Mid- to late Holocene geomorphological and hydrological changes in the south Taihu area of the Yangtze delta plain, China

The Taihu Plain of the Lower Yangtze valley, China was a centre of rice agriculture during the Neolithic period. Reasons for the rapid development of rice cultivation during this period, however, have not been fully understood for this coastal lowland, which is highly sensitive to sea-level change. To improve understanding of the morphological and hydrological context for evolution of prehistoric rice agriculture, two sediment cores (DTX4 and DTX10) in the East Tiaoxi River Plain, south Taihu Plain, were collected, and analysed for radiocarbon dating, diatoms, organic carbon and nitrogen stable isotopes (δ13C and δ15N), grain size and lithology. These multiproxy analyses revealed that prior to ca. 7500 cal. yr BP, the East Tiaoxi River Plain was a rapidly aggrading high-salinity estuary (the Palaeo-Taihu Estuary). After ca. 7500 cal. yr BP, low salinity conditions prevailed as a result of strong Yangtze freshwater discharge. Subsequently, seawater penetration occurred and saltmarsh developed between ca. 7000 and 6500 cal. yr BP due to accelerated relative sea-level rise. This transgression event influenced a large area of the Taihu Plain during the Holocene, as shown by multiple sediment records from previous studies. Persistent freshwater marsh (or subaerial land) formed due to dramatic shrinkage/closure of the Palaeo-Taihu Estuary after ca. 5600 cal. yr BP when sea level was relatively stable. We speculate that morphological and hydrological changes of the East Tiaoxi River Plain played an important role in agricultural development across the Taihu Plain during the Neolithic period. The closure of the Palaeo-Taihu Estuary and the formation of stable freshwater marsh (or subaerial land) after ca. 5600 cal. yr BP were critical preconditions encouraging the rapid rise of rice productivity in the Liangzhu period (5500-4500 cal. yr BP). This development changed the landscape and river systems, and thus provided adequate freshwater supply to the Taihu Plain

Salaklar Derneği, Sözen'i yılın adamı seçti

Taha Toros Arşivi, Dosya No: 207-Nurettin-Gürol-Metin SözenUnutma İstanbul projesi İstanbul Kalkınma Ajansı'nın 2016 yılı "Yenilikçi ve Yaratıcı İstanbul Mali Destek Programı" kapsamında desteklenmiştir. Proje No: TR10/16/YNY/010

T Luminescence Imaging and Biosensing in Cells and Tissues

Time-gated luminescence imaging and detection using brightly emitting complexes of the lanthanide elements Tb(III) and Eu(III) offer several distinct advantages for immunofluorescence microscopy and for designing biosensors of protein function. Lanthanide complexes emit in multiple, well separated bands, and lanthanide emission lifetimes are on the order of milleseconds. These features can be leveraged to develop highly sensitive, multiplexed protein imaging and screening assays based on Förster resonance energy transfer (FRET) between a Tb(III) or Eu(III) complex donor and a fluorescent protein acceptor. The donor emission can be easily filtered from sensitized acceptor emission, and is able to sensitize multiple differentially colored acceptors. While short-lived non-specific background, directly excited acceptor fluorescence, and autofluorescence are eliminated by time-gating, where pulsed light excites specimens, and a short delay is implemented before the detector starts collecting light. The main objectives of the studies in this dissertation were to expand the application of time-gated luminescence imaging in live cells and tissues, and to develop lanthanide-based biosensors for quantitative FRET imaging and HTS of PPIs in living cells with high sensitivity and signal-to-noise ratio. The feasibility of extracellular Tb-to-QD FRET biosensing was demonstrated by immunostaining different epitopes of epidermal growth factor receptor (EGFR) with QD- and Tb-antibody conjugates in A431 cells. By eliminating the non-specific background, time-gated luminescence microscopy (TGLM) enables the visualization of various markers and intermolecular, Tb(III)-to-dye FRET on FFPE tissue. Results also indicate the compatibility of TGLM with H&E staining in certain protocols. On the other hand, quantitative TGLM results from single chain lanthanide-based FRET biosensors were provided. Time-gated detection of PPI and/or its inhibition were performed in multi-well plate with lysised cells or live mammalian cells. High quality data were obtained by the indication of Z’ factor and strictly standardized mean difference (SSMD). The results strongly implicate the potential of lanthanide-based single-chain biosensors for hit selection in HTS assays. For future work, the interaction between protein phosphatase 1 regulatory subunit 12C (PPP1R12C) and its catalytic subunit alpha isozyme (PPP1CA), and their inhibition with a short peptide or other regulatory domain will be investigated to validate the ability of the biosensors to be utilized in HTS to discover effective small molecule inhibitors of PPIs. Finally, a new method, which combines split-DHFR, FRET, and time-gated detection, is proposed for mapping protein network or identifying potential hits of designated PPIs in living mammalian cells

Abundance estimations of major phyla for all four data types in a human gut microbiome.

<p>Abundance estimations of major phyla for all four data types in a human gut microbiome.</p

Summary of Shotgun and Full-length Simulated Datasets.

<p>Summary of Shotgun and Full-length Simulated Datasets.</p

E-value and Identity Cut-offs.

<p>E-value and Identity Cut-offs.</p

Comparison between the Complete Database and the Compressed Database.

<p>Comparison between the Complete Database and the Compressed Database.</p

OTU prediction performance evaluation for all simulated datasets.

<p>X-axis indicates read number, y-axis indicates value of corresponding performance metric ((A) for Bray-Curtis dissimilarity, (B) for sensitivity and (C) for specificity), each colored line indicates a different read-length.</p

Rarefaction curve of lean and obese samples.

<p>Error bars indicating 95% confidence interval.</p

Comparison of four computational methods for integrating taxonomic information.

<p>MLE stands for the maximum likelihood estimation method, MSC stands for the Minimum Set Covering method, MLE of MCS stands for the MSC method followed by the MLE method, and NN stands for the nearest neighbor method. Each data point indicates the sensitivity and specificity achieved by one simulated dataset using corresponding method.</p