CO2 and N2O emissions from gleyic soils in the Russian tundra and a German forest during freeze-thaw periods—a microcosm study

Knowledge is scarce on mineralization of soil organic carbon (SOC) in and N₂O emissions from tundra soils in periods of alternate freezing and thawing. Our objectives were to study the CO₂ and N₂O emissions from two silty gleyic soils formed in different climate zones (a gleyic Cryosol located in the Russian tundra, and a stagnic Gleysol located in an oak stand in central Germany) during freeze-thaw events. Soils were adjusted to a matric potential of −0.2 kPa and emissions were measured in 3-h intervals during an incubation period of 50 days including three freeze-thaw cycles. CO₂ emissions from the German oak forest soil were twofold higher than those of the tundra soil. The ratios of the mean CO₂ production rate before the freezing to the mean CO₂ production rate after thawing ranged from 0.63 to 0.73 for the forest soil and from 0.85 to 0.89 for the tundra soil. The specific CO₂-C production rate (CO₂-C/SOC) was 0.16 for the tundra soil and 0.57 for the forest soil. The results indicate that bioavailability of SOC was markedly smaller in the tundra soil than in the forest soil. Large N₂O emissions were found for the German forest soil, but no N₂O emissions were observed for the tundra soil. The main reason for the absence of N₂O emissions was most likely the negligible availability of nitrate for denitrification. There was some indication that the initial increase in mineralization of SOC induced by freezing and thawing differs between soils from various climatic regions, probably mainly due to a differing bioavailability of the SOC and differing releases of nutrients after thawing.     

How milk does the world good: vernacular sustainability and alternative food systems in post-socialist Europe

Scholarly debates on sustainable consumption have generally overlooked alternative agro-food networks in the economies outside of Western Europe and North America. Building on practice-based theories, this article focuses on informal raw milk markets in post-socialist Lithuania to examine how such alternative systems emerge and operate in the changing political, social, and economic contexts. It makes two contributions to the scholarship on sustainable consumption. In considering semi-subsistence practices and poverty-driven consumption, this article argues for a richer, more critical, and inclusive theory of sustainability that takes into consideration vernacular forms of exchange and approaches poor consumers as subjects of global history. Second, it revisits practice theories and infrastructures of consumption approaches to consider ruptures, discontinuities, and historical change in infrastructures as a way to account for inequalities and experiences of marginalization.     

Changes in the Fractional Composition of Organic Matter in the Soils of the Forest–Steppe Zone during Their Postagrogenic Evolution

Eurasian Soil Science - The postagrogenic dynamics of organic carbon (Corg), total nitrogen (Ntot), and density fractions of organic matter (OM) in the dark gray soil (Haplic Phaeozem, Belgorod...     

Weed hosts of Meloidogyne spp. and the effect of aqueous weed extracts on egg hatching

Weeds have a great economic impact on agricultural production because they compete with crops for resources and are alternative hosts for pests, microbial pathogens and plant-parasitic nematodes. This study aimed to investigate the susceptibility of weeds to the root-knot nematodes Meloidogyne javanica and Meloidogyne incognita and assess the effect of aqueous weed extracts on M. javanica egg hatching. Four experiments were conducted, two for each nematode species. Weeds were inoculated with 2000 nematode eggs and grown for 60 days under greenhouse conditions. Soyabean cv. Monsoy 7110 was used as control. The weeds Ipomoea grandifolia, Solanum americanum, Digitaria horizontalis, Amaranthus deflexus, Sorghum halepense and Commelina benghalensis were susceptible to M. javanica and M. incognita in at least one experiment (reproduction factor, RF >1). Crotalaria juncea and Eleusine indica were susceptible to M. incognita in one experiment, and Digitaria insularis, Sida rhombifolia, Bidens pilosa, Urochloa decumbens, Crotalaria breviflora, Cenchrus echinatus, Crotalaria ochroleuca and Crotalaria spectabilis were immune or resistant (RF <1 or RF = 0). Alternanthera tenella, C. juncea, S. rhombifolia, C. ochroleuca, C. spectabilis, C. breviflora, B. pilosa, E. indica, U. decumbens and C. echinatus were resistant or immune to M. javanica (RF <1 or RF = 0). Compared with the control (water), all weed extracts reduced M. javanica egg hatch. Our results highlight the importance of weed control in agricultural systems, as nematodes can survive and multiply in weed roots during the off-season. Weed leaves and shoots, however, may be an interesting source of compounds with nematicidal activity.     

Characteristics of Staphylococcus aureus from subclinical bovine mastitis in Brazil

A total of 127 Staphylococcus aureus strains isolated from milk samples of cows with subclinical bovine mastitis was examined for biotype, phage pattern, in-vitro antibiotic susceptibilities and ability to produce enterotoxins. The majority of the strains showed features consistent with bovine rather than human origin. All strains were sensitive to the antibiotics tested, except penicillin and streptomycin. Enterotoxigenicity was observed in 6 (4.7%) strains and only enterotoxins A and C were produced.     

Evaluation of important seed and sprout traits as potential selection criteria in breeding varieties for sprout soybeans

Soybean sprouts, a traditional vegetable in Asia, are gaining popularity in the United States. Soybean sprout demand has been supplied by natto (a Japanese soyfood) cultivars that share some seed characteristics with sprout cultivars. However, natto seeds do not meet all requirements of sprouts and are rejected by sprout manufacturers. The objectives of this study were to evaluate important seed and sprout traits as potential selection criteria in breeding sprout soybeans and to study the storage effect on soybean sprout quality. Almost all genotypes produced thicker and longer hypocotyls and higher fresh-sprouts than ‘MFS-561’, a commercial soybean sprout variety. Hypocotyl length ranged from 13.8 to 16.2 cm. Four fungi genera Bipolaris sp., Cercospora sp., Botrytis sp. and Caethomium sp. were isolated from seeds. Cracked cotyledons and abnormal seedlings were the two main constraints affecting soybean sprout quality. Correlation coefficients among all traits indicated that percentage and weight of high- and average-quality sprouts would determine sprout yield. Acceptable yield and several traits were recommended to be used simultaneously while breeding superior sprout soybean cultivars. Good sprout varieties should produce high-quality sprouts >48%, average-quality sprouts <38%, low-quality sprouts <14%, sprout yield >5.7 g/g seed, hypocotyl thickness >1.6 cm and hypocotyl length >13 cm. One-year seed storage at room temperature reduced sprout quality. V09-3876 and V12-1939 had superior seed and sprout traits and are promising lines for further evaluation for sprout production. Seed storage over time affects seed germination and seedling vigor, and fungi on seed can cause reduced seed quality.     

Melanoma Inhibition by Anthocyanins Is Associated with the Reduction of Oxidative Stress Biomarkers and Changes in Mitochondrial Membrane Potential

Anthocyanins are water soluble pigments which have been proved to exhibit health benefits. Several studies have investigated their effects on several types of cancer, but little attention has been given to melanoma. The phytochemical content of nine different berry samples was assessed by liquid chromatography followed by electrospray ionization mass spectrometry (LC-ESI⁺-MS). Twenty-six anthocyanins were identified, after a previous C₁₈ Sep-pak clean-up procedure. Chokeberry and red grape anthocyanins rich extracts (C-ARE and RG-ARE) were selected to be tested on normal and melanoma cell lines, due to their different chemical pattern. C-ARE composition consists of cyanidin aglycone glycosylated with different sugars; while RG-ARE contains glucosylated derivatives of five different aglycones. Both C-ARE and RG-ARE anthocyanins reduced proliferation, increased oxidative stress biomarkers and diminished mitochondrial membrane potential in melanoma cells, having no negative influence on normal cells. A synergistic response may be attributed to the five different aglycones present in RG-ARE, which proved to exert greater effects on melanoma cells than the mixture of cyanidin derivatives with different sugars (C-ARE). In conclusion, C-ARE and RG-ARE anthocyanins may inhibit melanoma cell proliferation and increase the level of oxidative stress, with opposite effect on normal cells. Therefore, anthocyanins might be recommended as active ingredients for cosmetic and nutraceutical industry.

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Graphical Abstract ?

     

养殖水体中藻毒素污染问题的研究进展

在水产养殖过程中,由于一些蓝藻水华产毒藻株的毒性作用,给水生生物的生长、繁殖、发育带来严重的影响和破坏,并间接地威胁食品安全和人类健康。在国内外研究的基础上,阐述了藻毒素对水生有机体的影响。     

Effects of protein and carbohydrate levels on survival,consumption and gonad index in adult sea urchin Strongylocentrotus purpuratus (Stimpson 1857) from Baja California,Mexico

A greater understanding of dietary protein and carbohydrate levels with regard to gonad production in Strongylocentrotus purpuratus would increase our nutritional knowledge of this sea urchin and guide the development of formulated diets for such aquaculture target species. A total of 255 purple sea urchins were captured from Ensenada Bay, Mexico, and maintained in 200‐L tanks for 9 weeks. Formulated diets that contained 30%, 26%, 23%, 20% and 17% of protein and 42%, 46%, 50%, 54% and 58% carbohydrates were offered ad libitum. Survival was affected by diets; urchins that were fed high‐protein–low‐carbohydrate diet experienced decreased survival. No significant differences were found in gonad index, but gonad production efficiency was lower in urchins that were fed a medium‐low‐protein–medium‐high‐carbohydrate diet. Urchins that were fed high carbohydrate levels utilized protein more efficiently and showed better digestibility of the diet and protein. These data suggest that all of our diets support gonad growth, but in terms of consumption, a diet that contains protein levels of 17% and 23% with carbohydrate levels of 50% and 58% are beneficial for S. purpuratus.     

The bone degenerative processes in senile fishes from Holocene Brazilian shell mounds

Zooarchaeological collections from shell mounds in Rio de Janeiro (2,470–4,632 cal BP) contain a high prevalence of swollen fish bones belonging to the Atlantic spadefish (Chaetodipterus faber), crevalle jack (Caranx hippos) and fat snook (Centropomus parallelus). Given the lack of knowledge of the bone degenerative process in senile fishes, this study analysed hyperostotic bone in zooarchaeological and modern specimens to obtain high‐resolution morphology and microstructure reconstruction. We used microCT as well as X‐ray diffraction to characterize the crystallographic changes associated with fish senility. Our results showed that trabecular microstructures in hyperostotic bones were consistent with estimated values of the per cent bone volume‐to‐total volume ratio (BV/TV) and were greater than 60% in cortical bone. Hyperostotic bones indicated a high radiograph density, and X‐ray diffractograms showed a decrease in hydroxyapatite [Ca₁₀(PO₄)₆(OH)₂] and calcite (CaCO₃) neocrystallization. These crystalline and density changes revealed an advanced stage of fish senile and indicate the vulnerability of ageing fish populations.