1,404 research outputs found

    SAM 2 balloon test (stratospheric aerosol measurement)

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    As a parallel effort to the LACATE balloon experiment a small optical system was constructed to enable a balloon test of a diode filter system similar to the type planned for the Nimbus-G SAM II experiment. The system was called the SAM II Balloon Test. Results of the balloon flight are summarized

    SAM-2 ground-truth plan: Correlative measurements for the Stratospheric Aerosol Measurement-2 (SAM 2) sensor on the Nimbus G satellite

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    The SAM-2 will fly aboard the Nimbus-G satellite for launch in the fall of 1978 and measure stratospheric vertical profiles of aerosol extinction in high latitude bands. The plan gives details of the location and times for the simultaneous satellite/correlative measurements for the nominal launch time, the rationale and choice of the correlative sensors, their characteristics and expected accuracies, and the conversion of their data to extinction profiles. The SAM-2 expected instrument performance and data inversion results are presented. Various atmospheric models representative of polar stratospheric aerosols are used in the SAM-2 and correlative sensor analyses

    Impact and collisional processes in the solar system

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    As impact cratered terrains have been successively recognized on certain planets and planetary satellites, it has become clear that impact processes are important to the understanding of the accretion and evolution of all solid planets. The noble gases in the normalized atmospheric inventories of the planets and the normalized gas content of meteorites are grossly similar, but demonstrate differences from each other which are not understood. In order to study shock devolatilization of the candidate carrier phases which are principally thought to be carbonaceous or hydrocarbons in planetesimals, experiments were conducted on noble gase implantation in various carbons: carbon black, activated charcoal, graphite, and carbon glass. These were candidate starting materials for impact devolatilization experiments. Initial experiments were conducted on vitreous amorphous carbon samples which were synthesized under vapor saturated conditions using argon as the pressurizing medium. An amino acid and surface analysis by laser ionization analyses were performed on three samples of shocked Murchison meteorite. A first study was completed in which a series of shock loading experiments on a porous limestone and on a non-porous gabbro in one and three dimensions were performed. Also a series of recovery experiments were conducted in which shocked molten basalt a 1700 C is encapsulated in molybdenum containers and shock recovered from up to 6 GPa pressures

    Predicting spatial spread of rabies in skunk populations using surveillance data reported by the public

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    Background: Prevention and control of wildlife disease invasions relies on the ability to predict spatio-temporal dynamics and understand the role of factors driving spread rates, such as seasonality and transmission distance. Passive disease surveillance (i.e., case reports by public) is a common method of monitoring emergence of wildlife diseases, but can be challenging to interpret due to spatial biases and limitations in data quantity and quality. Methodology/Principal findings: We obtained passive rabies surveillance data from dead striped skunks (Mephitis mephitis) in an epizootic in northern Colorado, USA. We developed a dynamic patch-occupancy model which predicts spatio-temporal spreading while accounting for heterogeneous sampling. We estimated the distance travelled per transmission event, direction of invasion, rate of spatial spread, and effects of infection density and season. We also estimated mean transmission distance and rates of spatial spread using a phylogeographic approach on a subsample of viral sequences from the same epizootic. Both the occupancy and phylogeographic approaches predicted similar rates of spatio-temporal spread. Estimated mean transmission distances were 2.3 km (95% Highest Posterior Density (HPD95): 0.02, 11.9; phylogeographic) and 3.9 km (95% credible intervals (CI95): 1.4, 11.3; occupancy). Estimated rates of spatial spread in km/year were: 29.8 (HPD95: 20.8, 39.8; phylogeographic, branch velocity, homogenous model), 22.6 (HPD95: 15.3, 29.7; phylogeographic, diffusion rate, homogenous model) and 21.1 (CI95: 16.7, 25.5; occupancy). Initial colonization probability was twice as high in spring relative to fall. Conclusions/Significance: Skunk-to-skunk transmission was primarily local (< 4 km) suggesting that if interventions were needed, they could be applied at the wave front. Slower viral invasions of skunk rabies in western USA compared to a similar epizootic in raccoons in the eastern USA implies host species or landscape factors underlie the dynamics of rabies invasions. Our framework provides a straightforward method for estimating rates of spatial spread of wildlife diseases

    ANALISA FAKTOR-FAKTOR PENCETUS DERAJAT SERANGAN ASMA PADA PENDERITA ASMA DI PUSKESMAS PERAK KABUPATEN JOMBANG TAHUN 2013

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    Asma merupakan gangguan pada saluran bronchial dimana penyakit ini dapat disebabkan oleh banyak faktor. Prevalensi dari penyakit ini meningkat dari tahun ke tahun. Di Indonesia prevalensi asma belum diketahui secara pasti namun diperkirakan 2-5% penduduk Indonesia menderita asma. Di Jawa Timur sendiri prevalensi asma mencapai 2,62%. Asma dicetuskan beberapa faktor diantaranya: alergen, aktivitas fisik, stres dan lain-lain. Tujuan penelitian ini adalah untuk menganalisa faktor-faktor pencetus derajat serangan asma di Puskesmas Perak Kabupaten Jombang tahun 2013. Metode penelitian menggunakan deskriptif analitik dengan pendekatan retrospektif. Populasi dalam penelitian ini adalah semua pengunjung penderita asma sebanyak 91 responden. Pemilihan sampel dilakukan secara Simple Random Sampling sebanyak 74 responden. Pengumpulan data menggunakan kuisioner dan data dianalisis dengan uji Mann-Whitney dan uji Spearman Rho. Hasil uji Mann-Whitney didapatkan nilai p value 0,002 yang menunjukkan hubungan faktor alergen dengan derajat serangan asma, dan hasil uji Spearman Rho didapatkan nilai p value 0,000 yang menunjukkan hubungan faktor aktivitas fisik dengan derajat serangan asma, dimana nilai 0,000 lebih kecil dari 0,005. Faktor-faktor pencetus derajat serangan asma menentukan tingkat serangan asma pada penderita asma itu sendiri. Dengan seringnya penderita terpapar dengan pencetus-pencetus tersebut maka serangan asma penderita akan sering terjadi berulang. Oleh karena itu diharapkan penderita untuk selalu menghindari faktor pencetus serangan asma dimana dari hasil penelitian faktor yang lebih dominan adalah faktor aktivitas fisik.   Kata Kunci: Pencetus Asma, Derajat, Serangan Asma &nbsp

    On a three-body confinement force in hadron spectroscopy

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    Recently it has been argued that a three-body colour confinement interaction can affect the stability condition of a three-quark system and the spectrum of a tetraquark described by any constituent quark model. Here we discuss the role of a three-body colour confinement interaction in a simple quark model and present some of its implications for the spectra of baryons, tetraquarks and six-quark systems.Comment: 19 pages (RevTeX), addition of new material regarding the NN interaction, more accurate discussion of the baryonic case, accepted for publication in Phys. Rev.

    The Nucleon-Nucleon Interaction in a Chiral Constituent Quark Model

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    We study the short-range nucleon-nucleon interaction in a chiral constituent quark model by diagonalizing a Hamiltonian comprising a linear confinement and a Goldstone boson exchange interaction between quarks. The six-quark harmonic oscillator basis contains up to two excitation quanta. We show that the highly dominant configuration is s4p2[42]O[51]FS>\mid s^4p^2[42]_O [51]_{FS}> due to its specific flavour-spin symmetry. Using the Born-Oppenheimer approximation we find a strong effective repulsion at zero separation between nucleons in both 3S1^3S_1 and 1S0^1S_0 channels. The symmetry structure of the highly dominant configuration implies the existence of a node in the S-wave relative motion wave function at short distances. The amplitude of the oscillation of the wave function at short range will be however strongly suppressed. We discuss the mechanism leading to the effective short-range repulsion within the chiral constituent quark model as compared to that related with the one-gluon exchange interaction.Comment: 31 pages, LaTe

    Variation in host home range size decreases rabies vaccination effectiveness by increasing the spatial spread of rabies virus

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    Animal movement influences the spatial spread of directly transmitted wildlife disease through host-host contact structure. Wildlife disease hosts vary in home range- associated foraging and social behaviours, which may increase the spread and intensity of disease outbreaks. The consequences of variation in host home range movement and space use on wildlife disease dynamics are poorly understood, but could help to predict disease spread and determine more effective disease management strategies. We developed a spatially explicit individual-based model to examine the effect of spatiotemporal variation in host home range size on the spatial spread rate, persistence and incidence of rabies virus (RABV) in raccoons (Procyon lotor). We tested the hypothesis that variation in home range size increases RABV spread and decreases vaccination effectiveness in host populations following pathogen invasion into a vaccination zone. We simulated raccoon demography and RABV dynamics across a range of magnitudes and variances in weekly home range size for raccoons. We examined how variable home range size influenced the relative effectiveness of three components of oral rabies vaccination (ORV) programmes targeting raccoons—timing and frequency of bait delivery, width of the ORV zone and proportion of hosts immunized. Variability in weekly home range size increased RABV spread rates by 1.2-fold to 5.2-fold compared to simulations that assumed a fixed home range size. More variable host home range sizes decreased relative vaccination effectiveness by 71% compared to less variable host home range sizes under conventional vaccination conditions. We found that vaccination timing was more influential for vaccination effectiveness than vaccination frequency or vaccination zone width. Our results suggest that variation in wildlife home range movement behaviour increases the spatial spread and incidence of RABV. Our vaccination results underscore the importance of prioritizing individual-level space use and movement data collection to understand wildlife disease dynamics and plan their effective control and elimination

    Final report on accomplishments of a Task Force on Campus Bridging sponsored workshop: Campus Leadership Engagement in Building a Coherent Campus Cyberinfrastructure

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    In 2010, the National Science Foundation (NSF) awarded a grant of $49,840 to the University of North Carolina Chapel Hill to organize a workshop on the topic of campus cyberinfrastructure with the title “Campus Bridging Taskforce Sponsored Workshop: Campus Leadership Engagement in Building a Coherent Campus Cyberinfrastructure.” This report discusses the contents of the full workshop report to the NSF as well as the accomplishments and outcomes reported via the NSF’s online reporting system.This material is based upon work supported by the National Science Foundation (NSF) under Grant No. 1059812 to the University of North Carolina at Chapel Hill, with Patrick Dreher as principal investigator and Craig Stewart, James Pepin, Guy Almes, and Michael Mundrane as co-principal investigators. Stewart’s involvement was supported by the Indiana University Pervasive Technology Institute, which is supported in part by the Lilly Endowment, Inc. (a private charitable trust). Any opinions, findings and conclusions, or recommendations expressed in this material are those of the author(s), and do not necessarily reflect the views of the NSF or the Lilly Endowment
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