Miracle-dz/UniFAR-FTUs huggingface dataset:
Five‐year climatological survey of the Gulf Stream system and its associated rings

A 5-year climatological survey of the Gulf Stream System's landward surface edge defines the mean, standard deviation, extreme limits, annual and interannual variabilities, and frequency distributions along 0.5° longitudinal transects from 91° to 44°W. The climatology covers the Loop Current in the Gulf of Mexico and the Gulf Stream in the northwest Atlantic Ocean. Autocorrelations and power spectra are derived for longitudinal transects between 79.5° and 57.5°W. The study also investigates the observed warm-core ring and cold-core ring movements and their areal extent. The observed data are compiled from the Oceanographic Analysis charts (produced by the National Oceanic and Atmospheric Administration) which utilize infrared satellite imagery and in situ observations. East of Cape Hatteras the Gulf Stream System Landward Surface Edge exhibits both interannual and annual signals. The interannual variability is equal to the annual variability. The mean monthly Gulf Stream position for the longitudinal band 70°–44°W shifts from farthest north in September to farthest south in February. The magnitude of the annual shift is largest near the Grand Banks. Frequency distributions of the Gulf Stream System position are quasi-normal nearly everywhere. Autocorrelation plots from the 5-year time series of Gulf Stream positions at longitudinal transects 79.5°–57.5°W exhibit three well-defined e-folding time regimes with a maximum time of 10 weeks at 72°W. Power spectrums from 79.5° to 57.5°W are red spectrums having dominant peaks of 1-year period or greater. The largest total spectra energies are found at 61°W. The Loop Current sheds rings at two apparent spatial scales which are labeled major (307-km mean) and minor (185-km mean) warm-core rings. Annually, the Loop Current sheds about one major warm-core ring which translates into the western basin of the Gulf of Mexico and one minor warm-core ring which is usually reabsorbed by the Loop Current. The major Loop Current warm-core ring sheddings have no seasonal preference. Loop Current warm-core rings have a mean velocity of 2.4 km/d west-southwest. An average of 22 Gulf Stream warm-core rings are formed and absorbed annually between 75° and 44°W. The largest frequency of warm-core ring formations is seen near the New England Seamounts, while the largest frequency of warm-core ring absorptions is found near Cape Hatteras. Gulf Stream warm-core rings can absorb each other as occurred in 14% of the absorption cases with the highest frequency just upstream of the New England Seamounts. The Gulf Stream warm-core rings have a surface diameter decay rate of − 0.026 per week (Loop Current warm-core rings are similar). The Gulf Stream warm-core rings have a mean velocity of 2.4 km/d west-southwest. Cold-core rings have a mean cool-core surface diameter of 105 km and a mean velocity of 1 km/d southwest. More definitive conclusions on cold-core rings are not possible, as ring identification and tracking by satellite infrared imagery is tentative.
Variations in oxygen and carbon isotopic compositions and microstructure of the shell of Adamussium colbecki (Bivalvia)

The oxygen and carbon isotopic variability within the calcitic shell of the Antarctic scallop Adamussium colbecki has been assessed by detailed sampling of the shell margin, an external transect along the line of maximum growth, and on the interior surface of the shell. The adult shell is largely calcitic, with aragonite restricted to myostracal deposits, an extremely thin layer of aragonitic homogeneous structure between the pallial line and the foliated inner layer of the right valve, and the fibrous ligament. No relationship between isotopic values and microstructure is apparent. Average {delta}{sup 18}O values are highest for the interior shell surface and lowest for the shell margin samples. The variability of {delta}{sup 18}O values is highest for the external shell surface. The relatively good agreement between {delta}{sup 18}O values of exterior surface samples along the growth transect of A. colbecki and estimated {delta}{sup 18}O values of calcite precipitated in equilibrium with ambient waters calculated indicate the precipitation of shell samples close to equilibrium. Because {delta}{sup 18}O values from A. colbecki reasonably well reflect ambient conditions, fossil forms would likely provide useful paleoenvironmental data. However, within shell variability in {delta}{sup 18}O values cautions against making interpretations based on a few microsamples. Carbonmore » isotopic values are highly variable throughout the shell and are likely influenced by vital effects. « less
The Dynamics of Soil Physical Properties and Exchangeable Cations in Secondary Forests Regenerating from Degraded Abandoned Rubber Plantation (Hevea brasiliensis) in Orogun Area of Southern Nigeria

The regeneration of soil physicochemical properties in three secondary forest fields aged 1, 5 and 10 years of age following the abandonment of degraded rubber (Hevea brasiliensis) plantation in Orogun were investigated. In addition a mature forest was selected and investigated as the control. Values of important indices of soil physicochemical parameters were ascertained for the three secondary forests categories and the mature forest. The results obtained revealed that there was no significant improvement or changes in soil particle size composition during the course of secondary forest regeneration. The concentrations of the exchangeable cations were higher in the mature forest than the different secondary forest categories. Soil bulk density decreased while water holding capacity and total porosity of soil increased with increasing age of secondary forest. Exchangeable cations improved in the first five year of secondary forest regeneration, after which their values declined by the tenth year in the topsoil (0-10cm layer). Similarly, exchangeable potassium and sodium improved significantly in the subsoil (10-30cm layer) by the fifth year of secondary forest regeneration from degraded abandoned rubber plantation, after which their values declined by the tenth year. However, exchangeable magnesium and calcium declined in the subsoil throughout the course of forest recovery. Effective cation exchange capacity in the topsoil and the subsoil increased linearly with increasing age of secondary forest, while soil pH decreased with increasing age of secondary forest. These results demonstrate that fallowing exerts beneficial effects on soil fertility (i.e. soil fertility improved as fallow age increased). Keywords: Dynamics, Secondary forests, Degraded, Abandoned rubber plantations, Exchangeable cations, total porosity.
The Classification and Origin of Beach Cusps

Among shore features, beach cusps have been the most difficult to explain. This is because of the quickness with which they grow when the exact adjustment required between waves and beach materials occurs. Beach cusps are here classified and the process of formation of each class described and explained. The fifth class is especially interesting and important as it is the one most commonly observed and the most difficult to explain. Numerous intercusp spaces were measured. These measurements show that the apparent uniformity of spacing of cusps is deceptive. Uniformity of spacing sometimes holds for short distances, but in a series of any considerable length the intercusp spacing commonly shows a wide variation.
Role of differentiation in glioblastoma invasion

Glioblastoma (GBM) is a highly infiltrative brain tumor in which cells with properties of stem cells, called glioblastoma stem cells (GSCs), have been identified. GSCs are thought to be responsible for the initiation, progression, invasion and recurrence of this tumor. In this study, we addressed the question whether the differentiation status of GBM cells is associated with their invasive capacity. For this, several primary GBM cell lines were used, cultured either as neurospheres known to enrich for GSCs or in medium supplemented with 10% FCS that promotes differentiation. The differentiation state of the cells was confirmed by determining the expression of stem cell and differentiation markers. The migration/invasion potential of these cells was tested using in vitro assays and intracranial mouse models. Interestingly, we found that serum-induced differentiation enhanced the invasive potential of GBM cells, which was associated with enhanced MMP9 expression. Chemical inhibition of MMP9 significantly reduced the invasive potential of differentiated cells in vitro. Furthermore, the differentiated cells could revert back to an undifferentiated/ stem cell state that were able to form neurospheres, although with a reduced efficiency as compared to non-differentiated counterparts. We propose a model in which differentiated GBM cells are most effective in infiltrating the brain and depending on microenvironmental cues a significant portion of these cells are able to revert back to an undifferentiated state with enhanced tumorigenic potential. Thus, effective therapy should target both GSCs and differentiated offspring and targeting of differentiation-associated pathways may offer therapeutic opportunities to reduce invasive growth of GBM.
Summary of the High Plains Regional Aquifer-System Analysis in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming

Introduction . High Plains Regional Aquifer-System Analysis Geohydrology . Physical setting . Hydrogeologic units . Ground-water hydraulics . Ground-water quality . Ground-water development . Irrigation pumpage . 1980 water use . Page Al 2 2 2 3 3 5 7 10 10 11 Page Effects of development . A13 Water-level changes . Saturated-thickness changes . Digital models . Model calibration . Model sensitivity . Effects of future pumpage . Pumpage estimates . Comparison of projections . Selected references . 13 13 16
Fixation of Ammonia by Organic Soils

Ammonia fixation in organic soils of varying carbon content was found to be linearly correlated with percent carbon. In the presence of oxygen 1 molecule of ammonia was fixed per 29 atoms of carbon, and 1 for every 45 atoms of carbon in the absence of oxygen. Treatment of these organic soils with ammonia usually resulted in decreased capacity to retain barium and cupric ions, but the amount of ammonia fixed bore no quantitative relation to the decrease in cation retention. Blocking hydroxyl groups in soil organic matter by treating with dimethyl sulfate decreased the capacity of the organic matter to fix ammonia, indicating that these groups are involved in the fixation reaction. Aldehyde groupings are apparently not involved. Formation of amides through the action of anhydrous ammonia on carboxylic esters may play a minor role in ammonia fixation. A tracer experiment showed that fixed ammonia is slowly made available to plants.
Daily variability of river concentrations and fluxes: indicators based on the segmentation of the rating curve

The variability of water chemistry on a daily scale is rarely addressed due to the lack of records. Appropriate tools, such as typologies and dimensionless indicators, which permit comparisons between stations and between river materials, are missing. Such tools are developed here for daily concentrations (C), specific fluxes or yields (Y) and specific river flow (q). The data set includes 128 long‐term daily records, for suspended particulate matter (SPM), total dissolved solids (TDS), dissolved and total nutrients, totalling 1236 years of records. These 86 river basins (103–106 km2) cover a wide range of environmental conditions in semi‐arid and temperate regions. The segmentation—truncation of C–q rating curves into two parts at median flows (q50) generates two exponents (b50inf and b50sup) that are different for 66% of the analysed rating curves. After segmentation, the analysis of records results in the definition of nine major C–q types combining concentrating, diluting or stable patterns, showing inflexions, chevron and U shapes. SPM and TDS are preferentially distributed among a few types, while dissolved and total nutrients are more widely distributed. Four dimensionless indicators of daily variability combine median (C50, Y50), extreme (C99, Y99) and flow‐weighted (C*, Y*) concentrations and yields (e.g. C99/C50, Y*/Y50). They vary over two to four orders of magnitude in the analysed records, discriminating stations and river material. A second set of four indicators of relative variability [e.g. (Y*/Y50)/(q*/q50)], takes into account the daily flow variability, as expressed by q*/q50 and q99/q50, which also vary over multiple orders of magnitude. The truncated exponent b50sup is used to describe fluxes at higher flows accounting for 75% (TDS) to 97% (SPM) of interannual fluxes. It ranges from − 0·61 to + 1·86 in the database. It can be regarded as the key amplificator (positive b50sup) or reductor (negative b50sup) of concentrations or yields variability. C50, Y50, b50sup can also be estimated in discrete surveys, which provides a new perspective for quantifying and mapping water quality variability at daily scale. Copyright © 2011 John Wiley & Sons, Ltd.
A seesaw structure in SLP anomalies between the Beaufort Sea and the Barents Sea

This paper reveals a new mode of winter (October–March) monthly mean atmospheric intraseasonal variability characterized by a seesaw structure in sea level pressure (SLP) anomalies between the Barents Sea and the Beaufort Sea with an equivalent barotropic structure. The Beaufort High varies out of phase with the Siberian High. Compared to the Arctic Oscillation (AO) and the dipole anomaly, the effect of this mode on Fram Strait sea ice flux is the most important so far, although it accounts for only 9.1% of the variance. The Beaufort High itself is not crucial for sea ice flux through Fram Strait.
Land use dynamics in the semi-arid region of Brazil (Quixaba, PE): Characterization by principal component analysis (PCA)

The changes caused by the pressure of human occupation can be observed by non-sustainable land use forms, in the Brazilian semi-arid region. The multitemporal analysis of changes in the caatinga land cover provides sufficient information about the dynamics of this typical land use. Within this frame, principal component analysis (PCA) was applied in combination with field survey data, which permitted estimation of point samples of new recovery/degradation. The area selected for this study is located in the central-southern semi-arid section of Pernambuco State, north-east Brazil. It covers an area of about 190 km 2 and is located between geographical coordinates 8° 00' to 8° 07' S and 39° 45' to 39° 53' W. Five classes of changed and unchanged multitemporal effects were discriminated. The results of this study were evaluated using combined Geographical Information System (GIS) and field survey techniques. This work was less time-consuming and economically significant for the time period 1983-96. An alternative PCA method was proposed based on the analysis of the results and errors in a confusion matrix. This alternative method is based on the controlled rotative analogy of the PCA transformation, where a smaller angle of rotation was applied.
Soil behavior during freezing and thawing using variable and constant confining pressure triaxial tests

Although variable confining pressure (VCP) triaxial tests are generally preferred to constant confining pressure (CCP) triaxial tests due to the more realistic stress application, VCP tests have never been utilized when investigating freezethaw effects on unbound road materials. In this study, three soils were investigated for resilient behavior during freezing and thawing utilizing both VCP and CCP triaxial testing. The soils were tested at selected temperatures between +20 and 10°C during one full freezethaw cycle. The results were analyzed in terms of the traditionally used resilient modulus and Poisson's ratio, as well as volumetric and shear components, and indicate a significant difference in moduli computed from CCP and VCP data. However, resilient moduli display compatible values when interpreted in terms of mean values of deviator stress and mean normal stress. With regard to freezevthaw effects on resilient moduli, the results are inconsistent with previous findings. However, this can be expl.
Overview of Brain Metastasis and Treatment Modalities

Brain metastasis (BM) is the commonest form of intracranial malignancy, historically considered a single disease entity with a gloomy outcome, often resulting in a palliative approach to clinical management. Primary cancers that most frequently spread to the brain are lung, breast, and renal carcinomas as well as malignant melanomas. Global incidence of brain metastasis is on the rise but may still be underestimated. About 67% of patients with BM present with either generalized or focal symptoms and sometimes both. A thorough clinical workup and application of verified prognostic scores lead to optimal stratification and strongly influences therapeutic decisions and patients’ outcomes. Management is multidisciplinary and involves symptomatic treatment, use of best supportive care, radiotherapy, surgery as well as targeted therapy.
Towards new paradigms: multiple pathways for the Arabian Neolithic

The origin and course of the Neolithic on the Arabian Peninsula is the subject of an ongoing academic debate. Faunal data suggest an origin for domestication of animals in the Levant and these can be found in Arabia from the sixth millennium onwards. In contrast, lithic evidence does not support the hypothesis that Neolithic herders, accompanying their herds, spread over the entire Peninsula, as they did not leave significant traces of their material culture. Although Pre-Pottery Neolithic A (PPNA)/PPNB influences can be traced across the northern part of Arabia, it is barely possible to observe them further south. By contrast, lithic technology in this region is characterised by major indigenous developments that might originate from a Pleistocene cultural heritage. By discussing the process of Neolithisation in Arabia from different points of view we can avoid the pitfalls of simplistic or monocausal models as well as preconceptions. Furthermore, we will be able to demonstrate that the Neolithic developed differently in different regions of the Arabian Peninsula.
A review on some discrete variational techniques for the approximation of essential boundary conditions

We review different techniques to enforce essential boundary conditions, such as the (nonhomogeneous) Dirichlet boundary condition, within a discrete variational framework, and especially techniques that allow to account for them in a weak sense. Those are of special interest for discretizations such as geometrically unfitted finite elements or high order methods, for instance. Some of them remain primal, and add extra terms in the discrete weak form without adding a new unknown: this is the case of the boundary penalty and Nitsche techniques. Others are mixed, and involve a Lagrange multiplier with or without stabilization terms. For a simple setting, we detail the different associated formulations, and recall what is known about them, with emphasis on their stability and convergence properties.
Induced Seismicity during the Stimulation of a Geothermal hfr Reservoir in the Cooper Basin, Australia

A long-term fluid-injection experiment was performed in the Cooper Basin (Australia) in 2003 to stimulate a geothermal reservoir. More than 20,000 m 3 of water were injected into the granitic crust at 4250 m depth. During reservoir stimulation about 27,000 induced seismic events were detected by a local, eight- station seismic monitoring system deployed in nearby boreholes. Hypocenter locations for 11,068 events were determined by using an averaged velocity model that was calibrated by associating early events with the injection point. The spatial hypocenter distribution forms a nearly subhorizontal structure with a lateral extension of 2 km × 1.5 km and an apparent thickness of approximately 150–200 m, which is in the order of the hypocenter location confidence limits. The hypocenter distribution exhibits a high degree of spatiotemporal ordering with the seismic activity systematically migrating away from the injection well with increasing time. Previously activated regions become seismically quiet indicating relaxation processes. High-resolution relative hypocenter locations determined for clusters of “similar” events locally reduce the apparent thickness of the structure to the level of a few tens of meters indicating that the reservoir is dominated by a single fracture zone only. Consistent with these findings, a subsequently drilled well intersects a dominating, high-permeable fracture within 15 m of the predicted intersection depth. Based on drilling and logging information, the fracture zone is interpreted as a preexisting (possibly tectonically formed) feature that (partly) sheared during stimulation. Triggering of the induced seismicity is found to be predominantly controlled by the increase of fluid pressure implicating a (local) reduction of the effective normal stress resolved on the fracture plane. Additionally, perturbations of the stress field caused by the largest-magnitude events may trigger seismicity (“aftershocks”) on a local, short-ranging scale.