In soils of the temperate zone, there is an increase in the magnetic susceptibility χ of an upper layer compared to χC of parent rocks. The difference between χ and χC characterizes the magnetic ...“enhancement” Δχ, which is usually considered as associated with mean annual precipitation (MAP), allowing the reconstruction of MAP of the past from Δχ values of paleosols. which is widely enough used. However, in regions with a wide MAP range, non-monotonic dependence of Δχ on MAP is observed, making this reconstruction ambiguous. To construct climatic functions for reconstructing the past climate, we subdivided the south of European Russia into three regions, where climatic functions such as MAP(Δχ) of modern soils are monotonic and close to linear. These regions are relatively dry, humid, and semi-humid cold. We considered an extended set of climatic features including potential evapotranspiration (PET), actual evapotranspiration (AET), water deficit (WD = PET–AET), moisture index (MI = MAP/PET), an index of De Martonne (IDM = MAP/(MAT+10), where MAT is the mean annual temperature). The links of Δχ with MAP were positive in dry and negative in humid and semi-humid cold where they are weaker, but there were closer links with temperature-dependent WD and PET. Reliable (with R2 > 0.7) climatic functions were constructed for dry and semi-humid cold, but such reliable functions were absent in humid part. Since the differences in soil - forming material, it is necessary to identify some parameter to characterize lithological factors. For this reason, we include in consideration median grain sizes (lgSz) in soil profiles and total iron (Fet) to obtain some explanations for the results. Although the use of Δχ, lgSz and Fet together made the climatic functions more reliable (R2 ∼ 0.8), but Δχ played the main role, while lgSz and Fet were not always significant. Based on the obtained data, it appears possible to provide a more detailed subdivision of paleoecological periods in the Late Holocene for the steppe and forest-steppe zones of the Eastern Europe. Taking into account the diversity of soil conditions in different regions, equations using soil profile MS enhancement to reconstruct rainfall should be used locally and regionally, taking into account the identified limitations and eliminating the possible ambiguity of reconstructions.
In a multifactor vegetation experiment, the effect of composition and properties of soils and soil-sand substrates contaminated with various doses of copper acetate on the morphometric parameters of ...spring barley seedlings was studied. It has been shown that germination and seed germination energy, as well as the length of roots, aboveground parts, and dry biomass of plants depend in a complex way on the concentration of Cu in soils and substrates, as well as on their buffering capacity to heavy metals. Two mechanisms of Cu influence on plant development have been revealed, i.e., metabolic at С
Cu
≤ 500 mg/kg of soil and diffusional at С
Cu
≥ 500 mg/kg. Using the methods of regression analysis of experimental data, a multiple regression equation has been obtained that combines the morphometric index of plants, the concentration of Cu in substrates, and the buffering capacity of soils to Cu. On its basis, in the soil buffering capacity–Cu concentration coordinates, a curve of values of the maximum permissible concentrations of Cu in soils was built on a plane in the range from 17 to 2047 mg/kg. It permits us to separate the zone of permissible development of barley plants (a decrease of the morphometric index by 15%) from the zone of exceeding the accepted values of the maximum permissible concentration of Cu. Thus, the maximum permissible concentration is considered to be a function of Cu concentration, the soil buffering capacity to heavy metals, and plant species rather than a fixed value.
Analysis of relationships between the richness of three taxonomic ranks of vascular plants in the Middle Volga region and climate showed that the climatic factor explains 74% of variance in the ...number of species and families and 76% of variance in the number of genera. Taxonomic parameters of a floristic sample collected on 25 polygons 100 km
2
in size each were compared with climatic parameters and their functions. Multiple regression models were produced for the three taxonomic ranks (numbers of families, genera, and species), and maps have been constructed on the basis of these models. The main predictors were climatic parameters at the beginning of spring and in winter months. Statistically significant correlations between the richness of species, genera, and families and some functions of climatic parameters that are usually excluded from analysis were identified. The essence of these functions is discussed in the context of their effect on snow melting processes in early spring.
Many rare ovarian cancer subtypes, such as small-cell carcinoma of the ovary, hypercalcemic type (SCCOHT), have poor prognosis due to their aggressive nature and resistance to standard platinum- and ...taxane-based chemotherapy. The development of effective therapeutics has been hindered by the rarity of such tumors. We sought to identify targetable vulnerabilities in rare ovarian cancer subtypes.
We compared the global proteomic landscape of six cases each of endometrioid ovarian cancer (ENOC), clear cell ovarian cancer (CCOC), and SCCOHT to the most common subtype, high-grade serous ovarian cancer (HGSC), to identify potential therapeutic targets. IHC of tissue microarrays was used as validation of arginosuccinate synthase (ASS1) deficiency. The efficacy of arginine-depriving therapeutic ADI-PEG20 was assessed
using cell lines and patient-derived xenograft mouse models representing SCCOHT.
Global proteomic analysis identified low ASS1 expression in ENOC, CCOC, and SCCOHT compared with HGSC. Low ASS1 levels were validated through IHC in large patient cohorts. The lowest levels of ASS1 were observed in SCCOHT, where ASS1 was absent in 12 of 31 cases, and expressed in less than 5% of the tumor cells in 9 of 31 cases. ASS1-deficient ovarian cancer cells were sensitive to ADI-PEG20 treatment regardless of subtype
. Furthermore, in two cell line mouse xenograft models and one patient-derived mouse xenograft model of SCCOHT, once-a-week treatment with ADI-PEG20 (30 mg/kg and 15 mg/kg) inhibited tumor growth
.
Preclinical
and
studies identified ADI-PEG20 as a potential therapy for patients with rare ovarian cancers, including SCCOHT.
Spherical neutral detector for VEPP-2M collider Achasov, M.N; Aulchenko, V.M; Baru, S.E ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2000, Letnik:
449, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The Spherical Neutral Detector (SND) operates at VEPP-2M collider in Novosibirsk studying e
+e
− annihilation in the energy range up to 1.4
GeV. Detector consists of a fine granulated spherical ...scintillation calorimeter with 1632 NaI(Tl) crystals, two cylindrical drift chambers with 10 layers of sense wires, and a muon system made of streamer tubes and plastic scintillation counters. The detector design, performance, data acquisition and processing are described.
Effective quantitative land surface analyses in soil science need scale-free land surface attributes (morphometric variables, MVs) to be introduced for making comparable results obtained at different ...scales. To investigate the problem in more detail, a conceptual scheme and curvatures studied earlier in Shary (1995) Math. Geol. 27 (1995) 373 are further developed in this paper, formulae for a complete system of 12 curvatures and some other MVs are given, and modified Evans–Young algorithm for curvature calculation is described that does not emphasize grid directions. The conceptual scheme is based on that MVs often describe not the land surface itself, but rather the system “land surface+vector field”, where vector fields of common interest are gravitational field and solar irradiation. Correspondingly, morphometric variables and concepts may (1) refer to this system description (field-specific), or (2) be invariant with respect to any vector field (field-invariant), that is, describing the land surface itself, its geometrical form. From the other side, MVs and concepts may be (1) local, (2) regional, which need extended portions of a restricted part of land surface for their determination at a given point, or (3) global (planetary), when elevations of all the Earth are needed for their determination at a given point. Global MVs do not consist subject of this paper; so, the four classes of MVs are considered here: class A (local field-specific MVs), class B (regional field-specific), class C (local field-invariant), and class D (regional field-invariant). MVs of these classes permit description of geometrical land form, pre-requisits of surface runoff, thermal regime of slopes, and altitude zonality. Class A contains three independent MVs expressed by first derivatives of elevation
Z by plan coordinates (slope steepness, slope direction, solar insolation) and seven curvatures expressed by second derivatives of
Z; class C contains five curvatures; class B contains two variables (catchment and dispersal areas); MVs of class D are not introduced yet. Also, some non-system MVs of class A are described, sense of all MVs is described, and interrelationships between MVs are shown. Three curvatures are independent, not two, as this is often implied. It is experimentally shown that average depth of a depression defined in class B may not depend upon scale, while local MVs may not have limit values for large scales. Scale-free morphometric variables are defined here as those that have limit values for large scales. It is experimentally shown that maximal catchment area (class B) is a scale-free variable for thalwegs. These results show that local MVs are scale-specific (except elevation), but scale-free regional MVs might be introduced as a generalization of curvature concept. Two surface runoff accumulation mechanisms are considered in their relation to local and regional field-specific MVs; although the first one is generalized to a regional MV (catchment area), there is no regional MV for the second one description, although it is of great importance in soil science as describing slow profile changes. Geometrical forms were little studied in soil science; arguments are given that they may be useful for studying memory in soils, which is determined by temporal shifts between land surface formation and soil formation processes. The following topics are discussed: the current state of morphometry, an ambiguity in land form definitions, and a possibility to generalize curvature concept for regional scale-free MVs. The consideration is restricted by methods of the general geomorphometry; partial approaches are considered only by selection.
We studied the relationship of the yield of winter wheat and spring barley with slope exposure components in the west of the Oka River basin. The size of the study area was 250 km by 360 km. The ...yield characteristics included the maximal yield obtained when applying the optimal dose of fertilizers, the yield without applying fertilizers (control) and the maximal addition to yield, that is, their difference. The addition is shown to be most sensitive to climatic factors. For wheat, the addition increased on the warmer south-western slopes, and for barley—on the wetter north-eastern slopes. The high sensitivity of the addition for barley to moisture is shown using it comparison with climatic water deficit. To compare slopes by the energy of incident solar radiation, we used the slope insolation in energy units. Although the difference in energy between the south-west and north-east slopes was only 2.2%, wheat addition on these slopes varied by more than a factor of two. The reasons for this are discussed. The results obtained show that when choosing locations for crop areas, it is advisable to take into account the exposure of the slopes.
Specially protected natural conservation areas in the Middle Volga River region serve to preserve both rare and endangered species and the entire biotic complex, including typical floristic ...communities of vascular plants. We have identified 25 sites, 100 km2 each, where the flora is represented in full the most. We studied the relationships between the general species richness (SR) and the richness of particular life forms (LF) of vascular plants with climate and relief using multiple regression methods. Our study shows that the special function of March precipitation is the factor that influences the most the spatial change of the SR and LF. When increasing the precipitation in the model by only 1 mm, this leads to a decrease in the number of species by 7.1%. Winter precipitation and temperature are important factors as well; together they are responsible for 70-82% of the SR variation. These close links made it possible to develop the maps of the species richness of the study area. The SR model did not include solar radiation, one of the most important environmental factors, as a significant predictor. This factor was omitted due to the analysis of the number of species of particular LF, which showed the maximum illumination of the slopes as a highly significant factor for number of them. The two dominant LFs (hemicryptophytes and therophytes), which account for 73% of the total number of species, depend oppositely on the illumination. This fact indicates a decrease in competition between LFs due to their separation in space, since hemicryptophytes, in contrast to therophytes, predominate on well-illuminated slopes. In addition, opposite LF responses lead to omitting of illumination factor from the SR model for all species in the region.
In this paper, slow movement of a flat piston in compressed liquid is considered. The solution of the problem is constructed with two different methods: the first is based on the theory of Riemann’s ...simple waves, and the second on the small parameter method. Then we compare the results obtained by the two methods.
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