Influence of zinc on distiller’s yeast:cellular accumulation of zinc and impact on spirit congeners

Accumulation of zinc by a whisky distilling yeast strain of Saccharomyces cerevisiae was studied during fermentation of malt wort and synthetic defined medium. Zinc uptake by yeast cells was very rapid in malt wort, as zinc (0.32 μg/mL) was completely removed from the fermentation medium within one hour. The type of fermentable carbohydrate had an impact on the kinetics of zinc accumulation, with maltose most effective at enhancing metal uptake at zinc concentrations above 3.2 μg/mL. Enriching yeast cells with zinc by “preconditioning” impacted on the production of flavour congeners in the distillates produced from fermented cultures. Such distillates were characterized by an altered flavour and aroma profile. In particular, the production of some higher alcohols increased when yeast cells were preconditioned with zinc. This phenomenon is yeast strain related. Industrial fermentation processes, including brewing and distilling, may benefit from optimization of zinc bioavailability in yeast cultures resulting in more efficient fermentations and improved product quality

Cj0596 is a periplasmic peptidyl prolyl cis-trans isomerase involved in Campylobacter jejuni motility, invasion, and colonization

Abstract Background Campylobacter jejuni is a gastrointestinal pathogen of humans, but part of the normal flora of poultry, and therefore grows well at the respective body temperatures of 37°C and 42°C. Proteomic studies on temperature regulation in C. jejuni strain 81–176 revealed the upregulation at 37°C of Cj0596, a predicted periplasmic chaperone that is similar to proteins involved in outer membrane protein folding and virulence in other bacteria. Results The cj0596 gene was highly conserved in 24 strains and species of Campylobacter, implying the importance of this gene. To study the role that Cj0596 plays in C. jejuni pathogenesis, a mutant derivative of strain 81–176 was constructed in which the cj0596 gene was precisely deleted. A revertant of this mutant was isolated by restoring the gene to its original chromosomal location using streptomycin counterselection. The cj0596 mutant strain demonstrated a slightly decreased growth rate and lower final growth yield, yet was more motile and more invasive of human intestinal epithelial cells than wild-type. In either single or mixed infections, the mutant was less able to colonize mice than 81–176. The cj0596 mutant also expressed altered levels of several proteins. Conclusion Mutation of cj0596 has an effect on phenotypes related to C. jejuni pathogenesis, probably due to its role in the proper folding of critical outer membrane proteins.</p

Flow in a slowly-tapering channel with oscillating walls

The flow of a fluid in a channel with walls inclined at an angle to each other is investigated at arbitrary Reynolds number. The flow is driven by an oscillatory motion of the wall incorporating a time-periodic displacement perpendicular to the channel centreline. The gap between the walls varies linearly with distance along the channel and is a prescribed periodic function of time. An approximate solution is constructed assuming that the angle of inclination of the walls is small. At leading order the flow corresponds to that in a channel with parallel, vertically oscillating walls examined by Hall and Papageorgiou \cite{HP}. A careful study of the governing partial differential system for the first order approximation controlling the tapering flow due to the wall inclination is conducted. It is found that as the Reynolds number is increased from zero the tapering flow loses symmetry and undergoes exponential growth in time. The loss of symmetry occurs at a lower Reynolds number than the symmetry-breaking for the parallel-wall flow. A window of asymmetric, time-periodic solutions is found at higher Reynolds number, and these are reached via a quasiperiodic transient from a given set of initial conditions. Beyond this window stability is again lost to exponentially growing solutions as the Reynolds number is increased

Dissolved organic carbon uptake in streams: A review and assessment of reach‐scale measurements

Quantifying the role that freshwater ecosystems play in the global carbon cycle requires accurate measurement and scaling of dissolved organic carbon (DOC) removal in river networks. We reviewed reach‐scale measurements of DOC uptake from experimental additions of simple organic compounds or leachates to inform development of aquatic DOC models that operate at the river network, regional, or continental scale. Median DOC uptake velocity (vf) across all measurements was 2.28 mm min−1. Measurements using simple compound additions resulted in faster vf (2.94 mm min−1) than additions of leachates (1.11 mm min−1). We also reviewed published data of DOC bioavailability for ambient stream water and leaf leachate DOC from laboratory experiments. We used these data to calculate and apply a correction factor to leaf leachate uptake velocity to estimate ambient stream water DOC uptake rates at the reach scale. Using this approach, we estimated a median ambient stream DOC vf of 0.26 mm min−1. Applying these DOC vf values (0.26, 1.11, 2.28, and 2.94 mm min−1) in a river network inverse model in seven watersheds revealed that our estimated ambient DOC vf value is plausible at the network scale and 27 to 45% of DOC input was removed. Applying the median measured simple compound or leachate vf in whole river networks would require unjustifiably high terrestrial DOC inputs to match observed DOC concentrations at the basin mouth. To improve the understanding and importance of DOC uptake in fluvial systems, we recommend using a multiscale approach coupling laboratory assays, with reach‐scale measurements, and modeling

My mind is made up: Cancer concern and women’s preferences for contralateral prophylactic mastectomy

© 2019 John Wiley & Sons Ltd The fear of cancer recurrence is cited as a motivator of women's preferences between routine monitoring and contralateral prophylactic mastectomy (CPM) as methods of managing ongoing breast cancer risk. We conducted a discrete choice experiment among a general community sample of women who completed 12 hypothetical choices between routine monitoring and CPM described by aspects of treatment efficacy, safety, cost and involvement in decision-making. Respondents also completed a modified cancer worry question to assess cancer concern. Approximately 57.5% of 464 women always chose one option, typically routine monitoring. The majority (71.5%) reported being concerned about cancer recurrence when completing choice tasks. Latent class analysis identified three groups: preferred routine monitoring; preferred CPM; and “traders” (willing to swap between options). Among traders, women were less likely to choose an option associated with higher risk of recurrence. Women were more likely to choose options associated with less-intrusive monitoring methods and where they were involved in decision-making. Women concerned about cancer recurrence were more likely to choose CPM over monitoring. This study shows that women's preferences about how to manage breast cancer recurrence risk reflect the importance of the associated health effects, experience of care and attitudes to cancer recurrence

Intensive chemical weathering in the Arctic during the Miocene Climatic Optimum

The Arctic today has shallow, chemically immature, and frost-dominated weathering regimes. At Sokli, Finland (68°N), a 70 m deep palaeo-weathering profile is developed in a Devonian carbonatite pipe that represents fundamentally different past weathering environments. Formation of the apatite-francolite P-ore likely began under Palaeogene warm, humid climates. Later, cryptomelane (K-Mn oxide) crusts developed within the ore that have yielded peak 40Ar/39Ar ages of 16.20 ± 0.13 Ma (2σ)., The crusts formed at the redox front during the Miocene Climatic Optimum (∼16.9–14.7 Ma) under mean annual temperatures ∼12–14 °C warmer than today. The presence of the cryptomelane crust at shallow depth (15 m) indicates very low erosion rates since formation, consistent with its position on a tectonically stable Archaean craton and in the cold-based ice-divide zone of successive Fennoscandian ice sheets. The Miocene Climatic Optimum triggered a pulse of intensive weathering in mid- and low latitudes; the Sokli cryptomelane ages demonstrate that intensive chemical weathering extended into the Arctic.</p

A Complete Supersymmetric SO(10) Model

A complete supersymmetric SO(10) model is constructed, which is the most general consistent with certain $R$, discrete, and $U(1)$ flavor symmetries. The desired vacuum of the theory has vevs which lie in particular directions of group space. This leads to both doublet triplet splitting and to the generation of just four operators for charged fermion masses. The model illustrates how many features of superunification become related in the context of a complete theory. The features discussed here include: the weak mixing angle prediction, the doublet-triplet splitting problem, proton decay, the generation of the $\mu$ parameter, neutrino masses and the generation of the operators which lead to charged fermion mass predictions.Comment: 18 page

Salmon and jellies and herring, oh my! Abiotic and biotic-dependent trends in abundance and distribution of pelagic critters in Skagit Bay across 17 years

As a large fjord, the Salish Sea exhibits strong spatiotemporal variation in temperature and salinity due to various marine and freshwater inputs. These patterns are particularly evident in Skagit Bay where water conditions are influenced by marine inputs from Deception Pass and Saratoga Passage and seasonal pulses of fresh water from Skagit River. We investigated how abundance and community composition in pelagic surface waters of Skagit Bay varied from 2001-2017, and how temperature and salinity patterns can influence which species predominate in particular years. Data come from long-term monitoring of Skagit Bay using a Kodiak surface trawl that sweeps the uppermost 10 feet of the water column. We evaluated how temperature and salinity influenced species abundance and distribution and tested whether distributions were likely influenced by biotic interactions (e.g. predation, competition), focusing on diadromous species (e.g., salmon, lamprey, starry flounder), forage fish (e.g., Pacific herring, surf smelt, Pacific sandlance), and gelatinous zooplankton (e.g., ctenophores, scyphozoan and hydrozoan medusae). Our results provide evidence for strong abiotic structuring and weaker effects from biotic interactions, although certain species appeared to interact more than others. These results may help us understand how long-term increases in regional and local temperatures and freshening waters will affect Salish Sea ecology

Race and sex: teachers' views on who gets ahead in schools?

The research reported here was part of a large study of the impact of age, disability, race and sex on the teaching profession in England. The basic question asked in this research was how do these factors interact with career aspirations and achievements of classteachers, promoted teachers and headteachers? There were three different data sources: a large postal survey drawn from diverse geographic regions across England with over 2000 respondents; face‐to‐face individual interviews with over 100 teachers in 18 case study schools from across all of the main regions of England; discussions with special interest groups of teachers. Not surprisingly, the answer to the above question was complex. Nonetheless, the paper's conclusion highlights some of the noteworthy themes across this broad sample of teachers from primary, secondary and special schools