Search Results

You are looking at 1 - 10 of 12 items for

  • Author or Editor: M. Fuchs x
  • Refine by Access: All Content x
Clear All Modify Search

Abstract

Natural killer (NK) cells are innate lymphocytes that play important roles in the defense against microbial pathogens through secretion of IFN-γ and recognition and lysis of virally or bacterially infected host cells. A recently identified population of NK-like cells that shares characteristics of both NK cells and lymphoid tissue inducer (LTi) cells promotes innate immune responses in epithelial tissue through the secretion of IL-22. In contrast to classical NK cells, NK-like cells are localized preferentially at mucosal sites, such as the intestinal mucosa. In this review, we consider the function of NK and NK-like cells in anti-microbial defense as well as the maintenance of tissue integrity in the mucosal epithelium of the intestine, lung, and female reproductive tract. Current experimental evidence supports an important protective role for IL-22-producing NK-like cells during intestinal infections, whereas classical NK cells are crucial in the early defense against many pathogens in the respiratory tract. NK cells isolated from the pregnant uterus differ significantly in phenotype and function from those at other tissue locations. Uterine NK cells clearly contribute to the tissue remodeling that takes place during placentation, but their role in anti-microbial defense remains largely undefined.

Restricted access

Abstract  

The main purpose of this paper is to discuss the asymptotic behaviour of the difference s q,k(P(n)) - k(q-1)/2 where s q,k (n) denotes the sum of the first k digits in the q-ary digital expansion of n and P(x) is an integer polynomial. We prove that this difference can be approximated by a Brownian motion and obtain under special assumptions on P, a Strassen type version of the law of the iterated logarithm. Furthermore, we extend these results to the joint distribution of q 1-ary and q 2-ary digital expansions where q 1 and q 2 are coprime.

Restricted access

The soil cover of the world stores more carbon than that present in biomass and in the atmosphere, so the depth and distribution of soil organic matter (SOM) might be important in point of carbon sequestration and climate change mitigation. Texture, among several other factors, plays an important role in the distribution of SOM. Most national and the main international soil classification systems (Soil Taxonomy, World Reference Base for Soil Resources) have a separate unit for high clay content soils on the highest level of classification, as Vertisols. Due to the high swelling clay content, these soils open deep cracks when they are dry. During the process called “pedoturbation”, the high SOM content surface material falls into the cracks, where it accumulates and mixes with subsoil, and enhances the accumulation of SOM in great depth. Although the effect of texture on the stabilization, distribution and properties of SOM have been investigated, only little information is available on SOM distribution in high clay content soils. The objective of the present study was to analyze the vertical distribution of SOM in high clay content soils of Hungary. Our results, based on the investigations of the Hungarian TIM database supported the hypothesis that high clay content soils store significantly more SOM and in greater depth than other soils under similar climatic conditions.

Restricted access

The development of the recent European and global initiatives resulted in an increasing demand for harmonized digital soil information. One of the major limitations of harmonization is the great variation of field and analytical methods and classification systems. Since 1998, the World Reference Base for Soil Resources (WRB) is the global correlation scheme for soil classification and international communication. The one to one correlation of units, however, is difficult, if not impossible. Another problem is that the correct correlation of national units to WRB units might have spatial consequences. If the original map units need to be maintained, it is important to express the extent to which certain national units match with the WRB units. Taxonomic distance measurements were applied successfully to express numerically the correlation between the brown forest soil types (BFS) of the Hungarian Soil Classification System (HSCS) and WRB Reference Soil Groups (RSGs).

Restricted access

The current Hungarian Soil Classification System (HSCS) was elaborated during the 1960s, based on the genetic principles of Dokuchaev. It was developed before sufficient data and modern data processing tools were available and served different purposes than current users need or apply it for.The central unit is the soil type, grouping soils that were believed to have developed under similar soil-forming factors and processes. The major soil type is the highest category that groups soils based on climatic, geographical and genetic bases. Subtypes and varieties are distinguished according to the assumed dominance of soil-forming processes and observable/measurable morphogenetic properties. STEFANOVITS (1963) defined the 23 soil-forming processes that have a dominant impact on the differentiation of the 39 soil types of the system.Based on accumulated data and experience, as well as on numerical tools for defining taxonomic relationships a modernization process was carried out. The process included: linking processes to diagnostics, review and numerical study of similarities and dissimilarities of existing units, development of new central units, development of a computer assisted key, and definition of methodology to derive the lower level units. The new, 15 soil types are defined by stronger morphogenetic and measurable criteria, but with the application of legacy data and the developed key, the earlier units can be converted to the new ones, hence the value of legacy data can be preserved.

Restricted access
Acta Chromatographica
Authors: A. Bischoff, M. Eibisch, B. Fuchs, R. Süss, M. Schürenberg, D. Suckau, and J. Schiller

Summary

The analysis of lipid-phospholipid oxidation products is of primary importance. Although there are established HPLC and LC-MS techniques, it is shown here for the first time that the combination of matrix-assisted laser desorption and ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) and TLC represents a sensitive, fast, and convenient alternative. A mixture of 1-palmitoyl-2-linoleoyl-sn-phosphatidylcholine (PLPC) and -ethanolamine (PLPE) was oxidized under the influence of atmospheric oxygen and characterized by direct positive ion MALDI-TOF MS as well as combined TLC-MALDI. It is shown that much more detailed information — particularly related to the oxidation products of PLPE that have so far been scarcely investigated — can be obtained by TLC-MALDI. However, it is also shown that further methodological improvements are necessary to make this method generally applicable to complex lipid mixtures.

Full access
Agrokémia és Talajtan
Authors: R. K. Gangwar, M. Makádi, M. Fuchs, Á. Csorba, E. Michéli, I. Demeter, and T. Szegi

Soil samples were collected from salt-affected soils (Solonetz) under different land uses, namely arable (SnA) and pasture (SnP), to investigate the effects of land use on microbiological [basal soil respiration (BSR), microbial biomass carbon (MBC), dehydrogenase activity (DHA) and phosphatase activity] and chemical properties [organic carbon (OC), humic ratio (E4/E6), pH, electrical conductivity (EC), ammonium nitrogen (NH4-N), nitrate nitrogen (NO3-N), available forms of phosphorus (P2O5), potassium (K2O), calcium (Ca2+), magnesium (Mg2+), sodium (Na+)] and on the moisture content.

The results showed that the two sites, SnA and SnP, were statistically different from each other for all the microbiological and chemical parameters investigated except Na+ and moisture content. Higher values of MBC (575.67 μg g-1), BSR (9.71 μg CO2 g-1 soil h-1), DHA (332.76 μg formazan g-1 day-1) and phosphatase activity (0.161 μmol PNP g-1 hr-1) were observed for the SnP soil. Great heterogeneity was found in SnP in terms of microbiological properties, whereas the SnA plots showed more homogeneous microbiological activity due to ploughing. 75.34% of variance was explained by principal component one (PC1), which significantly separated SnA and SnP, especially on the basis of soil MBC and P2O5. Moreover, it was concluded that the pasture land (SnP) was microbiologically more active than arable land (SnA) among the Hungarian salt-affected soils investigated.

Restricted access