirements and anticipate that changes will probably continue to occur. Copyright© by International Journal of Pharmaceutical Compounding, Inc.

  2. Records via probability theory

    CERN Document Server

    Ahsanullah, Mohammad

    2015-01-01

    A lot of statisticians, actuarial mathematicians, reliability engineers, meteorologists, hydrologists, economists. Business and sport analysts deal with records which play important roles in various fields of statistics and its application. This book enables a reader to check his/her level of understanding of the theory of record values. We give basic formulae which are more important in the theory and present a lot of examples which illustrate the theoretical statements. For a beginner in record statistics, as well as for graduate students the study of our book needs the basic knowledge of the subject. A more advanced reader can use our book to polish his/her knowledge. An upgraded list of bibliography which will help a reader to enrich his/her theoretical knowledge and widen the experience of dealing with ordered observations, is also given in the book.

  3. 14 CFR Appendix E to Part 125 - Airplane Flight Recorder Specifications

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Airplane Flight Recorder Specifications E... AND OPERATIONS: AIRPLANES HAVING A SEATING CAPACITY OF 20 OR MORE PASSENGERS OR A MAXIMUM PAYLOAD... Appendix E to Part 125—Airplane Flight Recorder Specifications The recorded values must meet the designated...

  4. Spatio-temporal observations of the tertiary ozone maximum

    Directory of Open Access Journals (Sweden)

    V. F. Sofieva

    2009-07-01

    Full Text Available We present spatio-temporal distributions of the tertiary ozone maximum (TOM, based on GOMOS (Global Ozone Monitoring by Occultation of Stars ozone measurements in 2002–2006. The tertiary ozone maximum is typically observed in the high-latitude winter mesosphere at an altitude of ~72 km. Although the explanation for this phenomenon has been found recently – low concentrations of odd-hydrogen cause the subsequent decrease in odd-oxygen losses – models have had significant deviations from existing observations until recently. Good coverage of polar night regions by GOMOS data has allowed for the first time to obtain spatial and temporal observational distributions of night-time ozone mixing ratio in the mesosphere.

    The distributions obtained from GOMOS data have specific features, which are variable from year to year. In particular, due to a long lifetime of ozone in polar night conditions, the downward transport of polar air by the meridional circulation is clearly observed in the tertiary ozone maximum time series. Although the maximum tertiary ozone mixing ratio is achieved close to the polar night terminator (as predicted by the theory, TOM can be observed also at very high latitudes, not only in the beginning and at the end, but also in the middle of winter. We have compared the observational spatio-temporal distributions of the tertiary ozone maximum with that obtained using WACCM (Whole Atmosphere Community Climate Model and found that the specific features are reproduced satisfactorily by the model.

    Since ozone in the mesosphere is very sensitive to HOx concentrations, energetic particle precipitation can significantly modify the shape of the ozone profiles. In particular, GOMOS observations have shown that the tertiary ozone maximum was temporarily destroyed during the January 2005 and December 2006 solar proton events as a result of the HOx enhancement from the increased ionization.

  5. Estimating the maximum potential revenue for grid connected electricity storage :

    Energy Technology Data Exchange (ETDEWEB)

    Byrne, Raymond Harry; Silva Monroy, Cesar Augusto.

    2012-12-01

    The valuation of an electricity storage device is based on the expected future cash flow generated by the device. Two potential sources of income for an electricity storage system are energy arbitrage and participation in the frequency regulation market. Energy arbitrage refers to purchasing (stor- ing) energy when electricity prices are low, and selling (discharging) energy when electricity prices are high. Frequency regulation is an ancillary service geared towards maintaining system frequency, and is typically procured by the independent system operator in some type of market. This paper outlines the calculations required to estimate the maximum potential revenue from participating in these two activities. First, a mathematical model is presented for the state of charge as a function of the storage device parameters and the quantities of electricity purchased/sold as well as the quantities o ered into the regulation market. Using this mathematical model, we present a linear programming optimization approach to calculating the maximum potential revenue from an elec- tricity storage device. The calculation of the maximum potential revenue is critical in developing an upper bound on the value of storage, as a benchmark for evaluating potential trading strate- gies, and a tool for capital nance risk assessment. Then, we use historical California Independent System Operator (CAISO) data from 2010-2011 to evaluate the maximum potential revenue from the Tehachapi wind energy storage project, an American Recovery and Reinvestment Act of 2009 (ARRA) energy storage demonstration project. We investigate the maximum potential revenue from two di erent scenarios: arbitrage only and arbitrage combined with the regulation market. Our analysis shows that participation in the regulation market produces four times the revenue compared to arbitrage in the CAISO market using 2010 and 2011 data. Then we evaluate several trading strategies to illustrate how they compare to the

  6. Discontinuity of maximum entropy inference and quantum phase transitions

    International Nuclear Information System (INIS)

    Chen, Jianxin; Ji, Zhengfeng; Yu, Nengkun; Zeng, Bei; Li, Chi-Kwong; Poon, Yiu-Tung; Shen, Yi; Zhou, Duanlu

    2015-01-01

    In this paper, we discuss the connection between two genuinely quantum phenomena—the discontinuity of quantum maximum entropy inference and quantum phase transitions at zero temperature. It is shown that the discontinuity of the maximum entropy inference of local observable measurements signals the non-local type of transitions, where local density matrices of the ground state change smoothly at the transition point. We then propose to use the quantum conditional mutual information of the ground state as an indicator to detect the discontinuity and the non-local type of quantum phase transitions in the thermodynamic limit. (paper)

  7. On an Objective Basis for the Maximum Entropy Principle

    Directory of Open Access Journals (Sweden)

    David J. Miller

    2015-01-01

    Full Text Available In this letter, we elaborate on some of the issues raised by a recent paper by Neapolitan and Jiang concerning the maximum entropy (ME principle and alternative principles for estimating probabilities consistent with known, measured constraint information. We argue that the ME solution for the “problematic” example introduced by Neapolitan and Jiang has stronger objective basis, rooted in results from information theory, than their alternative proposed solution. We also raise some technical concerns about the Bayesian analysis in their work, which was used to independently support their alternative to the ME solution. The letter concludes by noting some open problems involving maximum entropy statistical inference.

  8. The maximum economic depth of groundwater abstraction for irrigation

    Science.gov (United States)

    Bierkens, M. F.; Van Beek, L. P.; de Graaf, I. E. M.; Gleeson, T. P.

    2017-12-01

    Over recent decades, groundwater has become increasingly important for agriculture. Irrigation accounts for 40% of the global food production and its importance is expected to grow further in the near future. Already, about 70% of the globally abstracted water is used for irrigation, and nearly half of that is pumped groundwater. In many irrigated areas where groundwater is the primary source of irrigation water, groundwater abstraction is larger than recharge and we see massive groundwater head decline in these areas. An important question then is: to what maximum depth can groundwater be pumped for it to be still economically recoverable? The objective of this study is therefore to create a global map of the maximum depth of economically recoverable groundwater when used for irrigation. The maximum economic depth is the maximum depth at which revenues are still larger than pumping costs or the maximum depth at which initial investments become too large compared to yearly revenues. To this end we set up a simple economic model where costs of well drilling and the energy costs of pumping, which are a function of well depth and static head depth respectively, are compared with the revenues obtained for the irrigated crops. Parameters for the cost sub-model are obtained from several US-based studies and applied to other countries based on GDP/capita as an index of labour costs. The revenue sub-model is based on gross irrigation water demand calculated with a global hydrological and water resources model, areal coverage of crop types from MIRCA2000 and FAO-based statistics on crop yield and market price. We applied our method to irrigated areas in the world overlying productive aquifers. Estimated maximum economic depths range between 50 and 500 m. Most important factors explaining the maximum economic depth are the dominant crop type in the area and whether or not initial investments in well infrastructure are limiting. In subsequent research, our estimates of

  9. Efficiency of autonomous soft nanomachines at maximum power.

    Science.gov (United States)

    Seifert, Udo

    2011-01-14

    We consider nanosized artificial or biological machines working in steady state enforced by imposing nonequilibrium concentrations of solutes or by applying external forces, torques, or electric fields. For unicyclic and strongly coupled multicyclic machines, efficiency at maximum power is not bounded by the linear response value 1/2. For strong driving, it can even approach the thermodynamic limit 1. Quite generally, such machines fall into three different classes characterized, respectively, as "strong and efficient," "strong and inefficient," and "balanced." For weakly coupled multicyclic machines, efficiency at maximum power has lost any universality even in the linear response regime.

  10. A comparison of methods of predicting maximum oxygen uptake.

    OpenAIRE

    Grant, S; Corbett, K; Amjad, A M; Wilson, J; Aitchison, T

    1995-01-01

    The aim of this study was to compare the results from a Cooper walk run test, a multistage shuttle run test, and a submaximal cycle test with the direct measurement of maximum oxygen uptake on a treadmill. Three predictive tests of maximum oxygen uptake--linear extrapolation of heart rate of VO2 collected from a submaximal cycle ergometer test (predicted L/E), the Cooper 12 min walk, run test, and a multi-stage progressive shuttle run test (MST)--were performed by 22 young healthy males (mean...

  11. Maximum length scale in density based topology optimization

    DEFF Research Database (Denmark)

    Lazarov, Boyan Stefanov; Wang, Fengwen

    2017-01-01

    The focus of this work is on two new techniques for imposing maximum length scale in topology optimization. Restrictions on the maximum length scale provide designers with full control over the optimized structure and open possibilities to tailor the optimized design for broader range...... of manufacturing processes by fulfilling the associated technological constraints. One of the proposed methods is based on combination of several filters and builds on top of the classical density filtering which can be viewed as a low pass filter applied to the design parametrization. The main idea...

  12. A Maximum Entropy Method for a Robust Portfolio Problem

    Directory of Open Access Journals (Sweden)

    Yingying Xu

    2014-06-01

    Full Text Available We propose a continuous maximum entropy method to investigate the robustoptimal portfolio selection problem for the market with transaction costs and dividends.This robust model aims to maximize the worst-case portfolio return in the case that allof asset returns lie within some prescribed intervals. A numerical optimal solution tothe problem is obtained by using a continuous maximum entropy method. Furthermore,some numerical experiments indicate that the robust model in this paper can result in betterportfolio performance than a classical mean-variance model.

  13. Thermal transfer recording media

    Science.gov (United States)

    Takei, T.; Taniguchi, M.; Fukushima, H.; Yamaguchi, Y.; Shinozuka, M.; Seikohsha, K. K. Suwa

    1988-08-01

    The recording media consist of more than or one coloring layer and a layer containing a flame retardant to ensure noncombustibility and good thermal transfer. Thus, a PET film was coated on a side with a compound containing Vylon 290 (polyester resin), AFR-1021 (decabromodiphenyl oxide) 8 and Polysafe 60 (Sb oxide), and coated on the other side with a compound containing carnauba wax, HNP-9 (paraffin wax), EV-410 (ethylene-vinyl acetate copolymer), and Cu phthalocyanine to give a thermal transfer recording medium which showed good noncombustibility and antiblocking properties, and provided high quality images.

  14. Optical recording medium

    International Nuclear Information System (INIS)

    Andriech, A.; Bivol, V.; Tridukh, G.; Tsiuleanu, D.

    2002-01-01

    The invention relates of the micro- and optoelectronics, computer engineering ,in particular, to tjhe optical information media and may be used in hilography. Summary of the invention consists in that the optical image recording medium, containing a dielectric substrates, onto one surface of which there are placed in series a transparent electricity conducting layer, a photo sensitive recording layer of chalcogenic glass and a thin film electrode of aluminium, is provided with an optically transparent protective layer, applied into the thin film electrode. The result of the invention consists in excluding the dependence of chemical processes course into the medium upon environmental conditions

  15. Recording Scientific Knowledge

    International Nuclear Information System (INIS)

    Bowker, Geof

    2006-01-01

    The way we record knowledge, and the web of technical, formal, and social practices that surrounds it, inevitably affects the knowledge that we record. The ways we hold knowledge about the past - in handwritten manuscripts, in printed books, in file folders, in databases - shape the kind of stories we tell about that past. In this talk, I look at how over the past two hundred years, information technology has affected the nature and production of scientific knowledge. Further, I explore ways in which the emergent new cyberinfrastructure is changing our relationship to scientific practice.

  16. LHC Report: staying cool despite record highs

    CERN Document Server

    Jorg Wenninger for the LHC team

    2016-01-01

    These two last weeks have been a highlight of LHC operation so far, delivering record luminosity.   LHC integrated luminosity in 2011, 2012, 2015 and 2016. It’s been a record-breaking period for the LHC. On the evening of Wednesday, 1 June, the maximum number of bunches achievable with the current configuration, based on the injection of 72-bunch trains with a spacing of 25 ns, was reached. 2040 bunches were circulating in the machine. The rest of the week continued in a similar vein: the luminosity record at 6.5 TeV was broken with a peak luminosity of just over 8 x 1033 cm-2s-1, reaching 80% of the design luminosity. This was followed by a new record for integrated luminosity in a single fill, with 370 pb-1 delivered in 18 hours of colliding beams. Finally, a third record was broken later in the week: with an availability for collisions of around 75% (the annual average is normally around 35%) and 6 long fills of particles brought into collision one...

  17. WIPP Project Records Management Handbook

    International Nuclear Information System (INIS)

    1991-01-01

    The Waste Isolation Pilot Plant (WIPP) Records Management Handbook provides the WIPP Project Records Management personnel with a tool to use to fulfill the requirements of the WIPP Records Program and direct their actions in the important area of records management. The handbook describes the various project areas involved in records management, and how they function. The handbook provides the requirements for Record Coordinators and Master Record Center (MRC) personnel to follow in the normal course of file management, records scheduling, records turnover, records disposition, and records retrieval. More importantly, the handbook provides a single reference which encompasses the procedures set fourth in DOE Order 1324.2A, ''Records Disposition'' ASME NQA-1, ''Quality Assurance Program Requirements for Nuclear Facilities'' and DOE-AL 5700.6B, ''General Operations Quality Assurance.'' These documents dictate how an efficient system of records management will be achieved on the WIPP Project

  18. Change-Point and Trend Analysis on Annual Maximum Discharge in Continental United States

    Science.gov (United States)

    Serinaldi, F.; Villarini, G.; Smith, J. A.; Krajewski, W. F.

    2008-12-01

    Annual maximum discharge records from 36 stations representing different hydro-climatic regimes in the continental United States with at least 100 years of records are used to investigate the presence of temporal trends and abrupt changes in mean and variance. Change point analysis is performed by means of two non- parametric (Pettitt and CUSUM), one semi-parametric (Guan), and two parametric (Rodionov and Bayesian Change Point) tests. Two non-parametric (Mann-Kendall and Spearman) and one parametric (Pearson) tests are applied to detect the presence of temporal trends. Generalized Additive Model for Location Scale and Shape (GAMLSS) models are also used to parametrically model the streamflow data exploiting their flexibility to account for changes and temporal trends in the parameters of distribution functions. Additionally, serial correlation is assessed in advance by computing the autocorrelation function (ACF), and the Hurst parameter is estimated using two estimators (aggregated variance and differenced variance methods) to investigate the presence of long range dependence. The results of this study indicate lack of long range dependence in the maximum streamflow series. At some stations the authors found a statistically significant change point in the mean and/or variance, while in general they detected no statistically significant temporal trends.

  19. [Taxonomic status of the Tyulek virus (TLKV) (Orthomyxoviridae, Quaranjavirus, Quaranfil group) isolated from the ticks Argas vulgaris Filippova, 1961 (Argasidae) from the birds burrow nest biotopes in the Kyrgyzstan].

    Science.gov (United States)

    L'vov, D K; Al'khovskiĭ, S V; Shchelkanov, M Iu; Shchetinin, A M; Deriabin, P G; Aristova, V A; Gitel'man, A K; Samokhvalov, E I; Botikov, A G

    2014-01-01

    The Tyulek virus (TLKV) was isolated from the ticks Argas vulgaris Filippova, 1961 (Argasidae), collected from the burrow biotopes in multispecies birds colony in the Aksu river floodplain near Tyulek village (northern part of Chu Valley, Kyrgyzstan). Recently, the TLKV was assigned to the Quaranfil group (including the Quaranfil virus (QRFV), Johnston Atoll virus (JAV), Lake Chad virus) that is a novel genus of the Quaranjavirus in the Orthomyxoviridae family. In his work, the complete genome (ID GenBank KJ438647-8) sequence of the TLKV was determined using next-generation sequencing (Illumina platform). Comparison of deduced amino acid sequences shows closed relationship of the TLKV with QRFV and JAV (86% and 84% identity for PB1 and about 70% for PB2 and PA, respectively). The identity level of the TLKV and QRFV in outer glycoprotein GP is 72% and 80% for nucleotide and amino acid sequences, respectively. The phylogenetic analysis showed that the TLKV belongs to the genus of the Quaranjavirus in the family Orthomyxoviridae.

  20. Genetic Analysis of Daily Maximum Milking Speed by a Random Walk Model in Dairy Cows

    DEFF Research Database (Denmark)

    Karacaören, Burak; Janss, Luc; Kadarmideen, Haja

    Data were obtained from dairy cows stationed at research farm ETH Zurich for maximum milking speed. The main aims of this paper are a) to evaluate if the Wood curve is suitable to model mean lactation curve b) to predict longitudinal breeding values by random regression and random walk models of ...... filter applications: random walk model could give online prediction of breeding values. Hence without waiting for whole lactation records, genetic evaluation could be made when the daily or monthly data is available......Data were obtained from dairy cows stationed at research farm ETH Zurich for maximum milking speed. The main aims of this paper are a) to evaluate if the Wood curve is suitable to model mean lactation curve b) to predict longitudinal breeding values by random regression and random walk models...... of maximum milking speed. Wood curve did not provide a good fit to the data set. Quadratic random regressions gave better predictions compared with the random walk model. However random walk model does not need to be evaluated for different orders of regression coefficients. In addition with the Kalman...

  1. EFFECTS OF A SAND RUNNING SURFACE ON THE KINEMATICS OF SPRINTING AT MAXIMUM VELOCITY

    Directory of Open Access Journals (Sweden)

    P E Alcaraz

    2011-05-01

    Full Text Available Performing sprints on a sand surface is a common training method for improving sprint-specific strength. For maximum specificity of training the athlete’s movement patterns during the training exercise should closely resemble those used when performing the sport. The aim of this study was to compare the kinematics of sprinting at maximum velocity on a dry sand surface to the kinematics of sprinting on an athletics track. Five men and five women participated in the study, and flying sprints over 30 m were recorded by video and digitized using biomechanical analysis software. We found that sprinting on a sand surface was substantially different to sprinting on an athletics track. When sprinting on sand the athletes tended to ‘sit’ during the ground contact phase of the stride. This action was characterized by a lower centre of mass, a greater forward lean in the trunk, and an incomplete extension of the hip joint at take-off. We conclude that sprinting on a dry sand surface may not be an appropriate method for training the maximum velocity phase in sprinting. Although this training method exerts a substantial overload on the athlete, as indicated by reductions in running velocity and stride length, it also induces detrimental changes to the athlete’s running technique which may transfer to competition sprinting.

  2. Electronic health record

    DEFF Research Database (Denmark)

    Kierkegaard, Patrick

    2011-01-01

    The European Commission wants to boost the digital economy by enabling all Europeans to have access to online medical records anywhere in Europe by 2020. With the newly enacted Directive 2011/24/EU on Patients’ Rights in cross border healthcare due for implementation by 2013, it is inevitable tha...

  3. Vintage Vinyl Record Design

    Science.gov (United States)

    Sacco, Michael

    2008-01-01

    In this article, the author describes a project in which his ninth-grade art students utilized a vinyl record as an unusual medium to create a work that exhibited solid design, great creativity, and strong craftsmanship. Students presented their pieces to the class for critique, explained the process, the media, and their feelings about their…

  4. Cine recording ophthalmoscope

    Science.gov (United States)

    Fitzgerald, J. W.

    1972-01-01

    Camera system provides accurate photographic recording during acceleration of centrifuge and permits immediate observation of dynamic changes in retinal circulation by a closed-circuit television loop. System consists of main camera, remote control unit, and strobe power supply unit, and is used for fluorescein studies and dynamometry sequences.

  5. Records on the water

    International Nuclear Information System (INIS)

    Regula, E.

    2003-01-01

    In this paper the electric power generation in hydro-power plants in the Slovak Republic during 2002 is reviewed. Year 2002 was rich on precipitation and the Hydro Power Plants (plants of the Slovenske elektrarne, a.s.) has reached record in generation of electric power when altogether the Water Power Plants produced 5,168.5 GWh. (author)

  6. A Miniature Recording Cardiotachometer

    DEFF Research Database (Denmark)

    Zsombor-Murray, Paul J; Vroomen, Louis J.; Hendriksen, Nils Thedin

    1981-01-01

    The design of a miniature, recording cardiotachometer is described. It is simple and can store digital data. Bench and field tests, using a hand-held display, are presented. Construction and principles of operation are discussed. Applications, with performing athlete subjects, are outlined....

  7. Andean glacial lakes and climate variability since the last glacial maximum

    Directory of Open Access Journals (Sweden)

    1995-01-01

    á registrada en la estratigrafía de varios lagos, incluyendo el Lago Titicaca. Los niveles de los lagos estaban subiendo y había neoglaciación en el Holoceno superior después de la fase de sequía en el Holoceno medio. Sediment cores from glacial lakes in the tropical-subtropical Andes provide a nearly continuous record of late glacial and Holocene paleoclimates. Basal radiocarbon dates from lakes and peats suggest that the last glacial maximum significantly predated the global maximum at 18 14C kyr BP. Most lakes have basal radiocarbon ages of <13 14C kyr BP, implying that there was a late-Pleistocene phase of glaciation that may have culminated about 14 14C kyr BP. Late glacial advances are recorded in several sediment records from lakes and by 10 14C kyr BP glaciers had retreated to within their modern limits. Mid-Holocene aridity is recorded in the stratigraphy from a number of lakes including Lago Titicaca. This phase of aridity was followed by rising lake levels and neoglaciation in the late Holocene.

  8. MAXIMUM RUNOFF OF THE FLOOD ON WADIS OF NORTHERN ...

    African Journals Online (AJOL)

    lanez

    The technique of account the maximal runoff of flood for the rivers of northern part of Algeria based on the theory of ... north to south: 1) coastal Tel – fertile, high cultivated and sown zone; 2) territory of Atlas. Mountains ... In the first case the empiric dependence between maximum intensity of precipitation for some calculation ...

  9. Scientific substantination of maximum allowable concentration of fluopicolide in water

    Directory of Open Access Journals (Sweden)

    Pelo I.М.

    2014-03-01

    Full Text Available In order to substantiate fluopicolide maximum allowable concentration in the water of water reservoirs the research was carried out. Methods of study: laboratory hygienic experiment using organoleptic and sanitary-chemical, sanitary-toxicological, sanitary-microbiological and mathematical methods. The results of fluopicolide influence on organoleptic properties of water, sanitary regimen of reservoirs for household purposes were given and its subthreshold concentration in water by sanitary and toxicological hazard index was calculated. The threshold concentration of the substance by the main hazard criteria was established, the maximum allowable concentration in water was substantiated. The studies led to the following conclusions: fluopicolide threshold concentration in water by organoleptic hazard index (limiting criterion – the smell – 0.15 mg/dm3, general sanitary hazard index (limiting criteria – impact on the number of saprophytic microflora, biochemical oxygen demand and nitrification – 0.015 mg/dm3, the maximum noneffective concentration – 0.14 mg/dm3, the maximum allowable concentration - 0.015 mg/dm3.

  10. Image coding based on maximum entropy partitioning for identifying ...

    Indian Academy of Sciences (India)

    A new coding scheme based on maximum entropy partitioning is proposed in our work, particularly to identify the improbable intensities related to different emotions. The improbable intensities when used as a mask decode the facial expression correctly, providing an effectiveplatform for future emotion categorization ...

  11. Computing the maximum volume inscribed ellipsoid of a polytopic projection

    NARCIS (Netherlands)

    Zhen, Jianzhe; den Hertog, Dick

    We introduce a novel scheme based on a blending of Fourier-Motzkin elimination (FME) and adjustable robust optimization techniques to compute the maximum volume inscribed ellipsoid (MVE) in a polytopic projection. It is well-known that deriving an explicit description of a projected polytope is

  12. Computing the Maximum Volume Inscribed Ellipsoid of a Polytopic Projection

    NARCIS (Netherlands)

    Zhen, J.; den Hertog, D.

    2015-01-01

    We introduce a novel scheme based on a blending of Fourier-Motzkin elimination (FME) and adjustable robust optimization techniques to compute the maximum volume inscribed ellipsoid (MVE) in a polytopic projection. It is well-known that deriving an explicit description of a projected polytope is

  13. Maximum super angle optimization method for array antenna pattern synthesis

    DEFF Research Database (Denmark)

    Wu, Ji; Roederer, A. G

    1991-01-01

    Different optimization criteria related to antenna pattern synthesis are discussed. Based on the maximum criteria and vector space representation, a simple and efficient optimization method is presented for array and array fed reflector power pattern synthesis. A sector pattern synthesized by a 2...

  14. correlation between maximum dry density and cohesion of ...

    African Journals Online (AJOL)

    HOD

    investigation on sandy soils to determine the correlation between relative density and compaction test parameter. Using twenty soil samples, they were able to develop correlations between relative density, coefficient of uniformity and maximum dry density. Khafaji [5] using standard proctor compaction method carried out an ...

  15. Molecular markers linked to apomixis in Panicum maximum Jacq ...

    African Journals Online (AJOL)

    Panicum maximum Jacq. is an important forage grass of African origin largely used in the tropics. The genetic breeding of this species is based on the hybridization of sexual and apomictic genotypes and selection of apomictic F1 hybrids. The objective of this work was to identify molecular markers linked to apomixis in P.

  16. Maximum likelihood estimation of the attenuated ultrasound pulse

    DEFF Research Database (Denmark)

    Rasmussen, Klaus Bolding

    1994-01-01

    The attenuated ultrasound pulse is divided into two parts: a stationary basic pulse and a nonstationary attenuation pulse. A standard ARMA model is used for the basic pulse, and a nonstandard ARMA model is derived for the attenuation pulse. The maximum likelihood estimator of the attenuated...

  17. On a Weak Discrete Maximum Principle for hp-FEM

    Czech Academy of Sciences Publication Activity Database

    Šolín, Pavel; Vejchodský, Tomáš

    -, č. 209 (2007), s. 54-65 ISSN 0377-0427 R&D Projects: GA ČR(CZ) GA102/05/0629 Institutional research plan: CEZ:AV0Z20570509; CEZ:AV0Z10190503 Keywords : discrete maximum principle * hp-FEM Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 0.943, year: 2007

  18. Gamma-ray spectra deconvolution by maximum-entropy methods

    International Nuclear Information System (INIS)

    Los Arcos, J.M.

    1996-01-01

    A maximum-entropy method which includes the response of detectors and the statistical fluctuations of spectra is described and applied to the deconvolution of γ-ray spectra. Resolution enhancement of 25% can be reached for experimental peaks and up to 50% for simulated ones, while the intensities are conserved within 1-2%. (orig.)

  19. Modeling maximum daily temperature using a varying coefficient regression model

    Science.gov (United States)

    Han Li; Xinwei Deng; Dong-Yum Kim; Eric P. Smith

    2014-01-01

    Relationships between stream water and air temperatures are often modeled using linear or nonlinear regression methods. Despite a strong relationship between water and air temperatures and a variety of models that are effective for data summarized on a weekly basis, such models did not yield consistently good predictions for summaries such as daily maximum temperature...

  20. Maximum Interconnectedness and Availability for Directional Airborne Range Extension Networks

    Science.gov (United States)

    2016-08-29

    IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 1 Maximum Interconnectedness and Availability for Directional Airborne Range Extension Networks Thomas...2 IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS I. INTRODUCTION Tactical military networks both on land and at sea often have restricted transmission...a standard definition in graph theoretic and networking literature that is related to, but different from, the metric we consider. August 29, 2016