„Két lábbal a földön, avagy miként próbál a talajtan válaszokat adni a globális kihívásokra”
Beszámoló a HUN-REN ATK Talajtani Intézetének Magyar Tudomány Ünnepe előadónapjáról
Abstract
Peanut butter and yoghurt are targeted for adulteration intended at consumer deception. This study aimed to fingerprint and detect peanut butter and yoghurt adulteration with cassava flour and starch using Near Infrared Spectroscopy (NIRS) in a quasi-experimental approach. Ingredients for laboratory sample preparation were obtained from the Kumasi Metropolis. Peanut butter was adulterated at 1, 3, 5, 10, 15, 20% w/w and yoghurt at 0.25, 0.5, 1, 3, 5, 10, 15, 20, 25, 45, 50% w/w. Selected concentrations mimicked practices on the market. Marketed products were randomly sampled from six markets in the Kumasi Metropolis to validate the study models. Samples were scanned with a hand-held NIRS in triplicates. Chemometric (Principal Component Analysis (PCA), Linear Discriminant Analysis (LDA) and Partial Least Square Regression (PLSR) models) statistical methods were employed to develop classification and prediction models. Peaks with spectral bands such as 1050 , 1200 and 1450 nm were observed for peanut butter and 990–1100 nm, 1100–1200 nm and 1300–1408 nm were observed for yoghurt in the NIR spectrum. Some yoghurt brands were suspected of containing cassava starch, while Peanut butter from the different markets differed based on classification models. Cassava flour and starch concentrations were quantitatively predicted by PLSR with an R2 CV of 0.98 and an error of 0.9 g/100 g (low error).
Abstract
Campylobacter infections and campylobacteriosis-associated post-infectious sequelae are a significant global health burden that needs to be addressed from a specific African perspective. We conducted a comprehensive literature search on NCBI PubMed to compile a comprehensive narrative review article on Campylobacter infections in Africa, focusing on key aspects in human and veterinary medicine as well as food hygiene. We specifically focused on the epidemiology of enteropathogenic Campylobacter spp. in sub-Saharan and North Africa considering antimicrobial susceptibility. The most significant sequela resulting from molecular mimicry to Campylobacter surface structures is the Guillain-Barré syndrome, which was mainly examined in the context of limited studies conducted in African populations. A dedicated subsection is allocated to the limited research on the veterinary medically important species Campylobacter fetus. There are significant differences in the composition of the gut microbiome, especially in rural areas, which affect the colonization with Campylobacter spp. and the manifestation of campylobacteriosis. There may be a problem of overdiagnosis due to asymptomatic colonization, particularly in the detection of Campylobacter using molecular biological techniques. To reduce the colonization and infection rate of Campylobacter, we propose implementing several control measures and urge further research to improve the current understanding of the peculiarities of campylobacteriosis in Africa.
Asymptotic uniform upper density, shortened as a.u.u.d., or simply upper density, is a classical notion which was first introduced by Kahane for sequences in the real line.
Syndetic sets were defined by Gottschalk and Hendlund. For a locally compact group 𝐺, a set 𝑆 ⊂ 𝐺 is syndetic, if there exists a compact subset 𝐶 ⋐ 𝐺 such that 𝑆𝐶 = 𝐺. Syndetic sets play an important role in various fields of applications of topological groups and semigroups, ergodic theory and number theory. A lemma in the book of Fürstenberg says that once a subset 𝐴 ⊂ ℤ has positive a.u.u.d., then its difference set 𝐴 − 𝐴 is syndetic.
The construction of a reasonable notion of a.u.u.d. in general locally compact Abelian groups (LCA groups for short) was not known for long, but in the late 2000’s several constructions were worked out to generalize it from the base cases of ℤ𝑑 and ℝ𝑑. With the notion available, several classical results of the Euclidean setting became accessible even in general LCA groups.
Here we work out various versions in a general locally compact Abelian group 𝐺 of the classical statement that if a set 𝑆 ⊂ 𝐺 has positive asymptotic uniform upper density, then the difference set 𝑆 − 𝑆 is syndetic.
Mária Radnóti-Alföldi (1926–2022)
Ein Kind des Zweiten Weltkrieges – ein Opfer der europäischen Teilung – eine hochgeschätzte Wissenschaftlerin und akademische Lehrerin
This study aims to answer the question whether the ancient Cēra kings sailed the seas and, if so, whether their technology was suitable for crossing the Indian Ocean, while it tries to summarize what we know about shipbuilding in ancient Southwest India. On the following pages, an attempt is made to introduce the most important passages of the Old Tamil Caṅkam literary sources in order to analyse their data in the light of Greek and Latin sources, and of Indian and Mediterranean inscriptions. It can be concluded that although inscriptions of Tamil traders can be found from Egypt to Thailand, and the Cēra kings built a maritime fleet for probably the first time in the history of ancient South India in order to punish their enemy, the kaṭampu tribe by sailing on the seas, their nautical contribution to the long-distance trade of the Arabian Sea as well as their engagement in coastal shipping can be classified as moderate and incidental in the antiquity.
Abstract
While three-dimensional measurement technology is spreading fast, its meaningful application to sedimentary geology still lacks content. Classical shape descriptors (such as axis ratios, circularity of projection) were not inherently three-dimensional, because no such technology existed. Recently a new class of three-dimensional descriptors, collectively referred to as mechanical descriptors, has been introduced and applied for a broad range of sedimentary particles. First-order mechanical descriptors (registered for each pebble as a pair {S, U} of integers), refer to the respective numbers of stable and unstable static equilibria and can be reliably detected by hand experiments. However, they have limited ability of distinction, as the majority of coastal pebbles fall into primary class
Abstract
Stable hydrogen isotope compositions of metamorphic rocks and minerals can provide information on the origin of metamorphic fluids, which is especially important in systems that had experienced multiple metamorphic events. The Sopron orthogneiss-micaschist complex is a good target as it records signs of Variscan and Alpine metamorphic events as well as Variscan granitic magmatism. In this study tourmaline-bearing rocks (pegmatitic orthogneisses and kyanite-chlorite-muscovite schists) of the Sopron metamorphic complex were sampled and their tourmaline grains were analyzed for stable hydrogen isotope compositions (δ2H). The δ2H values (−23 ± 1‰, relative to V-SMOW) are in accordance with a fluid flux from devolatilization of subducted, seawater-containing rocks. Tourmaline-chlorite hydrogen isotope fractionations correspond to about 550 °C, indicating that δ2H values formed close to peak metamorphic temperatures are preserved without retrograde isotope exchange during cooling.
Abstract
Real estate crowdfunding is a relatively new alternative financing and investing method. This research aims to identify factors which might increase investors' willingness to participate in real estate crowdfunding campaigns. We analyse 195 lending-based real estate crowdfunding campaigns from four Spanish platforms. Project success is measured by duration, i.e. the time required to reach the funding target. We assess the impact of the funding target, the annual return, the loan duration, several risk-related metrics and the minimum investment amount. We find that the higher the funding target and the minimum investment amount, the longer it takes to reach the target. We document that investors prefer projects where the maturity of the loan is shorter. We also find that construction-type projects reach the funding target faster than other type of fundraising goals. At the same time, we do not find any association between the annual return or risk-related metrics and project success. To assure successful fundraising, real estate crowdfunding platforms should prioritize those real estate projects which are highly popular among investors (i.e. construction-type projects with short maturity). Real estate developers, in turn, should crowdfund projects which are demanded by the crowdinvestors and use their traditional financing methods for the remaining projects.
