Cooperative wrapping of nanoparticles by membrane tubes

The bioactivity of nanoparticles crucially depends on their ability to cross biomembranes. Recent simulations indicate the cooperative wrapping and internalization of spherical nanoparticles in tubular membrane structures. In this article, we systematically investigate the energy gain of this cooperative wrapping by minimizing the energies of the rotationally symmetric shapes of the membrane tubes and of membrane segments wrapping single particles. We find that the energy gain for the cooperative wrapping of nanoparticles in membrane tubes relative to their individual wrapping as single particles strongly depends on the ratio of the particle radius and the range of the particle-membrane adhesion potential. For a potential range of the order of one nanometer, the cooperative wrapping in tubes is highly favorable for particles with a radius of tens of nanometers and intermediate adhesion energies, but not for particles that are significantly larger.Comment: 9 pages, 7 figures; to appear in Soft Matte

Cyclic thermal fluctuations can be burden or relief for an ectotherm depending on fluctuations’ average and amplitude

1. Predicting the implications of ongoing ocean climate warming demands a better understanding of how short-term thermal variability impacts marine ectotherms, particularly at beyond-optimal average conditions during summer heatwaves. 2. Using a globally important model species, the blue mussel Mytilus, in a 5-week-long experiment, we (a) assessed growth performance traits under 12 scenarios, consisting of four thermal averages (18.5, 21, 23.5 and 26℃) imposed as constant or daily fluctuating regimes with amplitudes of 2 or 4℃. Additionally, we conducted a short-term assay using different mussel individuals to (b) test for the species capacity for suppression and recovery of metabolic performance traits (feeding and aerobic respiration) when exposed to a 1-day thermal fluctuation regime (16.8–30.5℃). Using this high-resolution data, we (c) generated short-term thermal metabolic performance curves to predict and explain growth responses observed in the long-term experiment. 3. We found that daily high-amplitude thermal cycles (4℃) improved mussel growth when fluctuations were imposed around an extreme average temperature of 26℃, representing end-of-century heatwaves. In contrast, thermal cycles negatively affected mussel growth at a less extreme average temperature of 23.5℃, resembling current peak summer temperature scenarios. These results suggest that fluctuations ameliorate heat stress impacts only at critically high average temperatures. The short-term assay demonstrated that during the warming phase, animals stopped feeding between 24 and 30℃ while gradually suppressing respiration. In the subsequent cooling phase, feeding and respiration partially and fully recovered to pre-heating rates respectively. Furthermore, nonlinear averaging of short-term feeding responses (upscaling) well-predicted longer term growth responses to fluctuations. 4. Our findings suggest that fluctuations can be beneficial to or detrimental for the long-term performance of ectothermic animals, depending on the fluctuations' average and amplitude. Furthermore, the observed effects can be linked to fluctuation-mediated metabolic suppression and recovery. In a general framework, we propose various hypothetical scenarios of fluctuation impacts on ectotherm performance considering inter- or intra-species variability in heat sensitivity. Our research highlights the need for studying metabolic performance in relation to cyclic abiotic fluctuations to advance the understanding of climate change impacts on aquatic systems

A Method to Distinguish Potential Workplaces for Human-Robot Collaboration

The high dynamics of globalized markets and their increase in competition, as well as the demographic changes in western countries causing an increasing shortage of skilled personnel are resulting in major challenges for production companies today. These challenges relate in particular to the processes of assembly forming the last process step in the value chain due to its high share of manual labor. Collaborative assembly, which is characterized by immediate interaction of humans and robots, utilizes the strengths of both partners and is seen as an opportunity to achieve a higher level of flexibility in assembly just as well to support and relieve people of for instance non-ergonomic tasks through automation at work. Although almost every robot manufacturer already has collaborative systems in its product portfolio, these are not yet widely used in industrial production. This might have a variety of reasons, such as the fear of a risky investment or the lack of expertise within the company related to collaborative systems. This article shows a conceptual method that helps companies implementing human-robot-collaboration in their production more quickly and with less implied risk, thus addressing the forthcoming challenges. As a first step, companies must be qualified to make a suitable selection for a possible collaboration scenario. To achieve this, they need a tool to analyze and to evaluate their production processes according to their suitability for human-robot-collaboration. An important feature for an easy and effective use is that the process is formalized so that employees of companies can quickly and easily analyze different processes. The necessary criteria and procedures are developed accordingly and are integrated into the selection method. The main goal is to give the company a recommendation which of their processes are most suitable for human-robot-collaboration, so that they can be used effectively in their production

Concurrent validity of skin carotenoid status as a concentration biomarker of vegetable and fruit intake compared to multiple 24-h recalls and plasma carotenoid concentrations across one year: a cohort study

Background Biological markers of vegetable and fruit (VF) intake are needed both for nutrition surveillance and for the evaluation of nutrition interventions. Optically assessed skin carotenoid status (SCS) has been proposed as a marker of intake but there are few published validity studies to date. Therefore, the objective of the study was to examine the concurrent validity of multiple methods of assessing VF intake cross-sectionally and seasonally over one year and to discuss the relative merits and limitations of each method. Methods Fifty-two 40–60 y old women completed a 1-year longitudinal study that included 1) SCS assessment using resonance Raman spectroscopy (RRS) and using pressure-mediated reflection spectroscopy (RS) at 12 timepoints, 2) thirty-six 24-h recalls using the Automated Self-Administered 24-Hour Dietary Assessment Tool (ASA24; total 1866 recalls), and 3) plasma carotenoid concentrations measured every 3 months. Pearson correlation coefficients and mixed linear models were used to estimate pairwise correlations between RRS, RS, ASA24, and plasma carotenoids. Results RS and RRS were strongly correlated at baseline and over the year (r = 0.86 and 0.76; respectively, P < 0.001). RS was strongly correlated with plasma carotenoids at baseline (r = 0.70) and moderately across the year (r = 0.65), as was RRS (r = 0.77 and 0.69, respectively, all P < 0.001). At baseline, self-reported VF was weakly correlated with RRS (r = 0.33; P = 0.016), but not with RS or plasma carotenoids. Across the year, self-reported VF intake was weakly correlated with both RS (r = 0.37; P = 0.008), RRS (r = 0.37; P = 0.007), and with plasma carotenoids (r = 0.36; P < 0.008). Conclusions SCS as measured by RS and RRS is moderately to strongly correlated with plasma carotenoid concentrations both cross-sectionally and longitudinally, indicating that it can be a powerful tool to assess carotenoid-rich VF intake in populations

Editorial: Influence of environmental variability on climate change impacts in marine ecosystems

multiple drivers, environmental variability, Climate change, marine heatwaves, stressmemory, Ecological memory, Thermal performance curves, acclimatio

Predicting international students' clinical and academic grades using two language tests (IELTS and C-test): a correlational research study

Academic English tests are used to ascertain if international English as a Second Language nursing students have sufficient language skills to commence their nursing degrees, and later, if they have sufficient English for nursing registration. However, an academic English test may not be appropriate for clinical contexts. This study examines the relationship between two types of English test and the performance of forty-nine undergraduate international nursing students in both their first year of theory-centred academic topics and practice-centred clinical topics. An academic English test, called the International English Language Testing System (IELTS), anda general English proficiency/processing speed test using a variation of the cloze-test (C-test) format were administered at the commencement of the students' course of study. At the end of one year, grade percentages were collected. It was found that both the IELTS test and the C-test were significantly correlated to both types of topic, albeit with different patterns. The two English tests were also tested for similarities in the constructs they measured, with a significant overlap found. The implications are to rethink the way English tests are applied to entry in university degrees involving a clinical component and, by extension, to direct universities to rethink how nursing students are supported during their degree. The question is also raised about the practice of using academic English tests for professional nursing registration purposes. The benefits of the two testing approaches are also considered, particularly the large differences in monetary outlay and time found between the two tests, given their performance in explaining the variance in grade outcomes

Neutrophil “plucking” on megakaryocytes drives platelet production and boosts cardiovascular disease

Intravascular neutrophils and platelets collaborate in maintaining host integrity, but their interaction can also trigger thrombotic complications. We report here that cooperation between neutrophil and platelet lineages extends to the earliest stages of platelet formation by megakaryocytes in the bone marrow. Using intravital microscopy, we show that neutrophils "plucked" intravascular megakaryocyte extensions, termed proplatelets, to control platelet production. Following CXCR4-CXCL12-dependent migration towards perisinusoidal megakaryocytes, plucking neutrophils actively pulled on proplatelets and triggered myosin light chain and extracellular-signal-regulated kinase activation through reactive oxygen species. By these mechanisms, neutrophils accelerate proplatelet growth and facilitate continuous release of platelets in steady state. Following myocardial infarction, plucking neutrophils drove excessive release of young, reticulated platelets and boosted the risk of recurrent ischemia. Ablation of neutrophil plucking normalized thrombopoiesis and reduced recurrent thrombosis after myocardial infarction and thrombus burden in venous thrombosis. We establish neutrophil plucking as a target to reduce thromboischemic events

Environmental variability in aquatic ecosystems: Avenues for future multifactorial experiments

The relevance of considering environmental variability for understanding and predicting biological responses to environmental changes has resulted in a recent surge in variability-focused ecological research. However, integration of findings that emerge across studies and identification of remaining knowledge gaps in aquatic ecosystems remain critical. Here, we address these aspects by: (1) summarizing relevant terms of variability research including the components (characteristics) of variability and key interactions when considering multiple environmental factors; (2) identifying conceptual frameworks for understanding the consequences of environmental variability in single and multifactorial scenarios; (3) highlighting challenges for bridging theoretical and experimental studies involving transitioning from simple to more complex scenarios; (4) proposing improved approaches to overcome current mismatches between theoretical predictions and experimental observations; and (5) providing a guide for designing integrated experiments across multiple scales, degrees of control, and complexity in light of their specific strengths and limitations