bluuebunny/crossref_metadata_2025_split huggingface dataset:
Palaeomagnetism and geochronology of mid-Neoproterozoic Yanbian dykes, South China: implications for a
c.
820–800 Ma true polar wander event and the reconstruction of Rodinia
Authors: Niu Jiawen , Li Zheng-Xiang , Zhu Weiguang 
Published: December 2015

Abstract

We present new palaeomagnetic data from two generations of mafic dykes in the Yanbian region of the western South China Block, dated by the zircon U–Pb method at 824±6 and 806±8 Ma, respectively. The primary origin for the characteristic remanent magnetizations is supported by a positive baked contact test, a dyke-tilt test and rock magnetic data. After tilt corrections, 10 dykes from the
c.
824 Ma group gave a mean remanent direction of
D
=230.1°,
I
=−72.6° with
k
=16.3 and α
95
=12.3°, corresponding to a palaeopole at 42.5 °N, 131.8 °E with
A
95
=19.0°. Three dykes from the
c.
806 Ma group give a mean direction of
D
=284.5°,
I
=42.6° with
k
=76.5 and α
95
=14.2, corresponding to a virtual geomagnetic pole (VGP) at 18.2 °N, 31.0 °E with
A
95
=20.4°. After correcting for a 5° vertical-axis rotation of the study region, the two pole positions are at 45.1 °N, 130.4 °E and 14.1 °N, 32.5 °E, respectively. The
c.
825–720 Ma palaeopole position from South China, East Svalbard and neighbouring continents fall on great circles on two alternative Rodinia reconstructions, possibly reflecting oscillating inertial interchange true polar wander events (IITPWs).
Inapproximability for Antiferromagnetic Spin Systems in the Tree Nonuniqueness Region
Authors: Galanis Andreas , Štefankovič Daniel , Vigoda Eric 
Published: December 2015

A remarkable connection has been established for antiferromagnetic 2-spin systems, including the Ising and hard-core models, showing that the computational complexity of approximating the partition function for graphs with maximum degree Δ undergoes a phase transition that coincides with the statistical physics uniqueness/nonuniqueness phase transition on the infinite Δ-regular tree. Despite this clear picture for 2-spin systems, there is little known for multispin systems. We present the first analog of this in approximability results for multispin systems.
The main difficulty in previous inapproximability results was analyzing the behavior of the model on random Δ-regular bipartite graphs, which served as the gadget in the reduction. To this end, one needs to understand the moments of the partition function. Our key contribution is connecting: (i) induced matrix norms, (ii) maxima of the expectation of the partition function, and (iii) attractive fixed points of the associated tree recursions (belief propagation). The view through matrix norms allows a simple and generic analysis of the second moment for any spin system on random Δ-regular bipartite graphs. This yields concentration results for any spin system in which one can analyze the maxima of the first moment. The connection to fixed points of the tree recursions enables an analysis of the maxima of the first moment for specific models of interest.

For
k
-colorings we prove that for even
k
, in a tree nonuniqueness region (which corresponds to
k
< Δ) there is no FPRAS, unless NP = RP, to approximate the number of colorings for triangle-free Δ-regular graphs. Our proof extends to the antiferromagnetic Potts model, and, in fact, to every antiferromagnetic model under a mild condition.
How we may think
Authors: Schuler Douglas 
Published: December 2015

Seventy years after Vannevar Bush's seminal article his paper argues that societal or group thinking is as important as individual thinking. The phenomenon of civic intelligence, the capability of collectivities to address significant shared issues efficiently and equitably, is explored, especially in relation to other social / psychological phenomena including collective intelligence and metacognition. The paper's strongest claim is that contemporary conditions absolutely compel us to take seriously the need for consciously improving the civic intelligence of the world's citizenry.
This article was originally published in the Spanda Journal in a special issue devoted to Systemic Change, Vol. VI, 1, 2015. (http://www.spanda.org/SpandaJounrnal_VI,1.pdf). It has been reprinted with permission from the author.
Altered Maturation Status and Possible Immune Exhaustion of CD8 T Lymphocytes in the Peripheral Blood of Patients Presenting With Acute Coronary Syndromes
Authors: Zidar David A. , Mudd Joseph C. , Juchnowski Steven , Lopes Joao P. , Sparks Sara , Park Samantha S. , Ishikawa Masakazu , Osborne Robyn , Washam Jeffrey B. , Chan Cliburn , Funderburg Nicholas T. , Owoyele Adeyinka , Alaiti Mohamad A. , Mayuga Myttle , Orringer Carl , Costa Marco A. , Simon Daniel I. , Tatsuoka Curtis , Califf Robert M. , Newby L. Kristin , Lederman Michael M. , Weinhold Kent J. 
Published: December 2015

Objective—
Inflammation in response to oxidized lipoproteins is thought to play a key role in acute coronary syndromes (ACS), but the pattern of immune activation has not been fully characterized. We sought to perform detailed phenotypic and functional analysis of CD8 T lymphocytes from patients presenting with ACS to determine activation patterns and potential immunologic correlates of ACS.

Approach and Results—

We used polychromatic flow cytometry to analyze the cytokine production profiles of naïve, effector, and memory CD8 T cells in patients with ACS compared with control subjects with stable coronary artery disease. ACS was associated with an altered distribution of circulating CD8
+
T-cell maturation subsets with reduced proportions of naïve cells and expansion of effector memory cells. ACS was also accompanied by impaired interleukin-2 production by phenotypically naïve CD8 T cells. These results were validated in a second replication cohort. Naïve CD8 cells from patients with ACS also had increased expression of programmed cell death-1, which correlated with interleukin-2 hypoproduction. In vitro, stimulation of CD8 T cells with oxidized low-density lipoprotein was sufficient to cause programmed cell death-1 upregulation and diminished interleukin-2 production by naïve CD8 T cells.

Conclusions—

In this exploratory analysis, naïve CD8
+
T cells from patients with ACS show phenotypic and functional characteristics of immune exhaustion: impaired interleukin-2 production and programmed cell death-1 upregulation. Exposure to oxidized low-density lipoprotein recapitulates these features in vitro. These data provide evidence that oxidized low-density lipoprotein could play a role in immune exhaustion, and this immunophenotype may be a biomarker for ACS.
Mutual Information, Fisher Information, and Efficient Coding
Authors: Wei Xue-Xin , Stocker Alan A. 
Published: December 2015

Fisher information is generally believed to represent a lower bound on mutual information (Brunel & Nadal, 1998 ), a result that is frequently used in the assessment of neural coding efficiency. However, we demonstrate that the relation between these two quantities is more nuanced than previously thought. For example, we find that in the small noise regime, Fisher information actually provides an upper bound on mutual information. Generally our results show that it is more appropriate to consider Fisher information as an approximation rather than a bound on mutual information. We analytically derive the correspondence between the two quantities and the conditions under which the approximation is good. Our results have implications for neural coding theories and the link between neural population coding and psychophysically measurable behavior. Specifically, they allow us to formulate the efficient coding problem of maximizing mutual information between a stimulus variable and the response of a neural population in terms of Fisher information. We derive a signature of efficient coding expressed as the correspondence between the population Fisher information and the distribution of the stimulus variable. The signature is more general than previously proposed solutions that rely on specific assumptions about the neural tuning characteristics. We demonstrate that it can explain measured tuning characteristics of cortical neural populations that do not agree with previous models of efficient coding.
Modeling the Interaction between Quasigeostrophic Vertical Motion and Convection in a Single Column
Authors: Nie Ji , Sobel Adam H. 
Published: December 2015

Abstract
A single-column modeling approach is proposed to study the interaction between convection and large-scale dynamics using the quasigeostrophic (QG) framework. This approach extends the notion of “parameterization of large-scale dynamics,” previously applied in the tropics via the weak temperature gradient approximation and other comparable methods, to the extratropics, where balanced adiabatic dynamics plays a larger role in inducing large-scale vertical motion. The diabatic heating in an air column is resolved numerically by a single-column model or a cloud-resolving model. The large-scale vertical velocity, which controls vertical advection of temperature and moisture, is computed through the QG omega equation including the dry adiabatic terms and the diabatic heating term. The component due to diabatic heating can be thought of as geostrophic adjustment to that heating and couples the convection to the large-scale vertical motion. The approach is demonstrated using two representations of convection: a single-column model and linear response functions derived by Z. Kuang from a large set of cloud-resolving simulations. The results are qualitatively similar in both cases. The behavior of convection that is strongly coupled to large-scale dynamics is significantly different from that in the uncoupled case. The positive feedback of the diabatic heating on the large-scale vertical motion reduces the stability of the system, extends the decay time scale after initial perturbations, and increases the amplitude of convective responses to transient large-scale perturbations or imposed forcings. The diabatic feedback of convection on vertical motion is strongest for horizontal wavelengths on the order of the Rossby deformation radius.
An Energy Conservation Analysis of Ocean Drift in the CMIP5 Global Coupled Models*
Authors: Hobbs Will , Palmer Matthew D. , Monselesan Didier 
Published: December 2015

Abstract
Climate model simulations of changes to Earth’s energy budget are fundamental to improve understanding of both historical and future climate change. However, coupled models are prone to “drift” (i.e., they contain spurious unforced trends in state variables) due to incomplete spinup or nonclosure of the energy budget. This work assesses the globally integrated energy budgets of 25 models in phase 5 of CMIP (CMIP5). It is shown that for many of the models there is a significant disagreement between ocean heat content changes and net top-of-atmosphere radiation. The disagreement is largely time-constant and independent of forcing scenario. Furthermore, most of the nonconservation seems to occur as a result of energy leaks external to the ocean model realm. After drift correction, the time-varying energy budget is consistent at decadal time scales, and model responses to climate forcing are not sensitive to the magnitude of their drift. This demonstrates that, although drift terms can be significant, model output can be corrected post hoc without biasing results.
Evaluating Satellite Precipitation Error Propagation in Runoff Simulations of Mountainous Basins
Authors: Mei Yiwen , Nikolopoulos Efthymios I. , Anagnostou Emmanouil N. , Borga Marco 
Published: December 2015

AbstractThis study investigates the error characteristics of six quasi-global satellite precipitation products and their error propagation in flow simulations for a range of mountainous basin scales (255–6967 km2) and two different periods (May–August and September–November) in northeast Italy. Statistics describing the systematic and random error, the temporal similarity, and error ratios between precipitation and runoff are presented. Overall, strong over-/underestimation associated with the near-real-time 3B42/Climate Prediction Center morphing technique (CMORPH) products is shown. Results suggest positive correlation between the systematic error and basin elevation. Performance evaluation of flow simulations yields a higher degree of consistency for the moderate to large basin scales and the May–August period. Gauge adjustment for the different satellite products is shown to moderate their error magnitude and increase their correlation with reference precipitation and streamflow simulations. Moreover, ratios of precipitation to streamflow simulation error metrics show dependencies in terms of magnitude and variability. Random error and temporal dissimilarity are shown to reduce from basin-average rainfall to the streamflow simulations, while the systematic error exhibits no clear pattern in the rainfall–runoff transformation.
Using coupled energy, airflow and indoor air quality software (TRNSYS/CONTAM) to evaluate building ventilation strategies
Authors: Dols W Stuart , Emmerich Steven J , Polidoro Brian J 
Published: December 2015

Building energy analysis tools are available in many forms that provide the ability to address a broad spectrum of energy-related issues in various combinations. Often these tools operate in isolation from one another, making it difficult to evaluate the interactions between related phenomena and interacting systems, forcing oversimplified assumptions to be made about various phenomena that could otherwise be addressed directly with another tool. One example of such interdependence is the interaction between heat transfer, inter-zone airflow, and indoor contaminant transport. To better address these interdependencies, the National Institute of Standards and Technology has developed an updated version of the multi-zone airflow and contaminant transport modeling tool, CONTAM, along with a set of utilities to enable coupling of the full CONTAM model with the TRNSYS simulation tool in a more seamless manner and with additional capabilities that were previously not available. This article provides an overview of these new capabilities and applies them to simulating a medium-size office building. These simulations address the interaction between whole-building energy, airflow, and contaminant transport in evaluating various ventilation strategies including natural and demand-controlled ventilation. Practical application: CONTAM has been in practical use for many years allowing building designers, as well as indoor air quality (IAQ) and ventilation system analysts, to simulate the complex interactions between building physical layout and HVAC system configuration in determining building airflow and contaminant transport. It has been widely used to design and analyze smoke management systems and evaluate building performance in response to chemical, biological, and radiological events. While CONTAM has been used to address design and performance of buildings implementing energy conserving ventilation systems, e.g. natural and hybrid, this new coupled simulation capability will enable users to apply the tool to couple CONTAM with existing energy analysis software to address the interaction between IAQ considerations and energy conservation measures in building design and analysis. This article presents two practical case studies using the coupled modeling tool to evaluate IAQ performance of a CO2-based demand-controlled ventilation system under different levels of building envelope air tightness and the design and analysis of a natural ventilation system.
Revival of monophasic contrast injection protocols: superiority of a monophasic injection protocol compared to a biphasic injection protocol in high-pitch CT angiography
Authors: Apitzsch Jonas , Jost Gregor , Bonifer Elisabeth , Keulers Annika , Pietsch Hubertus , Mahnken Andreas Horst 
Published: December 2015

Background Biphasic injection protocols are frequently used because they yield homogenous contrast enhancement. We hypothesize that with faster scanners and shorter scan times, biphasic injection protocols are no longer necessary. Purpose To evaluate whether a monophasic injection protocol is equivalent to a biphasic protocol in terms of contrast enhancement and homogeneity. Material and Methods Repeated high-pitch CTA (pitch 3) and conventional standard-pitch computed tomography angiography (CTA) (pitch 1.2) from the cervical region to the symphysis was performed in seven beagles (11.2 ± 2.5 kg) in a cross-over study design. Arterial contrast enhancement was measured along the z-axis in the ascending, descending, and abdominal aorta and the iliac arteries. The z-axis is the longitudinal axis of the human body and at the same time the direction in which the CT table is moving. The data were analyzed using repeated measures ANOVA with a post-hoc t-test and visual assessment of the scans. Results In high-pitch CTA, monophasic injection protocols were superior to biphasic injection protocols in enhancement levels ( P < 0.05) and enhancement homogeneity along the z-axis ( P < 0.05). In conventional CTA, enhancement levels did not differ. Contrast homogeneity was better for biphasic protocols. Conclusion High-pitch CTA monophasic injection protocols are superior to biphasic injection protocols, due to a higher and more homogeneous contrast enhancement with the same amount of contrast medium used.
In vivo molecular neuroimaging of glucose utilization and its association with fibrillar amyloid-β load in aged APPPS1-21 mice
Authors: Waldron Ann-Marie , Wintmolders Cindy , Bottelbergs Astrid , Kelley Jonathan B. , Schmidt Mark E. , Stroobants Sigrid , Langlois Xavier , Staelens Steven 
Published: December 2015

Abstract
Introduction
Radioligand imaging is a powerful in vivo method to assess the molecular basis of Alzheimer’s Disease. We therefore aimed to visualize the pathological deposition of fibrillar amyloid-β and neuronal dysfunction in aged double transgenic mice.

Methods
Using non-invasive positron emission tomography (PET) we assessed brain glucose utilization with [18F]FDG and fibrillar amyloidosis with [11C]PiB and [18F]AV45 in 12 month old APPPS1-21 (n = 10) mice and their age-matched wild-type controls (n = 15). PET scans were analyzed with statistical parametric mapping (SPM) to detect significant differences in tracer uptake between genotypes. After imaging, mice were sacrificed and ex vivo measures of amyloid-β burden with immunohistochemistry as well as glucose utilization with [14C]-2DG autoradiography were obtained as gold standards.

Results
Voxel-wise SPM analysis revealed significantly decreased [18F]FDG uptake in aged APPPS1-21 mice in comparison to WT with the thalamus (96.96 %, maxT = 3.35) and striatum (61.21 %, maxT = 3.29) demonstrating the most widespread reductions at the threshold of p < 0.01. [11C]PiB binding was significantly increased in APPPS1-21 mice, most notably in the hippocampus (87.84 %, maxT = 7.15) and cortex (69.08 %, maxT = 7.95), as detected by SPM voxel-wise analysis at the threshold of p < 0.01. Using the same threshold [18F]AV45 uptake was comparably lower with less significant differences. Compared to their respective ex vivo equivalents [18F]FDG demonstrated significant positive correlation to [14C]2-DG autoradiography (r = 0.67, p <0.0001) while [11C]PiB and [18F]AV45 binding did not correlate to ex vivo immunohistochemistry for amyloid-β (r = 0.25, p = 0.07 and r = 0.17, p = 0.26 respectively). Lastly no correlation was observed between regions of high amyloid burden and those with decreased glucose utilization (r = 0.001, p = 0.99).

Conclusions
Our findings support that fibrillar amyloid-β deposition and reduced glucose utilization can be visualized and quantified with in vivo μPET imaging in aged APPPS1-21 mice. Therefore, the combined use of [18F]FDG and amyloid μPET imaging can shed light on the underlying relationship between fibrillar amyloid-β pathology and neuronal dysfunction.
Diagnostic value of cerebrospinal fluid Aβ ratios in preclinical Alzheimer’s disease
Authors: Adamczuk Katarzyna , Schaeverbeke Jolien , Vanderstichele Hugo M. J. , Lilja Johan , Nelissen Natalie , Van Laere Koen , Dupont Patrick , Hilven Kelly , Poesen Koen , Vandenberghe Rik 
Published: December 2015

Abstract
Introduction
In this study of preclinical Alzheimer’s disease (AD) we assessed the added diagnostic value of using cerebrospinal fluid (CSF) Aβ ratios rather than Aβ42 in isolation for detecting individuals who are positive on amyloid positron emission tomography (PET).

Methods
Thirty-eight community-recruited cognitively intact older adults (mean age 73, range 65–80 years) underwent 18F-flutemetamol PET and CSF measurement of Aβ1-42, Aβ1-40, Aβ1-38, and total tau (ttau). 18F-flutemetamol retention was quantified using standardized uptake value ratios in a composite cortical region (SUVRcomp) with reference to cerebellar grey matter. Based on a prior autopsy validation study, the SUVRcomp cut-off was 1.57. Sensitivities, specificities and cut-offs were defined based on receiver operating characteristic analysis with CSF analytes as variables of interest and 18F-flutemetamol positivity as the classifier. We also determined sensitivities and CSF cut-off values at fixed specificities of 90 % and 95 %.

Results
Seven out of 38 subjects (18 %) were positive on amyloid PET. Aβ42/ttau, Aβ42/Aβ40, Aβ42/Aβ38, and Aβ42 had the highest accuracy to identify amyloid-positive subjects (area under the curve (AUC) ≥ 0.908). Aβ40 and Aβ38 had significantly lower discriminative power (AUC = 0.571). When specificity was fixed at 90 % and 95 %, Aβ42/ttau had the highest sensitivity among the different CSF markers (85.71 % and 71.43 %, respectively). Sensitivity of Aβ42 alone was significantly lower under these conditions (57.14 % and 42.86 %, respectively).

Conclusion
For the CSF-based definition of preclinical AD, if a high specificity is required, our data support the use of Aβ42/ttau rather than using Aβ42 in isolation.
Research-Focused Isolation of Human Islets From Donors With and Without Diabetes at the Alberta Diabetes Institute IsletCore
Authors: Lyon James , Manning Fox Jocelyn E. , Spigelman Aliya F. , Kim Ryekjang , Smith Nancy , O'Gorman Doug , Kin Tatsuya , Shapiro A. M. James , Rajotte Raymond V. , MacDonald Patrick E. 
Published: December 2015

Abstract
Recent years have seen an increased focus on human islet biology, and exciting findings in the stem cell and genomic arenas highlight the need to define the key features of mature human islets and β-cells. Donor and organ procurement parameters impact human islet yield, although for research purposes islet yield may be secondary in importance to islet function. We examined the feasibility of a research-only human islet isolation, distribution, and biobanking program and whether key criteria such as cold ischemia time (CIT) and metabolic status may be relaxed and still allow successful research-focused isolations, including from donors with type 1 diabetes and type 2 diabetes. Through 142 isolations over approximately 5 years, we confirm that CIT and glycated hemoglobin each have a weak negative impacts on isolation purity and yield, and extending CIT beyond the typical clinical isolation cutoff of 12 hours (to ≥ 18 h) had only a modest impact on islet function. Age and glycated hemoglobin/type 2 diabetes status negatively impacted secretory function; however, these and other biological (sex, body mass index) and procurement/isolation variables (CIT, time in culture) appear to make only a small contribution to the heterogeneity of human islet function. This work demonstrates the feasibility of extending acceptable CIT for research-focused human islet isolation and highlights the biological variation in function of human islets from donors with and without diabetes.