Late Glacial summer paleohydrology across Central Europe.

It is generally accepted that a weakening of the North Atlantic thermohaline circulation caused the Younger Dryas cooling. Although the role of seasonality was emphasized previously, this aspect is rarely considered yet, and it remains elusive how this impacted hydroclimate during winters and summers across Central Europe. Here, we coupled biomarker-based δO and δH from Bergsee in southern Germany to reconstruct deuterium excess as a proxy for evaporation history from the Bølling-Allerød to the Preboreal.

Summer paleohydrology during the Late Glacial and Early Holocene based on δH and δO from Bichlersee, Bavaria.

Isotope-based records provide valuable information on past climate changes. However, it is not always trivial to disentangle past changes in the isotopic composition of precipitation from possible changes in evaporative enrichment, and seasonality may need to be considered. Here, we analyzed δH on n-alkanes and δO on hemicellulose sugars in sediments from Bichlersee, Bavaria, covering the Late Glacial and Early Holocene.

Collective dynamics of capacity-constrained ride-pooling fleets.

Ride-pooling (or ride-sharing) services combine trips of multiple customers along similar routes into a single vehicle. The collective dynamics of the fleet of ride-pooling vehicles fundamentally underlies the efficiency of these services. In simplified models, the common features of these dynamics give rise to scaling laws of the efficiency that are valid across a wide range of street networks and demand settings.

Interaction of recent stressful life events and childhood abuse on orbitofrontal grey matter volume in adults with depression.

Background: The diathesis-stress model of major depressive disorder (MDD) predicts interactions of recent stressful life events (SLEs) in adulthood and early developmental risk factors. We tested, for the first time, the diathesis stress model on brain structure in a large group of MDD patients.

Methods: Structural magnetic resonance imaging data of 1465 participants (656 with lifetime diagnosis MDD; 809 healthy controls) were analyzed using voxel-based morphometry to identify clusters associated with recent SLEs (Life Events Questionnaire).

Central Mongolian lake sediments reveal new insights on climate change and equestrian empires in the Eastern Steppes.

The repeated expansion of East Asian steppe cultures was a key driver of Eurasian history, forging new social, economic, and biological links across the continent. Climate has been suggested as important driver of these poorly understood cultural expansions, but paleoclimate records from the Mongolian Plateau often suffer from poor age control or ambiguous proxy interpretation. Here, we use a combination of geochemical analyses and comprehensive radiocarbon dating to establish the first robust and detailed record of paleohydrological conditions for Lake Telmen, Mongolia, covering the past ~ 4000 years.

Response to Comment on "A global environmental crisis 42,000 years ago".

Our paper about the impacts of the Laschamps Geomagnetic Excursion 42,000 years ago has provoked considerable scientific and public interest, particularly in the so-called Adams Event associated with the initial transition of the magnetic poles. Although we welcome the opportunity to discuss our new ideas, Hawks’ assertions of misrepresentation are especially disappointing given his limited examination of the material.

Response to Comment on "A global environmental crisis 42,000 years ago".

Our study on the exact timing and the potential climatic, environmental, and evolutionary consequences of the Laschamps Geomagnetic Excursion has generated the hypothesis that geomagnetism represents an unrecognized driver in environmental and evolutionary change. It is important for this hypothesis to be tested with new data, and encouragingly, none of the studies presented by Picin . undermine our model.

TSC1 binding to lysosomal PIPs is required for TSC complex translocation and mTORC1 regulation.

The TSC complex is a critical negative regulator of the small GTPase Rheb and mTORC1 in cellular stress signaling. The TSC2 subunit contains a catalytic GTPase activating protein domain and interacts with multiple regulators, while the precise function of TSC1 is unknown. Here we provide a structural characterization of TSC1 and define three domains: a C-terminal coiled-coil that interacts with TSC2, a central helical domain that mediates TSC1 oligomerization, and an N-terminal HEAT repeat domain that interacts with membrane phosphatidylinositol phosphates (PIPs).

A global environmental crisis 42,000 years ago.

Geological archives record multiple reversals of Earth's magnetic poles, but the global impacts of these events, if any, remain unclear. Uncertain radiocarbon calibration has limited investigation of the potential effects of the last major magnetic inversion, known as the Laschamps Excursion [41 to 42 thousand years ago (ka)]. We use ancient New Zealand kauri trees () to develop a detailed record of atmospheric radiocarbon levels across the Laschamps Excursion.

The potential of δH and δO for paleoclimate reconstruction - A regional calibration study for South Africa.

The hydrogen isotopic composition of leaf wax-derived n-alkanes (δH) is a widely applied proxy for (paleo)climatic changes. It has been suggested that the coupling with the oxygen isotopic composition of hemicellulose-derived sugars (δO) - an approach dubbed 'paleohygrometer' - might allow more robust and quantitative (paleo)hydrological reconstructions. However, the paleohygrometer remains to be evaluated and tested regionally.

Climate deteriorations and Neanderthal demise in interior Iberia.

Time and circumstances for the disappearance of Neanderthals and its relationship with the advent of Modern Humans are not yet sufficiently resolved, especially in case of the Iberian Peninsula. Reconstructing palaeoenvironmental conditions during the last glacial period is crucial to clarifying whether climate deteriorations or competition and contacts with Modern Humans played the pivotal role in driving Neanderthals to extinction. A high-resolution loess record from the Upper Tagus Basin in central Spain demonstrates that the Neanderthal abandonment of inner Iberian territories 42 kyr ago coincided with the evolvement of hostile environmental conditions, while archaeological evidence testifies that this desertion took place regardless of modern humans' activities.

Structure of the Tuberous Sclerosis Complex 2 (TSC2) N Terminus Provides Insight into Complex Assembly and Tuberous Sclerosis Pathogenesis.

Tuberous sclerosis complex (TSC) is caused by mutations in the TSC1 and TSC2 tumor suppressor genes. The gene products hamartin and tuberin form the TSC complex that acts as GTPase-activating protein for Rheb and negatively regulates the mammalian target of rapamycin complex 1 (mTORC1). Tuberin contains a RapGAP homology domain responsible for inactivation of Rheb, but functions of other protein domains remain elusive.

Do n-alkane biomarkers in soils/sediments reflect the δ²H isotopic composition of precipitation? A case study from Mt. Kilimanjaro and implications for paleoaltimetry and paleoclimate research.

During the last decade compound-specific deuterium ((2)H) analysis of plant leaf wax-derived n-alkanes has become a promising and popular tool in paleoclimate research. This is based on the widely accepted assumption that n-alkanes in soils and sediments generally reflect δ(2)H of precipitation (δ(2)H(prec)). Recently, several authors suggested that δ(2)H of n-alkanes (δ(2)H(n-alkanes)) can also be used as a proxy in paleoaltimetry studies.

Peroxide release into saliva from five different home bleaching systems in vivo.

Purpose: This study determined hydrogen peroxide release into the oral cavity during use of different home bleaching products and compared them with accepted safe levels.

Methods: Determination of peroxide in saliva was performed with peroxidase, phenol and 4-aminoantipyrin in a photometric method. Upper jaw incisors were bleached with individual trays charged with 350 mg Opalescence 10%, Opalescence 15% (OP) and Vivastyle (V).

Immobilisation and activity of human alpha-amylase in the acquired enamel pellicle.

Unlabelled: Amylase is an important salivary component and structural element of the acquired enamel pellicle. Aim of the study was to establish a method for precise and direct determination of pellicle bound amylase activity in order to analyse kinetics and activity of the immobilised enzyme. Six bovine enamel slabs (5mm diameter) were fixed on individual maxillary trays and worn by five subjects for different times (3, 30 and 120 min) on buccal and palatal sites on different days.

Determination of peroxides in saliva--kinetics of peroxide release into saliva during home-bleaching with Whitestrips and Vivastyle.

Aim of the study was to determine peroxides in saliva, released during bleaching procedures. Upper incisors of five subjects were bleached with Whitestrips (5% H2O2) and Vivastyle (10% carbamide peroxide, tray charged with 225mg) for 30min, each on different days. Saliva was collected before and during the whole period of bleaching at different intervals.

Paraoxonase polymorphism in rabbits.

Paraoxonase in serum and liver of rabbits and cattle was investigated. In serum the two substrates paraoxon and phenylacetate are exclusively hydrolyzed by alpha-lipoprotein-bound paraoxonase. In rabbit liver paraoxon is hydrolyzed only by paraoxonase, while phenylacetate is hydrolyzed by paraoxonase (20%) and additionally by an organophosphate sensitive carboxylesterase (B-Esterase), which is responsible for 80% of total liver phenylacetate hydrolysis.

Organophosphate inhibition of human heart muscle cholinesterase isoenzymes.

The rate of acetylcholine hydrolysis of mammalian heart muscle influences cardiac responses to vagal innervation. We characterized cholinesterases of human left ventricular heart muscle with respect to both substrate specificity and irreversible inhibition kinetics with the organophosphorus inhibitor N,N'-di-isopropylphosphorodiamidic fluoride (mipafox). Specimens were obtained postmortem from three men and four women (61 +/- 5 years) with no history of cardiovascular disease.

[Age related decrease of high density lipoproteins (HDL) in women after menopause. Quantification of HDL with genetically determined HDL arylesterase in women with healthy coronary vessels and in women with angiographically verified coronary heart disease].

Background: The decline in the concentration of high density lipoproteins (HDL) observed in postmenopausal women is thought to contribute to the increasing incidence of coronary artery disease (CAD) after menopause. Human serum arylesterase (EC 3.1.

Mipafox differential inhibition assay for heart muscle cholinesterases: substrate specificity and inhibition of three isoenzymes by physostigmine and quinidine.

1. A differential inhibition assay was developed for the quantitative determination of cholinesterase isoenzymes acetylcholinesterase (AChE; EC 3.1.

Indirect parasympathomimetic activity of the class III antiarrhythmic substance D/L-sotalol in vitro: reversible inhibition of cholinesterase isoenzymes from blood and the human central nervous system.

Inhibitory effects of the class III antiarrhythmic compound D/L-sotalol on acetylcholinesterase (AChE; EC 3.1.1.

Indirect parasympathomimetic activity of metoclopramide: reversible inhibition of cholinesterases from human central nervous system and blood.

Inhibitory effects of the dopamine D2-receptor antagonistic benzamide compound metoclopramide (MCP) on acetylcholinesterase (AChE; EC 3.1.1.

Fasting, lactate, and insulin improve ischemia tolerance in rat heart: a comparison with ischemic preconditioning.

We tested the hypothesis that improved ischemia tolerance in an isolated working rat heart preparation can be achieved by interventions other than ischemic preconditioning. Hearts were perfused at near-physiological workload with bicarbonate buffer containing glucose (10 mM). A preischemic period of 25 min was followed by 15 min of global ischemia and 30 min of reperfusion under preischemic conditions.

Plasma and tissue kinetics of phenylbutazone and naproxen in dogs.

By means of tissue cages in which a sterile inflammation was induced after injection of carrageenan, plasma and tissue kinetics of two NSAIDs were followed. The first one, phenylbutazone, is characterized by a fairly short elimination half-life (3-6 hours) in dogs, whereas the other one, naproxen, has an average half-life of 67 hours in this species. After a single oral dose of 15 mg/kg, phenylbutazone reached concentrations of 13-20 micrograms/ml in the exudate from the tissue cages.