A strategy for recovering roots of bivariate polynomials modulo a prime

Let $p$ be a prime and \F_p the finite field with $p$ elements. We show how, when given an irreducible bivariate polynomial f \in \F_p[X,Y] and approximations to (v_0,v_1) \in \F_p^2 such that $f(v_0,v_1)=0$, one can recover $(v_0,v_1)$ efficiently, if the approximations are good enough. This result has been motivated by the predictability problem for non-linear pseudorandom number generators and, other potential applications to cryptography

Exploring aldehyde release in beer by 4-vinylpyridine and the effect of cysteine addition on the beer's pool of bound aldehydes

As a continuation of our previous work, which concerned the binding of aldehydes to bisulfite and cysteine, this article presents more results on the applicability of 4-vinylpyridine addition to beer prior to analysis aiming at release of aldehydes from these preformed bound states, thus making them quantifiable with the headspace solid-phase microextraction method combined with gas chromatography-mass spectrometry. This article also presents the first results on spiking beer samples with cysteine prior to forced-aging, pointing to the important role of cysteine in beer flavor stability. Both the levels in free and bound aldehydes show a relatively large degree of variation among different beers, but also between marker aldehydes. For some aldehydes (e.g., hexanal), the bound amount was shown to increase rather strongly upon forced beer aging, whereas for others (e.g., 2-methylpropanal), large amounts appeared to already be present in a bound state in the fresh samples. Spiking beer samples with cysteine prior to aging significantly lowered the aldehyde levels compared with nonspiked samples. Flavor stability of the cysteine-spiked beers was thereby greatly improved through aldehyde-cysteine adduct formation. It was further hypothesized that, in addition to efficient binding of aldehydes, cysteine also inhibits the formation of furfural during beer aging from Maillard reaction intermediates

Selecting the best: Interspecific and age-related diet differences among sympatric steppe passerines

Parental food provisioning is crucial for the growth and survival of offspring. Growth rate depends on food quality and food supplied to offspring may differ from what adults use for their own. In the case of steppe passerine birds, detailed characterization on nestling dietary composition, as well as prey choice and resource partitioning among species, is a pending subject. Dietary differences between nestlings and adults remain also largely unexplored. By using faecal DNA metabarcoding, we described the diet of nestlings and adults of five shrub-steppe passerine species over the 2017–2019 breeding seasons in central Spain. We also monitored arthropod availability in the field to assess dietary selection. We expected interspecific dietary differences to limit competition for food resources among sympatric species, as well as parental selection of high quality prey for nestlings. We also predicted age-related differences, with nestlings being fed nutrient-rich prey more frequently than adults. The main arthropod orders provisioned to nestlings were Orthoptera, Julida, Araneae and Lepidoptera. Nestlings of the different species showed high interspecific diet overlap, indicating both a coincidence in growth needs among bird species and no or little limitation of the most profitable resources during the breeding season. Adults of all species showed higher diet richness than nestlings, and age-related differences in prey composition were mainly driven by the selection of the most easily digestible, larger protein- and calcium-rich prey for nestlings, which may favour their rapid growth, and avoiding highly sclerotized and less nutritional prey such as ants. Our study sheds light on the basic ecology and conservation of these declining steppe birds, indicating that interspecific competition may not be a major factor during the breeding season. Given the current global decline of arthropods, further long-term research would be necessary, along with the implementation of effective conservation measures that ensure a sufficient availability of resources identified as key prey in the diet of steppe bird nestlings.This study was supported by the European Commission LIFE Ricotí (LIFE15-NAT-ES-000802) and LIFE Connect Ricotí (LIFE20-NAT-ES-000133) projects. This is a contribution to the Excellence Network Remedinal TE-CM (S2013/MAE2719). JG-C is funded by a Margarita Salas postdoctoral fellowship (CA4/RSUE/2022–00205) provided by the Spanish Ministry of Universities and Universidad Autónoma de Madrid (Spain). CPG acknowledges support from Ministerio de Educación y Formación Profesional through the Beatriz Galindo Fellowship (Beatriz Galindo-Convocatoria 2020) and JZ acknowledges support from Ministerio de Universidades through the predoctoral FPU fellowship program

On the contribution of malt quality and the malting process to the formation of beer staling aldehydes: a review

Despite decades of extensive research, beer flavour instability remains a challenge for both brewing and malting industries. Malt impacts the brewing process as well as the quality of the final beer. It also affects the stability of beer flavour, as it delivers to the brewing process various compounds with the potential to compromise the desired flavour characteristics of beer. These include staling aldehydes and their precursors, such as amino acids, reducing sugars, α-dicarbonyls and bound-state aldehydes. In general, the content of these compounds depends on barley variety and quality, the malting regime and final malt quality. Malt that represents a low potential for beer staling, i.e. that has low values of Kolbach Index, heat load, colour, LOX activity, Strecker aldehydes, transition metal ions and high antioxidative activity, leads to beer with enhanced flavour stability. However, the consistent production of malt with the desired quality remains challenging. Approaches to achieve this include adjustment of steeping and germination conditions, allowing control of grain modification and thus, the reservoir of aldehydes precursors. Also, the application of alternative kilning technologies may reduce the applied heat load, responsible for the formation of staling aldehydes and triggering development of the oxidising free radical species. This review provides an evaluation of current knowledge on the contribution of the malting process and malt quality to the formation of beer staling aldehydes. © 2021 The Authors. Journal of the Institute of Brewing published by John Wiley & Sons Ltd on behalf of The Institute of Brewing & Distilling

Familial hypercholesterolaemia in children and adolescents from 48 countries: a cross-sectional study

Background: Approximately 450 000 children are born with familial hypercholesterolaemia worldwide every year, yet only 2·1% of adults with familial hypercholesterolaemia were diagnosed before age 18 years via current diagnostic approaches, which are derived from observations in adults. We aimed to characterise children and adolescents with heterozygous familial hypercholesterolaemia (HeFH) and understand current approaches to the identification and management of familial hypercholesterolaemia to inform future public health strategies. Methods: For this cross-sectional study, we assessed children and adolescents younger than 18 years with a clinical or genetic diagnosis of HeFH at the time of entry into the Familial Hypercholesterolaemia Studies Collaboration (FHSC) registry between Oct 1, 2015, and Jan 31, 2021. Data in the registry were collected from 55 regional or national registries in 48 countries. Diagnoses relying on self-reported history of familial hypercholesterolaemia and suspected secondary hypercholesterolaemia were excluded from the registry; people with untreated LDL cholesterol (LDL-C) of at least 13·0 mmol/L were excluded from this study. Data were assessed overall and by WHO region, World Bank country income status, age, diagnostic criteria, and index-case status. The main outcome of this study was to assess current identification and management of children and adolescents with familial hypercholesterolaemia. Findings: Of 63 093 individuals in the FHSC registry, 11 848 (18·8%) were children or adolescents younger than 18 years with HeFH and were included in this study; 5756 (50·2%) of 11 476 included individuals were female and 5720 (49·8%) were male. Sex data were missing for 372 (3·1%) of 11 848 individuals. Median age at registry entry was 9·6 years (IQR 5·8-13·2). 10 099 (89·9%) of 11 235 included individuals had a final genetically confirmed diagnosis of familial hypercholesterolaemia and 1136 (10·1%) had a clinical diagnosis. Genetically confirmed diagnosis data or clinical diagnosis data were missing for 613 (5·2%) of 11 848 individuals. Genetic diagnosis was more common in children and adolescents from high-income countries (9427 [92·4%] of 10 202) than in children and adolescents from non-high-income countries (199 [48·0%] of 415). 3414 (31·6%) of 10 804 children or adolescents were index cases. Familial-hypercholesterolaemia-related physical signs, cardiovascular risk factors, and cardiovascular disease were uncommon, but were more common in non-high-income countries. 7557 (72·4%) of 10 428 included children or adolescents were not taking lipid-lowering medication (LLM) and had a median LDL-C of 5·00 mmol/L (IQR 4·05-6·08). Compared with genetic diagnosis, the use of unadapted clinical criteria intended for use in adults and reliant on more extreme phenotypes could result in 50-75% of children and adolescents with familial hypercholesterolaemia not being identified. Interpretation: Clinical characteristics observed in adults with familial hypercholesterolaemia are uncommon in children and adolescents with familial hypercholesterolaemia, hence detection in this age group relies on measurement of LDL-C and genetic confirmation. Where genetic testing is unavailable, increased availability and use of LDL-C measurements in the first few years of life could help reduce the current gap between prevalence and detection, enabling increased use of combination LLM to reach recommended LDL-C targets early in life

Guía de saúde infantil : actividades preventivas e de promoción da saúde en pediatría de atención primaria

Se trata de una guía de salud infantil dirigida a los profesionales que trabajan en el ámbito de la asistencia sanitaria a los niños y adolescentes en atención primaria del Sistema Público de Salud de Galicia.Trátase dunha guía de saúde infantil dirixida aos profesionais que traballan no ámbito da asistencia sanitaria aos nenos e adolescentes na atención primaria do Sistema Público de Saúde de Galicia

The genetic architecture of the human cerebral cortex

The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder

Unravelling formation and/or release of beer staling aldehydes

status: publishe

Beer flavour instability: Unravelling formation and/or release of staling aldehydes

The sensory perception of food and beverages is expected to be pleasant, characteristic, and consistent at the moment of consumption. However, in particular, beer has a limited shelf life because of flavour deterioration during transport and storage. All beers are subject to so-called flavour instability: the instability of beer in terms of odour, aroma, taste and mouthfeel. Beer flavour instability is very important from an economic point of view as the brewing industry represents a gigantic market. Therefore, more specifically, a prolonged flavour stability is essential, as it may be critical for acceptance or rejection of the product by the consumer. Flavour instability of beer is characterized by physical and chemical changes over beer storage. Two phenomena are considered to be of utmost importance with respect to the ageing of beer: a decrease in the intensity and the quality of the typical beer bitterness and, an increase in the levels of ageing aldehydes (so-called beer staling aldehydes). This PhD is focused on the second issue, mainly the generation of staling aldehydes as a function of beer ageing. Aldehydes might be formed (in the beer bottle but equally well during the brewing process) de novo from precursors. In particular, three major routes for de novo formation of aldehydes have been proposed: I) fatty acid oxidation (resulting in e.g. trans-2-nonenal), II) Strecker degradation of amino acids (resulting in e.g. 2‑methylpropanal), and III) the Maillard reaction (resulting in e.g. furfural). Alternatively, the formation of non-volatile bound-state aldehydes during the malting and/or brewing process has been proposed as a potential pathway to explain increases in staling aldehydes during beer ageing. Indeed, pre-formed non-volatile bound‑state aldehydes may survive the brewing and fermentation processes, thereby ending up in the final beer and, via subsequent decomposition result in the release of aldehydes during beer ageing. Several previous studies suggested that bound-state aldehydes might be formed through reaction of aldehydes with bisulphite during fermentation or through reaction of aldehydes with amino acids, peptides, or proteins to form imines during malting and brewing. In addition, very recent work pointed to the bound form of aldehydes with cysteine, so-called cysteinylated aldehydes or 2-substituted 1,3-thiazolidine-4-carboxylic acids, as potentially responsible for the beer staling problem. The major objective of this PhD is to better understand the binding/release behaviour of the most relevant beer staling aldehydes and to further investigate the potential role of aldehyde adducts with cysteine and bisulphite in relation to beer ageing. The most important marker aldehydes to be considered in beer ageing are 2-methylpropanal, 2‑methylbutanal, 3-methylbutanal, methional, phenylacetaldehyde, furfural, hexanal, and trans‑2‑nonenal. Therefore, in the first stage of this PhD, from these particular aldehydes all adducts with cysteine and bisulphite, respectively, were synthesized. Structure verification of aldehyde adducts was obtained via NMR (1H-NMR and 13C-NMR) and high mass accuracy UHPLC-MS. Moreover, purity was assessed by high mass accuracy UHPLC-MS. Upon successful synthesis of all bound-state aldehydes, these compounds were used throughout the PhD as new reference material in order to be able to conduct all subsequent studies. To this end, first of all, a methodology to reliably quantify both free and bound-state aldehydes, based on HS-SPME-GC-MS and UHPLC-MS, respectively, was implemented. Validation comprised linearity, accuracy, limits of detection (LOD) and quantification (LOQ), and demonstrated that the methodologies to analyse both, volatiles and non‑volatiles, are appropriate for quantification purposes within the desired concentration range (µg/L) and, thus, represent a truly integrated analytical GC-MS/UHPLC-MS methodology. Upon synthesizing the most relevant adducts of beer staling aldehydes and establishing an optimized analytical methodology, these tools were then applied in studies on (1) model solutions and (2) real malting and brewery samples. In model solutions, the influence of pH and temperature on the behaviour of cysteinylated aldehydes was investigated. Free and cysteine-bound aldehydes were analysed via HS‑SPME‑GC‑MS and UPLC‑PDA, respectively. To monitor the behaviour of cysteinylated aldehydes under malting and brewery relevant conditions in model solutions over a time frame of 24 hours, pH values of 2.0, 4.4, 5.2, 6.0, and 9.0 and temperatures of 0 ºC, 20 ºC and 40 ºC were selected. Cysteinylated aldehydes showed degradation and concomitant release of corresponding free aldehydes at the pH values 4.4, 5.2 and 6.0, that are related to malting and brewing. Furthermore, stability of the adducts was observed at alkaline pH. A higher degradation rate was noticed at 40 ºC compared to 0 ºC. In summary, our study in model solutions points to the potential importance of cysteinylated aldehydes as a possible source of staling aldehydes during beer storage. Following the work in model solutions, the raw material malt, intermediate brewery samples, final beer and forced aged beer were analysed for both free and bound-state aldehydes by applying the integrated methodology developed previously. Free aldehydes were quantified in all tested samples (from malt to beer). Cysteinylated aldehydes were detected from malt until the start or end of wort boiling, depending on the nature of the aldehyde. However, bisulphite‑bound aldehydes were not found in any of the samples. Malt contained all free and cysteinylated aldehydes under study. Analysis of samples taken at the onset of the mash compared to malt samples, showed the highest levels of cysteinylated aldehydes at mashing‑in and highest levels of free aldehydes in malt, pointing to additional formation (next to formation in malting) of cysteine‑aldehyde adducts at mashing-in. Furthermore, decreasing concentrations of both free and cysteine-bound aldehydes were observed throughout the brewing process. An exception was found however for the free aldehyde furfural which increased in levels when strong heat-load was applied, i.e. during wort boiling and wort clarification. In fresh beer, only traces of free aldehydes were detected. However, levels in free aldehydes increased during beer ageing, in particular for 2‑methylpropanal and furfural. In contrast, cysteinylated aldehydes were not quantifiable in fresh beer samples, neither during beer ageing, with the exception of the cysteinylated form of 2‑methylpropanal. Although these findings do not designate cysteine‑ or bisulphite‑bound aldehydes as being directly responsible for beer flavour deterioration in the beer matrix, they add evidence to the concept of bound‑state aldehydes, and therefore to further consider and investigate the potential contribution of bound-state aldehydes in relation to flavour instability of food and beverages. Consequently, in the final experimental part of the PhD, to further investigate potential formation of bound-state aldehydes in the beer matrix, labelled aldehydes, i.e. 2‑methylbutanal-d3 and furfural-d3, were added in fresh commercial pale lager beer. Binding of the selected deuterated aldehydes could however not be demonstrated. Moreover, release of deuterated aldehydes upon beer ageing was also not detected. Lastly, an initial study of de novo formation of aldehydes from amino acids was performed in the beer matrix. To this end, the labelled amino acids valine-d8 and leucine-d3 were added to a fresh commercial pale lager beer and potential formation of deuterated aldehydes was monitored during beer ageing up to 3 months at 30 ºC. Increasing concentrations of both corresponding deuterated free aldehydes (2-methylpropanal and 3-methylbutanal) were found over ageing. This finding represents the first unambiguous evidence of de novo formation of aldehydes from amino acids in the beer matrix.status: accepte