613 research outputs found
Small scale distribution patterns and vertical migration of North Sea erring larvae (Clupea harengus, Teleostei: Clupeidae) in relation to abiotic and biotic factors
The distribution of herring larvae in relation to environmental conditions and the occurrence of possible prey and predator organisms was studied during a 4-day period on a permanent station in the northern North Sea in September 1999. The vertical distribution of herring larvae was sampled in 20-m intervals by means of a multiple-closing net. To resolve the small-scale patchiness of herring larvae and planktonic prey and predator organisms, a towed in-situ video system was used, the Ichthyoplankton Recorder. A diel vertical migration of herring larvae was observed with different intensities depending on their body length. Small larvae (16 mm) showed the highest abundances in the upper water layers during the day and were concentrated in deeper water layers during the night. The presented results appear to be relevant for individual-based modelling of the fate of larval herring populations.
La distribución a pequeña escala y la migración vertical de larvas de arenque del Mar del Norte (Clupea harengus, Teleostei: Clupeidea) en relación con factores abióticos y bióticos. – Se han estudiado la distribución de las larvas de arenque en relación a las condiciones ambientales y la incidencia de posibles presas y organismos depredadores a lo largo de un periodo de 4 días en una estación permanente situada en el Mar del Norte en septiembre de 1999. La distribución vertical de las larvas de arenque fue muestreada en intervalos de 20 m mediante una red de apertura múltiple (multiple opening/closing net). Para determinar a pequeña escala la heterogeneidad en la distribución de las larvas de arenque, así como de las presas y depredadores planctónicos, se utilizó un sistema de vídeo in-situ (The Ichthyoplankton Recorder). Se observó una migración vertical nictimeral con diferentes intensidades dependiendo de la longitud corporal de las larvas. Las larvas pequeñas (16 mm) mostraban su mayor abundancia en las capas superiores de la columna de agua durante el día y se concentraban en capas de agua más profundas durante la noche. Los resultados presentados en este trabajo pueden ser relevantes para la modelización (individual based modeling) del destino de las poblaciones de larvas del arenque
Non-Surgical Periodontal Therapy with Adjunctive Amoxicillin/Metronidazole or Metronidazole When No Aggregatibacter actinomycetemcomitans Is Detected-A Randomized Clinical Trial.
BACKGROUND
The aim was to compare two different systemic antibiotics regimens adjunctive to non-surgical periodontal therapy when Aggregatibacter actinomycetemcomitans was not detected in the subgingival biofilm.
METHODS
A total of 58 patients with periodontitis and with no A. actinomycetemcomitans in the subgingival biofilm were treated with full-mouth subgingival instrumentation and either metronidazole (MET; n = 29) or amoxicillin/metronidazole (AMX/MET; n = 29). Probing depth (PD), clinical attachment level (CAL) and bleeding on probing (BOP) were recorded at baseline, as well as after three and six months. Subgingival biofilm and gingival crevicular fluid were collected and analyzed for major periodontopathogens and biomarkers.
RESULTS
PD, CAL and BOP improved at 3 and 6 months (each p < 0.001 vs. baseline) with no difference between the groups. Sites with initial PD ≥ 6 mm also improved in both groups after 3 and 6 months (p < 0.001) with a higher reduction of PD in the AMX/MET group (p < 0.05). T. forsythia was lower in the AMX/MET group after 3 months (p < 0.05). MMP-8 and IL-1β were without significant changes and differences between the groups.
CONCLUSION
When A. actinomycetemcomitans was not detected in the subgingival biofilm, the adjunctive systemic use of amoxicillin/metronidazole results in better clinical and microbiological outcomes of non-surgical periodontal therapy when the application of systemic antibiotics is scheduled
Ramsey numbers for sets of small graphs
AbstractThe Ramsey number r=r(G1-G2-⋯-Gm,H1-H2-⋯-Hn) denotes the smallest r such that every 2-coloring of the edges of the complete graph Kr contains a subgraph Gi with all edges of one color, of a subgraph Hi with all edges of a second color. These Ramsey numbers are determined for all sets of graphs with at most four vertices, and in the diagonal case (m=n,Gi=Hi) for all pairs of graphs, one with at most four and the other with five vertices, so as for all sets of graphs with five vertices
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Aerosol properties over Southeastern China from multi-wavelength Raman and depolarization lidar measurements
A dataset of particle optical properties of highly polluted urban aerosol over the Pearl River Delta, Guangzhou, China is presented. The data were derived from multi-wavelengths Raman and depolarization lidar PollyXT and AERONET sun photometer measurements. The measurement campaign was conducted from Nov 2011 to June 2012. High aerosol optical depth was observed in the polluted atmosphere over this megacity, with a mean value of 0.54 ± 0.33 and a peak value of even 1.9. For the particle characterization the lidar ratio and the linear particle depolarization ratio, both at 532 nm, were used. The mean values of these properties are 48.0 sr ± 10.7 sr for the lidar ratio and 4%+-4% for the particle depolarization ratio, which means most depolarization measurements stayed below 10%. So far, most of these results indicate urban pollution particles mixed with particles arisen from biomass and industrial burning
Physical Activity Levels and Domains Assessed by Accelerometry in German Adolescents from GINIplus and LISAplus
Background Physical activity (PA) is a well-known and underused protective factor for numerous health outcomes, and interventions are hampered by lack of objective data. We combined accelerometers with diaries to estimate the contributions to total activity from different domains throughout the day and week in adolescents. Methods Accelerometric and diary data from 1403 adolescents (45% male, mean age 15.6 +/- 0.5 years) were combined to evaluate daily levels and domains of sedentary, light, and moderate- to-vigorous activity (MVPA) during a typical week. Freedson's cutoff points were applied to determine levels of activity. Total activity was broken down into school physical education (PE), school outside PE, transportation to school, sport, and other time. Results About 2/3 of adolescents' time was spent sedentary, 1/3 in light activity, and about 5% in MVPA. Boys and girls averaged 46 (SD 22) and 38 (23) minutes MVPA per day. Adolescents were most active during leisure sport, spending about 30% of it in MVPA, followed by PE (about 20%) transport to school (14%) and either school class time or other time (3%). PE provided 5% of total MVPA, while leisure sport provided 16% and transportation to school 8%. School was the most sedentary part of the day with over 75% of time outside PE spent sedentary. Conclusions These German adolescents were typical of Europeans in showing low levels of physical activity, with significant contributions from leisure sport, transportation and school PE. Leisure sport was the most active part of the day, and participation did not vary significantly by sex, study center (region of Germany) or BMI. Transportation to school was frequent and thus accounted for a significant fraction of total MVPA. This indicates that even in a population with good access to dedicated sporting activities, frequent active transportation can add significantly to total MVPA
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Central Asian Dust Experiment (CADEX): Multiwavelength polarization Raman lidar observations in Tajikistan
For the first time lidar measurements of vertical aerosol profiles are conducted in Tajikistan/Central Asia. These measurements just started on March 17th, 2015. They are performed within the Central Asian Dust Experiment (CADEX) in Dushanbe and they will last at least one year. The deployed system for these observations is an updated version of the multiwavelength polarization Raman lidar PollyXT. Vertical profiles of the backscatter coefficient, the extinction coefficient, and the particle depolarization ratio are measured by this instrument. A first and preliminary measurement example of an aerosol layer over Dushanbe is shown
Renormalization Flow of Axion Electrodynamics
We study the renormalization flow of axion electrodynamics, concentrating on
the non-perturbative running of the axion-photon coupling and the mass of the
axion (like) particle. Due to a non-renormalization property of the
axion-photon vertex, the renormalization flow is controlled by photon and axion
anomalous dimensions. As a consequence, momentum-independent axion
self-interactions are not induced by photon fluctuations. The non-perturbative
flow towards the ultraviolet exhibits a Landau-pole-type behavior, implying
that the system has a scale of maximum UV extension and that the renormalized
axion-photon coupling in the deep infrared is bounded from above. Even though
gauge invariance guarantees that photon fluctuations do not decouple in the
infrared, the renormalized couplings remain finite even in the deep infrared
and even for massless axions. Within our truncation, we also observe the
existence of an exceptional RG trajectory, which is extendable to arbitrarily
high scales, without being governed by a UV fixed point.Comment: 12 pages, 4 figure
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