Biogeographic classification of the Caspian Sea

Like other inland seas, the Caspian Sea (CS) has been influenced by climate change and anthropogenic disturbance during recent decades, yet the scientific understanding of this water body remains poor. In this study, an eco-geographical classification of the CS based on physical information derived from space and in situ data is developed and tested against a set of biological observations. We used a two-step classification procedure, consisting of (i) a data reduction with self-organizing maps (SOMs) and (ii) a synthesis of the most relevant features into a reduced number of marine ecoregions using the hierarchical agglomerative clustering (HAC) method. From an initial set of 12 potential physical variables, 6 independent variables were selected for the classification algorithm, i.e., sea surface temperature (SST), bathymetry, sea ice, seasonal variation of sea surface salinity (DSSS), total suspended matter (TSM) and its seasonal variation (DTSM). The classification results reveal a robust separation between the northern and the middle/southern basins as well as a separation of the shallow nearshore waters from those offshore. The observed patterns in ecoregions can be attributed to differences in climate and geochemical factors such as distance from river, water depth and currents. A comparison of the annual and monthly mean Chl <i>a</i> concentrations between the different ecoregions shows significant differences (one-way ANOVA, <i>P</i> < 0.05). In particular, we found differences in phytoplankton phenology, with differences in the date of bloom initiation, its duration and amplitude between ecoregions. A first qualitative evaluation of differences in community composition based on recorded presence–absence patterns of 25 different species of plankton, fish and benthic invertebrate also confirms the relevance of the ecoregions as proxies for habitats with common biological characteristics

Detection and Verification of Mammalian Mirtrons by Northern Blotting

microRNAs (miRNAs) have vital roles in regulating gene expression—contributing to major diseases like cancer and heart disease. Over the last decade, thousands of miRNAs have been discovered through high throughput sequencing-based annotation. Different classes have been described, as well as a great dynamic range of expression levels. While sequencing approaches provide insight into biogenesis and allow confident identification, there is a need for additional methods for validation and characterization. Northern blotting was one of the first techniques used for studying miRNAs, and remains one of the most valuable as it avoids enzymatic manipulation of miRNA transcripts. Blotting can also provide insight into biogenesis by revealing RNA processing intermediates. Compared to sequencing, however, northern blotting is a relatively insensitive technology. This creates a challenge for detecting low expressed miRNAs, particularly those produced by inefficient, non-canonical pathways. In this chapter, we describe a strategy to study such miRNAs by northern blotting that involves ectopic expression of both miRNAs and miRNA-binding Argonaute (Ago) proteins. Through use of epitope tags, this strategy also provides a convenient method for verification of small RNA competency to be loaded into regulatory complexes

MicroRNA-196a as a Potential Diagnostic Biomarker for Esophageal Squamous Cell Carcinoma

We observed significant up-regulation of miR-196a in esophageal squamous cell carcinoma (ESCC) as compared with their adjacent normal tissue (p =.002). Receiver operating characteristics curve analysis confirmed the suitability of miR-196a as a potential tumor marker for diagnosis of ESCC. Furthermore, analysis of miR-196a levels in saliva samples determined an average of 27-fold up-regulations in ESCC patients compared with healthy group. Our results suggest that salivary miR-196a may be a suitable noninvasive biomarker for diagnosis of ESCC. In addition, molecular pathway enrichment analysis of microRNA (miR)-196a determined focal adhesion, spliceosome and p53 signaling pathways as the most relevant pathways with miR-196a targetome. © 2017 Taylor & Francis Group, LLC

CEO financial background and internal control weaknesses

Research question/issue: The existing literature documents that the functional expertise of Chief Executive Officers (CEOs) in finance reduces poor performance risk, improves financial reporting quality, and mitigates audit risk. In this study, we examine the association between CEOs\u27 financial background and internal control weaknesses (ICWs). Research findings/insights: Using a sample of Iranian listed companies for the period 2007–2017, we find a significant negative association between CEOs with financial expertise and ICWs. Furthermore, we show that the negative association between CEO financial expertise and ICWs is stronger if the CEO is recruited from inside the firm. Our main results are robust after controlling for the potential selection issue, random effects at the firm level, and the impact of the new Iranian internal control regulations. Moreover, our results remain unchanged after controlling for other CEO characteristics, audit committee characteristics, audit fees, and using an alternative measure of financial expertise. Theoretical/academic implications: Our study contributes to the extant literature by examining the association between CEOs\u27 financial background and ICWs, a theme that remains largely unexplored in previous research. We also extend the literature on CEO succession origin. Practitioner/policy implications: This study has important implications for regulators regarding the improvement of financial reporting quality and the effectiveness of internal controls, especially in the emerging markets. Particularly, our findings may be of benefit to auditors when assessing the risks regarding their clients\u27 material weaknesses, as well as to shareholders and boards of directors when hiring a new CEO

Past and Current Changes in the Largest Lake of the World: The Caspian Sea: Chapter 3

International audienceThe Caspian Sea (CS), located between Europe and Asia, is the largest lake in the world; however, its physical environment and its floor have oceanic characteristics. The CS is composed of a very shallow north basin with a very low salinity mostly below 5 psu. The middle and southern basins are deep and have a salinity of c. 13 psu. To the east, the Kara-Bogaz-Gol, a hypersaline lagoon, is connected to the middle basin. The CS is endorheic and therefore very sensitive to changes in hydrography and climate. Because of its long history of isolation following the disconnection of the Caspian Sea from the Paratethys c. 6 Ma ago, this ancient lake has many endemic species. The harsh environment of its brackish waters and the repeated salinity changes over the millennia however do not allow for a high biodiversity. The benthos is more varied than the plankton. The history of water-level changes remains poorly known even for the last centuries. Nevertheless, the amplitude was of &gt;150 m in the Quaternary, several 10 s of m in the Holocene and several m in the last century. Many factors affect its natural state, such as petroleum pollution (an industry dating back to Antiquity), nutrient increase (alongside &gt;14 million inhabitants along the coast), invasive species (e.g. the comb jelly Mnemiopsis leidyi), overfishing (including sturgeon) and modifications of its coastline (e.g. sand extraction). In comparison to other ancient lakes, the CS surface temperature has suffered from the fastest increase on record. Owing to the complex natural state of the CS, it is not easy to identify the Holocene-Anthropocene transition, although it may be suggested that is was approximately AD1950 when intense human activity started to modify the lake