The Littorina transgression in southeastern Sweden and its relation to mid-Holocene climate variability

Lateglacial and Holocene shoreline displacement along the Baltic coast resulted from both the isostatic land uplift and the ice-volume-equivalent sea-level rise. Relative changes of these two components led to alternating contact/isolation of the Baltic Basin with the North Sea during the Holocene. The Littorina transgression was a significant palaeoceanographic change that took place during the mid-Holocene in southern Sweden. However, the detailed pattern of the transgression has long been debated. As yet, the rate, magnitude and cause(s) of the transgression as well as the physical link with the North Atlantic climate are poorly known. In this study, shoreline displacement and coastal palaeoecology were reconstructed on the basis of multi-disciplinary studies of sediment sequences from four basins located at an elevation range between –1 and 8 m above present sea level in southeastern Sweden. Coastal basins with well defined thresholds may provide powerful constraints on relative sea-level changes. The timing of the Littorina transgression was determined by dating the lacustrine/brackish-marine transitions in sediment sequences recovered from these basins. Following a slight rise, the transgression culminated between 8000 and 7500 cal. BP, marked by a c. 8-m relative sea-level rise at an accelerated rate of ~15 mm yr-1. This relatively rapid rise can be ascribed to the partial collapse of the Antarctic Ice Sheet. From 6500 cal. BP, the relative level of the Baltic Sea fell as a result of the deceleration of global sea-level rise and continued isostatic rebound. Superimposed on this eustatic pattern are five minor transgressions identified during the middle Holocene: L1 8500–8200, L2 7800–6900, L3 6400–5600, L4 5300–4700, and L5 4500–4100 cal. BP. Evidence from the northwestern European coasts and Greenland ice cores suggests that these episodic sea-level rises may have been related to increased storminess in the North Atlantic realm, which overprinted global ice-volume changes at millennial time scales. Superimposed on a general highstand, the Baltic Sea level exhibited significant fluctuations at centennial time scales between 8500 and 3000 cal. BP. A close correlation between sea-level proxies and Greenland ice-core sea-salt ions implies that these cyclic fluctuations of Baltic Sea level might have been causally linked to periodical variations in regional wind pattern, probably operated by solar forcing in the Suess band through a thermodynamic mechanism. Other cycles may also be a signal of long-term changes in tidal intensity, when the connection of the Baltic basin with the North Sea was wider during the middle Holocene

A Hierarchical Bayesian Model for the Unmixing Analysis of Compositional Data subject to Unit-sum Constraints

Modeling of compositional data is emerging as an active area in statistics. It is assumed that compositional data represent the convex linear mixing of definite numbers of independent sources usually referred to as end members. A generic problem in practice is to appropriately separate the end members and quantify their fractions from compositional data subject to nonnegative and unit-sum constraints. A number of methods essentially related to polytope expansion have been proposed. However, these deterministic methods have some potential problems. In this study, a hierarchical Bayesian model was formulated, and the algorithms were coded in MATLABÒ. A test run using both a synthetic and real-word dataset yields scientifically sound and mathematically optimal outputs broadly consistent with other non-Bayesian methods. Also, the sensitivity of this model to the choice of different priors and structure of the covariance matrix of error were discussed

Serum cystatin C and chemerin levels in diabetic retinopathy

Peer reviewedPublisher PD

ImageSpace: An Environment for Image Ontology Management

More and more researchers have realized that ontologies will play a critical role in the development of the Semantic Web, the next generation Web in which content is not only consumable by humans, but also by software agents. The development of tools to support ontology management including creation, visualization, annotation, database storage, and retrieval is thus extremely important. We have developed ImageSpace, an image ontology creation and annotation tool that features (1) full support for the standard web ontology language DAML+OIL; (2) image ontology creation, visualization, image annotation and display in one integrated framework; (3) ontology consistency assurance; and (4) storing ontologies and annotations in relational databases. It is expected that the availability of such a tool will greatly facilitate the creation of image repositories as islands of the Semantic Web

A New Multistage Medical Segmentation Method Based on Superpixel and Fuzzy Clustering

The medical image segmentation is the key approach of image processing for brain MRI images. However, due to the visual complex appearance of image structures and the imaging characteristic, it is still challenging to automatically segment brain MRI image. A new multi-stage segmentation method based on superpixel and fuzzy clustering (MSFCM) is proposed to achieve the good brain MRI segmentation results. The MSFCM utilizes the superpixels as the clustering objects instead of pixels, and it can increase the clustering granularity and overcome the influence of noise and bias effectively. In the first stage, the MRI image is parsed into several atomic areas, namely, superpixels, and a further parsing step is adopted for the areas with bigger gray variance over setting threshold. Subsequently, designed fuzzy clustering is carried out to the fuzzy membership of each superpixel, and an iterative broadcast method based on the Butterworth function is used to redefine their classifications. Finally, the segmented image is achieved by merging the superpixels which have the same classification label. The simulated brain database from BrainWeb site is used in the experiments, and the experimental results demonstrate that MSFCM method outperforms the traditional FCM algorithm in terms of segmentation accuracy and stability for MRI image

Synchronous droughts and floods in the Southern Chinese Loess Plateau since 1646 CE in phase with decadal solar activities

Droughts and floods are two longstanding and devastating climatic threats to mankind. They are challenging to predict mainly due to the significant spatial and temporal variations of precipitation. Using historical archives back from 1646 CE, here we present a high-resolution catchment level dataset of droughts and floods in the southern Chinese Loess Plateau (hereafter, CLP) within the middle reaches of River Jing. We have analysed the occurrences of floods and droughts based a specially-developed statistics from historical archives, as well as the daily rainfall from present-day observations within the catchment. Overall, our results show that the frequency of droughts and floods in the region is synchronous on decadal timescales with solar activities and the Pacific Decadal Oscillation (hereafter, PDO) index, and they are also broadly in phase with changes in both global and regional reconstructed temperatures. At decadal to interannual timescales, PDO and El Niño and Southern Oscillation (hereafter, ENSO) drive an uneven distribution of precipitation in different seasons in the southern CLP, which could be one of the reasons for the strong association of floods and droughts with the PDO and ENSO signals in our catchment. If the global temperature continues to rise in the future, we expect that the risk of both droughts and floods in the study region will also increase

Advances in electronic skin research: a bibliometric analysis

Background: E-skin (electronic skin) is an active research area in human-computer interaction and artificial intelligence.Methods: A bibliometric analysis was performed to evaluate publications in the E-skin field between 2000 and 2021 based on the Web of Science (WoS) databases.Results: A total of 4,954 documents were identified. A detailed overview of E-skin research was presented from aspects of productive countries/regions, institutions, journals, citations, highly cited papers, keywords, and emerging topics. With the emergence of new functional materials, structural design, 3D printing, and nanofabrication techniques, E-skin research has achieved dramatic progress after 2013. Scholars and institutions in China, the United States and South Korea are leading the way in E-skin research. Pressure sensor, strain sensor, and flexible electronics are the most focused directions at present and Internet of things is the most emerging topic.Conclusion: E-skin research has achieved dramatic progress but there is still quite a challenging task in practical applications. Manufacturing process simplification, cost reduction, functional integration, energy supply, and biocompatibility are vital for the future development of E-skin

Improved heat transfer for pyroelectric energy harvesting applications using a thermal conductive network of aluminum nitride in PMN–PMS–PZT ceramics

The harvesting of waste heat is attracting increasing attention, due to its abundance and potential benefits to the environment. However, the need for high heat transfer rates in thermal harvesting systems is a longstanding obstacle for their practical application. In this work, we construct thermally conductive networks in Pb[(MnxNb1−x)1/2(MnxSb1−x)1/2]y(Zr95Ti5)1−yO3 (lead magnesium niobate–lead antimony–manganese–lead zirconate titanate: PMN–PMS–PZT) ceramics to improve heat transfer and enhance their ferroelectric properties by use of a thermally conductive AlN additive dispersed in the ceramic matrix. The ferroelectric properties, pyroelectric coefficient and thermal conductivity of the PMN–PMS–PZT: AlN composite materials are influenced by the AlN content as a result of the formation of random bridges or thermally conductive networks for phonon transfer in the ceramic matrix, thereby leading to high heat transfer. For a PMN–PMS–PZT composite with a 0.2 wt% AlN content, the ferroelectric properties, pyroelectric coefficient and thermal conductivity are shown to be enhanced owing to the improved crystallinity and density, and the relative permittivity is also reduced, which results in optimized pyroelectric figure of merits. This combination of materials property enhancements is shown to be beneficial for high performance pyroelectric materials in devices for energy harvesting applications