Spatial variability of phytoplankton absorption coefficients and pigments off Baja California during November 2002

We have estimated the spatial variability of phytoplankton specific absorption coefficients (a* _ph ) in the water column of the California Current System during November 2002, taking into account the variability in pigment composition and phytoplankton community structure and size. Oligotrophic conditions (surface Chl < 0.2 mg m⁻³) dominated offshore, while mesotrophic conditions (surface Chl 0.2 to 2.0 mg m⁻³) where found inshore. The specific absorption coefficient at 440 [a* _ph (440)] ranged from 0.025–0.281 m²mg⁻¹ while at 675 nm [a* _ph (675)] it varied between 0.014 and 0.087 m²mg⁻¹. The implementation of a size index based on HPLC data showed the community structure was dominated by picoplankton. This would reduce the package effect in the variability of a* _ph (675). Normalized a _ph curves were classified in two groups according to their shape, separating all spectra with peaks between 440 and 550 nm as the second group. Most samples in the first group were from surface layers, while the second group were from the deep chlorophyll maximum or deeper. Accessory photoprotective pigments (APP) tended to decrease with depth and accessory photosynthetic pigments (APS) to increase, indicating the importance of photoprotective mechanisms in surface layers and adaptation to low light at depth. Samples with higher ratios of APP:APS (>0.4) were considered as phytoplankton adapted to high irradiances, and lower ratios (<0.26) as adapted to low irradiances. We found a good relationship between APP:APS and a* _ph (440) for the deeper layer (DCM and below), but no clear evidence of the factors causing the variability of a* _ph (440) in the upper layer.     

Meiofauna of the deep Eastern Mediterranean Sea: distribution and abundance in relation to bacterial biomass, organic matter composition and other environmental factors

Quantitative information on the abundance and biomass of metazoan meiofauna was obtained from samples collected at 15 deep-sea stations in the Eastern Mediterranean Sea (533–2400m). Meiofaunal abundance was compared to bacterial biomass and other environmental factors such as the total sedimentary organic matter content, the concentrations of the main biochemical classes of organic compounds (i.e. proteins, carbohydrates and lipids) and to ATP. To estimate the sedimentation potential of primary organic matter, sediment bound chloroplastic pigment equivalents (CPE) were assayed. Meiofaunal density was very low ranging from 4 ind.10cm⁻² (Station A4, 1658m depth) to 290 ind.10cm⁻² (Station A12, 636m depth). Nematodes were the numerically dominant taxon (68% of total meiofauna) and were usually confined to the top 6cm of the sediments. Total meiofaunal biomass ranged from 2.78μgC 10cm⁻² (Station A4) to 598.34μgC 10cm⁻² (Station 15A). There was a significant decrease in the density of metazoan meiofauna with water depth. Bacterial biomass largely dominated the total biomass (as the sum of bacterial and meiofaunal biomass) with an average of 73.2% and accounted for 35.8% of the living biomass (as ATP carbon) whereas meiofaunal biomass accounted only for 6.56%. Bacterial biomass was significantly related to the DNA concentrations of the sediment. A significant correlation between ATP concentration and CPE content was also found. No correlations were found between meiofauna, ATP and CPE, or between meiofauna and bacterial parameters. The significant relationship between meiofaunal density and the ratio of labile organic matter/total organic matter indicates that deep-sea meiofauna inhabiting an extremely oligotrophic environment (such as the Eastern Mediterranean) may be more nutritionally dependent upon the quality than on the quantity of sedimentary organic matter.     

A simple population synthesis model for the continuum of the Seyfert type-2 galaxy Mk 348

The spectral energy distribution of the Seyfert type-2 galaxy Mk 348 is analyzed based on IUE observations and published data. It is found that most of the optical and near-IR flux comes from the underlying galaxy bulge population. The rest of the emission can be fitted by a power law of the formF _v v ^– with =0.6. In order to explain the X-ray emission this power law requires either a change of slope or a cutoff before 2 keV. The possibility that the emission originates in a young star cluster is discussed and a simple population synthesis model for the continuum of the galaxy is presented.     

The role of cultural and creative services in the evaluation of the world urban system

Traditionally, academic evaluation of the world urban system has been based on economic approaches and focused on primary cities. However, the recent convergence between economic and cultural spheres, known in specialist literature as the ‘new economy’ or ‘cognitive–cultural capitalism’, requires the inclusion of secondary cities and cultural parameters, such as creative and cultural services, to obtain knowledge of the world urban system with greater accuracy. Accordingly, the authors have developed the Synthetic Index of Cultural Components (objective 1). Subsequent statistical treatment through a principal component analysis and a cluster analysis not only shows a representation of the multifunctional character of the world urban system (objective 2) but also identifies the cultural specializations that urban planners use to position cities worldwide (objective 3). The results demonstrate that the reputation of a city derives not only from its productive economic character but also from other cultural creative services that give meaning to its multidimensional perspective. The authors conclude that these services are empirically valid when the cultural dimension is measured, as they are illustrative of the cultural mechanisms that help cities to supply symbolic, experiential, and cultural capital, all of which are vital in the competitive context of globalization.     

Multiproxy record for the last 4500 years from Lake Shkodra (Albania/Montenegro)

A multi‐proxy record is presented for approximately the last 4500 cal a BP from Lake Shkodra, Albania/Montenegro. Lithological analyses, C/N ratio and δ¹³C of the organic and inorganic carbon component suggest that organic matter and bulk carbonate are predominantly authigenic. The δ¹⁸O record of bulk carbonate indicates the presence of two prominent wet periods: one at ca. 4300 cal a BP and one at ca. 2500–2000 cal a BP. The latter phase is also found in southern Spain and Central Italy, and represents a prominent event in the western and central Mediterranean. In the last 2000 years, four relatively wet intervals occurred between ca. 1800 and 1500 cal a BP (150–450 AD), 1350–1250 (600–700 AD), 1100–800 (850–1150 AD), and at ca. 90 cal a BP (1860 AD). Between ca. 4100 and 2500 cal a BP δ¹⁸O values are relatively high, with three prominent peaks indicating drier conditions at ca. 4100–4000 cal a BP, ca. 3500 and at ca. 3300 cal a BP. Four additional drier events are identified at 1850 (ca. 100 AD), 1400 (ca. 550 AD), 1150 (800 AD) and ca.750 cal a BP (1200 AD). The pollen record does not show changes in accordance with these episodes owing to the poor sensitivity of vegetation in this area, which is dominated by an orographic rainfall effect and where changes in altitudinal vegetation belts do not affect the pollen rain in the lake catchment. However, since ca. 900 cal a BP a significant decrease in the percentage arboreal pollen and in pollen concentrations suggest major deforestation produced by human activities. Copyright © 2012 John Wiley & Sons, Ltd.     

A tephrostratigraphic record for the last glacial–interglacial cycle from Lake Ohrid,Albania and Macedonia

Here we present a tephrostratigraphic record (core Co1202) recovered from the northeastern part of Lake Ohrid (Republics of Macedonia and Albania) reaching back to Marine Isotope Stage (MIS) 6. Overall ten horizons (OT0702‐1 to OT0702‐10) containing volcanic tephra have been recognised throughout the 14.94 m long sediment succession. Four tephra layers were visible at macroscopic inspection (OT0702‐4, OT0702‐6, OT0702‐8 and OT0702‐9), while the remaining six are cryptotephras (OT0702‐1, OT0702‐2, OT0702‐3, OT0702‐5, OT0702‐7 and OT0702‐10) identified from peaks in K, Zr and Sr intensities, magnetic susceptibility measurements, and washing and sieving of the sediments. Glass shards of tephra layers and cryptotephras were analysed with respect to their major element composition, and correlated to explosive eruptions of Italian volcanoes. The stratigraphy and the major element composition of tephra layers and cryptotephras allowed the correlation of OT0702‐1 to AD 472 or AD 512 eruptions of Somma‐Vesuvius, OT0702‐2 to the FL eruption of Mount Etna, OT0702‐3 to the Mercato from Somma‐Vesuvius, OT0702‐4 to SMP1‐e/Y‐3 eruption from the Campi Flegrei caldera, OT0702‐5 to the Codola eruption (Somma‐Vesuvius or Campi Flegrei), OT0702‐6 to the Campanian Ignimbrite/Y‐5 from the Campi Flegrei caldera, OT0702‐7 to the Green Tuff/Y‐6 eruption from Pantelleria Island, OT0702‐8 to the X‐5 eruption probably originating from the Campi Flegrei caldera, OT0702‐9 to the X‐6 eruption of generic Campanian origin, and OT0702‐10 to the P‐11 eruption from Pantelleria Island. The fairly well‐known ages of these tephra layers and parent eruptions provide new data on the dispersal and deposition of these tephras and, furthermore, allow the establishment of a chronological framework for core Co1202 for a first interpretation of major sedimentological changes. Copyright © 2009 John Wiley & Sons, Ltd.     

Implementation of PhotoZ under Astro-WISE

We describe the implementation of the PhotoZ code in the framework of the Astro-WISE package and as part of the Photometric Classification Server of the PanSTARRS pipeline. Both systems allow the automatic measurement of photometric redshifts for the millions of objects being observed in the PanSTARRS project or expected to be observed by future surveys like KIDS, DES or EUCLID.