Miracle-dz/UniFAR-FTUs huggingface dataset:
A coral δ18O record of ENSO driven sea surface salinity variability in Fiji (south ‐western tropical Pacific)

The role of salinity in the dynamics and thermodynamics of El Niño ‐ Southern Oscillation (ENSO) events is increasingly being investigated. However, instrumental records of salinity are scarce and short in the tropical Pacific, and there is a clear need for a reliable salinity proxy to extend our knowledge of ENSO through time. Here, we present 40 years of δ18O data from a Fiji coral (16°48′S–177°27′E). The coral δ18O signal integrates both sea surface temperature (SST) and sea surface salinity (SSS) variations. On a seasonal timescale, δ18O is mainly driven by SST changes whereas on an interannual ENSO timescale, it is almost exclusively affected by SSS variability. Since interannual fluctuations of SSS are rather well correlated to the Southern Oscillation Index in Fiji, coral δ18O can be used to reconstruct paleo‐salinity data with some level of confidence. This may help for tracking ENSO influences back in time.
Reward Maximization Through Discrete Active Inference

Abstract Active inference is a probabilistic framework for modeling the behavior of biological and artificial agents, which derives from the principle of minimizing free energy. In recent years, this framework has been applied successfully to a variety of situations where the goal was to maximize reward, often offering comparable and sometimes superior performance to alternative approaches. In this article, we clarify the connection between reward maximization and active inference by demonstrating how and when active inference agents execute actions that are optimal for maximizing reward. Precisely, we show the conditions under which active inference produces the optimal solution to the Bellman equation, a formulation that underlies several approaches to model-based reinforcement learning and control. On partially observed Markov decision processes, the standard active inference scheme can produce Bellman optimal actions for planning horizons of 1 but not beyond. In contrast, a recently developed recursive active inference scheme (sophisticated inference) can produce Bellman optimal actions on any finite temporal horizon. We append the analysis with a discussion of the broader relationship between active inference and reinforcement learning.
Aerosol radiative forcing and climate sensitivity deduced from the Last Glacial Maximum to Holocene transition

We use the temperature, carbon dioxide, methane, and dust concentration record from the Vostok ice core to deduce the aerosol radiative forcing during the Last Glacial Maximum (LGM) to Holocene transition and the climate sensitivity. A novel feature of our analysis is the use of a cooling period between about 42 KYBP (thousand years before present) and LGM to provide a constraint on the aerosol radiative forcing. We find the change in aerosol radiative forcing during the LGM to Holocene transition to be 3.3 ± 0.8 W/m2 and the climate sensitivity between 0.36 and 0.68 K/Wm−2 with a mean value of 0.49 ± 0.07 K/Wm−2. This suggests a 95% likelihood of warming between 1.3 and 2.3 K due to doubling of atmospheric concentration of CO2. The ECHAM5 model simulation suggests that the aerosol optical depth during the LGM may have been almost twice the current value (increase from 0.17 to 0.32).
GEOLOGY OF KAPINGAMARANGI ATOLL, CAROLINE ISLANDS

Kapingamarangi Atoll of the Caroline Islands consists of a peripheral reef, 1000–4000 feet across, surrounding a nearly circular lagoon which is 5 by 6 nautical miles in area and about 240 feet at maximum depth. Thirty-three islands, most of which are less than half a mile in length, are scattered along the eastern half of the peripheral reef. At least 75 patch reefs, most of which are small, nearly symmetrical mounds, rise to the surface of the lagoon. The peripheral reef and the patch reefs, composed largely of the stony structures of corals and coralline algae, have flat upper surfaces, apparently the result of bevelling by waves during a recent lowering of sea level. The islands on the peripheral reef are formed of partially consolidated stratified sediments composed of clastic limestone particles and the shells of marine animals. These islands are migrating lagoonward across the reef flat because of erosion on the seaward sides and the growth of beaches and bars on the opposite sides. Soils on the islands are poorly developed and retain much of the texture, structure, and composition of the parent rock or sediment. They consist chiefly of mechanical mixtures of carbonaceous material and lime gravel, lime sand, or lime mud. Phosphorite is present on some islands and is still forming locally where apatite derived from bird guano is reacting with limestones. The tidal fluctuation of ground-water lenses, determined on islands of several sizes, ranges from about 4 to 18 inches. In one very small island where the water is brackish, the rise is much greater. The time lag between tidal movements and the rise and fall of fresh water in the islands ranges from a few minutes on very small islands up to 5 hours on some large ones. This time lag is controlled by the permeability of rocks composing an island and varies from one area to another according to the distribution of rock types. The lagoon contains six concentric belts of bottom sediment; in each, the composition and texture depend on the depth of water in which it occurs. Lime sand and lime gravel derived for the most part from the shells of animals form most of the sediment, but a lime mud covers the bottom of the deepest parts of the lagoon. Waves and currents cause gradation between types of sediment to a depth of about 30 feet, but little mixing was detected at greater depths.
Frictional estuarine flow in Juan de Fuca Strait, with implications for secondary circulation

Estuarine flow in Juan de Fuca Strait is highly seasonal in nature and an appreciable along-channel surface pressure gradient is coincident with the peak Fraser River discharge. An upper layer momentum balance requires the vertical eddy viscosity Av to be of the order of 0.02 m2 s−1, slightly larger than implied by conventional empirical formulae and used in current models. Mixing in an estuarine channel and a large vertical eddy viscosity should lead to significant cross-channel flows. This secondary circulation, which may resemble internal Ekman layers and intrusions of water mixed at the sloping sides of the strait, is much less understood than the basic along-channel estuarine exchange. Unfortunately, historical current meter data in Juan de Fuca Strait are of insufficient spatial resolution to show the predicted patterns.
Espaço comum de Ensino Superior da União Europeia, América Latina e Caribe (ECES - UEALC): nova forma de incorporação dependente?

Three objectives guide this paper which is focused on the construction of the Common Space of Higher Education - the European Union, Latin America and the Caribbean (CSHE-EUALC): to demonstrate that the imposition of a neoliberal rationale over the higher education systems in the region, via evaluating processes, aims to overcome beliefs and procedures, and to standardize and universalize methods and processes; to highlight the aligning process of higher education institutions from Latin American and Caribbean to the European Higher Education Area; to examine the scope of what may be a new form of incorporation of Latin America and the Caribbean. The central thesis to be discussed considers that the construction of the CSHE-EUALC with the use of means of subordination of the regional universities with use of some parameters and quality indicators are aligned to the interests of core countries of capitalist accumulation, and what is being called knowledge society.
Land-use change between 1978 and 1990 in Dhankuta District, Koshi Hills, Eastern Nepal.

Land-use change over a 12-year period was investigated for a pilot area of 200 km2 of the Middle Mountain zone in Dhankuta District. The studies were based on interpretation of air photographs taken in 1978 and 1990 and field checks on a sample of 13 sites of 300 ha each, representing a 20% sample. Six categories were mapped: agriculture (7 sub-categories); abandoned farmland; forest (7 sub-categories); grazing; shrub; and other (such as landslides, urban, and water). Separate measurements were made of crown cover of trees within arable lands. Population changes were estimated by house counts on the air photographs. The results indicated a stability in land use, despite an estimated 19% increase in population. No statistically significant changes in overall land use were detected but considerable internal trading occurred between categories within sample areas, especially between "forest" and "shrub,' demonstrating a fluidity of land use. Total forest cover increased from 36.5% of the sample area in 1978 to 38.8% in 1990. Forest land increased by 34%, indicating a significant improvement in on-farm fodder, fuelwood, and fruit tree resources. Landslide areas increased from 1.0% of the total sample in 1978 to 1.9% in 1990. The method developed proved to be rapid and sufficiently accurate for determining farm-level land-use changes in steeply dissected mountain terrain.
Fire spread through a porous forest fuel bed: a radiative and convective model including fire-induced flow effects

A simplified physical model for the steady-state propagation of an infinite fire front through a uniform forest fuel bed in still air is derived from a mechanistic approach that considers a forest fire as a compressible, reactive and radiative flow through a multiphase medium. This model, named the PIF97 model for shortness, includes the effects of the buoyancy induced gas flow on the preheating of the unburned fuel. Fuel is composed of one type of motionless particles uniformly distributed in a fuel bed of constant depth. The conservation equations used in the model are integrated over the fuel bed depth. The spatial domain is divided into the preheating zone ahead of the fire front and the flaming combustion zone. In the preheating zone (model A), pyrolysis and chemical reactions are neglected, and the gas flow is assumed to be one-dimensional. In the flaming combustion zone (model B), some average parameters over this zone are given in order to simplify the description of physical and chemical processes. Models A and B are coupled to form the PIF97 model. The predictions of this model are compared with experimental rates of spread measured during laboratory fire experiments in pine needle fuel beds. That shows the accomplished progress by comparison to the predictions of a purely radiative model and also the limits of the PIF97 model. Under the present experimental conditions, this model correctly predicts the effect of surface-to-volume ratio, and may predict the effect of fuel load, but the quantitative effect of slope is clearly underestimated. Possible reasons for the remaining discrepancies between predictions and experimental results are investigated through an analysis of separate predictions of model A and model B.
Status of Bengal Slow Loris Nycticebus bengalensis (Primates: Lorisidae) in Gibbon Wildlife Sanctuary, Assam, India

Gibbon Wildlife Sanctuary (GWLS) in the Jorhat District of Assam in northeastern India is rich in primate diversity with seven species. The plains alluvial semi-evergreen forest patches with high canopy cover support a variety of fauna. In October-November 2008, we carried out a survey to estimate the population status of Bengal Slow Loris (Nycticebus bengalensis) in GWLS, a species for which little data are available in India, and whose conservation status has only recently been changed from Data Deficient to Vulnerable. We estimated population abundance of 0.18 loris individuals/km using recce-survey transects’ method in GWLS.
A new, global, multi‐annual (2000–2007) burnt area product at 1 km resolution

This paper reports on the development and validation of a new, global, burnt area product. Burnt areas are reported at a resolution of 1 km for seven fire years (2000 to 2007). A modified version of a Global Burnt Area (GBA) 2000 algorithm is used to compute global burnt area. The total area burnt each year (2000–2007) is estimated to be between 3.5 million km2 and 4.5 million km2. The total amount of vegetation burnt by cover type according to the Global Land Cover (GLC) 2000 product is reported. Validation was undertaken using 72 Landsat TM scenes was undertaken. Correlation statistics between estimated burnt areas are reported for major vegetation types. The accuracy of this new global data set depends on vegetation type.
Hyporheic transport and biogeochemical reactions in pool‐riffle systems under varying ambient groundwater flow conditions

At the interface between stream water, groundwater, and the hyporheic zone (HZ), important biogeochemical processes that play a crucial role in fluvial ecology occur. Solutes that infiltrate into the HZ can react with each other and possibly also with upwelling solutes from the groundwater. In this study, we systematically evaluate how variations of gaining and losing conditions, stream discharge, and pool‐riffle morphology affect aerobic respiration (AR) and denitrification (DN) in the HZ. For this purpose, a computational fluid dynamics model of stream water flow is coupled to a reactive transport model. Scenarios of variations of the solute concentration in the upwelling groundwater were conducted. Our results show that solute influx, residence time, and the size of reactive zones strongly depend on presence, magnitude, and direction of ambient groundwater flow. High magnitudes of ambient groundwater flow lower AR efficiency by up to 4 times and DN by up to 3 orders of magnitude, compared to neutral conditions. The influence of stream discharge and morphology on the efficiency of AR and DN are minor, in comparison to that of ambient groundwater flow. Different scenarios of O2 and NO3 concentrations in the upwelling groundwater reveal that DN efficiency of the HZ is highest under low upwelling magnitudes accompanied with low concentrations of O2 and NO3. Our results demonstrate how ambient groundwater flow influences solute transport, AR, and DN in the HZ. Neglecting groundwater flow in stream‐groundwater interactions would lead to a significant overestimation of the efficiency of biogeochemical reactions in fluvial systems.
Working Papers Working Papers Working Papers Working Papers on Exchange Rate Regimes, Exchange Rate Fluctuations, and Fundamentals

for helpful discussions, as well as seminar participants at the Banca d'Italia, Boston College, the 1999 SED Meeting, and Wharton. All remaining errors are our own. The views expressed here are those of the authors and do not necessarily represent those of the Banca d'Italia, the Federal Reserve Bank of Philadelphia, or the Federal Reserve System. Abstract We develop a two-country, two-sector general equilibrium business cycle model with nominal rigidities featuring deviations from the law of one price. The paper shows that a model with these features can quantitatively account for the empirical fact that of the statistical properties of most macroeconomic variables, only the volatility of the real and nominal exchange rates has dramatically changed after the fall of the Bretton Woods system. In particular, we replicate some explicit non-structural tests proposed in the literature with simulated data from our artificial economy. We find that while the variability of observed fundamentals (e.g., output, money supply, and interest rates) is barely affected by the exchange rate regime, that of the exchange rate increases substantially under flexible rates.
Seasonal change effects on phenology of Argania spinosa (L.) in the fields

We investigated the relationship between shoot branching, shoot growth, leaf phenology and seasonal changes during three consecutive seasons in three natural populations of Argania spinosa ((L.) Skeels) in south west Morocco. Rainfall showed two peaks in autumn and winter but summer was dry. Locality, climatic season, genotype (tree/locality) and observation date influence differently all traits. Shoot branching, shoot elongation and leaf emergence were mainly dependant on cumulative rainfall recorded in autumn and winter. When water stress is high, trees were stressed and leaf fall was more intense since 75.4% and 78.9% of leaves were lost in late summer in dry seasons. But after lower or moderate water deficit, leaf drop was less important since only 57.7% of leaves were lost in humid seasons. If dry conditions were spread over a longer period, trees are completely defoliated. Thus, among the 90 trees in the three stations, 45.6% were completely defoliated in autumn in dry season, while only 2.2% were completely defoliated in autumn in humid season. This result suggests that some genotypes are resistant to dry conditions and will be useful for selecting plus trees which are essential for management and conservation practices of genetic resources in argan forest.
Southern Oscillation Anomalies and Their Relationship to Wildfire Activity in Florida

Some relationships between the EI Nino / Southern Oscillation (ENSO) and wildfire in Florida are examined. Unlike many ENSO / wildfire studies to date, no particular emphasis was placed on the positive side of the ENSO. Both the positive and negative sides were equally examined. Linear correlation coefficients, scatter diagrams and line graphs are constructed to compare acres burned with indices of central and eastern Pacific sea surface temperature and pressure anomalies. The study reveals a significant relationship between anomalous sea surface temperatures and sea level pressures in the tend and eastern Pacific, and acres burned in Florida due to wildfires. The typical fire season in Florida is during the winter months, and the best correlation coefficient ("r" 0.71) was derived from the average central Pacific sea surface temperature anomaly for the period January through my, indicating it correlated with up to 50% of the variance in acres burned during the years examined. The study further suggests that it may be possible to develop a predictive model for wildfii activity in Florida, based on observed anomalies of sea surface temperatwe and sea level pressure in the central and eastern Pacific.
Heme oxygenase‐1 is essential for and promotes tolerance to transplanted organs

This investigation focused on obtaining a further understanding of the role of heme oxygenase‐1 (HO‐1) in tolerance induction. Hearts from C57BL/6 (H‐2b) mice survived long‐term when transplanted into BALB/c (H‐2d) recipients treated with the tolerance‐inducing regimen of anti‐CD40L antibody (MR‐1) plus donor‐specific transfusion (DST). Grafts did not, however, survive long‐term in (HO‐1−/−) recipients given the same treatment. Similarly, long‐term survival induced by DST was ablated when HO‐1 activity was blocked by zinc protoporphyrin IX (ZnPPIX). We further asked whether modulation of HO‐1 expression/activity could be used to promote the induction of graft tolerance. DST alone (day 0) failed to promote any prolongation of survival of DBA/2 (H‐2d) hearts transplanted into B6AF1 (H‐2b,k/d) recipients. However, long‐term survival and (dominant peripheral) tolerance were readily induced when DST was combined with induction of HO‐1 expression by cobalt protoporphyrin IX (CoPPIX). HO‐1 induction plus DST led to a significant up‐regulation of Foxp3, TGF‐β, IL‐10, and CTLA4, which suggests a prominent role for CD4+CD25+ regulatory T cells (Tregs). In fact, the tolerogenic effect of HO‐1 plus DST was dependent on CD4+CD25+ Tregs as suggested by adoptively transferring these cells into irradiated recipients under various regimens. Taken together, these findings show that expression of HO‐1 in a graft recipient can be essential for long‐term graft survival and for induction of tolerance and that modulation of HO‐1 expression/activity can be used therapeutically to synergize in the generation of graft tolerance.
Hydrological and geomorphological significance of rock glaciers in the dry Andes, Chile (27°–33°S)

The latitudinal‐altitudinal distribution of rock glaciers in the dry Chilean Andes between 27° and 33°S was analysed and their hydrological and geomorphological significance evaluated. Statistical estimation techniques were used based on digital elevation models and air photo interpretation, and sediment budget models were applied to assess surface‐lowering rates. The estimated specific density of rock glaciers in the study area is 1.4 per cent, which corresponds to 147.5 km2 and a water equivalent of 2.37 km3. A comparison with glacier water equivalents derived from revised glacier inventory data shows that rock glaciers are more significant stores of frozen water than glaciers between 29° and 32°S. The latitudinal‐altitudinal distribution of rock glacier limits roughly follows the mean annual air 0°C isotherm, but in the southern part of the study area it extends into elevations where modern regional mean annual air temperatures exceed 0°C. High Andean surface‐lowering rates inferred from rock glacier sediment budget models are in the order of 0.6–0.7 mm yr−1, which is comparable to previous results from the dry Chilean Andes, but lower than in the more humid Andes further south. Copyright © 2009 John Wiley & Sons, Ltd.
Dating Early and Middle (Reid) Pleistocene Glaciations in Central Yukon by Tephrochronology

Abstract The late Cenozoic deposits of central Yukon contain numerous distal tephra beds, derived from vents in the Wrangell Mountains and Aleutian arc–Alaska Peninsula region. We use a few of these tephra beds to gain a better understanding on the timing of extensive Pleistocene glaciations that affected this area. Exposures at Fort Selkirk show that the Cordilleran Ice Sheet advanced close to the outer limit of glaciation about 1.5 myr ago. At the Midnight Dome Terrace, near Dawson City, exposed outwash gravel, aeolian sand, and loess, related to valley glaciers in the adjacent Ogilvie Mountains, are of the same age. Reid glacial deposits at Ash Bend on the Stewart River are older than oxygen isotope stage (OIS) 6 and likely of OIS 8 age, that is, about 250,000 yr B.P. Supporting evidence for this chronology comes from major peaks in the rates of terrigeneous sediment input into the Gulf of Alaska at 1.5 and 0.25 myr B.P.
Initial observations of polar mesospheric summer echoes using the EISCAT Svalbard Radar

Polar Mesospheric Summer Echoes (PMSE) have been observed at various frequencies from MF to UHF and at various latitudes. Here, we report the observation of PMSE over Svalbard (79°N) at 500 MHz. Although PMSE have been reported earlier at such high latitude at VHF (notably around 50 MHz), they had hitherto not been reported at such high frequency as 500 MHz. Furthermore, this observation represents the first one using a frequency between 224MHz and 933MHz. The PMSE scattering mechanism is still open to debate and is certainly frequency dependent: the new observations at 500 MHz will help to identify the transition frequency between different mechanisms.
DETAILED STUDIES OF FRICTIONAL SLIDING OF GRANITE AND IMPLICATIONS FOR THE EARTHQUAKE MECHANISM

DETAILED LABORATORY MEASUREMENTS HAVE BEEN MADE ON THE FRICTIONAL CHARACTERISTICS OF WESTERLY GRANITE WITH GROUND SURFACES AND TO NORMAL STRESSES OF 1 KB. THESE MEASUREMENTS SHOW THAT FOR THIS TYPE OF SURFACE THERE ARE THREE TYPES OF SLIDING: CONTINUOUSLY STABLE, EPISODIC STABLE, AND STICK- SLIP. ALL THREE OF THESE MODES HAVE ALSO BEEN OBSERVED ON THE SAN ANDREAS FAULT IN CENTRAL CALIFORNIA. IN OUR LABORATORY EXPERIMENTS, THERE IS A TRANSITION FROM FIRST TO THIRD MODE AT FROM 5 TO 15 BARS NORMAL STRESS, ABOVE WHICH STICK-SLIP PREDOMINATES. STICK-SLIP, HOWEVER, IS ALWAYS PRECEDED BY A SMALL AMOUNT OF STABLE SLIP. IF THIS OCCURS ON A LARGE SCALE ON FAULTS, IT MAY BE A PROMISING PREMONITORY EFFECT FOR EARTHQUAKE PREDICTION. LOADING RATE IS FOUND TO INFLUENCE THE FRICTIONAL STRENGTH INVERSELY, WHICH MAY BE AN EXPLANATION FOR STICK-SLIP. STRESS DROPS WERE FOUND TO INCREASE WITH SHEAR STRESS, BUT NOT LINEARLY, SUGGESTING THAT RADIATION EFFICIENCY MAY INCREASE WITH STRESS DROP.