Archaea can respond to changes in the environment by altering the composition of their membrane lipids, for example, by modification of the abundance and composition of glycerol dialkyl glycerol tetraethers (GDGTs). Here, we investigated the abundance and proportions of polar GDGTs (P-GDGTs) and core GDGTs (C-GDGTs) sampled in different seasons from Tengchong hot springs (Yunnan, China), which ...

The river Gacka springs catchment area is located in the Dinaric karst, which is globally known as the locus typicus, or classical Karst. It is composed of four major and several minor karst springs of different discharge rates. The river Gacka springs are characterised by great discharge and exceptional quality, so the catchment area of the river is indicated in the Water Management Strategy (...

One of the largest karst springs in North China, the Jinci Springs, dried up and has remained dry since 1994. We develop a correlation analysis with time-lag and a regression analysis with time-lag to study the relation between spring flow and precipitation. This allows us to obtain a better understanding of karst hydrological processes by differentiating the contribution of variation in precip...

A formulation for design of continuous, hinge-free compliant mechanisms is developed and examined within a continuum structural topology optimization framework. The formulation makes use of two distinctly different sets of springs, the first of which are artificial springs of relatively large stiffness attached to the input and output ports of the mechanism model, and the second of which are sp...

In this study, water samples were collected from 10 thermal and non-thermal springs of Mahalat setting during four periods in 2011. The discharge rates of these springs vary from 2 l/s to 45 l/s and their temperature range from an average minimum of 18oC to maximum 47oC. Spring water is high in SO4-Cl and this is related to gypsum dissolution. Correlation coefficient, principal component analys...

In this paper, we aim at minimizing the actuator torques of robots working on production lines by adding to the mechanism dynamic equilibrators based on nonlinear springs, that work in parallel with the joints. We propose a method to simultaneously optimize the trajectory of the robot and the force profiles of the nonlinear springs to minimize the actuator torques. First, we express the traject...

The Aleutian Islands were colonized, perhaps several times, from the Alaskan mainland. Earlier work documented transitions in the relative frequencies of mtDNA haplogroups over time, but little is known about potential source populations for prehistoric Aleut migrants. As part of a pilot investigation, we sequenced the mtDNA first hypervariable region (HVRI) in samples from two archaeological s...