Biofilm i mjölkningsanläggningar

Bakterier kan fastna och tillväxa i organiskt material i mjölkningsanläggningar vid ofullständig diskning. Dessa bakterier kan överleva pastöriseringen på mejeriet och senare orsaka problem i mejeriindustrin, framför allt i samband med tillverkning och försäljning av mjölkpulver

Egg buoyancy of flounder, Platichthys flesus , in the Baltic Sea—adaptation to salinity and implications for egg survival

Highlights: • Egg specific gravity vary between areas/subpopulations as an adaptation to salinity. • Egg diameter differ between areas/subpopulations whereas egg dry weight does not. • Habitat suitability for egg survival vary depending on salinity and oxygen conditions. • Egg survival probabilities increased following a major saline water inflow event. Abstract: Vertical distribution of eggs as determined by the egg buoyancy, i.e. the difference in specific gravity between the egg and the ambient water, have profound implications for the reproductive success and hence recruitment in fish. Here variability in egg specific gravity of flounder, Platichthys flesus, was studied along a salinity gradient and by comparing two reproductive strategies, spawning pelagic or demersal eggs. Egg characteristics of 209 egg batches (covering ICES subdivisions (SD) 22–29 in the brackish water Baltic Sea) was used to reveal the significance of egg diameter and egg dry weight for egg specific gravity (ESG), subpopulations, and egg survival probabilities of pelagic eggs following a major saline water inflow event. As an adaptation to salinity, ESG (at 7 °C) differed (p < 0.001) between areas; three subpopulations of flounder with pelagic eggs: 1.0152 ± 0.0021 (mean ± sd) g cm−3 in SD 22, 1.0116 ± 0.0013 g cm−3 in SD 24 and 25, and 1.0096 ± 0.0007 g cm−3 in SD 26 and 28, contrasting to flounder with demersal eggs, 1.0161 ± 0.0008 g cm−3. Egg diameter differed (p < 0.001) between subpopulations; from 1.08 ± 0.06 mm (SD 22) to 1.26 ± 0.06 mm (SD 26 and 28) for pelagic eggs and 1.02 ± 0.04 mm for demersal eggs, whereas egg dry weight was similar; 37.9 ± 5.0 μg (SD 22) and 37.2 ± 3.9 μg (SD 28) for pelagic, and 36.5 ± 6.5 μg for demersal eggs. Both egg diameter and egg dry weight were identified as explanatory variables, explaining 87% of the variation in ESG. ESG changed during ontogeny; a slight decrease initially but an increase prior to hatching. Egg survival probabilities judged by combining ESG and hydrographic data suggested higher egg survival in SD 25 (26 vs 100%) and SD 26 (32 vs 99%) but not in SD 28 (0 and 3%) after the inflow event, i.e. highly fluctuating habitat suitability. The results confirm the significance of ESG for egg survival and show that variability in ESG as and adaptation to salinity is determined mainly by water content manifested as differences in egg diameter; increase in diameter with decreasing salinity for pelagic eggs, and decreased diameter resulting in demersal eggs

Decomposition of Organic Matter in Caves

Decomposition of organic matter is a process, which includes mostly physical breakdown and biochemical transformation of complex organic molecules into simpler organic and inorganic molecules. The decomposition of organic matter is an important contributor to ecosystem respiration, which together with photosynthesis controls the net carbon emission from ecosystems. Subterranean ecosystems are extended all over the subsurface of our planet, and lack of light and consequently of photosynthetic activity. Understanding the drivers that control the dynamics of the decomposition processes in the deep subterranean spaces is important because they might differ from those at surface, due to factors as low species diversity and abundance, low microbial biomass, nutrient poor conditions, less pronounced variation of temperature, and higher humidity inside cave. Here, we review the existing studies of organic matter decomposition in caves. Decomposition rates are known from only nine caves representing four biogeographic regions, including Europe, North and South America. Most of the studies were performed in the aquatic compartment of caves. The decay of nine different organic substrates have been followed and the incubation time varied from 36 to 439 days. From a cave located in Australia the mass loss of leaf material from three plant species was investigated after 9 days incubation in the terrestrial compartment of the cave. Based on these observations, litter quality seems to be an important driver of decomposition in caves, and invertebrates have a stimulating effect on the decomposition within individual cave zones. The degree of connection to the surface also influences decomposition rate inside the cave. The lack of standard data among the studies is currently the major impediment to evaluate how differently the process proceeds in the underground compared to the surface, and to disentangle the main drivers of decomposition in caves across biomes. Improving our understanding of organic matter decomposition dynamics in caves will require the standardization of protocols and evaluation of the process over space and time, and a better comprehension on how decomposition changes over latitudinal, altitudinal and depth gradients.info:eu-repo/semantics/publishedVersio

The expression pattern of matrix-producing tumor stroma is of prognostic importance in breast cancer

Background: There are several indications that the composition of the tumor stroma can contribute to the malignancy of a tumor. Here we utilized expression data sets to identify metagenes that may serve as surrogate marker for the extent of matrix production and vascularization of a tumor and to characterize prognostic molecular components of the stroma. Methods: TCGA data sets from six cancer forms, two breast cancer microarray sets and one mRNA data set of xenografted tumors were downloaded. Using the mean correlation as distance measure compact clusters with genes representing extracellular matrix production (ECM metagene) and vascularization (endothelial metagene) were defined. Explorative Cox modeling was used to identify prognostic stromal gene sets. Results: Clustering of stromal genes in six cancer data sets resulted in metagenes, each containing three genes, representing matrix production and vascularization. The ECM metagene was associated with poor prognosis in renal clear cell carcinoma and in lung adenocarcinoma but not in other cancers investigated. Explorative Cox modeling using gene pairs identified gene sets that in multivariate models were prognostic in breast cancer. This was validated in two microarray sets. Two notable genes are TCF4 and P4HA3 which were included in the sets associated with positive and negative prognosis, respectively. Data from laser-microdissected tumors, a xenografted tumor data set and from correlation analyses demonstrate the stroma specificity of the genes. Conclusions: It is possible to construct ECM and endothelial metagenes common for several cancer forms. The molecular composition of matrix-producing cells, rather than the extent of matrix production seem to be important for breast cancer prognosis

Comparative studies on the gelling properties of cardosins extracted from Cynara cardunculus and chymosin on cow's skim milk

A comparative study was developed on the clottingactivities and gelling properties of cardosins A and B, extracted from dried flowers of Cynara cardunculus, and chymosin on cow’s skim milk, at various pH values. The determination of the total milk-clotting activity was performed followingan international standard, whereas a rheometer was employed to measure the viscoelastic properties of the gels subsequently formed: the evolution of the complex modulus (G ) and the phase angle (d) was monitored with time. The G values of the milk gels were higher for cardosins than for chymosin at pH 6.6, but the reverse held at pH 6.4 and 6.2. The d values were identical for all three enzymes tested. Chymosin exhibited the highest specific milk clotting activity, followed by cardosin B. The clottingactivity of chymosin seems to be more influenced than that of cardosins by the pH of milk

MSWI bottom ash used as basement at two pilot-scale roads: Comparison of leachate chemistry and reactive transport modeling

International audienceThe recycling of municipal solid waste incineration bottom ash as aggregates for road basement requires assessing the long-term evolution of leachate chemistry. The Dåva (Sweden) and Hérouville (France) pilot-scale roads were monitored during 6 and 10 years, respectively. Calculated saturation indices were combined to batch test modeling to set a simplified geochemical model of the bottom ash materials. A common reactive transport model was then applied to both sites. At Hérouville, pH and the concentration of most elements quickly drop during the first two years to reach a set of minimum values over 10 years. The decrease is less pronounced at Dåva. The evolutions of pH and major element concentrations are fairly well related to the following pH-buffering sequence: portlandite, C-S-H phases or pseudo-wollastonite and, finally, calcite in equilibrium with atmospheric CO2. Al(OH)3, barite, ettringite and monohydrocalcite may also control leachate chemistry. Cu release is correctly modeled by DOM complexation and tenorite equilibrium. Temperature has no significant effect on the modeling of leachate chemistry in the range 5-30 C, except at high pH. Effects at road edges and roadside slopes are important for the release of the less reactive elements and, possibly, for carbonation processes

What happens to people when machines replace them in the workplace?

New technologies are replacing workers in a growing range of occupations, causing loss of earnings and employment. However, these losses are smaller than those suffered by workers who experience mass layoffs. Per-Anders Edin, Tiernan Evans, Georg Graetz, Sofia Hernnäs and Guy Michaels write that, because the occupational decline they studied took years or even decades, its costs for individuals were likely mitigated through retirements, reduced entry into declining occupations and increased exits to other occupations