3,489 research outputs found
Characterization of a Second Bovine Rotavirus Serotype
Bovine rotavirus (BRV) V 1005 was characterized by two-way cross-neutralization tests as a second serotype of BRV. Virions and inner shell particles of 65 nm and 55 nm diameter respectively, and empty capsids of 65 nm and 55 nm diameter were separated by density gradient centrifugation. Three polypeptides of molecular weight 60,000, 36,000 and 28,000 (minor protein) could be identified in the outer shell of virions and in the larger empty capsids. Inner shell particles contained three polypeptides of molecular weight 105,000, 83,000 and 43,000. Both sizes of empty capsids showed two polypeptides of molecular weight 75,000 and 55,000 not found in virions. Pulse-labelling of infected cells revealed eight major and three minor intracellular viral polypeptides. Viral polypeptide synthesis started at about 6 hours p.i. and correlated in time with double-stranded RNA synthesis. As soon as viral polypeptide synthesis was detectable, newly synthesized viral polypeptides were incorporated into intracellular viral particles. Radioactive viral polypeptides appeared without a longer lag period in extracellular viruses from 6 hours p.i. onward
A modelling approach for allocating land-use in space to maximise social welfare - exemplified on the problem of wind power generation
Land-use conflicts arise if land is scarce, land-use types are mutually exclusive, and vary in their effects with regard to more than one incongruent policy objective. If these effects depend on the spatial location of the land-use measures the conflict can be mediated through an appropriate spatial allocation of land use. An example of this conflict is the welfare-optimal allocation of wind turbines (WT) in a region in order to achieve a given energy target at least social costs. The energy target is motivated by the fact that wind power production is associated with relatively low CO2 emissions and is currently the most efficient source of renewable energy supply. However, it is associated with social costs which comprise energy production costs as well as external costs caused by harmful impacts on humans and biodiversity. We present a modelling approach that combines spatially explicit ecological-economic modelling and choice experiments to determine the welfare-optimal spatial allocation of WT in Western Saxony, Germany. We show that external costs are significant. The welfare-optimal sites are therefore not those with the highest energy output (i.e., lowest production costs). However, they show lower external costs than the most productive sites. A sensitivity analysis reveals that the external costs represent about seven percent of the total costs (production costs plus external costs). Increasing the energy production target increases both production and external costs. The absolute (percentage) increase of production costs is higher (lower) than that of external costs. --choice experiment,ecological-economic modelling,externality,spatial allocation,welfare-optimal,wind power
EinfluĂ der Konservierungszeit auf die Konzentration mehrfach ungesĂ€ttigter FettsĂ€uren in Erythrozytenkonzentraten: Implikationen fĂŒr den endotoxin-induzierten akuten Lungenschaden in vivo
A Distributed Public Key Infrastructure Based on Threshold Cryptography for the HiiMap Next Generation Internet Architecture
In this article, a security extension for the HiiMap Next Generation Internet Architecture is presented. We regard a public key infrastructure which is integrated into the mapping infrastructure of the locator/identifier-split addressing scheme. The security approach is based on Threshold Cryptography which enables a sharing of keys among the mapping servers. Hence, a more trustworthy and fair approach for a Next Generation Internet Architecture as compared to the state of the art approach is fostered. Additionally, we give an evaluation based on IETF AAA recommendations for security-related systems
Berufsbedingte MultilokalitÀt - Zweitwohnsitzpotenziale als neue Aspekte der Stadtentwicklung
In den letzten Jahrzehnten hat die Zahl der Berufspendler stetig zugenommen. WĂ€hrend das Pendeln durch die amtliche Statistik ausreichend erfasst ist, existiert nur eine unzureichende
Datengrundlage zur Messung der Anzahl von berufsbedingten Zweitwohnungen (residenzielle MultilokalitĂ€t) in Deutschland. Der explorativ entwickelte Wohn- und MobilitĂ€tskostenrechner (WoMoKoR) berechnet daher den Anteil der Tagespendler, fĂŒr die sich theoretisch eine Zweitwohnung am Arbeitsort aus ökonomisch-monetĂ€rer Sicht lohnen wĂŒrde. Auf Basis eines Kostenvergleichs zwischen dem tĂ€glichen Pendeln und einer Zweitwohnung am Arbeitsort wird der Schnittpunkt beider Kostenfunktionen (Kritische Pendeldistanz) identifiziert und die Anzahl an potenziellen Zweitwohnungen fĂŒr den Untersuchungsraum Nordrhein-Westfalen (NRW) bestimmt. Auf Grundlage der Ergebnisse wird im Beitrag Stellung zu möglichen Folgen der ermittelten Potenziale fĂŒr die Stadtentwicklung genommen. Mit Bezug auf die Neuen Leitbilder der Raumordnung werden strategische Handlungsempfehlungen zum Umgang mit den beschriebenen Folgen und Potenzialen abgeleitet.Over the last two decades, the number of commuters has increased steadily. While commuting is adequately covered by official statistics, there is a lack of statistical data base for measuring the quantity of job-related second homes (residential multilocality) in Germany. Therefore the explorative developed residential and mobility cost calculator (WoMoKoR) calculates the proportion of daily commuters for which a second home
would be the rational choice. On basis of a cost comparison between the cost of daily commuting and a second home at the place of work the WoMoKoR identifies the intersection of the two cost functions (critical commuting distance) and determines the quantity of potential second homes for the research area of North Rhine-Westphalia (NRW). Based on the theoretical results, the article deals with possible consequences as a result of the identified second home potential for urban development. Referring to the new overall concepts of regional planning policy, multilocality is discussed and strategic recommendations are derived
Assessing handheld mobile laser scanners for forest surveys
Abstract: A handheld mobile laser scanning (HMLS) approach to forest inventory surveying allows virtual reconstructions of forest stands and extraction of key structural parameters from beneath the canopy, significantly reducing survey time when compared against static laser scan and fieldwork methods. A proof of concept test application demonstrated the ability of this technique to successfully extract diameter at breast height (DBH) and stem position compared against a concurrent terrestrial laser scan (TLS) survey. When stems with DBH > 10 cm are examined, an HMLS to TLS modelling success rate of 91% was achieved with the root mean square error (RMSE) of the DBH and stem position being 1.5 cm and 2.1 cm respectively. The HMLS approach gave a survey coverage time per surveyor of 50 m 2/min compared with 0.85 m2/min for the TLS instrument and 0.43 m2/min for the field study. This powerful tool has potential applications in forest surveying by providing much larger data sets at reduced operational costs to current survey methods. HMLS provides an efficient, cost effective, versatile forest surveying technique, which can be conducted as easily as walking through a plot, allowing much more detailed, spatially extensive survey data to be collected
\u3ci\u3eIn-situ\u3c/i\u3e-Investigation of Enzyme Immobilization on Polymer Brushes
Herein, we report on the use of a combined setup of quartz-crystal microbalance, with dissipation monitoring and spectroscopic ellipsometry, to comprehensively investigate the covalent immobilization of an enzyme to a polymer layer. All steps of the covalent reaction of the model enzyme glucose oxidase with the poly(acrylic acid) brush by carbodiimide chemistry, were monitored in-situ. Data were analyzed using optical and viscoelastic modeling. A nearly complete collapse of the polymer chains was found upon activation of the carboxylic acid groups with N-(3-Dimethylaminopropyl)-NâČ-ethylcarbodiimide and N-Hydroxysuccinimide. The reaction with the amine groups of the enzyme occurs simultaneously with re-hydration of the polymer layer. Significantly more enzyme was immobilized on the surface compared to physical adsorption at similar conditions, at the same pH. It was found that the pH responsive swelling behavior was almost not affected by the presence of the enzyme
Geodesic distance for right invariant Sobolev metrics of fractional order on the diffeomorphism group
We study Sobolev-type metrics of fractional order on the group
\Diff_c(M) of compactly supported diffeomorphisms of a manifold . We show
that for the important special case the geodesic distance on
\Diff_c(S^1) vanishes if and only if . For other manifolds we
obtain a partial characterization: the geodesic distance on \Diff_c(M)
vanishes for and for ,
with being a compact Riemannian manifold. On the other hand the geodesic
distance on \Diff_c(M) is positive for and
.
For we discuss the geodesic equations for these metrics. For
we obtain some well known PDEs of hydrodynamics: Burgers' equation for ,
the modified Constantin-Lax-Majda equation for and the
Camassa-Holm equation for .Comment: 16 pages. Final versio
Effects of deer on woodland structure revealed through terrestrial laser scanning
1. Terrestrial laser scanning (TLS) captures the three-dimensional structure of habitats. Compared to traditional methods of forest mensuration, it allows quantification of structure at increased resolution, and the derivation of novel metrics with which to inform ecological studies and habitat management.
2. Lowland woodlands in the UK have altered in structure over the last century due to increased abundance of deer and a decline in management. We compared whole-canopy profiles between woodlands with high (>10 deer kmâ2) and low deer density (c. 1 deer kmâ2), and in stands with and without records of management interventions in the last 20 years, providing a test case for the application of TLS in habitat assessment for conservation and management.
3. Forty closed-canopy lowland woodlands (height range 16·5â29·4 m) were surveyed using TLS in two regions of the UK, divided into areas of high- and low-deer abundance, and between plots which had been recently managed or were unmanaged. Three-dimensional reconstructions of the woodlands were created to document the density of foliage and stem material across the entire vertical span of the canopy.
4. There was a 68% lower density of understorey foliage (0·5â2 m above-ground) in high-deer woodlands, consistent in both regions. Despite this, total amounts of foliage detected across the full canopy did not differ between deer density levels. High-deer sites were 5 m taller overall and differed in the distribution of foliage across their vertical profile. Managed woodlands, in contrast, exhibited relatively minor differences from controls, including a lower quantity of stem material at heights from 2 to 5 m, but no difference in foliage density. All main effects were replicated equally in both regions despite notable differences in stand structures between them.
5. Synthesis and applications. Terrestrial laser scanning allows ecologists to move beyond two-dimensional measures of vegetation structure and quantify patterns across complex, heterogeneous, three-dimensional habitats. Our findings suggest that reduction of deer populations is likely to have a strong impact on woodland structures and aid in restoring the complex understorey habitats required by many birds, whereas management interventions as currently practiced have limited and inconsistent effects
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