Nuanced impacts of the invasive aquatic plant Crassula helmsii on Northwest European freshwater macroinvertebrate assemblages.

Invasive alien species are considered one of the greatest threats to global biodiversity, and are particularly problematic in aquatic systems. Given the foundational role of macrophytes in most freshwaters, alien aquatic plant invasions may drive strong bottom-up impacts on recipient biota. Crassula helmsii (New Zealand pygmyweed) is an Australasian macrophyte, now widespread in northwest Europe. Crassula helmsii rapidly invades small lentic waterbodies, where it is generally considered a serious threat to native biodiversity. The precise ecological impacts of this invasion remain poorly understood, however, particularly with respect to macroinvertebrates, which comprise the bulk of freshwater faunal biodiversity. We conducted a field study of ponds, ditches and small lakes across the core of C. helmsii's invasive range (United Kingdom, Belgium and the Netherlands), finding that invaded sites had higher macroinvertebrate taxon richness than uninvaded sites, and that many infrequent and rare macroinvertebrates co-occurred with C. helmsii. Alien macroinvertebrates were more abundant in C. helmsii sites, however, particularly the North American amphipod Crangonyx pseudogracilis. At the order level, water beetle (Coleoptera) richness and abundance were higher in C. helmsii sites, whereas true fly (Diptera) abundance was higher in uninvaded sites. Taxonomic and functional assemblage composition were both impacted by invasion, largely in relation to taxa and traits associated with detritivory, suggesting that the impacts of C. helmsii on macroinvertebrates are partly mediated by the availability and palatability of its detritus. The nuanced effects of C. helmsii on macroinvertebrates found here should encourage further quantitative research on the impacts of this invasive plant, and perhaps prompt a more balanced re-evaluation of its effects on native aquatic macrofauna.

Meta-analysis shows no consistent evidence for senescence in ejaculate traits across animals.

Male reproductive traits such as ejaculate size and quality, are expected to decline with advancing age due to senescence. It is however unclear whether this expectation is upheld across taxa. We perform a meta-analysis on 379 studies, to quantify the effects of advancing male age on ejaculate traits across 157 species of non-human animals. Contrary to predictions, we find no consistent pattern of age-dependent changes in ejaculate traits. This result partly reflects methodological limitations, such as studies sampling a low proportion of adult lifespan, or the inability of meta-analytical approaches to document non-linear ageing trajectories of ejaculate traits; which could potentially lead to an underestimation of senescence. Yet, we find taxon-specific differences in patterns of ejaculate senescence. For instance, older males produce less motile and slower sperm in ray-finned fishes, but larger ejaculates in insects, compared to younger males. Notably, lab rodents show senescence in most ejaculate traits measured. Our study challenges the notion of universal reproductive senescence, highlighting the need for controlled methodologies and a more nuanced understanding of reproductive senescence, cognisant of taxon-specific biology, experimental design, selection pressures, and life-history.

Seasonal weather impacts wine quality in Bordeaux.

Critics judge quality based upon subjective characteristics of wine. These judgments are converted by critics into quantitative scores, which allow for comparison of vintages. This paper uses high resolution discrete and continuous time-based weather estimates at both a local and regional level to determine the role of weather conditions on producing high quality Bordeaux vintages, as determined by critics scores. By using discrete-time weather variables across local AOCs, this study reveals climate-quality relationships across the whole year, including previously ignored season effects. By using continuous time weather variables, we reinforce the evidence for these local effects by finding higher quality wine is made in years with higher rainfall, warmer temperatures; and earlier, shorter seasons. We propose management impacts of our results and suggest that as the climate continues to change, the quality of Bordeaux wines may continue to improve.

MOSAIC - A Unified Trait Database to Complement Structured Population Models.

Despite exponential growth in ecological data availability, broader interoperability amongst datasets is needed to unlock the potential of open access. Our understanding of the interface of demography and functional traits is well-positioned to benefit from such interoperability. Here, we introduce MOSAIC, an open-access trait database that unlocks the demographic potential stored in the COMADRE, COMPADRE, and PADRINO open-access databases. MOSAIC data were digitised and curated through a combination of existing datasets and new trait records sourced from primary literature. In its first release, MOSAIC (v. 1.0.0) includes 14 trait fields for 300 animal and plant species: biomass, height, growth determination, regeneration, sexual dimorphism, mating system, hermaphrodism, sequential hermaphrodism, dispersal capacity, type of dispersal, mode of dispersal, dispersal classes, volancy, and aquatic habitat dependency. MOSAIC includes species-level phylogenies for 1,359 species and population-specific climate data. We identify how database integration can improve our understanding of traits well-quantified in existing repositories and those that are poorly quantified (e.g., growth determination, modularity). MOSAIC highlights emerging challenges associated with standardising databases and demographic measures.

Plasticity's role in adaptive evolution depends on environmental change components.

To forecast extinction risks of natural populations under climate change and direct human impacts, an integrative understanding of both phenotypic plasticity and adaptive evolution is essential. To date, the evidence for whether, when, and how much plasticity facilitates adaptive responses in changing environments is contradictory. We argue that explicitly considering three key environmental change components - rate of change, variance, and temporal autocorrelation - affords a unifying framework of the impact of plasticity on adaptive evolution. These environmental components each distinctively effect evolutionary and ecological processes underpinning population viability. Using this framework, we develop expectations regarding the interplay between plasticity and adaptive evolution in natural populations. This framework has the potential to improve predictions of population viability in a changing world.

The steroid hormone ecdysone regulates growth rate in response to oxygen availability.

In almost all animals, physiologically low oxygen (hypoxia) during development slows growth and reduces adult body size. The developmental mechanisms that determine growth under hypoxic conditions are, however, poorly understood. Here we show that the growth and body size response to moderate hypoxia (10% O2) in Drosophila melanogaster is systemically regulated via the steroid hormone ecdysone. Hypoxia increases level of circulating ecdysone and inhibition of ecdysone synthesis ameliorates the negative effect of low oxygen on growth. We also show that the effect of ecdysone on growth under hypoxia is through suppression of the insulin/IGF-signaling pathway, via increased expression of the insulin-binding protein Imp-L2. These data indicate that growth suppression in hypoxic Drosophila larvae is accomplished by a systemic endocrine mechanism that overlaps with the mechanism that slows growth at low nutrition. This suggests the existence of growth-regulatory mechanisms that respond to general environmental perturbation rather than individual environmental factors.

Larval Density, Sex, and Allocation Hierarchy Affect Life History Trait Covariances in a Bean Beetle.

AbstractLife history theory aims to understand how different environments result in differential investment in fitness-related traits. While trade-offs between traits are expected, many studies show positive or no correlation between pairs of costly traits. One hypothesis that may explain the inconsistency of trade-offs in the literature is that trait investment may occur in a dichotomous hierarchy (the tree model), which allows for differential trait investment weighted by the traits' respective positions within the hierarchy. Previous mathematical models predict different covariances between traits depending on their position on the allocation tree. While hierarchical differential investment is often used to discuss findings in life history theory, the role of an allocation hierarchy in trait covariances has not been directly tested. In turn, this study aims to identify trait covariances between behavioral and morphological phenotypes on different branches of an allocation tree for the bean beetle, Callosobruchus maculatus. While trade-offs between copulatory behaviors and morphology were found for both males and females, only traits at the base and far from each other in the hierarchy negatively covaried. This study empirically shows that trade-offs may be the result of hierarchical investment.

Four key challenges in the open-data revolution.

In Focus: Culina, A., Adriaensen, F., Bailey, L. D., et al. (2021) Connecting the data landscape of long-term ecological studies: The SPI-Birds data hub. Journal of Animal Ecology, https://doi.org/10.1111/1365-2656.13388. Long-term, individual-based datasets have been at the core of many key discoveries in ecology, and calls for the collection, curation and release of these kinds of ecological data are contributing to a flourishing open-data revolution in ecology. Birds, in particular, have been the focus of international research for decades, resulting in a number of uniquely long-term studies, but accessing these datasets has been historically challenging. Culina et al. (2021) introduce an online repository of individual-level, long-term bird records with ancillary data (e.g. genetics), which will enable key ecological questions to be answered on a global scale. As well as these opportunities, however, we argue that the ongoing open-data revolution comes with four key challenges relating to the (1) harmonisation of, (2) biases in, (3) expertise in and (4) communication of, open ecological data. Here, we discuss these challenges and how key efforts such as those by Culina et al. are using FAIR (Findable, Accessible, Interoperable and Reproducible) principles to overcome them. The open-data revolution will undoubtedly reshape our understanding of ecology, but with it the ecological community has a responsibility to ensure this revolution is ethical and effective.

Enfocado: Culina, A., Adriaensen, F., Bailey, L. D., et al. (2021) Connecting the data landscape of long-term ecological studies: the SPI-Birds data hub. Journal of Animal Ecology, https://doi.org/10.1111/1365-2656.13388. La información a largo plazo y a nivel de individuo ha cementado numerosos descubrimientos clave en la ecología, y las llamadas para la recopilación, conservación, y publicación de este tipo de datos ecológicos están contribuyendo a una revolución de información abierta en la ecología. Las aves, en particular, han sido el foco de la investigación internacional durante décadas, el cual ha resultado en una serie de estudios únicos a largo plazo. No obstante, historicamente el acceso libre a esta información ha representado un desafío importante. Culina y colegas (2021) presentan un repositorio online de registros de aves a nivel individual y de alta replicación temporal con metadatos (por ejemplo, genética) que permitirá explorar importantes preguntas ecológicas a grandes escalas espaciales. Sin embargo, además de las oportunidades presentadas en esta base de datos, argumentamos que la revolución de la información abierta viene con cuatro desafíos clave relacionados con (1) la armonización de, (2) los sesgos en, (3) la experiencia en y (4) la comunicación de información ecológica de forma abierta y transparente. Aquí discutimos estos desafíos y cómo esfuerzos clave como los de Culina y colaboradores están utilizando los principios FAIR (por sus siglas en inglés: Localizable, Accesible, Interoperable y Reproducible) para superarlos. La revolución de la información abierta sin duda remodelará nuestro entendimiento de la ecología. Sin embargo, la comunidad ecológica tiene la responsabilidad de garantizar que esta revolución sea ética y eficaz.

Plasticity Through Canalization: The Contrasting Effect of Temperature on Trait Size and Growth in Drosophila.

In most ectotherms, a reduction in developmental temperature leads to an increase in body size, a phenomenon known as the temperature size rule (TSR). In Drosophila melanogaster, temperature affects body size primarily by affecting critical size, the point in development when larvae initiate the hormonal cascade that stops growth and starts metamorphosis. However, while the thermal plasticity of critical size can explain the effect of temperature on overall body size, it cannot entirely account for the effect of temperature on the size of individual traits, which vary in their thermal sensitivity. Specifically, the legs and male genitalia show reduced thermal plasticity for size, while the wings show elevated thermal plasticity, relative to overall body size. Here, we show that these differences in thermal plasticity among traits reflect, in part, differences in the effect of temperature on the rates of cell proliferation during trait growth. Counterintuitively, the elevated thermal plasticity of the wings is due to canalization in the rate of cell proliferation across temperatures. The opposite is true for the legs. These data reveal that environmental canalization at one level of organization may explain plasticity at another, and vice versa.

Algal Bloom Expansion Increases Cyanotoxin Risk in Food.

As advances in global transportation infrastructure make it possible for out of season foods to be available year-round, the need for assessing the risks associated with the food production and expanded distribution are even more important. Risks for foodborne illness are associated with contamination by bacteria, viruses, mold, parasites, natural and synthetic toxins, chemical residues, and conditions that lead to contamination. An increase in the popularity of natural alternatives to pharmaceuticals, herbal remedies and the desire for consuming "super foods" is leading to a change in the dietary patterns of consumers. Similarly, dietary trends are plentiful, with more consumers adopting changes with little medical guidance to dietary plans that are supported by inadequate scientific data. In particular, U.S. consumers are acquiring novel foods that may not be adequately checked for the presence of marine toxins and heat stable toxins in dry or minimally processed foods. Some dry foods cultivated in or processed in regions that may utilize hypoxic agricultural waters high in cyanobacterial or algal contamination. These may perpetuate increased risks for chronic liver, kidney, and neurodegenerative disorders due to intoxication from preventable foodborne agents. Global climate change, which has the effect of potentially expanding the toxic waters into higher latitudes, forecasts an increase in the risk of food contamination with toxins.

[Hypertension-induced fibrosis: a balance story]. / La fibrose dans l'hypertension artérielle : une histoire d'équilibre.

Cardiac remodeling is a deleterious consequence of arterial hypertension. This remodeling results in cardiac transcriptomic changes induced by mechanical and hormonal factors (angiotensin II and aldosterone are the most important). The major features of cardiac remodeling are the hypertrophy of cardiomyocytes, interstitial and perivascular fibrosis, and microvascular rarefaction. Inappropriate stimulation of the renin-angiotensin-aldosterone system (RAAS) participates to the development of heart failure. The respective roles of angiotensin II and aldosterone in cardiac remodeling are poorly understood. The development of fibrosis in the heart depends of a balance between profibrotic (TGFß, CTGF, inflammation) and antifibrotic (BNP, ANP, BMP4 and BMP7) factors. The profibrotic and proinflammatory effects of angiotensin II and aldosterone are very well demonstrated; however, their actions on antifibrotic factors expression are unknown. In order to explore this, we used RenTgKC mice overexpressing renin into the liver, leading to an increased plasma angiotensin II and thus induction of severe hypertension, and AS mice overexpressing aldosterone synthase (AS) in cardiomyocytes which have a doubled intracardiac aldosterone concentration. Male AS mice have a dysfunction of the coronary arteries relaxation without structural and functional changes of the myocardium. Mice derived from a crossing between the RenTgKC and AS strains were used in this work. It is shown that angiotensin II induces the expression of BNP and BMPs which ultimately slows the progression of myocardial fibrosis, and that aldosterone inhibits the expression of these factors and thus worsens the fibrosis.

Lythrum hyssopifolia (lesser loosestrife) poisoning of sheep in Victoria.

OBJECTIVE: To document an ovine disease attributed to the consumption of Lythrum hyssopifolia (lesser loosestrife). PROCEDURES: Historical and histological review of field and experimental cases. RESULTS: 1-20% mortality occurred in sheep flocks grazing paddocks where L. hyssopifolia was the predominant green vegetation. Well-documented disease outbreaks occurred in summer on nine farms across Victoria between 1974 and 2002. Liver damage occurred in all nine outbreaks, with kidney damage in at least eight. Hepatocyte necrosis was usually zonal to midzonal (zone 2) in the liver samples from four farms and periacinar (zone 3) in those from three farms, but some livers showed only single-cell necrosis. Multinucleate hepatocytes near necrotic areas were a feature in six cases. Proximal tubular epithelium appeared to be the primary renal target and brown granules were often present in renal tubules. Biochemical and histological evidence of liver and kidney damage was obtained from two sheep experimentally pen-fed harvested L. hyssopifolia. CONCLUSION: Chemicals in L. hyssopifolia are toxic to ovine hepatocytes and renal tubular epithelial cells.

Cardiac myocyte neuronal nitric oxide synthase. New therapeutic target in heart failure?

Although nitric oxide-dependent regulation of contractile function is altered in the diseased and failing heart, several aspects of nitric oxide (NO) signalling in the myocardium remain poorly understood. Some apparently contrasting findings may have arisen from the use of non-isoform-specific inhibitors of NO synthase isoforms (NOS) as compared to the use of mouse models genetically deficient or overexpressing the NOS thought to be responsible for the increase in NO production in heart failure (mainly NOS2 and NOS3). In recent years, identification of the neuronal NOS (NOS1) isoform in cardiac myocytes and the recognition of the importance of its subcellular localisation have greatly advanced the understanding of the critical role of NOS1-derived NO in the control of myocardial contractility both in the normal and failing heart. The challenge is now to confirm these emerging findings on the critical role of NOS1-derived NO in human cardiac physiology and hopefully translate them into therapy.

Extracellular matrix and cardiac remodelling.

Cardiac remodelling associated with primitive and secondary cardiomyopathy is generally associated with changes in the expression in extracellular matrix (ECM) proteins as well as their transmembrane receptors, the integrins. It emerges now that the ECM provides a structural, chemical, and mechanical substrate that is essential in cardiac function and responses to pathophysiological signals. This review will describe the various elements of the ECM, its modifications that are associated with cardiac hypertrophy and heart failure, and the molecular basis bringing a better insight into the dynamics of the ECM.

[Mechanical and functional predictive factors for restenosis and arterial remodeling after experimental angioplasty]. / Facteurs prédictifs mécaniques et fonctionnels de la resténose et du remodelage artériel après angioplastie expérimentale.

Arterial remodelling plays an important part in post-angioplasty restenosis but the physiopathology of this process is not fully understood. Abundant collagen synthesis and endothelial dysfunction have been demonstrated after angioplasty, but their role in restenosis and remodelling has not been studied. The aim of this study was therefore to assess endothelial function and collagen with respect to the severity of restenosis and the type of arterial remodelling. Atherosclerosis was induced by an association of endothelial abrasion and a high cholesterol diet in the femoral arteries of 22 white New Zealand rabbits. Four weeks later, angioplasty was performed. The acetylcholine endothelium-dependant vasomotricity (expressed as % inhibition of contraction to phenylephrine), collagen and morphology were assessed 28 days after angioplasty. The change in acetylcholine endothelium-dependant vasomotricity was greater in severe restenosis (r = 0.61, p = 0.02). Endothelium-dependant relaxation was not significantly altered when remodelling was expansive and very abnormal when it was constrictive (35.5 +/- 13.0 vs 3.7 +/- 7.9%; p = 0.04). Restenosis was associated with an increase in collagen (r = 0.69, p = 0.004). The density of collagen was significantly higher in constrictive remodelling than in expansive remodelling (34.5 +/- 4.5 vs 18.2 +/- 4.7%; p = 0.03). Endothelial dysfunction and collagen accumulation are correlated with the severity of restenosis and with constrictive remodelling after angioplasty in an experimental model.

Coronary microvasculature alteration in hypertensive rats. Effect of treatment with a diuretic and an ACE inhibitor.

The development of hypertension is accompanied by rarefaction of arterioles and capillaries in both animal models and humans. Although many studies have examined the effects of antihypertensive therapies on hemodynamics, cardiac hypertrophy, and large vessel structure, the question of whether changes in microvascular density induced by hypertension can be restored by pharmacologic treatment has yet to be answered. We report a series of experiments performed in rats with renovascular hypertension induced by unilateral nephrectomy and renal artery stenosis (Goldblatt one-kidney, one-clip model). Animals were treated for 4 weeks, after renal artery clipping, either with an angiotensin converting enzyme inhibitor (perindopril [PER], 0.76 mg/kg/day), or with an indol derivative diuretic with specific vascular properties (indapamide [IDP], 0.24 mg/kg/day) or with the combination of both drugs at the same doses as during monotherapy. Coronary microvessel densities (arterioles and capillaries) were evaluated by double immunolabeling in nonserial cryostat sections of the left ventricular inner myocardium. After 4 weeks of hypertension (mean arterial pressure, 174+/-11 v 124+/-5 mm Hg in normotensive (NT) controls, P < .01), cardiac hypertrophy (+59%, P < .001) was associated with a significant increase in myocardial arteriolar density (+27%, P < .01), and a decrease in capillary density (-12%, P < .05). Treatment with PER prevented the increase in arterial pressure, heart weight, and arteriolar density, but did not significantly affect the low coronary capillary density in comparison with that measured in untreated hypertensive (HT) rats. Treatment with IDP preserved normal capillary myocardial density but did not significantly lower the blood pressure (BP) (169+/-9 mm Hg) and only slightly reduced the cardiac ventricular hypertrophy: - 14% v untreated HT (P < .05) and +37% v NT (P < .01). In the same way, IDP normalized the left ventricular capillary density in spontaneously HT rats (+18% v untreated rats, P < .01). The combination of both drugs, PER and IDP, at the same low doses as during monotherapy, resulted in normal levels of arterial pressure and complete normalization of cardiac hypertrophy and arteriolar and capillary myocardial densities. In conclusion, the results observed after PER suggest that blockade of the renin-angiotensin system could inhibit large coronary vessel growth but minimally affects the capillary density despite complete normalization of BP. Indapamide could have beneficial effect on myocardial capillary density. The combination of IDP and PER has additional effects and prevents the increase in BP and cardiac weight, and reverses microvascular rarefaction, specifically arteriolar and capillary densities.

Effect of pressure overload on angiotensin receptor expression in the rat heart during early postnatal life.

The development of cardiac hypertrophy during neonatal life and in adults implies different processes. The angiotensin II (Ang II) system is involved in the development of cardiac hypertrophy in adults, but its role in neonates remains unclear. The aim of this study was to estimate the influence of increased hemodynamic load on the developmental pattern of the AT1/AT2 receptor expression in the heart. Two-day-old rats submitted to abdominal aortic constriction (AC) or sham operation were sacrificed 2 h, and 1, 3, and 8 days after surgery. Ang II was evaluated in sera and immunohistology was performed to define the cardiac hypertrophy process. The Ang II receptor subtypes 1 and 2 were quantified at the receptor and mRNA levels by(125)I-Ang II binding and RT-PCR, respectively. Ang II content in sera increased transiently 2 h after surgery in the AC group. In sham-operated, AT1 and AT2 decreased throughout the period studied at both mRNA and receptor levels. However, the AT1 mRNA level decrease was more pronounced than that of AT2 (by 57% and 27%, respectively). AC not only prevented the postnatal decrease in AT mRNA level but resulted in an increase in AT1 mRNA 8 days after surgery (P<0.05). Besides in the AC groups, AT2 mRNA levels but not those of AT1 mRNA were linearly correlated with the left ventricular mass. At the receptor level, a significant transient (1 day after surgery) increase in both AT1 and AT2 was observed. In conclusion, our data demonstrated that imposition of pressure overload soon after birth altered the pattern of AT receptor expression.

Specific cellular features of atheroma associated with development of neointima after carotid endarterectomy: the carotid atherosclerosis and restenosis study.

BACKGROUND: The purpose of this study was to investigate whether some cellular and molecular features of tissue retrieved at carotid endarterectomy are associated with the extent of neointima formation at ultrasound follow-up. METHODS AND RESULTS: One hundred fifty patients were studied. Endarterectomy specimens were tested by immunocytochemistry with the use of (1) monoclonal antibodies that identify smooth muscle cells (SMCs) and fetal-type SMCs on the basis of smooth muscle and nonmuscle myosin content, (2) the anti-macrophage HAM 56, and (3) the anti-lymphocyte CD45RO. The maximum intima-media thickness (M-IMT) of the revascularized vessel was assessed by the use of B-mode ultrasonography 6 months after surgery. The M-IMT values were related positively to the number of SMCs (r=0.534, P<0.0005) and negatively to that of macrophages and lymphocytes (r=-0.428, P<0.0005, and -0.538, P=0.001, respectively). Patients were classified as class 1 (M-IMT 1.3 mm). An abundance of SMCs, mostly of fetal type, was found in the plaque of class 3 patients, whereas lesions from class 1 patients were rich in macrophages and lymphocytes. In the multivariate analysis, factors related to M-IMT were the number of SMCs and the percentage of fetal-type SMCs present in the plaque. CONCLUSIONS: Although the classic risk factors did not play a role, an abundance of SMCs and a scarcity of macrophages characterized the primary lesion of patients in whom neointima developed after surgery. In patients in whom neointima did not develop, lesions were rich in macrophages and lymphocytes. This approach can be useful in defining patients at risk of restenosis.