Miracle-dz/UniFAR-FTUs huggingface dataset:
Prädiktion der Alzheimer-Demenz

Zusammenfassung Die Prädiktion der Alzheimer-Demenz ist die Voraussetzung für indizierte Demenz-Prävention. Zu unterscheiden ist die Prädiktion im hausärztlichen Versorgungsbereich, der gekennzeichnet ist durch eine niedrige Prävalenz der Erkrankung und einen begrenzten Einsatz von apparativen Verfahren sowie die biomarkerbasierte Prädiktion im Expertensetting (z.B. Gedächtnisambulanz). Im hausärztlichen Versorgungsbereich können anhand einfach zu erhebender Parameter Patienten mit erhöhtem Demenzrisiko identifiziert werden. Allerdings werden keine hohen positiven prädiktiven Werte (PPW) erreicht. In spezialisierten Einrichtungen können aufgrund der höheren Prävalenz der Alzheimer-Krankheit und dem Einsatz von Biomarkern (Liquor, Bildgebung) eine deutlich höhere Vorhersage der Demenz, insbesondere bei Personen mit leichter kognitiver Störung (mild cognitive impairment, MCI) erreicht werden. Eine sichere Prädiktion der Alzheimer-Demenz bei einzelnen Individuen ist aber aufgrund von grenzwertigen oder widersprüchlichen Biomarkerbefunden nicht immer möglich. Summary Prediction of Alzheimer’s dementia is required for targeted prevention. It has to be differentiated between prediction in the low prevalence primary care setting with limited use of technical investigations and biomarker based prediction in specialized setting such as memory clinics. In the primary care setting, prediction is possible with easy to obtain information, but the achieved positive predictive value (PPV) is low. In the specialized setting, much higher PPV can be achieved due to higher prevalence of the disease and the use of biomarkers. Prediction on an individual level, however, is still frequently uncertain due to borderline or conflicting results of biomarkers.
Length scales for continental deformation in convergent, divergent, and strike‐slip Environments: Analytical and approximate solutions for a thin viscous sheet model

The deformation of a thin viscous layer that has a moving boundary is investigated for comparison with zones of deformation in the continental lithosphere. Exact analytical solutions, for the case of a Newtonian fluid, and approximate solutions, for the case of fluid with power law rheology, show that: When the imposed velocity vector is normal to the boundary (congressional or extensional regime) the deformation field decays away from the boundary with a characteristic length scale 1/3 to 1/10 the wavelength of the imposed boundary velocity distribution for n between 1 and 10, where n is the stress-strain exponent in the rheology; in contrast, when the imposed velocity vector is parallel to the boundary (transcurrent regime), the length scale of the deformation field is approximately 4 times smaller. In each case these length scales decrease approximately as n−½. The difference in length scales arises even in the absence of any buoyancy forces acting on thickened or thinned crust; such forces would modify the ratio of length scales, but not sufficiently to affect this result.
Microplate versus continuum descriptions of active tectonic deformation

Whether deformation of continents is more accurately described by the motions of a few small rigid plates or by quasi-continuous flow has important implications for lithospheric dynamics, fault mechanics, and earthquake hazard assessment. Actively deforming regions of the western United States, central Asia, Japan, and New Zealand show features that argue for both styles of movement, but new observations are necessary to determine which is most appropriate and at what scale the description applies. Geologic, geodetic, seismic, and paleomagnetic measurements tend to sample complementary aspects of the deformation field, so an integrated observation program can utilize the strengths of each method and overcome their separate spatial or temporal biases. Provided the total relative motion across each region is known and the distribution of active faults is well mapped, determination of fault slip rates can provide potentially decisive constraints. Reconnaissance geological studies supply useful slip rate estimates, but precise values depend upon detailed intensive investigation of individual sites. Geodetic survey measurements can determine the spatial pattern of contemporary movements and extract slip rate information, but the sometimes elusive effects of cyclic elastic strain buildup and relief must be accounted for in relating current movements to the long-term deformation pattern. Earthquake catalogs can be applied to determine seismic strain rates and relative velocities but must be averaged over large regions and are usually limited by the inadequate duration of historical or instrumental seismicity catalogs. Paleomagnetic determinations of vertical axis rotations provide estimates of block rotation rates but are often locally variable and averaged over many millions of years. Which of the two descriptions of continental tectonics is more nearly correct depends on the local rheological stratification of the lithosphere, especially the strength and thickness of the elastic crust relative to the ductile lithosphere, and dynamical models can provide contrasting forecasts of observable features with testable consequences.
ryanodine receptor calcium release channel Calcium Signaling and Cardiac Arrhythmias

The bivalent cation calcium (Ca) represents one of the most ubiquitous signal transduction molecules known. It mediates a diverse array of biological functions including muscle contraction, cellular exocytosis, neuronal activity, and triggering of programmed cell death. Since the first observation by Ringer in 1883 that Ca was required for cardiac contraction, the role of Ca as a signaling ion in the heart has become increasingly appreciated. In addition, it has become clear that abnormalities of Ca homeostasis can play a key role in the pathogenesis of common cardiovascular disorders, including cardiac arrhythmias. Human genetic studies of patients with inherited arrhythmia syndromes have uncovered inherited mutations in various Ca channels and Ca transporters, directly implicating dysfunction of these proteins in the disease mechanisms. Moreover, acquired modifications of various Ca-handling proteins have been associated with cardiac arrhythmias, including atrial fibrillation (AF) and ventricular arrhythmias in failing hearts. In this review, we provide a comprehensive overview of the potential contributions of Ca in arrhythmia mechanisms and highlight various gaps in knowledge and controversies in the field. Overview of Excitation–Contraction Coupling in the Heart Regular contraction of the heart requires the conversion of electric activation (excitation) into mechanical force (contraction). This process, known as excitation–contraction (EC) coupling, requires coordinated movement of Ca ions at the cardiomyocyte level (Figure 1A). Each action potential (AP), triggered by influx of sodium (Na) through the voltage-gated sodium channel (Nav1.5), thereby generating the I Na current, induces Ca influx through voltage-activated L-type Ca channels (LTCCs, Cav1.2), creating the I Ca,L current. This Ca triggers a much larger Ca release from the sarcoplasmic reticulum (SR), the principal intracellular Ca storage organelle. SR Ca release is mediated by specialized Ca-release channels known as ryanodine receptor type-2 (RyR2). This process of Ca-sensitive RyR2-mediated SR release is known as Ca-induced Ca-release (CICR). The cytosolic Ca binds to and activates cardiac troponin C (TnC), the Ca-sensing protein of the contractile apparatus and initiates myofilament contraction. During diastole, cardiac muscle relaxation occurs when Ca is removed from the cytosol either by sequestration Review
Rate of Loss of Carbon from Georgia Soils

The organic content of forest soils in Georgia was found to be rapidly lowered by cultivation. A mean decrease from 3.29% organic matter to 1.43% was found upon sampling 29 locations of forest soils and adjoining areas cultivated 25 years or more. A 20% average reduction in carbon occurred for 6 forested Piedmont soils brought under simulated cultivation for 24 months. Most of the carbon from green oats, crimson clover, and barnyard manure was lost in 24 months when added to cultivated Cecil soil at rates of 20 tons per acre. Sawdust and mature oat and wheat straw were more resistant. But even these materials decomposed fairly rapidly with simulated cultivation. The 20,000- and 40,000-pound application rates of green oats only slightly increased soil carbon after 12 months, and after 24 months only the 40,000-pound rate was higher (but not statistically) than the control. Rates of 2,000 and 5,000 pounds of green oats resulted in a slight decrease of soil carbon over the control after 24 months (but this was also not statistically significant at the 5% level).
Soil Aggregation and Associated Organic Carbon Fractions as Affected by Tillage in a Rice–Wheat Rotation in North India

Soil samples were obtained from a long-term trial conducted on a silty loam at Sardar Vallabhbhai Patel University of Agriculture & Technology, Modipuram (Meerut), in 2007-2008 to study the effects of various combinations of conventional and zero-tillage (ZT) and raised-bed systems on soil aggregation and associated organic C fractions in the 0- to 5-cm and 5- to 10-cm depth in a rice-wheat (Orysa sativa L.―Triticum aestivum L.) rotation. Macroaggregates increased under a ZT rice (direct-seeded or transplanted) and wheat rotation with the 2- to 4-mm fraction greater than that of the 0.25- to 2-mm fraction. Bulk and aggregate associated C increased in ZT systems with greater accumulation in macroaggregates. The fine (0.053-0.25 mm) intra-aggregate particulate organic C (iPOM-C), in 0.25- to 2-mm aggregates, was also higher in ZT than conventional tillage. A higher amount of macroaggregates along with greater accumulation of particulate organic C indicates the potential of ZT for improving soil C over the long-term in rice-wheat rotation.
Numerical simulation of the impact of sediment supply and streamflow variations on channel grain sizes and Chinook salmon habitat in mountain drainage networks

Climatically driven changes in streamflow and hillslope sediment supply could potentially alter stream surface grain size distribution patterns and thereby impact habitat for a number of threatened and endangered in‐stream fish species. Relatively little is known about hydrograph (shape, peak flow) influence or the relative importance of chronic and episodic hillslope inputs on channel conditions. To better understand these external drivers, we calculated sediment routing through a gravel‐bedded river network using a one‐dimensional (1D) bedload transport model. We calculated changes in grain sizes and estimated Chinook salmon habitat suitability caused by a dry year and an extreme flood hydrograph, and chronic (diffusive, overland flow) or pulse (landslide, debris flow) hillslope sediment supplies. To obtain accurate channel conditions, a relatively high reference Shields stress, representative of steep mountain streams, was needed. An extreme event flood without any hillslope sediment inputs caused widespread bed coarsening and a decrease in aquatic habitat. Chronic sediment input combined with this hydrograph eliminated any changes in grain size and habitat, although when combined with a dry year flow, caused systematic bed fining. The influence of a given hydrograph therefore highly depends on the hillslope sediment supply. Regardless of the flow hydrograph or sediment pulse timing, grain size distribution or location, pulse sediment inputs did not cause widespread grain size changes despite being 100 times the total chronic input volume. Widespread and continuous hillslope sediment inputs may influence channel grain sizes and aquatic habitat more than a single discrete sediment pulse. Depending on the magnitudes of flow hydrograph and sediment supply alterations, climate change may induce no differences in grain sizes or very dramatic changes with significant consequences for long‐term sustainability. Copyright © 2013 John Wiley & Sons, Ltd.
Evaluation of two rapid antigen assays, BioStar Strep A OIA and Pacific Biotech CARDS O.S., and culture for detection of group A streptococci in throat swabs

Dale et al. evaluated two rapid antigen assays to detect group A streptococci in throat swabs, the Strep A OIA (OIA; BioStar, Inc., Boulder, Col.) and CARDS O.S. (O.S.; Pacific Biotech, Inc., San Diego, Calif.) (1). The authors concluded that compared with their standard culture method, OIA is insufficiently sensitive to eliminate the need for backup cultures for specimens with negative OIA results. These conclusions are different from the ones we previously published (6). From the data the authors provided in their two tables, some comparisons which appear in our Tables 1 through 3 were calculated. Several discrepancies between these calculated values and what the authors report in their article exist. First, while the authors say that 746 swabs were obtained but 6 were excluded from analysis, our calculations indicate that 746 were actually used for the calculation of the statistics. Second, if these tables are correct, then the authors should explain how 10 false-positives could be detected on sheep blood agar (SBA) (Table 1). Third, the single-plate SBA culture detected 156 positive samples, while the Strep OIA detected 152 (from the authors’ Table 2 and our Table 3). The McNemar analysis shows the two methods to be equivalent and statistically indistinguishable from one another in sensitivity. We have several other points concerning the authors’ interpretation of the data. The authors state that ‘‘the performance of our standard SBA protocol. exceeded those of the culture methods used by Harbeck et al. . ’’ This statement is made without any supporting data. While the authors claim that the sensitivity of their SBA culture equalled 97.2%, the data in their Table 1 show that a sensitivity of 92.3% was achieved for the SBA swab used for the OIA test and 94.1% for the SBA swab used for the O.S. test. In addition, it is difficult to make direct comparisons between the two studies, since the authors used unmatched, dual swabs, while we used a single swab. The authors used dual SBA plates and Todd-Hewitt broth (TH) as their ‘‘gold standard. ’’ This biases the results in culture’s favor. In our studies we used TH when OIA and SBA were discrepant and as a tool to see if there were low levels of viable organisms present. From a clinical prospective, the routine agar culture (SBA with fluorescent antibody confirmation) reported by the authors suggests a different result than that indicated by the author’s choice of ‘‘true positives. ’’ Table 3 indicates that SBA culture missed 22 of 178 positives (the sum of OIA positives and SBA positives, OIA negatives and SBA TABLE 2. OIA results versus true positives
Surges of Antarctic Bottom Water into the North Atlantic

Abstract Current meter records show that Antarctic Bottom Water surges into the western North Atlantic with roughly a sixty-day period. A time-dependent mass budget which incorporates estimated volume fluxes from geostrophic calculations, surges with a sixty-day period, a known time-average volume of the very coldest water in the North Atlantic, and a constant mixing coefficient predicts vertical excursions of 160–230 meters for the 1.1° isotherm and 45–60 meters for the 1.2° isotherm. Available data do not reveal such an excursion. The reason for the lack of the excursions, is that earlier estimates of volume of the very coldest water were too small. Corrected tables are presented. The disagreement between the current meter results and the geostrophic circulations remains.
15-Deoxy-Δ12,14-prostaglandin J2Induces G1 Arrest and Differentiation Marker Expression in Vascular Smooth Muscle Cells

In search of substances useful for the treatment of atherosclerotic vascular diseases, we studied the effects of 15-deoxy-Δ12,14-prostaglandin J2(15d-PGJ2), a natural ligand for peroxisome proliferator-activated receptor γ, on the proliferation and differentiation of vascular smooth muscle cells (VSMCs). 15d-PGJ2 but not WY14643, an agonist for peroxisome proliferator-activated receptor α, dose-dependently inhibited VSMC proliferation; the effect was maximal at 12 μM. This compound strongly suppressed the activities of cyclin-dependent kinases (Cdk) 4, 6, and 2, thereby preventing the phosphorylation of the retinoblastoma protein. These Cdks seemed to be inhibited through two mechanisms: the down-regulation of cyclin D1 and the up-regulation of Cdk inhibitor p21Cip1/Waf1/Sdi1. 15d-PGJ2was found to inhibit the phosphatidylinositol 3-kinase/protein kinase B signaling pathway, which mediates cyclin D1 expression. Mitogenic stimulation of quiescent cells decreased the level of mRNA for the smooth muscle-specific myosin heavy-chain SM1, whereas this reduction was prevented by 15d-PGJ2. A long-term treatment of exponentially growing VSMCs with 15d-PGJ2 markedly elevated the mRNA level of SM1 and, moreover, induced SM2, another isoform expressed exclusively in mature VSMCs. 15d-PGJ2 also increased the expression levels of calponin-h1 and smooth muscle α-actin. These results suggest that 15d-PGJ2 induces G1 arrest by two distinct mechanisms and promotes VSMC differentiation.
Biogeophysics: A new frontier in Earth science research

“Biogeophysics” is a rapidly evolving Earth science discipline concerned with the geophysical signatures of microbial interactions with geologic media. It spans the established disciplines of geomicrobiology, biogeoscience, and geophysics. Biogeophysics research in the last decade has confirmed the potential for geophysical techniques to measure not simply the physical and chemical properties of the subsurface, as already well established, but also to detect microbes, microbial growth, and microbe‐mineral interactions, thus representing a major paradigm shift in geophysical thinking. In this review we begin by defining biogeophysics and provide a historical perspective. We then consider microbial alterations of petrophysical properties as such alteration is the source of most biogeophysical signals. Our review then focuses on geophysical interrogation of microbial processes, including the direct detection of microbial cells and biofilm formation, microbial metabolic by‐products, microbe‐mediated redox processes, and biogeochemical and microbe‐mineral transformations. We conclude by discussing challenges, opportunities, and potential new applications of biogeophysics to the exploration of life in extreme environments, e.g., the deep biosphere, the cryosphere, and other planets. We find that published biogeophysics studies to date are mostly observation based, presenting only empirical relationships between microbial and geophysical variables. Future research endeavors must focus on developing theoretical and/or numerical models for predicting geophysical signals arising from microbial activity.
Cognitive Reserve from the Perspective of Preclinical Alzheimer Disease: 2020 Update

The aging of the population, which is accompanied by an increasing prevalence of Alzheimer disease (AD), makes it imperative to identify factors that reduce risk of onset of dementia. The increasing evidence that AD pathologic process begins to be deposited in the brain by mid-life1 has led to an expanding focus on potentially modifiable lifestyle factors that may impact an individual’s risk of cognitive decline and dementia. One such commonly studied factor is cognitive reserve (CR). The concept of CR grew out of observations that there can be a marked discrepancy between an individual’s clinical symptomatology and estimates of the amount of neuropathologic process in the brain. For example, an early study by Stern and colleagues2 that began investigating this issue reported that among individuals with probable AD, and matched for clinical severity, those with more years of education had more advanced pathologic process, as indicated by less cerebral blood flow in ADvulnerable regions.
Delta progradation driven by an advancing sediment source: Coupled theory and experiment describing the evolution of elongated deltas

Most of the models of alluvial fan and delta morphodynamics to date have used one of two assumptions concerning the upstream boundary condition: (1) a fixed sediment feed point at the vertex or (2) a feed point corresponding to a bedrock‐alluvial transition that, e.g., migrates upstream under conditions of constant base level. Here, however, we present both experimental and numerical results pertaining to a new configuration, i.e., one in which the sediment feed point migrates downstream. The research is motivated by the operation of the tailings pond of a mine in which a delta forms. The mine operators must frequently move the outfalls of their slurry pipelines downstream to avoid their burial under sediment as the delta aggrades. This downstream migration results in a characteristic delta configuration. Under the right conditions, as the tailings delta progrades downstream, it does not have time to fill all the available space in the lateral direction, thus leaving unfilled open water on either side. The result is the formation of an elongated delta. Here we use both experiments and numerical modeling to characterize the control of the feed point migration rate on the lateral extent of the prograding deltas. We use these results to obtain a partial explanation of natural elongated deltas. In the case of such deltas, the downstream progradation of natural levees provides an analog to the downstream migration of the outfall of a slurry pipeline.
The structure and distribution of carbon in 3.5 Ga Apex chert: Implications for the biogenicity of Earth`s oldest putative microfossils

Abstract The oldest putative microfossils on Earth occur in the 3.5 Ga Apex chert of the Warrawoona Group, Western Australia. We have analyzed disseminated interstitial carbon found within Apex chert using transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS) to address the controversy regarding its state of structural disorder. We found that the carbonaceous material is structurally amorphous, with no evidence of graphitization, and contains aromatic domains, most likely as polyaromatic ring structures, similar to preserved kerogen in bonafide microfossils. In addition, amorphous carbonaceous material occurs as a grain boundary phase between quartz crystals and within fluid inclusions in quartz crystals, indicating that hydrocarbons moved through the chert during crystallization and hydrothermal alteration. The results suggest that the carbonaceous material is similar in structure to microfossil kerogen, implying the microbe-like features within Apex chert are also microfossils. However, this kerogen-like material may also be produced abiotically via Fischer- Tropsch-type (FTT) synthesis reactions in an ancient hydrothermal vent.