Relatos da pandemia: ser mulher e mãe em tempos de covid-19 / Pandemic reports: being a woman and mother in covid-19 times / Relatos de la pandemia: ser mujer y madre en tiempos del covid-19

Partindo da pergunta "Como tem sido ser mulher e mãe em tempos de pandemia?", o presente estudo convidou mulheres que são mães, em redes sociais virtuais, a partilhar um relato de suas experiências com a readaptação parental em função do distanciamento social causado pela pandemia de covid-19. O objetivo foi refletir sobre a experiência de ser mulher e mãe em tempos de covid-19 e distanciamento social, apontando algumas ressonâncias do cenário pandêmico na subjetividade dessas mulheres. O estudo teve como base o referencial psicanalítico, tanto na construção da pesquisa e análise dos relatos quanto na sua discussão. A análise dos cerca de 340 relatos coletados, os quais variaram de uma breve frase a longos parágrafos, apontou para uma série de questionamentos, pontos de análise e reflexões. A pandemia, e o decorrente distanciamento social, parece ter colocado uma lente de aumento sobre as angústias das mulheres que são mães, evidenciando sentimentos e sofrimentos sempre presentes. Destacaram-se, nos relatos, a sobrecarga das mulheres com as tarefas de cuidado dos filhos e da casa, a culpa, a solidão, a exaustão, e o sentimento de que não havia espaço nesse contexto para "ser mulher", sendo isso entendido especialmente a questões estéticas e de vaidade.(AU)

Starting from the question "How does it feel to be a woman and a mother in pandemic times?", this study invited women who are mothers, in virtual social networks, to share their experiences regarding parental adaptations due to social distancing caused by the COVID-19 pandemic. The objective was to reflect on the experience of being a woman and a mother in the context of COVID-19 and of social distancing, pointing out some resonances of the pandemic scenario in the subjectivity of these women. The study was based on the psychoanalytical framework, both in the construction of the research and analysis of the reports and in their discussion. The analysis of about 340 collected reports, which ranged from a brief sentence to long paragraphs, pointed to a series of questions, analysis topics, and reflections. The pandemic, and the resulting social distancing, seems to have placed a magnifying glass over the anguish of women who are mothers, showing ever-present feelings and suffering. The reports highlighted women's overload with child and house care tasks, the guilt, loneliness, exhaustion, and the feeling that there was no space in this context to "be a woman," and it extends to aesthetic and vanity related questions especially.(AU)

A partir de la pregunta "¿cómo te sientes siendo mujer y madre en tiempos de pandemia?", este estudio invitó por las redes sociales a mujeres que son madres a compartir un relato de sus experiencias sobre la readaptación parental en función del distanciamiento social causado por la pandemia del covid-19. Su objetivo fue reflexionar sobre la experiencia de ser mujer y madre en tiempos del covid-19 y el distanciamiento social, señalando algunas resonancias del escenario pandémico en la subjetividad de estas mujeres. Este estudio se basó en el marco psicoanalítico, tanto en la construcción de la investigación y análisis de los informes como en su discusión. El análisis de los casi 340 relatos, que variaron de una pequeña frase a largos párrafos, generó en las investigadoras una serie de cuestionamientos y reflexiones. La pandemia y el consecuente distanciamiento social parece haber agrandado las angustias de las mujeres que son madres, evidenciando sentimientos y sufrimientos siempre presentes. En los relatos destacan la sobrecarga de las mujeres con las tareas de cuidado de los hijos y del hogar, la culpa, la soledad, el cansancio, así como el sentimiento de que no hay espacio em este contexto para "ser mujer", relacionado principalmente a cuestiones estéticas y de vanidad.(AU)

Plant Secondary Metabolites Produced in Response to Abiotic Stresses Has Potential Application in Pharmaceutical Product Development.

Plant secondary metabolites (PSMs) are vital for human health and constitute the skeletal framework of many pharmaceutical drugs. Indeed, more than 25% of the existing drugs belong to PSMs. One of the continuing challenges for drug discovery and pharmaceutical industries is gaining access to natural products, including medicinal plants. This bottleneck is heightened for endangered species prohibited for large sample collection, even if they show biological hits. While cultivating the pharmaceutically interesting plant species may be a solution, it is not always possible to grow the organism outside its natural habitat. Plants affected by abiotic stress present a potential alternative source for drug discovery. In order to overcome abiotic environmental stressors, plants may mount a defense response by producing a diversity of PSMs to avoid cells and tissue damage. Plants either synthesize new chemicals or increase the concentration (in most instances) of existing chemicals, including the prominent bioactive lead compounds morphine, camptothecin, catharanthine, epicatechin-3-gallate (EGCG), quercetin, resveratrol, and kaempferol. Most PSMs produced under various abiotic stress conditions are plant defense chemicals and are functionally anti-inflammatory and antioxidative. The major PSM groups are terpenoids, followed by alkaloids and phenolic compounds. We have searched the literature on plants affected by abiotic stress (primarily studied in the simulated growth conditions) and their PSMs (including pharmacological activities) from PubMed, Scopus, MEDLINE Ovid, Google Scholar, Databases, and journal websites. We used search keywords: "stress-affected plants," "plant secondary metabolites, "abiotic stress," "climatic influence," "pharmacological activities," "bioactive compounds," "drug discovery," and "medicinal plants" and retrieved published literature between 1973 to 2021. This review provides an overview of variation in bioactive phytochemical production in plants under various abiotic stress and their potential in the biodiscovery of therapeutic drugs. We excluded studies on the effects of biotic stress on PSMs.

Navigating through chemical space and evolutionary time across the Australian continent in plant genus Eremophila.

Eremophila is the largest genus in the plant tribe Myoporeae (Scrophulariaceae) and exhibits incredible morphological diversity across the Australian continent. The Australian Aboriginal Peoples recognize many Eremophila species as important sources of traditional medicine, the most frequently used plant parts being the leaves. Recent phylogenetic studies have revealed complex evolutionary relationships between Eremophila and related genera in the tribe. Unique and structurally diverse metabolites, particularly diterpenoids, are also a feature of plants in this group. To assess the full dimension of the chemical space of the tribe Myoporeae, we investigated the metabolite diversity in a chemo-evolutionary framework applying a combination of molecular phylogenetic and state-of-the-art computational metabolomics tools to build a dataset involving leaf samples from a total of 291 specimens of Eremophila and allied genera. The chemo-evolutionary relationships are expounded into a systematic context by integration of information about leaf morphology (resin and hairiness), environmental factors (pollination and geographical distribution), and medicinal properties (traditional medicinal uses and antibacterial studies), augmenting our understanding of complex interactions in biological systems.

Oxidative Stress as a Possible Target in the Treatment of Toxoplasmosis: Perspectives and Ambiguities.

Toxoplasma gondii is an apicomplexan parasite causing toxoplasmosis, a common disease, which is most typically asymptomatic. However, toxoplasmosis can be severe and even fatal in immunocompromised patients and fetuses. Available treatment options are limited, so there is a strong impetus to develop novel therapeutics. This review focuses on the role of oxidative stress in the pathophysiology and treatment of T. gondii infection. Chemical compounds that modify redox status can reduce the parasite viability and thus be potential anti-Toxoplasma drugs. On the other hand, oxidative stress caused by the activation of the inflammatory response may have some deleterious consequences in host cells. In this respect, the potential use of natural antioxidants is worth considering, including melatonin and some vitamins, as possible novel anti-Toxoplasma therapeutics. Results of in vitro and animal studies are promising. However, supplementation with some antioxidants was found to promote the increase in parasitemia, and the disease was then characterized by a milder course. Undoubtedly, research in this area may have a significant impact on the future prospects of toxoplasmosis therapy.

Genomic insights into population history and biological adaptation in Oceania.

The Pacific region is of major importance for addressing questions regarding human dispersals, interactions with archaic hominins and natural selection processes1. However, the demographic and adaptive history of Oceanian populations remains largely uncharacterized. Here we report high-coverage genomes of 317 individuals from 20 populations from the Pacific region. We find that the ancestors of Papuan-related ('Near Oceanian') groups underwent a strong bottleneck before the settlement of the region, and separated around 20,000-40,000 years ago. We infer that the East Asian ancestors of Pacific populations may have diverged from Taiwanese Indigenous peoples before the Neolithic expansion, which is thought to have started from Taiwan around 5,000 years ago2-4. Additionally, this dispersal was not followed by an immediate, single admixture event with Near Oceanian populations, but involved recurrent episodes of genetic interactions. Our analyses reveal marked differences in the proportion and nature of Denisovan heritage among Pacific groups, suggesting that independent interbreeding with highly structured archaic populations occurred. Furthermore, whereas introgression of Neanderthal genetic information facilitated the adaptation of modern humans related to multiple phenotypes (for example, metabolism, pigmentation and neuronal development), Denisovan introgression was primarily beneficial for immune-related functions. Finally, we report evidence of selective sweeps and polygenic adaptation associated with pathogen exposure and lipid metabolism in the Pacific region, increasing our understanding of the mechanisms of biological adaptation to island environments.

Genomic adaptations to an endolithic lifestyle in the coral-associated alga Ostreobium.

The green alga Ostreobium is an important coral holobiont member, playing key roles in skeletal decalcification and providing photosynthate to bleached corals that have lost their dinoflagellate endosymbionts. Ostreobium lives in the coral's skeleton, a low-light environment with variable pH and O2 availability. We present the Ostreobium nuclear genome and a metatranscriptomic analysis of healthy and bleached corals to improve our understanding of Ostreobium's adaptations to its extreme environment and its roles as a coral holobiont member. The Ostreobium genome has 10,663 predicted protein-coding genes and shows adaptations for life in low and variable light conditions and other stressors in the endolithic environment. This alga presents a rich repertoire of light-harvesting complex proteins but lacks many genes for photoprotection and photoreceptors. It also has a large arsenal of genes for oxidative stress response. An expansion of extracellular peptidases suggests that Ostreobium may supplement its energy needs by feeding on the organic skeletal matrix, and a diverse set of fermentation pathways allows it to live in the anoxic skeleton at night. Ostreobium depends on other holobiont members for vitamin B12, and our metatranscriptomes identify potential bacterial sources. Metatranscriptomes showed Ostreobium becoming a dominant agent of photosynthesis in bleached corals and provided evidence for variable responses among coral samples and different Ostreobium genotypes. Our work provides a comprehensive understanding of the adaptations of Ostreobium to its extreme environment and an important genomic resource to improve our comprehension of coral holobiont resilience, bleaching, and recovery.

Yokukansankachimpihange, a traditional Japanese (Kampo) medicine, enhances the adaptation to circadian rhythm disruption by increasing endogenous melatonin levels.

The traditional Japanese (Kampo) medicines yokukansan (YKS) and yokukansankachimpihange (YKSCH) have similar formulas and the same indications. In animals or cultured cells, the neuropharmacological actions of YKS are sometimes more beneficial than those of YKSCH. Since both drugs are used to treat sleep disorders in Japan, we examined the ameliorative effects of YKS and YKSCH on circadian rhythm disturbance and compared their efficacy using a mouse model of circadian rhythm disruption. Ramelteon was used as the positive control. Ramelteon treatment significantly reversed decreased running wheel activity during the advanced dark phase, indicating facilitation of circadian adaptation. YKS treatment also reversed the activity in the early period of drug treatment; however, it was not statistically significant. YKSCH treatment significantly reversed the decreased activity during the advanced dark phase. Plasma melatonin (MT) levels were significantly increased in the YKSCH but not in the YKS group. The ameliorative effect of YKSCH on rhythm disruption was significantly inhibited by coadministration of the MT2 receptor antagonist. Therefore, the therapeutic effect of YKSCH on circadian rhythm disruption would be attributable, to elevated endogenous MT levels. Taken together, YKS and YKSCH have different pharmacological properties and may be more precisely prescribed depending on patients' psychological symptoms.

Rhodiola rosea L. modulates inflammatory processes in a CRH-activated BV2 cell model.

BACKGROUND: Rhodiola rosea L. (Crassulaceae) has been used for years in the traditional medicine of several countries as an adaptogen drug, able to preserve homeostasis in response to stress stimuli. Currently R. rosea roots and rhizome are classified as a traditional herbal medicinal product for temporary relief of symptoms of stress, such as fatigue and sensation of weakness by the European Medicines Agency. HYPOTHESIS/PURPOSE: Increasing evidences suggest the involvement of neuroinflammation in response to stress. However, whether the modulation of neuroinflammatory parameters could be involved in the anti-stress effect of R. rosea has been barely studied. Thus, the aim of this work is to investigate the possible modulation of molecular inflammatory processes elicited by a R. rosea roots and rhizome ethanolic extract in an in vitro model of corticotropin releasing hormone (CRH)-stimulated BV2 microglial cells. METHODS: BV2 cells were stimulated with CRH 100 nM and changes in cell viability, cytokines production and heat shock protein 70 (HSP70) levels were evaluated. Intracellular pathways related to inflammation, such as nuclear factor kappa-light-chain enhancer of activated B cells (NF-κB) nuclear translocation and mitogen-activated protein kinases (MAPK) activation were also analyzed. RESULTS: We found that R. rosea extract (2.7% m/m rosavin and 1% m/m salidroside) 20 µg/ml was able to counteract the neuroinflammatory effect of CRH by inhibiting NF-κB nuclear translocation with a mechanism of action involving the modulation of mitogen-activated protein kinase-activated protein kinase 2 (MKK2), extracellular signal-regulated kinase 1/2 (ERK 1/2) and c-Jun n-terminal kinase (JNK), resulting in a reduction of HSP70 expression. CONCLUSION: This work expands the knowledge of the intracellular mechanisms involved in R. rosea anti-stress activity and may be useful for the study of other adaptogen drugs.

Synaesthesia: a distinct entity that is an emergent feature of adaptive neurocognitive differences.

In this article, I argue that synaesthesia is not on a continuum with neurotypical cognition. Synaesthesia is special: its phenomenology is different; it has distinct causal mechanisms; and is likely to be associated with a distinct neurocognitive profile. However, not all synaesthetes are the same, and there are quantifiable differences between them. In particular, the number of types of synaesthesia that a person possesses is a hitherto underappreciated variable that predicts cognitive differences along a number of dimensions (mental imagery, sensory sensitivity, attention to detail). Together with enhanced memory, this may constitute a common core of abilities that may go some way to explaining why synaesthesia might have evolved. I argue that the direct benefits of synaesthesia are generally limited (i.e. the synaesthetic associations do not convey novel information about the world) but, nevertheless, synaesthesia may develop due to other adaptive functions (e.g. perceptual ability, memory) that necessitate changes to design features of the brain. The article concludes by suggesting that synaesthesia forces us to reconsider what we mean by a 'normal' mind/brain. There may be multiple 'normal' neurodevelopmental trajectories that can sculpt very different ways of experiencing the world, of which synaesthesia is but one. This article is part of a discussion meeting issue 'Bridging senses: novel insights from synaesthesia'.

Adaptation to mutational inactivation of an essential gene converges to an accessible suboptimal fitness peak.

The mechanisms of adaptation to inactivation of essential genes remain unknown. Here we inactivate E. coli dihydrofolate reductase (DHFR) by introducing D27G,N,F chromosomal mutations in a key catalytic residue with subsequent adaptation by an automated serial transfer protocol. The partial reversal G27- > C occurred in three evolutionary trajectories. Conversely, in one trajectory for D27G and in all trajectories for D27F,N strains adapted to grow at very low metabolic supplement (folAmix) concentrations but did not escape entirely from supplement auxotrophy. Major global shifts in metabolome and proteome occurred upon DHFR inactivation, which were partially reversed in adapted strains. Loss-of-function mutations in two genes, thyA and deoB, ensured adaptation to low folAmix by rerouting the 2-Deoxy-D-ribose-phosphate metabolism from glycolysis towards synthesis of dTMP. Multiple evolutionary pathways of adaptation converged to a suboptimal solution due to the high accessibility to loss-of-function mutations that block the path to the highest, yet least accessible, fitness peak.

Parental stressor exposure simultaneously conveys both adaptive and maladaptive larval phenotypes through epigenetic inheritance in the zebrafish (Danio rerio).

Genomic modifications occur slowly across generations, whereas short-term epigenetic inheritance of adaptive phenotypes may be immediately beneficial to large numbers of individuals, acting as a bridge for survival when adverse environments occur. In the present study, crude oil was used as an example of an environmental stressor. Adult zebrafish (P0) were dietarily exposed for 3 weeks to no, low, medium or high concentrations of crude oil. The F1 offspring obtained from the P0 groups were then assessed for transgenerational epigenetic transfer of oil-induced phenotypes. The exposure did not alter body length, body and organ mass or condition factor in the P0 groups. However, the P0 fecundity of both sexes decreased in proportion to the amount of oil fed. The F1 larvae from each P0 were then exposed from 3 hpf to 5 dpf to oil in their ambient water. Remarkably, F1 larvae derived from oil-exposed parents, when reared in oiled water, showed a 30% enhanced survival compared with controls (P<0.001). Unexpectedly, from day 3 to 5 of exposure, F1 larvae from oil-exposed parents showed poorer survival in clean water (up to 55% decreased survival). Additionally, parental oil exposure induced bradycardia (presumably maladaptive) in F1 larvae in both clean and oiled water. We conclude that epigenetic transgenerational inheritance can lead to an immediate and simultaneous inheritance of both beneficial and maladaptive traits in a large proportion of the F1 larvae. The adaptive responses may help fish populations survive when facing transient environmental stressors.

CopA Protects Streptococcus suis against Copper Toxicity.

Streptococcus suis is a zoonotic pathogen that causes great economic losses to the swine industry and severe threats to public health. A better understanding of its physiology would contribute to the control of its infections. Although copper is an essential micronutrient for life, it is toxic to cells when present in excessive amounts. Herein, we provide evidence that CopA is required for S. suis resistance to copper toxicity. Quantitative PCR analysis showed that copA expression was specifically induced by copper. Growth curve analyses and spot dilution assays showed that the ΔcopA mutant was defective in media supplemented with elevated concentrations of copper. Spot dilution assays also revealed that CopA protected S. suis against the copper-induced bactericidal effect. Using inductively coupled plasma-optical emission spectroscopy, we demonstrated that the role of CopA in copper resistance was mediated by copper efflux. Collectively, our data indicated that CopA protects S. suis against the copper-induced bactericidal effect via copper efflux.

Taking a big bite: Working together to better understand the evolution of feeding in primates.

The study of adaptation requires the integration of an array of different types of data. A single individual can find such integration daunting, if not impossible. In an effort to clarify the role of diet in the evolution of the primate craniofacial and dental apparatus, we assembled a team of researchers that have various types and degrees of expertise. This interaction has provided a range of insights for all contributors, and this has helped to refine questions, clarify the possibilities and limitations that laboratory and field settings offer, and further explore the ways in which laboratory and field data can be suitably integrated. A complete and accurate picture of dietary adaptation cannot be gained in isolation. Collaboration provides the bridge to a more holistic view of primate biology and evolution.

Alternative splicing coupled to nonsense-mediated mRNA decay contributes to the high-altitude adaptation of maca (Lepidium meyenii).

Alpine plants remain the least studied plant communities in terrestrial ecosystems. However, how they adapt to high-altitude environments is far from clear. Here, we used RNA-seq to investigate a typical alpine plant maca (Lepidium meyenii) to understand its high-altitude adaptation at transcriptional and post-transcriptional level. At transcriptional level, we found that maca root significantly up-regulated plant immunity genes in day-time comparing to night-time, and up-regulated abiotic (cold/osmotic) stress response genes in Nov and Dec comparing to Oct. In addition, 17 positively selected genes were identified, which could be involved in mitochondrion. At post-transcriptional level, we found that maca had species-specific characterized alternative splicing (AS) profile which could be influenced by stress environments. For example, the alternative 3' splice site events (A3SS, 39.62%) were predominate AS events in maca, rather than intron retention (IR, 23.17%). Interestingly, besides serine/arginine-rich (SR) proteins and long non-coding RNAs (lncRNAs), a lot of components in nonsense-mediated mRNA decay (NMD) were identified under differential alternative splicing (DAS), supporting AS coupled to NMD as essential mechanisms for maca's stress responses and high-altitude adaptation. Taken together, we first attempted to unveil maca's high-altitude adaptation mechanisms based on transcriptome and post-transcriptome evidence. Our data provided valuable insights to understand the high-altitude adaptation of alpine plants.

Penicillin-binding protein 3 is a common adaptive target among Pseudomonas aeruginosa isolates from adult cystic fibrosis patients treated with ß-lactams.

OBJECTIVE: Determining the mechanisms that modulate ß-lactam resistance in clinical Pseudomonas aeruginosa (P. aeruginosa) isolates can be challenging, as the molecular profiles identified in mutation-based or expression-based resistance determinant screens may not correlate with in vitro phenotypes. One of the lesser studied resistance mechanisms in P. aeruginosa is the modification of penicillin-binding protein 3 (pbpB/ftsI). This study reported that nonsynonymous polymorphisms within pbpB frequently occur among ß-lactam resistant sputum isolates, and are associated with unique antibiotic susceptibility patterns. METHODS: Longitudinally collected isolates (n = 126) from cystic fibrosis (CF) patients with or without recent ß-lactam therapy or of non-clinical origin were tested for susceptibility to six ß-lactams (aztreonam, ceftazidime, cefsulodin, cefepime, meropenem, and piperacillin). Known ß-lactam resistance mechanisms were characterised by polymerase chain reaction (PCR)-based methods, and polymorphisms in the transpeptidase-encoding domain of pbpB identified by sequencing. RESULTS: Twelve nonsynonymous polymorphisms were detected among 86 isolates (67%) from five CF patients with a history of ß-lactam therapy, compared with one polymorphism in 30 (3.3%) from three patients who had not received ß-lactam treatments. No nonsynonymous polymorphisms were found in ten environmental isolates. Multiple pbpB alleles, often with different combinations of polymorphisms, were detected within the population of strains from each CF patient for up to 2.6 years. Traditional patterns of ampC or mexA de-repression reduced expression of oprD or the presence of extended-spectrum ß-lactamases were not observed in resistant isolates with nonsynonymous polymorphisms in pbpB. CONCLUSION: This study's findings suggest that pbpB is a common adaptive target, and may contribute to the development of ß-lactam resistance in P. aeruginosa.

On the adaptive value of monomorphic versus dimorphic enantiostyly in Solanum rostratum.

Background and Aims: Enantiostyly is a reproductive system with heteromorphic flowers characterized by asymmetrical deflection of the style, either to the left or to the right of the floral axis. There are two types of enantiostyly. In monomorphic enantiostyly, plants produce the two types of flowers in the same individual. Dimorphic enantiostyly is restricted to only seven species and their populations consist of individuals producing either the right or the left flower type. It is hypothesized that the dimorphic form is derived from monomorphic ancestors because it functions as an outcrossing mechanism. We tested this latter hypothesis and investigated if monomorphic enantiostyly is resistant to invasion by individuals with dimorphic enantiostyly, because it functions as a reproductive assurance mechanism. Methods: To determine the conditions favouring the invasion of dimorphic enantiostyly, measurements of reproductive success and outcrossing rates in 15 natural flowering patches of Solanum rostratum were made. To test if monomorphic enantiostyly provides a reproductive assurance mechanism, experimental plants with either manually created dimorphic or natural monomorphic reproductive systems were exposed to two different pollination scenarios (flower density treatments), and reproductive success and outcrossing rates were measured. Key Results: Naturally flowering patches experienced severe pollination limitation, showed marked differences in reproductive success and had relatively high outcrossing rates. Plants in the experimental patches also showed pollination limitation and high outcrossing rates. Individuals with dimorphic enantiostyly expressed higher reproductive and outcrossing advantages under high-density conditions. These advantages disappeared in the low-density treatment, where the monomorphic form attained a higher reproductive success and no differences in outcrossing rates were detected. Conclusions: Monomorphic enantiostyly should be resistant to invasion of the dimorphic form because the prevalent ecological conditions favour the maintenance of geitonogamous individuals that are able to take advantage of ecological heterogeneity and generalized pollination limitation.

Dietary inferences through stable isotope analysis at the Neolithic and Bronze Age in the southern Caucasus (sixth to first millenium BC, Azerbaijan): From environmental adaptation to social impacts.

OBJECTIVES: Subsistence strategies are of great interest for understanding how prehistoric societies adapted to their environment. This is particularly the case for the southern Caucasus where relationships have been shown with the northern Caucasus and Mesopotamia since the Neolithic and where societies are alternately described as sedentary and mobile. This article aims, for the first time, to characterize human diets and their evolution using biochemical markers, from the Neolithic to the Bronze Age (sixth-first millenium BC), at Mentesh Tepe, a site in the middle Kura valley in Azerbaijan. MATERIALS AND METHODS: The data set belongs to 40 humans, 32 domestic and wild animals, and 42 charred seeds discovered in situ and perfectly dated. Stable isotope analyses were performed, including (a) δ13 Cco and δ15 N for animal and human bone collagens and for seeds, and (b) δ13 Cap for human bone apatite. RESULTS: Almost all the data (25/31) suggest an increased contribution of cereals, lentils, and freshwater fish during the Neolithic, whereas afterwards, until the Late Bronze Age, all individuals consumed more animal proteins from their livestock. None of the biological criteria (age at death and sex) and burial types (mass/single graves) were found to be related to a specific diet over time. Comparisons with other isotopic data from contemporary sites in Georgia argue in favor of a wide variety of dietary sources in the vicinity of the Kura valley and for highly mobile populations. Clear evidence of millet consumption has only been found for the Late Bronze Age.

Species coexistence through simultaneous fluctuation-dependent mechanisms.

Understanding the origins and maintenance of biodiversity remains one of biology's grand challenges. From theory and observational evidence, we know that variability in environmental conditions through time is likely critical to the coexistence of competing species. Nevertheless, experimental tests of fluctuation-driven coexistence are rare and have typically focused on just one of two potential mechanisms, the temporal storage effect, to the neglect of the theoretically equally plausible mechanism known as relative nonlinearity of competition. We combined experiments and simulations in a system of nectar yeasts to quantify the relative contribution of the two mechanisms to coexistence. Resource competition models parameterized from single-species assays predicted the outcomes of mixed-culture competition experiments with 83% accuracy. Model simulations revealed that both mechanisms have measurable effects on coexistence and that relative nonlinearity can be equal or greater in magnitude to the temporal storage effect. In addition, we show that their effect on coexistence can be both antagonistic and complementary. These results falsify the common assumption that relative nonlinearity is of negligible importance, and in doing so reveal the importance of testing coexistence mechanisms in combination.

Yeast Cth2 protein represses the translation of ARE-containing mRNAs in response to iron deficiency.

In response to iron deficiency, the budding yeast Saccharomyces cerevisiae undergoes a metabolic remodeling in order to optimize iron utilization. The tandem zinc finger (TZF)-containing protein Cth2 plays a critical role in this adaptation by binding and promoting the degradation of multiple mRNAs that contain AU-rich elements (AREs). Here, we demonstrate that Cth2 also functions as a translational repressor of its target mRNAs. By complementary approaches, we demonstrate that Cth2 protein inhibits the translation of SDH4, which encodes a subunit of succinate dehydrogenase, and CTH2 mRNAs in response to iron depletion. Both the AREs within SDH4 and CTH2 transcripts, and the Cth2 TZF are essential for translational repression. We show that the role played by Cth2 as a negative translational regulator extends to other mRNA targets such as WTM1, CCP1 and HEM15. A structure-function analysis of Cth2 protein suggests that the Cth2 amino-terminal domain (NTD) is important for both mRNA turnover and translation inhibition, while its carboxy-terminal domain (CTD) only participates in the regulation of translation, but is dispensable for mRNA degradation. Finally, we demonstrate that the Cth2 CTD is physiologically relevant for adaptation to iron deficiency.

A midline thalamic circuit determines reactions to visual threat.

How our internal state is merged with our visual perception of an impending threat to drive an adaptive behavioural response is not known. Mice respond to visual threats by either freezing or seeking shelter. Here we show that nuclei of the ventral midline thalamus (vMT), the xiphoid nucleus (Xi) and nucleus reuniens (Re), represent crucial hubs in the network controlling behavioural responses to visual threats. The Xi projects to the basolateral amygdala to promote saliency-reducing responses to threats, such as freezing, whereas the Re projects to the medial prefrontal cortex (Re→mPFC) to promote saliency-enhancing, even confrontational responses to threats, such as tail rattling. Activation of the Re→mPFC pathway also increases autonomic arousal in a manner that is rewarding. The vMT is therefore important for biasing how internal states are translated into opposing categories of behavioural responses to perceived threats. These findings may have implications for understanding disorders of arousal and adaptive decision-making, such as phobias, post-traumatic stress and addictions.