Characterization of distributed Raman amplification-induced amplitude and phase impairments on unrepeated coherent transmission links

We experimentally characterize the distributed Raman amplification induced amplitude and phase impairments and evaluate the performance dependence of unrepeated 28 Gbaud 16QAM coherent transmissions over standard single mode fiber.

Dimensioning RS codes for mitigation of phase noise induced cycle slips in DQPSK systems

We present a semi-analytical method for dimensioning Reed-Solomon codes for coherent DQPSK systems with laser phase noise and cycle slips. We evaluate the accuracy of our method for a 28 Gbaud system using numerical simulations.

Novel BCH code design for mitigation of phase noise induced cycle slips in DQPSK systems

We show that by proper code design, phase noise induced cycle slips causing an error floor can be mitigated for 28 Gbaud DQPSK systems. Performance of BCH codes are investigated in terms of required overhead. © 2014 OSA.

Vector solitons in mode locked fibre lasers

We overview our recent results on polarisation dynamics of vector solitons in erbium doped fibre laser mode locked with carbon nanotubes. Our experimental and theoretical study revealed new families of vector solitons for fundamental and bound-state soliton operations. The observed scenario of the evolution of the states of polarisation (SOPs) on the Poincare sphere includes fast polarisation switching between two and three SOPs along with slow SOP evolution on a double scroll chaotic attractor. The underlying physics presents an interplay between effects of birefringence of the laser cavity and light induced anisotropy caused by polarisation hole burning. © 2014 IEEE.

Mitigation of EEPN in long-haul n-PSK coherent transmission system using modified optical pilot carrier

We present the compensation of the equalization enhanced phase noise (EEPN) in the long-haul n-level phase shift keying (n-PSK) coherent optical transmission system, by employing a scheme of phase modulated optical pilot carrier. © OSA 2013.

Analysis of carrier phase extraction methods in 112-Gbit/s NRZ-PDM-QPSK coherent transmission system

We present a comparative analysis on three carrier phase extraction approaches, including a one-tap normalized least mean square method, a block-average method, and a Viterbi-Viterbi method, in coherent transmission system considering equalization enhanced phase noise. © OSA 2012.

Influence of digital dispersion equalization on phase noise enhancement in coherent optical system

The phase noise enhancement due to digital dispersion equalization is investigated, which indicates that the phase noise from transmitter laser can also interact with the dispersion depending on the choice of digital dispersion compensation methods. © OSA 2012.

Methane and stable isotope record of ice core EDML from Dronning Maud Land, Antarctica

Precise knowledge of the phase relationship between climate changes in the two hemispheres is a key for understanding the Earth's climate dynamics. For the last glacial period, ice core studies have revealed strong coupling of the largest millennial-scale warm events in Antarctica with the longest Dansgaard-Oeschger events in Greenland through the Atlantic meridional overturning circulation. It has been unclear, however, whether the shorter Dansgaard-Oeschger events have counterparts in the shorter and less prominent Antarctic temperature variations, and whether these events are linked by the same mechanism. Here we present a glacial climate record derived from an ice core from Dronning Maud Land, Antarctica, which represents South Atlantic climate at a resolution comparable with the Greenland ice core records. After methane synchronization with an ice core from North Greenland, the oxygen isotope record from the Dronning Maud Land ice core shows a one-to-one coupling between all Antarctic warm events and Greenland Dansgaard-Oeschger events by the bipolar seesaw. The amplitude of the Antarctic warm events is found to be linearly dependent on the duration of the concurrent stadial in the North, suggesting that they all result from a similar reduction in the meridional overturning circulation.

Data compilation on the biological response to ocean acidification: environmental and experimental context of data sets and related literature

The exponential growth of studies on the biological response to ocean acidification over the last few decades has generated a large amount of data. To facilitate data comparison, a data compilation hosted at the data publisher PANGAEA was initiated in 2008 and is updated on a regular basis (doi:10.1594/PANGAEA.149999). By January 2015, a total of 581 data sets (over 4 000 000 data points) from 539 papers had been archived. Here we present the developments of this data compilation five years since its first description by Nisumaa et al. (2010). Most of study sites from which data archived are still in the Northern Hemisphere and the number of archived data from studies from the Southern Hemisphere and polar oceans are still relatively low. Data from 60 studies that investigated the response of a mix of organisms or natural communities were all added after 2010, indicating a welcomed shift from the study of individual organisms to communities and ecosystems. The initial imbalance of considerably more data archived on calcification and primary production than on other processes has improved. There is also a clear tendency towards more data archived from multifactorial studies after 2010. For easier and more effective access to ocean acidification data, the ocean acidification community is strongly encouraged to contribute to the data archiving effort, and help develop standard vocabularies describing the variables and define best practices for archiving ocean acidification data.

Location and ages of terrestrial peatlands located on continental shelves and in coastal sediments

This synthesis dataset contains records of freshwater peat and lake sediments from continental shelves and coastal areas. Information included is site location (when available), thickness and description of terrestrial sediments as well as underlying and overlying sediments, dates (when available), and references.

Suspended paticulate matter and respiration experiments of Laternula elliptica in Potter Cove, King George Island, Western Antarctic Peninsula

Recent rapid changes of air temperature on the western side of the Antarctic Peninsula results in increased sediment discharge and ice scouring frequencies in coastal regions. These changes are bound to especially affect slow growing, sessile filter feeders such as the Antarctic bivalve, Laternula elliptica, a long-lived and abundant key species with circumpolar distribution. We investigated the effect of sedimentation and ice scouring on small/young and large/old individuals at two closely located stations, distinctly influenced by both types of disturbance. Small individuals dealt better with disturbance in terms of their respiratory response to sediment exposure, reburrowing ability, and survival after injury, compared to larger animals. At the more disturbed station L. elliptica population density was lower, but larger animals reburrowed faster after iceberg disturbance and reduced their metabolic rate under strong sediment coverage, compared to larger animals of the less disturbed station, indicating that an adaptation or learning response to both types of disturbance may be possible. Smaller individuals were not influenced. Laternula elliptica seems capable of coping with the rapidly changing environmental conditions. Due to a decrease in population density and mean population lifespan, L. elliptica could however lose its key role in the bentho-pelagic carbon flux in areas of high sediment deposition.

Detección precoz de trastornos del comportamiento alimentario. Dos variables: adolescencia y estilo educativo familiar

Bastantes años de práctica de la psicología educativa-comunitaria y especialmente en sus aspectos preventivos y de intervención familiar, hacen plantearse multitud de dudas que no siempre la ciencia escrita consultada resuelve de manera satisfactoria. Es difícil trabajar directamente con los adolescentes sobre los factores de riesgo de padecer TCA, por iatrogenia, pero cuando se actúa con los padres, podríamos conseguir disminuir o impedir, de manera preventiva, padecer este trastorno, sobre todo después de una detección precoz a través de sus factores de riesgo. Así, la hipótesis fundamental planteada es: la información y formación temprana a las familias sobre el desarrollo físico, emocional, social…, las estrategias educativas y de aprendizaje, el cambio y manejo de comportamientos y los criterios básicos en el establecimiento de normas y límites, podrán motivar cambio de actitud y generar estilos educativos que favorecerán la aparición de factores de protección, no solo respecto a los TCA, sino también a otras problemáticas derivadas de la crisis adolescente.. Desde la psicología comunitaria (Smetana, Campione-Barr, y Metzger, 2006) es necesario ajustar los criterios de lo que significa buena investigación en la práctica y tener claro que el objetivo es saber si la práctica implantada se ha hecho según lo previsto, se mantiene en el tiempo y los factores de sostenibilidad que hay que tener en cuenta. (Hoagwood y Johnson, 2003). Las intervenciones según el modelo de salud bio-psico-social (OMS, 1989), están íntimamente relacionadas con lo que las personas hacen, en el medio en el que normalmente se desenvuelven y con los recursos con los que cuentan (Bronfrenbenner, 2005; Tudge, Mokrova, Hatfield y Karnik, 2009). Con estos presupuestos, parece claro, que ni la familia, ni la institución educativa, ni la institución sanitaria por sí solas tienen la respuesta a tan complejas situaciones y es desde el trabajo multidisciplinar desde donde hay que abordarlas (Fernández y Vidal, 2008; Hombrados, 2013). Puede existir un desequilibrio durante la pubertad entre las áreas relacionadas con el proceso emocional y la corteza prefrontal. Este desajuste temporal puede contribuir a la desregulación emocional y un posterior riesgo de sufrir patologías, en muchos casos (Dahl y Gunnar, 2009; Ladouceur, 2012)...

Spatial organisation of groundwater dynamics and streamflow response from different hydropedological units in a montane catchment

Funding was provided by the Leibniz Association (SAW-2012-IGB 4167) within the International Leibniz Graduate School: Aquatic boundaries and linkages- Aqualink. We would like to thank the NRI staff for their help during field work.