A study of the thermal transformation of alkylammonium cations adsorbed on the surface of a montmorillonite in various conditions of hydration has been carried out. The experimental conditions were: inert atmosphere, temperatures below 250°C and time periods up to 270 days. The reactions observed are mainly transalkylations, for which a mechanism of acid catalysis is proposed. A high degree of dissociation of the water remaining on the surface of the clay is required and is attained for an optimal, and rather low, water content of the clay.

The nineteenth century was a dynamic period for hacienda workers on the south coast of Peru. Former Jesuit vineyards with two of the largest enslaved African-descended populations in rural coastal Peru—the haciendas of San Joseph (San José) and San Francisco Xavier (San Javier)—and their annexes in Nasca's Ingenio Valley underwent dramatic transformations with the replacement of their grapevines with cotton and the introduction of new types of workers. Cantonese indentured workers were contracted beginning in the 1830s, and the majority-enslaved workforce was legally emancipated in 1854. Seasonally, highland Andean workers joined the demographically shifting permanent hacienda population. We use evidence from excavated midden contexts at San Joseph, San Xavier, and San Joseph's annex of Hacienda La Ventilla to explore these changing agroindustrial dynamics and worker well-being in the eighteenth and nineteenth centuries. Despite the transformations at the estates, we find that culinary practices developed by enslaved Africans and their descendants during the Jesuit administration, such as the preparation of one-pot meals and stews, continued into the republican era among Cantonese indentured laborers and wage workers of Indigenous, mestizo, and Cantonese origins. We argue that such strategies centered on foodways were a crucial aspect of worker self-care regimes and broader well-being.

Manen et al. provide here a reply to the critical comment published by A. J. Ammerman regarding their article “The Neolithic Transition in the Western Mediterranean: a complex and non-linear diffusion process—the radiocarbon record revisited,” published in 2019 in Radiocarbon. They also use this occasion to reaffirm the need to elaborate novel interpretive frameworks that combine both geo-chronological and cultural data.

Previous studies attest that early bilinguals can modify their perceptual identification according to the fine-grained phonetic detail of the language they believe they are hearing. Following Gonzales et al. (2019), we replicate the double phonemic boundary effect in late learners (LBs) using conceptual-based cueing. We administered a forced choice identification task to 169 native English adult learners of Spanish in two sessions. In both sessions, participants identified the same /b/-/p/ voicing continuum, but language context was cued conceptually using the instructions. The data were analyzed using Bayesian multilevel regression. Learners categorized the continuum in a similar manner when they believed they were hearing English. However, when they believed they were hearing Spanish, “voiceless” responses increased as a function of L2 proficiency. This research demonstrates the double phonemic boundary effect can be conceptually cued in LBs and supports accounts positing selective activation of independent perception grammars in L2 learning.

High-starch diets (HSDs) fed to high-producing ruminants are often responsible for rumen dysfunction and could impair animal health and production. Feeding HSDs are often characterized by transient rumen pH depression, accurate monitoring of which requires costly or invasive methods. Numerous clinical signs can be followed to monitor such diet changes but no specific indicator is able to make a statement at animal level on-farm. The aim of this pilot study was to assess a combination of non-invasive indicators in dairy cows able to monitor a HSD in experimental conditions. A longitudinal study was conducted in 11 primiparous dairy cows fed with two different diets during three successive periods: a 4-week control period (P1) with a low-starch diet (LSD; 13% starch), a 4-week period with an HSD (P2, 35% starch) and a 3-week recovery period (P3) again with the LSD. Animal behaviour was monitored throughout the experiment, and faeces, urine, saliva, milk and blood were sampled simultaneously in each animal at least once a week for analysis. A total of 136 variables were screened by successive statistical approaches including: partial least squares-discriminant analysis, multivariate analysis and mixed-effect models. Finally, 16 indicators were selected as the most representative of a HSD challenge. A generalized linear mixed model analysis was applied to highlight parsimonious combinations of indicators able to identify animals under our experimental conditions. Eighteen models were established and the combination of milk urea nitrogen, blood bicarbonate and feed intake was the best to detect the different periods of the challenge with both 100% of specificity and sensitivity. Other indicators such as the number of drinking acts, fat:protein ratio in milk, urine, and faecal pH, were the most frequently used in the proposed models. Finally, the established models highlight the necessity for animals to have more than 1 week of recovery diet to return to their initial control state after a HSD challenge. This pilot study demonstrates the interest of using combinations of non-invasive indicators to monitor feed changes from a LSD to a HSD to dairy cows in order to improve prevention of rumen dysfunction on-farm. However, the adjustment and robustness of the proposed combinations of indicators need to be challenged using a greater number of animals as well as different acidogenic conditions before being applied on-farm.

Distributed models and a good knowledge of the catchment studied are required to assess mitigation measures for nitrogen (N) pollution. A set of alternative scenarios (change of crop management practices and different strategies of landscape management, especially different sizes and distribution of set-aside areas) were simulated with a fully distributed model in a small agricultural catchment. The results show that current practices are close to complying with current regulations, which results in a limited effect of the implementation of best crop management practices. The location of set-aside zones is more important than their size in decreasing nitrate fluxes in stream water. The most efficient location is the lower parts of hillslopes, combining the dilution effect due to the decrease of N input per unit of land and the interception of nitrate transferred by sub-surface flows. The main process responsible for the interception effect is probably uptake by grassland and retention in soils since the denitrification load tends to decrease proportionally to N input and, for the scenarios considered, is lower in the interception scenarios than in the corresponding dilution zones.

The Neolithic transition is a particularly favorable field of research for the study of the emergence and evolution of cultures and cultural phenomena. In this framework, high-precision chronologies are essential for decrypting the rhythms of emergence of new techno-economic traits. As part of a project exploring the conditions underlying the emergence and dynamics of the development of the first agro-pastoral societies in the Western Mediterranean, this paper proposes a new chronological modeling. Based on 45 new radiocarbon (14C) dates and on a Bayesian statistical framework, this work examines the rhythms and dispersal paths of the Neolithic economy both on coastal and continental areas. These new data highlight a complex and far less unidirectional dissemination process than that envisaged so far.

Silicification and illitization due to diagenesis result in the modification of porosity and permeability in many North Sea reservoirs, including Greater Alwyn. A good estimation of the mineral composition is required as input/output data for geochemical modelling modes intended to reproduce these effects. Using sedimentological studies to determine laterally equivalent facies, three facies were chosen. ‘Initial states’ for modelling were thus defined as the present-day composition of less-evolved laterally-equivalent facies, ‘final states’ as the present-day composition in the most evolved part of the basin. Precise actual mineral compositions were calculated using a reconciliation program, DATREC. Average compositions calculated for each facies in each field provided data useful in constraining input/output values used in modelling, and gave insights into depositional variation. Arithmetic tests assuming isochemical transformations, constraining the chemical compositions of ‘initial states’ to fit actual mineralogical compositions of ‘final states’, were run using this software. They show that, from an arithmetical point of view, if the assumption of equivalent facies holds, isochemical reactions can occur in some, but not in all facies, thereby demonstrating the importance of checking equivalence of facies and diagenesis hypotheses by quantitative calculations.

We assessed clinicians’ continuing professional development (CPD) needs at family practice teaching clinics in the province of Quebec. Our mixed methodology design comprised an environmental scan of training programs at four family medicine departments, an expert panel to determine priority clinical situations for senior care, a supervisors survey to assess their perceived CPD needs, and interviews to help understand the rationale behind their needs. From the environmental scan, the expert panel selected 13 priority situations. Key needs expressed by the 352 survey respondents (36% response rate) included behavioral and psychological symptoms of dementia, polypharmacy, depression, and cognitive disorders. Supervisors explained that these situations were sometimes complex to diagnose and manage because of psychosocial aspects, challenges of communicating with patients and families, and coordination of interprofessional teams. Supervisors also reported more CPD needs in long-term and home care, given the presence of caregivers and complexity of senior care in these settings.

Synchrotron-based micro-X-ray fluorescence (μXRF) equipment has been used to analyze impurities in polar ice. A customized sample holder has been developed and the μXRF equipment has been adapted with a thermal control system to keep samples unaltered during analyses. Artificial ice samples prepared from ultra-pure water were analyzed to investigate possible contamination and/or experimental artefacts. Analyses of polar ice from Antarctica (Dome C and Vostok) confirm this μXRF technique is non-destructive and sensitive. Experiments can be reproduced to confirm or refine results by focusing on interesting spots such as crystal grain boundaries or specific inclusions. Integration times and resolution can be adjusted to optimize sensitivity. Investigation of unstable particles is possible due to the short analysis time. In addition to identification of elements in impurities, μXRF is able to determine their speciations. The accuracy and reliability of the results confirm the potential of this technique for research in glaciology.

The Brangus breed was developed to combine the superior characteristics of both of its founder breeds, Angus and Brahman. It combines the high adaptability to tropical and subtropical environments, disease resistance, and overall hardiness of Zebu cattle with the reproductive potential and carcass quality of Angus. It is known that the major histocompatibility complex (MHC, also known as bovine leucocyte antigen: BoLA), located on chromosome 23, encodes several genes involved in the adaptive immune response and may be responsible for adaptation to harsh environments. The objective of this work was to evaluate whether the local breed ancestry percentages in the BoLA locus of a Brangus population diverged from the estimated genome-wide proportions and to identify signatures of positive selection in this genomic region. For this, 167 animals (100 Brangus, 45 Angus and 22 Brahman) were genotyped using a high-density single nucleotide polymorphism array. The local ancestry analysis showed that more than half of the haplotypes (55.0%) shared a Brahman origin. This value was significantly different from the global genome-wide proportion estimated by cluster analysis (34.7% Brahman), and the proportion expected by pedigree (37.5% Brahman). The analysis of selection signatures by genetic differentiation (F st ) and extended haplotype homozygosity-based methods (iHS and Rsb) revealed 10 and seven candidate regions, respectively. The analysis of the genes located within these candidate regions showed mainly genes involved in immune response-related pathway, while other genes and pathways were also observed (cell surface signalling pathways, membrane proteins and ion-binding proteins). Our results suggest that the BoLA region of Brangus cattle may have been enriched with Brahman haplotypes as a consequence of selection processes to promote adaptation to subtropical environments.

Predictions of marine ice-sheet behaviour require models able to simulate grounding-line migration. We present results of an intercomparison experiment for plan-view marine ice-sheet models. Verification is effected by comparison with approximate analytical solutions for flux across the grounding line using simplified geometrical configurations (no lateral variations, no buttressing effects from lateral drag). Perturbation experiments specifying spatial variation in basal sliding parameters permitted the evolution of curved grounding lines, generating buttressing effects. The experiments showed regions of compression and extensional flow across the grounding line, thereby invalidating the boundary layer theory. Steady-state grounding-line positions were found to be dependent on the level of physical model approximation. Resolving grounding lines requires inclusion of membrane stresses, a sufficiently small grid size (<500 m), or subgrid interpolation of the grounding line. The latter still requires nominal grid sizes of <5 km. For larger grid spacings, appropriate parameterizations for ice flux may be imposed at the grounding line, but the short-time transient behaviour is then incorrect and different from models that do not incorporate grounding-line parameterizations. The numerical error associated with predicting grounding-line motion can be reduced significantly below the errors associated with parameter ignorance and uncertainties in future scenarios.

Quantitative assessment of mitigation measures for nitrogen (N) pollution requires adequate models, good knowledge of catchment functioning and a thorough understanding of agricultural systems and stakeholder constraints. The current paper analyses a set of results from simulations, with two models, of agricultural changes in two catchments in different contexts with different constraints. The results show that reducing N inputs and increasing grassland areas are the most efficient measures, not only because they reduce N fluxes in streams but also because they enhance N use by agriculture and the whole catchment system. Introducing catch crops, hedgerows and riparian buffers are interesting complementary measures but of limited impact when implemented alone. These results are sensitive to the way mitigation measures are translated into model inputs, and their operational implications are discussed.

We take up the old problem of Calvert (J. Fluid Mech., vol. 29, 1967, pp. 691–703) concerning the wake of a cylinder inclined with respect to the flow direction, and consider it from the viewpoint of transition to turbulence. For cylinders placed perpendicular to the flow direction, we address the disagreement between numerical simulation of the ideal axisymmetric configuration and experimental observations. We demonstrate that for a disk (a cylinder of aspect ratio infinity) and a flat cylinder of aspect ratio ${\it\chi}=6$ (ratio of diameter to height), the numerically predicted transition scenario is limited to very small inclination angles and is thus difficult to test experimentally. For inclination angles of about $4^{\circ }$ and more, a joint numerical and experimental study shows that the experimentally observed scenario agrees qualitatively well with the results of numerical simulations. For the flat cylinder ${\it\chi}=6$ , we obtain satisfactory agreement with regard to dependence of the critical Reynolds number ( $\mathit{Re}$ ) of the onset of vortex shedding on the inclination angle. Both for infinitely flat disks and cylinders of aspect ratio ${\it\chi}=6$ , a small inclination tends to promote vortex shedding, that is, to lower the instability threshold, whereas for inclination angles exceeding $20^{\circ }$ the opposite effect is exhibited. The Strouhal number of oscillations is found to be only very weakly dependent on the Reynolds number, and very good agreement is obtained between values reported by Calvert (J. Fluid Mech., vol. 29, 1967, pp. 691–703) at high Reynolds numbers and our simulations at $\mathit{Re}=250$ . In contrast, we observe relatively poor agreement in Strouhal numbers when comparing the results of our numerical simulations and the data acquired from the experimental set-up described in this paper. Closer analysis shows that confidence can be placed in the numerical results because the discrepancy can be attributed to the influence of the support system of the flat cylinder. Suggestions for improvement of the experimental set-up are provided.

This article describes the nitrogen flows in the environment and points to the specificities of the livestock production. Till the beginning of the 20th century, the symbiotic fixation and the recycling of animal excreta supplied the nitrogen necessary for the fertility of soil. In 1913, the Haber-Bosch process allowed the industrial synthesis of ammonia and made possible the fertilisation without association of crop production with the livestock farming. The efficiency of the nitrogen in livestock farming is low with nearly half or more of the inputs losses to the environment. These losses have diverse impacts that intervene at various spatial scales owing to the nitrogen cascade. Quantitative assessment of nitrogen flows at the scale of regions started in the early 1980s in Western Europe and North America. These studies provided estimates of the spatial variability of nitrogen discharge within a region. They confirmed the differences between areas with a high animal density such as Brittany (western region, France) and other regions. It was also found that the same nitrogenous losses could lead to different levels of environmental impacts according to the sensibility of a given environment and its capacity to cope with nitrogen excess. Climate, soils characteristics, animal density, and proportions of agricultural land under annual and perennial crops are drivers of this sensibility.

The nitrogen efficiency is the ratio between the output of nitrogen in the animal products and the input required for the livestock production. This ratio is a driver of the economic profitability and can be calculated at various levels of the production system: animal, field or farm. Calculated at the scale of the animal, it is generally low with less than half-ingested nitrogen remaining in the milk, the eggs or the meat in the form of proteins; the major part of the nitrogen being rejected in the environment. Significant gains were achieved in the past via the genetic improvement and the adjustment of feed supply. At the farm level, the efficiency increases to 45% to 50%, thanks to the recycling of animal excreta as fertilisers. From excretion to land application of manure, the losses of nitrogen are very variable depending on the animal species and the manure management system. Considering the risks of pollution swapping, all management and handling steps need to be considered. Collective initiatives or local rules on agricultural practices allow new opportunities to restore nitrogen balances on local territory.