Ice characteristics, and mercury content of ice, air and underlying seawater in the eastern Beaufort Sea

The Arctic sea-ice environment has been undergoing dramatic changes in the past decades; to which extent this will affect the deposition, fate, and effects of chemical contaminants remains virtually unknown. Here, we report the first study on the distribution and transport of mercury (Hg) across the ocean-sea-ice-atmosphere interface in the Southern Beaufort Sea of the Arctic Ocean. Despite being sampled at different sites under various atmospheric and snow cover conditions, Hg concentrations in first-year ice cores were generally low and varied within a remarkably narrow range (0.5-4 ng/L), with the highest concentration always in the surface granular ice layer which is characterized by enriched particle and brine pocket concentration. Atmospheric Hg depletion events appeared not to be an important factor in determining Hg concentrations in sea ice except for frost flowers and in the melt season when snowpack Hg leaches into the sea ice. The multiyear ice core showed a unique cyclic feature in the Hg profile with multiple peaks potentially corresponding to each ice growing/melting season. The highest Hg concentrations (up to 70 ng/L) were found in sea-ice brine and decrease as the melt season progresses. As brine is the primary habitat for microbial communities responsible for sustaining the food web in the Arctic Ocean, the high and seasonally changing Hg concentrations in brine and its potential transformation may have a major impact on Hg uptake in Arctic marine ecosystems under a changing climate.

Sea-suface microlayer (SML) and underlying water (ULW) samples focusing on CDOM spectral characteristics during METEOR cruise M91

The coastal upwelling system off the coast of Peru is characterized by high biological activity and a pronounced subsurface oxygen minimum zone, as well as associated emissions of atmospheric trace gases such as N2O, CH4 and CO2. From 3 to 23 December 2012, R/V Meteor (M91) cruise took place in the Peruvian upwelling system between 4.59 and 15.4°S, and 82.0 to 77.5°W. During M91 we investigated the composition of the sea-surface microlayer (SML), the oceanic uppermost boundary directly subject to high solar radiation, often enriched in specific organic compounds of biological origin like chromophoric dissolved organic matter (CDOM) and marine gels. In the SML, the continuous photochemical and microbial recycling of organic matter may strongly influence gas exchange between marine systems and the atmosphere. We analyzed SML and underlying water (ULW) samples at 38 stations focusing on CDOM spectral characteristics as indicator of photochemical and microbial alteration processes. CDOM composition was characterized by spectral slope (S) values and excitation-emission matrix fluorescence (EEMs), which allow us to track changes in molecular weight (MW) of DOM, and to determine potential DOM sources and sinks. Spectral slope S varied between 0.012 to 0.043 1 nm-1 and was quite similar between SML and ULW, with no significant differences between the two compartments. Higher S values were observed in the ULW of the southern stations below 15°S. By EEMs, we identified five fluorescent components (F1-5) of the CDOM pool, of which two had excitation/emission characteristics of amino-acid-like fluorophores (F1, F4) and were highly enriched in the SML, with a median ratio SML : ULW of 1.5 for both fluorophores. In the study region, values for CDOM absorption ranged from 0.07 to 1.47 m-1. CDOM was generally highly concentrated in the SML, with a median enrichment with respect to the ULW of 1.2. CDOM composition and changes in spectral slope properties suggested a local microbial release of DOM directly in the SML as a response to light exposure in this extreme environment. In a conceptual model of the sources and modifications of optically active DOM in the SML and underlying seawater (ULW), we describe processes we think may take place (Fig. 1); the production of CDOM of higher MW by microbial release through growth, exudation and lysis in the euphotic zone, includes the identified fluorophores (F1, F2, F3, F4, F5). Specific amino-acid-like fluorophores (F1, F4) accumulate in the SML with respect to the ULW, as photochemistry may enhance microbial CDOM release by (a) photoprotection mechanisms and (b) cell-lysis processes. Microbial and photochemical degradation are potential sinks of the amino-acid-like fluorophores (F1, F4), and potential sources of reworked and more refractory humic-like components (F2, F3, F5). In the highly productive upwelling region along the Peruvian coast, the interplay of microbial and photochemical processes controls the enrichment of amino-acid-like CDOM in the SML. We discuss potential implications for air-sea gas exchange in this area.

Factors Underlying the Formation of Industrial Clusters in Japan and Industrial Cluster Policy: A Quantitative Survey

The purpose of this report is to use information provided by a questionnaire survey to analyze the factors and processes underlying the formation of industrial clusters in Japan. The study, based on questionnaire surveys, forms part of an "Industrial Cluster Project". The Japanese government has implemented policies for industrial clusters so as to enable Japanese industries to maintain competitive power in global markets, and to aid the self-sufficient expansion of local industries. The government's project goes under the heading "Industry Agglomeration for the Recovery of Local Industries with respect to so-called "Industry Clusters." The authors aim to identify what expectations are held of government by the enterprises that make up industrial clusters. As part of our investigation, we used the results of a survey conducted by UNDP in 2004. Tsuji's study, published by the Osaka School of International Public Policy, surveyed 1198 small or medium sized manufacturing companies located in O ward, Tokyo and Higashi Osaka city, Osaka prefecture. The outcome of the present study, together with data from Tsuji's work on IT usage by SMEs in Japan, is meant to form the basis for policy design and implementation.

A common mechanism of defective channel trafficking underlying DFNA2 hearing loss result in different cell surface expression levels of KCNQ4 mutants

KCNQ4 mutations underlie DFNA2, a subtype of autosomal dominant hearing loss. We had previously identified the pore-region p.G296S mutation that impaired channel activity in two manners: it greatly reduced surface expression and abolished channel function. Moreover, G296S mutant exerted a strong dominant-negative effect on potassium currents by reducing the channel expression at the cell surface representing the first study to identify a trafficking-dependent dominant mechanism for the loss of KCNQ4 channel function in DFNA2. Here, we have investigated the pathogenic mechanism associated with all the described KCNQ4 mutations (F182L, W242X, E260K, D262V, L274H, W276S, L281S, G285C, G285S and G321S) that are located in different domains of the channel protein. F182L mutant showed a wild type-like cell-surface distribution in transiently transfected NIH3T3 fibroblasts and the recorded currents in Xenopus oocytes resembled those of the wild-type. The remaining KCNQ4 mutants abolished potassium currents, but displayed distinct levels of defective cell-surface expression in NIH3T3 as quantified by flow citometry. Co-localization studies revealed these mutants were retained in the ER, unless W242X, which showed a clear co-localization with Golgi apparatus. Interestingly, this mutation results in a truncated KCNQ4 protein at the S5 transmembrane domain, before the pore region, that escapes the protein quality control in the ER but does not reach the cell surface at normal levels. Currently we are investigating the trafficking behaviour and electrophysiological properties of several KCNQ4 truncated proteins artificially generated in order to identify specific motifs involved in channel retention/exportation. Altogether, our results indicate that a defect in KCNQ4 trafficking is the common mechanism underlying DFNA2