Semi-Markov Arnason-Schwarz models.

Science.gov (United States)

King, Ruth; Langrock, Roland

2016-06-01

We consider multi-state capture-recapture-recovery data where observed individuals are recorded in a set of possible discrete states. Traditionally, the Arnason-Schwarz model has been fitted to such data where the state process is modeled as a first-order Markov chain, though second-order models have also been proposed and fitted to data. However, low-order Markov models may not accurately represent the underlying biology. For example, specifying a (time-independent) first-order Markov process involves the assumption that the dwell time in each state (i.e., the duration of a stay in a given state) has a geometric distribution, and hence that the modal dwell time is one. Specifying time-dependent or higher-order processes provides additional flexibility, but at the expense of a potentially significant number of additional model parameters. We extend the Arnason-Schwarz model by specifying a semi-Markov model for the state process, where the dwell-time distribution is specified more generally, using, for example, a shifted Poisson or negative binomial distribution. A state expansion technique is applied in order to represent the resulting semi-Markov Arnason-Schwarz model in terms of a simpler and computationally tractable hidden Markov model. Semi-Markov Arnason-Schwarz models come with only a very modest increase in the number of parameters, yet permit a significantly more flexible state process. Model selection can be performed using standard procedures, and in particular via the use of information criteria. The semi-Markov approach allows for important biological inference to be drawn on the underlying state process, for example, on the times spent in the different states. The feasibility of the approach is demonstrated in a simulation study, before being applied to real data corresponding to house finches where the states correspond to the presence or absence of conjunctivitis. © 2015, The International Biometric Society.

Johann P. Arnason & Kurt A. Raaflaub, The Roman Empire in Context: Historical and Comparative Perspectives (Chichester: Wiley & Sons, 2011

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Michael Gibbons

2012-03-01

Full Text Available Arnason and Raaflaub’s edited volume, The Roman Empire in Context: Historical and Comparative Perspectives, is the fifth volume in a series entitled The Ancient World: Comparative Histories. The overarching aim of the series is to bring a comparative perspective to studies of ancient histories, and earlier titles focus either on content or geography. This is the only volume to date that focuses on a specific civilization, and Rome is of course significant enough to merit its own volume.

Phytochemicals in nutrition and health

National Research Council Canada - National Science Library

International Phytochemical Conference (3rd : 2000 : California State Polytechnic University); Meskin, Mark S

2002-01-01

... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . JOHN T. ARNASON, SHANNON E. BINNS, and BERNARD R. BAUM 9 CHAPTER 3 Phytochemicals in the Vaccinium Family: Bilberries, Blueberries, and Cranberries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....

Toxity of Gedunin, Piperine and Crude Extracts of their Natural ...

African Journals Online (AJOL)

Toxity of Gedunin, Piperine and Crude Extracts of their Natural Products on Growth and Development of Ostrinia Nubilalis Hbner (Lepidoptera: Pyrarlidae). F K Ewete, J T Arnason, T Durst, S Mackinnon ...

genetic variability characterisation of tanzania sorghum landraces ...

African Journals Online (AJOL)

jen

molecular markers, eleven clusters were observed. ... et 7 pour les marqueurs microsatellites ou SSRs (simple sequence repeats) ont été ...... Inc, USA. Teshome, A., Baum, B.R., Fahrig, L., Torrance,. J.K., Arnason, T.J. and Lambert, J.D. 1997.

Botanical Extracts as Medical Countermeasures for Radiation Induced DNA Damage

Science.gov (United States)

2012-03-01

20 Figure 9: CYP3A4 inhibition HPLC assay for GSE4 and LT ..................................................... 21...the final stages of this project, Dr. John Arnason at the University of Ottawa for preliminary botanicals information and HPLC data, Aimee Jones for...flavanols, flavonols, stilbenes (resveratrol) and phenolic acids (31, 32). Previous studies have shown that proanthocyanidin (oligomer chain of flavonoid

Den visuelle oplevelses økonomi – klassisk, neoklassisk, relationel

DEFF Research Database (Denmark)

Michelsen, Anders Ib

2009-01-01

Det foreliggende kapitel søger kortfattet at skitsere en relation mellem visuel kultur og økonomi, som i videre forstand er et konkret input til en mulig teori om vi- suel kulturøkonomi. Med udgangspunkt i en sammenstilling af Johann P. Arnasons teori om en ”kulturel artikulation af verden” med P...... kulturøkonomi, der går ud over den traditionelle diskrepans mel- lem kulturbegreber, fx af antropologisk art, og økonomibegreber, fx af neoklassisk art....

Crystallisation of mela-aillikites of the Narsaq region, Gardar alkaline province, south Greenland and relationships to other aillikitic carbonatitic associations in the province

Science.gov (United States)

Upton, B. G. J.; Craven, J. A.; Kirstein, L. A.

2006-11-01

Aillikites (carbonated, melilite-free ultramafic lamprophyres grading to carbonatites) are minor components of the Gardar alkaline igneous province. They occur principally as minor intrusions and as clasts in diatremes, but more voluminous aillikitic intrusions crop out near the Ilímaussaq Complex, which they predate by a few million years. These larger intrusions were emplaced at 1160 ± 5 Ma. They are essentially carbonate-free and, consisting almost wholly of ferromagnesian silicate and oxide minerals, are mela-aillikites. Typically the mela-aillikites are fine-grained rocks composed largely of olivine, clinopyroxene, phlogopite and magnetite that crystallised in open systems, permitting loss of volatile-rich residues. The petrography is highly complex, involving at least 28 mineral species. Pyroxenitic veins were emplaced while the host-rocks were still at high temperatures and represent channels through which fluorinated silico-carbonatitic residual melts escaped, with exsolving CO 2 as propellant. Precipitation of Ca-rich minerals including monticellite, perovskite, vesuvianite, wollastonite and cuspidine was a result of dissociation of the calcium carbonate in the residual melts. Late-stage crystallisation was in a highly oxidising environment in which the 'common minerals' attain extreme compositions (almost pure forsterite, ferrian-diopside, highly magnesian ilmenite, Ba-Ti-rich phlogopite and Sr-rich kaersutite). Spatially associated diatremes may be vents through which CO 2-rich gases erupted. The whole-rock compositions are considered to be well removed from those of co-existing melts: compaction and expulsion of highly mobile residual melts is inferred to have left the mela-aillikites as aberrant cumulates. The mela-aillikites are a late-Gardar manifestation of the aillikitic magmatism that occurred intermittently in the province for over 120 Ma. Repetitive formation of metasomite vein systems in the deep lithospheric mantle is postulated. These

Approaches for the direct estimation of lambda, and demographic contributions to lambda, using capture-recapture data

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Nichols, James D.; Hines, James E.

2002-01-01

We first consider the estimation of the finite rate of population increase or population growth rate, u i , using capture-recapture data from open populations. We review estimation and modelling of u i under three main approaches to modelling openpopulation data: the classic approach of Jolly (1965) and Seber (1965), the superpopulation approach of Crosbie & Manly (1985) and Schwarz & Arnason (1996), and the temporal symmetry approach of Pradel (1996). Next, we consider the contributions of different demographic components to u i using a probabilistic approach based on the composition of the population at time i + 1 (Nichols et al., 2000b). The parameters of interest are identical to the seniority parameters, n i , of Pradel (1996). We review estimation of n i under the classic, superpopulation, and temporal symmetry approaches. We then compare these direct estimation approaches for u i and n i with analogues computed using projection matrix asymptotics. We also discuss various extensions of the estimation approaches to multistate applications and to joint likelihoods involving multiple data types.

AUDIT OF INJURIES IN A PREMIERSHIP FOOTBALL SQUAD OVER A FIVE-YEAR PERIOD

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Aslam Chougle

2005-06-01

Full Text Available Football is currently the most popular sport in the world. The competitive nature of the sport makes it prone to injuries with the estimated frequency being 10 to 35 per 1000 playing hours (Dvorak and Junge, 2000. The aim of this study was to identify the injury patterns and rehabilitation periods with specific injuries in a premiership football club. Player injuries were retrospectively analysed from a local database (Microsoft Access 2000 at the Blackburn Rovers Football Club, UK from December 1998 to March 2004. The club physiotherapist and physician recorded details of all injuries sustained during both training and matches during that period. Clear distinctions were made between acute and overuse injuries and rehabilitation times for each injury were noted (Arnason et al., 2004. Data was analysed using SPSS (Chicago, Illinois, USA. Differences between the groups were assessed using the independent samples t-test. P values of < 0.05 were considered statistically significant. There were 483 injuries in 91 players. Of these 133 injuries occurred as a result of overuse and 350 as a result of direct trauma. 440 injuries were treated conservatively while 43 were treated operatively. Table 1 shows the range and number of injuries, which occurred during this period along with the average rehabilitation time for each injury. Injuries grouped as "Other" in table 1 accounted for less than 1% of all injuries and could not always be directly attributed to football even though this appeared to be the precipitating factor in all cases. There was no statistical difference between rehabilitation times for acute injuries (18 days, standard deviation 30 as compared to overuse injuries (20 days, standard deviation 39 (p = 0.640. The mean rehabilitation time however for injuries treated conservatively (15 days , standard deviation 24 as compared to injuries treated surgically (61 days, standard deviation 67 was found to be statistically significant (p = 0

Emigration and retention of Palinurus elephas (Fabricius, 1787 in a central western Mediterranean marine protected area

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Maria Cristina Follesa

2007-06-01

Full Text Available This study describes the results obtained by applying the Arnason Schwartz multistate mark-recapture model to eight years of data collected in and around a small no-fishing marine protected area (MPA; 4 km2 in the central western Mediterranean. From 1997 to 2004, a total of 4044 specimens of Palinurus elephas (Fabr., 1787 were tagged and 317 recaptured. The most parsimonious model which best explained the data variability was that of a temporally constant rate of apparent survival and movement in each of the two strata. The absence of any temporal influence in the apparent survival rate inside the no-take area suggested that spillover and mortality are constant for each period of the study. The lower apparent survival rate in surrounding zones than inside the MPA (0.26 ± 0.04 (SE vs 0.94 ± 0.03 (SE is presumed to be a function of fishing effort. A continuous movement of P. elephas across the boundary of the small MPA was also tested. This information on retention of lobsters in the MPA contributes to our understanding of the effect of introducing MPAs into a managed commercial fishery system.

B cell receptor pathway in chronic lymphocytic leukemia: specific role of CC-292

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Arnason JE

2014-01-01

Full Text Available Jon E Arnason,1 Jennifer R Brown21Beth Israel Deaconess Medical Center, 2CLL Center, Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USAAbstract: Chronic lymphocytic leukemia (CLL is the most common adult leukemia. The current treatment paradigm involves the use of chemoimmunotherapy, when patients develop an indication for therapy. With this strategy, a majority of patients will obtain a remission, though cure remains elusive. While treatable, the majority of CLL patients will die of complications of their disease. Recent advances in the understanding of the importance of the B cell receptor (BCR pathway in CLL have led to the development of a number of agents targeting this pathway. In this review, we discuss recent developments in the targeting of the BCR pathway, with a focus on CC-292. CC-292 covalently binds to Bruton's tyrosine kinase, a key mediator of BCR signaling, and has demonstrated preclinical and clinical activity in CLL, with acceptable tolerability. Based on the success of CC-292 and other inhibitors of the BCR pathway, these agents are being investigated in combination with standard therapy, with the hope that they will increase the depth and length of response, without significant toxicity.Keywords: Bruton's tyrosine kinase inhibitor, ibrutinib

Interpretation in reproductive genetic counseling: a methodological framework.

Science.gov (United States)

Tóth, Adél; Szeverényi, Péter

2007-09-01

In case of genetic risk, parents are often faced with reproductive decisions affecting their life essentially, so it is advisable to pursue careful deliberation. For this reason, the genetic counselor is expected to help the counselee make well-informed and well-considered decisions, which requires the understanding of the patient as an individual. To reach emphatic understanding, physicians can use the results of the Gadamerian theory of interpretation that contains the idea -- as it has been summarized by V. Arnason -- that four aspects of openness are necessary to fully understand the other, such as openness to oneself, to the other, to the subject matter and to tradition. In our paper, we are applying the four-openness model of interpretation to genetic consultation, and we argue that during counseling double interpretation takes place: the physician interprets the patient, and the patient interprets the physician. Double interpretation leads to the clarification of those factors which influence the patient's decision-making: the counselor's attitude and prejudices, the counselee's values and needs, the medical, social, and moral implications of the genetic disease, and the social expectations. By adopting the theory of interpretation, counselors can also advance the provision of emotional support patients need in hard situations.

Deuterium and tritium profile through the Vatnajoekull icecap

International Nuclear Information System (INIS)

Arnasson, B.

1974-06-01

During the years 1971-73 a research project was carried out at the Science Institute of the University of Iceland with the financial support of the IAEA. A rotary drill for deep coring in temperate ice has been developed, and a 415 m deep hole was drilled during the summer of 1972 into the temperate accumulation area of the Vatnajoekull glacier, Iceland, at an altitude of 1800 m a.s.l. The core recovery was 99%. The bottom, at 480-500 m depth, was not reached because of a fault in the cable. Detail on the drill is given in: Arnason, Bjoernsson and Theodorsson, J. of Glaciology, 13, 133 (1974). Several volcanic ash layers have been recognized in the ice core and associated with historically known eruptions. This provides the age-depth relationship. Isotopic analyses along the core show that precipitation in the period 1931-1960 is enriched by 5 per mil in deuterium with respect to that in the period 1891-1920, in agreement with the 1degC increase in the mean air temperature occurred from the beginning of the century. Tritium analyses show appreciable isotopic exchange due to water percolation (summer rains and ice melting). The Na + and Cl - content decreases with depth (from 1 μg/g ice to 0.1 μg/g ice). This decrease has been attributed to dissolution of ions in water percolating along the ice crystals. Other studies of the ice core, in progress or planned, include: size and orientation of ice crystals, size and pressure of air bubbles, measurement of F - , SO 4 -- and Hg

Uranium districts defined by reconnaissance geochemistry in South Greenland

International Nuclear Information System (INIS)

Armour-Brown, A.; Steenfelt, A.; Kunzendorf, H.

1983-01-01

A reconnaissance exploration survey over 14 000 km 2 of Precambrian terrain in South Greenland using stream-sediment and stream-water samples delineated a central uranium district of 2000 km 2 with enhanced uranium levels and smaller anomalous zones in the south of the field area. Limited follow-up work located 8 pitchblende occurrences in this extensive district. The pitchblende is in veins which contain quartz, calcite, iron oxide, fluorite and minor sulphides. The isotopic (U-Pb) age of the pitchblende, which ranges from 1180-1090 Ma, corresponds to the late stages of Gardar alkaline igneous activity. It is concluded, therefore, that the reconnaissance geochemistry reflects a district-wide hydrothermal event related to the late volatile differentiates derived from the highly fractionated alkaline magma. A combination of primary and secondary features have complemented each other in enhancing the geochemical reconnaissance data and emphasized its importance but has not materially altered the interpretation. (Auth.)

Unravelling the sulphur isotope systematics of an alkaline magmatic province: implications for REE mineralization and exploration

Science.gov (United States)

Hutchison, W.; Finch, A.; Boyce, A.; Friis, H.; Borst, A. M.; Horsburgh, N. J.

2017-12-01

Some of the world's best alkaline rare earth element (REE) deposits are formed in magmatic systems that are sealed (i.e., those that are autometasomatised and maintain reducing conditions). Conversely, in open systems where oxidizing fluids infiltrate, it is commonly assumed that REE are redistributed over a wider (less concentrated) zone. Sulphur isotope fractionation is sensitive to variations in temperature and redox, and, although sulphide minerals are relatively abundant in alkaline systems, there have been few attempts to test these hypotheses and develop a sulphur isotope proxy for alkaline metasomatism and formation of associated REE deposits. The Gardar Rift Province in southern Greenland was volcanically active in two periods between 1300 and 1100 Ma and is an ideal natural laboratory to explore sulphur isotope systematics because a near-complete alkaline magmatic lineage is exposed. We present new δ34S from across the province with a particular focus on three alkaline systems (Ilímaussaq, Motzfeldt and Ivigtût) that also host major REE deposits. Primitive mafic rocks from regional Gardar dykes and lavas have a restricted range of δ34S between 0 and 3 ‰ and fractional crystallization imparts no observable change in δ34S. In a few cases high-δ34S rocks (>15 ‰) occur when intrusive units have assimilated local sedimentary crust (δ34S = 25 ‰). Most δ34S variation takes place in the roof zones of alkaline intrusions during late-magmatic and hydrothermal stages, and we identify clear differences between the complexes. At Ilímaussaq, where the magmatic series is exceptionally reduced (below QFM buffer), roof zone δ34S remains narrow (0-3 ‰). At Motzfeldt, a more open oxidizing roof zone (MH buffer), δ34S ranges from -12 ‰ in late-stage fluorite veins to +12 ‰ where local crust has been assimilated. Ivigtût is intermediate between these end-members varying between -5 to +5 ‰. The δ34S variations primarily relate to temperature and

Quaternary magnetic excursions recorded in marine sediments.

Science.gov (United States)

Channell, J. E. T.

2017-12-01

This year is the golden (50th) anniversary of the first documentation of a magnetic excursion, the Laschamp excursion in volcanics from the Chaine des Puys (Bonhommet and Babkine, 1967). The first recording of an excursion in sediments was from the Blake Outer Ridge (Smith and Foster, 1969). Magnetic excursions are directional aberrations of the geomagnetic field apparently involving short-lived reversal of the main dipole field. They have durations of a few kyrs, and are therefore rarely recorded in sediments with mean sedimentation rates Palma), and 670 ka (Osaka Bay), implying at least 11 excursions in the Brunhes Chron. For the Matuyama Chron, excursions have been recorded in marine sediments at 868 ka (Kamikatsura?), 932 ka (Santa Rosa), 1051 ka (Intra-Jaramillo), 1115 ka (Punaruu), 1255 ka (Bjorn), 1476 ka (Gardar), 1580 ka (Gilsa), and 2737 ka (Porcupine). Excursions coincide with minima in relative paleointensity (RPI) records. Ages are from correlation of excursion records to oxygen isotope records in the same cores, and ice-volume calibration of the oxygen isotope template. The marine sediment record of excursions, combined with independent documentation of excursions in lavas with Ar/Ar age control, is progressively strengthening our knowledge of the excursion inventory in the Quaternary, and enhancing the importance of excursions and RPI in Quaternary stratigraphy.

Large-scale deep-water seafloor mapping from the Rockall to the Hatton basins, NE Atlantic

Science.gov (United States)

Monteys, X.; Thébaudeau, B.; Murcia, C.; Duncan, N.

2016-02-01

Multibeam data acquired in 2000 and 2001 during the Irish National Seabed Survey (INSS) are used for the first detailed investigation of the seabed geomorphology and sediment type in the Hatton-Rockall basin area of the North East Atlantic Ocean, covering an area of approximately 80,000 km². The original multibeam survey produced bathymetric and backscatter datasets that allowed the creation of a Digital Terrain Models of approximately 50 m in resolution in water depths between 500 and 3500 m. Near-surface sediments for the entire region haven been classified using features derived from multibeam angular backscatter data (12kHz) and robust unsupervised clustering techniques. Additionally, sub bottom data imaging the shallow stratigraphy and geomagnetic measurements collected at the time of the MBES survey are combined to further characterise some of the features identified. The features presented in detail include parts of the Hatton and Gardar contourite drifts, volcanic mounds identified by their morphology and magnetic signature, deep-water coral mounds, iceberg scours as well as canyons, gullies and escarpments along and down the slopes of the banks and mounds. This study highlights for the first time the variety and complexity of the seafloor present at the seabed in the Irish Hatton-Rockall basin area

Uranium occurrences in the Granite Zone

International Nuclear Information System (INIS)

Nyegaard, P.; Armour-Brown, A.

1986-04-01

This report describes the work and results of the South Greenland Exploration Programme (Sydex) during the 1984 field season in the Granite Zone, and discusses the results and conclusions that can be drawn from them. It also contains a structural analysis of the Ivigtut-Julianehaab region, which will help in future exploration by indicating the likely directions of uraniferous faults and fractures. It also includes suggestions for future work with both exploration and scientific aspects. The project was carried out by the Geological Survey Greenland (GGU) in co-operation with Risoe National Laboratory. It was financed by the Danish Ministry of Energy. The structural analysis was carried out using previous geological maps, our own field observations and an analysis of lineament frequencies taken from aerial photographs and satellite images. Major lineaments in the region are due to E-W sinistral wrench faults and NE-SW normal faults. Analysis of the minor lineaments showed that the region could be divided into three blocks which have each reacted differently to the same regional stress field which was active throughout the Gardar period. A northern block which has been influenced by an older system of faults in the Archaean gneiss, a central block dominated by a graben, and a southern block where there is a change to a less intensively faulted area. 2 maps, 27 refs. (EG)

The petrology and petrogenesis of the Swaldale region, Motzfeldt Center, South Greenland

Science.gov (United States)

Reekie, Callum; Finch, Adrian

2016-04-01

Motzfeldt is one of several high-level alkaline plutonic centers that collectively define the mid-Proterozoic Gardar Province of South Greenland. Despite pyrochlore-hosted Ta-enrichment (± Nb-Zr-REE), the petrology, geochemistry and petrogenesis across the center remain to be fully constrained. We present petrological and geochemical data for the Swaldale region, an arcuate band of nepheline syenite and associated intrusives on Motzfeldt's NW margin. Work for this present study was undertaken in collaboration with the license holder, Regency Mines plc. Swaldale comprises two geochemically distinct magmatic members. The largest, the Motzfeldt Sø Formation (MSF; EuN/Eu*N = 0.35), is a suite of diverse syenite variants that show significant petrological and geochemical heterogeneity. These rocks have a relatively restricted SiO2 range (57.4-62.9 wt.%) with concurrent variation in (Na+K)/Al (0.75-0.95), Mg/(Mg+Fe) (2.18-19.82) and ΣREE (595.0-3095.9 ppm), emphasizing their evolved but not peralkaline nature. Fractionation is mirrored by pyroxene geochemistry with evolution from aegirine-augite, aegirine-hedenbergite, to aegirine. Accessory pyrochlore, titanite, and zircon are rare; however, anomalous facies of zircon-rich (~2 wt.%) syenite are observed. Intercumulus fluorite is a common accessory within MSF rocks. Hydrothermal alteration, marked by hematized alkali-feldspar, is pervasive and ubiquitous. Further peraluminous syenite of the Geologfjeld Formation ((Na+K)/Al = 0.74; EuN/Eu*N = 1.60) marks the truncated remnant of an early syenite stock to the north of the MSF. These rocks contain salite, which, in addition to a lower ΣREE and higher Mg/(Mg+Fe) (18.01), demonstrates the less-fractionated nature of this stock in comparison with the MSF. Sheeted intrusions of peralkaline syenite ((Na+K)/Al = 1.1; Ta = 32.4 ppm) truncate the MSF across central Swaldale. On a mineralogical basis, it is hypothesized that such intrusions reflect outward sheeting of the