Miracle-dz/UniFAR-FTUs huggingface dataset:
A wind comparison study using an ocean general circulation model for the 1997–1998 El Niño

Predictions of the 1997–1998 El Nino exhibited a wide range of forecast skill that were dependent, in part, on the wind-driven initial conditions for the ocean. In this study the results of a reduced gravity, primitive equation, sigma coordinate ocean general circulation model are compared and contrasted when forced by several different wind products for the 1997–1998 El Nino/La Nina. The different wind products include atmospheric model winds, satellite wind products, and a subjective analysis of ship and in situ winds. The model results are verified against fields of observed sea level anomalies from TOPEX/Poseidon data, sea surface temperature analyses, and subsurface temperature from the Tropical Atmosphere-Ocean buoy array. Depending on which validation data type one chooses, different wind products provide the best forcing fields for simulating the observed signal. In general, the model results forced by satellite winds provide the best simulations of the spatial and temporal signal of the observed sea level. This is due to the accuracy of the meridional gradient of the zonal wind stress component that these products provide. Differences in wind forcing also affect subsurface dynamics and thermodynamics. For example, the wind products with the weakest magnitude best reproduce the sea surface temperature (SST) signal in the eastern Pacific. For these products the mixed layer is shallower, and the thermocline is closer to the surface. For such simulations the subsurface thermocline variability influences the variation in SST more than in reality. The products with the greatest wind magnitude have a strong cold bias of >1.5°C in the eastern Pacific because of increased mixing. The satellite winds along with the analysis winds correctly reproduce the depth of the thermocline and the general subsurface temperature structure.
High frequency measurements of HFCs at a remote site in east Asia and their implications for Chinese emissions

High frequency monitoring of hydrofluorocarbons (HFCs) and some other halocarbons in the atmosphere has been performed at Hateruma Island (lat. 24.1°N, long. 123.8°E), a background site in east Asia. The observed concentrations showed occasional short‐term enhancement events over hours to days as well as a clear seasonal variation, being lower in summer than in other seasons. We found that HFC‐23 enhancements were closely related to the air transport from China. Using a tagged simulation from three‐dimensional transport model and a tracer‐ratio technique, the emission rate of HFC‐23 from China was estimated to amount to 10 Gg (= 10 000 metric tonnes) per year with an uncertainty of 50%, which could account for two thirds of the total global emission. HFCs emitted from Japan, Korea, and Taiwan were characterized by a predominance of HFC‐134a with very little contribution of HFC‐23.
Long-Term Exposure to Concentrated Ambient PM2.5 Increases Mouse Blood Pressure through Abnormal Activation of the Sympathetic Nervous System: A Role for Hypothalamic Inflammation

Background: Exposure to particulate matter ≤ 2.5 μm in diameter (PM2.5) increases blood pressure (BP) in humans and animal models. Abnormal activation of the sympathetic nervous system may have a role in the acute BP response to PM2.5 exposure. The mechanisms responsible for sympathetic nervous system activation and its role in chronic sustenance of hypertension in response to PM2.5 exposure are currently unknown. Objectives: We investigated whether central nervous system inflammation may be implicated in chronic PM2.5 exposure-induced increases in BP and sympathetic nervous system activation. Methods: C57BL/6J mice were exposed to concentrated ambient PM2.5 (CAPs) for 6 months, and we analyzed BP using radioactive telemetric transmitters. We assessed sympathetic tone by measuring low-frequency BP variability (LF-BPV) and urinary norepinephrine excretion. We also tested the effects of acute pharmacologic inhibitors of the sympathetic nervous system and parasympathetic nervous system. Results: Long-term CAPs exposure significantly increased basal BP, paralleled by increases in LF-BPV and urinary norepinephrine excretion. The increased basal BP was attenuated by the centrally acting α2a agonist guanfacine, suggesting a role of increased sympathetic tone in CAPs exposure–induced hypertension. The increase in sympathetic tone was accompanied by an inflammatory response in the arcuate nucleus of the hypothalamus, evidenced by increased expression of pro-inflammatory genes and inhibitor kappaB kinase (IKK)/nuclear factor–kappaB (NF-κB) pathway activation. Conclusion: Long-term CAPs exposure increases BP through sympathetic nervous system activation, which may involve hypothalamic inflammation. Citation: Ying Z, Xu X, Bai Y, Zhong J, Chen M, Liang Y, Zhao J, Liu D, Morishita M, Sun Q, Spino C, Brook RD, Harkema JR, Rajagopalan S. 2014. Long-term exposure to concentrated ambient PM2.5 increases mouse blood pressure through abnormal activation of the sympathetic nervous system: a role for hypothalamic inflammation. Environ Health Perspect 122:79–86; http://dx.doi. org/10.1289/ehp.1307151
Things We Do For No Reason: Supplemental Oxygen for Patients without Hypoxemia.

Inspired by the ABIM Foundation’s Choosing Wisely® campaign, the “Things We Do for No ReasonTM” (TWDFNR) series reviews practices that have become common parts of hospital care but may provide little value to our patients. Practices reviewed in the TWDFNR series do not represent “black and white” conclusions or clinical practice standards but are meant as a starting place for research and active discussions among hospitalists and patients. We invite you to be part of that discussion.
Integrated 2D 4-C OBC velocity analysis of near-seafloor sediments, Green Canyon, Gulf of Mexico

Using 2D four-component ocean-bottom-cable (2D 4-C OBC) seismic data processed in common-receiver gathers, we developed robust VP and VS interval velocities for the near-seafloor strata. A vital element of the study was to implement iterative interpretation techniques to correlate near-seafloor P-P and P-SV images. Initially, depth-equivalent P-P and P-SV layers were interpreted by visually matching similar events in both seismic modes. Complementary 1D ray-tracing analyses then determined interval values of subsea-floor VP and VS velocities across a series of earth layers extending from the seafloor to below the base of the hydrate stability zone (BHSZ) to further constrain these interpretations. Iterating interpretation of depth-equivalent horizons with velocity analyses allowed us to converge on physically reasonable velocity models. Simultaneous VP and VS velocity analysis provided additional model constraints in areas where data quality of one reflection mode (usually VP in the near-seafloor environm.
Trends in River-Ice Break-up Data for the Western James Bay Region of Canada

Trends in river-ice break-up date for the Moose, Albany, and Attawapiskat rivers located in the western James Bay region were examined. Regression analyses revealed several significant, but weak, linear relationships between river ice break-up date and calendar year. The directions of these relationships were also inconsistent, and so the results of the statistical analyses were considered to be inconclusive. Local and indigenous knowledge broadened our analyses with more information on changes in the timing of freeze/thaw cycles. Relatively rapid changes in climate can create problems for conventional approaches including statistical analyses, which require large data sets and long-term trends. The study indicates that while trends in river ice break-up were weak, very recent changes in break-up characteristics (signaled through local knowledge) showed that potentially drastic and rapid changes have occurred within the past few years. Future research in climate and river-ice studies ought to incorporate other knowledge systems to understand important indicators of climate changes.
Evolutionary mysteries in meiosis

Meiosis is a key event of sexual life cycles in eukaryotes. Its mechanistic details have been uncovered in several model organisms, and most of its essential features have received various and often contradictory evolutionary interpretations. In this perspective, we present an overview of these often “weird” features. We discuss the origin of meiosis (origin of ploidy reduction and recombination, two-step meiosis), its secondary modifications (in polyploids or asexuals, inverted meiosis), its importance in punctuating life cycles (meiotic arrests, epigenetic resetting, meiotic asymmetry, meiotic fairness) and features associated with recombination (disjunction constraints, heterochiasmy, crossover interference and hotspots). We present the various evolutionary scenarios and selective pressures that have been proposed to account for these features, and we highlight that their evolutionary significance often remains largely mysterious. Resolving these mysteries will likely provide decisive steps towards understanding why sex and recombination are found in the majority of eukaryotes.
Airborne observations of dust aerosol over the North Atlantic Ocean during ACE-2: Indications for heterogeneous ozone destruction

Aerosol size distribution measurements have been performed in the free troposphere during the Second Aerosol Characterization Experiment (ACE 2) near Tenerife, Canary Islands, in July 1997. During one measurement flight, on July 8, a uniform aerosol layer was encountered between 2.5 and 5.5 km altitude, characterized by a relatively low Aitken mode particle number concentration and high concentrations of accumulation and coarse mode particles, resulting in a relatively large aerosol surface area and mass, which is estimated to be about 400 μg m−3. Five-day backward trajectories indicate that the aerosol in this layer was mineral dust originating from arid regions on the North African continent. The dust layer was associated with reduced ozone mixing ratios. Model simulations have been performed with a photochemical box model including different heterogeneous removal reactions to study the interaction between gas phase chemistry and mineral aerosol. The best agreement between the observed and modeled ozone concentrations was obtained when heterogeneous removal of ozone and precursor gases on dust aerosol were taken into account. Heterogeneous O3 loss is estimated at 4 ppbv O3 per day. Although uncertainties concerning heterogeneous ozone removal remain, in particular related to the reactive uptake coefficient of O3, it is likely that the loss of O3 and precursor gases on mineral dust aerosol significantly reduces the O3 abundance in large-scale dust plumes.
The transition from high temperature creep to fracture in Maryland diabase

The transition from high-temperature creep to brittle fracture in Maryland diabase was investigated as a function of confining pressure and strain rate. Experiments were conducted at 1000°C. Confining pressure was varied to 450 MPa and strain rates from 2×10−3 s−1 to 4×10−6 s−1 At fixed strain rate, the rock strength first increased with pressure, reached a maximum, and then decreased with increasing pressure. Finally, with high pressures, the strength reached an asymptotic value which was the steady state creep strength at that temperature and strain rate. The positive pressure sensitive domain corresponded to brittle behavior, the negative pressure sensitivity domain to a transitional behavior, and the pressure insensitive domain to dislocation creep. The boundary between the last two domains occurred where the strength of the rock was about equal to the confining pressure. Similar variations in strength have been reported in the literature for carbonates and silicates, although not associated with a transitional behavior. Unfaulted specimens deformed in the transitional field showed microcracks and plastically deformed minerals. The boundaries of the transitional domain were extrapolated to geological conditions corresponding to the oceanic lithosphere. The transition depth near ridges is in close agreement with the base of the seismogenic layer (Tapponnier and Francheteau, 1978). However, the old oceanic lithosphere is probably totally brittle over its whole thickness.
The Influence of Disorder in the Synthesis, Characterization and Applications of a Modifiable Two-Dimensional Covalent Organic Framework

Two-dimensional covalent organic frameworks (2D-COFs) have been of increasing interest in the past decade due to their porous structures that ideally can be highly ordered. One of the most common routes to these polymers relies on Schiff-base chemistry, i.e., the condensation reaction between a carbonyl and an amine. In this report, we elaborate on the condensation of 3,6-dibromobenzene-1,2,4,5-tetraamine with hexaketocyclohexane (HKH) and the subsequent carbonylation of the resulting COF, along with the possibility that the condensation reaction on HKH can result in a trans configuration resulting in the formation of a disordered 2D-COF. This strategy enables modification of COFs via bromine substitution reactions to place functional groups within the pores of the materials. Ion-sieving measurements using membranes from this COF, reaction of small molecules with unreacted keto groups along with modeling studies indicate disorder in the COF polymerization process. We also present a Monte Carlo simulation that demonstrates the influence of even small amounts of disorder upon both the 2D and 3D structure of the resulting COF.
Carbon-isotope composition of Lower Cretaceous fossil wood: Ocean-atmosphere chemistry and relation to sea-level change

The carbon-isotope composition of fossil wood fragments, collected through a biostratigraphically well-constructed Aptian (Lower Cretaceous) shallow-marine siliciclastic succession on the Isle of Wight, southern Britain, shows distinct variations with time. The results indicate that the stratigraphic signature of {delta}{sup 13}C{sub wood} through the Aptian was influenced primarily by fluctuations in the isotopic composition of CO{sub 2} in the global ocean-atmosphere system, as registered in marine carbonates elsewhere, and was not governed by local paleoenvironmental and/or paleoecological factors. Negative and positive excursions in {delta}{sup 13}C{sub wood} through the lower Aptian occur in phase with inferred transgressions and regressions, respectively -- a pattern that contrasts with that observed in many previous studies for different time intervals. The relationship between {delta}{sup 13}C variations and relative sea-level change is tentatively interpreted as a response to various climatic and eustatic factors, relating to rapid sea-floor spreading, thermal uplift of ocean floor, emplacement of plateaus, volcanic CO{sub 2} emissions, weathering, and sedimentary rate.
Performance Of LED Street Lights InHot Environments

Solid-state LED street lights present significant benefits to street light operators as well as drivers and pedestrians. Questions remain, however, about their performance in high temperature conditions. This paper explores the performance of LED street light in one of the hottest regions in the world. Two LED street lights were installed in an actual street in the city of Al Ain, United Arab Emirates. The street was closed to the traffic and illuminance measurements were taken daily every 10 minutes throughout the summer of 2010. Temperature and relative humidity values were also taken inside the two light fixtures as well as outside the fixtures. The summer of 2010 had significantly high temperatures with one week in July reaching maximum ambient temperatures of 53C. This paper shows the Lux levels as well as the temperature and relative humidity data acquired in the field. Results show fairly stable light levels throughout the summer. The Lux levels did not change by more than 10% throughout the summer.
Russia’s arctic strategies and the future of the Far North

Russia’s Arctic Strategies and the Future of the Far North is an outstanding piece of scholarship, which brings much needed light and depth to a better understanding of Russia’s Arctic interests and strategies. The book thoroughly investigates the key actors and issues involved in Russia’s Arctic. Chapter one explores the politics of Russia’s Arctic policies, from key institutions to the decision-making process, and the role the Arctic plays in Russia’s foreign policy. Chapter two looks at the place the Far North plays in Russian identity. Chapter three discusses the spatial and demographic challenges Russia faces in developing the Far North. Chapter four calculates the impact of Arctic climate change on Russia and evaluates Russia’s climate change policy. Chapter five examines Russia’s stance on Arctic territorial disputes such as the Svarlbard Archipelago, and those relating to the Barents, Bering and Chukchi Seas. Chapter six is a knowledgeable, sober, analysis of Russian military power in the Arctic. Laruelle urges the reader to look beyond the headlines to examine the reality that present-day Russian military engagement is on a very different scale and order to that followed in the Cold War era. Chapter seven elucidates the see-saw between nationalism and pragmatism in Russia’s Arctic resource exploitation policies. Meanwhile, chapter eight is an informed, and informative, narration of the issues involved in opening up the Northern Sea Route to increase internal and international shipping traffic. Professor Laruelle is a Russian expert, the author of numerous books and scholarly papers on Russian affairs. She has a rich understanding of Russian politics, history and society and is a fluent Russian speaker. She also has a deep understanding of Arctic political, legal, scientific and strategic issues. So, her book can be read as both an interesting account of modern Russia’s policies towards a globally significant region, which is also a key but neglected area of Russia, and a thoughtful analysis of how Russian foreign policy fits within emerging Arctic governance issues. The book is beautifully written, and it is a pleasure to read. It is rich in primary and secondary documentary sources. Russia’s Arctic Strategies and the Future of the Far North makes an extremely useful contribution towards enhancing understandings of local and global perspectives on Arctic affairs and is highly recommended to those who wish to understand both modern Russia and Arctic politics better.
The surface temperature-vegetation index space for land cover and land-cover change analysis

Abstract Most previous applications of coarse scale remote sensing data for land-cover mapping and land-cover change analysis were based on multi-temporal Normalized Difference Vegetation Index (NDVI) data. Recent empirical studies have documented that the combination of measurements of thermal infrared radiation (e.g., land brightness temperature, Ts) and vegetation indices (VI) improves the mapping and monitoring of land cover at broad scales. We investigate the biophysical justification for such a combination, using 10 years of Advanced Very High Resolution Radiometer (AVHRR) global area coverage ( GAC) data over the African continent. First, we review recent findings on the biophysical interpretation of the TS-VI space. Second, we analyse the seasonal time trajectories of different biomes in the TS-NDVI space. Third, we measure the relative role of multi-temporal NDVI and Ts data in the discrimination of land cover classes for land-cover mapping. Fourth, we analyse trajectories of land-cover change in.
A Simulation-Based Method for Quantifying and Mitigating the Effects of Anthropogenic Sound on Marine Mammals

SAFESIMM (Statistical Algorithms For Estimating the Sonar Influence on Marine Megafauna) is a simulation-based framework for calculating the probable numbers of animals affected by underwater sounds; such as active sonar, which has been implicated in marine mammal fatalities. SAFESIMM is the culmination of a large, multi-year collaborative project between BAE Systems and the University of St Andrews. The resulting software tool uses the latest research on the effects of sound on marine mammals together with data on the distribution, abundance and hearing characteristics of these species. The end result is a simulation-based statistical model that quantifies the probability of physical effects and behavioural responses, along with the expected numbers of occurrences and associated uncertainty in the predictions. The parameters used in each simulation are easily altered, allowing rapid comparison of alternative scenarios. This paper describes: 1. The problem in general terms; 2. The logical high-level solut.
Streaming potentials of granular media: Influence of the Dukhin and Reynolds numbers

Laboratory experiments are performed to understand the controlling parameters of the electrical field associated with the seepage of water through a porous material. We use seven glass bead packs with varying mean grain size in an effort to obtain a standard material for the investigation of these electrical potentials. The mean grain size of these samples is in the range 56–3000 μm. We use pure NaCl electrolytes with conductivity in the range 10−4 to 10−1 S m−1 at 25°C. The flow conditions cover viscous and inertial laminar flow conditions but not turbulent flow. In the relationship between the streaming potential coupling coefficient and the grain size, three distinct domains are defined by the values of two dimensionless numbers, the Dukhin and the Reynolds numbers. The Dukhin number represents the ratio between the surface conductivity of the grains (due to conduction in the electrical double layer coating the surface of the grains) and the pore water electrical conductivity. At high Dukhin numbers (≫1) and low Reynolds numbers (≪1), the magnitude of the streaming potential coupling coefficient decreases with the increase of the Dukhin number and depends on the mean grain diameter (and therefore permeability) of the medium. At low Dukhin and Reynolds numbers (≪1), the streaming potential coupling coefficient becomes independent of the microstructure and is given by the well-known Helmholtz-Smoluchowski equation widely used in the literature. At high Reynolds numbers, the magnitude of the streaming potential coupling coefficient decreases with the increase of the Reynolds number in agreement with a new model developed in this paper. A numerical application is made illustrating the relation between the self-potential signal and the intensity of seepage through a leakage in an embankment.
Application of a Convex Phase Retrieval Method to Blind Seismic Deconvolution

A classical strategy for blind seismic deconvolution is to first estimate the autocorrelation of the unknown source wavelet from the data and then recover the wavelet by assuming it has minimum phase. However, computing the minimum phase wavelet directly from the amplitude spectrum can be sensitive to even extremely small errors, especially in the coefficients close to zero. Since the minimum phase requirement follows from an assumption that the wavelet should be as impulsive as possible, we propose to directly estimate an impulsive wavelet by minimizing a weighted $l_2$ penalty subject to a constraint on its amplitude spectrum. This nonconvex model has the form of a phase retrieval problem, in this case recovering a signal given only estimates of the magnitudes of its Fourier coefficients. Following recent work on convex relaxations of phase retrieval problems, we propose a convex semidefinite program for computing an impulsive minimum phase wavelet whose amplitude spectrum is close to a given estimate, and we show that this can be robustly solved by a Douglas Rachford splitting method for convex optimization.