Viability Of Species Research Articles

Establishment of Fungal Decomposition Model Based on OLS and Logistic Model

By using the OLS model, an equation for the rate of decomposing wood by a variety of fungi was established. We analyzed the effects of various fungi in the experimental data under different temperature and humidity. Based on the growth performance of different fungi at different temperatures and humidity, we use the method of systematic cluster to divide the fungi into 5 categories, and introduce competition levels as the viability of different species of fungi. We have established a logistic model that introduces competition levels to obtain a fungal habitat model. The fungal habitat model includes predictions about the relative advantages and disadvantages for each species and combinations of species likely to persist, and do so for different environments including arid, semi-arid, temperate, arboreal, and tropical rain forests.

Fecal Metabolome Signature in the HIV-1 Elite Control Phenotype: Enrichment of Dipeptides Acts as an HIV-1 Antagonist but a Prevotella Agonist.

HIV-1 elite controllers (EC) are a rare group among HIV-1-infected individuals who can naturally control viral replication for a prolonged period. Due to their heterogeneous nature, no universal mechanism could be attributed to the EC status; instead, several host and viral factors have been discussed as playing a role. In this study, we investigated the fecal metabolome and microbiome in a Swedish cohort of EC (n = 14), treatment-naive viremic progressors (VP; n = 16), and HIV-negative individuals (HC; n = 12). Fecal untargeted metabolomics was performed by four ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). Molecular docking and biochemical microscale thermophoresis (MST) were used to describe the peptide-metabolite interactions. Single-cycle infectivity assays were performed in TZM-Bl cell lines using CCR5- and CXCR4-tropic HIV-1 strains. The microbiome analysis was performed using 16S rRNA sequencing. Th effects of metabolites on bacterial species viability were determined using several clinical isolates. We observed an enrichment of dipeptides in EC compared to VP and HC (adjusted P < 0.05). In silico analysis by molecular docking, in vitro biochemical assays, and ex vivo infection assays identified anti-HIV-1 properties for two dipeptides (WG and VQ) that could bind to the HIV-1 gp120, of which WG was more potent. The microbiome analysis identified enrichment of the genus Prevotella in EC, and these dipeptides supported bacterial growth of the genus Prevotella in vitro. The enrichments of the dipeptides and higher abundance of Prevotella have a distinct mechanism of elite control status in HIV-1 infection that influences host metabolism. IMPORTANCE HIV-1 elite controllers (EC) are a rare group among HIV-1-infected individuals who can naturally control viral replication for a prolonged period. Due to their heterogeneous nature, no universal mechanism could be attributed to the EC status; instead, several host and viral factors have been discussed as playing a role. In this study, we investigated the fecal metabolome and microbiome in a Swedish cohort of EC, treatment-naive viremic progressors (VP), and HIV-negative individuals (HC). We observed an enrichment of dipeptides in EC compared to the other two study groups. In silico and in vitro analyses identified anti-HIV-1 properties for two dipeptides that could bind to the HIV-1 gp120 and act as an HIV-1 antagonist. Furthermore, these dipeptides supported bacterial growth of the genus Prevotella in vitro that was enriched in EC, which influences host metabolism. Thus, increased levels of both dipeptides and Prevotella could provide beneficial effects for EC.

Milk Macrophage Function in Bovine Leukemia Virus-Infected Dairy Cows.

The implications of bovine leukemia virus (BLV) on innate and adaptive immune responses have been widely investigated; however, the effects of BLV on mammary gland immunity require further investigation. The present study investigated the viability, phagocytic capacity, and intracellular production of reactive oxygen and nitrogen species (RONS) by macrophages in milk samples from dairy cows naturally infected with BLV with or without persistent lymphocytosis (PL). No effect of BLV infection in the overall number of macrophages per milliliter and in the percentage of viable macrophages among overall milk viable cells was found. Furthermore, BLV-infected dairy cows had a higher frequency of viable milk macrophages, while healthy animals had a tendency toward a higher percentage of apoptotic milk macrophages. The percentage of milk macrophages that phagocytosed Staphylococcus aureus in seronegative animals was higher than that in BLV-infected dairy cows. No effect of BLV infection on the intracellular RONS production and the intensity of phagocytosis by milk macrophages was observed. Thus, this study provides new insights into the implications of BLV infections in the bovine mammary gland.

Effect of blue laser on viability of Proteus mirabilis

The usage of blue laser has been considered as a therapeutic approach to prohibit the viability of bacterial species, but there is no agreement about optimum parameters to be used. The aim of this project is to study the influence of blue laser (450 nm) on the viability of the gram-negative bacteria Proteus mirabilis isolated from burn wounds, using different exposure times (i.e. doses) in vitro. Seventy swab samples were collected from burn wounds of patients admitted to the burns unit in AL-Yarmouk teaching hospital in Baghdad, during the period from June to August 2019. The Bacteria were isolated and identified depending on their culture characteristics, biochemical tests, gram staining, and morphology, being finally confirmed by API 20E Test System. By using the disk diffusion method, susceptibility of the isolates to 12 different antibiotics was examined. One isolate of P. mirabilis was elected according to susceptibility to all antibiotics used. To prepare bacterial solution, P. mirabilis was mixed with normal saline solution. Dilution of 10-6 cell/ml for p. mirabilis was selected from other serial dilutions. A number of colonies and colony forming units (CFUs/ml) were achieved and correlated to controls. P. mirabilis was irradiated by blue diode laser (450 nm, 500mw) and exposed to different doses (24, 48, 72, 96, 120J/cm2) corresponding to respective exposure times (4, 8,12,16,20 minutes). The results of antibiotic susceptibility test indicate that the entire isolates of P. mirabilis were multidrug resistant. With the increase in laser dose (exposure times), the number of colonies and CFUs/ml were reduced, reaching a highest inhibition in CFU/ml at exposure time of 20 minutes, i.e. a dose of 120J/cm2 , with irradiance of 0.1 watt/ cm2. No significant reduction was recorded in CFU/ml at exposure time of 4 min (a dose of 24J/cm2). As a conclusion, the blue laser irradiation at wavelength of 450 nm and 500mw had antibacterial effects on P. mirabilis isolated from burn wounds with irradiance of 0.1watt/cm2 in vitro, as evidenced by the effective reduction in the viability of bacteria at a dose of 120J/cm2 corresponding to exposure time of 20 minutes.

Synthesis of Rhodium and Iridium Complexes Supported by Bis(indolylphosphino)silyl Pincer Ligation: Competitive N–H and C–H Bond Activation by an Ir(I) Species

The synthesis of five-coordinate amido hydride PSiP pincer complexes of both RhIII and IrIII was pursued. The preparation of such complexes by a salt metathesis route was initially targeted to assess the synthetic viability of such species. Isolable anilido hydride complexes of both Rh and Ir proved accessible, and rare examples of thermally robust Ir alkylamido hydride complexes were found to be viable synthetic targets. The preparation of amido hydride species by N–H oxidative addition was also pursued. Toward this end, the generation of coordinatively unsaturated (iPr-PSiPInd)MI (M = Rh, Ir) species was investigated. Dehydrohalogenation of (iPr-PSiPInd)RhH(Cl) (1) under N2 afforded the isolable complex [(iPr-PSiPInd)Rh]2(μ-N2) (8a). While the N2 ligand could be displaced to afford (iPr-PSiPInd)RhL (L = PMe3, DMAP, H2NPh), such RhI species proved unreactive toward N–H oxidative addition of aniline. Dehydrohalogenation of (iPr-PSiPInd)IrH(Cl) (2) in benzene solution resulted in activation of the solvent to afford (iPr-PSiPInd)IrH(Ph) (11), which undergoes facile arene exchange with benzene-d6. In cyclohexane solution, treatment with aniline afforded a mixture of N–H and aniline sp2-C–H bond oxidative addition products, with the latter species being favored. Although the observation of arene exchange involving (iPr-PSiPInd)IrH(Ph) suggests that C–H bond oxidative addition is reversible, attempts to drive the reactivity with aniline in the direction of N–H bond oxidative addition were unsuccessful. This reactivity differs significantly from that of previously reported complexes supported by related PSiP ligation. Most notably, it appears that for (iPr-PSiPInd)Ir, products resulting from N–H- and C–H-oxidative addition of aniline substrates do not readily interconvert, although both are postulated to share a common intermediate of the type (iPr-PSiPInd)Ir(NH2Ph).

Influence of Physicochemical Characteristics and Stability of Gold and Silver Nanoparticles on Biological Effects and Translocation across an Intestinal Barrier-A Case Study from In Vitro to In Silico.

A better understanding of their interaction with cell-based tissue is a fundamental prerequisite towards the safe production and application of engineered nanomaterials. Quantitative experimental data on the correlation between physicochemical characteristics and the interaction and transport of engineered nanomaterials across biological barriers, in particular, is still scarce, thus hampering the development of effective predictive non-testing strategies. Against this background, the presented study investigated the translocation of gold and silver nanoparticles across the gastrointestinal barrier along with related biological effects using an in vitro 3D-triple co-culture cell model. Standardized in vitro assays and quantitative polymerase chain reaction showed no significant influence of the applied nanoparticles on both cell viability and generation of reactive oxygen species. Transmission electron microscopy indicated an intact cell barrier during the translocation study. Single particle ICP-MS revealed a time-dependent increase of translocated nanoparticles independent of their size, shape, surface charge, and stability in cell culture medium. This quantitative data provided the experimental basis for the successful mathematical description of the nanoparticle transport kinetics using a non-linear mixed effects modeling approach. The results of this study may serve as a basis for the development of predictive tools for improved risk assessment of engineered nanomaterials in the future.

Increased Arctic climate extremes constrain expected higher plant reproductive success in a warmer climate

The low reproductive success of Arctic plants is predicted to increase as the climate warms. However, climate extremes add complexity to these predictions. In the extremely cold year of 2018, multiple Arctic trophic levels experienced reproductive failure. We analysed a unique long-term record of seed viability from experimentally warmed and ambient plots at Alexandra Fiord, Ellesmere Island, which has been running since 1992 and included 2018 and the extremely warm year of 2019. Positive and negative July temperature anomalies and summer temperatures have increased significantly by 0.5, −0.3, and 0.4 °C/decade since 1977, respectively, resulting in greater extremes and increased inter-annual variation. Seed viability of some species has increased with climate warming. Across years, seed viability of woody species was consistently higher in warmed than ambient plots while the opposite was true for forbs. In 2018, seed viability of woody species in ambient plots was significantly lower than normal but comparable with past years for forb species. Not all species returned to normal seed viability levels in 2019. Our study highlights the potential for greater sexual reproductive failure in tundra plants with increasing climate extremes. We suggest that poor seed viability of woody species in cold years could constrain shrub recruitment and may aid forb species establishment on bare tundra.

Protective effects of upregulated HO-1 gene against the apoptosis of human retinal pigment epithelial cells in vitro.

To investigate the protective effect of heme oxygenase-1 (HO-1) against H2O2-induced apoptosis in human ARPE-19 cells. The lentiviral vector expressing HO-1 was prepared and transfected into apoptotic ARPE-19 cells induced by H2O2. Functional experiments including cell counting kit-8 (CCK-8) assay, flow cytometry (FCM) and mitochondrial membrane potential assay were conducted. The ultrastructure of ARPE-19 cells was observed using transmission electron microscope (TEM). It was found that exogenous HO-1 significantly ameliorated H2O2-induced loss of cell viability, apoptosis and intracellular levels of reactive oxygen species (ROS) in ARPE-19 cells. The overexpression of HO-1 facilitated the transfer of nuclear factor erythroid-2-related factor 2 (Nrf2) from cytoplasm to nucleus, which in turn upregualted expressions HO-1 and B-cell lymphoma-2 (Bcl-2). Furthermore, HO-1 upregulation further inhibited H2O2-induced release of cysteinyl aspartate specific proteinase-3 (caspase-3). Exogenous HO-1 protect ARPE-19 cells against H2O2-induced oxidative stress by regulating the expressions of Nrf2, HO-1, Bcl-2, and caspase-3.

Platelet-rich plasma protects human melanocytes from oxidative stress and ameliorates melanogenesis induced by UVB irradiation.

To investigate the role of platelet-rich plasma (PRP) from different sources in alleviating oxidative stress and ameliorating melanogenesis in UVB-irradiated PIG1 cells, PIG1 cells were irradiated with 80 mJ/cm2 UVB prior to 1% PRP application and the following experiments were taken: the viability of UVB-irradiated PIG1 cells, cellular malondialdehyde (MDA) and reactive oxygen species (ROS) content, and activities of antioxidant enzymes. Western blotting was utilized to detect the expression level of proteins associated with melanin synthesis, apoptosis, and DNA lesions. We found that PRP intervention promoted cell proliferation, reduced MDA and ROS content, increased the activities of series of antioxidant enzymes, and alleviated DNA damages in UVB-damaged PIG1 cells. It is important to note that PRP treatment inhibited UVB-induced melanogenesis via the PI3K/Akt/GSK3β signal pathway. Therefore, we suppose PRP treatment exerts a protective role through their antioxidation effect on UVB-damaged PIG1 cells and hinders melanogenesis induced by UVB irradiation.

Field testing an "acoustic lighthouse": Combined acoustic and visual cues provide a multimodal solution that reduces avian collision risk with tall human-made structures.

Billions of birds fatally collide with human-made structures each year. These mortalities have consequences for population viability and conservation of endangered species. This source of human-wildlife conflict also places constraints on various industries. Furthermore, with continued increases in urbanization, the incidence of collisions continues to increase. Efforts to reduce collisions have largely focused on making structures more visible to birds through visual stimuli but have shown limited success. We investigated the efficacy of a multimodal combination of acoustic signals with visual cues to reduce avian collisions with tall structures in open airspace. Previous work has demonstrated that a combination of acoustic and visual cues can decrease collision risk of birds in captive flight trials. Extending to field tests, we predicted that novel acoustic signals would combine with the visual cues of tall communication towers to reduce collision risk for birds. We broadcast two audible frequency ranges (4 to 6 and 6 to 8 kHz) in front of tall communication towers at locations in the Atlantic migratory flyway of Virginia during annual migration and observed birds' flight trajectories around the towers. We recorded an overall 12-16% lower rate of general bird activity surrounding towers during sound treatment conditions, compared with control (no broadcast sound) conditions. Furthermore, in 145 tracked "at-risk" flights, birds reduced flight velocity and deflected flight trajectories to a greater extent when exposed to the acoustic stimuli near the towers. In particular, the 4 to 6 kHz stimulus produced the greater effect sizes, with birds altering flight direction earlier in their trajectories and at larger distances from the towers, perhaps indicating that frequency range is more clearly audible to flying birds. This "acoustic lighthouse" concept reduces the risk of collision for birds in the field and could be applied to reduce collision risk associated with many human-made structures, such as wind turbines and tall buildings.

Genetic Structure and Diversity of the Endemic Carolina Madtom and Conservation Implications

AbstractIdentification and conservation of genetic diversity within and among freshwater fish populations are important to better manage and conserve imperiled species. The Carolina Madtom Noturus furiosus is a small, nongame catfish that is endemic to the Tar and Neuse River basins of North Carolina. Genetic structure has not been studied in the species, and given recent population declines in both basins, identification of remaining genetic diversity within the species is vital for informing conservation efforts. To assess the status and trends of Carolina Madtom genetic structure, we analyzed genetic markers from 173 individuals to (1) define population genetic structure, (2) assess intra‐ and interbasin genetic differentiation in the Tar and Neuse River basins, and (3) present management implications to guide conservation efforts. Using 10 microsatellite primers developed for the related Yellowfin Madtom N. flavipinnis, we observed low genetic diversity in Carolina Madtoms. Genotype frequencies within samples were not in Hardy–Weinberg equilibrium, with a deficit of heterozygotes that could be due to family structure, inbreeding, or segregation of null alleles. Mean (±SD) M‐ratios for the Tar River (0.414 ± 0.117) and Neuse River (0.117 ± 0.102) basin collections indicated that both populations have experienced recent demographic bottlenecks, with that in the Neuse River basin population being more severe. Effective population size estimates for the respective populations were small, on the order of tens of individuals, driving low genetic diversity within populations. However, the multilocus population differentiation metrics (mean ± SE = 0.135 ± 0.031) and DEST (0.125 ± 0.029) were significantly different from zero (P &lt; 0.001), indicating significant genetic differentiation between the Tar and Neuse River basin populations. Our findings will inform managers on the status of genetic variation in the Carolina Madtom and will guide conservation toward protective listing and management decisions to maintain the viability of this important endemic species.

Symbiotic NCR Peptide Fragments Affect the Viability, Morphology and Biofilm Formation of Candida Species.

The increasing rate of fungal infections causes global problems not only in human healthcare but agriculture as well. To combat fungal pathogens limited numbers of antifungal agents are available therefore alternative drugs are needed. Antimicrobial peptides are potent candidates because of their broad activity spectrum and their diverse mode of actions. The model legume Medicago truncatula produces >700 nodule specific cysteine-rich (NCR) peptides in symbiosis and many of them have in vitro antimicrobial activities without considerable toxicity on human cells. In this work we demonstrate the anticandidal activity of the NCR335 and NCR169 peptide derivatives against five Candida species by using the micro-dilution method, measuring inhibition of biofilm formation with the XTT (2,3-Bis-(2-Methoxy-4-Nitro-5-Sulfophenyl)-2H-Tetrazolium-5-Carboxanilide) assay, and assessing the morphological change of dimorphic Candida species by microscopy. We show that both the N- and C-terminal regions of NCR335 possess anticandidal activity as well as the C-terminal sequence of NCR169. The active peptides inhibit biofilm formation and the yeast-hypha transformation. Combined treatment of C. auris with peptides and fluconazole revealed synergistic interactions and reduced 2-8-fold the minimal inhibitory concentrations. Our results demonstrate that shortening NCR peptides can even enhance and broaden their anticandidal activity and therapeutic potential.

An enigmatic mass mortality event of Blanding’s Turtles (Emydoidea blandingii) in a protected area

Mass mortality events (MMEs) can remove up to 90% of individuals in a population and are especially damaging to population viability of long-lived species with slow life histories. Our goal was to elucidate the cause(s) of a MME of 53 Blanding’s Turtles (Emydoidea blandingii (Holbrook, 1838)), a globally endangered species, in a protected area. We investigated disease, winter-kill, and depredation as potential causes of the mortality. The turtle carcasses lacked soft tissue to test for disease, so we examined tissue from co-occurring live Leopard Frogs (Lithobates pipiens (Schreber, 1782)) and found no evidence of ranavirus, indicating that the disease was not present at our study site. Water temperature and dissolved aquatic oxygen at known overwintering sites and sites which yielded carcasses did not differ, suggesting that winter-kill did not cause the MME. Carcass condition, comparisons with descriptions of turtle depredation events in the literature, and trail cameras paired with turtle decoys identified potential predators within the study site and suggested that mass depredation, enabled by low water levels and a concomitant reduction in aquatic habitat, was the most likely cause of mortality. Our study can inform conservation of the study population and the management of MMEs of long-lived species elsewhere.

Genetic signatures of population bottlenecks, relatedness, and inbreeding highlight recent and novel conservation concerns in the Egyptian vulture.

The assessment of temporal variation in genetic features can be particularly informative on the factors behind demography and viability of wildlife populations and species. We used molecular methods to evaluate neutral genetic variation, relatedness, bottlenecks, and inbreeding in a declining population of Egyptian vulture (Neophron percnopterus) in central Spain. The results show that the genetic diversity remained relatively stable over a period of twelve years despite the decline in census and effective population sizes in the last decades. A relatively high proportion of nestlings from different and distant territories showed high relatedness in each study year. We also found support for an increasing impact of severe recent (contemporary) rather than distant (historical) past demographic bottlenecks, and the first evidence of inbred mating between full siblings coinciding with lethal malformations in offspring. The inbred nestling with feather malformations was positive to beak and feather disease virus recorded for the first time in this species. These results alert on recent and novel threats potentially affecting health and reducing the adaptive potential of individuals in this threatened species.

Photosymbiosis in planktonic foraminifera across the Paleocene–Eocene thermal maximum

AbstractUnder stress, corals and foraminifera may eject or consume their algal symbionts (“bleach”), which can increase mortality. How bleaching relates to species viability over warming events is of great interest given current global warming. We use size-specific isotope analyses and abundance counts to examine photosymbiosis and population dynamics of planktonic foraminifera across the Paleocene–Eocene thermal maximum (PETM, ~56 Ma), the most severe Cenozoic global warming event. We find variable responses of photosymbiotic associations across localities and species. In the NE Atlantic (DSDP Site 401) PETM, photosymbiotic clades (acarininids and morozovellids) exhibit collapsed size-δ13C gradients indicative of reduced photosymbiosis, as also observed in Central Pacific (ODP Site 1209) and Southern Ocean (ODP Site 690) acarininids. In contrast, we find no significant loss of size-δ13C gradients on the New Jersey shelf (Millville) or in Central Pacific morozovellids. Unlike modern bleaching-induced mass mortality, populations of photosymbiont-bearing planktonic foraminifera increased in relative abundance during the PETM. Multigenerational adaptive responses, including flexibility in photosymbiont associations and excursion taxon evolution, may have allowed some photosymbiotic foraminifera to thrive. We conclude that deconvolving the effects of biology on isotope composition on a site-by-site basis is vital for environmental reconstructions.

Environmental Genomics Applications for Environmental Management Activities in the Oil and Gas Industry - State of the Art Review and Future Research Needs

The International Association of Oil and Gas Producers (IOGP) Environmental Genomics Joint Industry Program (JIP) was formed in June 2019. The aim of the JIP is to facilitate the development of guidelines for the application of environmental genomics to support environmental management activities in the oil and gas industry. Towards this goal, a white paper summarizing the state-of-the-art in environmental genomics research and how it may be used to advance technology development opportunities for the oil and gas industry was drafted. More specifically, a series of applications and focus areas of primary interest to oil and gas companies were covered including: baseline assessments; detection of key species; rapid assessment of invasive species; population status and dynamics; monitoring of environmental effects of oil and gas activities; remediation and restoration; sampling design; data analysis and interpretation; community representation; species abundance, distribution and viability; and real-time on-site measurement and analysis. baseline assessments; detection of key species; rapid assessment of invasive species; population status and dynamics; monitoring of environmental effects of oil and gas activities; remediation and restoration; sampling design; data analysis and interpretation; community representation; species abundance, distribution and viability; and real-time on-site measurement and analysis. In addition to the literature review, consultation of professionals from academic, regulatory, and industrial backgrounds with expertise on these topics was conducted. While there was a consensus that the application of environmental genomics has advanced greatly in a short period of time with demonstrable benefit potential, there was acknowledgement that key aspects of best management practices are still lacking. Furthermore, while the majority of regulators interviewed were aware to varying degrees of the methodological limitations which restrict the present use of environmental genomics in regulatory affairs, it transpired that there is considerable appetite and capacity amongst the regulatory community to engage in collaborative research initiatives with the oil and gas industry and academia. Through these academic, regulatory, and industrial consultation, specific environmental genomics study areas and applications requiring further development and refinement were identified. These include: methodological standardization, persistence and dispersal of eDNA; eDNA data integration with various other data types; improvement of reference databases; and refinement of molecular indices. methodological standardization, persistence and dispersal of eDNA; eDNA data integration with various other data types; improvement of reference databases; and refinement of molecular indices. Based on the above and considering the most efficient path to greater regulatory uptake for environmental genomic approaches for the oil and gas industry, the JIP’s recommendation is to pursue a Common-Garden Experiment. Such experiment should seek the involvement and ultimately endorsement from the Regulators marking the path towards wider regulatory acceptance and uptake of eDNA-based approaches.

The trade-offs of foraging at landfills: Landfill use enhances hatching success but decrease the juvenile survival of their offspring on white storks (Ciconia ciconia).

During the last decades, landfills have become a valuable food source for wildlife, being in some cases determinants of large avian population increases. Superabundant food resources at landfills can increase reproductive and/or survival parameters; however, negative effects such as intoxication, plastic ingestion, skeletal deformities, unbalanced oxidative stress, and other health problems have also been reported. White stork (Ciconia ciconia) commonly benefits from landfill resources. Here, we evaluate potential landfill effects on demographic parameters (reproduction and offspring survival) at the individual level in a single population. Our results show that a more intense use of landfills by breeders has a positive effect on hatching success but a negative effect on juvenile survival probability after emancipation, at least during the first year of life. High amount of food and proximity to landfill may explain their beneficial effect on reproductive parameters. On the other hand, poor quality food, pollutants, and pathogens acquired during early development from a diet based on refuse may be responsible for reduced future survival probability. Consequently, both positive and negative effects were detected, being foraging at landfills at low to medium levels the better strategy. Although our study shows that intense foraging on rubbish can imply both costs and benefits at an individual level, the benefits of superabundant food provisioning observed at population level by other studies cannot be ignored. Management actions should be designed to improve natural food resources, reduce non-natural mortality and/or human disturbances to guarantee the species viability under current European Union regulations designed to ban open-air landfills in a near future.

Accounting for sources of uncertainty when forecasting population responses to climate change.

In Focus: Jaatinen, K., Westerbom, M., Norkko, A., Mustonen, O., & Koons, D. N. (2021). Detrimental impacts of climate change may be exacerbated by density-dependent population regulation in blue mussels. Journal of Animal Ecology, 90, 562-573, https://doi.org/10.1111/1365-2656.13377. Conservation strategies for threatened species are increasingly dependent on forecasts of population responses to climate change. For such forecasts to be accurate, they must account for multiple sources of uncertainty, including those associated with projections of future climate scenarios and those associated with the models used to describe population dynamics. While many population forecasts incorporate parameter uncertainty in abiotic effects and process variance related to unexplained temporal variation, most forecasts overlook the importance of evaluating uncertainty in the structure of the population model itself. By accounting for structural uncertainties in a model of population growth for blue mussels, Jaatinen et al. (2021) demonstrated that density-dependent processes are likely to exacerbate adverse effects of climate change and reduce population viability of this keystone species. These findings highlight the importance of incorporating structural unknowns in population forecasts and the value of approaches that account for multiple sources of climate and model uncertainties. Forecasts that capture a range of possible population trajectories under climate change will help ensure efficient allocation of limited conservation resources.

A Toxic Synergy between Aluminium and Amyloid Beta in Yeast.

Alzheimer’s disease (AD), the most prevalent, age-related, neurodegenerative disease, is associated with the accumulation of amyloid beta (Aβ) and oxidative stress. However, the sporadic nature of late-onset AD has suggested that other factors, such as aluminium may be involved. Aluminium (Al3+) is the most ubiquitous neurotoxic metal on earth, extensively bioavailable to humans. Despite this, the link between Al3+ and AD has been debated for decades and remains controversial. Using Saccharomyces cerevisiae as a model organism expressing Aβ42, this study aimed to examine the mechanisms of Al3+ toxicity and its interactions with Aβ42. S. cerevisiae cells producing Aβ42 treated with varying concentrations of Al3+ were examined for cell viability, growth inhibition, and production of reactive oxygen species (ROS). Al3+ caused a significant reduction in cell viability: cell death in yeast producing green fluorescent protein tagged with Aβ42 (GFP–Aβ42) was significantly higher than in cells producing green fluorescent protein (GFP) alone. Additionally, Al3+ greatly inhibited the fermentative growth of yeast producing GFP–Aβ42, which was enhanced by ferric iron (Fe3+), while there was negligible growth inhibition of GFP cells. Al3+- induced ROS levels in yeast expressing native Aβ42 were significantly higher than in empty vector controls. These findings demonstrate Al3+ has a direct, detrimental toxic synergy with Aβ42 that can be influenced by Fe3+, causing increased oxidative stress. Thus, Al3+ should be considered as an important factor, alongside the known characteristic hallmarks of AD, in the development and aetiology of the disease.

Platinum-group elements sorption by living macroalgae under different contamination scenarios

Increasing emissions of Platinum-Group Elements (PGE) into marine environments may negatively impact ecosystems services and organisms wellbeing. Removing PGE from contaminated systems using efficient and low-cost technologies can therefore provide a sustainable solution to aquatic systems remediation. Previous studies highlight algae’s high binding ability to metals in solution. Assessing the viability of various algae species to remove PGE from contaminated solutions, while identifying differences in performance among algae and among elements, was the purpose of this study. For this, six macroalgae species (Ulva lactuca, Ulva intestinalis, Fucus spiralis, Fucus vesiculosus, Osmundea pinnatifida and Gracilaria sp., 3 g L−1) were exposed to PGE (Palladium, Rhodium, Ruthenium, Iridium and Platinum)-spiked seawater (10 and 500 µg L−1) for 72 h. Removal rates varied with time and among macroalgae and elements. Palladium was easily removed by all species (up to 83 %), while other PGE showed lower affinity to macroalgae. Removal sequence was Pd > Rh > Ru > Ir > Pt. Initial concentration rise induced faster and higher removal. U. lactuca performed best for all elements, while brown macroalgae were the less effective. Macroalgae external area and chemical composition were considered major factors influencing sorption, although each element and macroalgae should be examined individually. Results evidence living macroalgae (particularly U. lactuca) as a promising alternative to remediate PGE contaminated waters.